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Sample records for hot extrusion process

  1. Residence time modeling of hot melt extrusion processes.

    Science.gov (United States)

    Reitz, Elena; Podhaisky, Helmut; Ely, David; Thommes, Markus

    2013-11-01

    The hot melt extrusion process is a widespread technique to mix viscous melts. The residence time of material in the process frequently determines the product properties. An experimental setup and a corresponding mathematical model were developed to evaluate residence time and residence time distribution in twin screw extrusion processes. The extrusion process was modeled as the convolution of a mass transport process described by a Gaussian probability function, and a mixing process represented by an exponential function. The residence time of the extrusion process was determined by introducing a tracer at the extruder inlet and measuring the tracer concentration at the die. These concentrations were fitted to the residence time model, and an adequate correlation was found. Different parameters were derived to characterize the extrusion process including the dead time, the apparent mixing volume, and a transport related axial mixing. A 2(3) design of experiments was performed to evaluate the effect of powder feed rate, screw speed, and melt viscosity of the material on the residence time. All three parameters affect the residence time of material in the extruder. In conclusion, a residence time model was developed to interpret experimental data and to get insights into the hot melt extrusion process. Copyright © 2013 Elsevier B.V. All rights reserved.

  2. Generation and use of process maps for hot extrusion of seamless tubes for nuclear applications

    International Nuclear Information System (INIS)

    Vaibhaw, Kumar; Jha, S.K.; Saibaba, N.; Jayaraj, R.N.

    2009-01-01

    Full text: Hot extrusion is known as significant bulk deformation step in manufacturing of seamless tube production. Elevated temperature deformation carried out above the recrystallization temperature would enable imposition of large strains in single step. This deformation causes a significant change in the microstructure of the material and depends on extrusion process parameters such as temperature and strain rate (Ram speed). Basic microstructure developed at this deformation stage has significant bearing on the final properties of the material fabricated with subsequent cold working steps. Zirconium alloys and special nuclear grade austenitic stainless steels are two important groups of materials used as structural and core components in thermal and fast reactors world wide respectively. The properties of former alloy are very sensitive to the thermo mechanical fabrication steps initiated with hot extrusion due to their anisotropic deformation behaviour. However, nuclear grade austenitic stainless steels have many variants from their commercial grades in terms of micro and macro alloy chemistry. Factors such as these significantly affect the workability of the materials and require proper selection of extrusion parameters especially working temperature and extrusion speed plays a key role in the quality of the product. Modern developments in processing technology envisage the application of processing maps based on dynamic material model for selection of hot extrusion parameters. The present paper is aimed at bringing out significance of the map in selection of working domain with respect to the industrial process conditions for both groups of nuclear materials mentioned earlier. Developed process maps of certain alloys suggest use of extremely slow strain rate and low temperature extrusion which can not be achieved during bulk processing due to design of equipment and heat transfer constraints in industrial scale production. Attempts are made to highlight

  3. Study on Hot Deformation Behavior of 7085 Aluminum Alloy during Backward Extrusion Process

    Directory of Open Access Journals (Sweden)

    R. B. Mei

    2015-01-01

    Full Text Available Compression test was carried out and the true stress-strain curves were obtained from the hot compression of 7085 alloy. A numerical simulation on the deformation behavior of 7085 aluminum alloy during the backward extrusion was also performed by finite element method. The results show that dynamic recrystallization occurs in the hot compression of 7085 alloy and the peak stress reaches higher values as the strain rate increases and deformation temperature decreases. The backward extrusion processes include contact deformation, initial deformation, and steady deformation. Severe plastic deformation of shear and compression occurs when the metal flowed into the channel between fillet of punch and wall of die so that the grain size can be refined by backward extrusion. The deformation in the region of top of wall is too small to meet the mechanical properties of requirements and the metal usually needs to be trimmed. The experiments with the same parameters as simulation had been carried out and the experimental cup after extrusion has better quality.

  4. Optimized manufacture of nuclear fuel cladding tubes by FEA of hot extrusion and cold pilgering processes

    Science.gov (United States)

    Gaillac, Alexis; Ly, Céline

    2018-05-01

    Within the forming route of Zirconium alloy cladding tubes, hot extrusion is used to deform the forged billets into tube hollows, which are then cold rolled to produce the final tubes with the suitable properties for in-reactor use. The hot extrusion goals are to give the appropriate geometry for cold pilgering, without creating surface defects and microstructural heterogeneities which are detrimental for subsequent rolling. In order to ensure a good quality of the tube hollows, hot extrusion parameters have to be carefully chosen. For this purpose, finite element models are used in addition to experimental tests. These models can take into account the thermo-mechanical coupling conditions obtained in the tube and the tools during extrusion, and provide a good prediction of the extrusion load and the thermo-mechanical history of the extruded product. This last result can be used to calculate the fragmentation of the microstructure in the die and the meta-dynamic recrystallization after extrusion. To further optimize the manufacturing route, a numerical model of the cold pilgering process is also applied, taking into account the complex geometry of the tools and the pseudo-steady state rolling sequence of this incremental forming process. The strain and stress history of the tube during rolling can then be used to assess the damage risk thanks to the use of ductile damage models. Once validated vs. experimental data, both numerical models were used to optimize the manufacturing route and the quality of zirconium cladding tubes. This goal was achieved by selecting hot extrusion parameters giving better recrystallized microstructure that improves the subsequent formability. Cold pilgering parameters were also optimized in order to reduce the potential ductile damage in the cold rolled tubes.

  5. A method for manufacturing a tool part for an injection molding process, a hot embossing process, a nano-imprint process, or an extrusion process

    DEFF Research Database (Denmark)

    2013-01-01

    The present invention relates to a method for manufacturing a tool part for an injection molding process, a hot embossing process, nano-imprint process or an extrusion process. First, there is provided a master structure (10) with a surface area comprising nanometre-sized protrusions (11...

  6. Development of poloxamer gel formulations via hot-melt extrusion technology.

    Science.gov (United States)

    Mendonsa, Nicole S; Murthy, S Narasimha; Hashemnejad, Seyed Meysam; Kundu, Santanu; Zhang, Feng; Repka, Michael A

    2018-02-15

    Poloxamer gels are conventionally prepared by the "hot" or the "cold" process. But these techniques have some disadvantages such as high energy consumption, requires expensive equipment and often have scale up issues. Therefore, the objective of this work was to develop poloxamer gels by hot-melt extrusion technology. The model drug selected was ketoprofen. The formulations developed were 30% and 40% poloxamer gels. Of these formulations, the 30% poloxamer gels were selected as ideal gels. DSC and XRD studies showed an amorphous nature of the drug after extrusion. It was observed from the permeation studies that with increasing poloxamer concentration, a decrease in drug permeation was obtained. Other studies conducted for the formulations included in-vitro release studies, texture analysis, rheological studies and pH measurements. In conclusion, the hot-melt extrusion technology could be successfully employed to develop poloxamer gels by overcoming the drawbacks associated with the conventional techniques. Published by Elsevier B.V.

  7. Application of heat treatment and hot extrusion processes to improve mechanical properties of the AZ91 alloy

    Directory of Open Access Journals (Sweden)

    T. Reguła

    2010-04-01

    Full Text Available The main aim of this paper is to evaluate the effects of hot working (extrusion and hest treatment on room temperature mechanical properties of magnesium-based AZ91 alloy. The results were compared with as-cast condition. The examined material had been obtained by gravity casting to permanent moulds and subsequently subjected to heat treatment and/or processed by extrusion at 648 K. Microstructural and mechanical properties of properly prepared specimens were studied. Rm, Rp02 and A5 were determined from tensile tests. Brinell hardness tests were also conducted. The research has shown that hot working of AZ91 alloy provides high mechanical properties unattainable by cast material subjected to heat-treatment. The investigated alloy subjected to hot working and subsequently heat-treated has doubled its strength and considerably improved the elongation - compared with the as-cast material.

  8. Manufacturing and mechanical property test of the large-scale oxide dispersion strengthened martensitic mother tube by hot isostatic pressing and hot extrusion process

    International Nuclear Information System (INIS)

    Narita, Takeshi; Ukai, Shigeharu; Kaito, Takeji; Ohtsuka, Satoshi; Fujiwara, Masayuki

    2003-09-01

    Mass production capability of Oxide Dispersion Strengthened (ODS) ferritic steel cladding (9Cr) is evaluated in the Phase II of the Feasibility Studies on Commercialized Fast Reactor Cycle System. The cost for manufacturing mother tube is a dominant factor in the total cost for manufacturing ODS ferritic cladding. In this study, the large-scale 9Cr-ODS martensitic mother tube was produced by overseas supplier with mass production equipments for commercialized ODS steels. The process of manufacturing the ODS mother tube consists of raw material powder production, mechanical alloying by high energy ball mill, hot isostatic pressing(HIP), and hot extrusion. Following results were obtained in this study. (1) Micro structure of the ODS steels is equivalent to that of domestic products, and fine oxides are uniformly distributed. The mechanical alloying by large capacity (1 ton) ball mill can be satisfactorily carried out. (2) A large scale mother tube (65 mm OD x 48 mm ID x 10,000 mm L), which can produce about 60 pieces of 3 m length ODS ferritic claddings by four times cold rolling, have been successfully manufactured through HIP and Hot Extrusion process. (3) Rough surface of the mother tubes produced in this study can be improved by selecting the reasonable hot extrusion condition. (4) Hardness and tensile strength of the manufactured ODS steels are lower than domestic products with same chemical composition. This is owing to the high aluminum content in the product, and those properties could be improved by decreasing the aluminum content in the raw material powder. (author)

  9. Hot melt extrusion versus spray drying: hot melt extrusion degrades albendazole.

    Science.gov (United States)

    Hengsawas Surasarang, Soraya; Keen, Justin M; Huang, Siyuan; Zhang, Feng; McGinity, James W; Williams, Robert O

    2017-05-01

    The purpose of this study was to enhance the dissolution properties of albendazole (ABZ) by the use of amorphous solid dispersions. Phase diagrams of ABZ-polymer binary mixtures generated from Flory-Huggins theory were used to assess miscibility and processability. Forced degradation studies showed that ABZ degraded upon exposure to hydrogen peroxide and 1 N NaOH at 80 °C for 5 min, and the degradants were albendazole sulfoxide (ABZSX), and ABZ impurity A, respectively. ABZ was chemically stable following exposure to 1 N HCl at 80 °C for one hour. Thermal degradation profiles show that ABZ, with and without Kollidon ® VA 64, degraded at 180 °C and 140 °C, respectively, which indicated that ABZ could likely be processed by thermal processing. Following hot melt extrusion, ABZ degraded up to 97.4%, while the amorphous ABZ solid dispersion was successfully prepared by spray drying. Spray-dried ABZ formulations using various types of acids (methanesulfonic acid, sulfuric acid and hydrochloric acid) and polymers (Kollidon ® VA 64, Soluplus ® and Eudragit ® E PO) were studied. The spray-dried ABZ with methanesulfonic acid and Kollidon ® VA 64 substantially improved non-sink dissolution in acidic media as compared to bulk ABZ (8-fold), physical mixture of ABZ:Kollidon ® VA 64 (5.6-fold) and ABZ mesylate salt (1.6-fold). No degradation was observed in the spray-dried product for up to six months and less than 5% after one-year storage. In conclusion, amorphous ABZ solid dispersions in combination with an acid and polymer can be prepared by spray drying to enhance dissolution and shelf-stability, whereas those made by melt extrusion are degraded.

  10. Hot-melt extrusion of sugar-starch-pellets.

    Science.gov (United States)

    Yeung, Chi-Wah; Rein, Hubert

    2015-09-30

    Sugar-starch-pellets (syn. sugar spheres) are usually manufactured through fluidized bed granulation or wet extrusion techniques. This paper introduces hot-melt extrusion (HME) as an alternative method to manufacture sugar-starch-pellets. A twin-screw extruder coupled with a Leistritz Micro Pelletizer (LMP) cutting machine was utilized for the extrusion of different types (normal-, waxy-, and high-amlyose) of corn starch, blended with varying amounts of sucrose. Pellets were characterized for their physicochemical properties including crystallinity, particle size distribution, tensile strength, and swelling expansion. Furthermore, the influence of sugar content and humidity on the product was investigated. Both sucrose and water lowered the Tg of the starch system allowing a convenient extrusion process. Mechanical strength and swelling behavior could be associated with varying amylose and amylopectin. X-ray powder diffractometric (XRPD) peaks of increasing sucrose contents appeared above 30%. This signified the oversaturation of the extruded starch matrix system with sucrose. Otherwise, had the dissolved sucrose been embedded into the molten starch matrix, no crystalline peak could have been recognized. The replacement of starch with sucrose reduced the starch pellets' swelling effect, which resulted in less sectional expansion (SEI) and changed the surface appearance. Further, a nearly equal tensile strength could be detected for sugar spheres with more than 40% sucrose. This observation stands in good relation with the analyzed values of the commercial pellets. Both techniques (fluidized bed and HME) allowed a high yield of spherical pellets (less friability) for further layering processes. Thermal influence on the sugar-starch system is still an obstacle to be controlled. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Study on the Hot Extrusion Process of Advanced Radiation Resistant Oxide Dispersion Strengthened Steel Tubes

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Byoungkwon; Noh, Sanghoon; Kim, Kibaik; Kang, Suk Hoon; Chun, Youngbum; Kim, Tae Kyu [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    Ferritic/martensitic steel has a better thermal conductivity and swelling resistance than austenitic stainless steel. Unfortunately, the available temperature range of ferritic/martensitic steel is limited at up to 650 .deg. C. Oxide dispersion strengthened (ODS) steels have been developed as the most prospective core structural materials for next generation nuclear systems because of their excellent high strength and irradiation resistance. The material performances of this new alloy are attributed to the existence of uniformly distributed nano-oxide particles with a high density, which is extremely stable at high temperature in a ferritic/martensitic matrix. This microstructure can be very attractive in achieving superior mechanical properties at high temperatures, and thus, these favorable microstructures should be obtained through the controls of the fabrication process parameters during the mechanical alloying and hot consolidation procedures. In this study, a hot extrusion process for advanced radiation resistant ODS steel tube was investigated. ODS martensitic steel was designed to have high homogeneity, productivity, and reproducibility. Mechanical alloying and hot consolidation processes were employed to fabricate the ODS steels. A microstructure observation and creep rupture test were examined to investigate the effects of the optimized fabrication conditions. Advanced radiation resistant ODS steel has been designed to have homogeneity, productivity, and reproducibility. For these characteristics, modified mechanical alloying and hot consolidation processes were developed. Microstructure observation revealed that the ODS steel has uniformly distributed fine-grain nano-oxide particles. The fabrication process for the tubing is also being propelled in earnest.

  12. Study on the Hot Extrusion Process of Advanced Radiation Resistant Oxide Dispersion Strengthened Steel Tubes

    International Nuclear Information System (INIS)

    Choi, Byoungkwon; Noh, Sanghoon; Kim, Kibaik; Kang, Suk Hoon; Chun, Youngbum; Kim, Tae Kyu

    2014-01-01

    Ferritic/martensitic steel has a better thermal conductivity and swelling resistance than austenitic stainless steel. Unfortunately, the available temperature range of ferritic/martensitic steel is limited at up to 650 .deg. C. Oxide dispersion strengthened (ODS) steels have been developed as the most prospective core structural materials for next generation nuclear systems because of their excellent high strength and irradiation resistance. The material performances of this new alloy are attributed to the existence of uniformly distributed nano-oxide particles with a high density, which is extremely stable at high temperature in a ferritic/martensitic matrix. This microstructure can be very attractive in achieving superior mechanical properties at high temperatures, and thus, these favorable microstructures should be obtained through the controls of the fabrication process parameters during the mechanical alloying and hot consolidation procedures. In this study, a hot extrusion process for advanced radiation resistant ODS steel tube was investigated. ODS martensitic steel was designed to have high homogeneity, productivity, and reproducibility. Mechanical alloying and hot consolidation processes were employed to fabricate the ODS steels. A microstructure observation and creep rupture test were examined to investigate the effects of the optimized fabrication conditions. Advanced radiation resistant ODS steel has been designed to have homogeneity, productivity, and reproducibility. For these characteristics, modified mechanical alloying and hot consolidation processes were developed. Microstructure observation revealed that the ODS steel has uniformly distributed fine-grain nano-oxide particles. The fabrication process for the tubing is also being propelled in earnest

  13. Friction conditions in the bearing area of an aluminium extrusion process

    NARCIS (Netherlands)

    Ma, X.; de Rooij, Matthias B.; Schipper, Dirk J.

    2012-01-01

    In aluminium extrusion processes, friction inside the bearing channel is important for controlling the surface quality of the extrusion products. The contact materials show a large hardness difference, one being hot aluminium, and the other being hardened tool steel. Further, the contact pressure is

  14. Microstructural modelling and lubrication study during zirconium alloy hot extrusion

    International Nuclear Information System (INIS)

    Gaudout, B.

    2009-01-01

    Using torsion tests (with strain rate jumps) and an experimental hot mini-extrusion apparatus, several samples zirconium alloy have been deformed: Zircaloy-4 (high α range) and Zr-1Nb (α + β domain). The fragmentation of the microstructure and post-dynamic grain growth have been examined. The main difference between these two alloys is that Zr-1Nb does not show grain growth during a heat treatment within the α + β domain after hot deformation. The recrystallization volume fraction has been measured on extruded samples with or without heat treatment. These rheological and microstructural data have been used to determine the parameters of a microstructural model including: a work-hardening model (Laaasraoui/Jonas), a continuous dynamic recrystallization model (Gourdet/Montheillet) and a grain growth model. This model leads to a good prediction of recrystallization volume fraction for Zircaloy-4 extrusion. However, the Zr-1Nb model cannot be validated because of the difficulty to observe deformed microstructures. Extrusion process is lubricated with a solid film. Trapping tests show that this lubricant is thermoviscoplastic. Friction along the container and several observations show the lubrication is not realized by a continuous film. Indeed, the heterogeneousness of deformation of these alloys causes a rupture of the lubricant film. Experiments and numerical simulations show that the radial gradient of axial displacement is affected by friction but also by stress softening of the alloys. (author)

  15. Oscillatory Shear Rheology in Examining the Drug-Polymer Interactions Relevant in Hot Melt Extrusion

    DEFF Research Database (Denmark)

    Aho, Johanna; Edinger, Magnus; Botker, Johan

    2016-01-01

    The flow properties of drug-polymer mixtures have a significant influence on their processability when using techniques such as hot melt extrusion (HME). Suitable extrusion temperature and screw speed to be used in laboratory scale HME were evaluated for mixtures containing 30% of paracetamol (PRC...... of the drug substances. Consecutively, the mixtures were extruded, and the maximum plasticizing weight fraction of each drug was determined by means of rheological measurements. IBU was found to have an efficient plasticizing functionality, decreasing the viscosity of the mixtures even above its apparent...

  16. Effect of extrusion processing on the microstructure, mechanical properties, biocorrosion properties and antibacterial properties of Ti-Cu sintered alloys

    International Nuclear Information System (INIS)

    Zhang, Erlin; Li, Shengyi; Ren, Jing; Zhang, Lan; Han, Yong

    2016-01-01

    Ti-Cu sintered alloys, Ti-Cu(S) alloy, have exhibited good anticorrosion resistance and strong antibacterial properties, but low ductility in previous study. In this paper, Ti-Cu(S) alloys were subjected to extrusion processing in order to improve the comprehensive property. The phase constitute, microstructure, mechanical property, biocorrosion property and antibacterial activity of the extruded alloys, Ti-Cu(E), were investigated in comparison with Ti-Cu(S) by X-ray diffraction (XRD), optical microscopy (OM), scanning electronic microscopy (SEM) with energy disperse spectroscopy (EDS), mechanical testing, electrochemical testing and plate-count method in order to reveal the effect of the extrusion process. XRD, OM and SEM results showed that the extrusion process did not change the phase constitute but refined the grain size and Ti 2 Cu particle significantly. Ti-Cu(E) alloys exhibited higher hardness and compressive yield strength than Ti-Cu(S) alloys due to the fine grain and Ti 2 Cu particles. With the consideration of the total compressive strain, it was suggested that the extrusion process could improve the ductility of Ti-Cu alloy(S) alloys. Electrochemical results have indicated that the extrusion process improved the corrosion resistance of Ti-Cu(S) alloys. Plate-count method displayed that both Ti-Cu(S) and Ti-Cu(E) exhibited strong antibacterial activity (> 99%) against S. aureus. All these results demonstrated that hot forming processing, such as the extrusion in this study, refined the microstructure and densified the alloy, in turn improved the ductility and strength as well as anticorrosion properties without reduction in antibacterial properties. - Highlights: • Hot extrusion refined the grain size and Ti 2 Cu phase significantly. • Hot extrusion increased the mechanical properties and the corrosion resistance. • The antibacterial properties was not affected by the hot process.

  17. Hot-Melt Extrusion: from Theory to Application in Pharmaceutical Formulation.

    Science.gov (United States)

    Patil, Hemlata; Tiwari, Roshan V; Repka, Michael A

    2016-02-01

    Hot-melt extrusion (HME) is a promising technology for the production of new chemical entities in the developmental pipeline and for improving products already on the market. In drug discovery and development, industry estimates that more than 50% of active pharmaceutical ingredients currently used belong to the biopharmaceutical classification system II (BCS class II), which are characterized as poorly water-soluble compounds and result in formulations with low bioavailability. Therefore, there is a critical need for the pharmaceutical industry to develop formulations that will enhance the solubility and ultimately the bioavailability of these compounds. HME technology also offers an opportunity to earn intellectual property, which is evident from an increasing number of patents and publications that have included it as a novel pharmaceutical formulation technology over the past decades. This review had a threefold objective. First, it sought to provide an overview of HME principles and present detailed engineered extrusion equipment designs. Second, it included a number of published reports on the application of HME techniques that covered the fields of solid dispersions, microencapsulation, taste masking, targeted drug delivery systems, sustained release, films, nanotechnology, floating drug delivery systems, implants, and continuous manufacturing using the wet granulation process. Lastly, this review discussed the importance of using the quality by design approach in drug development, evaluated the process analytical technology used in pharmaceutical HME monitoring and control, discussed techniques used in HME, and emphasized the potential for monitoring and controlling hot-melt technology.

  18. Inline monitoring and a PAT strategy for pharmaceutical hot melt extrusion.

    Science.gov (United States)

    Wahl, Patrick R; Treffer, Daniel; Mohr, Stefan; Roblegg, Eva; Koscher, Gerold; Khinast, Johannes G

    2013-10-15

    Implementation of continuous manufacturing in the pharmaceutical industry requires tight process control. This study focuses on a PAT strategy for hot melt extrusion of vegetable calcium stearate (CaSt) as matrix carrier and paracetamol as active pharmaceutical ingredient (API). The extrusion was monitored using in-line near-infrared (NIR) spectroscopy. A NIR probe was located in the section between the extrusion screws and the die, using a novel design of the die channel. A chemometric model was developed based on premixes at defined concentrations and was implemented in SIPAT for real time API concentration monitoring. Subsequently, step experiments were performed for different API concentrations, screw speeds and screw designs. The predicted API concentration was in good agreement with the pre-set concentrations. The transition from one API plateau to another was a smooth curve due to the mixing behaviour of the extruder. The accuracy of the model was confirmed via offline HPLC analysis. The screw design was determined as the main influential factor on content uniformity (CU). Additionally the influence of multiple feeders had a significant impact on CU. The results demonstrate that in-line NIR measurements is a powerful tool for process development (e.g., mixing characterization), monitoring and further control strategies. Copyright © 2013. Published by Elsevier B.V.

  19. Inline UV/Vis spectroscopy as PAT tool for hot-melt extrusion.

    Science.gov (United States)

    Wesholowski, Jens; Prill, Sebastian; Berghaus, Andreas; Thommes, Markus

    2018-01-11

    Hot-melt extrusion on co-rotating twin screw extruders is a focused technology for the production of pharmaceuticals in the context of Quality by Design. Since it is a continuous process, the potential for minimizing product quality fluctuation is enhanced. A typical application of hot-melt extrusion is the production of solid dispersions, where an active pharmaceutical ingredient (API) is distributed within a polymer matrix carrier. For this dosage form, the product quality is related amongst others to the drug content. This can be monitored on- or inline as critical quality attribute by a process analytical technology (PAT) in order to meet the specific requirements of Quality by Design. In this study, an inline UV/Vis spectrometer from ColVisTec was implemented in an early development twin screw extruder and the performance tested in accordance to the ICH Q2 guideline. Therefore, two API (carbamazepine and theophylline) and one polymer matrix (copovidone) were considered with the main focus on the quantification of the drug load. The obtained results revealed the suitability of the implemented PAT tool to quantify the drug load in a typical range for pharmaceutical applications. The effort for data evaluation was minimal due to univariate data analysis, and in combination with a measurement frequency of 1 Hz, the system is sufficient for real-time data acquisition.

  20. In situ production of tantalum carbide nanodispersoids in a copper matrix by reactive milling and hot extrusion

    Energy Technology Data Exchange (ETDEWEB)

    Manotas-Albor, Milton, E-mail: manotasm@uninorte.edu.co [Grupo de Investigación en Física Aplicada, Departamento de Física, Universidad del Norte, Km. 5 vía a Puerto Colombia, Barranquilla (Colombia); Departamento de Ingeniería Mecánica, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Beauchef 850, Santiago (Chile); Vargas-Uscategui, Alejandro [Laboratorio de Materiales a Nanoescala, Departamento de Ciencia de los Materiales, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Tupper Av. 2069, Santiago (Chile); Palma, Rodrigo [Departamento de Ingeniería Mecánica, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Beauchef 850, Santiago (Chile); Mosquera, Edgar [Laboratorio de Materiales a Nanoescala, Departamento de Ciencia de los Materiales, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Tupper Av. 2069, Santiago (Chile)

    2014-06-15

    Highlights: • Tantalum carbide nanodispersoids were obtained in a copper matrix. • Nanodispersoids were obtained by means of reactive milling followed by hot extrusion. • Hexane was used as the liquid medium for the reactive mechanical alloying process. • Hexane provides the carbon (C) needed for the process. • The reaction of tantalum carbide formation takes place in the hot extrusion. - Abstract: This paper presents a study of the in situ production of tantalum carbide nanodispersoids in a copper matrix. The copper matrix composites were produced by means of reactive milling in hexane (C{sub 6}H{sub 14}) followed by hot extrusion. The composite materials were characterized by means of optical emission spectroscopy (OES), X-ray fluorescence (XRF), scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM) and Vickers micro-hardness. The effect of milling time was analyzed in 10, 20 and 30 h in a composite with a nominal composition Cu–5 vol.% TaC. A systematic increase of the dislocations density and the carbon concentration were observed when the milling time was increased, whereas the crystallite size of the composite matrix decreased. The material milled for 30 h and hot-extruded showed a density of 9037 kg m{sup −3} (98.2% densification) and a softening resistance of 204 HV; however the latter value showed an abrupt drop after an annealing treatment at 923 K for 1 h. Finally, the TEM analysis showed the presence of tantalum carbide (Ta{sub 4}C{sub 3}) nanodispersoids.

  1. Hot-melt extrusion microencapsulation of quercetin for taste-masking.

    Science.gov (United States)

    Khor, Chia Miang; Ng, Wai Kiong; Kanaujia, Parijat; Chan, Kok Ping; Dong, Yuancai

    2017-02-01

    Besides its poor dissolution rate, the bitterness of quercetin also poses a challenge for further development. Using carnauba wax, shellac or zein as the shell-forming excipient, this work aimed to microencapsulate quercetin by hot-melt extrusion for taste-masking. In comparison with non-encapsulated quercetin, the microencapsulated powders exhibited significantly reduced dissolution in the simulated salivary pH 6.8 medium indicative of their potentially good taste-masking efficiency in the order of zein > carnauba wax > shellac. In vitro bitterness analysis by electronic tongue confirmed the good taste-masking efficiency of the microencapsulated powders. In vitro digestion results showed that carnauba wax and shellac-microencapsulated powders presented comparable dissolution rate with the pure quercetin in pH 1.0 (gastric) and 6.8 (intestine) medium; while zein-microencapsulated powders exhibited a remarkably slower dissolution rate. Crystallinity of quercetin was slightly reduced after microencapsulation while its chemical structure remained unchanged. Hot-melt extrusion microencapsulation could thus be an attractive technique to produce taste-masked bioactive powders.

  2. The microstructures and mechanical properties of Al-15Si-2.5Cu-0.5Mg/(wt%)B{sub 4}C composites produced through hot pressing technique and subjected to hot extrusion

    Energy Technology Data Exchange (ETDEWEB)

    Ozer, Alpay, E-mail: alpiozer@gmail.com

    2016-11-01

    In this study, B{sub 4}C (5, 10, and 15 wt%) particle-reinforced Ecka Alumix 231{sup ®} aluminum matrix composites were produced through the hot pressing technique. Some of these samples were subjected to hot extrusion as a secondary treatment at 4:1 ratio at a temperature of 555 °C. The obtained samples were subjected to density measurement, hardness test, microstructure analysis, and three-point bending test, and their fracture surfaces were examined. A density of over 99% was found in the samples. Al-rich solid solution and primary Si, CuAl{sub 2}, Al{sub 2}CuMg, and Mg{sub 2}Si phases in the microstructure were determined through X-ray diffraction analysis. Grain sizes were found to be 20 μm and 2 μm in the microstructures of the samples produced through hot pressing technique and of those subjected to additional hot extrusion, respectively. High hardness values were obtained in the samples subjected to hot extrusion. In these samples, wt% B{sub 4}C particle ratio and transverse rupture strength increased considerably. Furthermore, the highest compressive strain value was obtained in the 10 wt% B{sub 4}C particle-reinforced composites subjected to hot extrusion. - Highlights: • Liquid phase formed at the temperature of hot pressing and hot extrusion. • In the samples, over 99.19% density was obtained. • Average matrix grain size was measured to be 2 μm through hot extrusion. • As wt% B{sub 4}C ratio increased, transverse rupture strength values increased. • High compressive strain values were obtained in the hot extrusion samples.

  3. Aluminum-graphite composite produced by mechanical milling and hot extrusion

    International Nuclear Information System (INIS)

    Flores-Zamora, M.I.; Estrada-Guel, I.; Gonzalez-Hernandez, J.; Miki-Yoshida, M.; Martinez-Sanchez, R.

    2007-01-01

    Aluminum-graphite composites were produced by mechanical milling followed by hot extrusion. Graphite content was varied between 0 and 1 wt.%. Al-graphite mixtures were initially mixed in a shaker mill without ball, followed by mechanical milling in a High-energy simoloyer mill for 2 h under argon atmosphere. Milled powders were subsequently pressed at ∼950 MPa for 2 min, and next sintered under vacuum for 3 h at 823 K. Finally, sintered products were held for 0.5 h at 823 K and hot extruded using indirect extrusion. Tension and compression tests were carried out to determine the yield stress and maximum stress of the materials. We found that the mechanical resistance increased as the graphite content increased. Microstructural characterization was done by transmission electron microscopy. Al-O-C nanofibers and graphite nanoparticles were observed in extruded samples by transmission electron microscopy. These nanoparticles and nanofibers seemed to be responsible of the reinforcement phenomenon

  4. Reduced activation ODS ferritic steel - recent development in high speed hot extrusion processing

    Energy Technology Data Exchange (ETDEWEB)

    Oksiuta, Zbigniew [Faculty of Mechanical Engineering, Bialystok Technical University (Poland); Lewandowska, Malgorzata; Kurzydlowski, Krzysztof [Faculty of Materials Science and Engineering, Warsaw University of Technology (Poland); Baluc, Nadine [Ecole Polytechnique Federale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas, Association Euratom-Confederation Suisse, Villigen PSI (Switzerland)

    2010-05-15

    The paper presents the microstructure and mechanical properties of an oxide dispersion strengthened (ODS), reduced activation, ferritic steel, namely the Fe-14Cr-2W-0.3Ti-0.3Y{sub 2}O{sub 3} alloy, which was fabricated by hot isostatic pressing followed by high speed hydrostatic extrusion (HSHE) and heat treatment HT at 1050 C. Transmission electron microscopy (TEM) observations revealed significant differences in the grain size and dislocation density between the as-HIPped and as-HSHE materials. It was also found that the microstructure of the steel is stable after HT. The HSHE process improves significantly the tensile and Charpy impact properties of the as-HIPped steel. The ultimate tensile strength at room temperature increases from 950 up to 1350 MPa, while the upper shelf energy increases from 3.0 up to 6.0 J. However, the ductile-to-brittle transition temperature (DBTT) remains relatively high (about 75 C).These results indicate that HSHE is a promising method for achieving grain refinement and thus improving the mechanical properties of ODS ferritic steels. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  5. Polymorphic Transformation of Indomethacin during Hot Melt Extrusion Granulation: Process and Dissolution Control.

    Science.gov (United States)

    Xu, Ting; Nahar, Kajalajit; Dave, Rutesh; Bates, Simon; Morris, Kenneth

    2018-05-10

    To study and elucidate the effect of the intensity and duration of processing stresses on the possible solid-state changes during a hot melt extrusion granulation process. Blends of α-indomethacin and PEG 3350 (w/w 4:1) were granulated using various screw sizes/designs on the melt extruder under different temperature regimes. Differential Scanning Calorimetry and X-ray Powder Diffraction were employed for characterization. The dissolution behavior of the pure polymorphs and the resulting granules was determined using in-situ fiber optic UV testing system. An XRPD quantitation method using Excel full pattern fitting was developed to determine the concentration of each constituent (amorphous, α and γ indomethacin and PEG) in samples collected from each functioning zone and in granules. Analysis of in-process samples and granules revealed that higher temperature (≥130°C) and shear stress accelerated the process induced phase transitions from amorphous and/or the α form to γ indomethacin during heating stage. However, rapid cooling resulted in an increased percentage of the α form allowing isolation of the meta-stable form. By determining the conditions that either prevent or facilitate process induced transformations of IMC polymorphs during melt granulation, a design space was developed to control the polymorph present in the resulting granules. This represents the conditions necessary to balance the thermodynamic relationships between the polymorphs of the IMC system and the kinetics of the possible transformations as a function of the processing stresses.

  6. Development and Performance of a Highly Sensitive Model Formulation Based on Torasemide to Enhance Hot-Melt Extrusion Process Understanding and Process Development.

    Science.gov (United States)

    Evans, Rachel C; Kyeremateng, Samuel O; Asmus, Lutz; Degenhardt, Matthias; Rosenberg, Joerg; Wagner, Karl G

    2018-02-27

    The aim of this work was to investigate the use of torasemide as a highly sensitive indicator substance and to develop a formulation thereof for establishing quantitative relationships between hot-melt extrusion process conditions and critical quality attributes (CQAs). Using solid-state characterization techniques and a 10 mm lab-scale co-rotating twin-screw extruder, we studied torasemide in a Soluplus® (SOL)-polyethylene glycol 1500 (PEG 1500) matrix, and developed and characterized a formulation which was used as a process indicator to study thermal- and hydrolysis-induced degradation, as well as residual crystallinity. We found that torasemide first dissolved into the matrix and then degraded. Based on this mechanism, extrudates with measurable levels of degradation and residual crystallinity were produced, depending strongly on the main barrel and die temperature and residence time applied. In addition, we found that 10% w/w PEG 1500 as plasticizer resulted in the widest operating space with the widest range of measurable residual crystallinity and degradant levels. Torasemide as an indicator substance behaves like a challenging-to-process API, only with higher sensitivity and more pronounced effects, e.g., degradation and residual crystallinity. Application of a model formulation containing torasemide will enhance the understanding of the dynamic environment inside an extruder and elucidate the cumulative thermal and hydrolysis effects of the extrusion process. The use of such a formulation will also facilitate rational process development and scaling by establishing clear links between process conditions and CQAs.

  7. Development and efficiency assessment of process lubrication for hot forging

    Science.gov (United States)

    Kargin, S.; Artyukh, Viktor; Ignatovich, I.; Dikareva, Varvara

    2017-10-01

    The article considers innovative technologies in testing and production of process lubricants for hot bulk forging. There were developed new compositions of eco-friendly water-graphite process lubricants for hot extrusion and forging. New approaches to efficiency assessment of process lubricants are developed and described in the following article. Laboratory and field results are presented.

  8. Effects of Hot-Hydrostatic Canned Extrusion on the Stock Utilization, Microstructure and Mechanical Properties of TiBw/TC4 Composites with Quasi-Continuous Network.

    Science.gov (United States)

    Feng, Yangju; Li, Bing; Cui, Guorong; Zhang, Wencong

    2017-10-25

    In-situ TiB whisker-reinforced Ti-6Al-4V (TC4) titanium matrix composites (TiBw/TC4) with quasi-continuous networks were successfully fabricated by vacuum hot-pressing sintering. The effects of the hot-hydrostatic canned extrusion on stock utilization, microstructure and mechanical properties of the TiBw/TC4 composites were investigated. It was satisfactory that the utilization of composites could be obviously improved by canned extrusion compared to that extruded without canned extrusion. The microstructure results showed that after canned extrusion the grain was refined and the TiB whiskers were distributed from a random array state to a state in which the whiskers were distributed along the extrusion direction. The properties testing results revealed that the tensile strength, the hardness and the ductility of the composites all significantly improved after extrusion due to the grain refinement and orientation of the TiB whisker caused by extrusion. Tensile fracture results showed that when the TiB whiskers were randomly distributed only part of them played a role in strengthening the matrix during the deformation process (as-sintered composites), while when the TiB whiskers were oriented all whiskers could strengthen the matrix during the tensile testing process (as-extruded composites).

  9. Influence of twin-screw hot extrusion on linolenic acid retention in flaxseed meal

    International Nuclear Information System (INIS)

    Imran, M.

    2014-01-01

    flaxseed (linum usitatissimum l.) provides multiple nutritional benefits including high quality protein, dietary fiber and is the most abundant source of alpha-linolenic acid (c18:3). This study focuses on the effect of twin-screw hot extrusion on alpha-linolenic acid retention in full-fat flaxseed meal. the ranges of processing variables selected using box-behnken design were barrel exit temperature (bet) of 120-140 degree c; screw speed (ss) of 200-400 rpm; feed rate (fr) of 1-2 kg/h and feed moisture (fm) of 20-30%. The amount of alpha-linolenic acid retention in extruded samples ranged from 89.2% to 99.3%. Optimal operating conditions were stablished; bet (121degree c), ss (388 rpm), fr (1 kg/h) and fm (22.2%) for maximum (99.9%) retention of degree-linolenic acid. This effect was mainly dependent on bet and fm (p degree 0.01), whereas ss and fr imparted a lesser effect (p=0.05). The results of this study demonstrated that the twin-screw hot extrusion can be successfully explored to produce fatty meals with significant fatty acids retention for commercially food or feed purposes. (author)

  10. Development of Maltodextrin-Based Immediate-Release Tablets Using an Integrated Twin-Screw Hot-Melt Extrusion and Injection-Molding Continuous Manufacturing Process.

    Science.gov (United States)

    Puri, Vibha; Brancazio, Dave; Desai, Parind M; Jensen, Keith D; Chun, Jung-Hoon; Myerson, Allan S; Trout, Bernhardt L

    2017-11-01

    The combination of hot-melt extrusion and injection molding (HME-IM) is a promising process technology for continuous manufacturing of tablets. However, there has been limited research on its application to formulate crystalline drug-containing immediate-release tablets. Furthermore, studies that have applied the HME-IM process to molded tablets have used a noncontinuous 2-step approach. The present study develops maltodextrin (MDX)-based extrusion-molded immediate-release tablets for a crystalline drug (griseofulvin) using an integrated twin-screw HME-IM continuous process. At 10% w/w drug loading, MDX was selected as the tablet matrix former based on a preliminary screen. Furthermore, liquid and solid polyols were evaluated for melt processing of MDX and for impact on tablet performance. Smooth-surfaced tablets, comprising crystalline griseofulvin solid suspension in the amorphous MDX-xylitol matrix, were produced by a continuous process on a twin-screw extruder coupled to a horizontally opening IM machine. Real-time HME process profiles were used to develop automated HME-IM cycles. Formulation adjustments overcame process challenges and improved tablet strength. The developed MDX tablets exhibited adequate strength and a fast-dissolving matrix (85% drug release in 20 min), and maintained performance on accelerated stability conditions. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  11. The influence of Ni addition and hot-extrusion on the microstructure and tensile properties of Al–15%Mg2Si composite

    International Nuclear Information System (INIS)

    Emamy, M.; Khodadadi, M.; Honarbakhsh Raouf, A.; Nasiri, N.

    2013-01-01

    Highlights: ► Ni content on the microstructure and tensile properties of Al–Mg 2 Si composite. ► Ni changed the size of primary Mg 2 Si from 42 μm to 17 μm. ► Higher UTS and elongation values obtained by addition of 5 wt% Ni. ► Fracture behavior changed from brittle to ductile by Ni addition and extrusion. - Abstract: The effects of nickel addition and hot-extrusion on the microstructure and tensile properties of in situ Al–15%Mg 2 Si composite specimens have been investigated. Al–15%Mg 2 Si composite ingots were prepared by an in situ process and different amounts of nickel (0.1, 0.3, 0.5, 1.0, 3.0 and 5.0 wt% Ni) were added to the remelted composite. Optical microscopy (OM) and scanning electron microscopy (SEM) indicated that Ni addition changes the morphology of both primary and eutectic Mg 2 Si phases and decreases the size of primary Mg 2 Si particles from 42 μm to 17 μm. Hot-extrusion was found to be powerful in breaking the eutectic network and changing the size and morphology of pseudo-eutectic Mg 2 Si phase. The results obtained from tensile testing revealed that both Ni addition and hot-extrusion process improve ultimate tensile strength (UTS) and elongation values. Fracture surface examinations revealed a transition from brittle fracture mode in as-cast composite to ductile fracture in hot-extruded composite after Ni addition. This can be attributed to the changes in size and morphology of primary and eutectic Mg 2 Si phases and also the formation of more and finer α-Al phase

  12. Effect of extrusion stem speed on extrusion process for a hollow aluminum profile

    International Nuclear Information System (INIS)

    Zhang, Cunsheng; Zhao, Guoqun; Chen, Zhiren; Chen, Hao; Kou, Fujun

    2012-01-01

    Highlights: ► Extrusion stem speed has significant effects on extrusion process. ► An optimum value of stem speed exists for uniform metal flow distribution. ► A higher stem speed leads to a higher required extrusion force. ► A high stem speed leads to an improved welding quality of aluminum profile. - Abstract: Extrusion stem speed is one of important process parameters during aluminum profile extrusion, which directly influences the profile quality and choice of extrusion equipments. In this paper, the extrusion process of a thin-walled hollow aluminum profile was simulated by means of the HyperXtrude commercial software. Through a serial of numerical simulation, the effects of stem speed on extrusion process, such as metal flow behavior at die exit, temperature distribution, extrusion force, and welding pressure, have been investigated. The numerical results showed that there existed an optimum value of stem speed for flow velocity distribution. With the increasing stem speed, the temperature of the extrudate and required extrusion force increased, and the welding quality of extrudate would be improved. Through comprehensive comparison and analysis, the appropriate stem speed could be determined for practical extrusion production. Thus, the research results could give effective guideline for determining initial billet and die temperature and choosing the proper extrusion press in aluminum profile industry.

  13. Mechanical properties of copper-lithium alloys produced by mechanic alloyed and hot extrusion

    International Nuclear Information System (INIS)

    Castillo B, Ricardo; Gorziglia S, Ezio; Penaloza V, Augusto

    2004-01-01

    In this work are presented the progress carried out on the characterization of some physical and mechanical properties, together with the determination of the micro mechanism of fracture of the Cu-2% wt Li, that was obtained by mechanical alloying followed hot extrusion at 500 o C and 700 o C. Hardness and tensile mechanical tests were performed together with metallographic and fractographic analysis. The experimental results obtained with powders of the Cu-Li alloy studied are compared with powder of pure copper, under similar test conditions. The results show that by hot extrusion was allowed to obtain very high densification levels for the materials under study. Moreover, it was found that lithium reduce both the tensile strength and elongation, of copper by a mechanism of embrittlement. The results are compares with the literature (au)

  14. Hot Melt Extrusion and Spray Drying of Co-amorphous Indomethacin-Arginine With Polymers.

    Science.gov (United States)

    Lenz, Elisabeth; Löbmann, Korbinian; Rades, Thomas; Knop, Klaus; Kleinebudde, Peter

    2017-01-01

    Co-amorphous drug-amino acid systems have gained growing interest as an alternative to common amorphous formulations which contain polymers as stabilizers. Several preparation methods have recently been investigated, including vibrational ball milling on a laboratory scale or spray drying in a larger scale. In this study, the feasibility of hot melt extrusion for continuous manufacturing of co-amorphous drug-amino acid formulations was examined, challenging the fact that amino acids melt with degradation at high temperatures. Furthermore, the need for an addition of a polymer in this process was evaluated. After a polymer screening via the solvent evaporation method, co-amorphous indomethacin-arginine was prepared by a melting-solvent extrusion process without and with copovidone. The obtained products were characterized with respect to their solid-state properties, non-sink dissolution behavior, and stability. Results were compared to those of spray-dried formulations with the same compositions and to spray-dried indomethacin-copovidone. Overall, stable co-amorphous systems could be prepared by extrusion without or with copovidone, which exhibited comparable molecular interaction properties to the respective spray-dried products, while phase separation was detected by differential scanning calorimetry in several cases. The formulations containing indomethacin in combination with arginine and copovidone showed enhanced dissolution behavior over the formulations with only copovidone or arginine. Copyright © 2016 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  15. FDM 3D printing of modified drug-delivery systems using hot melt extrusion: a new approach for individualized therapy.

    Science.gov (United States)

    Cunha-Filho, Marcilio; Araújo, Maísa Rp; Gelfuso, Guilherme M; Gratieri, Tais

    2017-11-01

    The production process of 3D-printed drugs offers unique advantages such as the possibility of individualizing the drug therapy and easily associating different drugs and release technologies in the same pharmaceutical unit. Fused deposition modeling, a 3D printing technique, seems especially interesting for pharmaceutical applications, due to its low cost, precise and reproducible control of the printed structures, and versatility for industrial and laboratory scale. This technique combined with another technology already adapted for the pharmaceutical industry, the hot melt extrusion, is able to incorporate various mechanisms of modified drug release. This special report aims to bring together data of the experimental progress achieved using the fused deposition modeling 3D printing combined with hot melt extrusion technique and its potential in drug delivery. [Formula: see text].

  16. Process design and control of a twin screw hot melt extrusion for continuous pharmaceutical tamper-resistant tablet production.

    Science.gov (United States)

    Baronsky-Probst, J; Möltgen, C-V; Kessler, W; Kessler, R W

    2016-05-25

    Hot melt extrusion (HME) is a well-known process within the plastic and food industries that has been utilized for the past several decades and is increasingly accepted by the pharmaceutical industry for continuous manufacturing. For tamper-resistant formulations of e.g. opioids, HME is the most efficient production technique. The focus of this study is thus to evaluate the manufacturability of the HME process for tamper-resistant formulations. Parameters such as the specific mechanical energy (SME), as well as the melt pressure and its standard deviation, are important and will be discussed in this study. In the first step, the existing process data are analyzed by means of multivariate data analysis. Key critical process parameters such as feed rate, screw speed, and the concentration of the API in the polymers are identified, and critical quality parameters of the tablet are defined. In the second step, a relationship between the critical material, product and process quality attributes are established by means of Design of Experiments (DoEs). The resulting SME and the temperature at the die are essential data points needed to indirectly qualify the degradation of the API, which should be minimal. NIR-spectroscopy is used to monitor the material during the extrusion process. In contrast to most applications in which the probe is directly integrated into the die, the optical sensor is integrated into the cooling line of the strands. This saves costs in the probe design and maintenance and increases the robustness of the chemometric models. Finally, a process measurement system is installed to monitor and control all of the critical attributes in real-time by means of first principles, DoE models, soft sensor models, and spectroscopic information. Overall, the process is very robust as long as the screw speed is kept low. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Dry sliding tribological behavior and mechanical properties of Al2024–5 wt.%B4C nanocomposite produced by mechanical milling and hot extrusion

    International Nuclear Information System (INIS)

    Abdollahi, Alireza; Alizadeh, Ali; Baharvandi, Hamid Reza

    2014-01-01

    Highlights: • Nanostructured Al2024 and Al2024–B 4 C nanocomposite prepared via mechanical milling. • The milled powders formed by hot pressing and then exposed to hot extrusion. • Tribological behavior and mechanical properties of samples were investigated. • Al2024–B 4 C nanocomposite showed a better wear resistance and mechanical properties. - Abstract: In this paper, tribological behavior and mechanical properties of nanostructured Al2024 alloy produced by mechanical milling and hot extrusion were investigated before and after adding B 4 C particles. Mechanical milling was used to synthesize the nanostructured Al2024 in attrition mill under argon atmosphere up to 50 h. A similar process was used to produce Al2024–5 wt.%B 4 C composite powder. The milled powders were formed by hot pressing and then were exposed to hot extrusion in 750 °C with extrusion ratio of 10:1. To study the microstructure of milled powders and hot extruded samples, optical microscopy, transmission electron microscopy and scanning electron microscopy (SEM) equipped with an energy dispersive X-ray spectrometer (EDS) were used. The mechanical properties of samples were also compared together using tension, compression and hardness tests. The wear properties of samples were studied using pin-on-disk apparatus under a 20 N load. The results show that mechanical milling decreases the size of aluminum matrix grains to less than 100 nm. The results of mechanical and wear tests also indicate that mechanical milling and adding B 4 C particles increase strength, hardness and wear resistance of Al2024 and decrease its ductility remarkably

  18. Extrusion product defects: a statistical study

    International Nuclear Information System (INIS)

    Qamar, S.Z.; Arif, A.F.M.; Sheikh, A.K.

    2003-01-01

    In any manufacturing environment, defects resulting in rework or rejection are directly related to product cost and quality, and indirectly linked with process, tooling and product design. An analysis of product defects is therefore integral to any attempt at improving productivity, efficiency and quality. Commercial aluminum extrusion is generally a hot working process and consists of a series of different but integrated operations: billet preheating and sizing, die set and container preheating, billet loading and deformation, product sizing and stretching/roll-correction, age hardening, and painting/anodizing. Product defects can be traced back to problems in billet material and preparation, die and die set design and maintenance, process variable aberrations (ram speed, extrusion pressure, container temperature, etc), and post-extrusion treatment (age hardening, painting/anodizing, etc). The current paper attempts to analyze statistically the product defects commonly encountered in a commercial hot aluminum extrusion setup. Real-world rejection data, covering a period of nine years, has been researched and collected from a local structural aluminum extrusion facility. Rejection probabilities have been calculated for all the defects studied. The nine-year rejection data have been statistically analyzed on the basis of (i) an overall breakdown of defects, (ii) year-wise rejection behavior, (iii) breakdown of defects in each of three cost centers: press, anodizing, and painting. (author)

  19. Complex deformation routes for direct recycling aluminium alloy scrap via industrial hot extrusion

    Science.gov (United States)

    Paraskevas, Dimos; Kellens, Karel; Kampen, Carlos; Mohammadi, Amirahmad; Duflou, Joost R.

    2018-05-01

    This paper presents the final results of an industrial project, aiming for direct hot extrusion of wrought aluminium alloy scrap at an industrial scale. Two types of complex deformation/extrusion routes were tested for the production of the same profile, starting from AA6060 scrap in form of machining chips. More specifically scrap-based billets were extruded through: a 2-porthole and a 4-porthole die-set, modified for enhanced scrap consolidation and grain refinement. For comparison reasons, cast billets of the same alloy were extruded through the modified 2-porthole die set. The tensile testing results as well as microstructural investigations show that the 4-porthole extrusion route further improves scrap consolidation compared to the 2-porthole die output. The successful implementation of solid state recycling, directly at industrial level, indicates the technological readiness level of this research.

  20. How extrusion shapes food processing

    Science.gov (United States)

    This month's column will explore food extrusion. Extrusion is one of the most commonly used food manufacturing processes. Its versatility enables production of a diverse array of food products. This column will review the basic principles and provide an overview of applications. I would like to ...

  1. W-Cu composites subjected to heavy hot deformation

    International Nuclear Information System (INIS)

    Yu, Yang; Xu, Xiaoqiang; Zhang, Wencong

    2017-01-01

    The effect of plastic deformation on the properties and microstructure of W-Cu composites produced by multi-pass hot extrusion with steel cup was investigated. W-Cu composites were sintered at 1 100 C and then the sintered billets were firstly extruded at 900 C with different extrusion ratios. The second hot extrusion was performed at 900 C. The plastic deformation of copper phase plays a dominant part during the whole extrusion process. The microstructural evolution of W phase during the whole processing of heavy hot deformation can be divided into different stages. Experimental results indicate that the W agglomeration will be broken into fine particles effectively when the accumulated plastic deformation amounts to 97.6 % after the second extrusion.

  2. W-Cu composites subjected to heavy hot deformation

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Yang; Xu, Xiaoqiang; Zhang, Wencong [Harbin Institute of Technology-Weihai (China). School of Materials Science and Engineering

    2017-04-15

    The effect of plastic deformation on the properties and microstructure of W-Cu composites produced by multi-pass hot extrusion with steel cup was investigated. W-Cu composites were sintered at 1 100 C and then the sintered billets were firstly extruded at 900 C with different extrusion ratios. The second hot extrusion was performed at 900 C. The plastic deformation of copper phase plays a dominant part during the whole extrusion process. The microstructural evolution of W phase during the whole processing of heavy hot deformation can be divided into different stages. Experimental results indicate that the W agglomeration will be broken into fine particles effectively when the accumulated plastic deformation amounts to 97.6 % after the second extrusion.

  3. A Miniaturized Extruder to Prototype Amorphous Solid Dispersions: Selection of Plasticizers for Hot Melt Extrusion.

    Science.gov (United States)

    Lauer, Matthias E; Maurer, Reto; Paepe, Anne T De; Stillhart, Cordula; Jacob, Laurence; James, Rajesh; Kojima, Yuki; Rietmann, Rene; Kissling, Tom; van den Ende, Joost A; Schwarz, Sabine; Grassmann, Olaf; Page, Susanne

    2018-05-19

    Hot-melt extrusion is an option to fabricate amorphous solid dispersions and to enhance oral bioavailability of poorly soluble compounds. The selection of suitable polymer carriers and processing aids determines the dissolution, homogeneity and stability performance of this solid dosage form. A miniaturized extrusion device (MinEx) was developed and Hypromellose acetate succinate type L (HPMCAS-L) based extrudates containing the model drugs neurokinin-1 (NK1) and cholesterylester transfer protein (CETP) were manufactured, plasticizers were added and their impact on dissolution and solid-state properties were assessed. Similar mixtures were manufactured with a lab-scale extruder, for face to face comparison. The properties of MinEx extrudates widely translated to those manufactured with a lab-scale extruder. Plasticizers, Polyethyleneglycol 4000 (PEG4000) and Poloxamer 188, were homogenously distributed but decreased the storage stability of the extrudates. Stearic acid was found condensed in ultrathin nanoplatelets which did not impact the storage stability of the system. Depending on their distribution and physicochemical properties, plasticizers can modulate storage stability and dissolution performance of extrudates. MinEx is a valuable prototyping-screening method and enables rational selection of plasticizers in a time and material sparing manner. In eight out of eight cases the properties of the extrudates translated to products manufactured in lab-scale extrusion trials.

  4. A comparative study between hot-melt extrusion and spray-drying for the manufacture of anti-hypertension compatible monolithic fixed-dose combination products.

    Science.gov (United States)

    Kelleher, J F; Gilvary, G C; Madi, A M; Jones, D S; Li, S; Tian, Y; Almajaan, A; Senta-Loys, Z; Andrews, G P; Healy, A M

    2018-07-10

    The purpose of this work was to investigate the application of different advanced continuous processing techniques (hot melt extrusion and spray drying) to the production of fixed-dose combination (FDC) monolithic systems comprising of hydrochlorothiazide and ramipril for the treatment of hypertension. Identical FDC formulations were manufactured by the two different methods and were characterised using powder X-ray diffraction (PXRD) and modulated differential scanning calorimetry (mDSC). Drug dissolution rates were investigated using a Wood's apparatus, while physical stability was assessed on storage under controlled temperature and humidity conditions. Interestingly both drugs were transformed into their amorphous forms when spray dried, however, hydrochlorothiazide was determined, by PXRD, to be partially crystalline when hot melt extruded with either polymer carrier (Kollidon® VA 64 or Soluplus®). Hot melt extrusion was found to result in significant degradation of ramipril, however, this could be mitigated by the inclusion of the plasticizer, polyethylene glycol 3350, in the formulation and appropriate adjustment of processing temperature. The results of intrinsic dissolution rate studies showed that hot-melt extruded samples were found to release both drugs faster than identical formulations produced via spray drying. However, the differences were attributable to the surface roughness of the compressed discs in the Wood's apparatus, rather than solid state differences between samples. After a 60-day stability study spray dried samples exhibited a greater physical stability than the equivalent hot melt extruded samples. Copyright © 2018 Elsevier B.V. All rights reserved.

  5. Hot Melt Extrusion as Solvent-Free Technique for a Continuous Manufacturing of Drug-Loaded Mesoporous Silica

    DEFF Research Database (Denmark)

    Genina, Natalja; Hadi, Batol; Löbmann, Korbinian

    2018-01-01

    The aim of this study is to explore hot melt extrusion (HME) as a solvent-free drug loading technique for preparation of stable amorphous solid dispersions using mesoporous silica (PSi). Ibuprofen and carvedilol were used as poorly soluble active pharmaceutical ingredients (APIs). Due to the high...... friction of an API:PSi mixture below the loading limit of the API, it was necessary to add the polymer Soluplus(®) (SOL) in order to enable the extrusion process. As a result, the APIs were distributed between the PSi and SOL phase after HME. Due to its higher affinity to PSi, ibuprofen was mainly adsorbed...... into the PSi, whereas carvedilol was mainly found in the SOL phase. Intrinsic dissolution rate was highest for HME formulations, containing PSi, compared to pure crystalline (amorphous) APIs and HME formulations without PSi. HME is a feasible solvent-free drug loading technique for preparation of PSi...

  6. Extrusion processing : effects on dry canine diets

    NARCIS (Netherlands)

    Tran, Q.D.

    2008-01-01

    Keywords: Extrusion, Canine diet, Protein, Lysine, Starch gelatinization, Palatability, Drying.

    Extrusion cooking is a useful and economical tool for processing animal feed. This high temperature, short time processing technology causes chemical and physical changes that alter the

  7. Rheology Guided Rational Selection of Processing Temperature To Prepare Copovidone-Nifedipine Amorphous Solid Dispersions via Hot Melt Extrusion (HME).

    Science.gov (United States)

    Yang, Fengyuan; Su, Yongchao; Zhang, Jingtao; DiNunzio, James; Leone, Anthony; Huang, Chengbin; Brown, Chad D

    2016-10-03

    The production of amorphous solid dispersions via hot melt extrusion (HME) relies on elevated temperature and prolonged residence time, which can result in potential degradation and decomposition of thermally sensitive components. Herein, the rheological properties of a physical mixture of polymer and an active pharmaceutical ingredient (API) were utilized to guide the selection of appropriate HME processing temperature. In the currently studied copovidone-nifedipine system, a critical temperature, which is substantially lower (∼13 °C) than the melting point of crystalline API, was captured during a temperature ramp examination and regarded as the critical point at which the API could molecularly dissolve into the polymer. Based on the identification of this critical point, various solid dispersions were prepared by HME processing below, at, and above the critical temperature (both below and above the melting temperature (T m ) of crystalline API). In addition, the resultant extrudates along with two control solid dispersions prepared by physical mixing and cryogenic milling were assessed by X-ray diffraction, differential scanning calorimetry, hot stage microscopy, rheology, and solid-state NMR. Physicochemical properties of resultant solid dispersions indicated that the identified critical temperature is sufficient for the polymer-API system to reach a molecular-level mixing, manifested by the transparent and smooth appearance of extrudates, the absence of API crystalline diffraction and melting peaks, dramatically decreased rheological properties, and significantly improved polymer-API miscibility. Once the critical temperature has been achieved, further raising the processing temperature only results in limited improvement of API dispersion, reflected by slightly reduced storage modulus and complex viscosity and limited improvement in miscibility.

  8. Continuous production of fenofibrate solid lipid nanoparticles by hot-melt extrusion technology: a systematic study based on a quality by design approach.

    Science.gov (United States)

    Patil, Hemlata; Feng, Xin; Ye, Xingyou; Majumdar, Soumyajit; Repka, Michael A

    2015-01-01

    This contribution describes a continuous process for the production of solid lipid nanoparticles (SLN) as drug-carrier systems via hot-melt extrusion (HME). Presently, HME technology has not been used for the manufacturing of SLN. Generally, SLN are prepared as a batch process, which is time consuming and may result in variability of end-product quality attributes. In this study, using Quality by Design (QbD) principles, we were able to achieve continuous production of SLN by combining two processes: HME technology for melt-emulsification and high-pressure homogenization (HPH) for size reduction. Fenofibrate (FBT), a poorly water-soluble model drug, was incorporated into SLN using HME-HPH methods. The developed novel platform demonstrated better process control and size reduction compared to the conventional process of hot homogenization (batch process). Varying the process parameters enabled the production of SLN below 200 nm. The dissolution profile of the FBT SLN prepared by the novel HME-HPH method was faster than that of the crude FBT and a micronized marketed FBT formulation. At the end of a 5-h in vitro dissolution study, a SLN formulation released 92-93% of drug, whereas drug release was approximately 65 and 45% for the marketed micronized formulation and crude drug, respectively. Also, pharmacokinetic study results demonstrated a statistical increase in Cmax, Tmax, and AUC0-24 h in the rate of drug absorption from SLN formulations as compared to the crude drug and marketed micronized formulation. In summary, the present study demonstrated the potential use of hot-melt extrusion technology for continuous and large-scale production of SLN.

  9. Microstructure and textural characterization of hot extruded Zr-2.5Nb alloy PHWR pressure tube fabricated by various ingot processing route

    International Nuclear Information System (INIS)

    Vaibhaw, Kumar; Jha, S.K.; Saibaba, N.; Neogy, S.; Mani Krishna, K.V.; Srivastava, D.; Dey, G.K.

    2011-01-01

    Zr-2.5 Nb alloys finds its applications as a pressure tube component in pressure tube type thermal reactors such as PHWRs and RBMK due to properties attributed such as low neutron absorption cross section, high temperature strength and corrosion resistance etc. Manufacturing of this life time components involves series of thermo-mechanical processes of hot working and cold working with intermediate annealing. The life time of Pressure tube are limited due to their diametral creep properties which is governed by metallurgical characteristics such as texture, microstructure dislocation density etc. The primary breakdown of cast structure in Vacuum Arc Melted ingot can be effected by either hot extrusion or forging in single or multiple stages before final hot extrusion step into the blank for manufacturing of seamless pressure tube. Elevated temperature deformation carried out in hot working above the recrystallization temperature would enable impositions of large strains in single step. This deformation causes a significant change in the microstructure of the material and depends on process parameters such as extrusion ratio, temperature and strain rate. Basic microstructure developed at this deformation stage has significant bearing on the final properties of the material fabricated with subsequent cold working steps. The major texture in α+β Zr-2.5 Nb alloy is established during final extrusion to blank which does not change significantly during subsequent cold pilgering. However, microstructure is modified significantly in subsequent cold working which can be effected by cold pilgering or cold drawing in single or multiple steps. Present paper brings out the various ingot processing routes using forging and or extrusion followed for fabrication of pressure tubes. The development of texture and microstructures has been discussed at the blank stage from these processing routes and also with respect to varying extrusion variable such as extrusion ratio

  10. Micro-scale prediction method for API-solubility in polymeric matrices and process model for forming amorphous solid dispersion by hot-melt extrusion.

    Science.gov (United States)

    Bochmann, Esther S; Neumann, Dirk; Gryczke, Andreas; Wagner, Karl G

    2016-10-01

    A new predictive micro-scale solubility and process model for amorphous solid dispersions (ASDs) by hot-melt extrusion (HME) is presented. It is based on DSC measurements consisting of an annealing step and a subsequent analysis of the glass transition temperature (Tg). The application of a complex mathematical model (BCKV-equation) to describe the dependency of Tg on the active pharmaceutical ingredient (API)/polymer ratio, enables the prediction of API solubility at ambient conditions (25°C). Furthermore, estimation of the minimal processing temperature for forming ASDs during HME trials could be defined and was additionally confirmed by X-ray powder diffraction data. The suitability of the DSC method was confirmed with melt rheological trials (small amplitude oscillatory system). As an example, ball milled physical mixtures of dipyridamole, indomethacin, itraconazole and nifedipine in poly(vinylpyrrolidone-co-vinylacetate) (copovidone) and polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft copolymer (Soluplus®) were used. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Application of physical and numerical simulations for interpretation of peripheral coarse grain structure during hot extrusion of AA7020 aluminum alloy

    NARCIS (Netherlands)

    Eivani, A.R.; Zhou, J.

    2017-01-01

    In this research, hot compression test is used to simulate the metallurgical phenomena occurring in the peripheral part of AA7020 aluminum alloy extrudates during hot extrusion and leading to the formation of the peripheral coarse grain (PCG) structure. The temperature profiles at a tracking

  12. Numerical simulation of hot-melt extrusion processes for amorphous solid dispersions using model-based melt viscosity.

    Science.gov (United States)

    Bochmann, Esther S; Steffens, Kristina E; Gryczke, Andreas; Wagner, Karl G

    2018-03-01

    Simulation of HME processes is a valuable tool for increased process understanding and ease of scale-up. However, the experimental determination of all required input parameters is tedious, namely the melt rheology of the amorphous solid dispersion (ASD) in question. Hence, a procedure to simplify the application of hot-melt extrusion (HME) simulation for forming amorphous solid dispersions (ASD) is presented. The commercial 1D simulation software Ludovic ® was used to conduct (i) simulations using a full experimental data set of all input variables including melt rheology and (ii) simulations using model-based melt viscosity data based on the ASDs glass transition and the physical properties of polymeric matrix only. Both types of HME computation were further compared to experimental HME results. Variation in physical properties (e.g. heat capacity, density) and several process characteristics of HME (residence time distribution, energy consumption) among the simulations and experiments were evaluated. The model-based melt viscosity was calculated by using the glass transition temperature (T g ) of the investigated blend and the melt viscosity of the polymeric matrix by means of a T g -viscosity correlation. The results of measured melt viscosity and model-based melt viscosity were similar with only few exceptions, leading to similar HME simulation outcomes. At the end, the experimental effort prior to HME simulation could be minimized and the procedure enables a good starting point for rational development of ASDs by means of HME. As model excipients, Vinylpyrrolidone-vinyl acetate copolymer (COP) in combination with various APIs (carbamazepine, dipyridamole, indomethacin, and ibuprofen) or polyethylene glycol (PEG 1500) as plasticizer were used to form the ASDs. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Analysis and modeling of hot extrusion die for its service life enhancement

    Science.gov (United States)

    Akhtar, Syed Sohail

    Aluminum extrusion finds extensive application in the construction, automobile and aerospace industries. High pressures, elevated temperatures, complex and intricate section geometries lead to repeated mechanical and thermal stresses in the die and affiliated tooling. Product rework and rejects can be traced back to various defects spread over the die life cycle: die design, die manufacture and heat treatment, process parameters, inprocess die maintenance/correction and, billet type and quality. Therefore, improved and efficient service life of die and related tooling used in the extrusion press is one the most important factors in maximizing productivity and minimizing cost for ensuring the economical efficiency of an aluminum extrusion plant. How often a die has to be scrapped and replaced with a new one directly contributes to the commercial viability of producing a certain profile. The focus of the current work is on three distinct yet inter-related studies pertaining to the improvement of aluminum extrusion die. Study-A (Die Failure Analysis) is an investigation of various modes and critical failure types based on industrial data (Chapter-2 ), examination of failed dies and finite element simulation for identification of critical process parameters and design features in die fatigue-life (Chapter-3). In Study-B (Die Surface Hardening Treatment), two-stage controlled gas nitriding process for H13 steel is evaluated, both experimentally and numerically, in terms of nitrided case morphology and properties (Chapter-4) followed by experimental and numerical investigation of the effects of repeated nitriding (Chapter-5), pre-nitriding surface preparation (Chapter-6) and die profile geometry (Chapter-7) on nitriding performance in regard to die service life. In Study-C (Effect of Billet Quality on Die Life), the effect of billet quality and related influencing extrusion parameters on the die service life is investigated based on industrial data and some regression

  14. Hot Deformation Behavior and Processing Maps of Diamond/Cu Composites

    Science.gov (United States)

    Zhang, Hongdi; Liu, Yue; Zhang, Fan; Zhang, Di; Zhu, Hanxing; Fan, Tongxiang

    2018-06-01

    The hot deformation behaviors of 50 vol pct uncoated and Cr-coated diamond/Cu composites were investigated using hot isothermal compression tests under the temperature and strain rate ranging from 1073 K to 1273 K (800 °C to 1000 °C) and from 0.001 to 5 s-1, respectively. Dynamic recrystallization was determined to be the primary restoration mechanism during deformation. The Cr3C2 coating enhanced the interfacial bonding and resulted in a larger flow stress for the Cr-coated diamond/Cu composites. Moreover, the enhanced interfacial affinity led to a higher activation energy for the Cr-coated diamond/Cu composites (238 kJ/mol) than for their uncoated counterparts (205 kJ/mol). The strain-rate-dependent constitutive equations of the diamond/Cu composites were derived based on the Arrhenius model, and a high correlation ( R = 0.99) was observed between the calculated flow stresses and experimental data. With the help of processing maps, hot extrusions were realized at 1123 K/0.01 s-1 and 1153 K/0.01 s-1 (850 °C/0.01 s-1 and 880 °C/0.01 s-1) for the uncoated and coated diamond/Cu composites, respectively. The combination of interface optimization and hot extrusion led to increases of the density and thermal conductivity, thereby providing a promising route for the fabrication of diamond/Cu composites.

  15. Extrusion and Extruded Products: Changes in Quality Attributes as Affected by Extrusion Process Parameters: A Review.

    Science.gov (United States)

    Alam, M S; Kaur, Jasmeen; Khaira, Harjot; Gupta, Kalika

    2016-01-01

    Extrusion of foods is an emerging technology for the food industries to process and market a large number of products of varying size, shape, texture, and taste. Extrusion cooking technology has led to production of wide variety of products like pasta, breakfast cereals, bread crumbs, biscuits, crackers, croutons, baby foods, snack foods, confectionery items, chewing gum, texturized vegetable protein (TVP), modified starch, pet foods, dried soups, dry beverage mixes etc. The functional properties of extruded foods plays an important role for their acceptability which include water absorption, water solubility, oil absorption indexes, expansion index, bulk density and viscosity of the dough. The aim of this review is to give the detailed outlines about the potential of extrusion technology in development of different types of products and the role of extrusion-operating conditions and their effect on product development resulting in quality changes i.e physical, chemical, and nutritional, experienced during the extrusion process.

  16. High strength Al–Al2O3p composites: Optimization of extrusion parameters

    DEFF Research Database (Denmark)

    Luan, B.F.; Hansen, Niels; Godfrey, A.

    2011-01-01

    Composite aluminium alloys reinforced with Al2O3p particles have been produced by squeeze casting followed by hot extrusion and a precipitation hardening treatment. Good mechanical properties can be achieved, and in this paper we describe an optimization of the key processing parameters...... on an investigation of their mechanical properties and microstructure, as well as on the surface quality of the extruded samples. The evaluation shows that material with good strength, though with limited ductility, can be reliably obtained using a production route of squeeze casting, followed by hot extrusion....... The parameters investigated are the extrusion temperature, the extrusion rate and the extrusion ratio. The materials chosen are AA 2024 and AA 6061, each reinforced with 30vol.% Al2O3 particles of diameter typically in the range from 0.15 to 0.3μm. The extruded composites have been evaluated based...

  17. Mechanical properties and drug release of venlafaxine HCl solid mini matrices prepared by hot-melt extrusion and hot or ambient compression.

    Science.gov (United States)

    Avgerinos, Theodoros; Kantiranis, Nikolaos; Panagopoulou, Athanasia; Malamataris, Stavros; Kachrimanis, Kyriakos; Nikolakakis, Ioannis

    2018-02-01

    Objective/significance: To elucidate the role of plasticizers in different mini matrices and correlate mechanical properties with drug release. Cylindrical pellets were prepared by hot-melt extrusion (HME) and mini tablets by hot (HC) and ambient compression (AC). Venlafaxine HCl was the model drug, Eudragit ® RSPO the matrix former and citric acid or Lutrol ® F127 the plasticizers. The matrices were characterized for morphology, crystallinity, and mechanical properties. The influence of plasticizer's type and content on the extrusion pressure (P e ) during HME and ejection during tableting was examined and the mechanical properties were correlated with drug release parameters. Resistance to extrusion and tablet ejection force were reduced by Lutrol ® F127 which also produced softer and weaker pellets with faster release, but harder and stronger HC tablets with slower release. HME pellets showed greater tensile strength (T) and 100 times slower release than tablets. P e correlated with T and resistance to deformation of the corresponding pellets (r 2  = 0.963 and 0.945). For both HME and HC matrices the decrease of drug release with T followed a single straight line (r 2  = 0.990) and for HME the diffusion coefficient (D e ) and retreat rate constant (k b ) decreased linearly with T (r 2  = 0.934 and 0.972). Lutrol ® F127 and citric acid are efficient plasticizers and Lutrol ® F127 is a thermal binder/lubricant in HC compression. The different bonding mechanisms of the matrices were reflected in the mechanical strength and drug release. Relationships established between T and drug release parameters for HME and HC matrices may be useful during formulation work.

  18. MODERNIZATION OF TECHNOLOGICAL LINE FOR CELLULAR EXTRUSION PROCESS

    Directory of Open Access Journals (Sweden)

    Tomasz Garbacz

    2014-06-01

    As part of the modernization of the cellular extrusion technology the extrusion head was designed and made. During the designing and modeling of the head the Auto CAD programe was used. After the prototyping the extrusion head was tested. In the article specification of cellular extrusion process of thermoplastics was presented. In the research, the endothermal chemical blowing agents in amount 1,0% by mass were used. The quantity of used blowing agent has a direct influence on density and structure of the extruded product of modified polymers. However, these properties have further influence on porosity, impact strength, hardness, tensile strength and another.

  19. Investigation of Thermal and Viscoelastic Properties of Polymers Relevant to Hot Melt Extrusion, IV: Affinisol™ HPMC HME Polymers.

    Science.gov (United States)

    Gupta, Simerdeep Singh; Solanki, Nayan; Serajuddin, Abu T M

    2016-02-01

    Most cellulosic polymers cannot be used as carriers for preparing solid dispersion of drugs by hot melt extrusion (HME) due to their high melt viscosity and thermal degradation at high processing temperatures. Three HME-grade hydroxypropyl methylcelluloses, namely Affinisol™ HPMC HME 15 cP, Affinisol™ HPMC HME 100 cP, and Affinisol™ HPMC HME 4 M, have recently been introduced by The Dow Chemical Co. to enable the preparation of solid dispersion at lower and more acceptable processing temperatures. In the present investigation, physicochemical properties of the new polymers relevant to HME were determined and compared with that of Kollidon(®) VA 64. Powder X-ray diffraction (PXRD), modulated differential scanning calorimetry (mDSC), thermogravimetric analysis (TGA), moisture sorption, rheology, and torque analysis by melt extrusion were applied. PXRD and mDSC showed that the Affinisol™ polymers were amorphous in nature. According to TGA, the onset of degradation for all polymers was >220°C. The Affinisol™ polymers exhibited less hygroscopicity than Kollidon(®) VA 64 and another HPMC polymer, Methocel™ K100LV. The complex viscosity profiles of the Affinisol™ polymers as a function of temperature were similar. The viscosity of the Affinisol™ polymers was highly sensitive to the shear rate applied, and unlike Kollidon(®) VA 64, the viscosity decreased drastically when the angular frequency was increased. Because of the very high shear rate encountered during melt extrusion, Affinisol™ polymers showed capability of being extruded at larger windows of processing temperatures as compared to that of Kollidon(®) VA 64.

  20. Effect of extrusion processing on the microstructure, mechanical properties, biocorrosion properties and antibacterial properties of Ti-Cu sintered alloys.

    Science.gov (United States)

    Zhang, Erlin; Li, Shengyi; Ren, Jing; Zhang, Lan; Han, Yong

    2016-12-01

    Ti-Cu sintered alloys, Ti-Cu(S) alloy, have exhibited good anticorrosion resistance and strong antibacterial properties, but low ductility in previous study. In this paper, Ti-Cu(S) alloys were subjected to extrusion processing in order to improve the comprehensive property. The phase constitute, microstructure, mechanical property, biocorrosion property and antibacterial activity of the extruded alloys, Ti-Cu(E), were investigated in comparison with Ti-Cu(S) by X-ray diffraction (XRD), optical microscopy (OM), scanning electronic microscopy (SEM) with energy disperse spectroscopy (EDS), mechanical testing, electrochemical testing and plate-count method in order to reveal the effect of the extrusion process. XRD, OM and SEM results showed that the extrusion process did not change the phase constitute but refined the grain size and Ti2Cu particle significantly. Ti-Cu(E) alloys exhibited higher hardness and compressive yield strength than Ti-Cu(S) alloys due to the fine grain and Ti2Cu particles. With the consideration of the total compressive strain, it was suggested that the extrusion process could improve the ductility of Ti-Cu alloy(S) alloys. Electrochemical results have indicated that the extrusion process improved the corrosion resistance of Ti-Cu(S) alloys. Plate-count method displayed that both Ti-Cu(S) and Ti-Cu(E) exhibited strong antibacterial activity (>99%) against S. aureus. All these results demonstrated that hot forming processing, such as the extrusion in this study, refined the microstructure and densified the alloy, in turn improved the ductility and strength as well as anticorrosion properties without reduction in antibacterial properties. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Optimal design of an extrusion process for a hinge bracket

    International Nuclear Information System (INIS)

    Na, Geum Ju; Jang, Myung Geun; Kim, Jong Bong

    2016-01-01

    This study considers process design in forming a hinge bracket. A thin hinge bracket is typically produced by bending a sheet panel or welding a hollow bar into a sheet panel. However, the hinge bracket made by bending or welding does not have sufficient durability in severe operating conditions because of the stress concentration in the bended region or the low corrosion resistance of the welded region. Therefore, this study uses forming to produce the hinge bracket part of a foldable container and to ensure durability in difficult operating conditions. An extrusion process for a T-shaped hinge bracket is studied using finite element analysis. Preliminary analysis shows that a very high forging load is required to form the bracket by forging. Therefore, extrusion is considered as a candidate process. Producing the part through the extrusion process enables many brackets to be made in a single extrusion and through successive cutting of the extruded part, thereby reducing the manufacturing cost. The design focuses on reducing the extrusion load and on ensuring shape accuracy. An initial billet is designed to reduce the extrusion load and to obtain a geometrically accurate part. The extruded part is bent frequently because of uneven material flow. Thus, extrusion die geometries are designed to obtain straight parts.

  2. Optimal design of an extrusion process for a hinge bracket

    Energy Technology Data Exchange (ETDEWEB)

    Na, Geum Ju; Jang, Myung Geun; Kim, Jong Bong [Seoul National University, Seoul (Korea, Republic of)

    2016-05-15

    This study considers process design in forming a hinge bracket. A thin hinge bracket is typically produced by bending a sheet panel or welding a hollow bar into a sheet panel. However, the hinge bracket made by bending or welding does not have sufficient durability in severe operating conditions because of the stress concentration in the bended region or the low corrosion resistance of the welded region. Therefore, this study uses forming to produce the hinge bracket part of a foldable container and to ensure durability in difficult operating conditions. An extrusion process for a T-shaped hinge bracket is studied using finite element analysis. Preliminary analysis shows that a very high forging load is required to form the bracket by forging. Therefore, extrusion is considered as a candidate process. Producing the part through the extrusion process enables many brackets to be made in a single extrusion and through successive cutting of the extruded part, thereby reducing the manufacturing cost. The design focuses on reducing the extrusion load and on ensuring shape accuracy. An initial billet is designed to reduce the extrusion load and to obtain a geometrically accurate part. The extruded part is bent frequently because of uneven material flow. Thus, extrusion die geometries are designed to obtain straight parts.

  3. IMPORTANT DEGRADATIONS IN POLYETHYLENE TERAPHTALATE EXTRUSION PROCESS

    Directory of Open Access Journals (Sweden)

    Şule ALTUN

    2003-01-01

    Full Text Available Polyethylene terephthalate (PET is one of the most used thermo-plastic polymers. The total consumption of PET has been about 30 million tons in the year 2000. Polyester fibers constitute about 60 % of total synthetic fibers consumption. During extrusion, PET polymer is faced to thermal, thermo-oxidative and hydrolytic degradation, which result in severe reduction in its molecular weight, thereby adversely affecting its subsequent melt processability. Therefore, it is essential to understand degradation processes of PET during melt extrusion.

  4. COMPUTER MODELING IN DEFORM-3D FOR ANALYSIS OF PLASTIC FLOW IN HIGH-SPEED HOT EXTRUSION OF BIMETALLIC FORMATIVE PARTS OF DIE TOOLING

    Directory of Open Access Journals (Sweden)

    I. V. Kachanov

    2015-01-01

    Full Text Available The modern development of industrial production is closely connected with the use of science-based and high technologies to ensure competitiveness of the manufactured products on the world market. There is also much tension around an energy- and resource saving problem which can be solved while introducing new technological processes and  creation of new materials that provide productivity increase through automation and improvement of tool life. Development and implementation of such technologies are rather often considered as time-consuming processes  which are connected with complex calculations and experimental investigations. Implementation of a simulation modelling for materials processing using modern software products serves an alternative to experimental and theoretical methods of research.The aim of this paper is to compare experimental results while obtaining bimetallic samples of a forming tool through the method of speed hot extrusion and the results obtained with the help of computer simulation using DEFORM-3D package and a finite element method. Comparative analysis of plastic flow of real and model samples has shown that the obtained models provide high-quality and reliable picture of plastic flow during high-speed hot extrusion. Modeling in DEFORM-3D make it possible to eliminate complex calculations and significantly reduce a number of experimental studies while developing new technological processes.

  5. Analysis of Material Flow in Screw Extrusion of Aluminum

    International Nuclear Information System (INIS)

    Haugen, Bjoern; Oernskar, Magnus; Welo, Torgeir; Wideroee, Fredrik

    2010-01-01

    Screw extrusion of aluminum is a new process for production of aluminum profiles. The commercial potential could be large. Little experimental and numerical work has been done with respect to this process.The material flow of hot aluminum in a screw extruder has been analyzed using finite element formulations for the non-Newtonian Navier-Stokes equations. Aluminum material properties are modeled using the Zener-Holloman material model. Effects of stick-slip conditions are investigated with respect to pressure build up and mixing quality of the extrusion process.The numerical results are compared with physical experiments using an experimental screw extruder.

  6. Fabrication of SiCp/Al Alloy Composites by In-situ Vacuum Hot Press Process

    Energy Technology Data Exchange (ETDEWEB)

    Choi, S. W.; Hong, S. K.; Kim, Y. M.; Kang, C. S. [Chonnam National University, Kwangju (Korea); Chang, S. Y. [Hanyang University, Seoul (Korea)

    2001-07-01

    SiCp/pure Al and SiCp/2024Al MMCs were fabricated by in-situ VHP process designed specially just in this study which is composed of the vacuum hot press at range from R.T. to 500 deg.C and the continuous extrusion without canning process at 520 deg.C. It was investigated the effect of SiC particle size, volume fraction and extrusion ratio on the tensile properties and micro structure in all composites. In case of the 10:1 extrusion ratio, but SiCp/pure Al and SiCp/2024Al composites were shown a sound appearance and a good micro structure without crack of SiCp as well as uniform distribution of SiCp. However, in case of the 16:1 extrusion ratio, the number of cracked SiC particles more than increased in a higher volume fraction composite and 2024Al matrix composite compared with pure Al matrix one. The tensile strength of the composites reinforced smaller SiCp was higher than that of the bigger SiCp reinforced in same volume fraction and extrusion ratio. (author) 14 refs., 14 figs.

  7. Extrusion: An environmentally friendly process for PEMFC membrane elaboration

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, J.-Y.; Iojoiu, C.; Marechal, M. [LEPMI, UMR 5631 CNRS-INPG-UJF, ENSEEG, BP 75, F-38402, Saint Martin d' Heres (France); Chabert, F.; El Kissi, N. [Rheologie, UMR 5520 CNRS-INPG-UJF, ENSHMG, BP 53, F-38041, Grenoble (France); Salomon, J.; Mercier, R. [LMOPS UMR CNRS 5041, BP 24, F-69390 Vernaison (France); Piffard, Y. [CNRS Universite de Nantes, Institut des Materiaux Jean Rouxel, UMR 6502, BP 32229, F-44322, Nantes Cedex 3 (France); Galiano, H. [CEA, Le Ripault Research Center, BP 16, F-37260, Monts (France)

    2007-12-31

    The paper deals with the use of extrusion to process PEMFC filled and unfilled membranes. Several routes including the sulfonation of filled and unfilled extruded membranes and the extrusion of filled and unfilled ionomers are reported. Thanks to the use of selected water-soluble aid process plasticizers, acid and alkaline forms of sulfonated polyethersulfone were, for the first time, successfully extruded. The extrusion process did not lead to any degradation of the ionomer performances. Decreasing the membrane cost while using environmentally friendly elaboration conditions, it should be helpful to an industrial production. In addition, avoiding filler sedimentation it should allow homogeneous composite membranes to be obtained. (author)

  8. Towards Extrusion of Ionomers to Process Fuel Cell Membranes

    Directory of Open Access Journals (Sweden)

    Jean-Yves Sanchez

    2011-07-01

    Full Text Available While Proton Exchange Membrane Fuel Cell (PEMFC membranes are currently prepared by film casting, this paper demonstrates the feasibility of extrusion, a solvent-free alternative process. Thanks to water-soluble process-aid plasticizers, duly selected, it was possible to extrude acidic and alkaline polysulfone ionomers. Additionally, the feasibility to extrude composites was demonstrated. The impact of the plasticizers on the melt viscosity was investigated. Following the extrusion, the plasticizers were fully removed in water. The extrusion was found to impact neither on the ionomer chains, nor on the performances of the membrane. This environmentally friendly process was successfully validated for a variety of high performance ionomers.

  9. Finite element analysis of the combined fine blanking and extrusion process

    Science.gov (United States)

    Zheng, Peng-Fei

    The combined fine blanking and extrusion process is such a metal forming process that fine blanking and forward extrusion are carried out on sheet metal material at the same time. There are two typical characteristics in this process, one is the fine blanking whose deformation mechanism is different from conventional blanking; the other is the sheet metal extrusion, which is different from the conventional extrusion. Even though fine blanking has been used in industry for many years, only limited literature can be found which deals with the theoretical analysis of it. On the other hand, no publications on the theoretical analysis of the sheet metal extrusion have been found. Intensive work should be carried out to reveal the mechanism of both fine blanking process and sheet metal extrusion process, and further the combined fine blanking and extrusion process. The scope of this thesis is to study the mechanics of fine blanking, sheet metal extrusion, and combined fine blanking and extrusion process one by one with the rigid-plastic finite element method. All of above processes are typical unsteady ones, especially the fine blanking process in which extremely severe and localized deformation occurs. Therefore, commercial programs can not be used to solve these problems up till now. Owing to this reason, a rigid-plastic finite element program was developed for simulating these processes where remeshing and mesh tracing techniques as well as the golden section method were adopted according to the characteristics of these processes in this thesis. Moreover, a permissible kinematic velocity field was adopted as the initial velocity field for simulating extrusion process successfully. Results from the simulation included the distorted mesh, the field of material flow, the stress and the strain distributions at various moments of deformation. Results under different deformation conditions such as different blanking clearances, different diameters of the extrusion punch and

  10. FEM analysis of hollow hub forming in rolling extrusion process

    Directory of Open Access Journals (Sweden)

    J. Bartnicki

    2014-10-01

    Full Text Available In this paper are presented the results of numerical calculations of rolling extrusion process of a hollow hub. As the flanges manufacturing at both sides of the product is required, in the analyzed process of rolling extrusion, a rear bumper was implemented as additional tool limiting axial metal flow. Numerical calculations of the hub forming process were conducted basing on finite element method, applying software Deform3D and Simufact in conditions of three dimensional state of strain. The obtained satisfactory results show that it is possible to conduct the further research works of experimental character, with the application of a modernized aggregate for the rolling extrusion process PO-2.

  11. Enhanced performance of nano-sized SiC reinforced Al metal matrix nanocomposites synthesized through microwave sintering and hot extrusion techniques

    Directory of Open Access Journals (Sweden)

    M. Penchal Reddy

    2017-10-01

    Full Text Available In the present study, nano-sized SiC (0, 0.3, 0.5, 1.0 and 1.5 vol% reinforced aluminum (Al metal matrix composites were fabricated by microwave sintering and hot extrusion techniques. The structural (XRD, SEM, mechanical (nanoindentation, compression, tensile and thermal properties (co-efficient of thermal expansion-CTE of the developed Al-SiC nanocomposites were studied. The SEM/EDS mapping images show a homogeneous distribution of SiC nanoparticles into the Al matrix. A significant increase in the strength (compressive and tensile of the Al-SiC nanocomposites with the addition of SiC content is observed. However, it is noticed that the ductility of Al-SiC nanocomposites decreases with increasing volume fraction of SiC. The thermal analysis indicates that CTE of Al-SiC nanocomposites decreases with the progressive addition of hard SiC nanoparticles. Overall, hot extruded Al 1.5 vol% SiC nanocomposites exhibited the best mechanical and thermal performance as compared to the other developed Al-SiC nanocomposites. Keywords: Al-SiC nanocomposites, Microwave sintering, Hot extrusion, Mechanical properties, Thermal expansion

  12. Extrusion Cooking Systems and Textured Vegetable Proteins

    Directory of Open Access Journals (Sweden)

    2015-02-01

    Full Text Available Many fabricated foods are cooked industrially and are given desired textures, shapes, density and rehydration characteristics by an extrusion cooking process. This relatively new process is used in the preparation of “engineered” convenience foods: textured vegetable proteins, breakfast cereals, snacks, infant foods, dry soup mixes, breading, poultry stuffing, croutons, pasta products, beverage powders, hot breakfast gruels, and in the gelatinization of starch or the starchy component of foods.

  13. Study on reactive extrusion processes of block copolymer

    International Nuclear Information System (INIS)

    Wu Lili; Jia Yuxi; Sun Sheng; Zhang Guofang; Zhao Guoqun; An Lijia

    2007-01-01

    The anionic copolymerization process of styrene-butadiene (S/B) block copolymer in a closely intermeshing co-rotating twin screw extruder with butyl-lithium initiator was studied. According to the anionic copolymerization mechanism and the reactive extrusion characteristics, the mathematical models of monomer conversion, average molecular weight and fluid viscosity during the anionic copolymerization of S/B were constructed, and then the reactive extrusion process was simulated by means of the finite volume method and the uncoupled semi-implicit iterative algorithm. Finally, the influence of the feeding mixture composition on conversion was discussed. The simulated results were nearly in agreement with the experimental results

  14. Microstructure and mechanical properties of 2.5 vol. % TiBw/Ti6Al4V composites plates fabricated by hot-hydrostatic canned extrusion

    Science.gov (United States)

    Zhang, Wencong; Zhang, Lingjia; Feng, Yangju; Cui, Guorong; Chen, Wenzhen

    2018-04-01

    Plates of 2.5 vol. % TiB whisker-reinforced Ti6Al4V titanium matrix composites (TiBw/Ti64) with network structure were successfully fabricated by hot-hydrostatic extrusion with steel cup at 1100 °C. The dimensions of plates were about 150mm in length, 27mm in width and 2mm in thickness. After extrusion, the original equiaxed-network structure formed by TiB whiskers still existed, but was compressed in cross-section and stretched in longitudinal section and then the TiB whiskers were directional distribution along the extrusion direction. Furthermore, the mechanical properties results showed that the strength, hardness and ductility of the plates were significantly improved compared to as-sintered composites.

  15. Using Flory-Huggins phase diagrams as a pre-formulation tool for the production of amorphous solid dispersions: a comparison between hot-melt extrusion and spray drying.

    Science.gov (United States)

    Tian, Yiwei; Caron, Vincent; Jones, David S; Healy, Anne-Marie; Andrews, Gavin P

    2014-02-01

    Amorphous drug forms provide a useful method of enhancing the dissolution performance of poorly water-soluble drugs; however, they are inherently unstable. In this article, we have used Flory-Huggins theory to predict drug solubility and miscibility in polymer candidates, and used this information to compare spray drying and melt extrusion as processes to manufacture solid dispersions. Solid dispersions were prepared using two different techniques (hot-melt extrusion and spray drying), and characterised using a combination of thermal (thermogravimetric analysis and differential scanning calorimetry), spectroscopic (Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction methods. Spray drying permitted generation of amorphous solid dispersions across a wider drug concentration than melt extrusion. Melt extrusion provided sufficient energy for more intimate mixing to be achieved between drug and polymer, which may improve physical stability. It was also confirmed that stronger drug-polymer interactions might be generated through melt extrusion. Remixing and dissolution of recrystallised felodipine into the polymeric matrices did occur during the modulated differential scanning calorimetry analysis, but the complementary information provided from FTIR confirms that all freshly prepared spray-dried samples were amorphous with the existence of amorphous drug domains within high drug-loaded samples. Using temperature-composition phase diagrams to probe the relevance of temperature and drug composition in specific polymer candidates facilitates polymer screening for the purpose of formulating solid dispersions. © 2013 Royal Pharmaceutical Society.

  16. Physical and mathematical modelling of extrusion processes

    DEFF Research Database (Denmark)

    Arentoft, Mogens; Gronostajski, Z.; Niechajowics, A.

    2000-01-01

    The main objective of the work is to study the extrusion process using physical modelling and to compare the findings of the study with finite element predictions. The possibilities and advantages of the simultaneous application of both of these methods for the analysis of metal forming processes...

  17. Tribological characterization of Al7075–graphite composites fabricated by mechanical alloying and hot extrusion

    International Nuclear Information System (INIS)

    Deaquino-Lara, R.; Soltani, N.; Bahrami, A.; Gutiérrez-Castañeda, E.; García-Sánchez, E.; Hernandez-Rodríguez, M.A.L.

    2015-01-01

    Highlights: • Al7075–graphite composites were synthesized by mechanical alloying and hot extrusion. • Effects of graphite content and milling time on the mechanical and wear properties of fabricated composites were analyzed. • Microstructure and worn surfaces of samples were studied by transmission and scanning electron microscope. • The friction coefficient, wear rate and debris thickness of fabricated composite were investigated. - Abstract: Aluminum matrix composites (AMCs) are candidate materials for aerospace and automotive industry owing to their large elastic modulus, improved strength and low wear rate. A simple method for fabrication of Al7075–graphite composites produced by mechanical alloying (MI) and hot extrusion is described in this paper. Effects of milling time (0–10 h) and graphite concentration (0–1.5 wt.%) on friction, hardness and wear resistance of the AMC were investigated. Wear resistance was determined by the pin-on-disk wear method using 20 and 40 N normal loads at a 0.367 m/s sliding velocity. The worn surfaces were examined by scanning electron microscopy (SEM) to identify distinct topographical features for elucidation of the prevailing wear mechanisms. Experimental results indicated considerable improvement in AMC hardness and wear resistance by adding 1.5% G (wt.) and 10 h of milling, showing homogenous distribution of the reinforcement particles in the Al-base metal-matrix composite. It was found that abrasion is the dominant wear mechanism in all extruded composites, whilst a combination of adhesion and delamination seems to be the governing mechanism for the 7075 aluminum alloy

  18. Extrusion Processing of Raw Food Materials and by-products: A Review.

    Science.gov (United States)

    Offiah, Vivian; Kontogiorgos, Vassilis; Falade, Kolawole O

    2018-05-22

    Extrusion technology has rapidly transformed the food industry with its numerous advantages over other processing methods. It offers a platform for processing different products from various food groups by modifying minor or major ingredients and processing conditions. Although cereals occupy a large portion of the extruded foods market, several other types of raw materials have been used. Extrusion processing of various food groups, including cereals and pseudo cereals, roots and tubers, pulses and oilseeds, fruits and vegetables, and animal products, as well as structural and nutritional changes in these food matrices are reviewed. Value addition by extrusion to food processing wastes and by-products from fruits and vegetables, dairy, meat and seafood, cereals and residues from starch, syrup and alcohol production, and oilseed processing are also discussed. Extrusion presents an economical technology for incorporating food processing residues and by-products back into the food stream. In contemporary scenarios, rising demand for extruded products with functional ingredients, attributed to evolving lifestyles and preferences, have led to innovations in the form, texture, color and content of extruded products. Information presented in this review would be of importance to processors and researchers as they seek to enhance nutritional quality and delivery of extruded products.

  19. Extrusion Process by Finite Volume Method Using OpenFoam Software

    International Nuclear Information System (INIS)

    Matos Martins, Marcelo; Tonini Button, Sergio; Divo Bressan, Jose; Ivankovic, Alojz

    2011-01-01

    The computational codes are very important tools to solve engineering problems. In the analysis of metal forming process, such as extrusion, this is not different because the computational codes allow analyzing the process with reduced cost. Traditionally, the Finite Element Method is used to solve solid mechanic problems, however, the Finite Volume Method (FVM) have been gaining force in this field of applications. This paper presents the velocity field and friction coefficient variation results, obtained by numerical simulation using the OpenFoam Software and the FVM to solve an aluminum direct cold extrusion process.

  20. Effect of extrusion temperature and moisture content of corn flour on crystallinity and hardness of rice analogues

    Science.gov (United States)

    Budi, Faleh Setia; Hariyadi, Purwiyatno; Budijanto, Slamet; Syah, Dahrul

    2015-12-01

    Rice analogues are food products made of broken rice and/or any other carbohydrate sources to have similar texture and shape as rice. They are usually made by hot extrusion processing. The hot extrusion process may change the crystallinity of starch and influence the characteristic of rice analogues. Therefore, this research aimed to study the effect of moisture content of incoming dough and temperature of extrusion process on the crystallinity and hardness of resulting rice analogues. The dough's were prepared by mixing of corn starch-flour with ratio 10/90 (w/w) and moisture content of 35%, 40% and 45% (w/w) and extrusion process were done at temperature of 70, 80, 90°C by using of twin screw extruder BEX-DS-2256 Berto. The analyses were done to determine the type of crystal, degree of crystallinity, and hardness of the resulting rice analogues. Our result showed that the enhancement of extrusion temperature from 70 - 90°C increased degree of crystallinity from 5.86 - 15.00% to 10.70 - 18.87% and hardness from 1.71 - 4.36 kg to 2.05 - 5.70 kg. The raising of dough moisture content from 35 - 45% decreased degree of crystallinity from 15.00 - 18.87% to 5.86 - 10.70% and hardness from 4.36 - 5.70 kg to 1.71 - 2.05 kg. The increase of degree of crystallinity correlated positively with the increase of hardness of rice analogues (r = 0.746, p = 0.05).

  1. COMPUTER MODELING OF STRAINS ON PHASE BOUNDARIES IN DUCTILE CAST IRON AT HOT EXTRUSION

    Directory of Open Access Journals (Sweden)

    A. I. Pokrovsky

    2017-01-01

    Full Text Available The computer modeling of the strain distribution in the structure of ductile iron with ferrite-pearlite matrix and inclusions of spherical graphite dependence on increasing degree of deformation during direct hot extrusion was researched. Using a software system of finite-element analysis ANSYS the numerical values of the strains at the phase boundaries: ferrite-perlite, graphiteferrite and also inside the graphite inclusions were defined. The analysis of the strain distribution in the investigated structures was performed and local zones of increased strains were discovered. The results of modeling are compared with metallographic analysis and fracture patterns. The obtained results could be used in the prediction of fracture zones in the cast iron products. 

  2. Pellet manufacturing by extrusion-spheronization using process analytical technology

    DEFF Research Database (Denmark)

    Sandler, Niklas; Rantanen, Jukka; Heinämäki, Jyrki

    2005-01-01

    The aim of this study was to investigate the phase transitions occurring in nitrofurantoin and theophylline formulations during pelletization by extrusion-spheronization. An at-line process analytical technology (PAT) approach was used to increase the understanding of the solid-state behavior...... of the active pharmaceutical ingredients (APIs) during pelletization. Raman spectroscopy, near-infrared (NIR) spectroscopy, and X-ray powder diffraction (XRPD) were used in the characterization of polymorphic changes during the process. Samples were collected at the end of each processing stage (blending......, granulation, extrusion, spheronization, and drying). Batches were dried at 3 temperature levels (60 degrees C, 100 degrees C, and 135 degrees C). Water induced a hydrate formation in both model formulations during processing. NIR spectroscopy gave valuable real-time data about the state of water in the system...

  3. CHARACTERIZATION OF NEW TOOL STEEL FOR ALUMINUM EXTRUSION DIES

    OpenAIRE

    José Britti Bacalhau; Fernanda Moreno Rodrigues; Rafael Agnelli Mesquita

    2014-01-01

    Aluminum extrusion dies are an important segment of application on industrial tools steels, which are manufactured in steels based on AISI H13 steel. The main properties of steels applied to extrusion dies are: wear resistance, impact resistance and tempering resistance. The present work discusses the characteristics of a newly developed hot work steel to be used on aluminum extrusion dies. The effects of Cr and Mo contents with respect to tempering resistance and the Al addition ...

  4. Raw material changes and their processing parameters in an extrusion cooking process

    DEFF Research Database (Denmark)

    Cheng, Hongyuan; Friis, Alan

    In this work, the effects of raw material and process parameters on product expansion in a fish feed extrusion process were investigated. Four different recipes were studied with a pilot-scale twin-screw co-rotating extruder according to a set of pre-defined processing conditions. In the four rec...

  5. Bioavailability enhancement of atovaquone using hot melt extrusion technology.

    Science.gov (United States)

    Kate, Laxman; Gokarna, Vinod; Borhade, Vivek; Prabhu, Priyanka; Deshpande, Vinita; Pathak, Sulabha; Sharma, Shobhona; Patravale, Vandana

    2016-04-30

    Emerging parasite resistance and poor oral bioavailability of anti-malarials are the two cardinal issues which hinder the clinical success of malaria chemotherapy. Atovaquone-Proguanil is a WHO approved fixed dose combination used to tackle the problem of emerging resistance. However, Atovaquone is a highly lipophilic drug having poor aqueous solubility (less than 0.2 μg/ml) thus reducing its oral bioavailability. The aim of the present investigation was to explore hot melt extrusion (HME) as a solvent-free technique to enhance solubility and oral bioavailability of Atovaquone and to develop an oral dosage form for Atovaquone-Proguanil combination. Solid dispersion of Atovaquone was successfully developed using HME. The solid dispersion was characterized for DSC, FTIR, XRD, SEM, and flow properties. It was filled in size 2 hard gelatin capsules. The formulation showed better release as compared to Malarone® tablets, and 3.2-fold and 4.6-fold higher bioavailability as compared to Malarone® tablets and Atovaquone respectively. The enhanced bioavailability also resulted in 100% anti-malarial activity in murine infection model at 1/8(th) therapeutic dose. Thus the developed methodology shows promising potential to solve the problems associated with Atovaquone therapy, namely its high cost and poor oral bioavailability, resulting in increased therapeutic efficacy of Atovaquone. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Adaptive Control of Freeze-Form Extrusion Fabrication Processes (Preprint)

    National Research Council Canada - National Science Library

    Zhao, Xiyue; Landers, Robert G; Leu, Ming C

    2008-01-01

    Freeze-form Extrusion Fabrication (FEF) is an additive manufacturing process that extrudes high solids loading aqueous ceramic pastes in a layer-by-layer fashion below the paste freezing temperature for component fabrication...

  7. Integrated hot-melt extrusion - injection molding continuous tablet manufacturing platform: Effects of critical process parameters and formulation attributes on product robustness and dimensional stability.

    Science.gov (United States)

    Desai, Parind M; Hogan, Rachael C; Brancazio, David; Puri, Vibha; Jensen, Keith D; Chun, Jung-Hoon; Myerson, Allan S; Trout, Bernhardt L

    2017-10-05

    This study provides a framework for robust tablet development using an integrated hot-melt extrusion-injection molding (IM) continuous manufacturing platform. Griseofulvin, maltodextrin, xylitol and lactose were employed as drug, carrier, plasticizer and reinforcing agent respectively. A pre-blended drug-excipient mixture was fed from a loss-in-weight feeder to a twin-screw extruder. The extrudate was subsequently injected directly into the integrated IM unit and molded into tablets. Tablets were stored in different storage conditions up to 20 weeks to monitor physical stability and were evaluated by polarized light microscopy, DSC, SEM, XRD and dissolution analysis. Optimized injection pressure provided robust tablet formulations. Tablets manufactured at low and high injection pressures exhibited the flaws of sink marks and flashing respectively. Higher solidification temperature during IM process reduced the thermal induced residual stress and prevented chipping and cracking issues. Polarized light microscopy revealed a homogeneous dispersion of crystalline griseofulvin in an amorphous matrix. DSC underpinned the effect of high tablet residual moisture on maltodextrin-xylitol phase separation that resulted in dimensional instability. Tablets with low residual moisture demonstrated long term dimensional stability. This study serves as a model for IM tablet formulations for mechanistic understanding of critical process parameters and formulation attributes required for optimal product performance. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Investigation of the process energy demand in polymer extrusion: A brief review and an experimental study

    International Nuclear Information System (INIS)

    Abeykoon, Chamil; Kelly, Adrian L.; Brown, Elaine C.; Vera-Sorroche, Javier; Coates, Phil D.; Harkin-Jones, Eileen; Howell, Ken B.; Deng, Jing; Li, Kang; Price, Mark

    2014-01-01

    Highlights: • Energy consumption and losses in polymer extrusion are discussed. • This compares energy consumption in polymer extrusion at different conditions. • The role of power factor on energy efficiency in polymer extrusion is explored. • Empirical models on extruder energy consumption are provided. • Computer modelling of energy consumption of polymer extrusion is performed. - Abstract: Extrusion is one of the fundamental production methods in the polymer processing industry and is used in the production of a large number of commodities in a diverse industrial sector. Being an energy intensive production method, process energy efficiency is one of the major concerns and the selection of the most energy efficient processing conditions is a key to reducing operating costs. Usually, extruders consume energy through the drive motor, barrel heaters, cooling fans, cooling water pumps, gear pumps, etc. Typically the drive motor is the largest energy consuming device in an extruder while barrel/die heaters are responsible for the second largest energy demand. This study is focused on investigating the total energy demand of an extrusion plant under various processing conditions while identifying ways to optimise the energy efficiency. Initially, a review was carried out on the monitoring and modelling of the energy consumption in polymer extrusion. Also, the power factor, energy demand and losses of a typical extrusion plant were discussed in detail. The mass throughput, total energy consumption and power factor of an extruder were experimentally observed over different processing conditions and the total extruder energy demand was modelled empirically and also using a commercially available extrusion simulation software. The experimental results show that extruder energy demand is heavily coupled between the machine, material and process parameters. The total power predicted by the simulation software exhibits a lagging offset compared with the

  9. A Novel Continuous Extrusion Process to Fabricate Wedge-Shaped Light Guide Plates

    Directory of Open Access Journals (Sweden)

    Wen-Tse Hsiao

    2013-01-01

    Full Text Available Backlight modules are key components in thin-film transistor liquid crystal displays (TFT-LCD. Among the components of a backlight module, the light guide plate (LGP plays the most important role controlling the light projected to the eyes of users. A wedge-shaped LGP, with its asymmetrical structure, is usually fabricated by an injection proces, but the fabrication time of this process is long. This study proposes a continuous extrusion process to fabricate wedge-shaped LGPs. This continuous process has advantages for mass production. Besides a T-die and rollers, this system also has an in situ monitor of the melt-bank that forms during the extrusion process, helping control the plate thickness. Results show that the melt bank has a close relationship with the plate thickness. The temperature of the bottom heater and roller was adjusted to reduce the surface deformation of the wedge-shaped plate. This continuous extrusion system can successfully manufacture wedge-shaped LGPs for mass production.

  10. Study of the microstructure evolution of ferritic stainless ODS steels during hot working

    International Nuclear Information System (INIS)

    Karch, Abdellatif

    2014-01-01

    The production of ODS steels involves a powder consolidation step usually using the hot extrusion (HE) process. The anisotropic properties of extruded materials, especially in the ODS ferritic grades (≥wt%12Cr), need a better understanding of the metallurgical phenomena which may occur during HE and lead to the observed microstructure. The hot working behavior of these materials is of particular interest. The methodology of this work includes the microstructure analysis after interrupted hot extrusion, hot torsion and hot compression (1000-1200 C) tests of ferritic steels with 14%Cr and different amounts in Ti and Y 2 O 3 . The microstructure evolution during hot extrusion process is associated with continuous dynamic recrystallization (CDRX). It leads to the creation of new grains by the formation of low angle boundaries, and then the increase of their misorientation under plastic deformation. The investigations highlight also the role of precipitation on the kinetics of this mechanism; it remains incomplete in the presence of fine and dense nano-precipitates. After hot deformation in torsion and compression, it is noticed that both precipitates and temperature deformation have a significant impact on the deformation mechanisms and microstructure evolution. Indeed, the CDRX is dominant when temperature and amount of reinforcement are limited. However, when they are increased, limited microstructure evolution is observed. In this case, the results are interpreted through a mechanism of strain accommodation at grain boundaries, with low dislocation activity in the bulk of the grains. (author) [fr

  11. Downstream processing of a ternary amorphous solid dispersion: The impacts of spray drying and hot melt extrusion on powder flow, compression and dissolution.

    Science.gov (United States)

    Davis, Mark T; Potter, Catherine B; Walker, Gavin M

    2018-06-10

    Downstream processing aspects of a stable form of amorphous itraconazole exhibiting enhanced dissolution properties were studied. Preparation of this ternary amorphous solid dispersion by either spray drying or hot melt extrusion led to significantly different powder processing properties. Particle size and morphology was analysed using scanning electron microscopy. Flow, compression, blending and dissolution were studied using rheometry, compaction simulation and a dissolution kit. The spray dried material exhibited poorer flow and reduced sensitivity to aeration relative to the milled extrudate. Good agreement was observed between differing forms of flow measurement, such as Flow Function, Relative flow function, Flow rate index, Aeration rate, the Hausner ratio and the Carr index. The stability index indicated that both powders were stable with respect to agglomeration, de-agglomeration and attrition. Tablet ability and compressibility studies showed that spray dried material could be compressed into stronger compacts than extruded material. Blending of the powders with low moisture, freely-flowing excipients was shown to influence both flow and compression. Porosity studies revealed that blending could influence the mechanism of densification in extrudate and blended extrudate formulations. Following blending, the powders were compressed into four 500 mg tablets, each containing a 100 mg dose of amorphous itraconazole. Dissolution studies revealed that the spray dried material released drug faster and more completely and that blending excipients could further influence the dissolution rate. Copyright © 2018 Elsevier B.V. All rights reserved.

  12. Etching Behavior of Aluminum Alloy Extrusions

    Science.gov (United States)

    Zhu, Hanliang

    2014-11-01

    The etching treatment is an important process step in influencing the surface quality of anodized aluminum alloy extrusions. The aim of etching is to produce a homogeneously matte surface. However, in the etching process, further surface imperfections can be generated on the extrusion surface due to uneven materials loss from different microstructural components. These surface imperfections formed prior to anodizing can significantly influence the surface quality of the final anodized extrusion products. In this article, various factors that influence the materials loss during alkaline etching of aluminum alloy extrusions are investigated. The influencing variables considered include etching process parameters, Fe-rich particles, Mg-Si precipitates, and extrusion profiles. This study provides a basis for improving the surface quality in industrial extrusion products by optimizing various process parameters.

  13. Quasi-superplasticity of a banded-grained Al-Mg-Y alloy processed by continuous casting-extrusion

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Furong, E-mail: cfr-lff@163.com [School of Materials Science and Engineering, Northeastern University, Shenyang 110819 (China); Zhu, Xiaotong [School of Materials Science and Engineering, Northeastern University, Shenyang 110819 (China); Huaian Dekema Semiconductor Co., Ltd., Huaian 223300 (China); Wang, Shuncheng [Institute of Materials Processing and Forming Technology, Guangdong General Research Institute of Industrial Technology, Guangzhou 510650 (China); Shi, Lu [School of Materials Science and Engineering, Northeastern University, Shenyang 110819 (China); Xu, Guangming [State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819 (China); Wen, Jinglin [School of Materials Science and Engineering, Northeastern University, Shenyang 110819 (China)

    2017-04-06

    The continuous casting-extrusion (CTE) process is a short-route technology for fabricating aluminum and aluminum alloy wires. A novel Al-1.44Mg-1.09Y alloy was prepared by CTE, and its mechanical properties and microstructure evolution were investigated at elevated temperatures to explore the hot tensile ductility of aluminum alloy wire. A true strain to failure of 1.159 was obtained at 773 K and 1.67×10{sup −2} s{sup −1}, and the present alloy exhibits high strain rate quasi-superplasticity. Microstructure observations reveal that it is difficult to realize the equiaxedness of elongated or textured grains through hot tensile deformation. A new deformation mechanism map (DMM) was constructed which predicts that dislocation climb at high stress dominates the high-temperature deformation process. This theoretical prediction using the DMM is in good agreement with experimental transmission-electron-microscopy results and with the estimated true stress exponent of 5 and the activation energy for deformation in the range 127.378―141.536 kJ mol{sup −1}. A new three-dimensional histogram containing a dynamic recovery (DRV) or dynamic recrystallization factor was constructed to demonstrate that the DRV mechanism dominates the deformation. Most experimental results are consistent with prediction using this histogram.

  14. Quasi-superplasticity of a banded-grained Al-Mg-Y alloy processed by continuous casting-extrusion

    International Nuclear Information System (INIS)

    Cao, Furong; Zhu, Xiaotong; Wang, Shuncheng; Shi, Lu; Xu, Guangming; Wen, Jinglin

    2017-01-01

    The continuous casting-extrusion (CTE) process is a short-route technology for fabricating aluminum and aluminum alloy wires. A novel Al-1.44Mg-1.09Y alloy was prepared by CTE, and its mechanical properties and microstructure evolution were investigated at elevated temperatures to explore the hot tensile ductility of aluminum alloy wire. A true strain to failure of 1.159 was obtained at 773 K and 1.67×10 −2 s −1 , and the present alloy exhibits high strain rate quasi-superplasticity. Microstructure observations reveal that it is difficult to realize the equiaxedness of elongated or textured grains through hot tensile deformation. A new deformation mechanism map (DMM) was constructed which predicts that dislocation climb at high stress dominates the high-temperature deformation process. This theoretical prediction using the DMM is in good agreement with experimental transmission-electron-microscopy results and with the estimated true stress exponent of 5 and the activation energy for deformation in the range 127.378―141.536 kJ mol −1 . A new three-dimensional histogram containing a dynamic recovery (DRV) or dynamic recrystallization factor was constructed to demonstrate that the DRV mechanism dominates the deformation. Most experimental results are consistent with prediction using this histogram.

  15. Metal extrusion using hydrostatic pressures

    International Nuclear Information System (INIS)

    Sauve, Ch.

    1965-01-01

    The main problems connected with the deformation of metals due to extrusion are described. A method is put forward for calculating the rational rate of percentage deformation in the case of bar extrusion using a cylindrical container; reference is made to previous work on extrusion using a hydrostatic pressure with or without back-pressure. An extrusion process is described using hydrostatic pressure, without back-pressure, and using the lubricant for transmitting the thrust. This process has been used for eight years by the C.E.A. for the extrusion of a very wide range of metals, from beryllium to uranium and including steels; it leads to excellent surface textures. A very fine crystallization can be obtained on extruded products when the rate of extrusion is very low. There appears to be nothing against the use of high extrusion rates using this method. (author) [fr

  16. Statistical reliability analyses of two wood plastic composite extrusion processes

    International Nuclear Information System (INIS)

    Crookston, Kevin A.; Mark Young, Timothy; Harper, David; Guess, Frank M.

    2011-01-01

    Estimates of the reliability of wood plastic composites (WPC) are explored for two industrial extrusion lines. The goal of the paper is to use parametric and non-parametric analyses to examine potential differences in the WPC metrics of reliability for the two extrusion lines that may be helpful for use by the practitioner. A parametric analysis of the extrusion lines reveals some similarities and disparities in the best models; however, a non-parametric analysis reveals unique and insightful differences between Kaplan-Meier survival curves for the modulus of elasticity (MOE) and modulus of rupture (MOR) of the WPC industrial data. The distinctive non-parametric comparisons indicate the source of the differences in strength between the 10.2% and 48.0% fractiles [3,183-3,517 MPa] for MOE and for MOR between the 2.0% and 95.1% fractiles [18.9-25.7 MPa]. Distribution fitting as related to selection of the proper statistical methods is discussed with relevance to estimating the reliability of WPC. The ability to detect statistical differences in the product reliability of WPC between extrusion processes may benefit WPC producers in improving product reliability and safety of this widely used house-decking product. The approach can be applied to many other safety and complex system lifetime comparisons.

  17. Hot-melt extrusion for enhanced delivery of drug particles.

    Science.gov (United States)

    Miller, Dave A; McConville, Jason T; Yang, Wei; Williams, Robert O; McGinity, James W

    2007-02-01

    With the recent advent of nanotechnology for pharmaceutical applications, drug particle engineering is the focus of increasing interest as a viable approach for overcoming solubility limitations of poorly water-soluble drugs. Although these particle engineering techniques have been proven successful for enhancing the dissolution properties of many poorly water-soluble drugs, there are limitations associated with them such as particle aggregation, morphological instability, and poor wettability. The aim of this study was to demonstrate a processing technique in which hot-melt extrusion (HME) is utilized to overcome these limitations. Micronized particles of amorphous itraconazole (ITZ) stabilized with PVP or HPMC were produced and subsequently melt extruded with poloxamer 407 and PEO 200 M to deaggregate and disperse the particles into the hydrophilic polymer matrix. Differential scanning calorimetry, X-ray diffraction, and scanning electron microscopy were used to demonstrate that the HME process did not alter the properties of the micronized particles. Dissolution testing conducted at sink conditions revealed that the dissolution rate of the micronized particles was improved by HME due to particle deaggregation and enhanced wetting. Supersaturation dissolution testing demonstrated that the ITZ-HPMC micronized particle extrudates provided superior supersaturation of ITZ compared to the ITZ-PVP micronized particle extrudates. Supersaturation dissolution testing incorporating a pH change (from pH 1.2 to 6.8 at 2 h) revealed that neither micronized particle extrudate formulation significantly reduced the rate of ITZ precipitation from supersaturated solution once pH was increased. Moreover, the two extrudate formulations performed very similarly when only considering dissolution testing from just before pH adjustment through the duration of testing at neutral pH. From oral dosing of rats, it was determined that the two extrudate formulations performed similarly in

  18. Microstructures and recrystallization behavior of severely hot-deformed tungsten

    International Nuclear Information System (INIS)

    Mathaudhu, S.N.; De Rosset, A.J.; Hartwig, K.T.; Kecskes, L.J.

    2009-01-01

    When coarse-grained (CG) tungsten (W) is heavily worked by equal-channel angular extrusion (ECAE), the grain size is reduced to the ultrafine-grained/nanocrystalline regimes (UFG/NC) and the strength and ductility increase. Because of the brittle nature of CG W, the material must be hot-extruded, and, if the temperatures are near the recrystallization temperature (T rc ), gains in properties may not be maximized. In this study, the recrystallization behavior of ECAE-processed CG W is examined as a function of the imparted strain (i.e., number of extrusions) and the hot-working extrusion temperature. Up to four ECAE passes were performed in tooling with a 90 deg. channel intersection, and at temperatures of 1000 deg. C or 1200 deg. C. Subsequent 60 min annealing of the worked material to 1600 deg. C allowed for the determination of T rc . Vickers microhardness measurements and scanning electron microscopy, were used to characterize the microstructures in the as-worked and recrystallized states. The ECAE-processed W shows increased microstructural break-up and refinement with increasing strain and decreasing hot-working temperature in the fully worked state. T rc was determined to be ∼1400 deg. C, which is nearly independent of the number of extrusions and the working temperature. These results show that if ECAE is accomplished below 1400 deg. C (i.e., at 1000 deg. C or lower) the attractive properties of the UFG/NC-worked W may be retained. Specifically, below 1000 deg. C, with increasing strain imparted to the material, high hardness values with a concomitant grain size refinement (∼350 nm) could be expected

  19. Influence of Extrusion Temperature on the Aging Behavior and Mechanical Properties of an AA6060 Aluminum Alloy

    Directory of Open Access Journals (Sweden)

    Nadja Berndt

    2018-01-01

    Full Text Available Processing of AA6060 aluminum alloys for semi-products usually includes hot extrusion with subsequent artificial aging for several hours. Processing below the recrystallization temperature allows for an increased strength at a significantly reduced annealing time by combining strain hardening and precipitation hardening. In this study, we investigate the potential of cold and warm extrusion as alternative processing routes for high strength aluminum semi-products. Cast billets of the age hardening aluminum alloy AA6060 were solution annealed and then extruded at room temperature, 120 or 170 °C, followed by an aging treatment. Electron microscopy and mechanical testing were performed on the as-extruded as well as the annealed materials to characterize the resulting microstructural features and mechanical properties. All of the extruded profiles exhibit similar, strongly graded microstructures. The strain gradients and the varying extrusion temperatures lead to different stages of dynamic precipitation in the as-extruded materials, which significantly alter the subsequent aging behavior and mechanical properties. The experimental results demonstrate that extrusion below recrystallization temperature allows for high strength at a massively reduced aging time due to dynamic precipitation and/or accelerated precipitation kinetics. The highest strength and ductility were achieved by extrusion at 120 °C and subsequent short-time aging.

  20. Global approach for the validation of an in-line Raman spectroscopic method to determine the API content in real-time during a hot-melt extrusion process.

    Science.gov (United States)

    Netchacovitch, L; Thiry, J; De Bleye, C; Dumont, E; Cailletaud, J; Sacré, P-Y; Evrard, B; Hubert, Ph; Ziemons, E

    2017-08-15

    Since the Food and Drug Administration (FDA) published a guidance based on the Process Analytical Technology (PAT) approach, real-time analyses during manufacturing processes are in real expansion. In this study, in-line Raman spectroscopic analyses were performed during a Hot-Melt Extrusion (HME) process to determine the Active Pharmaceutical Ingredient (API) content in real-time. The method was validated based on a univariate and a multivariate approach and the analytical performances of the obtained models were compared. Moreover, on one hand, in-line data were correlated with the real API concentration present in the sample quantified by a previously validated off-line confocal Raman microspectroscopic method. On the other hand, in-line data were also treated in function of the concentration based on the weighing of the components in the prepared mixture. The importance of developing quantitative methods based on the use of a reference method was thus highlighted. The method was validated according to the total error approach fixing the acceptance limits at ±15% and the α risk at ±5%. This method reaches the requirements of the European Pharmacopeia norms for the uniformity of content of single-dose preparations. The validation proves that future results will be in the acceptance limits with a previously defined probability. Finally, the in-line validated method was compared with the off-line one to demonstrate its ability to be used in routine analyses. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Matrix-assisted cocrystallization (MAC) simultaneous production and formulation of pharmaceutical cocrystals by hot-melt extrusion.

    Science.gov (United States)

    Boksa, Kevin; Otte, Andrew; Pinal, Rodolfo

    2014-09-01

    A novel method for the simultaneous production and formulation of pharmaceutical cocrystals, matrix-assisted cocrystallization (MAC), is presented. Hot-melt extrusion (HME) is used to create cocrystals by coprocessing the drug and coformer in the presence of a matrix material. Carbamazepine (CBZ), nicotinamide (NCT), and Soluplus were used as a model drug, coformer, and matrix, respectively. The MAC product containing 80:20 (w/w) cocrystal:matrix was characterized by differential scanning calorimetry, Fourier transform infrared spectroscopy, and powder X-ray diffraction. A partial least squares (PLS) regression model was developed for quantifying the efficiency of cocrystal formation. The MAC product was estimated to be 78% (w/w) cocrystal (theoretical 80%), with approximately 0.3% mixture of free (unreacted) CBZ and NCT, and 21.6% Soluplus (theoretical 20%) with the PLS model. A physical mixture (PM) of a reference cocrystal (RCC), prepared by precipitation from solution, and Soluplus resulted in faster dissolution relative to the pure RCC. However, the MAC product with the exact same composition resulted in considerably faster dissolution and higher maximum concentration (∼five-fold) than those of the PM. The MAC product consists of high-quality cocrystals embedded in a matrix. The processing aspect of MAC plays a major role on the faster dissolution observed. The MAC approach offers a scalable process, suitable for the continuous manufacturing and formulation of pharmaceutical cocrystals. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

  2. Effect of Thermo-extrusion Process Parameters on Selected Quality ...

    African Journals Online (AJOL)

    Effect of Thermo-extrusion Process Parameters on Selected Quality Attributes of Meat Analogue from Mucuna Bean Seed Flour. ... Nigerian Food Journal ... The product functional responses with coefficients of determination (R2) ranging between 0.658 and 0.894 were most affected by changes in barrel temperature and ...

  3. Microstructure and properties of ultrafine grain nickel 200 after hydrostatic extrusion processes

    Science.gov (United States)

    Sitek, R.; Krajewski, C.; Kamiński, J.; Spychalski, M.; Garbacz, H.; Pachla, W.; Kurzydłowski, K. J.

    2012-09-01

    This paper presents the results of the studies of the structure and properties of ultrafine grained nickel 200 obtained by hydrostatic extrusion processes. Microstructure was characterized by means of optical microscopy and electron transmission microscopy. Corrosion resistance was studied by impedance and potentiodynamic methods using an AutoLab PGSTAT 100 potentiostat in 0.1 M Na2SO4 solution and in acidified (by addition of H2SO4) 0.1 M NaCl solution at pH = 4.2 at room temperature. Microhardness tests were also performed. The results showed that hydrostatic extrusion produces a heterogeneous, ultrafine-grained microstructure in nickel 200. The corrosive resistance tests showed that the grain refinement by hydrostatic extrusion is accompanied by a decreased corrosive resistance of nickel 200.

  4. Improvement of the mechanical properties and corrosion resistance of biodegradable β-Ca3(PO4)2/Mg-Zn composites prepared by powder metallurgy: the adding β-Ca3(PO4)2, hot extrusion and aging treatment.

    Science.gov (United States)

    Yan, Yang; Kang, Yijun; Li, Ding; Yu, Kun; Xiao, Tao; Deng, Youwen; Dai, Han; Dai, Yilong; Xiong, Hanqing; Fang, Hongjie

    2017-05-01

    In this study, 10%β-Ca 3 (PO 4 ) 2 /Mg-6%Zn (wt.%) composites with Mg-6%Zn alloy as control were prepared by powder metallurgy. After hot extrusion, the as-extruded composites were aged for 72h at 150°C. The effects of the adding β-Ca 3 (PO 4 ) 2 , hot extrusion and aging treatment on their microstructure, mechanical properties and corrosion resistance were investigated. The XRD results identified α-Mg, MgZn phase and β-Ca 3 (PO 4 ) 2 phase in these composites. After hot extrusion, grains were significantly refined, and the larger-sized β-Ca 3 (PO 4 ) 2 particles and coarse MgZn phases were broken into linear-distributed β-Ca 3 (PO 4 ) 2 and MgZn phases along the extrusion direction. After aging treatment, the elements of Zn, Ca, P and O presented a more homogeneous distribution. The compressive strengths of the β-Ca 3 (PO 4 ) 2 /Mg-Zn composites were approximately double those of natural bone, and their densities and elastic moduli matched those of natural bone. The immersion tests and electrochemical tests revealed that the adding β-Ca 3 (PO 4 ) 2 , hot extrusion and aging treatment could promote the formation of protective corrosion product layer on the sample surface in Ringer's solution, which improved corrosion resistance of the β-Ca 3 (PO 4 ) 2 /Mg-Zn composites. The XRD results indicated that the corrosion product layer contained Mg(OH) 2 , β-Ca 3 (PO 4 ) 2 and hydroxyapatite (HA). The cytotoxicity assessments showed the as-extruded β-Ca 3 (PO 4 ) 2 /Mg-Zn composite aged for 72h was harmless to L-929 cells. These results suggested that the β-Ca 3 (PO 4 ) 2 /Mg-Zn composites prepared by powder metallurgy were promising to be used for bone tissue engineering. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Tribological investigations of the applicability of surface functionalization for dry extrusion processes

    Science.gov (United States)

    Teller, Marco; Prünte, Stephan; Ross, Ingo; Temmler, André; Schneider, Jochen M.; Hirt, Gerhard

    2017-10-01

    Cold extrusion processes are characterized by large relative contact stresses combined with a severe surface enlargement of the workpiece. Under these process conditions a high risk for galling of workpiece material to the tool steel occurs especially in processing of aluminum and aluminum alloys. In order to reduce adhesive wear lubricants for separation of workpiece and tool surfaces are used. As a consequence additional process steps (e.g. preparation and cleaning of workpieces) are necessary. Thus, the realization of a dry forming process is aspired from an environmental and economic perspective. In this paper a surface functionalization with self-assembled-monolayers (SAM) of the tool steels AISI D2 (DIN 1.2379) and AISI H11 (DIN 1.2343) is evaluated by a process-oriented tribological test. The tribological experiment is able to resemble and scale the process conditions of cold extrusion related to relative contact stress and surface enlargement for the forming of pure aluminum (Al99.5). The effect of reduced relative contact stress, surface enlargement and relative velocity on adhesive wear and tool lifetime is evaluated. Similar process conditions are achievable by different die designs with decreased extrusion ratios and adjusted die angles. The effect of surface functionalization critically depends on the substrate material. The different microstructure and the resulting differences in surface chemistry of the two tested tool steels appear to affect the performance of the tool surface functionalization with SAM.

  6. Role of lipids in the extrusion cooking processes

    Directory of Open Access Journals (Sweden)

    Berghofe, E.

    2000-04-01

    Full Text Available Extrusion is a versatile and very efficient technology that is widely used in food and feed processing. The cooking extruders have found many applications, which include: breakfast cereals, snack foods, other cereal based products, pet food and aquatic foods, texturized vegetable proteins, confectionery products, chemical and biochemical reactions, and oil extraction. Lipids are components that play an important role in most of the extrusion cooking processes. They can act as plastificizers or emulsifiers, and affect more significantly texture and stickiness of the extrudate. This paper reviews effect of oils and other lipids reactions during extrusion cooking as well as the effects of amylase-lipid complexation on extrudate quality.La extrusión es, en general, una tecnología versátil y muy eficiente, que se aplica ampliamente en la elaboración de alimentos y piensos. Los equipos de cocción-extrusión tienen numerosas aplicaciones, entre las que pueden incluirse: los cereales de desayuno listos para comer, los aperitivos, diferentes productos basados en cereales, los piensos para animales domésticos y peces, proteínas vegetales texturizadas, productos de pastelería, reacciones químicas y bioquímicas, y la extracción de aceites. Los lípidos son componentes que juegan un papel importante en la mayoría de los procesos de cocción-extrusión. Pueden actuar como plastificantes o como emulsionantes, suministrando lubricación. En este artículo se revisan con detalle los efectos de las reacciones de los aceites y otros lípidos durante el proceso de cocción-extrucción así como el efecto de la formación de complejos amilasa-lípidos sobre la calidad de los extrudados.

  7. The Development and Numerical Analysis of the Conical Radiator Extrusion Process

    Directory of Open Access Journals (Sweden)

    Michalczyk J.

    2017-12-01

    Full Text Available The article presents a newly developed method for single-operation extrusion of conical radiators. This is the author’s radiator manufacturing method being the subject of a patent application. The proposed method enables the manufacture of radiators either with or without an inner opening and with an integral plate. Selected results of numerical computations made within Forge®3D, a finite element method (FEM-based software program, were presented during the analysis of the process. A comparative analysis of the proposed manufacturing method using the double-sided extrusion method was also made.

  8. Hydrostatic extrusion of magnesium alloys

    NARCIS (Netherlands)

    Sillekens, W.H.; Bohlen, J.

    2012-01-01

    This chapter deals with the capabilities and limitations of the hydrostatic extrusion process for the manufacturing of magnesium alloy sections. Firstly, the process basics for the hydrostatic extrusion of materials in general and of magnesium in particular are introduced. Next, some recent research

  9. Co-extrusion as a processing technique to manufacture a dual sustained release fixed-dose combination product.

    Science.gov (United States)

    Vynckier, An-Katrien; Voorspoels, Jody; Remon, Jean Paul; Vervaet, Chris

    2016-05-01

    This study aimed to design a fixed-dose combination dosage form which provides a sustained release profile for both the freely water-soluble metformin HCl and the poorly soluble gliclazide, two antidiabetic compounds used to treat diabetes mellitus. Hot-melt co-extrusion was used as an innovative manufacturing technique for a pharmaceutical fixed-dose combination product. In this way, a matrix formulation that sustained metformin release could be developed, despite the high drug load in the formulation and the freely soluble nature of the drug. It was clear that co-extrusion was perfectly suited to produce a fixed-dose combination product with adequate properties for each of the incorporated APIs. A coat layer, containing at least 30% CAPA(®) 6506 as a hydrophobic polymer, was necessary to adequately sustain the release of the highly dosed freely soluble drug from the 70% metformin HCl-loaded CAPA(®) 6506 core of the co-extrudate. To obtain a complete gliclazide release over 24-h solubilization in Kollidon(®) VA, added as a second polymer to the CAPA(®) 6506 in the coat, was needed. Both active pharmaceutical ingredients (APIs), which have different physicochemical characteristics, were formulated in a single dosage form, using co-extrusion. © 2016 Royal Pharmaceutical Society, Journal of Pharmacy and Pharmacology.

  10. CHARACTERIZATION OF NEW TOOL STEEL FOR ALUMINUM EXTRUSION DIES

    Directory of Open Access Journals (Sweden)

    José Britti Bacalhau

    2014-06-01

    Full Text Available Aluminum extrusion dies are an important segment of application on industrial tools steels, which are manufactured in steels based on AISI H13 steel. The main properties of steels applied to extrusion dies are: wear resistance, impact resistance and tempering resistance. The present work discusses the characteristics of a newly developed hot work steel to be used on aluminum extrusion dies. The effects of Cr and Mo contents with respect to tempering resistance and the Al addition on the nitriding response have been evaluated. From forged steel bars, Charpy impact test and characterization via EPMA have been conducted. The proposed contents of Cr, Mo, and Al have attributed to the new VEX grade a much better tempering resistance than H13, as well as a deeper and harder nitrided layer. Due to the unique characteristics, this new steel provides an interesting alternative to the aluminum extrusion companies to increase their competitiveness.

  11. Mechanical properties and thermal stability of Al–Fe–Ni alloys prepared by centrifugal atomisation and hot extrusion

    Energy Technology Data Exchange (ETDEWEB)

    Průša, F., E-mail: Filip.Prusa@vscht.cz; Vojtěch, D.; Michalcová, A.; Marek, I.

    2014-05-01

    In this work, Al–12Fe and Al–7Fe–5Ni (wt%) alloys prepared by a novel technique including centrifugal atomisation and hot extrusion were studied. The microstructures were investigated using light microscopy, electron scanning microscopy, transmission electron microscopy and X-ray diffraction. The mechanical properties were determined by Vickers hardness measurements and compressive stress–strain tests. To study the thermal stability, the mechanical properties were also measured after 100 h of annealing at 300 °C and 400 °C. In addition, creep tests at a stress of 120 MPa and a temperature of 300 °C were performed. The investigated materials were composed of fine-grained α-Al and intermetallic phases identified as Al{sub 13}Fe{sub 4} and Al{sub 9}FeNi. The Vickers hardness and compressive yield strength were 68 HV5 and 183 MPa, respectively, for the Al–12Fe alloy and 73 HV5 and 226 MPa, respectively, for the Al–7Fe–5Ni alloy. After long-term annealing, the change in the mechanical properties was negligible, indicating the excellent thermal stability of both materials. The creep tests confirmed the highest thermal stability of the Al–7Fe–5Ni alloy with a total compressive creep strain of 15%. The “thermally stable” casting Al–12Si–1Cu–1Mg–1Ni alloy treated by the T6 regime was used as a reference material. The casting alloy exhibited sufficient mechanical properties (hardness and compressive yield strength) at room temperature. However, annealing remarkably softened and reduced its compressive yield strength to almost 50% of the initial values. Additionally, the total creep strain of the casting reference material was almost three times higher than that of the Al–7Fe–5Ni alloy. It has been proven that centrifugally atomised materials quickly compacted via hot extrusion can compete or even exceed the properties of common casting aluminium alloys that are used in automotive industry.

  12. Mechanical properties and thermal stability of Al–Fe–Ni alloys prepared by centrifugal atomisation and hot extrusion

    International Nuclear Information System (INIS)

    Průša, F.; Vojtěch, D.; Michalcová, A.; Marek, I.

    2014-01-01

    In this work, Al–12Fe and Al–7Fe–5Ni (wt%) alloys prepared by a novel technique including centrifugal atomisation and hot extrusion were studied. The microstructures were investigated using light microscopy, electron scanning microscopy, transmission electron microscopy and X-ray diffraction. The mechanical properties were determined by Vickers hardness measurements and compressive stress–strain tests. To study the thermal stability, the mechanical properties were also measured after 100 h of annealing at 300 °C and 400 °C. In addition, creep tests at a stress of 120 MPa and a temperature of 300 °C were performed. The investigated materials were composed of fine-grained α-Al and intermetallic phases identified as Al 13 Fe 4 and Al 9 FeNi. The Vickers hardness and compressive yield strength were 68 HV5 and 183 MPa, respectively, for the Al–12Fe alloy and 73 HV5 and 226 MPa, respectively, for the Al–7Fe–5Ni alloy. After long-term annealing, the change in the mechanical properties was negligible, indicating the excellent thermal stability of both materials. The creep tests confirmed the highest thermal stability of the Al–7Fe–5Ni alloy with a total compressive creep strain of 15%. The “thermally stable” casting Al–12Si–1Cu–1Mg–1Ni alloy treated by the T6 regime was used as a reference material. The casting alloy exhibited sufficient mechanical properties (hardness and compressive yield strength) at room temperature. However, annealing remarkably softened and reduced its compressive yield strength to almost 50% of the initial values. Additionally, the total creep strain of the casting reference material was almost three times higher than that of the Al–7Fe–5Ni alloy. It has been proven that centrifugally atomised materials quickly compacted via hot extrusion can compete or even exceed the properties of common casting aluminium alloys that are used in automotive industry

  13. Turbine airfoil fabricated from tapered extrusions

    Science.gov (United States)

    Marra, John J

    2013-07-16

    An airfoil (30) and fabrication process for turbine blades with cooling channels (26). Tapered tubes (32A-32D) are bonded together in a parallel sequence, forming a leading edge (21), a trailing edge (22), and pressure and suction side walls (23, 24) connected by internal ribs (25). The tapered tubes may be extruded without camber to simplify the extrusion process, then bonded along matching surfaces (34), forming a non-cambered airfoil (28), which may be cambered in a hot forming process and cut (48) to length. The tubes may have tapered walls that are thinner at the blade tip (T1) than at the base (T2), reducing mass. A cap (50) may be attached to the blade tip. A mounting lug (58) may be forged (60) on the airfoil base and then machined, completing the blade for mounting in a turbine rotor disk.

  14. A novel hot-melt extrusion formulation of albendazole for increasing dissolution properties.

    Science.gov (United States)

    Martinez-Marcos, Laura; Lamprou, Dimitrios A; McBurney, Roy T; Halbert, Gavin W

    2016-02-29

    The main aim of the research focused on the production of hot-melt extrusion (HME) formulations with increased dissolution properties of albendazole (ABZ). Therefore, HME was applied as a continuous manufacturing technique to produce amorphous solid dispersions of the poorly water soluble drug ABZ combined with the polymer matrix polyvinylpyrrolidone PVP K12. HME formulations of ABZ-PVP K12 comprised a drug content of 1%, 5% and 10% w/w. The main analytical characterisation techniques used were scanning electron microscopy (SEM), micro-computed tomography (μ-CT), X-ray powder diffraction (XRPD), differential scanning calorimetry (DSC) and dissolution profile studies. The application of SEM, XRPD and DSC evidenced drug physical transformation from crystalline to amorphous state and therefore, the achievement of an amorphous solid dispersion. The introduction of a novel technique, μ-CT, to characterise the internal structure of these materials revealed key information regarding materials distribution and void content. Dissolution profile studies evidenced a high increase in drug release profile compared to pure ABZ. These promising results can lead to a great enhancement of the oral bioavailability of ABZ dosage forms. Therefore, HME is a potential continuous manufacturing technique to overcome ABZ poor solubility properties and lead to a significant increase in the therapeutic effect. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Improving significantly the failure strain and work hardening response of LPSO-strengthened Mg-Y-Zn-Al alloy via hot extrusion speed control

    Science.gov (United States)

    Tan, Xinghe; Chee, Winston; Chan, Jimmy; Kwok, Richard; Gupta, Manoj

    2017-07-01

    The effect of hot extrusion speed on the microstructure and mechanical properties of MgY1.06Zn0.76Al0.42 (at%) alloy strengthened by the novel long-period stacking ordered (LPSO) phase was systematically investigated. Increase in the speed of extrusion accelerated dynamic recrystallization of α-Mg via particle-stimulated nucleation and grain growth in the alloy. The intensive recrystallization and grain growth events weakened the conventional basal texture and Hall-Petch strengthening in the alloy which led to significant improvement in its failure strain from 4.9% to 19.6%. The critical strengthening contribution from LPSO phase known for attributing high strength to the alloy was observed to be greatly undermined by the parallel competition from texture weakening and the adverse Hall-Petch effect when the alloy was extruded at higher speed. Absence of work hardening interestingly observed in the alloy extruded at lower speed was discussed in terms of its ultra-fine grained microstructure which promoted the condition of steady-state defect density in the alloy; where dislocation annihilation balances out the generation of new dislocations during plastic deformation. One approach to improve work hardening response of the alloy to prevent unstable deformation and abrupt failure in service is to increase the grain diameter in the alloy by judiciously increasing the extrusion speed.

  16. The reactive extrusion of thermoplastic polyurethane

    NARCIS (Netherlands)

    Verhoeven, Vincent Wilhelmus Andreas

    2006-01-01

    The objective of this thesis was to increase the understanding of the reactive extrusion of thermoplastic polyurethane. Overall, several issues were identified: • Using a relative simple extrusion model, the reactive extrusion process can be described. This model can be used to further investigate

  17. Investigation of cold extrusion process using coupled thermo-mechanical FEM analysis and adaptive friction modeling

    Science.gov (United States)

    Görtan, Mehmet Okan

    2017-10-01

    Cold extrusion processes are known for their excellent material usage as well as high efficiency in the production of large batches. Although the process starts at room temperature, workpiece temperatures may rise above 200°C. Moreover, contact normal stresses can exceed 2500 MPa, whereas surface enlargement values can reach up to 30. These changes affects friction coefficients in cold extrusion processes. In the current study, friction coefficients between a plain carbon steel C4C (1.0303) and a tool steel (1.2379) are determined dependent on temperature and contact pressure using the sliding compression test (SCT). In order to represent contact normal stress and temperature effects on friction coefficients, an empirical adaptive friction model has been proposed. The validity of the model has been tested with experiments and finite element simulations for a cold forward extrusion process. By using the proposed adaptive friction model together with thermo-mechanical analysis, the deviation in the process loads between numerical simulations and model experiments could be reduced from 18.6% to 3.3%.

  18. Process Parameter Optimization of Extrusion-Based 3D Metal Printing Utilizing PW-LDPE-SA Binder System.

    Science.gov (United States)

    Ren, Luquan; Zhou, Xueli; Song, Zhengyi; Zhao, Che; Liu, Qingping; Xue, Jingze; Li, Xiujuan

    2017-03-16

    Recently, with a broadening range of available materials and alteration of feeding processes, several extrusion-based 3D printing processes for metal materials have been developed. An emerging process is applicable for the fabrication of metal parts into electronics and composites. In this paper, some critical parameters of extrusion-based 3D printing processes were optimized by a series of experiments with a melting extrusion printer. The raw materials were copper powder and a thermoplastic organic binder system and the system included paraffin wax, low density polyethylene, and stearic acid (PW-LDPE-SA). The homogeneity and rheological behaviour of the raw materials, the strength of the green samples, and the hardness of the sintered samples were investigated. Moreover, the printing and sintering parameters were optimized with an orthogonal design method. The influence factors in regard to the ultimate tensile strength of the green samples can be described as follows: infill degree > raster angle > layer thickness. As for the sintering process, the major factor on hardness is sintering temperature, followed by holding time and heating rate. The highest hardness of the sintered samples was very close to the average hardness of commercially pure copper material. Generally, the extrusion-based printing process for producing metal materials is a promising strategy because it has some advantages over traditional approaches for cost, efficiency, and simplicity.

  19. Process Parameter Optimization of Extrusion-Based 3D Metal Printing Utilizing PW–LDPE–SA Binder System

    Directory of Open Access Journals (Sweden)

    Luquan Ren

    2017-03-01

    Full Text Available Recently, with a broadening range of available materials and alteration of feeding processes, several extrusion-based 3D printing processes for metal materials have been developed. An emerging process is applicable for the fabrication of metal parts into electronics and composites. In this paper, some critical parameters of extrusion-based 3D printing processes were optimized by a series of experiments with a melting extrusion printer. The raw materials were copper powder and a thermoplastic organic binder system and the system included paraffin wax, low density polyethylene, and stearic acid (PW–LDPE–SA. The homogeneity and rheological behaviour of the raw materials, the strength of the green samples, and the hardness of the sintered samples were investigated. Moreover, the printing and sintering parameters were optimized with an orthogonal design method. The influence factors in regard to the ultimate tensile strength of the green samples can be described as follows: infill degree > raster angle > layer thickness. As for the sintering process, the major factor on hardness is sintering temperature, followed by holding time and heating rate. The highest hardness of the sintered samples was very close to the average hardness of commercially pure copper material. Generally, the extrusion-based printing process for producing metal materials is a promising strategy because it has some advantages over traditional approaches for cost, efficiency, and simplicity.

  20. Process Parameter Optimization of Extrusion-Based 3D Metal Printing Utilizing PW–LDPE–SA Binder System

    Science.gov (United States)

    Ren, Luquan; Zhou, Xueli; Song, Zhengyi; Zhao, Che; Liu, Qingping; Xue, Jingze; Li, Xiujuan

    2017-01-01

    Recently, with a broadening range of available materials and alteration of feeding processes, several extrusion-based 3D printing processes for metal materials have been developed. An emerging process is applicable for the fabrication of metal parts into electronics and composites. In this paper, some critical parameters of extrusion-based 3D printing processes were optimized by a series of experiments with a melting extrusion printer. The raw materials were copper powder and a thermoplastic organic binder system and the system included paraffin wax, low density polyethylene, and stearic acid (PW–LDPE–SA). The homogeneity and rheological behaviour of the raw materials, the strength of the green samples, and the hardness of the sintered samples were investigated. Moreover, the printing and sintering parameters were optimized with an orthogonal design method. The influence factors in regard to the ultimate tensile strength of the green samples can be described as follows: infill degree > raster angle > layer thickness. As for the sintering process, the major factor on hardness is sintering temperature, followed by holding time and heating rate. The highest hardness of the sintered samples was very close to the average hardness of commercially pure copper material. Generally, the extrusion-based printing process for producing metal materials is a promising strategy because it has some advantages over traditional approaches for cost, efficiency, and simplicity. PMID:28772665

  1. Aluminum extrusion with a deformable die

    NARCIS (Netherlands)

    Assaad, W.

    2010-01-01

    Aluminum extrusion process is one of metal forming processes. In aluminum extrusion, a work-piece (billet) is pressed through a die with an opening that closely resembles a desired shape of a profile. By this process, long profiles with an enormous variety of cross-sections can be produced to

  2. Design and Evaluation of Topical Diclofenac Sodium Gel Using Hot Melt Extrusion Technology as a Continuous Manufacturing Process with Kolliphor® P407.

    Science.gov (United States)

    Pawar, Jaywant; Narkhede, Rajkiran; Amin, Purnima; Tawde, Vaishali

    2017-08-01

    The aim of the present context was to develop and evaluate a Kolliphor® P407-based transdermal gel formulation of diclofenac sodium by hot melt extrusion (HME) technology; central composite design was used to optimize the formulation process. In this study, we have explored first time ever HME as an industrially feasible and continuous manufacturing technology for the manufacturing of gel formulation using Kolliphor® P407 and Kollisolv® PEG400 as a gel base. Diclofenac sodium was used as a model drug. The HME parameters such as feeding rate, screw speed, and barrel temperature were crucial for the semisolid product development, and were optimized after preliminary trials. For the processing of the gel formulation by HME, a modified screw design was used to obtain a uniform product. The obtained product was evaluated for physicochemical characterization such as differential scanning calorimetry (DSC), X-ray diffraction (XRD), pH measurement, rheology, surface tension, and texture profile analysis. Moreover, it was analyzed for general appearance, spreadibility, surface morphology, and drug content. The optimized gel formulation showed homogeneity and transparent film when applied on a glass slide under microscope, pH was 7.02 and uniform drug content of 100.04 ± 2.74 (SD = 3). The DSC and XRD analysis of the HME gel formulation showed complete melting of crystalline API into an amorphous form. The Kolliphor® P407 and Kollisolv® PEG400 formed excellent gel formulation using HME with consistent viscoelastic properties of the product. An improved drug release was found for the HME gel, which showed a 100% drug release than that of a marketed product which showed only 88% of drug release at the end of 12 h. The Flux value of the HME gel was 106 than that of a marketed formulation, which showed only about 60 value, inferring a significant difference (P process for manufacturing of topical semisolid products.

  3. Improving the API dissolution rate during pharmaceutical hot-melt extrusion I: Effect of the API particle size, and the co-rotating, twin-screw extruder screw configuration on the API dissolution rate.

    Science.gov (United States)

    Li, Meng; Gogos, Costas G; Ioannidis, Nicolas

    2015-01-15

    The dissolution rate of the active pharmaceutical ingredients in pharmaceutical hot-melt extrusion is the most critical elementary step during the extrusion of amorphous solid solutions - total dissolution has to be achieved within the short residence time in the extruder. Dissolution and dissolution rates are affected by process, material and equipment variables. In this work, we examine the effect of one of the material variables and one of the equipment variables, namely, the API particle size and extruder screw configuration on the API dissolution rate, in a co-rotating, twin-screw extruder. By rapidly removing the extruder screws from the barrel after achieving a steady state, we collected samples along the length of the extruder screws that were characterized by polarized optical microscopy (POM) and differential scanning calorimetry (DSC) to determine the amount of undissolved API. Analyses of samples indicate that reduction of particle size of the API and appropriate selection of screw design can markedly improve the dissolution rate of the API during extrusion. In addition, angle of repose measurements and light microscopy images show that the reduction of particle size of the API can improve the flowability of the physical mixture feed and the adhesiveness between its components, respectively, through dry coating of the polymer particles by the API particles. Copyright © 2014. Published by Elsevier B.V.

  4. Procyanidin content of grape seed and pomace, and total anthocyanin content of grape pomace as affected by extrusion processing.

    Science.gov (United States)

    Khanal, R C; Howard, L R; Prior, R L

    2009-08-01

    Grape juice processing by-products, grape seed and pomace are a rich source of procyanidins, compounds that may afford protection against chronic disease. This study was undertaken to identify optimal extrusion conditions to enhance the contents of monomers and dimers at the expense of large molecular weight procyanidin oligomers and polymers in grape seed and pomace. Extrusion variables, temperature (160, 170, and 180 degrees C in grape seed, and 160, 170, 180, and 190 degrees C in pomace) and screw speed (100, 150, and 200 rpm in both) were tested using mixtures of grape seed as well as pomace with decorticated white sorghum flour at a ratio of 30 : 70 and moisture content of 45%. Samples of grape seed and pomace were analyzed for procyanidin composition before and after extrusion, and total anthocyanins were determined in pomace. Additionally, chromatograms from diol and normal phase high-performance liquid chromatography were compared for the separation of procyanidins. Extrusion of both grape by-products increased the biologically important monomer and dimers considerably across all temperature and screw speeds. Highest monomer content resulted when extruded at a temperature of 170 degrees C and screw speed of 200 rpm, which were 120% and 80% higher than the unextruded grape seed and pomace, respectively. Increases in monomer and dimer contents were apparently the result of reduced polymer contents, which declined by 27% to 54%, or enhanced extraction facilitated by disruption of the food matrix during extrusion. Extrusion processing reduced total anthocyanins in pomace by 18% to 53%. Extrusion processing can be used to increase procyanidin monomer and dimer contents in grape seed and pomace. Procyanidins in grape by-products have many health benefits, but most are present as large molecular weight compounds, which are poorly absorbed. Extrusion processing appears to be a promising technology to increase levels of the bioactive low molecular weight

  5. Reduction of Ochratoxin A in Oat Flakes by Twin-Screw Extrusion Processing.

    Science.gov (United States)

    Lee, Hyun Jung; Dahal, Samjhana; Perez, Enrique Garcia; Kowalski, Ryan Joseph; Ganjyal, Girish M; Ryu, Dojin

    2017-10-01

    Ochratoxin A (OTA) is one of the most important mycotoxins owing to its widespread occurrence and toxicity, including nephrotoxicity and potential carcinogenicity to humans. OTA has been detected in a wide range of agricultural commodities, including cereal grains and their processed products. In particular, oat-based products show a higher incidence and level of contamination. Extrusion cooking is widely used in the manufacturing of breakfast cereals and snacks and may reduce mycotoxins to varying degrees. Hence, the effects of extrusion cooking on the stability of OTA in spiked (100 μg/kg) oat flake was investigated by using a laboratory-scale twin-screw extruder with a central composite design. Factors examined were moisture content (20, 25, and 30% dry weight basis), temperature (140, 160, and 180°C), screw speed (150, 200, and 250 rpm), and die size (1.5, 2, and 3 mm). Both nonextruded and extruded samples were analyzed for reductions of OTA by high-performance liquid chromatography, coupled with fluorescence detection. The percentage of reductions in OTA in the contaminated oat flakes upon extrusion processing were in the range of 0 to 28%. OTA was partially stable during extrusion, with only screw speed and die size having significant effect on reduction (P < 0.005). The highest reduction of 28% was achieved at 180°C, 20% moisture, 250 rpm screw speed, and a 3-mm die with 193 kJ/kg specific mechanical energy. According to the central composite design analyses, up to 28% of OTA can be reduced by a combination of 162°C, 30% moisture, and 221 rpm, with a 3-mm die.

  6. Interfacial reaction between SiC and aluminium due to extrusion and heat treatment process

    International Nuclear Information System (INIS)

    Junaidah Jai; Fauzi Ismail; Samsiah Sulaiman; Patthi Hussain, Azmi Idris; Yoichi Murakoshi

    1999-01-01

    Chemical interaction between aluminium (Al) and silicon carbide (SiC) produces aluminium carbide (Al 4 C 3 ) which presents potential problems in the production and application of Al/SiC Metal Matrix Composit (MMC). The Al 4 C 3 formed can reduce material properties such as strength in the MMC. This research work investigates the interface reaction in Al 7075/SiC MMC made through hot extrusion process. Mixed Al 7075/SiC MMC powders were pressed at 300 degree C and extruded at 500 degree C, with a reduction ratio of 20:1. The extruded MMC was then heat-treated in air at various temperatures from 560 degree C, 600 degree C, 640 degree C, 700 degree C to 800 degree C in order to observe the interface reaction of the MMC materials. The heat-treated MMCs were then analyzed under the optical microscope, X-ray Diffraction (XRD) Spectroscope and Scanning Electron Microscope (SEM) with Energy Dispersive X-ray (EDAZ) attachment to observe the interface reaction within the MMCs. This investigation confirms there was interface reaction between SiC and aluminium

  7. Evaluation of Extrusion Technique for Nanosizing Liposomes

    Directory of Open Access Journals (Sweden)

    Sandy Gim Ming Ong

    2016-12-01

    Full Text Available The aim of the present study was to study the efficiency of different techniques used for nanosizing liposomes. Further, the aim was also to evaluate the effect of process parameters of extrusion techniques used for nanosizing liposomes on the size and size distribution of the resultant liposomes. To compare the efficiency of different nanosizing techniques, the following techniques were used to nanosize the liposomes: extrusion, ultrasonication, freeze-thaw sonication (FTS, sonication and homogenization. The extrusion technique was found to be the most efficient, followed by FTS, ultrasonication, sonication and homogenization. The extruder used in the present study was fabricated using readily available and relatively inexpensive apparatus. Process parameters were varied in extrusion technique to study their effect on the size and size distribution of extruded liposomes. The results obtained indicated that increase in the flow rate of the extrusion process decreased the size of extruded liposomes however the size homogeneity was negatively impacted. Furthermore, the liposome size and distribution was found to decline with decreasing membrane pore size. It was found that by extruding through a filter with a pore size of 0.2 µm and above, the liposomes produced were smaller than the pore size, whereas, when they were extruded through a filter with a pore size of less than 0.2 µm the resultant liposomes were slightly bigger than the nominal pore size. Besides that, increment of extrusion temperature above transition temperature of the pro-liposome had no effect on the size and size distribution of the extruded liposomes. In conclusion, the extrusion technique was reproducible and effective among all the methods evaluated. Furthermore, processing parameters used in extrusion technique would affect the size and size distribution of liposomes. Therefore, the process parameters need to be optimized to obtain a desirable size range and homogeneity

  8. Influence of hot rolling and high speed hydrostatic extrusion on the microstructure and mechanical properties of RAF ODS steel

    International Nuclear Information System (INIS)

    Oksiuta, Z.; Kurzydlowski, K.J.; Baluc, N.

    2009-01-01

    Argon gas atomized, pre-alloyed Fe-14Cr-2W-0.3Ti oxide dispersion strengthened (ODS) ferritic steel powder was mechanically alloyed with 0.3Y2O3 (wt.%) nano-particles in attritor ball mill and consolidated by hot isostatic pressing (HIP) at 1150 deg. C under pressure of 200 MPa for 3 hrs. To improve mechanical properties of as HIPped ODS ingots the material was undergone further thermo-mechanical treatment (TMT), namely: hot rolling (HR) at 850 deg. C or high speed hot extrusion (HSHE) at 850 deg. C. After TMT both materials were annealed at 1050 deg. C for 1 h in vacuum. Transmission electron microscopy (TEM) observations of the ODS alloys after TMT and heat treatment exhibited elongated in a longitudinal direction grains with an average size of 75 μm. However, an equiaxed, smaller than 500 nm grains were also found in the microstructure of both materials. Different size and morphology of oxides particles were also observed. Bigger, about 150 nm Ti-Al-O particles were usually located at grain boundaries whereas Y-Ti-O nanoclusters of about 5 nm were uniformly distributed in ODS steel matrix. The Charpy impact tests revealed significantly better about 90% (5.8 J) upper shelf energy (USE) of material after HSHE but ductile to brittle transition temperature (DBTT) of both alloys was unsatisfactory. As-HR ODS steel has shown DBTT of about 55 deg. C whereas HSHE ODS steel has about 75 deg. C. This relatively high values of transition temperature were probably caused by oxides particles present at grain boundaries of the ODS alloys which decreased fracture properties of the ODS steels. High temperature tensile properties of both ODS alloys are found to be satisfactory in full range of the testing temperature from 23 up to 750 deg. C. However, about 15% better UTS and YS0.2 (1350 MPa and 1285 MPa, respectively) as well as ductility were measured in the case of the as-HSHE ODS steel. These results indicates that HSHE process of the ODS steel can be considered as more

  9. Study on the combustion behavior of high impact polystyrene nanocomposites produced by different extrusion processes

    Directory of Open Access Journals (Sweden)

    2008-08-01

    Full Text Available The combustion behavior of a blend made of high impact polystyrene (HIPS with sodium montmorillonite (MMT-Na+ and triphenyl phosphite (TPP, as a halogen-free flame retardant, is analyzed in detail in this work. The blend is processed through various extrusion methods aimed to improve clay dispersion. The UL94 method in vertical position, oxygen index and cone calorimetric measurements assess HIPS blend behavior in combustion. TGA, FTIR, SEM and X-ray measurements, together with mechanical and rheological tests evaluate the thermal degradation, morphology, intercalation and degree of dispersion of particles. The use of a static-mixing die placed at the extreme of a single screw extruder improves clay platelets distribution and reduces the peak heat release rate better than employing a twin screw extrusion process. In addition, mechanical and rheological properties are affected substantially by changing the extrusion process. A correlation between clay dispersion and HIPS fire retardant properties is found, as the peak heat release rate decreases with good clay dispersion in cone calorimetric tests.

  10. Meltlets(®) of soy isoflavones: process optimization and the effect of extrusion spheronization process parameters on antioxidant activity.

    Science.gov (United States)

    Deshmukh, Ketkee; Amin, Purnima

    2013-07-01

    In the current research work an attempt was made to develop "Melt in mouth pellets" (Meltlets(®)) containing 40% herbal extract of soy isoflavones that served to provide antioxidants activity in menopausal women. The process of extrusion-spheronization was optimized for extruder speed, extruder screen size, spheronization speed, and time. While doing so the herbal extract incorporated in the pellet matrix was subjected to various processing conditions such as the effect of the presence of other excipients, mixing or kneading to prepare wet mass, heat generated during the process of extrusion, spheronization, and drying. Thus, the work further investigates the effect of these processing parameters on the antioxidant activity of the soy isoflavone herbal extract incorporated in the formula. Thereby, the antioxidant activity of the soya bean herbal extract, Meltlets(®) and of the placebo pellets was evaluated using DPPH free radical scavenging assay and total reduction capacity.

  11. ODS steel fabrication: relationships between process, microstructure and mechanical properties

    International Nuclear Information System (INIS)

    Couvrat, M.

    2011-01-01

    Oxide Dispersion Strengthened (ODS) steels are promising candidate materials for generation IV and fusion nuclear energy systems thanks to their excellent thermal stability, high-temperature creep strength and good irradiation resistance. Their superior properties are attributed both to their nano-structured matrix and to a high density of Y-Ti-O nano-scale clusters (NCs). ODS steels are generally prepared by Mechanical Alloying of a pre-alloyed Fe-Cr-W-Ti powder with Y 2 O 3 powder. A fully dense bar or tube is then produced from this nano-structured powder by the mean of hot extrusion. The aim of this work was to determine the main parameters of the process of hot extrusion and to understand the link between the fabrication process, the microstructure and the mechanical properties. The material microstructure was characterized at each step of the process and bars were extruded with varying hot extrusion parameters so as to identify the impact of these parameters. Temperature then appeared to be the main parameter having a great impact on microstructure and mechanical properties of the extruded material. We then proposed a cartography giving the microstructure versus the process parameters. Based on these results, it is possible to control very accurately the obtained material microstructure and mechanical properties setting the extrusion parameters. (author) [fr

  12. Influence of processing conditions on apparent viscosity and system parameters during extrusion of distiller's dried grains-based snacks.

    Science.gov (United States)

    Singha, Poonam; Muthukumarappan, Kasiviswanathan; Krishnan, Padmanaban

    2018-01-01

    A combination of different levels of distillers dried grains processed for food application (FDDG), garbanzo flour and corn grits were chosen as a source of high-protein and high-fiber extruded snacks. A four-factor central composite rotatable design was adopted to study the effect of FDDG level, moisture content of blends, extrusion temperature, and screw speed on the apparent viscosity, mass flow rate or MFR, torque, and specific mechanical energy or SME during the extrusion process. With increase in the extrusion temperature from 100 to 140°C, apparent viscosity, specific mechanical energy, and torque value decreased. Increase in FDDG level resulted in increase in apparent viscosity, SME and torque. FDDG had no significant effect (p > .5) on mass flow rate. SME also increased with increase in the screw speed which could be due to the higher shear rates at higher screw speeds. Screw speed and moisture content had significant negative effect ( p  extruder and the system parameters were affected by the processing conditions. This study will be useful for control of extrusion process of blends containing these ingredients for the development of high-protein high-fiber extruded snacks.

  13. Application of carrier and plasticizer to improve the dissolution and bioavailability of poorly water-soluble baicalein by hot melt extrusion.

    Science.gov (United States)

    Zhang, Yilan; Luo, Rui; Chen, Yi; Ke, Xue; Hu, Danrong; Han, Miaomiao

    2014-06-01

    The objective of this study was to develop a suitable formulation for baicalein (a poorly water-soluble drug exhibiting high melting point) to prepare solid dispersions using hot melt extrusion (HME). Proper carriers and plasticizers were selected by calculating the Hansen solubility parameters, evaluating melting processing condition, and measuring the solubility of obtained melts. The characteristic of solid dispersions prepared by HME was evaluated. The dissolution performance of the extrudates was compared to the pure drug and the physical mixtures. Physicochemical properties of the extrudates were characterized by differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), and Fourier transform infrared spectroscopy (FTIR). Relative bioavailability after oral administration in beagle dogs was assessed. As a result, Kollidon VA64 and Eudragit EPO were selected as two carriers; Cremophor RH was used as the plasticizer. The dissolution of all the extrudates was significantly improved. DSC and PXRD results suggested that baicalein in the extrudates was amorphous. FTIR spectroscopy revealed the interaction between drug and polymers. After oral administration, the relative bioavailability of solid dispersions with VA64 and EPO was comparative, about 2.4- and 2.9-fold greater compared to the pure drug, respectively.

  14. Microstructure development and texture evolution of aluminum multi-port extrusion tube during the porthole die extrusion

    Energy Technology Data Exchange (ETDEWEB)

    Fan, X.H. [State Key Laboratory of Mechanical System and Vibration, Shanghai Jiao Tong University, Shanghai 200240 (China); School of Mechanical Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China); Tang, D., E-mail: tangding@sjtu.edu.cn [State Key Laboratory of Mechanical System and Vibration, Shanghai Jiao Tong University, Shanghai 200240 (China); School of Mechanical Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China); Fang, W.L.; Li, D.Y.; Peng, Y.H. [State Key Laboratory of Mechanical System and Vibration, Shanghai Jiao Tong University, Shanghai 200240 (China); School of Mechanical Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China)

    2016-08-15

    Aluminum multi-port extrusion tube is processed by the porthole die extrusion and the internal tube walls are welded through the solid state metallurgical bonding. In order to observe the development of grains and their orientations under severe plastic deformation and solid state welding, the extrusion butt together with the die is quenched immediately after extrusion to preserve the grain structure in the processing. The forming histories of selected material points are obtained by analyzing the optical microscopy graph. The evolution of the microstructure along the forming path is characterized by electro backscattered diffraction. It is found that geometrical dynamic recrystallization happens in the process. Grains are elongated, scattered at the transition zone and shear intensive zone, and then pinched off when they are pushed out from the die orifice. The shear-type orientations are predominant at the surface layer on the longitudinal section of the tube web and have penetrated into the intermediate layer. The rolling-type orientations are formed at the central layer. Texture gradient through the thickness of the tube web is observed. And cube orientated grains are found at the seam weld region. - Highlights: •Microstructure of extrusion butt is preserved after the micro scale porthole die extrusion. •Grain morphology history along forming path is investigated. •Texture evolutions on three material flows are present. •Texture gradient exists on the longitudinal section of the internal wall of profile. •Rolling-type and cube textures are found at the solid state welding region.

  15. Zr Extrusion – Direct Input for Models & Validation

    Energy Technology Data Exchange (ETDEWEB)

    Cerreta, Ellen Kathleen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-08-07

    As we examine differences in the high strain rate, high strain tensile response of high purity, highly textured Zr as a function of loading direction, temperature and extrusion velocity with primarily post mortem characterization techniques, we have also developed a technique for characterizing the in-situ extrusion process. This particular measurement is useful for partitioning energy of the system during the extrusion process: friction, kinetic energy, and temperature

  16. Coupling 3D printing with hot-melt extrusion to produce controlled-release tablets.

    Science.gov (United States)

    Zhang, Jiaxiang; Feng, Xin; Patil, Hemlata; Tiwari, Roshan V; Repka, Michael A

    2017-03-15

    The main objective of this work was to explore the potential of coupling fused deposition modeling in three-dimensional (3D) printing with hot-melt extrusion (HME) technology to facilitate additive manufacturing, in order to fabricate tablets with enhanced extended release properties. Acetaminophen was used as the model drug and different grades and ratios of polymers were used to formulate tablets. Three-point bending and hardness tests were performed to determine the mechanical properties of the filaments and tablets. 3D-printed tablets, directly compressed mill-extruded tablets, and tablets prepared from a physical mixture were evaluated for drug release rates using a USP-II dissolution apparatus. The surface and cross-sectional morphology of the 3D-printed tablets were assessed by scanning electron microscopy. Differential scanning calorimetry and thermogravimetric analysis were used to characterize the crystal states and thermal properties of materials, respectively. The 3D-printed tablets had smooth surfaces and tight structures; therefore, they showed better extended drug release rates than the directly compressed tablets did. Further, this study clearly demonstrated the feasibility of coupling HME with 3D printing technology, which allows for the formulation of drug delivery systems using different grades and ratios of pharmaceutical polymers. In addition, formulations can be made based on the personal needs of patients. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Osmotic mechanism of the loop extrusion process

    Science.gov (United States)

    Yamamoto, Tetsuya; Schiessel, Helmut

    2017-09-01

    The loop extrusion theory assumes that protein factors, such as cohesin rings, act as molecular motors that extrude chromatin loops. However, recent single molecule experiments have shown that cohesin does not show motor activity. To predict the physical mechanism involved in loop extrusion, we here theoretically analyze the dynamics of cohesin rings on a loop, where a cohesin loader is in the middle and unloaders at the ends. Cohesin monomers bind to the loader rather frequently and cohesin dimers bind to this site only occasionally. Our theory predicts that a cohesin dimer extrudes loops by the osmotic pressure of cohesin monomers on the chromatin fiber between the two connected rings. With this mechanism, the frequency of the interactions between chromatin segments depends on the loading and unloading rates of dimers at the corresponding sites.

  18. Optimization of extrusion process for production of nutritious pellets

    Directory of Open Access Journals (Sweden)

    Ernesto Aguilar-Palazuelos

    2012-03-01

    Full Text Available A blend of 50% Potato Starch (PS, 35% Quality Protein Maize (QPM, and 15% Soybean Meal (SM were used in the preparation of expanded pellets utilizing a laboratory extruder with a 1.5 × 20.0 × 100.0 mm die-nozzle. The independent variables analyzed were Barrel Temperature (BT (75-140 °C and Feed Moisture (FM (16-30%. The effect of extrusion variables was investigated in terms of Expansion Index (EI, apparent density (ApD, Penetration Force (PF and Specific Mechanical Energy (SME, viscosity profiles, DSC, crystallinity by X-ray diffraction, and Scanning Electronic Microscopy (SEM. The PF decreased from 30 to 4 kgf with the increase of both independent variables (BT and FM. SME was affected only by FM, and decreased with the increase in this variable. The optimal region showed that the maximum EI was found for BT in the range of 123-140 °C and 27-31% for FM, respectively. The extruded pellets obtained from the optimal processing region were probably not completely degraded, as shown in the structural characterization. Acceptable expanded pellets could be produced using a blend of PS, QPM, and SM by extrusion cooking.

  19. Robotic extrusion processes for direct ink writing of 3D conductive polyaniline structures

    Science.gov (United States)

    Holness, F. Benjamin; Price, Aaron D.

    2016-04-01

    The intractable nature of intrinsically conductive polymers (ICP) leads to practical limitations in the fabrication of ICP-based transducers having complex three-dimensional geometries. Conventional ICP device fabrication processes have focused primarily on thin-film deposition techniques; therefore this study explores novel additive manufacturing processes specifically developed for ICP with the ultimate goal of increasing the functionality of ICP sensors and actuators. Herein we employ automated polymer paste extrusion processes for the direct ink writing of 3D conductive polyaniline (PANI) structures. Realization of these structures is enabled through a modified fused filament fabrication delta robot equipped with an integrated polymer paste extruder. This unique robot-controlled additive manufacturing platform is capable of fabricating high-resolution 3D conductive PANI and has been utilized to produce structures with a minimum feature size of 1.5 mm. The required processability of PANI is achieved by means of a counter-ion induced thermal doping method. Using this method, a viscous paste is formulated as the extrudate and a thermo-chemical treatment is applied post extrusion to finalize the complexation.

  20. Antioxidant activity and polyphenolic compound stability of lentil-orange peel powder blend in an extrusion process.

    Science.gov (United States)

    Rathod, Rahul P; Annapure, Uday S

    2017-03-01

    Lentil contains substantial amount of protein, carbohydrate, fibre and other nutrients and orange peels powder rich in carbohydrate and fiber content The present study was aimed to investigate the effects of extrusion processing parameter on the level of total phenolic content (TPC), total flavonoid content (TFC), total tannin content and antioxidant activity of lentil-orange peel powder blend, also to investigate the possibility of blend as a candidate for production of protein rich extruded product by using response surface methodology. It was observed that, the physicochemical properties and sensory characteristics of lentil-orange peel based extrudate were highly dependent on process variables. The blend of lentil and orange peel powder has a huge potential for extrusion to produce ready-to-eat extruded with good acceptance. The overall best quality product was optimized and obtained at 16% moisture, 150 °C die temperature and 200 rpm screw speed. Extrusion process increased nutritional value of extruded product with TPC and TFC of 70.4 and 67.62% respectively and antioxidant activity of 60.6%. It showed higher stability at 150 °C with intermediate feed moisture content and despite the use of high temperatures in the extrusion-cooking is possible to minimize the loss of bioactive compounds to achieve products. Thus, results indicated that blend of lentil and orange peel may be used as raw material for the production of extruded snacks with great nutritional value.

  1. Study of microstructure, texture and mechanical properties of Zr–2.5Nb alloy pressure tubes fabricated with different processing routes

    International Nuclear Information System (INIS)

    Saibaba, N.; Vaibhaw, Kumar; Neogy, S.; Mani Krishna, K.V.; Jha, S.K.; Phani Babu, C.; Ramana Rao, S.V.; Srivastava, D.; Dey, G.K.

    2013-01-01

    Different fabrication trials involving the variation in three important stages of Zr–2.5Nb pressure tube were undertaken. The variations were with respect to the mode of breaking the cast structure of the ingot (forging vs extrusion), the hot extrusion ratio and the number of subsequent cold work stages to produce the finished tube. It was observed that the forging process resulted in superior performance in breaking the cast structure. Higher extrusion ratios resulted in more favorable texture and microstructure. More continuity of the beta phase was observed in the final microstructure for the route involving the single cold work step subsequent to hot extrusion

  2. Integrated bottom up and top down approach to optimization of the extrusion process

    NARCIS (Netherlands)

    Vaneker, Thomas H.J.; Koenis, P.T.G.; van Ouwerkerk, Gijs; van Ouwerkerk, Gijs; Nilsen, K.E.; van Houten, Frederikus J.A.M.

    2008-01-01

    Boal BV and the University of Twente participate in research projects focused on improvement of die design methods for aluminum extrusion dies. Within this research empirical knowledge is combined with insights gained from numerical process simulations. Design rules for improvements to the geometry

  3. Continuous vulcanization of extruded profile by microwave process

    International Nuclear Information System (INIS)

    Lim Hun Soo

    1994-01-01

    Continuous vulcanization is being increasingly used today in the manufacture of extrusion profiles. This is particularly so with the microwave/hot air continuous vulcanization process. Although this process is now quite widely used in Europe and to a lesser extent in USA, it is still not used in Malaysia. To improve the technological capability of the rubber-based industry in extrusion product, the RRIM has acquired a microwave/hot air tunnel continuous vulcanization equipment to enable development work in this area to be carried out with the aim of upgrading the rubber industry towards this more automated manufacturing process. This is particularly pertinent in view of the anticipated labour shortage, and, increasing labour and energy cost. This paper outlines the basic principles of operation of the microwave/hot air tunnel continuous vulcanization process and describes some aspects of compounding involving natural and synthetic rubbers for use in the process. As temperature increase is one of the major factors influencing the vulcanization of profile in this process, study was therefore concentrated on the heat generation aspect in the microwave tunnel

  4. Impacts of Scarification and Degermination on the Expansion Characteristics of Select Quinoa Varieties during Extrusion Processing.

    Science.gov (United States)

    Aluwi, Nicole A; Gu, Bon-Jae; Dhumal, Gaurav S; Medina-Meza, Ilce G; Murphy, Kevin M; Ganjyal, Girish M

    2016-12-01

    Extrusion of 2 quinoa varieties, Cherry Vanilla and Black (scarified and unscarified) and a mixed quinoa variety, Bolivian Royal (scarified and degermed) were studied for their extrusion characteristics. A corotating twin-screw extruder with a 3 mm round die was used. Feed moisture contents of 15%, 20%, and 25% (wet basis) were studied. The extruder barrel temperature was kept constant at 140 °C and screw speeds were varied from 100, 150, and 200 revolutions per minutes. Process responses (specific mechanical energy, back pressure, and torque) and product responses (expansion ratio, unit density, and water absorption index/water solubility index) were evaluated. The degermed Bolivian Royal showed the highest expansion in comparison to all other varieties, attributed to its significantly low levels of fat, fiber, and protein. The scarified Cherry Vanilla resulted in the lowest expansion ratio. This was attributed to the increase in the protein content from the removal of the outer layer. The results indicate that all the varieties performed differently in the extrusion process due to their modification processes as well as the individual variety characteristics. © 2016 Institute of Food Technologists®.

  5. Reduction of cyanogenic glycosides by extrusion - influence of temperature and moisture content of the processed material

    Directory of Open Access Journals (Sweden)

    Čolović Dušica S.

    2015-01-01

    Full Text Available Тhe paper presents results of the investigation of the influence of extrusion temperature and moisture content of treated material on the reduction of cyanogenic glycosides (CGs in linseed-based co-extrudate. CGs are the major limitation of the effective usage of linseed in animal nutrition. Hence, some technological process must be applied for detoxification of linseed before its application as a nutrient. Extrusion process has demonstrated several advantages in reducing the present CGs, since it combines the influences of heating, shearing, high pressure, mixing, etc. According to obtained results, the increase in both temperature and moisture content of the starting mixture decreased the content of CGs in the processed material. HCN content, as a measurement of GCs presence, ranged from 25.42 mg/kg, recorded at the moisture content of 11.5%, to 126 mg/kg, detected at the lowest moisture content of 7%. It seems that moisture content and temperature had the impact on HCN content of equal importance. However, the influence of extrusion parameters other than temperature and moisture content could not be neglected. Therefore, the impact of individual factors has to be tested together. [Projekat Ministarstva nauke Republike Srbije, br. III 46012

  6. Jute fiber reinforced polypropylene produced by continuous extrusion compounding. Part 1. Processing and ageing properties

    NARCIS (Netherlands)

    Oever, van den M.J.A.; Snijder, M.H.B.

    2008-01-01

    This article addresses the processing and ageing properties of jute fiber reinforced polypropylene (PP) composites. The composite has been manufactured by a continuous extrusion process and results in free flowing composite granules, comprising up to 50 weight percent (wt %) jute fiber in PP. These

  7. Validation of measured friction by process tests

    DEFF Research Database (Denmark)

    Eriksen, Morten; Henningsen, Poul; Tan, Xincai

    The objective of sub-task 3.3 is to evaluate under actual process conditions the friction formulations determined by simulative testing. As regards task 3.3 the following tests have been used according to the original project plan: 1. standard ring test and 2. double cup extrusion test. The task...... has, however, been extended to include a number of new developed process tests: 3. forward rod extrusion test, 4. special ring test at low normal pressure, 5. spike test (especially developed for warm and hot forging). Validation of the measured friction values in cold forming from sub-task 3.1 has...... been made with forward rod extrusion, and very good agreement was obtained between the measured friction values in simulative testing and process testing....

  8. Study of mechanical properties on powdermetalurgy aluminium matrix composites fabricated by stamping or extrusion

    International Nuclear Information System (INIS)

    Busquets, D.; Gomez, L.; Amigo, V.; Salvador-Moya, M. D.

    2005-01-01

    We have developed composite materials from AA6061 aluminium alloy powders used as matrix and ceramics powders of boron carbide, silicon carbide and boron nitride, used as reinforcements in 2.5, 5.0, 7.5 and 10% vol. by mechanical mixing and milling in planetary mill at 360 rpm vial velocity for 4 h followed of hot stamping and extrusion process on green compacts. Mechanical properties obtained from tensile tests are influenced by the heat treatment, reinforcement fractions and nature. Moreover, these mechanical characteristic are dependent from the processing route. Optical and Scanning Electron Microscopy analysis revealed the microstructure of materials and let describe the tripartite relation; structure-processing-properties, of the developed materials. (Author) 20 refs

  9. Analysis of Crystallographic Textures in Aluminum Plates Processed by Equal Channel Angular Extrusion

    DEFF Research Database (Denmark)

    Li, Saiyi; Mishin, Oleg

    2014-01-01

    A modeling and experimental investigation has been conducted to explore the effect of processing route on texture evolution during equal channel angular extrusion (ECAE) of aluminum plate samples. It is found that although the textures in the plates develop along orientation fibers previously ide...... identified for ECAE-processed rods and bars, the main components and strength of these textures vary significantly with processing route, which may lead to considerable differences in the plastic anisotropy of the plates....

  10. Comparisons of microstructures and texture and mechanical properties of magnesium alloy fabricated by compound extrusion and direct extrusion

    Energy Technology Data Exchange (ETDEWEB)

    Hu, H.-J., E-mail: hhj@cqut.edu.cn [Chongqing University of Technology, Chongqing 400050 (China); PLA Chongqing Logistics Engineering College, 401311 (China); Ying, Y.-L. [Chongqing University of Technology, Chongqing 400050 (China); Ou, Z.-W. [PLA Chongqing Logistics Engineering College, 401311 (China); Wang, X.-Q. [The University of Alabama, Tuscaloosa, AL 35487 (United States)

    2017-05-17

    In this study, microstructure evolution, textures and mechanical properties of AZ61 magnesium alloy were investigated by optical microscopy (OM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and tensile tests. The samples were processed by a new compound extrusion (CE) which combines direct extrusion (DE) and two steps of equal channel anger extrusion (ECAE). The results show that CE process can refine the microstructure more effectively than the DE process. The CE-fabricated samples have a weaker texture (0002), and a more fine and homogeneous microstructures, which attributes to the additional two steps of ECAE in CE process. In CE process, twin dynamic recrystallization and rotational dynamic recrystallization occurred, which enhances the refinement of the grains and weakening of the texture. In addition, the samples fabricated by CE process display a higher tensile properties (yield strength, tensile strength and elongation) with an excellent balance of strength and tensile ductility. Based on this study, severe plastic deformation (SPD) techniques combining conventional DE and two steps ECAE into a single process are feasibility to improve the mechanical properties of AZ61 Mg alloy.

  11. Processing of non-oxide ceramics from sol-gel methods

    Science.gov (United States)

    Landingham, Richard; Reibold, Robert A.; Satcher, Joe

    2014-12-12

    A general procedure applied to a variety of sol-gel precursors and solvent systems for preparing and controlling homogeneous dispersions of very small particles within each other. Fine homogenous dispersions processed at elevated temperatures and controlled atmospheres make a ceramic powder to be consolidated into a component by standard commercial means: sinter, hot press, hot isostatic pressing (HIP), hot/cold extrusion, spark plasma sinter (SPS), etc.

  12. Microstructure evolution and mechanical properties of nano-SiCp/AZ91 composite processed by extrusion and equal channel angular pressing (ECAP)

    Energy Technology Data Exchange (ETDEWEB)

    Qiao, X.G.; Ying, T. [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Zheng, M.Y., E-mail: zhenghe@hit.edu.cn [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Wei, E.D.; Wu, K.; Hu, X.S. [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Gan, W.M.; Brokmeier, H.G. [Institute of Materials Research, Helmholtz-Centre Geesthacht, D-21502 Geesthacht (Germany); Golovin, I.S. [Department of Physical Metallurgy of Non-Ferrous Metals, National University of Science and Technology “MISiS”, Leninsky ave. 4, 119049 Moscow (Russian Federation)

    2016-11-15

    Nano-SiCp/AZ91 magnesium matrix composite was fabricated by stir casting. The as-cast ingots were extruded at 350 °C, then processed by equal channel angular pressing (ECAP) at various temperatures (250 °C, 300 °C and 350 °C). Grains are significantly refined after the extrusion and the ECAP. A basal fibre texture was detected by neutron diffraction after the extrusion, which inclines about 45° to the extrusion direction (ED) after the ECAP. Nano-scaled SiC particles agglomerate in the as-cast composite. After the extrusion, the agglomeration tends to form continuous or discontinuous strips along the extrusion direction. By application of the ECAP, the agglomerated SiC particles are partly dispersed and the strips formed during the extrusion tend to be thinner and broken with the increasing pass number. The yield tensile strength (YTS) and the ultimate tensile strength (UTS) of the composite are dramatically increased after the extrusion. ECAP for one pass at various temperatures further increases the strength, however, the YTS decreases with the increasing ECAP temperature and the pass number. The Orowan equations predict the maximum YTS of the composite may be up to 400 MPa providing SiC particles are homogenously distributed in the matrix. - Highlights: •Nano-scaled SiC particles were successfully added into AZ91 by stirring casting. •Agglomeration of nano-particles were improved by extrusion and ECAP. •Yield strength of the composite is 328 MPa after one pass of ECAP. •Further ECAP process with optimized parameters may fully disperse nano-particles. •Yield strength is predicted to up to 400 MPa when particles are fully dispersed.

  13. Use of a high temperature hydrostatic extrusion technique for powders strengthening

    International Nuclear Information System (INIS)

    Decours, J.; Gavinet, J.; Weisz, M.

    1975-01-01

    A conventional 575 tonnes extrusion press has been modified by a device permitting the extrusion process by hydrostatic pression through a leakless mechanical set (13,000 bars maximum), from room temperature to 1,200 deg C. This new device allows: the high temperature hydrostatic extrusion for strengthening of powders, the isostatic compression of powders. Examples of realisations obtained by this process are described, including the influence of different parameters: pressure, temperature, extrusion ratio and for different materials: pure metals (iron, nickel, niobium, etc...) and alloys (stainless steel, molybdenum, niobium nickel alloys, etc...). Then, the advantages of the process are emphasized [fr

  14. The Influence of Segregation Phenomena on Quality of Product in Extrusion Process

    Directory of Open Access Journals (Sweden)

    G. Skorulski

    2010-07-01

    Full Text Available The segregation phenomena and formation of agglomerate have the basic influence on structure of the final product. The aim of this workis analyzing the phenomena of segregation in semi-solid extrusion process, using several kind of substitute materials, which can simulate the thixotrophic fluid behavior and displacement of solid particles. The experimental researches are made to investigation of segregation in the near-wall layers and the formation of agglomerate. Especially, the distribution of the solid particles at the end of extrusion process have been taken into consideration. Theoretical criteria describe the critical value of the energy liberated at the surfaces by the action of forces depends on the temperature, the pressure, the yield stress and the physical state and degree of intimacy of the contacting surfaces. The theory has been tested experimentally using a silicon polymer as a substitute material. Experimental stand with a Plexiglass die was prepared, such that the velocity fields at the surfaces could be observed and measured during plastic flow, allowing the empirical coefficients in the mathematical formulation to be estimated. On the basis of the theory and experiment an optimal die chamber was designed for a die with a complex shape.

  15. Soluplus®/TPGS-based solid dispersions prepared by hot-melt extrusion equipped with twin-screw systems for enhancing oral bioavailability of valsartan.

    Science.gov (United States)

    Lee, Jae-Young; Kang, Wie-Soo; Piao, Jingpei; Yoon, In-Soo; Kim, Dae-Duk; Cho, Hyun-Jong

    2015-01-01

    Soluplus(®) (SP) and D-alpha-tocopherol polyethylene glycol 1000 succinate (TPGS)-based solid dispersion (SD) formulations were developed by hot-melt extrusion (HME) to improve oral bioavailability of valsartan (VST). HME process with twin-screw configuration for generating a high shear stress was used to prepare VST SD formulations. The thermodynamic state of the drug and its dispersion in the polymers were evaluated by solid-state studies, including Fourier-transform infrared, X-ray diffraction, and differential scanning calorimetry. Drug release from the SD formulations was assessed at pH values of 1.2, 4.0, and 6.8. Pharmacokinetic study was performed in rats to estimate the oral absorption of VST. HME with a high shear rate produced by the twin-screw system was successfully applied to prepare VST-loaded SD formulations. Drug amorphization and its molecular dispersion in the polymer matrix were verified by several solid-state studies. Drug release from SD formulations was improved, compared to the pure drug, particularly at pH 6.8. Oral absorption of drug in rats was also enhanced in SP and TPGS-based SD groups compared to that in the pure drug group. SP and TPGS-based SDs, prepared by the HME process, could be used to improve aqueous solubility, dissolution, and oral absorption of poorly water-soluble drugs.

  16. Friction measurement and modelling in forward rod extrusion

    DEFF Research Database (Denmark)

    Tan, Xincai; Bay, Niels; Zhang, Wenqi

    2003-01-01

    Forward extrusion is one of the important processes in bulk metal forming. Friction stress can be estimated from the slope of the load±displacement curve at the steady state after the maximum load in a forward extrusion test. In this paper, forward rod extrusion tests are carried out to determine...... as the lubricant. Friction stresses are obtained from measurements of slopes of extrusion pressure±punch travel curves at the steady state stage. Normal pressures are evaluated by using Mohr’s circle, in which shear ¯ow stresses are estimated at the maximum elastic deformation points from the same extrusion...... pressure±punch travel curves. It is found that the relationship between normal pressure and friction stress appears linear, and therefore Coulomb’s friction model ®ts the experimental data very well. Extrusion pressure±punch travel curves before the steady state can be divided into four stages: elastic...

  17. Towards predictive control of extrusion weld seams: an integrated approach

    NARCIS (Netherlands)

    Bakker, A.J. den; Werkhoven, R.J.; Sillekens, W.H.; Katgerman, L.

    2010-01-01

    Longitudinal weld seams are an intrinsic feature in hollow extrusions produced with porthole dies. The formation of longitudinal weld seams is a solid bonding process, controlled by the local conditions in the extrusion die. Being the weakest areas within the extrusion cross section, it is desirable

  18. Deformation behavior of commercial Mg-Al-Zn-Mn type alloys under a hydrostatic extrusion process at elevated temperatures

    International Nuclear Information System (INIS)

    Yoon, Duk Jae; Lee, Sang Mok; Lim, Seong Joo; Kim, Eung Zu

    2010-01-01

    This paper presents the deformation behavior of commercial Mg-Al-Zn-Mn type alloys during hydrostatic extrusion process at elevated temperatures. In the current study commercial Mg-Al-Zn-Mn type alloys with different Al contents were subjected to hydrostatic extrusion process at a range of temperatures and at ram speeds of 4.5, 10 and 17 mm/sec. Under the hydrostatic condition at 518K, the alloy with Al contents of 2.9 wt% was successfully extruded at all applied speeds. The alloys with Al content of 5.89 and 7.86 wt% were successful up to 10mm/sec, and finally extrusion of alloy with Al content 8.46wt% was successful only at 4.5 mm/sec. These results show that the deformation limit in the Mg alloys in terms of extrusion speed greatly extended to higher value in the proximity of lower Al content. It is presumed that deformation becomes harder as Al content increases because of strengthening mechanism by solute drag to increase of supersaturated Mg 17 Al 12 precipitates. Also, microstructures of cast and extruded Mg alloys were compared. Defect-wide microstructure of cast alloy completely evolved into dense and homogeneous microstructure with equiaxed grains

  19. Final Technical Report - Advanced Optical Sensors to Minimize Energy Consumption in Polymer Extrusion Processes

    Energy Technology Data Exchange (ETDEWEB)

    Susan J. Foulk

    2012-07-24

    Project Objective: The objectives of this study are to develop an accurate and stable on-line sensor system to monitor color and composition on-line in polymer melts, to develop a scheme for using the output to control extruders to eliminate the energy, material and operational costs of off-specification product, and to combine or eliminate some extrusion processes. Background: Polymer extrusion processes are difficult to control because the quality achieved in the final product is complexly affected by the properties of the extruder screw, speed of extrusion, temperature, polymer composition, strength and dispersion properties of additives, and feeder system properties. Extruder systems are engineered to be highly reproducible so that when the correct settings to produce a particular product are found, that product can be reliably produced time after time. However market conditions often require changes in the final product, different products or grades may be processed in the same equipment, and feed materials vary from lot to lot. All of these changes require empirical adjustment of extruder settings to produce a product meeting specifications. Optical sensor systems that can continuously monitor the composition and color of the extruded polymer could detect process upsets, drift, blending oscillations, and changes in dispersion of additives. Development of an effective control algorithm using the output of the monitor would enable rapid corrections for changes in materials and operating conditions, thereby eliminating most of the scrap and recycle of current processing. This information could be used to identify extruder systems issues, diagnose problem sources, and suggest corrective actions in real-time to help keep extruder system settings within the optimum control region. Using these advanced optical sensor systems would give extruder operators real-time feedback from their process. They could reduce the amount of off-spec product produced and

  20. Study on extrusion process of SiC ceramic matrix

    Science.gov (United States)

    Dai, Xiao-Yuan; Shen, Fan; Ji, Jia-You; Wang, Shu-Ling; Xu, Man

    2017-11-01

    In this thesis, the extrusion process of SiC ceramic matrix has been systematically studied.The effect of different cellulose content on the flexural strength and pore size distribution of SiC matrix was discussed.Reselts show that with the increase of cellulose content, the flexural strength decreased.The pore size distribution in the sample was 1um-4um, and the 1um-2um concentration was more concentrated. It is found that the cellulose content has little effect on the pore size distribution.When the cellulose content is 7%, the flexural strength of the sample is 40.9Mpa. At this time, the mechanical properties of the sample are the strongest.

  1. Modelling extrudate expansion in a twin-screw food extrusion cooking process through dimensional analysis methodology

    DEFF Research Database (Denmark)

    Cheng, Hongyuan; Friis, Alan

    2010-01-01

    A new phenomenological model is proposed to correlate extrudate expansion and extruder operation parameters in a twin-screw food extrusion cooking process. Buckingham's pi dimensional analysis method is applied to establish the model. Three dimensionless groups, i.e. pump efficiency, water content...

  2. Microstructure, mechanical properties, and thermoelectric properties of hot-extruded p-type Te-doped Bi{sub 0.5}Sb{sub 1.5}Te{sub 3} compounds

    Energy Technology Data Exchange (ETDEWEB)

    Park, K; Seo, J; Lee, C

    1997-07-01

    The p-type Bi{sub 0.5}Sb{sub 1.5}Te{sub 3} compounds with Te dopant (4.0 and 6.0 wt%) and without dopant were fabricated by hot extrusion in the temperature range of 300 to 510 C under an extrusion ratio of 20:1. The undoped and Te doped compounds were highly dense and showed high crystalline quality. The grains contained many dislocations and were fine equiaxed ({approximately}1.0 {micro}m) owing to the dynamic recrystallization during the extrusion. The hot extrusion gave rise to the preferred orientation of grains. The bending strength and the figure of merit of the undoped and Te doped compounds were increased with increasing the extrusion temperature. The Te dopant significantly increased the figure of merit. The values of the figure of merit of the undoped and 4.0 wt% Te-doped compounds hot extruded at 440 C were 2.11 x 10{sup {minus}3}/K and 2.94 x 10{sup {minus}3}/K, respectively.

  3. Development of Tablet Formulation of Amorphous Solid Dispersions Prepared by Hot Melt Extrusion Using Quality by Design Approach.

    Science.gov (United States)

    Agrawal, Anjali; Dudhedia, Mayur; Deng, Weibin; Shepard, Kevin; Zhong, Li; Povilaitis, Edward; Zimny, Ewa

    2016-02-01

    The objective of the study was to identify the extragranular component requirements (level and type of excipients) to develop an immediate release tablet of solid dispersions prepared by hot melt extrusion (HME) process using commonly used HME polymers. Solid dispersions of compound X were prepared using polyvinyl pyrrolidone co-vinyl acetate 64 (PVP VA64), Soluplus, and hypromellose acetate succinate (HPMCAS-LF) polymers in 1:2 ratio by HME through 18 mm extruder. A mixture design was employed to study effect of type of polymer, filler (microcrystalline cellulose (MCC), lactose, and dicalcium phosphate anhydrous (DCPA)), and disintegrant (Crospovidone, croscarmellose sodium, and sodium starch glycolate (SSG)) as well as level of extrudates, filler, and disintegrant on tablet properties such as disintegration time (DT), tensile strength (TS), compactibility, and dissolution. Higher extrudate level resulted in longer DT and lower TS so 60-70% was the maximum amount of acceptable extrudate level in tablets. Fast disintegration was achieved with HPMCAS-containing tablets, whereas Soluplus- and PVP VA64-containing tablets had higher TS. Crospovidone and croscarmellose sodium were more suitable disintegrant than SSG to achieve short DT, and MCC was a suitable filler to prepare tablets with acceptable TS for each studied HME polymer. The influence of extragranular components on dissolution from tablets should be carefully evaluated while finalizing tablet composition, as it varies for each HME polymer. The developed statistical models identified suitable level of fillers and disintegrants for each studied HME polymer to achieve tablets with rapid DT (tablet porosity), and their predictivity was confirmed by conducting internal and external validation studies.

  4. The comparative study of pressing and extrusion like processes of construction ceramic products in the Metropolitan Area of Cucuta

    International Nuclear Information System (INIS)

    Gelves, J. F.; Monroy, R.; Sanchez, J.; Ramirez, R. P.

    2013-01-01

    The present work studies the principal variables of control in the manufacturing process of construction pieces of the Metropolitan Area of San Jose de Cucuta by extrusion and pressing techniques for its forming. The investigation was taken out using clayey samples of the two principal geological formations of the region where the raw material is taken for processing at an industrial level. The clayey samples milling was made by dry means as well as by moisture means and its particle size was measured. Subsequently the forming process was taken over by using an hydraulic press and extruder with vacuum system , both equipment s at laboratory scale, the pieces shaped were dry and firing between 980 degree centigrade and 1180 degree centigrade at the end of the process the tests were made to determine water absorption, contraction and mass loss at the pieces firing. The study results left to see that the extrusion technique allowed a faster vitrification for the region's clay in comparing with the pressing technique, the contractions of drying and firing are less marked on the pressing techniques with standard deviations much lower than in extrusion. (Author) 13 refs.

  5. Creating Drug Solubilization Compartments via Phase Separation in Multicomponent Buccal Patches Prepared by Direct Hot Melt Extrusion-Injection Molding.

    Science.gov (United States)

    Alhijjaj, Muqdad; Bouman, Jacob; Wellner, Nikolaus; Belton, Peter; Qi, Sheng

    2015-12-07

    Creating in situ phase separation in solid dispersion based formulations to allow enhanced functionality of the dosage form, such as improving dissolution of poorly soluble model drug as well as being mucoadhesive, can significantly maximize the in vitro and in vivo performance of the dosage form. This formulation strategy can benefit a wide range of solid dosage forms for oral and alternative routes of delivery. This study using buccal patches as an example created separated phases in situ of the buccal patches by selecting the excipients with different miscibility with each other and the model drug. The quaternary dispersion based buccal patches containing PEG, PEO, Tween 80, and felodipine were prepared by direct hot melt extrusion-injection molding (HME-IM). The partial miscibility between Tween 80 and semicrystalline PEG-PEO led to the phase separation after extrusion. The Tween phases acted as drug solubilization compartments, and the PEG-PEO phase had the primary function of providing mucoadhesion and carrier controlled dissolution. As felodipine was preferably solubilized in the amorphous regions of PEG-PEO, the high crystallinity of PEG-PEO resulted in an overall low drug solubilizing capacity. Tween 80 was added to improve the solubilization capacity of the system as the model drug showed good solubility in Tween. Increasing the drug loading led to the supersaturation of drug in Tween compartments and crystalline drug dispersed in PEG-PEO phases. The spatial distribution of these phase-separated compartments was mapped using X-ray micro-CT, which revealed that the domain size and heterogeneity of the phase separation increased with increasing the drug loading. The outcome of this study provides new insights into the applicability of in situ formed phase separation as a formulation strategy for the delivery of poorly soluble drugs and demonstrated the basic principle of excipient selection for such technology.

  6. Extrusion and drawing of zircaloy 2. Production of pressure tubes for EL-4

    International Nuclear Information System (INIS)

    Thevenet, J.

    1964-01-01

    The authors give briefly the physical mechanical and chemical properties of zircaloy 2, as far as the transformation of this alloy is concerned. Extrusion: After a few general remarks concerning the extrusion and co-extrusion, including a comparison of the deformation resistance of canning metals and of zircaloy 2, the following points are considered: - the difficulties occurring because of the use of this alloy: - atmosphere protection - adjustment on to the machine tools - low thermal conductivity - economy of the metal (price) - the factors affecting the quality of the extruded products extrusion under a copper can and under lubricant glass - fine grain structure - temperature homogeneity - working temperature The transformation cycle - '550 kg ingot - preliminary shape 'for drawing of EL-4 tubes (112 x 120 L 12 m)' - is described in detail (extrusion or forging of the φ = 340 ingot into φ = 220 billets, cutting into lengths and hot drilling at φ = 125, fixing into a copper can and rough extrusion). Drawing: The main difficulties are due to seizing of the tools and to the necessity of protecting the alloy from the atmosphere during annealings. A brief description is given of drawing out on a short mandrel, on a long mandrel, of laminating on a reducing machine and of the carrying out of an annealing, as well as of the production of EL-4 tubes (φ =107 x 113 L 430 m) by drawing out shapes having a size of 112 x 120 on long mandrels. Conclusion: It is possible by extrusion and drawing to produce zircaloy 2 tubes similar to those which may be obtained normally using stainless steel. (authors) [fr

  7. Density and superconducting properties of metal-sheathed YBa2Cu3Oy ceramic processed by hydrostatic extrusion

    International Nuclear Information System (INIS)

    Karpov, M.I.; Korzhov, V.P.; Artamoshin, A.V.; Prokopenko, V.M.

    1994-01-01

    Brittle materials can be deformed without cracking and rupturing using hydrostatic extrusion, which provides the greatest pore annihilation in powder-processed materials and allows large degrees of one-step deformation, which is favorable for texturing. Earlier, a casting slip prepared by mixing a starting powder of Y-based ceramic with an organic binder was conventionally extruded to produce a wire 150 μm in diameter. After special sintering, the critical-current density in the material attained a few hundred amperes per square centimeter at 77 K, and the wire could be rolled into a winding ≥0.3 m in diameter. Hydrostatic extrusion of an assembly composed of Y-based ceramic in a bimetallic Nb/Cu tube 30 mm in diameter was used to produce rods 6 mm in diameter; drawing of these rods yielded samples of wire 2 to 3 mm in diameter. It was shown that the extrusion pressure and strain substantially influence the yield of the rupture-free wire. No signs of rupturing, cracking, or necking were observed in wire extruded at pressures ≤700 MPa and degrees of deformation ≤50%. A pronounced instability of the hydrostatic extrusion, the appearance of defects, and even the rupture of the rods were caused by an increase in the pressure up to 2000 MPa and in the degree of one-step deformation up to 80%. In this work, the authors focus on the possibility of producing thin YBa 2 Cu 3 O y superconductors using only hydrostatic extrusion. They determined the parameters for the hydrostatic extrusion of the metal-sheathed YBa 2 Cu 3 O y ceramic to a diameter of 3 mm or to a rectangular cross section. Effects of the ceramic core, and of the reduction coefficient on superconducting-transition parameters and the critical-current density of the ceramic were examined

  8. Magma extrusion during the Ubinas 2013-2014 eruptive crisis based on satellite thermal imaging (MIROVA) and ground-based monitoring

    Science.gov (United States)

    Coppola, Diego; Macedo, Orlando; Ramos, Domingo; Finizola, Anthony; Delle Donne, Dario; del Carpio, José; White, Randall; McCausland, Wendy; Centeno, Riky; Rivera, Marco; Apaza, Fredy; Ccallata, Beto; Chilo, Wilmer; Cigolini, Corrado; Laiolo, Marco; Lazarte, Ivonne; Machaca, Roger; Masias, Pablo; Ortega, Mayra; Puma, Nino; Taipe, Edú

    2015-09-01

    After 3 years of mild gases emissions, the Ubinas volcano entered in a new eruptive phase on September 2nd, 2013. The MIROVA system (a space-based volcanic hot-spot detection system), allowed us to detect in near real time the thermal emissions associated with the eruption and provided early evidence of magma extrusion within the deep summit crater. By combining IR data with plume height, sulfur emissions, hot spring temperatures and seismic activity, we interpret the thermal output detected over Ubinas in terms of extrusion rates associated to the eruption. We suggest that the 2013-2014 eruptive crisis can be subdivided into three main phases: (i) shallow magma intrusion inside the edifice, (ii) extrusion and growing of a lava plug at the bottom of the summit crater coupled with increasing explosive activity and finally, (iii) disruption of the lava plug and gradual decline of the explosive activity. The occurrence of the 8.2 Mw Iquique (Chile) earthquake (365 km away from Ubinas) on April 1st, 2014, may have perturbed most of the analyzed parameters, suggesting a prompt interaction with the ongoing volcanic activity. In particular, the analysis of thermal and seismic datasets shows that the earthquake may have promoted the most intense thermal and explosive phase that culminated in a major explosion on April 19th, 2014. These results reveal the efficiency of space-based thermal observations in detecting the extrusion of hot magma within deep volcanic craters and in tracking its evolution. We emphasize that, in combination with other geophysical and geochemical datasets, MIROVA is an essential tool for monitoring remote volcanoes with rather difficult accessibility, like those of the Andes that reach remarkably high altitudes.

  9. Die Defects and Die Corrections in Metal Extrusion

    Directory of Open Access Journals (Sweden)

    Sayyad Zahid Qamar

    2018-05-01

    Full Text Available Extrusion is a very popular and multi-faceted manufacturing process. A large number of products for the automotive, aerospace, and construction sectors are produced through aluminum extrusion. Many defects in the extruded products occur because of the conditions of the dies and tooling. The problems in dies can be due to material issues, design and manufacturing, or severe usage. They can be avoided by maintaining the billet quality, by controlling the extrusion process parameters, and through routine maintenance. Die problems that occur on a day-to-day basis are mostly repairable and are rectified through various types of die correction operations. These defects and repair operations have not been reported in detail in the published literature. The current paper presents an in-depth description of repairable die defects and related die correction operations in metal extrusion. All major die defects are defined and classified, and their causes, preventive measures, and die correction operations are described. A brief frequency-based statistical study of die defects is also carried out to identify the most frequent die corrections. This work can be of direct benefit to plant engineers and operators and to researchers and academics in the field of metal extrusion.

  10. Die design and process optimization of plastic gear extrusion

    Science.gov (United States)

    Zhang, Lei; Fu, Zhihong; Yao, Chen; Zang, Gongzheng; Wan, Yue

    2018-01-01

    The flow velocity of the melt in the extruder was simulated by using software Polyflow, and the size of the die channel with the best flow uniformity was obtained. The die profile shape is obtained by reverse design. The length of the shaping section is determined by Ansys transient thermal analysis. According to the simulation results, the design and manufacture of extrusion die of plastic gear and vacuum cooling setting were obtained. The influence of the five process parameters on the precision of the plastic gear were studied by the single factor analysis method, such as the die temperature T, the screw speed R, the die spacing S, the vacuum degree M and the hauling speed V. The optimal combination of process parameters was obtained by using the neural network particle swarm optimization algorithm(T = 197.05 °C, R = 9.04rpm, S = 67mm, M = -0.0194MPa). The tooth profile deviation of the extruded plastic gear can reach 9 level of accuracy.

  11. Consumer acceptance and aroma characterization of navy bean (Phaseolus vulgaris) powders prepared by extrusion and conventional processing methods.

    Science.gov (United States)

    Szczygiel, Edward J; Harte, Janice B; Strasburg, Gale M; Cho, Sungeun

    2017-09-01

    Food products produced with bean ingredients are gaining in popularity among consumers due to the reported health benefits. Navy bean (Phaseolus vulgaris) powder produced through extrusion can be considered as a resource-efficient alternative to conventional methods, which often involve high water inputs. Therefore, navy bean powders produced with extrusion and conventional methods were assessed for the impact of processing on consumer liking in end-use products and odor-active compounds. Consumer acceptance results reveal significant differences in flavor, texture and overall acceptance scores of several products produced with navy bean powder. Crackers produced with extruded navy bean powder received higher hedonic flavor ratings than those produced with commercial navy bean powder (P < 0.001). GC-O data showed that the commercial powder produced through conventional processing had much greater contents of several aliphatic aldehydes commonly formed via lipid oxidation, such as hexanal, octanal and nonanal with descriptors of 'grassy', 'nutty', 'fruity', 'dusty', and 'cleaner', compared to the extruded powder. Extrusion processed navy bean powders were preferred over commercial powders for certain navy bean powder applications. This is best explained by substantial differences in aroma profiles of the two powders that may have been caused by lipid oxidation. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  12. Extrusion-cooking to improve the animal feed quality of broad beans

    NARCIS (Netherlands)

    Moscicki, L.; Wojcik, S.; Plaur, K.; Zuilichem, van D.J.

    1984-01-01

    Extrusion-cooking of broad beans with a single-screw extruder has been investigated. Attention was focused on process requirements as well as on the nutritional effects of extrusion-cooked broad beans in a chicken feed formulation. The optimal thermal process conditions required for a product of

  13. Prediction of extrusion die wear by use of an artificial neural network

    International Nuclear Information System (INIS)

    Naidim, O.; Epureanu, A.; Tabacaru, V.

    2000-01-01

    In its vision of designing a technology, the process of optimisation of a material extrusion is an on-line process. The tool life is an important factor in selecting the objective function that represents the cost of the extruded product. This work is intended to realise the prediction of die wear evolution within the extrusion process, based on information obtained from numerical modelling. In order to reduce the number of experiments and to realise a flexible process of designing the necessary tools for an extrusion process, finite element (FE) modelling was used to determine designing space against the shape of the extruded product, the work conditions, the material and wear conditions. The information generated using FE was then used to train a neural network using backpropagation algorithm. Parameters considered in constructing neural networks include error tolerance, the factor of estimation of the 'best solution', the number of training cycles and the number of hidden layers. A general formula of calculus applicable in any extrusion process can be determined by establishing a relation between the stress state obtained within the extrusion process, deformation speed and friction on one hand, and wear on the other hand. The (1/W) parameter, where W is the tool wear in the active zone of the extrusion die, is a measure taken into account in calculating the die life as written in (1); this is the reason why it is important to make prediction of W value for geometries used in designing process or to optimise the die shape in order to reduce wear. (author)

  14. Functionality of extrusion--texturized whey proteins.

    Science.gov (United States)

    Onwulata, C I; Konstance, R P; Cooke, P H; Farrell, H M

    2003-11-01

    Whey, a byproduct of the cheesemaking process, is concentrated by processors to make whey protein concentrates (WPC) and isolates (WPI). Only 50% of whey proteins are used in foods. In order to increase their usage, texturizing WPC, WPI, and whey albumin is proposed to create ingredients with new functionality. Extrusion processing texturizes globular proteins by shearing and stretching them into aligned or entangled fibrous bundles. In this study, WPC, WPI, and whey albumin were extruded in a twin screw extruder at approximately 38% moisture content (15.2 ml/min, feed rate 25 g/min) and, at different extrusion cook temperatures, at the same temperature for the last four zones before the die (35, 50, 75, and 100 degrees C, respectively). Protein solubility, gelation, foaming, and digestibility were determined in extrudates. Degree of extrusion-induced insolubility (denaturation) or texturization, determined by lack of solubility at pH 7 for WPI, increased from 30 to 60, 85, and 95% for the four temperature conditions 35, 50, 75, and 100 degrees C, respectively. Gel strength of extruded isolates increased initially 115% (35 degrees C) and 145% (50 degrees C), but gel strength was lost at 75 and 100 degrees C. Denaturation at these melt temperatures had minimal effect on foaming and digestibility. Varying extrusion cook temperature allowed a new controlled rate of denaturation, indicating that a texturized ingredient with a predetermined functionality based on degree of denaturation can be created.

  15. Numerical investigations on the lateral angular co-extrusion of aluminium and steel

    Science.gov (United States)

    Behrens, B.-A.; Klose, C.; Chugreev, A.; Thürer, S. E.; Uhe, J.

    2018-05-01

    In order to save weight and costs, different materials can be combined within one component. In the novel process chain being developed within the Collaborative Research Centre (CRC) 1153, joined semi-finished workpieces are used to produce hybrid solid components with locally adapted properties. Different materials are joined in an initial step before the forming process takes place. Hereby, the quality of the joining zone is improved by means of the thermo-mechanical treatment during the forming and machining processes. The lateral angular co-extrusion (LACE) approach is used to produce semi-finished workpieces because it allows for the production of coaxial semi-finished products consisting of aluminium and steel. In the further process chain, these semi-finished products are processed into hybrid bearing bushings with locally adapted properties by die forging. In the scope of this work, numerical investigations of the co-extrusion of aluminium-steel compounds were carried out using finite element (FE) simulation in order to examine the influence of the process parameters on the co-extrusion process. For this purpose, the relevant material properties of the aluminium alloy EN AW-6082 were determined experimentally and subsequently implemented in the numerical model. The obtained numerical model was used to study the impact of different ram speeds, press ratios and billet temperatures on the resulting extrusion forces and the material flow. The numerical results have been validated using force-time curves obtained from experimental extrusion tests carried out on a 2.5 MN laboratory extrusion press.

  16. Single screw extrusion of apple pomace-enriched blends: Extrudate characteristics and determination of optimum processing conditions.

    Science.gov (United States)

    Singha, Poonam; Muthukumarappan, Kasiviswanathan

    2018-07-01

    Response surface methodology was used to investigate the single screw extrusion of apple pomace-defatted soy flour-corn grits blends and the product properties. Five different blends at a level of 0-20% w/w apple pomace were extrusion cooked with varied barrel and die temperature (100-140℃), screw speed (100-200 rpm), and feed moisture content (14-20% wet basis). Increasing apple pomace content in the blends significantly ( P extrudates. The expansion ratio increased with pomace inclusion level of 5% but decreased significantly ( P extruded snack products were at 140℃ barrel and die temperature, 20% feed moisture content, and 200 rpm screw speed. The results indicated active interaction between apple pomace and starch during expansion process.

  17. Machine for extrusion under vacuum

    International Nuclear Information System (INIS)

    Gautier, A.

    1958-01-01

    In a study of the behaviour of easily oxidised metals during the extrusion process, it is first necessary to find an effective mean of fighting corrosion, since this, even when barely detectable, has an important influence on the validity of the results recorded. The neatest and also the most efficient of all the methods tried consists in creating a vacuum around the test piece. Working on this principle, and at the same time respecting the conventional rules for extrusion tests (loading the sample after stabilisation at the testing temperature, differential measurements of lengthening, etc.) we found it necessary to construct an original machine. (author) [fr

  18. Cold Extrusion but Not Coating Affects Iron Bioavailability from Fortified Rice in Young Women and Is Associated with Modifications in Starch Microstructure and Mineral Retention during Cooking.

    Science.gov (United States)

    Hackl, Laura; Speich, Cornelia; Zeder, Christophe; Sánchez-Ferrer, Antoni; Adelmann, Horst; de Pee, Saskia; Tay, Fabian; Zimmermann, Michael B; Moretti, Diego

    2017-12-01

    Background: Rice can be fortified with the use of hot or cold extrusion or coating, but the nutritional qualities of the resulting rice grains have never been directly compared. Objective: Using fortified rice produced by coating or hot or cold extrusion, we compared 1 ) iron and zinc absorption with the use of stable isotopes, 2 ) iron and zinc retention during cooking, and 3 ) starch microstructure. Methods: We conducted 2 studies in young women: in study 1 [ n = 19; mean ± SD age: 26.2 ± 3.4 y; body mass index (BMI; in kg/m 2 ): 21.3 ± 1.6], we compared the fractional iron absorption (FAFe) from rice meals containing isotopically labeled ferric prophosphate ( 57 FePP), zinc oxide (ZnO), citric acid, and micronutrients fortified through hot extrusion (HER1) with rice meals fortified through cold extrusion containing 57 FePP, ZnO, citric acid, and micronutrients (CER); in study 2 ( n = 22; age: 24 ± 4 y; BMI: 21.2 ± 1.3), we compared FAFe and fractional zinc absorption (FAZn) from rice meals fortified through hot extrusion (HER2) compared with rice meals fortified through coating containing 57 FePP, ZnO, a citric acid and trisodium cirate mixture (CA/TSC), and micronutrients (COR) relative to rice meals extrinsically fortified with ferrous sulfate (reference). Rice types HER1 and CER contained citric acid, whereas types HER2 and COR contained CA/TSC. We assessed retention during standardized cooking experiments and characterized the rice starch microstructure. Results: FAFe (95% CI) was greater from CER [2.2% (1.4%, 3.4%)] than from HER1 [1.2% (0.7%, 2.0%)] ( P = 0.036). There was no difference in FAFe between HER2 [5.1% (3.7%, 7.1%)] and COR [4.0% (2.9%, 5.4%)] ( P = 0.14), but FAFe from COR was lower than that from the reference meal [6.6% (4.9%, 9.0%)] ( P = 0.003), and the geometric mean FAZn (95% CI) did not differ between HER2 [9.5% (7.9%, 11.6%)] and COR [9.6% (8.7%, 10.7%)] ( P = 0.92). Cooking in a rice-to-water ratio of 1:2 resulted in iron and zinc

  19. Consensus Control Design for 360 MN Extrusion Machine Producing Process

    Directory of Open Access Journals (Sweden)

    Chao Wang

    2014-01-01

    Full Text Available This paper mainly addresses the issue of 360 MN extrusion machine and focuses on the stabilization control of main table attitude. We will first introduce the problem and then model the extrusion machine. As the machine is a multi-input multioutput (MIMO and strong coupling system, it is challenging to apply existing control theory to design a controller to stabilize the main table attitude. Motivated by recent research in the field of multiagent systems, we design a consensus control protocol for our system and derive our convergence conditions based directly on Routh stability criterion. The advantages of the design are also demonstrated by numerical simulation.

  20. Magma extrusion during the Ubinas 2013–2014 eruptive crisis based on satellite thermal imaging (MIROVA) and ground-based monitoring

    Science.gov (United States)

    Coppola, Diego; Macedo, Orlando; Ramos, Domingo; Finizola, Anthony; Delle Donne, Dario; del Carpio, Jose; White, Randall A.; McCausland, Wendy; Centeno, Riky; Rivera, Marco; Apaza, Fredy; Ccallata, Beto; Chilo, Wilmer; Cigolini, Corrado; Laiolo, Marco; Lazarte, Ivonne; Machaca, Roger; Masias, Pablo; Ortega, Mayra; Puma, Nino; Taipe, Edú

    2015-01-01

    After 3 years of mild gases emissions, the Ubinas volcano entered in a new eruptive phase on September 2nd, 2013. The MIROVA system (a space-based volcanic hot-spot detection system), allowed us to detect in near real time the thermal emissions associated with the eruption and provided early evidence of magma extrusion within the deep summit crater. By combining IR data with plume height, sulfur emissions, hot spring temperatures and seismic activity, we interpret the thermal output detected over Ubinas in terms of extrusion rates associated to the eruption. We suggest that the 2013–2014 eruptive crisis can be subdivided into three main phases: (i) shallow magma intrusion inside the edifice, (ii) extrusion and growing of a lava plug at the bottom of the summit crater coupled with increasing explosive activity and finally, (iii) disruption of the lava plug and gradual decline of the explosive activity. The occurrence of the 8.2 Mw Iquique (Chile) earthquake (365 km away from Ubinas) on April 1st, 2014, may have perturbed most of the analyzed parameters, suggesting a prompt interaction with the ongoing volcanic activity. In particular, the analysis of thermal and seismic datasets shows that the earthquake may have promoted the most intense thermal and explosive phase that culminated in a major explosion on April 19th, 2014.These results reveal the efficiency of space-based thermal observations in detecting the extrusion of hot magma within deep volcanic craters and in tracking its evolution. We emphasize that, in combination with other geophysical and geochemical datasets, MIROVA is an essential tool for monitoring remote volcanoes with rather difficult accessibility, like those of the Andes that reach remarkably high altitudes.

  1. The friction influence on stress in micro extrusion

    Directory of Open Access Journals (Sweden)

    J. Piwnik

    2010-01-01

    Full Text Available Manufacturing of metallic parts by forming methods is industrially widespread due to high production rate, high accuracy, dimension’s and shape’s repeatability and good surface quality. The application of metal extrusion methods for the production of micro parts is possible, but there are some technological problems caused by small dimensions. Size effect is appearing. One of size effect symptom in micro extrusion, is a significant influence of rough contact between workpiece and tool while processing. In the case of rough contact without friction, material flows in the vicinity of the die surface. In order to explain more accurately a friction distribution in this area, the plastic wave friction model is proposed. This paper analyses specifications of a metal extrusion in micro scale. Using the friction model, a substitute friction shear factor mz and its influence on extrusion loading curves is determined in relationship to size of asperities.

  2. Quality by Design (QbD) Approach for Development of Co-Processed Excipient Pellets (MOMLETS) By Extrusion-Spheronization Technique.

    Science.gov (United States)

    Patel, Hetal; Patel, Kishan; Tiwari, Sanjay; Pandey, Sonia; Shah, Shailesh; Gohel, Mukesh

    2016-01-01

    Microcrystalline cellulose (MCC) is an excellent excipient for the production of pellets by extrusion spheronization. However, it causes slow release rate of poorly water soluble drugs from pellets. Co-processed excipient prepared by spray drying (US4744987; US5686107; WO2003051338) and coprecipitation technique (WO9517831) are patented. The objective of present study was to develop co-processed MCC pellets (MOMLETS) by extrusion-spheronization technique using the principle of Quality by Design (QbD). Co-processed excipient core pellets (MOMLETS) were developed by extrusion spheronization technique using Quality by Design (QbD) approach. BCS class II drug (telmisartan) was layered onto it in a fluidized bed processor. Quality Target Product Profile (QTPP) and Critical Quality Attributes (CQA) for pellets were identified. Risk assessment was reported using Ishikawa diagram. Plackett Burman design was used to check the effect of seven independent variables; superdisintegrant, extruder speed, ethanol: water, spheronizer speed, extruder screen, pore former and MCC: lactose; on percentage drug release at 30 min. Pareto chart and normal probability plot was constructed to identify the significant factors. Box-Behnken design (BBD) using three most significant factors (Extruder screen size, type of superdisintegrant and type of pore former) was used as an optimization design. The control space was identified in which desired quality of the pellets can be obtained. Co-processed excipient core pellets (MOMLETS) were successfully developed by QbD approach. Versatility, Industrial scalability and simplicity are the main features of the proposed research. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  3. Extrusion and properties of lead zirconate titanate piezoelectric ceramics

    DEFF Research Database (Denmark)

    Cai, S.; Millar, C.E.; Pedersen, L.

    1997-01-01

    The purpose of this work was to develop a procedure for fabricating electroceramic actuators with good piezoelectric properties. The preparation of lead zirconate titanate (PZT) piezoelectric ceramic rods and tubes by extrusion processing is described. The microstructure of extrudates was investi......The purpose of this work was to develop a procedure for fabricating electroceramic actuators with good piezoelectric properties. The preparation of lead zirconate titanate (PZT) piezoelectric ceramic rods and tubes by extrusion processing is described. The microstructure of extrudates...

  4. Inductive ingot heating for extrusion press applications; Induktive Bolzenerwaermung fuer Strangpressanwendungen

    Energy Technology Data Exchange (ETDEWEB)

    Beer, Stefan [I.A.S. Induktions-Anlagen + Service GmbH und Co. KG, Iserlohn (Germany)

    2013-03-15

    Inductive heating of large-format aluminium ingots on modern extrusion press lines generates significant process-engineering benefits. In addition, the proportion of special alloys processed is continuously increasing, accompanied simultaneously by ever smaller production batches, both of which are factors necessitating improvement of and greater flexibility in process-cycle control. This report examines a system concept recently commissioned on one of the world's largest aluminium extrusion presses. (orig.)

  5. A Taguchi approach on optimal process control parameters for HDPE pipe extrusion process

    Science.gov (United States)

    Sharma, G. V. S. S.; Rao, R. Umamaheswara; Rao, P. Srinivasa

    2017-06-01

    High-density polyethylene (HDPE) pipes find versatile applicability for transportation of water, sewage and slurry from one place to another. Hence, these pipes undergo tremendous pressure by the fluid carried. The present work entails the optimization of the withstanding pressure of the HDPE pipes using Taguchi technique. The traditional heuristic methodology stresses on a trial and error approach and relies heavily upon the accumulated experience of the process engineers for determining the optimal process control parameters. This results in setting up of less-than-optimal values. Hence, there arouse a necessity to determine optimal process control parameters for the pipe extrusion process, which can ensure robust pipe quality and process reliability. In the proposed optimization strategy, the design of experiments (DoE) are conducted wherein different control parameter combinations are analyzed by considering multiple setting levels of each control parameter. The concept of signal-to-noise ratio ( S/ N ratio) is applied and ultimately optimum values of process control parameters are obtained as: pushing zone temperature of 166 °C, Dimmer speed at 08 rpm, and Die head temperature to be 192 °C. Confirmation experimental run is also conducted to verify the analysis and research result and values proved to be in synchronization with the main experimental findings and the withstanding pressure showed a significant improvement from 0.60 to 1.004 Mpa.

  6. Effects of extrusion, infrared and microwave processing on Maillard reaction products and phenolic compounds in soybean.

    Science.gov (United States)

    Zilić, Slađana; Mogol, Burçe Ataç; Akıllıoğlu, Gül; Serpen, Arda; Delić, Nenad; Gökmen, Vural

    2014-01-15

    The Maillard reaction indicators furosine, hydroxymethylfurfural (HMF), acrylamide and color were determined to evaluate heat effects induced during extrusion, infrared and microwave heating of soybean. In addition, the present paper aimed to study changes in the phenolic compounds, as well as in the overall antioxidant properties of different soybean products in relation to heating at 45-140 °C during the processes. Soybean proteins were highly sensible to Maillard reaction and furosine was rapidly formed under slight heating conditions during extrusion and infrared heating. Microwave heating at lower temperatures for a longer time yielded lower acrylamide levels in the final soybean products, as a result of its partial degradation. However, during infrared heating, acrylamide formation greatly increased with decreasing moisture content. After a short time of extrusion and infrared heating at 140 °C and microwave heating at 135 °C for 5 min, concentrations of HMF increased to 11.34, 26.21 and 34.97 µg g(-1), respectively. The heating conditions caused formation of acrylamide, HMF and furosine in high concentration. The results indicate that the complex structure of soybeans provides protection of phenolic compounds from thermal degradation, and that Maillard reaction products improved the antioxidant properties of heat-treated soybean. © 2013 Society of Chemical Industry.

  7. Fatigue Behaviors of Materials Processed by Planar Twist Extrusion

    Science.gov (United States)

    Ebrahimi, Mahmoud

    2017-12-01

    Since the last decade, the fabrication of ultrafine grain and nanostructure metals and alloys has attracted much attention in the field of materials engineering. The present study aimed at experimentally investigating the fatigue properties that are of great importance in dynamic structures before and after the planar twist extrusion process for both commercially pure copper and 6061 aluminum alloy. The results indicated that the yield strength, tensile strength, hardness, and fatigue endurance of copper increased by about 398, 122, 198, and 183 pct, respectively, while they improved by about 429, 212, 227, and 148 pct, respectively, in aluminum alloy as compared to the initial conditions. The stress-strain curves displayed sizable reduction of strain hardening. Furthermore, grain-size correction factors based on the empirical results were introduced to include the effect of the grain-size effect on both low and high-cycle fatigue strengths of the material.

  8. Deformations in micro extrusion of metals

    Directory of Open Access Journals (Sweden)

    J. Piwnik

    2010-07-01

    Full Text Available Production technologies of small dimensions metallic elements are known for a long time. They are produced by machining methods:turning, milling, polishing. Recently, methods for manufacturing small details by forming are developed – microforming. This process ischaracterized by the high dimensions accuracy and the surface smoothness of received items and the high production rate. When a forming process is scaled down to micro dimensions, the microstructure of the workpiece, the surface topology of the workpiece and that of the tooling remain unchanged. Size effect is appearing. This paper analyses specifications of a metal extrusion in micro scale. To determine the impact of the tool surface roughness on deformation process the numerical model of roughness as triangle wave were developed. In paper the influence of the wave presence on the material flow is described. Impact of the forming conditions on extrusion forces there is also characterized.

  9. Microstructure and mechanical properties of Al-Mg-Si-Cu matrix composites reinforced with AINp. processed by extrusion of powders

    International Nuclear Information System (INIS)

    Ortiz, J. L.; Amigo, V.; Salvador, M. D.; Perz, C. R.

    2000-01-01

    This article presents an experimental investigation on the structure and mechanical properties of an Al-Mg-Si-Cu P/M alloy reinforced with 5%, 10% and 15% aluminum nitride, produced by extrusion of cold compacted powders mixtures. Mechanical properties in as extruded and T6 conditions are compared. Differential Scanning Calorimetry and Dilatometric analysis were conducted to gain further insight into the precipitation process of these materials. Low cost 6061 Al/AINp composites can be produced with rate and small porosity by extrusion of cold compacted shapes without canning. The mechanical properties of the MMCs obtained by this process have limitations for high particles fractions because of clustering effects. All materials are always harder than the matrix and shows a similar behavior during aging processes but kinetics is changed. Potential applications of dilatometric techniques in the aging investigations of aluminum alloys and aluminum matrix composites have been established. (Author) 23 refs

  10. Hydrodynamic modelling of hydrostatic magnesium extrusion

    NARCIS (Netherlands)

    Moodij, Ellen; de Rooij, Matthias B.; Schipper, Dirk J.

    2006-01-01

    Wilson’s hydrodynamic model of the hydrostatic extrusion process is extended to meet the geometry found on residual billets. The transition from inlet to work zone of the process is not considered sharp as in the model of Wilson but as a rounded edge, modelled by a parabolic function. It is shown

  11. Textural characteristics of ready-to-eat breakfast cereals produced from different types of cereal and with varying water addition during extrusion process

    Directory of Open Access Journals (Sweden)

    Žaneta Ugarčić-Hardi

    2010-01-01

    Full Text Available Textural characteristics of ready-to-eat breakfast cereals were evaluated in order to determine the influence of wheat, corn and rice flour, as well as a varying water addition during the extrusion process. Extruded breakfast cereal balls were made of wheat semolina in combination with wheat, corn or rice flour. Three different levels of water addition (21 %, 23 % and 27 % were used during the extrusion process. Samples were prepared with and without surface sugar coating. Sensory and instrumental assessments (TA.XT Plus were used to evaluate textural attributes of dry samples and samples during immersion in milk. Weibull equation was used for nonlinear estimation of experimental data obtained for milk absorption and crispiness as a function of time. Crispiness of dry extruded balls without coating was much higher than for samples with coating. The highest values for crispness were observed for wheat extruded balls and the lowest for samples with corn flour addition. Increasing water addition during the extrusion process significantly increased crispness of ready-to-eat breakfast cereals. The rate of milk absorption and loss of crispiness were significantly higher for samples without coating than for samples with coating.

  12. Hardness and microstructure homogeneity of pure copper processed by accumulative back extrusion

    International Nuclear Information System (INIS)

    Bazaz, B.; Zarei-Hanzaki, A.; Fatemi-Varzaneh, S.M.

    2013-01-01

    The present work deals with the microstructure evolution of a pure copper processed by a new severe plastic deformation method. A set of pure copper (99.99%) work-pieces with coarse-grained microstructures was processed by accumulative back extrusion (ABE) method at room temperature. The optical and scanning electron microscopy (SEM) and hardness measurements were utilized to study the microstructural evolution and hardness homogeneity. The results indicated that ABE is a capable process to provide a homogenous grain refined microstructure in pure copper. The observed grain refinement was discussed relying on the occurrence of dynamic restoration processes. The analysis of microstructure and hardness showed outstanding homogeneity improvement throughout the work-pieces as the consecutive ABE passes were applied. The homogeneity improvement was attributed to the propagation of the shear bands and also the heavily deformed regions. A reversing route was also applied in the ABE processing to investigate its effect on the development of microstructural homogeneity. Comparing to the conventional route, the application of the reversing route was found to yield better homogeneity after less passes of the process.

  13. Concept Feasibility Report for Using Co-Extrusion to Bond Metals to Complex Shapes of U-10Mo

    Energy Technology Data Exchange (ETDEWEB)

    Lavender, Curt A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Paxton, Dean M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Smith, Mark T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Soulami, Ayoub [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Joshi, Vineet V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Burkes, Douglas [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2013-12-01

    In support of the Convert Program of the U.S. Department of Energy’s National Nuclear Security Administration (DOE/NNSA) Global Threat Reduction Initiative (GTRI), Pacific Northwest National Laboratory (PNNL) has been investigating manufacturing processes for the uranium-10% molybdenum (U-10Mo) alloy plate fuel for the U.S. high-performance research reactors (USHPRR). This report documents the results of PNNL’s efforts to develop the extrusion process for this concept. The approach to the development of a co-extruded complex-shaped fuel has been described and an extrusion of DU-10Mo was made. The initial findings suggest that given the extrusion forces required for processing U-10Mo, the co-extrusion process can meet the production demands of the USHPRR fuel and may be a viable production method. The development activity is in the early stages and has just begun to identify technical challenges to address details such as dimensional tolerances and shape control. New extrusion dies and roll groove profiles have been developed and will be assessed by extrusion and rolling of U-10Mo during the next fiscal year. Progress on the development and demonstration of the co-extrusion process for flat and shaped fuel is reported in this document

  14. The FEM simulation of continuous rotary extrusion (CRE) of aluminum alloy AA3003

    Science.gov (United States)

    Rajendran, Nijenthan; Valberg, Henry; Misiolek, Wojciech Z.

    2017-10-01

    Continuous Rotary Extrusion (CRE) process is also known in literature under Conform TM name and it is mainly used for the continuous extrusion of Aluminum and Copper alloys. CRE use a feedstock in the form of rod, powders and chips, which are fed into the groove of the rotating wheel. As the wheel rotates the feedstock moves along with it due to friction with the wheel. Once the feedstock reaches the abutment the material deforms plastically and it is extruded through the die. CRE has lot to offer when compared to other more conventional extrusion processes such as low energy input, no limit in billet length as it is a continuous process as well as improved material physical properties due to plastic deformation under constant parameters. In this work a FEM model has been developed using Deform TM 3D, to study the metal flow and state variables of AA3003 CRE extrusion. The effect of extrusion wheel velocity has been investigated. The results show that increase in wheel velocity will heat up the feedstock metal due to high shear deformation and higher friction, which significantly changes metal flow conditions at the die exit.

  15. Experimental and finite element analyses of plastic deformation behavior in vortex extrusion

    International Nuclear Information System (INIS)

    Shahbaz, M.; Pardis, N.; Kim, J.G.; Ebrahimi, R.; Kim, H.S.

    2016-01-01

    Vortex extrusion (VE) is a single pass severe plastic deformation (SPD) technique which can impose high strain values with almost uniform distribution within cross section of the processed material. This technique needs no additional facilities for installation on any conventional extrusion equipment. In this study the deformation behavior of material during VE is investigated and the results are compared with those of conventional extrusion (CE). These investigations include finite element analysis, visioplasticity, and microstructural characterization of the processed samples. The results indicate that the VE process can accumulate a higher strain value by applying an additional torsional deformation. The role of this additional deformation mode on the microstructural evolution of the VE sample is discussed and compared with the results obtained on the CE samples.

  16. FINITE-ELEMENT MODELING OF HOT FORMING OF BUSHES MADE FROM HIGH-STRENGTH CAST IRON WITH A GRADIENT DISTRIBUTION OF GRAPHITE INCLUSIONS OVER CROSS-SECTION

    Directory of Open Access Journals (Sweden)

    A. I. Pokrovsky

    2016-01-01

    Full Text Available Imitation modeling of direct hot extrusion of bushes made from high-strength cast iron is performed using finite-element method. The evolution of stress and strain fields during processing and the probability of crack formation are evaluated. The specific feature of the work is that during hot forming a special technique was used which permitted obtaining a gradient distribution of graphite inclusions over the cross-section of bushes. The results of modeling are used in certain technologies which are implemented in industrial practice.

  17. Evaluation of advanced hot conditioning process for PHWRS

    International Nuclear Information System (INIS)

    Chandramohan, P.; Srinivasan, M.P.; Velmurugan, S.

    2015-01-01

    Hot-conditioning/hot functional test process is carried out to the PHT system of reactor before reactor going to critical/operational. The process is aimed in checking the component functionalities at high temperature and high pressure conditions, the process also checks/removes the suspended corrosion products in heat transport circuit. This process leads to formation of a passive or corrosion oxide film on the heat transport circuit surfaces which protects/mitigates the corrosion of the system circuits during the operation of plant. Major concerned alloy in the Primary Heat Transport (PHT) system of Indian PHWRs during the hot conditioning process and also during operation is the carbon steel due to its high corrosion. Hot-conditioning process mitigates the corrosion of carbon steel by the formation of iron oxide (Fe 3 O 4 ) as major oxide phase layer on the carbon steel surface with a typical thickness of 1.0 μm with particle size of 1μm after 336 h of process at 250 °C. But this passive oxide film thickness increase with time of operation of system with c.a. 10μm for 2.2 EFYP. The protectiveness of passive layer can be further enhanced by reducing the particle sizes in the passive film to nano meter range. The process can impact on the compactness of passive oxide layer with reduced pores in the oxide layer and properties of the nano nature oxide (transport properties) impacting the corrosion mitigation. The corrosion mitigation reduce the source term in the activated corrosion product generation. To achieve this a new process 'Advanced hot conditioning' was developed in water steam chemistry division, BARC for getting a passive oxide film with a lowered particle size in the passive film. The AHC process with 1g/L of PEG-8000 at 250 °C for 336 h showed a particle size <100 nm. The process was tested under the normal operating conditions as function of the time, the corrosion parameter like oxide film thickness, corrosion rate and metal ion

  18. Influence of hot rolling and high speed hydrostatic extrusion on the microstructure and mechanical properties of an ODS RAF steel

    Energy Technology Data Exchange (ETDEWEB)

    Oksiuta, Z., E-mail: oksiuta@pb.edu.pl [Bialystok Technical University, Faculty of Mechanical Engineering, Wiejska 45c, 15-352 Bialystok (Poland); Lewandowska, M.; Kurzydlowski, K.J. [Warsaw University of Technology, Faculty of Materials Science and Engineering, Woloska 141, 02-504 Warsaw (Poland); Baluc, N. [Ecole Polytechnique Federale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas, Association Euratom-Confederation Suisse, 5232 Villigen PSI (Switzerland)

    2011-02-15

    An argon gas atomized, pre-alloyed Fe-14Cr-2W-0.3Ti (wt.%) reduced activation ferritic (RAF) steel powder was mechanically alloyed with 0.3wt.% Y{sub 2}O{sub 3} nano-particles in an attritor ball mill and consolidated by hot isostatic pressing at 1150 {sup o}C under a pressure of 200 MPa for 3 h. In the aim to improve its mechanical properties the ODS steel was then submitted to a thermo-mechanical treatment (TMT): hot rolling (HR) at 850 deg. C or high speed hydrostatic extrusion (HSHE) at 900 deg. C, followed by heat treatment (HT). Transmission electron microscopy (TEM) observations of the ODS alloys after TMT and heat treatment revealed the presence of elongated grains in the longitudinal direction, with an average width of 8 {mu}m and an average length of 75 {mu}m, and equiaxed grains, a few microns in diameter, in the transverse direction. Two populations of oxide particles were observed by TEM: large Ti-Al-O particles, up to 250 nm in diameter, usually located at the grain boundaries and small Y-Ti-O nanoclusters, about 2.5 nm in diameter, uniformly distributed in the matrix. Charpy impact tests revealed that the HSHE material exhibits a larger upper shelf energy (5.8 J) than the HR material (2.9 J). The ductile-to-brittle transition temperature of both alloys is relatively high, in the range of 55-72 deg. C. Tensile mechanical properties of both ODS alloys were found satisfactory over the full range of investigated temperatures (23-750 deg. C). The HSHE material exhibits better tensile strength and ductility than the HR material. These results indicate that HSHE can be considered as a promising TMT method for improving the mechanical properties of ODS RAF steels.

  19. Experimental study on combined cold forging process of backward cup extrusion and piercing

    Science.gov (United States)

    Henry, Robinson; Liewald, Mathias

    2018-05-01

    A reduction in material usage of cold forged components while maintaining the functional requirements can be achieved using hollow or tubular preforms. These preforms are used to meet lightweight requirements and to decrease production costs of cold formed components. To increase production efficiency in common multi-stage cold forming processes, manufacturing of hollow preforms by combining the processes backward cup extrusion and piercing was established and will be discussed in this paper. Corresponding investigations and experimental studies are reported in this article. The objectives of the experimental investigations have been the detection of significant process parameters, determination of process limits for the combined processes and validation of the numerical investigations. In addition, the general influence concerning surface quality and diameter tolerance of hollow performs are discussed in this paper. The final goal is to summarize a guideline for industrial application, moreover, to transfer the knowledge to industry, as regards what are required part geometries to reduce the number of forming stages as well as tool cost.

  20. Dimensional accuracy of aluminium extrusions in mechanical calibration

    Science.gov (United States)

    Raknes, Christian Arne; Welo, Torgeir; Paulsen, Frode

    2018-05-01

    Reducing dimensional variations in the extrusion process without increasing cost is challenging due to the nature of the process itself. An alternative approach—also from a cost perspective—is using extruded profiles with standard tolerances and utilize downstream processes, and thus calibrate the part within tolerance limits that are not achievable directly from the extrusion process. In this paper, two mechanical calibration strategies for the extruded product are investigated, utilizing the forming lines of the manufacturer. The first calibration strategy is based on global, longitudinal stretching in combination with local bending, while the second strategy utilizes the principle of transversal stretching and local bending of the cross-section. An extruded U-profile is used to make a comparison between the two methods using numerical analyses. To provide response surfaces with the FEA program, ABAQUS is used in combination with Design of Experiment (DOE). DOE is conducted with a two-level fractional factorial design to collect the appropriate data. The aim is to find the main factors affecting the dimension accuracy of the final part obtained by the two calibration methods. The results show that both calibration strategies have proven to reduce cross-sectional variations effectively form standard extrusion tolerances. It is concluded that mechanical calibration is a viable, low-cost alternative for aluminium parts that demand high dimensional accuracy, e.g. due to fit-up or welding requirements.

  1. The comparative study of pressing and extrusion like processes of construction ceramic products in the Metropolitan Area of Cucuta; Estudio comparativo de las tecnicas de extrusion y prensado como procesos de conformado de productos ceramicos de construccion en el Area Metropolitana de Cucuta

    Energy Technology Data Exchange (ETDEWEB)

    Gelves, J. F.; Monroy, R.; Sanchez, J.; Ramirez, R. P.

    2013-02-01

    The present work studies the principal variables of control in the manufacturing process of construction pieces of the Metropolitan Area of San Jose de Cucuta by extrusion and pressing techniques for its forming. The investigation was taken out using clayey samples of the two principal geological formations of the region where the raw material is taken for processing at an industrial level. The clayey samples milling was made by dry means as well as by moisture means and its particle size was measured. Subsequently the forming process was taken over by using an hydraulic press and extruder with vacuum system , both equipment s at laboratory scale, the pieces shaped were dry and firing between 980 degree centigrade and 1180 degree centigrade at the end of the process the tests were made to determine water absorption, contraction and mass loss at the pieces firing. The study results left to see that the extrusion technique allowed a faster vitrification for the region's clay in comparing with the pressing technique, the contractions of drying and firing are less marked on the pressing techniques with standard deviations much lower than in extrusion. (Author) 13 refs.

  2. An investigation on diffusion bonding of aluminum to copper using equal channel angular extrusion process

    OpenAIRE

    Eslami, P.; Taheri, A. Karimi

    2011-01-01

    A new method for production of bimetallic rods, utilizing the equal channel angular extrusion (ECAE) process has been introduced before by previous researchers, but no attempt has been made to assess the effect of different temperatures and holding times in order to achieve a diffusional bond between the mating surfaces. In present research copper sheathed aluminum rods have been ECAEed at room temperature and subsequently held at a constant ECAE pressure, at different temperatures and holdin...

  3. Processing of Polypropylene-Organic Montmorillonite Nanocomposite by Equal Channel Multiangular Extrusion

    Directory of Open Access Journals (Sweden)

    V. A. Beloshenko

    2016-01-01

    Full Text Available By the example of polypropylene-organic montmorillonite composite (PP-OMMT, the abilities of the method of equal channel multiangular extrusion have been studied with respect to the modification of the structure and the properties of polymeric nanocomposites. With using X-ray structure analysis, TEM, DSC, and dilatometry, it has been demonstrated that this kind of processing provides an additional intercalation of the polymer into OMMT tactoids with the succeeding exfoliation and facilitates an increase in the aspect ratio, the degree of platelet orientation, the crystalline lamellar thickness, and a decrease in the dispersion of the crystallite thickness, as well as the formation of biaxial orientation of the OMMT and PP crystals. The observed structure rearrangements determine enhanced microhardness, ductility, and the heat distortion temperature of the PP-OMMT composite.

  4. Suitability of the Yield Criterion in Numerical Simulation of Stretch Bending of Aluminum Extrusions

    International Nuclear Information System (INIS)

    Li, X.Q.; Zhou, X.B.; Wu, X.D.; Gao, H.Z.

    2005-01-01

    Stretch bending is commonly used to shape thin-walled extrusions in aerospace and automotive industries. The extrusions are pre-stretched and bent over rigid curved dies. Effective application of this process demands sufficient knowledge of how different parameters influence the final shape of the product. Numerical simulation is an effective approach to investigate these issues presently. However, the validity of simulation result depends strongly on a precise description of the mechanical behavior of the material. Due to crystallographic texture caused by the extrusion process, aluminium extrusions exhibit significant plastic anisotropy which need be described by advanced constitutive model. In this work stretch bending of aluminum extrusions is simulated by using different anisotropic criteria (Hill quadratic, Barlat three-parameter). The influence of two yield criteria on predicting maximum die force immediately before unloading, permanent sagging and vertical springback displacement in the middle section of extrusion are compared. Maximum die force and springback calculated by two yield criteria are found to be almost same. Permanent sagging is obviously underestimated by two yield criteria, however, prediction by Barlat three-parameter is closer to experiment than one of Hill quadratic yield criterion

  5. Preparation and evaluation of enteric coated tablets of hot-melt extruded lansoprazole.

    Science.gov (United States)

    Alsulays, Bader B; Kulkarni, Vijay; Alshehri, Sultan M; Almutairy, Bjad K; Ashour, Eman A; Morott, Joseph T; Alshetaili, Abdullah S; Park, Jun-Bom; Tiwari, Roshan V; Repka, Michael A

    2017-05-01

    The objective of this work was to use hot-melt extrusion (HME) technology to improve the physiochemical properties of lansoprazole (LNS) to prepare stable enteric coated LNS tablets. For the extrusion process, we chose Kollidon ® 12 PF (K12) polymeric matrix. Lutrol ® F 68 was selected as the plasticizer and magnesium oxide (MgO) as the alkalizer. With or without the alkalizer, LNS at 10% drug load was extruded with K12 and F68. LNS changed to the amorphous phase and showed better release compared to that of the pure crystalline drug. Inclusion of MgO improved LNS extrudability and release and resulted in over 80% drug release in the buffer stage. Hot-melt extruded LNS was physically and chemically stable after 12 months of storage. Both formulations were studied for compatibility with Eudragit ® L100-55. The optimized formulation was compressed into a tablet followed by coating process utilizing a pan coater using L100-55 as an enteric coating polymer. In a two-step dissolution study, the release profile of the enteric coated LNS tablets in the acidic stage was less than 10% of the LNS, while that in the buffer stage was more than 80%. Drug content analysis revealed the LNS content to be 97%, indicating the chemical stability of the enteric coated tablet after storage for six months. HME, which has not been previously used for LNS, is a valuable technique to reduce processing time in the manufacture of enteric coated formulations of an acid-sensitive active pharmaceutical ingredient as compared to the existing methods.

  6. Physical processes in hot cosmic plasmas

    International Nuclear Information System (INIS)

    Fabian, A.G.; Giovannelli, F.

    1990-01-01

    The interpretation of many high energy astrophysical phenomena relies on a detailed knowledge of radiation and transport processes in hot plasmas. The understanding of these plasma properties is one of the aims of terrestrial plasma physics. While the microscopic properties of astrophysical plasmas can hardly be determined experimentally, laboratory plasmas are more easily accessible to experimental techniques, but transient phenomena and the interaction of the plasma with boundaries often make the interpretation of measurements cumbersome. This book contains the talks given at the NATO Advanced Research Workshop on astro- and plasma-physics in Vulcano, Sicily, May 29-June 2, 1989. The book focuses on three main areas: radiation transport processes in hot (astrophysical and laboratory) plasmas; magnetic fields; their generation, reconnection and their effects on plasma transport properties; relativistic and ultra-high density plasmas

  7. FEM simulation of friction testing method based on combined forward rod-backward can extrusion

    DEFF Research Database (Denmark)

    Nakamura, T; Bay, Niels; Zhang, Z. L

    1997-01-01

    A new friction testing method by combined forward rod-backward can extrusion is proposed in order to evaluate frictional characteristics of lubricants in forging processes. By this method the friction coefficient mu and the friction factor m can be estimated along the container wall and the conical...... curves are obtained by rigid-plastic FEM simulations in a combined forward rod-backward can extrusion process for a reduction in area R-b = 25, 50 and 70 percent in the backward can extrusion. It is confirmed that the friction factor m(p) on the punch nose in the backward cart extrusion has almost...... in a mechanical press with aluminium alloy A6061 as the workpiece material and different kinds of lubricants. They confirm the analysis resulting in reasonable values for the friction coefficient and the friction factor....

  8. Melting, casting, and alpha-phase extrusion of the uranium-2.4 weight percent niobium alloy

    International Nuclear Information System (INIS)

    Anderson, R.C.; Beck, D.E.; Kollie, T.G.; Zorinsky, E.J.; Jones, J.M.

    1981-10-01

    The experimental details of the melting, casting, homogenization, and alpha-phase extrusion process used to fabricate the uranium-2.4 wt % niobium alloy into 46-mm-diameter rods is described. Extrusion defects that were detected by an ultrasonic technique were eliminated by proper choice of extrusion parameters; namely, reduction ratio, ram speed, die angle, and billet preheat temperature

  9. Coupled analysis of material flow and die deflection in direct aluminum extrusion

    NARCIS (Netherlands)

    Assaad, W.; Geijselaers, Hubertus J.M.

    2010-01-01

    The design of extrusion dies depends on the experience of the designer. After the die has been manufactured, it is tested during an extrusion trial and machined several times until it works properly. The die is designed by a trial and error method which is an expensive process in terms of time and

  10. Optimization of extrusion process for production of nutritious pellets Otimização do processo de extrusão para a produção de pellets nutricional

    Directory of Open Access Journals (Sweden)

    Ernesto Aguilar-Palazuelos

    2012-03-01

    Full Text Available A blend of 50% Potato Starch (PS, 35% Quality Protein Maize (QPM, and 15% Soybean Meal (SM were used in the preparation of expanded pellets utilizing a laboratory extruder with a 1.5 × 20.0 × 100.0 mm die-nozzle. The independent variables analyzed were Barrel Temperature (BT (75-140 °C and Feed Moisture (FM (16-30%. The effect of extrusion variables was investigated in terms of Expansion Index (EI, apparent density (ApD, Penetration Force (PF and Specific Mechanical Energy (SME, viscosity profiles, DSC, crystallinity by X-ray diffraction, and Scanning Electronic Microscopy (SEM. The PF decreased from 30 to 4 kgf with the increase of both independent variables (BT and FM. SME was affected only by FM, and decreased with the increase in this variable. The optimal region showed that the maximum EI was found for BT in the range of 123-140 °C and 27-31% for FM, respectively. The extruded pellets obtained from the optimal processing region were probably not completely degraded, as shown in the structural characterization. Acceptable expanded pellets could be produced using a blend of PS, QPM, and SM by extrusion cooking.Neste trabalho foram elaborados pellets expandidos a partir da mistura de 50% de Amido de Batata (AB, 35% de Milho de Qualidade Protéica (MQP e 15% de Farelo de Soja (FS, utilizando extrusor de laboratório com matriz de 1,5 × 20,0 × 100,0 mm. As variáveis independentes analisadas foram: Temperatura de Extrusão (TE (75-140 °C e Umidade da Mistura (UM (16-30%. O efeito das variáveis de extrusão foram estudadas quanto ao Índice de Expansão (IE, a densidade aparente (DA, força de penetração (FP, Energia Mecânica Específica (EME, perfil de viscosidade, DSC, cristalinidade através de difração de raio X e Microscopia Eletrônica de Varredura (MEV. A PF diminuiu de 30 para 4 kgf com o aumento de ambas as variáveis independentes (TE e UM. EME foi afetada somente pela UM, diminuindo com o aumento desta variável. A regi

  11. 75 FR 80527 - Aluminum Extrusions From China

    Science.gov (United States)

    2010-12-22

    ...)] Aluminum Extrusions From China AGENCY: United States International Trade Commission. ACTION: Scheduling of... of subsidized and less-than-fair-value imports from China of aluminum extrusions, primarily provided... contained in Aluminum Extrusions From the People's Republic of China: Notice of Preliminary Determination of...

  12. Fluid Structure Interaction Techniques For Extrusion And Mixing Processes

    Science.gov (United States)

    Valette, Rudy; Vergnes, Bruno; Coupez, Thierry

    2007-05-01

    This work focuses on the development of numerical techniques devoted to the simulation of mixing processes of complex fluids such as twin-screw extrusion or batch mixing. In mixing process simulation, the absence of symmetry of the moving boundaries (the screws or the rotors) implies that their rigid body motion has to be taken into account by using a special treatment We therefore use a mesh immersion technique (MIT), which consists in using a P1+/P1-based (MINI-element) mixed finite element method for solving the velocity-pressure problem and then solving the problem in the whole barrel cavity by imposing a rigid motion (rotation) to nodes found located inside the so called immersed domain, each sub-domain (screw, rotor) being represented by a surface CAD mesh (or its mathematical equation in simple cases). The independent meshes are immersed into a unique background computational mesh by computing the distance function to their boundaries. Intersections of meshes are accounted for, allowing to compute a fill factor usable as for the VOF methodology. This technique, combined with the use of parallel computing, allows to compute the time-dependent flow of generalized Newtonian fluids including yield stress fluids in a complex system such as a twin screw extruder, including moving free surfaces, which are treated by a "level set" and Hamilton-Jacobi method.

  13. Embedded Multimaterial Extrusion Bioprinting.

    Science.gov (United States)

    Rocca, Marco; Fragasso, Alessio; Liu, Wanjun; Heinrich, Marcel A; Zhang, Yu Shrike

    2018-04-01

    Embedded extrusion bioprinting allows for the generation of complex structures that otherwise cannot be achieved with conventional layer-by-layer deposition from the bottom, by overcoming the limits imposed by gravitational force. By taking advantage of a hydrogel bath, serving as a sacrificial printing environment, it is feasible to extrude a bioink in freeform until the entire structure is deposited and crosslinked. The bioprinted structure can be subsequently released from the supporting hydrogel and used for further applications. Combining this advanced three-dimensional (3D) bioprinting technique with a multimaterial extrusion printhead setup enables the fabrication of complex volumetric structures built from multiple bioinks. The work described in this paper focuses on the optimization of the experimental setup and proposes a workflow to automate the bioprinting process, resulting in a fast and efficient conversion of a virtual 3D model into a physical, extruded structure in freeform using the multimaterial embedded bioprinting system. It is anticipated that further development of this technology will likely lead to widespread applications in areas such as tissue engineering, pharmaceutical testing, and organs-on-chips.

  14. Improvement of mechanical properties and corrosion resistance of biodegradable Mg-Nd-Zn-Zr alloys by double extrusion

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xiaobo, E-mail: xbxbzhang2003@163.com [School of Materials Science and Engineering, Nanjing Institute of Technology, Nanjing, 211167 (China); Wang, Zhangzhong [School of Materials Science and Engineering, Nanjing Institute of Technology, Nanjing, 211167 (China); Yuan, Guangyin [National Engineering Research Center of Light Alloy Net Forming, Shanghai Jiao Tong University, Shanghai, 200240 (China); Xue, Yajun [School of Materials Science and Engineering, Nanjing Institute of Technology, Nanjing, 211167 (China)

    2012-08-01

    Highlights: Black-Right-Pointing-Pointer Microstructure of Mg-Nd-Zn-Zr alloys was refined and homogenized by double extrusion process. Black-Right-Pointing-Pointer The mechanical properties of the alloys were significantly enhanced by double extrusion. Black-Right-Pointing-Pointer The biocorrosion resistance of the alloys was improved by double extrusion. - Abstract: Mg-Nd-Zn-Zr alloy is a novel and promising biodegradable magnesium alloy due to good biocompatibility, desired uniform corrosion mode and outstanding corrosion resistance in simulated body fluid (SBF). However, the corrosion resistance and mechanical properties should be improved to meet the requirement of the biodegradable implants, such as plates, screws and cardiovascular stents. In the present study, double extrusion process was adopted to refine microstructure and improve mechanical properties of Mg-2.25Nd-0.11Zn-0.43Zr and Mg-2.70Nd-0.20Zn-0.41Zr alloys. The corrosion resistance of the alloys after double extrusion was also studied. The results show that the microstructure of the alloys under double extrusion becomes much finer and more homogeneous than those under once extrusion. The yield strength, ultimate tensile strength and elongation of the alloys under double extrusion are over 270 MPa, 300 MPa and 32%, respectively, indicating that outstanding mechanical properties of Mg-Nd-Zn-Zr alloy can be obtained by double extrusion. The results of immersion experiment and electrochemical measurements in SBF show that the corrosion resistance of Alloy 1 and Alloy 2 under double extrusion was increased by 7% and 8% respectively compared with those under just once extrusion.

  15. Improvement of mechanical properties and corrosion resistance of biodegradable Mg–Nd–Zn–Zr alloys by double extrusion

    International Nuclear Information System (INIS)

    Zhang, Xiaobo; Wang, Zhangzhong; Yuan, Guangyin; Xue, Yajun

    2012-01-01

    Highlights: ► Microstructure of Mg–Nd–Zn–Zr alloys was refined and homogenized by double extrusion process. ► The mechanical properties of the alloys were significantly enhanced by double extrusion. ► The biocorrosion resistance of the alloys was improved by double extrusion. - Abstract: Mg–Nd–Zn–Zr alloy is a novel and promising biodegradable magnesium alloy due to good biocompatibility, desired uniform corrosion mode and outstanding corrosion resistance in simulated body fluid (SBF). However, the corrosion resistance and mechanical properties should be improved to meet the requirement of the biodegradable implants, such as plates, screws and cardiovascular stents. In the present study, double extrusion process was adopted to refine microstructure and improve mechanical properties of Mg–2.25Nd–0.11Zn–0.43Zr and Mg–2.70Nd–0.20Zn–0.41Zr alloys. The corrosion resistance of the alloys after double extrusion was also studied. The results show that the microstructure of the alloys under double extrusion becomes much finer and more homogeneous than those under once extrusion. The yield strength, ultimate tensile strength and elongation of the alloys under double extrusion are over 270 MPa, 300 MPa and 32%, respectively, indicating that outstanding mechanical properties of Mg–Nd–Zn–Zr alloy can be obtained by double extrusion. The results of immersion experiment and electrochemical measurements in SBF show that the corrosion resistance of Alloy 1 and Alloy 2 under double extrusion was increased by 7% and 8% respectively compared with those under just once extrusion.

  16. Influence of extrusion-cooking parameters on some quality aspects of precooked pasta-like products.

    Science.gov (United States)

    Wójtowicz, A; Mościcki, L

    2009-06-01

    The present article aims to evaluate some quality parameters and texture characteristics of precooked wheat pasta-like products. Using the methods for pasta and instant noodles the tested parameters were water absorption, starch gelatinization degree, cooking losses, and hardness. The texture profile was characterized using Zwick apparatus by cutting test with the head speed of 10 mm/min and expressed as hardness and firmness of hydrated products. SEM pictures were used to illustrate the internal structure of dry and cooked pasta-like products. Dough moisture content and process conditions influenced all tested quality parameters of the pasta-like products processed on a modified single screw extrusion-cooker TS-45 with L: D = 16: 1. Good organoleptical quality (notes higher than 4 in a 5-point scale) and firm texture were observed for common wheat flour pasta processed at 30% m.c. Hardness and firmness of hydrated products lowered with a longer hydration time in hot water. The firmest texture and low stickiness was observed for products with a highest starch gelatinization degree.

  17. Metal extrusion using hydrostatic pressures; Le filage des metaux sous pression hydrostatique

    Energy Technology Data Exchange (ETDEWEB)

    Sauve, Ch [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1965-07-01

    The main problems connected with the deformation of metals due to extrusion are described. A method is put forward for calculating the rational rate of percentage deformation in the case of bar extrusion using a cylindrical container; reference is made to previous work on extrusion using a hydrostatic pressure with or without back-pressure. An extrusion process is described using hydrostatic pressure, without back-pressure, and using the lubricant for transmitting the thrust. This process has been used for eight years by the C.E.A. for the extrusion of a very wide range of metals, from beryllium to uranium and including steels; it leads to excellent surface textures. A very fine crystallization can be obtained on extruded products when the rate of extrusion is very low. There appears to be nothing against the use of high extrusion rates using this method. (author) [French] On expose les problemes generaux lies a la deformation des metaux par filage. On propose un calcul de la vitesse rationnelle de deformation pour cent dans le cas du filage de barres a partir d'un conteneur cylindrique, et l'on cite les travaux anterieurs sur le filage par faction d'une pression hydrostatique sans ou avec une contre-pression. On decrit un procede de filage par l'action d'une pression hydrostatique, sans contre-pression, utilisant le lubrifiant pour transmettre la poussee. Ce procede employe depuis 8 ans au C.E.A. pour filer les metaux les plus divers, depuis le beryllium jusqu'a l'uranium en passant par les aciers, permet d'obtenir d'excellents etats de surface. Une cristallisation tres fine peut etre obtenue sur les produits files lorsque le filage est tres lent. Rien ne parait s'opposer a ce que des filages rapides soient effectues avec cette methode. (auteur)

  18. A brief review of extrusion-based tissue scaffold bio-printing.

    Science.gov (United States)

    Ning, Liqun; Chen, Xiongbiao

    2017-08-01

    Extrusion-based bio-printing has great potential as a technique for manipulating biomaterials and living cells to create three-dimensional (3D) scaffolds for damaged tissue repair and function restoration. Over the last two decades, advances in both engineering techniques and life sciences have evolved extrusion-based bio-printing from a simple technique to one able to create diverse tissue scaffolds from a wide range of biomaterials and cell types. However, the complexities associated with synthesis of materials for bio-printing and manipulation of multiple materials and cells in bio-printing pose many challenges for scaffold fabrication. This paper presents an overview of extrusion-based bio-printing for scaffold fabrication, focusing on the prior-printing considerations (such as scaffold design and materials/cell synthesis), working principles, comparison to other techniques, and to-date achievements. This paper also briefly reviews the recent development of strategies with regard to hydrogel synthesis, multi-materials/cells manipulation, and process-induced cell damage in extrusion-based bio-printing. The key issue and challenges for extrusion-based bio-printing are also identified and discussed along with recommendations for future, aimed at developing novel biomaterials and bio-printing systems, creating patterned vascular networks within scaffolds, and preserving the cell viability and functions in scaffold bio-printing. The address of these challenges will significantly enhance the capability of extrusion-based bio-printing. Copyright © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Physical simulation method for the investigation of weld seam formation during the extrusion of aluminum alloys

    NARCIS (Netherlands)

    Fang, G; Zhou, J.

    2017-01-01

    Extrusion through the porthole die is a predominant forming process used in the production of hollow aluminum alloy profiles across the aluminum extrusion industry. Longitudinal weld seams formed during the process may negatively influence the quality of extruded profiles. It is therefore of

  20. An investigation into the effect of equal channel angular extrusion process on mechanical and microstructural properties of middle layer in copper clad aluminum composite

    International Nuclear Information System (INIS)

    Tolaminejad, B.; Karimi Taheri, A.; Arabi, H.; Shahmiri, M.

    2009-01-01

    Equal channel angular extrusion is a promising technique for production of ultra fine-grain materials of few hundred nanometers size. In this research, the grain refinement of aluminium strip is accelerated by sandwiching it between two copper strips and then subjecting the three strips to Equal channel angular extrusion process simultaneously. The loosely packed copper-aluminium-copper laminated billet was passed through Equal channel angular extrusion die up to 8 passes using the Bc route. Then, tensile properties and some microstructural characteristics of the aluminium layer were evaluated. The scanning and transmission electron microscopes, and X-ray diffraction were used to characterize the microstructure. The results show that the yield stress of middle layer (Al) is increased significantly by about four times after application of Equal channel angular extrusion throughout the four consecutive passes and then it is slightly decreased when more Equal channel angular extrusion passes are applied. An ultra fine grain within the range of 500 to 600 nm was obtained in the Al layer by increasing the thickness of the copper layers. lt was observed that the reduction of grain size in the aluminium layer is nearly 55% more than that of a equal channel angular-extruded single layer aluminium billet, i.e. extruding a single aluminium strip or a billet without any clad for the same amount of deformation. This behaviour was attributed to the higher rates of dislocations interaction and cell formation and texture development during the Equal channel angular extrusion of the laminated composite compared to those of a single billet.

  1. KINETICS PROCESSES OF DEHYDRATION AND HEATING FISH DURING FRYING, DURING SEMI HOT AND HOT SMOKING

    Directory of Open Access Journals (Sweden)

    V. A. Pokholchenko

    2014-01-01

    Full Text Available Summary. Calculated methods of graphing of curves for kinetics of dehydration and fish heating during the processes of frying, semi hot smoking and hot smoking have been developed. The offered methods of calculating are based on the basic regularities of heat and mass exchanges of these processes. Based on the research of the regularities of dehydration on the kinetic curves, critical points were identified, that characterize the transition from the moisture removal with lower energy of its bond with material to the removal of one with higher energy bond, also the influence of the product shrinkage on the velocity of the moisture removal. These points are characteristic for the temperature curves as well. It’s suggested for the temperature curve to be replaced by broken line that consists of three straight lines that are crossing in points, corresponded with the critical moistures and critical temperatures. Significant amount of the experimental material of the research of the kinetics of dehydration and fish heating under different modes is shown by authors in the form of generalized dependencies. The method allows modeling the processes of heating and dehydrating of fish and choosing the most rational modes based on the calculated data. The proposed technique makes it possible to construct the curves of the kinetics of heating and dehydration kinetics in processes of roasting, semi hot and hot smoked fish, which allows to optimize a particular process, design more efficient in terms of consumption of raw materials and energy technology, as well as to create better machines or upgrade existing equipment into account the relationship of heat and mass transfer processes.

  2. Development of a simulation tool to analyze the orientation of LCPs during extrusion process

    Science.gov (United States)

    Ahmadzadegan, Arash

    In this thesis, different aspects of the rheology and directionality of the liquid crystalline polymers (LCPs) are investigated. The rheology of LCPs are modeled with different rheological models in different die geometries. The final goal in modeling the rheology and directionality of LCPs is to have a better understanding of their rheology during extrusion processing methods inside extrusion dies and eventually produce more isotropic films of LCPs. An attempt to design a die geometry that produces more isotropic films was made and it was shown that it is possible to use the inertia of the polymer to generate a more isotropic velocity profile at the lip of the die. This isotropic velocity profile can lead to alignment of directors along the streamlines and produce an isotropic film of LCP. It is shown that the rheological properties of the LCP should be altered to have a very low viscosity for this type of die to work. To be able to investigate the effect of processing on directionality of LCPs, it is essential to develop a method to simulate the directionality based on processing conditions. As a result, a user defined function (UDF) code was added to ANSYSRTM ~FLUENTRTM~ to simulate the directionality of LCPs. The rheology of the LCP is modeled using power-law fluid model and the consistency index (K) and power-law index (n) were estimated based on the experimental measurements done with capillary rheometry. Three main phenomena that affect the directionality namely effects of Franks elastic energy, the effect of shear and the effect of movement of crystals with the bulk of polymer are investigated. The results of this simulation are close to physical phenomena seen in real LCPs. To quantify the directionality of the LCPs, the order parameter of the domain were calculated and compared for different flow and fluid conditions. All polymers including LCPs are viscoelastic fluids in molten state. To understand the rheology of LCPs, a die-swell experiment was carried

  3. THE IMPACT OF EXTRUSION ON THE BIOGAS AND BIOMETHANE YIELD OF PLANT SUBSTRATES

    Directory of Open Access Journals (Sweden)

    Krzysztof Pilarski

    2016-09-01

    Full Text Available The objective of the present work was to determine the effect of pretreatment by extrusion on the biogas and biomethane yield of lignocellulosic substrates such as maize silage and maize straw silage. The biogas yields of the substrates before and after treatment were compared. Moreover, energy efficiency of pretreatment by extrusion was analyzed in order to assess the applicability of the process in an agricultural biogas plant. Extrusion tests were carried out in a short single-screw extruder KZM-2 in which the length-to-diameter ratio of the screw was 6:1 and rotational speed was 200 rpm. The biogas yield tests of the plant substrates after extrusion were carried out in a laboratory scale, using 15 biofermenters operated in a periodic manner, at a constant temperature of 39°C (mesophilic digestion and controlled pH conditions. The gas-emission analysis was performed using a certified gas analyzer from Geotech GA5000. Pretreatment by extrusion was observed to improve the quantity of methane generated: in terms of fresh matter for maize silage subjected to extrusion, the methane yield was 16.48% higher than that of the non-extruded silage. On the other hand, maize straw silage after extrusion gave 35.30% more methane than did the same, non-extruded, material. Differences in yields relative to dry organic matter are also described in this paper. Taking into account the amount of energy that is spent on pretreatment and the generated amount of methane, the energy balance for the process gives an idea of the economics of the operation. For maize silage, energy efficiency was lower by 13.21% (-553.2 kWh/Mg, in contrast to maize straw silage, where the increase in energy was 33.49% (678.4 kWh/Mg. The obtained results indicate that more studies on the pretreatment and digestion of maize silage are required in order to improve the efficiency of its use for making biogas. To fully utilize its potential, it is necessary to know thoroughly the effect of

  4. Microstructure Evolution in Mg-Zn-Zr-Gd Biodegradable Alloy: The Decisive Bridge Between Extrusion Temperature and Performance.

    Science.gov (United States)

    Yao, Huai; Wen, Jiu-Ba; Xiong, Yi; Lu, Yan; Huttula, Marko

    2018-01-01

    Being a biocompatible metal with similar mechanical properties as bones, magnesium bears both biodegradability suitable for bone substitution and chemical reactivity detrimental in bio-ambiences. To benefit its biomaterial applications, we developed Mg-2.0Zn-0.5Zr-3.0Gd (wt%) alloy through hot extrusion and tailored its biodegradability by just varying the extrusion temperatures during alloy preparations. The as-cast alloy is composed of the α-Mg matrix, a network of the fish-bone shaped and ellipsoidal (Mg, Zn) 3 Gd phase, and a lamellar long period stacking ordered phase. Surface content of dynamically recrystallized (DRXed) and large deformed grains increases within 330-350°C of the extrusion temperature, and decreases within 350-370°C. Sample second phase contains the (Mg, Zn) 3 Gd nano-rods parallel to the extrusion direction, and Mg 2 Zn 11 nanoprecipitation when temperature tuned above 350°C. Refining microstructures leads to different anticorrosive ability of the alloys as given by immersion and electrochemical corrosion tests in the simulated body fluids. The sample extruded at 350°C owns the best anticorrosive ability thanks to structural impacts where large DRXed portions and uniform nanosized grains reduce chemical potentials among composites, and passivate the extruded surfaces. Besides materials applications, the in vitro mechanism revealed here is hoped to inspire similar researches in biometal developments.

  5. Microstructure evolution in Mg-Zn-Zr-Gd biodegradable alloy: the decisive bridge between extrusion temperature and performance

    Science.gov (United States)

    Yao, Huai; Wen, Jiu-Ba; Xiong, Yi; Lu, Yan; Huttula, Marko

    2018-03-01

    Being a biocompatible metal with similar mechanical properties as bones, magnesium bears both biodegradability suitable for bone substitution and chemical reactivity detrimental in bio-ambiences. To benefit its biomaterial applications, we developed Mg-2.0Zn-0.5Zr-3.0Gd (wt%) alloy through hot extrusion and tailored its biodegradability by just varying the extrusion temperatures during alloy preparations. The as-cast alloy is composed of the α-Mg matrix, a network of the fish-bone shaped and ellipsoidal (Mg, Zn)3Gd phase, and a lamellar long period stacking ordered phase. Surface content of dynamically recrystallized (DRXed) and large deformed grains increases within 330-350 C of the extrusion temperature, and decreases within 350-370 C. Sample second phase contains the (Mg, Zn)3Gd nano-rods parallel to the extrusion direction, and Mg2Zn11 nanoprecipitation when temperature tuned above 350 C. Refining microstructures leads to different anticorrosive ability of the alloys as given by immersion and electrochemical corrosion tests in the simulated body fluids. The sample extruded at 350 C owns the best anticorrosive ability thanks to structural impacts where large DRXed portions and uniform nanosized grains reduce chemical potentials among composites, and passivate the extruded surfaces. Besides materials applications, the in vitro mechanism revealed here is hoped to inspire similar researches in biometal developments.

  6. Microstructure Evolution in Mg-Zn-Zr-Gd Biodegradable Alloy: The Decisive Bridge Between Extrusion Temperature and Performance

    Directory of Open Access Journals (Sweden)

    Huai Yao

    2018-03-01

    Full Text Available Being a biocompatible metal with similar mechanical properties as bones, magnesium bears both biodegradability suitable for bone substitution and chemical reactivity detrimental in bio-ambiences. To benefit its biomaterial applications, we developed Mg-2.0Zn-0.5Zr-3.0Gd (wt% alloy through hot extrusion and tailored its biodegradability by just varying the extrusion temperatures during alloy preparations. The as-cast alloy is composed of the α-Mg matrix, a network of the fish-bone shaped and ellipsoidal (Mg, Zn3Gd phase, and a lamellar long period stacking ordered phase. Surface content of dynamically recrystallized (DRXed and large deformed grains increases within 330–350°C of the extrusion temperature, and decreases within 350–370°C. Sample second phase contains the (Mg, Zn3Gd nano-rods parallel to the extrusion direction, and Mg2Zn11 nanoprecipitation when temperature tuned above 350°C. Refining microstructures leads to different anticorrosive ability of the alloys as given by immersion and electrochemical corrosion tests in the simulated body fluids. The sample extruded at 350°C owns the best anticorrosive ability thanks to structural impacts where large DRXed portions and uniform nanosized grains reduce chemical potentials among composites, and passivate the extruded surfaces. Besides materials applications, the in vitro mechanism revealed here is hoped to inspire similar researches in biometal developments.

  7. Microstructure examination of Fe–14Cr ODS ferritic steels produced through different processing routes

    Energy Technology Data Exchange (ETDEWEB)

    Oksiuta, Z., E-mail: z.oksiuta@pb.edu.pl [Bialystok University of Technology, Mechanical Department (Poland); Hosemann, P. [University of California Berkeley, Nuclear Engineering, 4169 Etcheverry Hall, Berkeley, CA 94720 (United States); Vogel, S.C. [Los Alamos Neutron Science Center, Los Alamos National Laboratory, PO Box 1663, NM (United States); Baluc, N. [Ecole Polytechnique Fédérale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas, Association Euratom-Confédération Suisse, Villigen PSI 5232 (Switzerland)

    2014-08-01

    Various thermo-mechanical treatments were applied to refine and homogenise grain size and improve mechanical properties of hot-isostatically pressed (HIP) 14%Cr ODS ferritic steel. The grain size was reduced, improving mechanical properties, tensile strength and Charpy impact, however bimodal-like distribution was also observed. As a result, larger, frequently elongated grains with size above 1 μm and refined, equiaxed grains with a diameter ranging from 250 to 500 nm. Neutron diffraction measurements revealed that for HIP followed by hydrostatic extrusion material the strongest fiber texture was observed oriented parallel to the extrusion direction. In comparison with hot rolling and hot pressing methods, this material exhibited promising mechanical properties: the ultimate tensile strength of 1350 MPa, yield strength of 1280 MPa, total elongation of 21.7% and Charpy impact energy of 5.8 J. Inferior Charpy impact energy of ∼3.0 J was measured for HIP and hot rolled material, emphasising that parameters of this manufacturing process still have to be optimised. As an alternative manufacturing route, due to the uniform microstructure and simplicity of the process, hot pressing might be a promising method for production of smaller parts of ODS ferritic steels. Besides, the ductile-to-brittle transition temperature of all thermo-mechanically treated materials, in comparison with as-HIPped ODS steel, was improved by more than 50%, the transition temperature ranging from 50 to 70 °C (323 and 343 K) remains still unsatisfactory.

  8. Effect of extrusion process on the functional properties of high amylose corn starch edible films and its application in mango (Mangifera indica L.) cv. Tommy Atkins.

    Science.gov (United States)

    Calderón-Castro, Abraham; Vega-García, Misael Odín; de Jesús Zazueta-Morales, José; Fitch-Vargas, Perla Rosa; Carrillo-López, Armando; Gutiérrez-Dorado, Roberto; Limón-Valenzuela, Víctor; Aguilar-Palazuelos, Ernesto

    2018-03-01

    Starch is an attractive raw material as ingredient for edible film manufacture because of its low cost, abundant availability, renewability, and biodegradability. Nevertheless, starch based films exhibit several disadvantages such as brittleness and poor mechanical and barrier properties, which restrict its application for food packaging. The use of the extrusion technology as a pretreatment of the casting technique to change the starch structure in order to obtain edible films, may constitute an alternative to generate coatings with good functional properties and maintain longer the postharvest quality and shelf life of fruits. For this reason, the objective of this study was to optimize the conditions of an extrusion process to obtain a formulation of modified starch to elaborate edible films with good functional properties using the casting technique and assess the effect during the storage when applied on a model fruit. The best conditions of the extrusion process and concentration of plasticizers were obtained using response surface methodology. From optimization study, it was found that appropriate conditions to obtain starch edible films with the best mechanical and barrier properties were an extrusion temperature of 100 °C and a screw speed of 120 rpm, while the glycerol content was 16.73%. Also, once applied in fruit, the loss of quality attributes was diminished.

  9. Optical Measurement Technology For Aluminium Extrusions

    International Nuclear Information System (INIS)

    Moe, Per Thomas; Willa-Hansen, Arnfinn; Stoeren, Sigurd

    2007-01-01

    Optical measurement techniques such as laser scanning, structured light scanning and photogrammetry can be used for accurate shape control for aluminum extrusion and downstream processes. The paper presents the fundamentals of optical shape measurement. Furthermore, it focuses on how full-field in- and off-line shape measurement during pure-bending of aluminum extrusions has been performed with stripe projection (structured light) using white light. Full field shape measurement is difficult to implement industrially, but is very useful as a laboratory tool. For example, it has been clearly shown how moderate internal air pressure (less than 5 bars) can significantly reduce undesirable cross-sectional shape distortions during pure bending, and how buckling of the compressive flange occurs at an early stage. Finally, a stretch-bending set-up with adaptive shape control using internal gas pressure and optical techniques is presented

  10. Extrusion of ECC: Recent Developments and Applications

    DEFF Research Database (Denmark)

    Stang, Henrik; Fredslund-Hansen, Helge; Puclin, Tony

    2008-01-01

    process. Extrusion of cementitious (fiber reinforced) materials has proven particularly difficult due to the high inter-particle friction combined with the disastrous effect of static zones in the flow pattern, and to the ease of phase migration or separation. In order to deal with these conflicting...

  11. Coercivities of hot-deformed magnets processed from amorphous and nanocrystalline precursors

    International Nuclear Information System (INIS)

    Tang, Xin; Sepehri-Amin, H.; Ohkubo, T.; Hioki, K.; Hattori, A.; Hono, K.

    2017-01-01

    Hot-deformed magnets have been processed from amorphous and nanocrystalline precursors and their hard magnetic properties and microstructures have been investigated in order to explore the optimum process route. The hot-deformed magnets processed from an amorphous precursor exhibited the coercivity of 1.40 T that is higher than that processed from nanocrystalline powder, ∼1.28 T. The average grain size was larger in the magnets processed from amorphous precursor. Detailed microstructure analyses by aberration corrected scanning transmission electron microscopy revealed that the Nd + Pr concentrations in the intergranular phases were higher in the hot-deformed magnet processed from the amorphous precursor, which is considered to lead to the enhanced coercivity due to a stronger pinning force against magnetic domain wall motion.

  12. Reduction of fumonisin B₁ in corn grits by twin-screw extrusion.

    Science.gov (United States)

    Jackson, Lauren S; Jablonski, Joseph; Bullerman, Lloyd B; Bianchini, Andreia; Hanna, Milford A; Voss, Kenneth A; Hollub, April D; Ryu, Dojin

    2011-08-01

    This study was designed to investigate the fate of fumonisins in flaking corn grits during twin-screw extrusion by measuring fumonisin B₁ (FB₁) and its analogs with a mass balance approach. Food grade corn grits and 2 batches of grits contaminated with FB₁ at 10 and 50 μg/g by Fusarium verticillioides M-2552 were processed with or without glucose supplementation (10%, w/w) with a twin-screw extruder. Extrusion reduced FB₁ in contaminated grits by 64% to 72% without glucose and 89% to 94% with added glucose. In addition, extrusion alone resulted in 26% to 73% reduction in the levels of fumonisin B₂ and fumonisin B₃, while levels of both mycotoxins were reduced by >89% in extruded corn grits containing 10% glucose. Mass balance analysis showed that 38% to 46% of the FB₁ species detected in corn extruded with glucose was N-(deoxy-D-fructos-1-yl)-FB₁, while 23% to 37% of FB₁ species detected in extruded corn grits with and without added glucose was bound to the matrix. It was also found that the hydrolyzed form of FB₁ was a minor species in extruded corn grits with or without added glucose, representing fumonisin analogues measured in this study. Research is needed to identify the reaction products resulting from extrusion processing of fumonisin-contaminated corn products. Twin-screw extrusion is widely used in food industry for its versatility. This technology may reduce the level of fumonisins in corn particularly with added glucose. Journal of Food Science © 2011 Institute of Food Technologists® No claim to original US government works.

  13. Hot Melt Extrusion and Spray Drying of Co-amorphous Indomethacin-Arginine With Polymers

    DEFF Research Database (Denmark)

    Lenz, Elisabeth; Löbmann, Korbinian; Rades, Thomas

    2017-01-01

    Co-amorphous drug-amino acid systems have gained growing interest as an alternative to common amorphous formulations which contain polymers as stabilizers. Several preparation methods have recently been investigated, including vibrational ball milling on a laboratory scale or spray drying......, and stability. Results were compared to those of spray-dried formulations with the same compositions and to spray-dried indomethacin-copovidone. Overall, stable co-amorphous systems could be prepared by extrusion without or with copovidone, which exhibited comparable molecular interaction properties...... to the respective spray-dried products, while phase separation was detected by differential scanning calorimetry in several cases. The formulations containing indomethacin in combination with arginine and copovidone showed enhanced dissolution behavior over the formulations with only copovidone or arginine....

  14. [Effect of extrusion on protein and starch bioavailability in corn and lima bean flour blends].

    Science.gov (United States)

    Pérez-Navarrete, Cecilia; Betancur-Ancona, David; Casotto, Meris; Carmona, Andrés; Tovar, Juscelino

    2007-09-01

    Extrusion is used to produce crunchy expanded foods, such as snacks. The nutritional impact of this process has not been studied sufficiently. In this study, in vitro and in vivo protein and starch bioavailability was evaluated in both raw and extruded corn (Zea mays)(C) and lima bean (Phaseolus lunatus)(B) flour blends, prepared in 75C/25B and 50C/ 50B (p/p) proportions. These were processed with a Brabender extruder at 160 degrees C, 100 rpm and 15.5% moisture content. Proximate composition showed that in the extruded products protein and ash contents increased whereas the fat level decreased. In vitro protein digestibility was higher in the extrudates (82%) than in the raw flours (77%). Potentially available starch and resistant starch contents decreased with extrusion. The in vitro assays indicated that extrusion improved protein and starch availability in the studied blends. In vivo bioavailability was evaluated using the rice weevil (Sithophilus oryzae) as a biological model. The most descriptive biomarkers of the changes suggested by the in vivo tests were body protein content (increased by extrusion) and intestinal a-amylase activity (decreased by processing). Overall, results suggest that extrusion notably increases the nutritional quality of corn and lima bean flour blends.

  15. The Energetics and Physiological Impact of Cohesin Extrusion.

    Science.gov (United States)

    Vian, Laura; Pękowska, Aleksandra; Rao, Suhas S P; Kieffer-Kwon, Kyong-Rim; Jung, Seolkyoung; Baranello, Laura; Huang, Su-Chen; El Khattabi, Laila; Dose, Marei; Pruett, Nathanael; Sanborn, Adrian L; Canela, Andres; Maman, Yaakov; Oksanen, Anna; Resch, Wolfgang; Li, Xingwang; Lee, Byoungkoo; Kovalchuk, Alexander L; Tang, Zhonghui; Nelson, Steevenson; Di Pierro, Michele; Cheng, Ryan R; Machol, Ido; St Hilaire, Brian Glenn; Durand, Neva C; Shamim, Muhammad S; Stamenova, Elena K; Onuchic, José N; Ruan, Yijun; Nussenzweig, Andre; Levens, David; Aiden, Erez Lieberman; Casellas, Rafael

    2018-05-17

    Cohesin extrusion is thought to play a central role in establishing the architecture of mammalian genomes. However, extrusion has not been visualized in vivo, and thus, its functional impact and energetics are unknown. Using ultra-deep Hi-C, we show that loop domains form by a process that requires cohesin ATPases. Once formed, however, loops and compartments are maintained for hours without energy input. Strikingly, without ATP, we observe the emergence of hundreds of CTCF-independent loops that link regulatory DNA. We also identify architectural "stripes," where a loop anchor interacts with entire domains at high frequency. Stripes often tether super-enhancers to cognate promoters, and in B cells, they facilitate Igh transcription and recombination. Stripe anchors represent major hotspots for topoisomerase-mediated lesions, which promote chromosomal translocations and cancer. In plasmacytomas, stripes can deregulate Igh-translocated oncogenes. We propose that higher organisms have coopted cohesin extrusion to enhance transcription and recombination, with implications for tumor development. Copyright © 2018 Elsevier Inc. All rights reserved.

  16. TWRS tank waste pretreatment process development hot test siting report

    International Nuclear Information System (INIS)

    Howden, G.F.; Banning, D.L.; Dodd, D.A.; Smith, D.A.; Stevens, P.F.; Hansen, R.I.; Reynolds, B.A.

    1995-02-01

    This report is the sixth in a series that have assessed the hot testing requirements for TWRS pretreatment process development and identified the hot testing support requirements. This report, based on the previous work, identifies specific hot test work packages, matches those packages to specific hot cell facilities, and provides recommendations of specific facilities to be employed for the pretreatment hot test work. Also identified are serious limitations in the tank waste sample retrieval and handling infrastructure. Recommendations are provided for staged development of 500 mL, 3 L, 25 L and 4000 L sample recovery systems and specific actions to provide those capabilities

  17. Effect of extrusion conditions on the physico-chemical properties and in vitro protein digestibility of canola meal.

    Science.gov (United States)

    Zhang, Bo; Liu, Guo; Ying, Danyang; Sanguansri, Luz; Augustin, Mary Ann

    2017-10-01

    Canola meal has potential as a high protein food ingredient. The extrusion-induced changes in color, pH, extractable protein and in vitro protein digestibility of canola meal under different extrusion conditions was assessed. The extrusion barrel moisture (24%, 30% or 36%) and screw kneading block length (0, 30 or 60mm) were used as independent process parameters. Extrusion at high barrel moisture (36%) favored protein aggregation resulting in lower extractable protein compared to extrusion at the lowest barrel moisture (24%). At lower barrel moisture contents (24% and 30%), a longer kneading block length increased extractable protein but this was not the case at 36% barrel moisture. Canola protein digestibility was improved upon extrusion at 30% barrel moisture but there was no significant change at lower (24%) or higher (36%) barrel moisture. The kneading block length of the screw had no significant effect on the canola protein digestibility within the same barrel moisture level. The relationship between the physico-chemical parameters and in vitro digestibility was examined. This study highlighted the complex interplay of extrusion processing variables that affect protein degradation and the interaction of components, with consequent effects on protein digestibility. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Discussion of Carbon Emissions for Charging Hot Metal in EAF Steelmaking Process

    Science.gov (United States)

    Yang, Ling-zhi; Jiang, Tao; Li, Guang-hui; Guo, Yu-feng

    2017-07-01

    As the cost of hot metal is reduced for iron ore prices are falling in the international market, more and more electric arc furnace (EAF) steelmaking enterprises use partial hot metal instead of scrap as raw materials to reduce costs and the power consumption. In this paper, carbon emissions based on 1,000 kg molten steel by charging hot metal in EAF steelmaking is studied. Based on the analysis of material and energy balance calculation in EAF, the results show that 146.9, 142.2, 137.0, and 130.8 kg/t of carbon emissions are produced at a hot metal ratio of 0 %, 30 %, 50 %, and 70 %, while 143.4, 98.5, 65.81, and 31.5 kg/t of carbon emissions are produced at a hot metal ratio of 0 %, 30 %, 50 %, and 70 % by using gas waste heat utilization (coal gas production) for EAF steelmaking unit process. However, carbon emissions are increased by charging hot metal for the whole blast furnace-electric arc furnace (BF-EAF) steelmaking process. In the condition that the hot metal produced by BF is surplus, as carbon monoxide in gas increased by charging hot metal, the way of coal gas production can be used for waste heat utilization, which reduces carbon emissions in EAF steelmaking unit process.

  19. Hot-crack test for aluminium alloys welds using TIG process

    Science.gov (United States)

    Niel, A.; Deschaux-Beaume, F.; Bordreuil, C.; Fras, G.

    2010-06-01

    Hot cracking is a critical defect frequently observed during welding of aluminium alloys. In order to better understand the interaction between cracking phenomenon, process parameters, mechanical factors and microstructures resulting from solidification after welding, an original hot-cracking test during welding is developed. According to in-situ observations and post mortem analyses, hot cracking mechanisms are investigated, taking into account the interaction between microstructural parameters, depending on the thermal cycles, and mechanical parameters, depending on geometry and clamping conditions of the samples and on the thermal field on the sample. Finally, a process map indicating the limit between cracking and non-cracking zones according to welding parameters is presented.

  20. Avoiding Carbon Bed Hot Spots in Thermal Process Off-Gas Systems

    International Nuclear Information System (INIS)

    Soelberg, Nick; Enneking, Joe

    2011-01-01

    Mercury has had various uses in nuclear fuel reprocessing and other nuclear processes, and so is often present in radioactive and mixed (radioactive and hazardous) wastes. Test programs performed in recent years have shown that mercury in off-gas streams from processes that treat radioactive wastes can be controlled using fixed beds of activated sulfur-impregnated carbon, to levels low enough to comply with air emission regulations such as the Hazardous Waste Combustor (HWC) Maximum Achievable Control Technology (MACT) standards. Carbon bed hot spots or fires have occurred several times during these tests, and also during a remediation of tanks that contained mixed waste. Hot spots occur when localized areas in a carbon bed become heated to temperatures where oxidation occurs. This heating typically occurs due to heat of absorption of gas species onto the carbon, but it can also be caused through external means such as external heaters used to heat the carbon bed vessel. Hot spots, if not promptly mitigated, can grow into bed fires. Carbon bed hot spots and fires must be avoided in processes that treat radioactive and mixed waste. Hot spots are detected by (a) monitoring in-bed and bed outlet gas temperatures, and (b) more important, monitoring of bed outlet gas CO concentrations. Hot spots are mitigated by (a) designing for appropriate in-bed gas velocity, for avoiding gas flow maldistribution, and for sufficient but not excessive bed depth, (b) appropriate monitoring and control of gas and bed temperatures and compositions, and (c) prompt implementation of corrective actions if bed hot spots are detected. Corrective actions must be implemented quickly if bed hot spots are detected, using a graded approach and sequence starting with corrective actions that are simple, quick, cause the least impact to the process, and are easiest to recover from.

  1. CHARACTERIZATION OF THE GRAINS IN 2014 ALUMINIUM ALLOY AFTER EQUAL CHANNEL ANGULAR EXTRUSION (ECAE PROCESS

    Directory of Open Access Journals (Sweden)

    Sonia Boczkal

    2011-05-01

    Full Text Available In 2014 alloy deformed by Equal Channel Angular Extrusion process (ECAE the changes in the size and shape of structural constituents were examined. The samples subjected after deformation to additional annealing at 300°C/10min were characterized by larger grains of nearly-equiaxial shapes. The microstructure after deformation was composed of a large number of the mutually crossing bands and microbands. The intersection of microbands resulted in formation of rectangular and rhombohedral grains. It was noted that the average grain size after ε = 4.6 (4 passes was 0.2 μm.

  2. Microstructure and mechanical properties of commercially pure aluminum processed by accumulative back extrusion

    International Nuclear Information System (INIS)

    Haghdadi, N.; Zarei-Hanzaki, A.; Abou-Ras, D.

    2013-01-01

    Accumulative back extrusion (ABE), as a new severe plastic deformation (SPD) method, was applied on a commercially pure aluminum, resulting in an ultrafine microstructure. The grain refinement was attributed to the shearing and/or to the mechanical partitioning of the initial coarse grains as well as different dynamic recrystallization mechanisms (i.e., discontinues and continues ones). The effects of imposing several passes along with the strain reversal path method during consecutive ABE passes were discussed. Mechanical characterization revealed that the yield and ultimate strength of pure Al were significantly increased through applying ABE. This was related to grain boundary and dislocation strengthening, as well as to Orowan dislocation bowing mechanisms. The elongation, however, was deteriorated after ABE processing. This was interpreted through the lack of ability of the material to accommodate the ABE-induced strain, inhomogeneous distribution of strain across the ABE-processed workpieces, and the reduced work hardening capacity of the fine-grained aluminum. The formability index and static toughness were also considered to verify the overall mechanical performance of the ABE-processed pure Al

  3. Diclofenac sodium sustained release hot melt extruded lipid matrices.

    Science.gov (United States)

    Vithani, K; Cuppok, Y; Mostafa, S; Slipper, I J; Snowden, M J; Douroumis, D

    2014-08-01

    Sustained release diclofenac sodium (Df-Na) solid lipid matrices with Compritol® 888 ATO were developed in this study. The drug/lipid powders were processed via cold and hot melt extrusion at various drug loadings. The influence of the processing temperatures, drug loading and the addition of excipients on the obtained dissolution rates was investigated. The physicochemical characterization of the extruded batches showed the existence of crystalline drug in the extrudates with a small amount being solubilized in the lipid matrix. The drug content and uniformity on the tablet surface were also investigated by using energy dispersive X-ray microanalysis. The dissolution rates were found to depend on the actual Df-Na loading and the nature of the added excipients, while the effect of the processing temperatures was negligible. The dissolution mechanism of all extruded formulations followed Peppas-Korsemeyer law, based on the estimated determination coefficients and the dissolution constant rates, indicating drug diffusion from the lipid matrices.

  4. Gear hot forging process robust design based on finite element method

    International Nuclear Information System (INIS)

    Xuewen, Chen; Won, Jung Dong

    2008-01-01

    During the hot forging process, the shaping property and forging quality will fluctuate because of die wear, manufacturing tolerance, dimensional variation caused by temperature and the different friction conditions, etc. In order to control this variation in performance and to optimize the process parameters, a robust design method is proposed in this paper, based on the finite element method for the hot forging process. During the robust design process, the Taguchi method is the basic robust theory. The finite element analysis is incorporated in order to simulate the hot forging process. In addition, in order to calculate the objective function value, an orthogonal design method is selected to arrange experiments and collect sample points. The ANOVA method is employed to analyze the relationships of the design parameters and design objectives and to find the best parameters. Finally, a case study for the gear hot forging process is conducted. With the objective to reduce the forging force and its variation, the robust design mathematical model is established. The optimal design parameters obtained from this study indicate that the forging force has been reduced and its variation has been controlled

  5. Hot deformation behavior of delta-processed superalloy 718

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Y., E-mail: wangyanhit@yahoo.cn [State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083 (China); School of Aeronautics and Astronautics, Central South University, Changsha 410083 (China); Shao, W.Z.; Zhen, L.; Zhang, B.Y. [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China)

    2011-03-25

    Research highlights: {yields} The peak stress for hot deformation can be described by the Z parameter. {yields} The grain size of DRX was inversely proportional to the Z parameter. {yields} The dissolution of {delta} phases was greatly accelerated under hot deformation. {yields}The {delta} phase stimulated nucleation can serve as the main DRX mechanism. - Abstract: Flow stress behavior and microstructures during hot compression of delta-processed superalloy 718 at temperatures from 950 to 1100 deg. C with strain rates of 10{sup -3} to 1 s{sup -1} were investigated by optical microscopy (OM), electron backscatter diffraction (EBSD) technique and transmission electron microscopy (TEM). The relationship between the peak stress and the deformation conditions can be expressed by a hyperbolic-sine type equation. The activation energy for the delta-processed superalloy 718 is determined to be 467 kJ/mol. The change of the dominant deformation mechanisms leads to the decrease of stress exponent and the increase of activation energy with increasing temperature. The dynamically recrystallized grain size is inversely proportional to the Zener-Hollomon (Z) parameter. It is found that the dissolution rate of {delta} phases under hot deformation conditions is much faster than that under static conditions. Dislocation, vacancy and curvature play important roles in the dissolution of {delta} phases. The main nucleation mechanisms of dynamic recrystallization (DRX) for the delta-processed superalloy 718 include the bulging of original grain boundaries and the {delta} phase stimulated DRX nucleation, which is closely related to the dissolution behavior of {delta} phases under certain deformation conditions.

  6. Preparation and investigation of novel gastro-floating tablets with 3D extrusion-based printing.

    Science.gov (United States)

    Li, Qijun; Guan, Xiaoying; Cui, Mengsuo; Zhu, Zhihong; Chen, Kai; Wen, Haoyang; Jia, Danyang; Hou, Jian; Xu, Wenting; Yang, Xinggang; Pan, Weisan

    2018-01-15

    Three dimensional (3D) extrusion-based printing is a paste-based rapid prototyping process, which is capable of building complex 3D structures. The aim of this study was to explore the feasibility of 3D extrusion-based printing as a pharmaceutical manufacture technique for the fabrication of gastro-floating tablets. Novel low-density lattice internal structure gastro-floating tablets of dipyridamole were developed to prolong the gastric residence time in order to improve drug release rate and consequently, improve bioavailability and therapeutic efficacy. Excipients commonly employed in the pharmaceutical study could be efficiently applied in the room temperature 3D extrusion-based printing process. The tablets were designed with three kinds of infill percentage and prepared by hydroxypropyl methylcellulose (HPMC K4M) and hydroxypropyl methylcellulose (HPMC E15) as hydrophilic matrices and microcrystalline cellulose (MCC PH101) as extrusion molding agent. In vitro evaluation of the 3D printed gastro-floating tablets was performed by determining mechanical properties, content uniformity, and weight variation. Furthermore, re-floating ability, floating duration time, and drug release behavior were also evaluated. Dissolution profiles revealed the relationship between infill percentage and drug release behavior. The results of this study revealed the potential of 3D extrusion-based printing to fabricate gastro-floating tablets with more than 8h floating process with traditional pharmaceutical excipients and lattice internal structure design. Copyright © 2017. Published by Elsevier B.V.

  7. Effect of Nano-clay on Rheological and Extrusion Foaming Process of a Block-Copolymerized Polypropylene

    Directory of Open Access Journals (Sweden)

    Wang Mingyi

    2016-01-01

    Full Text Available The effects of nano-clay and the corresponding coupling agent maleic anhydride grafted polypropylene (PP-g-MAH on thermal properties, rheological properties and extrusion foaming process of a block-copolymerized polypropylene (B-PP were studied. Supercritical CO2 (SC CO2 was used as the foaming agent with a concentration of 5wt%. Each step of foamed B-PP/ PP-g-MAH/ nano-clay composites processing is addressed, including mixing of the composites, manufacture of the composites, foaming process of the composites and characterization of the cell structure. The results showed that incorporation of nano-clay and PP-g-MAH caused reduced melt strength and complex viscosity of B-PP. However, the heterogeneous nucleation induced by nano-clay and PP-g-MAH improved the maximum foaming expansion ratio and cell-population density of B-PP foam.

  8. Chemical, physical and nutritional changes in soybean meal as a result of toasting and extrusion cooking

    NARCIS (Netherlands)

    Marsman, G.J.P.

    1998-01-01

    The effect of soybean meal extrusion and the development of shear forces during single-screw extrusion was compared with the toasting process of soybean meal. Attention was focused on chemical, physical and nutritional changes during these thermo-mechanical

  9. Thermo-mechanical processing (TMP) of Ti-48Al-2Nb-2Cr based alloys

    International Nuclear Information System (INIS)

    Fuchs, G.E.

    1995-02-01

    The effects of heat treatment and deformation processing on the microstructures and properties of γ-TiAl based alloys produced by ingot metallurgy (I/M) and powder metallurgy (P/M) techniques were examined. The alloy selected for this work is the second generation γ-TiAl based alloy -- Ti-48Al-2Nb-2Cr (at %). Homogenization of I/M samples was performed at a variety of temperatures, followed by hot working by isothermal forging. P/M samples were prepared from gas atomized powders, consolidated by both HIP and extrusion and some of the HIPed material was then hot worked by isothermal forging. The effects of processing, heat treatment and hot working on the microstructures and properties will be discussed

  10. Hot-crack test for aluminium alloys welds using TIG process

    Directory of Open Access Journals (Sweden)

    Deschaux-beaume F.

    2010-06-01

    Full Text Available Hot cracking is a critical defect frequently observed during welding of aluminium alloys. In order to better understand the interaction between cracking phenomenon, process parameters, mechanical factors and microstructures resulting from solidification after welding, an original hot-cracking test during welding is developed. According to in-situ observations and post mortem analyses, hot cracking mechanisms are investigated, taking into account the interaction between microstructural parameters, depending on the thermal cycles, and mechanical parameters, depending on geometry and clamping conditions of the samples and on the thermal field on the sample. Finally, a process map indicating the limit between cracking and non-cracking zones according to welding parameters is presented.

  11. Closure behavior of spherical void in slab during hot rolling process

    Science.gov (United States)

    Cheng, Rong; Zhang, Jiongming; Wang, Bo

    2018-04-01

    The mechanical properties of steels are heavily deteriorated by voids. The influence of voids on the product quality should be eliminated through rolling processes. The study on the void closure during hot rolling processes is necessary. In present work, the closure behavior of voids at the center of a slab at 800 °C during hot rolling processes has been simulated with a 3D finite element model. The shape of the void and the plastic strain distribution of the slab are obtained by this model. The void decreases along the slab thickness direction and spreads along the rolling direction but hardly changes along the strip width direction. The relationship between closure behavior of voids and the plastic strain at the center of the slab is analyzed. The effects of rolling reduction, slab thickness and roller diameter on the closure behavior of voids are discussed. The larger reduction, thinner slab and larger roller diameter all improve the closure of voids during hot rolling processes. Experimental results of the closure behavior of a void in the slab during hot rolling process mostly agree with the simulation results..

  12. 75 FR 22109 - Aluminum Extrusions from the People's Republic of China: Initiation of Antidumping Duty...

    Science.gov (United States)

    2010-04-27

    ... Aluminium, Ltd., a producer of aluminum extrusions, for the 2008 2009 fiscal year. See Volume II of the..., produced by an extrusion process, made from aluminum alloys having metallic elements corresponding to the alloy series designations published by The Aluminum Association commencing with the numbers 1, 3, and 6...

  13. Effect of materials and temperature on the forward extrusion of magnesium alloys

    International Nuclear Information System (INIS)

    Chandrasekaran, Margam; John, Yong Ming Shyan

    2004-01-01

    Magnesium alloys are being extensively used in weight-saving applications and as a potential replacement for plastics in electronic and computer applications. However, processing of magnesium has always been a challenge for manufacturing industries owing to their high brittleness despite their good EMI shielding property and high specific strength. Despite these advantages, they are limited by their processability. The present work aims to evaluate lower temperature formability of magnesium alloys. Three different materials were selected for axisymmetric extrusion tests, namely AZ31, AZ61 and the forging alloy, ZK 60. To establish the size and capacity of the press required to perform these forming trials and to know the formability, simulation using finite element analysis was carried on a representative material AZ31 using the properties established based on earlier work. A die set with a die shoe was designed to perform the forward extrusion trials. The area reduction ratio for forward extrusion was fixed at 41% for the die design and simulation. The maximum strain is given as ln(A o /A f ) ∼ 0.88 in the case of forward extrusion. The temperature was varied with a temperature controller built in-house from room temperature (RT) to 300 deg.C. However, the results provided below only include the tests carried out at RT, 100, 150, 175 and 200 deg.C. Although the forming trials were successful above 200 deg.C, there was difficulty in removing the specimens from the die cavity. Secondly, the process of removing the samples in the case of AZ31 and ZK 60 resulted in cracking, so it was difficult to evaluate the samples and the process. However, AZ61 samples did not show any evidence of crack formation during ejection of the formed sample. Simulation results and experimental trials showed that magnesium (AZ31) could be easily formed at elevated temperatures of 300 deg.C. Though there was a good correlation on the yield point prediction between simulation and

  14. Physical properties, molecular structures and protein quality of texturized whey protein isolate: effect of extrusion temperature

    Science.gov (United States)

    Extrusion is a powerful food processing operation, which utilizes high temperature and high shear force to produce a product with unique physical and chemical characteristics. Texturization of whey protein isolate (WPI) through extrusion for the production of protein fortified snack foods has provid...

  15. A New Method of Constructing a Drug-Polymer Temperature-Composition Phase Diagram Using Hot-Melt Extrusion.

    Science.gov (United States)

    Tian, Yiwei; Jones, David S; Donnelly, Conor; Brannigan, Timothy; Li, Shu; Andrews, Gavin P

    2018-04-02

    Current experimental methodologies used to determine the thermodynamic solubility of an API within a polymer typically involves establishing the dissolution/melting end point of the crystalline API within a physical mixture or through the use of the glass transition temperature measurement of a demixed amorphous solid dispersion. The measurable "equilibrium" points for solubility are normally well above the glass transition temperature of the system, meaning extrapolation is required to predict the drug solubility at pharmaceutically relevant temperatures. In this manuscript, we argue that the presence of highly viscous polymers in these systems results in experimental data that exhibits an under or overestimated value relative to the true thermodynamic solubility. In previous work, we demonstrated the effects of experimental conditions and their impact on measured and predicted thermodynamic solubility points. In light of current understanding, we have developed a new method to limit error associated with viscosity effects for application in small-scale hot-melt extrusion (HME). In this study, HME was used to generate an intermediate (multiphase) system containing crystalline drug, amorphous drug/polymer-rich regions as well as drug that was molecularly dispersed in polymer. An extended annealing method was used together with high-speed differential scanning calorimetry to accurately determine the upper and lower boundaries of the thermodynamic solubility of a model drug-polymer system (felodipine and Soluplus). Compared to our previously published data, the current results confirmed our hypothesis that the prediction of the liquid-solid curve using dynamic determination of dissolution/melting end point of the crystalline API physical mixture presents an underestimation relative to the thermodynamic solubility point. With this proposed method, we were able to experimentally measure the upper and lower boundaries of the liquid-solid curve for the model system. The

  16. Hot Deformation Behavior of Hot-Extruded AA7175 Through Hot Torsion Tests.

    Science.gov (United States)

    Lee, Se-Yeon; Jung, Taek-Kyun; Son, Hyeon-Woo; Kim, Sang-Wook; Son, Kwang-Tae; Choi, Ho-Joon; Oh, Sang-Ho; Lee, Ji-Woon; Hyun, Soong-Keun

    2018-03-01

    The hot deformation behavior of hot-extruded AA7175 was investigated with flow curves and processing maps through hot torsion tests. The flow curves and the deformed microstructures revealed that dynamic recrystallization (DRX) occurred in the hot-extruded AA7175 during hot working. The failure strain was highest at medium temperature. This was mainly influenced by the dynamic precipitation of fine rod-shaped MgZn2. The processing map determined the optimal deformation condition for the alloy during hot working.

  17. MM98.36 Strain Paths in Extrusion

    DEFF Research Database (Denmark)

    Lindegren, Maria; Wiwe, Birgitte; Wanheim, Tarras

    1998-01-01

    The extrusion process has been investigated for different geometries, in order to study the strain path of different material elements during their movements through the plastic zone. This is done by using the FEM code DEFORM and physical simulation with wax togehter with the coefficient method. ....... Calculations of strain paths have also been performed by ABAQUS....

  18. Mechanical considerations in the processing of high Tc superconductors

    International Nuclear Information System (INIS)

    Wright, R.N.; German, R.M.; Knorr, D.B.; Maccrone, R.K.; Rajan, K.

    1990-01-01

    This paper presents a brief review of deformation processing concepts germane to high-Tc superconductor processing, and illustrates some available techniques with results from recent work. It is noted that YBa2Cu3O(7-x) powder/binder cold extrusion technique is quite sensitive to binder formulation and processing conditions. With appropriate technique, indefinite lengths of YBa2Cu3O(7-x) powder/binder composite can be extruded with sufficient workability to allow coiling and other forming operations. With heat treatment, the resulting prototype wire is electrically continuous and manifests critical current densities of a few hundred A/sq cm. The hot extrusion of YBa2Cu3O(7-x) powder results in a modest, but favorable, development of a texture involving preferential rotation of the c-axis toward the radial direction. Billet designs involving larger powder charge diameters, and thinner container walls, produce the favorable texture. Unfortunately, such billet designs reduce workability. 29 refs

  19. Radioactive spent resins conditioning by the hot super-compaction process

    International Nuclear Information System (INIS)

    Roth, Andreas; Centner, Baudouin; Lemmens, Alain

    2007-01-01

    Spent ion exchanger media are considered to be problematic waste that, in many cases, requires special approaches and precautions during its immobilization to meet the acceptance criteria for disposal. The waste acceptance criteria define, among others, the quality of waste forms for disposal, and therefore will sometimes define appropriate treatment options. The selection of treatment options for spent ion exchange materials must consider their physical and chemical characteristics. Basically, the main methods for the treatment of spent organic ion exchange materials, following to pretreatment methods are: - Direct immobilization, producing a stable end product by using Cement, Bitumen, Polymer or High Integrity Containers, - The destruction of the organic compounds by using Thermochemical processes or Oxidation to produce an inorganic intermediate product that may or may not be further conditioned for storage and/or disposal, - The complete removal of the resin inner structural water by a thermal process. After a thorough technical economical analysis, Tractebel Engineering selected the Resin Hot Compaction Process to be installed at Tihange Nuclear Power Plant. The Resin Hot Compaction Process is used to make dense homogenous organic blocks from a wide range of particulate waste. In this process spent resins are first dewatered and dried to remove the inner structural water content. The drying takes place in a drying vessel that holds the contents of two 200 L drums (Figure). In the oil heated drying and mixing unit, the resins are heated to the necessary process temperature for the hot pressing step and then placed into special metal drums, which are automatically lidded and immediately transferred to a high force compactor. After high force compaction the pellets are transferred to a measuring unit, where the dose rate, height and weight are automatically measured and recorded. A volume reduction factor of approximately up to four (depending on the type of

  20. Stochastic behavior of cooling processes in hot nuclei

    International Nuclear Information System (INIS)

    de Oliveira, P.M.; Sa Martins, J.S.; Szanto de Toledo, A.

    1997-01-01

    The collapse of structure effects observed in hot nuclei is interpreted in terms of a dynamic lattice model which describes the process of nucleon (clusters) evaporation from a hot nucleus, predicting the final mass distribution. Results are compared with experimental data for the 10 B+ 9 Be and 10 B+ 10 B reactions, and indicate that the structures observed in the low-energy mass distributions in both simulation and experiment are a consequence of the competition between the residual interactions and the thermalization dissipative process. As a characteristic feature of complex evolving systems, this competition leads to long term memory during the dissipative path, the observables becoming thus insensitive to the actual microscopic interactions. copyright 1997 The American Physical Society

  1. Extrusão de misturas de castanha do Brasil com mandioca Extrusion of Brazil nut and cassava flour mixtures

    Directory of Open Access Journals (Sweden)

    Maria Luzenira de Souza

    2008-06-01

    Full Text Available Considerando-se que a castanha do Brasil apresenta elevado potencial nutritivo, baixo consumo no Brasil, baixo valor agregado e é um produto orgânico, além da alta produtividade, do baixo custo da mandioca e da tecnologia de extrusão termoplástica apresentarem ampla aplicabilidade e vantagens, este trabalho teve como objetivo empregar estas três variáveis, para formular misturas com castanha do Brasil e farinha de mandioca e processá-las por extrusão, visando à obtenção de produtos extrusados ricos em proteína vegetal e prontos para o consumo. Foram utilizadas torta de amêndoa de castanha do Brasil semidesengordurada e farinha de mandioca para formulações das misturas para extrusão. Aplicou-se o delineamento fatorial completo composto central (2³, com 3 variáveis independentes e a metodologia de superfície de resposta foi usada para avaliar os resultados da composição centesimal e o valor calórico, frente às variações de castanha, umidade e temperatura. Os resultados indicam que as formulações com maiores quantidades de castanha apresentam quantidades de proteínas, lipídios e cinzas mais elevadas, já as formulações com menores teores de castanha apresentam maiores percentuais de carboidratos. Os coeficientes de regressão médios do modelo estatístico para as respostas são: umidade 7,40; carboidratos 51,09; proteínas 15,34; lipídios 11,77; fibra total 9,92 e kcal 371,65. Os ensaios com menores teores de castanha e maiores de farinha apresentam-se mais expandidos e de cor clara, enquanto que aqueles com maiores teores de castanha não se expandem e têm a cor acinzentada. Conclui-se que a adição de castanha semidesengordurada à farinha de mandioca pode ser submetida à extrusão, originando um produto extrusado fonte de proteína vegetal, pronto para o consumo e que pode atender à exigência de consumidores que não utilizam proteínas de origem animal.Considering that Brazil nut presents high nutritional

  2. Synthesis, extrusion processing and ionic conductivity measurements of sodium β-alumina tubes

    Directory of Open Access Journals (Sweden)

    Karanja Avinash

    2015-09-01

    Full Text Available Pure and Li-doped sodium β-alumina (NaMg0.67Al10.33O17 ceramics were prepared from the stoichiometric mixture of raw powders. Pellets and tubes were formed from the precursor (NBA-1S and preformed sodium β-alumina powder through compaction and extrusion processing, respectively. The obtained specimens were finally sintered to dense ceramics. The ceramics were comparatively evaluated for their density, microstructure, phase formation and electrical properties. Both tubes and pellets processed with the preformed sodium β-alumina powder (NBA-2S showed enhanced densification along with relatively better phase purity and crystallinity. The ceramics prepared from the preformed powder exhibited higher density of 94–95% TD (theoretical densities in comparison to the ceramics processed from the raw mixture (NBA-1S with a density of 85–87% TD, which are complemented well through fractographs and microstructures. The ceramics processed using the preformed sodium β-alumina (NBA-2S also exhibited high room temperature AC conductivity of 1.77×10-4 S/cm (1 MHz with an increasing trend with temperature. The higher ionic conductivity at all temperatures in NBA-2S than in NBA-1S ceramics can be attributed to the relatively high phase purity, crystallinity and higher density values of NBA-2S ceramics.

  3. Investigation of the combined effect of MgO and PEG on the release profile of mefenamic acid prepared via hot-melt extrusion techniques.

    Science.gov (United States)

    Alshehri, Sultan M; Tiwari, Roshan V; Alsulays, Bader B; Ashour, Eman A; Alshetaili, Abdullah S; Almutairy, Bjad; Park, Jun-Bom; Morott, Joseph; Sandhu, Bhupinder; Majumdar, Soumyajit; Repka, Michael A

    2017-09-01

    This study aimed to investigate the combined effect of magnesium oxide (MgO) as an alkalizer and polyethylene glycol (PEG) as a plasticizer and wetting agent in the presence of Kollidon® 12 PF and 17 PF polymer carriers on the release profile of mefenamic acid (MA), which was prepared via hot-melt extrusion technique. Various drug loads of MA and various ratios of the polymers, PEG 3350 and MgO were blended using a V-shell blender and extruded using a twin-screw extruder (16-mm Prism EuroLab, ThermoFisher Scientific, Carlsbad, CA) at different screw speeds and temperatures to prepare a solid dispersion system. Differential scanning calorimetry and X-ray diffraction data of the extruded material confirmed that the drug existed in the amorphous form, as evidenced by the absence of corresponding peaks. MgO and PEG altered the micro-environmental pH to be more alkaline (pH 9) and increased the hydrophilicity and dispersibility of the extrudates to enhance MA solubility and release, respectively. The in vitro release study demonstrated an immediate release for 2 h with more than 80% drug release within 45 min in matrices containing MgO and PEG in combination with polyvinylpyrrolidone when compared to the binary mixture, physical mixture and pure drug.

  4. Modelling of anisotropy for Al-Li 2099 T83 extrusions and effect of precipitate density

    International Nuclear Information System (INIS)

    Bois-Brochu, Alexandre; Blais, Carl; Tchitembo Goma, Franck Armel; Larouche, Daniel

    2016-01-01

    The development of aluminum-lithium alloys for aerospace applications requires a thorough understanding of how processing and product geometry impact their microstructure, texture and mechanical properties. The anisotropy of the mechanical properties is in part related to the deformation texture formed during thermo-mechanical processing. In this study, two different extrusions of Al-Li 2099 T83 were characterized, a cylindrical extrusion and an integrally stiffened panel (ISP). A model is proposed to predict mechanical properties and their anisotropy as a function of the <111> fiber texture. Furthermore, the volume fraction of precipitates was measured in zones of high anisotropy (cylindrical extrusion) and low anisotropy (ISP). Results show that there is no significant difference between the two parts concerning volume fraction of precipitates.

  5. Modelling of anisotropy for Al-Li 2099 T83 extrusions and effect of precipitate density

    Energy Technology Data Exchange (ETDEWEB)

    Bois-Brochu, Alexandre, E-mail: Alexandre.Bois-Brochu.1@ulaval.ca; Blais, Carl, E-mail: Carl.Blais@gmn.ulaval.ca; Tchitembo Goma, Franck Armel, E-mail: Franck-Armel.Tchitembo-Goma.1@ulaval.ca; Larouche, Daniel, E-mail: Daniel.Larouche@gmn.ulaval.ca

    2016-09-15

    The development of aluminum-lithium alloys for aerospace applications requires a thorough understanding of how processing and product geometry impact their microstructure, texture and mechanical properties. The anisotropy of the mechanical properties is in part related to the deformation texture formed during thermo-mechanical processing. In this study, two different extrusions of Al-Li 2099 T83 were characterized, a cylindrical extrusion and an integrally stiffened panel (ISP). A model is proposed to predict mechanical properties and their anisotropy as a function of the <111> fiber texture. Furthermore, the volume fraction of precipitates was measured in zones of high anisotropy (cylindrical extrusion) and low anisotropy (ISP). Results show that there is no significant difference between the two parts concerning volume fraction of precipitates.

  6. Development of microstructure in thermomechanical processing of zirconium alloys

    International Nuclear Information System (INIS)

    Jha, S.K.; Saibaba, N.; Jayaraj, R.N.

    2009-01-01

    Zirconium based alloys are used for the manufacture of fuel tubes pressure tubes calandria tubes and other components of Pressurized Heavy Water Reactors (PHWRS). In single or two phase zirconium alloy system a variety of microstructure can be generated by suitable heat treatments by the process of equilibrium and non equilibrium phase transformations Microstructure can also be modified by alloying with α and β stabilizers. The microstructure in Zr alloys could be single hexagonal phase (α alloys) two phase bcc and hexagonal (α + β alloys) phase, single metastable martensitic microstructure and β with ω phase. The microstructural and micro textural evolution during thermo mechanical treatments depends strongly on such initial microstructure. Hot extrusion is a significant bulk deformation step which decides the initial microstructure of the alloy. It is carried out at elevated temperature i e above the recrystallization temperature, which enable imposition of large strains in single step. This deformation causes a significant change in the microstructure of the material and depends on extrusion process parameters such as temperature, strain rate (Ram speed), reduction ratio etc. In the present paper development of microstructures, microtexture and texture have been examined. An attempt is also made to optimise the hot working parameters for different Zirconium alloys with help of these studies. (author)

  7. Enhanced Hot Tensile Ductility of Mg-3Al-1Zn Alloy Thin-Walled Tubes Processed Via a Combined Severe Plastic Deformation

    Science.gov (United States)

    Fata, A.; Eftekhari, M.; Faraji, G.; Mosavi Mashhadi, M.

    2018-05-01

    In the current study, combined parallel tubular channel angular pressing (PTCAP) and tube backward extrusion (TBE), as a recently developed severe plastic deformation (SPD) method, were applied at 300 °C on a commercial Mg-3Al-1Zn alloy tubes to achieve an ultrafine grained structure. Then, the microstructure, hardness, tensile properties, and fractography evaluations were done at room temperature on the SPD-processed samples. Also, to study the hot tensile ductility of the SPD-processed samples, tensile testing was performed at an elevated temperature of 400 °C, and then, the fractured surface of the tensile samples was studied. It was observed that a bimodal microstructure, with large gains surrounded by many tiny ones, was created in the sample processed by PTCAP followed by TBE. This microstructure led to reach higher hardness and higher strength at room temperature and also led to reach very high elongation to failure ( 181%) at 400 °C. Also, the value of elongation to failure for this sample was 14.1% at room temperature. The fractographic SEM images showed the occurrence of predominately ductile fracture in the samples pulled at 400 °C. This was mostly due to the nucleation of microvoids and their subsequent growth and coalescence with each other.

  8. Rapid production of hollow SS316 profiles by extrusion based additive manufacturing

    Science.gov (United States)

    Rane, Kedarnath; Cataldo, Salvatore; Parenti, Paolo; Sbaglia, Luca; Mussi, Valerio; Annoni, Massimiliano; Giberti, Hermes; Strano, Matteo

    2018-05-01

    Complex shaped stainless steel tubes are often required for special purpose biomedical equipment. Nevertheless, traditional manufacturing technologies, such as extrusion, lack the ability to compete in a market of customized complex components because of associated expenses towards tooling and extrusion presses. To rapid manufacture few of such components with low cost and high precision, a new Extrusion based Additive Manufacturing (EAM) process, is proposed in this paper, and as an example, short stainless steel 316L complex shaped and sectioned tubes were prepared by EAM. Several sample parts were produced using this process; the dimensional stability, surface roughness and chemical composition of sintered samples were investigated to prove process competence. The results indicate that feedstock with a 316L particle content of 92.5 wt. % can be prepared with a sigma blade mixing, whose rheological behavior is fit for EAM. The green samples have sufficient strength to handle them for subsequent treatments. The sintered samples considerably shrunk to designed dimensions and have a homogeneous microstructure to impart mechanical strength. Whereas, maintaining comparable dimensional accuracy and chemical composition which are required for biomedical equipment still need iterations, a kinematic correction and modification in debinding cycle was proposed.

  9. Design of an extrusion screw and solid fuel produced from coconut shell

    Directory of Open Access Journals (Sweden)

    Madhiyanon, T

    2006-03-01

    Full Text Available The objectives were to design an extrusion screw to produce biomass solid fuel in a cold extrusion process, and investigate the effects of molasses used as a selected adhesive on the physical properties of extruded products. The material employed consisted of crushed coconut shell char and coconut fiber char mixed at a ratio of 40:60. The ratios of molasses in the mixture were 10:100, 15:100 and 20:100 (by weight and the extrusion die angles were 1.0, 1.1, 1.2, and 1.3 degrees gradation per experiment. The experimental results showed that the newly designed screw could function properly in the output range 0.75-0.90 kg/min, which is close to the design value. Regarding the molasses's effect on solid fuel properties, increasing the share of molasses was positive for both output and strength of the resulting briquettes, whereas the results of increasing die angle showed decreases in both output and strength. The compressive strength varied between 2.49-2.87 MPa in all circumstances, which was considerably higher than acceptable industrial level. Furthermore, the extruded solid fuel showed excellent resistance to impact force. Regarding energy consumption, the amount of electrical energy used in the extrusion process was insignificant, ranging between 0.040-0.079 kWh/kg.

  10. Fate of Fusarium mycotoxins in maize flour and grits during extrusion cooking.

    Science.gov (United States)

    Scudamore, Keith A; Guy, Robin C E; Kelleher, Brian; MacDonald, Susan J

    2008-11-01

    Extrusion technology is used widely in the manufacture of a range of breakfast cereals and snacks for human consumption and animal feeds. To minimise consumer exposure to mycotoxins, the levels of deoxynivalenol (DON) and zearalenone (ZON) in cereals/cereal products and fumonisins B(1) and B(2) (FB(1) and FB(2)) in maize are controlled by European Union legislation. Relatively few studies, however, have examined the loss of Fusarium mycotoxins during processing. The behaviour of FB(1), FB(2) and fumonisin B(3) (FB(3)), DON and ZON during extrusion of naturally contaminated maize flour and maize grits is examined using pilot-scale equipment. DON and ZON are relatively stable during extrusion cooking but the fumonisins are lost to varying degrees. There is some loss of ZON when present in low concentrations and extruded at higher moisture contents. The presence of additives, such as reducing sugars and sodium chloride, can also affect mycotoxin levels. Moisture content of the cereal feed during extrusion is important and has a greater effect than temperature, particularly on the loss of fumonisins at the lower moistures. The effects are complex and not easy to explain, although more energy input to the extruder is required for drier materials. However, on the basis of these studies, the relationship between the concentration of Fusarium toxins in the raw and finished product is toxin- and process-dependent.

  11. A comparative study of the effect of spray drying and hot-melt extrusion on the properties of amorphous solid dispersions containing felodipine.

    Science.gov (United States)

    Mahmah, Osama; Tabbakh, Rami; Kelly, Adrian; Paradkar, Anant

    2014-02-01

    To compare the properties of solid dispersions of felodipine for oral bioavailability enhancement using two different polymers, polyvinylpyrrolidone (PVP) and hydroxypropyl methylcellulose acetate succinate (HPMCAS), by hot-melt extrusion (HME) and spray drying. Felodipine solid dispersions were prepared by HME and spray drying techniques. PVP and HPMCAS were used as polymer matrices at different drug : polymer ratios (1 : 1, 1 : 2 and 1 : 3). Detailed characterization was performed using differential scanning calorimetry, powder X-ray diffractometry, scanning electron microscopy and in-vitro dissolution testing. Dissolution profiles were evaluated in the presence of sodium dodecyl sulphate. Stability of different solid dispersions was studied under accelerated conditions (40°C/75% RH) over 8 weeks. Spray-dried formulations were found to release felodipine faster than melt extruded formulations for both polymer matrices. Solid dispersions containing HMPCAS exhibited higher drug release rates and better wettability than those produced with a PVP matrix. No significant differences in stability were observed except with HPMCAS at a 1 : 1 ratio, where crystallization was detected in spray-dried formulations. Solid dispersions of felodipine produced by spray drying exhibited more rapid drug release than corresponding melt extruded formulations, although in some cases improved stability was observed for melt extruded formulations. © 2013 Royal Pharmaceutical Society.

  12. Flow behavior of polymers during the roll-to-roll hot embossing process

    International Nuclear Information System (INIS)

    Deng, Yujun; Yi, Peiyun; Peng, Linfa; Lai, Xinmin; Lin, Zhongqin

    2015-01-01

    The roll-to-roll (R2R) hot embossing process is a recent advancement in the micro hot embossing process and is capable of continuously fabricating micro/nano-structures on polymers, with a high efficiency and a high throughput. However, the fast forming of the R2R hot embossing process limits the time for material flow and results in complicated flow behavior in the polymers. This study presents a fundamental investigation into the flow behavior of polymers and aims towards the comprehensive understanding of the R2R hot embossing process. A three-dimensional (3D) finite element (FE) model based on the viscoelastic model of polymers is established and validated for the fabrication of micro-pyramids using the R2R hot embossing process. The deformation and recovery of micro-pyramids on poly(vinyl chloride) (PVC) film are analyzed in the filling stage and the demolding stage, respectively. Firstly, in the analysis of the filling stage, the temperature distribution on the PVC film is discussed. A large temperature gradient is observed along the thickness direction of the PVC film and the temperature of the top surface is found to be higher than that of the bottom surface, due to the poor thermal conductivity of PVC. In addition, creep strains are demonstrated to depend highly on the temperature and are also observed to concentrate on the top layer of the PVC film because of high local temperature. In the demolding stage, the recovery of the embossed micro-pyramids is obvious. The cooling process is shown to be efficient for the reduction of recovery, especially when the mold temperature is high. In conclusion, this research advances the understanding of the flow behavior of polymers in the R2R hot embossing process and might help in the development of the highly accurate and highly efficient fabrication of microstructures on polymers. (paper)

  13. Significance of fundamental processes of radiation chemistry in hot atom chemical processes: electron thermalization

    International Nuclear Information System (INIS)

    Nishikawa, M.

    1984-01-01

    The author briefly reviews the current understanding of the course of electron thermalization. An outline is given of the physical picture without going into mathematical details. The analogy of electron thermalization with hot atom processes is taken as guiding principle in this paper. Content: secondary electrons (generation, track structure, yields); thermalization (mechanism, time, spatial distribution); behaviour of hot electrons. (Auth.)

  14. Effect of hot-dip galvanizing processes on the microstructure and mechanical properties of 600-MPa hot-dip galvanized dual-phase steel

    Science.gov (United States)

    Kuang, Chun-fu; Zheng, Zhi-wang; Wang, Min-li; Xu, Quan; Zhang, Shen-gen

    2017-12-01

    A C-Mn dual-phase steel was soaked at 800°C for 90 s and then either rapidly cooled to 450°C and held for 30 s (process A) or rapidly cooled to 350°C and then reheated to 450°C (process B) to simulate the hot-dip galvanizing process. The influence of the hot-dip galvanizing process on the microstructure and mechanical properties of 600-MPa hot-dip galvanized dual-phase steel (DP600) was investigated using optical microscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and tensile tests. The results showed that, in the case of process A, the microstructure of DP600 was composed of ferrite, martensite, and a small amount of bainite. The granular bainite was formed in the hot-dip galvanizing stage, and martensite islands were formed in the final cooling stage after hot-dip galvanizing. By contrast, in the case of process B, the microstructure of the DP600 was composed of ferrite, martensite, bainite, and cementite. In addition, compared with the yield strength (YS) of the DP600 annealed by process A, that for the DP600 annealed by process B increased by approximately 50 MPa because of the tempering of the martensite formed during rapid cooling. The work-hardening coefficient ( n value) of the DP600 steel annealed by process B clearly decreased because the increase of the YS affected the computation result for the n value. However, the ultimate tensile strength (UTS) and elongation ( A 80) of the DP600 annealed by process B exhibited less variation compared with those of the DP600 annealed by process A. Therefore, DP600 with excellent comprehensive mechanical properties (YS = 362 MPa, UTS = 638 MPa, A 80 = 24.3%, n = 0.17) was obtained via process A.

  15. Modelling the Thermo-Mechanical Behavior of Magnesium Alloys during Indirect Extrusion

    International Nuclear Information System (INIS)

    Steglich, D.; Ertuerk, S.; Bohlen, J.; Letzig, D.; Brocks, W.

    2010-01-01

    One of the basic metal forming process for semi-finished products is extrusion. Since extrusion involves complex thermo-mechanical and multiaxial loading conditions resulting in large strains, high strain rates and an increase in temperature due to deformation, a proper yield criterion and hardening law should be used in the numerical modelling of the process. A phenomenological model based on a plastic potential has been proposed that takes strain, strain rate and temperature dependency on flow behaviour into consideration. A hybrid methodology of experiment and finite element simulation has been adopted in order to obtain necessary model parameters. The anisotropy/asymmetry in yielding was quantified by tensile and compression tests of specimens prepared from different directions. The identification of the corresponding model parameters was performed by a genetic algorithm. A fully coupled thermo-mechanical analysis has been used in extrusion simulations for calculation of the temperature field by considering heat fluxes and heat generated due to plastic deformation. The results of the approach adopted in this study appeared to be successful showing promising predictions of the experiments and thus may be extended to be applicable to other magnesium alloys or even other hcp metals.

  16. Conceptual design report of hot cell modification and process for fission Mo-99 production

    International Nuclear Information System (INIS)

    Park, Jin Ho; Choung, W. M.; Lee, K. I.; Hwang, D. S.; Kim, Y. K.; Park, K. B.; Jung, Y. J.; Kim, D. S.; Park, Y. C.

    2001-05-01

    In this conceptual design report, the basic data and design guides for detail design of fission Mo-99 production process and hot cell modification are included.The basic data and design guides for detail design of fission Mo-99 production process contains following contents. -design capacity, the basic process, process flow diagram, process material balance, process data. The basic data and design guides for modification of existing hot cell contains following contents. - plot plan of hot cell facility, the plan for shield reinforcement of hot cell, the plan for management and storage of high level liquid wastes, the plan of ventilation system, the plan for modification of auxiliary facilities. And also, the results of preliminary safety analysis(normal operation and accidents) and criticality analysis are included in this conceptual design report

  17. Conceptual design report of hot cell modification and process for fission Mo-99 production

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jin Ho; Choung, W. M.; Lee, K. I.; Hwang, D. S.; Kim, Y. K.; Park, K. B.; Jung, Y. J.; Kim, D. S.; Park, Y. C

    2001-05-01

    In this conceptual design report, the basic data and design guides for detail design of fission Mo-99 production process and hot cell modification are included.The basic data and design guides for detail design of fission Mo-99 production process contains following contents. -design capacity, the basic process, process flow diagram, process material balance, process data. The basic data and design guides for modification of existing hot cell contains following contents. - plot plan of hot cell facility, the plan for shield reinforcement of hot cell, the plan for management and storage of high level liquid wastes, the plan of ventilation system, the plan for modification of auxiliary facilities. And also, the results of preliminary safety analysis(normal operation and accidents) and criticality analysis are included in this conceptual design report.

  18. Melt extrusion vs. spray drying: The effect of processing methods on crystalline content of naproxen-povidone formulations.

    Science.gov (United States)

    Haser, Abbe; Cao, Tu; Lubach, Joe; Listro, Tony; Acquarulo, Larry; Zhang, Feng

    2017-05-01

    Our hypothesis is that melt extrusion is a more suitable processing method than spray drying to prepare amorphous solid dispersions of drugs with a high crystallization tendency. Naproxen-povidone K25 was used as the model system in this study. Naproxen-povidone K25 solid dispersions at 30% and 60% drug loadings were characterized by modulated DSC, powder X-ray diffraction, FT-IR, and solid-state 13 C NMR to identify phase separation and drug recrystallization during processing and storage. At 30% drug loading, hydrogen bond (H-bond) sites of povidone K25 were not saturated and the glass transition (T g ) temperature of the formulation was higher. As a result, both melt-extruded and spray-dried materials were amorphous initially and remained so after storage at 40°C. At 60% drug loading, H-bond sites were saturated, and T g was low. We were not able to prepare amorphous materials. The initial crystallinity of the formulations was 0.4%±0.2% and 5.6%±0.6%, and increased to 2.7%±0.3% and 21.6%±1.0% for melt-extruded and spray-dried materials, respectively. Spray-dried material was more susceptible to re-crystallization during processing, due to the high diffusivity of naproxen molecules in the formulation matrix and lack of kinetic stabilization from polymer solution. A larger number of crystalline nucleation sites and high surface area made the spray-dried material more susceptible to recrystallization during storage. This study demonstrated the unique advantages of melt extrusion over spray drying for the preparation of amorphous solid dispersions of naproxen at high drug level. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Parallel assembling and equation solving via graph algorithms with an application to the FE simulation of metal extrusion processes

    CERN Document Server

    Unterkircher, A

    2005-01-01

    We propose methods for parallel assembling and iterative equation solving based on graph algorithms. The assembling technique is independent of dimension, element type and model shape. As a parallel solving technique we construct a multiplicative symmetric Schwarz preconditioner for the conjugate gradient method. Both methods have been incorporated into a non-linear FE code to simulate 3D metal extrusion processes. We illustrate the efficiency of these methods on shared memory computers by realistic examples.

  20. Application of processing maps in the optimization of the parameters of a hot working process. Part 1. Theoretical review

    International Nuclear Information System (INIS)

    Al Omar, A.; Prado, J.M.

    1997-01-01

    The hot working processes constitute an important step in the manufacture of components for engineering applications. In the past, the mechanical processing have been used to impart a shape to the engineering materials. More recently, however, the hot working processes are used not only to achieve the required shape but also to impart desirable mechanical and microstructural characteristics by an adequate design of the thermomechanical process. The aim of the present paper is to summarize the general characteristics of the Dynamic Materials Model. In this model, the work piece material under hot working conditions is considered to be a dissipator of power. Also, the extreme principles of irreversible thermodynamics applied to large plastic flow are described to develop a continuum criterion capable to predict the metallurgical instabilities in a hot worked material. (Author) 22 refs

  1. Novel fiber-rich lentil flours as snack-type functional foods: an extrusion cooking effect on bioactive compounds.

    Science.gov (United States)

    Morales, P; Berrios, J De J; Varela, A; Burbano, C; Cuadrado, C; Muzquiz, M; Pedrosa, M M

    2015-09-01

    Novel snack-type functional foods based on extruded lentil flours could convey the related health benefit of their bioactive compounds, provide a gluten-free alternative to consumers, and potentially increase the consumption of pulses. Extrusion treatment promoted an increase in galactopinitol, ciceritol, raffinose, stachyose and total α-galactoside content, in most lentil flours. As α-galactosides may act as prebiotics, they could convey beneficial effects to human and monogastric animals. Conversely, extrusion significantly (p < 0.05) reduced the inositol hexaphosphate content to less phosphorylated phytates (inositol pentaphosphate and inositol tetraphosphate), which provide health effects. The gluten-free formulation (control formulation #3) presented the highest significant (p < 0.05) drop in the inositol hexaphosphate of 14.7-fold decrease, but had a large increase in inositol pentaphosphate, due to extrusion processing. These two results are desirable in the finished product. Extrusion also caused a significant (p < 0.05) reduction in the trypsin content and completely inactivated lectin, in all processed samples.

  2. Plasticized chitosan/polyolefin films produced by extrusion.

    Science.gov (United States)

    Matet, Marie; Heuzey, Marie-Claude; Ajji, Abdellah; Sarazin, Pierre

    2015-03-06

    Plasticized chitosan and polyethylene blends were produced through a single-pass extrusion process. Using a twin-screw extruder, chitosan plasticization was achieved in the presence of an acetic acid solution and glycerol, and directly mixed with metallocene polyethylene, mPE, to produce a masterbatch. Different dilutions of the masterbatch (2, 5 and 10 wt% of plasticized chitosan), in the presence of ethylene vinyl acetate, EVA, were subsequently achieved in single screw film extrusion. Very small plasticized chitosan domains (number average diameter <5 μm) were visible in the polymeric matrix. The resulting films presented a brown color and increasing haze with chitosan plasticized content. Mechanical properties of the mPE films were affected by the presence of plasticized chitosan, but improvement was observed as a result of some compatibility between mPE and chitosan in the presence of EVA. Finally the incorporation of plasticized chitosan affected mPE water vapor permeability while oxygen permeability remained constant. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. A sustainable solid state recycling of pure aluminum by means of friction stir extrusion process (FSE)

    Science.gov (United States)

    Mehtedi, Mohamad El; Forcellese, Archimede; Simoncini, Michela; Spigarelli, Stefano

    2018-05-01

    In this research, the feasibility of solid-state recycling of pure aluminum AA1099 machining chips using FSE process is investigated. In the early stage, a FE simulation was conducted in order to optimize the die design and the process parameters in terms of plunge rotational speed and extrusion rate. The AA1099 aluminum chips were produced by turning of an as-received bar without lubrication. The chips were compacted on a MTS machine up to 150KN of load. The extruded samples were analyzed by optical and electron microscope in order to see the material flow and to characterize the microstructure. Finally, micro-hardness Vickers profiles were carried out, in both longitudinal and transversal direction of the obtained profiles, in order to investigate the homogeneity of the mechanical properties of the extrudate.

  4. Application of extrusion-cooking technique for foamed starch-based materials

    Directory of Open Access Journals (Sweden)

    Combrzyński Maciej

    2018-01-01

    Full Text Available Foamed materials are widely used, mainly as a protection objects during transport of various products. Traditionally foams are produced from plastics so they are very difficult for waste management. It is the challenge for many scientific centres to develop a technology for the production of bio-based materials which can be rapidly decomposed. The task for the researcher is to obtain a relatively cheap, easy to use and completely biodegradable materials. The aim of this work was the selection of the main raw materials, functional additives and process parameters to obtain the most effective parameters of extrusion-cooking process for foamed starch-based materials. Properties of the products and processing costs were taken into account. During the study, the extrusion-cooking process was performed under various conditions: temperature, humidity, type of the die, screw rotational speed, various raw materials and additives blends. The best results were obtained for mixtures based on potato starch and with addition the foaming agent Plastron foam PDE and poly(vinyl alcohol PVA.

  5. Material testing of copper by extrusion-cutting

    DEFF Research Database (Denmark)

    Segalina, F.; De Chiffre, Leonardo

    2017-01-01

    was developed and implemented on a CNC lathe. An investigation was carried out extrusion-cutting copper discs using high-speed-steel cutting tools at 100 m/min cutting speed. Flow stress values for copper under machining-relevant conditions were obtained from measurement of the extrusion-cutting force...

  6. Effect of Multiple Extrusions on the Impact Properties of Polypropylene/Clay Nanocomposites

    DEFF Research Database (Denmark)

    Klitkou, Rasmus; Jensen, Erik Appel; Christiansen, Jesper de Claville

    2012-01-01

    Polypropylene (PP)-based polymer nanocomposites containing organically modified montmorillonite (OMMT) with and without maleic anhydride grafted PP, were compounded by twin-screw extrusion. The extrusion process was repeated various numbers of times to increase the extruder residence time (TR) and......) increased monotonically with increased TR by 70% from least dispersed to best dispersed, which was still 20% below the level for neat PP. Both the fracture initiation energy and propagation energy increased with TR, but the primary effect on ri came from the fracture propagation energy, which delivered 80...

  7. Ultrasound-Assist Extrusion Methods for the Fabrication of Polymer Nanocomposites Based on Polypropylene/Multi-Wall Carbon Nanotubes

    Science.gov (United States)

    Ávila-Orta, Carlos A.; Quiñones-Jurado, Zoe V.; Waldo-Mendoza, Miguel A.; Rivera-Paz, Erika A.; Cruz-Delgado, Víctor J.; Mata-Padilla, José M.; González-Morones, Pablo; Ziolo, Ronald F.

    2015-01-01

    Isotactic polypropylenes (iPP) with different melt flow indexes (MFI) were used to fabricate nanocomposites (NCs) with 10 wt % loadings of multi-wall carbon nanotubes (MWCNTs) using ultrasound-assisted extrusion methods to determine their effect on the morphology, melt flow, and electrical properties of the NCs. Three different types of iPPs were used with MFIs of 2.5, 34 and 1200 g/10 min. Four different NC fabrication methods based on melt extrusion were used. In the first method melt extrusion fabrication without ultrasound assistance was used. In the second and third methods, an ultrasound probe attached to a hot chamber located at the exit of the die was used to subject the sample to fixed frequency and variable frequency, respectively. The fourth method is similar to the first method, with the difference being that the carbon nanotubes were treated in a fluidized air-bed with an ultrasound probe before being used in the fabrication of the NCs with no ultrasound assistance during extrusion. The samples were characterized by MFI, Optical microscopy (OM), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), electrical surface resistivity, and electric charge. MFI decreases in all cases with addition of MWCNTs with the largest decrease observed for samples with the highest MFI. The surface resistivity, which ranged from 1013 to 105 Ω/sq, and electric charge, were observed to depend on the ultrasound-assisted fabrication method as well as on the melt flow index of the iPP. A relationship between agglomerate size and area ratio with electric charge was found. Several trends in the overall data were identified and are discussed in terms of MFI and the different fabrication methods. PMID:28793686

  8. Effects of raw material extrusion and steam conditioning on feed pellet quality and nutrient digestibility of growing meat rabbits.

    Science.gov (United States)

    Liao, Kuoyao; Cai, Jingyi; Shi, Zhujun; Tian, Gang; Yan, Dong; Chen, Delin

    2017-06-01

    This study was conducted to investigate the effects of raw material extrusion and steam conditioning on feed pellet quality and nutrient digestibility of growing meat rabbits, in order to determine appropriate rabbit feed processing methods and processing parameters. In Exp. 1, an orthogonal design was adopted. Barrel temperature, material moisture content and feed rate were selected as test factors, and acid detergent fiber (ADF) content was selected as an evaluation index to research the optimum extrusion parameters. In Exp. 2, a two-factor design was adopted. Four kinds of rabbit feeds were processed and raw material extrusion adopted optimum extrusion parameters of Exp. 1. A total of 40 healthy and 42-day-old rabbits with similar weight were used in a randomized design, which consisted of 4 groups and 10 replicates in each group (1 rabbits in each replicate). The adaptation period lasted for 7 d, and the digestion trial lasted for 4 d. The results showed as follows: 1) ADF was significantly affected by barrel temperature ( P  digestibility of dry matter and total energy ( P  digestibility of crude fiber (CF), ADF and NDF ( P  digestibility of rabbit feed. Thus, using extrusion and steam conditioning technology at the same time in the weaning rabbits feed processing can improve the pellet quality and nutrient apparent digestibility of rabbit feed.

  9. Expansion of the whole wheat flour extrusion

    DEFF Research Database (Denmark)

    Cheng, Hongyuan; Friis, Alan

    2008-01-01

    A new model framework is proposed to describe the expansion of extrudates with extruder operating conditions based on dimensional analysis principle. The Buckingham pi dimensional analysis method is applied to form the basic structure of the model from extrusion process operational parameters. Us....... Using the Central Composite Design (CCD) method, whole wheat flour was processed in a twin-screw extruder with 16 trials. The proposed model can well correlate the expansion of the 16 trials using 3 regression parameters. The average deviation of the correlation is 5.9%....

  10. Safety evaluation report of hot cell facilities for demonstration of advanced spent fuel conditioning process

    International Nuclear Information System (INIS)

    You, Gil Sung; Choung, W. M.; Ku, J. H.; Cho, I. J.; Kook, D. H.; Park, S. W.; Bek, S. Y.; Lee, E. P.

    2004-10-01

    The advanced spent fuel conditioning process(ACP) proposed to reduce the overall volume of the PWR spent fuel and improve safety and economy of the long-term storage of spent fuel. In the next phase(2004∼2006), the hot test will be carried out for verification of the ACP in a laboratory scale. For the hot test, the hot cell facilities of α- type and auxiliary facilities are required essentially for safe handling of high radioactive materials. As the hot cell facilities for demonstration of the ACP, a existing hot cell of β- type will be refurbished to minimize construction expenditures of hot cell facility. Up to now, the detail design of hot cell facilities and process were completed, and the safety analysis was performed to substantiate secure of conservative safety. The design data were submitted for licensing which was necessary for construction and operation of hot cell facilities. The safety investigation of KINS on hot cell facilities was completed, and the license for construction and operation of hot cell facilities was acquired already from MOST. In this report, the safety analysis report submitted to KINS was summarized. And also, the questionnaires issued from KINS and answers of KAERI in process of safety investigation were described in detail

  11. Extrusion of the uranium-0.75 weight percent titanium alloy

    International Nuclear Information System (INIS)

    Jackson, R.J.; Lundberg, M.R.; Boland, J.F.

    1975-01-01

    Procedures are described for extruding the U--0.75 wt percent Ti alloy in the high alpha region (600 to 640 0 C) , and in the upper gamma region (900 to 1000 0 C). The casting of sound extrusion billets has importance in the production of sound extrusions, and procedures are given for casting sound billets up to 1,100 kilograms . Also important in producing sound extrusions is the use of glass lubricants. Reduction ratios of greater than 50 to 1 were achieved on reasonably sized billets. Extrusion constants of 48,000 pounds per square inch (psi) [296 megapascals (MPa)] for alpha phase (630 0 C) and 8,000 psi (56 MPa) for gamma phase (950 0 C) were achieved. Gamma-phase extrusion has preference over alpha-phase extrusion in that larger billets can be used and temperature control is not as critical. However alpha-phase extrusion offers better surface finish, less die wear, and fewer oxidation problems. Billets up to 14 inches in diameter have been successfully gamma-extruded and plans exist for extruding billets up to 20 inches (508 millimetres) in diameter. (U.S.)

  12. Assessment of extrusion-sonication process on flame retardant polypropylene by rheological characterization

    Directory of Open Access Journals (Sweden)

    Guadalupe Sanchez-Olivares

    2016-05-01

    Full Text Available In this work, the rheological behavior of flame retardant polypropylene composites produced by two methods: 1 twin-screw extrusion and 2 ultrasound application combined with a static mixer die single-screw extrusion is analyzed in detail; results are related to the morphology of the composites. The flame retardant polymer composites are composed of a polypropylene matrix, an intumescent flame retardant system and functionalized clay. Scanning electron microscopy revealed that the combination of the static mixer die and on-line sonication reduced particle size and improved the dispersion and distribution of the intumescent additives in the polypropylene matrix at the micrometric level. From linear viscoelastic properties, the Han, Cole-Cole and van Gurp-Palmen diagrams characterized the improved particle dispersion of the flame retardant additives. Two well-defined rheological behaviors were observed in these diagrams. These behaviors are independent on clay presence and concentration. In fact, the ultrasound device generates a 3D highly interconnected structure similar to a co-continuous pattern observed in polymer blends as evidenced by rheological measurements. This improvement in the dispersion and distribution of the additives is attributed to the combined effect of the static mixer die and on-line sonication that allowed reducing the additive content while achieving the optimum classification UL94-V0.

  13. Microstructures and mechanical properties evolution of an Al–Fe–Cu alloy processed by repetitive continuous extrusion forming

    Energy Technology Data Exchange (ETDEWEB)

    Kong, Xiangxin [College of Materials Science and Engineering, Hunan University, Changsha 410082 (China); Zhang, Hui, E-mail: zhanghui63hunu@163.com [College of Materials Science and Engineering, Hunan University, Changsha 410082 (China); Hunan Province Key Laboratory for Spray Deposition Technology and Application, Hunan University, Changsha 410082 (China); Ji, Xiankun [College of Materials Science and Engineering, Hunan University, Changsha 410082 (China)

    2014-08-26

    Repetitive continuous extrusion forming process (R-Conform process), as a continuous severe plastic deformation method, was performed on a horizontal continuous casting Al–0.74Fe–0.23Cu alloy. The microstructural evolution and mechanical properties were studied by optical microscope, X-ray diffraction, scanning electron microscope, transmission electron microscope, and tensile testing. The results show that tensile ductility of the Al–0.74Fe–0.23Cu alloy is greatly improved but tensile strength is gradually decreased after repetitive Conform processing. The necking is more intense and the size of dimples becomes bigger with increasing Conform passes. The first pass Conform process induces obviously grains refining, dissolution of AlFe, AlFeSi and AlSi primary phases, strain-induced precipitation and transformation of crystal orientation distributions, but further Conform deformation only changes the redistribution of precipitates. The changes of mechanical properties may be attributed to a complex progress of recovery, recrystallization and redistribution of precipitates during repetitive Conform process.

  14. Some physicochemical properties of dextrin produced by extrusion process

    Directory of Open Access Journals (Sweden)

    Achmat Sarifudin

    2014-06-01

    Full Text Available Dextrinization of corn starch by twin screw extruder was studied. The effect of extruder operating conditions (five different screw speeds: 35, 45, 55, 65, and 70; and three temperatures: 125, 130, and 135 °C on some physicochemical properties of dextrin (total soluble solid, water absorption index, water solubility index, and total color difference was investigated. Results showed that as the screw speed and temperature of extrusion were increased the water absorption index of dextrin tended to drop meanwhile the total soluble solid, water solubility index, and color were inclined to rise. The range of total soluble solid, water absorption index, water solubility index and total color difference was 2.1–4.6 Brix, 159–203%, 20–51%, 3.5–14.1, respectively.

  15. Investigation of multi-stage cold forward extrusion process using coupled thermo-mechanical finite element analysis

    Science.gov (United States)

    Görtan, Mehmet Okan

    2018-05-01

    Cold extrusion processes are distinguished by their low material usage as well as great efficiency in the production of mid-range and large component series. Although majority of the cold extruded parts are produced using die systems containing multiple forming stages, this subject has rarely been investigated so far. Therefore, the characteristics of multi-stage cold forward rod extrusion is studied in the current work using thermo-mechanically coupled finite element (FE) analysis. A case hardening steel, 16MnCr5 (1.7131) was used as experimental material. Its strain, strain rate and temperature dependent mechanical characteristics were determined using compression testing and modeled in FE simulations via a Johnson-Cook material model. Friction coefficients for the same material while in contact with a tool steel (1.2379) were determined dependent on temperature and contact pressure using sliding compression test (SCT) and modeled by an adaptive friction model developed by the author. In the first set of simulations, rod material with a diameter of 14.9 mm was extruded down to a diameter of 9.6 mm in a single step using three different die opening angles (2α); 20°, 40° and 60°. In the second set of investigations, the same rod was reduced first to 12 mm and then to 9.6 mm in two steps within the same forming die. Press forces, contact normal stresses between extruded material and forming die, material temperature and axial stresses are compared in these two set of simulations and the differences are discussed.

  16. Real-time monitoring of the laser hot-wire welding process

    Science.gov (United States)

    Liu, Wei; Liu, Shuang; Ma, Junjie; Kovacevic, Radovan

    2014-04-01

    The laser hot-wire welding process was investigated in this work. The dynamics of the molten pool during welding was visualized by using a high-speed charge-coupled device (CCD) camera assisted by a green laser as an illumination source. It was found that the molten pool is formed by the irradiation of the laser beam on the filler wire. The effect of the hot-wire voltage on the stability of the welding process was monitored by using a spectrometer that captured the emission spectrum of the laser-induced plasma plume. The spectroscopic study showed that when the hot-wire voltage is above 9 V a great deal of spatters occur, resulting in the instability of the plasma plume and the welding process. The effect of spatters on the plasma plume was shown by the identified spectral lines of the element Mn I. The correlation between the Fe I electron temperature and the weld-bead shape was studied. It was noted that the electron temperature of the plasma plume can be used to real-time monitor the variation of the weld-bead features and the formation of the weld defects.

  17. Statistical analysis of process parameters to eliminate hot cracking of fiber laser welded aluminum alloy

    Science.gov (United States)

    Wang, Jin; Wang, Hui-Ping; Wang, Xiaojie; Cui, Haichao; Lu, Fenggui

    2015-03-01

    This paper investigates hot cracking rate in Al fiber laser welding under various process conditions and performs corresponding process optimization. First, effects of welding process parameters such as distance between welding center line and its closest trim edge, laser power and welding speed on hot cracking rate were investigated experimentally with response surface methodology (RSM). The hot cracking rate in the paper is defined as ratio of hot cracking length over the total weld seam length. Based on the experimental results following Box-Behnken design, a prediction model for the hot cracking rate was developed using a second order polynomial function considering only two factor interaction. The initial prediction result indicated that the established model could predict the hot cracking rate adequately within the range of welding parameters being used. The model was then used to optimize welding parameters to achieve cracking-free welds.

  18. Acid-extrusion from tissue: the interplay between membrane transporters and pH buffers.

    Science.gov (United States)

    Hulikova, Alzbeta; Harris, Adrian L; Vaughan-Jones, Richard D; Swietach, Pawel

    2012-01-01

    The acid-base balance of cells is related to the concentration of free H⁺ ions. These are highly reactive, and their intracellular concentration must be regulated to avoid detrimental effects to the cell. H⁺ ion dynamics are influenced by binding to chelator substances ('buffering'), and by the production, diffusion and membrane-transport of free H⁺ ions or of the H⁺-bound chelators. Intracellular pH (pHi) regulation aims to balance this system of diffusion-reaction-transport processes at a favourable steady-state pHi. The ability of cells to regulate pHi may set a limit to tissue growth and can be subject to selection pressures. Cancer cells have been postulated to respond favourably to such selection pressures by evolving a better means of pHi regulation. A particularly important feature of tumour pHi regulation is acid-extrusion, which involves H⁺-extrusion and HCO₃⁻-uptake by membrane-bound transporter-proteins. Extracellular CO₂/HCO₃⁻ buffer facilitates these membrane-transport processes. As a mobile pH-buffer, CO₂/HCO₃⁻ protects the extracellular space from excessive acidification that could otherwise inhibit further acid-extrusion. CO₂/HCO₃⁻ also provides substrate for HCO₃⁻-transporters. However, the inherently slow reaction kinetics of CO₂/HCO₃⁻ can be rate-limiting for acid-extrusion. To circumvent this, cells can express extracellular-facing carbonic anhydrase enzymes to accelerate the attainment of equilibrium between CO₂, HCO₃⁻ and H⁺. The acid-extrusion apparatus has been proposed as a target for anti-cancer therapy. The major targets include H⁺ pumps, Na⁺/H⁺ exchangers and carbonic anhydrases. The effectiveness of such therapy will depend on the correct identification of rate-limiting steps in pHi regulation in a specific type of cancer.

  19. Demonstration of pharmaceutical tablet coating process by injection molding technology.

    Science.gov (United States)

    Puri, Vibha; Brancazio, David; Harinath, Eranda; Martinez, Alexander R; Desai, Parind M; Jensen, Keith D; Chun, Jung-Hoon; Braatz, Richard D; Myerson, Allan S; Trout, Bernhardt L

    2018-01-15

    We demonstrate the coating of tablets using an injection molding (IM) process that has advantage of being solvent free and can provide precision coat features. The selected core tablets comprising 10% w/w griseofulvin were prepared by an integrated hot melt extrusion-injection molding (HME-IM) process. Coating trials were conducted on a vertical injection mold machine. Polyethylene glycol and polyethylene oxide based hot melt extruded coat compositions were used. Tablet coating process feasibility was successfully demonstrated using different coating mold designs (with both overlapping and non-overlapping coatings at the weld) and coat thicknesses of 150 and 300 μm. The resultant coated tablets had acceptable appearance, seal at the weld, and immediate drug release profile (with an acceptable lag time). Since IM is a continuous process, this study opens opportunities to develop HME-IM continuous processes for transforming powder to coated tablets. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Coercivity enhancement of HDDR-processed Nd-Fe-B permanent magnet with the rapid hot-press consolidation process

    Energy Technology Data Exchange (ETDEWEB)

    Nozawa, N. [Magnetic Materials Research Laboratory, NEOMAX Company, Hitachi Metals Ltd., Osaka 618-0013 (Japan); Sepehri-Amin, H. [Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba 305-8571 (Japan); Magnetic Materials Center, National Institute for Materials Science, Tsukuba 305-0047 (Japan); Ohkubo, T. [Magnetic Materials Center, National Institute for Materials Science, Tsukuba 305-0047 (Japan); Hono, K. [Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba 305-8571 (Japan); Magnetic Materials Center, National Institute for Materials Science, Tsukuba 305-0047 (Japan); Nishiuchi, T. [Magnetic Materials Research Laboratory, NEOMAX Company, Hitachi Metals Ltd., Osaka 618-0013 (Japan); Hirosawa, S., E-mail: Satoshi_Hirosawa@hitachi-metals.co.j [Magnetic Materials Research Laboratory, NEOMAX Company, Hitachi Metals Ltd., Osaka 618-0013 (Japan)

    2011-01-15

    High coercivity, fully dense anisotropic permanent magnets of submicron grain sizes were produced by rapid hot-press consolidation of hydrogenation-disproportionation-desorption-recombination (HDDR) processed Nd-Fe-Co-B powders. In the hot-press process, the coercivity of the consolidated material showed a sharp minimum prior to full densification. Thereafter, it reached a value 25% higher than that of the initial powder. Scanning electron microscopy and transmission electron microscopy observations revealed that the variation in H{sub cJ} was caused by a redistribution of Nd along the grain boundaries during hot pressing and that the high coercivity was attributable to the formation of thin, continuous Nd-rich phase along the grain boundaries.

  1. Oxide dispersion strengthened ferritic alloys. 14/20% chromium: effects of processing on deformation texture, recrystallization and tensile properties

    International Nuclear Information System (INIS)

    Regle, H.

    1994-01-01

    The ferritic oxide dispersion strengthened alloys are promising candidates for high temperature application materials, in particular for long life core components of advanced nuclear reactors. The aim of this work is to control the microstructure, in order to optimise the mechanical properties. The two ferritic alloys examined here, MA956 and MA957, are obtained by Mechanical Alloying techniques. They are characterised by quite anisotropic microstructure and mechanical properties. We have investigated the influence of hot and cold working processes (hot extrusion, swaging and cold-drawing) and recrystallization heat treatments on deformation textures, microstructures and tensile properties. The aim was to control the size of the grains and their anisotropic shape, using recrystallization heat treatments. After consolidation and hot extrusion, as-received materials present a extremely fine microstructure with elongated grains and a very strong (110) deformation texture with single-crystal character. At that stage of processing, recrystallization temperature are very high (1450 degrees C for MA957 alloy and 1350 degrees C for MA956 alloy) and materials develop millimetric recrystallized grains. Additional hot extrusion induce a fibre texture. Cold-drawing maintains a fibre texture, but the intensity decreases with increasing cold-work level. For both materials, the decrease of texture intensities correspond to a decrease of the recrystallization temperatures (from 1350 degrees C for a low cold-work level to 750 degrees C for 60 % cold-deformation, case of MA956 alloy) and a refinement of the grain size (from a millimetric size to less than an hundred of micrometer). Swaging develop a cyclic component where the intensity increases with increasing deformation in this case, the recrystallization temperature remains always very high and the millimetric grain size is slightly modified, even though cold-work level increases. Technologically, cold-drawing is the only way

  2. Limits of Lubrication in Backward Can Extrusion

    DEFF Research Database (Denmark)

    Bennani, B; Bay, Niels

    1996-01-01

    The increasing demand in industry to produce cans at low reduction by the backward extrusion process involves better understanding of this process. To analyse the process, numerical simulations by the finite-element method and experimental simulations by physical modelling using wax as a model...... on the reduction, the punch geometry, the workpiece material and the friction factor, in order to avoid the risk of damage caused by stiction of the workpiece material to the punch face. The influence of these different parameters on the distribution of the surface expansion along the inner can wall and bottom...... is determined. The numerical and experimental simulations showed good accordance....

  3. Control of material flow in a combined backward can - forward rod extrusion

    DEFF Research Database (Denmark)

    Kuzman, K; Pfeifer, E; Bay, Niels

    1996-01-01

    of tool geometry, friction and lubrication as well as workpiece properties on balanced material flow in a combined extrusion process. The FEM analysis applying the DEFORM code has been used in order to predict the process parameters and to estimate its stability. The subsequent experimental verification...

  4. The Process of Thinking among Junior High School Students in Solving HOTS Question

    Science.gov (United States)

    Bakry, Md Nor Bin Bakar

    2015-01-01

    Higher order thinking skills (HOTS) is one of the important aspect of teaching and learning mathematics. By using HOTS, student will be able to acquire a deep understand of mathematical concepts and can be applied in real life. Students ability to develop the capacity of the HOTS is closely related with thinking processes while solving mathematics…

  5. Incorporation of ladle furnace slag in ceramic formulations: study of extrusion zones

    International Nuclear Information System (INIS)

    Feitosa, E.F.; Santana, C.M.; Luna, D.S.; Santos, D.M.S.; Silva, G.S.; Noleto, L.T.; Almeida, N.C.; Rabelo, A.A.; Fagury Neto, E.

    2016-01-01

    This study aimed to investigate the effect of incorporation of ladle furnace slag (LFS) in two clays with higher and lower plasticity, used for the manufacture of structural ceramics. The LFS from a local steel making plant was added to ceramic compositions in proportions of 8 %, 14 % and 16 %. The formulations were tested in appropriate equipment that measures the liquid limit and plastic limit. The property examined was the plasticity index, in order to make a study of the extrusion zones. Results showed that the addition of slag into clay mixtures alters the plasticity; however, the extrusion process was not hampered. (author)

  6. Experimental and numerical investigation of ram extrusion of bread dough

    Science.gov (United States)

    Mohammed, M. A. P.; Wanigasooriya, L.; Charalambides, M. N.

    2016-10-01

    An experimental and numerical study on ram extrusion of bread dough was conducted. A laboratory ram extrusion rig was designed and manufactured, where dies with different angles and exit radii were employed. Rate dependent behaviour was observed from tests conducted at different extrusion speeds, and higher extrusion pressure was reported for dies with decreasing exit radius. A finite element simulation of extrusion was performed using the adaptive meshing technique in Abaqus. Simulations using a frictionless contact between the billet and die wall showed that the model underestimates the response at high entry angles. On the other hand, when the coefficient of friction value was set to 0.09 as measured from friction experiments, the dough response was overestimated, i.e. the model extrusion pressure was much higher than the experimentally measured values. When a critical shear stress limit, τmax, was used, the accuracy of the model predictions improved. The results showed that higher die angles require higher τmax values for the model and the experiments to agree.

  7. Simulation and analysis of hot forging process for industrial locking gear elevators

    Science.gov (United States)

    Maarefdoust, M.; Kadkhodayan, M.

    2010-06-01

    In this paper hot forging process for industrial locking gear elevators is simulated and analyzed. An increase in demand of industrial locking gear elevators with better quality and lower price caused the machining process to be replaced by hot forging process. Production of industrial locking gear elevators by means of hot forging process is affected by many parameters such as billet temperature, geometry of die and geometry of pre-formatted billet. In this study the influences of billet temperature on effective plastic strain, radius of die corners on internal stress of billet and thickness of flash on required force of press are investigated by means of computer simulation. Three-dimensional modeling of initial material and die are performed by Solid Edge, while simulation and analysis of forging are performed by Super Forge. Based on the computer simulation the required dies are designed and the workpieces are formed. Comparison of simulation results with experimental data demonstrates great compatibility.

  8. Study on effects of powder and flake chemistry and morphology on the properties of Al-Cu-Mg-X-X-X powder metallurgy advanced aluminum alloys

    Science.gov (United States)

    Meschter, P. J.; Lederich, R. J.; Oneal, J. E.; Pao, P. S.

    1985-01-01

    The effects of alloy chemistry and particulate morphology on consolidation behavior and consolidated product properties in rapid solidification processed, powder-metallurgical Al-3Li-1.5Cu-1Mg-0.5Co-0.2Zr and Al-4.4Cu-1.5Mg-Fe-Ni-0.2Zr extrusions and forgings were studied. Microstructures and mechanical properties of both alloys are largely unaffected by particulate production method (vacuum atomization, ultrasonic atomization, or twin-roller quenching) and by particulate solidification rates between 1000 and 100,000 K/s. Consolidation processing by canning, cold compaction, degassing, and hot extrusion is sufficient to yield mechanical properties in the non-Li-containing alloy extrusions which are similar to those of 7075-Al, but ductilities and fracture toughnesses are inferior owing to poor interparticle bonding caused by lack of a vacuum-hot-pressing step during consolidation. Mechanical properties of extrusions are superior to those of forgings owing to the stronger textures produced by the more severe hot working during extrusion. The effects on mechanical properties of dispersoid size and volume fraction, substructural refinement, solid solution strengthening by Mg, and precipitate size and distribution are elucidated for both alloy types.

  9. Fabricating tungsten crucibles by drawing and extrusion spinning

    International Nuclear Information System (INIS)

    Edstrom, C.M.

    1981-01-01

    The fabrication of seamless tungsten crucibles 127-mm ID x 265-mm high x 6.25-mm wall thickness (5 in. x 10 1/2 in. x 1/4 in.) involved three drawing operations and extrusion spinning. The success of the drawing operations came from a combination of low draw reduction percentage, generous draw radii, large punch-to-die clearance, and attention to drawing temperature. The extrusion spinning success related to good drawn-cup-to-spinning-mandrel fit prior to making the extrusion passes, removal of stress risers in the part prior to spinning, and special attention to part and mandrel temperature

  10. Functionalization of whey proteins by reactive supercritical fluid extrusion

    Directory of Open Access Journals (Sweden)

    Khanitta Ruttarattanamongkol

    2012-09-01

    Full Text Available Whey protein, a by-product from cheese-making, is often used in a variety of food formulations due to its unsurpassednutritional quality and inherent functional properties. However, the possibilities for the improvement and upgrading of wheyprotein utilization still need to be explored. Reactive supercritical fluid extrusion (SCFX is a novel technique that has beenrecently reported to successfully functionalize commercially available whey proteins into a product with enhanced functionalproperties. The specific goal of this review is to provide fundamental understanding of the reinforcement mechanism andprocessing of protein functionalization by reactive SCFX process. The superimposed extrusion variables and their interactionmechanism affect the physico-chemical properties of whey proteins. By understanding the structure, functional properties andprocessing relationships of such materials, the rational design criteria for novel functionalized proteins could be developedand effectively utilized in food systems.

  11. Ultrasound-Assist Extrusion Methods for the Fabrication of Polymer Nanocomposites Based on Polypropylene/Multi-Wall Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Carlos A. Ávila-Orta

    2015-11-01

    Full Text Available Isotactic polypropylenes (iPP with different melt flow indexes (MFI were used to fabricate nanocomposites (NCs with 10 wt % loadings of multi-wall carbon nanotubes (MWCNTs using ultrasound-assisted extrusion methods to determine their effect on the morphology, melt flow, and electrical properties of the NCs. Three different types of iPPs were used with MFIs of 2.5, 34 and 1200 g/10 min. Four different NC fabrication methods based on melt extrusion were used. In the first method melt extrusion fabrication without ultrasound assistance was used. In the second and third methods, an ultrasound probe attached to a hot chamber located at the exit of the die was used to subject the sample to fixed frequency and variable frequency, respectively. The fourth method is similar to the first method, with the difference being that the carbon nanotubes were treated in a fluidized air-bed with an ultrasound probe before being used in the fabrication of the NCs with no ultrasound assistance during extrusion. The samples were characterized by MFI, Optical microscopy (OM, Scanning electron microscopy (SEM, Transmission electron microscopy (TEM, electrical surface resistivity, and electric charge. MFI decreases in all cases with addition of MWCNTs with the largest decrease observed for samples with the highest MFI. The surface resistivity, which ranged from 1013 to 105 Ω/sq, and electric charge, were observed to depend on the ultrasound-assisted fabrication method as well as on the melt flow index of the iPP. A relationship between agglomerate size and area ratio with electric charge was found. Several trends in the overall data were identified and are discussed in terms of MFI and the different fabrication methods.

  12. Oral transmucosal delivery of domperidone from immediate release films produced via hot-melt extrusion technology.

    Science.gov (United States)

    Palem, Chinna Reddy; Kumar Battu, Sunil; Maddineni, Sindhuri; Gannu, Ramesh; Repka, Michael A; Yamsani, Madhusudan Rao

    2013-02-01

    The objective of the study was to prepare and characterize the domperidone (DOM) hot-melt extruded (HME) buccal films by both in vitro and in vivo techniques. The HME film formulations contained PEO N10 and/or its combination with HPMC E5 LV or Eudragit RL100 as polymeric carriers, and PEG3350 as a plasticizer. The blends were co-processed at a screw speed of 50 rpm with the barrel temperatures ranging from 120-160°C utilizing a bench top co-rotating twin-screw hot-melt extruder using a transverse-slit die. The HME films were evaluated for drug content, drug excipient interaction, in vitro drug release, mechanical properties, in vivo residence time, in vitro bioadhesion, swelling and erosion, ex vivo permeation from HME films and the selected optimal formulation was subjected for bioavailability studies in healthy human volunteers. The extruded films demonstrated no drug excipient interaction and excellent content uniformity. The selected HME film formulation (DOM2) exhibited a tensile strength (0.72 Kg/mm(2)), elongation at break (28.4% mm(2)), in vivo residence time (120 min), peak detachment force (1.55 N), work of adhesion (1.49 mJ), swelling index (210.2%), erosion (10.5%) and in vitro drug release of 84.8% in 2 h. Bioavailability from the optimized HME buccal films was 1.5 times higher than the oral dosage form and the results showed statistically significant (p buccal-adhesive films with improved bioavailability characteristics.

  13. Fabrication of an eyeball-like spherical micro-lens array using extrusion for optical fiber coupling

    International Nuclear Information System (INIS)

    Shen, S C; Huang, J C; Pan, C T; Chao, C H; Liu, K H

    2009-01-01

    Batch fabrication of an eyeball-like spherical micro-lens array (ESMA) not only can reduce micro assembly cost, but also can replace conventional ball lenses or costly gradient refractive index without sacrificing performance. Compared to the conventional half-spherical micro-lenses, the ESMA is an eyeball-like spherical lens which can focus light in all directions, thus providing application flexibility for optical purposes. The current ESMA is made of photoresist SU-8 using the extrusion process instead of the traditional thermal reflow process. For the process of an ESMA, this research develops a new process at ambient temperature by spin-coating SU-8 on a surface of a silicon wafer which serves as an extrusion plate and extruding it through a nozzle to form an ESMA. This nozzle consists of a nozzle orifice and nozzle cavity. The nozzle orifice is defined and made of SU-8 photoresist using ultra-violet lithography, which exhibits good mechanical property. The fabrication process of a nozzle cavity employs bulk micromachining to fabricate the cavities. Next, viscous SU-8 spun on the extrusion plate is extruded through the nozzle orifice to form an ESMA. Based on the effect of surface tension, by varying the amount of SU-8 on the plate extruded through different nozzle orifices, various diameters of ESMA can be fabricated. In this paper, a 4 × 4 ESMA with a numerical aperture of about 0.38 and diameters ranging from 60 to 550 µm is fabricated. Optical measurements indicate a diameter variance within 3% and the maximum coupling efficiency is approximately 62% when the single mode fiber is placed at a distance of 10 µm from the ESMA. The research has proved that the extrusion fabrication process of an ESMA is capable of enhancing the coupling efficiency

  14. Martensitic microstructural transformations from the hot stamping, quenching and partitioning process

    International Nuclear Information System (INIS)

    Liu Heping; Jin Xuejun; Dong Han; Shi Jie

    2011-01-01

    Hot stamping, which combines forming and quenching in one process, produces high strength steels with limited ductility because the quenching is uncontrolled. A new processing technique has been proposed in which the hot stamping step is followed by a controlled quenching and partitioning process, producing a microstructure containing retained austenite and martensite. To investigate this microstructure, specimens were heated at a rate of 10 deg. C/s to the austenitizing temperature of 900 deg. C, held for 5 min to eliminate thermal gradients, and cooled at a rate of 50 deg. C/s to a quenching temperature of 300 deg. C, which is between the martensite start temperature and the martensite finish temperatures. The resulting microstructure was examined using optical microscope, scanning electron microscopy and transmission electron microscopy. The material produced contains irregular, fragmented martensite plates, a result of the improved strength of the austenite phase and the constraints imposed by a high dislocation density. - Research Highlights: → A novel heat treatment of advanced high strength steels is proposed. → The processing technique is hot stamping plus quenching and partitioning process. → The material produced contains irregular, fragmented martensite plates. → The reason is strength of austenite phase and constraint of dislocation density.

  15. Development of rheological characterization and twin-screw extrusion/spiral winding processing methods for functionally-graded tissue engineering scaffolds and characterization of cell/biomaterial interactions

    Science.gov (United States)

    Ozkan, Seher

    Tissue engineering involves the fabrication of biodegradable scaffolds, on which various types of cells are grown, to provide tissue constructs for tissue repair/regeneration. Native tissues have complex structures, with functions and properties changing spatially and temporally, and require special tailoring of tissue engineering scaffolds to allow mimicking of their complex elegance. The understanding of the rheological behavior of the biodegradable polymer and the thermo-mechanical history that the polymer experiences during processing is critical in fabricating scaffolds with appropriate microstructural distributions. This study has first focused on the rheological material functions of various gel-like fluids including biofluids and hydrogels, which can emulate the viscoelastic behavior of biofluids. Viscoplasticity and wall slip were recognized as key attributes of such systems. Furthermore, a new technology base involving twin-screw extrusion/spiral winding (TSESW) process was developed for the shaping of functionally-graded scaffolds. This novel scaffold fabrication technology was applied to the development of polycaprolactone (PCL) scaffolds, incorporated with tricalcium phosphate nanoparticles and various porogens in graded fashion. The protein encapsulation and controlled release capabilities of the TSESW process was also demonstrated by dispersing bovine serum albumin (BSA) protein into the PCL matrix. Effects of processing conditions and porosity distributions on compressive properties, surface topography, encapsulation efficiency, release profiles and the secondary structure of BSA were investigated. The PCL scaffolds were determined to be biocompatible, with the proliferation rates of human fetal osteoblast cells (hFOB) increasing with increasing porosity and decreasing concentration of TCP. BSA proteins were determined to be denatured to a greater extent with melt extrusion in the 80-100°C range (in comparison to wet extrusion using organic

  16. Processing hot-dip galvanized AHSS grades: a challenging task

    Energy Technology Data Exchange (ETDEWEB)

    Pichler, A.; Hebesberger, T.; Tragl, E.; Traint, S.; Faderl, J.; Angeli, G.; Koesters, K. [voestalpine Stahl GmbH, Linz (Austria)

    2005-07-01

    High-strength thin sheet steel grades have gained a considerable market share. At present a very strong demand has been observed for DP (dual-phase), CP (complex phase) and TRIP grades, which are often summarized as advanced high-strength steel grades (AHSS). The potential benefits of applying AHSS grades were impressively demonstrated in the ULSAC-AVC project, in which a remarkable reduction in mass and an increase in stiffness and crash safety were achieved by using a very high share of AHSS steel grades. The present contribution concentrates on hot-dip galvanized AHSS thin sheet grades. The hot-dip galvanizeability of such grades is critically discussed after an overview is provided of the metallurgy of AHSS grades, including microstructure, mechanical properties, phase transformations and required alloy design. Based on these fundamentals, the processing of AHSS grades in the hot-dip galvanizing line is discussed and the resulting properties presented. (orig.)

  17. An upper bound solution for the spread extrusion of elliptical sections

    International Nuclear Information System (INIS)

    Abrinia, K.; Makaremi, M.

    2007-01-01

    The three dimensional problem of extrusion of elliptical sections with side material flow or spread has been formulated using the upper bound theory. The shape of the die for such a process is such that it could allow the material to flow sideways as well as in the forward direction. When flat faced dies are used a deforming region is developed with dead metal zones. Therefore this deforming region has been represented in the formulation based on the definitions of streamlines and stream surfaces. A generalized kinematically admissible velocity field was then derived for this formulation and strain rate components obtained for the upper bound solution. The general formulation for the deforming region and the velocity and strain rate fields allow for the optimization of the upper bound solution so that the nearest geometry of the deforming region and dead metal zone to the actual one was obtained.Using this geometry a die with similar surfaces to those of the dead metal zone is designed having converging and diverging surfaces to lead the material flow. The analysis was also carried out for this die and results were obtained showing a reduction in the extrusion pressure compared to the flat faced die. Effects of reduction of area, shape complexity, spread ratio and friction on the extrusion process were also investigated

  18. Moisture content during extrusion of oats impacts the initial fermentation metabolites and probiotic bacteria during extended fermentation by human fecal microbiota.

    Science.gov (United States)

    Brahma, Sandrayee; Weier, Steven A; Rose, Devin J

    2017-07-01

    Extrusion exposes flour components to high pressure and shear during processing, which may affect the dietary fiber fermentability by human fecal microbiota. The objective of this study was to determine the effect of flour moisture content during extrusion on in vitro fermentation properties of whole grain oats. Extrudates were processed at three moisture levels (15%, 18%, and 21%) at fixed screw speed (300rpm) and temperature (130°C). The extrudates were then subjected to in vitro digestion and fermentation. Extrusion moisture significantly affected water-extractable β-glucan (WE-BG) in the extrudates, with samples processed at 15% moisture (lowest) and 21% moisture (highest) having the highest concentration of WE-BG. After the first 8h of fermentation, more WE-BG remained in fermentation media in samples processed at 15% moisture compared with the other conditions. Also, extrusion moisture significantly affected the production of acetate, butyrate, and total SCFA by the microbiota during the first 8h of fermentation. Microbiota grown on extrudates processed at 18% moisture had the highest production of acetate and total SCFA, whereas bacteria grown on extrudates processed at 15% and 18% moisture had the highest butyrate production. After 24h of fermentation, samples processed at 15% moisture supported lower Bifidobacterium counts than those produced at other conditions, but had among the highest Lactobacillus counts. Thus, moisture content during extrusion significantly affects production of fermentation metabolites by the gut microbiota during the initial stages of fermentation, while also affecting probiotic bacteria counts during extended fermentation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Influence of hard particle addition and chemical interdiffusion on the properties of hot extruded tool steel compounds

    International Nuclear Information System (INIS)

    Silva, P.A.; Weber, S.; Inden, G.; Pyzalla, A.R.

    2009-01-01

    Low alloyed steel bars were co-extruded with pre-sintered tool steel powders with the addition of tungsten carbides (W 2 C/WC) as hard particles. During the hot extrusion process of these massive and powdery materials, an extrudate is formed consisting of a completely densified wear resistant coating layer and a bulk steel bar as the tough substrate core. This work combines experimental measurements (EPMA) and diffusion calculations (DICTRA TM ) to investigate the effect of hard particle addition and its dissolution, as well as the formation of M 6 C carbides on the properties of two different PM tool steel coatings hot extruded with a 1.2714 steel bar. A carburization effect resulting from the W 2 C hard particles is responsible for an increase of the 1.2344 steel matrix hardness. The mechanical properties of the interface region between coating matrix and substrate are influenced by chemical interdiffusion of carbon and other alloying elements occurring during heat treatment.

  20. FORMING TUBES AND RODS OF URANIUM METAL BY EXTRUSION

    Science.gov (United States)

    Creutz, E.C.

    1959-01-27

    A method and apparatus are presented for the extrusion of uranium metal. Since uranium is very brittle if worked in the beta phase, it is desirable to extrude it in the gamma phase. However, in the gamma temperature range thc uranium will alloy with the metal of the extrusion dic, and is readily oxidized to a great degree. According to this patent, uranium extrusion in thc ganmma phase may be safely carried out by preheating a billet of uranium in an inert atmosphere to a trmperature between 780 C and 1100 C. The heated billet is then placed in an extrusion apparatus having dies which have been maintained at an elevated temperature for a sufficient length of time to produce an oxide film, and placing a copper disc between the uranium billet and the die.

  1. Dual temperature isotope exchange process using hot feed with liquid recycle from the humidifier

    International Nuclear Information System (INIS)

    Paulis, G.J.C.A.

    1977-01-01

    This invention relates to an improvement in the dual temperature substances at two temperatures. It provides hot feed process, which while keeping the water purity advantages offered by a recycle of liquid, reduces the energy requirements of the process saving in capital cost over previous hot feed process, at equal production rate, or conversely which offers a substantial increase in production rate at equal capital costs

  2. Effects of extrusion variables on the properties of waxy hulless barley extrudates.

    Science.gov (United States)

    Köksel, Hamit; Ryu, Gy-Hyung; Başman, Arzu; Demiralp, Hande; Ng, Perry K W

    2004-02-01

    The objective of this research was to investigate the extrudability of waxy hulless barley flour under various extrusion conditions. Waxy hulless barley flour was processed in a laboratory-scale corotating twin-screw extruder with different levels of feed moisture content (22.3, 26.8, and 30.7%) and die temperature (130, 150, and 170 degrees C) to develop a snack food with high beta-glucan content. The effects of extrusion condition variables (screw configuration, moisture, and temperature) on the system variables (pressure and specific mechanical energy), the extrudate physical properties (sectional expansion index, bulk density), starch gelatinization, pasting properties (cold peak viscosity, trough viscosity, and final viscosity), and beta-glucan contents were determined. Results were evaluated by using response surface methodology. Increased extrusion temperature and feed moisture content resulted in decreases in exit die pressure and specific mechanical energy values. For extrudates extruded under low shear screw configuration (LS), increased barrel temperature decreased sectional expansion index (SEI) values at both low and high moisture contents. The feed moisture seems to have an inverse relationship with SEI over the range studied. Bulk density was higher at higher moisture contents, for both low and high barrel temperatures, for samples extruded under high shear screw configuration (HS) and LS. Cold peak viscosities (CV) were observed in all samples. The CV increased with the increase in extrusion temperature and feed moisture content. Although beta-glucan contents of the LS extrudates were comparable to that of barley flour sample, HS samples had generally lower beta-glucan contents. The extrusion cooking technique seems to be promising for the production of snack foods with high beta-glucan content, especially using LS conditions.

  3. Effect of Different Extrusion Parameters on Dietary Fiber in Wheat Bran and Rye Bran.

    Science.gov (United States)

    Andersson, Annica A M; Andersson, R; Jonsäll, Anette; Andersson, Jörgen; Fredriksson, Helena

    2017-06-01

    Wheat bran and rye bran are mostly used as animal feed today, but their high content of dietary fiber and bioactive components are beneficial to human health. Increased use of bran as food raw material could therefore be desirable. However, bran mainly contains unextractable dietary fiber and deteriorates the sensory properties of products. Processing by extrusion could increase the extractability of dietary fiber and increase the sensory qualities of bran products. Wheat bran and rye bran were therefore extruded at different levels of moisture content, screw speed and temperature, in order to find the optimal setting for increased extractability of dietary fiber and positive sensory properties. A water content of 24% for wheat bran and 30% for rye bran, a screw speed of 400 rpm, and a temperature of 130 °C resulted in the highest extractability of total dietary fiber and arabinoxylan. Arabinoxylan extractability increased from 5.8% in wheat bran to 9.0% in extruded wheat bran at those settings, and from 14.6% to 19.2% for rye bran. Total contents of dietary fiber and arabinoxylan were not affected by extrusion. Content of β-glucan was also maintained during extrusion, while its molecular weight decreased slightly and extractability increased slightly. Extrusion at these settings is therefore a suitable process for increasing the use of wheat bran and rye bran as a food raw material. © 2017 Institute of Food Technologists®.

  4. Orthodontic extrusion in the transitional dentition: a simple technique.

    LENUS (Irish Health Repository)

    Darby, Laura J

    2009-11-01

    Extrusion of teeth may be necessary in cases of delayed eruption, primary retention, traumatically intruded teeth, or subgingivally fractured teeth. Removable appliances are advantageous, as anchorage is not as tooth-dependant as in the case of fixed appliances. They are cost-effective, operator friendly, and a valuable treatment option to consider in cases where extrusion of anterior teeth in the transitional dentition is necessary. The purpose of this paper was to describe a simple, cost-effective technique using a removable appliance for extrusion of incisors in the transitional dentition.

  5. Multidrug and toxin extrusion proteins as transporters of antimicrobial drugs.

    Science.gov (United States)

    Nies, Anne T; Damme, Katja; Schaeffeler, Elke; Schwab, Matthias

    2012-12-01

    Antimicrobial drugs are essential in the treatment of infectious diseases. A better understanding of transport processes involved in drug disposition will improve the predictability of drug-drug interactions with consequences for drug response. Multidrug And Toxin Extrusion (MATE; SLC47A) proteins are efflux transporters mediating the excretion of several antimicrobial drugs as well as other organic compounds into bile and urine, thereby contributing to drug disposition. This review summarizes current knowledge of the structural and molecular features of human MATE transporters including their functional role in drug transport with a specific focus on antimicrobial drugs. The PubMed database was searched using the terms "MATE1," "MATE-2K," "MATE2," "SLC47A1," "SLC47A2," and "toxin extrusion protein" (up to June 2012). MATE proteins have been recognized as important transporters mediating the final excretion step of cationic drugs into bile and urine. These include the antiviral drugs acyclovir, amprenavir, and ganciclovir, the antibiotics cephalexin, cephradine and levofloxacin, as well as the antimalarial agents chloroquine and quinine. It is therefore important to enhance our understanding of the role of MATEs in drug extrusion with particular emphasis on the functional consequences of genetic variants on disposition of these antimicrobial drugs.

  6. Process and equipment development for hot isostatic pressing treatability study

    Energy Technology Data Exchange (ETDEWEB)

    Bateman, Ken; Wahlquist, Dennis; Malewitz, Tim

    2015-03-01

    Battelle Energy Alliance (BEA), LLC, has developed processes and equipment for a pilot-scale hot isostatic pressing (HIP) treatability study to stabilize and volume reduce radioactive calcine stored at Idaho National Laboratory (INL). In 2009, the U. S. Department of Energy signed a Record of Decision with the state of Idaho selecting HIP technology as the method to treat 5,800 yd^3 (4,400 m^3) of granular zirconia and alumina calcine produced between 1953 and 1992 as a waste byproduct of spent nuclear fuel reprocessing. Since the 1990s, a variety of radioactive and hazardous waste forms have been remotely treated using HIP within INL hot cells. To execute the remote process at INL, waste is loaded into a stainless-steel or aluminum can, which is evacuated, sealed, and placed into a HIP furnace. The HIP simultaneously heats and pressurizes the waste, reducing its volume and increasing its durability. Two 1 gal cans of calcine waste currently stored in a shielded cask were identified as candidate materials for a treatability study involving the HIP process. Equipment and materials for cask-handling and calcine transfer into INL hot cells, as well as remotely operated equipment for waste can opening, particle sizing, material blending, and HIP can loading have been designed and successfully tested. These results demonstrate BEA’s readiness for treatment of INL calcine.

  7. Analysis and Prediction of the Billet Butt and Transverse Weld in the Continuous Extrusion Process of a Hollow Aluminum Profile

    Science.gov (United States)

    Lou, Shumei; Wang, Yongxiao; Liu, Chuanxi; Lu, Shuai; Liu, Sujun; Su, Chunjian

    2017-08-01

    In continuous extrusions of aluminum profiles, the thickness of the billet butt and the length of the discarded extrudate containing the transverse weld play key roles in reducing material loss and improving product quality. The formation and final distribution of the billet butt and transverse weld depend entirely on the flow behavior of the billet skin material. This study examined the flow behavior of the billet skin material as well as the formation and evolution of the billet butt and the transverse weld in detail through numerical simulation and a series of experiments. In practical extrusions, even if the billet skin is removed by lathe turning shortly before extrusion, billet skin impurities are still distributed around the transverse weld and in the billet butt. The thickness of the scrap billet butt and the length of the discarded extrudate containing the transverse weld can be exactly predicted via simulation.

  8. Shield wall evaluation of hot cell facility for advanced spent fuel conditioning process

    International Nuclear Information System (INIS)

    Cho, I. J.; Kuk, D. H.; Ko, J. H.; Jung, W. M.; Yoo, G. S.; Lee, E. P.; Park, S. W.

    2002-01-01

    The future hot cell is located in the Irradiated Material Experiment Facility (IMEF) at the Korea Atomic Energy Research Institute (KAERI). It is β-γ type hot cell that was constructed on the base floor in IMEF building for irradiated material testing. And this hot cell will be used for carrying out the Advanced spent fuel Conditioning Process (ACP). The radiation shielding capability of hot cell should be sufficient to meet the radiation dose requirements in the related regulations. Because the radioactive sources of ACP are expected to be higher than radioactive sources of IMEF design criteria, the future hot cell in current status is unsatisfactory to hot test of ACP. So the shielding analysis of the future hot cell is performed to evaluate shielding ability of concrete shield wall. The shielding analysis included (a) identification of ACP source term; (b) photon source spectrum; (c) shielding analysis by QADS and MCNP-4C; and (d) enhancement of concrete shield wall. In this research, dose rates are obtained according to ACP source, geometry and hot cell shield wall thickness. And the evaluation and reinforcement thickness of the shield wall about future hot cell are concluded

  9. Effect of hot extrusion, other constituents, and temperature on the strength and fracture of polycrystalline MgO

    Energy Technology Data Exchange (ETDEWEB)

    Rice, R.W. (W.R. Grace and Co.-Conn, Columbia, MD (United States))

    1993-12-01

    Improved agreement was confirmed between the Petch intercept and single-crystal yield stresses at 22 C. Hot-extruded MgO crystal specimens stressed parallel with the resultant axial texture (1) gave the highest and least-scattered strength-grain size results at 22 C, (2) showed direct fractographic evidence of microplastic initiated fracture at 22 C and showed macroscopic yield at 1,315 and especially 1,540 C, and (3) fractured entirely via transgranular cleavage, except for intergranular failure initiation from one or a few grain boundary surfaces exposed on the subsequent fracture surface, mainly at 1,540 C. Hot-extruded, hot-pressed MgO billets gave comparable strength when fracture initiated transgranularly, but lower strength when fracture initiated from one or especially a few grain boundary surfaces exposed on the fracture. The extent and frequency of such boundary fracture increased with test temperature. While oxide additions of [<=] 5% or impurities in hot-pressed or hot-extruded MgO can make limited strength increases at larger grain sizes, those having limited solubility can limit strength at finer grain sizes, as can coarser surface finish. Overall, MgO strength is seen as a balance between flaw and microplastic controlled failure, with several parameters shifting the balance.

  10. Effect of composition in the development of carbamazepine hot-melt extruded solid dispersions by application of mixture experimental design.

    Science.gov (United States)

    Djuris, Jelena; Ioannis, Nikolakakis; Ibric, Svetlana; Djuric, Zorica; Kachrimanis, Kyriakos

    2014-02-01

    This study investigates the application of hot-melt extrusion for the formulation of carbamazepine (CBZ) solid dispersions, using polyethyleneglycol-polyvinyl caprolactam-polyvinyl acetate grafted copolymer (Soluplus, BASF, Germany) and polyoxyethylene-polyoxypropylene block copolymer (Poloxamer 407). In agreement with the current Quality by Design principle, formulations of solid dispersions were prepared according to a D-optimal mixture experimental design, and the influence of formulation composition on the properties of the dispersions (CBZ heat of fusion and release rate) was estimated. Prepared solid dispersions were characterized using differential scanning calorimetry, attenuated total reflectance infrared spectroscopy and hot stage microscopy, as well as by determination of the dissolution rate of CBZ from the hot-melt extrudates. Solid dispersions of CBZ can be successfully prepared using the novel copolymer Soluplus. Inclusion of Poloxamer 407 as a plasticizer facilitated the processing and decreased the hardness of hot-melt extrudates. Regardless of their composition, all hot-melt extrudates displayed an improvement in the release rate compared to the pure CBZ, with formulations having the ratio of CBZ : Poloxamer 407 = 1 : 1 showing the highest increase in CBZ release rate. Interactions between the mixture components (CBZ and polymers), or quadratic effects of the components, play a significant role in overall influence on the CBZ release rate. © 2013 Royal Pharmaceutical Society.

  11. Process considerations for hot pressing ceramic nuclear waste forms

    International Nuclear Information System (INIS)

    Wilson, C.N.; Brite, D.W.

    1981-01-01

    Spray calcined simulated ceramic nuclear waste powders were hot pressed in graphite, nickel-lined graphite and ZrO 2 -lined Al 2 O 3 dies. Densification, initial off-gas, waste element retention and pellet-die interactions were evaluated. Indicated process considerations and limitations are discussed. 15 figures

  12. Embedded Multimaterial Extrusion Bioprinting

    NARCIS (Netherlands)

    Rocca, Marco; Fragasso, Alessio; Liu, Wanjun; Heinrich, Marcel A.; Zhang, Yu Shrike

    Embedded extrusion bioprinting allows for the generation of complex structures that otherwise cannot be achieved with conventional layer-by-layer deposition from the bottom, by overcoming the limits imposed by gravitational force. By taking advantage of a hydrogel bath, serving as a sacrificial

  13. An analysis of hot plate initial temperature effect on rectangular narrow gap quenching process

    International Nuclear Information System (INIS)

    M-Hadi Kusuma; Mulya Juarsa; Anhar Riza Antariksawan; Nandy Putra

    2012-01-01

    The understanding about thermal management in the event of a severe accident such as the melting nuclear reactor fuel and reactor core, became a priority to maintain the integrity of reactor pressure vessel. Thus the debris will not out from the reactor pressure vessel and resulting impact of more substantial to the environment. One way to maintain the integrity of the reactor pressure vessel was cooling of the excess heat generated due to the accident. To get understanding of this aspect, there search focused on the effect of the initial temperature of the hot plate in the rectangular narrow gap quenching process. The initial temperature effect on quenching process is related to cooling process (thermal management) when the occurrence of a nuclear accident due to loss of coolant accident or severe accident. In order to address the problem, it is crucial to conduct research to get a better understanding of thermal management regarding to nuclear cooling accident. The research focused on determining the rewetting temperature of hot plate cooling on 220°C, 400°C, and 600°C with 0.2 liters/sec cooling water flowrate. Experiments were carried out by injecting 85°C cooling water temperature into the narrow gap at flowrates of 0.2 liters/sec. Data of transient temperature measurements were recorded using a data acquisition system in order to know the rewetting temperature during the quenching process. This study aims to understand the effect of hot plate initial temperature on rewetting during rectangular narrow gap quenching process. The results obtained show that the rewetting point on cooling the hot plate 220°C, 400°C and 600°occurs at varying rewetting temperatures. At 220°C hot plate initial temperature, the rewetting temperature occurs on 220°C. At 400°C hot plate initial temperature, the rewetting temperature occurs on 379.51°C. At 600°C hot plate initial temperature, the rewetting temperature occurs on 426.63°C. Significant differences of hot plate

  14. Characterization of the interfacial heat transfer coefficient for hot stamping processes

    Science.gov (United States)

    Luan, Xi; Liu, Xiaochuan; Fang, Haomiao; Ji, Kang; El Fakir, Omer; Wang, LiLiang

    2016-08-01

    In hot stamping processes, the interfacial heat transfer coefficient (IHTC) between the forming tools and hot blank is an essential parameter which determines the quenching rate of the process and hence the resulting material microstructure. The present work focuses on the characterization of the IHTC between an aluminium alloy 7075-T6 blank and two different die materials, cast iron (G3500) and H13 die steel, at various contact pressures. It was found that the IHTC between AA7075 and cast iron had values 78.6% higher than that obtained between AA7075 and H13 die steel. Die materials and contact pressures had pronounced effects on the IHTC, suggesting that the IHTC can be used to guide the selection of stamping tool materials and the precise control of processing parameters.

  15. Effects of Processing Parameters on the Forming Quality of C-Shaped Thermosetting Composite Laminates in Hot Diaphragm Forming Process

    Science.gov (United States)

    Bian, X. X.; Gu, Y. Z.; Sun, J.; Li, M.; Liu, W. P.; Zhang, Z. G.

    2013-10-01

    In this study, the effects of processing temperature and vacuum applying rate on the forming quality of C-shaped carbon fiber reinforced epoxy resin matrix composite laminates during hot diaphragm forming process were investigated. C-shaped prepreg preforms were produced using a home-made hot diaphragm forming equipment. The thickness variations of the preforms and the manufacturing defects after diaphragm forming process, including fiber wrinkling and voids, were evaluated to understand the forming mechanism. Furthermore, both interlaminar slipping friction and compaction behavior of the prepreg stacks were experimentally analyzed for showing the importance of the processing parameters. In addition, autoclave processing was used to cure the C-shaped preforms to investigate the changes of the defects before and after cure process. The results show that the C-shaped prepreg preforms with good forming quality can be achieved through increasing processing temperature and reducing vacuum applying rate, which obviously promote prepreg interlaminar slipping process. The process temperature and forming rate in hot diaphragm forming process strongly influence prepreg interply frictional force, and the maximum interlaminar frictional force can be taken as a key parameter for processing parameter optimization. Autoclave process is effective in eliminating voids in the preforms and can alleviate fiber wrinkles to a certain extent.

  16. Influence of material and solution composition on the extrusion/erosion behaviour of compacted bentonite

    International Nuclear Information System (INIS)

    Schatz, Timothy; Martikainen, Jari; Koskinen, Kari

    2010-01-01

    Document available in extended abstract form only. In principle, in a KBS-3 type repository, the volume of a deposition hole is fixed and the bentonite buffer mass accordingly balanced to lead to the development of a suitable swelling pressure upon saturation. However, fractures intersecting the deposition holes give rise to the possibility that volume constrained conditions do not universally exist. Such fractures may provide pathways for the continued, localised, free swelling of bentonite buffer material. Loss of mass from the deposition hole by extrusion into intersecting fractures may compromise the long-term safety and performance of the buffer component of the engineered barrier system. Furthermore, the continued hydration and expansion of extruded bentonite in these fracture environments could lead to the separation of colloid-sized (or larger) particles by diffusion or shear which may have to be accounted for in possible radionuclide migration scenarios. Geochemical conditions, with respect to both solution and material composition, are considered to play important roles regarding the fracture extrusion/erosion of bentonite buffer material. For example, calcium-montmorillonite exhibits limited free swelling relative to sodium-montmorillonite and the colloidal and rheological properties of montmorillonite dispersions are sensitive to the presence of electrolytes. Insofar as both the buffer material composition (due to ion exchange) and groundwater composition (dilution resulting from infiltration of glacial melt water) are expected to evolve with time, so too might the potential for fracture extrusion/erosion of buffer material vary over time. The hydraulic characteristics of the intersecting fracture are expected to influence the extrusion/erosion process as well. To evaluate the effect of material and solution composition on the potential for extrusion of buffer mass into intersecting fractures, a series of batch experiments were performed. In these

  17. Characterization of Al–Li 2099 extrusions and the influence of fiber texture on the anisotropy of static mechanical properties

    International Nuclear Information System (INIS)

    Bois-Brochu, Alexandre; Blais, Carl; Goma, Franck Armel Tchitembo; Larouche, Daniel; Boselli, Julien; Brochu, Mathieu

    2014-01-01

    The development of aluminum–lithium alloys for aerospace applications requires a thorough understanding of how processing and product geometry impact their microstructure, texture and mechanical properties. The anisotropy of the mechanical properties is in part related to the deformation texture formed during thermo-mechanical processing. In this study, two different extrusions of Al–Li 2099 T83 were characterized, a cylindrical extrusion and an integrally stiffened panel (ISP). A decrease of tensile properties was observed from the longitudinal direction to the transverse direction with a minimum in the 45° direction, the magnitude of which depends on the location in the extrusions. The 〈111〉 fiber texture is prominent in most locations of the extrusion with a smaller intensity of the 〈100〉 component. Rolling textures were observed in two locations of the ISP that have a larger cross sectional aspect ratio. Variations of strength and anisotropy as a function of location in the extrusion correlate well with the intensity of the 〈111〉 fiber texture. On the other hand, our findings show an absence of correlation between the Taylor factor and the anisotropy. These results suggest that strength anisotropy may be controlled by the volume fraction of T 1 precipitates that could itself be related to the intensity of the 〈111〉 fiber texture

  18. Characterization of Al–Li 2099 extrusions and the influence of fiber texture on the anisotropy of static mechanical properties

    Energy Technology Data Exchange (ETDEWEB)

    Bois-Brochu, Alexandre, E-mail: Alexandre.Bois-Brochu.1@ulaval.ca [Department of Mining and Metallurgy, Adrien-Pouliot Building, Université Laval, 1065 Rue de la medicine, Québec, Québec G1V 0A6 (Canada); Blais, Carl, E-mail: Carl.Blais@gmn.ulaval.ca [Department of Mining and Metallurgy, Adrien-Pouliot Building, Université Laval, 1065 Rue de la medicine, Québec, Québec G1V 0A6 (Canada); Goma, Franck Armel Tchitembo, E-mail: Franck-Armel.Tchitembo-Goma.1@ulaval.ca [Department of Mining and Metallurgy, Adrien-Pouliot Building, Université Laval, 1065 Rue de la medicine, Québec, Québec G1V 0A6 (Canada); Larouche, Daniel, E-mail: Daniel.Larouche@gmn.ulaval.ca [Department of Mining and Metallurgy, Adrien-Pouliot Building, Université Laval, 1065 Rue de la medicine, Québec, Québec G1V 0A6 (Canada); Boselli, Julien, E-mail: Julien.Boselli@alcoa.com [Alcoa Technical Center, Alcoa, PA 15069 (United States); Brochu, Mathieu, E-mail: Mathieu.Brochu@mcgill.ca [Department of Mining and Materials Engineering, Wong Building, McGill University, 3610 University Street, Montréal, Québec H3A 2B2 (Canada)

    2014-03-01

    The development of aluminum–lithium alloys for aerospace applications requires a thorough understanding of how processing and product geometry impact their microstructure, texture and mechanical properties. The anisotropy of the mechanical properties is in part related to the deformation texture formed during thermo-mechanical processing. In this study, two different extrusions of Al–Li 2099 T83 were characterized, a cylindrical extrusion and an integrally stiffened panel (ISP). A decrease of tensile properties was observed from the longitudinal direction to the transverse direction with a minimum in the 45° direction, the magnitude of which depends on the location in the extrusions. The 〈111〉 fiber texture is prominent in most locations of the extrusion with a smaller intensity of the 〈100〉 component. Rolling textures were observed in two locations of the ISP that have a larger cross sectional aspect ratio. Variations of strength and anisotropy as a function of location in the extrusion correlate well with the intensity of the 〈111〉 fiber texture. On the other hand, our findings show an absence of correlation between the Taylor factor and the anisotropy. These results suggest that strength anisotropy may be controlled by the volume fraction of T{sub 1} precipitates that could itself be related to the intensity of the 〈111〉 fiber texture.

  19. Towards the damage evaluation using Gurson-Tvergaard-Needleman (GTN) model for hot forming processes

    Science.gov (United States)

    Imran, Muhammad; Bambach, Markus

    2018-05-01

    In the production of semi-finished metal products, hot forming is used to eliminate the pores and voids from the casting process under compressive stresses and to modify the microstructure for further processing. In the case of caliber and flat rolling processes, tensile stresses occur at certain roll gap ratios which promote pore formation on nonmetallic inclusion. The formation of new pores contributes to ductile damage and reduces the load carrying capacity of the material. In the literature, the damage nucleation and growth during the hot forming process are not comprehensively described. The aim of this study is to understand the damage initiation and growth mechanism during hot forming processes. Hot tensile tests are performed at different temperatures and strain rates for 16MnCrS5 steel. To investigate the influence of geometrical variations on the damage mechanism, specimens with different stress triaxiality ratios are used. Finite element simulations using the Gurson-Tvergaard-Needleman (GTN) damage model are performed to estimate the critical void fraction for the damage initiation and the evolution of the void volume fraction. The results showed that the GTN model underestimates the softening of the material due to the independence of the temperature and the strain rate.

  20. Effect of extrusion, espansion and toasting on the nutritional value of peas, faba beans and lupins

    Directory of Open Access Journals (Sweden)

    Filippo Rossi

    2010-01-01

    Full Text Available An assessment was made of the effect that different treatments (toasting, expansion, extrusion have on the nutritionalvalue of protein plants (pea, faba bean, lupin. In a randomized block design, feeds were screened for enzymaticdigestibility of starch and protein, N solubility and in vitro protein degradability. Expansion and extrusion cause increasedstarch enzymatic degradability while toasting produced virtually no effects. In peas this value increased from 11.80% inmeal to 39.70% in the extruded product; 85.37% is the percentage for the expanded product, while 10.90% is the starchdigestibility value for toasted peas. In faba beans the extrusion process increased starch digestibility from 11.39% to85.05%, while in extruded lupins a complete starch hydrolysis was obtained, while in the meal the polysaccharide digestionwas 54.48%.The expansion and extrusion processes significantly decreased rumen degradability during the first 8 hours of incubation.Toasted peas had lower degradability if compared with controls but not with the other treatments. The onlypotentially alternative source to soybean is the extruded faba bean. In spite of its lower protein content, this feed ischaracterized by a considerably lower in vitro protein degradability than soybean. This implies that the digestible foodprotein content is comparable (124.90 g/kg DM to that of soybean (109.78 g/kg DM and definitely higher than thatof all other protein plants.

  1. Domain Immersion Technique And Free Surface Computations Applied To Extrusion And Mixing Processes

    Science.gov (United States)

    Valette, Rudy; Vergnes, Bruno; Basset, Olivier; Coupez, Thierry

    2007-04-01

    This work focuses on the development of numerical techniques devoted to the simulation of mixing processes of complex fluids such as twin-screw extrusion or batch mixing. In mixing process simulation, the absence of symmetry of the moving boundaries (the screws or the rotors) implies that their rigid body motion has to be taken into account by using a special treatment. We therefore use a mesh immersion technique (MIT), which consists in using a P1+/P1-based (MINI-element) mixed finite element method for solving the velocity-pressure problem and then solving the problem in the whole barrel cavity by imposing a rigid motion (rotation) to nodes found located inside the so called immersed domain, each subdomain (screw, rotor) being represented by a surface CAD mesh (or its mathematical equation in simple cases). The independent meshes are immersed into a unique backgound computational mesh by computing the distance function to their boundaries. Intersections of meshes are accounted for, allowing to compute a fill factor usable as for the VOF methodology. This technique, combined with the use of parallel computing, allows to compute the time-dependent flow of generalized Newtonian fluids including yield stress fluids in a complex system such as a twin screw extruder, including moving free surfaces, which are treated by a "level set" and Hamilton-Jacobi method.

  2. 16. Hot dense plasma atomic processes

    International Nuclear Information System (INIS)

    Werner, Dappen; Totsuji, H.; Nishii, Y.

    2002-01-01

    This document gathers 13 articles whose common feature is to deal with atomic processes in hot plasmas. Density functional molecular dynamics method is applied to the hydrogen plasma in the domain of liquid metallic hydrogen. The effects of the density gradient are taken into account in both the electronic kinetic energy and the exchange energy and it is shown that they almost cancel with each other, extending the applicability of the Thomas-Fermi-Dirac approximation to the cases where the density gradient is not negligible. Another article reports about space and time resolved M-shell X-ray measurements of a laser-produced gas jet xenon plasma. Plasma parameters have been measured by ion acoustic and electron plasma waves Thomson scattering. Photo-ionization becomes a dominant atomic process when the density and the temperature of plasmas are relatively low and when the plasma is submitted to intense external radiation. It is shown that 2 plasmas which have a very different density but have the same ionization parameters, are found in a similar ionization state. Most radiation hydrodynamics codes use radiative opacity data from available libraries of atomic data. Several articles are focused on the determination of one group Rosseland and Planck mean analytical formulas for several single elements used in inertial fusion targets. In another paper the plasma density effect on population densities, effective ionization, recombination rate coefficients and on emission lines from carbon and Al ions in hot dense plasma, is studied. The last article is devoted to a new atomic model in plasmas that considers the occupation probability of the bound state and free state density in the presence of the plasma micro-field. (A.C.)

  3. Apical extrusion of debris: a literature review of an inherent occurrence during root canal treatment.

    Science.gov (United States)

    Tanalp, J; Güngör, T

    2014-03-01

    Extrusion of intracanal debris as well as irrigants is a common occurrence during root canal treatment, and no instrument or technique has thoroughly solved this problem. Because flare-ups may arise with any irritation directed towards periapical tissues, a shaping or irrigation technique should minimize the risk of apical extrusion, even though it may not be prevented. There has been a rapid evolution of root canal instruments and irrigation systems through the last decade, and many have been assessed for their debris extrusion potential. The purpose of this review was to identify publications regarding the evaluation of debris, bacteria and irrigant extrusion during root canal treatment. A PubMed, Ovid and MEDLINE search was conducted using the keywords "apical extrusion", "debris extrusion" and "endodontic treatment". The literature search extended over a period of more than 30 years up to 2012. Content of the review was limited to apical extrusion of debris and irrigants, extrusion of liquid by irrigation methods and bacterial extrusion. Issues relevant to apical extrusion were obtained by further search in the reference sections of the retrieved articles. The review provides an update on the current status of apical extrusion. © 2013 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  4. A hybrid twin screw extrusion/electrospinning method to process nanoparticle-incorporated electrospun nanofibres

    International Nuclear Information System (INIS)

    Erisken, Cevat; Kalyon, Dilhan M; Wang Hongjun

    2008-01-01

    A new hybrid methodology that fully integrates the processing capabilities of the twin screw extrusion process (conveying solids, melting, dispersive and distributive mixing, pressurization, temperature profiling, devolatilization) with electrospinning is described. The hybrid process is especially suited to the dispersion of nanoparticles into polymeric binders and the generation of nanoparticle-incorporated fibres and nanofibres. The new technology base is demonstrated with the dispersion of β-tricalcium phosphate (β-TCP) nanoparticles into poly(ε-caprolactone) (PCL) to generate biodegradable non-woven meshes that can be targeted as scaffolds for tissue engineering applications. The new hybrid method yielded fibre diameters in the range of 200-2000 nm for both PCL and β-TCP/PCL (35% by weight) composite scaffolds. The degree of crystallinity of polycaprolactone meshes could be manipulated in the 35.1-41% range, using the voltage strength as a parameter. The electrospinning process, integrated with dispersive kneading disc elements, facilitated the decrease of the cluster sizes and allowed the continuous compounding of the nanoparticles into the biodegradable polymer prior to electrospinning. Thermogravimetric analysis (TGA) of the non-woven meshes validated the continuous incorporation of 35 ± 1.5% (by weight) β-TCP nanoparticles for a targeted concentration of 35%. Uniaxial tensile testing of the meshes with and without the nanoparticles indicated that the ultimate tensile strength at break of the meshes increased from 0.47 ± 0.04 to 0.79 ± 0.08 MPa upon the incorporation of the β-TCP nanoparticles. This demonstration study suggests that the new technology base is particularly suitable for the concomitant dispersion and electrospinning of nanoparticles in the generation of myriad types of functional nanofibres

  5. Mechanical Properties and Microstructure of High-Strength Steel Controlled by Hot Stamping Process

    Science.gov (United States)

    Ou, Hang; Zhang, Xu; Xu, Junrui; Li, Guangyao; Cui, Junjia

    2018-03-01

    A novel design and manufacturing method, dubbed "precast," of the cooling system and tools for a hot forming process was proposed in this paper. The integrated structures of the punch and blank holder were determined by analyzing the bending and reverse-bending deformation of the forming parts. The desired crashworthiness performance of an automotive front bumper constructed with this process was obtained by a tailored phase transformation, which generated martensite-bainite in the middle and full martensite transformation in the corner areas. Varying cooling effects in the formed parts caused the highest temperature to be located in the bottom and the lowest on the end of the formed parts. Moreover, the microstructural distributions demonstrated that the bottom possessed a relatively lower content of martensite, while, conversely, the end possessed a higher content. This was precisely the most desired phase distributions for the hot formed parts. For the six-process cycle stamping, the temperatures reached a stable status after an initial rapid increase in the first three process cycles. The microstructural results verified the feasibility of the hot forming tools under multiprocess cycles.

  6. The effects of polymers' visco-elastoplastic properties on the micro cavities filling step of hot embossing process

    Science.gov (United States)

    Cheng, Gang; Barrière, Thierry

    2018-05-01

    The hot embossing process has been widely used in the manufacturing of polymer components, especially for the fabrication of micro or nano components. The significant advantage of the hot embossing process compared to the traditional injection moulding process is the excellent effective filling ratio for the high aspect ratio components and large surface structural components. The lack of material behavior modeling and numerical simulation limits the further development the hot embossing process, especially at the micro and nano scales. In this paper, a visco-elastoplastic behavior law has been proposed to describe the amorphous thermoplastic polymer mechanical properties in the hot embossing processing temperature range, which is lightly above their glass transition temperature. Uniaxial compression tests have been carried out in order to investigate the amorphous thermoplastic polymers properties. The material parameters in the visco-elastoplastic model have been identified according to the experimental results. A 3D numerical model has been created in the simulation software, which is based on the finite element method. The numerical simulation of the filling step of the hot embossing process has been effectuated by taking into account the viscous, elastic and plastic behaviors of thermoplastic polymers. The micro hot embossing process has been carried out using horizontal injection compression moulding equipment. A complete compression mould tool, equipped with the heating system, the cooling system, the ejection system and the vacuum system, has been designed and elaborated for this research work. The microfluidic devices based on the amorphous thermoplastic polymers have been successfully elaborated by hot embossing process. Proper agreement between the numerical simulation and the experimental elaboration has been obtained.

  7. The extrusion of AZ-series magnesium alloys - extending the processing limits by hydrostatic extrusion; Erweiterung der Prozessgrenzen beim Strangpressen von Magnesiumknetlegierungen der AZ-Reihe durch das hydrostatische Strangpressverfahren

    Energy Technology Data Exchange (ETDEWEB)

    Swiostek, J. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Werkstofforschung

    2008-12-04

    The present study is concerned with the analysis of the influence of hydrostatic extrusion on the microstructural development and mechanical properties of extruded profiles of the AZ-series magnesium alloys. This work also deals with the correlation between the microstructure and resulting mechanical properties for the case extruded profiles. (orig.)

  8. Influence of parameters controlling the extrusion step in fused filament fabrication (FFF) process applied to polymers using numerical simulation

    Science.gov (United States)

    Shahriar, Bakrani Balani; Arthur, Cantarel; France, Chabert; Valérie, Nassiet

    2018-05-01

    Extrusion is one of the oldest manufacturing processes; it is widely used for manufacturing finished and semi-finished products. Moreover, extrusion is also the main process in additive manufacturing technologies such as Fused Filament Fabrication (FFF). In FFF process, the parts are manufactured layer by layer using thermoplastic material. The latter in form of filament, is melted in the liquefier and then it is extruded and deposited on the previous layer. The mechanical properties of the printed parts rely on the coalescence of each extrudate with another one. The coalescence phenomenon is driven by the flow properties of the melted polymer when it comes out the nozzle just before the deposition step. This study aims to master the quality of the printed parts by controlling the effect of the parameters of the extruder on the flow properties in the FFF process. In the current study, numerical simulation of the polymer coming out of the extruder was carried out using Computational Fluid Dynamics (CFD) and two phase flow (TPF) simulation Level Set (LS) method by 2D axisymmetric module of COMSOL Multiphysics software. In order to pair the heat transfer with the flow simulation, an advection-diffusion equation was used. Advection-diffusion equation was implemented as a Partial Differential Equation (PDE) in the software. In order to define the variation of viscosity of the polymer with temperature, the rheological behaviors of two thermoplastics were measured by extensional rheometer and using a parallel-plate configuration of an oscillatory rheometer. The results highlight the influence of the environment temperature and the cooling rate on the temperature and viscosity of the extrudate exiting from the nozzle. Moreover, the temperature and its corresponding viscosity at different times have been determined using numerical simulation. At highest shear rates, the extrudate undergoes deformation from typical cylindrical shape. These results are required to predict the

  9. Optimising Drug Solubilisation in Amorphous Polymer Dispersions: Rational Selection of Hot-melt Extrusion Processing Parameters.

    Science.gov (United States)

    Li, Shu; Tian, Yiwei; Jones, David S; Andrews, Gavin P

    2016-02-01

    The aim of this article was to construct a T-ϕ phase diagram for a model drug (FD) and amorphous polymer (Eudragit® EPO) and to use this information to understand the impact of how temperature-composition coordinates influenced the final properties of the extrudate. Defining process boundaries and understanding drug solubility in polymeric carriers is of utmost importance and will help in the successful manufacture of new delivery platforms for BCS class II drugs. Physically mixed felodipine (FD)-Eudragit(®) EPO (EPO) binary mixtures with pre-determined weight fractions were analysed using DSC to measure the endset of melting and glass transition temperature. Extrudates of 10 wt% FD-EPO were processed using temperatures (110°C, 126°C, 140°C and 150°C) selected from the temperature-composition (T-ϕ) phase diagrams and processing screw speed of 20, 100 and 200rpm. Extrudates were characterised using powder X-ray diffraction (PXRD), optical, polarised light and Raman microscopy. To ensure formation of a binary amorphous drug dispersion (ADD) at a specific composition, HME processing temperatures should at least be equal to, or exceed, the corresponding temperature value on the liquid-solid curve in a F-H T-ϕ phase diagram. If extruded between the spinodal and liquid-solid curve, the lack of thermodynamic forces to attain complete drug amorphisation may be compensated for through the use of an increased screw speed. Constructing F-H T-ϕ phase diagrams are valuable not only in the understanding drug-polymer miscibility behaviour but also in rationalising the selection of important processing parameters for HME to ensure miscibility of drug and polymer.

  10. Wear Behavior and Microstructure of Mg-Sn Alloy Processed by Equal Channel Angular Extrusion.

    Science.gov (United States)

    Chen, Jung-Hsuan; Shen, Yen-Chen; Chao, Chuen-Guang; Liu, Tzeng-Feng

    2017-11-16

    Mg-5wt.% Sn alloy is often used in portable electronic devices and automobiles. In this study, mechanical properties of Mg-5wt.% Sn alloy processed by Equal Channel Angular Extrusion (ECAE) were characterized. More precisely, its hardness and wear behavior were measured using Vickers hardness test and a pin-on-disc wear test. The microstructures of ECAE-processed Mg-Sn alloys were investigated by scanning electron microscope and X-ray diffraction. ECAE process refined the grain sizes of the Mg-Sn alloy from 117.6 μm (as-cast) to 88.0 μm (one pass), 49.5 μm (two passes) and 24.4 μm (four passes), respectively. Meanwhile, the hardness of the alloy improved significantly. The maximum wear resistance achieved in the present work was around 73.77 m/mm³, which was obtained from the Mg-Sn alloy treated with a one-pass ECAE process with a grain size of 88.0 μm. The wear resistance improvement was caused by the grain size refinement and the precipitate of the second phase, Mg₂Sn against the oxidation of the processed alloy. The as-cast Mg-Sn alloy with the larger grain size, i.e., 117.6 μm, underwent wear mechanisms, mainly adhesive wear and abrasive wear. In ECAE-processed Mg-Sn alloy, high internal energy occurred due to the high dislocation density and the stress field produced by the plastic deformation, which led to an increased oxidation rate of the processed alloy during sliding. Therefore, the oxidative wear and a three-body abrasive wear in which the oxide debris acted as the three-body abrasive components became the dominant factors in the wear behavior, and as a result, reduced the wear resistance in the multi-pass ECAE-processed alloy.

  11. Near-infrared chemical imaging (NIR-CI) of 3D printed pharmaceuticals

    DEFF Research Database (Denmark)

    Khorasani, Milad; Edinger, Magnus; Raijada, Dharaben Kaushikkumar

    2016-01-01

    Hot-melt extrusion and 3D printing are enabling manufacturing approaches for patient-centred medicinal products. Hot-melt extrusion is a flexible and continuously operating technique which is a crucial part of a typical processing cycle of printed medicines. In this work we use hot-melt extrusion...... for manufacturing of medicinal films containing indomethacin (IND) and polycaprolactone (PCL), extruded strands with nitrofurantoin monohydrate (NFMH) and poly (ethylene oxide) (PEO), and feedstocks for 3D printed dosage forms with nitrofurantoin anhydrate (NFAH), hydroxyapatite (HA) and poly (lactic acid) (PLA......). These feedstocks were printed into a prototype solid dosage form using a desktop 3D printer. These model formulations were characterized using near-infrared chemical imaging (NIR-CI) and, more specifically, the image analytical data were analysed using multivariate curve resolution-alternating least squares (MCR...

  12. Reprocessability of PHB in extrusion: ATR-FTIR, tensile tests and thermal studies

    Directory of Open Access Journals (Sweden)

    Leonardo Fábio Rivas

    Full Text Available Abstract Mechanical recycling of biodegradable plastics has to be encouraged, since the consumption of energy and raw materials can be reduced towards a sustainable development in plastics materials. In this study, the evolution of thermal and mechanical properties, as well as structural changes of poly(hydroxybutyrate (PHB up to three extrusion cycles were investigated. Results indicated a significant reduction in mechanical properties already at the second extrusion cycle, with a reduction above 50% in the third cycle. An increase in the crystallinity index was observed due to chemicrystallization process during degradation by chain scission. On the other hand, significant changes in the chemical structure or in thermal stability of PHB cannot be detected by Fourier transform infrared spectroscopy (FTIR and thermogravimetric analyses (TGA, respectively.

  13. Polycarbonate as an Elasto-Plastic Material Model for Simulation of the Microstructure Hot Imprint Process

    Directory of Open Access Journals (Sweden)

    Rokas Šakalys

    2013-08-01

    Full Text Available The thermal imprint process of polymer micro-patterning is widely applied in areas such as manufacturing of optical parts, solar energy, bio-mechanical devices and chemical chips. Polycarbonate (PC, as an amorphous polymer, is often used in thermoforming processes because of its good replication characteristics. In order to obtain replicas of the best quality, the imprint parameters (e.g., pressure, temperature, time, etc. must be determined. Therefore finite element model of the hot imprint process of lamellar periodical microstructure into PC has been created using COMSOL Multiphysics. The mathematical model of the hot imprint process includes three steps: heating, imprinting and demolding. The material properties of amorphous PC strongly depend on the imprint temperature and loading pressure. Polycarbonate was modelled as an elasto-plastic material, since it was analyzed below the glass transition temperature. The hot imprint model was solved using the heat transfer and the solid stress-strain application modes with thermal contact problem between the mold and polycarbonate. It was used for the evaluation of temperature and stress distributions in the polycarbonate during the hot imprint process. The quality of the replica, by means of lands filling ratio, was determined as well.

  14. Effect of conventional and extrusion pelleting on in situ ruminal degradability of starch, protein, and fibre in cattle

    DEFF Research Database (Denmark)

    Razzaghi, Ali; Larsen, Mogens; Lund, Peter

    2016-01-01

    +50% sugar beet pulp (SBP), or 50% maize+50% SBP. Meals were pelleted by either conventional pelleting, or by cooking extrusion using two distinct settings giving pellets with either high density (HD) or low density (LD). Ruminal degradation of starch, crude protein (CP) and NDF, and intestinal...... affected ruminal degradability of starch, protein, and NDF differently depending on both type of cereal and composition of the concentrate mixture.......>Pelleting>Meal). In contradiction, ESD for pure wheat and wheat mixtures was reduced, though differences were minor. Conventional pelleting reduced the effective protein degradability (EPD) for pure wheat, but extrusion did not further affect the EPD. In contrast, the most intense processing with extrusion LD increased EPD...

  15. Hot topics: Signal processing in acoustics

    Science.gov (United States)

    Gaumond, Charles F.

    2005-09-01

    Signal processing in acoustics is a multidisciplinary group of people that work in many areas of acoustics. We have chosen two areas that have shown exciting new applications of signal processing to acoustics or have shown exciting and important results from the use of signal processing. In this session, two hot topics are shown: the use of noiselike acoustic fields to determine sound propagation structure and the use of localization to determine animal behaviors. The first topic shows the application of correlation on geo-acoustic fields to determine the Greens function for propagation through the Earth. These results can then be further used to solve geo-acoustic inverse problems. The first topic also shows the application of correlation using oceanic noise fields to determine the Greens function through the ocean. These results also have utility for oceanic inverse problems. The second topic shows exciting results from the detection, localization, and tracking of marine mammals by two different groups. Results from detection and localization of bullfrogs are shown, too. Each of these studies contributed to the knowledge of animal behavior. [Work supported by ONR.

  16. Development of modified route for fabrication of Zr-2.5Nb alloy pressure tubes

    International Nuclear Information System (INIS)

    Saibaba, N.; Hemantha Rao, G.V.S.; Phani Babu, C.; Jha, S.K.; Ganesha, G.N.; Ramana Rao, S.V.; Kumar Vaibhaw; Dey, G.K.; Srivastava, D.; Neogy, S.; Mani Krishna, K.V.

    2013-01-01

    Different fabrication trials involving the variation in three important manufacturing stages of Zr-2.5%Nb pressure tube were partially undetaken. The variations were with respect of mode of breaking the cast structure of the ingot (forging vs extrution), ratio of hot extrusion and number of stages of subsequent cold work to produce the finished tube. It was observed that forging process resulted in superior performance in breaking the cast structure. Higher extrusion ratios resulted in more favorable texture and microstrucutre. Continuity of the beta phase in the final microstructure was observed to be more in case of route involving single cold work subsequent to hot extrusion. (author)

  17. Processing of Mo-Si-B intermetallics by extrusion and oxidation properties of the extruded Tl-MoSi2-MoB Systems

    International Nuclear Information System (INIS)

    Summers, Eric

    1999-01-01

    An extrusion process was developed that is able to consistently produce large quantities of Mo-Si-B rods without the presence of defects. Binder removal from the extruded rods was studied in detail and it was determined that heating rates on the order of 0.02degree/minute (1.2degree/hour) are necessary to remove the binder without the formation of defects. This low heating rate resulted in debinding times in excess of 70 hours (∼ 3 days). Wicking was investigated as a means to decrease the time necessary for binder removal. Using 0.05microm alumina powder as a wicking agent, binder removal times were reduced to 10 hours with heating rates up to 1degree/minute employed without defect formation. Once the extrusion process was complete the oxidation properties of the Tl-MoSi 2 -MoB extruded phase assemblage was investigated. It was determined that this composition exhibits catastrophic oxidation or pesting in the temperature range of 660--760 C, resulting in the material turning to dust. Outside of this temperature range the composition is oxidatively stable. Continuous mass measurements were taken at 1,300, 1,450, and 1,600 C to determine the oxidation rate constants of this material. Parabolic rate constants of 6.9 x 10 -3 , 1.3 x 10 -3 , and 9.1 x 10 -3 mg 2 /cm 4 /hr were determined for 1,300, 1,450, and 1,600 C respectively

  18. Rolling process simulation of a pair-crossed hot strip mill

    International Nuclear Information System (INIS)

    Chen Shaojie; Xu Jianzhong; Liu Xianghua; Wang Guodong

    2000-01-01

    Process simulation can help optimize the operating parameters aiming to improve the quality of rolled products. In this paper, software in Visual Basic language is developed to simulate the hot rolling process of a pair-crossed mill. The strip temperature is calculated by considering air cooling, water cooling, heat generation and conduction.The production parameters including rolling speeds, resistance to deformation, rolling forces, drive torques and powers are evaluated by mathematical models and their parameter identification support tools. The deformation of roll stack is calculated by influential function method. The roll temperature and expansion are calculated by finite differential method, and the roll wear is described by empirical formula. Based on these calculations as well as the effect of heredity is taken into account, the strip crown and flatness then can be obtained. The results show that the simulation software has friendly user interface, high accuracy and practicability. It can be served as a basis for the mill design and optimization of process parameters to acquire high quality of hot rolled strip. (author)

  19. In-process weld sampling during hot end welds of type W overpacks

    International Nuclear Information System (INIS)

    Barnes, G.A.

    1998-01-01

    Establish the criteria and process controls to be used in obtaining, testing, and evaluating in-process weld sample during the hot end welding of Type W Overpack capsules used to overpack CsCl capsules for storage at WESF

  20. The influence of processing on microstructure and properties of iron aluminides

    Energy Technology Data Exchange (ETDEWEB)

    Wright, R.N.; Wright, J.K. [Idaho National Engineering Lab., Idaho Falls, ID (United States)

    1996-08-01

    An Fe-28%Al alloy containing 5% Cr has been synthesized by reaction of elemental powders, followed by consolidation using hot extrusion. The resulting material is fully dense, homogeneous, and has a grain size of less than 5{mu}m. Reaction synthesis results in an Al{sub 2}O{sub 3} dispersion that is uniformly dispersed during hot extrusion. Under some circumstances the hot extruded material undergoes secondary recrystallization, resulting in grain sizes greater than 25 millimeters. The fine grained material exhibits improved yield strength compared to the coarse grained material up to test temperatures of 800{degrees}C. Creep testing has shown that the coarse grained material has significantly improved time to rupture compared to fine grained material. The oxide dispersion strengthened material has significantly improved creep resistance compared to conventional powder metallurgy material. With proper heat treatment, the coarse grained material exhibits time to rupture of 425 hours at 650{degrees}C and a stress of 75 MPa, compared to 40 hours for conventional material of similar composition.

  1. Cell Extrusion: A Stress-Responsive Force for Good or Evil in Epithelial Homeostasis.

    Science.gov (United States)

    Ohsawa, Shizue; Vaughen, John; Igaki, Tatsushi

    2018-02-05

    Epithelial tissues robustly respond to internal and external stressors via dynamic cellular rearrangements. Cell extrusion acts as a key regulator of epithelial homeostasis by removing apoptotic cells, orchestrating morphogenesis, and mediating competitive cellular battles during tumorigenesis. Here, we delineate the diverse functions of cell extrusion during development and disease. We emphasize the expanding role for apoptotic cell extrusion in exerting morphogenetic forces, as well as the strong intersection of cell extrusion with cell competition, a homeostatic mechanism that eliminates aberrant or unfit cells. While cell competition and extrusion can exert potent, tumor-suppressive effects, dysregulation of either critical homeostatic program can fuel cancer progression. Copyright © 2018 Elsevier Inc. All rights reserved.

  2. Co-extrusion of food grains-banana pulp for nutritious snacks: optimization of process variables.

    Science.gov (United States)

    Mridula, D; Sethi, Swati; Tushir, Surya; Bhadwal, Sheetal; Gupta, R K; Nanda, S K

    2017-08-01

    Present study was undertaken to optimize the process conditions for development of food grains (maize, defatted soy flour, sesame seed)-banana based nutritious expanded snacks using extrusion processing. Experiments were designed using Box-Behnken design with banana pulp (8-24 g), screw speed (300-350 rpm) and feed moisture (14-16% w.b.). Seven responses viz. expansion ratio (ER), bulk density (BD), water absorption index (WAI), protein, minerals, iron and sensory acceptability were considered for optimizing independent parameters. ER, BD, WAI, protein content, total minerals, iron content, and overall acceptability ranged 2.69-3.36, 153.43-238.83 kg/m 3 , 4.56-4.88 g/g, 15.19-15.52%, 2.06-2.27%, 4.39-4.67 mg/100 g (w.b.) and 6.76-7.36, respectively. ER was significantly affected by all three process variables while BD was influenced by banana pulp and screw speed only. Studied process variables did not affected colour quality except 'a' value with banana pulp and screw speed. Banana pulp had positive correlation with water solubility index, total minerals and iron content and negative with WAI, protein and overall acceptability. Based upon multiple response analysis, optimized conditions were 8 g banana pulp, 350 rpm screw speed and 14% feed moisture indicating the protein, calorie, iron content and overall sensory acceptability in sample as 15.46%, 401 kcal/100 g, 4.48 mg/100 g and 7.6 respectively.

  3. Finite Element Analysis and Die Design of Non-specific Engineering Structure of Aluminum Alloy during Extrusion

    International Nuclear Information System (INIS)

    Chen, D.-C.; Lu, Y.-Y.

    2010-01-01

    Aluminum extension applies to industrial structure, light load, framework rolls and conveyer system platform. Many factors must be controlled in processing the non-specific engineering structure (hollow shape) of the aluminum alloy during extrusion, to obtain the required plastic strain and desired tolerance values. The major factors include the forming angle of the die and temperature of billet and various materials. This paper employs rigid-plastic finite element (FE) DEFORM 3D software to investigate the plastic deformation behavior of an aluminum alloy (A6061, A5052, A3003) workpiece during extrusion for the engineering structure of the aluminum alloy. This work analyzes effective strain, effective stress, damage and die radius load distribution of the billet under various conditions. The analytical results confirm the suitability of the current finite element software for the non-specific engineering structure of aluminum alloy extrusion.

  4. Analysis of the hot cell lay-out for the advanced spent fuel conditioning process

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J. Y.; Kim, S. H.; Song, T. G.; Hong, D. H.; Kim, Y. H.; Yoon, J. S

    2003-04-01

    Equipment used for ACP must operate in intense radiation fields enclosed in a hot cell and be remotely maintained. For the reliable remote maintenance operation, several design aspects should be considered. Even though the design results seem to be satisfactory, all the remote operation should be checked prior to the hot demonstration. The best way to check the remote operability is a real mock-up test, but the mock-up test is too expensive and time consuming, and need refabrication of the design to deal with the problem found in the test operation. The 3D graphic simulator gives an alternate solution for this. It can check the remote operability of the process without fabrication of the process equipment. In other words, using a graphic simulator, remote operation task can be simulated in a computer(virtual environment), not the real environment. In this report, for the analysis on the hat cell layout for the ACP process, the verification from the concept of the process to the detailed motion of the equipment and the remote operation devices using virtual prototyping is described. Also, the requirement of the process equipment in the sense of size and remote maintenance, and that of the transportation and handling for the process material are described. Finally, from these results, the hot cell layout alternatives and the bases for the selection of the optimum layout are implemented. The graphical simulator and the results from this analysis can be effectively used not only for optimizing the hot cell layout but also designing the ACP equipment and maintenance process.

  5. The impact of extrusion on the nutritional composition, dietary fiber and in vitro digestibility of gluten-free snacks based on rice, pea and carob flour blends.

    Science.gov (United States)

    Arribas, C; Cabellos, B; Sánchez, C; Cuadrado, C; Guillamón, E; Pedrosa, M M

    2017-10-18

    Consumers and the food industry are demanding healthier products. Expanded snacks with a high nutritional value were developed from different rice, pea and carob flour blends. The proximate composition, starch (total and resistant), amylose and amylopectin, dietary fiber (soluble and insoluble) contents, and the in vitro protein digestibility of different rice-legume formulations, were evaluated before and after the extrusion process. Compared with the corresponding non-extruded blends (control), the extrusion treatment did not change the total protein content, however, it reduced the soluble protein (61-86%), the fat (69-92%) and the resistant starch contents (100%). The total starch content of all studied blends increased (2-19%) after extrusion. The processing increased the in vitro protein digestibility, reaching values around 88-95% after extrusion. Total dietary fiber was reduced around 30%, and the insoluble fraction was affected to a larger extent than the soluble fraction by the extrusion process. Because of its balanced nutritional composition, high dietary fiber content, as well as low energy density, these novel gluten-free snack-like foods could be considered as functional foods and a healthier alternative to commercially available gluten-containing or gluten-free and low nutritional value snacks.

  6. Instant blend from cassava derivatives produced by extrusion

    OpenAIRE

    Trombini, Fernanda Rossi Moretti; Mischan, Martha Maria; Leonel, Magali

    2016-01-01

    ABSTRACT: The current research aimed to evaluate the effects of extrusion parameters on the physical characteristics of extruded blends of cassava leaf flour and starch. A factorial central composite design with four independent variables and the response surface methodology were used to evaluate the results of color parameters (L*, a*, b*), water absorption index, water solubility index and paste properties, according to the variations in the leaf flour percentage (1.5 to 7.5%), extrusion te...

  7. Rapid Continuous Multimaterial Extrusion Bioprinting

    NARCIS (Netherlands)

    Liu, Wanjun; Zhang, Yu Shrike; Heinrich, Marcel A.; De Ferrari, F; Jang, HL; Bakht, SM; Alvarez, MM; Yang, J; Li, YC; Trujillo-de Stantiago, G; Miri, AK; Zhu, K; Khoshakhlagh, P; Prakash, G; Cheng, H; Guan, X; Zhong, Z; Ju, J; Zhu, GH; Jin, X; Ryon Shin, Su; Dokmeci, M.R.; Khademhosseini, Ali

    The development of a multimaterial extrusion bioprinting platform is reported. This platform is capable of depositing multiple coded bioinks in a continuous manner with fast and smooth switching among different reservoirs for rapid fabrication of complex constructs, through digitally controlled

  8. Effect of Pre-Oxidation Treatment of Nano-SiC Particulates on Microstructure and Mechanical Properties of SiC/Mg-8Al-1Sn Composites Fabricated by Powder Metallurgy Combined with Hot Extrusion.

    Science.gov (United States)

    Li, Chuan-Peng; Wang, Zhi-Guo; Zha, Min; Wang, Cheng; Yu, Hong-Chen; Wang, Hui-Yuan; Jiang, Qi-Chuan

    2016-11-26

    Nano-SiC particulates (n-SiC p ) reinforced Mg-8Al-1Sn (AT81) composites with different pre-oxidation parameters were fabricated by powder metallurgy (P/M) process combined with hot extrusion. The effects of pre-oxidization treatment of n-SiC p on the microstructure and tensile properties of 0.5 vol % n-SiC p /AT81 composites were investigated accordingly. The distribution of n-SiC p with different pre-oxidation parameters was homogeneous in the composites. Moreover, it was found that a thin MgAl₂O₄ layer formed at the interface when the n-SiC p were pre-oxidized at 1073 K for 2 h, while the MgAl₂O₄ layer became much thicker with pre-oxidization temperature increasing to 1273 K for 2 h. After an appropriate pre-oxidization treatment of n-SiC p at 1073 K for 2 h, the as-extruded 0.5 vol % n-SiC p /AT81 composites exhibited an enhanced strength. It was found that the yield strength (YS) and ultimate tensile strength (UTS) increased from 168 MPa and 311 MPa to 255 MPa and 393 MPa compared with the as-extruded AT81 alloy, reflecting 51.8% and 26.4% increments, respectively. The improvement of mechanical properties should be mainly attributed to the grain refinement and homogeneous distribution of n-SiC p in the composites. Moreover, a well-bonded interface and the formation of an appropriate amount of interfacial product (MgAl₂O₄) benefited the material's mechanical properties.

  9. REFINEMENT OF THE REVERSE EXTRUSION TEST TO DETERMINE THE TWO CONSISTENCY LIMITS

    Directory of Open Access Journals (Sweden)

    Kamil KAYABALI

    2015-11-01

    Full Text Available Liquid limit (LL and plastic limit (PL are the two most commonly used index proper- ties of fine-grained soils. They have been used in not only classification of soils but also in correlation with certain engineering properties. Therefore, they have been subjected to numerous researches since they were first introduced by Atterberg in 1911. While their me- chanisms were well defined in many codes and they have been in use for decades, criticisms often arose pertinent to the uncertainties inherent to them. Incredible amount of effort has been exerted to invent more rational testing methods in place of both the Casagrande’s cup and bead rolling methods. Part of those efforts has been on devicing a single tool to measure the two relative index properties together. Recently, the reverse extrusion test was brought into the use of geotechnical engineers. It was shown that this tool has a potential of measu- ring LL, PL, and even the shrinkage limit (SL. The aim of this investigation is to reassess the ability of the reverse extrusion test to determine LL and PL with further refinement. In this regard 70 fine-grained soils covering a large range of plasticity were employed. Fall-cone method and rolling-device method were employed to determine LL and PL, res- pectively. The reverse extrusion tests were carried out at least five different water contents per soil sample. Extrusion pressures were plotted against water content and a curve fitting was applied to data pairs, from which the y-intercept (the coefficient a and the slope (the coefficieent b of the curve were determined. Those reverse extrusion coefficients were utilized to determine the representative extrusion pressures corresponding to LL and PL, as was done by the earlier researchers; however, the degree of success for the prediction of LL and PL using the representative extrusion pressures was not encouraging. Different from the previously proposed approaches, the reverse extrusion

  10. Experimental and Simulation Analysis of Hot Isostatic Pressing of Gas Atomized Stainless Steel 316L Powder Compacts

    International Nuclear Information System (INIS)

    Lin, Dongguo; Park, Seong Jin; Ha, Sangyul; Shin, Youngho; Park, Dong Yong; Chung, Sung Taek; Bollina, Ravi; See, Seongkyu

    2016-01-01

    In this work, both experimental and numerical studies were conducted to investigate the densification behavior of stainless steel 316L (STS 316L) powders during hot isostatic pressing (HIP), and to characterize the mechanical properties of HIPed specimens. The HIP experiments were conducted with gas atomized STS 316L powders with spherical particle shapes under controlled pressure and temperature conditions. The mechanical properties of HIPed samples were determined based on a series of tensile tests, and the results were compared to a reference STS 316L sample prepared by the conventional process, i.e., extrusion and annealing process. Corresponding microstructures before and after tensile tests were observed using scanning electron microscopy and their relationships to the mechanical properties were addressed. Furthermore, a finite element simulation based on the power-law creep model was carried out to predict the density distribution and overall shape change of the STS316L powder compact during HIP process, which agreed well with the experimental results.

  11. Experimental and Simulation Analysis of Hot Isostatic Pressing of Gas Atomized Stainless Steel 316L Powder Compacts

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Dongguo; Park, Seong Jin [Pohang University of Science and Technology, Pohang (Korea, Republic of); Ha, Sangyul [Samsung Electro-Mechanics, Suwon (Korea, Republic of); Shin, Youngho [Doosan Heavy Industries and Construction Co., Ltd., Changwon (Korea, Republic of); Park, Dong Yong [Korea Institute of Energy Research, Daejeon (Korea, Republic of); Chung, Sung Taek [CetaTech Inc., Sacheon (Korea, Republic of); Bollina, Ravi [Bahadurpally Jeedimetla, Hyderabad (India); See, Seongkyu [POSCO, Pohang (Korea, Republic of)

    2016-10-15

    In this work, both experimental and numerical studies were conducted to investigate the densification behavior of stainless steel 316L (STS 316L) powders during hot isostatic pressing (HIP), and to characterize the mechanical properties of HIPed specimens. The HIP experiments were conducted with gas atomized STS 316L powders with spherical particle shapes under controlled pressure and temperature conditions. The mechanical properties of HIPed samples were determined based on a series of tensile tests, and the results were compared to a reference STS 316L sample prepared by the conventional process, i.e., extrusion and annealing process. Corresponding microstructures before and after tensile tests were observed using scanning electron microscopy and their relationships to the mechanical properties were addressed. Furthermore, a finite element simulation based on the power-law creep model was carried out to predict the density distribution and overall shape change of the STS316L powder compact during HIP process, which agreed well with the experimental results.

  12. Microcapsules loaded with the probiotic Lactobacillus paracasei BGP-1 produced by co-extrusion technology using alginate/shellac as wall material: Characterization and evaluation of drying processes.

    Science.gov (United States)

    Silva, Marluci P; Tulini, Fabricio L; Ribas, Marcela M; Penning, Manfred; Fávaro-Trindade, Carmen S; Poncelet, Denis

    2016-11-01

    Microcapsules containing Lactobacillus paracasei BGP-1 were produced by co-extrusion technology using alginate and alginate-shellac blend as wall materials. Sunflower oil and coconut fat were used as vehicles to incorporate BGP-1 into the microcapsules. The microcapsules were evaluated with regard the particle size, morphology, water activity and survival of probiotics after 60days of storage at room temperature. Fluidized bed and lyophilization were used to dry the microcapsules and the effect of these processes on probiotic viability was also evaluated. Next, dried microcapsules were exposed to simulated gastrointestinal fluids to verify the survival of BGP-1. Microcapsules dried by fluidized bed had spherical shape and robust structures, whereas lyophilized microcapsules had porous and fragile structures. Dried microcapsules presented a medium size of 0.71-0.86mm and a w ranging from 0.14 to 0.36, depending on the drying process. When comparing the effects of drying processes on BGP-1 viability, the fluidized bed was less aggressive than lyophilization. The alginate-shellac blend combined with coconut fat as core effectively protected the encapsulated probiotic under simulated gastrointestinal conditions. Thus, the production of microcapsules by co-extrusion followed by drying using the fluidized bed is a promising strategy for protection of probiotic cells. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Microstructures and mechanical responses of powder metallurgy non-combustive magnesium extruded alloy by rapid solidification process in mass production

    International Nuclear Information System (INIS)

    Kondoh, Katsuyoshi; Hamada, EL-Sayed Ayman; Imai, Hisashi; Umeda, Junko; Jones, Tyrone

    2010-01-01

    Spinning Water Atomization Process (SWAP), which was one of the rapid solidification processes, promised to produce coarse non-combustible magnesium alloy powder with 1-4 mm length, having fine α-Mg grains and Al 2 Ca intermetallic compounds. It had economical and safe benefits in producing coarse Mg alloy powders with very fine microstructures in the mass production process due to its extreme high solidification rate compared to the conventional atomization process. AMX602 (Mg-6%Al-0.5%Mn-2%Ca) powders were compacted at room temperature. Their green compacts with a relative density of about 85% were heated at 573-673 K for 300 s in Ar gas atmosphere, and immediately consolidated by hot extrusion. Microstructure observation and evaluation of mechanical properties of the extruded AMX602 alloys were carried out. The uniform and fine microstructures with grains less than 0.45-0.8 μm via dynamic recrystallization during hot extrusion were observed, and were much small compared to the extruded AMX602 alloy fabricated by using cast ingot. The extremely fine intermetallic compounds 200-500 nm diameter were uniformly distributed in the matrix of powder metallurgy (P/M) extruded alloys. These microstructures caused excellent mechanical properties of the wrought alloys. For example, in the case of AMX602 alloys extruded at 573 K, the tensile strength (TS) of 447 MPa, yield stress (YS) of 425 MPa and 9.6% elongation were obtained.

  14. 75 FR 69403 - Aluminum Extrusions From the People's Republic of China: Notice of Preliminary Determination of...

    Science.gov (United States)

    2010-11-12

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-570-967] Aluminum Extrusions From the... Commerce (``Department'') preliminarily determines that aluminum extrusions from the People's Republic of... of aluminum extrusions from the PRC filed in proper form by the Aluminum Extrusions Fair Trade...

  15. Effects of Texture and Grain Size on the Yield Strength of ZK61 Alloy Rods Processed by Cyclic Extrusion and Compression.

    Science.gov (United States)

    Zhang, Lixin; Zhang, Wencong; Cao, Biao; Chen, Wenzhen; Duan, Junpeng; Cui, Guorong

    2017-10-26

    The ZK61 alloy rods with different grain sizes and crystallographic texture were successfully fabricated by cyclic extrusion and compression (CEC). Their room-temperature tension & compression yield strength displayed a significant dependence on grain size and texture, essentially attributed to {10-12} twinning. The texture variations were characterized by the angle θ between the c-axis of the grain and the extrusion direction (ED) during the process. The contour map of room-temperature yield strength as a function of grain size and the angle θ was obtained. It showed that both the tension yield strength and the compression yield strength of ZK61 alloy were fully consistent with the Hall-Patch relationship at a certain texture, but the change trends of the tension yield strength and the compression yield strength were completely opposite at the same grain size while texture altered. The friction stresses of different deformation modes calculated based on the texture confirmed the tension yield strength of the CECed ZK61 alloy rods, which was determined by both the basal slip and the tension twinning slip during the tension deformation at room temperature, while the compression yield strength was mainly determined by the basal slip during the compression deformation.

  16. Characterization Of Flow Stress Of Different AA6082 Alloys By Means Of Hot Torsion Test

    International Nuclear Information System (INIS)

    Donati, Lorenzo; El Mehtedi, Mohamad

    2011-01-01

    FEM simulations are become the most powerful tools in order to optimize the different aspects of the extrusion process and an accurate flow stress definition of the alloy is a prerequisite for a reliable effectiveness of the simulation. In the paper the determination of flow stress by means of hot torsion test is initially presented and discussed: the several approximations that are usually introduced in flow stress computation are described and computed for an AA6082 alloy in order to evidence the final effect on curves shapes. The procedure for regressing the parameters of the sinhyperbolic flow stress definition is described in detailed and applied to the described results. Then four different alloys, extracted by different casting batches but all namely belonging to the 6082 class, were hot torsion tested in comparable levels of temperature and strain rate up to specimen failure. The results are analyzed and discussed in order to understand if a mean flow stress behavior can be identified for the whole material class at the different tested conditions or if specific testing conditions (chemical composition of the alloy, specimen shape, etc) influence the materials properties to a higher degree.

  17. Extrusion cooking technology: Principal mechanism and effect on direct expanded snacks – An overview

    Directory of Open Access Journals (Sweden)

    Ajita Tiwari

    2017-04-01

    Full Text Available The snack industry is one of the fastest growing food sectors and is an important contributor within the global convenience food market. Nowadays snacks and convenience foods are also consumed regularly in India. Properly designed convenience foods can make an important contribution to nutrition in societies where social changes are altering traditional patterns of food preparation. Extrusion cooking as a popular means of preparing snack foods based on cereals and plant protein foodstuff has elicited considerable interest and attention over the past 30 years. Several studies on the extrusion of cereals and pulses, using various proportions, have been conducted because blends of cereals and pulses produce protein enriched products. Special importance is placed on the physicochemical and chemical modifications of protein, starch and dietary fibre. Extruded products can be categorized for a particular application based on their functional properties such as water absorption and water solubility index, expansion ratio, bulk density and viscosity of the dough.Therefore, the literature was reviewed for effect of extrusion processing on product parameters, and nutritional and anti-nutritional properties of extruded products.

  18. Modeling And Simulation Of Combined Extrusion For Spark Plug Body Parts

    Science.gov (United States)

    Canta, T.; Noveanu, D.; Frunza, D.

    2004-06-01

    The paper presents the modeling and simulation for the extrusion technology of a new type of spark plug body for Dacia Supernova car. This technology was simulated using the finite elements modeling and analysis SuperForm software, designed for the simulation of plastic deformation processes. There is also presented a comparison between the results of the simulation and the industrial results.

  19. The origin of weld seam defects related to metal flow in the hot extrusion of aluminium alloys en AW-6060 and en AW-6082

    NARCIS (Netherlands)

    Bakker, A.J. den; Werkhoven, R.J.; Sillekens, W.H.; Katgerman, L.

    2014-01-01

    Longitudinal weld seams are an intrinsic feature in hollow extrusions produced with porthole dies. As these joins occur along the entire extruded length, it is desirable that these weld seams have a minimal impact on the structural integrity of the extrudate. In particular, defects associated with

  20. Extrusion of blends of cassava leaves and cassava flour: physical characteristics of extrudates

    Directory of Open Access Journals (Sweden)

    Cristiane da Cunha Salata

    2014-09-01

    Full Text Available A cassava-based puffed snack was produced using a single screw extruder to determine the effect of the raw material composition (cassava leaf flour and moisture and the process parameters (extrusion temperature and screw speed on the physical characteristics of an extruded-expanded snack. A central composite rotational design, including four factors with 30 treatments, was used with the following as dependent variables: expansion index, specific volume, water solubility index, water absorption index, color (L*, a*, b*, and hardness. Under conditions of low moisture content (12 to 14%, low percentage of cassava leaf flour (2 to 4%, and intermediate conditions of extrusion temperature (100°C and screw speed (230rpm, it was possible to obtain puffed snack products with desirable characteristics.

  1. 75 FR 57441 - Aluminum Extrusions From the People's Republic of China: Alignment of Final Countervailing Duty...

    Science.gov (United States)

    2010-09-21

    ... DEPARTMENT OF COMMERCE International Trade Administration [C-570-968] Aluminum Extrusions From the... countervailing duty investigation of aluminum extrusions from the People's Republic of China (PRC) with the final... antidumping duty investigations on aluminum extrusions from the PRC. See Aluminum Extrusions from the People's...

  2. Numerical studies of temperature effect on the extrusion fracture and swell of plastic micro-pipe

    Science.gov (United States)

    Ren, Zhong; Huang, Xingyuan; Xiong, Zhihua

    2018-03-01

    Temperature is a key factor that impacts extrusion forming quality of plastic micro-pipe. In this study, the effect of temperature on extrusion fracture and swell of plastic micro-pipe was investigated by numerical method. Under a certain of the melt’s flow volume, the extrusion pattern, extrusion swelling ratio of melt are obtained under different temperatures. Results show that the extrusion swelling ratio of plastic micro-pipe decreases with increasing of temperature. In order to study the reason of temperature effect, the physical distributions of plastic micro-pipe are gotten. Numerical results show that the viscosity, pressure, stress value of melt are all decreased with the increasing of temperature, which leads to decrease the extrusion swell and fracture phenomenon for the plastic micro-pipe.

  3. Solid State Bonding Mechanics In Extrusion And FSW: Experimental Tests And Numerical Analyses

    International Nuclear Information System (INIS)

    Buffa, G.; Fratini, L.; Donati, L.; Tomesani, L.

    2007-01-01

    In the paper the authors compare the different solid state bonding mechanics for both the processes of hollow profiles extrusion and Friction Stir Welding (FSW), through the results obtained from a wide experimental campaign on AA6082-T6 aluminum alloys. Microstructure evaluation, tensile tests and micro-hardness measurements realized on specimens extracted by samples of the two processes are discussed also by means of the results obtained from coupled FEM simulation of the processes

  4. Desenvolvimento de misturas instantâneas de mandioca e caseína: efeito do teor de proteína e parâmetros de extrusão sobre a viscosidade Development of instant blends of cassava flour and casein: effect of protein contents and extrusion parameters on viscosity

    Directory of Open Access Journals (Sweden)

    Beatriz Helena Borges Lustosa

    2010-09-01

    Full Text Available O interesse da indústria de alimentos por produtos desenvolvidos a partir de farinhas acrescidas de proteína não se deve somente às suas características nutricionais, senão também às suas propriedades funcionais e reológicas, as quais definem as suas aplicações comerciais. Este trabalho teve por objetivo avaliar o efeito de parâmetros operacionais do processo de extrusão sobre as propriedades de pasta de misturas de farinha de mandioca e caseína. O processo de extrusão seguiu o delineamento 'central composto rotacional' para três fatores: teor de proteína (2,5 a 9,5%, umidade (14,5 a 19,5% e temperatura de extrusão (65 a 135 ºC. As misturas antes e após a extrusão foram analisadas no Rapid Visco Analyser (RVA quanto a: viscosidade inicial, pico de viscosidade, quebra de viscosidade, viscosidade final e tendência à retrogradação. Os resultados obtidos nas misturas antes da extrusão mostraram aumento dos valores de viscosidade com o aumento da concentração de proteína até o ponto central (6% e, nos teores mais elevados de proteína, ocorreu redução destes. Após a extrusão, observou-se que o teor de proteína foi a variável de maior efeito sobre as propriedades de pasta, seguida pela umidade das misturas.The interest of the food industry in products developed from flours added with protein is not due only to their nutritional characteristics, but also due to their functional and rheological properties, which define their commercial applications. This study aimed to evaluate the effect of operational parameters of the extrusion process on the paste properties of cassava flour and casein blends. The process of extrusion followed the central composed rotational design with three factors: protein content (2.5 to 9.5%, moisture (14.5 to 19.5%, and extrusion temperature (65 to 135 ºC. Before and after extrusion, the blends were analyzed on a Rapid Visco Analyser using the following parameters: initial viscosity, peak

  5. 76 FR 30650 - Aluminum Extrusions from the People's Republic of China: Antidumping Duty Order

    Science.gov (United States)

    2011-05-26

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-570-967] Aluminum Extrusions from the...''), the Department is issuing an antidumping duty order on aluminum extrusions from the People's Republic... of material injury by reason of imports of certain aluminum extrusions from the PRC, and its negative...

  6. Extrusion conditions affect chemical composition and in vitro digestion of select food ingredients.

    Science.gov (United States)

    Dust, Jolene M; Gajda, Angela M; Flickinger, Elizabeth A; Burkhalter, Toni M; Merchen, Neal R; Fahey, George C

    2004-05-19

    An experiment was conducted to determine the effects of extrusion conditions on chemical composition and in vitro hydrolytic and fermentative digestion of barley grits, cornmeal, oat bran, soybean flour, soybean hulls, and wheat bran. Extrusion conditions altered crude protein, fiber, and starch concentrations of ingredients. Organic matter disappearance (OMD) increased for extruded versus unprocessed samples of barley grits, cornmeal, and soybean flour that had been hydrolytically digested. After 8 h of fermentative digestion, OMD decreased as extrusion conditions intensified for barley grits and cornmeal but increased for oat bran, soybean hulls, and wheat bran. Total short-chain fatty acid production decreased as extrusion conditions intensified for barley grits, soybean hulls, and soybean flour. These data suggest that the effects of extrusion conditions on ingredient composition and digestion are influenced by the unique chemical characteristics of individual substrates.

  7. Efeito de parâmetros de extrusão na cor E propriedades de pasta da farinha de mandioquinha-salsa (Arracacia xanthorrhiza Effect of extrusion parameters on color and pasting properties of peruvian carrot flour (Arracacia xanthorrhiza

    Directory of Open Access Journals (Sweden)

    Bruna Menegassi

    2007-12-01

    Full Text Available Processou-se neste trabalho a farinha de mandioquinha-salsa (Arracacia xanthorrhiza Bancr. em uma linha de extrusão (mono rosca variando as condições operacionais: umidade da farinha (11-19%, temperatura de extrusão (86-154ºC e taxa de rotação da rosca (136-272rpm. Os parâmetros de cor analisados foram luminosidade (L* e os componentes de cromaticidade a* e b*. Os parâmetros de propriedade de pasta analisados foram viscosidade inicial, pico de viscosidade, quebra de viscosidade, tendência a retrogradação e viscosidade final. Os resultados obtidos mostraram que a umidade da matéria-prima interferiu nos componentes de cor das farinhas com efeito significativo sobre a luminosidade e croma a*, e a temperatura interferiu no croma b* . Quanto ao efeito dos parâmetros de processo sobre as propriedades de pasta, a umidade interferiu nas viscosidades inicial e final dos produtos, pico e quebra de viscosidade, enquanto a temperatura de extrusão e a rotação da rosca tiveram influência sobre a tendência a retrogradação e viscosidade final dos produtos.In this work peruvian carrot flour (Arracacia xanthorrhiza Bancr. was processed in a single screw extruder at different moisture contents (11-19%, extrusion temperature (86-154ºC and screw speed (136-272rpm. The parameters L*, a* and b* of color were analyzed in extruded flours. The viscosity related parameters determined include initial viscosity, viscosity peak, breakdown, setback and final viscosity. The results showed effect of feed moisture on flour color (L* and a* and the extrusion temperature influenced b*. Moisture content of the feed had effect on initial and final viscosity, viscosity peak and breakdown. Extrusion temperature and screw speed had effect on final viscosity and setback.

  8. Continuously graded extruded polymer composites for energetic applications fabricated using twin-screw extrusion processing technology

    Science.gov (United States)

    Gallant, Frederick M.

    A novel method of fabricating functionally graded extruded composite materials is proposed for propellant applications using the technology of continuous processing with a Twin-Screw Extruder. The method is applied to the manufacturing of grains for solid rocket motors in an end-burning configuration with an axial gradient in ammonium perchlorate volume fraction and relative coarse/fine particle size distributions. The fabrication of functionally graded extruded polymer composites with either inert or energetic ingredients has yet to be investigated. The lack of knowledge concerning the processing of these novel materials has necessitated that a number of research issues be addressed. Of primary concern is characterizing and modeling the relationship between the extruder screw geometry, transient processing conditions, and the gradient architecture that evolves in the extruder. Recent interpretations of the Residence Time Distributions (RTDs) and Residence Volume Distributions (RVDs) for polymer composites in the TSE are used to develop new process models for predicting gradient architectures in the direction of extrusion. An approach is developed for characterizing the sections of the extrudate using optical, mechanical, and compositional analysis to determine the gradient architectures. The effects of processing on the burning rate properties of extruded energetic polymer composites are characterized for homogeneous formulations over a range of compositions to determine realistic gradient architectures for solid rocket motor applications. The new process models and burning rate properties that have been characterized in this research effort will be the basis for an inverse design procedure that is capable of determining gradient architectures for grains in solid rocket motors that possess tailored burning rate distributions that conform to user-defined performance specifications.

  9. Oxide dispersion strengthened ferritic alloys. 14/20% chromium: effects of processing on deformation texture, recrystallization and tensile properties; Alliages ferritiques 14/20% de chrome renforces par dispersion d`oxydes. Effets des procedes de mise en forme sur les textures de deformation, la recristallisation et les proprietes de traction

    Energy Technology Data Exchange (ETDEWEB)

    Regle, H

    1994-12-31

    The ferritic oxide dispersion strengthened alloys are promising candidates for high temperature application materials, in particular for long life core components of advanced nuclear reactors. The aim of this work is to control the microstructure, in order to optimise the mechanical properties. The two ferritic alloys examined here, MA956 and MA957, are obtained by Mechanical Alloying techniques. They are characterised by quite anisotropic microstructure and mechanical properties. We have investigated the influence of hot and cold working processes (hot extrusion, swaging and cold-drawing) and recrystallization heat treatments on deformation textures, microstructures and tensile properties. The aim was to control the size of the grains and their anisotropic shape, using recrystallization heat treatments. After consolidation and hot extrusion, as-received materials present a extremely fine microstructure with elongated grains and a very strong (110) deformation texture with single-crystal character. At that stage of processing, recrystallization temperature are very high (1450 degrees C for MA957 alloy and 1350 degrees C for MA956 alloy) and materials develop millimetric recrystallized grains. Additional hot extrusion induce a fibre texture. Cold-drawing maintains a fibre texture, but the intensity decreases with increasing cold-work level. For both materials, the decrease of texture intensities correspond to a decrease of the recrystallization temperatures (from 1350 degrees C for a low cold-work level to 750 degrees C for 60 % cold-deformation, case of MA956 alloy) and a refinement of the grain size (from a millimetric size to less than an hundred of micrometer). Swaging develop a cyclic component where the intensity increases with increasing deformation in this case, the recrystallization temperature remains always very high and the millimetric grain size is slightly modified, even though cold-work level increases. (Abstract Truncated)

  10. Intra-continental subduction and contemporaneous lateral extrusion of the upper plate: insights into Alps-Adria interactions

    Science.gov (United States)

    van Gelder, Inge; Willingshofer, Ernst; Sokoutis, Dimitrios; Cloetingh, Sierd

    2017-04-01

    A series of physical analogue experiments were performed to simulate intra-continental subduction contemporaneous with lateral extrusion of the upper plate to study the interferences between these two processes at crustal levels and in the lithospheric mantle. The lithospheric-scale models are specifically designed to represent the collision of the Adriatic microplate with the Eastern Alps, simulated by an intra-continental weak zone to initiate subduction and a weak confined margin perpendicular to the direction of convergence in order to allow for extrusion of the lithosphere. The weak confined margin is the analog for the opening of the Pannonian back-arc basin adjacent to the Eastern Alps with the direction of extension perpendicular to the strike of the orogen. The models show that intra-continental subduction and coeval lateral extrusion of the upper plate are compatible processes. The obtained deformation structures within the extruding region are similar compared to the classical setup where lateral extrusion is provoked by lithosphere-scale indentation. In the models a strong coupling across the subduction boundary allows for the transfer of abundant stresses to the upper plate, leading to laterally varying strain regimes that are characterized by crustal thickening near a confined margin and dominated by lateral displacement of material near a weak lateral confinement. During ongoing convergence the strain regimes propagate laterally, thereby creating an area of overlap characterized by transpression. In models with oblique subduction, with respect to the convergence direction, less deformation of the upper plate is observed and as a consequence the amount of lateral extrusion decreases. Additionally, strain is partitioned along the oblique plate boundary leading to less subduction in expense of right lateral displacement close to the weak lateral confinement. Both oblique and orthogonal subduction models have a strong resemblance to lateral extrusion

  11. Influence of extrusion parameters on sic distribution and properties of AA6061/SiC composites produced by kobo method

    Energy Technology Data Exchange (ETDEWEB)

    WoĨniak, Jarosáaw; Kostecki, Marek; Broniszewski, Kamil; Olszyna, Andrzej [Faculty of Material Science and Engineering, Warsaw University of Technology, Warsaw (Poland); Bochniak, Wáodzimierz [Faculty of Non-Ferrous Metals, AGH University of Science and Technology, Cracow (Poland)

    2013-07-01

    The influence of extrusion parameters on reinforcements distribution and properties of AA6061+x% vol. SiC p (x=0; 2.5; 5; 7.5; 10) composites was discussed in this paper The averages size of AA6061 and SiC particles were 10.6 μ m and 0.42 μ m, respectively. The composites were consolidated via powder metallurgy processing (without the sintering) and extruded by KoBo method. The microstructure was examined on each steps of production. High values of density for all produced composites were achieved. Additionally, hardness and Young’s modulus were investigated. The best reinforcement distribution and mechanical properties were obtained for composites extruded with the highest extrusion ratio. Key words: aluminum alloy, extrusion, aged hardening, metal matrix composites, microstructure.

  12. Grain Refinement and Enhancement of Mechanical Properties of Hot Extruded Rare-Earth Containing Magnesium Alloy

    Directory of Open Access Journals (Sweden)

    Bita Pourbahari

    2017-12-01

    Full Text Available The effects of rare earth addition and hot extrusion process on the grain refinement of magnesium alloy were studied. The as-cast Mg-6Al-1Zn (AZ61 alloy had the average grain size of ~ 64 µm and its microstructure consisted of α-Mg and Mg17Al12 phase. By partial substitution of Al with Gd to reach Mg-4.8Gd-1.2Al-1Zn alloy, it was observed that the Mg17Al12 phase disappeared and two new intermetallic phases, i.e. (Mg,Al3Gd and Al2Gd, were identified. The extrusion process showed significant effects on the shape and size of intermetallics and grain size of the matrix. The grain size of the extruded Mg-6Al-1Zn alloy was refined from 64 µm to 13.4 µm as a result of recrystallization. Regarding the Mg-4.8Gd-1.2Al-1Zn alloy, the grain refinement was much more pronounced, where the extruded grain size has been refined from 698 µm to 2.4 µm (extruded at 385 °C and 1.3 µm (extruded at 320 °C. This was related to the presence of fine and widely dispersed intermetallic phases. Tensile strength and total elongation of extruded alloys were much higher than their as-cast counterparts and the extruded Mg-6Zn-1Al alloy showed magnificent mechanical properties. The latter was related to the absence of intermetallic particles, which act as stress risers.

  13. Partial oxidation process for producing a stream of hot purified gas

    Science.gov (United States)

    Leininger, T.F.; Robin, A.M.; Wolfenbarger, J.K.; Suggitt, R.M.

    1995-03-28

    A partial oxidation process is described for the production of a stream of hot clean gas substantially free from particulate matter, ammonia, alkali metal compounds, halides and sulfur-containing gas for use as synthesis gas, reducing gas, or fuel gas. A hydrocarbonaceous fuel comprising a solid carbonaceous fuel with or without liquid hydrocarbonaceous fuel or gaseous hydrocarbon fuel, wherein said hydrocarbonaceous fuel contains halides, alkali metal compounds, sulfur, nitrogen and inorganic ash containing components, is reacted in a gasifier by partial oxidation to produce a hot raw gas stream comprising H{sub 2}, CO, CO{sub 2}, H{sub 2}O, CH{sub 4}, NH{sub 3}, HCl, HF, H{sub 2}S, COS, N{sub 2}, Ar, particulate matter, vapor phase alkali metal compounds, and molten slag. The hot raw gas stream from the gasifier is split into two streams which are separately deslagged, cleaned and recombined. Ammonia in the gas mixture is catalytically disproportionated into N{sub 2} and H{sub 2}. The ammonia-free gas stream is then cooled and halides in the gas stream are reacted with a supplementary alkali metal compound to remove HCl and HF. Alkali metal halides, vaporized alkali metal compounds and residual fine particulate matter are removed from the gas stream by further cooling and filtering. The sulfur-containing gases in the process gas stream are then reacted at high temperature with a regenerable sulfur-reactive mixed metal oxide sulfur sorbent material to produce a sulfided sorbent material which is then separated from the hot clean purified gas stream having a temperature of at least 1000 F. 1 figure.

  14. Factors affecting irrigant extrusion during root canal irrigation: a systematic review

    NARCIS (Netherlands)

    Boutsioukis, C.; Psimma, Z.; van der Sluis, L.W.M.

    2013-01-01

    The aim of the present study was to conduct a systematic review and critical analysis of published data on irrigant extrusion to identify factors causing, affecting or predisposing to irrigant extrusion during root canal irrigation of human mature permanent teeth. An electronic search was conducted

  15. Equal-channel angular sheet extrusion of interstitial-free (IF) steel: Microstructural evolution and mechanical properties

    International Nuclear Information System (INIS)

    Saray, O.; Purcek, G.; Karaman, I.; Neindorf, T.; Maier, H.J.

    2011-01-01

    Highlights: → IF-steel sheets can successfully be processed in the continuous manner using the equal-channel angular sheet extrusion (ECASE). → The ECASE produces the microstructures including dislocation cell and micro-shear bands inside the grains with mainly low-angle grain boundaries. → The ECASE results in a considerable increase in the strength but limited ductility. → A good strength-ductility balance in the ECASE-processed IF-steel sheets can be managed with a suitable annealing parameters. - Abstract: Interstitial-free steel (IF-steel) sheets were processed at room temperature using a continuous severe plastic deformation (SPD) technique called equal-channel angular sheet extrusion (ECASE). After processing, the microstructural evolution and mechanical properties have been systematically investigated. To be able to directly compare the results with those from the same material processed using discontinuous equal channel angular extrusion, the sheets were ECASE processed up to eight passes. The microstructural investigations revealed that the processed sheets exhibited a dislocation cell and/or subgrain structures with mostly low angle grain boundaries. The grains after processing have relatively high dislocation density and intense micro-shear band formation. The electron backscattering diffraction (EBSD) examination showed that the processed microstructure is not fully homogeneous along the sheet thickness due probably to the corner angle of 120 deg. in the ECASE die. It was also observed that the strengths of the processed sheets increase with the number of ECASE passes, and after eight passes following route-A and route-C, the yield strengths reach 463 MPa and 459 MPa, respectively, which is almost 2.5 times higher than that of the initial material. However, the tensile ductility considerably dropped after the ECASE. The limited ductility was attributed to the early plastic instability in the tensile samples due to the inhomogeneous

  16. A novel plastification agent for cemented carbides extrusion molding

    International Nuclear Information System (INIS)

    Ji-Cheng Zhou; Bai-Yun Huang

    2001-01-01

    A type of novel plastification agent for plasticizing powder extrusion molding of cemented carbides has been developed. By optimizing their formulation and fabrication method, the novel plastification agent, with excellent properties and uniform distribution characters, were manufactured. The thermal debinding mechanism has been studied, the extruding rheological characteristics and debinding behaviors have been investigated. Using the newly developed plastification agent, the cemented carbides extrusion rods, with diameter up to 25 mm, have been manufactured. (author)

  17. Effects of excessive grain growth on the magnetic and mechanical properties of hot-deformed NdFeB magnets

    Energy Technology Data Exchange (ETDEWEB)

    Lin, M., E-mail: linm@nimte.ac.c [Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Material Technology and Engineering Chinese Academy of Science, Ningbo 315201 (China); Wang, H.J. [Division of Functional Materials, Central Iron and Steel Research Institute, Beijing 100081 (China); Yi, P.P.; Yan, A.R. [Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Material Technology and Engineering Chinese Academy of Science, Ningbo 315201 (China)

    2010-08-15

    The magnetic and mechanical properties of rare-earth magnets hot-deformed at temperature range 750-950 deg. C have been investigated. The grains tended to grow excessively from dozens of nanometers to several microns at the temperatures above 850 deg. C. The alignment of grains was disrupted by the hot deformation at the high temperatures. The Nd-rich phase was extruded at the temperatures which are higher than 850 deg. C. The Nd-rich phase extrusion resulted in the reduction of density by 1% and the reduction of remanence from 1.42 to 0.72 T. The reduction of grain boundaries caused by flat platelet-shaped grains changing to spherical grains and the weak binding strength among large grains of Nd{sub 2}Fe{sub 14}B phase may be the main reasons for the low mechanical strength of hot-deformed magnets.

  18. Preparation of High Modulus Poly(Ethylene Terephthalate: Influence of Molecular Weight, Extrusion, and Drawing Parameters

    Directory of Open Access Journals (Sweden)

    Jian Min Zhang

    2017-01-01

    Full Text Available Poly(ethylene terephthalate (PET which is one of the most commercially important polymers, has for many years been an interesting candidate for the production of high performance fibres and tapes. In current study, we focus on investigating the effects of the various processing variables on the mechanical properties of PET produced by a distinctive process of melt spinning and uniaxial two-stage solid-state drawing (SSD. These processing variables include screw rotation speed during extrusion, fibre take-up speed, molecular weight, draw-ratio, and drawing temperature. As-spun PET production using a single-screw extrusion process was first optimized to induce an optimal polymer microstructure for subsequent drawing processes. It was found that less crystallization which occurred during this process would lead to better drawability, higher draw-ratio, and mechanical properties in the subsequent SSD process. Then the effect of drawing temperature (DT in uniaxial two-stage SSD process was studied to understand how DT (process in current work is simulated to an industrial production process for PET fibres; therefore, results and analysis in this paper have significant importance for industrial production.

  19. Relationship Between Preoperative Extrusion of the Medial Meniscus and Surgical Outcomes After Partial Meniscectomy.

    Science.gov (United States)

    Kim, Sung-Jae; Choi, Chong Hyuk; Chun, Yong-Min; Kim, Sung-Hwan; Lee, Su-Keon; Jang, Jinyoung; Jeong, Howon; Jung, Min

    2017-07-01

    No previous study has examined arthritic change after meniscectomy with regard to extrusion of the medial meniscus. (1) To determine the factors related to preoperative meniscal extrusion; (2) to investigate the relationship between medial meniscal extrusion and postoperative outcomes of partial meniscectomy, and to identify a cutoff point of meniscal extrusion that contributes to arthritic change after partial meniscectomy in nonosteoarthritic knees. Cohort study; Level of evidence, 3. A total of 208 patients who underwent partial meniscectomy of the medial meniscus between January 2000 and September 2006 were retrospectively reviewed. The extent of extrusion and severity of degeneration of the medial meniscus as shown on preoperative MRI were evaluated. The minimum follow-up duration was 7 years. Clinical function was assessed with the Lysholm knee scoring scale, the International Knee Documentation Committee (IKDC) subjective knee evaluation form, and the Tapper and Hoover grading system. Radiological evaluation was conducted by use of the IKDC radiographic assessment scale. Regression analysis was performed to identify factors affecting preoperative extrusion of the medial meniscus and factors influencing follow-up results after partial meniscectomy. Receiver operating characteristic curve was used to identify a cutoff point for the extent of meniscal extrusion that was associated with arthritic change. The mean ± SD preoperative Lysholm knee score was 65.0 ± 6.3 and the mean IKDC subjective score was 60.1 ± 7.5. The mean follow-up functional scores were 93.2 ± 5.1 ( P meniscus showed a tendency to increase as the extent of intrameniscal degeneration increased, and the medial meniscus was extruded more in patients with horizontal, horizontal flap, and complex tears. The preoperative extent of meniscal extrusion had a statistically significant correlation with follow-up Lysholm knee score (coefficient = -0.10, P = .002), IKDC subjective score (coefficient

  20. Definition of a JA2 equivalent propellant to be produced by continuous solvent-less extrusion

    NARCIS (Netherlands)

    Manning, T.G.; Leone, J.; Zebregs, M.; Ramlal, D.R.; Driel, C.A. van

    2013-01-01

    The aim of this work is to demonstrate the manufacturing of a propellant by solvent-less continuous twin screw extrusion processing while maintaining gun performance characteristics of conventional JA-2 propellant. This is elucidated by explicitly researching the relationship between interior

  1. Extrusion enhances metabolizable energy and ileal amino acids digestibility of canola meal for broiler chickens

    Directory of Open Access Journals (Sweden)

    Aljuobori Ahmed

    2014-01-01

    Full Text Available The aim of the current study was to determine the effect of extrusion process on apparent metabolizable energy (AME, crude protein (CP and amino acid (AA digestibility of canola meal (CM in broiler chickens. A total of 36, 42-day-old broilers were randomly assigned into adaptation diets (no CM or 30% CM with six replicates. After 4 days of adaptation period, on day 47, birds were allowed to consume the assay diets that contain CM or extruded canola meal (ECM as the sole source of energy and protein. Following 4 h after feeding, the birds were killed and ileal contents were collected. The results showed that ECM had greater (P<0.001 AME (10.87 vs 9.39 MJ/kg compared to CM. The extrusion also significantly enhanced apparent ileal digestibility of CP and some of AA such as Asp, Glu, Ser, Thr and Trp. In conclusion, the extrusion treatment appeared to be a practical and effective approach in enhancing the digestibility of AME, CP and some AA of CM in broiler chickens.

  2. Prediction of Proper Temperatures for the Hot Stamping Process Based on the Kinetics Models

    Science.gov (United States)

    Samadian, P.; Parsa, M. H.; Mirzadeh, H.

    2015-02-01

    Nowadays, the application of kinetics models for predicting microstructures of steels subjected to thermo-mechanical treatments has increased to minimize direct experimentation, which is costly and time consuming. In the current work, the final microstructures of AISI 4140 steel sheets after the hot stamping process were predicted using the Kirkaldy and Li kinetics models combined with new thermodynamically based models in order for the determination of the appropriate process temperatures. In this way, the effect of deformation during hot stamping on the Ae3, Acm, and Ae1 temperatures was considered, and then the equilibrium volume fractions of phases at different temperatures were calculated. Moreover, the ferrite transformation rate equations of the Kirkaldy and Li models were modified by a term proposed by Åkerström to consider the influence of plastic deformation. Results showed that the modified Kirkaldy model is satisfactory for the determination of appropriate austenitization temperatures for the hot stamping process of AISI 4140 steel sheets because of agreeable microstructure predictions in comparison with the experimental observations.

  3. Moisture sorption characteristics of extrusion-cooked starch protective loose-fill cushioning foams

    Science.gov (United States)

    Combrzyński, Maciej; Mościcki, Leszek; Kwaśniewska, Anita; Oniszczuk, Tomasz; Wójtowicz, Agnieszka; Sołowiej, Bartosz; Gładyszewska, Bożena; Muszyński, Siemowit

    2017-10-01

    The aim of this work was to determine the water vapour sorption properties of thermoplastic starch filling foams processed by extrusion-cooking technique from various combinations of potato starch and two foaming agents: poly(vinyl) alcohol and Plastronfoam, in amount of 1, 2 and 3% each. Foams were processed with the single screw extruder-cooker at two different screw rotational speeds 100 and 130 r.p.m. The sorption isotherms of samples were determined and described using the Guggenheim-Anderson-de Boer model. Also, the kinetics of water vapour adsorption by foams, as a function of time, was measured and fitted with Peleg model. On the basis of the analysis the influence of the applied foaming agents, as well as the technological parameters of extrusion-cooking process in relation to water vapour adsorption by thermoplastic starch foams was demonstrated. There was no difference between the shapes of the isotherms for poly(vinyl) alcohol foams while for Plastronfoam foams a notable difference among foams extruded at 100 r.p.m. was observed in the regions of low and high humidity content. The analysis of the Guggenheim-Anderson-de Boer model parameters showed that the water molecules were less strongly bound with the foam surface when extruded at a lower screw speed.

  4. Application of Electrostatic Extrusion – Flavour Encapsulation and Controlled Release

    OpenAIRE

    Manojlovic, Verica; Rajic, Nevenka; Djonlagic, Jasna; Obradovic, Bojana; Nedovic, Viktor; Bugarski, Branko

    2008-01-01

    The subject of this study was the development of flavour alginate formulations aimed for thermally processed foods. Ethyl vanilline was used as the model flavour compound. Electrostatic extrusion was applied for the encapsulation of ethyl vanilline in alginate gel microbeads. The obtained microbeads with approx. 10 % w/w of ethyl vanilline encapsulated in about 2 % w/w alginate were uniformly sized spheres of about 450 ?m. Chemical characterization by H-NMR spectroscopy revealed that the algi...

  5. A Mathematical Model on the Resolution of Extrusion Bioprinting for the Development of New Bioinks

    Directory of Open Access Journals (Sweden)

    Ratima Suntornnond

    2016-09-01

    Full Text Available Pneumatic extrusion-based bioprinting is a recent and interesting technology that is very useful for biomedical applications. However, many process parameters in the bioprinter need to be fully understood in order to print at an adequate resolution. In this paper, a simple yet accurate mathematical model to predict the printed width of a continuous hydrogel line is proposed, in which the resolution is expressed as a function of nozzle size, pressure, and printing speed. A thermo-responsive hydrogel, pluronic F127, is used to validate the model predictions. This model could provide a platform for future correlation studies on pneumatic extrusion-based bioprinting as well as for developing new bioink formulations.

  6. Information Use Differences in Hot and Cold Risk Processing: When Does Information About Probability Count in the Columbia Card Task?

    Science.gov (United States)

    Markiewicz, Łukasz; Kubińska, Elżbieta

    2015-01-01

    This paper aims to provide insight into information processing differences between hot and cold risk taking decision tasks within a single domain. Decision theory defines risky situations using at least three parameters: outcome one (often a gain) with its probability and outcome two (often a loss) with a complementary probability. Although a rational agent should consider all of the parameters, s/he could potentially narrow their focus to only some of them, particularly when explicit Type 2 processes do not have the resources to override implicit Type 1 processes. Here we investigate differences in risky situation parameters' influence on hot and cold decisions. Although previous studies show lower information use in hot than in cold processes, they do not provide decision weight changes and therefore do not explain whether this difference results from worse concentration on each parameter of a risky situation (probability, gain amount, and loss amount) or from ignoring some parameters. Two studies were conducted, with participants performing the Columbia Card Task (CCT) in either its Cold or Hot version. In the first study, participants also performed the Cognitive Reflection Test (CRT) to monitor their ability to override Type 1 processing cues (implicit processes) with Type 2 explicit processes. Because hypothesis testing required comparison of the relative importance of risky situation decision weights (gain, loss, probability), we developed a novel way of measuring information use in the CCT by employing a conjoint analysis methodology. Across the two studies, results indicated that in the CCT Cold condition decision makers concentrate on each information type (gain, loss, probability), but in the CCT Hot condition they concentrate mostly on a single parameter: probability of gain/loss. We also show that an individual's CRT score correlates with information use propensity in cold but not hot tasks. Thus, the affective dimension of hot tasks inhibits correct

  7. Evaluation of Enterococcus faecium NRRL B-2354 as a Surrogate for Salmonella During Extrusion of Low-Moisture Food.

    Science.gov (United States)

    Verma, Tushar; Wei, Xinyao; Lau, Soon Kiat; Bianchini, Andreia; Eskridge, Kent M; Subbiah, Jeyamkondan

    2018-04-01

    Salmonella in low-moisture foods is an emerging challenge due to numerous food product recalls and foodborne illness outbreaks. Identification of suitable surrogate is critical for process validation at industry level due to implementation of new Food Safety Modernization Act of 2011. The objective of this study was to evaluate Enterococcus faecium NRRL B-2354 as a surrogate for Salmonella during the extrusion of low-moisture food. Oat flour, a low-moisture food, was adjusted to different moisture (14% to 26% wet basis) and fat (5% to 15% w/w) contents and was inoculated with E. faecium NRRL B-2354. Inoculated material was then extruded in a lab-scale single-screw extruder running at different screw speeds (75 to 225 rpm) and different temperatures (75, 85, and 95 °C). A split-plot central composite 2nd order response surface design was used, with the central point replicated six times. The data from the selective media (m-Enterococcus agar) was used to build the response surface model for inactivation of E. faecium NRRL B-2354. Results indicated that E. faecium NRRL B-2354 always had higher heat resistance compared to Salmonella at all conditions evaluated in this study. However, the patterns of contour plots showing the effect of various product and process parameters on inactivation of E. faecium NRRL B-2354 was different from that of Salmonella. Although E. faecium NRRL B-2354 may be an acceptable surrogate for extrusion of low-moisture products due to higher resistance than Salmonella, another surrogate with similar inactivation behavior may be preferred and needs to be identified. Food Safety Modernization Act requires the food industry to validate processing interventions. This study validated extrusion processing and demonstrated that E. faecium NRRL B-2354 is an acceptable surrogate for extrusion of low-moisture products. The developed response surface model allows the industry to identify process conditions to achieve a desired lethality for their

  8. Hot mechanical behaviour of dispersion strengthened Cu alloys

    International Nuclear Information System (INIS)

    Garcia G, Jose; Espinoza G, Rodrigo; Palma H, Rodrigo; Sepulveda O, Aquiles

    2003-01-01

    This work is part of a research project which objective is the improvement of the high-temperature mechanical properties of copper, without an important decrease of the electrical or thermal conduction properties. The general hypothesis is that this will be done by the incorporation of nanometric ceramic dispersoids for hindering the dislocation and grain boundaries movement. In this context, the object of the present work is the study of the resistance to hot deformation of dispersion-strengthened copper alloys which have prepared by reactive milling. Two different alloys, Cu-2,39wt.%Ti-0.56wt.%C and Cu-1.18wt.%Al, were prepared so as obtain a copper matrix reinforced with nanometric TiC y Al 2 O 3 particles with a nominal total amount of 5 vol.%. The particles were developed by an in-situ formation process during milling. The materials were prepared in an attritor mill, and consolidated by extrusion at 750 o C, with an area reduction rate of 10:1. The resistance to hot deformation was evaluated by hot compression tests at 500 and 850 o C, at initial strain rates of 10 -3 and 10 -4 s-1. To evaluate the material softening due temperature, annealing at 400, 650 y 900 o C during 1h were applied; after that, hardness was measured at room temperature. Both studies alloys presented a higher resistance to hot deformation than pure copper, with or without milling. Moreover, the Cu-Ti-C alloy presented a mechanical resistance higher than that of the Cu-Al one. Both alloys presented strain-stress compression curves with a typical hot-work shape: an initial maximum followed by a stationary plateau. The Cu-Ti-C alloy had a higher hardness and did not present a hardness decay even after annealings at the higher temperature imposed (900 o C), while the Cu-Al alloy did exhibit a strong decay of hardness after the annealing at 900 o C. The best behaviour exhibited by the Cu-Ti C alloy, was attributed to the formation of a major quantity of dispersoids that in the Cu-Al alloy. In

  9. Current deformation rates and extrusion of the northwestern Okhotsk plate, northeast Russia

    Science.gov (United States)

    Hindle, D.; Fujita, K.; Mackey, K.

    2006-01-01

    Northeast Asia is a region of broad deformation resulting from the convergence of the Eurasian (EU) and North American (NA) plates. Part of this convergence has been suggested to be relieved by the extrusion and deformation of the Okhotsk plate (OK). Three models for the deformation of the seismically active northwestern corner of the Okhotsk plate, based on different modes of deformation partitioning, are calculated and compared to observations from GPS, seismicity, and geology. The results suggest that this region is being extruded southeastward and deforming internally by a mixture of pure contraction, ``smooth'' extrusion, and ``rigid'' extrusion. Calculated extrusion rates are ~3-5.5 mm/yr, comparable to estimates from geologic data, and internal deformation rates are ~3.0 × 10-9 yr -1. Internal deformation may be only partially accommodated by seismicity, but the short time span of seismic data leaves this subject to large uncertainty.

  10. Shielding calculation of a hot cell for the processing of fission products

    International Nuclear Information System (INIS)

    Rocha, A.C.S. da; Pina, J.L.S. de; Silva, J.J.G. da.

    1986-12-01

    A dose rate estimation is made for an operator of a lead wall, fission products processing hot cell, in a distance of 50 cm from the emission source, at Brazilian Institute of Nuclear Engineering (IEN). (L.C.J.A.)

  11. The interplay between subduction and lateral extrusion: A case study for the European Eastern Alps based on analogue models

    Science.gov (United States)

    van Gelder, I. E.; Willingshofer, E.; Sokoutis, D.; Cloetingh, S. A. P. L.

    2017-08-01

    A series of analogue experiments simulating intra-continental subduction contemporaneous with lateral extrusion of the upper plate are performed to study the interference between these two processes at crustal levels and in the lithospheric mantle. The models demonstrate that intra-continental subduction and coeval lateral extrusion of the upper plate are compatible processes leading to similar deformation structures within the extruding region as compared to the classical setup, lithosphere-scale indentation. Strong coupling across the subduction boundary allows for the transfer of stresses to the upper plate, where strain regimes are characterized by crustal thickening near a confined margin and dominated by lateral displacement of material near a weak lateral confinement. The strain regimes propagate laterally during ongoing convergence creating an area of overlap characterized by transpression. When subduction is oblique to the convergence direction, the upper plate is less deformed and as a consequence the amount of lateral extrusion decreases. In addition, strain is partitioned along the oblique plate boundary resulting in less subduction in expense of right lateral displacement close to the weak lateral confinement. Both oblique and orthogonal subduction models have a strong resemblance to lateral extrusion tectonics of the Eastern Alps (Europe), where subduction of the adjacent Adriatic plate beneath the Eastern Alps is debated. Our results imply that subduction of Adria is a valid mechanisms to induce extrusion-type deformation within the Eastern Alps lithosphere. Furthermore, our findings suggest that the Oligocene to Late Miocene structural evolution of the Eastern Alps reflects a phase of oblique subduction followed by a later stage of orthogonal subduction conform a Miocene shift in the plate motion of Adria. Oblique subduction also provides a viable mechanism to explain the rapid decrease in slab length of the Adriatic plate beneath the Eastern Alps

  12. Cervical artificial disc extrusion after a paragliding accident.

    Science.gov (United States)

    Niu, Tianyi; Hoffman, Haydn; Lu, Daniel C

    2017-01-01

    Cervical total disc replacement (TDR) is an established alternative to anterior cervical discectomy and fusion (ACDF) with excellent long-term outcomes and low failure rates. Cases of implant failure and migration are scarce and primarily limited to several years postoperatively. The authors report a case of anterior extrusion of a C4-C5 ProDisc-C (DePuy Synthes, West Chester, PA, USA) cervical artificial disc (CAD) 14 months after placement due to minor trauma. A 33-year-old female who had undergone C4-C5 CAD implantation presented with neck pain and spasm after experiencing a paragliding accident. A 4 mm anterior protrusion of the CAD was seen on x-ray. She underwent removal of the CAD followed by anterior fusion. Other cases of CAD extrusion in the literature are discussed and the device's durability and testing are considered. Overall, CAD extrusion is a rare event. This case is likely the result of insufficient osseous integration. Patients undergoing cervical TDR should avoid high-risk activities to prevent trauma that could compromise the disc's placement, and future design/research should focus on how to enhance osseous integration at the interface while minimizing excessive heterotopic ossification.

  13. Extrusion-mixing compared with hand-mixing of polyether impression materials?

    Science.gov (United States)

    McMahon, Caroline; Kinsella, Daniel; Fleming, Garry J P

    2010-12-01

    The hypotheses tested were two-fold (a) whether altering the base:catalyst ratio influences working time, elastic recovery and strain in compression properties of a hand-mixed polyether impression material and (b) whether an extrusion-mixed polyether impression material would have a significant advantage over a hand-mixed polyether impression material mixed to the optimum base:catalyst ratio. The polyether was hand-mixed at the optimum (manufacturers recommended) base:catalyst ratios (7:1) and further groups were made by increasing or decreasing the catalyst length by 25%. Additionally specimens were also made from an extrusion-mixed polyether impression material and compared with the optimum hand-mixed base:catalyst ratio. A penetrometer assembly was used to measure the working time (n=5). Five cylindrical specimens for each hand-mixed and extrusion mixed group investigated were employed for elastic recovery and strain in compression testing. Hand-mixing polyether impression materials with 25% more catalyst than that recommended significantly decreased the working time while hand-mixing with 25% less catalyst than that recommended significantly increased the strain in compression. The extrusion-mixed polyether impression material provided similar working time, elastic recovery and strain in compression to the hand-mixed polyether mixed at the optimum base:catalyst ratio.

  14. Effect of thermal and mechanical parameter’s damage numerical simulation cycling effects on defects in hot metal forming processes

    Science.gov (United States)

    El Amri, Abdelouahid; el yakhloufi Haddou, Mounir; Khamlichi, Abdellatif

    2017-10-01

    Damage mechanisms in hot metal forming processes are accelerated by mechanical stresses arising during Thermal and mechanical properties variations, because it consists of the materials with different thermal and mechanical loadings and swelling coefficients. In this work, 3D finite element models (FEM) are developed to simulate the effect of Temperature and the stresses on the model development, using a general purpose FE software ABAQUS. Explicit dynamic analysis with coupled Temperature displacement procedure is used for a model. The purpose of this research was to study the thermomechanical damage mechanics in hot forming processes. The important process variables and the main characteristics of various hot forming processes will also be discussed.

  15. Application of powder metallurgy and hot rolling processes for manufacturing aluminum/alumina composite strips

    Energy Technology Data Exchange (ETDEWEB)

    Zabihi, Majed, E-mail: m.zabihi@ma.iut.ac.ir [Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Toroghinejad, Mohammad Reza, E-mail: toroghi@cc.iut.ac.ir [Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Shafyei, Ali, E-mail: shafyei@cc.iut.ac.ir [Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of)

    2013-01-10

    In this study, aluminum matrix composites (AMC) with 2, 4, 6 and 10 wt% alumina were produced using powder metallurgy (PM), mechanical milling (MM) and vacuum hot pressing (VHP) techniques; then, this was followed by the hot-rolling process. During hot rolling, AMCs with 6 and 10 wt% Al{sub 2}O{sub 3} were fractured whereas strip composites with 2 and 4 wt% Al{sub 2}O{sub 3} were produced successfully. Microstructure and mechanical properties of the samples were investigated by optical and scanning electron microscopes and tensile and hardness tests, respectively. Microscopic evaluations of the hot-rolled composites showed a uniform distribution of alumina particles in the aluminum matrix. It was found that with increasing alumina content in the matrix, tensile strength (TS) and hardness increased and the percentage of elongation also decreased. Scanning electron microscope (SEM) was used to investigate aluminum/alumina interfaces and fracture surfaces of the hot rolled specimens after tensile test. SEM observations demonstrated that the failure mode in the hot-rolled Al-2 wt% Al{sub 2}O{sub 3} composite strips is a typical ductile fracture, while the failure mode was shear ductile fracture with more flat surfaces in Al-4 wt% Al{sub 2}O{sub 3} strips.

  16. Study and automatic control of the ceramic tile extrusion operation; Estudio y control automatico de la operacion de extrusion de baldosas ceramicas

    Energy Technology Data Exchange (ETDEWEB)

    Aguilella, M.; Foucard, L.; Mallol, G.; Sanchez, M. J.; Lopez, M.; Benasges, R.

    2012-07-01

    The ever-larger tile sizes demanded by the market, the higher quality requirements, and the increasingly similar installation to that of pressed products make it necessary to narrow the tolerance limits of final extruded tile size in order to maintain the products competitiveness. The results of this study show that, though mixing water has a great influence on drying shrinkage, it hardly affects extruded tile firing shrinkage. This indicates that control of the water added in the extrusion process is indispensable in order avoid variations in drying shrinkage and, thus, to assure good dimensional stability of the end product. (Author)

  17. MM98.43 Experimental determination of the heat transfer coefficient Under dynamic process conditions in backward can extrusion

    DEFF Research Database (Denmark)

    Henningsen, Poul; Hattel, Jesper Henri; Wanheim, Tarras

    1998-01-01

    The large deformations in backward can extrusion result in a rise of temperature of more than 200 oC. In the experiments, cans in low carbon steel are formed with a lubrication layer of phosphate soap. The temperature is measured by thermocouples in the die insert and the punch. The die insert...

  18. Hydrostatic extrusion of Cu-Ag melt spun ribbon

    Science.gov (United States)

    Hill, Mary Ann; Bingert, John F.; Bingert, Sherri A.; Thoma, Dan J.

    1998-01-01

    The present invention provides a method of producing high-strength and high-conductance copper and silver materials comprising the steps of combining a predetermined ratio of the copper with the silver to produce a composite material, and melt spinning the composite material to produce a ribbon of copper and silver. The ribbon of copper and silver is heated in a hydrogen atmosphere, and thereafter die pressed into a slug. The slug then is placed into a high-purity copper vessel and the vessel is sealed with an electron beam. The vessel and slug then are extruded into wire form using a cold hydrostatic extrusion process.

  19. Effect of rapid cooling and extrusion ratio on the mechanical property of Mg alloys

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Taek-Soo, E-mail: tskim@kitech.re.k [Center for Echo Materials and Processing, Korea Institute of Industrial Technology, 7-47 Techno-park Songdo, Incheon 406-130 (Korea, Republic of)

    2010-08-15

    Mg{sub 95}Zn{sub 4.3}Y{sub 0.7} (at.%) alloy powders were prepared using an inert gas atomizer, followed by warm extrusion. The powders were almost spherical in shape, and the grain size, compared with the cast product, was fine being less than 5 {mu}m. The microstructure of bars extruded was examined as a function of the extrusion ratio using scanning electron microscope (SEM), energy dispersive X-ray spectroscope (EDS) and X-ray diffractometer (XRD). As the extrusion ratio increased from 10:1 to 20:1, the powders fully deformed with refining the grain size. Both the ultimate strength and elongation also showed a dependence on the extrusion ratio.

  20. Nanosized-Particle Dispersion-Strengthened Al Matrix Composites Fabricated by the Double Mechanical Alloying Process.

    Science.gov (United States)

    Kim, Chungseok

    2018-03-01

    The objective of this study was to fabricate an Al metal matrix composite strengthened by nanosized Al3Ti particles via double mechanical alloying process. Several Al-xTi alloys were fabricated, including Al-12%Ti, Al-15%Ti, and Al-12%Ti-1%Y2O3. The lattice parameter of as-milled state was calculated to be 4.0485 Å; after a milling time of 540 min, it was 4.0401 Å. This decrease was induced by Ti solutionizing into the Al matrix. The equivalent size of a coarse Al3Ti particle was 200-500 nm after the heat treatment; however, the particles were uniformly distributed and were refined through the MA2 process. The particle size of a Al3Ti phase was 30 nm or less, and the particles were uniformly distributed. These particles remained in a fine state in the matrix without growth and coarsening, even after the hot extrusion process. The microstructure of hot extruded alloys consisted of a uniform distribution of Al3Ti particles and other dispersoids in the Al matrix.

  1. 75 FR 73041 - Aluminum Extrusions From the People's Republic of China: Postponement of Final Determination of...

    Science.gov (United States)

    2010-11-29

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-570-967] Aluminum Extrusions From the... investigation of aluminum extrusions from the People's Republic of China (``PRC'') on April 27, 2010.\\1\\ On..., 2011. \\1\\ See Aluminum Extrusions from the People's Republic of China: Initiation of Antidumping Duty...

  2. 75 FR 34982 - Aluminum Extrusions from the People's Republic of China: Notice of Postponement of Preliminary...

    Science.gov (United States)

    2010-06-21

    ... DEPARTMENT OF COMMERCE International Trade Administration [C-570-968] Aluminum Extrusions from the... in the Federal Register a notice of initiation of the countervailing duty investigation of aluminum extrusions from the People's Republic of China. See Aluminum Extrusions From the People's Republic of China...

  3. Características tecnológicas de farinhas de arroz pré-gelatinizadas obtidas por extrusão termoplástica Technological properties of pre-gelatinized rice flour obtained by thermoplastic extrusion

    Directory of Open Access Journals (Sweden)

    Maria Teresa Pedrosa Silva Clerici

    2008-10-01

    for thermoplastic extrusion. The GRF was extruded using a Brabender single screw extruder, varying moisture (19.2 - 24.8% and extrusion temperature (108 - 192ºC. Torque, expansion index (EI, viscographic properties, water absorption index (WAI, and water solubility index (WSI characteristics of GRF were analyzed using response surface methodology (RSM and main component analysis (PCA. The results, analyzed by MRS and PCA, indicated that during the process, the values of torque and EI increased when lower moisture was used. Considering viscographic properties, GRF presented a higher initial viscosity of the starch paste when in higher temperatures, while viscosities at 95ºC and at 50ºC increased when temperature and moisture were at extreme opposites. WAI decreased when lower temperatures and higher moisture were used. WSI was not influenced by temperature and moisture when analyzed using MRS, but with PCA, there was an increase when temperatures ranged between 120 - 150ºC and moisture between 19.2 - 22%. In conclusion, both MRS and PCA analysis showed that a variation in the technological properties of GRF were related to the use of opposite extremes of temperature and/or moisture during the extrusion process, and the PCA was able to complete the analysis done using MRS.

  4. Information use differences in hot and cold risk processing: When does information about probability count in the Columbia Card Task?

    Directory of Open Access Journals (Sweden)

    Lukasz eMarkiewicz

    2015-11-01

    Full Text Available Objective: This paper aims to provide insight into information processing differences between hot and cold risk taking decision tasks within a single domain. Decision theory defines risky situations using at least three parameters: outcome one (often a gain with its probability and outcome two (often a loss with a complementary probability. Although a rational agent should consider all of the parameters, decision maker could potentially narrow focus to only some of them, particularly when explicit Type 2 processes do not have the resources to override implicit Type 1 processes. Here we investigate differences in risky situation parameter(s influence on hot and cold decisions. Although previous studies show lower information use in hot as compared to cold processes, they do not provide decision weight changes and therefore do not explain whether this difference results from worse concentration on each parameter of a risky situation (probability, gain amount and loss amount or from ignoring some parameters. Methods: Two studies were conducted, with participants performing the Columbia Card Task (CCT in either its Cold or Hot version. In the first study, participants also performed the Cognitive Reflection Test (CRT to monitor their ability to override Type 1 processing cues (implicit processes with Type 2 explicit processes. Because hypothesis testing required comparison of the relative importance of risky situation decision weights (gain, loss, probability, we developed a novel way of measuring information use in the CCT by employing a conjoint analysis methodology. Results: Across the two studies, results indicated that in the CCT Cold condition decision makers concentrate on each information type (gain, loss, probability, but in the CCT Hot condition they concentrate mostly on a single parameter: probability of gain/loss. We also show that an individual’s CRT score correlates with information use propensity in cold but not hot tasks. Thus

  5. Information Use Differences in Hot and Cold Risk Processing: When Does Information About Probability Count in the Columbia Card Task?

    Science.gov (United States)

    Markiewicz, Łukasz; Kubińska, Elżbieta

    2015-01-01

    Objective: This paper aims to provide insight into information processing differences between hot and cold risk taking decision tasks within a single domain. Decision theory defines risky situations using at least three parameters: outcome one (often a gain) with its probability and outcome two (often a loss) with a complementary probability. Although a rational agent should consider all of the parameters, s/he could potentially narrow their focus to only some of them, particularly when explicit Type 2 processes do not have the resources to override implicit Type 1 processes. Here we investigate differences in risky situation parameters' influence on hot and cold decisions. Although previous studies show lower information use in hot than in cold processes, they do not provide decision weight changes and therefore do not explain whether this difference results from worse concentration on each parameter of a risky situation (probability, gain amount, and loss amount) or from ignoring some parameters. Methods: Two studies were conducted, with participants performing the Columbia Card Task (CCT) in either its Cold or Hot version. In the first study, participants also performed the Cognitive Reflection Test (CRT) to monitor their ability to override Type 1 processing cues (implicit processes) with Type 2 explicit processes. Because hypothesis testing required comparison of the relative importance of risky situation decision weights (gain, loss, probability), we developed a novel way of measuring information use in the CCT by employing a conjoint analysis methodology. Results: Across the two studies, results indicated that in the CCT Cold condition decision makers concentrate on each information type (gain, loss, probability), but in the CCT Hot condition they concentrate mostly on a single parameter: probability of gain/loss. We also show that an individual's CRT score correlates with information use propensity in cold but not hot tasks. Thus, the affective dimension of

  6. Apical extrusion of debris in four different endodontic instrumentation systems: A meta-analysis.

    Science.gov (United States)

    Western, J Sylvia; Dicksit, Daniel Devaprakash

    2017-01-01

    All endodontic instrumentation systems tested so far, promote apical extrusion of debris, which is one of the main causes of postoperative pain, flare ups, and delayed healing. Of this meta-analysis was to collect and analyze in vitro studies quantifying apically extruded debris while using Hand ProTaper (manual), ProTaper Universal (rotary), Wave One (reciprocating), and self-adjusting file (SAF; vibratory) endodontic instrumentation systems and to determine methods which produced lesser extrusion of debris apically. An extensive electronic database search was done in PubMed, Scopus, Cochrane, LILACS, and Google Scholar from inception until February 2016 using the key terms "Apical Debris Extrusion, extruded material, and manual/rotary/reciprocating/SAF systems." A systematic search strategy was followed to extract 12 potential articles from a total of 1352 articles. The overall effect size was calculated from the raw mean difference of weight of apically extruded debris. Statistically significant difference was seen in the following comparisons: SAF ProTaper. Apical extrusion of debris was invariably present in all the instrumentation systems analyzed. SAF system seemed to be periapical tissue friendly as it caused reduced apical extrusion compared to Rotary ProTaper and Wave One.

  7. Effects of selected process parameters in extrusion of yam flour (Dioscorea rotundata) on physicochemical properties of the extrudates.

    Science.gov (United States)

    Sebio, L; Chang, Y K

    2000-04-01

    Raw yam (Dioscorea rotundata) flour was cooked and extruded in a Brabender single-screw laboratory scale extruder. Response surface methodology using an incomplete factorial design was applied with various combinations of barrel temperature [100, 125, 150 degrees C], feed moisture content [18, 22, 26%] and screw speed [100, 150, 200 rpm]. Initial viscosity at 30 degrees C, water solubility index, expansion and hardness were determined. The highest values of initial viscosity were at the highest barrel temperatures and the highest moisture contents. At high feed moisture content and high barrel temperatures the yam extrudate flour showed the greatest values of water solubility index. The physical properties of the extruded product showed that at high temperature the lower the moisture content the greater the expansion index. Hardness was influenced directly by moisture content and inversely by extrusion temperature. The extrusion of yam flour led to the production of snacks and pre-gelatinized flours of diverse properties. Also extruded yam flour can be successfully used in the preparation of 'futu' (pre-cooked compact dough), a yam-based food, popular in Western Africa.

  8. Fabrication of Al-based composites reinforced with in situ devitrified Al{sub 84}Ni{sub 8.4}Y{sub 4.8}La{sub 1.8}Co{sub 1} particles by hot pressing consolidation

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Qing, E-mail: buaayq00@gmail.com; Zhang, Yitan; Zhang, Haiping; Zheng, Ruixiao; Xiao, Wenlong; Ma, Chaoli, E-mail: machaoli@buaa.edu.cn

    2015-11-05

    In this study, Al{sub 84}Ni{sub 8.4}Y{sub 4.8}La{sub 1.8}Co{sub 1} particles reinforced Al-based composites were prepared by hot pressing sintering and subsequent hot extrusion. The glassy powders were produced by gas atomization and then employed to mechanical milling. After hot pressing sintering, the nano-scale intermetallic compounds precipitated from metallic glass matrix due to higher temperature than super-cooled liquid region. The mechanical properties of 2024 alloy were improved by addition of glassy particles. The ultimate compressive stress increased from 482 MPa for 2024 alloy to 545 MPa, 627 MPa and 735 MPa for composites with 20 w.t.% 40 w.t.% and 60 w.t.% glassy powders addition, respectively, together with considerable fracture strain ranging between 2.9% and 13.6%. And the mechanical properties could be predicted by using the Rule of Mixture, which predicts the mechanical properties of the bulks from the volume weighed average of the constituent properties. - Highlights: • The composites are fabricate by hot pressing and extrusion. • The single phase of amorphous alloy is obtained by sieving. • The nano-scale compounds precipitates from glassy matrix. • The compressive strength reaches to the value of 735 MPa. • The strength can fit well with rule of mixture.

  9. AISI/DOE Advanced Process Control Program Vol. 3 of 6: MICROSTRUCTURAL ENGINEERING IN HOT-STRIP MILLS Part 2 of 2: Constitutive Behavior Modeling of Steels Under Hot-Rolling Conditions; FINAL

    International Nuclear Information System (INIS)

    Yi-Wen Cheng; Patrick Purtscher

    1999-01-01

    This report describes the development of models for predicting (1) constitutive behaviors and (2) mechanical properties of hot-rolled steels as functions of chemical composition, microstructural features, and processing variables. The study includes the following eight steels: A36, DQSK, HSLA-V, HSLA-Nb, HSLA-50/Ti-Nb, and two interstitial-free (IF) grades. These developed models have been integrated into the Hot-Strip Mill Model (HSMM), which simulates the hot strip rolling mills and predicts the mechanical properties of hot-rolled products. The HSMM model has been developed by the University of British Columbia-Canada as a part of project on the microstructural engineering in hot-strip mills

  10. MM98.04 Measurement of temperature and determination of heat transfer coefficient in backward can extrusion

    DEFF Research Database (Denmark)

    Henningsen, Poul; Hattel, Jesper Henri; Wanheim, Tarras

    1998-01-01

    Temperature is measured during backward can extrusion of steel. The process is characterised by large deformations and very high surface pressure. In the experiments, a can in low carbon steel with a lubrication layer of phosphate soap is formed. The temperature is measured by thermocouples...

  11. Hot cell renovation in the spent fuel conditioning process facility at the Korea Atomic Energy Research Institute

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Seung Nam; Lee, Jong Kwang; Park, Byung Suk; Cho, Il Je; Kim, Ki Ho [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    The advanced spent fuel conditioning process facility (ACPF) of the irradiated materials examination facility (IMEF) at the Korea Atomic Energy Research Institute (KAERI) has been renovated to implement a lab scale electrolytic reduction process for pyroprocessing. The interior and exterior structures of the ACPF hot cell have been modified under the current renovation project for the experimentation of the electrolytic reduction process using spent nuclear fuel. The most important aspect of this renovation was the installation of the argon compartment within the hot cell. For the design and system implementation of the argon compartment system, a full-scale mock-up test and a three-dimensional (3D) simulation test were conducted in advance. The remodeling and repairing of the process cell (M8a), the maintenance cell (M8b), the isolation room, and their utilities were also planned through this simulation to accommodate the designed argon compartment system. Based on the considered refurbishment workflow, previous equipment in the M8 cell, including vessels and pipes, were removed and disposed of successfully after a zoning smear survey and decontamination, and new equipment with advanced functions and specifications were installed in the hot cell. Finally, the operating area and isolation room were also refurbished to meet the requirements of the improved hot cell facility.

  12. Application of solar energy to the supply of industrial process hot water. Aerotherm final report, 77-235. [Can washing in Campbell Soup plant

    Energy Technology Data Exchange (ETDEWEB)

    None

    1977-01-01

    The objectives of the Solar Industrial Process Hot Water Program are to design, test, and evaluate the application of solar energy to the generation and supply of industrial process hot water, and to provide an assessment of the economic and resource benefits to be gained. Other objectives are to stimulate and give impetus to the use of solar energy for supplying significant amounts of industrial process heat requirements. The plant selected for the design of a solar industrial process hot water system was the Campbell Soup facility in Sacramento, California. The total hot water demand for this plant varies between 500 and 800 gpm during regular production shifts, and hits a peak of over 1,000 gpm for approximately one hour during the cleanup shift. Most of the hot water is heated in the boiler room by a combination of waste heat recovery and low pressure (5 psi) steam-water heat exchangers. The hot water emerges from the boiler room at a temperature between 160/sup 0/F and 180/sup 0/F and is transported to the various process areas. Booster heaters in the process areas then use low pressure (5 psi) or medium pressure (20 psi) steam to raise the temperature of the water to the level required for each process. Hot water is used in several processes at the Campbell Soup plant, but the can washing process was selected to demonstrate the feasibility of a solar hot water system. A detailed design and economic analysis of the system is given. (WHK)

  13. Equal Channel Angular Extrusion Simulation of High-Nb Containing β-γ TiAl Alloys

    Directory of Open Access Journals (Sweden)

    Lai-qi Zhang

    2015-01-01

    Full Text Available TiAl alloys containing high Nb are significantly promising for high-temperature structural applications in aerospace and automotive industries. Unfortunately the low plasticity at room temperature limits their extensive applications. To improve the plasticity, not only optimizing the opposition, but also refining grain size through equal channel angular extrusion (ECAE is necessary. The equal channel angular extrusion simulation of Ti-44Al-8Nb-(Cr,Mn,B,Y(at% alloy was investigated by using the Deform-3D software. The influences of friction coefficient, extrusion velocity, and different channel angles on effective strain, damage factor, and the load on the die were analyzed. The results indicate that, with the increasing of friction coefficient, effective strain is enhanced. The extrusion velocity has little effect on the uniformity of effective strain; in contrast it has large influence on the damage factor. Thus smaller extrusion rate is more appropriate. Under the condition of different channel angles, the larger one results in the lower effective strain magnitude and better strain distribution uniformity.

  14. Experimental Validation for Hot Stamping Process by Using Taguchi Method

    Science.gov (United States)

    Fawzi Zamri, Mohd; Lim, Syh Kai; Razlan Yusoff, Ahmad

    2016-02-01

    Due to the demand for reduction in gas emissions, energy saving and producing safer vehicles has driven the development of Ultra High Strength Steel (UHSS) material. To strengthen UHSS material such as boron steel, it needed to undergo a process of hot stamping for heating at certain temperature and time. In this paper, Taguchi method is applied to determine the appropriate parameter of thickness, heating temperature and heating time to achieve optimum strength of boron steel. The experiment is conducted by using flat square shape of hot stamping tool with tensile dog bone as a blank product. Then, the value of tensile strength and hardness is measured as response. The results showed that the lower thickness, higher heating temperature and heating time give the higher strength and hardness for the final product. In conclusion, boron steel blank are able to achieve up to 1200 MPa tensile strength and 650 HV of hardness.

  15. Study on lead extrusion damper as a seismic support

    International Nuclear Information System (INIS)

    Nomura, T.; Kojima, N.; Fujita, K.; Ito, T.

    1989-01-01

    The fundamental characteristics of two types of lead extrusion dampers (cylinder type, rotary type) for use as the nuclear power plant piping support of the elasto-plastic of damper are clarified. As a result, these lead extrusion dampers are found to have the following dynamic characteristics: hysteresis loop is both rectangular shape and bi-linear shape; maximum reaction force is independent of velocity and frequency but it increases as displacement exceeds the specified value; and the dissipated energy is very large and is independent of velocity, frequency and initial displacement (i.e., thermal expansion of pipings) in the range of test

  16. Stability of mycotoxins during food processing.

    Science.gov (United States)

    Bullerman, Lloyd B; Bianchini, Andreia

    2007-10-20

    The mycotoxins that commonly occur in cereal grains and other products are not completely destroyed during food processing operations and can contaminate finished processed foods. The mycotoxins most commonly associated with cereal grains are aflatoxins, ochratoxin A, fumonisins, deoxynivalenol and zearalenone. The various food processes that may have effects on mycotoxins include sorting, trimming, cleaning, milling, brewing, cooking, baking, frying, roasting, canning, flaking, alkaline cooking, nixtamalization, and extrusion. Most of the food processes have variable effects on mycotoxins, with those that utilize the highest temperatures having greatest effects. In general the processes reduce mycotoxin concentrations significantly, but do not eliminate them completely. However, roasting and extrusion processing show promise for lowering mycotoxin concentrations, though very high temperatures are needed to bring about much of a reduction in mycotoxin concentrations. Extrusion processing at temperatures greater than 150 degrees C are needed to give good reduction of zearalenone, moderate reduction of alfatoxins, variable to low reduction of deoxynivalenol and good reduction of fumonisins. The greatest reductions of fumonisins occur at extrusion temperatures of 160 degrees C or higher and in the presence of glucose. Extrusion of fumonisin contaminated corn grits with 10% added glucose resulted in 75-85% reduction in Fumonisin B(1) levels. Some fumonisin degredation products are formed during extrusion, including small amounts of hydrolyzed Fumonisin B(1) and N-(Carboxymethyl) - Fumonisin B(1) and somewhat higher amounts of N-(1-deoxy-d-fructos-1-yl) Fumonisin B(1) in extruded grits containing added glucose. Feeding trial toxicity tests in rats with extruded fumonisin contaminated corn grits show some reduction in toxicity of grits extruded with glucose.

  17. Development of Nutritious Snack from rice industry waste using twin screw extrusion

    Directory of Open Access Journals (Sweden)

    Sharma Renu

    2016-01-01

    Full Text Available Deoiled rice bran, a byproduct of rice milling industry was transformed into highly nutritious snack by the application of twin screw extrusion process. Response Surface Methodology (RSM with four- factor- five level central composite rotatable design (CCRD was employed to investigate the effects of extrusion conditions including moisture content of different raw flours, feed composition, barrel temperature and screw speed of extruder on properties of extrudates was studied. Second order quadratic regression model fitted adequately in the variation. The significance was established at P ≤ 0.05. The regression models can be used to interpret the effect of feed composition, moisture content, screw speed and barrel temperature on the properties of the final product. It was shown that higher rice bran in feed composition showed in minimum water absorption index and maximum water solubility index. Numerical optimization technique resulted in 123.83°C of barrel temperature, 294.68 rpm of screw speed, 13.94 % of feed moisture and 17.73 % of deoiled rice bran. The responses predicted for these optimum process conditions resulted water absorption index, 5.91468 g/g and water solubility index of 18.5553 % for the development of value added product with health benefits.

  18. Optimization of Extrusion Process of Directly Expanded Snacks Based on Potato Starch in a Single Step for the Formation of Type IV Resistant Starch.

    Science.gov (United States)

    Calvo-López, Amira Daniela; Martínez-Bustos, Fernando

    2017-09-01

    Resistant starch type IV (RSIV) can be produced by chemical modifications (etherized or esterified) such as conversion, substitution, or cross-linking, which can prevent its digestion by blocking enzyme access and forming atypical linkages. In this research, the effects of barrel temperature (145.86-174.14 °C), the screw speed (42.93-57.07 Hz) and derivatization (esterification) in the formation of RSIV content of directly expanded snacks (second generation snacks) were studied. Potato starch was chemically modified by phosphorylation and succinylation, and expanded by using the extrusion cooking process. Snacks with phosphorylated starch showed expansion index from 2.57 to 3.23, bulk density from 306.19 to 479.00 kg/m 3 and RSIV from 43.27 to 55.81%. Snacks with succinylated starch had expansion index from 3.52 to 3.82, bulk density from 99.85 to 134.51 kg/m 3 and RSIV from 23.17 to 35.01%. The results found in this work showed that it is possible to manufacture extruded directly expanded snacks (second-generation snacks) such as a ready-to-eat (RTE) with good physicochemical properties and without substantial loss of extrusion functionality, which could bring a healthy benefit due to the presence of RSIV.

  19. Cisão de cadeia na degradação termo-mecânica do poliestireno sob múltiplas extrusões Scission in the thermo mechanical degradation of polystyrene under multiple extrusions

    Directory of Open Access Journals (Sweden)

    Carlos A. Cáceres

    2008-01-01

    Full Text Available Determinou-se o número de cisões de cadeia gerado pela degradação termo-mecânica do poliestireno quando submetido a múltiplas extrusões. A degradação foi acompanhada pelas mudanças nas curvas de distribuição de massa molar. Seguindo-se o significado físico das massas molares médias de uma curva de MWD mostrou-se que a massa molar numérica media Mn é a única que pode ser relacionada diretamente com o número de moléculas do sistema. A partir desta calculou-se o número de cadeias clivadas (ns como uma relação entre a Mn da amostra degradada e a virgem. A função de distribuição de cisão de cadeia (CSDF mostra que o processo de degradação termo-mecânica do poliestireno submetido a múltiplas extrusões à 240 °C é do tipo aleatório, independente da massa molar inicial.The number of chain scissions during thermo-degradation of polystyrene under multiple extrusions was calculated. The degradation produces changes in the molecular weight distribution MWD curves. Following the physical meaning of the average molecular weights of a MWD curve it was shown that the number average molecular weight Mn is the only average that can be directly related to the number of molecules in the system. From that it was calculated the number of sectioned chains (ns as a ratio between the number of chains in the degraded and original polymers. The chain scission distribution function (CSDF shows that the thermo-mechanical degradation process of polystyrene under multiple extrusions at 240 °C is of a random type, independent of the initial molecular weight.

  20. Characterization of printed planar electromagnetic coils using digital extrusion and roll-to-roll flexographic processes

    Science.gov (United States)

    Rickard, Scott

    Electromagnets are a crucial component in a wide range of more complex electrical devices due to their ability to turn electrical energy into mechanical energy and vice versa. The trend for electronics becoming smaller and lighter has led to increased interest in using flat, planar electromagnetic coils, which have been shown to perform better at scaled down sizes. The two-dimensional geometry of a planar electromagnetic coil yields itself to be produced by a roll-to-roll additive manufacturing process. The emergence of the printed electronics field, which uses traditional printing processes to pattern functional inks, has led to new methods of mass-producing basic electrical components. The ability to print a planar electromagnetic coil using printed electronics could rival the traditional subtractive and semi-subtractive PCB process of manufacturing. The ability to print lightweight planar electromagnetic coils on flexible substrates could lead to their inclusion into intelligent packaging applications and could have specific use in actuating devices, transformers, and electromagnetic induction applications such as energy harvesting or wireless charging. In attempts to better understand the limitations of printing planar electromagnetic coils, the effect that the design parameters of the planar coils have on the achievable magnetic field strength were researched. A comparison between prototyping methods of digital extrusion and manufacturing scale flexographic printing are presented, discussing consistency in the printed coils and their performance in generating magnetic fields. A method to predict the performance of these planar coils is introduced to allow for design within required needs of an application. Results from the research include a demonstration of a printed coil being used in a flat speaker design, working off of actuating principles.

  1. An osteophyte in the tibial plateau is a risk factor for allograft extrusion after meniscus allograft transplantation.

    Science.gov (United States)

    Jeon, Byeongsam; Kim, Jong-Min; Kim, Jong-Min; Lee, Chang-Rack; Kim, Kyung-Ah; Bin, Seong-Il

    2015-05-01

    Osteophytes can be observed on the tibial plateau during meniscus allograft transplantation (MAT). However, no studies to date have evaluated the effect of these osteophytes on meniscus allograft extrusion. Osteophyte excision in the tibial plateau could reduce extrusion of the transplanted meniscus and improve short-term clinical outcomes with meniscus allograft transplantation. Cohort study; Level of evidence, 3. Between October 2004 and July 2012, a total of 323 patients underwent MAT at a single institution. Of these, 88 patients had a peripheral osteophyte in their tibial plateau, and they were enrolled in the study retrospectively. The mean age of the patients was 35.3 years (range, 15-56 years); there were 57 male and 31 female patients. Forty-four patients underwent osteophyte excision concomitantly with MAT and 44 patients underwent MAT only. The 2 groups showed no difference in terms of age, body mass index, time after meniscectomy, and preoperative knee scores. A medial meniscus allograft was transplanted in 13 cases (15%) and a lateral meniscus in 75 (85%). The absolute extrusion and relative percentage of extrusion were measured to evaluate allograft extrusion 12 months after MAT. The modified Lysholm scoring system and the Hospital for Special Surgery score at 2 years after MAT were used to evaluate clinical outcomes. The mean absolute extrusions at 1 year postoperatively in the excision and nonexcision groups were 3.5±1.5 and 5.5±1.6 mm, respectively. The mean relative percentages of extrusion were 34.1%±15.9% and 54.7%±20.7%, respectively. The rates of allograft extrusion (>3 mm) were 28 of 44 (63.6%) and 41 of 44 (93.2%) in the excision and nonexcision groups, respectively. The intergroup differences in absolute extrusion, relative percentage of extrusion, and rate of allograft extrusion were statistically significant (P<.001 for all 3 parameters). There were no significant differences in the clinical outcomes (modified Lysholm or Hospital of

  2. Reduction of Fumonisin Toxicity by Extrusion and Nixtamalization (Alkaline Cooking).

    Science.gov (United States)

    Voss, Kenneth; Ryu, Dojin; Jackson, Lauren; Riley, Ronald; Gelineau-van Waes, Janee

    2017-08-23

    Fumonisins are mycotoxins found in corn. They are toxic to animals and cause cancer in rodents and neural tube defects in LM/Bc mice. Reducing their concentrations in corn-based foods is therefore desirable. Chemical analysis or in vitro bioassays of food extracts might not detect toxic fumonisin reaction products that are unknown or unextractable from food matrices, thus potentially underestimating in vivo toxicity. The effectiveness of two common cooking methods, extrusion and nixtamalization (alkaline cooking), to reduce the toxicity of fumonisin-contaminated corn grits (extrusion) and whole kernel corn (nixtamalization) was shown by means of rat feeding bioassays using fumonisin-specific kidney effects as indicators of potential toxicity. A third bioassay showed that in contrast to fumonisin B 1 (FB 1 ), hydrolyzed fumonisin B 1 (HFB 1 ; formed from FB 1 during nixtamalization) did not cause neural tube defects in LM/Bc mice. The findings indicate that extrusion and nixtamalization reduce the potential toxicity of FB 1 -contaminated corn.

  3. Variation of microstructures and mechanical properties of hot heading process of super heat resisting alloy Inconel 718

    International Nuclear Information System (INIS)

    Choi, Hong Seok; Ko, Dae Chul; Kim, Byung Min

    2007-01-01

    Metal forming is the process changing shapes and mechanical properties of the workpiece without initial material reduction through plastic deformation. Above all, because of hot working carried out above recrystallization temperature can be generated large deformation with one blow, it can produce with forging complicated parts or heat resisting super alloy such as Inconel 718 has the worst forgeability. In this paper, we established optimal variation of hot heading process of the Inconel 718 used in heat resisting component and evaluated mechanical properties hot worked product. Die material is SKD61 and initial temperature is 300 .deg. C. Initial billet temperature and punch velocity changed, relatively. Friction coefficient is 0.3 as lubricated condition of hot working. CAE is carried out using DEFORM software before marking the tryout part, and it is manufactured 150 ton screw press with optimal condition. It is know that forming load was decreased according to decreasing punch velocity

  4. Effects of dope extrusion rate on the morphology and gas separation performance of asymmetric polysulfone hollow fiber membranes for O2/N2 separation

    Directory of Open Access Journals (Sweden)

    Ahmad Fausi Ismail

    2002-11-01

    Full Text Available The objective of this study was to investigate the influence of dope extrusion rates on morphology and gas separation performance of asymmetric polysulfone hollow fiber membranes. Asymmetric polysulfone hollow fiber membranes for gas separation were prepared from a solution consisting of 26.0 wt. % of polysulfone, 30.4 wt. % of N, N-dimethylacetamide, 30.4 wt. % of tetrahydrofuran and 13.2 wt. % ethanol. The dry/wet phase separation process was applied to a dry/wet spinning process. Fibers were spun at various dope extrusion rates (DER ranging from 1.5 - 3.0 cm3/min and hence at different levels of shear. The results suggest that as the dope extrusion rate is increased, the selectivity will increase until a critical level of shear is reached, beyond which the membrane performance deteriorates. Pressure-normalized-fluxes and selectivities were evaluated by using pure oxygen and nitrogen as test gases.

  5. Setting Mechanical Properties of High Strength Steels for Rapid Hot Forming Processes

    Science.gov (United States)

    Löbbe, Christian; Hering, Oliver; Hiegemann, Lars; Tekkaya, A. Erman

    2016-01-01

    Hot stamping of sheet metal is an established method for the manufacturing of light weight products with tailored properties. However, the generally-applied continuous roller furnace manifests two crucial disadvantages: the overall process time is long and a local setting of mechanical properties is only feasible through special cooling techniques. Hot forming with rapid heating directly before shaping is a new approach, which not only reduces the thermal intervention in the zones of critical formability and requested properties, but also allows the processing of an advantageous microstructure characterized by less grain growth, additional fractions (e.g., retained austenite), and undissolved carbides. Since the austenitization and homogenization process is strongly dependent on the microstructure constitution, the general applicability for the process relevant parameters is unknown. Thus, different austenitization parameters are analyzed for the conventional high strength steels 22MnB5, Docol 1400M, and DP1000 in respect of the mechanical properties. In order to characterize the resulting microstructure, the light optical and scanning electron microscopy, micro and macro hardness measurements, and the X-ray diffraction are conducted subsequent to tensile tests. The investigation proves not only the feasibility to adjust the strength and ductility flexibly, unique microstructures are also observed and the governing mechanisms are clarified. PMID:28773354

  6. Kit ligand promotes first polar body extrusion of mouse preovulatory oocytes

    Directory of Open Access Journals (Sweden)

    Ye Yinghui

    2009-04-01

    Full Text Available Abstract Background Shortly after stimulation by the preovulatory surge of luteinizing hormone (LH, oocytes arrested at the late prophase I resume meiosis characterized by germinal vesicle breakdown (GVBD, chromosome condensation, and extrusion of the first polar body in preparation for fertilization and early embryonic development. However, oocytes express few or no LH receptors and are insensitive to direct LH stimulation. Thus, factors released by granulosa or theca cells expect to convey the LH stimuli to oocytes. To identify candidate ligand-receptor pairs potentially involved in the process of oocyte maturation, we performed DNA microarray analyses of ovarian transcripts in mice and identified Kit ligand (Kitl as an ovarian factor stimulated by the LH/hCG surge. The purpose of this study is to investigate the roles of KITL in the nuclear and cytoplasmic maturation of preovulatory mouse oocytes. Methods The levels of Kitl and c-kit transcripts in mouse ovaries and isolated ovarian cells were determined by real-time RT-PCR, while expression of KITL protein was examined by immunohistochemistry. Follicle culture, cumulus-oocyte complexes (COC and denuded oocytes culture were used to evaluate the effect of KITL on mouse oocyte nuclear maturation. To assess the effect of KITL treatment on the cytoplasmic maturation of preovulatory oocytes, we performed in vitro maturation of oocytes followed by in vitro fertilization. Results Major increase of Kitl transcripts in granulosa cells and mouse ovaries, and predominant expression of c-kit in preovulatory oocytes were identified by real-time RT-PCR. Predominant expression of KITL protein was found in granulosa cells of preovulatory and small antral follicles at 4 h after hCG treatment. In vitro cultures demonstrated that treatment with KITL enhanced first polar body extrusion in a dose-dependent manner. Moreover, treatment of COC with KITL enhanced first polar body extrusion with increase in cyclin B1

  7. Extrusion Bioprinting of Shear-Thinning Gelatin Methacryloyl Bioinks.

    Science.gov (United States)

    Liu, Wanjun; Heinrich, Marcel A; Zhou, Yixiao; Akpek, Ali; Hu, Ning; Liu, Xiao; Guan, Xiaofei; Zhong, Zhe; Jin, Xiangyu; Khademhosseini, Ali; Zhang, Yu Shrike

    2017-06-01

    Bioprinting is an emerging technique for the fabrication of 3D cell-laden constructs. However, the progress for generating a 3D complex physiological microenvironment has been hampered by a lack of advanced cell-responsive bioinks that enable bioprinting with high structural fidelity, particularly in the case of extrusion-based bioprinting. Herein, this paper reports a novel strategy to directly bioprint cell-laden gelatin methacryloyl (GelMA) constructs using bioinks of GelMA physical gels (GPGs) achieved through a simple cooling process. Attributed to their shear-thinning and self-healing properties, the GPG bioinks can retain the shape and form integral structures after deposition, allowing for subsequent UV crosslinking for permanent stabilization. This paper shows the structural fidelity by bioprinting various 3D structures that are typically challenging to fabricate using conventional bioinks under extrusion modes. Moreover, the use of the GPG bioinks enables direct bioprinting of highly porous and soft constructs at relatively low concentrations (down to 3%) of GelMA. It is also demonstrated that the bioprinted constructs not only permit cell survival but also enhance cell proliferation as well as spreading at lower concentrations of the GPG bioinks. It is believed that such a strategy of bioprinting will provide many opportunities in convenient fabrication of 3D cell-laden constructs for applications in tissue engineering, regenerative medicine, and pharmaceutical screening. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Deformational Features and Microstructure Evolution of Copper Fabricated by a Single Pass of the Elliptical Cross-Section Spiral Equal-Channel Extrusion (ECSEE) Process

    Science.gov (United States)

    Wang, Chengpeng; Li, Fuguo; Liu, Juncheng

    2018-04-01

    The objectives of this work are to study the deformational feature, textures, microstructures, and dislocation configurations of ultrafine-grained copper processed by the process of elliptical cross-section spiral equal-channel extrusion (ECSEE). The deformation patterns of simple shear and pure shear in the ECSEE process were evaluated with the analytical method of geometric strain. The influence of the main technical parameters of ECSEE die on the effective strain distribution on the surface of ECSEE-fabricated samples was examined by the finite element simulation. The high friction factor could improve the effective strain accumulation of material deformation. Moreover, the pure copper sample fabricated by ECSEE ion shows a strong rotated cube shear texture. The refining mechanism of the dislocation deformation is dominant in copper processed by a single pass of ECSEE. The inhomogeneity of the micro-hardness distribution on the longitudinal section of the ECSEE-fabricated sample is consistent with the strain and microstructure distribution features.

  9. Deconvoluting the Friction Stir Weld Process for Optimizing Welds

    Science.gov (United States)

    Schneider, Judy; Nunes, Arthur C.

    2008-01-01

    In the friction stir welding process, the rotating surfaces of the pin and shoulder contact the weld metal and force a rotational flow within the weld metal. Heat, generated by the metal deformation as well as frictional slippage with the contact surface, softens the metal and makes it easier to deform. As in any thermo-mechanical processing of metal, the flow conditions are critical to the quality of the weld. For example, extrusion of metal from under the shoulder of an excessively hot weld may relax local pressure and result in wormhole defects. The trace of the weld joint in the wake of the weld may vary geometrically depending upon the flow streamlines around the tool with some geometry more vulnerable to loss of strength from joint contamination than others. The material flow path around the tool cannot be seen in real time during the weld. By using analytical "tools" based upon the principles of mathematics and physics, a weld model can be created to compute features that can be observed. By comparing the computed observations with actual data, the weld model can be validated or adjusted to get better agreement. Inputs to the model to predict weld structures and properties include: hot working properties ofthe metal, pin tool geometry, travel rate, rotation and plunge force. Since metals record their prior hot working history, the hot working conditions imparted during FSW can be quantified by interpreting the final microstructure. Variations in texture and grain size result from variations in the strain accommodated at a given strain rate and temperature. Microstructural data from a variety of FSWs has been correlated with prior marker studies to contribute to our understanding of the FSW process. Once this stage is reached, the weld modeling process can save significant development costs by reducing costly trial-and-error approaches to obtaining quality welds.

  10. Estimation of radiation exposure for hot cell workers during DUPIC fuel fabrication process in IMEF M6 cell

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Yong Bum; Baek, Sang Yeol; Park, Dae Kyu

    1997-06-01

    DUPIC(Direct Use of spent PWR fuel In CANDU) fuel cycle to utilize the PWR spent fuel in fabricating CANDU fuel, which is expected to reduce not only the total amount of high level radwastes but the energy sources is underway. IMEF M6 cell to be used as DUPIC fuel fabrication facility is refurbished and retrofitted. Radiation exposure for the hot cell worker by dispersion of the radioactive materials during the DUPIC process were estimated on the basis of the hot cell design information. According to the estimation results, DUPIC fuel fabrication process could be run without any severe impacts to the hot cell workers when the ventilation system to maintain the sufficient pressure difference between hotcell and working area and radiation monitoring system is supports the hot cell operation properly. (author). 4 tabs., 6 figs.

  11. A Covering Type Extrusion Die with Twin Cavities for Semi-Hollow Al-Profiles

    Science.gov (United States)

    Deng, Rurong; Huang, Xuemei

    2018-03-01

    A new structure named covering type with twin cavities in a die for the semi-hollow aluminum profiles was present. The determination of structure parameters was introduced in detail. Mainly including the selection of the machine, the arrangement of portholes, the structure design of chamber and the selection of bearing. The method of checking the die strength was introduced. According to the extrusion results, the structure of the traditional solid die, the porthole die with single cavity and the covering type structure with twin cavities were compared. The characteristics of the latter structure were simple and easy to process. The practical application shows that the new die structure can enhance the die life, improve the production efficiency and reduce the cost. The high precision and the surface brightness of the profiles were obtained. The structure is worth promoting. The aim is to provide reliable data and reference for the further research and development of this technology on the extrusion die with multi-cavities in a die.

  12. Criteria for prediction of plastic instabilities for hot working processes. (Part I: Theoretical review)

    International Nuclear Information System (INIS)

    Al Omar, A.; Prado, J. M.

    2010-01-01

    Hot working processes often induce high levels of deformation at high strain rates, and impose very complex multiaxial modes of solicitation. These processes are essentially limited by apparition and development of plastic instabilities. These may be the direct cause of rapid crack propagation, which lead to a possible final rupture. The complexity of deformation modes and the simultaneous intervention of several parameters have led many researchers to develop various criteria, with different approaches, to predict the occurrence of defects and to optimize process control parameters. The aim of the present paper is to summarize the general characteristics of some instability criteria, widely used in the literature, for the prediction of plastic instabilities during hot working. It was considered appropriate to divide the work into two parts: part I presents the phenomenological criteria for the prediction of plastic instabilities, based on descriptive observation of microscopic phenomena of the deformation (strain hardening and strain rate sensitivity), and discusses the continuum criteria based on the principle of maximum rate of entropy production of irreversible thermodynamics applied to continuum mechanics of large plastic flow. Also, this part provides a bibliographical discussion among several authors with regard to the physical foundations of dynamic materials model. In part II, of the work, a comparative study has been carried out to characterize the flow instability during a hot working process of a medium carbon microalloyed using phenomenological and continuum criteria. (Author) 83 refs.

  13. Characterisation of the wall-slip during extrusion of heavy-clay products

    Science.gov (United States)

    Kocserha, I.; Gömze, A. L.; Kulkov, S.; Kalatur, E.; Buyakova, S. P.; Géber, R.; Buzimov, A. Y.

    2017-01-01

    During extrusion through the extrusion die, heavy-clay compounds are usually show plug flow with extensive slip at the wall of the die. In this study, the viscosity and the thickness of the slip layer were investigated. For the examination a brick-clay from Malyi (Hungary) deposit was applied as a raw material. The clay was characterised by XRPD, BET, SEM and granulometry. As the slip layer consists of suspension of the fine clay fraction so the clay minerals content of the clay (dviscosity of suspension with different water content was measured by means of rotational viscosimeter. The thickness of the slip layer was calculated from the measured viscosity and other data obtained from an earlier study with capillary rheometer. The calculated thickness value showed a tendency to reach a limit value by increasing the extrusion speed.

  14. Microstructure quantification of ultrafine grained pure copper fabricated by simple shear extrusion (SSE) technique

    International Nuclear Information System (INIS)

    Bagherpour, E.; Qods, F.; Ebrahimi, R.; Miyamoto, H.

    2016-01-01

    In the present paper commercially pure copper was processed by simple shear extrusion (SSE) technique up to 12 passes using the so-called route C. For SSE processing an appropriate die with a linear die profile was designed and constructed. Effect of SSE passes on isotropy and uniformity of microstructures are focused. Electron back-scattering diffraction (EBSD) was used to evaluate the microstructure of the deformed samples in three orthogonal planes. To investigate the microstructural uniformity EBSD maps were taken from center to periphery of the extrusion direction plane (ED-plane) samples. Significant evolution in grain refinement was achieved down to sub-micron grain size in all planes. Hardness measurements show a considerable increase in hardness of the material after the processing, which confirms the microstructural evolutions. EBSD scans revealed a homogeneous ultrafine grained microstructure after 12 passes. Micro-shear bands were found as potential sites for accelerating the formation of new grains by fragmentation of the initial grains. The total frequency of coincidence site lattice (CSL) boundaries including Σ3 boundaries increased by the increasing of SSE passes. The higher fraction of low to high angle grain boundaries of SSE compared to equal channel angular pressing is an evidence for the cyclic behavior of SSE technique.

  15. Microstructure quantification of ultrafine grained pure copper fabricated by simple shear extrusion (SSE) technique

    Energy Technology Data Exchange (ETDEWEB)

    Bagherpour, E., E-mail: e.bagherpour@semnan.ac.ir [Faculty of Metallurgical and Materials Engineering, Semnan University, Semnan (Iran, Islamic Republic of); Department of Mechanical Engineering, Doshisha University, Kyotanabe, Kyoto 610-0394 (Japan); Qods, F., E-mail: qods@semnan.ac.ir [Faculty of Metallurgical and Materials Engineering, Semnan University, Semnan (Iran, Islamic Republic of); Ebrahimi, R., E-mail: ebrahimy@shirazu.ac.ir [Department of Materials Science and Engineering, School of Engineering, Shiraz University, Shiraz (Iran, Islamic Republic of); Miyamoto, H., E-mail: hmiyamot@mail.doshisha.ac.jp [Department of Mechanical Engineering, Doshisha University, Kyotanabe, Kyoto 610-0394 (Japan)

    2016-09-30

    In the present paper commercially pure copper was processed by simple shear extrusion (SSE) technique up to 12 passes using the so-called route C. For SSE processing an appropriate die with a linear die profile was designed and constructed. Effect of SSE passes on isotropy and uniformity of microstructures are focused. Electron back-scattering diffraction (EBSD) was used to evaluate the microstructure of the deformed samples in three orthogonal planes. To investigate the microstructural uniformity EBSD maps were taken from center to periphery of the extrusion direction plane (ED-plane) samples. Significant evolution in grain refinement was achieved down to sub-micron grain size in all planes. Hardness measurements show a considerable increase in hardness of the material after the processing, which confirms the microstructural evolutions. EBSD scans revealed a homogeneous ultrafine grained microstructure after 12 passes. Micro-shear bands were found as potential sites for accelerating the formation of new grains by fragmentation of the initial grains. The total frequency of coincidence site lattice (CSL) boundaries including Σ3 boundaries increased by the increasing of SSE passes. The higher fraction of low to high angle grain boundaries of SSE compared to equal channel angular pressing is an evidence for the cyclic behavior of SSE technique.

  16. Simulation of Bimetallic Bush Hot Rolling Bonding Process

    Directory of Open Access Journals (Sweden)

    Yaqin Tian

    2015-01-01

    Full Text Available Three-dimensional model of bimetallic bush was established including the drive roller and the core roller. The model adopted the appropriate interface assumptions. Based on the bonding properties of bimetallic bush the hot rolling process was analyzed. The optimum reduction ratio of 28% is obtained by using the finite element simulation software MARC on the assumption of the bonding conditions. The stress-strain distribution of three dimensions was research assumptions to interface deformation of rolling. At the same time, based on the numerical simulation, the minimum reduction ratio 20% is obtained by using a double metal composite bush rolling new technology from the experiment research. The simulation error is not more than 8%.

  17. Method of Determining the Filtration Properties of oil-Bearing Crops in the Process of Their Pressing by the Example of Rape-oil Extrusion

    Science.gov (United States)

    Slavnov, E. V.; Petrov, I. A.

    2014-07-01

    A method of determining the change in the fi ltration properties of oil-bearing crops in the process of their pressing by repeated dynamic loading is proposed. The use of this method is demonstrated by the example of rape-oil extrusion. It was established that the change in the mass concentration of the oil in a rape mix from 0.45 to 0.23 leads to a decrease in the permeability of the mix by 101.5-102 times depending on the pressure applied to it. It is shown that the dependence of the permeability of this mix on the pressure applied to it is nonmonotone in character.

  18. Antimicrobial Activity of Nisin and Natamycin Incorporated Sodium Caseinate Extrusion-Blown Films: A Comparative Study with Heat-Pressed/Solution Cast Films.

    Science.gov (United States)

    Colak, Basak Yilin; Peynichou, Pierre; Galland, Sophie; Oulahal, Nadia; Prochazka, Frédéric; Degraeve, Pascal

    2016-05-01

    Antimicrobial edible films based on sodium caseinate, glycerol, and 2 food preservatives (nisin or natamycin) were prepared by classical thermomechanical processes. Food preservatives were compounded (at 65 °C for 2.5 min) with sodium caseinate in a twin-screw extruder. Anti-Listeria activity assays revealed a partial inactivation of nisin following compounding. Thermoplastic pellets containing food preservatives were then used to manufacture films either by blown-film extrusion process or by heat-press. After 24 h of incubation on agar plates, the diameters of K. rhizophila growth inhibition zones around nisin-incorporated films prepared by solution casting (control), extrusion blowing or heat pressing at 80 °C for 7 min of nisin-containing pellets were 15.5 ± 0.9, 9.8 ± 0.2, and 8.6 ± 1.0 mm, respectively. Since heat-pressing for 7 min at 80 °C of nisin-incorporated pellets did not further inactivate nisin, this indicates that nisin inactivation during extrusion-blowing was limited. Moreover, the lower diameter of the K. rhizophila growth inhibition zone around films prepared with nisin-containing pellets compared to that observed around films directly prepared by solution casting confirms that nisin inactivation mainly occurred during the compounding step. Natamycin-containing thermoplastic films inhibited Aspergillus niger growth; however, by contrast with nisin-containing films, heat-pressed films had higher inhibition zone diameters than blown films, therefore suggesting a partial inactivation of natamycin during extrusion-blowing. © 2016 Institute of Food Technologists®

  19. Reduction of adhesive stain defect in flexible printed circuit board on hot pressing process: a case study of electronic component factory

    Directory of Open Access Journals (Sweden)

    Sakulkaew Srisang

    2014-09-01

    Full Text Available The objective of this research is a reduction of an adhesive stain defect in flexible printed circuit board in hot pressing process, the electronic factory. The manufacturing have been processing by sheet type of products with ninety-six pieces of flexible printed circuit boards. Causes of the problem include the before and internal hot pressing process. In process beginning times, the most right row of products between the cooling plate and the hot pressing machine has temperature 71.2◦C that is higher than glass transition temperature (Tg 60◦C. Those products’ temperature lead to evaporate a polyimide adhesive before hot pressing process beginning. The internal hot pressing process include the preheat times and the pressure time. In the preheat time the problem is a gap between lower and upper plate, was under specification(Under 1 mm and leaded to adhesive polyimide stain. In the actuality this time requires temperature and low pressure that mean a gap within 1 – 2 mm (between lower and upper plate. In pressure times the hot pressing plate surface is not flat and products are pressed by insufficient force that it lead to generate an adhesive stain on flexible printed circuit boards. That force is measured by the pre-scale paper and a result, RGB color, is provided. And then color density (From standard color sample and RGB color (From pre-scale paper is found out the relation by Photoshop program and multiple regression theory using. The formula is applied to compare with defect so as to find out the suitable color density (Defects reducing. The solving solutions is provided including the gap reduced adjustment between cooling plate and hot pressing machine before hot pressing process, the plate adjustment within specification in the preheat time and the pressing plate polishing in the pressure time. Results of study and solving are provide defect reduction from 24.4 percentage to 7.2 percentage of total study product.

  20. Reduction of adhesive stain defect in flexible printed circuit board on hot pressing process: A case study of electronic component factory

    Directory of Open Access Journals (Sweden)

    Sakulkaew Srisang

    2015-03-01

    Full Text Available The objective of this research is a reduction of an adhesive stain defect in flexible printed circuit board in hot pressing process, the electronic factory. The manufacturing have been processing by sheet type of products with ninety-six pieces of flexible printed circuit boards. Causes of the problem include the before and internal hot pressing process. In process beginning times, the most right row of products between the cooling plate and the hot pressing machine has temperature 71.2◦C that is higher than glass transition temperature (Tg 60◦C. Those products’ temperature lead to evaporate a polyimide adhesive before hot pressing process beginning. The internal hot pressing process include the preheat times and the pressure time. In the preheat time the problem is a gap between lower and upper plate, was under specification (Under 1 mm and leaded to adhesive polyimide stain. In the actuality this time requires temperature and low pressure that mean a gap within 1 – 2 mm (between lower and upper plate. In pressure times the hot pressing plate surface is not flat and products are pressed by insufficient force that it lead to generate an adhesive stain on flexible printed circuit boards. That force is measured by the pre-scale paper and a result, RGB color, is provided. And then color density (From standard color sample and RGB color (From pre-scale paper is found out the relation by Photoshop program and multiple regression theory using. The formula is applied to compare with defect so as to find out the suitable color density (Defects reducing. The solving solutions is provided including the gap reduced adjustment between cooling plate and hot pressing machine before hot pressing process, the plate adjustment within specification in the preheat time and the pressing plate polishing in the pressure time. Results of study and solving are provide defect reduction from 24.4 percentage to 7.2 percentage of total study product.

  1. Efeito dos parâmetros de extrusão sobre as propriedades funcionais de extrusados da farinha de batata-doce Effect of extrusion parameters on sweet potato extrudates

    Directory of Open Access Journals (Sweden)

    Alexandra M. Borba

    2005-12-01

    Full Text Available Farinha de batata-doce (Ipomoea batatas foi extrusada em equipamento de rosca simples, mantendo-se fixas as temperaturas na 1ª e 2ª zonas de extrusão (20ºC e 60ºC, respectivamente. O efeito das variáveis umidade da farinha (15, 18 e 21%, temperatura na 3ª zona (100, 120 e 140ºC e rotação da rosca (180, 210 e 240 rpm sobre as características dos extrusados foi investigado utilizando-se metodologia de superfície de resposta. O teor de umidade e a temperatura de extrusão influenciaram significativamente a expansão dos extrusados. O índice de expansão apresentou valores crescentes com a temperatura sob baixos teores de umidade. A dureza dos extrusados e também o índice de absorção de água e o índice de solubilidade em água das farinhas extrusadas não mostraram modelo de regressão significativo com as condições de processo. Quanto à cor das farinhas, o componente L* (luminosidade apresentou valores crescentes e o parâmetro a*, valores decrescentes com a elevação do teor de umidade até 20-21%. O parâmetro b* e a diferença de cor entre farinhas extrusadas e não extrusadas mostraram valores decrescentes com o aumento da umidade.Sweet potato flour was processed using a single-screw extruder, with extrusion temperatures in zones 1 and 2 of 20ºC and 60ºC, respectively. The effect of flour moisture content (15, 18 and 21%, barrel temperature in zone 3 (100, 120 and 140ºC and screw speed (180, 210 and 240 rpm on extrudate attributes was investigated using response surface methodology. Moisture content and extrusion temperature had a significant (p<0.05 influence on extrudates expansion. The expansion ratio of the extrudates showed increasing values with temperature under conditions of low moisture content. The firmness of extrudates and also the water absorption index and water solubility index of the pre-gelatinized flours did not show significant regression models with the processing conditions. The flours color was

  2. Machine for extrusion under vacuum; Machine de fluage sous vide

    Energy Technology Data Exchange (ETDEWEB)

    Gautier, A [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    In a study of the behaviour of easily oxidised metals during the extrusion process, it is first necessary to find an effective mean of fighting corrosion, since this, even when barely detectable, has an important influence on the validity of the results recorded. The neatest and also the most efficient of all the methods tried consists in creating a vacuum around the test piece. Working on this principle, and at the same time respecting the conventional rules for extrusion tests (loading the sample after stabilisation at the testing temperature, differential measurements of lengthening, etc.) we found it necessary to construct an original machine. (author) [French] L'etude du comportement au fluage des materiaux facilement oxydables exige, en premier lieu, une lutte efficace contre la corrosion qui, meme a peine decelable, prend une part preponderante quant a la validite des resultats enregistres. La solution la plus elegante, et, a vrai dire, la plus energique parmi toutes les methodes essayees, consiste a realiser le vide autour de l'eprouvette d'essai. Partant de ce principe, et pour sauvegarder les regles classiques de l'essai de fluage (mise en charge de l'eprouvette apres stabilisation en temperature d'essai, mesures differentielles des allongements, etc.) nous nous sommes trouves dans la necessite de construire une machine inedite. (auteur)

  3. 75 FR 51243 - Aluminum Extrusions from the People's Republic of China: Postponement of Preliminary...

    Science.gov (United States)

    2010-08-19

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-570-967] Aluminum Extrusions from the... Department of Commerce (``the Department'') initiated an antidumping duty investigation on Aluminum... Aluminum Extrusions from the People's Republic of China: Initiation of Antidumping Duty Investigation, 75...

  4. Effect of CaO on Hot Workability and Microstructure of Mg-9.5Zn-2Y Alloy

    Science.gov (United States)

    Kwak, Tae-yang; Kim, Daeguen; Yang, Jaehack; Yoon, Young-ok; Kim, Shae K.; Lim, Hyunkyu; Kim, Woo Jin

    Mg-Zn-Y system alloys have been a great interest because Mg-Zn-Y alloys with I-phase exhibited high ductility at room and elevated temperatures. According to our preliminary experiments, the addition of CaO improved strength, but the process window became narrow. Therefore, the aim of current work was to find optimum extrusion conditions for CaO added Mg-Zn-Y alloys by processing maps. The 0.3 wt.% of CaO added Mg-9.5Zn-2Y (Mg95.6Zn3.8Y0.6) alloy was prepared by casting into steel mold and homogenizing. Hot compression test were performed in the Gleeble machine at temperature range of 250-400 °C with various strain rates. The alloys were extruded with a reduction ratio of 20:1. To analyze the microstructure and texture, optical micrograph, scanning electron microscope and electron backscattered diffraction were used. Moreover, we investigated the effects of metallic Ca addition in this alloy to compare with the addition of CaO.

  5. Energy flux of hot atoms

    International Nuclear Information System (INIS)

    Wotzak, G.P.; Kostin, M.D.

    1976-01-01

    The process in which hot atoms collide with thermal atoms of a gas, transfer kinetic energy to them, and produce additional hot atoms is investigated. A stochastic method is used to obtain numerical results for the spatial and time dependent energy flux of hot atoms in a gas. The results indicate that in hot atom systems a front followed by an intense energy flux of hot atoms may develop

  6. 77 FR 74466 - Aluminum Extrusions From the People's Republic of China: Notice of Court Decision Not in Harmony...

    Science.gov (United States)

    2012-12-14

    ... DEPARTMENT OF COMMERCE International Trade Administration [C-570-968] Aluminum Extrusions From the... countervailing duty (CVD) investigation of aluminum extrusions from the People's Republic of China (PRC) \\1... Aluminum Extrusions From the People's Republic of China: Final Affirmative Countervailing Duty...

  7. Friction phenomena in hydrostatic extrusion of magnesium

    NARCIS (Netherlands)

    Moodij, Ellen

    2014-01-01

    When magnesium is hydrostatically extruded an inconsistent and sometimes bad surface quality is encountered. In hydrostatic extrusion the billet is surrounded by a lubricant, usually castor oil. The required pressure to deform the material is applied onto this lubricant and not directly to the

  8. Debris extrusion by glide-path establishing endodontic instruments with different geometries

    Directory of Open Access Journals (Sweden)

    Jung-Hong Ha

    2016-06-01

    Conclusion: Creating the glide-path using nickel-titanium rotary files produced lower amounts of debris extrusion than using manual stainless-steel files. The progressive taper design of ProGlider, the center-off cross-section of One G, and the alternative-pitch design of ScoutRace may have increased the efficiencies of debris removal with minimal extrusion during glide-path preparation. Glide-path preparation using NiTi rotary files have better clinical efficiency than the manual stainless-steel file.

  9. The influences of fluorine and process variations on polysilicon film stress and MOSFET hot carrier effects

    Science.gov (United States)

    Lowry, Lynn E.; Macwilliams, Kenneth P.; Isaac, Mary

    1991-01-01

    The use of fluorinated gate oxides may provide an improvement in nMOSFET reliability by enhancing hot carrier resistance. In order to clarify the mechanisms by which polysilicon processing and fluorination influence the oxide behavior, a matrix of nMOSFET structures was prepared using various processing, doping, and implantation strategies. These structures were evaluated for crystalline morphology and chemical element distribution. Mechanical stress measurements were taken on the polysilicon films from room temperature to cryogenic temperature. These examinations showed that fluorination of a structure with randomly oriented polysilicon can reduce residual mechanical stress and improve hot carrier resistance at room temperature.

  10. Recent Advances in Extrusion-Based 3D Printing for Biomedical Applications.

    Science.gov (United States)

    Placone, Jesse K; Engler, Adam J

    2018-04-01

    Additive manufacturing, or 3D printing, has become significantly more commonplace in tissue engineering over the past decade, as a variety of new printing materials have been developed. In extrusion-based printing, materials are used for applications that range from cell free printing to cell-laden bioinks that mimic natural tissues. Beyond single tissue applications, multi-material extrusion based printing has recently been developed to manufacture scaffolds that mimic tissue interfaces. Despite these advances, some material limitations prevent wider adoption of the extrusion-based 3D printers currently available. This progress report provides an overview of this commonly used printing strategy, as well as insight into how this technique can be improved. As such, it is hoped that the prospective report guides the inclusion of more rigorous material characterization prior to printing, thereby facilitating cross-platform utilization and reproducibility. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Forward impact extrusion of surface textured steel blanks using coated tooling

    Science.gov (United States)

    Hild, Rafael; Feuerhack, Andreas; Trauth, Daniel; Arghavani, Mostafa; Kruppe, Nathan C.; Brögelmann, Tobias; Bobzin, Kirsten; Klocke, Fritz

    2017-10-01

    A method to enable dry metal forming by the means of a self-lubricating coating and surface textures was researched using an innovative Pin-On-Cylinder-Tribometer. The experimental analysis was complemented by a numerical model of the complex contact conditions between coated tools and the surface textured specimen at the micro-level. Based on the results, the explanation of the tribological interactions between surface textured specimens and the tool in dry full forward extrusion is the objective of this work. Therefore, experimental dry extrusion tests were performed using a tool system. The extruded specimens were evaluated regarding their geometry as well as by the required punch force. Thereby, the effectiveness and the feasibility of dry metal forming on the example of full forward extrusion was evaluated. Thus, one more step towards the technical realization of dry metal forming of low alloy steels under industrial conditions was realized.

  12. Numerical investigation of the effect of friction conditions to increase die life

    Science.gov (United States)

    Mutlu, M. O.; Guleryuz, C. G.; Parlar, Z.

    2017-02-01

    The standard die materials in aluminium extrusion offer good mechanical properties like high tempering resistance, high strength and ductility. On the other hand, they struggle with the problem of sliding wear. As a result, there is a growing interest in using surface treatment techniques to increase the wear resistance of extrusion dies. In this study, it is aimed to observe the effects of the different friction conditions on material flow and contact pressure in extrusion process. These friction conditions can be obtained with the application of a variety of surface treatment. In this way, it is expected to decrease the friction force on the die bearing area and to increase the homogeneity of the material flow which will result in the increase of the quality of the extrudate as well as the improvement of the process economically by extending die life. For this purpose, an extrusion process is simulated with a finite element software. A die made of 1.2344 hot work tool steel-commonly used die material for aluminium extrusion process- has been modelled and Al 1100 alloy used as billet material. Various friction factor values defined on the die surface under the same process parameters and effects of changing frictional conditions on the die and the extrusion process have been discussed.

  13. The impact of hot melt extrusion and spray drying on mechanical properties and tableting indices of materials used in pharmaceutical development.

    Science.gov (United States)

    Iyer, Raman; Hegde, Shridhar; Zhang, Yu-E; Dinunzio, James; Singhal, Dharmendra; Malick, A; Amidon, Gregory

    2013-10-01

    The impact of melt extrusion (HME) and spray drying (SD) on mechanical properties of hypromellose acetate succinate (HPMCAS), copovidone, and their formulated blends was studied and compared with that of reference excipients. Tensile strength (TS), compression pressure (CP), elastic modulus (E), and dynamic hardness (Hd ) were determined along with Hiestand indices using compacts prepared at a solid fraction of ∼0.85. HPMCAS and copovidone exhibited lower Hd , lower CP, and lower E than the reference excipients and moderate TS. HPMCAS was found to be highly brittle based on brittle fracture index values. The CP was 24% and 61% higher for HPMCAS after SD and HME, respectively, than for unprocessed material along with a higher Hd . Furthermore, the TS of HPMCAS and copovidone decreased upon HME. Upon blending melt-extruded HPMCAS with plastic materials such as microcrystalline cellulose, the TS increased. These results suggest that SD and HME could impact reworkability by reducing deformation of materials and in case of HME, likely by increasing density due to heating and shear stress in a screw extruder. A somewhat similar effect was observed for the dynamic binding index (BId ) of the excipients and formulated blends. Such data can be used to quantitate the impact of processing on mechanical properties of materials during tablet formulation development. © 2013 Wiley Periodicals, Inc. and the American Pharmacists Association.

  14. Novel process chain for hot metal gas forming of ferritic stainless steel 1.4509

    Science.gov (United States)

    Mosel, André; Lambarri, Jon; Degenkolb, Lars; Reuther, Franz; Hinojo, José Luis; Rößiger, Jörg; Eurich, Egbert; Albert, André; Landgrebe, Dirk; Wenzel, Holger

    2018-05-01

    Exhaust gas components of automobiles are often produced in ferritic stainless steel 1.4509 due to the low thermal expansion coefficient and the low material price. Until now, components of the stainless steel with complex geometries have been produced in series by means of multi-stage hydroforming at room temperature with intermediate annealing operations. The application of a single-stage hot-forming process, also referred to as hot metal gas forming (HMGF), offers great potential to significantly reduce the production costs of such components. The article describes a novel process chain for the HMGF process. Therefore the tube is heated in two steps. After pre-heating of the semi-finished product outside the press, the tube is heated up to forming start temperature by means of a tool-integrated conductive heating before forming. For the tube of a demonstrator geometry, a simulation model for the conduction heating was set up. In addition to the tool development for this process, experimental results are also described for the production of the demonstrator geometry.

  15. Fabrication and tensile properties of rapidly solidified Cu-10wt. %Ni alloy. [Cu-10Ni

    Energy Technology Data Exchange (ETDEWEB)

    Baril, D; Angers, R; Baril, J [Dept. of Mining and Metallurgy, Laval Univ., Ste-Foy, Quebec (Canada)

    1992-10-15

    Cu-10wt.%Ni ribbons were produced by melt spinning and cut into small particles with a blade cutter mill. The powders were then hot consolidated to full density by hot pressing followed by hot extrusion. Tensile properties of the resulting pieces were measured. Cu-10wt.%Ni cast ingots were also hot extruded and mechanically tested to compare with the rapidly solidified alloy and to evaluate the possible benefits brought by the rapid solidification process.

  16. Shuttle Primary Reaction Control Subsystem Thruster Fuel Valve Pilot Seal Extrusion: A Failure Correlation

    Science.gov (United States)

    Waller, Jess; Saulsberry, Regor L.

    2003-01-01

    Pilot operated valves (POVs) are used to control the flow of hypergolic propellants monomethylhydrazine (fuel) and nitrogen tetroxide (oxidizer) to the Shuttle orbiter Primary Reaction Control Subsystem (PRCS) thrusters. The POV incorporates a two-stage design: a solenoid-actuated pilot stage, which in turn controls a pressure-actuated main stage. Isolation of propellant supply from the thruster chamber is accomplished in part by a captive polytetrafluoroethylene (PTFE) pilot seal retained inside a Custom 455.1 stainless steel cavity. Extrusion of the pilot seal restricts the flow of fuel around the pilot poppet, thus impeding or preventing the main valve stage from opening. It can also prevent the main stage from staying open with adequate force margin, particularly if there is gas in the main stage actuation cavity. During thruster operation on-orbit, fuel valve pilot seal extrusion is commonly indicated by low or erratic chamber pressure or failure of the thruster to fire upon command (Fail-Off). During ground turnaround, pilot seal extrusion is commonly indicated by slow gaseous nitrogen (GN2) main valve opening times (greater than 38 ms) or slow water main valve opening response times (greater than 33 ms). Poppet lift tests and visual inspection can also detect pilot seal extrusion during ground servicing; however, direct metrology on the pilot seat assembly provides the most quantitative and accurate means of identifying extrusion. Minimizing PRCS fuel valve pilot seal extrusion has become an important issue in the effort to improve PRCS reliability and reduce associated life cycle costs.

  17. A Preliminary Shielding Study on the Integrated Operation Verification System in the Head-End Hot-Cell of the Pyro-processing

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jinhwam; Kim, Yewon; Park, Se-Hwan; Ahn, Seong-Kyu; Cho, Gyuseong [KAIST, Daejeon (Korea, Republic of)

    2016-10-15

    Nuclear power accounts for more than 30 percent of power production in Korea. Its significance has annually been increased. Disposal spent fuel containing uranium, transuranic elements, and fission products is unavoidable byproduct of nuclear power production. it is recognized that finding appropriate sites for interim storage of disposal spent fuel is not easy because isolated sites should be required. Pyro-processing technology, Pyro-processing should be operated under high radiation environment in hot-cell structures. Because of this reason, all workers should be unauthorized to access inside the hot-cell areas under any circumstances except for acceptable dose verification and a normal operation should be remotely manipulated. For the reliable normal operation of pyroprocessing, it is noted that an evaluation of the space dose distribution in the hot-cell environments is necessary in advance in order to determine which technologies or instruments can be utilized on or near the process as the Integrated Operation Verification System (IOVS) is measured. Not like the electroreduction and electro-refining hot-cells, the head-end hot-cell equips Camera Radiation Detector (CRD) in which plutonium is securely measured and monitored for the safeguard of the pyro-processing. Results have been obtained using F2 surface tally in order to observe the magnitude of the gamma-ray and neutron flux which pass through the surface of the process cell. Furthermore, T-mesh tally has also been used to obtain the space dose distribution in the headend hot-cell. The hot-cell was divided into 7,668 cells in which each dimension was 1 x 1 x 1m for the T-mesh tally. To determine the position of the CRD and the surveillance camera, divergent approaches were required. Because the purpose of the CRD which contains a gamma-ray detector and a neutron detector is to identify the material composition as the process proceeds, the position in which detectable flux is exposed is required, whereas

  18. Distribution of E-cadherin and ß-catenin in relation to cell maturation and cell extrusion in rat and mouse small intestines

    DEFF Research Database (Denmark)

    Larsson, Lars-Inge

    2006-01-01

    of programmed cell death (PCD) in mouse small intestinal epithelium. We have studied if this also occurs in the intact rodent small intestine. Our results confirm that extruded cells are negatie for E-cadherin. However, loss of the E-cadherin-interacting protein ß-cetenin preceded both extrusion and loss of E......-cadherin. Thus, all extruded cells as well as all cells in the process of extrusion lacked staining for ß-catenin. Moreover, almost 80% of all cells undergoing programmed cell death, as detected by the TUNEL reaction, lacked ß-catenin whereas over 70% of such cells were positive for E-cadherin. However, most...... ells lacking ß-catenin did not display signs of PCD as detected by the TUNEL method or by staining for active caspase-3. Therefore, these results suggest that loss of ß-catenin precedes the onset of programmed cell death, loss of E-cadherin and extrusion from the villi....

  19. Chemistry and tensile properties of a recycled AA7050 via spray forming and ECAP/E

    Directory of Open Access Journals (Sweden)

    Alexandre Hyodo

    2012-10-01

    Full Text Available The aim of this work is to evaluate the conjugation of advanced processing techniques, such as spray forming, extrusion and ECAP as a processing route for reuse of machining chips generated during aircrafts manufacturing parts from AA7050-T7451 raw material plates supplied according to AMS 4050H¹. In this way, the sprayforming process was used for remelting, and billet production, followed by extrusion and ECAP. At the end of the process, an artificial aging according to AMS 2772E ² was conducted. An assessment of chemical composition, microstructure, and mechanical properties evolution throughout the process were performed. The results have showed that this proposed route may be used as a potential technological route for secondary aluminum source. For extrusion route for overaged condition, 144 MPa yield strength and 14% of elongation was attained. Beside this, at this stage of work, was verified that the hot extrusion process is more effective for reduction of porosity and microstructure development than ECAP, but on the other hand this one has reduced porosity dispersion significantly for the extrusion parameters adopted. The adopted homogenization schedule, followed by artificial aging after has resulted in excessive grain growth.

  20. Poly(lactic acid) (PLA) Based Tear Resistant and Biodegradable Flexible Films by Blown Film Extrusion

    OpenAIRE

    Norma Mallegni; Thanh Vu Phuong; Maria-Beatrice Coltelli; Patrizia Cinelli; Andrea Lazzeri

    2018-01-01

    Poly(lactic acid) (PLA) was melt mixed in a laboratory extruder with poly(butylene adipate-co-terephthalate) (PBAT) and poly(butylene succinate) (PBS) in the presence of polypropylene glycol di glycidyl ether (EJ400) that acted as both plasticizer and compatibilizer. The process was then scaled up in a semi-industrial extruder preparing pellets having different content of a nucleating agent (LAK). All of the formulations could be processed by blowing extrusion and the obtained films showed me...

  1. Exploring the potential of polacrilin potassium as a novel superdisintegrant in microcrystalline cellulose based pellets prepared by extrusion-spheronization

    Directory of Open Access Journals (Sweden)

    Amita K Joshi

    2011-01-01

    Full Text Available Polacrilin potassium (PP, an ion exchange resin, was used as a superdisintegrant to improve the dissolution of rifampicin, from microcrystalline cellulose (MCC based pellets prepared by extrusion-spheronization. Production of fast release pellets by extrusion-spheronization using MCC is a complicated process. In the present study, pellets were prepared containing 50% w/w rifampicin (BCS class II drug and 40% w/w MCC as extrusion-spheronization aid. Different levels of PP and lactose ratio investigated were 0:10, 2:8, 4:6, 6:4, 8:2, and 10:0. Pellets were evaluated for yield, size, size distribution, shape, porosity, friability, residual moisture, and dissolution efficiency (DE at 30 minutes. Incorporation of this novel superdisintegrant had no adverse effect on the mechanical and micromeritic characteristics of pellets. All the batches of pellets showed high yields′, ~90%; narrow particle size distribution; aspect ratio, 1.0-1.1; friability, <1%; and porosity, 45.51-49.84%. Dissolution profiles were compared using model-independent approaches; DE and similarity factor, f 2 . Addition of Polacrilin results in significant improvement in the DE of rifampicin. The dissolution profiles were significantly different from the dissolution profile of pellets formulated without PP. This preliminary study indicates that PP can serve as an effective superdisintegrant in MCC pellets prepared by extrusion-spheronization.

  2. Back extrusion of vocadlo-type fluids

    Czech Academy of Sciences Publication Activity Database

    David, Jiří; Filip, Petr; Kharlamov, Alexander

    2013-01-01

    Roč. 23, č. 4 (2013), , 45366-1-45366-8 ISSN 1430-6395 R&D Projects: GA ČR GA103/09/2066 Institutional support: RVO:67985874 Keywords : viscosity * back extrusion * annular pumping * vocadlo model * Robertson-stiff model Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.592, year: 2013 http://www.ar.ethz.ch/TMPPDF/23840225602.368/ApplRheol_23_45366.pdf

  3. The theoretical and experimental researches of Pb-Al composite materials extrusion

    Directory of Open Access Journals (Sweden)

    G. Ryzińska

    2012-07-01

    Full Text Available The work presents the analysis of the character of a simultaneous plastic flow of composite material of a hard core-soft sleeve structure. Experimental research work using model composite material Aluminium-Lead and theoretical analysis allowed to identify the initial cracking conditions, its character and localization, depending on geometrical parameters of the composite materials and the extrusion ratio value. It has been shown that the higher the parameters’ values are, the longer the flawless extruded product is (cracking appears in the further stages of the process.

  4. Preparation and Evaluation of Pellets Using Acacia and Tragacanth by Extrusion-Spheronization

    OpenAIRE

    S. Pirmoradi; M R. Abbaspour; A. Akhgari

    2011-01-01

    Background and the purpose of the study: Extrusion-spheronization is an established technique for the production of pellets for pharmaceutical applications. In this study, the feasibility and influence of the incorporation of acacia, by itself and in combination with tragacanth, on the ability of formulations containing 2 model of drugs (ibuprofen and theophylline) to form spherical pellets by extrusion-spheronization was investigated.Material and Methods: Formulations containing different ra...

  5. Laboratory evaluation of hot metal de siliconizing process in ladle; Avaliacao laboratorial do processo de dessiliciacao do gusa na panela

    Energy Technology Data Exchange (ETDEWEB)

    Passos, Sergio R.M.; Furtado, Henrique S.; Bentes, Miguel A.G.; Almeida, Pedro S. de [Companhia Siderurgica Nacional, Volta Redonda, RJ (Brazil). Centro de Pesquisas

    1996-12-31

    The attractiveness of hot metal de siliconizing in ladle, relative to the process in blast furnace runner, is the previous knowledge of silicon content of hot metal, without the constraints of slag removing by skimmer met in torpedo car, and the better efficiency in low range silicon content, making easier the process controllability. Meanwhile, the main question about this technology is the extent of the resulfurization of hot metal that may occur due to process be performed after the desulfurization. This work simulates de de siliconizing process in ladle by experiments in induction furnace to compare the efficiencies of various de siliconizing agents available at CSN iron and steel making plant, and to evaluate the resulfurization intensity able to occur during the process, as well as, unexpected increasing of refractory wear. (author) 4 refs., 8 figs., 6 tabs.

  6. The Simulation and Analysis of the Closed Die Hot Forging Process by A Computer Simulation Method

    Directory of Open Access Journals (Sweden)

    Dipakkumar Gohil

    2012-06-01

    Full Text Available The objective of this research work is to study the variation of various parameters such as stress, strain, temperature, force, etc. during the closed die hot forging process. A computer simulation modeling approach has been adopted to transform the theoretical aspects in to a computer algorithm which would be used to simulate and analyze the closed die hot forging process. For the purpose of process study, the entire deformation process has been divided in to finite number of steps appropriately and then the output values have been computed at each deformation step. The results of simulation have been graphically represented and suitable corrective measures are also recommended, if the simulation results do not agree with the theoretical values. This computer simulation approach would significantly improve the productivity and reduce the energy consumption of the overall process for the components which are manufactured by the closed die forging process and contribute towards the efforts in reducing the global warming.

  7. Root resorption after orthodontic intrusion and extrusion:.

    NARCIS (Netherlands)

    Han, G.; Huang, S.; Hoff, J.W. Von den; Zeng, X.; Kuijpers-Jagtman, A.M.

    2005-01-01

    The aim of this investigation was to compare root resorption in the same individual after application of continuous intrusive and extrusive forces. In nine patients (mean age 15.3 years), the maxillary first premolars were randomly intruded or extruded with a continuous force of 100 cN for eight

  8. Lateral extrusion of Tunisia : Contribution of Jeffara Fault (southern branch) and Petroleum Implications

    Science.gov (United States)

    Ghedhoui, R.; Deffontaines, B.; Rabia, M. C.

    2012-04-01

    Contrasting to the northward African plate motion toward Eurasia and due to its geographic position in the North African margin, since early cretaceous, Tunisia seems to be submitted to an eastward migration. The aim of this work is to study the southern branch of this inferred tectonic splay that may guide the Tunisian extrusion characterised to the east by the Mediterranean sea as a free eastern boundary. The Jeffara Fault zone (southern Tunisia), represent a case example of such deformation faced by Tunisia. Helped by the results of previous researchers (Bouaziz, 1995 ; Rabiaa, 1998 ; Touati et Rodgers, 1998 ; Sokoutis D. et al., 2000 ; Bouaziz et al., 2002 ; Jallouli et al., 2005 ; Deffontaines et al., 2008…), and new evidences developed in this study, we propose a geodynamic Tunisian east extrusion model, due to such the northern African plate migration to the Eurasian one. In this subject, structural geomorphology is undertaken herein based on both geomorphometric drainage network analysis (Deffontaines et al., 1990), the Digital Terrain Model photo-interpretation (SRTM) combined with photo-interpretation of detailed optical images (Landsat ETM+), and confirmed by field work and numerous seismic profiles at depth. All these informations were then integrated within a GIS (Geodatabase) (Deffontaines 1990 ; Deffontaines et al. 1994 ; Deffontaines, 2000 ; Slama, 2008 ; Deffontaines, 2008) and are coherent with the eastern extrusion of the Sahel block. We infer that the NW-SE Gafsa-Tozeur, which continue to the Jeffara major fault zone acting as a transtensive right lateral motion since early cretaceous is the southern branch of the Sahel block extrusion. Our structural analyses prove the presence of NW-SE right lateral en-echelon tension gashes, NW-SE aligned salt diapirs, numerous folds offsets, en-echelon folds, and so on that parallel this major NW-SE transtensive extrusion fault zone.These evidences confirm the fact that the NW-SE Jeffara faults correspond

  9. The preparation by extrusion/spheronization and the properties of pellets containing drugs, microcrystalline cellulose and glyceryl monostearate.

    Science.gov (United States)

    Chatchawalsaisin, Jittima; Podczeck, Fridrun; Newton, J Michael

    2005-01-01

    Pellets have been prepared by extrusion and spheronization containing microcrystalline cellulose (MCC) and four model drugs with decreasing order of solubility, paracetamol (P), diclofenac sodium (D), ibuprofen (IB) and indomethacin (IN) at a 10% level with and without the addition of a range of levels of glyceryl monostearate (GMS). The drugs differed in their response to extrusion in that all formulations containing the drug D had a 'steady state' extrusion profile whereas the other three drugs exhibited 'forced flow' indicating the possibility of water migration during the process of ram extrusion. The presence of GMS did not influence this effect. The drug D also required consistently less water to function than the other three drugs. In spite of these differences in extrusion performance, it was possible to prepare satisfactory pellets from formulations of all the drugs with 0, 30 and 60% GMS combined with 90, 60 or 30% of MCC at a range of water levels. It was also possible to prepare pellets containing the drug D with 70, 80 and 90% GMS, with corresponding quantities of 20, 10 and 0% of MCC. It was also possible to prepare the pellet formulations by dispersing the drugs in molten GMS, grinding and processing this with MCC and water. Such systems retained the processing characteristics of the composition made by the blending of the powder. The presence of GMS in all cases reduced the quantity of water required for the process to function. The steady state or the mean of the range of the forces observed during forced flow, were dependent on the composition and the quantity of water added. The surface of the extrudate appeared smooth and measurements of surface roughness established that the value of the rugosity R(a) for any of the extrudates did not exceed 6 microm. The extrudate diameter was found to increase with the quantity of GMS in the formulation. The pellets produced were all within a relatively narrow size range (three sieve fractions of a root two

  10. Impact of Thermomechanical Fiber Pre-Treatment Using Twin-Screw Extrusion on the Production and Properties of Renewable Binderless Coriander Fiberboards

    Science.gov (United States)

    Uitterhaegen, Evelien; Labonne, Laurent; Merah, Othmane; Talou, Thierry; Ballas, Stéphane; Véronèse, Thierry

    2017-01-01

    The aim of this study consisted of manufacturing renewable binderless fiberboards from coriander straw and a deoiled coriander press cake, thus at the same time ensuring the valorization of crop residues and process by-products. The press cake acted as a natural binder inside the boards owing to the thermoplastic behavior of its protein fraction during thermopressing. The influence of different fiber-refining methods was evaluated and it was shown that a twin-screw extrusion treatment effectively improved fiber morphology and resulted in fiberboards with enhanced performance as compared to a conventional grinding process. The best fiberboard was produced with extrusion-refined straw using a 0.4 liquid/solid (L/S) ratio and with 40% press cake addition. The water sensitivity of the boards was effectively reduced by 63% through the addition of an extrusion raw material premixing operation and thermal treatment of the panels at 200 °C, resulting in materials with good performance showing a flexural strength of 29 MPa and a thickness swelling of 24%. Produced without the use of any chemical adhesives, these fiberboards could thus present viable, sustainable alternatives for current commercial wood-based materials such as oriented strand board, particleboard and medium-density fiberboard, with high cost-effectiveness. PMID:28714928

  11. The interplay between subduction and lateral extrusion : A case study for the European Eastern Alps based on analogue models

    NARCIS (Netherlands)

    van Gelder, I. E.; Willingshofer, E.; Sokoutis, D.; Cloetingh, S. A.P.L.

    2017-01-01

    A series of analogue experiments simulating intra-continental subduction contemporaneous with lateral extrusion of the upper plate are performed to study the interference between these two processes at crustal levels and in the lithospheric mantle. The models demonstrate that intra-continental

  12. The Coupling of Back-arc Extension, Extrusion and Subduction Dynamics in the Eastern Mediterranean

    Science.gov (United States)

    Capitanio, Fabio A.

    2017-04-01

    Extension in the Aegean Sea and lateral Anatolian extrusion are contrasting and seemingly unrelated examples of continental tectonics In the Eastern Mediterranean. It is acknowledged that these must reconcile with the dynamics of Tethys closure and following continental collision along the convergent margin, however the underlying mechanisms have been difficult to pinpoint, thus far. Three-dimensional numerical modelling of the dynamics of subduction and coupling with the mantle and upper plates allows probing the evolution of similar areas, supporting inferences on the ultimate causes for the continental tectonics. I will present models that reproduce the force balance of subducting slabs' buoyancy, mantle flow and upper plate interiors, and emphasise the role of perturbations in the force balance that may have followed slab breakoff, collision and trench land-locking reconstructed during the oceanic closure in the Eastern Mediterranean. These perturbations lead to a range of different margin motions and strain regimes in the upper plate, from rollback and back-arc spreading, to indentation and extrusion along the collisional margin. Different spatial and temporal fingerprints are illustrated for these processes, and while the trench rollback and back-arc spreading are rather stable features, extrusion is transient. When these regimes overlap, rapid and complex rearrangements of the tectonics in the upper plate are the result. The remarkable similarity between the models' and the Eastern Mediterranean tectonic regimes and geophysical observable allows proposing viable driving mechanisms and support inferences on the Miocene-to-Pliocene evolution of this puzzling area.

  13. Lansoprazole induces apoptosis of breast cancer cells through inhibition of intracellular proton extrusion

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Shangrong; Wang, Yifan; Li, Shu Jie, E-mail: shujieli@nankai.edu.cn

    2014-06-13

    Highlights: • Lansoprazole (LPZ) induces cell apoptosis in breast cancer cells. • LPZ markedly inhibits intracellular proton extrusion. • LPZ induces an increase in intracellular ATP level, lysosomal alkalinization and ROS accumulation. - Abstract: The increased glycolysis and proton secretion in tumors is proposed to contribute to the proliferation and invasion of cancer cells during the process of tumorigenesis and metastasis. Here, treatment of human breast cancer cells with proton pump inhibitor (PPI) lansoprazole (LPZ) induces cell apoptosis in a dose-dependent manner. In the implantation of the MDA-MB-231 xenografts in nude mice, administration of LPZ significantly inhibits tumorigenesis and induces large-scale apopotosis of tumor cells. LPZ markedly inhibits intracellular proton extrusion, induces an increase in intracellular ATP level, lysosomal alkalinization and accumulation of reactive oxygen species (ROS) in breast cancer cells. The ROS scavenger N-acetyl-L-cysteine (NAC) and diphenyleneiodonium (DPI), a specific pharmacological inhibitor of NADPH oxidases (NOX), significantly abolish LPZ-induced ROS accumulation in breast cancer cells. Our results suggested that LPZ may be used as a new therapeutic drug for breast tumor.

  14. Lansoprazole induces apoptosis of breast cancer cells through inhibition of intracellular proton extrusion

    International Nuclear Information System (INIS)

    Zhang, Shangrong; Wang, Yifan; Li, Shu Jie

    2014-01-01

    Highlights: • Lansoprazole (LPZ) induces cell apoptosis in breast cancer cells. • LPZ markedly inhibits intracellular proton extrusion. • LPZ induces an increase in intracellular ATP level, lysosomal alkalinization and ROS accumulation. - Abstract: The increased glycolysis and proton secretion in tumors is proposed to contribute to the proliferation and invasion of cancer cells during the process of tumorigenesis and metastasis. Here, treatment of human breast cancer cells with proton pump inhibitor (PPI) lansoprazole (LPZ) induces cell apoptosis in a dose-dependent manner. In the implantation of the MDA-MB-231 xenografts in nude mice, administration of LPZ significantly inhibits tumorigenesis and induces large-scale apopotosis of tumor cells. LPZ markedly inhibits intracellular proton extrusion, induces an increase in intracellular ATP level, lysosomal alkalinization and accumulation of reactive oxygen species (ROS) in breast cancer cells. The ROS scavenger N-acetyl-L-cysteine (NAC) and diphenyleneiodonium (DPI), a specific pharmacological inhibitor of NADPH oxidases (NOX), significantly abolish LPZ-induced ROS accumulation in breast cancer cells. Our results suggested that LPZ may be used as a new therapeutic drug for breast tumor

  15. Hot deformation behavior and hot working characteristic of Nickel-base electron beam weldments

    International Nuclear Information System (INIS)

    Ning, Yongquan; Yao, Zekun; Guo, Hongzhen; Fu, M.W.

    2014-01-01

    Highlights: • The Hot deformation behavior of electron beam (EB) Nickel-base weldments was investigated. • The constitutive equation represented by temperature, strain rate and true strain was developed. • Processing map approach was adopted to optimize the hot forging process of EB weldments. • True strain has a great effect on the efficiency of power dissipation (η). -- Abstract: The electron beam welding (EBW) of Nickel-base superalloys was conducted, and the cylindrical compression specimens were machined from the central part of the electron beam (EB) weldments. The hot deformation behavior of EB weldments was investigated at the temperature of 960–1140 °C and the strain rate of 0.001–1.0 s −1 . The apparent activation energy of deformation was calculated to be 400 kJ/mol, and the constitutive equation that describes the flow stress as a function of strain rate and deformation temperature was proposed for modeling of the hot deformation process of EB weldments. The processing map approach was adopted to investigate the deformation mechanisms during the hot plastic deformation and to optimize the processing parameters of EB weldments. It is found that the true strain has a significant effect on the efficiency of power dissipation (η). The η value in the safe processing domain (1140 °C, 1.0 s −1 ) increases from 0.32 to 0.55. In the unsafe processing domain (1080 °C, 0.001 s −1 ), however, the η value greatly decreases with the increase of strain. When the strain is 0.40, the efficiency of power dissipation becomes negative. The flow instability is predicted to occur since the instability parameter ξ(ε) becomes negative. The hot deformation of EB weldments can be carried out safely in the domain with the strain rate range of 0.1–1.0 s −1 and the temperature range of 960–1140 °C. When the height reduction is about 50%, the optimum processing condition is (T opi : 1140 °C, ε opi : 1.0 s −1 ) with the peak efficiency of 0

  16. Hot deformation behavior and hot working characteristic of Nickel-base electron beam weldments

    Energy Technology Data Exchange (ETDEWEB)

    Ning, Yongquan, E-mail: ningke521@163.com [School of Materials Science and Engineering, Northwestern Polytechnical University, Xi’an 710072 (China); Yao, Zekun; Guo, Hongzhen [School of Materials Science and Engineering, Northwestern Polytechnical University, Xi’an 710072 (China); Fu, M.W. [Department of Mechanical Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong (China)

    2014-01-25

    Highlights: • The Hot deformation behavior of electron beam (EB) Nickel-base weldments was investigated. • The constitutive equation represented by temperature, strain rate and true strain was developed. • Processing map approach was adopted to optimize the hot forging process of EB weldments. • True strain has a great effect on the efficiency of power dissipation (η). -- Abstract: The electron beam welding (EBW) of Nickel-base superalloys was conducted, and the cylindrical compression specimens were machined from the central part of the electron beam (EB) weldments. The hot deformation behavior of EB weldments was investigated at the temperature of 960–1140 °C and the strain rate of 0.001–1.0 s{sup −1}. The apparent activation energy of deformation was calculated to be 400 kJ/mol, and the constitutive equation that describes the flow stress as a function of strain rate and deformation temperature was proposed for modeling of the hot deformation process of EB weldments. The processing map approach was adopted to investigate the deformation mechanisms during the hot plastic deformation and to optimize the processing parameters of EB weldments. It is found that the true strain has a significant effect on the efficiency of power dissipation (η). The η value in the safe processing domain (1140 °C, 1.0 s{sup −1}) increases from 0.32 to 0.55. In the unsafe processing domain (1080 °C, 0.001 s{sup −1}), however, the η value greatly decreases with the increase of strain. When the strain is 0.40, the efficiency of power dissipation becomes negative. The flow instability is predicted to occur since the instability parameter ξ(ε) becomes negative. The hot deformation of EB weldments can be carried out safely in the domain with the strain rate range of 0.1–1.0 s{sup −1} and the temperature range of 960–1140 °C. When the height reduction is about 50%, the optimum processing condition is (T{sub opi}: 1140 °C, ε{sub opi}: 1.0 s{sup −1}) with

  17. Machine for extrusion under vacuum; Machine de fluage sous vide

    Energy Technology Data Exchange (ETDEWEB)

    Gautier, A. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    In a study of the behaviour of easily oxidised metals during the extrusion process, it is first necessary to find an effective mean of fighting corrosion, since this, even when barely detectable, has an important influence on the validity of the results recorded. The neatest and also the most efficient of all the methods tried consists in creating a vacuum around the test piece. Working on this principle, and at the same time respecting the conventional rules for extrusion tests (loading the sample after stabilisation at the testing temperature, differential measurements of lengthening, etc.) we found it necessary to construct an original machine. (author) [French] L'etude du comportement au fluage des materiaux facilement oxydables exige, en premier lieu, une lutte efficace contre la corrosion qui, meme a peine decelable, prend une part preponderante quant a la validite des resultats enregistres. La solution la plus elegante, et, a vrai dire, la plus energique parmi toutes les methodes essayees, consiste a realiser le vide autour de l'eprouvette d'essai. Partant de ce principe, et pour sauvegarder les regles classiques de l'essai de fluage (mise en charge de l'eprouvette apres stabilisation en temperature d'essai, mesures differentielles des allongements, etc.) nous nous sommes trouves dans la necessite de construire une machine inedite. (auteur)

  18. Elasto-viscoplastic FEM simulations of the aluminium flow in the bearing area for extrusion of thin-walled sections

    NARCIS (Netherlands)

    Lof, J.

    2001-01-01

    The use of the finite element method (FEM) is getting increasingly important in the understanding of processes that occur during aluminium extrusion. The bearing area is one of the most difficult areas to model in a numerical simulation. To investigate the phenomena that occur in the bearing,

  19. Management of vaginal extrusion after tension-free vaginal tape procedure for urodynamic stress incontinence.

    Science.gov (United States)

    Giri, Subhasis K; Sil, Debasri; Narasimhulu, Girish; Flood, Hugh D; Skehan, Mark; Drumm, John

    2007-06-01

    To report our experience in the management of vaginal extrusion after the tension-free vaginal tape (TVT) procedure for urodynamic stress incontinence. Five patients diagnosed with vaginal extrusion after a TVT procedure performed at our institution were identified. We reviewed the patients' records retrospectively. The interval from TVT placement to diagnosis, presenting symptoms and signs, duration of symptoms, diagnostic test findings, treatment, and postoperative results were recorded. Patients were followed up for at least 12 months. From January 2001 to June 2004, a total of 166 patients underwent the TVT procedure. Of these, 5 patients (3%) were diagnosed with isolated vaginal extrusion 4 to 40 months postoperatively. No cases of urethral or bladder erosion occurred in this series. The symptoms included vaginal discharge, pain, bleeding, and dyspareunia. The eroded margin of the vaginal mucosa was trimmed, mobilized, and closed over the tape with interrupted vertical mattress sutures in a single layer using 2-0 polyglactin 910 to avoid mucosal inversion. All patients remained symptom free without any evidence of defective healing or additional extrusion at a minimal follow-up of 12 months. Primary reclosure of the vaginal mucosa over the TVT tape is an effective first-line treatment option for vaginal extrusion without compromising continence. Patients undergoing the TVT procedure should be adequately counseled about the possibility of this complication and the available treatment options.

  20. Hot workability of γ + α2 titanium aluminide: Development of processing map and constitutive equations

    International Nuclear Information System (INIS)

    Gupta, R.K.; Narayana Murty, S.V.S.; Pant, Bhanu; Agarwala, Vijaya; Sinha, P.P.

    2012-01-01

    Highlights: ► Deformation studies of five TiAl alloys carried out through processing map. ► DRX domain and superplastic domain identified in power efficiency map. ► Safe working zone for alloys found at 1223–1423 K at strain rates (10 −2 –10 −3 s −1 ). ► Strain rate sensitivity, activation energy, Zener Hollomon parameter (Z) are obtained. ► Constitutive equations derived and verified. DRX grain size correlated with Z. - Abstract: Gamma titanium alumindes are intermetallics, which have very narrow working range. Hot isothermal working is the most suitable process for hot working of alloy. Accordingly, hot isothermal compression test is carried out on reaction synthesized and homogenized titanium aluminide alloys at different temperatures and strain rates using Gleeble thermomechanical simulator. Three alloys of Ti48Al2Cr2Nb0.1B (atom%) have been used in the study. Stress–strain data obtained from the test has been used to construct processing map, which indicates the safe and unsafe working zone. Strain rate sensitivity and Zener–Hollomon parameter has been calculated. Further, constitutive equations have been generated and verified. It is found that alloy has good workability in the temperature range of 1223–1423 K at strain rates of 0.01–0.001 s −1 . In this range of parameters, the alloys nearly follow the constitutive equations.