WorldWideScience

Sample records for billet extrusion process

  1. Kinematics Performance and Structural Analysis for the Design of a Serial-parallel Manipulator Transferring a Billet for a Hot Extrusion Forging Process

    Directory of Open Access Journals (Sweden)

    Chu Anh My

    2015-12-01

    Full Text Available To reduce the downtime and optimize the use of energy and manpower, a serial-parallel manipulator is designed for transferring heavy billets for a hot extrusion forging station. With the purpose of increasing the structural rigidity and restricting the end-effector (a gripper so that it always moves in parallel with the ground surface, parallel links are added in between the serial links of the manipulator. This modification of the conventional structure must be considered in the modelling and analysis of the design. This paper addresses a methodology to investigate the kinematics performance and strength analysis of the designed robot. With respect to the parallel links, the constraint equation is derived and put together with the kinematical model. Based on the entire model that is formulated, the inverse kinematics, the transferring time, the reachable workspace, the degree of dexterity and the manipulability index are analysed and discussed to demonstrate its kinematical performance. In addition, to investigate the structural characteristics of the end-effector module, the static displacement and stress distributed on module's components are computed and simulated using the computer-aided finite element method (FEM. These research results are effective and useful in assessing and improving the robot’s design.

  2. OPTIMIZING AN ALUMINUM EXTRUSION PROCESS

    Directory of Open Access Journals (Sweden)

    Mohammed Ali Hajeeh

    2013-01-01

    Full Text Available Minimizing the amount of scrap generated in an aluminum extrusion process. An optimizing model is constructed in order to select the best cutting patterns of aluminum logs and billets of various sizes and shapes. The model applied to real data obtained from an existing extrusion factory in Kuwait. Results from using the suggested model provided substantial reductions in the amount of scrap generated. Using sound mathematical approaches contribute significantly in reducing waste and savings when compared to the existing non scientific techniques.

  3. Extrusion Upsetting Multiple Processing in Sandglass Die

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A new method of getting ultrafine grain size has been investigated, which is called "Extrusion Upsetting Multiple Processing in Sandglass Die" or "Sandglass Extrusion" (SE). Since the shape of tested billet can remain unchanged after SE, the billet can be extruded repeatedly in order to get large plastic strain. The ultrafine grain size can be obtained in the billet material due to the large plastic strain and the dynamic recrystallization during SE. The experiments on SE of Zn-5%Al alloy have been done. The SE technology, microstructures, microhardness and superplasticity of tested material after SE have been studied. The experimental results show that the equal-axial ultrafine microstructures can be introduced to the bulk test material during sandglass extrusion. The high strain rate superplasticity can be realized.

  4. 纯镍N6挤压坯料的高温变形行为及加工图%Hot Deformation Behavior and Processing Map of Nickel N6 from Extrusion Billet

    Institute of Scientific and Technical Information of China (English)

    莫戈; 曾攀

    2016-01-01

    目的:以来源于挤压坯料的纯镍N6作为研究对象,分析其高温压缩变形行为及微观组织演化,为挤压工艺参数设计提供有效依据。方法利用Gleeble-1500D热-力模拟试验机,对实验样品在温度900~1200℃和应变速率0.01~10 s-1范围进行热压缩变形,获得了材料真应力-真应变曲线,利用光镜观察了变形后的微观组织。结果建立了双曲正弦函数形式的本构方程,得到材料的本构参数为Q=272.77 kJ/mol,α=0.01024 MPa-1,n=4.045。基于动态材料模型建立了材料的热加工图,判断材料具有低温低应变速率和高温高应变速率2个适宜的加工区间。结论纯镍N6极易发生晶粒长大,温度和应变速率对变形组织影响显著,在变形条件为1200℃/1 s-1时,晶粒平均尺寸已经到达84.83μm。加工图失稳区间内的微观组织呈现不均匀性,为粗大变形晶粒与细小再结晶晶粒混杂的两级结构,因此在热挤压加工工艺设计中需要避开相应的参数区域。%ABSTRACT:Hot deformation behavior and microstructure evolution of nickel N6 from extrusion billet were studied to help design extrusion process. Specimens were tested at temperature range of 900~1200 ℃ and strain rate range of 0.01~10 s-1 on Gleeble-1500D thermal-mechanical testing device and true stress-strain curves were obtained. Microstructure after deformation was also studied using optical microscope. Hyperbolic-sine and Arrhenius-type constitutive model were obtained with whose parameters of Q=272.77 kJ/mol,α=0.01024 MPa-1,and n=4.045. Processing map was made using DMM model that concluded there were two regions suitable for material processing. Grain size of nickel N6 was prone to grow and significantly impacted by temperature and strain rate. When material was deformed at 1200℃/1 s-1,average grain size was up to 84.83μm. When the material was deformed,the microstructure in the region of instability exhibited in

  5. A process planning system for cold extrusion

    Directory of Open Access Journals (Sweden)

    SANTOSH KUMAR,

    2010-12-01

    Full Text Available A Process Planning system ProEx-Cold is developed for extrusion shapes to eliminate the tedious and expensive procedure of trial and correction of a proper die and the process. The system has three modules as: feature recognition, upper bound analysis and 3D graphics generation & display using OpenGL application engine. The input parameters to the proposed CAPP system includes: die type, billet TYPE & material, geometrical details of the product, ram speed,reduction, friction condition and billet condition etc. to influence parameters like production rate, extrusion ram pressure etc. C-programming, OpenGL graphics and Visual C++ editor has been used to implement ProEx-Cold.

  6. A 3D FEM simulation study on the isothermal extrusion of a 7075 aluminium billet with a predetermined non-linear temperature distribution

    Science.gov (United States)

    Li, L.; Zhou, J.; Duszczyk, J.

    2003-05-01

    In this paper, computer simulations were performed on the extrusion of 7075 aluminium billets with non-uniform temperature distributions in order to inhibit excessive temperature rise that tends to occur during the conventional extrusion of a uniformly preheated billet. The simulations showed that when a linear temperature distribution was imposed on a billet with its rear end 150°C colder than its front end, the maximum temperature of the workpiece would still increase from 450°C to over 520°C at the end of an extrusion cycle, giving rise to hot shortness. Assigning a non-linear temperature distribution during preheating the billet could however significantly lessen this undesirable temperature increase, leading to isothermal extrusion. Such a non-linear temperature distribution was determined on the basis of the results obtained from the simulation of the extrusion of a billet with a linear temperature distribution. With this predetermined non-linear temperature distribution, the maximum temperature of the workpiece remained stable near the die entrance. The radial temperature variation on the cross-section of the extrudate became less significant as the material flowed through the die. In addition, the simulations showed another advantage of isothermal extrusion, i.e. an invariable die face pressure throughout an extrusion cycle. The maximum positive (tensile) principle stress was revealed at the corner of the die orifice, indicating that tearing tended to occur there.

  7. Uniformity and continuity of effective strain in AZ91D processed by multi-pass equal channel angular extrusion

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiao-hua; LUO Shou-jing; DU Zhi-ming

    2008-01-01

    AZ91D magnesium alloy was processed by equal channel angular extrusion(ECAE). The influence of extrusion temperature, extrusion pass and extrusion route on the ultimate strength of the extruded billet was analyzed. The process of multi-pass extrusion was simulated with the method of finite element analysis, and the continuity and uniformity of effective strain in multi-pass extrusion were investigated. The results show that extrusion pass plays the most important role in improving the ultimate strength of AZ91D magnesium alloy, the extrusion route is the second, and the extrusion temperature is the last. From the numerical simulation, there exists the continuity of the accumulated deformation in multi-pass extrusion and the effective strain increases linearly. The tendency of the strain uniformity is different in multi-pass extrusion with extrusion routes. The results of experiment agree with those of numerical simulation.

  8. 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.

  9. Effects of extrusion-billet preheating on the microstructure and properties of Zr-2.5Nb pressure tube materials

    Energy Technology Data Exchange (ETDEWEB)

    Choubey, R.; Cann, C.D. [Atomic Energy of Canada Limited, Pinawa, Manitoba (Canada). Whiteshell Labs.; Aldridge, S.A. [Nu-Tech Precision Metals, Inc., Arnprior, Ontario (Canada); Theaker, J.R.; Coleman, C.E. [Atomic Energy of Canada Ltd., Chalk River, Ontario (Canada). Chalk River Labs.

    1996-12-31

    The effects of extrusion temperature and pre-heat soak time for billets on the mechanical properties of Zr-2.5Nb pressure tubes for CANDU reactors have been examined. The {beta}-quenched billets from a quadruple-melted ingot containing approximately 1,200 ppm of oxygen were extruded at 780, 815, and 850 C with pre-heat soak times of 15 to 300 min. The extruded hollows were finished by cold drawing (with a 28% reduction in area) and then stress relieving at 400 C. The {alpha}-phase grain structure, tensile strength, and fracture toughness properties were found to vary with the pre-heat temperature and soak time. All the materials were tough because embrittling impurities were absent. The tubes with 780 C preheat had a very fine and uniform {alpha}-grain structure, giving high strength and toughness at all soak times. The opposite was true for the 850 C soaks; the grain structure was coarse and inhomogeneous and the materials tended to be less strong and less touch. The tubes with the 815 C soaks showed intermediate values of strength and toughness. These variations in mechanical properties are discussed in terms of {alpha}-grain refinement and oxygen enrichment.

  10. The Effects of Process Parameters on Evolutions of Thermodynamics and Microstructures for Composite Extrusion of Magnesium Alloy

    Directory of Open Access Journals (Sweden)

    H.-J. Hu

    2013-01-01

    Full Text Available To research the effects of process parameters on evolutions of extrusion force and temperature rise and microstructures for composite extrusion of magnesium alloy which includes initial extrusion and shearing process subsequently and is shortened for “ES” in this paper, the ES extrusion process has been researched by using finite element modeling (FEM technology. The rules of temperature rise and the extrusion force varying with process parameters have been developed. The thermal-mechanical coupling finite element models including the geometric and FEM models and solution conditions were applied to calculate the effective strain and temperature and extrusion force during ES extrusion. The maximum temperature rises in the billets do not increase with billet temperature rising. The temperature of rod surface increased continuously with development of ES extrusion. The evolutions of extrusion load curve and effective stress and temperature can be divided into three stages obviously. Extrusion experiments have been constructed to validate the FEM models with different process conditions. The simulation results and microstructure observation showed that ES process can introduce compressive and accumulated shear strain into the magnesium alloy. The ES extrusion would cause severe plastic deformation and improve the dynamic recrystallization during ES extrusion. The microstructures show that ES is an efficient and inexpensive grain refinement method for magnesium alloys.

  11. Process optimization diagram based on FEM simulation for extrusion of AZ31 profile

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The ram speed and the billet temperature are the primary process variables that determine the quality of the extruded magnesium profile and the productivity of the extrusion operation.The optimization of the extrusion process concerns the interplay between these two variables in relation to the extrudate temperature and the peak extrusion pressure The 3D computer simulations were performed to determine the eriects of the ram speed and the billet temperature on the extrudate temperature and the peak extrusion pressure,thereby providing guidelines for the process optimization and minimizing the number of trial extrusion runs needed for the process optimization.A case study on the extrusion of an AZ31 X-shaped profile was conducted.The correlations between the process variables and the response from the deformed material,extrudate temperature and peak extrusion pressure,were established from the 3D FEM simulations and verified by the experiment.The research opens up a way to rational selection of the process variables for ensured quality and maximum productivity of the magnesium extrusion.

  12. Effect of Process Variables on the Formation of Streak Defects on Anodized Aluminum Extrusions: An Overview

    Science.gov (United States)

    Zhu, Hanliang; Couper, Malcolm J.; Dahle, Arne K.

    2012-04-01

    Streak defects are often present on anodized extrusions of 6xxx series aluminum alloys, increasing the fabrication cost of these products. Moreover, streaking often only becomes visible after etching and anodizing treatments, rather than in the as-extruded condition, making it difficult to identify the original causes and influencing factors of these defects. In this paper, various process variables that influence the formation of streak defects on anodized aluminium extrusions are reviewed on the basis of a literature review, industrial practice and experimental results. The influencing factors involved in various processing steps such as billet quality, extrusion process, die design and etching process are considered. Effective measures for preventing the formation of streak defects in industrial extrusion products are discussed.

  13. Control of surface temperature of an aluminum alloy billet by air flow during a heating process at elevated temperature

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Young [KITECH, Cheonan (Korea, Republic of); Park, Joon Hong [Dong-A University, Busan (Korea, Republic of)

    2016-06-15

    The procedure of semi-solid forming is composed of heating a billet, forming, compression holding and ejecting step. There are several methods to heat a billet during semi-solid forming process such as electric heating and induction heating. Usually in semi-solid forming process, induction heating has been adopted to achieve more uniform temperature of semi-solid material. Although induction heating is better method than any others, however, there is still difference of temperature between internal part and surface part of semi-solid material. Worse yet, in case of high liquid fraction of semi-solid material, liquid of the billet will flow down though solid of the billet still remains, which is very difficult to handle. In the present study, induction heating of the billet during thixoforging process with forced surface cooling has been performed to obtain more uniform distribution of temperature, microstructure and shape of the billet. Distribution of temperature of the billets was measured and compared with that of conventional distribution of temperature. Microscopic and macroscopic aspects of the billets were discussed according to location of the measuring points. By this new induction heating method, not only temperature distributions over the whole billet become uniform, but also control of temperature distribution between inside and outside part of the billet is possible as user's experimental intentions,.

  14. Effects of electromagnetic field and lubricate condition on the surface quality of magnesium alloy billet during LFEC processing

    Institute of Scientific and Technical Information of China (English)

    LE QiChi; ZHANG ZhiQiang; CUI JianZhong

    2009-01-01

    The microstructures of the magnesium billets could be improved markedly by low-frequency electro-magnetic casting (LFEC) processing. In fact, the low-frequency electromagnetic field (LFEF) also has favorite effect on the surface quality of billet. However, few public reports on the surface quality of LFEC magnesium billets could be found. Therefore, a new crystallizer with a metal internal sleeve to-gether with a kind of lubricant was designed aiming at lowing surface turning quantity, and the effects of casting velocity, electromagnetic condition and lubrication on the surface quality of magnesium billets were investigated. The results indicate that LFEF together with the lubricate condition would be responsible for the surface quality of the billets, and the high surface quality billets could be achieved by optimizing the casting conditions.

  15. Extrusion Processing of Cactus Pear

    Directory of Open Access Journals (Sweden)

    Preetam Sarkar

    2011-04-01

    Full Text Available Whole fruit utilization using extrusion technology has received limited attention in the food processing industry. The objective of this study was to investigate the utilization of prickly pear fruit solids in extruded food products. Peeled prickly pear fruits were ground to form a paste. This paste was strained to remove the seeds and then mixed with rice flour in three different solid ratios. The three blends were dried to a moisture level of 13% (w/w basis and ground to form fine flour. These feed mixes were extruded in a twin screw extruder (Clextral EV-25 at a feed rate of 15 kg/h, feed moisture content of 13% (w/w, screw speed of 400 rpm and L/D ratio of 40:1. The temperature profile from feed to die end was maintained as: 25, 30, 40, 50, 60, 70, 80, 100, 120, 140ºC. The extruded products were analyzed for physical and textural properties. Apparent density and breaking strength of the cactus pear extrudates increased from 116.07 to 229.66 kg/m3 and 58.5 to 178.63 kPa, respectively with increase in fruit solid level. However, true density, porosity and radial expansion ratio decreased from 837.89 to 775.84 kg/m3, 86.12 to 70.34% and 12.37 to 6.6, respectively with increase in fruit solid level. This study demonstrated the potential of extrusion processing to utilize peeled cactus pear fruits for production of expanded food products.

  16. Application of Hot Strength and Ductility Test to Optimization of Secondary Cooling System in Billet Continuous Casting Process

    Institute of Scientific and Technical Information of China (English)

    WANG Biao; JI Zhen-ping; LIU Wen-hong; MA Jiao-cheng; XIE Zhi

    2008-01-01

    By means of Gleeble-1500 dynamic thermomechanical simulator,the continuous casting process for HRB335C steel was simulated using solidifying method and hot ductility and strength of the steel were determined.The test results indicate that there are three temperature regions of brittleness for HRB335C billet in the temperature range from 700℃ to solidification point;the first temperature region of brittleness is 1 300℃ to solidification point of the billet,the second temperature region of brittleness is 1 200-1 000℃,and the third temperature region of brittleness is 700-850℃;the steel is plastic at 850-1 000℃.The cracking sensitivity was studied in the different temperature zones of the brittleness for steel HRB335C and the target surface temperature curve for the secondary cooling is determined.With optimized process,the mathematical model of the steady temperature field with two-dimensional heat transfer for 150 mm×150 mm HRB335C steel billet was established to optimize the secondary cooling process.The conic relation of water distribution between secondary cooling water flux and casting speed is regressed.Keeping the surface temperature of billet before the straightening point above 1 000℃,the results of billet test indicate that there is free central shrinkage cavity.The billet defect is decreased greatly,and the quality of billet is obviously improved.

  17. Effect of die shape on the metal flow pattern during direct extrusion process

    Energy Technology Data Exchange (ETDEWEB)

    Solomon, N.; Solomon, I.

    2010-07-01

    The geometric shape of the tools is the main factor by which an optimum technological process can be developed. In the case of extrusion process the strain distribution and other important variables that influence material structure, such as hydrostatic stress, are strongly dependent on the geometry of the die. Careful design of the extrusion die profile can therefore control the product structure and can be used to minimise the amount of inhomogeneity imparted into the product. A possibility to minimise the amount of product inhomogeneity is the using of a flat die with a fillet radius in front to the bearing surface with leads to a minimum dead zone and consequently to a minimum friction at billet-container interface. In the case of aluminium alloy type 2024, for an extrusion ratio of R=8.5, good results were obtained with a fillet radius of 3.0 mm. The experimental data have been used for the finite element numerical simulation of the extrusion process. The data obtained by numerical simulation with FORGE2 programme confirm the theoretical and experimental outcomes. The aim of this paper is to study the influence of such flat die on the material flow during direct extrusion process and consequently on extruded product microstructure and mechanical properties. (Author).

  18. 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.

  19. 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...

  20. Application of ANOVA and Taguchi-based Mutation Particle Swarm Algorithm for Parameters Design of Multi-hole Extrusion Process

    Directory of Open Access Journals (Sweden)

    Wen-Jong Chen

    2013-08-01

    Full Text Available This study presents the Taguchi method and the Particle Swarm Optimization (PSO technique which uses mutation (MPSO and dynamic inertia weight to determine the best ranges of process parameters (extrusion velocity, eccentricity ratio, billet temperature and friction coefficient at the die interface for a multi-hole extrusion process. A L18(21×37 array, signal-to-noise (S/N ratios and analysis of variance (ANOVA at 99% confidence level were used to indicate the optimum levels and the effect of the process parameters with consideration of mandrel eccentricity angle and exit tube bending angle. As per the Taguchi-based MPSO algorithm using DEFORMTM 3D Finite Element Analysis (FEA software, the minimum mandrel eccentricity and exit tube bending angles were respectively calculated to be 0.03°, which are significantly less than those based on Genetic Algorithm (GA and the Taguchi method, respectively. This indicates that the Taguchi-based MPSO algorithm can effectively and remarkably reduce the warp angles of Ti-6Al-4V extruded products and the billet temperature is the most influencing parameter. The results of this study can be extended to multi-hole extrusion beyond four holes and employed as a predictive tool to forecast the optimal parameters of the multi-hole extrusion process.

  1. Improved corn protein (zein) extrusion processing

    Science.gov (United States)

    Melt processing using a single and twin screw extruder has been carried out on zein where extrusion temperatures were varied between 100ºC and 300ºC. In addition, melt reprocessing (up to seven times) of zein was undertaken using a single screw extruder. Differential scanning calorimetry (DSC) and t...

  2. Extrusion instability in an aramid fibre spinning process

    NARCIS (Netherlands)

    Drost, S.

    2015-01-01

    The efficiency of polymer extrusion processes can be severely limited by the occurrence of viscoelastic extrusion instabilities. In a para-aramid fibre spinning process, for example, a μm-scale extrusion instability is responsible for the waste of tons of polymer per year. At present, a considerab

  3. Preparation of AZ91D magnesium alloy semi-solid billet by new strain induced melt activated method

    Institute of Scientific and Technical Information of China (English)

    JIANG Ju-fu; LUO Shou-jing; ZOU Jing-xiang

    2006-01-01

    New strain induced melt activated (new SIMA) method for preparing AZ91D magnesium alloy semi-solid billet is introduced by applying equal channel angular extrusion into strain induced step in SIMA method, by which semi-solid billet with fine spheroidal grains and average grain size of 18 μm can be prepared. Furthermore, average grain size of semi-solid billet is reduced with increasing extrusion pass of AZ91D magnesium alloy obtained in ECAE process. By using semi-solid billet prepared by new SIMA, thixoforged magazine plates component with high mechanical properties such as yield strength of 201.4 MPa, ultimate tensile strength of 321.8 MPa and elongation of 15.3%, can be obtained.

  4. Hydrodynamic modelling of hydrostatic magnesium extrusion

    NARCIS (Netherlands)

    Moodij, E.; Rooij, de M.B.; Schipper, D.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 th

  5. LINER FOR EXTRUSION BILLET CONTAINERS

    Science.gov (United States)

    METAL FORMING PRESSES, *DIES, *CERAMIC COATINGS, MATERIALS, REFRACTORY COATINGS, NICKEL ALLOYS, CHROMIUM ALLOYS, COBALT ALLOYS, ZIRCONIUM COMPOUNDS, STAINLESS STEEL, STEEL, MOLYBDENUM ALLOYS, HIGH TEMPERATURE, ALUMINATES .

  6. Hydrodynamic Analysis to Process of Hydrostatic Extrusion for Tungsten Alloy

    Institute of Scientific and Technical Information of China (English)

    Fuchi WANG; Zhaohui ZHANG; Shukui LI

    2001-01-01

    The hydrodynamic analysis to the process of the hydrostatic extrusion for tungsten alloy is carried through the hydrodynamic lubrication theory and Reynolds equation in this paper. The critical velocity equation when the hydrodynamic lubrication conditions appear between the surfaces of the work- piece and the die is obtained, and the relationship between the critical velocity and the extrusion parameters is discussed, which build the theoretical bases to the application of the hydrostatic extrusion for tungsten alloy.

  7. 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.

  8. Center Segregation with Final Electromagnetic Stirring in Billet Continuous Casting Process

    Science.gov (United States)

    Jiang, Dongbin; Zhu, Miaoyong

    2017-02-01

    With a multiphase solidification model built, the effect of F-EMS parameters on center segregation was investigated in 160 mm × 160 mm billet continuous casting process. In the model, the initial growth of equiaxed grains which could move freely with liquid was treated as slurry, while the coherent equiaxed zone was regarded as porous media. The results show that the stirring velocity is not the main factor influencing center segregation improvement, which is more affected by current intensity and stirring pool width. Because solute transport is controlled by solidification rate as stirring pool width is 73 mm, center segregation declines continuously with current intensity increasing. As liquid pool width decreases to 61 mm and less latent heat needs to dissipate in the later solidification, the center segregation could be improved more obviously by F-EMS. Due to center liquid solute enrichment and liquid phase accumulation in the stirring zone, center segregation turns to rise reversely with higher current intensity and becomes more serious with stirring pool width further decreasing to 43 mm. As the stirring pool width is 25 mm, the positive segregation has already formed and solute could still concentrate with weak stirring, leading to center segregation deterioration. With the optimized current intensity (400 A) and stirring pool width (61 mm) set for continuous mode, center segregation improvement is better than that of alternative mode.

  9. Rheologic behaviors of A356 aluminum alloy billet produced by semisolid continuous casting process

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    The experiments for rheologic behaviors of semisolid continuous casting billets of A356 alloy in semisolid state had been carried out with a rnultifunctional rheometer. The results show that the deformation rate increases with loading time, the maximum strain reaches to 120 % ( which is one time larger than that of traditional mold casting billet) and the strain can be rapidly elirninated to 10% after unloading. Moreover, there is a critic stress for billet deformation even in semisolid state, which is named as critic shear stress. This stress increases with the decreasing of heating time. The rheologic behaviors can be expressed by five elements mechanical model (H2 - [N1 | H2] - [N2|S] ) and can be modified with the increasing of heating time.

  10. 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.

  11. PEACH POMACE PROCESSING USING TWIN SCREW EXTRUSION

    Directory of Open Access Journals (Sweden)

    Preetam Sarkar

    2014-02-01

    Full Text Available Fruit by-products have found limited applications in the food industry. They have been primarily used as animal feed, applied to agricultural land for soil amendment or composted and applied to farms for growing crops. Some of these disposal methods are not environment friendly, while others are costly. This study was undertaken to examine the possibility of utilizing peach pomace as a source of soluble dietary fiber in expanded extruded food products. Peach pomace was combined with rice flour at four different levels. The four blends were mixed, dried to a moisture level of 13.5% (w/w and ground to flour. These blends were extruded in a twin-screw extruder (Clextral EV-25 at a feed flow rate of 15 kg/h. The extruded products were analyzed for physical and textural properties. The apparent and true densities for the extrudates decreased from 183.93 to 133.94 kg/m3 and 1275.31 to 1171.2 kg/m3, respectively. A linear increase in extrudate porosity (85.11-88.54% and radial expansion ratio (13.5-19.3 and a steady decrease in breaking strength (104-50.74 kPa were observed with increasing peach pomace level in the blends. This study demonstrates the potential of extrusion processing as a tool for fruit by-product utilization, which will not only enhance consumption of soluble dietary fiber but will also increase the overall fruit utilization.

  12. Encapsulation of orange terpenes investigating a plasticisation extrusion process.

    Science.gov (United States)

    Tackenberg, Markus W; Krauss, Ralph; Schuchmann, Heike P; Kleinebudde, Peter

    2015-01-01

    Extrusion is widely used for flavour encapsulation. However, there is a lack of process understanding. This study is aimed at improving the understanding of a counter rotating twin screw extrusion process. Orange terpenes as model flavour, maltodextrin and sucrose as matrix materials, and a water feed rate between 4.0% and 5.7% were applied. Product temperatures < 80 °C and specific mechanical energy inputs <260 Wh/kg resulted. Amorphous and partly crystalline samples were obtained. The loss of crystalline sucrose was linked to a dissolution process of the sugar in the available water amount. Melting of the excipients did not arise, resulting in a plasticisation extrusion process. Maximally 67% of the flavour was retained (corresponding to a 4.1% product flavour load). The flavour loss correlated with insufficient mixing during the process and flavour evaporation after extrusion. Based on these results, recommendations for an improved encapsulation process are given.

  13. Heat Treated AZ61 Magnesium Alloy Obtained by Direct Extrusion and Continuous Rotary Extrusion Process

    Directory of Open Access Journals (Sweden)

    Bigaj M.

    2016-03-01

    Full Text Available The results of studies carried out on the heat treated AZ61 magnesium alloy extruded by two methods, i.e. direct extrusion and continuous rotary extrusion, were presented. As part of the work, parameters of the T6 heat treatment were proposed and aging curves were plotted. The solution heat treatment process was accompanied by the grain growth. During artificial aging, due to the decomposition of solid solution, the β-Mg17Al12 phase was precipitated from the supersaturated α solution. It precipitated in a coagulated form at the grain boundaries and in the form of fine-dispersed plates arranged in a preferred direction relative to the grain orientation. Rods obtained by continuous rotary extrusion, unlike those made by the direct process, exhibited a low degree of texturing and lack of anisotropic properties.

  14. A new engineering model for understanding extrusion process

    DEFF Research Database (Denmark)

    Cheng, Hongyuan; Friis, Alan

    A new engineering method is proposed to understand extrudate expansion and extrusion operation parameters for starch based food extrusion cooking process through dimensional analysis principle, i.e. Buckingham pi theorem. Three dimensionless groups, i.e. pump efficiency, water content...... and temperature, are suggested to describe the extrudate expansion. Using the three dimensionless groups, an equation is derived to express the extrudate expansion. The model has been used to correlate the experimental data for whole wheat flour and fish feed extrusion cooking. The average deviations...

  15. Continuous extrusion and rolling forming of copper strips

    Directory of Open Access Journals (Sweden)

    Yun Xinbing

    2016-01-01

    Full Text Available Continuous extrusion and rolling technology was proposed as a new strip production technology. It conducts a hot rolling process using waste heat after continuous extrusion. The continuous extrusion and rolling forming was simulated with DEFORM-3DT. Influences of extrusion wheel velocity and rolling reduction on the continuous extrusion and rolling forming were analyzed. It was shown that as extrusion wheel velocity increases, torque of extrusion wheel, chamber force and rolling force, will drop; temperature of the billet in the area of abutment which is highest will increase. As the rolling reduction is increased, torque of the extrusion wheel and force acting on the chamber decrease, while torque and force of the rolls increase. The experimental results showed that a homogeneously distributed and equiaxed grains microstructure can be formed in copper strip billets with an average grain size of about 80 μm, after continuous extrusion. Grains of the copper strips are stretched clearly, during rolling, along the rolling direction, to form a stable orientation. Nevertheless, the grain boundaries are still relatively clear to see.

  16. STRAIN ANALYSIS OF LATERAL EXTRUSION PROCESS

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    The strain distribution of equal-cross section lateral extrusion(ECSLE) has been simulated by finite element method. Considering the effect of friction and the width of sample, the simulation results are very close to the reality. The simulated results showed that, around the corner of die, the strain is distributed by sharp layers, and the gradient of the layers is very large, which means that the deformation is just plane shear deformation; the larger the width of sample or the smaller the friction, the more uniform the strain distribution is.

  17. FEM and FVM compound numerical simulation of aluminum extrusion processes

    Institute of Scientific and Technical Information of China (English)

    周飞; 苏丹; 彭颖红; 阮雪榆

    2003-01-01

    The finite element method (FEM) and the finite volume method (FVM) numerical simulation methods have been widely used in forging industries to improve the quality of products and reduce the costs. Because of very concentrative large deformation during the aluminum extrusion processes, it is very difficult to simulate the whole forming process only by using either FEM or FVM. In order to solve this problem, an FEM and FVM compound simulation method was proposed. The theoretical equations of the compound simulation method were given and the key techniques were studied. Then, the configuration of the compound simulation system was established. The tube extrusion process was simulated successfully so as to prove the validity of this approach for aluminum extrusion processes.

  18. Dynamic globularization prediction during cogging process of large size TC11 titanium alloy billet with lamellar structure

    Institute of Scientific and Technical Information of China (English)

    Hong-wu SONG; Shi-hong ZHANG; Ming CHENG

    2014-01-01

    The flow behavior and dynamic globularization of TC11 titanium alloy during subtransus deformation are investigated through hot compression tests. A constitutive model is established based on physical-based hardening model and phenomenological softening model. And based on the recrystallization mechanisms of globularization, the Avrami type kinetics model is established for prediction of globularization fraction and globularized grain size under large strain subtransus deformation of TC11 alloy. As the preliminary application of the previous results, the cogging process of large size TC11 alloy billet is simulated. Based on subroutine development of the DEFORM software, the coupled simulation of one fire cogging process is developed. It shows that the predicted results are in good agreement with the experimental results in forging load and microstructure characteristic, which validates the reliability of the developed FEM subroutine models.

  19. 钢丝缠绕黑色金属挤压筒的设计%Design of Steel Wire Wound Extrusion Containers for Steel Hot Extrusion Process

    Institute of Scientific and Technical Information of China (English)

    刘长勇; 张磊; 林峰; 张人佶; 颜永年; 康飞宇

    2013-01-01

    挤压筒是大口径厚壁无缝钢管热挤压工艺中最为重要的模具,传统的多层组合挤压筒设计方法面临很大挑战.提出采用钢丝缠绕预紧挤压筒的方案,由于钢丝在高温下存在蠕变加速和应力松弛,将钢丝缠绕技术应用于挤压筒的最大问题是解决挤压筒预热与钢丝防护之间的矛盾.针对此矛盾,分析钢丝缠绕挤压筒设计中的关键问题包括预热、钢丝防护和预应力分布控制,提出高温钢锭内置预热和电加热预热两种设计方案,分别分析两种设计方案存在的问题、解决方法和优缺点.针对电加热预热挤压筒,提出新型的热致预应力方法来产生预紧力,将内衬和中衬预热至350℃以上,中衬和外衬之间设有隔热层,经隔热后外衬和钢丝层温度低于80℃,利用两者之间温度差而导致的热膨胀量差值来产生预紧力.基于此想法,设计制造内直径170 mm的挤压筒原理样件,通过温度测试和应力测试,表明所提出的电加热预热挤压筒可达到预期的预紧效果,为挤压筒的设计探讨一种新型的设计方法.%Extrusion container is the most important tooling in large steel tube extrusion process. Traditional design approaches such as multi-layered extrusion container would meet great challenges for large extrusion container. Steel wire wound extrusion is proposed. Due to accelerated creep behavior and stress relaxation of steel wire under high temperature, the primary difficulty of applying steel wire winding to the design of extrusion container is to solve the conflict between preheating and protection of the wire from high temperature. The key problems of wire wound containers including preheating, steel wire protection and control of prestress distribution are analyzed. Two solutions to preheating are proposed including hot billet preheating and electrical heating rods. The problems, solutions, advantages and disadvantages are discussed respectively. A

  20. Effects of process parameters and die geometry on longitudinal welds quality in aluminum porthole die extrusion process

    Institute of Scientific and Technical Information of China (English)

    LIU Jian; LIN Gao-yong; FENG Di; ZOU Yan-ming; SUN Li-ping

    2010-01-01

    By using the rigid-visco-plasticity finite element method,the welding process of aluminum porthole die extrusion to form a tube was simulated based on Deform-3D software.The welding chamber height(H),back dimension of die leg(D),process velocity and initial billet temperature were used in FE simulations so as to determine the conditions in which better longitudinal welding quality can be obtained.According to K criterion,the local welding parameters such as welding pressure,effective stress and welding path length on the welding plane are linked to longitudinal welds quality.Simulation turns out that pressure-to-effective stress ratio(p/σ)and welding path length(L)are the key factors affecting the welding quality.Higher welding chamber best and sharper die leg give better welding quality.When H=10 mm and D=0.4 mm,the longitudinal welds have the best quality.Higher process velocity decreases welds quality.The proper velocity is 10 mm/s for this simulation.In a certain range,higher temperature is beneficial to the longitudinal welds.It is found that both 450 and 465℃ can satisfy the requirements of the longitudinal welds.

  1. Effect of die shape on the metal flow pattern during direct extrusion process

    Directory of Open Access Journals (Sweden)

    Solomon, N.

    2010-10-01

    Full Text Available The geometric shape of the tools is the main factor by which an optimum technological process can be developed. In the case of extrusion process the strain distribution and other important variables that influence material structure, such as hydrostatic stress, are strongly dependent on the geometry of the die. Careful design of the extrusion die profile can therefore control the product structure and can be used to minimise the amount of inhomogeneity imparted into the product. A possibility to minimise the amount of product inhomogeneity is the using of a flat die with a fillet radius in front to the bearing surface with leads to a minimum dead zone and consequently to a minimum friction at billet-container interface. In the case of aluminium alloy type 2024, for an extrusion ratio of R=8.5, good results were obtained with a fillet radius of 3.0 mm. The experimental data have been used for the finite element numerical simulation of the extrusion process. The data obtained by numerical simulation with FORGE2 programme confirm the theoretical and experimental outcomes. The aim of this paper is to study the influence of such flat die on the material flow during direct extrusion process and consequently on extruded product microstructure and mechanical properties.La forma geométrica de las herramientas es el principal factor a través del cual un proceso óptimo de deformación plástica puede ser mejor desarrollado. En el caso del proceso de extrusión, la distribución de la deformación y otras variables importantes, como la presión hidrostática, que pueden influir en la estructura del material, son fuertemente dependientes de la geometría del molde. Mediante un diseño apropiado del perfil del molde de extrusión se pueden controlar la estructura y las propiedades mecánicas del producto y, por lo tanto, se puede utilizar para minimizar la cantidad de la no homogeneidad del producto. Una posibilidad para reducir al mínimo la cantidad de

  2. 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...... experimentally friction stress at various normal pressures, reductions in area, billet heights and lubrications. Tested materials include aluminium alloy, low carbon steel and stainless steel. Two lubrication methods are applied, conversion coating followed by either alkaline soap or molybdenum disulphide...... 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...

  3. An improved billet on billet extrusion process of continuous aluminium alloy shapes for cryogenic applications in the Compact Muon Solenoid experiment

    CERN Document Server

    Tavares, S S

    2003-01-01

    The Compact Muon Solenoid (CMS) is one of the experiments being designed in the framework of the Large Hadron Collider accelerator at CERN. CMS will contain the largest and the most powerful superconducting solenoid magnet ever built in terms of stored energy. It will work at 4.2 K, will have a magnetic length of 12.5 m, with a free bore of 6m and will be manufactured as a layered and modular structure of NbTi cables embedded in a high purity (99.998%) Al- stabiliser. Each layer consists of a wound continuous length of 2.55 km. In order to withstand the high electromagnetic forces, two external aluminium alloy reinforcing sections are foreseen. These reinforcements, of 24 mm multiplied by 18 mm cross-section, will be continuously electron beam (EB) welded to the pure Al-stabiliser. The alloy EN AW-6082 has been selected for the reinforcements due to its excellent extrudability, high strength in the precipitation hardened state, high toughness and strength at cryogenic temperatures and ready EB weldability. Ea...

  4. 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...... hydrate (nitrofurantoin), dehydration was observed at higher temperatures. To reach an understanding of the process and to find the critical process parameters, the use of complementary analytical techniques are absolutely necessary when signals from APIs and different excipients overlap each other....

  5. 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.

  6. Numerical simulation of burst defects in cold extrusion process

    Science.gov (United States)

    Labergère, C.; Lestriez, P.; Saanouni, K.

    2007-05-01

    The formation of the central bursts in axisymmetric cold extrusion is numerically simulated by using 2D finite element analysis (FEA) accounting for the mixed isotropic and kinematic hardening together with the ductile damage effect. The coupling between the ductile damage and the elastoplastic constitutive equations is formulated in the framework of the thermodynamics of irreversible processes together with the Continuum Damage Mechanics (CDM) theory. An isotropic ductile damage model is fully coupled with elastoplastic constitutive equations including non linear isotropic and kinematic hardening. A modified ductile damage criterion based on linear combination of the stress tensor invariants is used in order to predict the occurrence of micro-crack initiation as a discontinuous central bursts along the bar axis. The implicit integration scheme of the fully coupled constitutive equations and the Dynamic Explicit resolution scheme to solve the associated initial and boundary value problem are outlined. Application is made to the prediction of the chevron shaped cracks in cold extrusion of a round bar. The effect of various process parameters, as the diameter reduction ratio, the die semi-angle, the friction coefficient and the material ductility, on the central bursts occurrence are discussed.

  7. Feed extrusion process description Descrição do processo de extrusão do alimento

    Directory of Open Access Journals (Sweden)

    Galen J. Rokey

    2010-07-01

    Full Text Available The following work discusses the main features of feed extrusion process explaining the expected effects on the final product according to the raw material used as starch, protein, fat and fiber. The selection of processing equipments as feeder, preconditioner and extruder is discussed considering the involved costs and the probability of future expansion. Dryers are also essential in the extrusion process as it reduces the level of moisture in an extrusion cooked product. High moisture levels increase the water activity which favors the bacterial and mold growth so an overview of different kinds of dryers is considered. Guidelines for an economic prediction are shown to determine the potential for profit considering the input of raw material cost, energy cost and capital equipment cost as related to the extrusion module.Este trabalho aborda as principais características do processo de extrusão de alimentos, explicando os efeitos esperados no produto final, em função do tipo de componente utilizado na receita, como amido, proteínas, gorduras e fibras. O dimensionamento dos equipamentos da linha de extrusão, como silo, pré-condicionador e extrusor, é tratado considerando-se os custos envolvidos e a possibilidade de expansões futuras. Secadores também são essenciais no processo de extrusão, pois reduzem o nível de umidade do produto final. Altos níveis de umidade aumentam a atividade de água, favorecendo a proliferação de bactérias e mofo, portanto, uma visão geral de diferentes tipos de secadores é considerada. Orientações para uma previsão econômica são apresentadas para se determinar o potencial de lucro, considerando-se os custos com a matéria-prima, a energia utilizada no processo de fabricação e os equipamentos relacionados ao módulo de extrusão.

  8. 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.

  9. The positioning algorithm based on feature variance of billet character

    Science.gov (United States)

    Yi, Jiansong; Hong, Hanyu; Shi, Yu; Chen, Hongyang

    2015-12-01

    In the process of steel billets recognition on the production line, the key problem is how to determine the position of the billet from complex scenes. To solve this problem, this paper presents a positioning algorithm based on the feature variance of billet character. Using the largest intra-cluster variance recursive method based on multilevel filtering, the billet characters are segmented completely from the complex scenes. There are three rows of characters on each steel billet, we are able to determine whether the connected regions, which satisfy the condition of the feature variance, are on a straight line. Then we can accurately locate the steel billet. The experimental results demonstrated that the proposed method in this paper is competitive to other methods in positioning the characters and it also reduce the running time. The algorithm can provide a better basis for the character recognition.

  10. Visualization of the Crystallization in Foam Extrusion Process

    Science.gov (United States)

    Tabatabaei Naeini, Alireza

    In this study, crystal formation of polypropylene (PP) and poly lactic acid (PLA) in the presence of CO2 in foam extrusion process was investigated using a visualization chamber and a CCD camera. The role of pre-existing crystals on the foaming behavior of PP and PLA were studied by characterizing the foam morphology. Visualization results showed that crystals formed within the die before foaming and these crystals affect the cell nucleation behavior and expansion ratio of PP and PLA significantly. Due to the fast crystallization kinetics of PP, crystallinity should be optimum to achieve uniform cell structure with high cell density and high expansion ratio. In PLA, enhancement of crystallinity is crucial for getting foam with a high expansion ratio. It was also visualized that CO2 significantly suppresses the crystallization temperature in PP through the plasticization effect as well as its influence on flow induced crystallinity.

  11. 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...

  12. Simulation of a combustion process of a billet reheating furnace; Simulacao do processo de combustao de um forno de reaquecimento de tarugos

    Energy Technology Data Exchange (ETDEWEB)

    Goncalves, Eduardo Sergio da Silva; Barros, Jose Eduardo Mautone [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Engenharia Mecanica; Ribeiro, Vicente Aleixo Pinheiro [ArcelorMittal Monlevade, Serra, ES (Brazil); Moura Junior, Jose dos Reis Vieira de [ArcelorMittal Long Carbon Americas (Luxembourg); Belisario, Leandro Pego [Universidade Federal de Ouro Preto (UFOP), MG (Brazil)

    2010-07-01

    Real data-based energy balances with few simplifications are a powerful tool for furnaces energy performance evaluation, helping technical people to guide efforts in energy consumption issues, and consequently, in a final product cost reduction. This paper presents a methodology to simulate the combustion process in several operational conditions of a walking-hearth reheat furnace for billets in rolling mill facilities. The computational model consists, basically, in a dynamical solution which measured input variables are supplied from the furnaces supervisory and compared to measures by instruments in the system. Finally, it is made a variability analysis of the furnace and heat exchangers efficiencies.. (author)

  13. Parametric Optimization of Simulated Extrusion of Square to Square Section Through Linear Converging Die

    Science.gov (United States)

    Mohapatra, S. K.; Maity, K. P.

    2016-02-01

    The effect of various process parameters for determining extrusion load has been studied for square to square extrusion of Al-6061 alloy, a most used aluminium alloy series in forming industries. Parameters like operating temperature, friction condition, ram velocity, extrusion ratio and die length have been chosen as an input variable for the above study. Twenty five combinations of parameters were set for the investigation by considering aforementioned five parameters in five levels. The simulations have been carried out by Deform-3D software for predicting maximum load requirement for the complete extrusion process. Effective stress and strain distribution across the billet has been checked. Operating temperature, extrusion ratio, friction factor, ram velocity and die length have the significant effect in decreasing order on the maximum load requirement.

  14. Leavened dough processing by supercritical fluid extrusion (SCFX).

    Science.gov (United States)

    Hicsasmaz, Zeynep; Dogan, Esref; Chu, Cindy; Rizvi, Syed S H

    2003-10-08

    Yeast-leavened dough processing is semicontinuous due to the requirement for fermentation at constant temperature and humidity. Also, new regulations on the emission of alcohols are becoming burdensome on the baking industry. Extrusion processing of dough with supercritical carbon dioxide (SC-CO(2)) is envisioned to alleviate emission problems and to decrease production time by eliminating fermentation. A bread dough formulation with 50% (w/w) moisture was leavened by injecting 1.5% (w/w) SC-CO(2) in a twin-screw extruder at 37 degrees C. Specific mechanical energy input was 260 kJ/kg. The operating apparent shear rate range was 60-260 s(-1). SCFX-leavened dough density (420-430 kg/m(3)) was in good agreement with values reported for similar doughs. The flow behavior index, obtained by an on-line slit rheometer, was 0.49 for the nonleavened control and 0.63 for the SCFX-leavened dough. Apparent viscosity of the SCFX-leavened dough varied from 37 to 23 Pa-s. This new continuous process offers attractive possibilities for industrial applications if further developed.

  15. Applications of polymer extrusion technology to coal processing

    Science.gov (United States)

    Lewis, D. W.

    1981-01-01

    Upon heating, many of the middle-aged bituminous coals exhibit a plasticity very similar to polyethylene for a few minutes. Plastic coal can be extruded, pelletized or molded using common plastics technology and equipment. Investigations concerning the plastic state of coals are conducted with the objective to develop techniques which will make useful commercial applications of this property possible. Experiments which show the characteristics of plastic-state coal are discussed, and problems related to a continuous extrusion of coal are considered. Probably the most significant difference between the continuous extrusion of coal and the extrusion of a thermoplastic polymer is that volatiles are continuously being released from the coal. Attention is given to aspects of dragflow, solids feeding, and melt pumping. Application potentials for plastic coal extrusion might be related to coal gasification, direct liquefaction, and coal combustion.

  16. Processing and Microstructural Evolution of Superalloy Inconel 718 during Hot Tube Extrusion

    Institute of Scientific and Technical Information of China (English)

    Shihong ZHANG; Zhongtang WANG; Bing QIAO; Yi XU; Tingfeng XU

    2005-01-01

    The processing parameters of tube extrusion for superalloy Inconel 718 (IN 718), such as slug temperature, tools temperature, choice of lubricant, extrusion ratio and extrusion speed, were determined by experiment in this paper. An appropriate temperature range recommended for the slug is 1080~1120℃, and the temperature range recommended for the tools is 350~500℃. The microstructural evolution of superalloy IN 718 during tube extrusion was analyzed.With the increase of the deformation the cross crystal grains were slightly refined. While the vertical crystal grain is elongated evidently and the tensile strength increased along the axial rake. Glass lubricants have to be spread on the slug surface after being heated to 150~200℃, vegetable oil or animal oil can be used as the lubricant on the surface of the tools to reduce the extrusion force remarkably.

  17. 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...... and temperature, are formed to model the extrusion process from dimensional analysis. The model is evaluated with experimental data for extrusion of whole wheat flour and fish feed. The average deviations of the model correlations are 5.9% and 9% based on experimental data for the whole wheat flour and fish feed...

  18. Structure optimization of porthole die based on aluminum profile extrusion process numerical simulation

    Institute of Scientific and Technical Information of China (English)

    WU Xiang-hong; ZHAO Guo-qun; LUAN Yi-guo; LOU Shu-mei; MA Xin-wu

    2006-01-01

    Porthole die extrusion method is used to produce hollow aluminum profile. Due to the complexity of the porthole die structure and the material flow, it is very difficult to get ideal profile products with the firstly designed die structure. Finite volume numerical simulation was used to analyze the extrusion process of a hollow profile with porthole die and the problem of non-uniform material flow was found. Optimization was made to the originally designed die to solve the problem. Lower load, reasonable seaming location and even extruded forepart with uniform material flow in the optimized die extrusion were obtained. Guidelines to porthole die design were given and it is also concluded that finite volume method with Eulerian description avoids mesh regeneration and is suitable to numerical simulation of severe deformation processes, such as profile extrusion.

  19. Modeling and numerical simulation of multiflux die in the multilayer co-extrusion process

    Science.gov (United States)

    Mun, Jun Ho; Kim, Ju Hyeon; Mun, Sang Ho; Kim, See Jo

    2017-02-01

    It is of great importance to understand the stretching and folding mechanism in the multiflux co-extrusion die to get uniform multilayer distribution at the end of die lip in the multilayer co-extrusion processes. In this work, to understand the mechanism of the layer distribution, modeling and numerical simulation were carried out for three-dimensional flow analysis in the multilayer co-extrusion die. The multilayer flow fields were numerically visualized and analyzed on the arbitrary cross-section of the multiflux die. In addition, numerical results for the multiflux die characteristics were obtained for non-Newtonian fluids in terms of power-law index for the cross model, which will be useful for the optimal design of screw and die, simultaneously, in the multilayer co-extrusion process.

  20. Temperature Field for Improving Internal Quality of Stretched Round Billet

    Institute of Scientific and Technical Information of China (English)

    QIU Ping; XIAO Hong

    2009-01-01

    Based on the rigid-plastic theory, using a coupled thermomechanieal model, the stretching process of a cir-cular section billet is simulated by means of FEM software Deform-2D. Through the distribution of internal stress fields of stretched round billet, it is found that the shear stress field is the main factor to induce Mannesmann's effect. The simulation results show that a reasonable distribution of the temperature field may improve the internal quality of the circular section billet in the stretching process.

  1. Some physicochemical properties of dextrin produced by extrusion process

    OpenAIRE

    2014-01-01

    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 tend...

  2. Lubrication in Hot Tube Extrusion of Superalloys and Ti Alloys

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Tubular products made of superalloys and titanium alloys usually work in high temperature environment and applied heavy loading. Hot extrusion is the best technology to form tubular billets with fine microstructures and good mechanical properties. Lubrication is one of the key techniques in hot extrusion, glass lubricants are most suitable for hot extrusion. Lubrication technique in hot extrusion is dealt with in this paper, the lubrication principle of hot tube extrusion is presented. Experiments of glass lubricated backward tube extrusion of titanium alloys and forward tube extrusion of superalloys are also discussed.

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

    Science.gov (United States)

    2008-05-01

    speed of 127 mm/s and a resolution of 2.54 µm. The axes are controlled by a Delta–Tau Turbo PMAC (Programmable Multi–Axis Controller) PCI board. The...digital conversion board (Delta–Tau ACC28) with a voltage range of ±5 V converts the analog signal from the load cell into a digital signal in the PMAC ...controllers on the PMAC control board. Estimation and control algorithms for the extrusion mechanism are implemented in PLC programs, which are also

  4. Pharmaceutical approaches to preparing pelletized dosage forms using the extrusion-spheronization process.

    Science.gov (United States)

    Trivedi, Namrata R; Rajan, Maria Gerald; Johnson, James R; Shukla, Atul J

    2007-01-01

    Pelletized dosage forms date back to the 1950s, when the first product was introduced to the market. Since then, these dosage forms have gained considerable popularity because of their distinct advantages, such as ease of capsule filling because of better flow properties of the spherical pellets; enhancement of drug dissolution; ease of coating; sustained, controlled, or site-specific delivery of the drug from coated pellets; uniform packing; even distribution in the GI tract; and less GI irritation. Pelletized dosage forms can be prepared by a number of techniques, including drug layering on nonpareil sugar or microcrystalline cellulose beads, spray drying, spray congealing, rotogranulation, hot-melt extrusion, and spheronization of low melting materials or extrusion-spheronization of a wet mass. This review discusses recent developments in the pharmaceutical approaches that have been used to prepare pelletized dosage forms using the extrusion-spheronization process over the last decade. The review is divided into three parts: the first part discusses the extrusion-spheronization process, the second part discusses the effect of varying formulation and process parameters on the properties of the pellets, and the last part discusses the different approaches that have been used to prepare pelletized dosage forms using the extrusion-spheronization process.

  5. Forming of tubes and bars of alumina/LY12 composites by liquid extrusion process

    Institute of Scientific and Technical Information of China (English)

    齐乐华; 李贺军; 崔培玲; 史忠科

    2003-01-01

    Tube and bar products of aluminum alloy composites reinforced by alumina short-fiber were formed in a single process with liquid extrusion technology. The microstructure verifies that the reinforcing effect is obvious in the deformation direction since fibers are distributed along this direction, which is resulted from the flow and crystallization under pressure of liquid metal and large plastic deformation of solidified metal in the process. The interface between fiber and matrix belongs to mechanical bonding. The fractograph demonstrates ductile mode. Liquid extrusion process opens up a new way for fabricating tube, bar and shaped products.

  6. Sheets of branched poly(lactic acid) obtained by one step reactive extrusion calendering process: Melt rheology analysis

    OpenAIRE

    Cailloux, J.; Santana, O.O.; E. Franco-Urquiza; Bou, J. J.; F. Carrasco; J. Gamez-Perez; M. L. Maspoch

    2013-01-01

    One-step reactive extrusion-calendering process (REX-Calendering) was used in order to obtain sheets of 1mm from two PD,L-LA extrusion grades modified with a styrene-acrylic multifunctional oligomeric agent. In a preliminary internal mixer study, torque versus time was monitored in order to determine chain extender ratios and reaction time. Once all parameters were optimized, reactive extrusion experiments were performed. Independently of the processing method employed, under the same pro...

  7. The dimensional accuracy of the sintered billets

    Directory of Open Access Journals (Sweden)

    Чингиз Ариф оглы Алиев

    2016-01-01

    Full Text Available The article presents the results of assessing the impact of the behaviour stability of the components included in the compositions and process parameters of their production, on the dimensional accuracy of workpieces. It was found that by increasing the amount of oxide in the composition is greater compaction of the sintered billet in the process of heat treatment. This also increases the density of all components of the composition

  8. 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.

  9. FEM Analysis of Force Parameters During Hot Extrusion Expanding and Reducing Tube Process

    Institute of Scientific and Technical Information of China (English)

    WANG Fenghui; JIAO Anyuan; LI Haidong; GAO Xingqi; YANG Siqiong

    2006-01-01

    In this paper, based on the plastic forming large deformation theory and thermodynamic elastic-plastic FEM, the process of expanding and reducing tube was analyzed by using nonlinear finite element software MARC. The coupled thermal-mechanical models for the thermal-extrusion tube process were established, and the dynamic simulation to them was carried out. By the study on 3D deformation regulation of the thermal-extrusion tube, the distribution of stress,strain and the curves between the force of extrusion and the distance were obtained. As a result, with only a small quantity of necessary experiments, the select of the schemes and parameters can conveniently be performed in the computers. So, not only large numbers of experiments can be avoided, but also trial-manufacture period is consumedly shortened and some costs may be saved. In addition, in order to validate our numerical calculation, an experiment of the tube made of 20 steel is presented in this paper. Good agreement is shown between measured and predicted results of the theoretical analysis model. The study provides a scientific basis for parametric optimizations of the thermal extrusion expanding and reducing tube production equipment. At the same time, the method used in the present paper has important referential value for studying the similar thermal extrusion parts.

  10. Die Radius Affecting Sheet Metal Extrusion Quality for Fine Blanking Process

    Directory of Open Access Journals (Sweden)

    Chatkaew Suriyapha

    2010-01-01

    Full Text Available Problem statement: Sheet metal extrusion is a process in which the punch penetrates one surface of the sheet metal material to cause it to extrude and flow toward the outlet of the die. Therefore, the process can invent different thickness of sheet metal work piece. From these advantages on the sheet metal extrusion, nowadays, it is generally used in many manufacturing of industrial elements fields. The Sheet Metal Extrusions in Fine Blanking (SME-FB advantages, over a conventional extrusion, are possible due to a blank holder force, a counterpunch force and a large die radius. However, the selection on those parameter values affects on the material flow and the surface quality on the extrusion parts also. Namely, it causes the crack surface and shrinkage failure which are the general problems in the SME-FB. Approach: Objective of this research was to study the effect of die radius on the SME-FB surface which investigated the formation of the failure defection with respect to the several die radiuses by using the Finite Element Method (FEM. Results: From the results, it indicated that applying the small die radius caused the material flow difficult resulting in the decreasing of smooth surface. Vice versa, in the case of large die radius, the material flow easy is resulting in the increasing of smooth surface. Conclusion: The FEM simulation results of a larger die radius will cause the residual stress at work piece.

  11. A study on material flow in isothermal extrusion by FEM simulation

    Science.gov (United States)

    Peng, Zhi; Sheppard, Terry

    2004-09-01

    Numerous methods have been suggested or are being used to employ isothermal extrusion operation in commercial presses. The most popular methods may be broadly divided into two types: setting up a longitudinal thermal gradient in the billet or controlling the extrudate exit temperature by varying the ram speed. If the velocity gradient varies it could cause the extrusion to bend or twist, creating residual stress, and the same is true for variation in temperature. So, it is relevant to understand how the material flows through the die and ascertain how the flow pattern in isothermal extrusion differs from the normal extrusion process. In this study, with the help of previous experiments and finite element method (FEM) simulations, isothermal extrusion by two differing methodologies are investigated and discussed: the material flow pattern and the extrudate surface formation in isothermal extrusion. The extrusion force, the exit temperature, the temperature distribution in the transverse direction of the extrudate, the pressure on the tooling, the strain and strain rate distribution are also discussed to assist in the evaluation of isothermal extrusion.

  12. Thermoplastic starch/polyester films: effects of extrusion process and poly (lactic acid) addition.

    Science.gov (United States)

    Shirai, Marianne Ayumi; Olivato, Juliana Bonametti; Garcia, Patrícia Salomão; Müller, Carmen Maria Olivera; Grossmann, Maria Victória Eiras; Yamashita, Fabio

    2013-10-01

    Biodegradable films were produced using the blown extrusion method from blends that contained cassava thermoplastic starch (TPS), poly(butylene adipate-co-terephthalate) (PBAT) and poly(lactic acid) (PLA) with two different extrusion processes. The choice of extrusion process did not have a significant effect on the mechanical properties, water vapor permeability (WVP) or viscoelasticity of the films, but the addition of PLA decreased the elongation, blow-up ratio (BUR) and opacity and increased the elastic modulus, tensile strength and viscoelastic parameters of the films. The films with 20% PLA exhibited a lower WVP due to the hydrophobic nature of this polymer. Morphological analyses revealed the incompatibility between the polymers used.

  13. Replication of micro-sized pillars in polypropylene using the extrusion coating process

    DEFF Research Database (Denmark)

    Okulova, Nastasia; Johansen, Peter; Christensen, Lars

    2017-01-01

    A recent advancement in nano-pattern replication using roll-to-roll extrusion coating (R2R-EC) shows potential for many biomimetic applications. For further development of the technique a study of the micro-replication regime is carried out. In this study a full and partial replication in polypro......A recent advancement in nano-pattern replication using roll-to-roll extrusion coating (R2R-EC) shows potential for many biomimetic applications. For further development of the technique a study of the micro-replication regime is carried out. In this study a full and partial replication...... in polypropylene (PP) of micro-sized pillars has been demonstrated using the extrusion coating process. The replication fidelity of the pillars is investigated in a systematic variation of different process parameters: the line-speed of the rolls, the extruder output, the cooling roll temperature and the pressure...

  14. Using artificial neural networks to model extrusion processes for the manufacturing of polymeric micro-tubes

    Science.gov (United States)

    Mekras, N.; Artemakis, I.

    2012-09-01

    In this paper a methodology and an application example are presented aiming to show how Artificial Neural Networks (ANNs) can be used to model manufacturing processes when mathematical models are missing or are not applicable e.g. due to the micro- & nano-scaling, due to non-conventional processes, etc. Besides the ANNs methodology, the results of a Software System developed will be presented, which was used to create ANNs models for micro & nano manufacturing processes. More specifically results of a specific application example will be presented, concerning the modeling of extrusion processes for polymeric micro-tubes. ANNs models are capable for modeling manufacturing processes as far as adequate experimental and/or historical data of processes' inputs & outputs are available for their training. The POLYTUBES ANNs models have been trained and tested with experimental data records of process' inputs and outputs concerning a micro-extrusion process of polymeric micro-tubes for several materials such as: COC, PC, PET, PETG, PP and PVDF. The main ANN model of the extrusion application example has 3 inputs and 9 outputs. The inputs are: tube's inner & outer diameters, and the material density. The model outputs are 9 process parameters, which correspond to the specific inputs e.g. process temperature, die inner & outer diameters, extrusion pressure, draw speed etc. The training of the ANN model was completed, when the errors for the model's outputs, which expressed the difference between the training target values and the ANNs outputs, were minimized to acceptable levels. After the training, the micro-extrusion ANN is capable to simulate the process and can be used to calculate model's outputs, which are the process parameters for any new set of inputs. By this way a satisfactory functional approximation of the whole process is achieved. This research work has been supported by the EU FP7 NMP project POLYTUBES.

  15. 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

  16. Microstructure analysis of aluminum extrusion: grain size distribution in AA6060, AA6082 and AA7075 alloys

    Energy Technology Data Exchange (ETDEWEB)

    Schikorra, M.; Tekkaya, A. E. [Institute of Forming Technology and Lightweight Construction, Dortmund (Germany); Donate, L.; Iomesani, L. [University of Bologna, Bologna (Italy)

    2007-10-15

    Microstructure and material flow of aluminum alloys have a significant influence on the mechanical properties and surface quality. In extrusion of aluminum billets at high temperatures the microstructure is dependent on the alloy and the forming and temperature history. A prediction of grain size and precipitation is of increasing importance in order to design the process by adjustment of parameters such as punch speed, temperatures, and quenching. To give references for microstructure prediction based on material flow, and with it strain and strain rate history, this paper deals with the microstructure during the extrusion process of AA6060, AA6082, and AA7075 alloys. Billets have been partly extruded to axisymmetric round profiles and the microstructure of the press rests consisting of the billet rests in container and die has been considered. Furthermore, these rests have been analyzed to show the material flow, dynamic and static recrystallization based on macro etchings and visible microstructure under different conditions, e.g. as in the area of high strain rate near the container wall, or in dead zones. To allow an accurate simulation of the extrusion process, punch force and temperature conditions during the tests have been measured and are presented in this paper, too.

  17. Preparation of semi-solid billet of magnesium alloy and its thixoforming

    Institute of Scientific and Technical Information of China (English)

    JIANG Ju-fu; LUO Shou-jing

    2007-01-01

    Preparation of semi-solid billet of magnesium alloy and thixoforming was investigated by applying equal channel angular extrusion to magnesium alloy. The results show that mechanical properties of AZ91D alloy at room temperature, such as yield strength(YS), ultimate tensile strength(UTS) and elongation, are enhanced greatly by four-pass equal channel angular extrusion(ECAE) at 573 K and microstructure of AZ91D alloy is refined to the average grain size of 20 μm. Through using ECAE as strain induced step in SIMA and completing melt activated step by semi-solid isothermal treatment, semi-solid billet with fine spheroidal grains of 25 μm can be prepared successfully. Compared with common SIMA, thixoformed satellite angle frame components using semi-solid billet prepared by new SIMA have higher mechanical properties at room temperature and high temperature of 373 K.

  18. PRELIMINARY INVESTIGATION OF PASTA EXTRUSION PROCESS: RHEOLOGICAL CHARACTERIZATION OF SEMOLINA DOUGH

    Directory of Open Access Journals (Sweden)

    Angelo Fabbri

    2007-06-01

    Full Text Available Rheological measurements were conducted on semolina doughs. Two doughs were considered, one directly taken from an extrusion plant and another mixed in lab conditions. A rotational viscometer was used in the plate-plate configuration. Creep tests were carried on too, to verify the possibility to neglect the elastic component of strain. It was investigated the influence of the temperature on the viscous behaviour of both doughs, while only on the lab mixed dough was tested the influence of moisture content. The aim of this research is the determination of a rheological model useful for a subsequent CFD analysis of the extrusion process.

  19. 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...

  20. Food extrusion.

    Science.gov (United States)

    Harper, J M

    1978-01-01

    Extrusion processing has become an important food process in the manufacture of pasta, ready-to-eat cereals, snacks, pet foods, and textured vegetable protein (TVP). An extruder consists of tightly fitting screw rotating within a stationary barrel. Preground and conditioned ingredients enter the screw where they are conveyed, mixed, and heated by a variety of processes. The product exits the extruder through a die where it usually puffs and changes texture from the release of steam and normal forces. Mathematical models for extruder flow and torque have been found useful in describing exclusion operations. Scale-up can be facilitated by the application of these models. A variety of food extruder designs have developed. The differences and similarity of design are discussed. Pertinent literature on the extrusion of cereal/snack products, full-fat soy, TVP, pet foods (dry and semi-moist), pasta, and beverage or other food bases are discussed. In many of these applications, the extruder is a high temperature, short time process which minimizes losses in vitamins and amino acids. Color, flavor, and product shape and texture are also affected by the extrusion process. Extrusion has been widely applied in the production of nutritious foods. Emphasis is placed on the use of extrusion to denature antinutritional factors and the improvement of protein quality and digestibility.

  1. Study of Microstructure and Mechanical Properties Effects on Workpiece Quality in Sheet Metal Extrusion Process

    Directory of Open Access Journals (Sweden)

    Chatkaew Suriyapha

    2015-01-01

    Full Text Available Sheet metal extrusion is a metal forming process in which the movement of a punch penetrates a sheet metal surface and it flows through a die orifice; the extruded parts can be deflected to have an extrusion cavity and protrusion on the opposite side. Therefore, this process results in a narrow region of highly localized plastic deformation due to the formation and microstructure effect on the work piece. This research investigated the characteristics of the material-flow behavior during the formation and its effect on the microstructure of the extruded sheet metal using the finite element method (FEM. The actual parts and FEM simulation model were developed using a blank material made from AISI-1045 steel with a thickness of 5 mm; the material’s behavior was determined subject to the punch penetration depths of 20%, 40%, 60%, and 80% of the sheet thickness. The results indicated the formation and microstructure effects on the sheet metal extrusion parts and defects. Namely, when increasing penetration, narrowing the die orifice the material flows through, the material was formed by extruding, and defects were visibility, and the microstructure of the material’s grains’ size was flat and very fine. Extrusion defects were not found in the control material flow. The region of highly localized plastic deformation affected the material gain and mechanical properties. The FEM simulation results agreed with the experimental results. Moreover, FEM could be investigated as a tool to decrease the cost and time in trial and error procedures.

  2. DEPOSITION OF TiBN HARD FILMS ON HOT-WORKING-STEEL DIES FOR ALUMINIUM EXTRUSION VIA A DUPLEX PROCESS

    Institute of Scientific and Technical Information of China (English)

    K. MUller

    2001-01-01

    Hot working steels have been used as die materials for hot extrusion of aluminium.Due to tribological interaction at elevated temperature between the die bearing and thesurface of extruded aluminium profiles, not only the surface quality of the extrudedproduct, but also the lifetime of the dies decreases. Deposition of TiBN hard films onthe die bearing could improve the die performance. Treatment should be done in aduplex process process combining a plasma nitriding pretreatment (PN) and a plasmaassisted chemical vapour deposition (PACVD) of TiBN. In this study the influence ofthe process conditions on the properties of the duplex coatings was investigated. Therelationship between structure and mechanical property was researched. For testingthese TiBN hardfilms under elevated temperature conditions and for comparison withother possible coatings special extrusion dies with different coated bearings were used.The extrusion trials were performed on the 8MN-extrusion press at the research anddevelopment center for extrusion, Technical University of Berlin.

  3. 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 bill

  4. Studies in reactive extrusion processing of biodegradable polymeric materials

    Science.gov (United States)

    Balakrishnan, Sunder

    Various reaction chemistries such as Polymerization, Polymer cross-linking and Reactive grafting were investigated in twin-screw extruders. Poly (1,4-dioxan-2-one) (PPDX) was manufactured in melt by the continuous polymerization of 1,4-dioxan-2-one (PDX) monomer in a twin-screw extruder using Aluminum tri-sec butoxide (ATSB) initiator. Good and accurate control over molecular weight was obtained by controlling the ratio of monomer to initiator. A screw configuration consisting of only conveying elements was used for the polymerization. The polymerization reaction was characterized by a monomer-polymer dynamic equilibrium, above the melting temperature of the polymer, limiting the equilibrium conversion to 78-percent. Near complete (˜100-percent) conversion was obtained on co-polymerizing PDX monomer with a few mol-percent (around 8-percent) Caprolactone (CL) monomer in a twin-screw extruder using ATSB initiator. The co-polymers exhibited improved thermal stability with reduction in glass transition temperature. The extruder was modeled as an Axial Dispersed Plug Flow Reactor for the polymerization of CL monomer using Residence Time Distribution (RTD) Analysis. The model provided a good fit to the experimental RTD and conversion data. Aliphatic and aliphatic-aromatic co-polyesters, namely Polycaprolactone (PCL) and Poly butylenes (adipate-co-terephthalate) (Ecoflex) were cross-linked in a twin-screw extruder using radical initiator to form micro-gel reinforced biodegradable polyesters. Cross-linked Ecoflex was further extrusion blended with talc to form blends suitable to be blown into films. A screw configuration consisting of conveying and kneading elements was found to be effective in dispersion of the talc particles (5--10 microns) in the polyester matrix. While the rates of crystallization increased for the talc filled polyester blends, overall crystallinity reduced. Mechanical, tear and puncture properties of films made using the talc filled polyester blends

  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) with a ......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. 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.

  7. Visualization and process understanding of material behavior in the extrusion barrel during a hot-melt extrusion process using Raman spectroscopy.

    Science.gov (United States)

    Saerens, Lien; Vervaet, Chris; Remon, Jean-Paul; De Beer, Thomas

    2013-06-04

    The aim of this research was to improve understanding of material behavior in pharmaceutical hot-melt extrusion by implementing a Raman probe in each section of the barrel. Fourier-transform infrared spectroscopy measurements were performed to confirm the Raman observations. Metoprolol tartrate (MPT) concentration (10 and 40% in Eudragit RSPO), extrusion temperature (100, 120, and 140 °C), and screw speed (80 and 160 rpm) were varied to examine their influence on polymer-drug solid state throughout the barrel. When extruding a formulation with a 40% MPT concentration, the broadening of MPT peaks indicates melting of MPT between sections 2 and 3, caused by the first kneading zone. Decreasing the concentration to 10% shows an additional spectral difference (i.e., peak shifts indicating interactions between MPT and the carrier) between sections 5 and 6, due to formation of a solid solution. At a 10% MPT load, increasing the extrusion temperature does not influence the solid state or the barrel section where the final solid state is obtained. At a drug load of 40%, the solid state of the end product is reached further down the barrel when the temperature decreases. Doubling the screw speed when processing a 10% MPT formulation does not affect the solid state of the product or the location where it is obtained. In contrast, at a 40% drug load, the section where the final product is produced, is situated earlier in the barrel, when applying a higher speed. The Raman spectra provide real-time information about polymer-drug behavior throughout the barrel, facilitating process understanding and optimization.

  8. Experimental investigation and numerical simulation of plastic flow behavior during forward-backward-radial extrusion process

    OpenAIRE

    A. Farhoumand; R. Ebrahimi

    2016-01-01

    Finite element method was employed to investigate the effect of process parameters of plastic deformation behavior in Forward-Backward-Radial Extrusion (FBRE) process. The result of an axisymmetric model shows that the friction between die components and the sample has a substantial effect on the material flow behavior. Although strain heterogeneity index (SHI) slightly decreases with an increase in friction, large portion of the sample experiences significant strain heterogeneity. Increasing...

  9. Solidification Structure and Macrosegregation of Billet Continuous Casting Process with Dual Electromagnetic Stirrings in Mold and Final Stage of Solidification: A Numerical Study

    Science.gov (United States)

    Jiang, D.; Zhu, M.

    2016-12-01

    Coupling macroscale heat transfer and fluid flow with microscale grain nucleation and crystal growth, a mixed columnar-equiaxed solidification model was established to study the SWRT82B steel solidification structure and macrosegregation in 160 mm × 160 mm billet continuous casting with dual electromagnetic stirrings in mold and final stage of solidification (M-EMS and F-EMS). In the model, the phases of liquid, columnar, and equiaxed were treated separately and the initial growing equiaxed phase, which could move freely with liquid, was regarded as slurry. To obtain the equiaxed grains nucleation and columnar front evolution, the unit tracking method and the columnar front tracking model were built. The model was validated by magnetic induction intensity of stirrer, billet surface temperature, and carbon segregation. The equiaxed phase evolution and the solute transport with effect of fluid flow and grains transport were described in this article. The results show that the equiaxed phase ratio will not increase obviously with higher current intensity of M-EMS, while the negative segregation near the strand surface becomes more serious. The negative segregation zone near the billet center and the center positive segregation come into being with the effect of equiaxed grains sedimentation and liquid thermosolutal flow. It is also found that the liquid solute transport in the F-EMS zone becomes the main factor with higher current intensity rather than the solidification rate, and therefore, the final billet center segregation decreases first and then turns to rise with the current intensity. The optimal current intensities of M-EMS and F-EMS proposed for SWRT82B billet continuous casting are 200 and 400 A, respectively.

  10. Solidification Structure and Macrosegregation of Billet Continuous Casting Process with Dual Electromagnetic Stirrings in Mold and Final Stage of Solidification: A Numerical Study

    Science.gov (United States)

    Jiang, D.; Zhu, M.

    2016-08-01

    Coupling macroscale heat transfer and fluid flow with microscale grain nucleation and crystal growth, a mixed columnar-equiaxed solidification model was established to study the SWRT82B steel solidification structure and macrosegregation in 160 mm × 160 mm billet continuous casting with dual electromagnetic stirrings in mold and final stage of solidification (M-EMS and F-EMS). In the model, the phases of liquid, columnar, and equiaxed were treated separately and the initial growing equiaxed phase, which could move freely with liquid, was regarded as slurry. To obtain the equiaxed grains nucleation and columnar front evolution, the unit tracking method and the columnar front tracking model were built. The model was validated by magnetic induction intensity of stirrer, billet surface temperature, and carbon segregation. The equiaxed phase evolution and the solute transport with effect of fluid flow and grains transport were described in this article. The results show that the equiaxed phase ratio will not increase obviously with higher current intensity of M-EMS, while the negative segregation near the strand surface becomes more serious. The negative segregation zone near the billet center and the center positive segregation come into being with the effect of equiaxed grains sedimentation and liquid thermosolutal flow. It is also found that the liquid solute transport in the F-EMS zone becomes the main factor with higher current intensity rather than the solidification rate, and therefore, the final billet center segregation decreases first and then turns to rise with the current intensity. The optimal current intensities of M-EMS and F-EMS proposed for SWRT82B billet continuous casting are 200 and 400 A, respectively.

  11. A process planning system with feature based neural network search strategy for aluminum extrusion die manufacturing

    CERN Document Server

    Butdee, S; Tichkiewitch, Serge

    2009-01-01

    Aluminum extrusion die manufacturing is a critical task for productive improvement and increasing potential of competition in aluminum extrusion industry. It causes to meet the efficiency not only consistent quality but also time and production cost reduction. Die manufacturing consists first of die design and process planning in order to make a die for extruding the customer's requirement products. The efficiency of die design and process planning are based on the knowledge and experience of die design and die manufacturer experts. This knowledge has been formulated into a computer system called the knowledge-based system. It can be reused to support a new die design and process planning. Such knowledge can be extracted directly from die geometry which is composed of die features. These features are stored in die feature library to be prepared for producing a new die manufacturing. Die geometry is defined according to the characteristics of the profile so we can reuse die features from the previous similar p...

  12. 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

    2016-12-01

    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.

  13. 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.

  14. 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

  15. 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.

  16. ENERGY EFFICIENCY IN CUTTING PROCESS OF COMPONENT BILLET SURFACE ON ANALYSIS BASIS FOR ENERGY-CONSUMPTION INDICES OF TECHNOLOGICAL EQUIPMENT

    Directory of Open Access Journals (Sweden)

    V. Adamenko

    2012-01-01

    Full Text Available The paper contains investigation results and proposes a method for calculation of optimum cutting rate. The method takes into account energy-consumption indices of technological equipment that permits to improve technological energy efficiency of cutting process.

  17. Dynamic Water Modeling and Application of Billet Continuous Casting

    Institute of Scientific and Technical Information of China (English)

    LIU Wen-hong; XIE Zhi; JI Zhen-ping; WANG Biao; LAI Zhao-yi; JIA Guang-lin

    2008-01-01

    The continuous casting process is used for solidifying molten steel into semi-finished steel. The technology of secondary cooling is extremely important for output of the casting machine and billet quality. A dynamic water model was introduced, including solidification model in the secondary cooling, feedforward control strategy based on continuous temperature measurement in tundish, and feedback control strategy based on surface temperature measurement. The mathematical model of solidification process was developed according to the principle of solidification, and the solidification model was validated by measuring billet shell thickness through shooting nail and sulfur print. Primary water distribution was calculated by the solidification model according to procedure parameters, and it was adjusted by the other two control strategies online. The model was applied on some caster and billet quality was obviously improved, indicating that the dynamic water model is better than conventional ones.

  18. 3D FE Analysis of Thermal Behavior of Billet in Rod and Wire Hot Continuous Rolling Process

    Institute of Scientific and Technical Information of China (English)

    YUAN Si-yu; ZHANG Li-wen; LIAO Shu-lun; QI Min; ZHEN Yu; GUO Shu-qi

    2007-01-01

    An FE model was developed to study thermal behavior during the rod and wire hot continuous rolling process. The FE code MSC.Marc was used in the simulation using implicit static arithmetic. The whole rolling process of 30 passes was separated and simulated with several continuous 3D elastic-plastic FE models. A rigid pushing body and a data transfer technique were introduced into this model. The on-line experiments were conducted on 304 stainless steel and GCr15 steel hot continuous rolling process to prove the results of simulation by implicit static FEM. The results show that the temperature results of finite element simulations are in good agreement with experiments, which indicate that the FE model developed in this study is effective and efficient.

  19. RESOURCE-SAVING TECHNOLOGY FOR HIGH-SPEED HOT EXTRUSION OF BIMETALLIC ROD PARTS

    Directory of Open Access Journals (Sweden)

    I. V. Kachanov

    2016-01-01

    Full Text Available Processes of high-speed shaping changes and especially high-speed hot extrusion create efficient conditions for treatment of weakly plastic and poorly deformable materials which are widely used in tool making facilities. Due to the fact that high-speed stamping provides accurate billets with increased mechanical properties, it can be used as a technological process for manufacturing rod parts of die tooling operating under conditions of increased loads and wear. The purpose of the given paper is to carry out experimental investigations on the possibility to obtain a bimetallic rod tool where structural steel is considered as a basis of the tool and a working cavity is made of high-alloyed tool steel with its saving up to 90 %. A scheme of loading and geometry of conjugated surfaces of the composite billet have been developed in the paper. Technology for obtaining bimetallic rod parts of die tooling with deformation at speed of vд = 70–80 m/s and composite billet temperature of Т = (1150±20 ºС has been experimentally tested with formation of a compound due to plastic flow of two billet parts on contact surface with removal of surface oxide films. Microstructures of the bimetallic compounds obtained with the help of high-speed hot extrusion method for compositions of structural and high-alloy steels have been investigated and their high quality has been proved during the investigations. Dependences of micro-hardness distribution have been established outbound two steel contact plane in the zone of connection that are characterized by a minimum micro-hardness value in the connection joint. Availability of more plastic zone in the contact plane contributes to reduction of residual stresses due to their relaxation in this zone and higher joint strength.

  20. The effect of extrusion processing on the physiochemical properties of extruded orange pomace.

    Science.gov (United States)

    Huang, Ya-Ling; Ma, Ya-Sheng

    2016-02-01

    Soluble dietary fibre (SDF) is considered the most effective fraction of dietary fibre (DF) for human health. In this study, extrusion technology was applied to enhance the SDF obtained from orange pomace, a byproduct of juice extraction containing a high level of DF. The pomace was processed in a single-screw extruder at various barrel temperatures (X1; 115-135 °C), feed moistures (X2; 10-18 g/100g), and screw speeds (X3; 230-350 rpm). Based on response surface methodology, the optimum extrusion conditions, which produced a maximum SDF value of 30.36%, were as follows: barrel temperature, 129 °C; feed moisture, 15%; and screw speed, 299 rpm. Compared with unextruded pomace, SDF fraction in extrudate had a higher level of uronic acid. Furthermore, the extrusion process improved the physicochemical properties of extrudate, increasing the water-holding capacity, swelling, water solubility index, and cation-exchange capacity and decreasing the oil-holding capacity.

  1. Numerical Simulation on Process of Hydrostatic Extrusion for Tungsten Alloy through Concave Dies with Equal-strain Contour Lines

    Institute of Scientific and Technical Information of China (English)

    Zhaohui ZHANG; Fuchi WANG

    2001-01-01

    The numerical simulation to the process of hydrostatic extrusion for tungsten alloy through the concave dies with the equal-strain contour lines was carried out in this paper by the large deformation and elasto-plastic finite theory and ANSYS software. Both the pressure in the process of extrusion and the stress-strain distribution in the sample were analyzed, which founds a basis to the engineering application.

  2. EXPERIMENTS AND SIMULATIONS OF A NEW DEVELOPED FORMING TECHNOLOGY-SHEAR-EXTRUSION PROCESS OF COMPONENTS WITH BRANCHES

    Institute of Scientific and Technical Information of China (English)

    H.L. Yang; D.C. Kang; Z.L. Zhang; X.H. Piao; Z.D. Shi

    2001-01-01

    Shear-extrusion process and its forming parameters are proposed, whilst its laborsae ing characteristic is utilized to forge large-size shutoff valve body on middle-due pre ss.This new process is intended for the manufacture of large-size forged tubular components with branches on middle-due press. Experiments are carried out and proeessing parameters are obtained regarding the shear-extrusion process of a large-size shutoff valve body. Deformation and metal flow in the shear-extrnsion process are investigated. In order to verify the laborsaving characteristic of this new procss some contrastive experiments of extrusion foree are performed between shear-extrusion and upsetting-extrusion for forming tubular components with branches. Based on rigidplastic FEM a plane-strain model is established to analyze shear-extrusion process of tubular components with branches. The analysis results by 2-dimensions FEM are comparatively quite well consistent with those of experiments. Both simulated anl etperimental results show that this new forming process is feasible for forging large-size tubular components with branches on middle-due press.

  3. Influence of macromolecular architecture on necking in polymer extrusion film casting process

    Energy Technology Data Exchange (ETDEWEB)

    Pol, Harshawardhan; Banik, Sourya; Azad, Lal Busher; Doshi, Pankaj; Lele, Ashish [CSIR-National Chemical Laboratory, Pune, Maharashtra (India); Thete, Sumeet [Purdue University, West Lafayette, Indiana (United States)

    2015-05-22

    Extrusion film casting (EFC) is an important polymer processing technique that is used to produce several thousand tons of polymer films/coatings on an industrial scale. In this research, we are interested in understanding quantitatively how macromolecular chain architecture (for example long chain branching (LCB) or molecular weight distribution (MWD or PDI)) influences the necking and thickness distribution of extrusion cast films. We have used different polymer resins of linear and branched molecular architecture to produce extrusion cast films under controlled experimental conditions. The necking profiles of the films were imaged and the velocity profiles during EFC were monitored using particle tracking velocimetry (PTV) technique. Additionally, the temperature profiles were captured using an IR thermography and thickness profiles were calculated. The experimental results are compared with predictions of one-dimensional flow model of Silagy et al{sup 1} wherein the polymer resin rheology is modeled using molecular constitutive equations such as the Rolie-Poly (RP) and extended Pom Pom (XPP). We demonstrate that the 1-D flow model containing the molecular constitutive equations provides new insights into the role of macromolecular chain architecture on film necking.{sup 1}D. Silagy, Y. Demay, and J-F. Agassant, Polym. Eng. Sci., 36, 2614 (1996)

  4. Solute distribution in columnar crystal zone of continuous casting billets

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The periodic bending deformation in the direction of casting occurs at the liquid/solid interface of billet due to the roller supporting force and the pressure of molten metal in the process of continuous casting. Based on this fact, a qualitative expression of solute concentration in columnar crystal zone for continuous casting billet is established, which agrees with the experimental results basically. Therefore, it is favorable to gain a columnar structure with less segregation by adopting a caster with compactly distributed small rollers and enhancing the cooling intensity in secondary-cooling zone.

  5. Meltlets® of soy isoflavones: Process optimization and the effect of extrusion spheronization process parameters on antioxidant activity

    Directory of Open Access Journals (Sweden)

    Ketkee Deshmukh

    2013-01-01

    Full Text Available 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.

  6. Fractal characteristics of surface crack evolution in the process of gas-containing coal extrusion

    Institute of Scientific and Technical Information of China (English)

    Chen Peng; Wang Enyuan; Ou Jianchun; Li Zhonghui; Wei Mingyao; Li Xuelong

    2013-01-01

    In this paper,simulated experiment device of coal and gas outburst was employed to perform the experiment on gas-containing coal extrusion.In the experiment,coal surface cracks were observed with a highspeed camera and then the images were processed by sketch.Based on the above description,the paper studied the fractal dimension values from different positions of coal surface as well as their changing laws with time.The results show that there is a growing parabola treen of crack dimension value in the process of coal extrusion.Accordingly,we drew the conclusion that extruded coal crack evolution is a process of fractal dimension value increase.On the basis of factal dimension values taken from different parts of coal masses,a fractal dimension of the contour map was drawn.Thus,it is clear that the contour map involves different crack fractal dimension values from different positions.To be specific,where there are complicated force and violent movement In coal mass,there are higher fractal dimension values,i.e.,the further the middle of observation surface is from the exit of coal mass,and the lower the fractal dimension value is.In line with fractal geometry and energy theory of coal and gas outburst,this study presents the relation between fractal dimension and energy in the process of extruding.In conclusion,the evolution of crack fractal dimension value can signify that of energy,which has laid a solid foundation for the quantification research on the mechanism of gas-containing coal extrusion.

  7. 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.

  8. Sheets of branched poly(lactic acid obtained by one step reactive extrusion calendering process: Melt rheology analysis

    Directory of Open Access Journals (Sweden)

    J. Cailloux

    2013-03-01

    Full Text Available One-step reactive extrusion-calendering process (REX-Calendering was used in order to obtain sheets of 1mm from two PD,L-LA extrusion grades modified with a styrene-acrylic multifunctional oligomeric agent. In a preliminary internal mixer study, torque versus time was monitored in order to determine chain extender ratios and reaction time. Once all parameters were optimized, reactive extrusion experiments were performed. Independently of the processing method employed, under the same processing conditions, PD,L-LA with the lower D enantiomer molar content revealed a higher reactivity towards the reactive agent, induced by its higher thermal sensitivity. REXCalendering process seemed to minimize the degradations reactions during processing, although a competition between degradation and chain extension/branching reactions took place in both processes. Finally, the rheological characterization revealed a higher degree of modification in the melt rheological behaviour for REX-Calendered samples.

  9. THE STUDY OF PATTERNS OF PRE-EXTRUSION PREPARATION OIL CULTURES TO THE PRESSING PROCESS

    Directory of Open Access Journals (Sweden)

    L. N. Frolova

    2015-01-01

    Full Text Available One of the most promising oil crops in the Russian Federation is saffron. Camelina seeds contain from 26 to 46% oil, which is different from other oils rich in cruciferous gondoinic, linolenic and linoleic acids, and relatively low erucic acid, has a high content of the biologically active substances (sterols, carotenes and carotenoids, chlorophylls and tocopherols. The main task in the processing of oilseeds is the maximum extraction of oil with a high quality of the products obtained: unrefined oil, cake and meal. In conventional technology of oil, the raw material is subjected to repeated heating significantly. Proposed the following processing flow chart: camelina seeds were subjected to moisture-heat treatment beforehand in an extruder, and then hot-pressed to a screw press a single action, so that the oil content of the cake after pressing was 17-19%. When using an extrusion process is suppressed anti-nutritional properties contained in the seeds of camelina. Found that the oil obtained after the preliminary preparation of the extrusion as compared with the oil produced by traditional technology, comprises more tocopherols, phospholipids less chlorophyll, free fatty acids and peroxides. Thus, it has a longer shelf life, has good fluidity, easily refined.

  10. Development of Replacements for Phoscoating Used in Forging, Extrusion and Metal Forming Processes

    Energy Technology Data Exchange (ETDEWEB)

    Kerry Barnett

    2003-03-01

    Many forging, extrusion, heading and other metal forming processes use graphite-based lubricants, phosphate coatings, and other potentially hazardous or harmful substances to improve the tribology of the metal forming process. The application of phosphate-based coatings has long been studied to determine if other synthetic ''clean'' lubricants could provide the same degree of protection afforded by phoscoatings and its formulations. So far, none meets the cost and performance objectives provided by phoscoatings as a general aid to the metal forming industry. In as much as phoscoatings and graphite have replaced lead-based lubricants, the metal forming industry has had previous experience with a legislated requirement to change processes. However, without a proactive approach to phoscoating replacement, many metal forming processes could find themselves without a cost effective tribology material necessary for the metal forming process

  11. Spray deposition for making large size billet with swing atomizer

    Institute of Scientific and Technical Information of China (English)

    LI Jian-ping; LIU Tao; TANG Qing-yun; HAN Lei; ZHONG Jue

    2008-01-01

    The movement mode of the atomizer is a very important parameter during spray deposition process, which has direct influence on the size and surface texture of the billets. To resolve the problem of manufacturing large size billets, a method of spray deposition by the atomizer with off-center swing was put forward. The atomizer was driven by the alternating current servomotor to swing within 7° at varying speed. The influence of the atomizer parameters, such as translation of the atomizer, swing angle of the atomizer, substrate falling speed and spraying pressure, on the spray deposition was studied. The optimized parameters of the spray deposition process were obtained. The results show that the large size billets with uniform surface quality can be made through adjusting swing frequency and angle of the atomizer, offset distance of the atomizer and inclined angle of the substrate; the valid spray area will decrease and the dimension of top surface will reduce when pressure is less than 0.4 MPa within certain spray distance; meantime, the moving time and cooling time of the droplets are extended, which will lead to loose structure and bad densification. When the pressure, the swing angle and the eccentric offset of the atomization equal 0.5MPa, 7° and 60mm,respectively, large size billets with fine texture and diameter of 500mm can be produced.

  12. 昆钢70高碳钢炼钢工艺优化及铸坯质量分析%Research of billet quality and optimization of steel-making process for 70 high-carbon steel in KISC

    Institute of Scientific and Technical Information of China (English)

    张卫强; 陈伟; 李金柱

    2012-01-01

    To improve quality of product the steel making process of 70 high-carbon steel in KISC is optimized and improved and the macrostructure and index of central carbon segregation in the billet are analyzed by sampling. In the meanwhile inclusions in the billet are researched by using large sample electrolysis, scanning electron microscopy and spectroscopy test. The results show that quality of billet is improved significantly after process optimization, defect level of macrostructure for the most 71) high-carbon steel bil- lets is less than 0. 5 grade,ratio of equiaxed zone for the billet is more than 40 % ;index of central carbon segregation in billet is decreased from 1.06 to 1.03 and segregation of chemical compositions is small. The total amount of inclusions in 10 kg large sample e- lectrolysis is reduced from 28.95 mg to 9.78 mg and the inclusions are mainly composed of SiO2-A1203-CaO and SiO2-MnO-A1203 with low melting point and good plastic. The drawing break ratio of wire rod in one hundred tons is decreased from 7. 5 times to 4. 9 times and the drawing performance of wire rod is improved obviously.%为改善产品质量,武钢集团昆明钢铁股份有限公司对70钢炼钢工艺进行了优化改进,对铸坯取样进行了低倍组织、中心碳偏析检验分析,对夹杂物进行了大样电解、扫描电镜及能谱检验分析。结果表明:工艺优化后,70高碳硬线钢铸坯质量显著改善,低倍组织大部份缺陷级别不大于0.5级,铸坯中心等轴晶面积比率大于40%;铸坯中心碳偏析指数由1.06降至1.03,成分偏析减小;111kg铸坯大样电解夹杂物总量由28.95g降至9.78mg,夹杂物以低熔点的锰铝榴石、硅铝酸钙塑性夹杂为主;盘条拉拔断丝率南每百吨7.5次降至4.9次,拉拔性能显著改善。

  13. 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.

  14. TECHNOLOGY FOR OBTAINING BIMETALLIC SHAPING PARTS OF DIE TOOLING USING METHOD OF HIGH-SPEED HOT EXTRUSION

    Directory of Open Access Journals (Sweden)

    I. V. Kachanov

    2014-01-01

    Full Text Available Processes of high-speed shaping changes and especially high-speed hot extrusion create efficient conditions for treatment of weakly plastic and poorly deformable materials which are widely used in tool making facilities. Due to the fact that high-speed stamping provides accurate billets with increased mechanical properties, it can be used as a technological process for manufacturing shaping parts of die tooling parts operating which are subjected to increased loads and wear.The purpose of the paper is to carry out experimental investigations on the possibility to obtain a bimetallic tool where structural steel is considered as a basis of the tool and a working cavity is made of high-alloyed tool steel with its saving up to 90 %. A scheme of loading and geometry of conjugated surfaces of the composite billet have been developed in the paper. Technology for obtaining bimetallic shaping parts of die tooling with deformation at speed of vR = 40-50 m/s and composite billet temperature of T = 1150 °C has been experimentally tested with formation of a compound due to plastic flow of two billet parts on contact surface with removal of surface oxide films.Microstructures of the bimetallic compounds obtained with the help of high-speed hot extrusion method for compositions of structural and high-alloy steels have been investigated and their high quality has been proved during the investigations. Dependences of micro-hardness distribution have been established outbound two- steel contact plane in the zone of connection that are characterized by a minimum micro-hardness value in the connection joint. Availability of more plastic zone in the contact plane contributes to reduction of residual stresses due to their relaxation in this zone and higher joint strength.

  15. [Chemical and nutritional changes during preparation of whole corn tortillas prepared with instant flour obtained by extrusion process].

    Science.gov (United States)

    Gómez Aldapa, C A; Martínez Bustos, F; Figueroa Cárdenas, J D; Ordorica Falomir, C A; González Hernández, J

    1996-12-01

    Chemical changes of some nutritional components (protein, total dietary fiber, vitamins, lysine, tryptophan, ether extract and fatty acids) of tortillas made from instant whole corn flour prepared by extrusion process (CINVESTAV process) were evaluated. The tortillas prepared by extrusion process were compared with tortillas made by traditional process and raw corn. The protein content of tortillas from both processes were statistically similar to those of the raw corn, although the traditional tortillas showed the lowest actual values. Tortillas from traditional process contained the lowest amount of total dietary fiber and available lysine. The loss of protein, crude fiber, total dietary fiber, available lysine, tryptophan, and vitamin contents during traditional tortillas process, was attributable to the partial loss of pericarp, aleurone and germ tissue during the process. Tortillas prepared by both processes showed loss of vitamins. The thermal treatment in both processes (traditional and extrusion) decreased the ether extract and fatty acids contents. Tortillas prepared by extrusion process showed better nutritional characteristics than traditional tortillas prepared by nixtamalization process.

  16. Obtaining Ready-to-Eat Blue Corn Expanded Snacks with Anthocyanins Using an Extrusion Process and Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Anayansi Escalante-Aburto

    2014-12-01

    Full Text Available Extrusion is an alternative technology for the production of nixtamalized products. The aim of this study was to obtain an expanded nixtamalized snack with whole blue corn and using the extrusion process, to preserve the highest possible total anthocyanin content, intense blue/purple coloration (color b and the highest expansion index. A central composite experimental design was used. The extrusion process factors were: feed moisture (FM, 15%–23%, calcium hydroxide concentration (CHC, 0%–0.25% and final extruder temperature (T, 110–150 °C. The chemical and physical properties evaluated in the extrudates were moisture content (MC, %, total anthocyanins (TA, mg·kg−1, pH, color (L, a, b and expansion index (EI. ANOVA and surface response methodology were applied to evaluate the effects of the extrusion factors. FM and T significantly affected the response variables. An optimization step was performed by overlaying three contour plots to predict the best combination region. The extrudates were obtained under the following optimum factors: FM (% = 16.94, CHC (% = 0.095 and T (°C = 141.89. The predicted extrusion processing factors were highly accurate, yielding an expanded nixtamalized snack with 158.87 mg·kg−1 TA (estimated: 160 mg·kg−1, an EI of 3.19 (estimated: 2.66, and color parameter b of −0.44 (estimated: 0.10.

  17. 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

  18. The Effect of Paraffinic Mineral Oil Lubrication in Cold Forward Extrusion

    Directory of Open Access Journals (Sweden)

    Mohd Hafis - Sulaiman

    2011-09-01

    Full Text Available This paper presents the results of cold forward extrusion modelling and the analysis of the contact sliding behaviour on the die-billet surface by paraffinic mineral oil lubrication with kinematic viscosity of 92 mm2/s at 40 °C. The analysis dealt with the plasticity flow that was investigated by finite element method in order to identify the loads acting on the billet. The finite element analysis of stresses was performed based on load distributions calculated from experimental test. The time behaviour of the displacements on the billet was then used as inputs for the extrusion model. The present method provided good results with reduced computation time. The results of the extrusion model revealed that the zones of high stress situated at the sharp edges of the die, which explains the observed extrusion force to reach a peak value.

  19. Formation of integral fins function-surface by extrusion-ploughing process

    Institute of Scientific and Technical Information of China (English)

    CHEN Ping; TANG Yong; LIU Xiao-kang; LIU Xiao-qing

    2006-01-01

    An extrusion-ploughing process was presented to fabricate the integral fin function-surface. Cutting edge inclination angle and rake angle can be calculated from the tool's geometry relationship. The description of fins' geometry characters was standardized. The experiments show that, when the middle cutting edge's inclination angle η is less than 35-, continuous fin will come out; when η is between 35- and 55-, the fins will be saw-tooth ones, and the fins will be torn when this angle is above 55-; when the extrusion angle θ is between 60- and 150-, the fins will appear, or else, the fins will be torn into chips from the base. Forming angle and clearance angle have little effect on fin's formation. For continuous fin, its height is close to cutting depth when it is small, but it will become approximately constant as cutting depth grows; for saw-tooth fins, the width, the height, as well as the clearance will increase with the increase of cutting depth, but the increment of clearance is small; neither for continuous fin, nor for saw-tooth ones, cutting velocity has little influence on their structure parameters.

  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.

  1. 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.

  2. Processing of low Carbon steel by dual rolls equal channel extrusion

    Science.gov (United States)

    Rusz, S.; Cizek, L.; Salajka, M.; Kedron, J.; Tylsar, S.

    2014-08-01

    This paper introduces a new method of forming for achievement of grain structure refinement by processing in DRECE (Dual Rolls Equal Channel Extrusion) equipment. The DRECE device was developed at the VSB - Technical University of Ostrava. It allows grain refinement in strip plate with dimensions of 58 mm (width) × 2 mm (thickness) × 1000 mm (length). The influence of the number of passes on the mechanical properties and related structure refinement was examined experimentally. The effect of a heat treatment (500 °C/1 h/steady air) on the grain refinement of low carbon steel after severe plastic deformation is analysed. Through this novel technique, the grain structure can be converted into a submicron grain structure.

  3. Development of geometry of forming tools for extrusion of strip sheet by SPD process

    Science.gov (United States)

    Rusz, S.; Salajka, M.; Džugan, J.; Hilšer, O.; Bořuta, J.; Pastrňák, M.; Švec, J.

    2017-02-01

    On VSB -Technical University of Ostrava developed a method that uses the principle of severe plastic deformation to refine the structure and enhance mechanical properties of sheet metal strips. The greatest importance in practice represents an increase in yield strength and ultimate strength of sheet metal strips. The DRECE method (Dual Rolls Equal Channel Extrusion) is a newly developed method. Severe plastic deformation results in a high degree of the material deformation. The method can be used to produce metallic materials with a very fine grain structure. The paper analyses the effects of the values of angles of the newly developed forming tools on the achievement of mechanical properties in selected carbon steels by SPD process. The one type of steels (Ck55) was verified experimentally. Experiments were performed on the sheet metal strip with dimensions 58 (width) × 2 (thickness) × 1000 (length) mm with different inclination angle α.

  4. Sheets of branched poly(lactic acid) obtained by one step reactive extrusion calendering process: Physical Aging and Fracture Behaviour

    OpenAIRE

    Cailloux, Jonathan; Santana Pérez, Orlando Onofre; FRANCO URQUIZA, EDGAR ADRIAN; Bou Serra, Jordi; Carrasco Alonso, Félix Ángel; Maspoch Rulduà, Mª Lluïsa

    2014-01-01

    The architectural modifications of a linear poly(D,L-Lactide) acid (PD,L-LA) commercial grade were induced by a one-step reactive extrusion-calendering process using a styrene-glycidyl acrylate copolymer as reactive agent. The melt degradation was counteracted by chain extension and branching reactions, leading to a stabilization of the melt properties and an increase in the molecular weight. For such modified samples [poly(lactic acid) (PLA)-reactive extrusion (REX)], the rate of physical ag...

  5. Manufacture of porous biodegradable polymer conduits by an extrusion process for guided tissue regeneration

    Science.gov (United States)

    Widmer, M. S.; Gupta, P. K.; Lu, L.; Meszlenyi, R. K.; Evans, G. R.; Brandt, K.; Savel, T.; Gurlek, A.; Patrick, C. W. Jr; Mikos, A. G.; McIntire, L. V. (Principal Investigator)

    1998-01-01

    We have fabricated porous, biodegradable tubular conduits for guided tissue regeneration using a combined solvent casting and extrusion technique. The biodegradable polymers used in this study were poly(DL-lactic-co-glycolic acid) (PLGA) and poly(L-lactic acid) (PLLA). A polymer/salt composite was first prepared by a solvent casting process. After drying, the composite was extruded to form a tubular construct. The salt particles in the construct were then leached out leaving a conduit with an open-pore structure. PLGA was studied as a model polymer to analyze the effects of salt weight fraction, salt particle size, and processing temperature on porosity and pore size of the extruded conduits. The porosity and pore size were found to increase with increasing salt weight fraction. Increasing the salt particle size increased the pore diameter but did not affect the porosity. High extrusion temperatures decreased the pore diameter without altering the porosity. Greater decrease in molecular weight was observed for conduits manufactured at higher temperatures. The mechanical properties of both PLGA and PLLA conduits were tested after degradation in vitro for up to 8 weeks. The modulus and failure strength of PLLA conduits were approximately 10 times higher than those of PLGA conduits. Failure strain was similar for both conduits. After degradation for 8 weeks, the molecular weights of the PLGA and PLLA conduits decreased to 38% and 43% of the initial values, respectively. However, both conduits maintained their shape and did not collapse. The PLGA also remained amorphous throughout the time course, while the crystallinity of PLLA increased from 5.2% to 11.5%. The potential of seeding the conduits with cells for transplantation or with biodegradable polymer microparticles for drug delivery was also tested with dyed microspheres. These porous tubular structures hold great promise for the regeneration of tissues which require tubular scaffolds such as peripheral nerve

  6. Fusion processing of itraconazole solid dispersions by kinetisol dispersing: a comparative study to hot melt extrusion.

    Science.gov (United States)

    DiNunzio, James C; Brough, Chris; Miller, Dave A; Williams, Robert O; McGinity, James W

    2010-03-01

    KinetiSol Dispersing (KSD) is a novel high energy manufacturing process investigated here for the production of pharmaceutical solid dispersions. Solid dispersions of itraconazole (ITZ) and hypromellose were produced by KSD and compared to identical formulations produced by hot melt extrusion (HME). Materials were characterized for solid state properties by modulated differential scanning calorimetry and X-ray diffraction. Dissolution behavior was studied under supersaturated conditions. Oral bioavailability was determined using a Sprague-Dawley rat model. Results showed that KSD was able to produce amorphous solid dispersions in under 15 s while production by HME required over 300 s. Dispersions produced by KSD exhibited single phase solid state behavior indicated by a single glass transition temperature (T(g)) whereas compositions produced by HME exhibited two T(g)s. Increased dissolution rates for compositions manufactured by KSD were also observed compared to HME processed material. Near complete supersaturation was observed for solid dispersions produced by either manufacturing processes. Oral bioavailability from both processes showed enhanced AUC compared to crystalline ITZ. Based on the results presented from this study, KSD was shown to be a viable manufacturing process for the production of pharmaceutical solid dispersions, providing benefits over conventional techniques including: enhanced mixing for improved homogeneity and reduced processing times.

  7. Experimental investigation and numerical simulation of plastic flow behavior during forward-backward-radial extrusion process

    Directory of Open Access Journals (Sweden)

    A. Farhoumand

    2016-12-01

    Full Text Available Finite element method was employed to investigate the effect of process parameters of plastic deformation behavior in Forward-Backward-Radial Extrusion (FBRE process. The result of an axisymmetric model shows that the friction between die components and the sample has a substantial effect on the material flow behavior. Although strain heterogeneity index (SHI slightly decreases with an increase in friction, large portion of the sample experiences significant strain heterogeneity. Increasing the friction factor also localizes the strain heterogeneity effect in the backward section, and spread the effect in the forward section. Decreasing the friction in the FBRE process can reduce the amount of the strain heterogeneity in the product while decreases the required punch force substantially. Furthermore, an increase in gap thickness increases the deformation in the area close to the lower punch at the expense of the area in the vicinity of the upper punch. The numerical simulation has a good agreement with the experimental results which confirms the accuracy of the proposed finite element model.

  8. Characterization and performance assessment of solid dispersions prepared by hot melt extrusion and spray drying process.

    Science.gov (United States)

    Agrawal, Anjali M; Dudhedia, Mayur S; Patel, Ashwinkumar D; Raikes, Michelle S

    2013-11-30

    The present study investigated effect of manufacturing methods such as hot melt extrusion (HME) and spray drying (SD) on physicochemical properties, manufacturability, physical stability and product performance of solid dispersion. Solid dispersions of compound X and PVP VA64 (1:2) when prepared by SD and HME process were amorphous by polarized light microscopy, powder X-ray diffractometry, and modulated differential scanning calorimetry analyses with a single glass transition temperature. Fourier transform infrared (FT-IR) and Raman spectroscopic analyses revealed similar molecular level interactions between compound X and PVP VA64 as evident by overlapping FT-IR and FT Raman spectra in SD and HME solid dispersions. The compactibility, tabletability, disintegration and dissolution performance were similar for solid dispersions prepared by both processing techniques. Differences in material properties such as surface area, morphological structure, powder densities, and flow characteristics were observed between SD and HME solid dispersion. The SD solid dispersion was physically less stable compared to HME solid dispersion under accelerated stability conditions. Findings from this study suggest that similar product performance could be obtained if the molecular properties of the solid dispersion processed by two different techniques are similar. However differences in material properties might affect the physical stability of the solid dispersions.

  9. Microstructure evolution of processed Mg-Al-Zn alloy by equal channel angular extrusion in semi-solid isothermal treatment

    Institute of Scientific and Technical Information of China (English)

    JIANG Ju-fu; LUO Shou-jing

    2006-01-01

    Microstructure evolution of processed Mg-Al-Zn alloy by equal channel angular extrusion(ECAE) in semi-solid isothermal treatment was investigated. The results show that with increasing semi-solid isothermal treatment temperature, the α phase solid grain size of processed Mg-Al-Zn alloy by ECAE increases firstly due to coarsening of α phase solid grains, then decreases due to melting of α phase solid grains. With the increase of extrusion passes during ECAE, the α phase solid grain size in the following semi-solid isothermal treatment decreases. The α phase solid grain size of processed Mg-Al-Zn alloy by ECAE under route BC is the smallest, while the α phase solid grain size of processed material by ECAE under route A is the largest. The primary mechanism of spheroid formation depends on the melting of recrystallizing boundaries and diffusion of solute atoms in the semi-solid state.

  10. Novel Controlled Release Polymer-Lipid Formulations Processed by Hot Melt Extrusion.

    Science.gov (United States)

    Maniruzzaman, Mohammed; Islam, Muhammad T; Halsey, Sheelagh; Amin, Devyani; Douroumis, Dennis

    2016-02-01

    The aim of the study was to investigate the effect of novel polymer/lipid formulations on the dissolution rates of the water insoluble indomethacin (INM), co-processed by hot melt extrusion (HME). Formulations consisted of the hydrophilic hydroxypropyl methyl cellulose polymer (HPMCAS) and stearoyl macrogol-32 glycerides-Gelucire 50/13 (GLC) were processed with a twin screw extruder to produce solid dispersions. The extrudates characterized by X-ray powder diffraction (XRPD), differential scanning calorimetry (DSC) and hot stage microscopy (HSM) indicated the presence of amorphous INM within the polymer/lipid matrices. In-line monitoring via near-infrared (NIR) spectroscopy revealed significant peak shifts indicating possible interactions and H-bonding formation between the drug and the polymer/lipid carriers. Furthermore, in vitro dissolution studies showed a synergistic effect of the polymer/lipid carrier with 2-h lag time in acidic media followed by enhanced INM dissolution rates at pH > 5.5.

  11. 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.

  12. Numerical and experimental investigation of central cavity formation in aluminum during forward extrusion process

    Energy Technology Data Exchange (ETDEWEB)

    Hosseini, S. H.; Sedighi, M.; Mosayebnezhad, J. [Iran Univ., Tehran (Iran, Islamic Republic of)

    2016-05-15

    In the presented paper central cavity formation during the forward extrusion of commercially pure aluminum was investigated. For this purpose finite element analysis was utilized for simulation of this defect. The experimental tests were carried out on commercially pure aluminum. A good agreement between finite element simulations and experimental tests verified the adaptability of finite element simulations with the real process conditions. Taguchi method was performed for classifying the simulations regarding to consider synergistic parameters. The parameters include reduction of area, friction coefficient and die angle. Critical thickness, the representative waste material, was presented as a new criterion for optimizing the parametric study. By utilizing the Analyze Taguchi design, critical thickness was optimized and the effect of each parameter was recognized for different levels. In addition, the best levels with the minimum waste material were gained in which friction coefficient, die angle and reduction of area were 0.2, 5 .deg. and 20%, respectively. Also the amount of waste material was forecasted by just about 2% errors without FEA by Taguchi method.

  13. Numerical simulation of a sheet metal extrusion process by using thermal-mechanical coupling EAS FEM

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The thermal-mechanical coupling finite element method (FEM) was used to simulate a non-isothermal sheet metal extrusion process. On the basis of the finite plasticity consistent with multiplicative decomposition of the deformation gradient, the enhanced assumed strain (EAS) FEM was applied to carry out the numerical simulation. In order to make the computation reliable and avoid hourglass mode in the EAS element under large compressive strains, an alterative form of the original enhanced deformation gradient was employed. In addition, reduced factors were used in the computation of the element local internal parameters and the enhanced part of elemental stiffness. Numerical resultsshow that the hourglass can be avoided in compression region. In the thermal phase, the boundary energy dissipation due to heat convection was taken into account. As an example, a circular steel plate protruded by cylindrical punch was simulated. The step-wise decoupled strategyis adopted to handle coupling between mechanical deformation and the temperature variation. By comparing with the experimental results, thenumerical simulation was verified.

  14. Poly(ether ester) Ionomers as Water-Soluble Polymers for Material Extrusion Additive Manufacturing Processes.

    Science.gov (United States)

    Pekkanen, Allison M; Zawaski, Callie; Stevenson, André T; Dickerman, Ross; Whittington, Abby R; Williams, Christopher B; Long, Timothy E

    2017-03-28

    Water-soluble polymers as sacrificial supports for additive manufacturing (AM) facilitate complex features in printed objects. Few water-soluble polymers beyond poly(vinyl alcohol) enable material extrusion AM. In this work, charged poly(ether ester)s with tailored rheological and mechanical properties serve as novel materials for extrusion-based AM at low temperatures. Melt transesterification of poly(ethylene glycol) (PEG, 8k) and dimethyl 5-sulfoisophthalate afforded poly(ether ester)s of sufficient molecular weight to impart mechanical integrity. Quantitative ion exchange provided a library of poly(ether ester)s with varying counterions, including both monovalent and divalent cations. Dynamic mechanical and tensile analysis revealed an insignificant difference in mechanical properties for these polymers below the melting temperature, suggesting an insignificant change in final part properties. Rheological analysis, however, revealed the advantageous effect of divalent countercations (Ca(2+), Mg(2+), and Zn(2+)) in the melt state and exhibited an increase in viscosity of two orders of magnitude. Furthermore, time-temperature superposition identified an elevation in modulus, melt viscosity, and flow activation energy, suggesting intramolecular interactions between polymer chains and a higher apparent molecular weight. In particular, extrusion of poly(PEG8k-co-CaSIP) revealed vast opportunities for extrusion AM of well-defined parts. The unique melt rheological properties highlighted these poly(ether ester) ionomers as ideal candidates for low-temperature material extrusion additive manufacturing of water-soluble parts.

  15. 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.

  16. Modelling and Validation of Synthesis of Poly Lactic Acid Using an Alternative Energy Source through a Continuous Reactive Extrusion Process

    Directory of Open Access Journals (Sweden)

    Satya P. Dubey

    2016-04-01

    Full Text Available PLA is one of the most promising bio-compostable and bio-degradable thermoplastic polymers made from renewable sources. PLA is generally produced by ring opening polymerization (ROP of lactide using the metallic/bimetallic catalyst (Sn, Zn, and Al or other organic catalysts in a suitable solvent. In this work, reactive extrusion experiments using stannous octoate Sn(Oct2 and tri-phenyl phosphine (PPh3 were considered to perform ROP of lactide. Ultrasound energy source was used for activating and/or boosting the polymerization as an alternative energy (AE source. Ludovic® software, designed for simulation of the extrusion process, had to be modified in order to simulate the reactive extrusion of lactide and for the application of an AE source in an extruder. A mathematical model for the ROP of lactide reaction was developed to estimate the kinetics of the polymerization process. The isothermal curves generated through this model were then used by Ludovic software to simulate the “reactive” extrusion process of ROP of lactide. Results from the experiments and simulations were compared to validate the simulation methodology. It was observed that the application of an AE source boosts the polymerization of lactide monomers. However, it was also observed that the predicted residence time was shorter than the experimental one. There is potentially a case for reducing the residence time distribution (RTD in Ludovic® due to the ‘liquid’ monomer flow in the extruder. Although this change in parameters resulted in validation of the simulation, it was concluded that further research is needed to validate this assumption.

  17. 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.

  18. GRAPHITE EXTRUSIONS

    Science.gov (United States)

    Benziger, T.M.

    1959-01-20

    A new lubricant for graphite extrusion is described. In the past, graphite extrusion mixtures have bcen composed of coke or carbon black, together with a carbonaceous binder such as coal tar pitch, and a lubricant such as petrolatum or a colloidal suspension of graphite in glycerin or oil. Sinee sueh a lubricant is not soluble in, or compatible with the biiider liquid, such mixtures were difficult to extrude, and thc formed pieees lacked strength. This patent teaches tbe use of fatty acids as graphite extrusion lubricants and definite improvemcnts are realized thereby since the fatty acids are soluble in the binder liquid.

  19. Twin screw extrusion processing of feed blends containing distillers dried grains with solubles

    Science.gov (United States)

    Extrusion trials were conducted with varying levels of distillers dried grains with solubles (DDGS) along with soy flour, corn flour, fish meal, vitamin mix, mineral mix and net protein content adjusted to 28% using a Wenger TX-52 twin screw extruder. The properties of extrudates obtained with exper...

  20. UBET analysis of process of extruding aluminum alloy ribbed thin-wall pipes through a porthole die

    Institute of Scientific and Technical Information of China (English)

    谢建新; 裴强; 刘静安

    2002-01-01

    Using the upper bound element technique (UBET), a numerical model was proposed for analyzing the metal deformation behavior in the extrusion process of ribbed thin-wall pipes through a porthole die. Optimization parameters were contained in the numerical model and determined through minimizing the total work of metal deformation. Taking the extrusion process of thin-wall pipe with one rib as an example, the calculated results using the proposed model are as follows: the extrusion pressure p is linearly related to the extrusion ratio R by p = a+bR 0.683, where a =14.13, b =0.911. When the length of the billet remaining in container is shorter than a quarter of the container diameter, the plastic region extends over the whole of the remained billet and the extrusion process reaches the state of funnel deformation. There exists an optimum depth of welding chamber in respect of the extrusion pressure, and to the calculated example the optimum depth is about 10% of the circumscribed diameter of portholes. To obtain more equitable metal flow in welding chamber, it is required to make the dividing planes in container to be consistent with corresponding welding planes in the chamber ( θ max i = θ′ max i ) through choosing different entering area for each of the portholes.

  1. Through-Thickness Variations of Deformed and Annealed Microstructures in ECAE-Processed Copper

    DEFF Research Database (Denmark)

    Mishin, Oleg; Bowen, Jacob R.

    2009-01-01

    Through-thickness variations of the microstructure in copper processed using equal channel angular extrusion (ECAE) to a strain of ~10 without rotations between passes have been investigated in deformed and partially recrystallized conditions. It is found that the through-thickness heterogeneity...... strain. Compared to other inspected layers the bottom part of the billet was less refined after ECAE and remained less recrystallized after annealing....

  2. Polycarbonate modified with crystallisable bis-ester tetra-amide units in a reaction extrusion process

    NARCIS (Netherlands)

    Zuiderduin, W.C.J.; Gaymans, R.J.

    2008-01-01

    Dry blends of polycarbonate (PC) and a bis-ester tetra-amide were extruded at 305 °C with a mini twin screw extruder. The bis-ester tetra-amide diamide (T6T6T-dimethyl) was composed of two and a half repeat units of Nylon 6,T and had methyl ester endgroups. During the extrusion, a trans-esterificati

  3. The numerical simulation of powder canning hot extrusion of W-4OCu alloy%W-40Cu粉末包套热挤压过程数值模拟

    Institute of Scientific and Technical Information of China (English)

    李达人; 蔡一湘; 王尔德

    2012-01-01

    采用DEFORM-2D软件对W-40Cu粉末包套热挤压过程进行了数值模拟,研究了挤压过程中内部多孔体粉末坯料和外部塑性钢套的温度场、应力应变场和速度场的分布情况,并深入分析了坯料的等效应力应变和坯料、包套的最大流动速度随挤压温度、挤压速度、挤压比等的变化情况,以及包套厚度对粉末包套热挤压过程的影响.结果表明:粉末包套挤压过程中在模口附近出现最高温度值,等效应力的最大值出现在锥形区转角处,等效应变最大值出现在模口附近的包套表面,坯料最大流动速度值出现在模口附近的坯料芯部位置,包套最大流速值出现在挤压头部位置;坯料等效应变和流动速度随包套壁厚的增加先升高后降低,在包套壁厚为7.5mm时应变值最高;包套底厚影响挤压坯的形状和材料利用率.模拟得到的不同温度和挤压比下的变形载荷与实验值误差小于10%,吻合较好.%Numerical simulation of W-40Cu powder canning hot extrusion was carried out by DEF0RM-2D. The distribution of temperature, stress/strain and velocity field either in the porous billet or plastic steel can were discussed. The variation of effective stress/strain and max flow speed of billets and steel can with extrusion temperature, extrusion speed, extrusion ratio and the effect of can thickness on hot extrusion process were also studied. The results show that, the flow speed of billets and steel can increases with the increasing extrusion speed and ratio. The effective strain and flow speed of billet first increase and then decrease with the increasing wall thickness of can, the shape and utilization ratio of porous billet are affected by bottom thickness of can. The simulative extrusion load with different extrusion temperature and ratio is in accord with experimental extrusion load.

  4. 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

  5. Present Situation of the Anti-Fatigue Processing of High-Strength Steel Internal Thread Based on Cold Extrusion Technology: A Review

    Science.gov (United States)

    Miao, Hong; Jiang, Cheng; Liu, Sixing; Zhang, Shanwen; Zhang, Yanjun

    2017-03-01

    The adoption of cold-extrusion forming for internal thread net forming becomes an important component of anti-fatigue processing with the development of internal thread processing towards high performance, low cost and low energy consumption. It has vast application foreground in the field of aviation, spaceflight, high speed train and etc. The internal thread processing and anti-fatigue manufacture technology are summarized. In terms of the perspective of processing quality and fatigue serving life, the advantages and disadvantages of the processing methods from are compared. The internal thread cold-extrusion processing technology is investigated for the purpose of improving the anti-fatigue serving life of internal thread. The superiorities of the plastic deformation law and surface integrity of the metal layer in the course of cold extrusion for improving its stability and economy are summed up. The proposed research forecasts the development tendency of the internal thread anti-fatigue manufacturing technology.

  6. Scale up tools in reactive extrusion and compounding processes. Could 1D-computer modeling be helpful?

    Science.gov (United States)

    Pradel, J.-L.; David, C.; Quinebèche, S.; Blondel, P.

    2014-05-01

    Industrial scale-up (or scale down) in Compounding and Reactive Extrusion processes is one of the most critical R&D challenges. Indeed, most of High Performances Polymers are obtained within a reactive compounding involving chemistry: free radical grafting, in situ compatibilization, rheology control... but also side reactions: oxidation, branching, chain scission... As described by basic Arrhenius and kinetics laws, the competition between all chemical reactions depends on residence time distribution and temperature. Then, to ensure the best possible scale up methodology, we need tools to match thermal history of the formulation along the screws from a lab scale twin screw extruder to an industrial one. This paper proposes a comparison between standard scale-up laws and the use of Computer modeling Software such as Ludovic® applied and compared to experimental data. Scaling data from a compounding line to another one, applying general rules (for example at constant specific mechanical energy), shows differences between experimental and computed data, and error depends on the screw speed range. For more accurate prediction, 1D-Computer Modeling could be used to optimize the process conditions to ensure the best scale-up product, especially in temperature sensitive reactive extrusion processes. When the product temperature along the screws is the key, Ludovic® software could help to compute the temperature profile along the screws and extrapolate conditions, even screw profile, on industrial extruders.

  7. Biodegradable polymer blends based on corn starch and thermoplastic chitosan processed by extrusion.

    Science.gov (United States)

    Mendes, J F; Paschoalin, R T; Carmona, V B; Sena Neto, Alfredo R; Marques, A C P; Marconcini, J M; Mattoso, L H C; Medeiros, E S; Oliveira, J E

    2016-02-10

    Blends of thermoplastic cornstarch (TPS) and chitosan (TPC) were obtained by melt extrusion. The effect of TPC incorporation in TPS matrix and polymer interaction on morphology and thermal and mechanical properties were investigated. Possible interactions between the starch molecules and thermoplastic chitosan were assessed by XRD and FTIR techniques. Scanning Electron Microscopy (SEM) analyses showed a homogeneous fracture surface without the presence of starch granules or chitosan aggregates. Although the incorporation of thermoplastic chitosan caused a decrease in both tensile strength and stiffness, films with better extensibility and thermal stability were produced.

  8. Detection of Non-metallic Inclusions in Centrifugal Continuous Casting Steel Billets

    Science.gov (United States)

    Wang, Qiangqiang; Zhang, Lifeng; Seetharaman, Sridhar; Yang, Shufeng; Yang, Wen; Wang, Yi

    2016-06-01

    In the current study, automated particle analysis was employed to detect non-metallic inclusions in steel during a centrifugal continuous casting process of a high-strength low alloy steel. The morphology, composition, size, area fraction, amount, and spatial distribution of inclusions in steel were obtained. Etching experiment was performed to reveal the dendrite structure of the billet and to discuss the effect of centrifugal force on the distribution of oxide inclusions in the final solidified steel by comparing the solidification velocity with the critical velocity reported in literature. It was found that the amount of inclusions was highest in samples from the tundish (~250 per mm2), followed by samples from the mold (~200 per mm2), and lowest in billet samples (~86 per mm2). In all samples, over 90 pct of the inclusions were smaller than 2μm. In steel billets, the content of oxides, dual-phase oxide-sulfides, and sulfides in inclusions were found to be 10, 30, and 60 pct, respectively. The dual-phase inclusions were oxides with sulfides precipitated on the outer surface. Oxide inclusions consisted of high Al2O3 and high MnO which were solid at the molten steel temperature, implying that the calcium treatment was insufficient. Small oxide inclusions very uniformly distributed on the cross section of the billet, while there were more sulfide inclusions showing a banded structure at the outside 25 mm layer of the billet. The calculated solidification velocity was higher than the upper limit at which inclusions were entrapped by the solidifying front, revealing that for oxide inclusions smaller than 8μm in this study, the centrifugal force had little influence on its final distribution in billets. Instead, oxide inclusions were rapidly entrapped by solidifying front.

  9. 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.

  10. 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.

  11. 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 a

  12. 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.

  13. Electrical, Mechanical, and Thermal Properties of LDPE Graphene Nanoplatelets Composites Produced by Means of Melt Extrusion Process

    Directory of Open Access Journals (Sweden)

    Karolina Gaska

    2017-01-01

    Full Text Available Composites of LDPE filled with different amounts of graphene nanoplatelets (GnP were prepared in form of films by means of precoating technique and single screw melt-extrusion using two types of screws, compression and mixing. This manufacturing process imposes strong anisotropy on the sample’s morphology, in which the nanoplatelets become oriented along the extrusion direction. Such orientation of GnP in LDPE matrix is confirmed by scanning electron microscopy observations and it yields unique electrical properties. As compared to pure LDPE, significant reductions of the through-plane conductivity are found for the composites at relatively low electric fields (<20 kV/mm at low filler concentrations. Above the field level of 20 kV/mm, a crossover effect is observed that results in a strong field dependency of the conductivity where the non-linear behavior starts to dominate. Moreover, differential scanning calorimetry (DSC results indicate a decrease in polymer crystallinity of the composite matrix with increasing filler content, whereas thermogravimetric (TG analysis shows a slight increase in the material’s thermal stability. Application of GnP also leads to improvement of mechanical properties, manifested by the increase of Young’s modulus and tensile strength in both types of samples.

  14. Resource-saving technology for manufacturing billets for piston’s rings

    Directory of Open Access Journals (Sweden)

    A. N. Krutilin

    2010-10-01

    Full Text Available Piston’s rings are one of the most critical parts of heavy-duty engines for wear-work in conditions of prolonged exposure of alternating loads and high temperatures. Currently in the world production of billets for piston’s rings is dominated by the two methods of casting: production of individual and oiling billets of gray and ductile cast iron in green-sand mold and shell mold and centrifugal casting method (intended primarily for oiling billets of ductile iron; the technology for individual production billets for piston’s rings with a diameter up to 250 mm, from 250 to 450 mm with individual and oiling ways, over 450 mm - preference of oiling billet. The best parameters of physical-mechanical and operational characteristics piston’s rings are in the case of manufacture of billets to the maximum extent approaching the configuration to the finished product. The rings made of shaped billets are characterized by uniform distribution of properties from the perimeter, provide a given diagram of pressures and full fit to the cylinder. Because of deficiencies of traditional methods of casting, continuous quality requirements for billets, the need for economy of material, fuel and energy resources, are finding new progressive technological processes of production of high-quality billets for piston’s rings. One of the most promising for piston rings billet is a method of casting consists of immersing the sand molds into the melt. It is interesting idea, expressed by A. Sutherland and subsequently patented in several countries in the way of casting method, called "immersion pouring technology" (ICT-Immersion Casting Technique [1]. Experiments, conducted in the laboratory of the Belarusian National Technical University, have identified significant shortcomings of immersion method of casting. When forms are immersing, have an intensive gassing in molten metal, and freezing of the metal on the out surface of the form. But despite some

  15. Influence of Molecular Weight of Carriers and Processing Parameters on the Extrudability, Drug Release, and Stability of Fenofibrate Formulations Processed by Hot-Melt Extrusion.

    Science.gov (United States)

    Alsulays, Bader B; Park, Jun-Bom; Alshehri, Sultan M; Morott, Joseph T; Alshahrani, Saad M; Tiwari, Roshan V; Alshetaili, Abdullah S; Majumdar, Soumyajit; Langley, Nigel; Kolter, Karl; Gryczke, Andreas; Repka, Michael A

    2015-10-01

    The objective of this study was to investigate the extrudability, drug release, and stability of fenofibrate (FF) formulations utilizing various hot-melt extrusion processing parameters and polyvinylpyrrolidone (PVP) polymers of various molecular weights. The different PVP grades selected for this study were Kollidon(®) 12 PF (K12), Kollidon(®) 30 (K30), and Kollidon(®) 90 F (K90). FF was extruded with these polymers at three drug loadings (15%, 25%, and 35% w/w). Additionally, for FF combined with each of the successfully extruded PVP grades (K12 and K30), the effects of two levels of processing parameters for screw design, screw speed, and barrel temperature were assessed. It was found that the FF with (K90) was not extrudable up to 35% drug loading. With low drug loading, the polymer viscosity significantly influenced the release of FF. The crystallinity remaining was vital in the highest drug-loaded formulation dissolution profile, and the glass transition temperature of the polymer significantly affected its stability. Modifying the screw configuration resulted in more than 95% post-extrusion drug content of the FF-K30 formulations. In contrast to FF-K30 formulations, FF release and stability with K12 were significantly influenced by the extrusion temperature and screw speed.

  16. Processing of Copper by Hydrostatic Extrusion – Studies of Microstructure and Properties

    Directory of Open Access Journals (Sweden)

    Leszczyńska-Madej B.

    2016-09-01

    Full Text Available The present study attempts to apply HE to 99.99% pure copper. The microstructure of the samples was investigated by both light microscopy and scanning transmission electron microscopy (STEM. Additionally, the microhardness was measured, the tensile test was made, and statistical analysis of the grains and subgrains was performed. Based on Kikuchi diffraction patterns, misorientation was determined. The obtained results show that microstructure of copper deformed by hydrostatic extrusion (HE is rather inhomogeneous. The regions strongly deformed with high dislocation density exist near cells and grains/subgrains free of dislocations. The measurements of the grain size have revealed that the sample with an initial in annealed-state grain size of about 250 μm had this grain size reduced to below 0.35μm when it was deformed by HE to the strain ε=2.91. The microhardness and UTS are stable within the whole investigated range of deformation.

  17. Precision analysis in billet preparation for micro bulk metal forming

    DEFF Research Database (Denmark)

    Mahshid, Rasoul; Hansen, Hans N.

    2015-01-01

    press. When using a vertical mechanical press, the material is fed as billets into the forming zone. Therefore, a large number of highly uniform billets are required to run mass production in such a setup. Shearing technique was used for manufacturing the billets. The efficiency of the shearing tool...... is examined in terms of volume control, circularity, dimension and sheared surface quality. The shearing tool is based on holders for both bar and cutoff. The tool is fixed in dimensions, since the dimensions of billets are fixed throughout experiments of this research. The paper presents the experimental...

  18. Twin screw extrusion of kodo millet-chickpea blend: process parameter optimization, physico-chemical and functional properties.

    Science.gov (United States)

    Geetha, R; Mishra, H N; Srivastav, P P

    2014-11-01

    Kodo millet-chickpea flour blend (70:30) was explored for development of directly expanded snack by twin-screw extrusion. Effect of process parameters like temperature (80-150 °C), screw speed (250-300 rpm) and feeder speed (15-30 rpm) on physical properties (expansion ratio, bulk density, hardness, crispiness) of extrudates were investigated and optimized using response surface methodology. Desirable crispy extrudates were obtained at higher screw speed 293 rpm, lower feeder speed 19 rpm, and medium to high temperature of 123 °C. Effect of extreme and intermediate process conditions on functional, proximate quality and colour of the extrudates were also evaluated.

  19. Modelling of stress fields during LFEM DC casting of aluminium billets by a meshless method

    Science.gov (United States)

    Mavrič, B.; Šarler, B.

    2015-06-01

    Direct Chill (DC) casting of aluminium alloys is a widely established technology for efficient production of aluminium billets and slabs. The procedure is being further improved by the application of Low Frequency Electromagnetic Field (LFEM) in the area of the mold. Novel LFEM DC processing technique affects many different phenomena which occur during solidification, one of them being the stresses and deformations present in the billet. These quantities can have a significant effect on the quality of the cast piece, since they impact porosity, hot-tearing and cold cracking. In this contribution a novel local radial basis function collocation method (LRBFCM) is successfully applied to the problem of stress field calculation during the stationary state of DC casting of aluminium alloys. The formulation of the method is presented in detail, followed by the presentation of the tackled physical problem. The model describes the deformations of linearly elastic, inhomogeneous isotropic solid with a given temperature field. The temperature profile is calculated using the in-house developed heat and mass transfer model. The effects of low frequency EM casting process parameters on the vertical, circumferential and radial stress and on the deformation of billet surface are presented. The application of the LFEM appears to decrease the amplitudes of the tensile stress occurring in the billet.

  20. Microstructure, Texture, and Tensile Properties of Ultrafine/Nano-Grained Magnesium Alloy Processed by Accumulative Back Extrusion

    Science.gov (United States)

    Fatemi, S. M.; Zarei-Hanzaki, A.; Cabrera, J. M.

    2017-02-01

    An AZ31 wrought magnesium alloy was processed by employing multipass accumulative back extrusion process. The obtained microstructure, texture, and room temperature tensile properties were characterized and discussed. Ultrafine-grained microstructure including nano-grains were developed, where the obtained mean grain size was decreased from 8 to 0.5 μm by applying consecutive passes. The frequency of both low angle and high angle boundaries increased after processing. Strength of the experimental alloy was decreased after processing, which was attributed to the obtained texture involving the major component lying inclined to the deformation axis. Both the uniform and post-uniform elongations of the processed materials were increased after processing, where a total elongation of 68 pct was obtained after six-pass deformation. The contribution of different twinning and slip mechanisms was described by calculating corresponding Schmid factors. The operation of prismatic slip was considered as the major deformation contributor. The significant increase in post-uniform deformation of the processed material was discussed relying on the occurrence of grain boundary sliding associated with the operation of prismatic slip.

  1. Three-Dimensional CFD Simulation Coupled with Thermal Contraction in Direct-Chill Casting of A390 Aluminum Alloy Hollow Billet

    Science.gov (United States)

    Zuo, Kesheng; Zhang, Haitao; Qin, Ke; Cui, Jianzhong; Chen, Qingzhang

    2016-11-01

    A three-dimensional CFD model coupled with melt flow, heat transfer, and thermal contraction was developed to simulate the direct-chill (DC) casting process of A390 alloy hollow billet with a cross-section size of Φ164 mm/Φ60 mm. This study considered the effects of contact height and air gap width between the core and the hollow billet, which dominated the heat transfer at the inner wall of the hollow billet. The effects of core taper angle, relative vertical position of core in the mold, and casting speed on the steady-state temperature distribution and formability of hollow billet were investigated. According to the criterion used in this study, the optimal core taper angle is 3 deg for DC casting of A390 alloy hollow billet. With the optimal core taper angle, the A390 alloy hollow billet can be cast successfully regardless of the variation of the relative vertical position of core in the mold and casting speed. The coupled model developed in this study can be applied to optimize the core taper angle and study the effects of casting parameters in various dimensions of hollow billet.

  2. Three-Dimensional CFD Simulation Coupled with Thermal Contraction in Direct-Chill Casting of A390 Aluminum Alloy Hollow Billet

    Science.gov (United States)

    Zuo, Kesheng; Zhang, Haitao; Qin, Ke; Cui, Jianzhong; Chen, Qingzhang

    2017-02-01

    A three-dimensional CFD model coupled with melt flow, heat transfer, and thermal contraction was developed to simulate the direct-chill (DC) casting process of A390 alloy hollow billet with a cross-section size of Φ164 mm/Φ60 mm. This study considered the effects of contact height and air gap width between the core and the hollow billet, which dominated the heat transfer at the inner wall of the hollow billet. The effects of core taper angle, relative vertical position of core in the mold, and casting speed on the steady-state temperature distribution and formability of hollow billet were investigated. According to the criterion used in this study, the optimal core taper angle is 3 deg for DC casting of A390 alloy hollow billet. With the optimal core taper angle, the A390 alloy hollow billet can be cast successfully regardless of the variation of the relative vertical position of core in the mold and casting speed. The coupled model developed in this study can be applied to optimize the core taper angle and study the effects of casting parameters in various dimensions of hollow billet.

  3. Microstructure and property of a functionally graded aluminum silicon alloy fabricated by semi-solid backward extrusion process

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Kai [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Yu, Hao, E-mail: yhzhmr@126.com [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Liu, Jun-you [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Li, Yan-xia [Department of Materials, North China Institute of Aerospace Engineering, Langfang 065000 (China); Liu, Jian; Zhang, Jia-liang [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China)

    2015-01-29

    In this paper, the microstructure and mechanical property of a graded aluminum silicon alloy were investigated and a new preparation method for the graded material was proposed. The cup-shaped sample was fabricated by the backward extrusion process during the semi-solid state of A390 cast alloy. Characteristics and distribution of the primary particles were assessed by the optical microscopy (OM), scanning electron microscopy (SEM), energy dispersive spectrum (EDS) and image analyzer software. The results showed that the content of primary Si gradually decreased from the bottom region to the upper region. The hardness and wear rate of the samples were measured to evaluate the variation in the mechanical properties corresponding to the variation in microstructure. The hardness values and wear resistance along the axis of the cup-shaped sample gradually increased from the upper region to the bottom region and from the inner region to the outer layer, respectively. The maximum average hardness value is 138.7 HB. The observations of fracture surface were analyzed by scanning electron microscopy to understand the fracture mechanism. The results also indicated that the ultimate tensile strength (UTS) of the graded material after T6 treatment are 275 MPa, increases 32.3% compared to the original backward extrusion alloy. Optical microscopy and electron probe micro-analyzer were used to study the distribution of elements and the microstructure of different intermetallic phases formed. Electron microprobe analysis (EMPA) results showed that the content of the prominent elements (Cu, Fe, Mg) in the upper region was higher than for the bottom part of the cup-shaped specimens.

  4. Studies on Microstructure and Thermoelectric Properties of p-Type Bi-Sb-Te Based Alloys by Gas Atomization and Hot Extrusion Processes

    Science.gov (United States)

    Park, Ki-Chan; Madavali, Babu; Kim, Eun-Bin; Koo, Kyung-Wan; Hong, Soon-Jik

    2016-10-01

    p-Type Bi2Te3 + 75% Sb2Te3 based thermoelectric materials were fabricated via gas atomization and the hot extrusion process. The gas atomized powder showed a clean surface with a spherical shape, and expanded in a wide particle size distribution (average particle size 50 μm). The phase of the fabricated extruded and R-extruded bars was identified using x-ray diffraction. The relative densities of both the extruded and R-extruded samples were measured by Archimedes principle with ˜98% relative density. The R-extruded bar exhibited finer grain microstructure than that of single extrusion process, which was attributed to a recrystallization mechanism during the fabrication. The R-extruded sample showed improved Vickers hardness compared to the extruded sample due to its fine grain microstructure. The electrical conductivity improved for the extruded sample whereas the Seebeck coefficient decreases due to its high carrier concentration. The peak power factor, ˜4.26 × 10-3 w/mK2 was obtained for the single extrusion sample, which is higher than the R-extrusion sample owing to its high electrical properties.

  5. Virtual Orthogonal Experiment Study on Needle Piercing Extrusion Process of Inconel690 Alloy Large-Diameter Thick-Walled Tube%基于虚拟正交试验的Inconel690合金大口径厚壁管挤压工艺仿真

    Institute of Scientific and Technical Information of China (English)

    张保军; 杨合; 郭良刚; 谷瑞杰; 寇永乐

    2013-01-01

    It is an important issue for the optimization design and refined control of extrusion process of large-diameter hard wrought alloy profiles to reveal the effects of forming parameters on the process and to determine the reasonable range of each forming parameter. And it's also significant for the R&D, debugging and application of the large tonnage (such as 200 MN) extrusion press. Therefore, we developed an applicable and reliable FE model for the needle piercing extrusion process for Inconel690 alloy large-diameter thick-walled tube (Φ420 mm×60 mm) under the DEFORM-2D software environment. And the effects of forming parameters (i.e. extruding ratio A, die taper angle a, sizing belt length h, billet initial temperature T and ram speed v) on the peak temperature of billet Tmax, the peak damage of billet Dmax, the uniformity of flow rate at die export Fsdv and the peak extrusion load Lmax were investigated using virtual orthogonal experiment based on the developed FE model. The results show that the order of forming parameters' significance to rmax, Dmax, Fsdv and Lmax are T>v>λ>h>a, a>v≈λ>T>h, h>v>T>α>λ, and λ>T>α>v>h, respectively. Comprehensively considering the quality of the extruded tube and the extrusion load, we pointed out that the reasonable ranges of forming parameters are as follows: λ=5.74~6.37, λ=35°~45°, h=60~120 mm, T=1080~1180 ℃, and v=150~250 mm/s.%研究挤压成形参数影响规律并确定合理的参数取值范围,是开发难变形合金大型型材挤压工艺技术和挤压过程精细化控制,以及大吨位(如2万吨)挤压机的研发、调试及应用迫切需要开展的重要内容.基于DEFORM-2D平台,以规格为Φ420 mm×60mm的难变形Inconel690合金管材穿孔针挤压为研究对象,建立了适用、可靠的无缝管材穿孔L针挤压过程的有限元仿真模型;选取挤压比λ、模角α、定径带长度h、坯料初始温度T、挤压速度v等重要成形参数为影响因素,以坯料

  6. Increasing the accuracy during the production of curved metallic billets by bending deformation

    Science.gov (United States)

    Brovman, T. V.; Kutuzov, A. A.

    2016-05-01

    The elastoplastic deformation of a billet by bending is considered. The deformation forces are determined and formulas are derived to estimate the accuracy of the curvature of the billet. A bending technology is developed to increase the accuracy of a billet and to decrease the metal losses. The results obtained were used at Tver' Glass Company to produce curved billets.

  7. 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.

  8. 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.

  9. Dissolution enhancement of poorly water-soluble APIs processed by hot-melt extrusion using hydrophilic polymers.

    Science.gov (United States)

    Maniruzzaman, M; Rana, M M; Boateng, J S; Mitchell, J C; Douroumis, D

    2013-02-01

    The aim of this study was to investigate the efficiency of hydrophilic polymers to enhance the dissolution rate of poorly water-soluble active pharmaceutical ingredients (APIs) processed by hot-melt extrusion (HME). Indomethacin (INM) and famotidine (FMT) were selected as model active substances while polyvinyl caprolactam graft copolymer, soluplus (SOL) and vinylpyrrolidone-vinyl acetate copolymer grades, Kollidon VA64 (VA64) and Plasdone S630 (S630) were used as hydrophilic polymeric carriers. For the purpose of the study, drug-polymer binary blends at various ratios were processed by a Randcastle single screw extruder. The physicochemical properties and the morphology of the extrudates were evaluated through X-ray diffraction (XRD), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). Increased drug loadings of up to 40% were achieved in the extruded formulations for both drugs. INM and FMT exhibited strong plasticization effects with increasing concentrations and were found to be molecularly dispersed within the polymer blends. The in vitro dissolution studies showed increased INM/FMT release rates for all formulations compared to that of pure APIs alone.

  10. Study of Solidification of Continuously Cast Steel Round Billets Using Numerical Modelling

    Directory of Open Access Journals (Sweden)

    Tkadlečková M.

    2016-03-01

    Full Text Available The paper is dedicated to the verification of solidification of continuously cast round steel billets using numerical modelling based on the finite element method. The aim of numerical modelling is to optimize the production of continuously cast steel billets of round format. The paper describes the pre-processing, processing and post-processing phases of numerical modelling. Also, the problems with determination of the thermodynamic properties of materials and the heat transfer between the individual parts of the casting system, including the definition of the heat losses along the casting strand in the primary and secondary cooling, were discussed. The first results of numerical simulation show the so-called thermal steady state of continuous casting. The temperature field, the metallurgical length and the thickness of the shell at the end of the mould were predicted. The further research will be concentrated on the prediction the risk of the cracks and the porosity based on the different boundary conditions.

  11. Innovation of Embedding Eggshell to Enhance Physical-Mechanical-Thermal Properties in Fired Clay Bricks via Extrusion Process

    Directory of Open Access Journals (Sweden)

    Tangboriboon Nuchnapa

    2016-01-01

    Full Text Available Eggshell functioned as a bio-filler and sintering aid added into earthenware clay compounds to make fire clay bricks via extrusion process. The main composition of eggshell is calcium carbonate (CaCO3 while the main composition of earthenware is aluminosilcate (Al2O3.2SiO2.2H2O and other oxide compounds. Calcium carbonate in eggshell can react to chemical substances in earthenware clay compound to form calcium alumnosilicate or anorthite and wollastonite or calcium silicate phase formation of the fired clay bricks. Adding 20%wt eggshell powder into clay bricks and fired at 1000°C for 5 hrs., affects to the physical-mechanical-thermal properties, i.e. high compressive strength and hardness, good thermal expansion coefficient, good true density, and low water absorption. In general, the theoretical compressive strength, hardness, and water absorption of desired refractory are more than 7.0 MPa, 6.0 HV, and less than 25%wt, respectively. Therefore, the obtained fired clay bricks added eggshell powder and fired at 1000°C for 5 hrs., are potential for use as bricks for construction and thermal insulation.

  12. Blasting extrusion processing: the increase of soluble dietary fiber content and extraction of soluble-fiber polysaccharides from wheat bran.

    Science.gov (United States)

    Yan, Xiaoguang; Ye, Ran; Chen, Ye

    2015-08-01

    In this study, soluble dietary fiber (SDF) content of wheat bran was significantly increased from 9.82 ± 0.16 (w/w, %) to 16.72 ± 0.28 (w/w, %) by a novel blasting extrusion processing with enhanced water retention capacity and the swelling capacity. In addition, a water-soluble polysaccharide (WBP) was isolated and extracted from extruded SDF. WBP was successfully purified from SDF by column chromatography systems with the average molecular weight (Mw) of 4.7 × 10(4)Da, containing arabinose, xylose, glucose, and galactose. With the molar ratio of 0.76:0.99:1.00:0.12. Our results suggest that WBP owned 1 → 2, 1 → 3, 1 → 2, 6 and 1 → 4, 1 → 4, 6 glycosidic bonds in the absence of 1 →, 1 → 6 glycosidic bonds. In vitro antioxidant assays (DPPH, ABTS+ radical scavenging capacities, and ferric ion reducing capacity) demonstrated that WBP possesses good antioxidant capacity, and it could be potentially used as a natural antioxidant for use in functional food, cosmetic and pharmaceutical industries.

  13. Microstructure and mechanical properties of 7075 aluminum alloy nanostructured composites processed by mechanical milling and indirect hot extrusion

    Energy Technology Data Exchange (ETDEWEB)

    Flores-Campos, R., E-mail: ruben.flores@itesm.mx [Centro de Investigacion en Materiales Avanzados (CIMAV), Laboratorio Nacional de Nanotecnologia, Miguel de Cervantes No. 120, CP 31109, Chihuahua, Chih., Mexico (Mexico); Tecnologico de Monterrey Campus Saltillo, Departamento de Ingenieria, Prol. Juan de la Barrera No. 1241 Ote., Col. Cumbres, CP 25270, Saltillo, Coah., Mexico (Mexico); Estrada-Guel, I., E-mail: ivanovich.estrada@cimav.edu.mx [Centro de Investigacion en Materiales Avanzados (CIMAV), Laboratorio Nacional de Nanotecnologia, Miguel de Cervantes No. 120, CP 31109, Chihuahua, Chih., Mexico (Mexico); Miki-Yoshida, M., E-mail: mario.miki@cimav.edu.mx [Centro de Investigacion en Materiales Avanzados (CIMAV), Laboratorio Nacional de Nanotecnologia, Miguel de Cervantes No. 120, CP 31109, Chihuahua, Chih., Mexico (Mexico); Martinez-Sanchez, R., E-mail: roberto.martinez@cimav.edu.mx [Centro de Investigacion en Materiales Avanzados (CIMAV), Laboratorio Nacional de Nanotecnologia, Miguel de Cervantes No. 120, CP 31109, Chihuahua, Chih., Mexico (Mexico); Herrera-Ramirez, J.M., E-mail: martin.herrera@cimav.edu.mx [Centro de Investigacion en Materiales Avanzados (CIMAV), Laboratorio Nacional de Nanotecnologia, Miguel de Cervantes No. 120, CP 31109, Chihuahua, Chih., Mexico (Mexico)

    2012-01-15

    Nanostructured composites of 7075 aluminum alloy and carbon coated silver nanoparticles were produced by mechanical milling and indirect hot extrusion. The milling products were obtained in a high energy SPEX ball mill, and then were compacted by uniaxial load and pressure-less sintered under argon atmosphere. Finally, the sintered product was hot extruded. Carbon coated silver nanoparticles were well distributed in the matrix of the extruded material. Tensile tests were carried out to corroborate the hypothesis that second phase particles, well dispersed in the matrix, improve the strength of the material. High resolution transmission electron microscopy was employed to locate and make sure that the silver nanoparticles were homogeneously and finely dispersed. Highlights: Black-Right-Pointing-Pointer 7075 Al nanostructured composites can be produced by mechanical milling. Black-Right-Pointing-Pointer Carbon coated silver nanoparticles are well dispersed into aluminum matrix. Black-Right-Pointing-Pointer Ductile Ag-C NP's improve the mechanical properties of the 7075 Al-alloy. Black-Right-Pointing-Pointer Ag-C NP's content has an important effect in the particle and crystallite size. Black-Right-Pointing-Pointer Ag-C NP's keep their morphology after milling and conformation processes.

  14. Some problems of realizing the process of casting billet hot delivery and hot charging in the wire and rod production (2)%线棒材生产实现连铸坯热送热装的若干问题(二)

    Institute of Scientific and Technical Information of China (English)

    席约强

    2001-01-01

    介绍了在线、棒材轧制中实现连铸坯热送热装的节能降耗效果,连铸坯热送方式,连铸与轧钢之间的热连接方式,并对热装工艺提出了看法,指出提高管理水平是提高热送热装效果的关键。%The effects of saving energy and reducing consumption of casting billet hot delivery and hot charging, the types of hot delivery and the hot connections between casting and steel rolling are introduced. The paper put forward some opinion for hot charging process, and pointed out that the management level is the key measure of improving the process effects.

  15. Anisotropy and oxidative resistance of highly crosslinked UHMWPE after deformation processing by solid-state ram extrusion.

    Science.gov (United States)

    Kurtz, Steven M; Mazzucco, Dan; Rimnac, Clare M; Schroeder, Dave

    2006-01-01

    Solid-state deformation processing is a promising technique for modifying the physical and mechanical properties of highly crosslinked ultra-high molecular weight polyethylene (UHMWPE) beyond simple thermal treatment cycles that have been employed previously. This study evaluates anisotropy and oxidative resistance in a novel, radiation crosslinked (50 kGy) UHMWPE material (ArComXL: Biomet, Inc., Warsaw, IN), incorporating solid-state, deformation processing by extrusion below the melt transition for application in total hip arthroplasty. Tensile, compression, and small punch tests were conducted to evaluate the material properties in the three principal axes of the resulting material. Furthermore, short-term oxidative resistance was evaluated using Fourier transform infrared spectroscopy and the small punch test in conjunction with accelerated shelf aging protocols. The results of this testing indicate that the material is anisotropic, with significantly enhanced strength oriented along the long axis of the rod. For certain other properties, the magnitude of the anisotropy was relatively slight, especially in the elastic regime, in which only a 20% difference was noted between the long axis of the rod and the orthogonal, radial direction. The highly crosslinked material contains detectable free radicals, at a concentration that is 90% less than control, gamma inert sterilized UHMWPE. An unexpected finding of this study was evidence of oxidative stability of the deformation-processed material, even after 4 weeks of accelerated aging in a pressure vessel containing five atmospheres of oxygen (ASTM F2003), which resulted in macroscopic embrittlement of the control material. The oxidative stability observed in ArComXL suggests that the deformation-processed material may be suitable for air-permeable packaging and gas sterilization, which has thus far been reserved for remelted highly crosslinked UHMWPE.

  16. Analysis of Process Parameters for Optimization of Plastic Extrusion in Pipe Manufacturing

    Directory of Open Access Journals (Sweden)

    Mr. Sandip S. Gadekar

    2015-05-01

    Full Text Available The objective of this paper is to study the defects in the plastic pipe, to optimize the plastic pipe manufacturing process. It is very essential to learn the process parameter and the defect in the plastic pipe manufacturing process to optimize it. For the optimization Taguchi techniques is used in this paper. For the research work Shivraj HY-Tech Drip Irrigation pipe manufacturing, Company was selected. This paper is specifically design for the optimization in the current process. The experiment was analyzed using commercial Minitab16 software, interpretation has made, and optimized factor settings were chosen. After prediction of result the quality loss is calculated and it is compare with before implementation of DOE. The research works has improves the Production, quality and optimizes the process.

  17. 触头成型工艺分析与挤压模设计%Forming process analysis of contact and design of extrusion die

    Institute of Scientific and Technical Information of China (English)

    史慧玲

    2014-01-01

    Based on analysis of the forming process of Cu-Cr contact, the effects of differ-ent hot extrusion forming process schemes on the material utilization ratio were studied and compared. The hot extrusion of special-shaped stationary contact was performed by moving die with which can the material utilization and productivity be greatly increased.%在铜铬触头成型工艺分析的基础上,用不同的热挤压成型工艺方案对材料的利用率进行了分析对比,运用活动凹模对异型静触头进行了热挤压,材料利用率和生产效率得到大幅度提高。

  18. 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

  19. Modeling, Prediction, and Control of Heating Temperature for Tube Billet

    Directory of Open Access Journals (Sweden)

    Yachun Mao

    2015-01-01

    Full Text Available Annular furnaces have multivariate, nonlinear, large time lag, and cross coupling characteristics. The prediction and control of the exit temperature of a tube billet are important but difficult. We establish a prediction model for the final temperature of a tube billet through OS-ELM-DRPLS method. We address the complex production characteristics, integrate the advantages of PLS and ELM algorithms in establishing linear and nonlinear models, and consider model update and data lag. Based on the proposed model, we design a prediction control algorithm for tube billet temperature. The algorithm is validated using the practical production data of Baosteel Co., Ltd. Results show that the model achieves the precision required in industrial applications. The temperature of the tube billet can be controlled within the required temperature range through compensation control method.

  20. 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 (Tm) 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.

  1. Physical modelling and numerical simulation of the round-to-square forward extrusion

    DEFF Research Database (Denmark)

    Gouveia, B.P.P.A.; Rodrigues, J.M.C.; Martins, P.A.F.

    2001-01-01

    In this paper, three-dimensional forward extrusion of a square section from a round billet through a straight converging die is analysed using both physical modelling and numerical simulation (finite element and upper bound analysis). Theoretical fundamentals for each method are reviewed......, and comparisons are made between the numerical predictions and experimental data obtained through the utilisation of physical modelling. Assessment is made in terms of flow pattern and strain distribution for two different cross-sections corresponding to the axial symmetry planes of the three......-dimensional extrusion part. The experimental distribution of strain is determined from the shape change of quadrilateral grids previously printed on the surface of the axial cross-sections of the undeformed billets by means of large deformation square-grid analysis. Good agreement is obtained between physical...

  2. The Extrusion Process as an Alternative for Improving the Biological Potential of Sorghum Bran: Phenolic Compounds and Antiradical and Anti-Inflammatory Capacity

    Science.gov (United States)

    Salazar Lopez, Norma Julieta; Loarca-Piña, Guadalupe; Campos-Vega, Rocío; Gaytán Martínez, Marcela; Morales Sánchez, Eduardo; Esquerra-Brauer, J. Marina; Gonzalez-Aguilar, Gustavo A.

    2016-01-01

    Approximately 80% of sorghum phenolic compounds are linked to arabinoxylans by ester bonds, which are capable of resisting the digestion process in the upper gastrointestinal tract, compromising their bioaccessibility and biological potential. The aim of this study was to evaluate the effect of the extrusion process on the content of phenolic compounds in sorghum bran and its impact on phenolic compounds and antiradical and anti-inflammatory capacity. Results revealed that the extrusion process increased total phenol content in sorghum bran compared to nonextruded sorghum, particularly for extrusion at 180°C with 20% moisture content (2.0222 ± 0.0157 versus 3.0729 ± 0.0187 mg GAE/g +52%), which positively affected antiradical capacity measured by the DPPH and TEAC assays. The percentage of inhibition of nitric oxide (NO) production by RAW cells due to the presence of extruded sorghum bran extract was significantly higher than that of nonextruded sorghum bran extract (90.2 ± 1.9% versus 76.2 ± 1.3%). The results suggest that extruded sorghum bran could be used as a functional ingredient and provide advantages to consumers by reducing diseases related to oxidative stress and inflammation. PMID:27738445

  3. Compression and evaluation of extended release matrix pellets prepared by the extrusion/spheronization process into disintegrating tablets

    Directory of Open Access Journals (Sweden)

    Raveendra Pai

    2012-03-01

    Full Text Available In this study, a novel approach for compression of matrix pellets into disintegrating tablets has been studied in an attempt to overcome the issues pertaining to rupture of polymer coat during compression of reservoir-type pellets. Extended release matrix pellets were prepared by the extrusion/spheronization technique using commercially available aqueous dispersions of ethyl cellulose, acrylic polymers and sodium alginate at 10%, 20% and 30%w/w levels. Sertraline hydrochloride was used as the model drug and an in vitro release profile of 12 h was targeted. Tablets containing matrix pellets were prepared by the direct compression process. Acceptance Value, a pharmacopeial test, was applied to study the uniformity of drug distribution. Effect of compression force (2-6 kN, extrusion screen aperture size, diluent blend composition and pellet percentage on drug release and acceptance value were studied. As polymer is uniformly distributed within each pellet, the drug release pattern from uncompressed pellets was comparable to compressed tablets. Surface morphological changes due to calcium chloride treatment were observed using Scanning electron microscopy. The pellet segregated from the surface of the tablet was found to be flattened in the direction of applied compression force with minor deformities. In conclusion, matrix pellets can constitute an alternative approach to reservoir-type pellets in obtaining disintegrating tablets for extended delivery of drugs.Nesse trabalho, estudou-se nova abordagem para a compressão de matrizes de péletes em comprimidos desintegrantes, com o intuito de resolver os problemas relativos à ruptura do polímero de revestimento durante a compressão dos péletes do tipo reservatório. Matrizes de péletes de liberação estendida foram preparadas pela técnica de extrusão/esferonização, utilizando dispersões aquosas comercialmente disponíveis de etil celulose, polímeros acrílicos e alginato de sódio a 10

  4. Elaboration de membranes pour piles a combustible par extrusion

    OpenAIRE

    Chabert, France

    2004-01-01

    The aim of these studies was to process membranes by extrusion to be used in fuel cells. The functional polymers used are generally processed by polluting techniques like casting-evaporation, which are not easily transposable on industrial scale. Extrusion is a widely used shaping operation in the polymer processing industry. However, extrusion had not been used until now for arylsulfonic ionic polymers. In order to avoid any risk of degradation of the polymer during extrusion, it was necessa...

  5. EFFECTS OF LINEAR ELECTROMAGNETIC STIRRING ON THE SOLIDIFICATION STRUCTURE OF BILLET

    Institute of Scientific and Technical Information of China (English)

    H.L. Zhang; E.G. Wang; G.L. Jia; J.C. He

    2001-01-01

    The effects of linear electromagnetic stirring (EMS) on the solidification steacture of billet were investigated by experiments, and the electromagnetic fields and flow fields during the stirring process were analyzed by numerical simulation. The results show that the billet of almost 100% equiaxed grains can be obtained by applying linear EMS at the maximum intensity of 1414A.Hz1/2, while the maximum electromagnetic force and the maximum velocity in the molten steel are 6386N-m-3 and 0.22m.s-1,respectively. It is presented that the pulsating electromagnetic force perpendicular to the movement of the molten steel, is an important factor of increasing the equiaxed zone ratio in the solidification structure, which further prevents the appearance of white band and internal defects.

  6. Application of extrusion-cooking for processing of thermoplastic starch (TPS)

    NARCIS (Netherlands)

    Moscicki, Leszek; Mitrus, Marcin; Wojtowicz, Agnieszka; Oniszczuk, Tomasz; Rejak, Andrzej; Janssen, Leon; Mościcki, Leszek

    2012-01-01

    Thermoplastic starch (TPS) as fully biodegradable biopolymer appeared to be one of the most useful and promising materials for packaging purpose. To obtain TPS thermal and mechanical processing should disrupt semi-crystalline starch granules. As the melting temperature of pure starch is substantiall

  7. [Effect of the extrusion process on the functional characteristics and protein quality of quinua (Chenopodium quinoa, Willd)].

    Science.gov (United States)

    Romero, A; Bacigalupo, A; Bressani, R

    1985-03-01

    In order to have available a human food of high nutritive value, and conscious of the protein quality of the quinua, as well as its carbohydrate, vitamin and mineral content, its behavior during the extrusion process was tested in the present study. To eliminate saponins, a simple method was developed which consisted of washing the seeds through an aluminum container, using a wooden stirrer. Seven treatments were studied: washed quinua, washed and cooked quinua, washed and expanded quinua No. 1 and No. 2, and washed and texturized quinua No. 1 and No. 2; casein was used as control. Biological evaluation trials were carried out in Holtzman rats, following the PER method. To detect the possible effects of the processed quinua on the experimental animals, hematological as well as histopathological studies of the vital organs were performed. A maximum PER of 2.43 was obtained for the texturized quinua, 2.16 for the expanded quinua, 2.6 for the cooked quinua, while the casein control yielded a PER of 3.00. The physico-chemical characteristics of the quinua flour were determined, as well as those of the expanded and texturized products. The product obtained was subjected to an organoleptic trial and it can be stated that the results obtained were satisfactory. The product can be consumed directly without major modifications and has an acceptable flavor. The nutritive value of quinua was not impaired; it compared favorably with the best diets recommended for the population, especially of those with a lower income. The results obtained in the present study suggest the possibility of increasing the nutritional value of the product, as well as its acceptability.

  8. 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.

  9. Development of Rolling Schedules for Equal Channel Angular Extrusion (ECAE)-Processed AZ31 Magnesium Alloy

    Science.gov (United States)

    2016-04-01

    failing to comply with a collection of information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE...processed AZ31 magnesium plates have been developed. Using a temperature of 300 °C and a 10% reduction per rolling pass, the initially 9-mm-thick plates were... measured ductility along the longitudinal and transverse directions, respectively, than does texture C. 15. SUBJECT TERMS magnesium, AZ31, ECAE

  10. Chemical changes during extrusion cooking. Recent advances.

    Science.gov (United States)

    Camire, M E

    1998-01-01

    Cooking extruders process a variety of foods, feeds, and industrial materials. Greater flexibility in product development with extruders depends upon understanding chemical reactions that occur within the extruder barrel and at the die. Starch gelatinization and protein denautration are the most important reactions during extrusion. Proteins, starches, and non-starch polysaccharides can fragment, creating reactive molecules that may form new linkages not found in nature. Vitamin stability varies with vitamin structure, extrusion conditions, and food matrix composition. Little is known about the effects of extrusion parameters on phytochemical bioavailability and stability. Reactive extrusion to create new flavor, antioxidant and color compounds will be an area of interest in the future.

  11. Modelling the influence of the gas to melt ratio on the fraction solid of the surface in spray formed billets

    DEFF Research Database (Denmark)

    Hattel, Jesper Henri; Pryds, Nini

    2006-01-01

    In this paper, the relationship between the Gas to Melt Ratio (GMR) and the solid fraction of an evolving billet surface is investigated numerically. The basis for the analysis is a recently developed integrated procedure for modelling the entire spray forming process. This model includes the ato...

  12. Spray forming: A numerical investigation of the influence of the gas to melt ratio on the billet surface temperature

    DEFF Research Database (Denmark)

    Pryds, Nini; Hattel, Jesper

    2005-01-01

    The relationship between the Gas to Melt Ratio (GMR) and the surface temperature of an evolving billet surface in spray forming is investigated numerically. The basis for the analysis is an integrated approach for modelling the entire spray forming process. This model includes the droplet atomisa...

  13. Twin screw extrusion processing of distillers dried grains with solubles (DDGS)-based Yellow Perch (Perca flavescens) feeds

    Science.gov (United States)

    Increases in global aquaculture production, compounded with limited availabilities of fish meal for fish feed, has created the need for alternative protein sources. Twin-screw extrusion studies were performed to investigate the production of nutritionally-balanced feeds for juvenile yellow perch (Pe...

  14. THE PHYSICAL SIMULATION ON EXTRUSION PROCESS OF GLASS FIBER COMPOSITE WIRE COATED BY LEAD

    Institute of Scientific and Technical Information of China (English)

    H.F. Sun; W.B. Fang; F. Han; W.X. He; E.D. Wang

    2004-01-01

    The method of manufacturing the composite wire by extruding lead to coated glass fiber is described. The different composite wire that diameter is from 0.5 to 1.0mm has been produced by two kinds of different extruding technology (getting wire along horizontal direction and getting wire along perpendicular direction). The optimal extruding technological parameter has been given in different extruding technology by the physical simulation (H: 300℃, 550kN, 0.16mm. P: 300℃, 215kN, 0.16mm). The effect on the coating speed by other extruding technological parameters in the different extruding technology has been discussed. The extruding temperature and extruding force is higher, the coating speed is faster. It has been pointed, that the affection on the extruding technology by the extruding temperature has also behaved as the extruding temperature rising up spontaneously. The reason for exiting the minimum extruding force and maximum extruding force also has been discussion in this paper. It is also important to the extruding process and coating speed that is the coating clearance.

  15. Influence of DE-value on the physicochemical properties of maltodextrin for melt extrusion processes.

    Science.gov (United States)

    Castro, Natalia; Durrieu, Vanessa; Raynaud, Christine; Rouilly, Antoine

    2016-06-25

    In this study, five different types of maltodextrins (DE-2, DE-6, DE-12, DE-17 and DE-19) were characterized for the physico-chemical properties. TGA, DVS and SEC analyses were carried out and additionally apparent melt-viscosity (in a micro-extruder) and the glass transition temperature (analyzed by DMA) of maltodextrin/plasticizer mixtures were also measured in order to evaluate both the effect of plasticizer nature and content and the effect of the DE-value. For this, three plasticizing agents were compared: water, d-sorbitol and glycerin. The adsorption isotherms showed that depending on the DE-value and the relative humidity they were exposed to, different behavior could be obtained. For example, for relative humidities below 60% RH maltodextrin DE-2 was the least hygroscopic. And on the contrary for relative humidities above 75% RH maltodextrin DE-2 was the most hygroscopic. The rheology measurements showed that the viscosity decreased with the increase of the DE-value and with the plasticizer content, as expected. On the contrary, no direct correlation could be established between the DE-value and the glass transition temperature. These results demonstrated that to predict maltodextrins behavior and to better adapt the process conditions, combined analyses are mandatory as the DE-value alone is not sufficient. The most compelling evidence was obtained by size exclusion chromatography, which pointed out that maltodextrins had a bimodal molecular weight distribution composed of high and low molecular weight oligo-saccharides. Indeed, maltodextrins are highly polydisperse materials (i.e. polydispersity index ranging from 5 to 12) and that should be the reason why such distinct behaviors were observed in some of the physico-chemical analyses that were preformed.

  16. Physicochemical and dissolution profile characterization of pellets containing different binders obtained by the extrusion-spheronization process

    Directory of Open Access Journals (Sweden)

    Michele Georges Issa

    2012-09-01

    Full Text Available With the purpose of evaluating the behavior of different polymers employed as binders in small-diameter pellets for oral administration, we prepared formulations containing paracetamol and one of the following polymers: PVP, PEG 1500, hydroxypropylmethylcellulose and methylcellulose, and we evaluated their different binding properties. The pellets were obtained by the extrusion/spheronization process and were subsequently subjected to fluid bed drying. In order to assess drug delivery, the United States Pharmacopeia (USP apparatus 3 (Bio-Dis was employed, in conjunction with the method described by the same pharmacopeia for the dissolution of paracetamol tablets (apparatus 1. The pellets were also evaluated for granulometry, friability, true density and drug content. The results indicate that the different binders used are capable of affecting production in different ways, and some of the physicochemical characteristics of the pellets, as well as the dissolution test, revealed that the formulations acted like immediate-release products. The pellets obtained presented favorable release characteristics for orally disintegrating tablets. USP apparatus 3 seems to be more adequate for discriminating among formulations than the basket method.Com a finalidade de se avaliar o comportamento de diferentes polímeros empregados como aglutinantes em pellets de pequeno diâmetro para uso oral foram preparadas formulações contendo paracetamol e um dos seguintes polímeros: PVP, PEG 1500, hidroxipropilmetilcelulose e metilcelulose por apresentarem diferentes propriedades aglutinantes. Os pellets foram obtidos pelo processo de extrusão/esferonização e secagem em leito fluidizado. Para avaliar a liberação do fármaco, empregou-se o método 3 da Farmacopeia Americana, também conhecido como Bio-Dis e o método preconizado pela mesma farmacopeia para comprimidos de paracetamol. Os pellets foram avaliados, ainda, com relação à granulometria, friabilidade

  17. Study on Energy Consumption Analysis Modeling and Simulation in the Extrusion Process%挤压过程能耗分析及建模仿真

    Institute of Scientific and Technical Information of China (English)

    蒋攀

    2015-01-01

    A problem of high energy consumption and serious heat loss exists in the aluminum extrusion process and the main factor is the inefficiency of the extruder.The study was based on 10MN extruder.Energy consumption model was established about the hydraulic system in the extrusion process.The energy transmission,conversion and consumption were analysed. the key components of energy consumption were summarized and the theoretical formulas of Energy consumption were also presented. Using AMESim software to establish the simulation model and the validity of the model was proved .Then energy curves was analysed in the extrusion process.The results indicated that the mainly energy loss came from overflow losses,which have theoretical significance for energy-saving and optimize design of extruder.%铝挤压工艺能耗高、热量损失严重,挤压机的工作效率不高是主要因素,以10 MN铝挤压机为研究对象,针对挤压过程液压系统进行能耗建模:分析系统的能量传输、能量转换及能量消耗,总结出关键的耗能元件,并给出相应的理论能耗公式;利用AMESim软件建立仿真模型,证明了模型的正确性,分析了挤压过程各元件的能耗曲线,结果表明溢流损失是主要的能量损失方式,这对于挤压机的节能优化具有理论指导意义。

  18. Research on Process Parameters of AZ31 Magnesium Alloy Profile Expanding Extrusion%AZ31镁合金型材宽展挤压工艺参数研究

    Institute of Scientific and Technical Information of China (English)

    王锐

    2012-01-01

    在某镁业有限公司的挤压车间进行了AZ31镁合金型材宽展挤压温度、挤压速度和变形程度等工艺参数的研究,在某铝业有限公司进行了AZ31镁合金型材宽展挤压.通过对挤压温度、挤压速度和变形程度进行控制,有效地提高了出品速度和成品率,对于镁合金型材宽展挤压技术具有实践意义.%Extruding process parameters of AZ31 magnesium alloy profile expanding width were researched at a magnesium co., ltd., such as extrusion temperature, extrusion speed, deformation degree, etc., and AZ31 magnesium alloy profile expanding extrusion were implemented at as aluminium w,, ltd. Producing speed and finished product ratio were effectively elevated by effective control of extrusion temperature, extrusion speed and deformation degree. The research has practical significance for magnesium alloy profile expanding extrusion.

  19. An integrated numerical model for the prediction of Gaussian and billet shapes

    DEFF Research Database (Denmark)

    Hattel, Jesper; Pryds, Nini; Pedersen, Trine Bjerre

    2004-01-01

    Separate models for the atomisation and the deposition stages were recently integrated by the authors to form a unified model describing the entire spray-forming process. In the present paper, the focus is on describing the shape of the deposited material during the spray-forming process, obtained...... by this model. After a short review of the models and their coupling, the important factors which influence the resulting shape, i.e. Gaussian or billet, are addressed. The key parameters, which are utilized to predict the geometry and dimension of the deposited material, are the sticking efficiency...

  20. Development of a copy-peeling machine for machining the surface of hot rolled square billets

    Science.gov (United States)

    Koch, R. E.; Fangmeier, R.; Seppelt, B.

    1986-01-01

    A copy-peeling system to replace the high-pressure grinding method, especially for stainless steel qualities, was developed. The copy-peeling process for square billets was accomplished on an existing planing machine with special test attachments as well as on a specially developed copy-peeling machine. The attainable material removals and the tool life reached during the tests with stainless steel are not sufficient to offer an economic and technically advanced alternative to high-pressure grinding. The advantages of copy peeling with respect to safety and health of the operational personnel are obvious. However, it cannot be expected that this process will be applied extensively.

  1. 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.

  2. Application of quality by design (QbD) to formulation and processing of naproxen pellets by extrusion-spheronization.

    Science.gov (United States)

    Wang, Junlin; Kan, Shuling; Chen, Tong; Liu, Jianping

    2015-03-01

    The aim of this research was to apply quality by design (QbD) to the development of naproxen loaded core pellets which can be used as the potential core for colon-specific pellets. In the early stages of this study, prior knowledge and preliminary studies were systematically incorporated into the risk assessment using failure mode and effect analysis (FMEA) and fishbone diagram. Then Plackett-Burman design was used to screen eight potential high risk factors (spheronization speed, spheronization time, extrusion speed, drying method, CCMC-Na concentration, lactose concentration, water concentration and Tween 80 concentration) obtained from the above risk assessment. It was discovered that out of the eight potential high risk factors only three factors (spheronization speed, extrusion speed and CCMC-Na concentration) had significant effects on the quality of the pellets. This allowed the use of Box-Behnken design (BBD) to fully elucidate the relationship between the variables and critical quality attribute (CQA). Finally, the final control space was established within which the quality of the pellets can meet the requirement of colon-specific drug delivery system. This study demonstrated that naproxen loaded core pellets were successfully designed using QbD principle.

  3. Hot extrusion of Be–Ti powder

    Energy Technology Data Exchange (ETDEWEB)

    Kurinskiy, P., E-mail: petr.kurinskiy@kit.edu [Karlsruhe Institute of Technology, Institute for Applied Materials—Applied Materials Physics (IAM—AWP), PO Box 3640, 76021 Karlsruhe (Germany); Leiste, H. [Karlsruhe Institute of Technology, Institute for Applied Materials—Applied Materials Physics (IAM—AWP), PO Box 3640, 76021 Karlsruhe (Germany); Goraieb, A.A. [Karlsruhe Beryllium Handling Facility (KBHF GmbH), Herrmann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Mueller, S. [Extrusion Research and Development Center, TU Berlin, Sekr. TIB 4/1-2, Gustav-Meyer-Allee 25, 13355 Berlin (Germany)

    2015-10-15

    Highlights: • Extrusion in double-walled containment of Be–Ti blended powder was investigated. • Fabrication of Be–Ti rods by extrusion at 700 °C showed more satisfactory results compared to an extrusion at 900 °C. • Factors which influence homogeneous and stable metal flow during extrusion are discussed. - Abstract: Be–30.8 wt.%Ti powder mixture was extruded in copper and steel containers at 700 and 900 °C, respectively. In both cases, achieved extrusion ratio was 7:1. Investigations of microstructure of manufactured Be–Ti rods revealed that processing temperature has a great influence on the metal flow during the extrusion as well as formation of beryllide phases. The results obtained by X-ray diffraction (XRD) analysis proved that brittle intermetallic phases were formed by processing at 900 °C; while no evidence of reaction between beryllium and titanium was detected after extrusion at 700 °C. Additionally, high-temperature annealing tests of produced Be–Ti samples were performed in order to study the evolution of the phase composition after the heat treatment. The effects of different mechanical properties of core materials (beryllium and titanium) and containers on uniform deformation are discussed in this work.

  4. Co-extrusion of piezoelectric ceramic fibres

    OpenAIRE

    Ismael Michen, Marina

    2011-01-01

    The present work successfully developed a methodology for fabricating lead zirconate titanate [PZT] thin solid- and hollow-fibres by the thermoplastic co-extrusion process. The whole process chain, that includes: a) compounding, involving the mixing of ceramic powder with a thermoplastic binder, b) rheological characterizations, c) preform composite fabrication followed by co-extrusion, d) debinding and, finally, e) sintering of the body to near full density, is systematical...

  5. 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...... demands on the rheological properties of cementitious particulate materials, various methods have been suggested to dewater the particle suspension during extrusion, however practical extrusion of thin-walled cementitious large-scale elements has not been possible until the discovery of the “dewatering...

  6. 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.)

  7. Numerical Simulation of Tube-expanding Extrusion Process of Magnesium Alloy%镁合金扩管挤压过程的有限元数值模拟

    Institute of Scientific and Technical Information of China (English)

    沈群; 吴志林; 袁人枢; 宋德锋

    2013-01-01

    利用DEFORM-3D软件对AZ31镁合金扩管挤压成形过程进行了数值模拟,分析了不同温度和不同模具角度对成形挤压力的影响.结果表明,温度越高,挤压力越小;在给定的工艺参数下,得到了最佳模具角度,使得挤压力最小.数值模拟计算出的挤压力可以为挤压设备的选择提供依据.选取合适的挤压温度和最佳模具角度进行了挤压模拟,得到了挤压过程中等效应力场、等效应变场等的变化过程和分布规律,发现内外模具圆角处的应力应变值最大.分析了产生的原因,这能为模具优化提供参考.%The tube-expanding extrusion forming process of AZ31 magnesium alloy tube was numerically simulated by DEFORM-3D software. The influences of different temperatures and die angles on the extrusion force were analyzed. The results show that, the higher the temperature is, the smaller the extrusion force is. Under the given process parameters, the optimal die angle is obtained, making the extrusion force minimum. The extrusion force from numerical simulation can provide evidence for selecting the extrusion equipment. Choosing the suitable extrusion temperature and the optimal die angle, the extrusion simulation was carried out. The laws of extrusion process were obtained, including the effective stress field, the effective strain field, etc. It is found that the stress and strain value is biggest at the internal and external rounded corners of the die. The reason was analyzed, which provide reference for the optimization design of die.

  8. Extrusion of ECC-Material

    DEFF Research Database (Denmark)

    Stang, Henrik; Li, Victor C.

    1999-01-01

    in recent years at Department of Civil and Envirionmetal Engineering, University of Michigan. These materials have been developed with the special aim of producing high performance , strain hardening materials with low volume concentrations of short fibers in a cementitious material.ECC material spcimens...... have until now been produced by traditional casting processes. In the present paper results from a recent collaborative reserach project are documented - demonstrating that ECC materials can be extruded in the process referred to above.......An extrusion process especially designed for extrusion of pipes made from fiber reinforced cementitious materials has been developed at Department of Structural Engineering and Materials at the Technical University of DenmarkEngineered Cementitious Composite (ECC) materials have been developed...

  9. 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.

  10. Whole process modeling of joining of flareless AA 6061-T4 tube by extrusion-bulging forming using a polyurethane elastomer medium

    Science.gov (United States)

    Yang, J. C.; Li, H.; Yang, H.; Li, G. J.

    2016-08-01

    The tube joining by plastic deformation proves to be a more efficient and environmentally friendly way to achieve the tube-tube joining compared with other traditional types, such as metallurgical joining and mechanical joining. In this study, to reveal the effects of the processing parameters on the filling quality and residual contact stress, an axisymmetric finite element (FE) model of the whole joining process, including extrusion-bulging forming and unloading, was established and validated. The aluminum alloy (AA) 6061-T4 tubes, the stainless steel (ST) 15-5PH sleeve and polyurethane (PU) elastomer medium were characterized and modeled. And the implicit algorithm was adopted by comparing the prediction results between explicit and implicit FE models. The characteristics of stress distribution and plastic strain for the tube, PU elastomer and sleeve were discussed.

  11. 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

  12. Raman spectroscopy for the in-line polymer-drug quantification and solid state characterization during a pharmaceutical hot-melt extrusion process.

    Science.gov (United States)

    Saerens, L; Dierickx, L; Lenain, B; Vervaet, C; Remon, J P; De Beer, T

    2011-01-01

    The aim of this study was to evaluate the suitability of Raman spectroscopy as a Process Analytical Technology (PAT) tool for the in-line determination of the active pharmaceutical ingredient (API) concentration and the polymer-drug solid state during a pharmaceutical hot-melt extrusion process. For in-line API quantification, different metoprolol tartrate (MPT)--Eudragit® RL PO mixtures, containing 10%, 20%, 30% and 40% MPT, respectively, were extruded and monitored in-line in the die using Raman spectroscopy. A PLS model, regressing the MPT concentrations versus the in-line collected Raman spectra, was developed and validated, allowing real-time API concentration determination. The correlation between the predicted and real MPT concentrations of the validation samples is acceptable (R(2)=0.997). The predictive performance of the calibration model is rated by the root mean square error of prediction (RMSEP), which is 0.59%. Two different polymer-drug mixtures were prepared to evaluate the suitability of Raman spectroscopy for in-line polymer-drug solid state characterization. Mixture 1 contained 90% Eudragit® RS PO and 10% MPT and was extruded at 140°C, hence producing a solid solution. Mixture 2 contained 60% Eudragit® RS PO and 40% MPT and was extruded at 105°C, producing a solid dispersion. The Raman spectra collected during these extrusion processes provided two main observations. First, the MPT Raman peaks in the solid solution broadened compared to the corresponding solid dispersion peaks, indicating the presence of amorphous MPT. Second, peak shifts appeared in the spectra of the solid dispersion and solid solution compared to the physical mixtures, suggesting interactions between Eudragit® RS PO and MPT, most likely hydrogen bonds. These shifts were larger in the spectra of the solid solution. DSC analysis confirmed these Raman solid state observations and the interactions seen in the spectra. Raman spectroscopy is a potential PAT-tool for in

  13. Finite Element Analysis on Backward Extrusion Process for Vacuum Cup Inner Cylinder of AZ31 Magnesium Alloy%AZ31镁合金保温杯内筒反挤压成形模拟研究

    Institute of Scientific and Technical Information of China (English)

    钟兵

    2012-01-01

    运用DEFORM-3D有限元分析软件模拟了AZ31镁合金保温杯内筒反挤压过程,分析了温度和挤压速度对AZ31镁合金反挤压过程中的等效应力、挤压力的影响.模拟结果表明:凸模圆角处的等效应力值最大;随着温度的升高,所需要的最大挤压力变小;挤压速度越大,最大挤压力越大.%The backward extrusion process for the vacuum cup inner cylinder of AZ31 magnesium alloy was simulated by DEFORM-3D finite element software. The effects of the temperature and the extrusion speed on the equivalent stress and extrusion force were analyzed. The results show that the maximum equivalent stress was mainly concentrated around the punch round. With temperature increasing, the maximum extrusion force decreases. The greater the extrussion speed, the larger the maximum extrusion force.

  14. Processing of Mo-Si-B intermetallics by extrusion and oxidation properties of the extruded Tl-MoSi2-MoB System

    Energy Technology Data Exchange (ETDEWEB)

    Summers, Eric [Iowa State Univ., Ames, IA (United States)

    1999-11-08

    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 0.02°/minute (1.2°/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 (approximately 3 days). Wicking was investigated as a means to decrease the time necessary for binder removal. Using 0.05μm alumina powder as a wicking agent, binder removal times were reduced to 10 hours with heating rates up to 1°/minute employed without defect formation. Once the extrusion process was complete the oxidation properties of the Tl-MoSi2-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 mg2/cm4/hr were determined for 1,300, 1,450, and 1,600 C respectively.

  15. Processing of Mo-Si-B intermetallics by extrusion and oxidation properties of the extruded Tl-MoSi{sub 2}-MoB System

    Energy Technology Data Exchange (ETDEWEB)

    Summers, Eric

    1999-11-08

    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 0.02{degree}/minute (1.2{degree}/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 (approximately 3 days). Wicking was investigated as a means to decrease the time necessary for binder removal. Using 0.05{micro}m alumina powder as a wicking agent, binder removal times were reduced to 10 hours with heating rates up to 1{degree}/minute employed without defect formation. Once the extrusion process was complete the oxidation properties of the Tl-MoSi{sub 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{sup {minus}3}, 1.3 x 10{sup {minus}3}, and 9.1 x 10{sup {minus}3} mg{sup 2}/cm{sup 4}/hr were determined for 1,300, 1,450, and 1,600 C respectively.

  16. Comparison of the amount of apical debris extrusion associated with different retreatment systems and supplementary file application during retreatment process

    Science.gov (United States)

    Çiçek, Ersan; Koçak, Mustafa Murat; Koçak, Sibel; Sağlam, Baran Can

    2016-01-01

    Background: The type of instrument affects the amount of debris extruded. The aim of this study was to compare the effect of retreatment systems and supplementary file application on the amount of apical debris extrusion. Materials and Methods: Forty-eight extracted mandibular premolars with a single canal and similar length were selected. The root canals were prepared with the ProTaper Universal system with a torque-controlled engine. The root canals were dried and were obturated using Gutta-percha and sealer. The specimens were randomly divided into four equal groups according to the retreatment procedures (Group 1, Mtwo retreatment files; Group 2, Mtwo retreatment files + Mtwo rotary file #30 supplementary file; Group 3, ProTaper Universal retreatment (PTUR) files; and Group 4, PTUR files + ProTaper F3 supplementary file). The extruded debris during instrumentation were collected into preweighed Eppendorf tubes. The amount of apically extruded debris was calculated by subtracting the initial weight of the tube from the final weight. Three consecutive weights were obtained for each tube. Results: No statistically significant difference was found in the amount of apically extruded debris between Groups 1 and 3 (P = 0.590). A significant difference was observed between Groups 1 and 2 (P < 0.05), and between Groups 3 and 4 (P < 0.05). Conclusions: The use of supplementary file significantly increased the amount of apically extruded debris. PMID:27563185

  17. Method and apparatus for forming billets from metallic chip scraps

    Science.gov (United States)

    Girshov, Vladimir Leonidovich; Treschevskiy, Arnold Nikolayevich; Kochkin, Victor Georgievich; Abramov, Alexey Alexandrovich; Sidenko, Natalja Semenovna

    2006-05-02

    After recycled titanium alloy chips are crushed and cleaned, they are pressed into cylindrically briquettes with a relative density of 0.6, and placed into capsules. The capsules are heated and placed into a preheated pressing rig. The pressing rig repetitively applies axial force to the capsule, resulting in a relative density of at least 0.95. The product billets are used for consumable electrodes, secondary casting alloys, forgings, extruded semi-finished products and the like.

  18. An analysis of the relative importance of the comptroller billet across Navy activities

    OpenAIRE

    McPadden, Russell P.

    1983-01-01

    Approved for public release; distribution is unlimited This study examines the level of correlation between the billet requirements for Navy comptrollers and the organizational importance of their respective commands within the Navy hierarchy. Data were collected on the comptroller­ billets at 148 Navy shore activities which have military comptrollers. Each comptroller billet was ranked on pay grade, required education and experience. Commands were ranked according to overall command c...

  19. 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.

  20. 2A12合金的无润滑管材挤压工艺实验研究%Research of 2A12 alloy pipe extrusion process experiment with no lubrication

    Institute of Scientific and Technical Information of China (English)

    胡世军; 张代录; 梁东旭; 袁铭; 王瑞哲; 张红香

    2012-01-01

    In order to complete no lubrication extrusion on domestic 35 MN extruder, and reduce waste generation, by analyzing the material properties of 2A12 alloy and the structure characteristics of domestic 35 MN extruder, the transform of the extruder perforation needle system structure was performed and a no lubrication pipe extrusion experiment of the 2A12 alloy pipe on the machine was made. The experimental results show that the no lubrication pipe extrusion of 2A12 alloy can be realized in the proper control of process parameters, such as the extrusion speed, extrusion temperature and heating temperature. The inner surfaces of the extrusion product has good quality, its eccentricity is also improved greatly.%为了在国产35 MN挤压机上实现2A12合金管材的无润滑挤压,减少废品的产生,通过分析2A12合金的材料性能及国产35 MN挤压机的结构特点,对挤压机的穿孔针系统结构进行改造,并在该挤压机上进行了2A12合金的无润滑管材挤压实验.实验结果表明,在合理控制挤压速度、挤压温度、铸锭加热温度等工艺参数的条件下,可以实现2A12合金的无润滑管材挤压;挤压产品的内表面质量好,偏心度得到很大改善.

  1. Solidification Structure of Continuous Casting Large Round Billets under Mold Electromagnetic Stirring

    Institute of Scientific and Technical Information of China (English)

    Tao SUN; Feng YUE; Hua-jie WU; Chun GUO; Ying LI; Zhong-cun MA

    2016-01-01

    The solidification structure of a continuous casting large round billet was analyzed by a cellular-automaton-finite-element coupling model using the ProCAST software.The actual and simulated solidification structures were compared under mold electromagnetic stirring (MEMS)conditions (current of 300 A and frequency of 3 Hz).There-after,the solidification structures of the large round billet were investigated under different superheats,casting speeds,and secondary cooling intensities.Finally,the effect of the MEMS current on the solidification structures was obtained under fixed superheat,casting speed,secondary cooling intensity,and MEMS frequency.The model accurately simulated the actual solidification structures of any steel,regardless of its size and the parameters used in the continuous casting process.The ratio of the central equiaxed grain zone was found to increase with decreasing su-perheat,increasing casting speed,decreasing secondary cooling intensity,and increasing MEMS current.The grain size obviously decreased with decreasing superheat and increasing MEMS current but was less sensitive to the casting speed and secondary cooling intensity.

  2. The Influence of Extrusion Ratio on W-40 % Cu Alloy Produced by Powder Canning Hot Extrusion%挤压比对粉末包套热挤压致密W-40%Cu合金的影响

    Institute of Scientific and Technical Information of China (English)

    李达人; 蔡一湘; 刘祖岩; 王尔德

    2012-01-01

    采用不同挤压比对W-40%Cu混合粉末进行粉末包套热挤压,获得了W--40%Cu合金.研究了模具总挤压比λ对热挤压坯料致密化以及组织性能的影响.结果表明,随着挤压比的增加,热挤压坯料的相对密度也增加,同时电导率和硬度值也随之提高.由于含铜量比较高(质量分数为40%),即便在挤压比为25时,挤压坯内部W相也不发生变形,主要是铜相产生变形.进一步将模具总挤压比λ细分为不考虑体积变形的坯料总挤压比α,除去体积变形因素的坯料塑性挤压比β以及包套挤压比γ三种实际挤压比,分析了不同挤压比对热挤压致密化过程的影响.%W-40 wt.%Cu alloys with different extrusion ratio have been obtained by powder canning hot extrusion. The experimental results show that, the relative density, specific conductance and hardness of the billets increase with the adding extrusion ratio. There is no shape change of W phase after powder canning hot extrusion even if the extrusion ratio is up to 25 due to high content of Cu phase (40 wt.%). The deformation mainly occurs in Cu phase. The total extrusion ratio (λ) is divided into three kinds of actual extrusion ratio: the extrusion ratio of billet (α) without considering the volumetric deformation; the plastic extrusion ratio (β) excluding the influence of volumetric deformation; the extrusion ratio of can (γ). This article studies the influence of these three kinds of actual extrusion ratio on the densification of W-40 wt.% Cu alloy by powder canning hot extrusion.

  3. CAD implementation of design rules for aluminium extrusion dies

    NARCIS (Netherlands)

    Ouwerkerk, van Gijs

    2009-01-01

    Aluminium extrusion is an industrial forming process that is used to produce long profiles of a constant cross-section. This cross-section is shaped by the opening in a steel tool known as the die. The understanding of the mechanics of the aluminium extrusion process is still limited. The flow of al

  4. Quantification of microstructure refinement in aluminium deformed by equal channel angular extrusion: Route A vs. route Bc in a 90° die

    DEFF Research Database (Denmark)

    Mishin, Oleg; Bowen, Jacob R.; Lathabai, S.

    2010-01-01

    Microstructures in the centre of two commercial purity aluminium billets extruded through a 90° die either with or without 90° rotations between passes have been investigated using electron backscatter diffraction after eight passes of equal channel angular extrusion. Local heterogeneities in the...... in the form of low misorientation regions were present in both samples. The fraction of high-angle boundaries was found to be slightly greater in the sample extruded without rotation....

  5. 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

    2017-01-20

    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 < 0.05) at the end of 1 h. This study demonstrates a novel application of the hot melt extrusion

  6. 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...

  7. Numerical Modeling of Frictional Stress in the Contact Zone of Direct Extrusion of Aluminum Alloys under Starved Lubrication

    Science.gov (United States)

    Tomar, P.; Pandey, R. K.; Nath, Y.

    2013-11-01

    The objective of this article is to investigate numerically frictional stress in the contact zone at the die/billet interface in the direct extrusion of aluminum alloys considering starved lubricated conditions. In the modeling, both the inlet and work zones have been investigated by coupled solution of the governing equations. The influences of the billet material's strain hardening and its heating due to the plastic deformation are accounted for in the numerical computation. The frictional shear stress at the die/billet interface is computed using three different lubricating oils. Numerical results have been presented herein for the various operating parameters viz. starvation factor ( ψ = 0.2-0.6), lubricants' viscosities ( η 0 = 0.05 Pa s-0.2 Pa s), semi die angle ( β = 10°-20°), and material parameter ( G = 0.56-2.25). It has been observed that the frictional stress increases with an increase in the severity of the lubricant's starvation for the given values of semi-die angle, extrusion speed, and material parameter.

  8. The thermal distortion of continuous-casting billet molds

    Science.gov (United States)

    Samarasekera, I. V.; Anderson, D. L.; Brimacombe, J. K.

    1982-03-01

    Preliminary mathematical analyses involving plate bending theory and two-dimensional elastic calculations have revealed that the dominant component contributing to the distortion of continuous-casting billet molds is thermal expansion in the transverse directions. A three-dimensional, elasto-plastic, finite-element analysis of the mold wall has then shown that localized yielding initiates in a region close to the meniscus. The plastic flow is a result of the high thermal stresses induced by the geometric restraint to bending coupled with the locally high temperatures. The resultant distortion profile of the mold down the centerline of a face exhibits a maximum outward bulge of 0.1 to 0.3 mm, which is bounded above by a region of negative taper (1˜2 pct/m) and below by a region of positive taper (˜0.4 pct/m). Measurements of mold wall movement in an operating billet caster using linear displacement transducers compare favorably with model predictions, except in the meniscus region. Case studies of several industrial billet molds have shown that lowering the meniscus level with respect to the location of constraints, or modifying the method of support of the mold tube within its housing so as to reduce the restraint to thermal expansion in the meniscus region, may minimize the extent of permanent distortion. Also, wall thickness can have a significant effect on thermal distortion. Increasing wall thickness results in an increase in both peak wall temperatures and thermal gradients. The former increases the local distortion while the latter causes higher thermal stress levels and possibly permanent distortion. Of the casting variables that can be manipulated to major advantage, cooling water flow rate is the most important. Increasing the water velocity reduces mold wall temperatures, as well as both the total and permanent distortion of the wall.

  9. Influence of formulation and process parameters on the release characteristics of ethylcellulose sustained-release mini-matrices produced by hot-melt extrusion.

    Science.gov (United States)

    Verhoeven, E; De Beer, T R M; Van den Mooter, G; Remon, J P; Vervaet, C

    2008-05-01

    Mini-matrices (multiple unit dosage form) with release-sustaining properties were developed by hot-melt extrusion (cylindrical die: 3mm) using metoprolol tartrate as model drug and ethylcellulose as sustained-release agent. Dibutyl sebacate was selected as plasticizer and its concentration was optimized to 50% (w/w) of the ethylcellulose concentration. Xanthan gum, a hydrophilic polymer, was added to the formulation to increase drug release. Changing the xanthan gum concentration modified the in vitro drug release: increasing xanthan gum concentrations (1%, 2.5%, 5%, 10% and 20%, w/w) yielded a faster drug release. Zero-order drug release was obtained at 5% (w/w) xanthan gum. Using kneading paddles, smooth extrudates were obtained when processed at 60 degrees C. At least one mixing zone was required to obtain smooth and homogeneous extrudates. The mixing efficacy and drug release were not affected by the number of mixing zones or their position along the extruder barrel. Raman analysis revealed that metoprolol tartrate was homogeneously distributed in the mini-matrices, independent of screw design and processing conditions. Simultaneously changing the powder feed rate (6-25-50 g/min) and screw speed (30-100-200 rpm) did not alter extrudate quality or dissolution properties.

  10. Effects of Process Parameters on Fabrication of 2D- C f/Al Composite Parts by Liquid-Solid Extrusion Following the Vacuum Infiltration Technique

    Science.gov (United States)

    Ma, Y. Q.; Qi, L. H.; Zhou, J. M.; Zhang, T.; Li, H. J.

    2017-02-01

    Two-dimensional, carbon-fiber-reinforced aluminum matrix composites (2D- C f/Al composites) were prepared using liquid-solid extrusion by following the vacuum infiltration technique (LSEVI), which was an integrated and comprehensive process that resulted in as composite special-shaped part with ideal infiltration and a satisfied forming effect. According to the current research, we found preheating temperature, squeeze temperature, squeeze pressure, and melting temperature were the key parameters of the LSEVI technique, and it was very important to optimize these process parameters to obtain the ideal composite part. Through the research of orthogonal experimental design of these process parameters, results showed that squeeze pressure was the most significant influence parameter, and optimized parameters of aforementioned parameters were 888 K, 893 K, and 1053 K (615 °C, 620 °C, and 780 °C), 70 MPa, respectively. An infiltration effect of the C f/Al composite was full and uniform, and preparation defects could be avoided effectively under the above process parameters. Two-dimensional (2D) T300 carbon fiber preform was prepared by the method of carbon fiber laminates, and the 2D- C f/Al composite special-shaped part was fabricated successfully using the former optimized parameters of LSEVI. Results indicated a forming effect of the special-shaped part was obtained and that its sizes were reasonable. Through the analyses of microstructure and tensile property test, its infiltration effect and fracture morphology were satisfied. Carbon fibers in the composite played the reinforced effect effectively, so the ultimate tensile strength of the composite part was improved by 115.8 pct than that of the matrix, which proved that the optimized process parameters of the LSEVI technique were reasonable.

  11. An investigation into the influence of drug-polymer interactions on the miscibility, processability and structure of polyvinylpyrrolidone-based hot melt extrusion formulations.

    Science.gov (United States)

    Chan, Siok-Yee; Qi, Sheng; Craig, Duncan Q M

    2015-12-30

    While hot melt extrusion is now established within the pharmaceutical industry, the prediction of miscibility, processability and structural stability remains a pertinent issue, including the issue of whether molecular interaction is necessary for suitable performance. Here we integrate the use of theoretical and experimental drug-polymer interaction assessment with determination of processability and structure of dispersions in two polyvinylpyrrolidone-based polymers (PVP and PVP vinyl acetate, PVPVA). Caffeine and paracetamol were chosen as model drugs on the basis of their differing hydrogen bonding potential with PVP. Solubility parameter and interaction parameter calculations predicted a greater miscibility for paracetamol, while ATR-FTIR confirmed the hydrogen bonding propensity of the paracetamol with both polymers, with little interaction detected for caffeine. PVP was found to exhibit greater interaction and miscibility with paracetamol than did PVPVA. It was noted that lower processing temperatures (circa 40°C below the Tg of the polymer alone and Tm of the crystalline drug) and higher drug loadings with associated molecular dispersion up to 50% w/w were possible for the paracetamol dispersions, although molecular dispersion with the non-interactive caffeine was noted at loadings up to 20% w./w. A lower processing temperature was also noted for caffeine-loaded systems despite the absence of detectable interactions. The study has therefore indicated that theoretical and experimental detection of miscibility and drug-polymer interactions may lead to insights into product processing and extrudate structure, with direct molecular interaction representing a helpful but not essential aspect of drug-polymer combination prediction.

  12. 利用反应挤出技术改善淀粉基聚合物性能的研究%Application of Reactive Extrusion in Starch-based Polymer Processing

    Institute of Scientific and Technical Information of China (English)

    刘莉

    2012-01-01

    淀粉基聚合物的开发利用很大程度地减轻了环境污染,具有广阔的应用前景.鉴于反应挤出技术在改变产品的结构和化学性质方面极具优势,综述了反应挤出技术在淀粉基接枝共聚物和纳米复合材料等多相复合体系中的发展应用.%Development of starch-based polymer reduces the environmental pollution to a large extent and has broad application prospect. In view that the reactive extrusion technology has many advantages in modifying structure and chemical properties of polymer during processing, this paper focuses on the application of reactive extrusion in starch-based polymer processing, which includes graft copolymers and nanocom- posites.

  13. Reactive Extrusion of Zein with Glyoxal

    Science.gov (United States)

    Cross-linked zein has been produced using glyoxal as the cross-linking reagent via reactive extrusion for the first time in a twin screw extruder using dilute sodium hydroxide as catalyst. Tri(ethylene glycol) was used as a plasticizer for various items. The extrudate was then ground and processed...

  14. Influence of Billet Size on Flow, Solidification and Solute Transport in Continuous Casting

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hong-wei; WANG En-gang; HE Ji-cheng

    2003-01-01

    The influence of billet size on continuous casting was studied using the 3-D coupled turbulent flow, solidification and solute transport model. It is shown that the larger the billet size is, the larger the inlet velocity is; The deeper the stream penetration is and more liquid steel is pushed by mainstream, the stronger turbulent flow is observed in the upper part of mold. For Fe-C binary alloy system, the thickness of solidified shell is determined by temperature and solute concentration. The more serious macrosegregation and thinner shell are observed for smaller billet, thus a longer mold should be used.

  15. Formation of internal cracks in steel billets during soft reduction

    Institute of Scientific and Technical Information of China (English)

    Wenjun Wang; Linxin Ning; Raimund Biilte; Wolfgang Bleck

    2008-01-01

    To investigate the formation of internal cracks in steel billets during soft reduction, fully coupled thermo-mechanical finite element models were developed using the commercial software ABAQUS, also casting and soft reduction tests were carried out in a laboratory strand casting machine. With the finite element models, the temperature distribution, the stress and strain states in the bil- let were calculated. The relation between internal cracks and equivalent plastic strain, as well as maximal principal stress was ana- lyzed. The results indicate that tensile stresses can develop in the mushy zone during soft reduction and the equivalent strain nearby the zero ductility temperature (ZDT) increases with decreasing sofid fraction. Internal cracks can be initiated when the accumulated strain exceeds the critical strain or the applied tensile stress exceeds the critical fracture stress during solidification.

  16. Numerical Simulation for Canning Extrusion Process of FGH96%FGH96合金包覆挤压过程数值模拟

    Institute of Scientific and Technical Information of China (English)

    朱兴林; 刘东; 杨艳慧; 牛关梅

    2013-01-01

    The configuration and dimension of the die are critical for canning extrusion of FGH96 P/M superalloy. In this paper, the influence of die angle, band length and entrance fillet of the dies on the canning integrality, extrusion ratio of the core, and extrusion force were analyzed comprehensively by using FEM and orthogonal method. The results of FEM numerical simulation and orthogonal a-nalysis indicate that the integrality of canning and extrusion ratio of the core were improved with the decrease in die angle, band length and increase in entrance fillet of the die. The optimal combination of the structural parameters of the extrusion die was obtained.%采用有限元数值模拟与正交设计相结合的方法对热等静压态FGH96合金包覆挤压过程进行了数值模拟,系统分析了模具模角、工作带长度、入口圆角半径等模具关键结构参数对包覆层完整性、芯料挤压比和成形载荷的影响规律.确定了模具结构参数的最佳组合.结果表明:随着模角的减小、工作带长度的缩短和入口圆角半径的增大,有利于提高包覆层安全性,增大芯料挤压比.

  17. Estimation of design space for an extrusion-spheronization process using response surface methodology and artificial neural network modelling.

    Science.gov (United States)

    Sovány, Tamás; Tislér, Zsófia; Kristó, Katalin; Kelemen, András; Regdon, Géza

    2016-09-01

    The application of the Quality by Design principles is one of the key issues of the recent pharmaceutical developments. In the past decade a lot of knowledge was collected about the practical realization of the concept, but there are still a lot of unanswered questions. The key requirement of the concept is the mathematical description of the effect of the critical factors and their interactions on the critical quality attributes (CQAs) of the product. The process design space (PDS) is usually determined by the use of design of experiment (DoE) based response surface methodologies (RSM), but inaccuracies in the applied polynomial models often resulted in the over/underestimation of the real trends and changes making the calculations uncertain, especially in the edge regions of the PDS. The completion of RSM with artificial neural network (ANN) based models is therefore a commonly used method to reduce the uncertainties. Nevertheless, since the different researches are focusing on the use of a given DoE, there is lack of comparative studies on different experimental layouts. Therefore, the aim of present study was to investigate the effect of the different DoE layouts (2 level full factorial, Central Composite, Box-Behnken, 3 level fractional and 3 level full factorial design) on the model predictability and to compare model sensitivities according to the organization of the experimental data set. It was revealed that the size of the design space could differ more than 40% calculated with different polynomial models, which was associated with a considerable shift in its position when higher level layouts were applied. The shift was more considerable when the calculation was based on RSM. The model predictability was also better with ANN based models. Nevertheless, both modelling methods exhibit considerable sensitivity to the organization of the experimental data set, and the use of design layouts is recommended, where the extreme values factors are more represented.

  18. Ram speed profile design for isothermal extrusion of AZ31 magnesium alloy by using FEM simulation

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In the conventional hot extrusion of metallic materials,the temperature of the workpiece varies during the whole extrusion process,leading to the non-uniformity of the product dimension,microstructure and properties.In the present research,a simulation model based on the principle of PID control was developed to establish ram speed profiles that can suppress the temperature evolution during the process to allow for isothermaI extrusion.With this simulation model,the real-time extrusion ram speed was adjusted according to the simulated exit temperature.The results show that temperature homogeneity is significantly improved not only along the extrudate length but also on its cross section in the case of extrusion in the isothermal mode with a designed ram speed profile in the extrusion process of AZ31 magnesium.In addition,die temperature varies over a more narrow range in comparison with extrusion in the conventional iso-speed mode.

  19. Calibrator device for the extrusion of cable coatings

    Science.gov (United States)

    Garbacz, Tomasz; Dulebová, Ľudmila; Spišák, Emil; Dulebová, Martina

    2016-05-01

    This paper presents selected results of theoretical and experimental research works on a new calibration device (calibrators) used to produce coatings of electric cables. The aim of this study is to present design solution calibration equipment and present a new calibration machine, which is an important element of the modernized technology extrusion lines for coating cables. As a result of the extrusion process of PVC modified with blowing agents, an extrudate in the form of an electrical cable was obtained. The conditions of the extrusion process were properly selected, which made it possible to obtain a product with solid external surface and cellular core.

  20. Formation of Chromosomal Domains by Loop Extrusion

    Directory of Open Access Journals (Sweden)

    Geoffrey Fudenberg

    2016-05-01

    Full Text Available Topologically associating domains (TADs are fundamental structural and functional building blocks of human interphase chromosomes, yet the mechanisms of TAD formation remain unclear. Here, we propose that loop extrusion underlies TAD formation. In this process, cis-acting loop-extruding factors, likely cohesins, form progressively larger loops but stall at TAD boundaries due to interactions with boundary proteins, including CTCF. Using polymer simulations, we show that this model produces TADs and finer-scale features of Hi-C data. Each TAD emerges from multiple loops dynamically formed through extrusion, contrary to typical illustrations of single static loops. Loop extrusion both explains diverse experimental observations—including the preferential orientation of CTCF motifs, enrichments of architectural proteins at TAD boundaries, and boundary deletion experiments—and makes specific predictions for the depletion of CTCF versus cohesin. Finally, loop extrusion has potentially far-ranging consequences for processes such as enhancer-promoter interactions, orientation-specific chromosomal looping, and compaction of mitotic chromosomes.

  1. The stability of beam with two billeting arbitrarily, but symmetrical support under action of follow loading

    Directory of Open Access Journals (Sweden)

    V.Ts. Gnuni

    2016-03-01

    Full Text Available The non-conservative stability problem of pressing beam when two support billeting symmetrical on arbitrarily distance from the end is considered. It is show the possibility statical form loss of stability. The critical loads are determined.

  2. Volume calculation of the spur gear billet for cold precision forging with average circle method

    Institute of Scientific and Technical Information of China (English)

    Wangjun Cheng; Chengzhong Chi; Yongzhen Wang; Peng Lin; Wei Liang; Chen Li

    2014-01-01

    Forging spur gears are widely used in the driving system of mining machinery and equipment due to their higher strength and dimensional accuracy. For the purpose of precisely calculating the volume of cylindrical spur gear billet in cold precision forging, a new theoretical method named average circle method was put forward. With this method, a series of gear billet volumes were calculated. Comparing with the accurate three-dimensional modeling method, the accuracy of average circle method by theoretical calculation was estimated and the maximum relative error of average circle method was less than 1.5%, which was in good agreement with the experimental results. Relative errors of the calculated and the experimental for obtaining the gear billet volumes with reference circle method are larger than those of the average circle method. It shows that average circle method possesses a higher calculation accuracy than reference circle method (traditional method), which should be worth popularizing widely in calculation of spur gear billet volume.

  3. Semisolid casting with ultrasonically melt-treated billets of Al-7mass%Si alloys

    Directory of Open Access Journals (Sweden)

    Yoshiki Tsunekawa

    2012-02-01

    Full Text Available The demand for high performance cast aluminum alloy components is often disturbed by increasing impurity elements, such as iron accumulated from recycled scraps. It is strongly required that coarse plate-like iron compound of モ-Al5FeSi turns into harmless form without the need for applying refining additives or expensive virgin ingots. The microstructural modification of Al-7mass%Si alloy billets with different iron contents was examined by applying ultrasonic vibration during the solidification. Ultrasonically melt-treated billets were thixocast right after induction heating up to the semisolid temperature of 583 ìC, the microstructure and tensile properties were evaluated in the thixocast components. Globular primary メ-Al is required to fill up a thin cavity in thixocasting, so that the microstructural modification by ultrasonic melt-treatment was firstly confirmed in the billets. With ultrasonic melt-treatment in the temperature range of 630 ìC to 605 ìC, the primary メ-Al transforms itself from dendrite into fine globular in morphology. The coarse plate-like モ-Al5FeSi compound becomes markedly finer compared with those in non-treated billets. Semisolid soaking up to 583 ìC, does not appreciably affect the size of モ-Al5FeSi compounds; however, it affects the solid primary メ-Al morphology to be more globular, which is convenient for thixocasting. After thixocasting with preheated billets, eutectic silicon plates are extremely refined due to the rapid solidification arising from low casting temperature. The tensile strength of thixocast samples with different iron contents does not change much even at 2mass% of iron, when thixocast with ultrasonically melt-treated billets. However, thixocast Al-7mass%Si-2mass%Fe alloy with non-treated billets exhibits an inferior strength of 80 MPa, compared with 180 MPa with ultrasonically melt-treated billets. The elongation is also improved by about a factor of two in thixocastings with

  4. Effects of Ram Speed on AZ31 Mg Alloy Thin-walled Tube Porthole Extrusion Based on FEM%AZ31镁合金薄壁管分流挤压速度影响规律仿真研究

    Institute of Scientific and Technical Information of China (English)

    张保军; 杨合; 郭良刚; 石磊; 谷瑞杰; 寇永乐

    2012-01-01

    基于DEFORM-3D平台,以军用战地发射塔天线用AZ31镁合金薄壁管分流挤压工艺过程为研究对象,研究建立了精确、高效的AZ31镁合金薄壁管分流挤压有限元模型.模拟研究揭示了挤压速度对挤压力、焊合压力及模口坯料金属峰值温度的影响规律.基于所得规律,综合考虑挤压力、焊合质量及挤出管材表面质量要求,获得了该规格AZ31镁合金薄壁管在2000t挤压机上的合理挤压速度范围为3.5~7 mm/s.%A precise and efficient 3D-FE model of the porthole extrusion process for AZ31 Mg alloy thin-walled tube, used to manufacture towers antenna in battlefield, was developed in the DEFORM-3D software environment. And the influencing laws of ram speed on the load, welding pressure and the peak temperature of billet at die export were investigated and revealed by comprehensive numerical simulations. With integrated consideration of the extrusion load, quality of welding area and surface quality of the extruded tube, it is proposed that the optimum ram speed range is about 3.5-7 mm/s for the extrusion of AZ31 Mg alloy thin-walled tube on a 2000 t extrusion machine.

  5. ROLE OF MELT EXTRUSION IN THE ENHANCEMENT OF BIOAVAILABILITY

    Directory of Open Access Journals (Sweden)

    Sahil Bansode* and S. S. Poddar

    2012-11-01

    Full Text Available Starting from plastic industry, today melt extrusion has found its place in the array of pharmaceutical manufacturing processes. Melt extrusion processes are currently applied in the pharmaceutical field for the formulation of variety of dosage forms such as granules, pellets, tablets, implants, transdermal systems & ophthalmic inserts. This technology represents an efficient pathway for increasing the solubility of poorly soluble drugs. The process forms a solid dispersion where the drug is presented in an amorphous & molecularly dispersed state in a carrier. This leads to an increase in solubility, as no lattice energy has to be overcome during dissolution. Melt extrusion is considered to be an efficient technology in the field of formulation of solid dispersions to improve bioavailability with particular advantages over solvent processes. This article highlights on the technology of Hot Melt Extrusion (HME.

  6. Initial billet and forging dies shape optimization: Application on an axisymetrical forging with a hammer

    Science.gov (United States)

    Meng, Fanjuan; Labergere, Carl; Lafon, Pascal

    2011-05-01

    In metal forming process, the forging die design is the most important step for products quality control. Reasonable dies shape can not only reduce raw material cost but also improving material flow and eliminating defects. The main objective of this paper is to obtain some optimal parameters of the initial billet and forging dies shape according to the simulation results of a two-step metal forming process (platting step and forging step). To develop this metal forming process optimization system several numerical tools are required: geometric modelling (CATIA V5™), FEM analysis (ABAQUS®), work-flow control and optimization computation (MODEFRONTIER®). This study is done in three stages: simulating the two-step metal forming process, building surrogate meta-models to relate response and variables and optimizing the process by using advanced optimization algorithms. In this paper, a two-step axisymmetric metal forming project was studied as an example. By using our simulation model, we get 581 correct real simulation results totally. According to all these real values, we build the surrogate meta-models and obtain Pareto points for a two-objective optimization process. The choice of a solution in all Pareto points will be done by the engineer who can choose his best values according to their criterions of project.

  7. Eulerian hydrocode modeling of a dynamic tensile extrusion experiment (u)

    Energy Technology Data Exchange (ETDEWEB)

    Burkett, Michael W [Los Alamos National Laboratory; Clancy, Sean P [Los Alamos National Laboratory

    2009-01-01

    Eulerian hydrocode simulations utilizing the Mechanical Threshold Stress flow stress model were performed to provide insight into a dynamic extrusion experiment. The dynamic extrusion response of copper (three different grain sizes) and tantalum spheres were simulated with MESA, an explicit, 2-D Eulerian continuum mechanics hydrocode and compared with experimental data. The experimental data consisted of high-speed images of the extrusion process, recovered extruded samples, and post test metallography. The hydrocode was developed to predict large-strain and high-strain-rate loading problems. Some of the features of the features of MESA include a high-order advection algorithm, a material interface tracking scheme and a van Leer monotonic advection-limiting. The Mechanical Threshold Stress (MTS) model was utilized to evolve the flow stress as a function of strain, strain rate and temperature for copper and tantalum. Plastic strains exceeding 300% were predicted in the extrusion of copper at 400 m/s, while plastic strains exceeding 800% were predicted for Ta. Quantitative comparisons between the predicted and measured deformation topologies and extrusion rate were made. Additionally, predictions of the texture evolution (based upon the deformation rate history and the rigid body rotations experienced by the copper during the extrusion process) were compared with the orientation imaging microscopy measurements. Finally, comparisons between the calculated and measured influence of the initial texture on the dynamic extrusion response of tantalum was performed.

  8. Application of the Billet Casting Method to Determine the Onset of Incipient Melting of 319 Al Alloy Engine Blocks

    Science.gov (United States)

    Lombardi, A.; Ravindran, C.; MacKay, R.

    2015-06-01

    The increased use of Al for automotive applications has resulted from the need to improve vehicle fuel efficiency. Aluminum alloy engine blocks fulfil the need of lightweighting. However, there are many challenges associated with thermo-mechanical mismatch between Al and the gray cast iron cylinder liners, which result in large tensile residual stress along the cylinder bores. This requires improced mechanical properties in this region to prevent premature engine failure. In this study, replicating billet castings were used to simulate the engine block solution heat treatment process and determine the onset of incipient melting. Microstructural changes during heat treatment were assessed with SEM and EDX, while thermal analysis was carried out using differential scanning calorimetry. The results suggest that solution heat treatment at 500 °C was effective in dissolving secondary phase particles, while solutionizing at 515 or 530 °C caused incipient melting of Al2Cu and Al5Mg8Cu2Si6. Incipient melting caused the formation ultra-fine eutectic clusters consisting of Al, Al2Cu, and Al5Mg8Cu2Si6 on quenching. In addition, DSC analysis found that incipient melting initiated at 507 °C for all billets, although the quantity of local melting reduced with microstructural refinement as evidenced by smaller endothermic peaks and energy absorption. The results from this study will assist in improving engine block casting integrity and process efficiency.

  9. Encapsulation of Liquids Via Extrusion--A Review.

    Science.gov (United States)

    Tackenberg, Markus W; Kleinebudde, Peter

    2015-01-01

    Various encapsulation techniques are known for pharmaceutical applications. Extrusion is of minor importance. However, extrusion is used to obtain granules with encapsulate liquid active ingredients (AI) like essential oils and flavours for food applications since decades. Many of these AIs can be used for agrochemical, home care, and pharmaceutical products, too. Thus, the focus of this review is on the interdisciplinary presentation and evaluation of the available knowledge about the encapsulation process via extrusion. The desired microcapsule structure is discussed at the outset. The microcapsule is compared to the alternative glassy solid solution system, before an overview of suitable excipients is given. In the next section the development of the extrusion technique, used for encapsulation processes, is presented. Thereby, the focus is on encapsulation using twin-screw extruders. Additionally, the influence of the downstream processes on the products is discussed, too. The understanding of the physical processes during extrusion is essential for specifically adjustment of the desired product properties and thus, highlighted in this paper. Unfortunately not all processes, especially the mixing process, are well studied. Suggestions for further studies, to improve process understanding and product quality, are given, too. The last part of this review focuses on the characterization of the obtained granules, especially AI content, encapsulation efficiency, and storage stability. In conclusion, extrusion is a standard technique for flavour encapsulation, but future studies, may lead to more (pharmaceutical) applications and new products.

  10. 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...

  11. Two-Layer Linear MPC Approach Aimed at Walking Beam Billets Reheating Furnace Optimization

    Directory of Open Access Journals (Sweden)

    Silvia Maria Zanoli

    2017-01-01

    Full Text Available In this paper, the problem of the control and optimization of a walking beam billets reheating furnace located in an Italian steel plant is analyzed. An ad hoc Advanced Process Control framework has been developed, based on a two-layer linear Model Predictive Control architecture. This control block optimizes the steady and transient states of the considered process. Two main problems have been addressed. First, in order to manage all process conditions, a tailored module defines the process variables set to be included in the control problem. In particular, a unified approach for the selection on the control inputs to be used for control objectives related to the process outputs is guaranteed. The impact of the proposed method on the controller formulation is also detailed. Second, an innovative mathematical approach for stoichiometric ratios constraints handling has been proposed, together with their introduction in the controller optimization problems. The designed control system has been installed on a real plant, replacing operators’ mental model in the conduction of local PID controllers. After two years from the first startup, a strong energy efficiency improvement has been observed.

  12. Effect of original microstructures on microstructural evolution of A2017 semi-solid alloy billets during reheating

    Institute of Scientific and Technical Information of China (English)

    WANG Shun-cheng; CAO Fu-rong; WEN Jing-lin

    2005-01-01

    The microstructural evolution of the A2017 semi-solid alloy billets provided with rheocasting and extruding/extending forming by shearing-cooling-rolling(SCR) technology during reheating in semi-solid state was investigated. The microstructural differences and their generation causes for both billets were also analyzed. The results show that during reheating, the grains of rheocasting billets grow up and spheroidize gradually with the prolongation of isothermal holding time, the eutectic liquid phase at low melting point forms mainly among the grains. However, the grains of the extruding/extending forming billets grow up abnormally through grain coalescence in the initial stage of the reheating, the entrapment of large amount of liquid within grains occurs, and the grain sizes in the reheating billets are coarse and inhomogeneous. Compared with extruding/extending forming billets, rheocasting billets have smaller and uniform grains in reheating microstructure and can rapidly form liquid phase among grains. Therefore, rheocasting billets are more suitable for the semi-solid forming than the extruding/extending forming billets.

  13. Study on Numerical Simulation of Hot Extrusion Process of Automobile's Hollow Front Axle%汽车前桥空心短轴的热挤压成形工艺数值模拟研究

    Institute of Scientific and Technical Information of China (English)

    韦国强; 管延锦; 朱立华; 解振东; 孙德朋

    2016-01-01

    A hot extrusion process was proposed to improve the productivity and the material utilization in the manufacture of automobile's hollow front axle . Numerical simulations under various conditions designed by the orthogonal method were done to optimize parameters of the final step of hot extrusion process . Finally the production efficiency , material utilization and product quality were improved and the optimal shaping quality was achieved .%针对某汽车前桥短轴类零件成形制造中存在的生产效率和材料利用率低的问题,提出并设计了热挤压成形制造工艺。通过正交法设计多组参数条件进行数值模拟,实现了热挤压终成形工步的工艺参数优化,获得了最优的成形效果,达到了提高生产效率、材料利用率以及零件质量的目标。

  14. Hot Extrusion Process Effect on Mechanical Behavior of Stir Cast Al Based Composites Reinforced with Mechanically Milled B4C Nanoparticles

    Institute of Scientific and Technical Information of China (English)

    A. Alizadeh1; E. Taheri-Nassaj; M. Hajizamani

    2011-01-01

    In this study, aluminum alloy (Al-2 wt% Cu) matrix composites reinforced with 1, 2 and 4 wt% boron carbide nanoparticles fabricated through mechanical milling with average size of 100 nm were fabricated via stir casting method at 850℃. Cast ingots of the matrix alloy and the composites were extruded at 500℃ at an extrusion ratio of 10:1 to investigate the effects of hot extrusion on the mechanical properties of the composites. The microstructures of the as-cast and the extruded composites were investigated by scanning electron microscopy (SEM). Density measurement, hardness and tensile tests were carried out to identify the mechanical properties of the composites. The extruded samples revealed a more uniform distribution of B4C nanoparticles. Also, the extruded samples had strength and ductility values superior to those of the as-cast counterparts. In the as-cast and the extruded samples, with increasing amount of B4C nanoparticles, yield strength and tensile strength increased but elongation to fracture decreased.

  15. The effect of gas assisted length on polymer melt extrusion based on the gas-assisted extrusion technique

    Science.gov (United States)

    Wan, B.; Ren, Z.; Liu, G. D.; Huang, X. Y.

    2017-02-01

    In this study, the gas-assisted technique was used into the process of polymer melt extrusion to overcome the extrudate swell problem. The gas length is an important factors in the gas-assisted extrusion technique. To ascertain the mechanism of the gas-assisted extrusion technique, and to determine the optimal gas length, the effect of gas length on the extrudate swell ratio of melt was numerically investigated. In finite element numerical simulation, PTT constitutive model and full slip boundary condition were used to achieve the gas-assisted mode. Compared with the traditional no gas-assisted extrusion, numerical results showed that the extrudate swell problem was well eliminated by the gas-assisted method. Moreover, the extrudate swell of melt decreased with the increasing of the gas length because the pressure and shear stress of melt were greatly decreased. Moreover, the flow velocity of melt is uniform at the die outlet.

  16. Improvement of center segregation in high-carbon steel billets using soft reduction

    Institute of Scientific and Technical Information of China (English)

    Wenjun Wang; Xionggang Hu; Linxin Ning; Raimund Bülte; Wolfgang Bleck

    2006-01-01

    Center segregation is the main reason for cup fracture of high-carbon wire rod during drawing. Therefore, to continuously produce cast billets with very low center segregation is an important objective. The soft reduction technology is considered to be an effective method to minimize center segregation. To elucidate the effect of soft reduction on the internal quality of high-carbon steel billets, soft reduction was applied with different solid fractions in the core area of billets in a laboratory casting machine. A coupled temperature/displacement finite element model was developed to calculate the solid fraction using the commercial software ABAQUS.Center segregation, center porosity, homogeneity of elements, and equiaxed crystal zone were obviously improved by applying soft reduction, especially when the solid fraction was less than 1.0. The optimal results were obtained when the solid fraction was approximately 0.9.

  17. Experimental and numerical analyses of pure copper during ECFE process as a novel severe plastic deformation method

    Directory of Open Access Journals (Sweden)

    M. Ebrahimi

    2014-02-01

    Full Text Available In this paper, a new severe plastic deformation method called equal channel forward extrusion (ECFE process has been proposed and investigated by experimental and numerical approaches on the commercial pure copper billets. The experimental results indicated that the magnitudes of yield strength, ultimate tensile strength and Vickers micro-hardness have been markedly improved from 114 MPa, 204 MPa and 68 HV as the annealed condition to 269 MPa, 285 MPa and 126 HV after the fourth pass of ECFE process, respectively. In addition, scanning electron microscopy observation of the samples showed that the average grain size of the as-received state which is about 22 μm has been reduced to 1.4 μm after the final pass. The numerical investigation suggested that although one pass ECFE process fabricates material with the mean effective strain magnitude of about 1, the level of imposed effective plastic strain gradually diminishes from the circumference to the center of the deformed billet.

  18. THE COMBINED PROCESSES STUDY FOR MANUFACTURING AIRCRAFT PARTS

    Directory of Open Access Journals (Sweden)

    Mr. Boris N. Maryin

    2016-06-01

    Full Text Available The article is devoted to research of the combined processes of forming tubular billets with various media in the process of bending-expanding, breaking-down -expanding while using thermal effects. The paper discusses the processes of forming tubular billets of hard punches, using elastic-granular materials, the peculiarities of forming tubular billets, while the breaking-down -expanding of crimp in a hard punch using elastic-granular bodies. The article presents experimental studies of the bending-expanding of tubular billets in horn-shaped blanks. The authors established the main features of billet distorting in the combined process. The article shows a diagram of the true distorting distribution in the process of stretching and compression in the horn-shaped blanks. The recommendations allow increasing the bending moment and realizing better shaping. The authors make conclusions about the prospects of the application of combined processes in air and rocket.

  19. Induction heating of rotating nonmagnetic billet in magnetic field produced by high-parameter permanent magnets

    Directory of Open Access Journals (Sweden)

    Ivo Doležel

    2014-04-01

    Full Text Available An advanced way of induction heating of nonmagnetic billets is discussed and modeled. The billet rotates in a stationary magnetic field produced by unmoving high-parameter permanent magnets fixed on magnetic circuit of an appropriate shape. The mathematical model of the problem consisting of two coupled partial differential equations is solved numerically, in the monolithic formulation. Computations are carried out using our own code Agros2D based on a fully adaptive higher-order finite element method. The most important results are verified experimentally on our own laboratory device.

  20. Performance of Halogen-Free Flame Retardant Cable and Extrusion Process%试析无卤低烟阻燃电缆性能与挤出工艺

    Institute of Scientific and Technical Information of China (English)

    王冬梅

    2013-01-01

    近年来,我国经济发展迅猛,电缆材料的阻燃技术也随之提高,无卤低烟阻燃将成为电缆行业主要的发展趋势。本文分析了无卤低烟阻燃电缆的结构与性能,阐述了这种电缆在生产过程中使用的挤制工艺。%In recent years, China's economy is rapidly developing, and the flame retardant technology of cable material is also increased. Halogen-free flame retardant will become the major trends in the cable industry. This paper analyzes the structure and property of the halogen-free flame retardant cable, and elaborates the extrusion process of the cable in the production process.

  1. 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....... 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%....

  2. 新型耐磨锡青铜合金包套挤压工艺及组织性能%Microstructure and properties of wear-resisting Cu-Sn-Pb-Ni alloy prepared by canning extrusion process

    Institute of Scientific and Technical Information of China (English)

    赵培峰; 周延军; 宋克兴; 张彦敏

    2012-01-01

    Directing to the difficulties in the densification of Cu-Sn-Pb-Ni alloy containing 8%~12% tin by conventional plastic forming,the plastic deformation of Cu-Sn-Pb-Ni alloy was carried out by the canning extrusion process.The microstructure and properties of as-cast alloy and as-extruded alloy were analyzed.The as-extruded alloy with the density of 8.98g/cm3 and strength of 345MPa was obtained.The results reveal that the properties of the Cu-Sn-Pb-Ni alloy can be improved via the canning extrusion process.%针对锡含量为8%~12%的锡青铜合金脆性大,难以通过塑性变形实现较高致密度的问题,采用包套挤压工艺制备新型耐磨Cu-Sn-Pb-Ni合金,分析其铸态及包套挤压态的微观组织及性能.包套挤压的密度和硬度分别达到8.98g/cm3和HB135.7;挤压后合金抗拉强度和伸长率分别为345.366MPa和11.4%.结果表明,合金在外加包套作用下塑性有所提高.

  3. Effect of process and machine parameters on physical properties of extrudate during extrusion cooking of sorghum, horse gram and defatted soy flour blends.

    Science.gov (United States)

    Basediya, A L; Pandey, Sheela; Shrivastava, S P; Khan, Khursheed Alam; Nema, Anura

    2013-02-01

    Extrusion cooking of sorghum (Sorghum vulgaris), horse gram (Dolichos biflorus) and defatted soy (Glycine max) flour blends was done to prepare snacks by using a Brabender single-screw laboratory extruder. The combined effect of moisture content, blend ratio of feed, barrel temperature and screw speed of extruder on physical parameters of extrudate was studied. It was observed that 15% moisture content of feed, 80:10:10 (sorghum flour: horse gram flour: defatted soy flour) of blend ratio, 130 °C barrel temperature and 130 rpm of screw speed gave the highest sectional expansion index and longitudinal expansion index of extrudate, while 12% moisture content, 75:15:10 of blend ratio of feed, 135 °C of barrel temperature and 135 rpm of screw speed gave lowest bulk density of extrudate. A central composite rotable design (CCRD) of response surface methodology was used to develop prediction model. Second order quadratic regression model fitted adequately in the variation. The significance was established at p ≤ 0.05. It was also observed that increasing feed moisture content results in a higher density and lower expansion of extrudate. Increasing barrel temperature and screw speed reduced density but increased expansion of extrudate.

  4. ANÁLISIS BACTERIOLÓGICO DE BILLETES CIRCULANTES EN LA UNIVERSIDAD DEL PACÍFICO PARAGUAY. 2013

    OpenAIRE

    Nathalia Aguilera –Benítez; Amanda Fretes– Gómez; Janira Medina– Meza

    2016-01-01

    Introducción: Los billetes de algodón poseen una estructura porosa que le permite alojar diferentes tipos de detritus y que posibilitaría la colonización microbiana de dicho papel. Objetivos: Describir la presencia y tipo de contaminación bacteriana en dos variedades de billetes circulantes en Paraguay, en el año 2013. Materiales y métodos: Se recolectaron 50 billetes de cinco mil guaraníes (25 de polímero y 25 de algodón) proveídos por estudiantes mediante un muestreo por conveniencia. El an...

  5. Numerical Analysis of the Forming Process of Head Toothing in Rolling Extrusion on a Shaft from Aluminum Alloy 7075 / Analiza Numeryczna Kształtowania Uzębienia Czołowego W Procesie Przepychania Obrotowego Na Wałku Ze Stopu Aluminium 7075

    Directory of Open Access Journals (Sweden)

    Bartnicki J.

    2015-12-01

    Full Text Available This paper presents the forming method of head toothing with the application of rolling extrusion technology. Tools numerical models were used in numerical calculations. The presented numerical results concern metals flow kinematics, distributions of stresses and strains. Determined in the process technological parameters of head toothing forming allow foreseeing real material flow in the experiment planned for conducting.

  6. Numerical Analysis of the Forming Process of Head Toothing in Rolling Extrusion on a Shaft from Aluminum Alloy 7075 / Analiza Numeryczna Kształtowania Uzębienia Czołowego W Procesie Przepychania Obrotowego Na Wałku Ze Stopu Aluminium 7075

    OpenAIRE

    Bartnicki J.; Tomczak J.

    2015-01-01

    This paper presents the forming method of head toothing with the application of rolling extrusion technology. Tools numerical models were used in numerical calculations. The presented numerical results concern metals flow kinematics, distributions of stresses and strains. Determined in the process technological parameters of head toothing forming allow foreseeing real material flow in the experiment planned for conducting.

  7. 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 treatments.Monitoring target parameters we

  8. 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...

  9. 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...

  10. Compact multipurpose sub-sampling and processing of in-situ cores with press (pressurized core sub-sampling and extrusion system)

    Energy Technology Data Exchange (ETDEWEB)

    Anders, E.; Muller, W.H. [Technical Univ. of Berlin, Berlin (Germany). Chair of Continuum Mechanics and Material Theory

    2008-07-01

    Climate change, declining resources and over-consumption result in a need for sustainable resource allocation, habitat conservation and claim for new technologies and prospects for damage-containment. In order to increase knowledge of the environment and to define potential hazards, it is necessary to get an understanding of the deep biosphere. In addition, the benthic conditions of sediment structure and gas hydrates, temperature, pressure and bio-geochemistry must be maintained during the sequences of sampling, retrieval, transfer, storage and downstream analysis. In order to investigate highly instable gas hydrates, which decomposes under pressure and temperature change, a suite of research technologies have been developed by the Technische Universitat Berlin (TUB), Germany. This includes the pressurized core sub-sampling and extrusion system (PRESS) that was developed in the European Union project called HYACE/HYACINTH. The project enabled well-defined sectioning and transfer of drilled pressure-cores obtained by a rotary corer and fugro pressure corer into transportation and investigation chambers. This paper described HYACINTH pressure coring and the HYACINTH core transfer. Autoclave coring tools and HYACINTH core logging, coring tools, and sub-sampling were also discussed. It was concluded that possible future applications include, but were not limited to, research in shales and other tight formations, carbon dioxide sequestration, oil and gas exploration, coalbed methane, and microbiology of the deep biosphere. To meet the corresponding requirements and to incorporate the experiences from previous expeditions, the pressure coring system would need to be redesigned to adapt it to the new applications. 3 refs., 5 figs.

  11. Protein Stability during Hot Melt Extrusion: The Effect of Extrusion Temperature, Hydrophilicity of Polymers and Sugar Glass Pre-stabilization

    NARCIS (Netherlands)

    Teekamp, Naomi; Olinga, Peter; Frijlink, Henderik W.; Hinrichs, Wouter

    2015-01-01

    Purpose Biodegradable polymers have been widely investigated for controlled release formulations for protein delivery. However, the processing stability of proteins remains a major challenge. The aim of this research is to assess the influence of the hot melt extrusion process on the activity of a m

  12. Effect of extrusion ratio on coating extrusion of Pb-GF composite wire by numerical simulation and experimental investigation

    Institute of Scientific and Technical Information of China (English)

    WANG Xin; SUN Hong-fei; FANG Wen-bin

    2009-01-01

    The extrusion ratio is one of the key parameters for manufacturing the lead-glass fiber (Pb-GF) composite wire by coating extrusion. The effect of extrusion ratio on coating extrusion of Pb-GF composite wire was studied by finite element numerical simulation with the use of the DEFOEM simulation software. The simulation result shows that the higher the extrusion ratio, the higher the effective stress that the glass fiber bears during extrusion. It is also observed that the extrusion force increases with the increase of the extrusion ratio. The extrusion experiment of Pb-GF composite wire reveals that extrusion ratio is changed by changing the quantity of glass fiber and composite diameter. The rule that increasing the extrusion ratio enhances the coating speed limit suggests that the load on the glass fiber increases with increasing extrusion ratio. Both the simulation and the extrusion experiments show that the extrusion force increases with increasing extrusion ratio.

  13. Digestibilidade e atividade enzimática intestinal de coelhos em crescimento alimentados com diferentes fontes de amido processadas ou não por extrusão Digestibility and intestinal enzymatic activity of growing rabbits fed different sources of starch processed or not by extrusion

    Directory of Open Access Journals (Sweden)

    Luciana Kazue Otutumi

    2005-04-01

    Full Text Available Foram conduzidos dois experimentos para avaliar a digestibilidade do amido e a atividade específica das enzimas amilase (ATAM e maltase (ATMAL, em duas porções do intestino delgado (jejuno e íleo, em coelhos com idades iniciais de 28 e 49 dias, alimentados com quatro fontes de amido (milho, sorgo, triticale e mandioca, processados ou não por extrusão. Em cada experimento, foram utilizados 64 coelhos da raça Nova Zelândia Branco, distribuídos em um delineamento inteiramente casualizado com oito tratamentos e oito repetições. Ao final do período experimental, os animais foram abatidos para retirada de amostra do conteúdo do jejuno e íleo, além da raspagem da mucosa do jejuno, para determinação da ATAM e ATMAL. O processamento melhorou o coeficiente de digestibilidade (CD do amido do milho e do sorgo. Entre as fontes não-extrusadas, os maiores CD do amido foram apresentados pelo triticale e pela mandioca. A ATAM da parede do jejuno foi maior aos 60 dias. A ATMAL no conteúdo do jejuno e do íleo foi maior aos 37 dias. As diferentes fontes de amido diferiram entre si quanto à ATMAL e ATAM do conteúdo do jejuno e do íleo. A ATMAL foi maior no jejuno. Maiores ATAM do conteúdo do jejuno ocorreu aos 60 dias para os animais que receberam milho extrusado e sorgo. A ATAM aos 37 dias foi maior no íleo em comparação com o jejuno para os animais que receberam milho e sorgo. O processamento foi efetivo para o milho e sorgo, porém, todas as fontes, processadas ou não, apresentaram bom CD do amido, podendo ser utilizadas na alimentação de coelhos.Two experiments were carried out to study the digestibility of starch and the specific activity of amylase (ACAMY and maltase (ACMAL enzymes in two portions of small intestine (jejunum and ileum, in rabbits with initial ages of 28 and 49 days, fed with four sources of starch (corn, sorghum, triticale and cassava processed or not by extrusion. Sixty-four White New Zealand rabbits were used in

  14. Improving tensile properties of dilute Mg-0.27Al-0.13Ca-0.21Mn (at.%) alloy by low temperature high speed extrusion

    Energy Technology Data Exchange (ETDEWEB)

    Nakata, T., E-mail: s123055@stn.nagaokaut.ac.jp [Nagaoka University of Technology, 1603-1, Kamitomioka, Nagaoka 940-2188 (Japan); Mezaki, T.; Xu, C.; Oh-ishi, K. [Nagaoka University of Technology, 1603-1, Kamitomioka, Nagaoka 940-2188 (Japan); Shimizu, K.; Hanaki, S. [Sankyo Tateyama, Inc., Sankyo Material-Company, 8-3, Nagonoe, Imizu, Toyama 934-8515 (Japan); Kamado, S. [Nagaoka University of Technology, 1603-1, Kamitomioka, Nagaoka 940-2188 (Japan)

    2015-11-05

    As-cast Mg-0.27Al-0.13Ca-0.21Mn (at.%) alloy was extruded at temperatures from 350 °C to 500 °C. We examined the microstructural changes during extrusion at different temperatures to clarify dynamic recrystallization mechanisms during extrusion, and also investigated the effect of extrusion temperature on microstructures and mechanical properties of the alloy. High extrusion exit speed of 60 m/min was successfully achieved at wide range of temperatures from 350 °C to 500 °C even when as-cast dilute Mg-0.27Al-0.13Ca-0.21Mn (at.%) alloy was used as a billet for the extrusion. The extrusion at low temperature refines grain size and weakens basal texture due to continuous dynamic recrystallization (CDRX) together with double twinning. As a result, the alloy sample extruded at 350 °C exhibits higher tensile proof stress of 206 MPa and higher tensile ductility of 29% than T5-treated 6063 aluminum alloy and commercial AZ31 magnesium alloy even in an as-extruded condition. Furthermore, Hall–Petch coefficient for compressive proof stress is 1.8 times larger than that for tensile one, resulting in improvement of yield stress anisotropy (compressive proof stress/tensile yield stress ratio). - Highlights: • Dilute Mg–Al–Ca–Mn alloy can be extruded at high die-exit speed of 60 m/min. • The extrusion at low temperature refines recrystallized grain size and weakens basal texture. • Grain refining improves mechanical properties of dilute Mg–Al–Ca–Mn alloys.

  15. Diffusion between glass and metals for optical fiber preform extrusion

    Science.gov (United States)

    Yeo, Felicia Yan Xin; Zhang, Zhifeng; Kumar Chakkathara Janardhanan Nair, Dileep; Zhang, Yilei

    2015-07-01

    When silica is extruded, diffusion of metal atoms into silica results contamination to the silica being heated, and thus is a serious concern for the glass extrusion process, such as extrusion of glass fiber preform. This paper examines diffusion between fused silica and two high strength metals, the stainless steel SS410 and the superalloy Inconel 718, at 1000 °C and under the normal atmosphere condition by SEM and Electron Dispersion Spectrum. It is found that diffusion occurs between silica and SS410, and at the same time, SS410 is severely oxidized during diffusion experiment. On the contrary, the diffusion between Inconel 718 and silica is unnoticeable, suggesting excellent high temperature performance of Inconel 718 for glass extrusion.

  16. Numerical Solution of Heat Tranfer Problem with Flow and Solidification in Round Billet Continuous Casting of Steel

    Institute of Scientific and Technical Information of China (English)

    JiahongGUO; XinHong

    1999-01-01

    In this paper,two dimensional unsteady flow and energy equations are employed for simulation of the flow and heat transfer in round billet continuous casting A numerical method is developed,by using finite volume method and equivalent specific heat method to solve the equations of flow and heat transfer with solidification.The numerical result shows that the method of this paper is efficient for analyzing the flow and heat transfer with solidification of round billet continuous casting.

  17. Influence of melt feeding scheme and casting parameters during direct-chill casting on microstructure of an AA7050 billet

    OpenAIRE

    Zhang, L; T. Subroto; Katgerman, L.; Eskin, DG; Miroux, A

    2012-01-01

    © The Minerals, Metals & Materials Society and ASM International 2012 Direct-chill (DC) casting billets of an AA7050 alloy produced with different melt feeding schemes and casting speeds were examined in order to reveal the effect of these factors on the evolution of microstructure. Experimental results show that grain size is strongly influenced by the casting speed. In addition, the distribution of grain sizes across the billet diameter is mostly determined by melt feeding scheme. Grains...

  18. Mathematical model of determination of die bearing length in design of aluminum profile extrusion die

    Institute of Scientific and Technical Information of China (English)

    闫洪; 王高潮; 夏巨谌; 李志刚

    2004-01-01

    Based on the finite element simulation of profile extrusion process, the effect of local extrusion ratio, die bearing area and the distance between extrusion cylindrical center and local die orfice center on mental flow velocity was investigated. The laws of deformed metalflow on profile extrusion process were obtained. The smaller the local extrusion ratio, the faster the metal flow velocity; the smaller the area of die bearing, the faster the metal flow velocity; the smaller the distance of position of local die orifice(the closer the distance of position of local die orifice from extrusion cylindrical axis), the faster the metal flow velocity. The effect of main parameters of die structure on metal flow velocity was integrated and the mathematical model of determination of die bearing length in design of aluminum profile extrusion die was proposed. The calculated results with proposed model were well compared with the experimental results. The proposed model can be applied to determine die bearing length in design of aluminum profile extrusion die.

  19. Complex Nonmetallic Inclusions Formed in Billets Heated for Rolling and Characteristics of Structural Steels

    Science.gov (United States)

    Zaitsev, A. I.; Koldaev, A. V.; Arutyunyan, N. A.; Shaposhnikov, N. G.; Dunaev, S. F.

    2017-03-01

    Complex bimetallic inclusions formed in billets from steels 09G2S and K52 during heating for rolling are studied by methods of electron microscopy and local x-ray spectrum analysis. To check the established evolution of oxide inclusions based on aluminomagnesium spinel and other oxide compositions, individual inclusions of manganese sulfide and complex oxide-sulfide inclusions, a method developed by the Severstal'Company and the Karpov NIFKhI for determining the content of corrosion-active nonmetallic inclusions (CANI) as a function of the heating mode is applied to the steels studied. It is recommended to increase the temperature and duration of heating of billets for hot rolling in order to lower the content of CANI and to raise the resistance of the steels to local corrosion.

  20. 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...

  1. Theoretical Analysis of the Solidification of Aluminum Alloy Billet in Air-Slip DC Mold

    Institute of Scientific and Technical Information of China (English)

    于赟; 马乃恒; 许振明; 李建国

    2004-01-01

    Based on the heat transfer analysis of Air-Slip DC mold, a numerical model was presented to study the quantitative relationships between critical solidification layer and casting rate, pouring temperature and mold cooling ability etc. The analytical results show that the Air-Slip mold heat transfer condition plays important roles on choices of a casting rate and the pouring temperature, and that the product of billet diameter and casting rate is a certain constant under a certain condition of the mold.

  2. Thermal Response of Mould in High Speed Casting of Stainless Steel Billet

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    An industrial trial was conducted on a billet-casting machine at Atlas Steel, Canada, during which a mould was instrumented with 52 thermocouples. The measured data of ten heats were collected to determine mould wall temperature profiles for different steel grades at different casting speeds. Based on these data, heat fluxes were calculated with inverse heat conduction model. Heat fluxes for different operating parameters were compared and analyzed.

  3. A Quality by Experimental Design Approach to Assess the Effect of Formulation and Process Variables on the Extrusion and Spheronization of Drug-Loaded Pellets Containing Polyplasdone® XL-10.

    Science.gov (United States)

    Saripella, Kalyan K; Loka, Nikhil C; Mallipeddi, Rama; Rane, Anuja M; Neau, Steven H

    2016-04-01

    Successful pellet production has been reported in literature with cross-linked poly(vinylpyrrolidone), Polyplasdone® XL-10 and INF-10. In the present study, a quality by experimental design approach was used to assess several formulation and process parameter effects on the characteristics of Polyplasdone® XL-10 pellets, including pellet size, shape, yield, usable yield, friability, and number of fines. The hypothesis is that design of experiments and appropriate data analysis allow optimization of the Polyplasdone product. High drug loading was achieved using caffeine, a moderately soluble drug to allow in vitro release studies. A five-factor, two-level, half-fractional factorial design (Resolution V) with center point batches allowed mathematical modeling of the influence of the factors and their two-factor interactions on five of the responses. The five factors were Polyplasdone® level in the powder blend, volume of water in the wet massing step, wet mixing time, spheronizer speed, and spheronization time. Each factor and/or its two-factor interaction with another factor influenced pellet characteristics. The behavior of these materials under various processing conditions and component levels during extrusion-spheronization have been assessed, discussed, and explained based on the results. Numerical optimization with a desirability of 0.974 was possible because curvature and lack of fit were not significant with any of the model equations. The values predicted by the optimization described well the observed responses. The hypothesis was thus supported.

  4. Physical Simulation Method for the Investigation of Weld Seam Formation During the Extrusion of Aluminum Alloys

    Science.gov (United States)

    Fang, Gang; Nguyen, Duc-Thien; Zhou, Jie

    2016-12-01

    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 great importance to understand the formation of weld seams inside the welding chamber during extrusion, as affected by extrusion process variables and die design. Previously developed physical simulation methods could not fully reproduce the thermomechanical conditions inside the welding chamber of porthole die. In this research, a novel physical simulation method for the investigation of weld seam formation during extrusion was developed. With a tailor-designed tooling set mounted on a universal testing machine, the effects of temperature, speed, and strain on the weld seam quality of the 6063 alloy were investigated. The strains inside the welding chamber were found to be of paramount importance for the bonding of metal streams, accompanied by microstructural changes, i.e., recovery or recrystallization, depending on the local deformation condition. The method was shown to be able to provide guidelines for the design of porthole dies and choice of extrusion process variables, thereby reducing the scrap rate of aluminum extrusion operation.

  5. Flow properties of 6061 aluminum alloy processed by equal channel angular extrusion%6061铝合金等通道转角挤压时的流变性能

    Institute of Scientific and Technical Information of China (English)

    董洪波; 黄映霞

    2011-01-01

    Extrusion deformation experiments for annealed and solution-aged 6061 aluminum alloy were carried out by using equal channel angular extrusion (ECAE) technique. The samples were extruded in the ECAE die for eight and four passes at room temperature,respectively. Meanwhile, the deformation behavior of the alloy was simulated by FEM using software Deform-3D. The deformed microstructure and flow properties of 6061 aluminum alloy were investigated. The results show that the grains are refined by equal channel angular extrusion, and the metal flow lines distribute nearly along the diagonal direction on longitudinal section. The surface hardness of annealed 6061 aluminium alloy increases continuously with increasing the ECAE passes. However, the peak value of deforming load in each ECAE process does not show monotonic increase with increasing passes, but rises at first, then falls down, and increases again. The maximum surface hardness and maximum deforming load of the solution-aged 6061 aluminium alloy occurs after ECAE for two passes.Surface hardness of the alloy depends on its strengthening mechanisms and movement of dislocations, and deforming load is related to the friction of ECAE die and sample and material strength. The simulation shows that the peak value of deforming load for each ECAE pass increase slowly with increasing of strain, so the calculated values are not in agreement with the measured ones. In order to characterize the flow behavior of the alloy correctly, the constitutive relationship of the material should be modified properly due to the change of its microstructure and properties greatly with severe plastic deformation.%分别对退火态和固溶时效态6061铝合金进行8道次及4道次等通道转角挤压,用有限元软件Deform-3D模拟变形过程,研究连续大变形对组织性能的影响规律.结果表明:等通道挤压使晶粒破碎细化,金属流线走向与剖面对角线方向基本一致;退火态合金的表面硬度随

  6. Statistical characterization of three grades of large billet-graphites: Stackpole 2020, Union Carbide TS1792, and Toyo Tanso IG11

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, C R

    1987-09-01

    Large billets of three fine-grained, isostatically molded graphites (three billets each of grade TS1792 from Union Carbide Corporation, six billets of grade IG11 from Toyo Tanso, and thirteen billets of grade 2020 from Stackpole Corporation) were evaluated by nondestructive methods, and the results were analyzed. The results of sonic testing were shown to be interrelated to both the mean and variance of strenth obtained from destructive testing. The virtue of the nondestructive evaluation is clearly illustrated by the practical ability to evaluate up to 100% of the billet volume, thus giving a more accurate description of the materials' mechanical properties. It was shown that the randomness of the mean strength in these billets makes it very unlikely that test results from small-sample volumes removed from the billet will be representative of the billet as a whole. In critical applications requiring a high level of quality assurance, a more complete nondestructive evaluation of the billet appears to be required.

  7. 面向节能优化的加热钢坯特征参数模型研%The Research on Characteristic Parameter Model of Billet Heating for Optimizing Retrench Energy

    Institute of Scientific and Technical Information of China (English)

    周里; 杨承志

    2011-01-01

    本文基于钢坯加热的热流密度的慨率密度分布关联加热能耗的原理,提出一种建立加热钢坯表面的热流密度的概率密度分布曲面模型的方法,以期将来能通过调节表征加热能耗的热流密度概率密度分布曲面形状特点,使钢坯加热工艺过程能耗调节具有较好的操控性,达到钢坯加热节能控制之目的.%The method is proposed about building the probability density distribution surface model of heat flux density of surface of billet heating, based on the principle to associate the probability density distribution surface model of heat flux density of surface of billet heating with the heating energy consumption.It is hoped that it can provide the better controllability about adjusting the energy consumption in the process of billet heating and meet requirement of retrench energy sources and control through adjusting the probability density distribution surface figure of heat flux density which can represent the heating energy consumption.

  8. Environmental assessment: Transfer of normal and low-enriched uranium billets to the United Kingdom, Hanford Site, Richland, Washington

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-11-01

    Under the auspices of an agreement between the U.S. and the United Kingdom, the U.S. Department of Energy (DOE) has an opportunity to transfer approximately 710,000 kilograms (1,562,000 pounds) of unneeded normal and low-enriched uranium (LEU) to the United Kingdom; thus, reducing long-term surveillance and maintenance burdens at the Hanford Site. The material, in the form of billets, is controlled by DOE`s Defense Programs, and is presently stored as surplus material in the 300 Area of the Hanford Site. The United Kingdom has expressed a need for the billets. The surplus uranium billets are currently stored in wooden shipping containers in secured facilities in the 300 Area at the Hanford Site (the 303-B and 303-G storage facilities). There are 482 billets at an enrichment level (based on uranium-235 content) of 0.71 weight-percent. This enrichment level is normal uranium; that is, uranium having 0.711 as the percentage by weight of uranium-235 as occurring in nature. There are 3,242 billets at an enrichment level of 0.95 weight-percent (i.e., low-enriched uranium). This inventory represents a total of approximately 532 curies. The facilities are routinely monitored. The dose rate on contact of a uranium billet is approximately 8 millirem per hour. The dose rate on contact of a wooden shipping container containing 4 billets is approximately 4 millirem per hour. The dose rate at the exterior of the storage facilities is indistinguishable from background levels.

  9. The Influence of Chemical Composition of Steels on the Numerical Simulation of a Continuesly Cast of Billet

    Directory of Open Access Journals (Sweden)

    František KAVIČKA

    2010-12-01

    Full Text Available The chemical composition of steels has significant influence on the actual concasting process, and on the accuracy of its numerical simulation and optimization. The chemical composition of steel affects the thermophysical properties (heat conductivity, specific heat capacity and density in the solid and liquid states often requires more time than the actual numerical calculation of the temperature fields of a continuously cast steel billet. Therefore, an analysis study of these thermophysical properties was conducted. The order of importance within the actual process and the accuracy of simulation were also determined. The order of significance of the chemical composition on thermophysical properties was determined with respect to the metallurgical length. The analysis was performed by means of a so-called calculation experiment, i.e. by means of the original numerical concasting model developed by the authors of this paper. It is convenient to conduct such an analysis in order to facilitate the simulation of each individual case of concasting, thus enhancing the process of optimization.

  10. Compound fabrication technology of semi-solid billet of Al-Si alloy based on SIMA method

    Institute of Scientific and Technical Information of China (English)

    XUE Ke-min; MI Guang-bao; WANG Qing-rui

    2006-01-01

    Based on SIMA, the Al-Si alloy semi-solid billets were successfully fabricated by means of strain inducement and isothermal treatment for AlSi9Mg poured in the range of near-liquidus. Through orthogonal test, the effects of combination action of near-liquidus casting, strain inducement and isothermal treatment on the morphology of primary α-Al phase of AlSi9Mg close to eutectic point were investigated, and the optimal match relation between the processing parameters of solidification, deformation parameters of strain inducement, processing parameters of isothermal treatment and microstructure parameters of semi-solid alloy was established. The results indicate that compared with the single near-liquidus casting or SIMA, the microstructure of primary α-Al phase in AlSi9Mg alloy prepared by compound fabrication process is more homogeneous, with more globular and finer particles,which has average grain size of 40-50 μm and shape factor of greater than 0.75. After holding at 605 ℃ for 30-40 min under a certain cooling rate, increased deformation volume in SIMA benefits the refinement of the grain and the improvement of the morphology for primary phase.

  11. Tailoring properties of commercially pure titanium by gradation extrusion

    Science.gov (United States)

    Bergmann, Markus; Rautenstrauch, Anja; Selbmann, René; de Oliveira, Raoni Barreto; Coelho, Rodrigo Santiago; Landgrebe, Dirk

    2016-10-01

    Commercially pure titanium (CP Ti) is of great importance in medical applications due to its attractive properties, such as high biocompatibility, excellent corrosion resistance and relatively low density and suitable stiffness. Compared to the commonly used Ti-6Al-4V alloy, its lower strength has to be increased. The most attractive approach is to subject CP Ti to severe plastic deformation (SPD) processes such as Equal Channel Angular Pressing (ECAP). The resulting decreased grain size in CP Ti yields a significant increase in hardness and strength. Common SPD-processes typically provide a uniform modification of the material. Their material efficiency and productivity are critical and limiting factors. A new approach is to tailor the material properties by using Gradation Extrusion, which produces a distinct gradient in microstructure and strength. The forming process combines a regular impact extrusion process and severe plastic deformation in the lateral area of the material. This efficient process can be integrated easily into forming process chains, for instance for dental implants. This paper presents the forming process and the applied die geometry. The results of numerical simulations are used to illustrate the potential of the process to modify and strengthen the titanium material. Experiments show that the material is successfully processed by gradation extrusion. By characterizing the hardness and its distribution within the formed parts the effects of the process are investigated.

  12. Densification of powder metallurgy billets by a roll consolidation technique

    Science.gov (United States)

    Sellman, W. H.; Weinberger, W. R.

    1973-01-01

    Container design is used to convert partially densified powder metallurgy compacts into fully densified slabs in one processing step. Technique improves product yield, lowers costs and yields great flexibility in process scale-up. Technique is applicable to all types of fabricable metallic materials that are produced from powder metallurgy process.

  13. Effect of Processing Steps on the Mechanical Properties and Surface Appearance of 6063 Aluminium Extruded Products

    Directory of Open Access Journals (Sweden)

    Juan Asensio-Lozano

    2014-05-01

    Full Text Available 6063 aluminum anodized extrusions may exhibit a common surface defect known as streaking, characterized by the formation of narrow bands with a surface gloss different from the surrounding material. The origin of this banding lies in the differential surface topography produced after etching during the anodizing stage, shown to be connected to certain microstructural characteristics. The present study has attempted to determine the origin of these defects and measure the mechanical properties in these zones, properties which were either barely acceptable or did not meet the specification’s requirements. Quantitative metallography and mechanical testing, both tensile and microhardness, were used for materials assessment at the different steps of the process of manufacturing 6063 anodized extrusions. The results of this research show that nonequilibrium solidification rates during billet casting could lead to the formation of coarse eutectic Mg2Si particles which have a deleterious effect on both mechanical properties and surface appearance in the anodized condition. However, differences in the size and density of the coarse Mg2Si particles have been found to exist in the streak profile compared to the surrounding zones. The study revealed the importance of these particles in explaining the origin of the marginal or sub-marginal properties and anodizing surface defects found.

  14. Co-extrusion as manufacturing technique for multilayer mini-matrices with dual drug release.

    Science.gov (United States)

    Dierickx, L; Remon, J P; Vervaet, C

    2013-11-01

    The aim of this work was to develop by means of co-extrusion a multilayered dosage form characterized by a dual release profile of the same drug. Co-extrudates consisted of two concentric polymer matrices: a core having a lipophilic character and a coat with a hydrophilic character. Diclofenac sodium (DS) was incorporated as model drug in both layers. Several polymers were screened on the basis of their processability via hot melt extrusion (HME) and in vitro drug release. Polymer combinations with suitable properties (i.e., similar extrusion temperature, appropriate drug release profile) were processed via co-extrusion. (Co-) extruded samples were characterized in terms of solid state (XRD, SEM), in vitro drug release, core/coat adhesion, and bioavailability. Based on the polymer screening, two polymer combinations were selected for co-extrusion: ethylcellulose (core) combined with Soluplus® (coat) and polycaprolactone (core) with PEO (coat). These combinations were successfully co-extruded. XRD revealed that DS remained crystalline during extrusion in ethylcellulose, Soluplus®, polycaprolactone, and PEO. The polycaprolactone/PEO combination could be processed at a lower temperature (70 °C), vs. 140 °C for ethylcellulose/Soluplus®. The maximum drug load in core and coat depended on the extrusion temperature and the die dimensions, while adhesion between core and coat was mainly determined by the drug load and by the extrusion temperature. In vitro drug release from the co-extruded formulations was reflected in the in vivo behavior: formulations with a higher DS content in the coat (i.e., faster drug release) resulted in higher Cmax and higher AUC values. Co-extrusion is a viable method to produce in a single step a multilayer dosage form with dual drug release.

  15. Influence of Melt Feeding Scheme and Casting Parameters During Direct-Chill Casting on Microstructure of an AA7050 Billet

    Science.gov (United States)

    Zhang, L.; Eskin, D. G.; Miroux, A.; Subroto, T.; Katgerman, L.

    2012-12-01

    Direct-chill (DC) casting billets of an AA7050 alloy produced with different melt feeding schemes and casting speeds were examined in order to reveal the effect of these factors on the evolution of microstructure. Experimental results show that grain size is strongly influenced by the casting speed. In addition, the distribution of grain sizes across the billet diameter is mostly determined by melt feeding scheme. Grains tend to coarsen towards the center of a billet cast with the semi-horizontal melt feeding, while upon vertical melt feeding the minimum grain size was observed in the center of the billet. Computer simulations were preformed to reveal sump profiles and flow patterns during casting under different melt feeding schemes and casting speeds. The results show that solidification front and velocity distribution of the melt in the liquid and slurry zones are very different under different melt feeding scheme. The final grain structure and the grain size distribution in a DC casting billet is a result of a combination of fragmentation effects in the slurry zone and the cooling rate in the solidification range.

  16. Extrusion Pretreatment of Lignocellulosic Biomass: A Review

    Directory of Open Access Journals (Sweden)

    Jun Zheng

    2014-10-01

    Full Text Available Bioconversion of lignocellulosic biomass to bioethanol has shown environmental, economic and energetic advantages in comparison to bioethanol produced from sugar or starch. However, the pretreatment process for increasing the enzymatic accessibility and improving the digestibility of cellulose is hindered by many physical-chemical, structural and compositional factors, which make these materials difficult to be used as feedstocks for ethanol production. A wide range of pretreatment methods has been developed to alter or remove structural and compositional impediments to (enzymatic hydrolysis over the last few decades; however, only a few of them can be used at commercial scale due to economic feasibility. This paper will give an overview of extrusion pretreatment for bioethanol production with a special focus on twin-screw extruders. An economic assessment of this pretreatment is also discussed to determine its feasibility for future industrial cellulosic ethanol plant designs.

  17. Enhancement of Aluminum Alloy Forgings through Rapid Billet Heating

    Energy Technology Data Exchange (ETDEWEB)

    Kervick, R.; Blue, C. A.; Kadolkar, P. B.; Ando, T.; Lu, H.; Nakazawa, K.; Mayer, H.; Mochnal, G.

    2006-06-01

    Forging is a manufacturing process in which metal is pressed, pounded or squeezed under great pressure and, often, under high strain rates into high-strength parts known as forgings. The process is typically performed hot by preheating the metal to a desired temperature before it is worked. The forging process can create parts that are stronger than those manufactured by any other metal working process. Forgings are almost always used where reliability and human safety are critical. Forgings are normally component parts contained inside assembled items such airplanes, automobiles, tractors, ships, oil drilling equipment, engines missiles, and all kinds of capital equipment Forgings are stronger than castings and surpass them in predictable strength properties, producing superior strength that is assured, part to part.

  18. EXTRUSION FORMING OF A DOUBLE BASE SOLID ROCKET PROPELLANT BY FINITE ELEMENT METHOD

    Directory of Open Access Journals (Sweden)

    Barış KALAYCIOĞLU

    2007-01-01

    Full Text Available In this study, three dimensional modelling of extrusion forming of a double base solid rocket propellant is performed on Ansys® finite element simulation package. For the purpose of initial model construction and later comparisons with elastoviscoplastik model, the solid propellant is assumed to obey the elastic-plastic material response during the direct extrusion process. Taking into account the contact surface behavior with Coulomb friction and geometric and material nonlinearities, an incremental large large strain solution methodology has been adapted in the simulation. The hydrostatic pressure, stress, strain, and displacement values during extrusion of the solid rocket propellant are obtained from the simulation.

  19. The Igwisi Hills extrusive 'kimberlites'

    Science.gov (United States)

    Reid, A. M.; Donaldson, C. H.; Dawson, J. B.; Brown, R. W.; Ridley, W. I.

    1975-01-01

    The petrography and mineral chemistry of volcanic rocks from the Igwisi Hills in Tanzania are discussed. There is considerable evidence to suggest that the Igwisi rocks are extrusive kimberlites: a two-component nature with high P-T minerals in a low P-T matrix; the presence of chrome pyrope, Al enstatite, chrome diopside, chromite and olivine; a highly oxidized, volatile-rich matrix with serpentine, calcite, magnetite, perovskite; high Sr, Zr, and Nb contents; occurrence in a narrow isolated vent within a stable shield area. The Igwisi rocks differ from kimberlite in the lack of magnesian ilmenite, the scarcity of matrix phlogopite, and the overall low alkali content. They apparently contain material from phlogopite-bearing garnet peridotites with a primary mineral assemblage indicative of equilibrium at upper mantle temperatures and pressures. This primary assemblage was brought rapidly to the surface in a gas-charged, carbonate-rich fluid. Rapid upward transport, extrusion, and rapid cooling have tended to prevent reaction between inclusions and the carbonate-rich matrix that might otherwise have yielded a more typical kimberlite.

  20. Material Analysis of Failed Cold-Drawn Billet

    Science.gov (United States)

    2009-02-01

    substrate. Mechanical testing of the material , particularly fracture toughness and charpy impact energy, has shown that the cold-drawn material has...dynamic stresses generated during the explosive bonding process. To prevent additional failures during cladding , a minimum fracture toughness value...mechanical properties testing, etc. The investigation revealed the extremely low toughness of the cold-drawn material when compared to the forged material

  1. 异形坯双注流保护浇注工艺应用试验%Double Injection Currents Protection Pouring of Profiled Billet

    Institute of Scientific and Technical Information of China (English)

    杨志杰; 周晓雷

    2016-01-01

    结合莱钢生产实际情况,对采用定径水口与浸入式水口相结合方式开发的异形坯双注流保护浇注工艺进行了现场工业应用试验,并采集现场实际数据作为试验结果进行对比分析。结果表明,钢水的洁净度显著提升,对于需要添加合金的钢种,对比敞开浇注工艺,双注流保护浇注工艺降低钢液增氮10×10-6,铸坯中夹杂物总量减少约54%,工艺稳定可靠,满足了现场生产的需求。%According to the practice of Laiwu iron and steel production, the combination approach of the sizing nozzle and the submerged nozzle was developed for the profiled billet double injection protection casting process of industrial field application test. And the actual data of the field was collected as the test results to carry on the comparative analysis. The results showed that the cleanliness of molten steel was significantly improved. For the alloy steels, compared with the open casting process, double jet flow protective casting can reduce 10×10-6 of the nitrogen increasing in molten steel, about 54%of the total nitrogen in casting billet was reduced, about 45.5%of total inclusions in rolling materials was reduced than the open casting process. The process is stable and reliable, and meets the needs of the field production.

  2. Development and acceptability of a novel milk-free soybean-maize-sorghum ready-to-use therapeutic food (SMS-RUTF) based on industrial extrusion cooking process.

    Science.gov (United States)

    Owino, Victor O; Irena, Abel H; Dibari, Filippo; Collins, Steve

    2014-01-01

    Peanut milk-based ready-to-use therapeutic food (P-RUTF) primarily used to treat severe acute malnutrition at community setting is expensive. We developed an alternative milk-free soybean-maize-sorghum-based RUTF (SMS-RUTF) using locally grown ingredients that have the potential to support local economy and reduce the cost of RUTF. We describe the production process and results of acceptability of the new product. Acceptability and tolerance of SMS-RUTF was compared with P-RUTF among 45 children aged 4-11 years old based on a cross-over design. Each child consumed 250 g RUTF for 10 days followed by a five-day washout period and a subsequent 10-day period on the second RUTF. The SMS-RUTF was as acceptable as the P-RUTF among normal children aged 4-11 years of age with no associated adverse effects. SMS-RUTF was stable for at least 12 months without detectable microbiological or chemical deterioration. The major challenge encountered in SMS-RUTF development was the difficulty to accurately determine key nutrient composition due to its high oil content. Use of diversified locally available ingredients to produce RUTF is feasible. The SMS-RUTF meets expected standards and is acceptable to children aged 4-11 months old. Effectiveness and cost-effectiveness of SMS-RUTF is required.

  3. 玉米蛋白粉吸水性挤压膨化工艺的优化%Process Optimization for Extrusion of Corn Gluten Meal

    Institute of Scientific and Technical Information of China (English)

    王丽艳; 郭树国

    2013-01-01

    To explore the optimum process of corn gluten meal,the influence of moisture content of corn gluten meal,screw rotation speed and extruding cylinder temperature on WAI (Water-Absorption Index)of corn gluten meal were studied with rotational composite design of quadratic regression.The results indicated that moisture content of corn gluten meal had great effect on experiment index;the major factors in order of importance were moisture content of corn gluten meal, screw rotation speed and extruding cylinder temperature.The optimized combination of factors were moisture content of corn gluten meal 43%,screw rotation speed 243 r/min and extruding cylinder temperature 157℃,under the optimum conditions WAI was 7.50.%为获得吸水性较高的玉米蛋白粉,采用二次通用旋转组合设计试验方法考察了玉米蛋白粉含水率、螺杆转速和机筒温度对玉米蛋白粉吸水性的影响,并对其加工工艺进行了优化。结果表明:影响玉米蛋白粉吸水性的主要因素是玉米蛋白粉含水量,其次是螺杆转速和机筒温度。在玉米蛋白粉含水率为43%、转速为243 r/min、机筒温度为157℃的挤压条件下,玉米蛋白粉的吸水性最高,吸水指数为7.50。

  4. 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.

  5. Standard method of macroetch testing steel bars, billets, blooms, and forgings

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2001-01-01

    1.1 Macroetching, which is the etching of specimens for macrostructural examination at low magnifications, is a frequently used technique for evaluating steel products such as bars, billets, blooms, and forgings. 1.2 Included in this method is a procedure for rating steel specimens by a graded series of photographs showing the incidence of certain conditions. The method is limited in application to bars, billets, blooms, and forgings of carbon and low alloy steels. 1.3 A number of different etching reagents may be used depending upon the type of examination to be made. Steels react differently to etching reagents because of variations in chemical composition, method of manufacture, heat treatment and many other variables. Establishment of general standards for acceptance or rejection for all conditions is impractical as some conditions must be considered relative to the part in which it occurs. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is ...

  6. Original position statistic distribution analysis study of low alloy steel continuous casting billet

    Institute of Scientific and Technical Information of China (English)

    WANG; Haizhou; ZHAO; Pei; CHEN; Jiwen; LI; Meiling; YANG; Z

    2005-01-01

    The homogeneity of low alloy steels continuous casting billet obtained under different technological conditions has been investigated by original position statistic distribution analysis technique. On the basis of systematic analysis of ten thousands primary optical signals at the corresponding original positions, the quantitative statistic distribution information of each element was obtained. The biggest degrees of segregation of low alloy steel continuous casting billet were calculated accurately according to the quantitative distribution maps of the contents. It was suggested that the weight ratio in a certain content range was used to judge the homogeneity of the materials, and the two models -- the total weight ratio of contents (the degree of statistic homogeneity, H) within the permissive content range (C0±R) and the median value confidence extension ratio (the degree of statistic segregation, S) at 95% of confidence limit of weight ratio -- were put forward. The two models reflect the composition and state distribution regularity of the metal materials in a large region. The difference between the sample with high columnar crystal and the sample with high equiaxed crystal has been studied by using the two models.

  7. RESEARCH ON THE SELECTION OF FRICTION MODELS IN THE FINITE ELEMENT SIMULATION OF WARM EXTRUSION

    Institute of Scientific and Technical Information of China (English)

    X.B. Lin; H.S. Xiao; Z.L. Zhang

    2003-01-01

    During the process of finite element simulation of precision warm forging, the selec-tion of friction models has a direct effect on the precision accuracy of finite elementsimulation results. Among all the factors which influence the selection of frictionmodels, the distribution rule of normal stress at the tool-workpiece interface is a keyone. To find out the distribution rule of normal stress at the tool-workpiece inter-face, this paper has made a systematic research on three typical plastic deformationprocesses: forward extrusion, backward extrusion, and lateral extrusion by a methodof finite element simulation. Then on the base of synthesizing and correcting tradi-tional friction models, a new general friction model which is fit for warm extrusion isdeveloped at last.

  8. Effect of extrusion temperature on the physical properties of high-silicon aluminum alloy

    Institute of Scientific and Technical Information of China (English)

    YANG Fuliang; GAN Weiping; CHEN Zhaoke

    2007-01-01

    Light-weight high-silicon aluminum alloys are used for electronic packaging in the aviation and space- flight industry. Al-30Si and Al-40Si are fabricated with air- atomization and vacuum-canning hot-extrusion process. The density, thermal conductivity, hermeticity and thermal expan- sion coefficients of the material are measured, and the relationship between extrusion temperature and properties is obtained. Experimental results show that the density of high- silicon aluminum alloys prepared with this method is as high as 99.64% of the theory density, and increases with elevating extrusion temperature. At the same time, thermal conductiv- ity varies between 104-140W/(m.K); with the extrusion temperature, thermal expansion coefficient also increases but within 13 × 10-6 (at 100℃) and hermeticity of the material is high to 10-9 order of magnitude.

  9. 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.

  10. HA/UHMWPE Nanocomposite Produced by Twin-screw Extrusion

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The HA/UHMWPE nanocomposite is compounded by twin-screw extrusion of the HA and UHMWPE powder mixture in paraffin oil and then compression molded to a sheet form. TGA measurement shows the HA weight loss after processing is about 1%-2% . FTIR spectra indicate the paraffin oil residue is trivial and UHMWPE is not oxidized. SEM reveals the HA nano particles are homogeneously dispersed by twin- screw extrusion and the inter-particle spaces are penetrated with UHMWPE fibrils by swelling treatment. HRTEM image indicates the HA particles and UHMWPE are intimately contacted by mechanical interlocking. Compared with the unfilled UHMWPE, stiffness of the composite with the HA volume fraction 0.23 was significantly enhanced to 9 times without detriment of the yield strength and the ductility.

  11. Technologies for Use in the Formation of a Differentiated Structure in Iron Billets Used in Glass Molds

    Science.gov (United States)

    Leushin, I. O.; Chistyakov, D. G.

    2016-09-01

    Causes for the failure of pig iron press molds that are parts of a glass mold are described. Criteria for differentiating the structure of pig iron are established. Ways of obtaining a differentiated structure of a casting product are outlined. A heat treatment regime for the billets is determined.

  12. Formation of chromosomal domains in interphase by loop extrusion

    Science.gov (United States)

    Fudenberg, Geoffrey

    While genomes are often considered as one-dimensional sequences, interphase chromosomes are organized in three dimensions with an essential role for regulating gene expression. Recent studies have shown that Topologically Associating Domains (TADs) are fundamental structural and functional building blocks of human interphase chromosomes. Despite observations that architectural proteins, including CTCF, demarcate and maintain the borders of TADs, the mechanisms underlying TAD formation remain unknown. Here we propose that loop extrusion underlies the formation TADs. In this process, cis-acting loop-extruding factors, likely cohesins, form progressively larger loops, but stall at TAD boundaries due to interactions with boundary proteins, including CTCF. This process dynamically forms loops of various sizes within but not between TADs. Using polymer simulations, we find that loop extrusion can produce TADs as determined by our analyses of the highest-resolution experimental data. Moreover, we find that loop extrusion can explain many diverse experimental observations, including: the preferential orientation of CTCF motifs and enrichments of architectural proteins at TAD boundaries; TAD boundary deletion experiments; and experiments with knockdown or depletion of CTCF, cohesin, and cohesin-loading factors. Together, the emerging picture from our work is that TADs are formed by rapidly associating, growing, and dissociating loops, presenting a clear framework for understanding interphase chromosomal organization.

  13. Hot-melt extrusion technology and pharmaceutical application.

    Science.gov (United States)

    Wilson, Matthew; Williams, Marcia A; Jones, David S; Andrews, Gavin P

    2012-06-01

    The use of hot-melt extrusion (HME) within the pharmaceutical industry is steadily increasing, due to its proven ability to efficiently manufacture novel products. The process has been utilized readily in the plastics industry for over a century and has been used to manufacture medical devices for several decades. The development of novel drugs with poor solubility and bioavailability brought the application of HME into the realm of drug-delivery systems. This has specifically been shown in the development of drug-delivery systems of both solid dosage forms and transdermal patches. HME involves the application of heat, pressure and agitation through an extrusion channel to mix materials together, and subsequently forcing them out through a die. Twin-screw extruders are most popular in solid dosage form development as it imparts both dispersive and distributive mixing. It blends materials while also imparting high shear to break-up particles and disperse them. HME extrusion has been shown to molecularly disperse poorly soluble drugs in a polymer carrier, increasing dissolution rates and bioavailability. The most common difficulty encountered in producing such dispersions is stabilization of amorphous drugs, which prevents them from recrystallization during storage. Pharmaceutical industrial suppliers, of both materials and equipment, have increased their development of equipment and chemicals for specific use with HME. Clearly, HME has been identified as an important and significant process to further enhance drug solubility and solid-dispersion production.

  14. ANÁLISIS BACTERIOLÓGICO DE BILLETES CIRCULANTES EN LA UNIVERSIDAD DEL PACÍFICO PARAGUAY. 2013

    Directory of Open Access Journals (Sweden)

    Nathalia Aguilera –Benítez

    2016-07-01

    Full Text Available Introducción: Los billetes de algodón poseen una estructura porosa que le permite alojar diferentes tipos de detritus y que posibilitaría la colonización microbiana de dicho papel. Objetivos: Describir la presencia y tipo de contaminación bacteriana en dos variedades de billetes circulantes en Paraguay, en el año 2013. Materiales y métodos: Se recolectaron 50 billetes de cinco mil guaraníes (25 de polímero y 25 de algodón proveídos por estudiantes mediante un muestreo por conveniencia. El análisis consistió en el aislamiento bacteriológico presente en superficies de billetes. Fueron sumergidos e incubados a 37° durante 24 hs. en caldo de infusión cerebro corazón (BHI y posteriormente sembrados en placas de agar Sangre y MacConkey. Finalmente se procedió a la tipificación de los aislamientos obtenidos. Resultados: El 74%(37/50 de los billetes evaluados presentaron contaminación bacteriana; las frecuencias fueron del 100%(25/25 y 48%(12/25 respectivamente para los de algo­dón y polímero. En el primer grupo se aislaron con mayor frecuencia bacterias de la familia Enterobacteriaceae en el 61%(17/28 y del género Staphylococcus spp. en el 39%(11/28. En el segundo grupo se aislaron Staphylococcus spp. en el 44%(11/25 y Escherichia coli en 4 %(1/25. Conclusión: El estudio ha permitido evidenciar que los billetes contribuyen a la proliferación y transmisión de microorganismos al ser humano, pudiendo causar daños a la salud según estado inmunológico de la persona. Se evidenció que billetes de algodón presentan mayor frecuencia y variabilidad de contaminación por bacterias. Palabras Clave: Microbiología, Dinero, Bacterias, aislamiento & purificación.

  15. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Lavender, Curt A.; Paxton, Dean M.; Smith, Mark T.; Soulami, Ayoub; Joshi, Vineet V.; Burkes, Douglas

    2013-12-30

    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

  17. 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.

  18. Investigations on the influence of the shape factor and friction in compression processes of cylindrical billets of AA 6082-T6 aluminum alloy by numerical and experimental techniques; Investigaciones sobre la influencia del factor de forma y del rozamiento en procesos de compresion de piezas cilindricas de aleacion de aluminio AA 6082-T6 mediante tecnicas numericas y experimentales

    Energy Technology Data Exchange (ETDEWEB)

    Marin, M. M.; Camacho, A. M.; Bernal, C.; Sebastian, M. A.

    2013-09-01

    The material characterization under similar load conditions to those applied during manufacturing is important in order to analyse Bulk Forming Compression Processes from a more realistic point of view. Open die forging of AA 6082-T6 aluminum alloy has been analysed by using experimental techniques and Finite Elements Method (FEM). The influence of the work piece geometry on the effects that friction produces in typical process variables such as applied forces, contact pressures and stresses and strains in work pieces has been analysed by FEM simulation. It has been shown that higher shape factors of the initial work piece geometry are recommended in such a way that friction effect is minimised. These results are interesting in order to decrease the required energy of the process and the tool wear, and could be used in further analysis of stamping processes. (Author)

  19. Intrusion and extrusion of a liquid on nanostructured surfaces

    Science.gov (United States)

    Amabili, M.; Giacomello, A.; Meloni, S.; Casciola, C. M.

    2017-01-01

    Superhydrophobicity is connected to the presence of gas pockets within surface asperities. Upon increasing the pressure this ‘suspended’ state may collapse, causing the complete wetting of the rough surface. In order to quantitatively characterize this process on nanostructured surfaces, we perform rare-event atomistic simulations at different pressures and for several texture geometries. Such an approach allows us to identify for each pressure the stable and metastable states and the free energy barriers separating them. Results show that, by starting from the superhydrophobic state and increasing the pressure, the suspended state abruptly collapses at a critical intrusion pressure. If the pressure is subsequently decreased, the system remains trapped in the metastable state corresponding to the wet surface. The liquid can be extruded from the nanostructures only at very negative pressures, by reaching the critical extrusion pressure (spinodal for the confined liquid). The intrusion and extrusion curves form a hysteresis cycle determined by the large free energy barriers separating the suspended and wet states. These barriers, which grow very quickly for pressures departing from the intrusion/extrusion pressure, are shown to strongly depend on the texture geometry.

  20. Meniscus Behavior in Electromagnetic Soft-Contact Continuous Casting Round Billet Mold

    Institute of Scientific and Technical Information of China (English)

    DENG An-yuan; WANG En-gang; HE Ji-cheng

    2006-01-01

    Using molten Pb-Sn-Bi alloy, the meniscus shape under high frequency magnetic field of φ100 mm round billet caster was investigated. The effect of some parameters on meniscus shape was studied. The results show that for a mold with 12 segments, the meniscus shape is relatively stable. With increasing power input, the meniscus height increases with intensification of fluctuation. For the given caster, the reasonable power input is about 70 kW. The coil should be near to the top of mold and/or the initial meniscus should be near to the center of the coil. The lower the frequency, the higher is the meniscus height. With increasing frequency, the free surface is more flattened and meniscus becomes more stable. In practice, the power input should be increased simultaneously with frequency. The optimal frequency is about 20 kHz.

  1. Effects of calculation approaches for thermal conductivity on the simulation accuracy of billet continuous casting

    Institute of Scientific and Technical Information of China (English)

    Zun Peng; Yan-ping Bao; Ya-nan Chen; Li-kang Yang; Cao Xie; Feng Zhang

    2014-01-01

    An unsteady, two-dimensional, explicitly solved finite difference heat transfer model of a billet caster was presented to clarify the influence of the thermal conductivity of steel on model accuracy. Different approaches were utilized for calculating the thermal conductivity of solid, mushy and liquid steels. Model results predicted by these approaches were compared, and the advantages of advocated approaches were discussed. It is found that the approach for calculating the thermal conductivity of solid steel notably influences model predictions. Convection effects of liquid steel should be considered properly while calculating the thermal conductivity of mushy steel. Different values of the effective thermal conductivity of liquid steel adopted could partly be explained by the fact that different models adopted dissimilar ap-proaches for calculating the thermal conductivity of solid and mushy steels.

  2. 不同蛋白质源对高蛋白质水产饲料膨化工艺参数和加工质量的影响%Effects of Different Protein Sources on Extrusion Processing Parameters and Processing Quality for High Protein Aquatic Feed

    Institute of Scientific and Technical Information of China (English)

    梁晓芳; 李军国; 薛敏; 王嘉; 吴秀峰; 郑银桦; 韩芳; 秦玉昌

    2016-01-01

    In this study, we determined the effects of fish meal ( FM) , cottonseed protein concentrate ( CPC) and fermented soybean meal ( FSM) formulated as sole or combined protein sources in aquatic feed on the ex⁃trusion processing parameters and processing quality. Extrusion processing was conducted by a twin⁃screw ex⁃truder with steam heating and pre⁃conditioning system. FM diet was set as control diet, CPC and FSM were sole or combined used to replace 47% or 100% of FM, and then, seven diets with 45.45% to 48.55% crude protein and 18.11 to 20.33 MJ/kg gross energy were formulated and named as FM, FM×CPC, FM×FSM, CPC, FM×CPC×FSM, FSM and CPC×FSM, respectively. The results showed that the reduction of extrusion temperature and increase of screw speed and energy consumption were caused after the FM was replaced by plant proteins. With the plant protein proportion increasing, the extrusion temperature was reduced, and there was a significant negative correlation between them ( R2=0.926 2) . Processing quality parameters except dura⁃ble index of extrusion feed were significantly affected by different protein sources. The bulk density and stabili⁃ty in water in FM group were significantly higher than those in other group ( P<0.05) . On the contrary, with the increase of plant protein proportion, hardness and expansion degree of extrusion feed were increased. More⁃over, the radial expansion degree in CPC group was significantly higher than that in other groups ( P< 0.05) , and there was a significant positive correlation between the supplementation of fermented soybean meal and hardness of extrusion feed (R2=0.978 1). In conclusion, both FSM and CPC can significantly increase feed radial expansion and energy consumption compared with FM. Moreover, the bulk density of CPC is significant⁃ly lower than that of FSM and FM, which is beneficial to the production of floating feed, but not good to the production of sinking feed.%

  3. The Effect of Cooling Rate after Homogenization on the Microstructure and Properties of 2017a Alloy Billets for Extrusion with Solution Heat Treatment on the Press

    Directory of Open Access Journals (Sweden)

    Woźnicki A.

    2016-09-01

    Full Text Available The influence of cooling rate after homogenization on the 2017A alloy microstructure was analysed. The capability of the θ (Al2Cu particles, precipitated during various homogenization coolings, for rapid dissolution was estimated. For this purpose, the DSC test was used to determine the effect of the cooling rate after homogenization on the course of melting during a rapid heating. Moreover, the samples after solution heat treatment (with short time annealing and ageing, were subjected to the microstructure investigations and the microhardness of grains interiors measurements. It was found that cooling after homogenization at 160 °C/h is sufficient for precipitation of fine θ phase particles, which dissolve during the subsequent rapid heating. The cooling at 40 °C/h, causes the precipitation of θ phase in the form of large particles, incapable of further fast dissolution.

  4. Continuous manufacturing of solid lipid nanoparticles by hot melt extrusion.

    Science.gov (United States)

    Patil, Hemlata; Kulkarni, Vijay; Majumdar, Soumyajit; Repka, Michael A

    2014-08-25

    Solid lipid nanoparticles (SLN) can either be produced by hot homogenization of melted lipids at higher temperatures or by a cold homogenization process. This paper proposes and demonstrates the formulation of SLN for pharmaceutical applications by combining two processes: hot melt extrusion (HME) technology for melt-emulsification and high-pressure homogenization (HPH) for size reduction. This work aimed at developing continuous and scalable processes for SLN by mixing a lipid and aqueous phase containing an emulsifier in the extruder barrel at temperatures above the melting point of the lipid and further reducing the particle size of emulsion by HPH linked to HME in a sequence. 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 (for 60 mg/ml lipid solution at a flow rate of 100ml/min). Among the several process parameters investigated, the lipid concentration, residence time and screw design played major roles in influencing the size of the SLN. This new process demonstrates the potential use of hot melt extrusion technology for continuous and large-scale production of SLN.

  5. Mitotic chromosome compaction via active loop extrusion

    Science.gov (United States)

    Goloborodko, Anton; Imakaev, Maxim; Marko, John; Mirny, Leonid; MIT-Northwestern Team

    During cell division, two copies of each chromosome are segregated from each other and compacted more than hundred-fold into the canonical X-shaped structures. According to earlier microscopic observations and the recent Hi-C study, chromosomes are compacted into arrays of consecutive loops of ~100 kilobases. Mechanisms that lead to formation of such loop arrays are largely unknown. Here we propose that, during cell division, chromosomes can be compacted by enzymes that extrude loops on chromatin fibers. First, we use computer simulations and analytical modeling to show that a system of loop-extruding enzymes on a chromatin fiber self-organizes into an array of consecutive dynamic loops. Second, we model the process of loop extrusion in 3D and show that, coupled with the topo II strand-passing activity, it leads to robust compaction and segregation of sister chromatids. This mechanism of chromosomal condensation and segregation does not require additional proteins or specific DNA markup and is robust against variations in the number and properties of such loop extruding enzymes. Work at NU was supported by the NSF through Grants DMR-1206868 and MCB-1022117, and by the NIH through Grants GM105847 and CA193419. Work at MIT was supported by the NIH through Grants GM114190 R01HG003143.

  6. ZM6镁合金焊丝热挤压-热拉拔工艺研究%Hot Extrusion-hot Drawing for ZM6 Alloy Welding Wire

    Institute of Scientific and Technical Information of China (English)

    张铁磊; 吉泽升; 赵振华; 武淑艳

    2012-01-01

    ZM6 alloy welding wire with diameter of 3mm was prepared by the hot extrusion - hot drawing method and the microstructure evolution was observed. The results show that the φ4mm wire billet can be produced by the reasonable choice of extrusion parameters, such as extrusion ratio, extrusion temperature and extrusion speed. By the further choice of drawing pass times and drawing temperature, the φ3mm ZM6 alloy welding wire with good surface quality was prepared. After hot extrusion, the grain of ZM6 alloy were refined significantly and the grains sizes were further reduced after 4 times drawing pass.%采用热挤压-热拉拔的方法制备了(φ)3 mm的ZM6镁合金焊丝,并对组织演变进行了观察.结果表明,通过对挤压比、挤压温度、挤压速度的合理选择可以制备出(φ)4mm的焊丝坯料,再选用适当的拉拔道次和拉拔温度等参数能够生产出表面质量良好的(φ)3 mm的ZM6镁合金焊丝.ZM6镁合金热挤压后晶粒明显细化,经过4个道次热拉拔后晶粒尺寸进一步减小.

  7. Chem-Prep PZT 95/5 for neutron generator applications : development of laboratory-scale powder processing operations.

    Energy Technology Data Exchange (ETDEWEB)

    Montoya, Ted V.; Moore, Roger Howard; Spindle, Thomas Lewis Jr.

    2003-12-01

    Chemical synthesis methods are being developed as a future source of PZT 95/5 powder for neutron generator voltage bar applications. Laboratory-scale powder processes were established to produce PZT billets from these powders. The interactions between calcining temperature, sintering temperature, and pore former content were studied to identify the conditions necessary to produce PZT billets of the desired density and grain size. Several binder systems and pressing aids were evaluated for producing uniform sintered billets with low open porosity. The development of these processes supported the powder synthesis efforts and enabled comparisons between different chem-prep routes.

  8. Modeling of severe deformation and mechanical properties in Mg-3A1-1Zn alloy through asymmetric hot-extrusion

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    One-pass asymmetric hot extrusion performed at 673 K was applied to fabricate an AZ31 magnesium alloy sheet.Finite element method(FEM)was used to model the process of asymmetric hot-extrusion.Simulation results indicate that strain rate gradient througa the thickness introduced a grain size gradient along the thickness direction and shear deformation during the asymmetric hot-extrusion results in weakened and tilted(0002)basal texture.The asymmetric hot extrusion effectively weakens the basal texture and improves the ductility,at room temperature.

  9. 超高分子量聚乙烯气辅挤出影响因素的数值模拟及分析%Numerical Simulation and Analysis of the Effect of Some Materials and Processing Parameters on the Gas Assisted Extrusion of Ultra-high Molecular Weight Polyethylene

    Institute of Scientific and Technical Information of China (English)

    柳和生; 张小霞

    2012-01-01

    After the numerical simulation of the isothermal flow of ultra-high molecular weight polyethylene melt in a gas assisted circular tube die, the numerical simulation and analysis were finished for the effect of such materials and processing parameters as entrance flow rate, relax time and zero-shear viscosity on the die swell rate, velocity distribution, die pressure drop and shear rate on the melt external face. Such analysis indicated that gas assisted extrusion was an effective technique for extrusion of ultra-high molecular weight polyethylene, which could overcome the difficulty occurring in the conventional extrusion of ultra-high molecular weight polyethylene.%以超高分子量聚乙烯的圆形轴对称气辅口模挤出为研究对象,在采用Polyflow软件对气辅口模挤出时的等温流动进行数值模拟之后,就入口流率、松弛时间以及零剪切黏度等物性和工艺参数对挤出胀大、速度分布、口模压降和熔体外表面上剪切速率的影响进行了数值模拟和分析.分析表明:气辅挤出是克服超高分子量聚乙烯传统挤出时面临一系列困难的有效加工方式.

  10. 热挤压

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Effects of adding La-rich mischmetal on the microstructure and mechanical properties of hot extruded Mg-8Al alloys; Effects of extrusion conditions on hot extruding characteristics of magnesium alloy;Expert evaluation of hydraulic press reliability; Extrudability improvement and energy consumption estimation in AI extrusion process of a 7003 alloy; Fabrication of composite pipes by multi-billet extrusion technique

  11. Combined application of extrusion and irradiation technologies: A strategy oriented for green and cost-effective chemistry

    Directory of Open Access Journals (Sweden)

    Ali Ayoub

    2013-02-01

    Full Text Available Reactive extrusion is an attractive green route for cost-effective polymer processing, which has the potential to enhance the commercial viability of biomass-derived materials. In reactive extrusion, compatibilizers can be generated in the blend preparation through polymer-polymer grafting reactions using functionalized polymers. One very interesting new green strategy for processing is the use of intense UV-irradiation to create free radicals and controllable, ultra-fast reactions. It is reasonable to expect that the use of extrusion/irradiation green technology will be an important way to improve properties and compatibility of renewable biomass- derived polymers. We believe that in the future, many more cost-effective, sustainable extrusion/irradiation reaction processes will be developed to replace inefficient conventional biomass conversion procedures and stimulate the bioproduct-based industry.

  12. Study on Extrusion Technological Parametersof Brown Rice

    Institute of Scientific and Technical Information of China (English)

    ZhuYongyi; ZhouXianqing; LingLizhong

    2001-01-01

    Abstract: Extrusion is an efficient measure to improve the texture and physic-chemical properties of brown rice. The polynomial degree two model of extrusiontechnological parameters and gelatinized degree, water absorption index, water solubleindex and moisture content of extruded matter was obtained by methods of single factorand response surface methodology, R2=0.9649, 0.8745, 0.9079, 0.8677. The optimaltechnoiogica! parameters of brown rice extrusion were figured out as follows:moisturecontent of brown rice, 11.42%, speed of screw, 30rpm, feeding speed, and 20rpm.

  13. Photoplastic studies of three-dimensional strain field in the continuous cladding process

    Science.gov (United States)

    He, Youliang; Bai, Guangrun; Song, Baoyun

    1998-08-01

    A great development in CONFORM (Continuous Extrusion) technology is the application of the process for the cladding or sheathing of hard or soft cores to manufacture aluminium clad steel wires or fibre optic cables, in particular, OPGW and coaxial CATV cables. There is an alarming lack of understanding of the ways in which various forming parameters, such as strain, strain rate, friction, temperature and billet dimensions affect the flow pattern and quality of the final product. A key requirement for precise analysis of the forming process is an accurate description of the three-dimensional strain distributions within the body undergoing deformation. Because of the complexity of the die geometry in the continuous cladding process, plane-strain assumptions do not apply. An experimental technique with a capability for providing generalized three-dimensional strain information is sorely needed. It is toward this goal that the method of photoplasticity is used to obtain the strain distributions in the deforming body. This paper presents the procedures of the experiment and gives the three-dimensional strain distributions in the die chamber of the continuous cladding process.

  14. Smooth Particle Hydrodynamics Simulation of Micro-Cup-Extrusion Using a Graphit-ic Coating

    Directory of Open Access Journals (Sweden)

    Li Shi-Cheng

    2014-01-01

    Full Text Available Microextrusion is becoming increasingly important for the manufacturing of microcomponents. However, this reduction in scale to a microlevel means that the influence of friction and the need for suitable lubrication are greatly increased. This study therefore looks at the use of a low-friction and highly wear resistant Graphit-ic coating on the mold-forming section of a microextrusion mold, this coating being applied by a closed-field unbalanced magnetron sputter ion plating technique. A microcup of CuZn33 brass alloy was then extruded, with a wall thickness of 0.45 mm, outside diameter of 2.9 mm, and an internal diameter of 2 mm. The experimental results in which extrusion uses the mold coating with Graphit-ic film are compared against the experimental results in which extrusion uses the mold uncoating with Graphit-ic film. This showed that the load was decreased a lot and the self-lubricating solid coating facilitates a smooth extrusion process. As the extrusion rate was quite high, smoothed particle hydrodynamics method simulations of the extrusion process were conducted, these being then compared with the experimental results. These result showed that the SPH simulation can be applied to show the deformation of materials and predict the load trend.

  15. Optimization of pneumatic sheet extrusion of whole wheat flour poory dough using response surface methodology.

    Science.gov (United States)

    Murthy, K Venkatesh; Sudha, M L; Ravi, R; Raghavarao, K S M S

    2015-07-01

    Pneumatic extrusion of whole wheat flour dough is a challenge in the preparation of Poory. In the present study, the pneumatic extrusion process variables (pneumatic pressure, rate of extrusion) and quality of deep fried product (oil uptake, frying time, puffed height) was evaluated to get Poory of maximum overall sensory quality, minimum shear and minimum oil uptake. These parameters depend on the moisture content of wheat dough. Response surface methodology was demonstrated to be an efficient tool for the optimization of process parameters of pneumatic extrusion. The results indicated that extrusion pressure ranging from 3 ~ 6 × 10(5) Pa for the whole wheat flour dough with added moisture of 56 ~ 60 % was found to give a uniform rate of extruded sheet. It was observed that submerged frying time for the extruded dough sheet was in the range of 35 ~ 40 s, with the temperature of the vegetable oil to be in the range of 180 ~ 185 °C. Oil uptake during frying was about 12 ± 1 % and the textural shear force was found to be 9.9 N with an overall sensory score of 7.2 ± 0.5 on nine point scale. The experimental errors for all attributes were non-significant (p > 0.05) and thus optimum variables predicted by the model are found suitable.

  16. Die swell as an objective in the design of polymer extrusion dies

    Science.gov (United States)

    Siegbert, Roland; Behr, Marek; Elgeti, Stefanie

    2016-10-01

    This paper focuses on developing a suitable objective function for the inverse form of profile extrusion die design. First, the problem is motivated by introducing the extrusion die design process. After describing how Computer Aided Engineering enhances the traditional design process, a set of applicable objective functions is introduced. The main criteria for identifying the most suitable are computational applicability, robustness and smoothness of the functional. After discussing the results of several simulations, an objective function is proposed for the implementation in an existing optimization framework utilizing parameter-based optimization.

  17. AZ系列镁合金热模拟挤压过程中挤压力的研究%Extrusion Force of AZ Series Mg Alloy During Thermal Simulated Extrusion Forming

    Institute of Scientific and Technical Information of China (English)

    彭建; 周绸; 李权

    2011-01-01

    AZ 10, AZ31, AZ61 and AZ91 magnesium alloys were deformed with simulated extrusion system on Gleeble 1500D, which can determine the extrusion force during extrusion forming process. The microstructure of the alloys and the evolution of extrusion force were investigated. The results show that the extrusion force increases gradually with the increase of alloy element. Aimed at the same magnesium alloy, the deformed alloy with previous homogenization before extrusion has more extrusion force than that without homogenization, and dynamic recrystallization is a decisive factor in extrusion force during extrusion forming.%通过在Gleeble1500D热模拟试验机上对AZ10、AZ31、AZ61和AZ91镁合金进行模拟挤压,并对热模拟挤压成形过程中的挤压力进行测定,研究AZ系列镁合金热模拟挤压成形过程挤压力及其组织变化.研究结果表明,在AZ系列镁合金中,随着合金元素含量的增多,挤压力逐渐增大,并且同种镁合金在挤压前经均匀化退火处理后所需的挤压力比未经均匀化处理的合金所需挤压力大,动态再结晶是影响其挤压力大小的决定性因素.

  18. Development of expanded extrusion food products for an Advanced Life Support system.

    Science.gov (United States)

    Zasypkin, D V; Lee, T C

    1999-01-01

    Extrusion processing was proposed to provide texture and to expand the variety of cereal food products in an isolated Advanced Life Support (ALS) system. Rice, wheat, and soy are the baseline crops selected for growing during long-term manned space missions. A Brabender single-screw laboratory extruder (model 2003, L/D 20:1), equipped with round nozzles of various lengths, was used as a prototype of a small-size extruder. Several concepts were tested to extend the variety and improve the quality of the products, to decrease environmental loads, and to promote processing stability. These concepts include: the blending of wheat and soybean flour, the extrusion of a coarser rice flour, separation of wheat bran, and optimization of the extruder nozzle design. An optimal nozzle length has been established for the extrusion of rice flour. Bran separating was necessary to improve the quality of wheat extrudates.

  19. 环模制粒粉体旋转挤压成型扭矩模型构建及试验%Modeling and experiment on rotary extrusion torque in ring-die pelleting process

    Institute of Scientific and Technical Information of China (English)

    武凯; 孙宇; 彭斌彬; 丁武学; 王栓虎

    2013-01-01

    环模制粒成型技术以其高效率、高成型率、低污染等优点广泛应用于饲料机械、生物质能源机械、化工、制药等领域,而环模制粒过程扭矩模型的缺失已成为制约制粒技术发展的瓶颈之一。该文旨在通过理论分析、数值模拟与试验研究,建立粉体旋转挤压制粒成型过程精确扭矩模型,为粉体旋转挤压制粒成型装备的节能降耗及优化设计奠定理论基础。针对各向同性粉体物料,基于微单元受力分析及广义胡克定律,建立了旋转挤压制粒成型过程中模孔不同深度位置挤压压强的计算公式;基于DPC模型及实际辊轧工艺,建立了旋转挤压成型过程有限元分析模型,进行了压紧区应力分析;基于有限元模拟分析结果,设定变形压紧区的压强分布为二次曲线,建立了变形压紧区、挤压区的压强分布模型;最后建立了粉体旋转挤压制粒成型扭矩模型。以无线扭矩测试系统及环模制粒机为试验平台进行了鸡饲料的环模挤压制粒试验,求解得到了所有模型常量。设计了9组扭矩测试试验进行模型验证,测试结果与理论计算对比表明,试验值与计算值差距较小,最大计算误差仅为2.6%,这反映出建立的模型正确有效,对指导环模制粒机结构优化与节能降耗具有重要的意义。%Rotary roll extrusion pelleting technology is a kind of mainstream technology in the area of pellet forming technology, and the pellet mill has been widely used in the biomass-energy industry, feed industry, chemical industry, pharmacy, and so on. The pellet produced by the pellet mill has many advantages, such as a high forming rate, high absorption rate, high calorific value, and low pollution. But because of absence of the torque modeling theory, the existing pelleting technology with high consumption, low productivity, and low service life has been the bottleneck of industrial

  20. Effects of extrusion conditions on the extrusion responses and the quality of brown rice pasta.

    Science.gov (United States)

    Wang, Li; Duan, Wei; Zhou, Sumei; Qian, Haifeng; Zhang, Hui; Qi, Xiguang

    2016-08-01

    This research investigated the effects of extrusion temperature and screw speed on the extrusion system parameters and the qualities of brown rice pasta. The die pressure and motor torque value reached a maximum at 90°C but decreased when the screw speed increased from 80 to 120rpm. The extrusion temperature and screw speed also significantly affected the cooking quality and textural properties of brown rice pasta. The pasta produced at an extrusion temperature of 120°C and screw speed of 120rpm had the best quality with a cooking loss, hardness and adhesiveness of 6.7%, 2387.2g and -7.0g⋅s, respectively, similar to those of pasta made from gluten-free flour. The results indicated that brown rice can be used to produce gluten-free pasta with improved nutrition.

  1. Immediate release pellets with lipid binders obtained by solvent-free cold extrusion.

    Science.gov (United States)

    Krause, Julia; Thommes, Markus; Breitkreutz, Jörg

    2009-01-01

    Lipid-based drug delivery systems have spread in their use in pharmaceutical drug development. This work focuses on the use of lipid binders as alternative non-toxic extrusion aid for pellet formulations. The preparation of immediate release pellets with solid lipid binders through a solvent-free cold extrusion/spheronisation process was investigated in this study. Various binary, ternary and quaternary mixtures of powdered lipids and the model drug sodium benzoate were investigated and compared to well-known wet extrusion binders like microcrystalline cellulose and kappa-carrageenan. The cold lipid extrusion process offers multiple advantages as it is suitable for thermal sensitive as well as for hygroscopic drugs, furthermore no drying process to evaporate the solvent is needed and the process is feasible for different extruder types. Some of the developed pellets showed favourable properties like spherical shape, narrow size distribution, a high drug load of 80% sodium benzoate and a drug release of more than 90% within 40 min. The stability of drug release, which can be problematic when using lipid excipients, was sufficient for some mixtures, as storage under elevated temperatures changed the release profiles only slightly and no formulation released less than 80% within the first 60 min. A formulation with a mixture of hard fat, glycerol distearate and glycerol trimyristate showed the best results, as pellets with a low aspect ratio, narrow size distribution and complete drug release were obtained. Using appropriate mixtures of acylglycerides it becomes possible to produce pharmaceutical pellets with immediate release characteristics by cold extrusion and subsequent spheronisation. Thus, lipids are very promising alternatives to commonly used extrusion/spheronisation binders.

  2. 75 FR 80527 - Aluminum Extrusions From China

    Science.gov (United States)

    2010-12-22

    ... Republic of China: Postponement of Final Determination of Sales at Less Than Fair Value, 75 FR 73041... Sales at Less Than Fair Value, and Preliminary Determination of Targeted Dumping, 75 FR 69403, November... Affirmative Countervailing Duty Determination, 75 FR 54302, September 7, 2010, and Aluminum Extrusions...

  3. Robo-Enabled Tumor Cell Extrusion.

    Science.gov (United States)

    Richardson, Helena E; Portela, Marta

    2016-12-19

    How aberrant cells are removed from a tissue to prevent tumor formation is a key question in cancer biology. Reporting in this issue of Developmental Cell, Vaughen and Igaki (2016) show that a pathway with an important role in neural guidance also directs extrusion of tumor cells from epithelial tissues.

  4. 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 wee

  5. Energy aspects in food extrusion-cooking

    NARCIS (Netherlands)

    Janssen, L.P.B.M.; Moscicki, L.; Mitrus, M.

    2002-01-01

    Theoretical and practical energy balance considerations in food extrusion-cooking are presented in the paper. Based on the literature review as well as on own measurement results, the baro-thermal treatment of different vegetable raw materials is discussed together with the engineering aspects of th

  6. Application of Six-sigma Management for Continuously Casting Square Billets of High Carbon Steel%六西格玛管理在高碳钢小方坯连铸中的应用

    Institute of Scientific and Technical Information of China (English)

    齐志宇; 李泽林; 梅雪辉; 温荣宇

    2016-01-01

    Considering the problem on the high scrap rate of billets for hard wire steel rods with high carbon in No.2 Branch of General Steelmaking Plant of Angang Steel Co., Ltd., the six-sigma management system was used to analyze the problems existing in the fields of the process engineering, equipment management and basic management. After taking such measures as contro-lling the degree of superheat of molten steel in tundish and the specific water flow of secondary cooling water, stabilizing the casting speed and controlling the electromagnetic stirring frequency and current, the scrap rate of billets for hard wire steel rods with high carbon was reduced up to 0.12%.%针对鞍钢股份有限公司炼钢总厂二分厂高碳硬线钢铸坯废品率高的问题,采用六西格玛管理的方法分析了工艺技术、设备和基础管理几方面存在的问题,通过控制中间包钢水过热度、二冷水比水量、稳定拉速并控制电磁搅拌频率和电流,高碳硬线钢铸坯的废品率降至0.12%以下。

  7. Effect of extrusion rate on morphology of Kaolin/PolyEtherSulfone (PESf) membrane precursor

    Science.gov (United States)

    Misaran, M. S.; Sarbatly, R.; Bono, A.; Rahman, M. M.

    2016-11-01

    This study aims to investigate the influence of apparent viscosity induced by spinneret geometry and extrusion rate on morphology of Kaolin/PESf hollow fiber membranes. Different extrusion rates at two different rheology properties were introduced on a straight and conical spinneret resulting in various shear rates. The hollow fiber membrane precursors were spun using the wet spinning method to decouple the effect of shear and elongation stress due to gravity stretched drawing. The morphology of the spun hollow fiber was observed under Scanning Electron Microscope (SEM) and the overall porosity were measured using mercury intrusion porosimeter. Shear rate and apparent viscosity at the tip of the spinneret annulus were simulated using a computational fluid dynamics package; solidworks floworks. Simulation data shows that extrusion rate increment increases the shear rate at the spinneret wall which in turn reduce the apparent viscosity; consistent with a non Newtonian shear thinning fluid behavior. Thus, the outer finger-like region grows as the shear rate increases. Also, overall porosity of hollow fiber membrane decreases with extrusion rate increment which is caused by better molecular orientation; resulting in denser hollow fiber membrane. Thin outer finger-like region is achieved at low shear experience of 109.55 s-1 via a straight spinneret. Increasing the extrusion rate; thus shear rate will cause outer finger-like region growth which is not desirable in a separation process.

  8. Extrusion – back to the future: Using an established technique to reform automated chemical synthesis

    Science.gov (United States)

    2017-01-01

    Herein, the benefits which extrusion can provide for the automated continuous synthesis of organic compounds are highlighted. Extrusion is a well-established technique that has a vital role in the manufacturing processes of polymers, pharmaceuticals and food products. Furthermore, this technique has recently been applied to the solvent-free continuous synthesis of co-crystals and coordination compounds including metal-organic frameworks (MOFs). To date, a vast amount of research has already been conducted into reactive extrusion (REX), particularly in the polymer industry, which in many cases has involved organic transformations, however, it has not received significant recognition for this. This review highlights these transformations and discusses how this previous research can be applied to the future of organic compound manufacture. PMID:28179950

  9. Extrusion - back to the future: Using an established technique to reform automated chemical synthesis.

    Science.gov (United States)

    Crawford, Deborah E

    2017-01-01

    Herein, the benefits which extrusion can provide for the automated continuous synthesis of organic compounds are highlighted. Extrusion is a well-established technique that has a vital role in the manufacturing processes of polymers, pharmaceuticals and food products. Furthermore, this technique has recently been applied to the solvent-free continuous synthesis of co-crystals and coordination compounds including metal-organic frameworks (MOFs). To date, a vast amount of research has already been conducted into reactive extrusion (REX), particularly in the polymer industry, which in many cases has involved organic transformations, however, it has not received significant recognition for this. This review highlights these transformations and discusses how this previous research can be applied to the future of organic compound manufacture.

  10. Key Problems in Microforming Processes of Microparts

    Institute of Scientific and Technical Information of China (English)

    Chunju WANG; Debin SHAN; Bin GUO; Jian ZHOU; Lining SUN

    2007-01-01

    From the viewpoint of production engineering, microforming is considered as an effective process to fabricate various microparts. Several key problems in microforming processes were investigated. A new microforming apparatus with a high stiffness piezoelectric actuator as the punch driver was developed to produce microparts.To improve the forming abilities and locate the billets, a floating microdie was designed. The size effects of the billets and die cavities on the microforming abilities were studied with upsetting and coining tests, respectively.And the isothermal microforming process of microgears was performed with the developed microforming apparatus. Several analysis methods were used to evaluate the forming quality of the microparts.

  11. Influence of Mg Content on Deformability of AlMg Alloys during Extrusion

    Directory of Open Access Journals (Sweden)

    Leśniak D.

    2016-03-01

    Full Text Available In this study the research on deformability of AlMg alloys with high Mg contents in extrusion was carried out. The different shapes from AlMg alloys containing 3.5%, 4.5% and 5.5% of Mg were extruded on 500 T semi-industrial press by using one-hole and multi-hole flat dies. The extrudates surface quality was under investigations in relation with the temperature-speed parameters of the extrusion process. The metal exit speed was estimated depending on the extrudates shape, wall thickness and Mg content. The alloy’s border solidus and liquidus temperatures were also determined.

  12. Effect of fermentation and extrusion on the release of selected minerals from lupine grain preparations

    Directory of Open Access Journals (Sweden)

    Rafał W. Wójciak

    2009-09-01

    Full Text Available Introduction. Antinutritional factors in legumes lower the nutritional value of foods by lowering the digestibility or bioavailability of nutrients. Technological processes applied in food production (e.g. extrusion, fermentation, germination may influence the leguminous seeds matrix composition which in consequence may affect (improve or decrease mineral bioaccessibility and uptake in animals and humans. The aim of this study was to determine the effect of fermentation and extrusion processing, as well as their combination, on the potential availability of Fe, Cu, and Zn from lupine grain preparations. Materials and methods. The content and the release of Fe, Cu and Zn from three different lupine species (Lupinus albus, Lupinus luteus, Lupinus angustifolius was determined. The samples were subjected to enzymatic digestion under in vitro conditions. The content of minerals in lupine grains before and after enzymatic digestion was determined by the flame atomic absorption spectrometry. Results. The degree of release of Fe, Cu, and Zn from dehulled lupine grains was higher than from whole grains. Fermentation processing increased the degree of Fe release, extrusion decreased the degree of Cu release, while the extrusion after fermentation processing increased the degree of Fe release from lupine grain preparations. Conclusions. The degree of mineral release from lupine grains depends on the hull content, technological processing applied and the lupine variety.

  13. 半固态挤压成形ZCuSn10铜合金的微观组织研究%Microstructure of ZCuSn10 Alloy in Semi-Solid Thixo-Extrusion

    Institute of Scientific and Technical Information of China (English)

    陆常翁; 肖寒; 卢德宏; 蒋业华; 周荣

    2015-01-01

    对采用冷轧-重熔应变诱导熔化激活法制备的ZCuSn10铜合金坯料进行了半固态挤压成形和组织演变分析,研究了ZCuSn10铜合金的半固态挤压成形性。结果表明,采用冷轧-重熔法制备的ZCuSn10铜合金坯料具有均匀、细小颗粒的半固态组织,在960℃保温25 min后挤压成形可获得表面光洁、组织细小、分布均匀的挤压件。%The semi-solid thixo-extrusion ZCuSn10 copper alloy prepared by strain induced melt activated (SIMA)method with cold rolling and remelting was carried out.The semi-solid extrusion formability of ZCuSn10 copper alloy was described through the analysis of microstructure evolution.The results indi-cate that microstructure of ZCuSn10 alloy billets by SIMA method with cold rolling and remelting exhib-its uniform,fine particles.The extrusion part with surface finish,fine and homogeneous microstructure can be obtained at 960 ℃ for 25 min.

  14. Profile extrusion of wood plastic cellular composites and formulation evaluation using compression molding

    Science.gov (United States)

    Islam, Mohammad Rubyet

    Wood Plastic Composites (WPCs) have experienced a healthy growth during the last decade. However, improvement in properties is necessary to increase their utility for structural applications. The toughness of WPCs can be improved by creating a fine cellular structure while reducing the density. Extrusion processing is one of the most economical methods for profile formation. For our study, rectangular profiles were extruded using a twin-screw extrusion system with different grades of HDPE and with varying wood fibre and lubricant contents together with maleated polyethylene (MAPE) coupling agent to investigate their effects on WPC processing and mechanical properties. Work has been done to redesign the extrusion system setup to achieve smoother and stronger profiles. A guiding shaper, submerged in the water, has been designed to guide the material directly through water immediately after exiting the die; instead of passing it through a water cooled vacuum calibrator and then through water. In this way a skin was formed quickly that facilitated the production of smoother profiles. Later on chemical blowing agent (CBA) was used to generate cellular structure in the profile by the same extrusion system. CBA contents die temperatures, drawdown ratios (DDR) and wood fibre contents (WF) were varied for optimization of mechanical properties and morphology. Cell morphology and fibre alignment was characterized by a scanning electron microscope (SEM). A new compression molding system was developed to help in quick evaluation of different material formulations. This system forces the materials to flow in one direction to achieve higher net alignment of fibres during sample preparation, which is the case during profile extrusion. Operation parameters were optimized and improvements in WPC properties were observed compared to samples prepared by conventional hot press and profile extrusion.

  15. Solid lipid extrusion of sustained release dosage forms.

    Science.gov (United States)

    Reitz, Claudia; Kleinebudde, Peter

    2007-09-01

    The applicability of the solid lipid extrusion process as preparations method for sustained release dosage forms was investigated in this study. Two lipids with similar melting ranges but of different composition, glyceryl palmitostearate (Precirol ATO 5) and glyceryl trimyristate (Dynasan 114), and mixtures of each lipid with 50% or 75% theophylline were extruded at temperatures below their melting ranges. Extrudates were analyzed using differential scanning calorimetry, scanning electron microscopy, porosity measurements and in vitro drug dissolution studies. The possibility of processing lipids by softening instead of complete melting and without subsequent formation of low-melting, metastable polymorphs could be demonstrated. Extrudates based on formulations of glyceryl palmitostearate/theophylline (50:50) and glyceryl trimyristate/theophylline (50:50) showed sustained release properties. An influence of extrusion conditions on the matrix structure was shown for extrudates based on a mixture of glyceryl trimyristate and theophylline (50:50). Glyceryl trimyristate tended to solidify in porous structures after melting. Exceeding a material temperature of 50.5 degrees C led to porous extrudate matrices with a faster drug release. The production of novel, non porous sustained release matrices was possible at a material temperature of 49.5 degrees C. Extrudates based on glyceryl trimyristate/theophylline (50:50) only slight changes in melting enthalpy and stable drug release profiles.

  16. 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

  17. 6201铝合金管材连续流变扩展挤压过程中温度场和流场的数值模拟%Simulation of temperature field and metal flow during continuous semisolid extending extrusion process of 6201 alloy tube

    Institute of Scientific and Technical Information of China (English)

    管仁国; 赵占勇; 钞润泽; 连超; 温景林

    2012-01-01

    A continuous semisolid extending extrusion (CSEP) method was proposed.Temperature field and metal flow during continuous semisolid extending extrusion process of 6201 alloy tube were studied.During the process,the temperature in the roll-shoe cavity decreases gradually,and the isothermal lines of the alloy deviate from the shoe side to the work roll side in the roll-shoe gap.Metal flow velocity decreases gradually from the surface of the work roll to the surface of the shoe.In the extrusion mould,alloy temperature decreases gradually from the entrance to the exit and from the center to the sidewall of the mould.The extending cavity is radially filled with the alloy.The flow lines in the tube corresponding to the centers of the splitflow orifices and the welding gaps are dense,and the corresponding harness values are high; there are 8 transitional bands between them.In order to prepare 6201 alloy tubes with good surface quality,the pouring temperature from 750 ℃ to 780 ℃ was suggested.%利用自行设计的连续半固态扩展挤压成形装置制备6201铝合金管材,并采用数值模拟研究此过程的温度场和流场分布规律.结果表明:辊-靴型腔内合金的温度从入口到出口处逐渐降低,等温线向轧辊侧偏移,金属流动速度沿工作辊表面向辊靴表面依次递减.在扩展挤压模具内,合金呈放射状填充到模具中,温度由入口到出口处逐渐降低,且模具扩展腔中心的温度高于壁面的温度.分流孔中心位置和焊合部位对应的成形管材截面流线密集,此处相应的金属硬度也高,在两者之间出现8条流线的舒缓过渡带.为制备表面质量良好的6201铝合金管材,合理的浇注温度为750~780℃.

  18. 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 ballis

  19. Analysis of Key Technologies and Equipments Development of Largescale Melted Extrusion Manufacturing Systems

    Institute of Scientific and Technical Information of China (English)

    Lei ZHANG; Sheng CHEN; Yongnian YAN; Renji ZHANG

    2003-01-01

    To develop large-scale RP systems used to producing functional parts and large-sized models has become an urgentcall now. In this paper, a large-scale RP system, MEM600-l, based on the melted extrusion manufacturing (MEM)process has been developed success

  20. Polymeric formulations for drug release prepared by hot melt extrusion : application and characterization

    NARCIS (Netherlands)

    Stanković, Milica; Frijlink, Henderik W; Hinrichs, Wouter L J

    2015-01-01

    Over the past few decades hot melt extrusion (HME) has emerged as a powerful processing technology for the production of pharmaceutical solid dosage forms in which an active pharmaceutical ingredient (API) is dispersed into polymer matrices. It has been shown that formulations using HME can provide

  1. 超音速电弧喷射成形工艺参数对AgNiCu15-5沉积坯致密性的影响%The Effects of Ultrasonic Arc Spray Formation Parameters on the Density of AgNiCu15-5 Deposited Billets

    Institute of Scientific and Technical Information of China (English)

    张科; 秦国义; 许思勇; 郭锦新; 马光

    2012-01-01

    The orthogonal design approach was used to investigate the effects of technical parameters of ultrasonic arc spray formation ( UASF ) on the density of AgNiCu15_5 deposited billets. The morphology of the deposited billets was studied by SEM. The experimental results show that, under the condition of 250 mm spray length, both the arc voltage(U) and the pressure of atomization gases(P) have great effects on the density of deposited billet, whereas the arc current (I) and the substrate rotation speed ( Z) have no marked effects. The optimal process parameters of preparing the AgNiCu15-5 deposited billet are given as follows; the arc voltage is 32 V, the pressure of atomization gases is 0. 9 MPa, the arc current is 220 A, the substrate rotation speed is 800 r/min. SEM revealed that the microstructure of the deposited billets obtained under the optimal process parameters is compact.%采用正交设计方法和通过极差分析研究了超音速电弧喷射成形工艺参数对AgNiCu15-5沉积坯致密性的影响,同时采用SEM对沉积坯的组织形貌进行观察.研究结果表明,当沉积距离L为250 mm时,影响沉积坯致密性的工艺参数的主次顺序为:电弧电压U、雾化气压P、电弧电流I、沉积盘转速Z;综合分析表明,优化的沉积工艺参数为U2P2I3Z2,即U为32 V、P为0.9 MPa、I为220 A、Z为800 r/min.SEM分析表明,优化工艺参数制备的沉积坯内部组织致密,孔隙极少.

  2. Noise-induced variability of volcanic extrusions

    Science.gov (United States)

    Alexandrov, D. V.; Bashkirtseva, I. A.; Ryashko, L. B.

    2016-11-01

    Motivated by important physical applications, we study a non-linear dynamics of volcanic extrusions on the basis of a simple pressure-mass flow model. We demonstrate that the deterministic phase portrait represents either the bulbous-type curves or closed paths stretched to their left depending on the initial conditions. The period of phase trajectories therewith increases when the pressure drop between the conduit top and bottom compensates the lava column pressure in it. Stochastic forcing changes the system dynamics drastically. We show that a repetitive scenario of volcanic behaviour with intermittency of stochastic oscillations of different extrusion amplitudes and frequencies appears in the presence of noises. As this takes place, the mean values of interspike intervals characterizing the system periodicity have a tendency to grow with increasing the noise intensity. The probability distribution functions confirming this dynamic behaviour are constructed.

  3. Continuous Severe Plastic Deformation Processing of Aluminum Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Raghavan Srinivasan (PI); Prabir K. Chaudhury; Balakrishna Cherukuri; Qingyou Han; David Swenson; Percy Gros

    2006-06-30

    by SPD techniques. This combination of properties makes UFG metals produced by SPD very attractive as machining, forging or extrusion stock, both from the point of view of formability as well as energy and cost saving. However, prior to this work there had been no attempt to transfer these potential benefits observed in the laboratory scale to industrial shop floor. The primary reason for this was that the laboratory scale studies had been conducted to develop a scientific understanding of the processes that result in grain refinement during SPD. Samples that had been prepared in the laboratory scale were typically only about 10-mm diameter and 50-mm long (about 0.5-inch diameter and 2-inches long). The thrust of this project was three-fold: (i) to show that the ECAE/P process can be scaled up to produce long samples, i.e., a continuous severe plastic deformation (CSPD) process, (ii) show the process can be scaled up to produce large cross section samples that could be used as forging stock, and (iii) use the large cross-section samples to produce industrial size forgings and demonstrate the potential energy and cost savings that can be realized if SPD processed stock is adopted by the forging industry. Aluminum alloy AA-6061 was chosen to demonstrate the feasibility of the approach used. The CSPD process developed using the principles of chamber-less extrusion and drawing, and was demonstrated using rolling and wire drawing equipment that was available at Oak Ridge National Laboratory. In a parallel effort, ECAE/P dies were developed for producing 100-mm square cross section SPD billets for subsequent forging. This work was carried out at Intercontinental Manufacturing Co. (IMCO), Garland TX. Forging studies conducted with the ECAE/P billets showed that many of the potential benefits of using UFG material can be realized. In particular, the material yield can be increased, and the amount of material that is lost as scrap can be reduced by as much as 50%. Forging

  4. The extrusion properties of potato granules

    OpenAIRE

    Kooi, Eng Teong

    1982-01-01

    Potato granules from different sources were found, on extrusion, to produce potato snacks of variable quality. In some instances strip formation was unsatisfactory, in other instances blistering of the snack occurred on frying. In total, about 20-25 batches of potato granules were examined and classified in relation to these two phenomena. The amylose/amylopectin ratios of these samples of potato granules were determined by the semi-micro potentiometric iodine titration technique, but it was ...

  5. Phenomenological model of maize starches expansion by extrusion

    Science.gov (United States)

    Kristiawan, M.; Della Valle, G.; Kansou, K.; Ndiaye, A.; Vergnes, B.

    2016-10-01

    During extrusion of starchy products, the molten material is forced through a die so that the sudden abrupt pressure drop causes part of the water to vaporize giving an expanded, cellular structure. The objective of this work was to elaborate a phenomenological model of expansion and couple it with Ludovic® mechanistic model of twin screw extrusion process. From experimental results that cover a wide range of thermomechanical conditions, a concept map of influence relationships between input and output variables was built. It took into account the phenomena of bubbles nucleation, growth, coalescence, shrinkage and setting, in a viscoelastic medium. The input variables were the moisture content MC, melt temperature T, specific mechanical energy SME, shear viscosity η at the die exit, computed by Ludovic®, and the melt storage moduli E'(at T > Tg). The outputs of the model were the macrostructure (volumetric expansion index VEI, anisotropy) and cellular structure (fineness F) of solid foams. Then a general model was established: VEI = α (η/η0)n in which α and n depend on T, MC, SME and E' and the link between anisotropy and fineness was established.

  6. Extrusion foaming of protein-based thermoplastic and polyethylene blends

    Science.gov (United States)

    Gavin, Chanelle; Lay, Mark C.; Verbeek, Casparus J. R.

    2016-03-01

    Currently the extrusion foamability of Novatein® Thermoplastic Protein (NTP) is being investigated at the University of Waikato in collaboration with the Biopolymer Network Ltd (NZ). NTP has been developed from bloodmeal (>86 wt% protein), a co-product of the meat industry, by adding denaturants and plasticisers (tri-ethylene glycol and water) allowing it to be extruded and injection moulded. NTP alone does not readily foam when sodium bicarbonate is used as a chemical blowing agent as its extensional viscosity is too high. The thermoplastic properties of NTP were modified by blending it with different weight fractions of linear low density polyethylene (LLDPE) and polyethylene grafted maleic anhydride (PE-g-MAH) compatibiliser. Extrusion foaming was conducted in two ways, firstly using the existing water content in the material as the blowing agent and secondly by adding sodium bicarbonate. When processed in a twin screw extruder (L/D 25 and 10 mm die) the material readily expanded due to the internal moisture content alone, with a conditioned expansion ratio of up to ± 0.13. Cell structure was non-uniform exhibiting a broad range cell sizes at various stages of formation with some coalescence. The cell size reduced through the addition of sodium bicarbonate, overall more cells were observed and the structure was more uniform, however ruptured cells were also visible on the extrudate skin. Increasing die temperature and introducing water cooling reduced cell size, but the increased die temperature resulted in surface degradation.

  7. Effect of Temperature and Ram Speed on Isothermal Extrusion for Large-size Tube with Piece-wing

    Institute of Scientific and Technical Information of China (English)

    He YANG; Jun ZHANG; Yangmin HE; Bingtao HAN

    2005-01-01

    Heat energy change during the extrusion of 7075 aluminium alloy large-size tube with piece-wing in a container was analyzed. Extrusion load vs ram displacement diagrams and exit temperature vs ram displacement diagrams at various speeds were obtained by 3D FEM simulation. Results show that the exit temperature becomes higher as the ram speed and displacement increase. For large-size tube with piece-wing, there is certainly a curve of ram speed decreasing with increasing ram displacement, which enables isothermal extrusion to be achieved. Therefore,an attempt was made to divide the working stroke into five different zones. Each of them has a preset speed that decreases from the ram displacement beginning to the ending. And then, new exit temperature vs ram displacement diagram was obtained by 3D FEM simulation for the five different speeds. It is shown that the variation of exit temperature is very small. Through the above research, a basic method for realizing isothermal extrusion of 7075large-size tube with piece-wing was obtained, that is, the working stroke was divided into several different zones with a decreasing speed during extrusion, each zones' speed was real-time adjusted on the feedback signal of exit temperature by proportional hydraulic valve through closed-loop control. The engineering experiment verification was carried out on 100 MN aluminium extrusion press with oil-driven double action. The experimental results of the exit temperature agrees with the simulation ones. The achievements of this study may serve as a significant guide to the practice of the relevant processes, particularly for isothermal extrusion. The verified method has been used in the design and manufacture of 125 MN aluminium extrusion press with oil-driven double action.

  8. Learning through Plastic Filament Extrusion

    Science.gov (United States)

    Orr, Taylor; Flowers, Jim

    2015-01-01

    3D printing is becoming ever more popular in both the manufacturing world as well as in technology and engineering education classrooms all over the United States. 3D printing is an additive manufacturing process in which successive layers of material are built up to produce three-dimensional objects from computer-aided design (CAD) files, making…

  9. Extrusion process of corn stalk powder in single orifice die processing based on discrete element method%玉米秸秆粉料单模孔致密成型过程离散元模拟

    Institute of Scientific and Technical Information of China (English)

    李永奎; 孙月铢; 白雪卫

    2015-01-01

    Mechanical behavior in the densification of biomass material is closely related to pellet quality. In order to explore the forming mechanism of typical biomass material from loose state to consolidation, the discrete element method (DEM) was introduced to investigate the movement and interaction of the milled corn stalk particles in the compacting process, and the verification experiments were carried out to test the effectiveness of the DEM simulation in this study. Firstly, the three-dimensional (3D) particle contact model of corn stalk powder based on the soft-sphere model of DEM was established, and the constraining walls in DEM model were completely consistent with the compressing cavity boundary conditions in geometric shape and dimension of experimental tests conducted in December, 2014; the loading speed in simulation was also set as the same value as the DEM model. Secondly, the diameter range of simulated particles was configured to 0.4-1.0 mm in accordance to the particle size distribution acquired through the screening experiment and calculation, and the generated particles were fully filled into the whole cavity at the original state before the compressing force was loaded. The mechanical parameters of the particles, such as normal stiffness, shear stiffness and friction coefficient between the 2 contact particles, were set to the values generated at random in specific range which was determined according to compacting experimental data. Thirdly, the comparison of compression stress relaxation data between tests and simulation was carried out and the validity of the simulation was verified by the hypothesis test. It was found that the force data with time from the hypothesis tests and DEM simulation followed the similar tendency, and the absolute error was not higher than 100 N in both initial loading stage and 20 seconds after stress relaxation. In the first 20 seconds of stress relaxation course, the values of absolute error were obviously higher

  10. The influence of extrusion on the content of polyphenols and antioxidant/antiradical activity of rye grains (Secale cereale L.

    Directory of Open Access Journals (Sweden)

    Dorota Gumul

    2007-12-01

    Full Text Available The aim of the study was to check the influence of extrusion on the content of polyphenol and antioxidant/antiradical activity of rye grains. The extrudates prepared from three cultivars of rye were obtained at different process parameters. Total polyphenol, antioxidant and antiradical activity was measured in the samples. Extrusion resulted in a decrease of total polyphenol content (TPC on average by 40% in rye grains, and the largest loss of endogenic phenolic compounds was observed at the extrusion conditions: 20% moisture of raw material and 120°C. Extrudates obtained at: 14% moisture of raw material and 180°C exhibited either increase of these compounds or no change. It was found that rye extrudates exhibited the highest antiradical activity (measured by the methods with DPPH and ABTS when raw material contained 14% of moisture and at temperature of the extrusion – 180°C, while the lowest when the parameters were 20% and 120°C. Antioxidant activity in beta-carotene-linoleate model system was high when rye extrusion was performed at 14% and 20% moisture and temperature 180°C. The negative influence of extrusion on the antioxidant activity of rye grains was observed at 20% moisture and 120°C.

  11. The Development of PVC Extrusions for a 14,000 Ton Self-Supporting Structure for the Detection of Neutrinos

    Energy Technology Data Exchange (ETDEWEB)

    Grudzinski, J. J. [Argonne; Talaga, R. L. [Argonne; Pla-Dalmau, A. [Fermilab; Fagan, J. E. [Fermilab; Grozis, C. [Fermilab; Kephart, K. [Fermilab; Fischer, R. [Argonne

    2014-01-01

    The NOvA Neutrino Experiment has built a one of a kind self-supporting plastic structure, potentially the largest ever built. The PVC structure serves as a neutrino detector and is composed of 28 individual blocks that measure 15.5 m (51 feet) high by 15.5 m (51 feet) wide by 2.1 m (7 feet) deep. The primary parts in the detector construction are 15.5m (51 foot), 15-cell PVC extrusions. These extrusions from the basis of the detector modules which are laminated together in a crossed pattern to form the individual blocks and then filled with mineral oil based liquid scintillator. The self-supporting nature of the detector places important structural requirements on both the PVC formulation and the extrusions. Block assembly requirements impose narrow geometric tolerances. Due to the method of detecting neutrinos, the extrusions must possess exceptionally high reflectivity over a particular wavelength range. The requirement places additional restrictions on the components of the PVC formulation. Altogether, the PVC extrusions have to maintain important reflectivity characteristics, provide structural support to the detector, and meet relatively tight geometric requirements for assembly. In order to meet these constraints, a custom PVC formulation had to be created and extruded. We describe the purpose and requirements of the NOvA detector leading to the production of our unique PVC extrusion, summarize the R&D process, and discuss the lessons learned.

  12. Intrusion and extrusion of water in hydrophobic mesopores

    OpenAIRE

    Barrat, Jean-Louis; Lefevre, Benoit; Bocquet, Lyderic; Saugey, Anthony; Vigier, Gérard; Gobin, Pierre-François; Charlaix, Elisabeth

    2003-01-01

    We present experimental and theoretical results on intrusion-extrusion cycles of water in hydrophobic mesoporous materials, characterized by independent cylindrical pores. The intrusion, which takes place above the bulk saturation pressure, can be well described using a macroscopic capillary model. Once the material is saturated with water, extrusion takes place upon reduction of the externally applied pressure; Our results for the extrusion pressure can only be understood by assuming that th...

  13. Gel-extrusion: A new continuous forming technique

    Energy Technology Data Exchange (ETDEWEB)

    Millan, A.J. [Department of Materials, IUT Federico Rivero Palacios, Caracas (Venezuela); Santacruz, I.; Sanchez-Herencia, A.J.; Nieto, M.I.; Moreno, R. [Instituto de Ceramica y Vidrio, CSIC, Camino de Valdelatas s/n, E-28048, Cantoblanco, Madrid (Spain)

    2002-12-01

    In recent years a variety of direct shaping methods has been developed for the near-net shaping of ceramic powders. The main aim in developing these methods is to provide a simple route for manufacturing bulk complex-shaped bodies with increased green resistance in order to reduce or avoid final machining, which is the most expensive step in the fabrication process. This communication reports a novel processing route for the continuous manufacture of ceramic and/or metal hollow or solid bodies based on the extrusion of aqueous suspensions that contain a small amount (<1 wt.-%) of a gelling additive that gelates on passing through a refrigerated die. (Abstract Copyright [2002], Wiley Periodicals, Inc.)

  14. Deformation and microstructure characterization during semi-solid extrusion of Al-4Cu-Mg alloy

    Institute of Scientific and Technical Information of China (English)

    LU Ya-lin; LI Miao-quan; LI Xing-cheng

    2006-01-01

    Effects of the process parameters, including deformation temperature, punch velocity and extrusion ratio, on the deformation and microstructure characterization during the semi-solid extrusion of Al-4Cu-Mg alloy, were investigated. The experimental results show that the load decreases with an increase of deformation temperature and/or a decrease of punch velocity.When the displacement is more than 4 mm, the load decreases significantly with an increase of the deformation temperature, which is related to the high liquid fraction. The microstructure varies with the process parameters and deformation regions. It can be found that the dynamic recovery occurs during the semi-solid extrusion of Al-4Cu-Mg alloy at lower deformation temperature.Subsequently, the microstructure elongated gradually polygonizes with an increase of deformation temperature. So, the higher deformation temperature should be chosen during the semi-solid extrusion of Al-4Cu-Mg alloy because the grains polygonized and high liquid fractions are beneficial to deformation.

  15. 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.

  16. 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...... has resulted in a conclusion that modern computer aided tools, tuned by proper experimental sets, can be used for fast and reliable cold metal forging process planning....

  17. Conservation of extrusion as an exit mechanism for Chlamydia.

    Science.gov (United States)

    Zuck, Meghan; Sherrid, Ashley; Suchland, Robert; Ellis, Tisha; Hybiske, Kevin

    2016-10-01

    Chlamydiae exit via membrane-encased extrusion or through lysis of the host cell. Extrusions are novel, pathogen-containing structures that confer infectious advantages to Chlamydia, and are hypothesized to promote cell-to-cell spread, dissemination to distant tissues and facilitate immune evasion. The extrusion phenomenon has been characterized for several Chlamydia trachomatis serovars, but a thorough investigation of extrusion for additional clinically relevant C. trachomatis strains and Chlamydia species has yet to be performed. The key parameters investigated in this study were: (i) the conservation of extrusion across the Chlamydia genus, (ii) the functional requirement for candidate Chlamydia genes in extrusion formation i.e. IncA and CT228 and (iii) extrusion-mediated uptake, and consequent survival of Chlamydia inside macrophages. Inclusion morphology was characterized by live fluorescence microscopy, using an inverted GFP strategy, at early and mid-stages of infection. Enriched extrusions were used to infect bone marrow-derived macrophages, and bacterial viability was measured following macrophage engulfment. Our results demonstrate that extrusion is highly conserved across chlamydiae, including ocular, STD and LGV biovars and divergent Chlamydia species. Consequently, this exit mechanism for Chlamydia may fulfill common advantages important for pathogenesis.

  18. Experimental Study and Finite Element Polycrystal Model Simulation of the Cold Rolling Textures in a Powder Metallurgy Processed Pure Aluminum Plate

    Institute of Scientific and Technical Information of China (English)

    Liqing CHEN; Naoyuki Kanetake

    2005-01-01

    Ingot metallurgy (IM) aluminum has long been the subject and attracted the attention of many metallurgists and textural researchers of materials. Due to the introduction of large amounts of ex situ interfaces, however, the textures in powder metallurgy (PM) processed aluminum has been rarely reported. In this article, a pure aluminum plate was prepared via PM route. The starting billet was first produced with uni-axially cold compaction and flat hot-extrusion and then followed by cold rolling processes. The hot-extruded and cold rolling deformation textures of the pure PM aluminum at 50%, 80% and 90% cold rolling reductions were studied by orientation distribution functions (ODFs) analysis. The finite element polycrystal model (FEPM) was finally utilized to simulate the cold rolling textural evolution at various stages of cold rolling. In FEPM simulation, the initial hot-extruded textures were taken into account as inputs. The results showed that typical β-fiber texture formed in pure PM aluminum with the cold rolling reduction increased till 80%, and there was not much change after excessive cold rolling deformation.Homogeneous slip is not the only deformation mode in PM processed pure aluminum plate at over 80% cold rolling reduction. The experimental results were qualitatively in good agreement with the simulated ones.

  19. IMPROVED PROPERTIES OF METALLOCENE-CATALYZED LINEAR LOW-DENSITY POLYETHYLENE/POLYPROPYLENE BLENDS DURING ULTRASONIC EXTRUSION

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Metallocene-catalyzed linear low-density polyethylene/polypropylene (mLLDPE/PP) blends were prepared by ultrasonic extrusion in this work. Their extrusion processing behaviors were estimated by online measured data, such as the die pressure and flow rate. Crystallization and mechanical properties of the blends were also investigated. The results show that the addition of PP improves the processing behaviors of mLLDPE, but has little effect on its mechanical properties. On the other hand, the addition of mLLDPE improves the impact strength of PP, but has little effect on its processing behavior. The processing behaviors and mechanical properties of mLLDPE/PP blends get further improved due to the presence of ultrasonic oscillation during extrusion. Compared with PP-rich blends, the apparent viscosity drop of mLLDPE-rich blends is more sensitive to ultrasonic oscillation. The ultrasonic oscillation affects the crystal nucleation, while barely the other crystalline behaviors of the blends.

  20. 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

  1. 钢坯试样铣磨床总体方案的创新设计%Innovative design for overall Scheme of milling-grinding machine for billet steel sample

    Institute of Scientific and Technical Information of China (English)

    薛会民; 欧阳晶晖

    2011-01-01

    It expounds the innovative design for overall scheme of the milling-grinding machineAc-cording to the processing requirements of high efficiency and high surface quality for billet test sample,the principle scheme of machine tool was proposed based on combined innovation, which achieves a composite process of milling and grindingJn addition the grinding adopts modern belt grinding.The motion scheme of the machine tool was designed through analyzing movement functionsAs for general structure of the machine tool fixed beam gantry frame structure is adopted based on structural variation.The result indicates that the overall scheme innovation realizes the uniqueness design of the machine tool,which has good performance and can well satisfy the processing requirements of billet steel sample.%阐述了铣磨床总体方案的创新设计,针对钢坯检测试样高效率、高表面质量的加工要求,采用组合创新的方法,提出了在同一机床上实现铣削、磨削复合加工的工艺原理方案,并且机床的磨削加工采用了现代砂带磨削.通过分析机床的各种运动功能,设计了机床的运动方案.对于机床的总体结构布局,采用结构变异的方法,确定其为定梁龙门式框架结构.结果表明,通过总体方案的创新,实现了机床的独特性设计,所设计机床性能优良,很好地满足了钢坯检测试样的加工要求.

  2. Extrusão dos implantes em portadores de cavidade anoftálmica Anophthalmic cavity and implant extrusion

    Directory of Open Access Journals (Sweden)

    Silvana Artioli Schellini

    2007-10-01

    Full Text Available OBJETIVO: Avaliar as características dos portadores de cavidades anoftálmicas que desenvolveram extrusão do implante. MÉTODOS: Estudo retrospectivo, observacional, tendo sido avaliados 37 portadores de cavidade anoftálmica que tiveram extrusão do implante de cavidade, na Faculdade de Medicina de Botucatu-UNESP. RESULTADOS: As extrusões ocorreram em cavidades enucleadas ou evisceradas, a maioria delas submetidas a cirurgia em decorrência de phthisis bulbi ou trauma, em geral de 1 a 2 anos após a cirurgia inicial. A deiscência precedeu a extrusão em todos os casos, tendo a extrusão ocorrido com todos os tipos de implantes empregados. CONCLUSÃO: Após a colocação de implantes de cavidade podem ocorrer complicações. A deiscência e extrusão das esferas são possibilidades que podem requerer nova intervenção cirúrgica, para a qual o paciente e o oftalmologista devem estar preparados.PURPOSE: To evaluate the characteristics of patients with anophthalmic cavity who developed sphere extrusion. METHODS: A retrospective observational study was done evaluating 37 patients with anophthalmic cavity and sphere extrusion at the "Faculdade de Medicina de Botucatu-UNESP". RESULTS: Extrusion was observed in enucleated and eviscerated cavities. The majority of the patients had the eye removed because of phthisis bulbi or trauma and the extrusion happened 1 or 2 years after the surgery. Extrusion was preceded by conjunctival dehiscence and exposure of the sphere and occurred with all used implants. CONCLUSION: Complications after orbital implant placement are a possibility. Dehiscence and sphere extrusion may happen and another surgery would be necessary. The patient and the ophthalmologist have to be prepared for this.

  3. The Favourable Choice of the Shape of Billet's Contact Surface to Quality of Extruded Aluminium Profiles

    Directory of Open Access Journals (Sweden)

    G. Skorulski

    2010-07-01

    Full Text Available The theoretical and experimental method of optimization the aluminium billet’s contact surface during extrusion have been presented inthis paper. The theoretical assumption, based on welding criteria, have been confirmed by experimental researches. The technique ofmeasurement has been shown as well. Experiments are made using plasticine as a substiute material. Some kind of different variants have been investigated. The theory and experiments have been provided to optimize the modeling shape and may help in design and technology.The theory has been tested experimentally using a plasticine as a substitute material and a plexiglass die 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 experiments an optimal billet’s contact surface was proposed.

  4. The effect of extrusion on the functional components and in vitro lycopene bioaccessibility of tomato pulp added corn extrudates.

    Science.gov (United States)

    Tonyali, Bade; Sensoy, Ilkay; Karakaya, Sibel

    2016-02-01

    The effect of processing on functional ingredients and their in vitro bioaccessibility should be investigated to develop better food products. Tomato pulp was added as a functional ingredient to extrudates. The effects of extrusion on the functional properties of the extrudates and the in vitro bioaccessibility of lycopene were investigated. Two different temperature sets were applied during extrusion: 80 °C, 90 °C, 100 °C and 130 °C and 80 °C, 100 °C, 130 °C and 160 °C. Screw speed and feed rate were kept constant at 225 rpm and 36 ± 1 g min(-1), respectively. The feed moisture content was adjusted to 30 ± 1% by mixing the tomato pulp to the corn grit. Antioxidant activity and the total phenolic content decreased after the extrusion process. High performance liquid chromatography (HPLC) analysis indicated that the lycopene content decreased after the extrusion process when feed and extrudates were compared. In vitro bioaccessibility of lycopene for the extruded samples with 160 °C last zone treatment temperature was higher than the feed and extruded samples with 130 °C last zone treatment temperature. The results indicate that extrusion affects the food matrix and the release of functional components.

  5. Stabilité en extrusion des polymères fondus. Effets de la pression et de la structure des copolymères triblocs de type ABA

    OpenAIRE

    Santanach Carreras, Enric

    2005-01-01

    Extrusion is a processing operation widely used in various industries such as polymer processing, metallurgy, ceramics or still in the food industry. Materials undergo high pressures and stresses when extruded at acceptable rates. The aim of this thesis is to gain some insight on the pressure and stress conditions and to better understand theirs effects on the properties and extrusion stability of polymers. Moreover, these effects will be related to the mesoscopic structure of polymers.4 poly...

  6. A Review of Dynamic Models of Hot-Melt Extrusion

    Directory of Open Access Journals (Sweden)

    Jonathan Grimard

    2016-06-01

    Full Text Available Hot-melt extrusion is commonly applied for forming products, ranging from metals to plastics, rubber and clay composites. It is also increasingly used for the production of pharmaceuticals, such as granules, pellets and tablets. In this context, mathematical modeling plays an important role to determine the best process operating conditions, but also to possibly develop software sensors or controllers. The early models were essentially black-box and relied on the measurement of the residence time distribution. Current models involve mass, energy and momentum balances and consists of (partial differential equations. This paper presents a literature review of a range of existing models. A common case study is considered to illustrate the predictive capability of the main candidate models, programmed in a simulation environment (e.g., MATLAB. Finally, a comprehensive distributed parameter model capturing the main phenomena is proposed.

  7. Scalable Approach for Extrusion and Perfusion of Tubular, Heterotypic Biomaterials

    Science.gov (United States)

    Jeronimo, Mark David

    Soft material tubes are critical in the vasculature of mammalian tissues, forming networks of blood vessels and airways. Homogeneous and heterogeneous hydrogel tubes were extruded in a one-step process using a three layer microfluidic device. Co-axial cylindrical flow of crosslinking solutions and an alginate matrix is generated by a radial arrangement of microfluidic channels at the device's vertical extrusion outlet. The flow is confined and begins a sol-gel transition immediately as it extrudes at velocities upwards of 4 mm/s. This approach allows for predictive control over the dimensions of the rapidly formed tubular structures for outer diameters from 600 microm to 3 mm. A second microfluidic device hosts tube segments for controlled perfusion and pressurization using a reversible vacuum seal. On-chip tube deflection is observed and modeled as a measure of material compliance and circumferential elasticity. I anticipate applications of these devices for perfusion cell culture of cell-laden hydrogel tubes.

  8. Polymer Processing and Characterization Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The purpose is to process and evaluate polymers for use in nonlinear optical, conductive and structural Air Force applications. Primary capabilities are extrusion of...

  9. Dynamic simulation on effect of flame arrangement on thermal process of regenerative reheating furnace

    Institute of Scientific and Technical Information of China (English)

    OU Jian-ping; MA Ai-chun; ZHAN Shu-hua; ZHOU Jie-min; XIAO Ze-qiang

    2007-01-01

    By analyzing the characteristics of combustion and billet heating process, a 3-D transient computer fluid dynamic simulation system based on commercial software CFX4.3 and some self-programmed codes were developed to simulate the thermal process in a continuous heating furnace using high temperature air combustion technology. The effects of different switching modes on injection entrancement of multi burners, combustion and billet heating process in furnace were analyzed numerically, and the computational results were compared with on-site measurement, which verified the practicability of this numerical simulation system.The results indicate that the flow pattern and distribution of temperature in regenerative reheating furnace with partial same-side-switching combustion mode are favorable to satisfy the high quality requirements of reheating, in which the terminal heating temperature of billets is more than 1 460 K and the temperature difference between two nodes is not more than 10 K. But since the surface average temperature of billets apart from heating zone is only about 1 350 K and continued heating is needed in soaking zone, the design and operation of current state are still needed to be optimized to improve the temperature schedule of billet heating. The distribution of velocity and temperature in regenerative reheating furnace with same-side-switching combustion mode cannot satisfy the even and fast heating process. The terminal heating temperature of billets is lower than that of the former case by 30 K. The distribution of flow and temperature can be improved by using cross-switching combustion mode, whose terminal temperature of billets is about 1 470 K with small temperature difference within 10 K.

  10. 75 FR 34482 - Certain Aluminum Extrusions From China

    Science.gov (United States)

    2010-06-17

    ... Commission, Washington, DC, and by publishing the notice in the Federal Register of April 6, 2010 (75 FR... COMMISSION Certain Aluminum Extrusions From China Determinations On the basis of the record \\1\\ developed in... reason of imports from China of certain aluminum extrusions, provided for in subheadings 7604.21,...

  11. 76 FR 29007 - Certain Aluminum Extrusions From China

    Science.gov (United States)

    2011-05-19

    ... in the Federal Register on December 22, 2010 (75 FR 80527). The hearing was held in Washington, DC... COMMISSION Certain Aluminum Extrusions From China Determinations On the basis of the record \\1\\ developed in... certain aluminum extrusions from ] China other than finished heat sinks, provided for in subheadings...

  12. Numerical Studies of Low Cycle Fatigue in Forward Extrusion Dies

    DEFF Research Database (Denmark)

    Pedersen, Thomas Ø

    2000-01-01

    Forward extrusion dies typically fail due to transverse fatigue cracks or wear. Fatigue cracks are initiated in regions where the material is subjected to repeated plastic deformations, e.g. the transition radius in a forward extrusion die, in the present work, a material model capable of describ...

  13. Abl suppresses cell extrusion and intercalation during epithelium folding.

    Science.gov (United States)

    Jodoin, Jeanne N; Martin, Adam C

    2016-09-15

    Tissue morphogenesis requires control over cell shape changes and rearrangements. In the Drosophila mesoderm, linked epithelial cells apically constrict, without cell extrusion or intercalation, to fold the epithelium into a tube that will then undergo epithelial-to-mesenchymal transition (EMT). Apical constriction drives tissue folding or cell extrusion in different contexts, but the mechanisms that dictate the specific outcomes are poorly understood. Using live imaging, we found that Abelson (Abl) tyrosine kinase depletion causes apically constricting cells to undergo aberrant basal cell extrusion and cell intercalation. abl depletion disrupted apical-basal polarity and adherens junction organization in mesoderm cells, suggesting that extruding cells undergo premature EMT. The polarity loss was associated with abnormal basolateral contractile actomyosin and Enabled (Ena) accumulation. Depletion of the Abl effector Enabled (Ena) in abl-depleted embryos suppressed the abl phenotype, consistent with cell extrusion resulting from misregulated ena Our work provides new insight into how Abl loss and Ena misregulation promote cell extrusion and EMT.

  14. Application of Twin Screw Extrusion in the Manufacture of Cocrystals, Part I: Four Case Studies

    Directory of Open Access Journals (Sweden)

    Karthik Nagapudi

    2011-08-01

    Full Text Available The application of twin screw extrusion (TSE as a scalable and green process for the manufacture of cocrystals was investigated. Four model cocrystal forming systems, Caffeine-Oxalic acid, Nicotinamide-trans cinnamic acid, Carbamazepine-Saccharin, and Theophylline-Citric acid, were selected for the study. The parameters of the extrusion process that influenced cocrystal formation were examined. TSE was found to be an effective method to make cocrystals for all four systems studied. It was demonstrated that temperature and extent of mixing in the extruder were the primary process parameters that influenced extent of conversion to the cocrystal in neat TSE experiments. In addition to neat extrusion, liquid-assisted TSE was also demonstrated for the first time as a viable process for making cocrystals. Notably, the use of catalytic amount of benign solvents led to a lowering of processing temperatures required to form the cocrystal in the extruder. TSE should be considered as an efficient, scalable, and environmentally friendly process for the manufacture of cocrystals with little to no solvent requirements.

  15. Quality evaluation of Al-5Ti-1B grain refiner produced by continuous casting and extrusion process with electromagnetic stirring%电磁搅拌连续铸挤Al-5Ti-1B合金晶粒细化剂的质量评价

    Institute of Scientific and Technical Information of China (English)

    王顺成; 戚文军; 郑开宏; 李建湘; 宁长维

    2014-01-01

    采用电磁搅拌连续铸挤技术生产Al-5Ti-1B合金晶粒细化剂,研究了Al-5Ti-1B合金的化学成分、显微组织和晶粒细化效果,并与美国KBA、荷兰KBM、英国LSM 公司生产的Al-5Ti-1B合金进行了比较,对电磁搅拌连续铸挤Al-5Ti-1B合金的质量进行了评价.结果表明:电磁搅拌连续铸挤Al-5Ti-1B合金中Ti和B元素含量分别为5.08%和1.02%.Fe ,Si及V杂质元素含量分别为0.11%,0.087%和0.011%;T iA l3相呈块状,平均尺寸为15.7μm ,而T iB2粒子呈颗粒状均匀分布于α-A l基体,平均尺寸为0.74μm ;添加0.2%的A l-5 T i-1B合金,可使纯铝晶粒平均尺寸从2800μm细化到68μm .比较结果表明:电磁搅拌连续铸挤A l-5 T i-1B合金的元素含量更稳定、杂质元素含量更低,T iA l3相和T iB2粒子更细小均匀,对铝晶粒的细化能力更强.%The Al-5Ti-1B grain refiner was produced by continuous casting and extrusion process with elec-tromagnetic stirring .The chemical compositions ,microstructure and grain refining efficiency of Al-5Ti-1B grain refiner were studied and compared with that of Al-5Ti-1B grain refiner produced by KBA ,KBM and LSM .The quality of Al-5Ti-1B grain refiner produced by continuous casting and extrusion process with e-lectromagnetic stirring was evaluated .Results show that the content of alloying elements Ti and B are 5 .08% and 1 .02% ,respectively .T he content of impurity elements Fe ,Si and V are 0 .11% ,0 .087% and 0 .011% ,respectively .The average size of fine TiAl3 phase with square shape is 15 .7 μm .The average size of fine TiB2 particles uniformly distributed in the α-Al is 0 .74 μm .The grains average size of pure Al with adding 0 .2% Al-5Ti-1B grain refiner can be refined from 2800μm to 68μm .The compared results in-dicate that the Al-5Ti-1B grain refiner produced by continuous casting and extrusion process with electro-magnetic stirring have many

  16. Co-extrusion as manufacturing technique for fixed-dose combination mini-matrices.

    Science.gov (United States)

    Dierickx, L; Saerens, L; Almeida, A; De Beer, T; Remon, J P; Vervaet, C

    2012-08-01

    The aim of this study was to develop a multilayer (core/coat) dosage form via co-extrusion, the core providing sustained drug release and the coat immediate drug release. In this study polymers were selected which can be combined in a co-extruded dosage form. Several thermoplastic polymers were hot-melt extruded and evaluated for processability and macroscopic properties (surface smoothness, die swell). Metoprolol tartrate (MPT) and hydrochlorothiazide (HCT) were incorporated as sustained and immediate release model drugs, respectively. Based on the polymer screening experiments a combination of polycaprolactone (core) and polyethylene oxide (coat) was selected for co-extrusion trials, taking into account their drug release profiles and extrusion temperature (70 °C). This combination (containing 10% HCT in the coat and 45% MPT in the core) was successfully co-extruded (diameter core: 3 mm/thickness coat: 0.5 mm). Adhesion between the two polymer layers was good. HCT release from the coat was complete within 30 min, while MPT release was sustained over 24 h (55%, 70%, 85% and 100% after 4, 8, 12 and 2 4h, respectively). DSC, XRD and Raman spectroscopy revealed that MPT remained crystalline during extrusion, whereas HCT was dissolved in the polyethylene oxide matrix. The in vivo study revealed no significant differences between the experimental formulation and the reference formulation (Zok-Zid tablet). Fixed-dose combination mini-tablets with good in vitro and in vivo performance were successfully developed by means of co-extrusion, using a combination of polycaprolactone and polyethylene oxide.

  17. Application of twin screw extrusion to the manufacture of cocrystals: scale-up of AMG 517-sorbic acid cocrystal production.

    Science.gov (United States)

    Daurio, Dominick; Nagapudi, Karthik; Li, Lan; Quan, Peter; Nunez, Fernando-Alvarez

    2014-01-01

    The application of twin screw extrusion (TSE) in the scale-up of cocrystal production was investigated by using AMG 517-sorbic acid as a model system. Extrusion parameters that influenced conversion to the cocrystal such as temperature, feed rate and screw speed were investigated. Extent of conversion to the cocrystal was found to have a strong dependence on temperature and a moderate dependence on feed rate and screw speed. Cocrystals made by the TSE process were found to have superior mechanical properties than solution grown cocrystals. Additionally, moving to a TSE process eliminated the need for solvent.

  18. Process on cold crucible electromagnetic casting for titanium alloy

    Directory of Open Access Journals (Sweden)

    CHEN Rui-run

    2007-08-01

    Full Text Available The parameters and factors that influence the surface quality and macrostructure of titanium alloy with reactive properties under liquid state were studied experimentally using a cold crucible electromagnetic casting method. The variations in the process parameters have great impact on the surface quality and macrostructure of cast billets. Billets with crack free and smooth surfaces as well as directional solidified primary structures were obtained after the selection of optimized process parameters. The formation mechanisms of defects such as cracks and non-directional structural morphology were interpreted briefly. Finally, the casting of billets with good outer qualities and inner column grains has been attained successfully, which in turn gives a solid foundation for further development of the technology.

  19. Powder metallurgy processing of high strength turbine disk alloys

    Science.gov (United States)

    Evans, D. J.

    1976-01-01

    Using vacuum-atomized AF2-1DA and Mar-M432 powders, full-scale gas turbine engine disks were fabricated by hot isostatically pressing (HIP) billets which were then isothermally forged using the Pratt & Whitney Aircraft GATORIZING forging process. While a sound forging was produced in the AF2-1DA, a container leak had occurred in the Mar-M432 billet during HIP. This resulted in billet cracking during forging. In-process control procedures were developed to identify such leaks. The AF2-1DA forging was heat treated and metallographic and mechanical property evaluation was performed. Mechanical properties exceeded those of Astroloy, one of the highest temperature capability turbine disk alloys presently used.

  20. Process on cold crucible electromagnetic casting for titanium alloy

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The parameters and factors that influence the surface quality and macrostructure of titanium alloy with reactive properties under liquid state were studied experimentally using a cold crucible electromagnetic casting method. The variations in the process parameters have great impact on the surface quality and macrostructure of cast billets. Billets with crack free and smooth surfaces as well as directional solidified primary structures were obtained after the selection of optimized process parameters. The formation mechanisms of defects such as cracks and non-directional structural morphology were interpreted briefly. Finally, the casting of billets with good outer qualities and inner column grains has been attained successfully, which in turn gives a solid foundation for further development of the technology.

  1. Replication of nanopits and nanopillars by roll-to-roll extrusion coating using a structured cooling roll

    DEFF Research Database (Denmark)

    Murthy, Swathi; Pranov, Henrik; Pedersen, Henrik Chresten

    2016-01-01

    This paper investigates a novel, very high throughput, roll-to-roll (R2R) process for nanostructuring of polymer foils, called R2R extrusion coating. It has the potential to accelerate the integration of nanostructured materials in consumer products for a variety of applications, including optical......, technical, and functional surfaces and devices. In roll-to-roll extrusion coating, a molten polymer film is extruded through a flat die forming a melt curtain, and then laminated onto a carrier foil. The lamination occurs as the melt curtain is pressed between a cooling roller and a counter roller....... By mounting a nanostructured metal shim on the surface of the cooling roller, the relief structure from the shim can be replicated onto a thermoplastic foil. Among the benefits of P oil, the process are availability of a wide range of commercial extruders, off-the-shelf extrusion grade polymers, functional...

  2. Microstructure evolution of semi-solid 2024 alloy during two-step reheating process

    Institute of Scientific and Technical Information of China (English)

    WANG Shun-cheng; LI Yuan-yuan; CHEN Wei-ping; ZHENG Xiao-ping

    2008-01-01

    A two-step reheating process was proposed and applied to perform reheating experiments on the semi-solid 2024 alloy billet. In this process, the semi-solid billet was firstly heated over liquidus temperature and then isothermally held at solid-liquid zone temperature. Microstructure evolution of the semi-solid billet during two-step reheating was studied by optical microscope and compared with that during isothermal reheating. The results show that the remelting rate of the semi-solid billet during two-step reheating is faster than that during isothermal reheating. Under the same reheating time, the grains of the semi-solid billet reheated by two-step reheating process are finer and rounder than those by isothermal reheating process. The present experimental results indicate that accelerating the formation of liquid phase during the two-step reheating process can restrain the coalescence of grains to a certain extent, and thus refine the grain size and promote the grain spheroidization.

  3. Thermal Stabilization study of polyacrylonitrile fiber obtained by extrusion

    Directory of Open Access Journals (Sweden)

    Robson Fleming Ribeiro

    2015-12-01

    Full Text Available A low cost and environmental friendly extrusion process of the Polyacrylonitrile (PAN polymer was viabilized by using the 1,2,3-propanetriol (glycerol as a plasticizer. The characterization of the fibers obtained by this process was the object of study in the present work. The PAN fibers were heat treated in the range of 200 °C to 300 °C, which is the temperature range related to the stabilization/oxidation step. This is a limiting phase during the carbon fiber processing. The characterization of the fibers was made using infrared spectroscopy, thermal analysis and microscopy. TGA revealed that the degradation of the extruded PAN co-VA fibers between 250 °C and 350 °C, corresponded to a 9% weight loss to samples analyzed under oxidizing atmosphere and 18% when the samples were analyzed under inert atmosphere. DSC showed that the exothermic reactions on the extruded PAN co-VA fibers under oxidizing synthetic air was broader and the cyclization started at a lower temperature compared under inert atmosphere. Furthermore, FT-IR analysis correlated with thermal anlysis showed that the stabilization/oxidation process of the extruded PAN fiber were coherent with other works that used PAN fibers obtained by other spinning processes.

  4. Extrusion Roller Imprinting with a Variotherm Belt Mold

    Directory of Open Access Journals (Sweden)

    Raymond Frenkel

    2014-12-01

    Full Text Available Although many precision fabrication techniques have demonstrated the ability to produce microstructures and micro-devices with sub 100 nm accuracy, we are yet to see a scalable manufacturing process for large-area production. One promising solution to scalable micro- and nanofabrication is thermal roller imprinting. However, existing investigations on thermal roller imprinting revealed poor pattern transfer fidelity, especially for high aspect ratio features. The standard roller imprinting process suffers from the lack of an effective holding and cooling stage so that the adverse effects from the viscoelastic nature of polymers are not managed. To rectify this problem and further improve the production rate, a new extrusion roller imprinting process with a variotherm belt mold is designed, and its prototype was established at a laboratory scale. The process testing results demonstrate that a 30 μm sawtooth pattern can be faithfully transferred to extruded polyethylene film at take-up speeds higher than 10 m/min. The results are promising in that microfeatures or even nanofeatures may be successfully replicated by a robust and scalable industrial process suitable for large-area, continuous production.

  5. Sugar production from barley straw biomass pretreated by combined alkali and enzymatic extrusion.

    Science.gov (United States)

    Duque, A; Manzanares, P; Ballesteros, I; Negro, M J; Oliva, J M; González, A; Ballesteros, M

    2014-04-01

    A pretreatment that combines a thermo-mechanical process (extrusion) with chemical and biological catalysts to produce fermentable sugars from barley straw (BS) biomass was investigated. BS was firstly extruded with alkali and then, the pretreated material (extrudate) was submitted to extrusion with hydrolytic enzymes (bioextrusion). The bioextrudate was found to have 35% (w/w dwb) of total solids in soluble form, partly coming from carbohydrate hydrolysis during bioextrusion. About 48% of soluble solids dry weight is comprised by sugars, mostly glucose and xylose. Further enzymatic hydrolysis of bioextrudate could be successfully carried out at high solid loading level of 30% (w/v), with sugar production yield of 32 g glucose and 18 g xylose/100g bioextrudate at 72 h incubation (equivalent to 96 and 52 g/l concentration, respectively). These results, together with the high level of integration of the process, indicate a great potential of this pretreatment technology for sugar production from lignocellulosic substrates.

  6. Formation mechanism of external finned tubes by extrusion-plough method

    Institute of Scientific and Technical Information of China (English)

    TANG Yong; LU Long-sheng; PAN Min-qing; LIU Xiao-kang; LIU Xiao-qing

    2006-01-01

    The formation mechanism of bulge on the work's surface during the extrusion process was analyzed. The bulge's size and the reasons for abscission were studied. The results show that the abscission of bulge from works is resulted from the integrated actions of pressure and friction between the plough tool and works. During the extrusion-plough process, it is noticed that four kinds of fins are appeared, which are gestation fin, multi-dimensional fin, tumor and overlap fin, when using different machining parameters. And multi-dimensional fin which has high heat transmission efficiency is a kind of complicated fin with cockscomb-like 3D substructure fin on the tip of 3D macrostructure fin. Based on the studies of those four kinds of fins, the conditions of their formation are concluded, as well as the formation mechanism is obtained.

  7. Convergence and extrusion are required for normal fusion of the mammalian secondary palate.

    Directory of Open Access Journals (Sweden)

    Seungil Kim

    2015-04-01

    Full Text Available The fusion of two distinct prominences into one continuous structure is common during development and typically requires integration of two epithelia and subsequent removal of that intervening epithelium. Using confocal live imaging, we directly observed the cellular processes underlying tissue fusion, using the secondary palatal shelves as a model. We find that convergence of a multi-layered epithelium into a single-layer epithelium is an essential early step, driven by cell intercalation, and is concurrent to orthogonal cell displacement and epithelial cell extrusion. Functional studies in mice indicate that this process requires an actomyosin contractility pathway involving Rho kinase (ROCK and myosin light chain kinase (MLCK, culminating in the activation of non-muscle myosin IIA (NMIIA. Together, these data indicate that actomyosin contractility drives cell intercalation and cell extrusion during palate fusion and suggest a general mechanism for tissue fusion in development.

  8. 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

    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......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...

  9. Non-isothermal FEM analyses of large-strain back extrusion forging

    Energy Technology Data Exchange (ETDEWEB)

    Flower, E.C.; Hallquist, J.O.; Shapiro, A.B.

    1986-06-19

    Back extrusion forging is a complex metal forming operation dominated by large-strain, non-isothermal deformation. NIKE2D, a fully vectorized implicit finite-element program developed at Lawrence Livermore National Laboratory, was applied to a two-stage isothermal back extrusion forging process. Modeling of the forging process required special features in the FEM code such as friction and interactive rezoning that allows for remeshing of the distorted mesh while maintaining a complete history of all the state variables. To model conditions of the non-isothermal forging process required implementing TOPAZ2D, our LLNL-developed two-dimensional implicit finite element code for heat conduction analysis, as a subroutine into NIKE2D. The fully coupled version maintains all the original features of both codes and can account for the contribution of heat generation during plastic deformation. NIKE/TOPAZ-2D was applied to the piercing operation of the back extrusion forging process. The thermal deformation history of the die, punch, and workpiece and the effective plastic strains were calculated.

  10. 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 conic...... 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....

  11. Effects of hot extrusion and annealing treatment on microstructures,properties and texture of AZ31 Mg alloy

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hui; YAN Yun-qi; WENG Wen-ping; ZHONG Hao; CHEN Qi

    2006-01-01

    Effects of extrusion deformation and heat treatment on microstructures, mechanical properties and texture of AZ31 Mg alloy were investigated.The results show that the microstructures of as-cast AZ31 alloy are markedly refined after hot extruding, the average grain size is about 25 μm and strong fiber texture exists in the extruded AZ31 alloy. The mechanical properties are improved obviously. The grain size is somewhat inhomogeneous and strip structure emerges along the extrusion direction due to incomplete dynamic recrystallization during the extrusion process. With increasing annealing temperature, the small grain grows up and turns into equiaxed grain, and the texture is weakened with the visible growing up of grains.

  12. Study On Extrusion Technological Parameters Of Brown Rice

    Institute of Scientific and Technical Information of China (English)

    Zhu Yongyi; Zhou Xianqing; Ling Lizhong

    2001-01-01

    Extrusion is an efficient measure to improve the texture and physic-s of brown rice. The polynomial degree two model of extrusion parameters and gelatinized degree, water absorption index, water soluble index and moisture content of extruded matter was obtained by methods of single factor and response surface methodology, R2=0.9649, 0.8745, 0.9079, 0.8677. The optimal parameters of brown rice extrusion were figured out as follows:moisture nrice, 11.42%, speed of screw, 30rpm, feeding speed, and 20rpm.

  13. 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.

  14. EXTRUSION DIE CAE OF THE STEEL REINFORCED PLASTIC PIPE

    Institute of Scientific and Technical Information of China (English)

    W.Q. Ma; H.Y. Sun; D.C. Kang; K.D. Zhao

    2004-01-01

    The steel reinforced plastic pipe is a new kind of pressure pipe. It is made up with steel wires and plastic. Because reinforced skeleton of the steel wire increase the complexity of plastic flow during the extrusion phase, the traditional design criteria of extrusion die is not suitable. The study on extrusion die of the kind of pipe is very important step in produce development. Using finite element (FE) method in this paper, the flow rule of molten plastic inside the die has been predicted and a group of optimal structural parameters was obtained. These results are helpful for reducing the design cycle and improve the quality of the final product.

  15. Study of an industrial process for the synthesis of high molar mass ethylene oxide-propylene oxide copolymers usable as extrusible electrolyte; Etude d`un procede industriel de synthese de copolymeres oxyde d`ethylene-oxyde de propylene de hautes masses molaires utilisables comme electrolyte extrudable

    Energy Technology Data Exchange (ETDEWEB)

    Gramain, Ph. [Ecole Nationale Superieure de Chimie de Montpellier, 34 (France); Caselles, E. [Centre National de la Recherche Scientifique (CNRS), 67 - Strasbourg (France)

    1996-12-31

    The aim of this work is to develop an industrial process for the synthesis of an extrusible electrolyte polymer for lithium batteries. From literature data and precise specifications the high molar mass EO/OP copolymers synthesis by coordinative catalysis has been studied in order to reach a high productivity and to minimize the treatment steps. Two catalytic systems have been studied: the aluminium alkoxide-based Vandenberg-type catalysis and the calcium alcoholate amides catalysis. The first catalysis performed in solution gives excellent results. Its adaptation to silicon supported catalysis leads to a directly usable polymer in suspension but the productivity falls down and remains to be optimized. The calcium amide catalysis in heptane suspension generates acceptable productivities but also a too high proportion of low molar masses. Various approaches have been studied to minimize this proportion due to the presence of secondary sites that generate a cationic mechanism. The two synthesis ways explored are promising but remain to be optimized in order to increase the productivity of the efficient catalytic site and to reduce the formation of low molar masses generated by parasite catalytic sites. (J.S.) 9 refs.

  16. Experimental investigation and numerical simulation of large-sized aluminum tube extrusion forming

    Institute of Scientific and Technical Information of China (English)

    吕亚臣; 骆俊廷; 马春荣; 徐岩

    2008-01-01

    Large-sized aluminum tube has big section effect, aspect ratio and thin thickness, so that the extrusion technology is complex and the large specific pressure is generated in extrusion cavity. The temperature variation and velocity effect is difficult to control. The extrusion forming of large-sized aluminum tube was researched and simulated. Three-dimensional thermo-mechanical coupled finite element model was constructed and appropriate boundary conditions were given out. The results show that large-sized aluminum tube can be formed by isothermal extrusion through controlling the extrusion velocity and founding the relationship between extrusion velocity and extrusion temperature.

  17. MICROSTRUCTURE OF Mg-6.4Zn-1.1Y ALLOY FABRICATED BY RAPID SOLIDIFICATION AND RECIPROCATING EXTRUSION

    Institute of Scientific and Technical Information of China (English)

    Z.M. Zhang; C.J. Xu; X.F. Guo

    2008-01-01

    In order to explore the methods to prepare high-strength quasicrystal-reinforced magnesium alloys, the flakes of rapidly solidified Mg-6.4Zn-1.1 Y magnesium alloy with a thickness of 50-60 um were obtained by a melt spinning single-roller device, and the flakes were then processed into rods by reciprocating extrusion and direct extrusion. The microstructure of the alloy was analyzed by optical microscope and SEM, and the constituent phases were identified by XRD. Phase transformation and its onset temperature were determined by differential thermal analyzer (DTA). The analysis result shows that rapid solidification for Mg-6.4Zn-1.1Y alloy can inhibit the eutectic reactions, broaden the solid solubility of Zn in a-Mg solute solution, and impede the formation of Mg3 Y2 Zn3 and MgZn2 compounds, and thus help the icosahedral Mg3 YZn6 quasicrystal formed directly from the melt. The mierostrueture of the flakes consists of the a-Mg solid solution and icosahedral Mg3 YZn6 quasierystal. Dense rods can be made from the flakes by two-pass reciprocating extrusion and direct extrusion. The interfaces between flakes in the rods can be welded and jointed perfectly. During the reciprocating extrusion and direct extrusion process, more Mg3 YZn6 compounds are precipitated and distributed uniformly, whereas the rods possess fine microstructures inherited from rapidly solidified flakes. The rods contain only two phases: amagnesium solid solution as matrix and fine icosahedral Mg3 YZn6 quasicrystal which disperses uniformly in the matrix.

  18. 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.

  19. Exploration of cold extrusion for the preparation of enteric minitablets of isoniazid

    Directory of Open Access Journals (Sweden)

    Gohel M

    2008-01-01

    Full Text Available The objective of the present work was to formulate the enteric minitablets of isoniazid by cold extrusion method. The minitablets were prepared using isoniazid, hydroxylpropylmethylcellulose phthalate and dibasic calcium phosphate. The minitablets were coated using hydroxypropylmethylcellulose phthalate. Full factorial design was adopted to optimize the formulation. The minitablets showed good flow and acceptable friability. The drug release was resisted in 0.1 N HCl for 2 h from the optimized batch. The optimized batch showed more than 90% of drug release in phosphate buffer in 15 min. Capsules containing rifampicin powder and enteric isoniazid minitablets showed complete drug release in acidic and alkaline media respectively. The process of cold extrusion appears to be an attractive alternative to by-pass the existing patents.

  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. Similar extrusion and mapping optimization of die cavity modeling for special-shaped products

    Institute of Scientific and Technical Information of China (English)

    QI Hong-yuan; WANG Shuang-xin; ZHU Heng-jun

    2006-01-01

    Aimed at the modeling issues in design and quick processing of extruding die for special-shaped products, with the help of Conformal Mapping theory, Conformal Mapping function is determined by the given method of numerical trigonometric interpolation. Three-dimensional forming problems are transformed into two-dimensional problems, and mathematical model of die cavity surface is established based on different kinds of vertical curve, as well as the mathematical model of plastic flow in extruding deformation of special-shaped products gets completed. By upper bound method, both vertical curves of die cavity and its parameters are optimized. Combining the optimized model with the latest NC technology, NC Program of die cavity and its CAM can be realized. Taking the similar extrusion of square-shaped products with arc radius as instance, both metal plastic similar extrusion and die cavity optimization are carried out.

  2. Extrusion of xylans extracted from corn cobs into biodegradable polymeric materials.

    Science.gov (United States)

    Bahcegul, Erinc; Akinalan, Busra; Toraman, Hilal E; Erdemir, Duygu; Ozkan, Necati; Bakir, Ufuk

    2013-12-01

    Solvent casting technique, which comprises multiple energy demanding steps including the dissolution of a polymer in a solvent followed by the evaporation of the solvent from the polymer solution, is currently the main technique for the production of xylan based polymeric materials. The present study shows that sufficient water content renders arabinoglucuronoxylan (AGX) polymers extrudable, enabling the production of AGX based polymeric materials in a single step via extrusion, which is economically advantageous to solvent casting process for mass production. AGX polymers with water content of 27% were found to yield extrudates at an extrusion temperature of 90°C. The extruded strips showed very good mechanical properties with an ultimate tensile strength of 76 ± 6 MPa and elongation at break value of 35 ± 8%, which were superior to the mechanical properties of the strips obtained from polylactic acid.

  3. 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.

  4. 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.

  5. Effect of Extrusion Cooking on Bioactive Compounds in Encapsulated Red Cactus Pear Powder

    Directory of Open Access Journals (Sweden)

    Martha G. Ruiz-Gutiérrez

    2015-05-01

    Full Text Available Red cactus pear has significant antioxidant activity and potential as a colorant in food, due to the presence of betalains. However, the betalains are highly thermolabile, and their application in thermal process, as extrusion cooking, should be evaluated. The aim of this study was to evaluate the effect of extrusion conditions on the chemical components of red cactus pear encapsulated powder. Cornstarch and encapsulated powder (2.5% w/w were mixed and processed by extrusion at different barrel temperatures (80, 100, 120, 140 °C and screw speeds (225, 275, 325 rpm using a twin-screw extruder. Mean residence time (trm, color (L*, a*, b*, antioxidant activity, total polyphenol, betacyanin, and betaxanthin contents were determined on extrudates, and pigment degradation reaction rate constants (k and activation energies (Ea were calculated. Increases in barrel temperature and screw speed decreased the trm, and this was associated with better retentions of antioxidant activity, total polyphenol, betalain contents. The betacyanins k values ranged the −0.0188 to −0.0206/s and for betaxanthins ranged of −0.0122 to −0.0167/s, while Ea values were 1.5888 to 6.1815 kJ/mol, respectively. The bioactive compounds retention suggests that encapsulated powder can be used as pigments and to provide antioxidant properties to extruded products.

  6. Effect of extrusion cooking on bioactive compounds in encapsulated red cactus pear powder.

    Science.gov (United States)

    Ruiz-Gutiérrez, Martha G; Amaya-Guerra, Carlos A; Quintero-Ramos, Armando; Pérez-Carrillo, Esther; Ruiz-Anchondo, Teresita de J; Báez-González, Juan G; Meléndez-Pizarro, Carmen O

    2015-05-18

    Red cactus pear has significant antioxidant activity and potential as a colorant in food, due to the presence of betalains. However, the betalains are highly thermolabile, and their application in thermal process, as extrusion cooking, should be evaluated. The aim of this study was to evaluate the effect of extrusion conditions on the chemical components of red cactus pear encapsulated powder. Cornstarch and encapsulated powder (2.5% w/w) were mixed and processed by extrusion at different barrel temperatures (80, 100, 120, 140 °C) and screw speeds (225, 275, 325 rpm) using a twin-screw extruder. Mean residence time (trm), color (L*, a*, b*), antioxidant activity, total polyphenol, betacyanin, and betaxanthin contents were determined on extrudates, and pigment degradation reaction rate constants (k) and activation energies (Ea) were calculated. Increases in barrel temperature and screw speed decreased the trm, and this was associated with better retentions of antioxidant activity, total polyphenol, betalain contents. The betacyanins k values ranged the -0.0188 to -0.0206/s and for betaxanthins ranged of -0.0122 to -0.0167/s, while Ea values were 1.5888 to 6.1815 kJ/mol, respectively. The bioactive compounds retention suggests that encapsulated powder can be used as pigments and to provide antioxidant properties to extruded products.

  7. Green route to modification of wood waste, cellulose and hemicellulose using reactive extrusion.

    Science.gov (United States)

    Vaidya, Alankar A; Gaugler, Marc; Smith, Dawn A

    2016-01-20

    A large volume of wood waste is produced in timber processing industry which traditionally used in low value applications. Here, value addition to the wood waste (Sander dust) and cellulose, hemicellulose isolated thereof by functionalisation using cyclic anhydrides in a solvent-free and green reactive extrusion process is reported. The effect of extrusion temperature, catalyst and different weight ratios of Sander dust (SD):succinic anhydride (SA) on the esterification reaction is evaluated. The esterified products were characterised by the acid value, degree of substitution (DS), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), solid state (13)C NMR and thermo-gravimetric analysis (TGA). Under optimum extrusion conditions, mixed esters are formed, with highest acid value obtained for succinylation of cellulose (0.122 g/g at DS of 0.350) which is two times higher compared to succinylated SD (0.059 g/g at a weight gain of 0.452) and hemicellulose (0.043 g/g at DS of 0.290). The reactivity trend for individual anhydride was: (1) SA-Cellulose>SD>hemicellulose; (2) maleic anhydride (MA)-SD>hemicellulose>cellulose and (3) dodecenyl succinic anhydride (DDSA)-SD ≈ cellulose ≫ hemicellulose. The pendant free carboxyl groups generated through functionalisation of wood waste, cellulose and hemicellulose without the presence of polymeric carriers will allow more tailored or targeted modification of wood-plastic composites.

  8. 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.

  9. The Effect of Multiple Extrusions on the Properties of Montmorillonite Filled Polypropylene

    Directory of Open Access Journals (Sweden)

    Laurens Delva

    2014-12-01

    Full Text Available Nanocomposites have attracted a great deal of interest during recent years. Much research has been conducted towards the incorporation of clay particles in a polypropylene matrix. However, the effect of extrusion reprocessing on the material properties has not been studied in depth. In this study, composites of polypropylene (PP reinforced with organic modified montmorillonite (MMT (4 wt% and coupling agent were subjected to 15 extrusion cycles. The materials were characterized by melt flow index (MFI, plate-plate rheometry, tensile testing and impact measurements, differential scanning calorimetry (DSC, X-ray diffraction (XRD and scanning electron microscopy (SEM. The results showed an improved intercalation of the MMT clay in the first few extrusions, thus improving the mechanical properties. Increasing the processing steps furthermore lead to a decrease in elastic modulus and impact strength, which was attributed to a reduction in matrix-filler interaction, most probably caused by organoclay degradation as shown by thermogravimetric analysis (TGA. The results of this study provide a useful insight in either the recycling of PP/MMT waste streams or the use of clay particles as a strengthening filler agent in the recycling process of different polymer waste streams.

  10. Making Ceramic/Polymer Parts By Extrusion Stereolithography

    Science.gov (United States)

    Stuffle, Kevin; Mulligan, A.; Creegan, P.; Boulton, J. M.; Lombardi, J. L.; Calvert, P. D.

    1996-01-01

    Extrusion stereolithography developmental method of computer-controlled manufacturing of objects out of ceramic/polymer composite materials. Computer-aided design/computer-aided manufacturing (CAD/CAM) software used to create image of desired part and translate image into motion commands for combination of mechanisms moving resin dispenser. Extrusion performed in coordination with motion of dispenser so buildup of extruded material takes on size and shape of desired part. Part thermally cured after deposition.

  11. Electrostatic extrusion as a dispersion technique for encapsulation of cells and bioactive compounds

    Directory of Open Access Journals (Sweden)

    Kostić Ivana T.

    2012-01-01

    Full Text Available Significant development of cells and bioactive compound encapsulation technologies is taking place due to an exceptional possibility of their application in various scientific disciplines, including biomedicine, pharmacy, cosmetology, food and agricultural sciences, beverage production, industrial waste treatment. Despite the broad application of microencapsulation, the literature reviews on dispersion techniques for microcapsule/microbead production, their advantages, restrictions and drawbacks are scarce. The purpose of this paper is to assess the possibilities of electrostatic extrusion for encapsulation of biological material, including living cells in hydrogel microbeads. The paper presents an overview of the mechanisms of droplet formation and controlling experimental parameters for producing microbeads by means of electrostatic extrusion. Electrostatic droplet formation utilizes a special type of physical process taking advantage of electrostatic effects occurring in flowing conductive liquids after introduction of an electric field.When an electrostatic field is applied to the metal needle and an electric charge is induced in the liquid flowing out of the needle, the size of droplet detaching from the needle tip decreases as a funcion of applied electrostatic field. It has been shown that few parameters affect microbead size: applied voltage, electrode geometry, needle size, polarity arrangement and polymer concentration. The electrostatic droplet formation is one of the most precise methods, which enables one to produce spherical and uniform particles ranging from 100 μm up to 1000 μm. Most of the authors report that the encapsulated compounds (drugs, enzymes and living cells remain unaltered after electrostatic extrusion. This technique seems to be particularly promising in biotechnology, pharmaceutical and cosmetics industries, where a low-temperature process, preserving heat-sensitive material is a prerequisite. Future efforts in

  12. Modelling the processing of aluminium alloys in the semi-solid state

    Energy Technology Data Exchange (ETDEWEB)

    Wahlen, A. [ARC Leichtmetallkompetenzzentrum Ranshofen GmbH, Ranshofen (Austria)

    2002-07-01

    Thixoforming, an innovative technique in which metals are formed in their semi-solid state, permits the cost-efficient production of components with improved properties and performance compared to conventional pressure die casting. Since this process is still relatively new, great technical advances can be expected in the near future. These advances should allow production of near-net-shape components with good mechanical properties, combined with low manufacturing cost. Due to the distinct thixotropic flow pattern of the semi-solid slurry, high production speeds similar to those of conventional pressure die casting can be achieved, yet the disadvantages of the latter are eliminated: thixoformed components possess a good combination of strength and ductility, and they are heat-treatable and weldable. The requirement for thixotropic flow behaviour is a particular microstructure in the semi-solid state. At the onset of forming, the solid phase of the material must exhibit a globular morphology, a feature that can be produced with a novel casting technique called new rheocasting (NRC). Cast billets of several aluminium alloys and resulting microstructures show the feasibility of the chosen process variant. Constitutive models for the distinct flow behaviour of thixotropic aluminium alloys in the semi-solid state are derived with respect to temperature, strain rate and microstructure. Experimental techniques such as deformation tests, backward extrusion experiments, differential thermal analysis and quantitative metallurgy provide the necessary data to calibrate the materials models. For the implementation in a special-purpose FE software package, constitutive models for the thixotropic flow stress, the specific thixotropic flow stress, the specific heat capacity and the thermal conductivity of cast and wrought aluminium alloys in the semi-solid state are provided. For the optimization of the thixoforming manufacturing process these models were implemented in the FE

  13. 采用气雾化Zn-22%Al粉末挤压制造微型螺旋齿轮%Fabrication of miniature helical gears by powder extrusion using gas atomized Zn-22%Al powder

    Institute of Scientific and Technical Information of China (English)

    LEE Kyung-Hun; LEE Jung-Min; PARK Joon-Hong; KIM Byung-Min

    2012-01-01

    基于Zn-22%Al共析合金的超塑性,采用粉末挤压工艺制造微型螺旋齿轮,以减小成形压力和获得细小的显微组织.该螺旋齿轮的规格为:模数0.3,齿数1.2,螺旋角15°.将粉末压制坯通过烧结和固溶热处理进行致密化.致密化的坯料由层状和细晶状组织组成.在温度250°C,应变速率2.36×i0-3和1.18×10-1s-1的条件下对坯料进行挤压,并对挤压成形的螺旋齿轮的力学性能进行测试.%Powder extrusion,which is based on the superplastic behavior of Zn-22%A1 eutectoid alloy,was proposed to reduce the forming load and promises to provide fine microstructures in the manufacture of miniature helical gears.The specifications of the helical gears were as follows:module,0.3; number of teeth,12; and helix angle,15°.Compacted powders were consolidated by sintering and solution heat treatment.The consolidated billets consisted of lamellar and fine-grained microstructures.Extrusion experiments were carried out under the following conditions:temperature,250 °C; strain rates,2.36× 10ˉ3 sˉ1 and 1.18× 10-1 s- 1.The mechanical properties of the extruded helical gears were investigated by measurement of the Vickers hardness and extrusion load,and by scanning electron microscopy.

  14. Precision Control of Billet Limited WeightCutting Technology Cutting Technology%方坯定重切割精度控制的提高

    Institute of Scientific and Technical Information of China (English)

    左康君; 李智勇; 王振涛; 朱童峰

    2011-01-01

    This article introduces the steel works are shipped on the billet limited weight cutting technology characteristics of control and detailed analysis of the technology in cutting,weighing,network management need to solve the problem.%炼钢厂方坯定重切割精度控制的技术特点,分析该技术在切割控制、称重、网络管理方面需要解决的问题。

  15. Viscoplastic flow in an extrusion damper

    CERN Document Server

    Syrakos, Alexandros; Georgiou, Georgios C; Tsamopoulos, John

    2016-01-01

    Numerical simulations of the flow in an extrusion damper are performed using a finite volume method. The damper is assumed to consist of a shaft, with or without a spherical bulge, oscillating axially in a containing cylinder filled with a viscoplastic material of Bingham type. The response of the damper to a forced sinusoidal displacement is studied. In the bulgeless case the configuration is the annular analogue of the well-known lid-driven cavity problem, but with a sinusoidal rather than constant lid velocity. Navier slip is applied to the shaft surface in order to bound the reaction force to finite values. Starting from a base case, several problem parameters are varied in turn in order to study the effects of viscoplasticity, slip, damper geometry and oscillation frequency to the damper response. The results show that, compared to Newtonian flow, viscoplasticity causes the damper force to be less sensitive to the shaft velocity; this is often a desirable damper property. The bulge increases the required...

  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. Arquitectura de un Billete Electrónico Anónimo: Medios Electrónicos de Pagos Architecture of an Anonymous Electronic Bill: Electronic Payments Systems

    Directory of Open Access Journals (Sweden)

    M.E. García

    2005-01-01

    Full Text Available En este artículo se propone la estructura de una secuencia organizada de bits que representa un billete electrónico. Los procedimientos considerados en el trabajo fueron: la comparación y análisis de los sistemas de pago electrónico actuales (First Virtual, Cybercash, Cybercoin, Millicent, eCash, Mondex y Tarjetas Inteligentes, y el análisis de las propiedades de un billete bancario en México. El billete electrónico generado se construye con Funciones Hash, Firmas Digitales y Códigos MAC, y se demuestra que posee buenos atributos de anonimato, integridad y autenticidad, condiciones necesarias en un sistema de pago electrónico.In this paper the structure of an organized sequence of bits that represents an electronic bill is proposed. Two procedures were considered in this work: the comparison and analysis of the current systems of electronic payment (First Virtual, Cybercash, Cybercoin, Millicent, eCash, Mondex and Smart Cards, and the analysis of the properties of a bank bill in Mexico. The generated electronic bill is built with Hash Functions, Digital Signatures and MAC Codes, and it is demonstrated that it has good attributes of anonymity, integrity and authenticity, necessary conditions of an electronic payment system.

  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. Pellets de trigo e soja produzidos por extrusão Wheat and soybean pellets produced by extrusion-cooking

    Directory of Open Access Journals (Sweden)

    Sin Huei Wang

    2008-09-01

    Full Text Available A mistura de trigo e soja representa uma importante fonte calórico-protéica com proteínas de boa qualidade. Apesar disso, a utilização da soja como ingrediente tem sido limitada pelo seu sabor de feijão cru (beany flavor, o qual é melhorado pelo processo de extrusão. Foram estudados os efeitos de umidade da mistura, Temperatura de Barril (TB e Velocidade de Rotação de Parafuso (VRP, Nº 5 do extrusor no Índice de Expansão (IE, no Índice de Solubilidade em Água (ISA e nas características sensoriais de pellets produzidos com mistura de trigo e soja (90:10, objetivando a otimização deste processo para a obtenção de pellets fritos com melhores qualidades sensoriais. A farinha mista crua foi extrusada em 2 umidades (32 e 35%, 4 TB (60 a 90 °C e 4 VRP (60 a 150 rpm, totalizando 32 tratamentos. O pellet frito, preparado com a farinha mista com 32% de umidade e extrusada em 60 rpm a 80 °C, apresentou o maior IE e as melhores qualidades sensoriais (aparência, sabor e textura, sendo preferido pela equipe de provadores não treinados, tanto com sabor de bacon como com sabor de queijo.The mixture of wheat with soybean represents an important calorie-protein source with good protein quality. In spite of this, the use of soybeans as an ingredient has been limited by their beany flavor, which is improved by the extrusion process. Effects of mixture moisture, Barrel Temperature (BT and Screw-Speed (SS, Nº 5 on Expansion Index (EI, Water Solubility Index (WSI and sensory characteristics of pellets produced with a wheat-soybean (90:10 mixture were studied, in order to optimize this process for obtaining fried pellets with better sensory qualities. Raw mixed flour was extruded at two moisture contents (32 and 35%, four BT (60 to 90 °C and four SS (60 to 150 rpm, totalizing 32 treatments. The fried pellets, prepared with the mixed flour with 32% moisture and extruded at 60 rpm and 80 °C, presented the greatest EI and the best sensory

  20. Development of papain containing pellets produced by extrusion-spheronization: an operational stage approach.

    Science.gov (United States)

    Varca, Gustavo H C; Lopes, Patricia S; Ferraz, Humberto G

    2015-03-01

    The performance of the standardized extrusion-spheronization technique, operational conditions, formulation parameters and storage of the final product over the bioactivity of papain containing pellets has been evaluated to obtain an insight into the potential of the technique for the manufacture of solid protein formulations. The pellets produced were assayed in terms of biological activity - monitored at each operational stage using N-benzoyl-dl-arginine ρ-nitroanilide as a substrate, and according to the physical properties - evaluated by means of size distribution, apparent density and friability. The produced pellets presented adequate physical and mechanical properties. Monitoring biological activity at each production stage revealed that the most critical steps corresponded to drying and storage, with bioactivity decay ranging from 5 to 30% and 5 to 20% for each process. Dry mixing and extrusion did not hold any influence over papain activity, while wet massing decreased the bioactivity by approximately 0-5% and the spheronization 0-2%. The results varied as a function of the experimental conditions and formulation components. In conclusion, the extrusion--spheronization technique was suitable to produce solid multiparticulate dosage forms for papain, considering the possibility to originate pellets with relatively low bioactivity decay. However, weak points of the technique corresponded to the wet massing and drying stages as well as storage.

  1. Influence of orthodontic derotation and extrusion on pulpal and periodontal condition of autotransplanted immature third molars.

    Science.gov (United States)

    Bauss, Oskar; Schwestka-Polly, Rainer; Kiliaridis, Stavros

    2004-04-01

    The aim of this study was to determine the influence of orthodontic treatment on the pulpal and periodontal condition of 91 transplanted immature third molars. In patients with atrophy of the alveolar process or unfavorable root morphology, transplants had to be placed in extreme rotated or infraoccluded positions. After 3 to 6 months, these transplants were derotated (45 degrees to 90 degrees) to a correct position in the dental arch (derotation group; n = 28) or extruded to the occlusal plane (extrusion group; n = 21). Finally, approximal spaces were closed in both groups. A sample of 42 transplanted third molars with no orthodontic treatment need served as the control group. All transplants were followed clinically and radiologically for a mean period of 4.0 years. With respect to pulpal and periodontal conditions, no significant differences were observed between the control and the extrusion group. In contrast, compared with the control group, transplants in the derotation group had a significantly poorer pulpal and periodontal condition. In the derotated transplants, a significant correlation was detected between pulp necrosis and orthodontic treatment of multi-rooted transplants. This study indicates that orthodontic extrusion and minor lateral movements of autotransplanted immature third molars, as well as rotation of single-rooted third-molar transplants, represent no additional risk to transplant survival. In contrast, rotation of multi-rooted transplants seems to initiate later severance of the vascular and nerval supply to the pulp.

  2. Precooked bran-enriched wheat flour using extrusion: dietary fiber profile and sensory characteristics.

    Science.gov (United States)

    Gajula, H; Alavi, S; Adhikari, K; Herald, T

    2008-05-01

    The effect of precooking by extrusion processing on the dietary fiber profile of wheat flour substituted with 0%, 10%, 20%, and 30% wheat bran was evaluated. Depending on the level of bran, total dietary fiber (TDF) and soluble dietary fiber (SDF) in uncooked flours ranged from 4.2% to 17.2% and 1.5% to 2.4%, respectively. Precooking by extrusion significantly increased SDF in flours (by 22% to 73%); although in most cases it also led to a significant decrease in TDF. Cookies and tortillas produced from uncooked and precooked flours with 0% and 20% substituted bran were evaluated for consumer acceptability using a 9-point hedonic scale. With a few exceptions, all cookies had scores ranging from 6 to 7 ("like slightly" to "like moderately") for each attribute, including overall acceptability, appearance, texture, crumbliness, and flavor. Tortillas were rated for the same attributes except for crumbliness, which was replaced with chewiness. In most cases, tortilla scores ranged from 5 to 7 ("neither like nor dislike" to "like moderately"). Consumer acceptability scores of cookies from uncooked flour did not change significantly with increase in bran substitution from 0% to 20%. However, consumer scores for tortillas did decrease significantly with increase in bran level. Extrusion precooking of the flours did not improve the consumer acceptability of cookies and tortillas; however, it did improve their dietary fiber profile by increasing the SDF significantly.

  3. Extrusion Conditions and Amylose Content Affect Physicochemical Properties of Extrudates Obtained from Brown Rice Grains.

    Science.gov (United States)

    González, Rolando José; Pastor Cavada, Elena; Vioque Peña, Javier; Torres, Roberto Luis; De Greef, Dardo Mario; Drago, Silvina Rosa

    2013-01-01

    The utilization of whole grains in food formulations is nowadays recommended. Extrusion cooking allows obtaining precooked cereal products and a wide range of ready-to-eat foods. Two rice varieties having different amylose content (Fortuna 16% and Paso 144, 27%) were extruded using a Brabender single screw extruder. Factorial experimental design was used to study the effects of extrusion temperature (160, 175, and 190°C) and grits moisture content (14%, 16.5%, and 19%) on extrudate properties. Specific mechanical energy consumption (SMEC), radial expansion (E), specific volume (SV), water absorption (WA), and solubility (S) were determined on each extrudate sample. In general, Fortuna variety showed higher values of SMEC and S (703-409 versus 637-407 J/g; 33.0-21.0 versus 20.1-11.0%, resp.) than those of Paso 144; on the contrary SV (8.64-3.47 versus 8.27-4.53 mL/g) and WA tended to be lower (7.7-5.1 versus 8.4-6.6 mL/g). Both varieties showed similar values of expansion rate (3.60-2.18). Physical characteristics depended on extrusion conditions and rice variety used. The degree of cooking reached by Paso rice samples was lower than that obtained for Fortuna. It is suggested that the presence of germ and bran interfered with the cooking process, decreasing friction level and broadening residence time distribution.

  4. 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.

  5. Development of a HPMC-based controlled release formulation with hot melt extrusion (HME).

    Science.gov (United States)

    Ma, Decheng; Djemai, Abdenour; Gendron, Colleen M; Xi, Hanmi; Smith, Michelle; Kogan, Jessica; Li, Li

    2013-07-01

    The objective of this study was to develop hydroxypropyl methylcellulose (HPMC) based controlled release (CR) formulations via hot melt extrusion (HME) with a highly soluble crystalline active pharmaceutical ingredient (API) embedded In the polymer phase. HPMC is considered a challenging CR polymer for extrusion due to its high glass transition temperature (Tg), low degradation temperature, and high viscosity. These problems were partially overcome by plasticizing the HPMC with up to 40% propylene glycol (PG). Theophylline was selected as the model API. By using differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), dynamic mechanical analysis (DMA), and X-ray powder diffraction (XRPD), the physical properties of the formulations were systematically characterized. Five grades of HPMC (Methocel(®)) - E6, K100LV, K4M, K15M, and K100M - were tested. The extrusion trials were conducted on a 16 mm twIn screw extruder with HPMC/PG placebo and formulations containing theophylline/HPMC/PG (30:42:28, w/w/w). The dissolution results showed sustained release profiles without burst release for the HPMC K4M, K15M, and K100M formulations. The extrudates have good dissolution stability after being stressed for 2 weeks under 40°C/75% RH open dish conditions and the crystalline API form did not change upon storage. Overall, the processing windows were established for the HPMC based HME-CR formulations.

  6. Rheological study of the mixture of acetaminophen and polyethylene oxide for hot-melt extrusion application.

    Science.gov (United States)

    Suwardie, Herman; Wang, Peng; Todd, David B; Panchal, Viral; Yang, Min; Gogos, Costas G

    2011-08-01

    There is a growing interest of extrusion drug and polymer together to manufacture various solid dosages. In those cases, the drug's release profiles are greatly affected by the miscibility of two materials. The goal of this study is to test the drug's solubility in molten polymer and obtain the mixture's rheological properties for the purpose of optimizing the extrusion process. The dynamic and steady viscosities of APAP-PEO mixture were determined using oscillatory and capillary rheometers. The curves of viscosity vs. drug loading generally have a "V" shape, and the minimal point gives the APAP's solubility in PEO. The test results suggest that different dynamic methods lead to essentially the same solubility data. At high shear rates, the mixtures show shear thinning behavior and the viscosity becomes less sensitive to the drug loading. In other words, it is desirable to use a low shear rate in order to deduce the drug's solubility in polymer from the viscosity data. On the other hand, viscosity data at high shear rates are more representative of the materials' rheological properties during extrusion.

  7. Physical and chemical effects of ultrasound vibration on polymer melt in extrusion.

    Science.gov (United States)

    Chen, Jinyao; Chen, Yingzi; Li, Huilin; Lai, Shih-Yaw; Jow, Jinder

    2010-01-01

    The physical and chemical effects of ultrasound on polypropylene (PP) melts in extrusion were investigated. By applying ultrasound vibration to the entrance of the die, apparent pressure and viscosity of PP can be obviously decreased under the appropriate ultrasound power. Ultrasound has both physical and chemical effects on the polymer melt. In our study with specific polymer and ultrasound system, we determined that the chemical effect makes up 35-40% of the total effect of ultrasound on the apparent viscosity reduction of PP melts at most of the studied intensities. The physical effect plays a more important role in the ultrasound-applied extrusion than the chemical effect. This chemical effect is an irreversible and permanent change in molecule weight and the molecular-weight distribution due to ultrasound. As the ultrasound intensity increases, the molecular weight of PP reduces and its molecular-weight distribution becomes narrower; the orientation of PP molecules along the flow direction reduces (in melt state) and the crystallinity of PP samples (in solid state) decreases by applying the ultrasound vibration. Ultrasound vibration increases the motion of molecular chains and makes them more disorder; it also affects the relaxation process of polymer melts by shortening the relaxation time of chain segments, leading to weakening the elastic effect and decreasing the extruding swell ratios. All the factors discussed above reduce the non-Newtonian flow characteristics of the polymer melt and result in the viscosity drop of the polymer melt in extrusion.

  8. Continuous Severe Plastic Deformation Processing of Aluminum Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Raghavan Srinivasan (PI); Prabir K. Chaudhury; Balakrishna Cherukuri; Qingyou Han; David Swenson; Percy Gros

    2006-06-30

    by SPD techniques. This combination of properties makes UFG metals produced by SPD very attractive as machining, forging or extrusion stock, both from the point of view of formability as well as energy and cost saving. However, prior to this work there had been no attempt to transfer these potential benefits observed in the laboratory scale to industrial shop floor. The primary reason for this was that the laboratory scale studies had been conducted to develop a scientific understanding of the processes that result in grain refinement during SPD. Samples that had been prepared in the laboratory scale were typically only about 10-mm diameter and 50-mm long (about 0.5-inch diameter and 2-inches long). The thrust of this project was three-fold: (i) to show that the ECAE/P process can be scaled up to produce long samples, i.e., a continuous severe plastic deformation (CSPD) process, (ii) show the process can be scaled up to produce large cross section samples that could be used as forging stock, and (iii) use the large cross-section samples to produce industrial size forgings and demonstrate the potential energy and cost savings that can be realized if SPD processed stock is adopted by the forging industry. Aluminum alloy AA-6061 was chosen to demonstrate the feasibility of the approach used. The CSPD process developed using the principles of chamber-less extrusion and drawing, and was demonstrated using rolling and wire drawing equipment that was available at Oak Ridge National Laboratory. In a parallel effort, ECAE/P dies were developed for producing 100-mm square cross section SPD billets for subsequent forging. This work was carried out at Intercontinental Manufacturing Co. (IMCO), Garland TX. Forging studies conducted with the ECAE/P billets showed that many of the potential benefits of using UFG material can be realized. In particular, the material yield can be increased, and the amount of material that is lost as scrap can be reduced by as much as 50%. Forging

  9. 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).

  10. Use of Enterococcus faecium as a surrogate for Salmonella enterica during extrusion of a balanced carbohydrate-protein meal.

    Science.gov (United States)

    Bianchini, Andreia; Stratton, Jayne; Weier, Steve; Hartter, Timothy; Plattner, Brian; Rokey, Galen; Hertzel, Gerry; Gompa, Lakshmi; Martinez, Bismarck; Eskridge, Kent M

    2014-01-01

    Multiple outbreaks of salmonellosis have been associated with the consumption of low-moisture products, including extruded products. Therefore, there is a need for a nonpathogenic, surrogate microorganism that can be used to validate extrusion processes for Salmonella. The objective of this research was to determine if Enterococcus faecium NRRL B-2354 is an adequate surrogate organism for Salmonella during extrusion. Extrusions at different temperatures were done in material contaminated with both organisms. Results indicated that the minimum temperature needed to achieve a 5-log reduction of E. faecium was 73.7°C. Above 80.3°C, the enumeration of E. faecium showed counts below the detectable levels (detection limit of the method. The data show that E. faecium is inactivated at higher temperatures than Salmonella, indicating that its use as a surrogate would provide an appropriate margin of error in extrusion processes designed to eliminate this pathogen. Attempting to minimize risk, the industry could validate different formulations, in combination with thermal treatments, using E. faecium as a safer alternative for those validation studies.

  11. Analysis on the Deflection Angle of Columnar Dendrites of Continuous Casting Steel Billets Under the Influence of Mold Electromagnetic Stirring

    Science.gov (United States)

    Wang, Xincheng; Wang, Shengqian; Zhang, Lifeng; Sridhar, Seetharaman; Conejo, Alberto; Liu, Xuefeng

    2016-11-01

    In the current study, the deflection angle of columnar dendrites on the cross section of steel billets under mold electromagnetic stirring (M-EMS) was observed. A mathematical model was developed to define the effect of M-EMS on fluid flow and then to analyze the relationship between flow velocities and deflection angle. The model was validated using experimental data that was measured with a Tesla meter on magnetic intensity. By coupling the numerical results with the experimental data, it was possible to define a relationship between the velocities of the fluid with the deflection angle of high-carbon steel. The deflection angle of high-carbon steel reached maximum values from 18 to 23 deg for a velocity from 0.35 to 0.40 m/s. The deflection angles of low-carbon steel under different EM parameters were discussed. The deflection angle of low-carbon steel was increased as the magnetic intensity, EM force, and velocity of molten steel increased.

  12. Effects of Extrusion Process Factors on Expanding Rate of Colocasia esculenta Chip%挤压加工因子对芋头酥片膨化率的影响

    Institute of Scientific and Technical Information of China (English)

    李共国; 缪夏蝉; 张仁杰; 马建芳; 田方; 孙志栋

    2012-01-01

    研究了物料配料、挤出脆片坯厚度和油炸温度等挤压加工因子对芋艿酥片膨化率的影响。结果表明:加工物料中加入黑米能改善产品的色泽和质地,从而提高其感官品质。挤出脆片坯的厚度对酥片膨化率的影响达到显著水平(p〈0.05),而物料配比和油炸温度对酥片膨化率也有明显的影响(p〈0.1)。芋艿酥片适宜的工艺组合为A2B2C2,即m(芋艿)∶m(黑米)配比为1︰0.25、挤出酥片坯厚度1.2 mm、油炸温度230℃。%Effects of material composition,extrudate thickness and fry temperature on expanding rate of Colocasia esculenta chip was studied by the orthogonal design L9(33).The result showed that the chip's color and texture could be advanced by addition of Colocasia esculenta curd.ANOVA analysis showed: extrudate thickness produced a great influence on expanding rate of the chip(p0.05),so did expanding rate of the chip for various material composition and fry temperature(p0.1).The optimum processing conditions were as follows: the ratio of Colocasia esculenta to black stickyrice 1︰0.25,1.2 mm of extrudate thickness and 230 ℃ of fry temperature.

  13. Mitochondrial Extrusion through the cytoplasmic vacuoles during cell death.

    Science.gov (United States)

    Nakajima, Akihito; Kurihara, Hidetake; Yagita, Hideo; Okumura, Ko; Nakano, Hiroyasu

    2008-08-29

    Under various conditions, noxious stimuli damage mitochondria, resulting in mitochondrial fragmentation; however, the mechanisms by which fragmented mitochondria are eliminated from the cells remain largely unknown. Here we show that cytoplasmic vacuoles originating from the plasma membrane engulfed fragmented mitochondria and subsequently extruded them into the extracellular spaces in undergoing acute tumor necrosis factor alpha-induced cell death in a caspase-dependent fashion. Notably, upon fusion of the membrane encapsulating mitochondria to the plasma membrane, naked mitochondria were released into the extracellular spaces in an exocytotic manner. Mitochondrial extrusion was specific to tumor necrosis factor alpha-induced cell death, because a genotoxic stress-inducing agent such as cisplatin did not elicit mitochondrial extrusion. Moreover, intact actin and tubulin cytoskeletons were required for mitochondrial extrusion as well as membrane blebbing. Furthermore, fragmented mitochondria were engulfed by cytoplasmic vacuoles and extruded from hepatocytes of mice injected with anti-Fas antibody, suggesting that mitochondrial extrusion can be observed in vivo under pathological conditions. Mitochondria are eliminated during erythrocyte maturation under physiological conditions, and anti-mitochondrial antibody is detected in some autoimmune diseases. Thus, elucidating the mechanism underlying mitochondrial extrusion will open a novel avenue leading to better understanding of various diseases caused by mitochondrial malfunction as well as mitochondrial biology.

  14. A unified spray forming model for the prediction of billet shape geometry

    DEFF Research Database (Denmark)

    Hattel, Jesper; Pryds, Nini

    2004-01-01

    In the present work a unified model for simulating the spray forming process has been developed. Models for the atomization and the deposition processes have been coupled together in order to obtain a new unified description of the spray forming process. The model is able to predict the shape and...

  15. 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.

  16. Novel application of hot-melt extrusion for the preparation of monolithic matrices containing enteric-coated particles.

    Science.gov (United States)

    Schilling, Sandra U; McGinity, James W

    2010-11-15

    The objective was to investigate a novel application of hot-melt extrusion for the preparation of multiparticulate matrices comprising delayed-release particles. Multiparticulates of different mechanical strengths (theophylline granules, wet-mass extruded/spheronized pellets and drug-layered microcrystalline cellulose spheres) were coated with Eudragit(®) L30D-55 and characterized regarding potency, moisture content, dissolution properties and tensile strength. The coated particles were incorporated into a water-soluble matrix using hot-melt extrusion. Six hydrophilic polymers including polyethylene glycols, poloxamers and polyethylene oxides were studied as the carrier material for the extrusion. Dissolution testing showed that the maintenance of the delayed-release properties of the incorporated particles was independent of the particle tensile strength, but influenced by the nature of the carrier polymer. High miscibility between the carrier and the coating polymer correlated with increased film permeability and higher drug release in acidic media. Of the materials tested, poloxamer 407 exhibited lower miscibility with the Eudragit(®) L polymer and matrices containing up to 40% enteric pellets were compliant with the USP dissolution requirements for delayed-release dosage forms. The potential advantages of hot-melt extrusion over direct compression for the processing of soft drug granules coated with Eudragit(®) L polymer were demonstrated.

  17. Effect of Mould Electromagnetic Stirring on Solidification Structure of 45 Steel Billet%结晶器电磁搅拌对45钢方坯凝固结构的影响研究

    Institute of Scientific and Technical Information of China (English)

    吴华杰; 魏宁; 包燕平; 王国新; 留津津; 杜建新

    2011-01-01

    通过在160 mmX200 mm连铸机上进行的试验,研究了结晶器电磁搅井对45钢方坯凝固结构的影响.研究表明,同一频率下,随搅拌电流强度的增加,铸坯的等抽晶率明显增加;电流强度不变时,随着频率的增加,等轴晶率基本保持不变;并讨论了衡量电磁搅拌效果的指标问题,通过分析磁感应强度、电磁扭矩与电磁搅拌参教的关系可以得出,铸坯等轴晶率变化趋势与电磁扭矩变化趋势有良好的一致性,电磁扭矩比磁感应强度更有效地反映电磁搅拌效果,前者更真实地衡量了电磁揽拌对钢液的搅拌强度,随着搅拌强度的提高,铸坯等轴晶率提高.通过研究,优化了结晶器电磁搅拌工艺,使铸坯等轴晶率达60%以上,改善了中心碳偏析,降低了硫松及缩孔程度.%Effect of mould electromagnetic stirring(M-EMS) on solidification structure of 45 steel billet was studied by testing in 160 mm × 200 mm continuous caster. The results showed that equiaxed crystal ratio increased obviously with increase of electromagnetic intensity of M-EMS, but the equiaxed crystal ratio did not changed with increase of frequency of M-EMS. The indexes for effecting electromagnetic stirring were also discussed by analyzing the relationship between magnetic flux density, electromagnetic torque and parameters of M-EMS. The change trend of equiaxed crystal ratio was accord well with the change trend of electromagnetic torque. That is to say, electromagnetic torque can reflect the effect of electromagnetic stirring in billet more effectively than magnetic flux density. Electromagnetic torque is the real index for measurement the stirring strength of steel by electromagnetic stirring technology, and equiaxed crystal ratio is increased with increase of the stirring strength of steel. The process of M-EMS was optimizing after this study, which make equiaxed crystal ratio of 45 steel billet increased to more than 60%, the carbon segregation

  18. Instant blend from cassava derivatives produced by extrusion

    Directory of Open Access Journals (Sweden)

    Fernanda Rossi Moretti Trombini

    2016-03-01

    Full Text Available 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 temperature (60 to 100ºC, screw speed (175 to 231rpm and moisture (20 to 30%. Extrusion conditions affect color, water absorption and water solubility indexes and paste properties of blends. The intermediate tested conditions of variable parameters lead to obtain extruded products with higher cold viscosity and water absorption index and light color, desirable qualities for rapid preparation products.

  19. Stress Analysis and Optimum Design of Hot Extrusion Dies

    Institute of Scientific and Technical Information of China (English)

    帅词俊; 肖刚; 倪正顺

    2004-01-01

    A three-dimensional model of a hot extrusion die was developed by using ANSYS software and its second development language-ANSYS parametric design language.A finite element analysis and optimum design were carried out.The three-dimensional stress diagram shows that the stress concentration is rather severe in the bridge of the hot extrusion die, and that the stress distribution is very uneven.The optimum dimensions are obtained.The results show that the optimum height of the extrusion die is 89.596 mm.The optimum radii of diffluence holes are 65.048 mm and 80.065 mm.The stress concentration is reduced by 27%.

  20. NUMERICAL DESIGN OF DIE LAND FOR SHAPE EXTRUSION

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In the extrusion of shapes with flat-faced die,the proper design of die land is of critical importance in avoiding the generations of geometry defects.A methodology for the design of die land,which consists of a simulation-adjustment iteration,is proposed.The metal flow in extrusion is simulated by the three dimensional finite element method and the die land is adjusted according to the simulation result.Both the formulae for adjustment of the die land and the criterion for the judgment of proper die land are suggested.The extrusion of an L-section shape is chosen as the computational example and the result is compared with the industrial design.

  1. Die land optimization of section extrusion by finite element method

    Institute of Scientific and Technical Information of China (English)

    卫兴华; 田柱平

    2001-01-01

    In the extrusion of sections with flat-faced die, the proper design of die land is critically important in avoid ing geometry defects. A methodology for the design of die land, which consists of a simulation-adjustment iteration, isproposed. The metal flow in extrusion is simulated by the three dimensional finite element method and the die land is adjusted according to the simulation result. The simulation-adjustment iteration is conducted repeatedly until the uniform metal flow in die land exit is obtained. Both the formulae for adjustment of the die land and the criterion for the judgment of proper die land are suggested. The extrusion of a C-section is chosen as the computational example.

  2. Micronutrient and protein-fortified whole grain puffed rice made by supercritical fluid extrusion.

    Science.gov (United States)

    Paraman, Ilankovan; Wagner, Michael E; Rizvi, Syed S H

    2012-11-07

    Supercritical fluid extrusion (SCFX) was used to produce shelf-stable puffed rice fortified with protein, dietary fiber, and micronutrients. Product ingredients and process parameters were evaluated for end-product nutritional and textural qualities. Supercritical carbon dioxide (SC-CO(2)) served as a viscosity-lowering plasticizer and blowing agent during the process, which has been shown to produce expanded products with good textural qualities at lower temperatures (~100 °C) than conventional steam-based extrusion (130-180 °C). The fortified puffed rice contained 8% dietary fiber, 21.5% protein, and iron, zinc, and vitamins A and C at their recommended daily values in 100 g of product. The SCFX process allowed for the complete retention of all added minerals, 55-58% retention of vitamin A, and 64-76% retention of vitamin C. All essential amino acids including lysine were retained at exceptionally high levels (98.6%), and no losses were observed due to Maillard reaction or oxidation. All of the essential amino acid contents were equal to the reference protein recommended by FAO/WHO. Soy protein fortification improved the total amount of protein in the final rice products and provided a complementary amino acid profile to that of rice; the lysine content improved from 35 to 60 mg/protein, making the end product an excellent source of complete protein. Thus, SC-CO(2)-assisted extrusion is an effective process-based approach to produce cereal grain-based, low-moisture (5-8%) expanded products fortified with protein and any cocktail of micronutrients, without compromising the end-product sensory or nutritional qualities. These products are ideally suited for consumption as breakfast cereals, snack foods, and as part of nutrition bars for school lunch programs. The balanced nutritional profile and use of staple crop byproducts such as broken rice makes these expanded crisps unique to the marketplace.

  3. Desenvolvimento de Eurytrema coelomaticum (Giard & Billet (Digenea, Dicrocoeliidae em Bradybaena similaris (Férussac (Gastropoda, Xanthonychidae Development of Eurytrema coelomaticum (Giard & Billet (Digenea, Dicrocoeliidae in Bradybaena similaris (Férussac (Gastropoda, Xanthonychidae

    Directory of Open Access Journals (Sweden)

    Solange Viana Paschoal Blanco Brandolini

    2001-06-01

    Full Text Available To follow the larval developmenl of Eurytrema coelomaticum (Giard & Billet, 1892 in Bradybaena similaris (Férussac, 1821 snails were separated in three classes using the shell diameter: Class A (14.5-10.2 mm, Class B (10.1-6.9 mm and Class C (6.8-2.6 mm. Only snails belonging to classes A and B acquired the infection. Specimens of E. coelomaticum removed from the pancreatic ducts were exposed to three physiological solutions: Earle, Locke and saline 0.85%, to obtain eggs for the experimental infections, The Locke solution induced the best egg release. The route of migration the intramolluscan development of E. coelomaticum was studied with the aid of histology. The minimal period of intramolluscan developmenl, ending at the expelling of daughter sporocysts, was 107 days for the snails infected in March, and 79 days for the snails infected in November. The Student "t" test and the Chi-square test showed a significant difference (α = 5% between the two periods, although the mean temperature registered during the experiments did not significantly differed (α = 5%. The elimination of daughter sporocysts occurred through the snail's pneumostome, and always at night. Most sporocysts were eliminated at intervals that varied between one to three days, without regularity. The time of elimination of the daughter sporocysts was different for the two infection period studied: 12 weeks for the snails infected in March, and three weeks for those infected in November. Positive correlation between the number of sporocysts expelled by the snail host and higher temperatures registered in the laboratory was observed. This correlation was more evident in November infection.

  4. Satellite Based Extrusion Rates for the 2006 Augustine Eruption

    Science.gov (United States)

    Dehn, J.; Bailey, J. E.; Dean, K. G.; Skoog, R.; Valcic, L.

    2006-12-01

    Extrusion rates were calculated from polar orbiting infrared satellite data for the 2006 eruption of Augustine Volcano, Alaska. The pixel integrated brightness temperatures from the satellite data were converted to estimates of ground temperature by making assumptions and using first hand observations about the geometry of the hot area (lava dome, flows and pyroclastic flow deposits) relative to the cold area in the kilometer scale pixels. Extrusion rate is calculated by assuming that at a given temperature, a lava emits an amount of radiation proportional to its volume. On ten occasions during the activity, helicopter based infrared imagers were used to validate the satellite observations. The pre-January 11 thermal activity was not significantly above background in satellite data. The first strong thermal anomalies were recorded during the first explosive phase on January 11. During successive explosive phases in January, bright thermal signals were observed, often saturating the sensors. Large areas (many km2) were observed to be warm in the satellite data, indicative of pyroclastic flows. Sometime during or after January 29, during a phase of sustained ash emission, the thermal signal became persistent, suggesting the beginning of lava effusion. The extrusion rates derived from satellite data varied from 0 to nearly 7 m3/s, giving an eruption rate of 2.7 m3/s. The extrusion event produced two blocky lava flows which moved down the north flank of the volcano. Extrusion occurred through at least March 15 (day 76) when a sharp drop in extrusion rate and thermal signal is observed. Based on the derived extrusion rates, it is estimated that 18 million m3 of lava was extruded during the course of the eruption. This value agreed well with photogrammetric measurements, but does not agree with volumes derived through subtraction of digital elevation models post- and pre- eruption. It should be noted that the thermal approach only works for hot lavas, and does not

  5. Physicochemical, Phytochemical and Nutrimental Impact of Fortified Cereal Based Extrudate Snacks: Effect of Jackfruit Seed Flour Addition and Extrusion Cooking

    Directory of Open Access Journals (Sweden)

    Yogesh Gat

    2015-05-01

    Full Text Available Aim of present study was to estimate quantitative changes in nutrimental, physicochemical and phytochemical properties of rice-jackfruit seed flour blend extrudates. Rice-jackfruit seed flour blend was prepared at 70:30 proportions and was subjected to extrusion cooking. Effect of barrel temperature (140-180°C and screw speed (100-300 rpm on nutrimental, physicochemical (expansion, density, WSI, WAI and hardness and phytochemical (TPC and TFC properties were studied. Rice flour extrudate was found to have 6.63% protein and 0.17% fiber which were further increased to about 8.44 and 0.8%, respectively after addition of jackfruit seed flour at 180°C with 300 rpm. Extrusion cooking at lower barrel temperature resulted in increase in TPC and TFC. Rice-jackfruit seed flour blend extrudate at 180°C with 100 rpm resulted in highest antioxidant capacity and reducing power (208.56 µmol of TE/g and 0.26 mg of AAE/g of dry powder respectively. Practical applications: Although there is increased use of extrusion processing, but still there is no fully developed theory to predict the effects of process variables on various raw materials and their mixtures. Any change in feed composition and process variables can influence extrusion performance as well as product quality. Therefore, it is crucial to study the effect of extrusion process parameters (barrel temperature and screw speed on extrudate characteristics. Also, the researchers, so far, tried lots of combinations for nutraceutical enrichment of extrudate snacks. To the best of our knowledge, this is first report on extrusion cooking of RF fortified with JFSF. In future, this data could be useful for food processing industries. Originality of this study demonstrates the feasibility of developing value added extrudates with improved nutrimental and nutraceutical appeal. Present study shows potential for utilization of jackfruit seed which is part of the waste generated in large quantities when the

  6. Numerical Modeling of Induction Heating Process using Inductors with Circular Shape Turns

    Directory of Open Access Journals (Sweden)

    Mihaela Novac

    2008-05-01

    Full Text Available This paper is focused on the problemof numerical modeling of electromagneticfield coupled with the thermal one in theheating process of the steel billets, usinginductors with circular shape turns. As resultswe have: electromagnetic field lines evolutionand map temperatures in piece at the endingof heating process.

  7. Effects of Process Parameters on the Temperature Field in Ti-6A1-4V Alloy Blade Precision Forging Process

    Institute of Scientific and Technical Information of China (English)

    Yuli LIU; He YANG; Tao GAO; Mei ZHAN

    2006-01-01

    Blade precision forging is a high temperature and large plastic deformation process. Process parameters have a great effect on temperature distribution in billet, so in this paper, by taking a Ti-6Al-4V alloy blade with a tenon as an object, the influence of process parameters on the temperature distribution in precision forging process was investigated using 3D coupled thermo-mechanical FEM (finite element method) code developed by the authors. The results obtained illustrate that: (1) the gradient of temperature distribution increases with increasing the deformation degree; (2) with increasing the initial temperature of the billet, the zones of high temperature become larger, and the gradient of temperature distribution hardly has any increase; (3)friction factors have little effect on the distribution of temperature field; (4) with increasing upper die velocity,temperature of the billet increases while the temperature gradient in billet decreases. The results are helpful to the design and optimization of the process parameters in precision forging process of Ti-alloy blade.

  8. Deformation temperature and postdeformation annealing effects on severely deformed TiNi alloy by equal channel angular extrusion

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Micron TiNi alloy blocks were fabricated at high temperature by equal channel angular extrusion (ECAE) using hotforged Ti-50.3at%Ni alloy as the raw material and the effects of deformation temperature and postdeformation annealing on the severely deformed TiNi alloy by ECAE were investigated. The results show that the TiNi alloy processed by ECAE undergoes severe plastic deformation, and lowering the deformation temperature and increasing the number of extrusions contribute to grain refinement. When the annealing temperature is below 873 K, static recovery is the main restoration process; when the temperature rises to 973 K, static recrystallization occurs. It is found that fine particles are precipitated when the TiNi alloy processed by ECAE is annealed at 773 K.

  9. 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.

  10. The combined effects of extrusion, thermoforming and welding on the physical properties of plastics

    Energy Technology Data Exchange (ETDEWEB)

    Fisher, G. [Fisher Co. and Moore, North Salt Lake, UT (United States)

    1996-11-01

    The application of plastic linings to steel structures and the fabrication of dual laminate vessels involves a number of steps. These may include heating, stretching, adhering, welding, and testing. The combination of these steps together with stresses associated with the liner extrusion process may be cumulative even multiplicative to the overall stress of the liner affecting its integrity and performance in a lined steel or dual laminate vessel. This paper will review the methods of testing and evaluation adopted by the authors` company to insure the maximum performance of vessel lining materials.

  11. Effects of equal channel angular extrusion on microstructure, strength and ballistic performance of AA5754 plates

    DEFF Research Database (Denmark)

    Mishin, Oleg; Hong, Chuanshi; Toftegaard, Helmuth Langmaack

    2014-01-01

    The microstructure, hardness, tensile properties and ballistic performance have been investigated in thick plates of the AA5754 alloy both in a coarse-grained as-received condition and after 4 passes of equal channel angular extrusion (ECAE) conducted at elevated temperatures. It is found that ECAE...... refines the microstructure to an average subgrain size of 0.3 μm, which results in significantly increased hardness and strength. Although ductility decreases due to ECAE, the uniform elongation is still fairly large, ~10%. The ballistic performance of the ECAE-processed material is found...

  12. 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.

  13. Extrusion of polysaccharide nanocrystal reinforced polymer nanocomposites through compatibilization with poly(ethylene oxide).

    Science.gov (United States)

    Pereda, Mariana; El Kissi, Nadia; Dufresne, Alain

    2014-06-25

    Polysaccharide nanocrystals with a rodlike shape but with different dimensions and specific surface area were prepared from cotton and capim dourado cellulose, and with a plateletlike morphology from waxy maize starch granules. The rheological behavior of aqueous solutions of poly(ethylene oxide) (PEO) with different molecular weights when adding these nanoparticles was investigated evidencing specific interactions between PEO chains and nanocrystals. Because PEO also bears hydrophobic moieties, it was employed as a compatibilizing agent for the melt processing of polymer nanocomposites. The freeze-dried mixtures were used to prepare nanocomposite materials with a low density polyethylene matrix by extrusion. The thermal and mechanical behavior of ensuing nanocomposites was studied.

  14. Durable and rechargeable biocidal polypropylene polymers and fibers prepared by using reactive extrusion.

    Science.gov (United States)

    Badrossamay, Mohammad Reza; Sun, Gang

    2009-04-01

    Incorporation of N-halamine precursor onto polypropylene was explored by using a reactive extrusion process. Several cyclic and acyclic halamine precursors were grafted onto polypropylene backbone through a melt free radical graft copolymerization. The structures and morphology of the grafted polymer were characterized with FTIR, and scanning electron microscope. Thermal properties of the polymers were evaluated by differential scanning calorimetry. The halogenated products of the corresponding grafted samples exhibited potent antimicrobial properties against Escherichia coli, and the antimicrobial properties were durable and regenerable. The relationship between effective surface contact and biocidal efficacy are further discussed.

  15. 电磁搅拌条件下小方坯结晶器内钢液流动行为的数值模拟%Numerical Simulation of Flow Field in Mold for Small Billets Under Electromagnetic Stirring

    Institute of Scientific and Technical Information of China (English)

    胡国旭

    2012-01-01

    采用数模分析结合生产实践的方法,对小方坯连铸结晶器电磁搅拌过程及相关问题进行了理论与实践分析.结果表明,电流强度与频率对磁感应强度有直接影响;150 mm×150 mm断面的最佳搅拌频率为4Hz;当搅拌电流在250~400 A之间变化时,搅拌速度大小范围在0.71~ 1.06 m/s;该计算应用于生产实践取得了较好的生产实效.%The electromagnetic stirring process and related problems of the mold for small billets were theoretically and practically analyzed with the method of combining digital-to-analog analysis with production practice. The results show that the current strength and its frequency has a direct impact on the magnetic induction. The best stirring frequency is 4 Hz for 150 mm×l50 mm section; and when the mixing current changes in the range of 250~400 A, corresponding stirring speed is in the rage of 0.71~1.06 m/s. Applying the simulation results to practical production, a good production efficiency has been obtained.

  16. A simplified model for V-ATPase H+ extrusion.

    Science.gov (United States)

    Luo, Chuan; Clark, John W; Heming, Thomas A; Bidani, Akhil

    2004-12-01

    An analytical model of V-type H+-translocating ATPase (V-ATPase) was developed based on an approximation to the mechanochemical model of Grabe et al. (Biophys. J., pp. 2798-2813, vol. 78, 2000). Grabe's work utilizes structural information and physiological assumptions to construct a detailed mechanochemical model of the V-ATPase. Due to the complexity of their model, it does not give a readily usable mathematical expression for the V-ATPase current. Based on their analysis of the structure of the proton pump, we develop a two-compartment model of the V-ATPase, which contains a membrane "half-channel" for proton translocation separated by a hydrophilic strip and a hydrophobic wall from the cytoplasm. Using the Langevin equation to describe proton transport across the membrane, we simplify the model based on their assumptions on the molecular structure of the pump and arrive at a general form of solution to the proton pump flux driven by ATP hydrolysis based on assumptions on the physiological properties of the strip and the wall, as well as the two fluid compartments. In this process of simplification, we explicitly relate V-ATPase structure, stoichiometry, pump efficiency, and ATP hydrolysis energy to the active pump current. The simplified model is used to provide model-generated approximations to measured data from a variety of laboratories. In addition, it provides a very compact characterization of V-ATPase, which can be used as a proton extruder in a variety of different cell membranes, as well as in the membranes of intracellular organelles. Index Terms-Electrophysiology, mechanochemstry, molecular motors, proton extrusion

  17. Dynamics of the spurt instability in polymer extrusion

    NARCIS (Netherlands)

    Dubbeldam, J.L.A.; Molenaar, J.

    2003-01-01

    A study of a phenomenological model describing the spurt instability in polymer extrusion is presented. Following Georgiou and Crochet [J. Rheol. 38 (1994) 639], we assume a nonmonotonic wall shear stress versus wall slip velocity relation. In this way we obtain a two-dimensional dynamical system fo

  18. 75 FR 17436 - Certain Aluminum Extrusions From China

    Science.gov (United States)

    2010-04-06

    ... amended, 67 FR 68036 (November 8, 2002). Even where electronic filing of a document is permitted, certain... Electronic Filing Procedures, 67 FR 68168, 68173 (November 8, 2002). In accordance with sections 201.16(c... COMMISSION Certain Aluminum Extrusions From China AGENCY: United States International Trade...

  19. Track with overlapping links for dry coal extrusion pumps

    Science.gov (United States)

    Saunders, Timothy; Brady, John D

    2014-01-21

    A chain for a particulate material extrusion pump includes a plurality of links, each of the plurality of links having a link body and a link ledge, wherein each link ledge of the plurality of links at least partially overlaps the link body of an adjacent one of the plurality of links.

  20. Load beam unit replaceable inserts for dry coal extrusion pumps

    Science.gov (United States)

    Saunders, Timothy; Brady, John D.

    2012-11-13

    A track assembly for a particulate material extrusion pump according to an exemplary aspect of the present disclosure includes a link assembly with a roller bearing. An insert mounted to a load beam located such that the roller bearing contacts the insert.

  1. Protein Modifications after Foxtail Millet Extrusion: Solubility and Molecular Weight

    Directory of Open Access Journals (Sweden)

    Xuewei Zhao

    2015-03-01

    Full Text Available With the aim of illustrating the effects of extrusion cooking on the solubility of proteins in foxtail millet and their molecular basis, foxtail millet was extruded at five barrel temperature profiles and feed moisture contents. The proteins of raw and extrudate samples were extracted with six solutions sequentially. Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis (SDS-PAGE of total protein and Starch Granule-Associate Protein (SGAP was performed. Extrusion caused a significant decrease in globulin, setarin and glutelin fractions with a corresponding increase in SDS- and SDS+2-ME-soluble and residual fractions. Increasing extrusion temperature or moisture content all led to SDS-soluble fraction decrease, while SDS+2-ME-soluble fraction increase. SDS-PAGE demonstrated that disulfide bond cross-linking occurred among glutelin and with setarin subunits. Extrusion had a less pronounced impact on the 60 kDa SGAP than the other middle-high molecular weight subunits. It is the protein-protein interaction shift from electrostatic force to hydrophobic and/or hydrogen forces and covalent disulfide cross-links that contributed to the decreased solubility of protein in foxtail millet extrudates.

  2. Research Status and Prospect of UHMWPE Extrusion Forming%超高摩尔质量聚乙烯挤出成型技术及发展

    Institute of Scientific and Technical Information of China (English)

    牟冰松; 樊志新; 孙静

    2012-01-01

    引入了熔融理论、形态控制和自增强理论,详细地总结了超高摩尔质量聚乙烯的挤出成型方法,包括熔融挤出、近熔点挤出、固态挤出.发掘超高摩尔质量聚乙烯加工难题的求解历程与规律;并展望了超高摩尔质量聚乙烯连续挤压研究的历史趋势.%In this paper, melting theory, morphology control and self-reinforced theory were introduced. Some extrusion forming methods of UHMWPE were summarized including melting extrusion, nearby melting point extrusion and solid extrusion. The solving course and law of UHMWPE processing difficult problem were disinterred, and the prospect of UHMWPE continuous extrusion research historical trend was shown.

  3. Co-Extrusion: Advanced Manufacturing for Energy Devices

    Energy Technology Data Exchange (ETDEWEB)

    Cobb, Corie Lynn [PARC, Palo Alto, CA (United States)

    2016-11-18

    The development of mass markets for large-format batteries, including electric vehicles (EVs) and grid support, depends on both cost reductions and performance enhancements to improve their economic viability. Palo Alto Research Center (PARC) has developed a multi-material, advanced manufacturing process called co-extrusion (CoEx) to remove multiple steps in a conventional battery coating process with the potential to simultaneously increase battery energy and power density. CoEx can revolutionize battery manufacturing across most chemistries, significantly lowering end-product cost and shifting the underlying economics to make EVs and other battery applications a reality. PARC’s scale-up of CoEx for electric vehicle (EV) batteries builds on a solid base of experience in applying CoEx to solar cell manufacturing, deposition of viscous ceramic pastes, and Li-ion battery chemistries. In the solar application, CoEx has been deployed commercially at production scale where multi-channel CoEx printheads are used to print viscous silver gridline pastes at full production speeds (>40 ft/min). This operational scale-up provided invaluable experience with the nuances of speed, yield, and maintenance inherent in taking a new technology to the factory floor. PARC has leveraged this experience, adapting the CoEx process for Lithium-ion (Li-ion) battery manufacturing. To date, PARC has worked with Li-ion battery materials and structured cathodes with high-density Li-ion regions and low-density conduction regions, documenting both energy and power performance. Modeling results for a CoEx cathode show a path towards a 10-20% improvement in capacity for an EV pouch cell. Experimentally, we have realized a co-extruded battery structure with a Lithium Nickel Manganese Cobalt (NMC) cathode at print speeds equivalent to conventional roll coating processes. The heterogeneous CoEx cathode enables improved capacity in thick electrodes at higher C-rates. The proof-of-principle coin cells

  4. Nanoporous nanocomposite membranes via hybrid twin-screw extrusion-multijet electrospinning.

    Science.gov (United States)

    Senturk-Ozer, Semra; Aktas, Seda; He, Jing; Fisher, Frank T; Kalyon, Dilhan M

    2017-01-13

    Non-woven nanoporous membranes of poly(caprolactone), PCL, incorporated with multi-walled carbon nanotubes, CNTs, could be fabricated via an industrially-scalable hybrid twin screw extrusion and electrospinning process. The utilization of a spinneret with multiple nozzles allowed the increase of the flow rate beyond what is possible with conventional electrospinning using a single nozzle, albeit at the expense of difficulties in the control of the thickness distributions of the nanofibrous membranes. The thickness and orientation distributions and the resulting mechanical properties of the membranes could be modified via changes in voltage, angular velocity of the collector mandrel and separation distance of the collector from the spinneret. The increases in crystallinity due to the presence of the CNTs and the preferential alignment of the nanofibers via rotation of the collecting mandrel led to increases in the tensile properties of the nanoporous membranes. The use of poly(ethylene oxide), PEO, together with PCL, followed by the dissolution of the PEO, rendered the nanofibers themselves nanoporous with typical surface porosity values of around 50% and pore sizes of about 220 nm. The demonstrated versatility of the hybrid twin screw extrusion and electrospinning process and the manipulation of mesh dimensions and properties are indicative of the applicability of the hybrid process for fabrication of nanoporous membranes for myriad diverse industrial applications ranging from water treatment to tissue engineering applications.

  5. Modelling of semi-liquid aluminium flow in extrusion with temperature effect

    Directory of Open Access Journals (Sweden)

    G. Skorulski

    2007-04-01

    Full Text Available material remains stiff and holds its shape so it can be readily handled, but rapidly thins and flows like a liquid when sheared. It is this behaviour that is the key to the thixoforming process where material flows as a semi-liquid slurry into a die, as in conventional die-casting. Modelling the influence of the temperature distribution heterogeneity on deformation mechanisms during extrusion of the aluminium alloys in semi - liquid phase, the way of preparing samples and experimental technique has been analysed in the following work. There were made an analysis on the influence of the possible temperature distribution in recipient obtained during heating it on the extrusion process proceedings. The conclusions concerning stability of the process and appearing during it deformation mechanisms had been drawn on the ground of the received results. The plasticine and rape oil have been choosen as a substitute materials. Some kind of different variants have been investigated used a special experimental stand. The results of the tests presented below prove that the proposed technique can provide valuable insight into the material flow during deformation of aluminium alloys in the semi-liquid state and thus can give some guidance concerning the desirable temperature distribution within the workpiece.

  6. 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 in th...... and the workpiece are compared with a number of FEM simulations computed with different heat transfer coefficients. The current heat transfer coefficient is determined from the simulations....

  7. Continuous production of itraconazole-based solid dispersions by hot melt extrusion: Preformulation, optimization and design space determination.

    Science.gov (United States)

    Thiry, Justine; Lebrun, Pierre; Vinassa, Chloe; Adam, Marine; Netchacovitch, Lauranne; Ziemons, Eric; Hubert, Philippe; Krier, Fabrice; Evrard, Brigitte

    2016-12-30

    The purpose of this work was to increase the solubility and the dissolution rate of itraconazole, which was chosen as the model drug, by obtaining an amorphous solid dispersion by hot melt extrusion. Therefore, an initial preformulation study was conducted using differential scanning calorimetry, thermogravimetric analysis and Hansen's solubility parameters in order to find polymers which would have the ability to form amorphous solid dispersions with itraconazole. Afterwards, the four polymers namely Kollidon(®) VA64, Kollidon(®) 12PF, Affinisol(®) HPMC and Soluplus(®), that met the set criteria were used in hot melt extrusion along with 25wt.% of itraconazole. Differential scanning confirmed that all four polymers were able to amorphize itraconazole. A stability study was then conducted in order to see which polymer would keep itraconazole amorphous as long as possible. Soluplus(®) was chosen and, the formulation was fine-tuned by adding some excipients (AcDiSol(®), sodium bicarbonate and poloxamer) during the hot melt extrusion process in order to increase the release rate of itraconazole. In parallel, the range limits of the hot melt extrusion process parameters were determined. A design of experiment was performed within the previously defined ranges in order to optimize simultaneously the formulation and the process parameters. The optimal formulation was the one containing 2.5wt.% of AcDiSol(®) produced at 155°C and 100rpm. When tested with a biphasic dissolution test, more than 80% of itraconazole was released in the organic phase after 8h. Moreover, this formulation showed the desired thermoformability value. From these results, the design space around the optimum was determined. It corresponds to the limits within which the process would give the optimized product. It was observed that a temperature between 155 and 170°C allowed a high flexibility on the screw speed, from about 75 to 130rpm.

  8. Extrusion Conditions and Amylose Content Affect Physicochemical Properties of Extrudates Obtained from Brown Rice Grains

    Directory of Open Access Journals (Sweden)

    Rolando José González

    2013-01-01

    Full Text Available The utilization of whole grains in food formulations is nowadays recommended. Extrusion cooking allows obtaining precooked cereal products and a wide range of ready-to-eat foods. Two rice varieties having different amylose content (Fortuna 16% and Paso 144, 27% were extruded using a Brabender single screw extruder. Factorial experimental design was used to study the effects of extrusion temperature (160, 175, and 190°C and grits moisture content (14%, 16.5%, and 19% on extrudate properties. Specific mechanical energy consumption (SMEC, radial expansion (E, specific volume (SV, water absorption (WA, and solubility (S were determined on each extrudate sample. In general, Fortuna variety showed higher values of SMEC and S (703–409 versus 637–407 J/g; 33.0–21.0 versus 20.1–11.0%, resp. than those of Paso 144; on the contrary SV (8.64–3.47 versus 8.27–4.53 mL/g and WA tended to be lower (7.7–5.1 versus 8.4–6.6 mL/g. Both varieties showed similar values of expansion rate (3.60–2.18. Physical characteristics depended on extrusion conditions and rice variety used. The degree of cooking reached by Paso rice samples was lower than that obtained for Fortuna. It is suggested that the presence of germ and bran interfered with the cooking process, decreasing friction level and broadening residence time distribution.

  9. Extrusion Conditions and Amylose Content Affect Physicochemical Properties of Extrudates Obtained from Brown Rice Grains

    Science.gov (United States)

    González, Rolando José; Pastor Cavada, Elena; Vioque Peña, Javier; Torres, Roberto Luis; De Greef, Dardo Mario; Drago, Silvina Rosa

    2013-01-01

    The utilization of whole grains in food formulations is nowadays recommended. Extrusion cooking allows obtaining precooked cereal products and a wide range of ready-to-eat foods. Two rice varieties having different amylose content (Fortuna 16% and Paso 144, 27%) were extruded using a Brabender single screw extruder. Factorial experimental design was used to study the effects of extrusion temperature (160, 175, and 190°C) and grits moisture content (14%, 16.5%, and 19%) on extrudate properties. Specific mechanical energy consumption (SMEC), radial expansion (E), specific volume (SV), water absorption (WA), and solubility (S) were determined on each extrudate sample. In general, Fortuna variety showed higher values of SMEC and S (703–409 versus 637–407 J/g; 33.0–21.0 versus 20.1–11.0%, resp.) than those of Paso 144; on the contrary SV (8.64–3.47 versus 8.27–4.53 mL/g) and WA tended to be lower (7.7–5.1 versus 8.4–6.6 mL/g). Both varieties showed similar values of expansion rate (3.60–2.18). Physical characteristics depended on extrusion conditions and rice variety used. The degree of cooking reached by Paso rice samples was lower than that obtained for Fortuna. It is suggested that the presence of germ and bran interfered with the cooking process, decreasing friction level and broadening residence time distribution. PMID:26904605

  10. Reactive Melt Extrusion To Improve the Dissolution Performance and Physical Stability of Naproxen Amorphous Solid Dispersions.

    Science.gov (United States)

    Liu, Xu; Zhou, Lin; Zhang, Feng

    2017-03-06

    The purpose of this study was to investigate the reaction between naproxen (NPX) and meglumine (MEG) at elevated temperature and to study the effect of this reaction on the physical stabilities and in vitro drug-release properties of melt-extruded naproxen amorphous solid dispersions (ASDs). Differential scanning calorimetry, hot-stage polarized light microscopy, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy analyses demonstrated that in situ salt formation with proton transfer between NPX and MEG occurred at elevated temperature during the melt extrusion process. The amorphous NPX-MEG salt was physically most stable when two components were present at a 1:1 molar ratio. Polymeric carriers, including povidone, copovidone, and SOLUPLUS, did not interfere with the reaction between NPX and MEG during melt extrusion. Compared to the traditional NPX ASDs consisting of NPX and polymer only, NPX-MEG ASDs were physically more stable and remained amorphous following four months storage at 40 °C and 75% RH (relative humidity). Based on nonsink dissolution testing and polarized light microscopy analyses, we concluded that the conventional NPX ASDs composed of NPX and polymers failed to improve the NPX dissolution rate due to the rapid recrystallization of NPX in contact with aqueous medium. The dissolution rate of NPX-MEG ASDs was two times greater than the corresponding physical mixtures and conventional NPX ASDs. This study demonstrated that the acid-base reaction between NPX and MEG during melt extrusion significantly improved the physical stability and the dissolution rate of NPX ASDs.

  11. Structural evolution of LC4 alloy in making thixotropic billet by SIMA method

    Institute of Scientific and Technical Information of China (English)

    罗守靖; 田文彤; 张广安

    2001-01-01

    The effect of SIMA process parameters on LC4 alloy's microstructure and the microstructural evolution of various soaking times have been studied. The results show that effective strain in cold deformation before reheating has a great influence on microstructural evolution. Grain size decreases and its shape also approaches to sphericity with increasing effective strain. The amount of liquid phase increases at grain boundaries and grain shape becomes smooth with increasing heating temperature. The main mechanism of grain coarsening is coalescence when eutectic liquid is rare and not totally distributed at all boundaries. Otherwise the main mechanism of grain coarsening is Ostwald ripening and the connection coarsening is more difficult to perform when the regions are nearly full of eutectic liquid.

  12. 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

    -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....

  13. Coaxial extrusion conversion concept for polymeric flat plate solar collectors. Final technical report, September 30, 1978-December 31, 1979

    Energy Technology Data Exchange (ETDEWEB)

    Rhodes, R.O.; Chapman, N.J.; Chao, K.C.; Sorenson, K.F.

    1980-01-01

    This study investigated materials and processes for fundamental improvements in flat-plate solar collector cost and performance. The goal was to develop a process for direct conversion of inexpensive raw materials into a completed solar collector unit, without labor intensive assembly operations. It was thought that materials carefully matched to the process and end-use environment would substantially reduce collector costs, as compared to conventional industry practice. The project studied the feasibility of a cost-effective, glazed solar collector, with low labor input, utilizing a coaxial extrusion of compatible polymeric materials. This study evaluated all considered materials for the desired application. In addition, there was a trial extrusion of the leading candidate glazing and absorber materials, which resulted in successfully performing a coaxial extrusion of one cell. At the time the study was conducted, there were no materials available that met the necessary requirements for the specified utilization. It was recommended that, if potentially compatible materials become available, further investigation into the suitability of those materials be researched. Then, if a suitable material was found, proceeding into Phase II would be recommended.

  14. 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.

  15. Formulation of ranitidine pellets by extrusion-spheronization with little or no microcrystalline cellulose.

    Science.gov (United States)

    Basit, A W; Newton, J M; Lacey, L F

    1999-01-01

    The present study was concerned with the feasibility of formulating ranitidine into pellets with a range of alternative excipients in place of microcrystalline cellulose (MCC). Eight ranitidine formulations employing two or more of the excipients lactose, barium sulfate, glyceryl monostearate, and MCC were processed by extrusion-spheronization, and characterized according to a series of physico-mechanical and dissolution criteria. Formulations containing lactose produced unsatisfactory pellets of wide size distribution and irregular shape, whereas formulations incorporating barium sulfate and glyceryl monostearate with or without MCC resulted in relatively spherical pellets of narrow size distribution and good mechanical properties. Ranitidine release was found to be rapid and virtually complete within 15 min, regardless of the pellet formulation. A direct relationship was observed between the concentration of MCC in the formulation and the properties of the pellets. In general, the higher the concentration of MCC, the rounder, stronger, and less friable the pellets. However, even pellets without MCC were also successfully prepared with a superior size distribution and shape over those with MCC. Overall, these results confirm that ranitidine can be formulated into pellet dosage forms with little or no MCC by the extrusion-spheronization process.

  16. 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.

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

    Science.gov (United States)

    Aho, Johanna; Edinger, Magnus; Botker, Johan; Baldursdottir, Stefania; Rantanen, Jukka

    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), ibuprofen (IBU), or indomethacin (IND), and 70% of polyethylene oxide, by using small amplitude oscillatory shear rheology. The initial evaluation of the drug:polyethylene oxide solubility was estimated by differential scanning calorimetry of the physical mixtures containing a wide range of weight fractions 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 saturation solubility, whereas IND and PRC initially lowered the viscosity of the mixture slightly but increased it significantly with increasing drug load. The main reason for the enhanced plasticization effect seems to be the lower melting temperature of IBU, which is closer to the used HME temperature, compared to PRC and IND. This study highlights the importance of rheological investigation in understanding the drug-polymer interactions in melt processing.

  18. Equal channel angular extrusion of ultra-high molecular weight polyethylene.

    Science.gov (United States)

    Reinitz, Steven D; Engler, Alexander J; Carlson, Evan M; Van Citters, Douglas W

    2016-10-01

    Ultra-high molecular weight polyethylene (UHMWPE), a common bearing surface in total joint arthroplasty, is subject to material property tradeoffs associated with conventional processing techniques. For orthopaedic applications, radiation-induced cross-linking is used to enhance the wear resistance of the material, but cross-linking also restricts relative chain movement in the amorphous regions and hence decreases toughness. Equal Channel Angular Extrusion (ECAE) is proposed as a novel mechanism by which entanglements can be introduced to the polymer bulk during consolidation, with the aim of imparting the same tribological benefits of conventional processing without complete inhibition of chain motion. ECAE processing at temperatures near the crystalline melt for UHMWPE produces (1) increased entanglements compared to control materials; (2) increasing entanglements with increasing temperature; and (3) mechanical properties between values for untreated polyethylene and for cross-linked polyethylene. These results support additional research in ECAE-processed UHMWPE for joint arthroplasty applications.

  19. KEY TECHNIQUES IN R&D OF OUT-SIZE EXTRUSION PRESS WITH OIL-DRIVEN DOUBLE ACTION

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jun; YANG He; XIE Donggang; HAN Bingtao

    2007-01-01

    A modern design method, in which traditional design formulas are conjoined with numerical simulation and optimization, is successfully used to design the out-size extrusion frame precisely so that the press cost can be saved. A new technology used for decompressing by a multi-steps dynamical mode is put forward, which makes it possible to decompress the large flow-volume high-pressure oil in the main cylinders. In addition, a method for realizing the fixed mandrel process by hydraulic support is proposed and its control equation is established. Pre-tightening frame tests are carried out by over-operating pressure on 100 MN aluminium extrusion press with oil-driven double action, which is developed based on the above key techniques and is the largest press so far in the world, and the results show that the frame structure designed is reasonable and reliable, and the modem design method used is an useful tool for designing large and out-size heavy plastic forming machinery. The results of decompressing curve in main cylinder and noise inspection indicate that multi-steps dynamical mode for decompressing the large flow-volume high pressure oil is valid and reliable. Meanwhile, the fixed mandrel process is well realized based on the control equation. These key techniques have been used in the development of 125 MN aluminium extrusion press with oil-driven double action.

  20. The effect of grain size on dynamic tensile extrusion behaviour

    Directory of Open Access Journals (Sweden)

    Park Leeju

    2015-01-01

    Full Text Available Dynamic tensile extrusion (DTE tests were conducted on coarse grained and ultrafine grained (UFG OFHC Cu, Interstitial free (IF Steel, and pure Ta. Equal channel angular pressing (ECAP of 16passes with Bc for Cu, IF Steel and 4 passes for Ta was employed to fabricated UFG materials. DTE tests were carried out by launching the sphere samples (Dia. 7.62 mm to the conical extrusion die at a speed of ∼500 m/sec. The fragmentation behavior of the soft-recovered fragments were examined and compared with each other. The DTE fragmentation behavior of CG and UFG was numerically simulated by the LS-DYNA FEM code.