WorldWideScience

Sample records for injection molding process

  1. Process and part filling control in micro injection molding

    DEFF Research Database (Denmark)

    Tosello, Guido; Hansen, Hans NØrgaard

    2008-01-01

    The influence of process parameters on ?-injection molding (?IM) and on ?-injection molded parts has been investigated using Design of Experiments. A mold with a sensor applied at injection location was used to monitor actual injection pressure and to determine the cavity filling time. Flow markers position was measured on the polymer ?-parts to evaluate filling behavior of the polymer melt flowing through ?-features. Experimental results obtained under different processing conditions were evaluated to correlate the process parameter levels influence on the selected responses. Results showed that the injection speed in one of the most influencing process parameters on the ?IM process and on the ?-parts filling.

  2. Development of the computer-aided process planning (CAPP) system for polymer injection molds manufacturing

    OpenAIRE

    J. Tepi?; V. Todi?; Luki?, D.; Miloševi?, M.; S. Borojevi?

    2011-01-01

    Beginning of production and selling of polymer products largely depends on mold manufacturing. The costs of mold manufacturing have significant share in the final price of a product. The best way to improve and rationalize polymer injection molds production process is by doing mold design automation and manufacturing process planning automation. This paper reviews development of a dedicated process planning system for manufacturing of the mold for injection molding, which integrates computer-...

  3. Micro injection molding: characterisation of cavity filling process

    OpenAIRE

    Zhang, Nan; Chu, J. S.; Gilchrist, M.D.

    2011-01-01

    Based on reciprocating micro injection molding machine, this paper characterizes the influence of machine process parameters and its transition response from velocity control to pressure control (V-P transition) on the micro cavity filling process. The method of Design of Experiment was employed to systematically and statistically investigate the effect of machine parameters on actual cavity filling process, which was described by the defined process characteristic val...

  4. RECENT METHODS FOR OPTIMIZATION OF PLASTIC INJECTION MOLDING PROCESS –A RETROSPECTIVE AND LITERATURE REVIEW

    OpenAIRE

    Bharti, P.K.; M. I. Khan,; Harbinder Singh

    2010-01-01

    Injection molding has been a challenging process for many manufacturers and researchers to produce products meeting requirements at the lowest cost. Faced with global competition in injection molding industry, using the trialand- error approach to determine the process parameters for injection molding is no longer good enough. Factors that affect the quality of a molded part can be classified into four categories: part design, mold design, machineperformance and processing conditions. The par...

  5. The Elastic Mold Deformation During the Filling and Packing Stage of the Injection Molding Process

    Directory of Open Access Journals (Sweden)

    Stefan Kleindel

    2014-03-01

    Full Text Available The accurate numerical prediction of the mold filling process of long and thin walled parts is dependent on numerous factors. This paper investigates the effect of various influencing variables on the filling pattern by means of simulation and experimental validation. It was found that mold temperature, process settings and venting conditions have little effect on the predicted filling pattern. However, in the actual case study, the filling behavior observed during the experiments was significantly different compared to the numerical prediction. A structural finite element analysis of the moving mold half showed an unacceptable large deformation of the mold plates under injection pressure. A very good correlation between simulation and experiment was attained after improving the stiffness of the mold. Therefore it can be concluded, that the elasticity of the mold may have a significant influence on the filling pattern when long and thin walled products are considered. Furthermore, it was shown, that even an apparently stiff mold can exhibit a distinct deformation during filling and packing stage.

  6. The effect of mold surface topography on plastic parat in-process shrinkage in injection molding

    DEFF Research Database (Denmark)

    ArlØ, Uffe Rolf; Hansen, Hans NØrgaard

    2003-01-01

    An experimental study of the effect of mold surface roughness on in-process in-flow linear part shrinkage in injection molding has been carried out. The investigation is based on an experimental two-cavity tool, where the cavities have different surface topographies, but are otherwise identical. The study has been carried out for typical commercial polystyrene and polypropylene grades. The relationship between mold surface topography and linear shrinkage has been investigated with an experimental two-cavity mold producing simple rectangular parts with the nominal dimensions 1 x 25 x 50 mm (see figure 1). The cavities have different surface topographies on one side, but are otherwise identical (see discussion of other contribution factors).

  7. Effects of process parameters in plastic, metal, and ceramic injection molding processes

    Science.gov (United States)

    Lee, Shi W.; Ahn, Seokyoung; Whang, Chul Jin; Park, Seong Jin; Atre, Sundar V.; Kim, Jookwon; German, Randall M.

    2011-09-01

    Plastic injection molding has been widely used in the past and is a dominant forming approach today. As the customer demands require materials with better engineering properties that were not feasible with polymers, powder injection molding with metal and ceramic powders has received considerable attention in recent decades. To better understand the differences in the plastic injection molding, metal injection molding, and ceramic injection molding, the effects of the core process parameters on the process performances has been studied using the state-of-the-art computer-aided engineering (CAE) design tool, PIMSolver® The design of experiments has been conducted using the Taguchi method to obtain the relative contributions of various process parameters onto the successful operations.

  8. Development of the computer-aided process planning (CAPP system for polymer injection molds manufacturing

    Directory of Open Access Journals (Sweden)

    J. Tepi?

    2011-10-01

    Full Text Available Beginning of production and selling of polymer products largely depends on mold manufacturing. The costs of mold manufacturing have significant share in the final price of a product. The best way to improve and rationalize polymer injection molds production process is by doing mold design automation and manufacturing process planning automation. This paper reviews development of a dedicated process planning system for manufacturing of the mold for injection molding, which integrates computer-aided design (CAD, computer-aided process planning (CAPP and computer-aided manufacturing (CAM technologies.

  9. Interrelationship between structure-property-processings in injection molded polymeric products

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyun Seog; Lee, Jae Wook [Sogang Univ., Seoul (Korea, Democratic People`s Republic of)

    1996-12-31

    Injection molding process is one of the major polymer processings for the polymeric products. This process is extensively used in the net-shaped production of plastic parts due to its capability to meet requirements of stringent dimensional accuracy and short cycle time. Specially the injection molding process consists of large, fast deformation and phase changes, which has much of processing parameters. Therefore it is important to optimize the injection molding conditions from the point of view of both productivity and product quality. In this study, we have investigated in the injection molding process for polymeric systems focusing on the understanding of structure-property-processing interrelationship and its utilization in the processing.

  10. Process control and product evaluation in micro molding using a screwless/two-plunger injection unit

    OpenAIRE

    Tosello, Guido; Hansen, Hans Nørgaard; Dormann, B.; Decker, C.; Guerrier, Patrick

    2010-01-01

    A newly developed ?-injection molding machine equipped with a screwless/two-plunger injection unit has been employed to mould miniaturized dog-bone shaped specimens on polyoxymethylene and its process capability and robustness have been analyzed. The influence of process parameters on ?-injection molding was investigated using the Design of Experiments technique. Injection pressure and piston stroke speed as well as part weight and dimensions were considered as qu...

  11. RECENT METHODS FOR OPTIMIZATION OF PLASTIC INJECTION MOLDING PROCESS –A RETROSPECTIVE AND LITERATURE REVIEW

    Directory of Open Access Journals (Sweden)

    P.K. Bharti

    2010-09-01

    Full Text Available Injection molding has been a challenging process for many manufacturers and researchers to produce products meeting requirements at the lowest cost. Faced with global competition in injection molding industry, using the trialand- error approach to determine the process parameters for injection molding is no longer good enough. Factors that affect the quality of a molded part can be classified into four categories: part design, mold design, machineperformance and processing conditions. The part and mold design are assumed as established and fixed. During production, quality characteristics may deviate due to drifting or shifting of processing conditions caused by machine wear, environmental change or operator fatigue. Determining optimal process parameter settings critically influences productivity, quality, and cost of production in the plastic injection molding (PIM industry. Previously, production engineers used either trial-and-error method or Taguchi’s parameter design method to determine optimal process parameter settings for PIM. However, these methods are unsuitable in present PIM because of the increasing complexity of product design and the requirement of multi-response quality characteristics. This article aims to review the recent research in designing and determining process parameters of injection molding. A number of research works based on various approaches have been performed in the domain of the parameter setting for injection molding. These approaches, including mathematical models, Taguchi method, Artificial Neural Networks (ANN,Fuzzy logic, Case Based Reasoning (CBR, Genetic Algorithms (GA, Finite Element Method(FEM,Non Linear Modeling, Response Surface Methodology, Linear Regression Analysis ,Grey Rational Analysis and Principle Component Analysis (PCA are described in this article. The strength and theweakness of individual approaches are discussed. It is then followed by conclusions and discussions of the potential research in determining process parameters for injection molding.

  12. Process control and product evaluation in micro molding using a screwless/two-plunger injection unit

    DEFF Research Database (Denmark)

    Tosello, Guido Technical University of Denmark,

    2010-01-01

    A newly developed ?-injection molding machine equipped with a screwless/two-plunger injection unit has been employed to mould miniaturized dog-bone shaped specimens on polyoxymethylene and its process capability and robustness have been analyzed. The influence of process parameters on ?-injection molding was investigated using the Design of Experiments technique. Injection pressure and piston stroke speed as well as part weight and dimensions were considered as quality factors over a wide range of process parameters. Experimental results obtained under different processing conditions were evaluated to correlate the process parameter levels influence on the selected responses, considering both average values and standard deviations.

  13. Ceramic injection molding

    International Nuclear Information System (INIS)

    Interest in making complex net-shape ceramic parts with good surface finishing and sharp tolerances without machining is a driving force for studying the injection molding technique. This method consists of softhening the ceramic material by means of adding some plastic and heating in order to inject the mixture under pressure into a relatively cold mold where solidification takes place. Essentially, it is the same process used in thermoplastic industry but, in the present case, the ceramic powder load ranges between 80 to 90 wt.%. This work shows results obtained from the fabrication of pieces of different ceramic materials (alumina, barium titanate ferrites, etc.) in a small scale, using equipments developed and constructed in the laboratory. (Author)

  14. Processing development of Si3N4 components by injection molding

    International Nuclear Information System (INIS)

    The development of complex-shaped ceramic components by powder injection molding has been considered as a promising technique by industry. In this study silicon nitride was used as a sample material for demonstrating the possibility of fabricating ceramic components by injection molding. An optimized process for the manufacture of components by injection molding will be presented. The effects of solid content, binder type, solvent and thermal debinding and effects of firing atmosphere will be discussed. Some promising physical and mechanical properties of sintered silicon nitride will be illustrated. Some prototypes will also be demonstrated. The developed technique could be extended for fabricating engine or functional components. (author)

  15. Experimental Investigation into Suitable Process Conditions for Plastic Injection Molding of Thin-Sheet Parts

    Directory of Open Access Journals (Sweden)

    Dyi-Cheng Chen

    2014-04-01

    Full Text Available This study performs an experimental investigation into the effects of the process parameters on the surface quality of injection molded thin-sheet thermoplastic components. The investigations focus specifically on the shape, number and position of the mold gates, the injection pressure and the injection rate. It can be seen that the gravity force entering point improved filling of the cavity for the same forming time and injection pressure. Moreover, it shows the same injection pressure and packing time, the taper-shape gate yields a better surface appearance than the sheet-shape gate. The experimental results provide a useful source of reference in suitable the process conditions for the injection molding of thin-sheet plastic components.

  16. Injection Molding of High Aspect Ratio Nanostructures

    DEFF Research Database (Denmark)

    Matschuk, Maria; Larsen, Niels Bent

    We present a process for injection molding of 40 nm wide and >100 nm high pillars (pitch: 200 nm). We explored the effects of mold coatings and injection molding conditions on the replication quality of nanostructures in cyclic olefin copolymer. We found that optimization of molding parameters using native nickel molds only lead to slight improvements in replication quality. In contrast, a fluorocarbon based antistiction coating (FDTS) was found to improve the replication quality significantly.

  17. Study of process parameters on optical qualities for injection-molded plastic lenses.

    Science.gov (United States)

    Lai, Huai En; Wang, Pei Jen

    2008-04-20

    Numerical simulations for mold-flow analysis and experimental measurements of injection-molded plastic lenses have been conducted for investigation of optical qualities, residual birefringence, and form accuracy resulting from various pertinent process conditions. First, residual birefringence distributions on the lens have been predicted and verified experimentally. Furthermore, full-scale factorial design of experiments was conducted to comprehend the influences of qualities, such as shear stresses, form accuracy, and volumetric deviation, on the measured primary or Seidel aberrations. In conclusion, residual birefringence induced by stresses represented by photoelasticity measurements agrees well with the numerical predictions and the experimental results indicate that the residual birefringence is mainly generated during the mold-filling stage. In addition, spherical aberration of the injection-molded plastic lenses is more sensitive to the pertinent qualities as compared to coma and astigmatism. PMID:18425174

  18. Development of Metal Plate with Internal Structure Utilizing the Metal Injection Molding (MIM Process

    Directory of Open Access Journals (Sweden)

    Kwangho Shin

    2013-12-01

    Full Text Available In this study, we focus on making a double-sided metal plate with an internal structure, such as honeycomb. The stainless steel powder was used in the metal injection molding (MIM process. The preliminary studies were carried out for the measurement of the viscosity of the stainless steel feedstock and for the prediction of the filling behavior through Computer Aided Engineering (CAE simulation. PE (high density polyethylene (HDPE and low density polyethylene (LDPE and polypropylene (PP resins were used to make the sacrificed insert with a honeycomb structure using a plastic injection molding process. Additionally, these sacrificed insert parts were inserted in the metal injection mold, and the metal injection molding process was carried out to build a green part with rectangular shape. Subsequently, debinding and sintering processes were adopted to remove the sacrificed polymer insert. The insert had a suitable rigidity that was able to endure the filling pressure. The core shift analysis was conducted to predict the deformation of the insert part. The 17-4PH feedstock with a low melting temperature was applied. The glass transition temperature of the sacrificed polymer insert would be of a high grade, and this insert should be maintained during the MIM process. Through these processes, a square metal plate with a honeycomb structure was made.

  19. Injection Molding of Plastics from Agricultural Materials

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharya, M.; Ruan, R.

    2001-02-22

    The objective of this research was to conduct a systematic study to relate injection molding parameters to properties of blends of starch and synthetic polymer. From this study, we wished to develop a thorough understanding of the injection molding process and gain significant insight into designing molds and aiding in developing products cheaply and efficiently.

  20. On Optimization of Injection Molding Cooling

    OpenAIRE

    Ra?nnar, Lars-erik

    2008-01-01

    This thesis is devoted to analysis and optimization of the injection molding process with a focus on the mold. In the analysis, both process parameters and the design of the mold are taken in consideration. A procedure has been developed, i.e. a method and a program code, which enables optimization of different quantities, not only restricted to injection molding simulation, by altering different variables. There are many ways to interpret the word “optimization”. In this work, “optimiz...

  1. Injection molding of Y-TZP powders prepared by colloidal processing

    International Nuclear Information System (INIS)

    TZP powders containing 3mol% Y2O3 were prepared from ZrOCl2 solution via an aqueous colloidal suspension of ZrO2. Processing variables were optimized to obtain powders suitable for injection molding. Wettability of powders with binders, fluidity of melting compound, removal of binder from green body, and properties of sintered body were investigated

  2. LCI Databases Sensitivity Analysis of the Environmental Impact of the Injection Molding Process

    Directory of Open Access Journals (Sweden)

    Ana Elduque

    2015-03-01

    Full Text Available During the last decades, society’s concern for the environment has increased. Specific tools like the Life Cycle Assessment (LCA, and software and databases to apply this method have been developed to calculate the environmental burden of products or processes. Calculating the environmental impact of plastic products is relevant as the global plastics production rose to 288 million tons in 2012. Among the different ways of processing plastics, the injection molding process is one of the most used in the industry worldwide. In this paper, a sensitivity analysis of the environmental impact of the injection molding process has been carried out. In order to perform this study, the EcoInvent database inventory for injection molding, and the data from which this database is created, have been studied. Generally, when an LCA of a product is carried out, databases such as EcoInvent, where materials, processes and transports are characterized providing average values, are used to quantify the environmental impact. This approach can be good enough in some cases but in order to assess a specific production process, like injection molding, a further level of detail is needed. This study shows how the final results of environmental impact differ for injection molding when using the PVC’s, PP’s or PET’s data. This aspect suggests the necessity of studying, in a more precise way, this process, to correctly evaluate its environmental burden. This also allows us to identify priority areas and thereby actions to develop a more sustainable way of manufacturing plastics.

  3. Injection molding ceramics to high green densities

    Science.gov (United States)

    Mangels, J. A.; Williams, R. M.

    1983-01-01

    The injection molding behavior of a concentrated suspension of Si powder in wax was studied. It was found that the injection molding behavior was a function of the processing techniques used to generate the powder. Dry ball-milled powders had the best molding behavior, while air classified and impact-milled powders demonstrated poorer injection moldability. The relative viscosity of these molding batches was studied as a function of powder properties: distribution shape, surface area, packing density, and particle morphology. The experimental behavior, in all cases, followed existing theories. The relative viscosity of an injection molding composition composed of dry ball-milled powders could be expressed using Farris' relation.

  4. Bonding strength between two injection molded Polymers

    OpenAIRE

    Stanic, Jasna Nilsson; Ploskic, Aida

    2008-01-01

    This Master Thesis project deals with the relevant factors that may effect replication and the bonding strength between two polymers injection molded by transfer injection molding. Great importance was attached to the processing parameters during injection molding of micro channels, and their influence on the replication and bonding strength quality. The finale component consists of two different polymers, several material combination was injection modled, Ultem 1000, Lexan 500...

  5. Validation of New Process Models for Large Injection-Molded Long-Fiber Thermoplastic Composite Structures

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Ba Nghiep; Jin, Xiaoshi; Wang, Jin; Kunc, Vlastimil; Tucker III, Charles L.

    2012-02-23

    This report describes the work conducted under the CRADA Nr. PNNL/304 between Battelle PNNL and Autodesk whose objective is to validate the new process models developed under the previous CRADA for large injection-molded LFT composite structures. To this end, the ARD-RSC and fiber length attrition models implemented in the 2013 research version of Moldflow was used to simulate the injection molding of 600-mm x 600-mm x 3-mm plaques from 40% glass/polypropylene (Dow Chemical DLGF9411.00) and 40% glass/polyamide 6,6 (DuPont Zytel 75LG40HSL BK031) materials. The injection molding was performed by Injection Technologies, Inc. at Windsor, Ontario (under a subcontract by Oak Ridge National Laboratory, ORNL) using the mold offered by the Automotive Composite Consortium (ACC). Two fill speeds under the same back pressure were used to produce plaques under slow-fill and fast-fill conditions. Also, two gating options were used to achieve the following desired flow patterns: flows in edge-gated plaques and in center-gated plaques. After molding, ORNL performed measurements of fiber orientation and length distributions for process model validations. The structure of this report is as follows. After the Introduction (Section 1), Section 2 provides a summary of the ARD-RSC and fiber length attrition models. A summary of model implementations in the latest research version of Moldflow is given in Section 3. Section 4 provides the key processing conditions and parameters for molding of the ACC plaques. The validations of the ARD-RSC and fiber length attrition models are presented and discussed in Section 5. The conclusions will be drawn in Section 6.

  6. The effects of process parameters on injection-molded PZT ceramics part fabrication- compounding process rheology.

    Energy Technology Data Exchange (ETDEWEB)

    Halbleib, Laura L.; Yang, Pin; Mondy, Lisa Ann; Burns, George Robert

    2005-05-01

    Solid solutions of lead-based perovskites are the backbone materials of the piezoelectric components for transducer, actuator, and resonator applications. These components, typically small in size, are fabricated from large sintered ceramic slugs using grinding and lapping processes. These operations increase manufacturing costs and produce a large hazardous waste stream, especially when component size decreases. To reduce costs and hazardous wastes associated with the production of these components, an injection molding technique is being investigated to replace the machining processes. The first step in the new technique is to compound an organic carrier with a ceramic powder. The organic carrier is a thermoplastic based system composed of a main carrier, a binder, and a surfactant. Understanding the rheology of the compounded material is necessary to minimize the creation of defects such as voids or cavities during the injection-molding process. An experiment was performed to model the effects of changes in the composition and processing of the material on the rheological behavior. Factors studied included: the surfactant of the organic carrier system, the solid loading of the compounded material, and compounding time. The effects of these factors on the viscosity of the material were investigated.

  7. The reflectivity, wettability and scratch durability of microsurface features molded in the injection molding process using a dynamic tool tempering system

    International Nuclear Information System (INIS)

    In this paper the replication qualities of periodically and randomly arranged micro-features molded in the injection molding process and their effects on surface properties are studied. The features are molded in PC, PMMA and PP at different mold wall temperatures in order to point out the necessity and profitability of a variotherm mold wall temperature control system. A one-dimensional heat conduction model is proposed to predict the cycle times of the variotherm injection molding processes. With regard to these processes, the molding results are compared to the molded surface feature heights using an atomic force microscope. In addition, the effects of the molded surface features on macroscopic surfaces are characterized in terms of light reflection using a spectrometer and in terms of water wettability by measuring the static contact angle. Furthermore, due to the sensitivity of the surface features on the molded parts, their durability is compared in a scratch test with a diamond tip. This leads to successful implementation in applications in which the optical appearance, in terms of gloss and reflection, and the water repellence, in terms of drag flow and adhesion, are of importance.

  8. Two component tungsten powder injection molding – An effective mass production process

    International Nuclear Information System (INIS)

    Tungsten and tungsten-alloys are presently considered to be the most promising materials for plasma facing components for future fusion power plants. The Karlsruhe Institute of Technology (KIT) divertor design concept for the future DEMO power plant is based on modular He-cooled finger units and the development of suitable mass production methods for such parts was needed. A time and cost effective near-net-shape forming process with the advantage of shape complexity, material utilization and high final density is Powder Injection Molding (PIM). This process allows also the joining of two different materials e.g. tungsten with a doped tungsten alloy, without brazing. The complete technological process of 2-Component powder injection molding for tungsten materials and its application on producing real DEMO divertor parts, characterization results of the finished parts e.g. microstructure, hardness, density and joining zone quality are discussed in this contribution

  9. Two component tungsten powder injection molding – An effective mass production process

    Energy Technology Data Exchange (ETDEWEB)

    Antusch, Steffen, E-mail: steffen.antusch@kit.edu; Commin, Lorelei; Mueller, Marcus; Piotter, Volker; Weingaertner, Tobias

    2014-04-01

    Tungsten and tungsten-alloys are presently considered to be the most promising materials for plasma facing components for future fusion power plants. The Karlsruhe Institute of Technology (KIT) divertor design concept for the future DEMO power plant is based on modular He-cooled finger units and the development of suitable mass production methods for such parts was needed. A time and cost effective near-net-shape forming process with the advantage of shape complexity, material utilization and high final density is Powder Injection Molding (PIM). This process allows also the joining of two different materials e.g. tungsten with a doped tungsten alloy, without brazing. The complete technological process of 2-Component powder injection molding for tungsten materials and its application on producing real DEMO divertor parts, characterization results of the finished parts e.g. microstructure, hardness, density and joining zone quality are discussed in this contribution.

  10. Optimization of plastic injection molding process parameters for manufacturing a brake booster valve body

    International Nuclear Information System (INIS)

    Highlights: • PIM process parameters have been optimized for a brake booster valve body. • The Taguchi method and computer-aided engineering have been integrated and used. • Seven key parameters of PIM process have been considered. • A nearly 12% improvement have been found by using the optimal PIM process parameters. • The efficient improvement can improve the safety performance of a vehicle. - Abstract: The plastic injection molding (PIM) process parameters have been investigated for manufacturing a brake booster valve body. The optimal PIM process parameters is determined with the application of computer-aided engineering integrating with the Taguchi method to improve the compressive property of the valve body. The parameters considered for optimization are the following: number of gates, gate size, molding temperature, resin temperature, switch over by volume filled, switch over by injection pressure, and curing time. An orthogonal array of L18 is created for the statistical design of experiments based on the Taguchi method. Then, Mold-Flow analyses are performed by using the designed process parameters based on the L18 orthogonal array. The signal-to-noise (S/N) ratio and the analysis of variance (ANOVA) are used to find the optimal PIM process parameters and to figure out the impact of the viscosity of resin, curing percentage, and compressive strength on a brake booster valve body. When compared with the average compression strength out of the 18 design experiments, the compression strength of the valve body produced using the optimal PIM process parameters showed a nearly 12% improvement

  11. Development of Metal Plate with Internal Structure Utilizing the Metal Injection Molding (MIM) Process

    OpenAIRE

    Kwangho Shin; Youngmoo Heo; Hyungpil Park; Sungho Chang; Byungohk Rhee

    2013-01-01

    In this study, we focus on making a double-sided metal plate with an internal structure, such as honeycomb. The stainless steel powder was used in the metal injection molding (MIM) process. The preliminary studies were carried out for the measurement of the viscosity of the stainless steel feedstock and for the prediction of the filling behavior through Computer Aided Engineering (CAE) simulation. PE (high density polyethylene (HDPE) and low density polyethylene (LDPE)) and polypropylene (PP)...

  12. Multi-scale filling simulation of micro-injection molding process

    International Nuclear Information System (INIS)

    This work proposes a multi-scale simulation method that can simulate filling during the micro-injection molding process. The multiscale simulation is comprised of two steps. In the first step, the macro-scale flow is analyzed using the conventional method. In the second step, the micro-scale simulation is conducted taking the slip and surface tension into consideration to investigate the filling of microcavity. Moreover, a conservative level set method is employed to accurately track the flow front. First, numerical tests have been done for circular micro-channels. The results show that slip and surface tension play important roles in the micro-regime. Second, to verify the multi-scale method, filling of a thin plate with micro-channel patterns has been simulated. The results show that the proposed multi-scale method is promising for micro-injection molding simulations

  13. Optimizing Injection Molding Processing Parameters for Enhanced Mechanical Performance of Oil Palm Empty Fruit Bunch High Density Polyethylene Composites

    OpenAIRE

    M. S. Ramli; M.R. Abdul Latif; P.S.M. Megat-Yusoff

    2011-01-01

    This study reports on the influence of injection molding processing parameters on mechanical properties of oil palm Empty Fruit Bunch (EFB) filled High Density Poly Ethylene (HDPE). The biocomposite pellets were first prepared using an extruder with 20 wt% EFB content before being processed in an injection-molding machine for specimen fabrication. Two processing parameters were varied systematically and independently during the composite sample fabrication. The holding pressure was increased ...

  14. Modeling of the flow continuum and optimal design of control-oriented injection systems in liquid composite molding processes

    Science.gov (United States)

    Gokce, Ali

    Several methodologies are presented in this dissertation that aim to ensure successful filling of the mold cavity consistently, during the mold filling stage of Liquid Composite Molding (LCM) processes such as Resin Transfer Molding (RTM), Vacuum Assisted Resin Transfer Molding (VARTM) and Seemann Composites Resin Infusion Molding (SCRIMP). Key parameters that affect the resin flow in the mold cavity can be divided into two main groups as continuum-related parameters and injection-related parameters. Flow continuum, which consists of all the spaces resin can reach in the mold cavity, has two major components: the porous medium, which is made up of the fiber reinforcements, and the flow channels that are introduced into the flow continuum unintentionally and offer an easy flow path to the resin. The properties that characterize the porous medium and the unintentional flow channels are continuum-related parameters. The injection-related parameters include resin injection locations (gates), resin injection conditions and air drainage locations (vents). Modeling the flow continuum is crucial in predicting the resin flow in the mold cavity. In this study, permeability, the key property of the porous medium, is predicted using the Method of Cells, a proven method to predict macroscopic properties of heterogeneous materials. Unintentional flow channels, which are also called racetracking channels, are modeled using a probabilistic approach. Injection-related parameters are the key tools to influence the resin flow in the mold cavity. In this study, Branch and Bound Search is modified for single gate optimization. Due to its pertinence to injection system design, the parameters that govern gate effectiveness in steering the resin advance are studied. A combinatorial search algorithm is proposed for vent optimization. Vent optimization and gate optimization algorithms are integrated for simultaneous gate and vent optimization. Overall, these methodologies reduce the cycle time and reject ratio of LCM processes by providing an accurate and complete model of the flow continuum and optimal control-oriented injection design solutions, increasing the profitability and feasibility of the process.

  15. Investigation of process parameters for an Injection molding component for warpage and Shrinkage

    Directory of Open Access Journals (Sweden)

    Mohammad Aashiq M1 , Arun A.P1 ,Parthiban M

    2013-04-01

    Full Text Available The purpose of the research is to explore the influence of different mold temperatures on the warpage & shrinkage of the injection molded component’s. The simulation software MOLDEX 3D was used for this study, the simulations were done by varying different mold temperatures and their corresponding warpage & shrinkage were collected. It was found that the different mold wall temperature causes the asymmetrical polymer flow in the cross-section due to which the asymmetrical structure in the parts cross-section occurs and this was observed using the flow analysis software. So it is required to assurehomogeneous mold wall temperature across the entire cavityduring the production of injection molded parts. This researchfinally concludes that warpage and shrinkage decreases for increased values of mold temperature

  16. Development of a Plastic Injection Molding Processing Laboratory for Freshman Mechanical Engineering Technology Students

    Science.gov (United States)

    Meckley, Jonathan A.

    As is the case with many educational institutions that offer a MET degree, an introductory course in manufacturing materials and processes is required. At Penn State Erie, The Behrend College, we offer first-year Mechanical Engineering Technology (MET) students the introductory manufacturing materials and processes course. The course has both a lecture and laboratory segment. During the lab segment of the course, students have the opportunity to experience: material testing, plant tours, manufacturing processes, statistical process control, and inspection/measurement techniques. With 10 PIM machines, 3 extrusion lines, 2 thermoforming machines, and 2 blow molding machines, Penn State Behrend has the largest educational plastic injection molding (PIM) laboratory in the country. Collaborative efforts were initiated between the Mechanical Engineering Technology and Plastics Engineering Technology departments to enhance the learning experience. Resulting from the collaboration a decision was made to add a PIM laboratory to emphasize the lecture on plastic materials and processes. The PIM laboratory was developed to give the student an introduction to the PIM process, machine, mold and the effects of processing variables on the parts. Also, students would gain knowledge regarding the effects of part design on the process. Prior to the implementation of this lab, the students went on plant tours or were shown videos of the PIM process.

  17. Numerical approach of the injection molding process of fiber-reinforced composite with considering fiber orientation

    International Nuclear Information System (INIS)

    One of the most important challenges in the injection molding process of the short-glass fiber/thermoplastic composite parts is being able to predict the fiber orientation, since it controls the mechanical and the physical properties of the final parts. Folgar and Tucker included into the Jeffery equation a diffusive type of term, which introduces a phenomenological coefficient for modeling the randomizing effect of the mechanical interactions between the fibers, to predict the fiber orientation in concentrated suspensions. Their experiments indicated that this coefficient depends on the fiber volume fraction and aspect ratio. However, a definition of the fiber interaction coefficient, which is very necessary in the fiber orientation simulations, hasn't still been proven yet. Consequently, this study proposed a developed fiber interaction model that has been introduced a fiber dynamics simulation in order to obtain a global fiber interaction coefficient. This supposed that the coefficient is a sum function of the fiber concentration, aspect ratio, and angular velocity. The proposed model was incorporated into a computer aided engineering simulation package C-Mold. Short-glass fiber/polyamide-6 composites were produced in the injection molding with the fiber weight concentration of 30 wt.%, 50 wt.%, and 70 wt.%. The physical properties of these composites were examined, and their fiber orientation distributions were measured by micro-computed-tomography equipment ?-CT. The simulation results showed a good agreement with experiment results

  18. Numerical approach of the injection molding process of fiber-reinforced composite with considering fiber orientation

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen Thi, T. B., E-mail: thanhbinh.skku@gmail.com, E-mail: yokoyama@kit.ac.jp; Yokoyama, A., E-mail: thanhbinh.skku@gmail.com, E-mail: yokoyama@kit.ac.jp [Department of Advanced Fibro-Science, Kyoto Institute of Technology (Japan); Ota, K., E-mail: kei-ota@toyobo.jp, E-mail: katsuhiro-kodama@toyobo.jp, E-mail: katsuhisa-yamashita@toyobo.jp, E-mail: yumiko-isogai@toyobo.jp, E-mail: kenji-furuichi@toyobo.jp, E-mail: chisato-nonomura@toyobo.jp; Kodama, K., E-mail: kei-ota@toyobo.jp, E-mail: katsuhiro-kodama@toyobo.jp, E-mail: katsuhisa-yamashita@toyobo.jp, E-mail: yumiko-isogai@toyobo.jp, E-mail: kenji-furuichi@toyobo.jp, E-mail: chisato-nonomura@toyobo.jp; Yamashita, K., E-mail: kei-ota@toyobo.jp, E-mail: katsuhiro-kodama@toyobo.jp, E-mail: katsuhisa-yamashita@toyobo.jp, E-mail: yumiko-isogai@toyobo.jp, E-mail: kenji-furuichi@toyobo.jp, E-mail: chisato-nonomura@toyobo.jp; Isogai, Y., E-mail: kei-ota@toyobo.jp, E-mail: katsuhiro-kodama@toyobo.jp, E-mail: katsuhisa-yamashita@toyobo.jp, E-mail: yumiko-isogai@toyobo.jp, E-mail: kenji-furuichi@toyobo.jp, E-mail: chisato-nonomura@toyobo.jp; Furuichi, K., E-mail: kei-ota@toyobo.jp, E-mail: katsuhiro-kodama@toyobo.jp, E-mail: katsuhisa-yamashita@toyobo.jp, E-mail: yumiko-isogai@toyobo.jp, E-mail: kenji-furuichi@toyobo.jp, E-mail: chisato-nonomura@toyobo.jp; Nonomura, C., E-mail: kei-ota@toyobo.jp, E-mail: katsuhiro-kodama@toyobo.jp, E-mail: katsuhisa-yamashita@toyobo.jp, E-mail: yumiko-isogai@toyobo.jp, E-mail: kenji-furuichi@toyobo.jp, E-mail: chisato-nonomura@toyobo.jp [Toyobo Co., LTD. Research Center (Japan)

    2014-05-15

    One of the most important challenges in the injection molding process of the short-glass fiber/thermoplastic composite parts is being able to predict the fiber orientation, since it controls the mechanical and the physical properties of the final parts. Folgar and Tucker included into the Jeffery equation a diffusive type of term, which introduces a phenomenological coefficient for modeling the randomizing effect of the mechanical interactions between the fibers, to predict the fiber orientation in concentrated suspensions. Their experiments indicated that this coefficient depends on the fiber volume fraction and aspect ratio. However, a definition of the fiber interaction coefficient, which is very necessary in the fiber orientation simulations, hasn't still been proven yet. Consequently, this study proposed a developed fiber interaction model that has been introduced a fiber dynamics simulation in order to obtain a global fiber interaction coefficient. This supposed that the coefficient is a sum function of the fiber concentration, aspect ratio, and angular velocity. The proposed model was incorporated into a computer aided engineering simulation package C-Mold. Short-glass fiber/polyamide-6 composites were produced in the injection molding with the fiber weight concentration of 30 wt.%, 50 wt.%, and 70 wt.%. The physical properties of these composites were examined, and their fiber orientation distributions were measured by micro-computed-tomography equipment ?-CT. The simulation results showed a good agreement with experiment results.

  19. Mechanical Properties of Sintered Martensitic Stainless Steel Fabricated by Metal Injection Molding Process

    Science.gov (United States)

    Nakayama, Hideki; Kyogoku, Hideki

    The effects of sintering and heat treatment conditions on the mechanical properties of martensitic stainless steel fabricated by metal injection molding (MIM) process were investigated. The specimens were made by injecting the mixture of gas-atomized powders of 5 µm and 10 µm in mean particle diameter and a polymer binder into a metallic mold. The injection molded compacts were debound in air at various temperatures between 533 K and 593 K for 7.2 ks. They were sintered in vacuum at various temperatures between 1273 K and 1623 K for 7.2 ks. And the specimens were tempered at various temperatures between 373 K and 973 K after vacuum hardening. The density of the as-sintered compact of 5 µm powder was higher than that of the as-sintered compact of 10 µm powder. In case of the as-sintered compact of 5 µm powder, the tensile strength depended on the change in density, and the tensile strength of the compact sintered at 1373 K was 1600 MPa. On the other hand, in the case of the as-sintered compact of 10 µm powder, the tensile strength was rather lower than that of the as-sintered compact of 5 µm powder because of coarsening of the grain size. The tensile strength and elongation of the heat-treated compact of 5 µm powder were 1800 MPa and 12 %, respectively. The tensile strength and elongation of the heat-treated compact of 10 µm powder were 1680 MPa and 10 %, respectively. Thus, the mechanical properties of the compacts were approximately equal to those of the wrought material.

  20. Study of soft magnetic iron cobalt based alloys processed by powder injection molding

    International Nuclear Information System (INIS)

    As a near net shape process, powder injection molding (PIM) opens new possibilities to process Fe-Co alloys for magnetic applications. Due to the fact that PIM does not involve plastic deformation of the material during processing, we envisioned the possibility of eliminating vanadium (V), which is generally added to Fe-Co alloys to improve the ductility in order to enable its further shaping by conventional processes such as forging and cold rolling. In our investigation we have found out two main futures related to the elimination of V, which lead to a cost-benefit gain in manufacturing small magnetic components where high-saturation induction is needed at low frequencies. Firstly, the elimination of V enables the achievement of much better magnetic properties when alloys are processed by PIM. Secondly, a lower sintering temperature can be used when the alloy is processed starting with elemental Fe and Co powders without the addition of V

  1. Optimizing Injection Molding Processing Parameters for Enhanced Mechanical Performance of Oil Palm Empty Fruit Bunch High Density Polyethylene Composites

    Directory of Open Access Journals (Sweden)

    M.S. Ramli

    2011-01-01

    Full Text Available This study reports on the influence of injection molding processing parameters on mechanical properties of oil palm Empty Fruit Bunch (EFB filled High Density Poly Ethylene (HDPE. The biocomposite pellets were first prepared using an extruder with 20 wt% EFB content before being processed in an injection-molding machine for specimen fabrication. Two processing parameters were varied systematically and independently during the composite sample fabrication. The holding pressure was increased from 60 to 90 bars while the injection temperature was varied from 150 to 210°C. The highest tensile strength of the composites was achieved at 70 bar holding pressure and 150°C injection temperature. However, the highest fracture strength was achieved at 80 bars whilst maintaining the injection temperature at 150°C. Flexural strength was shown to be unaffected by the varying pressure. The optimal processing parameters for highest mechanical performance were found to be at holding pressure of 80 bars and injection tempera

  2. Ceramic injection molding material analysis, modeling and injection molding simulation

    Science.gov (United States)

    Drummer, D.; Messingschlager, S.

    2014-05-01

    In comparison to unfilled polymers, a ceramic feedstocks has a very high viscosity, a very high heat conductivity and a different pvT-behavior. So far standard simulation tools for plastic injection molding are capable of simulating unfilled or fiber filled compounds with their typical low viscosity and heat conductivity etc. but not for very high ceramic powder filled polymers. This article shows an approach of preparing and adding ceramic feedstocks to standard injection molding tools. Two different feedstocks are used.

  3. Surface microstructure replication in injection molding

    DEFF Research Database (Denmark)

    Theilade, Uffe ArlØ; Hansen, Hans NØrgaard

    2006-01-01

    In recent years, polymer components with surface microstructures have been in rising demand for applications such as lab-on-a-chip and optical components. Injection molding has proven to be a feasible and efficient way to manufacture such components. In injection molding, the mold surface topography is transcribed onto the plastic part through complex mechanisms. This replication, however, is not perfect, and the replication quality depends on the plastic material properties, the topography itself, and the process conditions. This paper describes and discusses an investigation of injection molding of surface microstructures. The fundamental problem of surface microstructure replication has been studied. The research is based on specific microstructures as found in lab-on-a-chip products and on rough surfaces generated from EDM (electro discharge machining) mold cavities. Emphasis is put on the ability to replicate surface microstructures under normal injection-molding conditions, i.e., with commodity materials within typical process windows. It was found that within typical process windows the replication quality depends significantly on several process parameters, and especially the mold temperature. For the specific microstructures, evidence suggests that step-height replication quality depends linearly on structure width in a certain range

  4. Functional nanostructures on injection molded plastic

    DEFF Research Database (Denmark)

    Johansson, Alicia Charlotte; SØgaard, Emil

    Nanotechnology can be used to make inexpensive plastic parts with functional surfaces. The plastic parts can be molded using a standard injection molding process. The nanostructures are directly transferred from the surface of the molding tool to the surface of the molded plastic part during the molding process. The main advantage with this method is that surface treatments and chemical additives are avoided, which minimizes health risks and simplifies recycling. Another advantage is that the unique technology enables nanostructuring of free form molded parts. The functional surfaces can have many different properties including anti-reflective, self-cleaning, anti-stiction or color effects. In this work we focus on the superhydrophobic and self-cleaning properties.

  5. Experimental validation of viscous and viscoelastic simulations of micro injection molding process

    DEFF Research Database (Denmark)

    Gava, Alberto; Tosello, Guido

    2009-01-01

    The effects of two different rheological models used in the simulation of the micro injection molding (µIM) process are investigated. The Cross-WLF viscous model and the Giesekus viscoelastic model are selected and their performance evaluated using 3D models implemented on two different commercially available software packages. Simulation results are then compared with the experimental µIM process. Validation parameters for the comparison are the flow front position during filling of the micro cavity. They are respectively obtained by applying the short-shots method and the flow-markers method. The µIM part is a polystyrene tensile bar test weighting 20mg and with three µ-features 300µm wide.

  6. Injection molded superhydrophobic surfaces based on microlithography and black silicon processing

    DEFF Research Database (Denmark)

    SØgaard, Emil; Andersen, Nis Korsgaard

    2012-01-01

    This work is concerned with the design, development, and testing of nanostructured polymer surfaces with self-cleaning properties that can be manufactured by injection molding. In particular, the superimposed micro- and nanometer length scales of the so-called Lotus effect were investigated in detail with an engineering perspective on choice of materials and manufacturability by injection molding. Microscope slides with superhydrophobic properties were succesfully fabricated. Preliminary results indicate a contact angle increase from 95° for the unstructured polymer to a maximum 150°. The lowest drop roll off angles observed were in the range 1° to 5°.

  7. All polymer, injection molded nanoslits, fabricated through two-level UV-LIGA processes

    DEFF Research Database (Denmark)

    Østergaard, Peter Friis; Matteucci, Marco

    2012-01-01

    Micro- and nanofluidic systems fabricated in silicon and glass substrates are expensive and have long production cycles. To minimize the time used by researchers to fabricate their systems, rather than using them, medium to high volume throughput of specific chips, containing fluidic channels in the micro- and nanoregime is required. To obtain this, injection molding is included in the research process for making several chips (100-1000) with the same layout. The time it takes for the individual chip to be fabricated in this way is much shorter than with conventional cleanroom methods, and the price is equally lower. Optimization of the final chip is explored, by looking at which aspects ratios are possible to obtain in polymer chips. Finally, signal to noise ratio of the chips used for fluorescent experiments is investigated, by an expected reduction of the excitation of fluorescent states in the polymer with the use of chips in different colors.

  8. Injection molded self-cleaning surfaces

    DEFF Research Database (Denmark)

    SØgaard, Emil

    2014-01-01

    This PhD thesis concerns the development of superhydrophobic surfaces fabricated by injection molding. Today, injection molding is the prevalent production method for consumer plastic products. However, concerns regarding the environmental impact of a plastic production are increasing, especially because the use of potentially toxic self-cleaning coatings is used worldwide in a larger and larger scale. In this context, the work in this PhD project could be seen as a scientific effort towards reducing toxic compounds in manufactured plastic parts by developing injecting molded surfaces that are superhydrophobic based on topography rather than chemical compounds. Therefore, a novel method for fabricating superhydrophobic polymer surfaces with excellent water-repellant properties is developed. The method is based on microstructure fabrication and superposed nanostructures on silicon wafers. The nano- and microstructured silicon is electroplated with nickel and the resulting nickel shim with inverse polarity is used in an injection molding process. A versatile injection molding process capable of producing different nano- and microstructures on areas larger than 10 cm2 is developed. Variotherm mold heating is used to ensure complete filling of the mold and a mold cavity-depacking process step is introduced. The depacking step increases polymer shrinkage allowing the nano- and microstructures to be successfully demolded. A systematic wetting study on injection molded polymer surfaces is performed on periodic hierarchical structures with nanograss and holes. Water wetting tests are carried out using a pressure cell to control the water pressure. Microscopic wetting behavior of the structures is studied by optical transmission microscopy. Interestingly, it is found that the surface chemistry of the polymer changes over time causing a decrease in hydrophobicity. It is concluded that the material properties of the polymer is critical for maintaining superhydrophobicity under water exposure. A range of different structures with and without the hierarchical nanograss, pillars, micro cavities (holes), spruce like micropillars and pyramid shaped structures are examined. By employing deep ultra violet (DUV) projection lithography for mold fabrication, polymer surface feature sizes in the nanometer range could be realized over large surface areas. The superhydrophobic surfaces were fabricated from the amorphous polymer TOPAS 8007-S04 (COC) and the semi crystalline polymer PP HD601CF. An overview of the different types of structures in relation to applications is given. In particular, spruce like micropillars seems interesting. Here, the contact angles increase from 102° for unstructured polymer surfaces, to 172° for structured surfaces with a drop roll-off angle of less than 2°. Thereby, it is shown that an extremely water repellant surface can be injection molded directly with clear perspectives for more environmental and healthier plastic consumer products.

  9. Characterization of Injection Molded Structures

    DEFF Research Database (Denmark)

    Sun, Ling; SØgaard, Emil

    Microscopy has been widely applied to understand surface structures of solid samples. According to the instrumental methodology, there are different microscopy methods: optical microscopy, electron microscopy, and scanning probe microscopy (SPM). These microscopy methods have individual advantages and limitations. Therefore, it would be difficult to characterize complex, especially hierarchical structures by using only one method. Here we present a combined optical microscopy, scanning electron microscopy (SEM), and scanning probe microscopy study on injection molded structures. These structures are used for different applications. We show how to correlate the structures of the polymer replicas with respect to their functionalities. Furthermore, we introduce how we coordinate with all partners in the “Nanoplast” project, and how we utilize the existing facilities of each method to understand structure-properties relationship of the injection molded polymer samples. These results are very important in optimizing injection molding parameters.

  10. CENTRAL CONVEYING & AUTO FEEDING SYSTEMS FOR AN INJECTION MOLDING SHOP

    OpenAIRE

    Sanjeev Kumar,; Ashu Yadav; Prof. Mohd. Parvez

    2011-01-01

    Nowadays injection molding is probably the most important method of Processing of consumer and industrial goods, and is performed everywhere in the world. The developing of injection molding becomes a competition from day to day. This Process now integrated with computer control make the production better in quality and Better quantity. The trends of producing a plastics product in injection molding industries are recently changing from traditional method to using the FEA analysis. For inject...

  11. The research of UV curing injection molding

    Science.gov (United States)

    Xie, Pengcheng; Chang, Le; Song, Le; Cai, Tianze; Ding, Yumei; Yang, Weimin

    2015-05-01

    The micro-injection molding technology and the UV (ultraviolet) curing technique are combined to bring about a new plastic forming method, UV curing injection molding. The mean weight of micro-product is an important process characteristic for UV curing injection molding as well as the surface quality of micro-features is another important process characteristic for this new plastic forming method. This research investigates three effects of processing factors on the mass-change rate of micro-product and the surface quality of micro-features. In every particular, the following two factors are considered: UV material system temperature and the packing pressure. The study revealed that as usual, the micro-products gain weight with the imported increasing UV material system temperature and the improved packing pressure. Meanwhile, the increasing packing pressure also improves the surface quality, yet, warming the UV system temperature up has no effect on the quality of the product.

  12. Orientation distribution and process modeling of thermotropic liquid crystalline copolyester (TLCP) injection-moldings

    Science.gov (United States)

    Bubeck, Robert; Fang, Jun; Burghardt, Wesley; Burgard, Susan; Fischer, Daniel

    2009-03-01

    The influence of melt processing conditions upon mechanical properties and degrees of compound molecular orientation have been thoroughly studied for a series of well-defined injection molded samples fabricated from VECTRA (TM) A950 and 4,4'-dihydroxy-a-methylstilbene TLCPs. Fracture and tensile data were correlated with processing conditions, orientation, and molecular weight. Mechanical properties for both TLCPs were found to follow a ``universal'' Anisotropy Factor (AF) associated with the bimodal orientation states in the plaques determined from 2-D WAXS. Surface orientations were globally surveyed using Attenuated Total Reflectance -- Fourier Transform Infrared (ATR-FTIR) spectroscopy and C K edge Near-Edge X-ray Absorption Fine Structure (NEXAFS). The results derived from the two spectroscopy techniques confirmed each other well. These results along with those from 2-D WAXS in transmission were compared with the results of process modeling using a commercial program, MOLDFLOW(TM). The agreement between model predictions and the measured orientation states was gratifyingly good.

  13. Dynamic of taking out molding parts at injection molding

    Directory of Open Access Journals (Sweden)

    E. Ragan

    2012-10-01

    Full Text Available Most plastic parts used in automobile production are manufactured by injection molding. Their quality depends also on taking out molding and on the manipulators for it. Task of this contribution is to theoretically describe a transport of molding at taking out after injection molding in relation on its regulation. The following quantities are derived at it: the transition characteristic of the taking out system, the blocking diagram of taking out molding regulation, the amplitude and phase characteristic and the transition characteristic of action quantity at taking out molding regulation.

  14. Automatic polishing process of plastic injection molds on a 5-axis milling center

    CERN Document Server

    Pessoles, Xavier; 10.1016/j.jmatprotec.2008.08.034

    2010-01-01

    The plastic injection mold manufacturing process includes polishing operations when surface roughness is critical or mirror effect is required to produce transparent parts. This polishing operation is mainly carried out manually by skilled workers of subcontractor companies. In this paper, we propose an automatic polishing technique on a 5-axis milling center in order to use the same means of production from machining to polishing and reduce the costs. We develop special algorithms to compute 5-axis cutter locations on free-form cavities in order to imitate the skills of the workers. These are based on both filling curves and trochoidal curves. The polishing force is ensured by the compliance of the passive tool itself and set-up by calibration between displacement and force based on a force sensor. The compliance of the tool helps to avoid kinematical error effects on the part during 5-axis tool movements. The effectiveness of the method in terms of the surface roughness quality and the simplicity of impleme...

  15. Injection molding of silicon nitride

    International Nuclear Information System (INIS)

    Silicon Nitride with 9-13 vol% liquid phase, recrystallised at 1100-1400 C after sintering at 1850 C (2,5-3,5h) in a powder bed have been produced in near net shape by injection molding. During molding with a binder of polystyrene, micro wax and dispersion agents a maximum powder content of 62 vol% and 59 vol% was obtained for the the two Silicon Nitride powders (UBE, SN-ESP and HCST, S respectively). Due to microcracking during binder removal (Tmax=500 C) in atmospheric air the bending strength was low even at relative theoretical densities of 95,5%. (orig.)

  16. Modeling and Analysis of Process Parameters for Evaluating Shrinkage Problems During Plastic Injection Molding of a DVD-ROM Cover

    Science.gov (United States)

    Öktem, H.

    2012-01-01

    Plastic injection molding plays a key role in the production of high-quality plastic parts. Shrinkage is one of the most significant problems of a plastic part in terms of quality in the plastic injection molding. This article focuses on the study of the modeling and analysis of the effects of process parameters on the shrinkage by evaluating the quality of the plastic part of a DVD-ROM cover made with Acrylonitrile Butadiene Styrene (ABS) polymer material. An effective regression model was developed to determine the mathematical relationship between the process parameters (mold temperature, melt temperature, injection pressure, injection time, and cooling time) and the volumetric shrinkage by utilizing the analysis data. Finite element (FE) analyses designed by Taguchi (L27) orthogonal arrays were run in the Moldflow simulation program. Analysis of variance (ANOVA) was then performed to check the adequacy of the regression model and to determine the effect of the process parameters on the shrinkage. Experiments were conducted to control the accuracy of the regression model with the FE analyses obtained from Moldflow. The results show that the regression model agrees very well with the FE analyses and the experiments. From this, it can be concluded that this study succeeded in modeling the shrinkage problem in our application.

  17. Nanostructuring steel for injection molding tools

    DEFF Research Database (Denmark)

    Al-Azawi, A.; Smistrup, Kristian

    2014-01-01

    The production of nanostructured plastic items by injection molding with ridges down to 400 nm in width, which is the smallest line width replicated from nanostructured steel shims, is presented. Here we detail a micro-fabrication method where electron beam lithography, nano-imprint lithography and ion beam etching are combined to nanostructure the planar surface of a steel wafer. Injection molded plastic parts with enhanced surface properties, like anti-reflective, superhydrophobic and structural colors can be achieved by micro-and nanostructuring the surface of the steel molds. We investigate the minimum line width that can be realized by our fabrication method and the influence of etching angle on the structure profile during the ion beam etching process. Trenches down to 400 nm in width have been successfully fabricated into a 316 type electro-polished steel wafer. Afterward a plastic replica has been produced by injection molding with good structure transfer fidelity. Thus we have demonstrated that by utilizing well-established fabrication techniques, nanostructured steel shims that are used in injection molding, a technique that allows low cost mass fabrication of plastic items, are produced.

  18. Injection-Molded Long-Fiber Thermoplastic Composites: From Process Modeling to Prediction of Mechanical Properties

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Ba Nghiep; Kunc, Vlastimil; Jin, Xiaoshi; Tucker III, Charles L.; Costa, Franco

    2013-12-18

    This article illustrates the predictive capabilities for long-fiber thermoplastic (LFT) composites that first simulate the injection molding of LFT structures by Autodesk® Simulation Moldflow® Insight (ASMI) to accurately predict fiber orientation and length distributions in these structures. After validating fiber orientation and length predictions against the experimental data, the predicted results are used by ASMI to compute distributions of elastic properties in the molded structures. In addition, local stress-strain responses and damage accumulation under tensile loading are predicted by an elastic-plastic damage model of EMTA-NLA, a nonlinear analysis tool implemented in ABAQUS® via user-subroutines using an incremental Eshelby-Mori-Tanaka approach. Predicted stress-strain responses up to failure and damage accumulations are compared to the experimental results to validate the model.

  19. Progress in Titanium Metal Powder Injection Molding

    Directory of Open Access Journals (Sweden)

    Randall M. German

    2013-08-01

    Full Text Available Metal powder injection molding is a shaping technology that has achieved solid scientific underpinnings. It is from this science base that recent progress has occurred in titanium powder injection molding. Much of the progress awaited development of the required particles with specific characteristics of particle size, particle shape, and purity. The production of titanium components by injection molding is stabilized by a good understanding of how each process variable impacts density and impurity level. As summarized here, recent research has isolated the four critical success factors in titanium metal powder injection molding (Ti-MIM that must be simultaneously satisfied—density, purity, alloying, and microstructure. The critical role of density and impurities, and the inability to remove impurities with sintering, compels attention to starting Ti-MIM with high quality alloy powders. This article addresses the four critical success factors to rationalize Ti-MIM processing conditions to the requirements for demanding applications in aerospace and medical fields. Based on extensive research, a baseline process is identified and reported here with attention to linking mechanical properties to the four critical success factors.

  20. Birefringence characterization of injection molded microplates

    Science.gov (United States)

    Adhikari, Achyut; Asundi, Anand

    2015-03-01

    Birefringence affects the quality of image analysis in injection molded micro-plates. Depending upon their manufacturing / production processes and the type of material, different plates exhibit varying amounts of birefringence. This birefringence is attributed to residual stress generated during the molding process. Polarimeter is the standard tool for birefringence distribution visualization and quantification. Broad chemical resistance and high mechanical stability of the plates are the desirable properties that can be characterized by birefringence measurement. Birefringence, expressed in nm/cm is light retardance (nm) after passing through a sample with certain thickness (cm). Low or uniform birefringence plates provide high-resolution demonstrating higher performance, hence suitable for bio-chemical analysis.

  1. Binder removal from injection molded zirconia ceramics

    International Nuclear Information System (INIS)

    Binder removal characteristics of injection molded zirconia (ZrO2) ceramics in the form of one-closed end tubes were studied by thermal analysis methods such as thermogravimetry and calorimetry. Only a thermal treatment for the binder removal from the molded parts with thin walls is not suitable because of deformation resulted from high weight loss rates. Using a two-stage wicking-thermal treatment process, it is possible to produce parts having no defects. The process reduced time necessary for eliminating organics of fine-grained zirconia from several days to hours. (orig.)

  2. Influence of different process settings conditions on the accuracy of micro injection molding simulations: an experimental validation

    DEFF Research Database (Denmark)

    Tosello, Guido; Gava, Alberto

    2009-01-01

    Currently available software packages exhibit poor results accuracy when performing micro injection molding (µIM) simulations. However, with an appropriate set-up of the processing conditions, the quality of results can be improved. The effects on the simulation results of different and alternative process conditions are investigated, namely the nominal injection speed, as well as the cavity filling time and the evolution of the cavity injection pressure as experimental data. In addition, the sensitivity of the results to the quality of the rheological data is analyzed. Simulated results are compared with experiments in terms of flow front position at part and micro features levels, as well as cavity injection filling time measurements.

  3. CD injection molding I: Navier-Stokes

    Science.gov (United States)

    Powell, Adam C., IV

    2004-08-26

    State simplifying assumptions which can be made regarding radial injection molding of liquid polycarbonate polymer into a CD mold, and simplify the cylindrical form of the Navier-Stokes equations accordingly.

  4. Validation of three-dimensional micro injection molding simulation accuracy

    DEFF Research Database (Denmark)

    Tosello, Guido Technical University of Denmark,

    2011-01-01

    Data analysis and simulations on micro-molding experiments have been conducted. Micro molding simulations have been executed taking into account actual processing conditions implementation in the software. Various aspects of the simulation set-up have been considered in order to improve the simulation accuracy (i.e. decrease deviations from experimental values): injection speed profile, cavity injection pressure, melt and mold temperatures, three-dimensional mesh parameters, and material rheological characterization. Quality factors investigated for the quantitative comparisons were: short shot length, injection pressure profile, molding mass and flow pattern. The importance of calibrated micro molding process monitoring for an accurate implementation strategy of the simulation and its validation has been demonstrated. In fact, inconsistencies and uncertainties in the experimental data must be minimized to avoid introducing uncertainties in the simulation calculations. Simulations of bulky sub-100 milligrams micro molded parts have been validated and a methodology for accurate micro molding simulations was established.

  5. A Fully Coupled Simulation and Optimization Scheme for the Design of 3D Powder Injection Molding Processes

    International Nuclear Information System (INIS)

    The paper is concerned with optimization and parametric identification of Powder Injection Molding process that consists first in injection of powder mixture with polymer binder and then to the sintering of the resulting powders parts by solid state diffusion. In the first part, one describes an original methodology to optimize the injection stage based on the combination of Design Of Experiments and an adaptive Response Surface Modeling. Then the second part of the paper describes the identification strategy that one proposes for the sintering stage, using the identification of sintering parameters from dilatometer curves followed by the optimization of the sintering process. The proposed approaches are applied to the optimization for manufacturing of a ceramic femoral implant. One demonstrates that the proposed approach give satisfactory results

  6. Injection molding of high aspect ratio sub-100 nm nanostructures

    DEFF Research Database (Denmark)

    Matschuk, Maria; Larsen, Niels B

    2013-01-01

    We have explored the use of mold coatings and optimized processing conditions to injection mold high aspect ratio nanostructures (height-to-width >1) in cyclic olefin copolymer (COC). Optimizing the molding parameters on uncoated nickel molds resulted in slight improvements in replication quality as described by height, width and uniformity of the nanoscopic features. Use of a mold temperature transiently above the polymer glass transition temperature (Tg) was the most important factor in increasing the replication fidelity. Surface coating of the nickel molds with a fluorocarbon-containing thin film (FDTS) greatly enhanced the quality of replicated features, in particular at transient mold temperatures above Tg. Injection molding using the latter mold temperature regime resulted in a bimodal distribution of pillar heights, corresponding to either full or very poor replication of the individual pillars. The poorly replicated structures on nickel molds with or without FDTS coatings all appeared fractured. We investigated the underlying mechanism in a macroscopic model system and found reduced wetting and strongly decreased adhesion of solidified COC droplets on nickel surfaces after coating with FDTS. Reduced adhesion forces are consistent with lowered friction that reduces the risk of fracturing the nanoscopic pillars during demolding. Optimized mold surface chemistry and associated injection molding conditions permitted the fabrication of square arrays of 40 nm wide and 107 nm high (aspect ratio >2.5) pillars on a 200 nm pitch.

  7. Hydrogen silsesquioxane mold coatings for improved replication of nanopatterns by injection molding

    DEFF Research Database (Denmark)

    Hobæk, Thor Christian; Matschuk, Maria

    2015-01-01

    We demonstrate the replication of nanosized pillars in polymer (cyclic olefin copolymer) by injection molding using nanostructured thermally cured hydrogen silsesquioxane (HSQ) ceramic coatings on stainless steel mold inserts with mold nanostructures produced by a simple embossing process. At isothermal mold conditions, the average pillar height increases by up to 100% and a more uniform height distribution is observed compared to a traditional metal mold insert. Thermal heat transfer simulations predict that the HSQ film retards the cooling of the polymer melt during the initial stages of replication, thus allowing more time to fill the nanoscale cavities compared to standard metal molds. A monolayer of a fluorinated silane (heptadecafluorotrichlorosilane) deposited on the mold surface reduces the mold/polymer interfacial energy to support demolding of the polymer replica. The mechanical stability of thermally cured HSQ makes it a promising material for nanopattern replication on an industrial scale without the need for slow and energy intensive variotherm processes.

  8. Hydrogen silsesquioxane mold coatings for improved replication of nanopatterns by injection molding

    Science.gov (United States)

    Hobæk, Thor Christian; Matschuk, Maria; Kafka, Jan; Pranov, Henrik J.; Larsen, Niels B.

    2015-03-01

    We demonstrate the replication of nanosized pillars in polymer (cyclic olefin copolymer) by injection molding using nanostructured thermally cured hydrogen silsesquioxane (HSQ) ceramic coatings on stainless steel mold inserts with mold nanostructures produced by a simple embossing process. At isothermal mold conditions, the average pillar height increases by up to 100% and a more uniform height distribution is observed compared to a traditional metal mold insert. Thermal heat transfer simulations predict that the HSQ film retards the cooling of the polymer melt during the initial stages of replication, thus allowing more time to fill the nanoscale cavities compared to standard metal molds. A monolayer of a fluorinated silane (heptadecafluorotrichlorosilane) deposited on the mold surface reduces the mold/polymer interfacial energy to support demolding of the polymer replica. The mechanical stability of thermally cured HSQ makes it a promising material for nanopattern replication on an industrial scale without the need for slow and energy intensive variotherm processes.

  9. Modelling and monitoring in injection molding

    DEFF Research Database (Denmark)

    Thyregod, Peter

    2001-01-01

    This thesis is concerned with the application of statistical methods in quality improvement of injection molded parts. The methods described are illustrated with data from the manufacturing of parts for a medical device. The emphasis has been on the variation between cavities in multi-cavity molds. >From analysis of quality measurements from a longer period of manufacturing, it was found that differences in cavities was that source of variation with greatest influence on the lenght of the molded parts. The other large contribution to the lenght varation was the different machine settings. Samples taken within the same machine set-point did not cause great variation compared to the two preceding sources of variation. A simple graphical approach is suggested for finding patterns in the cavity differences. Applying this method to data from a 16 cavity mold, a clear connection was found between a parts lenght and the producing cavitys position in the mold. In a designed expriment it was possible to isolate the machine parameters contributing to the variation beteeen cavities. Thus, with a proper choice of levels for the machine variables, it was possible to reduce the varation between cavities substantially. Also an alternative model for the shrinkage of parts from a multi-cavity mold is suggested. From applying the model to data from a shringage study, it seemed that the observed part differences were not only due to differences in cavity dimensions. A model for the in-control varation for a multi-cavity molding process was suggested. Based on this model, control charting proceures have been suggested for monitoring the quality of the molded parts. Moreover, a capability index for multi-cavity molds has been suggested. Furthermore an alternative method for in-line quality charting is suggested. The method is for continuous control by attributes, and it is an alternative to the batch oriented approach mostly used. The procedure is especially efficient for quality requirements of very low proportion non-conformities. For the proposed charts the ARL function is derived. It is shown that in the case where a non-conforning unit is only expected very rarely during sampling, a moving sum chart and a CUSUM chart are equivalent. Finally, the correlation structure of 21 process variables has been studied prior to monitoring the process. Is is illustrated how the process can be analysed with multivariate techniques. It was found that two principal components reflected changes in machine set-points. Thus, there seems to be great potential in monitoring the process variables using a multivariate approach.

  10. Multi-height structures in injection molded polymer

    DEFF Research Database (Denmark)

    Andersen, Nis Korsgaard; Taboryski, Rafael J.

    2015-01-01

    We present the fabrication process for injection molded multi-height surface structures for studies of wetting behavior. We adapt the design of super hydrophobic structures to the fabrication constrictions imposed by industrial injection molding. This is important since many super hydrophobic surfaces are challenging to realize by injection molding due to overhanging structures and very high aspect ratios. In the fabrication process, we introduce several unconventional steps for producing the desired shapes, using a completely random mask pattern, exploiting the diffusion limited growth rates of different geometries, and electroforming a nickel mold from a polymer foil. The injection-molded samples are characterized by contact angle hysteresis obtained by the tilting method. We find that the receding contact angle depends on the surface coverage of the random surface structure, while the advancing contact angle is practically independent of the structure. Moreover, we argue that the increase in contact angle hysteresis correlates with the concentration of pinning sites among the random surface structures.

  11. IMAGE ANALYSIS DEDICATED TO POLYMER INJECTION MOLDING

    Directory of Open Access Journals (Sweden)

    David Garcia

    2011-05-01

    Full Text Available This work follows the general framework of polymer injection moulding simulation whose objectives are the mastering of the injection moulding process. The models of numerical simulation make it possible to predict the propagation of the molten polymer during the filling phase from the positioning of one point of injection or more. The objective of this paper is to propose a particular way to optimize the geometry of mold cavity in accordance with physical laws. A direct correlation is pointed out between geometric parameters issued from skeleton transformation and Hausdorff's distance and results provided by implementation of a classical model based on the Hele-Shaw equations which are currently used in the main computer codes of polymer injection.

  12. Fabrication of long-focal-length plano-convex microlens array by combining the micro-milling and injection molding processes.

    Science.gov (United States)

    Chen, Lei; Kirchberg, Stefan; Jiang, Bing-Yan; Xie, Lei; Jia, Yun-Long; Sun, Lei-Lei

    2014-11-01

    A uniform plano-convex spherical microlens array with a long focal length was fabricated by combining the micromilling and injection molding processes in this work. This paper presents a quantitative study of the injection molding process parameters on the uniformity of the height of the microlenses. The variation of the injection process parameters, i.e., barrel temperature, mold temperature, injection speed, and packing pressure, was found to have a significant effect on the uniformity of the height of the microlenses, especially the barrel temperature. The filling-to-packing switchover point is also critical to the uniformity of the height of the microlenses. The optimal uniformity was achieved when the polymer melts completely filled the mold cavity, or even a little excessively filled the cavity, during the filling stage. In addition, due to the filling resistance, the practical filling-to-packing switchover point can vary with the change of the filling processing conditions and lead to a non-negligible effect on the uniformity of the height of the microlenses. Furthermore, the effect of injection speed on the uniformity of the height of the microlenses was analyzed in detail. The results indicated that the effect of injection speed on the uniformity of the height of the microlenses is mainly attributed to the two functions of injection speed: transferring the filling-to-packing switchover point and affecting the distribution of residual flow stress in the polymer melt. PMID:25402902

  13. Injection molding integration of theory and modeling methods

    CERN Document Server

    Zheng, Rong; Fan, Xi-Jun

    2011-01-01

    This practical volume covers the fundamental principles and numerical methods related to modeling the injection molding process. It addresses the cutting edge of our understanding of simulation technologies, without losing sight of useful classical approaches.

  14. CENTRAL CONVEYING & AUTO FEEDING SYSTEMS FOR AN INJECTION MOLDING SHOP

    Directory of Open Access Journals (Sweden)

    Sanjeev Kumar

    2011-08-01

    Full Text Available Nowadays injection molding is probably the most important method of Processing of consumer and industrial goods, and is performed everywhere in the world. The developing of injection molding becomes a competition from day to day. This Process now integrated with computer control make the production better in quality and Better quantity. The trends of producing a plastics product in injection molding industries are recently changing from traditional method to using the FEA analysis. For injection molding industries, time and cost is very important aspects to consider because these two aspectswill directly related to the profits at a company. The next issue toconsider, to get the best parameter for the injection molding process, plastics has been waste. Through the experiment, operator will use large amount of plastics material to get the possibly parameters to setup the machine.To produce the parts with better quality and quantity these molding defects are the major obstacles in achieving the targets with quality & quantity. Various defects like Short shot, colour streaks and low productivity rates are associated with the material mixing and feeding as molded plastics are often a blend of two or more materials. Colors (master batch and other additives are often mixed (blended with the raw plastic material prior to the molding process in molding plants. So it is very necessary to work out auto blending and auto feeding of plasticgranules to the machine hopper. This paper will cover the studyof automatic blending unit & central conveying system for plasticgranule feeding to machine & will help in optimizing the injection molding process.

  15. Injection molding simulation with variothermal mold temperature control of highly filled polyphenylene sulfide

    Science.gov (United States)

    Birkholz, A.; Tschiersky, M.; Wortberg, J.

    2015-05-01

    For the installation of a fuel cell stack to convert chemical energy into electricity it is common to apply bipolar plates to separate and distribute reaction gases and cooling agents. For reducing manufacturing costs of bipolar plates a fully automated injection molding process is examined. The high performance thermoplastic matrix material, polyphenylene sulfide (PPS), defies against the chemical setting and the operation temperature up to 200 °C. To adjust also high electrical and thermal conductivity, PPS is highly filled with various carbon fillers up to an amount of 65 percentage by volume. In the first step two different structural plates (one-sided) with three different gate heights and molds are designed according to the characteristics of a bipolar plate. To cope with the approach that this plate should be producible on standard injection molding machines with variothermal mold temperature control, injection molding simulation is used. Additionally, the simulation should allow to formulate a quality prediction model, which is transferrable to bipolar plates. Obviously, the basis for a precise simulation output is an accurate description of the material properties and behavior of the highly filled compound. This, the design of the structural plate and mold and the optimization via simulation is presented, as well. The influence of the injection molding process parameters, e.g. injection time, cycle times, packing pressure, mold temperature, and melt temperature on the form filling have been simulated to determine optimal process conditions. With the aid of the simulation and the variothermal mold temperature control it was possible to reduce the required melt temperature below the decomposition temperature of PPS. Thereby, hazardous decomposition products as hydrogen sulfide are obviated. Thus, the health of the processor, the longevity of the injection molding machine as well as the material and product properties can be protected.

  16. Powder Injection Molding of Ceramic Engine Components for Transportation

    Science.gov (United States)

    Lenz, Juergen; Enneti, Ravi K.; Onbattuvelli, Valmikanathan; Kate, Kunal; Martin, Renee; Atre, Sundar

    2012-03-01

    Silicon nitride has been the favored material for manufacturing high-efficiency engine components for transportation due to its high temperature stability, good wear resistance, excellent corrosion resistance, thermal shock resistance, and low density. The use of silicon nitride in engine components greatly depends on the ability to fabricate near net-shape components economically. The absence of a material database for design and simulation has further restricted the engineering community in developing parts from silicon nitride. In this paper, the design and manufacturability of silicon nitride engine rotors for unmanned aerial vehicles by the injection molding process are discussed. The feedstock material property data obtained from experiments were used to simulate the flow of the material during injection molding. The areas susceptible to the formation of defects during the injection molding process of the engine component were identified from the simulations. A test sample was successfully injection molded using the feedstock and sintered to 99% density without formation of significant observable defects.

  17. Polyethylene ionomer-based nano-composite foams prepared by a batch process and MuCell injection molding

    International Nuclear Information System (INIS)

    To understand the correlation between foamability and melt rheology of polyethylene-based ionomers having different degrees of the neutralization and corresponding nano-composites, we have conducted the foam processing via a batch process in an autoclave and microcellular foam injection molding (FIM) process using the MuCell technology. We have discussed the obtainable morphological properties in both foaming processes. All cellular structures were investigated by using field emission scanning electron microscopy. The competitive phenomenon between the cell nucleation and the cell growth including the coalescence of cell was discussed in light of the interfacial energy and the relaxation rate as revealed by the modified classical nucleation theory and rheological measurement, respectively. The FIM process led to the opposite behavior in the cell growth and coalescence of cell as compared with that of the batch process, where the ionic cross-linked structure has significant contribution to retard the cell growth and coalescence of cell. The mechanical properties of the structural foams obtained by FIM process were discussed.

  18. Two component micro injection molding for MID fabrication

    DEFF Research Database (Denmark)

    Islam, Mohammad Aminul; Hansen, Hans NØrgaard

    2009-01-01

    Molded Interconnect Devices (MIDs) are plastic substrates with electrical infrastructure. The fabrication of MIDs is usually based on injection molding and different process chains may be identified from this starting point. The use of MIDs has been driven primarily by the automotive sector, but recently the medical sector seems more and more interested. In particular the possibility of miniaturization of 3D components with electrical infrastructure is attractive. The paper describes possible manufacturing routes and challenges of miniaturized MIDs based on two component micro injection molding and subsequent metallization. The technology will be demonstrated by an industrial component.

  19. Injection molding of bushes made of tribological PEEK composites

    Directory of Open Access Journals (Sweden)

    2007-12-01

    Full Text Available Polyetheretherketone (PEEK composites have been extensively studied because of the excellent tribological behavior among plastics. However, laboratory specimens and tests are generally discussed, whereas application studies on industrial components are infrequent. In this paper, an injection molded bush made of tribological PEEK was analyzed to correlate wear behavior and molded material structure. Bushes were tested under unlubricated sliding conditions by means of a short wear test. Surface analysis, differential scanning calorimetry (DSC and optical microscopy were used to evaluate the distribution of the different composite fillers (polytetrafluoroethylene, PTFE, graphite particles and carbon microfibers and their effect on the final bush behavior. A significant lack of homogeneity was observed in the molded bush and black bands appeared on the shaft surface after testing due to the sliding. The bush geometry and the injection molding process should be optimized to allow the best tribological behavior of the molded material under working conditions.

  20. 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)

    SØgaard, Emil Technical University of Denmark,

    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 minimum density of approximately 105 protrusions/mm2, the protrusions being positioned in a non- periodic, irregular pattern, said protrusions being created by a process comprising alternating passivation and etching into the master structure. Secondly, there is made a transfer of the master structure into a metal insert (20), the metal insert having a corresponding nanometre-sized pattern (21) from said protrusions, and thirdly, adapting the metal insert into a tool part (30) for enabling nanometre- sized patterns being formed by the tool part. The invention provides an easier and faster way of manufacturing the master structure, e.g. a black silicon wafer. It is a further advantage of the present invention that it provides an advantageous way of making tools capable of producing self-cleaning surfaces without the need for chemical coating.

  1. A Recurrent Neural Network for Warpage Prediction in Injection Molding

    OpenAIRE

    Alvarado-iniesta, A.; Valles-rosales, D. J.; Garci?a-alcaraz, J. L.; Maldonado-macias, A.

    2012-01-01

    Injection molding is classified as one of the most flexible and economical manufacturing processes with high volumeof plastic molded parts. Causes of variations in the process are related to the vast number of factors acting during aregular production run, which directly impacts the quality of final products. A common quality trouble in finishedproducts is the presence of warpage. Thus, this study aimed to design a system based on recurrent neural networksto predict warpage defects in product...

  2. Injection molding of zirconia oxygen sensor thimbles by an aqueous process

    International Nuclear Information System (INIS)

    This patent describes a method of forming the ceramic element in a zirconia oxygen sensor. It comprises: forming a mixture. It comprises: ZrO2 and a stabilizer selected from the element group consisting of oxides of Y, Ce, Mg, Ca and mixtures thereof and having an average particle size less than or equal to 1 micron; an agaroid gel-forming material having a gel strength, measured at a temperature between 0 degrees C and about 22 degrees C on a gel consisting essentially of about 4 wt % of the gel-forming material and water, of at least about 100 g/cm2; a gel-forming material solvent; and molding the mixture at a temperature sufficient to produce the ceramic element; and sintering the ceramic element at an elevated temperature to a density of at least 5.5 g/cm3

  3. Stability of FDTS monolayer coating on aluminum injection molding tools

    DEFF Research Database (Denmark)

    Cech, Jiri; Taboryski, Rafael J.

    2012-01-01

    The injection molding industry often employs prototype molds and mold inserts from melt spun (rapid solidification processing [1,2]) aluminum, especially for applications in optics [3,4], photonics [5] and microfludics. Prototypes are also used for verification of mold filling. The use of aluminum tools has reduced lead time (days instead of weeks) and manufacturing cost (30% of conventional mold). Moreover, for aluminum, a surface roughness (RMS) below 5 nm can be obtained with diamond machining [3,4,6]. Conventional mold coatings add cost and complexity, and coatings with thicknesses of a few microns can obliterate small features. The nanoimprint lithography community extensively uses functional monolayer coatings on silicon/SiO2 lithographic stamps [7–11]. This treatment dramatically reduces stiction, and improves yield and quality of replicated nanostructures. Here we report on a fluorinated trichloro-silane based coating deposited on aluminum or its alloys by molecular vapor deposition. Wehave tested the stability of this coating in challenging conditions of injection molding, an environment with high shear stress from the molten polymer, pressures up to 200 MPa, temperatures up to 250 ?C, and rapid thermal cycling.

  4. Orientation of Carbon Fibers in Copper matrix Produced by Powder Injection Molding

    Directory of Open Access Journals (Sweden)

    Irfan Shirazi M.

    2014-07-01

    Full Text Available Fiber orientation is a big challenge in short fiber reinforced composites. Powder injection molding (PIM process has some intrinsic fiber alignment associated with it. During PIM process fibers in skin region of moldings are aligned as these regions experience higher shear flow caused by the mold walls. Fibers in the core region remain randomly aligned as these regions are far from mold walls and experience lesser shear flow. In this study short carbon fiber (CF reinforced copper matrix composite was developed by PIM process. Two copper composite feedstock formulations were prepared having 5 vol% and 10 vol% CFs and a wax based binder system. Fiber orientation was controlled during injection molding by using a modified mold that has a diverging sprue. The sprue creates converging flow when feedstock enters into the mold cavity. Fiber orientation was analysed after molding using FESEM. The orientation of fibers can be controlled by controlling flow of feedstock into the mold.

  5. Injection molding of coarse 316L stainless steel powder

    International Nuclear Information System (INIS)

    Metal injection molding (MIM) process using 316L stainless steel powder of 45 ?m was investigated. The binder system consists of a major fraction of palm stearins and minor fraction of polyethylene with a powder loading of 65 vol. %. The rheological behaviour of the feedstock was determined using Capillary Rheometer. The feedstock then injected using vertical injection molding machine into the tensile test bar. Then molded parts were de bound and sintered in vacuum at temperature of 1360 degree Celsius. The results show that the viscosity of the feedstock decreased with the temperature increased. The best sintered density achieved was about 7.5 g/cm3 with the tensile strength of more than 460 MPa. The properties of the sintered specimens could be increased with the increasing of sintering temperature. (author)

  6. Investigating the Influence of Different Process Parameters on Shrinkage of Injection-Molded Parts

    Directory of Open Access Journals (Sweden)

    A. R. Jafarian

    2005-01-01

    Full Text Available Different models have been proposed to investigate the effects of various process parameters on shrinkage of plastic parts, which in most cases the effect of each parameter is obtained by changing one factor at a time. In this research, a simple flat model has been used and a simulation code has been developed. Then, through this simulation code, the effects of different process parameters have been investigated. This code was run for a typical thermoplastic (polycarbonate and finally, a Design Of Experiments (DOE approach was used to study the effects of multiple variables on shrinkage simultaneously.

  7. Assessment of Current Process Modeling Approaches to Determine Their Limitations, Applicability and Developments Needed for Long-Fiber Thermoplastic Injection Molded Composites

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Ba Nghiep; Holbery, Jim; Smith, Mark T.; Kunc, Vlastimil; Norris, Robert E.; Phelps, Jay; Tucker III, Charles L.

    2006-11-30

    This report describes the status of the current process modeling approaches to predict the behavior and flow of fiber-filled thermoplastics under injection molding conditions. Previously, models have been developed to simulate the injection molding of short-fiber thermoplastics, and an as-formed composite part or component can then be predicted that contains a microstructure resulting from the constituents’ material properties and characteristics as well as the processing parameters. Our objective is to assess these models in order to determine their capabilities and limitations, and the developments needed for long-fiber injection-molded thermoplastics (LFTs). First, the concentration regimes are summarized to facilitate the understanding of different types of fiber-fiber interaction that can occur for a given fiber volume fraction. After the formulation of the fiber suspension flow problem and the simplification leading to the Hele-Shaw approach, the interaction mechanisms are discussed. Next, the establishment of the rheological constitutive equation is presented that reflects the coupled flow/orientation nature. The decoupled flow/orientation approach is also discussed which constitutes a good simplification for many applications involving flows in thin cavities. Finally, before outlining the necessary developments for LFTs, some applications of the current orientation model and the so-called modified Folgar-Tucker model are illustrated through the fiber orientation predictions for selected LFT samples.

  8. Injection molding of M2 high speed steel

    International Nuclear Information System (INIS)

    The purpose of this work is to study the feasibility of Powder Injection Molding in order to obtain M2 High Speed Steels with higher performances than those obtained by conventional P/M. With this object trials have been carried out in order to optimize all the process steps (mixing,injection, debinding and sintering) and to evaluate the mechanical properties (hardness and transverse tensile strength) of the manufactured M2 HSS sample. (Author) 11 refs

  9. A Recurrent Neural Network for Warpage Prediction in Injection Molding

    Directory of Open Access Journals (Sweden)

    A. Alvarado-Iniesta

    2012-11-01

    Full Text Available Injection molding is classified as one of the most flexible and economical manufacturing processes with high volumeof plastic molded parts. Causes of variations in the process are related to the vast number of factors acting during aregular production run, which directly impacts the quality of final products. A common quality trouble in finishedproducts is the presence of warpage. Thus, this study aimed to design a system based on recurrent neural networksto predict warpage defects in products manufactured through injection molding. Five process parameters areemployed for being considered to be critical and have a great impact on the warpage of plastic components. Thisstudy used the finite element analysis software Moldflow to simulate the injection molding process to collect data inorder to train and test the recurrent neural network. Recurrent neural networks were used to understand the dynamicsof the process and due to their memorization ability, warpage values might be predicted accurately. Results show thedesigned network works well in prediction tasks, overcoming those predictions generated by feedforward neuralnetworks.

  10. Effect of starch types on properties of biodegradable polymer based on thermoplastic starch process by injection molding technique

    Directory of Open Access Journals (Sweden)

    Yossathorn Tanetrungroj

    2015-04-01

    Full Text Available In this study effects of different starch types on the properties of biodegradable polymer based on thermoplastic starch (TPS were investigated. Different types of starch containing different contents of amylose and amylopectin were used, i.e. cassava starch, mungbean starch, and arrowroot starch. The TPS polymers were compounded and shaped using an internal mixer and an injection molding machine, respectively. It was found that the amount of amylose and amylopectin contents on native starch influence the properties of the TPS polymer. A high amylose starch of TPMS led to higher strength, hardness, degree of crystallization than the high amylopectin starch of TPCS. In addition, function group analysis by Fourier transforms infrared spectrophotometer, water absorption, and biodegradation by soil burial test were also examined.

  11. Microstructural and mechanical characterization of injection molded 718 superalloy powders

    Energy Technology Data Exchange (ETDEWEB)

    Özgün, Özgür [Bingol University, Faculty of Engineering and Architecture, Mechanical Eng. Dep., 12000 Bingol (Turkey); Gülsoy, H. Özkan, E-mail: ogulsoy@marmara.edu.tr [Marmara University, Technology Faculty, Metallurgy and Materials Eng. Dep., 34722 Istanbul (Turkey); Y?lmaz, Ramazan [Sakarya University, Technology Faculty, Metallurgy and Materials Eng. Dep., 54187 Sakarya (Turkey); F?nd?k, Fehim [Sakarya University, Technology Faculty, Metallurgy and Materials Eng. Dep., 54187 Sakarya (Turkey) and International University of Sarajevo, Faculty of Engineering and Natural Sciences, Department of Mechanical Engineering, 71000 Sarajevo, Bosnia and Herzegovina (Bosnia and Herzegowina)

    2013-11-05

    Highlights: •Microstructural and mechanical properties of injection molded Nickel 718 superalloy were studied. •The maximum sintered density achieved this study was 97.3% at 1290 °C for 3 hours. •Tensile strength of 1022 MPa and elongation of 5.3% were achieved for sintered-heat treated samples. -- Abstract: This study concerns with the determination of optimum production parameters for injection molding 718 superalloy parts. And at the same time, microstructural and mechanical characterization of these produced parts was also carried out. At the initial stage, 718 superalloy powders were mixed with a multi-component binder system for preparing feedstock. Then the prepared feedstock was granulated and shaped by injection molding. Following this operation, the shaped samples were subjected to the debinding process. These samples were sintered at different temperatures for various times. Samples sintered under the condition that gave way to the highest relative density (3 h at 1290 °C) were solution treated and aged respectively. Sintered, solution treated and aged samples were separately subjected to microstructural and mechanical characterization. Microstructural characterization operations such as X-ray diffraction, optical microscope (OM), scanning electron microscope (SEM), transmission electron microscope (TEM) and elemental analysis showed that using polymeric binder system led to plentiful carbide precipitates to be occurred in the injection molded samples. It is also observed that the volume fractions of the intermetallic phases (?? and ??) obtained by aging treatment were decreased due to the plentiful carbide precipitation in the samples. Mechanical characterization was performed by hardness measurements and tensile tests.

  12. Injection molded 1-3 piezocomposite velocity sensors

    Science.gov (United States)

    Gentilman, Richard L.; Bowen, Leslie J.; Fiore, Daniel F.; Pham, Hong T.; Serwatka, William J.

    1996-04-01

    A cost-effective technology has been developed for producing 1-3 piezoelectric ceramic/polymer composites and transducers for underwater actuators, pressure sensors, and velocity sensors. Applications include active and passive sonar, underwater imaging, and active surface control. The key technology in the manufacturing process in the PZT ceramic injection molding process, in which an entire array of piezoelectric elements is molded to final net shape in one operation. Several designs of low-profile, area-averaging 1-3 piezocomposite accelerometers have been fabricated. The initial breadboard accelerometers were made using a prepoled 50×50 mm injection molded 1-3 PZT-5H preforms, containing 361 identical rods on a common baseplate. Additional mass was attached to the baseplate, which was metallized to serve as an electrode, and the free ends of the PZT rods were bonded to a fixed surface, which also functions as the other electrode. Subsequently, a manufacturing process was developed to create accelerometer ``islands'' within a 1-3 piezocomposite transducer. The accelerometers can be made in arbitrary areas, shapes, and arrangements within the transducer panel, with the remaining area used either as a hydrophone or an actuator. This integral accelerometer technology is being optimized as part of an ARPA-funded active surface control program. This paper reviews the current state-of-the-art of injection molded piezocomposite transducers and describes some of the velocity sensor configurations made using this technology.

  13. Reduction in Injection Cycle Time Using a Milling-Combined Laser Metal Sintered Mold

    Science.gov (United States)

    Yoneyama, Takeshi; Kagawa, Hiroyuki; Suehiro, Yoshiaki; Abe, Satoshi; Miyamaru, Mitsuru

    By composing a cooling channel just near the mold surface using the milling-combined laser metal sintering method, cooling during injection is promoted and the cooling time is reduced. In order to evaluate this effect, a cone with ribs inside the upper part is picked up. A spiral-cooling channel is fabricated along the side surface of the mold core and also between the ribs in the upper part. To compare with this, a steel mold with machined baffle channels was made. The diameter of the upper part of the molded cone was chosen as an evaluation dimension. The temperature on the upper surface of the core is kept low at around the cooling water temperature in the case of sintered mold during the cycle of the injection. On the other hand, the temperature on the upper surface of the steel mold increases far higher than the cooling water temperature. Cycle time for the same shrink ratio in the upper part of the molded cone was 25 s in the sintered mold and 40 s in the steel mold. Owing to the cooling time reduction, cycle time of the injection molding was reduced 35% by using the sintered mold with cooling channels. Simulation is available to evaluate the mold temperature distribution and is useful for improving the arrangement of cooling channels in the process of mold design.

  14. Integrated Numerical Analysis of Induction-Heating-Aided Injection Molding Under Interactive Temperature Boundary Conditions

    International Nuclear Information System (INIS)

    In recent years, several rapid-mold-heating techniques that can be used for the injection molding of thin-walled parts or micro/nano structures have been developed. High-frequency induction heating, which involves heating by electromagnetic induction, is an efficient method for the rapid heating of mold surfaces. The present study proposes an integrated numerical model of the high-frequency induction heating process and the resulting injection molding process. To take into account the effects of thermal boundary conditions in induction heating, we carry out a fully integrated numerical analysis that combines electromagnetic field calculation, heat transfer analysis, and injection molding simulation. The proposed integrated simulation is extended to the injection molding of a thin-wall part, and the simulation results are compared with the experimental findings. The validity of the proposed simulation is discussed according to the ways of the boundary condition imposition

  15. Foaming morphology control of microcellular injection molded parts with gas counter pressure and dynamic mold temperature control

    Science.gov (United States)

    Shiu, Tai-Yi; Huang, Chao-Tsai; Chang, Rong-Yu; Hwang, Shyh-Shin

    2014-05-01

    Microcellular injection molding process is a promising solution for products with special requirements such as weight reduction, extra thin wall, high dimensional stability, clamping force reduction, etc. Despite microcellular foaming application used in reciprocating screw injection molding machine was built more than a decade, some limitations, such as poor surface quality or poor foaming control, confine the usage of this technology. Earlier CAE simulation tool for microcellular injection molding was not successful due to insufficient physical and computational considerations, limited by complicated bubble growth mechanism; so that, an economic and efficient tool for examining foaming quality of injection foaming product was lack. In this study, a recent developed three-dimensional simulation tool is used to predict injection foaming process. Predictions are carried out with commodity polypropylene and polystyrene with nitrogen and carbon dioxide supercritical fluids (SCFs). Comparisons of simulations between microcellular injection molding with and without counter pressure are discussed to provide insights into the correlation of surface quality and cell size distribution near the surface of product. Furthermore, comparisons between simulation predictions and experimental results of molding process, which is featured with dynamic mold temperature and gas counter pressure, are given for understanding quality improvement by controlling foaming morphology, and benefit of industrial application.

  16. Investigation of the effect of nanoclay and processing parameters on the tensile strength and hardness of injection molded Acrylonitrile Butadiene Styrene–organoclay nanocomposites

    International Nuclear Information System (INIS)

    Highlights: • Development of polymer/clay nanocomposites. • Compatibility of ABS and montmorillonite nanoclay and composition capability of them. • Effect of nanoclay content and process parameters on the mechanical properties of nanocomposite. • Analyzing the distribution of nanoclay layers using XRD test. • Dependency of tensile strength and hardness to the nanoclay content and processing conditions. - Abstract: Polymer–clay nanocomposites have attracted considerable interest over recent years due to their dramatic improved mechanical properties. In the present study, compatibility of Acrylonitrile Butadiene Styrene (ABS) and organically modified montmorillonite nanoclay (Cloisite 30B) and composition capability of them are investigated. Polymethylmethacrylate (PMMA) in varying amount (0, 2, and 4 wt%) is used as the compatibilizer. In order to produce nanocomposite parts, the material is first compounded using a twin-screw extruder and then injected into a mold. The effect of the nanoclay percentage and processing parameters on the tensile strength and hardness of nanocomposite parts is also explored using Taguchi Design of Experiments method. Nanoclay content (in three levels: 0, 2 and 4 wt%), melt temperature (in three levels: 190, 200 and 210 °C), holding pressure (in three levels: 80, 105 and 130 MPa) and holding pressure time (in three levels: 1, 2.5 and 4 s) are considered as the variable parameters. Moreover, distribg Wide Angle X-ray Diffraction (XRD) test. XRD results displayed that with the presence of PMMA, nanoclay in ABS matrix is compounded in more exfoliated and less intercalated dispersion mode. Adding PMMA also leads to a remarkable increase in the fluidity of the melt during injection molding process. Results also illustrated that nanocomposites with medium loading level (i.e. 2%) of nanoclay have the highest tensile strength, while the highest hardness number belongs to nanocomposites with 4 wt% nanoclay. Obtained results also indicated that injection temperature has the most important effect on tensile strength and hardness of ABS–clay nanocomposites

  17. Injection molding tools with micro/nano-meter pattern

    DEFF Research Database (Denmark)

    Kristensen, Anders Technical University of Denmark,

    The present invention relates to methods for embedded a micrometer and/or nanometer pattern into an injection molding tool. In a first main aspect, a micro/nanometer structured imprinting device is applied in, or on, an active surface so as to transfer the micro/nanometer patterned structure to the tool while the imprinting device is, at least partly, within a cavity of the injection molding tool. In a second main aspect, a base plate with a micro/nanometer structured pattern positioned on an upper part is positioned on the active surface within the tool, the lower part of the base plate facing the tool, the active surface receiving the base plate being non-planar on a macroscopic scale. Both aspects enable a simple and effective way of transferring the pattern, and the pattern may be transferred on the active working site of tool immediately prior to molding without the need for extensive preparations or remounting of the tool before performing the molding process.

  18. Packing parameters effect on injection molding of polypropylene nanostructured surfaces

    DEFF Research Database (Denmark)

    Calaon, Matteo; Tosello, Guido

    2012-01-01

    In today´s industry, applications involving surface patterning of sub-?m to nanometer scale structures have shown a high growth potential. To investigate the injection molding capability of replicating sub-?m surface texture on a large scale area, a 30x80 mm2 tool insert with surface structures having a diameter of 500 nm was employed. The tool insert surface was produced using chemical-based-batch techniques such aluminum anodization and nickel electroplating. During the injection molding process, polypropylene (PP) was employed as material and packing phase parameters (packing time, packing pressure) were investigated. The replicated surface topographies were quantitatively characterized by atomic force microscopy using specific three-dimensional surface parameters and qualitatively inspected by scanning electron microscopy. Results showed that the degree of replication from the tool to the polymer part was mainly influenced by packing pressure level and distance from the gate.

  19. Replication of micro/nano-scale features by micro injection molding with a bulk metallic glass mold insert

    OpenAIRE

    Zhang, Nan; Chu, J. S.; Byrne, Cormac J.; et al, ...

    2012-01-01

    The development of MEMS and Microsystems needs a reliable mass production process to fabricate micro components with micro/nano scale features. In our study, we used the micro injection molding process to replicate micro/nano scale channels and ridges from a Bulk Metallic Glass (BMG) cavity insert. High density polyethylene (HDPE) was used as the molding material and Design of Experiment (DOE) was adopted to systematically and statistically investigate the relationship betwe...

  20. Injection molding of thermoplastic elastomers for microstructured substrates

    Science.gov (United States)

    Birkar, Smita

    Amorphous and semi-crystalline thermoplastic polymers have been widely investigated for injection molding of parts with microstructured surfaces. Microstructured surfaces injection molded from thermoplastic elastomers have emerging applications as superhydrobic surfaces and patterned adhesives, but there is a limited understanding of the factors affecting replication with these materials. This research was a continued investigation of block copolymer thermoplastic elastomers as well as the first in-depth examination of thermoplastic vulcanizates for injection molding microfeatures. The first focus of this research was the interactions between tooling aspect ratio and feature orientation (negative and positive tooling) and thermoplastic elastomer hard segment content on microfeature replication. Electroformed nickel tooling having positive and negative features with different geometries and aspect ratios of 0.02:1 to 2:1 were molded from three copolyester thermoplastic elastomers with similar chemistry and different hardness values. The tooling and part features were characterized for feature depth and height as well as feature definition using scanning electron microscopy and optical profilometry. Results were correlated with elastomer properties. In the second parts of this research, the effects of microfeature spacing on the replication of thermoplastic elastomer features was investigated using micropillars with two diameters (10 and 20 mum) and three spacing ratios (0.5:1, 1:1, and 2:1). The tooling and part features were characterized for feature depth and height as well as feature definition using scanning electron microscopy and optical profilometry. Feature spacing significantly affected the replication of micropillars using a thermoplastic elastomer. This replication was competition between cooling and pressurization of the melt. Wider spacing between smaller features allowed cooling in the tooling lands to dominate the feature filling. Higher pressures did not always produce better feature replication, suggesting that cooling effects in the tooling "holes" restricted filling. High pressures also produced surface porosity in the molded pillars. Although thermoplastic vulcanizates, thermoplastic elastomers with excellent processability and flexibility, are a widely used for over molding and automotive applications, the third section of this research was the first in-depth investigation of injection molding thermoplastic vulcanizates to create microstructured surfaces. In this study, nickel cobalt tooling was used to mold commercially-available thermoplastic vulcanizates with polypropylene/ethylene propylene diene monomer (PP/EPDM) backbones into 20-mum-diameter and 100-mum-wide features. These results were compared to those for a polypropylene homopolymer. The primary molding parameters, including melt and mold temperatures were evaluated for their effects on microfeature replication. Additionally, a two-level, three-factorial design of experiments was conducted to further evaluate the effects of key parameters (cooling time, hold pressure, and polymeric material) on the feature definition and depth ratios of the molded microfeatures. These results were compared to the properties of the thermoplastic vulcanizates.

  1. Modeling injection molding of net-shape active ceramic components.

    Energy Technology Data Exchange (ETDEWEB)

    Baer, Tomas (Gram Inc.); Cote, Raymond O.; Grillet, Anne Mary; Yang, Pin; Hopkins, Matthew Morgan; Noble, David R.; Notz, Patrick K.; Rao, Rekha Ranjana; Halbleib, Laura L.; Castaneda, Jaime N.; Burns, George Robert; Mondy, Lisa Ann; Brooks, Carlton, F.

    2006-11-01

    To reduce costs and hazardous wastes associated with the production of lead-based active ceramic components, an injection molding process is being investigated to replace the current machining process. Here, lead zirconate titanate (PZT) ceramic particles are suspended in a thermoplastic resin and are injected into a mold and allowed to cool. The part is then bisque fired and sintered to complete the densification process. To help design this new process we use a finite element model to describe the injection molding of the ceramic paste. Flow solutions are obtained using a coupled, finite-element based, Newton-Raphson numerical method based on the GOMA/ARIA suite of Sandia flow solvers. The evolution of the free surface is solved with an advanced level set algorithm. This approach incorporates novel methods for representing surface tension and wetting forces that affect the evolution of the free surface. Thermal, rheological, and wetting properties of the PZT paste are measured for use as input to the model. The viscosity of the PZT is highly dependent both on temperature and shear rate. One challenge in modeling the injection process is coming up with appropriate constitutive equations that capture relevant phenomenology without being too computationally complex. For this reason we model the material as a Carreau fluid and a WLF temperature dependence. Two-dimensional (2D) modeling is performed to explore the effects of the shear in isothermal conditions. Results indicate that very low viscosity regions exist near walls and that these results look similar in terms of meniscus shape and fill times to a simple Newtonian constitutive equation at the shear-thinned viscosity for the paste. These results allow us to pick a representative viscosity to use in fully three-dimensional (3D) simulation, which because of numerical complexities are restricted to using a Newtonian constitutive equation. Further 2D modeling at nonisothermal conditions shows that the choice of representative Newtonian viscosity is dependent on the amount of heating of the initially room temperature mold. An early 3D transient model shows that the initial design of the distributor is sub-optimal. However, these simulations take several months to run on 4 processors of an HP workstation using a preconditioner/solver combination of ILUT/GMRES with fill factors of 3 and PSPG stabilization. Therefore, several modifications to the distributor geometry and orientations of the vents and molds have been investigated using much faster 3D steady-state simulations. The pressure distribution for these steady-state calculations is examined for three different distributor designs to see if this can indicate which geometry has the superior design. The second modification, with a longer distributor, is shown to have flatter, more monotonic isobars perpendicular to the flow direction indicating a better filling process. The effects of the distributor modifications, as well as effects of the mold orientation, have also been examined with laboratory experiments in which the flow of a viscous Newtonian oil entering transparent molds is recorded visually. Here, the flow front is flatter and voids are reduced for the second geometry compared to the original geometry. A horizontal orientation, as opposed to the planned vertical orientation, results in fewer voids. Recently, the Navier-Stokes equations have been stabilized with the Dohrman-Bochev PSPP stabilization method, allowing us to calculate transient 3D simulations with computational times on the order of days instead of months. Validation simulations are performed and compared to the experiments. Many of the trends of the experiments are captured by the level set modeling, though quantitative agreement is lacking mainly due to the high value of the gas phase viscosity necessary for numerical stability, though physically unrealistic. More correct trends are predicted for the vertical model than the horizontal model, which is serendipitous as the actual mold is held in a vertical geometry. The full, transient mold fillin

  2. Fast prototyping of injection molded polymer microfluidic chips

    DEFF Research Database (Denmark)

    Hansen, Thomas Steen; Selmeczi, David

    2010-01-01

    We present fast prototyping of injection molding tools by the definition of microfluidic structures in a light-curable epoxy (SU-8) directly on planar nickel mold inserts. Optimized prototype mold structures could withstand injection molding of more than 300 replicas in cyclic olefin copolymer (COC) without any signs of failure or release. The key parameters to avoid mold failure are maximum adhesion strength of the epoxy to the nickel insert and minimum interfacial energy of the epoxy pattern to the molded polymer. Optimal molding of microstructures with vertical sidewalls was found for nickel inserts pre-coated by silicon oxide before applying the structured epoxy, followed by coating of the epoxy by a fluorocarbon layer prior to injection molding. Further improvements in the mold stability were observed after homogeneous coating of the patterned epoxy by a second reflowed layer of epoxy, likely due to the resulting reduction in sidewall steepness. We employed the latter method for injection molding bondable polymer microfluidic chips with integrated conducting polymer electrode arrays that permitted the culture and on-chip analysis of cell spreading by impedance spectroscopy.

  3. Comparative Thermal Analysis of Circular and Profiled Cooling Channels for Injection Mold Tools

    Directory of Open Access Journals (Sweden)

    A.M.A. Rani

    2011-01-01

    Full Text Available Injection Mold Thermal Management is a critical issue in plastic injection molding process and has major effects on production cycle times that is directly linked with cost and also has effects on part quality. For this reason, cooling system design has great significance for plastic products industry by injection molding. It is crucial not only to reduce molding cycle time but also it considerably affects the productivity and quality of the product. The cooling channels in injection molding have circular cross section due to the conventional manufacturing technique of drilling. In Rapid Prototyping and Tooling techniques of fabricating conformal cooling channels, the channel cross section is again circular. In circular channel, there can be a problem that the distance from the edges of channel to the cavity is not constant and it is variable even for conformal channels. This can give problem of not having even heat dissipation. In this study, injection mold designing and thermal simulations were performed and comparison is presented between molds having cooling channels of circular cross section with mold with profiled cross section channels. Thermal analysis and simulations can effectively predict the performance of circular channels as compared to profiled channels. Some concepts are also presented for the manufacturing of molds with circular and profiled channels with the use of metal filled epoxies.

  4. Investigations on injection molded, glass-fiber reinforced polyamide 6 integral foams using breathing mold technology

    Science.gov (United States)

    Roch, A.; Kehret, L.; Huber, T.; Henning, F.; Elsner, P.

    2015-05-01

    Investigations on PA6-GF50 integral foams have been carried out using different material systems: longfiber- and shortfiber-reinforced PA6 as well as unreinforced PA6 as a reference material. Both chemical and physical blowing agents were applied. Breathing mold technology (decompression of the mold) was selected for the foaming process. The integral foam design, which can be conceived as a sandwich structure, helps to save material in the neutral axis area and maintains a distance between load-bearing, unfoamed skin layers. For all test series an initial mold gap of 2.5 mm was chosen and the same amount of material was injected. In order to realize different density reductions, the mold opening stroke was varied. The experiments showed that, at a constant mass per unit area, integral polyamide 6 foams have a significantly higher bending stiffness than compact components, due to their higher area moment of inertia after foaming. At a constant surface weight the bending stiffness in these experiments could be increased by up to 600 %. Both shortfiber- and longfiber-reinforced polyamide 6 showed an increase in energy absorption during foaming.

  5. Injection-molded capsular device for oral pulsatile release: development of a novel mold.

    Science.gov (United States)

    Zema, Lucia; Loreti, Giulia; Macchi, Elena; Foppoli, Anastasia; Maroni, Alessandra; Gazzaniga, Andrea

    2013-02-01

    The development of a purposely devised mold and a newly set up injection molding (IM) manufacturing process was undertaken to prepare swellable/erodible hydroxypropyl cellulose-based capsular containers. When orally administered, such devices would be intended to achieve pulsatile and/or colonic time-dependent delivery of drugs. An in-depth evaluation of thermal, rheological, and mechanical characteristics of melt formulations/molded items made of the selected polymer (Klucel® LF) with increasing amounts of plasticizer (polyethylene glycol 1500, 5%-15% by weight) was preliminarily carried out. On the basis of the results obtained, a new mold was designed that allowed, through an automatic manufacturing cycle of 5 s duration, matching cap and body items to be prepared. These were subsequently filled and coupled to give a closed device of constant 600 ?m thickness. As compared with previous IM systems having the same composition, such capsules showed improved closure mechanism, technological properties, especially in terms of reproducibility of the shell thickness, and release performance. Moreover, the ability of the capsular container to impart a constant lag phase before the liberation of the contents was demonstrated irrespective of the conveyed formulation. PMID:23161022

  6. Binder Removal from Powder Injection Molded 316L Stainless Steel

    Directory of Open Access Journals (Sweden)

    M.A. Omar

    2011-01-01

    Full Text Available This study reports the results of preparation of 316L stainless steel polymer based injection molded feed stock, rheology of feed stock and injection molding. The plastic binder was extracted from molded samples. The binder extraction was carried out in two steps: by solvent and thermal techniques. The results showed that feed stock prepared was suitable for injection molding and this was confirmed by rheology data measured by using capillary rheometer. The test samples were injection molded without physical defects. Paraffin Wax (major binder was extracted by using solvent extraction for 300 min. The thermal debinding was performed four different heating rates rage 1-7C min-1. The SEM results showed that the PW was completely extracted from the test samples after 300 min.

  7. Optimizing the Filling Time and Gate of the Injection Mold on Plastic Air Intake Manifold of Engines

    Directory of Open Access Journals (Sweden)

    Shiqiang Zhang

    2013-01-01

    Full Text Available In order to acquire the best filling time, Mold trial is made by setting different injection time, or Mold flow software is used to analyze data recorded by computer. Whether doing successive trials or being simulated point by point, is very tedious. A new method is put forward-seeking the minimum of curve being simulated by Lagrange interpolation. The minimum of the curve is the best filling time. This method can improve the efficiency of the simulation analysis. The software Mold flow provides the possibility to simulate the flow processes of plastic air intake manifold with different gate location and number of injection mold and to predict the position of air traps and weld lines. The location and number of the gate in injection mold are determined by comparing analysis results and avoid mold adjustment and mold repairing. Finished injection mold of plastic air intake manifold on basis of simulation is perfect.

  8. Analysis of Cavity Pressure and Warpage of Polyoxymethylene Thin Walled Injection Molded Parts: Experiments and Simulations

    DEFF Research Database (Denmark)

    Guerrier, Patrick; Tosello, Guido

    2014-01-01

    Process analysis and simulations on molding experiments of 3D thin shell parts have been conducted. Moldings were carried out with polyoxymethylene (POM). The moldings were performed with cavity pressure sensors in order to compare experimental process results with simulations. The warpage was characterized by measuring distances using a tactile coordinate measuring machine (CMM). Molding simulations have been executed taking into account actual processing conditions. Various aspects have been considered in the simulation: machine barrel geometry, injection speed profiles, cavity injection pressure, melt and mold temperatures, material rheological and pvT characterization. Factors investigated for comparisons were: injection pressure profile, short shots length, flow pattern, and warpage. A reliable molding experimental database was obtained, accurate simulations were conducted and a number of conclusions concerning improvements to simulation accuracy are presented regarding: pvT data, mesh, short shots, cavity pressure for process control validation as well as molding machine geometry modelling. Eventually, a methodology for improved molding simulations of cavity injection pressure, filling pattern and warpage was established.

  9. Analysis of cavity pressure and warpage of polyoxymethylene thin walled injection molded parts: Experiments and simulations

    Science.gov (United States)

    Guerrier, P.; Tosello, G.; Hattel, J. H.

    2015-05-01

    Process analysis and simulations on molding experiments of 3D thin shell parts have been conducted. Moldings were carried out with polyoxymethylene (POM). The moldings were performed with cavity pressure sensors in order to compare experimental process results with simulations. The warpage was characterized by measuring distances using a tactile coordinate measuring machine (CMM). Molding simulations have been executed taking into account actual processing conditions. Various aspects have been considered in the simulation: machine barrel geometry, injection speed profiles, cavity injection pressure, melt and mold temperatures, material rheological and pvT characterization. Factors investigated for comparisons were: injection pressure profile, short shots length, flow pattern, and warpage. A reliable molding experimental database was obtained, accurate simulations were conducted and a number of conclusions concerning improvements to simulation accuracy are presented regarding: pvT data, mesh, short shots, cavity pressure for process control validation as well as molding machine geometry modelling. Eventually, a methodology for improved molding simulations of cavity injection pressure, filling pattern and warpage was established.

  10. The use of stereolithography rapid tools in the manufacturing of metal powder injection molding parts

    Directory of Open Access Journals (Sweden)

    Beal V. E.

    2004-01-01

    Full Text Available The utilization of stereolithography molds in the manufacture pre-series for injection molded plastic parts aims to reduce costs throughout the product life-time, but mainly during design and manufacturing phases. The use of this Rapid Tooling technique in powder metal injection molding is evaluated in this work. One of the greatest differences between traditional and stereolithography tools is related to the heat conductivity of the materials employed. For example, steel molds have a heat conductivity coefficient 300 times higher than molds made with the photosensitive resin used in the stereolithography process. The discrepancy regarding the cooling rate of the molded parts during the injection cycle must be compensated with adjustments in the injection molding parameters, such as temperature, pressure and speed. The optimization of these parameters made it possible to eject green parts from the mold without causing defects which would become evident in debinding and sintering stages. The dimensional analysis performed at the end of each case study showed that the shrinking factor of the component after the sintering had the same value obtained for components using traditional metallic molds. Moreover, the dimensional error remains under 2% which can be considered low for a pre-series of components (or prototype series.

  11. The use of stereolithography rapid tools in the manufacturing of metal powder injection molding parts

    Scientific Electronic Library Online (English)

    V. E., Beal; C. H., Ahrens; P. A., Wendhausen.

    2004-03-01

    Full Text Available The utilization of stereolithography molds in the manufacture pre-series for injection molded plastic parts aims to reduce costs throughout the product life-time, but mainly during design and manufacturing phases. The use of this Rapid Tooling technique in powder metal injection molding is evaluated [...] in this work. One of the greatest differences between traditional and stereolithography tools is related to the heat conductivity of the materials employed. For example, steel molds have a heat conductivity coefficient 300 times higher than molds made with the photosensitive resin used in the stereolithography process. The discrepancy regarding the cooling rate of the molded parts during the injection cycle must be compensated with adjustments in the injection molding parameters, such as temperature, pressure and speed. The optimization of these parameters made it possible to eject green parts from the mold without causing defects which would become evident in debinding and sintering stages. The dimensional analysis performed at the end of each case study showed that the shrinking factor of the component after the sintering had the same value obtained for components using traditional metallic molds. Moreover, the dimensional error remains under 2% which can be considered low for a pre-series of components (or prototype series).

  12. Computer Aided Design of The Cooling System for Plastic Injection Molds

    Directory of Open Access Journals (Sweden)

    Hakan GÜRÜN

    2009-02-01

    Full Text Available The design of plastic injection molds and their cooling systems affect both the dimension, the shape, the quality of a plastic part and the cycle time of process and the cost of mold. In this study, the solid model design of a plastic injection mold and the design of cooling sysytem were possibly carried out without the designer interaction. Developed program permited the use of three types of the cooling system and the different cavity orientations and the multible plastic part placement into the mold cores. The program which was developed by using Visual LISP language and the VBA (Visual BASIC for Application modules, was applicated in the AutoCAD software domain. Trial studies were presented that the solid model design of plastic injection molds and the cooling systems increased the reliability, the flexibility and the speed of the design.

  13. A Review of Effects of Molding Methods, Mold Thickness and Other Processing Parameters on Fiber Orientation in Polymer Composites

    Directory of Open Access Journals (Sweden)

    Ahmed N. Oumer

    2013-01-01

    Full Text Available In injection molded fiber reinforced composites, the mechanical and physical properties of the final product are highly dependent on the patterns of fibers alignment. The orientation of the fibers can be influenced by many factors such as molding methods, materials used, geometry of the part and other processing parameters. Thus, there is considerable interest in studying the factors that affect the fiber orientation, hence the properties of the final product. This study presented a general review on the effects of these factors on fiber orientation in injection molded fiber-reinforced polymer composites. The fiber orientation of a part made by conventional injection molding is compared with those produced by injection-compression and push-pull injection techniques. Effects of injection speed, type of flow and mold thickness on fiber orientation are also discussed. Hence, this review could assist in decisions regarding the design of composite products.

  14. FPGA-Based Multiprocessor System for Injection Molding Control

    OpenAIRE

    Osornio-Rios, Roque A.; Benitez-Rangel, Juan P.; Miguel Trejo-Hernandez; Carlos Rodriguez-Donate; Luis Morales-Velazquez; Romero-Troncoso, Rene de J.; Benigno Muñoz-Barron

    2012-01-01

    The plastic industry is a very important manufacturing sector and injection molding is a widely used forming method in that industry. The contribution of this work is the development of a strategy to retrofit control of an injection molding machine based on an embedded system microprocessors sensor network on a field programmable gate array (FPGA) device. Six types of embedded processors are included in the system: a smart-sensor processor, a micro fuzzy logic controller, a programmable logic...

  15. New Design and Injection Molding Analysis of a Low Smoke Zero Halogen Cable Trunk

    Directory of Open Access Journals (Sweden)

    Xiaoxun Zhang

    2012-09-01

    Full Text Available The traditional production process of a cable trunk is plastic extrusion with PVC or other halogen containing materials. However, they have many disadvantages such as easy burning, producing toxic gases and smokes. A low smoke zero halogen (LSZH cable trunk was designed and developed in the present study and the injection molding process was adopted to produce the LSZH cable trunk. Numerical simulations were applied to investigate the effects of the important process parameters on the warpage of the cable trunk. Comparing the simulation results under different process conditions and consideration both of the volumetric shrinkage and the total warpage displacement, it is found that the process parameters, including mold temperature 75°C, melt temperature 265°C, injection pressure 190 MPa, packing pressure 152 MPa, cooling water temperature 50°C and injection time 3 s, are the optimal process conditions for the injection molding process of the new designed cable trunk.

  16. A Recurrent Neural Network for Warpage Prediction in Injection Molding

    Scientific Electronic Library Online (English)

    A., Alvarado-Iniesta; D.J., Valles-Rosales; J.L., García-Alcaraz; A., Maldonado-Macias.

    2012-12-01

    Full Text Available La inyección de plásticos se considera como uno de los procesos de manufactura más flexibles y económicos con un gran volumen de producción de piezas de plástico. Las causas de variación durante la inyección de plásticos se relacionan con el amplio número de factores que intervienen durante un ciclo [...] de producción regular, tales variaciones impactan la calidad del producto final. Un problema común de calidad en productos terminados es la presencia de deformaciones. Así, este estudio tuvo como objetivo diseñar un sistema basado en redes neuronales recurrentes para predecir defectos de deformación en productos fabricados por medio de inyección de plásticos. Se emplean cinco parámetros del proceso por ser considerados críticos y que tienen un gran impacto en la deformación de componentes plásticos. El presente estudio hizo uso del software de análisis finito llamado Moldflow para simular el proceso de inyección de plásticos para recolectar datos con el fin de entrenar y probar la red neuronal recurrente. Redes neuronales recurrentes fueron utilizadas para entender la dinámica del proceso y debido a su capacidad de memorización, los valores de deformación pudieron ser predichos con exactitud. Los resultados muestran que la red diseñada funciona bien en términos de predicción, superando aquellas predicciones generadas por redes de propagación hacia adelante. Abstract in english Injection molding is classified as one of the most flexible and economical manufacturing processes with high volume of plastic molded parts. Causes of variations in the process are related to the vast number of factors acting during a regular production run, which directly impacts the quality of fin [...] al products. A common quality trouble in finished products is the presence of warpage. Thus, this study aimed to design a system based on recurrent neural networks to predict warpage defects in products manufactured through injection molding. Five process parameters are employed for being considered to be critical and have a great impact on the warpage of plastic components. This study used the finite element analysis software Moldflow to simulate the injection molding process to collect data in order to train and test the recurrent neural network. Recurrent neural networks were used to understand the dynamics of the process and due to their memorization ability, warpage values might be predicted accurately. Results show the designed network works well in prediction tasks, overcoming those predictions generated by feedforward neural networks.

  17. Aplicação das técnicas de planejamento e análise de experimentos no processo de injeção plástica / Application design of experiments in the injection molding process

    Scientific Electronic Library Online (English)

    Edwin V. Cardoza, Galdamez; Luiz C. Ribeiro, Carpinetti.

    2004-04-01

    Full Text Available Experimentos industriais são realizados pelas empresas com o intuito de melhorar o desempenho dos produtos e os processos de fabricação. Nesse sentido, este trabalho tem por objetivo estudar e aplicar as técnicas de planejamento e análise de experimentos na melhoria da qualidade industrial. Especifi [...] camente são aplicadas as técnicas de planejamento Fatorial Fracionado 2k-p, Metodologia de Superfície de Resposta e Análise de Variância, em um processo de moldagem por injeção plástica. Com essa pesquisa experimental foi possível identificar os níveis ótimos de regulagem e os parâmetros mais importantes da injeção plástica: temperatura da máquina e pressão de injeção. Para finalizar é avaliado o procedimento de implementação das técnicas de experimentação e as dificuldades práticas encontradas na empresa. Abstract in english Industrial experiments are made by companies in order to improve the quality characteristics of products and production processes. In this sense, the objective of this paper is to study and apply the design of experiments in the industrial quality improvement. In addition, as a part of the objective [...] , an application of the techniques of design Fractional Factorial 2k-p, Analysis of Variance and Response Surface Methodology is done. It is focused in an injection molding process applied by a company, that makes and trades plastic products for the civil construction. Using this experimental study, the most important parameters of plastic injection are identified: machine temperature and injection pressure. At the same time, the optimal levels of adjustment of these parameters are determined. From this study, it is evaluated both the implantation procedures of the designs of experiments as well as the difficulties faced. Also, this study tries to contribute to the university-company relationship.

  18. Aplicação das técnicas de planejamento e análise de experimentos no processo de injeção plástica Application design of experiments in the injection molding process

    Directory of Open Access Journals (Sweden)

    Edwin V. Cardoza Galdamez

    2004-04-01

    Full Text Available Experimentos industriais são realizados pelas empresas com o intuito de melhorar o desempenho dos produtos e os processos de fabricação. Nesse sentido, este trabalho tem por objetivo estudar e aplicar as técnicas de planejamento e análise de experimentos na melhoria da qualidade industrial. Especificamente são aplicadas as técnicas de planejamento Fatorial Fracionado 2k-p, Metodologia de Superfície de Resposta e Análise de Variância, em um processo de moldagem por injeção plástica. Com essa pesquisa experimental foi possível identificar os níveis ótimos de regulagem e os parâmetros mais importantes da injeção plástica: temperatura da máquina e pressão de injeção. Para finalizar é avaliado o procedimento de implementação das técnicas de experimentação e as dificuldades práticas encontradas na empresa.Industrial experiments are made by companies in order to improve the quality characteristics of products and production processes. In this sense, the objective of this paper is to study and apply the design of experiments in the industrial quality improvement. In addition, as a part of the objective, an application of the techniques of design Fractional Factorial 2k-p, Analysis of Variance and Response Surface Methodology is done. It is focused in an injection molding process applied by a company, that makes and trades plastic products for the civil construction. Using this experimental study, the most important parameters of plastic injection are identified: machine temperature and injection pressure. At the same time, the optimal levels of adjustment of these parameters are determined. From this study, it is evaluated both the implantation procedures of the designs of experiments as well as the difficulties faced. Also, this study tries to contribute to the university-company relationship.

  19. Injection molded dielectromagnets prepared from mixture of hard magnetic powders

    International Nuclear Information System (INIS)

    Dielectromagnets are permanent magnets prepared from a hard magnetic powder bonded by binder. These permanent magnets are termed also as bonded permanent magnets. There are two ways to prepare dielectromagnets: compression molding and injection molding. Dielectromagnets prepared by injection molding, from the same hard magnetic powders, have worse magnetic properties than dielectromagnets prepared by compression molding, but they are cheaper. Isotropic dielectromagnets prepared from ferrite powder have low value of magnetic properties, but their advantage is positive value of temperature coefficient of JHc. They are low in price. Dielectromagnets prepared from melt-spun Nd-Fe-B have high values of magnetic properties.Value of temperature coefficient of JHc is their weakness. They are more expensive than ferrite dielectromagnets. Comparison of advantages and disadvantages of dielectromagnets prepared from different kinds of hard magnetic powder has produced an idea of making dielectromagnets from the mixture of these powders prepared by compression molding have magnetic and thermal properties of values between values of dielectromagnets from Nd-Fe-B and ferrite powders. It was described elsewhere. The purpose of this investigation is to prepare injection molded dielectromagnets from mixture of powders of strontium ferrite and melt-spun ribbon Nd-Fe-B and to find correlation between the composition of the mixture and magnetic e composition of the mixture and magnetic properties of dielectromagnets. A result of mixture composition on magnetic properties of injection molded dielectromagnets is shown. (author)

  20. Design of Multimodel based MPC and IMC control schemes applied to injection molding machine

    Directory of Open Access Journals (Sweden)

    Kanaga Lakshmi

    2014-03-01

    Full Text Available Good control of plastic melt temperature for injection molding is very important in reducing operator setup time, ensuring product quality, and preventing thermal degradation of the melt. The controllability and set points of barrel temperature also depend on the precise monitoring and control of plastic melt temperature. Motivated by the practical temperature control of injection molding, this paper proposes MPC and IMC based control scheme. A robust system identification and control methodology is developed which uses canonical varieties analysis for identification and model predictive control for regulation. The injection molding process consists of three zones and the mathematical model for each of the zone is different. The control output for each zone controller is assigned a weight based on the computed probability of each model and the resulting action is the weighted average of the control moves of the individual zone controllers.   Keywords: Injection-Molding Machine (IMM, IMC Control, Temperature Control.

  1. Processing studies in sheet molding compound compression molding

    Science.gov (United States)

    Abrams, Lisa Marie

    Due to its high strength to weight ratio, corrosion resistance, and low cost. Sheet Molding Compound (SMC) production offers great potential for growth in the automotive and trucking industry. Much attention is now being given to improving the economy of SMC compression molding by reducing the cycle time required to produce acceptable parts in steady production. One of the fastest growing applications of Sheet Molding Compound (SMC) compression molding panels is the manufacture of truck body panels. Due to their large size, the molding forces developed are substantial and have a major influence in the molding cycle. The relevant process models for SMC flow are reviewed and a procedure is developed that can be used to obtain the closing force and calculate the needed material parameters. Experiments were done using commercially made SMC varying quantities of glass, filler, and thickener to verify the validity of this model and the compression force was predicted for commercially made automotive hoods. It was found that glass and filler had a significant impact on the material parameters. When the amount of glass was increased, both material parameters m/deltan and eta increased. Similar trends were seen when increasing the amount of filler. For the thickener used in this research (magnesium oxide), it was found that it had minimal effect on the material parameters. Molding conditions and initial SMC charge configurations were also varied to see their effects on molding force and material parameters. Initial charge dimensions and volume as well as mold closing speed showed no effect on material parameters, while molding temperature showed a minimal effect. Material parameters were calculated for each SMC composition. These parameters were used to predict the compression force for the Corvette hood and Fiero hood. These predictions were compared with actual Corvette and Fiero hoods manufactured in industry. They predicted the commercially made parts quite well.

  2. Experimental Analysis for Factors Affecting the Repeatability of Plastics Injection Molding Tests on the Self-developed Apparatus

    OpenAIRE

    Yuejun Liu; Yugang Huang; Duxin Li

    2013-01-01

    To improve the repeatability of the injection molding test result, the affecting factors were investigated by means of experiments. Besides the traditional processing parameter, the factors of test conditions were also considered. In order to focus on the molding process rather than the molded part, the curve measurement of the melt pressure at the entrance to the nozzle was used as the output characteristic. Experiments for polypropylene (PP) showed that the injected volume was the key proc...

  3. Fabrication of microstructures with extreme structural heights by vacuum reaction injection molding and electroforming

    International Nuclear Information System (INIS)

    Development work has resulted in a vacuum reaction injection molding (RIM) process which allows to fabricate plastic microstructures having minimum lateral dimensions in the micrometer range and structural heights of several hundred micrometers. The plastic structures generated by this method on an electrically conductive gate plate can be used directly as templates for the production of metallic microstructures through electroforming. The mold inserts for the molding tools used in the RIM process are fabricated by synchrotron radiation lithography and electroforming on an electrically conductive base plate. Particularly stable mold inserts made of one single material with extremely plane surfaces are obtained by electrodeposition of metal such that it stands by several millimeters over the resist structures generated by lithography. The mold insert produced in this way is separated from the base plate and the resist structures are subsequently removed. The molding tests were performed at a purpose developed vacuum RIM apparatus. Methacrylate base casting resins were used with an internal mold release agent added in order to reduce the adhesion of the produced part on the mold insert. By the example of fabrication of separation nozzle structures with minimum lateral dimensions of about 3 ?m and a maximum structural height of 310 ?m it has been demonstrated that molding can be performed at 100% yield and that service lives of the mold inserts can be achieved which are adequate for mass production. (orig./HP)

  4. Evaluation of stability for monolayer injection molding tools coating

    DEFF Research Database (Denmark)

    Cech, Jiri; Taboryski, Rafael J.

    2012-01-01

    We tested and characterized molecular coating of Aluminium and Nickel prototype molds and mold inserts for polymer replication via injection molding (IM). X-Ray photoelectron spectroscopy (XPS) data, sessile drop contact angles with multiple fluids, surface energy and roughness data have been collected and used to predict coating lifetimes. Samples have been characterized immediately after coating, after 500+ IM cycles to test durability and after 7 months to test temporal stability. Sessile drop contact angle was measured for multiple fluids, namely water, di-iodomethane and benzylacohol. Detectable coating presence was indicated by an increased angle on all post IM samples. To conclude, we present mold coating evaluation method, which is well suited for ultrathin, controlable, covalently bonded coating, that is reasonably durable, affordable, scalable to production, detectable on surface and especially suitable for rapid prototyping and mold geometry testing.

  5. Feed stock preparation and achievement of shape complexity using powder injection molding (PIM)

    International Nuclear Information System (INIS)

    Powder injection molding is one of the near net shape processing (NNSP) techniques used to produce geometrically complex shapes that need very little or no machining. This study presents the comparative study of feedstock preparation for Metal and Ceramic Injection Molding from the view point of achievement of shape complexity. Different variables of feedstock are studied, such as the role of binder, processing temperature, role of additives and the starting powder attributes on shape complexity. In this study, different binder systems; paraffin wax, polyethylene glycol, stearic acid, several thermoplastic resins and powders Fe and Al/sub 2/O/sub 3/ are studied. The differences between metal injection molding and ceramic injection molding are clearly emphasized. A major focus of this study is to attain the requisite engineering properties by a control of microstructure using different dies with increasing shape complexity. Powder is mixed with the binder system, the mix is injection molded into the desired shape cavity, the molded part is de-bound and after debinding it is sintered to produce high density products. (author)

  6. Injection molded polymeric micropatterns for bone regeneration study.

    Science.gov (United States)

    Zanchetta, Erika; Guidi, Enrica; Della Giustina, Gioia; Sorgato, Marco; Krampera, Mauro; Bassi, Giulio; Di Liddo, Rosa; Lucchetta, Giovanni; Conconi, Maria Teresa; Brusatin, Giovanna

    2015-04-01

    An industrially feasible process for the fast mass-production of molded polymeric micro-patterned substrates is here presented. Microstructured polystyrene (PS) surfaces were obtained through micro injection molding (?IM) technique on directly patterned stamps realized with a new zirconia-based hybrid spin-on system able to withstand 300 cycles at 90 °C. The use of directly patterned stamps entails a great advantage on the overall manufacturing process as it allows a fast, flexible, and simple one-step process with respect to the use of milling, laser machining, electroforming techniques, or conventional lithographic processes for stamp fabrication. Among the different obtainable geometries, we focused our attention on PS replicas reporting 2, 3, and 4 ?m diameter pillars with 8, 9, 10 ?m center-to-center distance, respectively. This enabled us to study the effect of the substrate topography on human mesenchymal stem cells behavior without any osteogenic growth factors. Our data show that microtopography affected cell behavior. In particular, calcium deposition and osteocalcin expression enhanced as diameter and interpillar distance size increases, and the 4-10 surface was the most effective to induce osteogenic differentiation. PMID:25756304

  7. Micro genetic algorithm based optimal gate positioning in injection molding design

    International Nuclear Information System (INIS)

    The paper deals with the optimization of runner system in injection molding design. The design objective is to locate gate positions by minimizing both maximum injection pressure at the injection port and maximum pressure difference among all the gates on a product with constraints on shear stress and/or weld-line. The analysis of filling process is conducted by a finite element based program for polymer flow. Micro genetic algorithm (mGA) is used as a global optimization tool due to the nature of inherent nonlinearlity in flow analysis. Four different design applications in injection molds are explored to examine the proposed design strategies. The paper shows the effectiveness of mGA in the context of optimization of runner system in injection molding design

  8. Finite Element Analysis of Reciprocating Screw for Injection Molding Machine

    OpenAIRE

    Nagsen B. Nagrale; Dr.R.N.Baxi

    2011-01-01

    This paper deals with, the solution of problem occurred for reciprocating screw of Injection molding machine. It identifies and solves the problem by using the modeling and simulation techniques. The problem occurred in the reciprocating screw of machine which was wearing of threads due to affect of temperature of mold materials(flow materials) i.e. Nylon, low density polypropylene, polystyrene, PVC etc., The main work was to model the components of machine with dimensions, assemble those com...

  9. Electrical and dielectric properties of foam injection-molded polypropylene/multiwalled carbon nanotube composites

    Science.gov (United States)

    Ameli, A.; Nofar, M.; Saniei, M.; Hossieny, N.; Park, C. B.; Pötschke, P.

    2015-05-01

    A combination of high dielectric permittivity (?') and low dielectric loss (tan ?) is required for charge storage applications. In percolative systems such as conductive polymer composites, however, obtaining high ?' and low tan ? is very challenging due to the sharp insulation-conduction transition near the threshold region. Due to the particular arrangement of conductive fillers induced by both foaming and injection molding processes, they may address this issue. Therefore, this work evaluates the application of foam injection molding process in fabricating polymer nanocomposites for energy storage. Polypropylene-multiwalled carbon nanotubes (PP-MWCNT) composites were prepared by melt mixing and foamed in an injection molding process. Electrical conductivity (?), ?' and tan ? were then characterized. Also, scanning and transmission electron microscopy (SEM and TEM) was used to investigate the carbon nanotube's arrangement as well as cellular morphology. The results showed that foam injection-molded composites exhibited highly superior dielectric properties to those of solid counterparts. For instance, foamed samples had ?'=68.3 and tan ? =0.05 (at 1.25 vol.% MWCNT), as opposed to ?'=17.8 and tan ?=0.04 in solid samples (at 2.56 vol.% MWCNT). The results of this work reveal that high performance dielectric nanocomposites can be developed using foam injection molding technologies for charge storage applications.

  10. The Shrinkage Behavior and Surface Topographical Investigation for Micro Metal Injection Molding

    DEFF Research Database (Denmark)

    Islam, Aminul; Giannekas, Nikolaos

    2014-01-01

    Metal injection molding (MIM) is a near net shape manufacturing technology that can produce highly complex and dimensionally stable parts for high end engineering applications. Despite the recent growth and industrial interest, micro metal molding is yet to be the field of extensive research especially when it is compared with micro molding of thermoplastics. The current paper presents a thorough investigation on the process of metal injection molding where it systematically characterizes the effects of important process conditions on the shrinkage and surface quality of molded parts with micro features. Effects of geometrical factors like feature dimensions and distance from the gate on the replication quality are studied. The influence of process conditions on the achievable roughness for the final metal parts is discussed based on the experimental findings. The test geometry is characterized by 2½D surface structures containing thin ribs of different aspect ratios and thicknesses in the sub-mm dimensional range. The test parts were molded from Catamold 316L with a conventional injection molding machine. Afterwards, the parts were de-binded and sintered to produce the final test samples. Among the different process parameters studied, the melt temperature was the most influential parameters for better replication and dimensional stability of the final part. The results presented in the paper clearly show that the shrinkage in metal part is not uniform in the micro scale. It depends on the feature dimensions and also on the process conditions. A thin section of the part exhibits higher relative shrinkage compared with a thicker section. Based on these findings, it can be concluded that a micro part molded by MIM process will have higher relative shrinkage compared to a macro part made with the same process.

  11. The shrinkage behavior and surface topographical investigation for micro metal injection molding

    Science.gov (United States)

    Islam, A.; Giannekas, N.; Marhöfer, D. M.; Tosello, G.; Hansen, H. N.

    2015-05-01

    Metal injection molding (MIM) is a near net shape manufacturing technology that can produce highly complex and dimensionally stable parts for high end engineering applications. Despite the recent growth and industrial interest, micro metal molding is yet to be the field of extensive research especially when it is compared with micro molding of thermoplastics. The current paper presents a thorough investigation on the process of metal injection molding where it systematically characterizes the effects of important process conditions on the shrinkage and surface quality of molded parts with micro features. Effects of geometrical factors like feature dimensions and distance from the gate on the replication quality are studied. The influence of process conditions on the achievable roughness for the final metal parts is discussed based on the experimental findings. The test geometry is characterized by 2½D surface structures containing thin ribs of different aspect ratios and thicknesses in the sub-mm dimensional range. The test parts were molded from Catamold 316L with a conventional injection molding machine. Afterwards, the parts were de-binded and sintered to produce the final test samples. Among the different process parameters studied, the melt temperature was the most influential parameters for better replication and dimensional stability of the final part. The results presented in the paper clearly show that the shrinkage in metal part is not uniform in the micro scale. It depends on the feature dimensions and also on the process conditions. A thin section of the part exhibits higher relative shrinkage compared with a thicker section. Based on these findings, it can be concluded that a micro part molded by MIM process will have higher relative shrinkage compared to a macro part made with the same process.

  12. Multiple Performance Optimization for the Best Metal Injection Molding Green Compact

    Directory of Open Access Journals (Sweden)

    M.R. Harun

    2011-01-01

    Full Text Available This study presents and demonstrates the effectiveness of optimizing multiple quality characteristics of the injection molding of the MIM green compacts via Taguchi method-based Grey analysis. The modified algorithm adopted here was successfully used for both detraining the optimum setting of the process parameters and for combining multiple quality characteristics into one integrated numerical value called Grey relational grade. The significant molding parameters were identified as (1 Injection Pressure (2 Injection Temperature (3 Powder Loading (4 Mold Temperature (5 Holding Pressure and (6 Injection Speed. In addition, the multiple quality characteristics required are: (1 less defects (2 strong and (3 denser compact. The result concluded that the powder loading (C is very significant for the combination of the quality characteristics.

  13. In situ synchrotron studies of structure development during injection molding of liquid crystalline polymers

    Science.gov (United States)

    Rendon, Stanley; Burghardt, Wesley

    2006-03-01

    As in all polymer materials, the effect of polymer processing on the underlying molecular structure has a profound effect on the properties of liquid crystalline polymer products. While in situ scattering techniques have proven powerful for studying complex polymer structure during comparatively simple shearing or channel flows, their application to processing flows has largely been limited to in situ x-ray scattering/diffraction studies of structure development during fiber spinning. Here we report a new experiment in which a lab-scale injection molding machine has been modified to allow real-time, in situ measurements of molecular orientation development and subsequent crystallization during injection molding. The experiment requires high x-ray energy to reduce absorption in the aluminum mold wall, and high flux and a fast area detectors to achieve the necessary resolution to track time-dependent changes in fluid structure during mold filling. Hence it is ideally suited to the capabilites of the Advanced Photon Source. We report measurements injection molding of a commercial liquid crystalline copolyester (Vectra A) as a function of position in the mold and various process variables.

  14. An apparatus for in situ x-ray scattering measurements during polymer injection molding

    Science.gov (United States)

    Rendon, Stanley; Fang, Jun; Burghardt, Wesley R.; Bubeck, Robert A.

    2009-04-01

    We report a novel instrument for synchrotron-based in situ x-ray scattering measurements during injection molding processing. It allows direct, real-time monitoring of molecular-scale structural evolution in polymer materials undergoing a complex processing operation. The instrument is based on a laboratory-scale injection molding machine, and employs customized mold tools designed to allow x-ray access during mold filling and subsequent solidification, while providing sufficient robustness to withstand high injection pressures. The use of high energy, high flux synchrotron radiation, and a fast detector allows sufficiently rapid data acquisition to resolve time-dependent orientation dynamics in this transient process. Simultaneous monitoring of temperature and pressure signals allows transient scattering data to be referenced to various stages of the injection molding cycle. Representative data on a commercial liquid crystalline polymer, Vectra® B950, are presented to demonstrate the features of this apparatus; however, it may find application in a wide range of polymeric materials such as nanocomposites, semicrystalline polymers and fiber-reinforced thermoplastics.

  15. Localized mold heating with the aid of selective induction for injection molding of high aspect ratio micro-features

    Science.gov (United States)

    Park, Keun; Lee, Sang-Ik

    2010-03-01

    High-frequency induction is an efficient, non-contact means of heating the surface of an injection mold through electromagnetic induction. Because the procedure allows for the rapid heating and cooling of mold surfaces, it has been recently applied to the injection molding of thin-walled parts or micro/nano-structures. The present study proposes a localized heating method involving the selective use of mold materials to enhance the heating efficiency of high-frequency induction heating. For localized induction heating, a composite injection mold of ferromagnetic material and paramagnetic material is used. The feasibility of the proposed heating method is investigated through numerical analyses in terms of its heating efficiency for localized mold surfaces and in terms of the structural safety of the composite mold. The moldability of high aspect ratio micro-features is then experimentally compared under a variety of induction heating conditions.

  16. Localized mold heating with the aid of selective induction for injection molding of high aspect ratio micro-features

    International Nuclear Information System (INIS)

    High-frequency induction is an efficient, non-contact means of heating the surface of an injection mold through electromagnetic induction. Because the procedure allows for the rapid heating and cooling of mold surfaces, it has been recently applied to the injection molding of thin-walled parts or micro/nano-structures. The present study proposes a localized heating method involving the selective use of mold materials to enhance the heating efficiency of high-frequency induction heating. For localized induction heating, a composite injection mold of ferromagnetic material and paramagnetic material is used. The feasibility of the proposed heating method is investigated through numerical analyses in terms of its heating efficiency for localized mold surfaces and in terms of the structural safety of the composite mold. The moldability of high aspect ratio micro-features is then experimentally compared under a variety of induction heating conditions.

  17. Injection molding of power-law polymer

    Science.gov (United States)

    Krane, Matthew J. M.

    2008-10-25

    A polymer in injected with a constant pressure gradient between two parallel plates. The progression of the polymer front is modeled for a power law fluid (typical of a polymer) and compared to results for a Newtonian fluid.

  18. Injection molded pinched flow fractionation device for enrichment of somatic cells in cow milk

    DEFF Research Database (Denmark)

    Jensen, Marie PØdenphant; Marie, Rodolphe

    2014-01-01

    In this paper the continuous microfluidic separation technique pinched flow fractionation is applied to the enrichment of somatic cells from cow milk. Somatic cells were separated from the smallest fat particles and proteins thus better imaging and analysis of the cells can be achieved. The enrichment was performed using an all-polymer pinched flow fractionation device fabricated by injection molding. The polymer chips were bonded to a 500 lm polymer foil using UV assisted thermal bonding. The quality of the final devices was reproducible and the injection molding process combined with the use of cheap materials ensures the possibility for device mass production

  19. Single Performance Optimization of Micro Metal Injection Molding for the Highest Green Strength by Using Taguchi Method

    Directory of Open Access Journals (Sweden)

    M.H.I Ibrahim

    2010-06-01

    Full Text Available Micro metal injection molding is drawing attention recently as one the most cost effective processes in powder metallurgy to produce small-scale intricate part and competitive cost for mass production of micro components where it is greatly influenced by injection parameter. Thus, this paper investigated the optimization of highest green strength which plays an important characteristic in determining the successful of micro MIM. Stainless steel SS 316L was used with composite binder, which consists of PEG and PMMA while SA works as a surfactant. Feedstock with 61.5% with several injection parameters were optimized which highly significant through screening experiment such as injection pressure(A, injection temperature(B, mold temperature(C, injection time(D and holding time(E. Besides that, interaction effects between injection pressure, injection temperature and mold temperature were also considered to optimize in the Taguchi’s orthogonal array. Analysis of variance (ANOVA in terms of signal-to-noise ratio (S/N-larger is better for green strength was also presented in this paper. Result shows that interaction between injection temperature and mold temperature (BxC give highest significant factor followed by interaction between injection pressure and injection temperature (AxB. Single factor that also contributes to significant optimization are mold temperature(C, injection time (D and injection pressure (A. Overall, this study shows that Taguchi method would be among the best method to solve the problem with minimum number of trials.

  20. FPGA-based multiprocessor system for injection molding control.

    Science.gov (United States)

    Muñoz-Barron, Benigno; Morales-Velazquez, Luis; Romero-Troncoso, Rene J; Rodriguez-Donate, Carlos; Trejo-Hernandez, Miguel; Benitez-Rangel, Juan P; Osornio-Rios, Roque A

    2012-01-01

    The plastic industry is a very important manufacturing sector and injection molding is a widely used forming method in that industry. The contribution of this work is the development of a strategy to retrofit control of an injection molding machine based on an embedded system microprocessors sensor network on a field programmable gate array (FPGA) device. Six types of embedded processors are included in the system: a smart-sensor processor, a micro fuzzy logic controller, a programmable logic controller, a system manager, an IO processor and a communication processor. Temperature, pressure and position are controlled by the proposed system and experimentation results show its feasibility and robustness. As validation of the present work, a particular sample was successfully injected. PMID:23202036

  1. FPGA-Based Multiprocessor System for Injection Molding Control

    Directory of Open Access Journals (Sweden)

    Roque A. Osornio-Rios

    2012-10-01

    Full Text Available The plastic industry is a very important manufacturing sector and injection molding is a widely used forming method in that industry. The contribution of this work is the development of a strategy to retrofit control of an injection molding machine based on an embedded system microprocessors sensor network on a field programmable gate array (FPGA device. Six types of embedded processors are included in the system: a smart-sensor processor, a micro fuzzy logic controller, a programmable logic controller, a system manager, an IO processor and a communication processor. Temperature, pressure and position are controlled by the proposed system and experimentation results show its feasibility and robustness. As validation of the present work, a particular sample was successfully injected.

  2. Measurement of solidification and melting behavior of resin in injection molding and detection of flaws molded parts by using ultrasonic waves

    International Nuclear Information System (INIS)

    Injection molding of thermoplastics is widely used in many industries. However, it is not so easy to design the mold and to determine the optimal injection conditions. Therefore, a number of CAR mold design software packages for simulating the injection molding process have been developed. In order to confirm the results obtained from CAE, it is necessary to compare the numerical results with the experimental ones. In practice, the filling behavior has been observed with an optical visualization technique, but the solidification behavior of melted resin filled into the cavity has not yet been observed. It has been indirectly detected by measuring the pressure in the mold cavity. On the other hand, the melting behavior of solid resin in the barrel of an infection molding machine has influence on the quality of a molded part. Therefore, it is important to observe the melting behavior of solid resin in the barrel. In this study a method for measuring the solidification behavior in the cavity and the melting behavior in the barrel have been developed by using ultrasonic waves. Moreover, a method of detecting a flaw or a different material included in the molded part has been developed by using ultrasonic waves. Especially, a flaw close to the surface of the molded part can be detected by separating the flaw echo from the surface echo of the molded part. It was determined that the thickness of the solid layer of the melted resin filled into the cavity can be measured by using ultrasonic waves. The melting behavior of the resin on the barrel surface can be observed by measuring the amplitude of the reflected echo on the interface between the barrel and resin. Moreover, the flaw close to the surface of the molded part can be detected by using the ultrasonic waves.

  3. Injection molding micro patterns with high aspect ratio using a polymeric flexible stamper

    Directory of Open Access Journals (Sweden)

    2011-11-01

    Full Text Available Poor filling occurs during the injection molding process of micro- or nano- scale patterns mainly because the hot polymer melt rapidly cools and its skin quickly solidifies upon contact with the mold surface. In this study, it is proposed to use Polyethylene terephthalate (PET film coated with patterned polyurethane acrylate (PUA as an effective thermal barrier. It can significantly hinder heat transfer into the mold during the molding process and thus may keep the melt viscosity low for longer duration. As a result, the replication would be improved not only during the filling phase but also during the packing phase. In order to verify the validity of the use of polymeric stamper, the melt-film interface temperature was evaluated by numerical simulation. Experimental results indicated that patterns possessing widths within the range of one to tens of micrometers and a height of approximately 10 µm were successfully filled and demolded.

  4. Micro Machining of Injection Mold Inserts for Fluidic Channel of Polymeric Biochips

    Directory of Open Access Journals (Sweden)

    Myeong-Woo Cho

    2007-08-01

    Full Text Available Recently, the polymeric micro-fluidic biochip, often called LOC (lab-on-a-chip, has been focused as a cheap, rapid and simplified method to replace the existing biochemical laboratory works. It becomes possible to form miniaturized lab functionalities on a chip with the development of MEMS technologies. The micro-fluidic chips contain many micro-channels for the flow of sample and reagents, mixing, and detection tasks. Typical substrate materials for the chip are glass and polymers. Typical techniques for micro-fluidic chip fabrication are utilizing various micro pattern forming methods, such as wet-etching, micro-contact printing, and hot-embossing, micro injection molding, LIGA, and micro powder blasting processes, etc. In this study, to establish the basis of the micro pattern fabrication and mass production of polymeric micro-fluidic chips using injection molding process, micro machining method was applied to form micro-channels on the LOC molds. In the research, a series of machining experiments using micro end-mills were performed to determine optimum machining conditions to improve surface roughness and shape accuracy of designed simplified micro-channels. Obtained conditions were used to machine required mold inserts for micro-channels using micro end-mills. Test injection processes using machined molds and COC polymer were performed, and then the results were investigated.

  5. Net shaping of tungsten components by micro powder injection molding

    International Nuclear Information System (INIS)

    For future fusion power plants, a He-cooled Divertor design has been developed by the Forschungszentrum Karlsruhe. The Divertor as one of the plasma facing components has to withstand high heat loads of 10 MW/m2 as well as sputtering due to ion impact on the surface of the Divertor. Tungsten is considered the most promising material to be used for this application. Because of the high hardness of tungsten, fabrication of these parts by standard shaping technologies for steels such as milling is, depending on the component, either difficult or even impossible. The objective of this work is the adoption of tungsten on powder injection moulding (PIM) as a widely used mass production method for net shaping of micro structured ceramic and metal parts. It is well known that for design accuracy and good surface quality as well as high sinter activity the particle size of powders applied to micro PIM should be as small as possible while the powder content of the feedstock should be as high as possible but at least 50 vol.%. In case of tungsten, industrial available powders are usually highly agglomerated. In order to provide a homogeneous feedstock with a solid load above 50 vol.%, powders applied to PIM have to be deagglomerated. Depending on the grain size, tungsten shows different kinds of agglomeration states. Ultra fine grain sizes below 1 ?m build sponge like agglomerates, while bigger grain sizes result in agglomerates being built of individually grown crystals. It was found that pre-milling of powders with a grain size of 0,7 ?m FSSS has nearly no effect on the resulting viscosity whereas in case of 3 ?m FSSS deagglomeration drastically improves the viscosity and the processability of the feedstock. For further improvement of the feedstock, in this paper grain size dependent variations of the solid load shall be discussed to define an optimised grain size for Micro PIM of tungsten components. For initial PIM experiments, a first feedstock based on a tungsten powder with a grain size of 2,5 ?m FSSS and a solid load of 55 vol.% was developed and a microstructured cavity for a gear housing as well as Slot Arrays with 24 Slots were injection molded. Further on, tensile test bars and charpy-test specimens were replicated to provide mechanical data of tungsten samples being prepared by PIM. By debinding and sintering of injection molded tungsten parts, a density of 96% and a residual carbon content <0,003 wt.% was achieved. (author)

  6. Metal Injection Molding (MIM) of NdFeB Magnets

    Science.gov (United States)

    Hartwig, T.; Lopes, L.; Wendhausen, P.; Ünal, N.

    2014-07-01

    Due to the increased and unstable prices for Rare Earth elements there are activities to develop alternative hard magnetic materials. Reducing the amount of material necessary to produce complex sintered NdFeB magnets can also help to reduce some of the supply problem. Metal Injection Molding (MIM) is able to produce near net shape parts and can reduce the amount of finishing to achieve final geometry. Although MIM of NdFeB has been patented and published fairly soon after the development of the NdFeB magnets there has never been an industrial production. This could be due to the fact that MIM was very young at that time and hardly developed. Thus, the feasibility of the process needs to be revaluated. This paper presents results of our work on determining the process parameters influencing the magnetic properties of the sintered magnets as well as the shrinkage during processing. The role of binder and powder loading on the alignment of the particles as well as on the carbon and oxygen contamination was examined.

  7. Metal Injection Molding (MIM of NdFeB Magnets

    Directory of Open Access Journals (Sweden)

    Hartwig T.

    2014-07-01

    Full Text Available Due to the increased and unstable prices for Rare Earth elements there are activities to develop alternative hard magnetic materials. Reducing the amount of material necessary to produce complex sintered NdFeB magnets can also help to reduce some of the supply problem. Metal Injection Molding (MIM is able to produce near net shape parts and can reduce the amount of finishing to achieve final geometry. Although MIM of NdFeB has been patented and published fairly soon after the development of the NdFeB magnets there has never been an industrial production. This could be due to the fact that MIM was very young at that time and hardly developed. Thus, the feasibility of the process needs to be revaluated. This paper presents results of our work on determining the process parameters influencing the magnetic properties of the sintered magnets as well as the shrinkage during processing. The role of binder and powder loading on the alignment of the particles as well as on the carbon and oxygen contamination was examined.

  8. Análise do desenvolvimento morfológico da blenda polimérica PBT/ABS durante as etapas de mistura por extrusão e moldagem por injeção Analysis of the morphological development of PBT/ABS blends during the extrusion and injection molding processes

    Directory of Open Access Journals (Sweden)

    Edson N. Ito

    2004-06-01

    Full Text Available O enfoque principal deste trabalho foi observar o desenvolvimento da morfologia de fases da blenda binária PBT/ABS e desta blenda compatibilizada pela adição de um copolímero acrílico reativo, durante a etapa de mistura por extrusão e de moldagem por injeção. A evolução da morfologia das blendas, durante a etapa de mistura, foi analisada através do uso de amostras coletadas de uma extrusora de rosca dupla co-rotacional, com acessório especialmente projetado para coleta in line. A morfologia observada nas amostras obtidas por injeção foi realizada utilizando amostras retiradas de corpos de prova moldados. As amostras obtidas por extrusão e por moldagem por injeção foram posteriormente preparadas através de crio-ultramicrotomia e observadas através de microscopia eletrônica de transmissão (TEM. Uma "Função Dispersão" foi desenvolvida neste trabalho para comparar as diversas morfologias sob diferentes condições de processamento e de compatibilização. A adição de compatibilizante favorece a formação de uma morfologia de domínios de ABS dispersos em PBT, ao longo do canhão da extrusora, e previne satisfatoriamente o fenômeno de coalescência destes domínios durante o processo de moldagem por injeção. A função dispersão foi utilizada principalmente para mostrar a tendência da evolução morfológica e mostrou um bom desempenho para tal.The aim of this work was to observe the development of the phase morphology of the PBT/ABS blends during their extrusion mixing and injection molding steps. The evolution of the blend morphology during the mixing stage was analyzed using a specially designed co-rotational twin-screw extruder with a collecting device located along the barrel. Blend samples were collected in-line along the length of the extruder barrel during the blending process. Blend morphology was also observed from specimens molded through injection molding. All the samples were observed by transmission electron microscopy (TEM. They were prepared by cryo-ultramicrotomy and the rubbery phase of the ABS contained in the blends was stained with osmium tetroxide (OsO4. A special function was established and is proposed to analyze the blend morphology trends through image analysis. In binary blends, the ABS phase showed better dispersion after the mixture passed through the extruder die. However, a coalescence phenomenon was observed during the next molding step. Compatibilized PBT/ABS blends showed better dispersion than binary blends, even after injection molding. The special function used to quantify the dispersion throughout the mixing and molding steps showed an excellent performance.

  9. Análise do desenvolvimento morfológico da blenda polimérica PBT/ABS durante as etapas de mistura por extrusão e moldagem por injeção / Analysis of the morphological development of PBT/ABS blends during the extrusion and injection molding processes

    Scientific Electronic Library Online (English)

    Edson N., Ito; Luiz A., Pessan; Elias, Hage Jr.; José A., Covas.

    2004-06-01

    Full Text Available O enfoque principal deste trabalho foi observar o desenvolvimento da morfologia de fases da blenda binária PBT/ABS e desta blenda compatibilizada pela adição de um copolímero acrílico reativo, durante a etapa de mistura por extrusão e de moldagem por injeção. A evolução da morfologia das blendas, du [...] rante a etapa de mistura, foi analisada através do uso de amostras coletadas de uma extrusora de rosca dupla co-rotacional, com acessório especialmente projetado para coleta in line. A morfologia observada nas amostras obtidas por injeção foi realizada utilizando amostras retiradas de corpos de prova moldados. As amostras obtidas por extrusão e por moldagem por injeção foram posteriormente preparadas através de crio-ultramicrotomia e observadas através de microscopia eletrônica de transmissão (TEM). Uma "Função Dispersão" foi desenvolvida neste trabalho para comparar as diversas morfologias sob diferentes condições de processamento e de compatibilização. A adição de compatibilizante favorece a formação de uma morfologia de domínios de ABS dispersos em PBT, ao longo do canhão da extrusora, e previne satisfatoriamente o fenômeno de coalescência destes domínios durante o processo de moldagem por injeção. A função dispersão foi utilizada principalmente para mostrar a tendência da evolução morfológica e mostrou um bom desempenho para tal. Abstract in english The aim of this work was to observe the development of the phase morphology of the PBT/ABS blends during their extrusion mixing and injection molding steps. The evolution of the blend morphology during the mixing stage was analyzed using a specially designed co-rotational twin-screw extruder with a [...] collecting device located along the barrel. Blend samples were collected in-line along the length of the extruder barrel during the blending process. Blend morphology was also observed from specimens molded through injection molding. All the samples were observed by transmission electron microscopy (TEM). They were prepared by cryo-ultramicrotomy and the rubbery phase of the ABS contained in the blends was stained with osmium tetroxide (OsO4). A special function was established and is proposed to analyze the blend morphology trends through image analysis. In binary blends, the ABS phase showed better dispersion after the mixture passed through the extruder die. However, a coalescence phenomenon was observed during the next molding step. Compatibilized PBT/ABS blends showed better dispersion than binary blends, even after injection molding. The special function used to quantify the dispersion throughout the mixing and molding steps showed an excellent performance.

  10. Mechanical properties depending on fiber orientation in injection molded short-fiber-reinforced plastic parts

    Energy Technology Data Exchange (ETDEWEB)

    Chung, S.T.; Kwon, T.H. [Pohang Univ. of Science and Technology (Korea, Democratic People`s Republic of)

    1996-12-31

    In injection molding of short-fiber-reinforced plastics, the fiber orientation during a mold filling process is determined by the flow field, while it is in turn affected by the orientation state of fibers. The Dinh and Armstrong`s orientation-dependent constitutive equation for fiber suspension was thus incorporated into the coupled analysis of mold filling flow and fiber orientation including the additional stresses due to the existence of fibers. The mold filling simulation was then performed by solving a new pressure equation and the energy equation via a finite element/finite difference method as well as evolution equations for the second-order orientation tensor via the fourth-order Runge-Kutta method. With the fiber orientation known, predictions of the anisotropic mechanical properties of the composites are obtained by using the Halpin-Tsai equations for unidirectional composites and taking an orientation average.

  11. Study of microcellular injection-molded polypropylene/waste ground rubber tire powder blend

    International Nuclear Information System (INIS)

    Microcellular polypropylene/waste ground rubber tire powder blend processing was performed on an injection-molding machine with a chemical foaming agent. The molded samples produced based on the design of experiments (DOE) matrices were subjected to tensile testing and scanning electron microscope (SEM) analyses. Molding conditions and waste ground rubber tire (WGRT) powder have been found to have profound effects on the cell structures and mechanical properties of polypropylene (PP) and waste ground rubber tire powder composite samples. The result shows that microcellular PP/WGRT blend samples exhibit smaller cell size and higher cell density compare with polypropylene resin. Among the molding parameters studied, chemical foaming agent weight percentage has the most significant effect on cell size, cell density, and tensile strength. The results also suggest that tensile strength of microcellular PP/WGRT composites is sensitive to weight reduction, and skin thickness.

  12. Initial verification of an induction heating set-up for injection molding

    DEFF Research Database (Denmark)

    Menotti, Stefano; Hansen, Hans NØrgaard

    2013-01-01

    Molding of thin and long parts by injection molding leads to special requirements for the mold in order to ensure proper filling and acceptable cycle time. This paper investigates the applicability of embedded induction heating for the improvement of the filling of thin long parts. The object selected for the investigation is a thin spiral. For the complete molding of the component, elevated mold temperatures are required. For this propose a new injection molding set-up was developed, which allows rapid heating of the cavity wall by an induction heating system. The temperature was measured by two thermocouples placed in the die insert. The system was used to heat up the cavity wall with heating rates of up to 10 °C/s. Experiments were carried out with ABS material. The lengths of the object were measured by a suitable measurement set up. The experimental result show that the use of the induction heating system process is an efficient way for improving the filling of the cavity.

  13. Surface topographic characterization for polyamide composite injection molds made of aluminum and copper alloys.

    Science.gov (United States)

    Pereira, A; Hernández, P; Martinez, J; Pérez, J A; Mathia, T G

    2014-01-01

    In order to ensure flexibility and rapid new product development, the mold industry made use of soft materials for cavity inserts in injection molds. However, materials of this kind are prone to wear. This article analyzes the topographic characterization of the surface and wear processes in injection molds cavities. Two materials have been used to produce the cavities: aluminum alloy EN AW?6082 T4 and copper alloy Cu Zn39 Pb3. The surface topography was measured with the use of optical interferometry profiling technology; roughness and surface parameters were determined according to ISO 4287, ISO 25178, and EUR 15178N. In order to complete this research, an experimental part with different thicknesses and shapes was designed, and cavity inserts of aluminum and copper were made. Polyamide PA6, with 30% fiberglass reinforcement, was employed in the experimental procedure. Measurements of cavity mold surfaces were performed after 9,200 cycles on each mold and at different locations on the mold. The surface measurement was made with a white light vertical scanning interferometry, also known as coherence scanning interferometry (ISO DIS 25178?604). The results are analyzed and differences between the two types of cavity inserts materials are discussed. PMID:23447356

  14. Rheological and Thermal Debinding Behaviors in Titanium Powder Injection Molding

    Science.gov (United States)

    Park, Seong-Jin; Wu, Yunxin; Heaney, Donald F.; Zou, Xin; Gai, Guosheng; German, Randall M.

    2009-01-01

    Powder injection molding (PIM) is suitable for the fabrication of complex shape titanium and its alloys and has a great potential in many applications. This article deals with the injection molding of hydride-dehydride (HDH) titanium powder, spheroidized HDH titanium powder, and gas-atomized (GA) titanium powder. Rheological and thermal debinding behaviors are compared between feedstocks made from the three powders. Torque and capillary rheometers are used to investigate rheological behavior as it relates to the power-law model of viscosity and moldability index. Thermogravimetric analysis (TGA) was employed to analyze debinding behavior given a master decomposition curve consisting of two sigmoids. Spheroidized HDH Ti powder behaves in a manner similar to GA Ti powder. The analysis of the results in this study indicates the possibility of using a combination of HDH and GA titanium powders for PIM.

  15. Pressureless sintering behavior of injection molded alumina ceramics

    Directory of Open Access Journals (Sweden)

    Liu W.

    2014-01-01

    Full Text Available The pressureless sintering behaviors of two widely used submicron alumina (MgOdoped and undoped with different solid loadings produced by injection molding have been studied systematically. Regardless of the sinterability of different powders depending on their inherent properties, solid loading plays a critical role on the sintering behavior of injection molded alumina, which greatly determines the densification and grain size, and leads to its full densification at low temperatures. As compared to the MgO-doped alumina powder, the undoped specimens exhibit a higher sinterability for its smaller particle size and larger surface area. While full densification could be achieved for MgO-doped powders with only a lower solid loading, due to the fact that MgO addition can reduce the detrimental effect of the large pore space on the pore-boundary separation.

  16. Determination of Optimal Manufacturing Parameters for Injection Mold by Inverse Model Basing on MANFIS

    OpenAIRE

    Chong-Ching Chang; Chung-Neng Huang

    2010-01-01

    Since plastic products are with the features as light, anticorrosive and low cost etc., that are generally used in several of tools or components. Consequently, the requirements on the quality and effectiveness in production are increasingly serious. However, there are many factors affecting the yield rate of injection products such as material characteristic, mold design, and manufacturing parameters etc. involved with injection machine and the whole manufacturing process. Traditionally, the...

  17. Measurement and computation of thermal stresses in injection molding of amorphous and crystalline polymers

    Science.gov (United States)

    Farhoudi, Yalda

    1998-12-01

    An integrated experimental and theoretical study of the residual thermal stresses has been carried out. The final stress profiles along the thickness were measured in an amorphous and a semi-crystalline injection molded polymer using the layer removal technique. The two materials exhibited drastically distinct residual profiles. Furthermore, processing parameters such as melt and coolant temperatures, pressure history, and mold thickness were found to modify the profiles. In order to elucidate the findings, two models were derived. The two-dimensional free mold shrinkage model was developed to provide a rapid estimation of thermal stresses and the main features of their profile. A more complex model was developed by integrating the stress analysis with the simulation of the complete injection molding cycle by McKam. This model accounts for the fountain flow effect, the crystallization, and the PVT behavior of the material. With the help of the model predictions, explanations were provided for the occurrence of various regions in the residual stress profiles. Transitions or reversal of the regions under variable conditions or material properties were observed to be mainly determined by the ratio of the thermal to the pressure effects. Using these concepts, practical conclusions were drawn for controlling the residual stresses. As an alternative for optimization of injection molding with respect to residual stresses, inverse methods were developed to calculate the pressure history or the initial temperature distribution required to produce a prescribed residual stress distribution. These methods were tested using direct solutions with added errors and experimental stress data.

  18. A Simulation Study of Conformal Cooling Channels in Plastic Injection Molding

    Directory of Open Access Journals (Sweden)

    Omar A. Mohamed, S.H. Masood, Abul Saifullah

    2013-09-01

    Full Text Available In injection molding process, the cooling channel performance is one of the most crucial factors because it has significant effect on both production rate and the quality of the plastic part. In order to reduce the cycle time, and control the uniform distribution of temperature, it is necessary to create conformal cooling channels, which conform to the shape of the mold cavity and core. This paper presents a simulation study of different types of cooling channels in an injection molded plastic part and compares the performance in terms of time to ejection temperature, shrinkage, temperature profile, and part warpage to determine which configuration is more appropriate to provide uniform cooling with minimum cycle time. Autodesk Moldflow Insight (AMI simulation software is used to examine the results of the cooling channels performance.

  19. Carbon Nanotubes Reinforced Copper Matrix Nanocomposites via Metal Injection Molding Technique

    Directory of Open Access Journals (Sweden)

    Norani M. Mohamed

    2012-01-01

    Full Text Available New thermal management solutions are required to provide cost-effective means of dissipating heat from next generation microelectronic devices. In this paper, fabrication of heat sink nanocomposite made of copper reinforced by multiwalled carbon nanotubes up to 10 Vol. % using metal injection molding technique is presented. A mixture of Cu-MWNTs was compounded using internal mixer machine for homogenous dispersion of the solid powder in the binder. To ensure a flow able feedstock during injection molding process, different binder systems and their Cu-MWNTs feedstocks were examined using capillary rheometer machine. In order to avoid binder degradation, TGA test was carried out. The TGA results showed that the processing temperature such as mixing and injection molding should be lower than 170°C. The injection molding was carried out at low pressure. A combination of solvent and thermal debinding was used for binder removal, and then the samples were isothermally sintered at different sintering temperatures (900-1050°C in argon atmosphere. The results showed that the sintered samples experienced an isotropic shrinkage around 17% with relatively homogeneous dispersion of MWNTs in the copper matrix which is expected to enhance the physical and mechanical properties of the final product.

  20. Advancements on the simulation of the micro injection moulding process

    DEFF Research Database (Denmark)

    Marhöfer, David Maximilian; Tosello, Guido

    2013-01-01

    Process simulations are applied in micro injection molding with the same purpose as in conventional injection molding: aiming at optimization and support of the design of mold, inserts, plastic products, and the process itself. Available software packages are however not well suited for micro injection molding, because they are developed for macro plastic parts and they are therefore limited in the capability of modeling the polymer flow in micro cavities properly. However, new opportunities for improved accuracy have opened up due to current developments of the simulation technology. Hence, new strategies and aspects for comprehensive simulation models which provide more precise results for micro injection molding are discussed. Modeling and meshing recommendations are presented, leading to a multi-scale mesh of all relevant units in the injection molding process. The implementation of the process boundary conditions is described, being followed by results illustrating their importance on the simulation output. Finally, the influence of the cooling simulation settings is analyzed.

  1. Experimental Study of Fiber Length and Orientation in Injection Molded Natural Fiber/Starch Acetate Composites

    OpenAIRE

    Amp Ttinen, Kalle N.; Bo Madsen; Roberts Joffe; Heidi Peltola

    2011-01-01

    Composite compounds based on triethyl citrate plasticized starch acetate and hemp and flax fibers were prepared by melt processing. Plasticizer contents from 20 to 35 wt% and fiber contents of 10 and 40 wt% were used. The compounded composites were injection molded to tensile test specimens. The effect of processing, melt viscosity and fiber type on the fiber length was investigated. The lengths of fully processed fibers were determined by dissolving the matrix and measuring the length of the...

  2. A study of magneto-crystalline alignment in sintered barium hexaferrite fabricated by powder injection molding

    International Nuclear Information System (INIS)

    Barium hexaferrite permanent magnets were produced by powder injection molding. Starting barium hexaferrite powder was prepared from a Fe2O3 and BaCO3 powder mixture by calcination followed by milling. The feedstock for powder injection molding was prepared by mixing barium hexaferrite powder with a low viscosity binder. Magnetic alignment was achieved by applying a high intensity magnetic field to the melted feedstock during the injection process. Green samples (with and without magnetic alignment) were subjected to solvent debinding and subsequent thermal debinding followed by sintering. Sintering conditions were optimized in order to achieve a maximum energy product value. Magneto-crystalline aligning in barium hexaferrite was studied on both green and sintered samples using X-ray diffraction, scanning electron microscope (SEM) and magnetic measurements (hysteresisgraphs). All measurements were made both in a parallel and perpendicular direction to the aligning magnetic field. The obtained results confirmed magneto-crystalline alignment

  3. SAXS studies of the injection molding effects on the nanostructure of polyesters. I: polybutylene terephthalate (PBT)

    International Nuclear Information System (INIS)

    In this work, the nanoperiodicity of some PBT samples, injection molded at different conditions, was evaluated as a function of the thickness of the samples. From the small angle X-ray scattering (SAXS) results, it was possible to observe that, as expected, there is a gradient of the L and lc values found through the thickness of the samples. It was also found that at the center of the PBT sample injection molded at low injection temperature, Ti, the crystallinity degree evaluated previously by wide angle X-Ray diffraction (WAXD) is high. In a previous study it was pointed out that a high orientation process could be present in the center of this sample, increasing the XC evaluated from WAXD. The SAXS results presented here show that this is not the case, because if orientation is high, the value of L at this region of the sample would be smaller. (author)

  4. Aplicação de redes Neuro Fuzzy ao processamento de peças automotivas por meio de injeção de polímeros / Application of neurofuzzy networks for the processing of automotive parts by polymer injection molding

    Scientific Electronic Library Online (English)

    Carlos de Oliveira, Affonso; Renato José, Sassi.

    Full Text Available O processamento de peças automotivas por meio de injeção de polímeros envolve vários fenômenos físicos que ocorrem simultaneamente e que possuem caráter não linear e multivariável. Softwares comerciais podem ser utilizados na previsão dos parâmetros do processo, o que pode ser caro e inviável. Pode- [...] se determinar os parâmetros de forma analítica, mas o tratamento desse problema requer a aplicação de teorias clássicas dos fenômenos de transporte, de difícil equacionamento. As redes NeuroFuzzy são aplicáveis a esse problema porque reúnem a capacidade de aprender das redes neurais artificiais com a capacidade da lógica Fuzzy de transformar variáveis linguísticas em regras. Neste trabalho combinou-se uma rede neural artificial Multilayer Perceptron e uma rede neural artificial Radial Basis Function à lógica Fuzzy para construir-se um modelo de inferência que previu o tempo de ciclo de processos de injeção de polímeros. Os resultados obtidos confirmam as redes NeuroFuzzy como opção para esse tipo de problema. Abstract in english The injection molding of automotive parts is a complex process due to the many non-linear and multivariable phenomena that occur simultaneously. Commercial software applications exist for modeling the parameters of polymer injection but can be prohibitively expensive. It is possible to identify thes [...] e parameters analytically, but applying classical theories of transport phenomena requires accurate information about the injection machine, product geometry, and process parameters. However, neurofuzzy networks, which achieve a synergy by combining the learning capabilities of an artificial neural network with a fuzzy set's inference mechanism, have shown success in this field. The purpose of this paper was to use a multilayer perceptron artificial neural network and a radial basis function artificial neural network combined with fuzzy sets to produce an inference mechanism that could predict injection mold cycle times. The results confirmed neurofuzzy networks as an effective alternative to solving such problems.

  5. Aplicação de redes Neuro Fuzzy ao processamento de peças automotivas por meio de injeção de polímeros / Application of neurofuzzy networks for the processing of automotive parts by polymer injection molding

    Scientific Electronic Library Online (English)

    Carlos de Oliveira, Affonso; Renato José, Sassi.

    2015-03-01

    Full Text Available O processamento de peças automotivas por meio de injeção de polímeros envolve vários fenômenos físicos que ocorrem simultaneamente e que possuem caráter não linear e multivariável. Softwares comerciais podem ser utilizados na previsão dos parâmetros do processo, o que pode ser caro e inviável. Pode- [...] se determinar os parâmetros de forma analítica, mas o tratamento desse problema requer a aplicação de teorias clássicas dos fenômenos de transporte, de difícil equacionamento. As redes NeuroFuzzy são aplicáveis a esse problema porque reúnem a capacidade de aprender das redes neurais artificiais com a capacidade da lógica Fuzzy de transformar variáveis linguísticas em regras. Neste trabalho combinou-se uma rede neural artificial Multilayer Perceptron e uma rede neural artificial Radial Basis Function à lógica Fuzzy para construir-se um modelo de inferência que previu o tempo de ciclo de processos de injeção de polímeros. Os resultados obtidos confirmam as redes NeuroFuzzy como opção para esse tipo de problema. Abstract in english The injection molding of automotive parts is a complex process due to the many non-linear and multivariable phenomena that occur simultaneously. Commercial software applications exist for modeling the parameters of polymer injection but can be prohibitively expensive. It is possible to identify thes [...] e parameters analytically, but applying classical theories of transport phenomena requires accurate information about the injection machine, product geometry, and process parameters. However, neurofuzzy networks, which achieve a synergy by combining the learning capabilities of an artificial neural network with a fuzzy set's inference mechanism, have shown success in this field. The purpose of this paper was to use a multilayer perceptron artificial neural network and a radial basis function artificial neural network combined with fuzzy sets to produce an inference mechanism that could predict injection mold cycle times. The results confirmed neurofuzzy networks as an effective alternative to solving such problems.

  6. Ion channel recordings on an injection-molded polymer chip

    DEFF Research Database (Denmark)

    Tanzi, Simone; Matteucci, Marco

    2013-01-01

    In this paper, we demonstrate recordings of the ion channel activity across the cell membrane in a biological cell by employing the so-called patch clamping technique on an injection-molded polymer microfluidic device. The findings will allow direct recordings of ion channel activity to be made using the cheapest materials and production platform to date and with the potential for very high throughput. The employment of cornered apertures for cell capture allowed the fabrication of devices without through holes and via a scheme comprising master origination by dry etching in a silicon substrate, electroplating in nickel and injection molding of the final part. The most critical device parameters were identified as the length of the patching capillary and the very low surface roughness on the inside of the capillary. The cross-sectional shape of the orifice was found to be less critical, as both rectangular and semicircular profiles seemed to have almost the same ability to form tight seals with cells with negligible leak currents. The devices were functionally tested using human embryonic kidney cells expressing voltage-gated sodium channels (Nav1.7) and benchmarked against a commercial state-of-the-art system for automated ion channel recordings. These experiments considered current–voltage (IV) relationships for activation and inactivation of the Nav1.7 channels and their sensitivity to a local anesthetic, lidocaine. Both IVs and lidocaine dose–response curves obtained from the injection-molded polymer device were in good agreement with data obtained from the commercial system.

  7. Correlation between Rheotens measurements and reinforcement of polymer nanocomposites in the injection molding compounder

    Science.gov (United States)

    Battisti, Markus G.; Friesenbichler, Walter; Duretek, Ivica; Guttmann, Peter

    2015-04-01

    The evaluation of the effectiveness of reinforcement of polymers and polymer nanocomposites(PNCs), in particular the improvement of Young's modulus, is made by performing standardized tensile tests. Structural and morphological characterizations typically are investigated using expensive techniques like transmission electron microscopy (TEM), X- ray scattering and sometimes also rheological analyses (rotational rheometry). The objective of this study is to generate faster and economically advantageous data to verify the quality of the produced PNC-compound in an on-line measurement system. Subsequently injection molded parts are processed by using the Injection Molding Compounder (PNC-IMC) “by only one plasticizing process”. In comparison to the conventional compounding process, where the compound has to be pelletized and fed into the injection molding machine for the second plasticizing process, injection molding compounding combines these two processing steps. This paper shows first results and problems with the implementation of the Rheotens equipment into the concept of the IMC. Different processing techniques and various processing conditions were compared and the occurring effects were detected both with tensile testing and extensional melt rheology. Both, the increase of the Young's modulus by using layered silicates as nanofillersis compared to the virgin polypropylene and the correlation of the level of melt strength with Rheotens measurements is shown. These results give a good overview on both the possibilities and the limitations of the material pre-tests by the use of extensional rheology in the concept of the IMC for producing PNCs. Further studies to enable a fast and efficient way of estimating the level of reinforcement in PNCs by means of Rheotens measurements will be carried out towards industrial usability. Furthermore the verification of exfoliation and intercalation of the layered silicates in the polymer matrix using small angle X- ray scattering is planned.

  8. Adhesion strength between thermoplastics and its polyurethane coating made by using the technology combination of injection molding and reaction injection molding

    Science.gov (United States)

    Bloß, P.; Böhme, A.; Müller, J.; Krajewsky, P.; Michaelis, J.

    2014-05-01

    A complete equipment for injection molding (IM) of a thermoplastic (TP) carrier and reaction injection molding (RIM) of polyurethane (PUR) coatings including IM and RIM machines, a color module for PUR, and a robot was built up. A modularly composed sliding split mold was constructed and manufactured allowing different parts including thicker (2 mm thickness) soft touch and thin (0.4 mm) lacquer PUR coatings. As TP PC/ABS and PA6 GF15 compounds were used, and aromatic and aliphatic PUR systems as well. From the parts made by IM+RIM, test specimens for peel force measurements were cut. These investigations were performed prior and after ageing under climatic conditions @ 50 % RH and temperature changes between -30 °C and 90 °C. By varying IM processing parameters, we have found that mold and TP temperatures are particularly important for the adhesion strength between TP and PUR. The waiting time between the end of TP cooling and PUR injection has a minor influence on its mean value. However, to short waiting times may result in inhomogeneous adhesion. It was surprising that surface defects of the TP carrier leads also to inhomogeneous adhesion. We have observed that ageing may cause an increase and decrease of adhesions strength depending on the TP+PUR system used. We have found that the results are valid only for the actual TP and PUR combination. A generalization seems to be inappropriate, hence, the actual combination should be investigated to prevent unwanted surprises when the coated TP part is in its application.

  9. Environmental impact estimation of mold making process

    Science.gov (United States)

    Kong, Daeyoung

    Increasing concern of environmental sustainability regarding depletion of natural resources and resulting negative environmental impact has triggered various movements to address these issues. Various regulations about product life cycle have been made and applied to industries. As a result, how to evaluate the environmental impact and how to improve current technologies has become an important issue to product developers. Molds and dies are very generally used manufacturing tools and indispensible parts to the production of many products. However, evaluating environmental impact in mold and die manufacturing is not well understood and not much accepted yet. The objective of this thesis is to provide an effective and straightforward way of environmental analysis for mold and die manufacturing practice. For this, current limitations of existing tools were identified. While conventional life cycle assessment tools provide a lot of life cycle inventories, reliable data is not sufficient for the mold and die manufacturer. Even with comprehensive data input, current LCA tools only provide another comprehensive result which is not directly applicable to problem solving. These issues are critical especially to the mold and die manufacturer with limited resource and time. This thesis addresses the issues based on understanding the needs of mold and die manufacturers. Computer aided manufacturing (CAM) is the most frequently used software tool and includes most manufacturing information including the process definition and sometimes geometric modeling. Another important usage of CAM software tools is problem identification by process simulation. Under the virtual environment, possible problems are detected and solved. Environmental impact can be handled in the same manner. To manufacture molds and dies with minimizing the associated environmental impact, possible environmental impact sources must be minimized before the execution in the virtual environment. Molds and dies are manufacturing intensive products and most of their environmental impact is generated by the energy consumption during the machining processes. Milling and EDM operations were selected as the most influential mold and die manufacturing processes. Process variability was found to be the key issue which must be addressed for reliable analysis. Acceleration and deceleration in the milling process and the dielectric contamination and resultant decrease of MRR in the EDM process were identified as main factors for the variability. Energy consumption of these two processes were analyzed and modeled including the variability. Experiments were carried out to validate and improve this model. Finally, this model is implemented as simulation software tools on the basis of CAM software (Esprit CAM(TM)). The CAM-based tool developed in this study can be more easily used in the mold and die manufacturing practice. Considering the variety of mold and die and their application, this tool would be just a small step to a long way to the environmentally benign mold and die manufacturing. However, with further research, the tool developed in this thesis will result in effective way to address environmentally benign mold and die manufacturing.

  10. Finite Element Analysis of Reciprocating Screw for Injection Molding Machine

    Directory of Open Access Journals (Sweden)

    Nagsen B. Nagrale

    2011-06-01

    Full Text Available This paper deals with, the solution of problem occurred for reciprocating screw of Injection molding machine. It identifies and solves the problem by using the modeling and simulation techniques. The problem occurred in the reciprocating screw of machine which was wearing of threads due to affect of temperature of mold materials(flow materials i.e. Nylon, low density polypropylene, polystyrene, PVC etc., The main work was to model the components of machine with dimensions, assemble those components and then simulate the whole assembly for rotation of the screw. The modeling software used is PRO-E wildfire 4.0 for modeling the machine components like body, movable platen, fixed platen, barrel, screw, nozzle, etc. The analysis software ANSYS is used to analyze the reciprocating screws. The objectives involved are:- • To model all the components using modeling software Pro-E 4.0 • To assemble all the components of the machine in the software. • To make the assembly run in Pro-E software.• Analysis of screw of machine using Ansys 11.0 software. • To identify the wearing of threads and to provide the possible solutions.This problem is major for all industrial injection molding machines which the industries are facing and they need the permanent solution, so if the better solution is achieved then the industries will think for implementing it. The industries are having temporary solution but it will affect the life of the screw, because the stresses will be more in machined screw on lathe machine as compared to normal screw. Also if the screw will fail after some years of operation, the new screw available in the market will have the same problem. Also the cost associated with new screw and its mounting is much more as it is the main component of machine.

  11. On the Injection Molding of Nanostructured Polymer Surfaces

    DEFF Research Database (Denmark)

    Pranov, Henrik; Rasmussen, Henrik K.

    2006-01-01

    Well-defined nano-topographies were prepared by electron-beam lithography and electroplated to form nickelshims. The surface pattern consisted of square pillars repeated equidistantly within the plane of the surface in a perpendicular arrangement. The width and distance between the squares both ranged from 310 to 3100 rim. All the pillars were 220 nm high. The nickel-shim was used as a surface-template during injection molding of polycarbonate. Secondly, a nickel shim, with a surface pattern consisted of a squared sine with a period of 700 nm and amplitude of 450 nm, was mounted on, and it was in good thermal contact with the upper plate in a hot-press. Polycarbonate/polystyrene was melted on the lower plate while the temperature of the shim was kept below the glass transition temperature. The upper plate was lowered until the shim was in contact with the melt. Experiments were carried out with a clean shim and a shim coated with a monolayer of fluorocarbonsilane. As a result of the surface coating, the amplitude of the replicated grating decreased from about 350 nm in polycarbonate and 100 nm in polystyrene to less than 10 nm. The experiments strongly suggest that the possibility to injection mold sub-micrometer surface structures in polymers mainly relates to adhesive energy between polymer and shim.

  12. Injection Molding Parameter Optimization of Titanium Alloy Powder Mix with Palm Stearin and Polyethylene for Multiple Performance Using Grey Relational Analysis

    Directory of Open Access Journals (Sweden)

    K.R. Jamaludin

    2011-01-01

    Full Text Available This paper outlines the optimization the process of injection molding parameters for feedstock of titanium alloy powder and palm stearin binder using grey relational analysis method. A Grey Relational Grade (GRG obtained from the Grey Relational Analysis (GRA is used to solve the injection molding operations with the multiple performance characteristic. The L27 (313 of orthogonal array of Taguchi method were performed. Defects, strength and density are important characteristics in determine the quality of the green part. Using these characteristics, the injection pressure, injection temperature, powder loading, mold temperature, holding pressure and injection speed are optimized in the study. From the analysis of variance (ANOVA, the injection temperature has the highest contribution to the quality of green part followed by injection pressure, powder loading, mold temperature, injection rate and holding pressure.

  13. Injection Molded Optical Lens Using a Heat Resistant Thermoplastic Resin with Electron Beam Cross-Linking

    Science.gov (United States)

    Tomomi Sano,; Yoshitomo Iyoda,; Takayuki Shimazu,; Michiko Harumoto,; Akira Inoue,; Makoto Nakabayashi,; Hiroshi Ito,

    2010-05-01

    The poor heat resistant properties of a transparent thermoplastic resin was improved by electron beam irradiation cross-linking. A correcting aspheric lens for a 635-nm laser diode was fabricated using an injection molding machine, and was irradiated with an electron beam. The near field pattern (NFP), the far field pattern (FFP) at the focus position and the transmittance of the lens did not change after exposure to a 260 °C reflow process for 60 s.

  14. Manufacturing of ceramic-metal composites by combining tape casting and injection molding

    OpenAIRE

    Baumann, A.; Lenk, R.; Moritz, T.

    2007-01-01

    In industry, material composites are of great interest if new applications can be developed by combining their physical properties. In two-component powder injection molding materials are required that can be co-fired, and that are characterized by an adjusted, stress-defined expansion behavior in the manufacturing process and application area. Additionally, powder packing concepts for the different materials of the feedstock are a crucial factor, as the green densities correlate with the exp...

  15. Characterization Of Metal Injection Molding (MIM Feedstock Based On Water Soluble Binder System

    Directory of Open Access Journals (Sweden)

    Norhamidi Muhamad

    2008-08-01

    Full Text Available Metal Injection Molding (MIM is a new manufacturing technique especially to produce small and complex precision parts. Characterization of feedstock is one of the important tasks in order to evaluate the homogeneity level of the feedstock prepared and to control the quality of the parts during injection molding process. This paper attempts to investigate the characteristics of the MIM feedstock by performing rheological test using the feedstock consisted of 316L stainless steel powder with a mean particle size of 12 micrometer and a major fraction of water soluble binder system known as polyethylene glycol (PEG. Three different weight percentage of PEG at 65, 75, and 85 respectively were used during the investigation. The viscosity of MIM feedstock at different temperatures and shear rates were measured and evaluated. Results show that increasing the PEG content would decrease the viscosity of the feedstock. The rheological properties of the feedstock showed that the proposed method of mixing is adequate to produce a homogeneous feedstock that is favorable for injection molding process.

  16. Pressure injection molding of glass and glass-ceramic parts

    Science.gov (United States)

    Blair, Henry M.

    1995-09-01

    Spin cast and fusion techniques have been available for the production of borosilicate mirrors for some time. Our efforts in pressure injection molding methodologies have been primarily devoted to developing eclectic geometric variety in substrate configuration, improved homogeneity of the medium, reduced face-plate bubbles, cross-sectional dimension control, and cost effectiveness. These attributes are intended to enhance the inherent characteristics of the existing techniques, i.e., savings in weight, high deflection, stiffness, and thermal stability. We have successfully molded mirror substrates in a diversity of sizes and shapes from 50 mm polygons through 1.4 meter rounds and 1.7 meter ellipses in a varity of aspect rations. Rib structure and mounting location is totally arbitrary and front and black plate geometry is unrestrained. In order to achieve reliable and repeatable results, it was necessary to develop new techniques in refractory design and fabrication, re-evaluate the raw media, redesign the existing furnace control and heating scenario and write new control and reporting software.

  17. Imprinted and injection-molded nano-structured optical surfaces

    DEFF Research Database (Denmark)

    Christiansen, Alexander Bruun Technical University of Denmark,

    2013-01-01

    Inspired by nature, nano-textured surfaces have attracted much attention as a method to realize optical surface functionality. The moth-eye antireflective structure and the structural colors of Morpho butterflies are wellknown examples used for inspiration for such biomimetic research. In this paper, nanostructured polymer surfaces suitable for up-scalable polymer replication methods, such as imprinting/embossing and injection-molding, are discussed. The limiting case of injection-moulding compatible designs is investigated. Anti-reflective polymer surfaces are realized by replication of Black Silicon (BSi) random nanostructure surfaces. The optical transmission at normal incidence is measured for wavelengths from 400 nm to 900 nm. For samples with optimized nanostructures, the reflectance is reduced by 50 % compared to samples with planar surfaces. The specular and diffusive reflection of light from polymer surfaces and their implication for creating structural colors is discussed. In the case of injection-moulding compatible designs, the maximum reflection of nano-scale textured surfaces cannot exceed the Fresnel reflection of a corresponding flat polymer surface, which is approx. 4 % for normal incidence. Diffraction gratings provide strong color reflection defined by the diffraction orders. However, the apperance varies strongly with viewing angles. Three different methods to address the strong angular-dependence of diffraction grating based structural color are discussed.

  18. Effect of Cross Sectional Geometry on PDMS Micro Peristaltic Pump Performance: Comparison of SU-8 Replica Molding vs. Micro Injection Molding

    OpenAIRE

    Graf, Neil J.; Bowser, Michael T.

    2013-01-01

    Two different fabrication methods were employed to fabricate micropumps with different cross-sectional channel geometries. The first was to fabricate rectangular cross-sectional microchannel geometries using the well known fabrication method of replica molding (REM).1 The second, and far less utilized fabrication technique, was to create microchannel molds using an in-house fabricated handheld micro injection molding apparatus. The injection mold apparatus was designed for use with elastomeri...

  19. Quality Control of Injection Molded Eyewear by Non-Contact Deflectometry

    Science.gov (United States)

    Speck, A.; Zelzer, B.; Langenbucher, A.; Eppig, T.

    2014-07-01

    Occupational eye wear such as safety spectacles are manufactured by injection molding techniques. Testing of the assembled safety spectacle lenses in transmission is state of the art, but there is a lack of surface measurement systems for occupational safety lenses. The purpose of this work was to validate a deflectometric setup for topography measurement, detection of defects and visualization of the polishing quality, e.g. casting indentations or impressions, for the production process of safety spectacles. The setup is based on a customized stereo phase measuring deflectometer (PMD), equipped with 3 cameras with f'1,2 = 16 mm and f'3 = 8.5 mm and a specified measurement uncertainty of ± 3 ?m. Sixteen plastic lenses and 8 corresponding injection molds from 4 parallel cavities were used for validation of the deflectometer. For comparison an interferometric method and a reference standard (< ?/10 super polished) was used. The accuracy and bias with a spherical safety spectacle sample was below 1 μm, according to DIN ISO 5725-2.2002-12. The repeatability was 2.1 ?m and 35.7 ?m for a blind radius fit. In conclusion, the PMD technique is an appropriate tool for characterizing occupational safety spectacle and injections mold surfaces. With the presented setup we were able to quantify the surface quality. This can be useful and may optimize the quality of the end product, in addition to standardized measuring systems in transmission.

  20. Highly conductive thermoplastic composite blends suitable for injection molding of bipolar plates

    International Nuclear Information System (INIS)

    This study aimed at developing highly conductive, lightweight, and low-cost bipolar plates for use in proton exchange membranes (PEM) fuel cells. Injection and compression molding of highly filled polypropylene, PP, and polyphenylene sulfide, PPS, based blends were used as a mean for mass production of bipolar plates. Loadings up to 60-wt% in the form of graphite, conductive carbon black and carbon fibers were investigated. The developed formulations have a combination of properties and processability suitable for bipolar plate manufacturing, such as good chemical resistance, sufficient fluidity, and good electrical and thermal conductivity. Electrical resistivities around 0.15 and 0.09 Ohm-cm were respectively achieved for the PP and PPS-based blends, respectively. Two bipolar plate designs were successfully fabricated by molding the gas flow channels over aluminum plates to form a metallic/polymer composite plate, or simply by direct injection molding of the conductive polymer composite. For the first design, overall plate resistivities of 0.2 and 0.1 Ohm-cm were respectively attained using PP and PPS based blends as conductive skin. A lower volume resistivity of around 0.06 Ohm-cm was attained for the second injected plate design with PPS based blend. (author)

  1. Investigation of sample preparation on the moldability of ceramic injection molding feedstocks

    Science.gov (United States)

    Ide, Jared

    Ceramic injection molding is a desirable option for those who are looking to make ceramic parts with complex geometries. Formulating the feedstock needed to produce ideal parts is a difficult process. In this research a series of feedstock blends will be evaluated for moldability. This was done by investigating their viscosity, and how certain components affect the overall ability to flow. These feedstocks varied waxes, surfactants, and solids loading. A capillary rheometer was used to characterize some of the materials, which led to one batch being selected for molding trials. The parts were sintered and further refinements were made to the feedstock. Solids loading was increased from 77.5% to 82%, which required different ratios of organics to flow. Finally, the ceramic powders were treated to lower their specific surface area before being compounded, which resulted in materials that would process easily through an extruder and exhibit properties suitable for CIM.

  2. Dimensional accuracy in rapid prototyping of ceramics formed by injection molding using rapid tooling

    Science.gov (United States)

    Judson, Elizabeth Ann

    Low pressure powder injection molding using rapid tooling technology is capable of producing sintered ceramic prototypes in less than one week from the design of the part. Prediction of the shrinkage, complicated by anisotropy, makes dimensioning of the tool a critical part of the process. A model has been developed that predicts die dimensions of alumina and zirconia ceramics formed by this process. The model incorporates anisotropic shrinkage that is a result of differential particle packing and orientation due to pressure-driven flow of particles in a suspension. The model can be integrated into the CAD package used to create the mold for the part. As an example, utilization of the model reduces average error from 1.11 mm (.044?) to 0.32 mm (.012?) on fired alumina parts with a flow length of 100 nun (3.94?). This significant reduction in error would lowers the dimensional variation of the part to within industry tolerances of 0.5%.

  3. Development of Defects Free Stainless Steel Parts Using Powder Injection Molding

    Directory of Open Access Journals (Sweden)

    M.A. Omar

    2013-01-01

    Full Text Available Austenitic 316L Stainless Steel (SS is widely used in aerospace, automotive, sports and medical industries due to its mechanical properties and corrosion resistance. Defects free molding of parts depends upon the features of feedstock. In powder injection molding, feedstock preparation is critical step and any deficiency at this stage cannot be retrieve in latter steps. The objective of this research work is to optimize solid loading for defects free injection molded parts. During the present research work five formulations having solid loading 60-71 vol% were prepared by using multi component binder system. The degradation temperature of feedstocks was determined by using Thermogravimetric analysis (TGA and flow behavior through rheometer. Homogeneity of the feedstock was verified by using Scanning Electron Microscopy (SEM. Finally, injection molding was done and it was found that the feedstocks having solid loading up to 69 vol% were successfully injection molded and components were without physical defects.

  4. Optimization of Micro Metal Injection Molding By Using Grey Relational Grade

    International Nuclear Information System (INIS)

    Micro metal injection molding (?MIM) which is a variant of MIM process is a promising method towards near net-shape of metallic micro components of complex geometry. In this paper, ?MIM is applied to produce 316L stainless steel micro components. Due to highly stringent characteristic of ?MIM properties, the study has been emphasized on optimization of process parameter where Taguchi method associated with Grey Relational Analysis (GRA) will be implemented as it represents novel approach towards investigation of multiple performance characteristics. Basic idea of GRA is to find a grey relational grade (GRG) which can be used for the optimization conversion from multi objectives case which are density and strength to a single objective case. After considering the form 'the larger the better', results show that the injection time(D) is the most significant followed by injection pressure(A), holding time(E), mold temperature(C) and injection temperature(B). Analysis of variance (ANOVA) is also employed to strengthen the significant of each parameter involved in this study.

  5. Fully-Integrated Numerical Analysis of Micro-Injection Molding with Localized Induction Heating

    Science.gov (United States)

    Park, Keun; Eom, Hyeju; Ik Lee, Sang

    2010-06-01

    High-frequency induction is an efficient way to heat mold surface by electromagnetic induction in a non-contact procedure. Due to its capability of rapid heating and cooling of mold surface, it has been recently applied to the injection molding of micro/nano structures. The present study investigates a localized heating method involving the selective use of mold materials to enhance the heating efficiency of high-frequency induction heating. A composite injection mold consisting of ferromagnetic material and paramagnetic material is used for localized induction heating. The feasibility of the localized heating method is investigated through numerical analyses in terms of its heating efficiency for localized mold surfaces and the resulting flow characteristics in a micro-channel. To take into account the effects of thermal boundary conditions of the localized induction heating, a fully-integrated numerical analysis effectively connecting electromagnetic field calculation, heat transfer analysis, thermal stress analysis, and injection molding simulation is carried out. The proposed integrated simulation is applied to the injection molding of a rectangular strip containing micro-channels, and the resulting mold heating capacity and replication characteristics of the micro-channels are compared with experimental findings in order to verify the validity of the proposed simulation.

  6. New Virtual Environment for Active Learning on Parameter Adjustment of Plastic Injection Molding

    OpenAIRE

    Marquez Sevillano, Juan de Juanes; Rodríguez Villagrá, María; Martinez Muneta, M. Luisa; Pérez García, Jesus Maria

    2009-01-01

    This paper describes some aspects of new software development and its academic application. This program is an alternative to enhance and to improve the available resources for students to acquire practical knowledge in plastic injection molding parameterization. A virtual injection molding environment has been developed, which allows preliminary machine capacity determination, number of cavities analysis, injection cycle parameter definition, and defects analysis and representation. The envi...

  7. Electroforming of Tool Inserts for Injection Molding of Optical or Microfluidic Components

    DEFF Research Database (Denmark)

    Tang, Peter Torben; Christensen, Thomas R.

    2004-01-01

    With a rapidly increasing international interest in “Lab-on-a-chip”-systems as well as affordable polymer optics, the combination of electroforming and injection molding offers an attractive fabrication solution. Miniaturized analysis systems can be used for medical, security (anti terror monitoring) and environmental (waste water monitoring) applications. Optical components in polymer materials can be used for consumer electronics and for sensor systems. The presentation will include the complete fabrication scheme for tool inserts based on machining and electroforming. Electroforming processes for nickel and copper will be disclosed. Processing parameters for the different types of tools as well as quality control measures will be presented.

  8. Numerical prediction of fiber orientation in injection-molded short-fiber/thermoplastic composite parts with experimental validation

    Science.gov (United States)

    Thi, Thanh Binh Nguyen; Morioka, Mizuki; Yokoyama, Atsushi; Hamanaka, Senji; Yamashita, Katsuhisa; Nonomura, Chisato

    2015-05-01

    Numerical prediction of the fiber orientation in the short-glass fiber (GF) reinforced polyamide 6 (PA6) composites with the fiber weight concentration of 30%, 50%, and 70% manufactured by the injection molding process is presented. And the fiber orientation was also directly observed and measured through X-ray computed tomography. During the injection molding process of the short-fiber/thermoplastic composite, the fiber orientation is produced by the flow states and the fiber-fiber interaction. Folgar and Tucker equation is the well known for modeling the fiber orientation in a concentrated suspension. They included into Jeffrey's equation a diffusive type of term by introducing a phenomenological coefficient to account for the fiber-fiber interaction. Our developed model for the fiber-fiber interaction was proposed by modifying the rotary diffusion term of the Folgar-Tucker equation. This model was presented in a conference paper of the 29th International Conference of the Polymer Processing Society published by AIP conference proceeding. For modeling fiber interaction, the fiber dynamic simulation was introduced in order to obtain a global fiber interaction coefficient, which is sum function of the fiber concentration, aspect ratio, and angular velocity. The fiber orientation is predicted by using the proposed fiber interaction model incorporated into a computer aided engineering simulation package C-Mold. An experimental program has been carried out in which the fiber orientation distribution has been measured in 100 x 100 x 2 mm injection-molded plate and 100 x 80 x 2 mm injection-molded weld by analyzed with a high resolution 3D X-ray computed tomography system XVA-160?, and calculated by X-ray computed tomography imaging. The numerical prediction shows a good agreement with experimental validation. And the complex fiber orientation in the injection-molded weld was investigated.

  9. Modeling of the injection of loaded thermoplastic mixtures with application in metal injection molding

    International Nuclear Information System (INIS)

    The study is focussed on the modeling and numerical simulation of the loaded thermoplastic mixtures currently used in metal injection molding. Due to the fact that the mixture is highly concentrated in metallic powders, the models based on the homogenization theory and using an equivalent viscosity are no longer suitable. So a biphasic formulation has been developed to describe the flow of such mixtures. An interaction term between powder and thermoplastic fluid polymer accounts for segregation or debinding effects. In this type of the problem, the solid phase fraction is a key fields variable. The associated equations are solved separately for each phase taking into account interactions and coupling effects. A general solver in 2D and 3D has been developed that account propagation of fluid front by the extension to biphasic cases of the VOF method. For solving the velocity/pressure problem the fractional step method has been extended to the biphasic cases. Numerical simulations have been compared to the experimental results obtained by a using multiple cavity with pressure and temperature sensors. Comparisons between numerical simulation results and experiments show good agreements in terms of pressure and temperature evolutions during molding. It is also demonstrated that the numerical results are accurate and sensitive to variation of the injection molding marameters. (author)

  10. FIBER LENGTH DISTRIBUTION MEASUREMENT FOR LONG GLASS AND CARBON FIBER REINFORCED INJECTION MOLDED THERMOPLASTICS

    Energy Technology Data Exchange (ETDEWEB)

    Kunc, Vlastimil [ORNL; Frame, Barbara J [ORNL; Nguyen, Ba N. [Pacific Northwest National Laboratory (PNNL); TuckerIII, Charles L. [University of Illinois, Urbana-Champaign; Velez-Garcia, Gregorio [Virginia Polytechnic Institute and State University

    2007-01-01

    Procedures for fiber length distribution (FLD) measurement of long fiber reinforced injection molded thermoplastics were refined for glass and carbon fibers. Techniques for sample selection, fiber separation, digitization and length measurement for both fiber types are described in detail. Quantitative FLD results are provided for glass and carbon reinforced polypropylene samples molded with a nominal original fiber length of 12.7 mm (1/2 in.) using equipment optimized for molding short fiber reinforced thermoplastics.

  11. In Situ X-ray Scattering Measurements and Polydomain Simulations of Molecular Orientation Development during Injection Molding of Liquid Crystalline Polymers

    Science.gov (United States)

    Fang, Jun; Burghardt, Wesley; Bubeck, Robert

    2009-03-01

    We report on a coordinated experimental/computational study of injection molding of commercial thermotropic LCPs. In situ synchrotron x-ray scattering, combined with a customized injection molding apparatus, is used to track development of molecular orientation during the mold filling process for a commercial LCP, Vectra A950, in two simple plaque mold geometries: square and T-shaped. Use of high brilliance undulator radiation at the Advanced Photon Source, coupled with a high speed CCD detector provides sufficient time resolution ( 12 frames per second) to resolve the transient orientation dynamics during and following mold filling. In addition to in- situ scattering measurements, ex-situ 2-D wide angle X-ray scattering measurements are conducted on the same injection molded plaques. The experiments are complemented by process simulations performed using commercial mold filling software. A very close analogy between the Folgar-Tucker fiber orientation model and the Larson-Doi polydomain model for textured liquid crystalline polymers is exploited to allow for the first tests of Larson-Doi model predictions in injection molding processing.

  12. Reaction injection molding and direct covalent bonding of OSTE+ polymer microfluidic devices

    Science.gov (United States)

    Sandström, N.; Shafagh, R. Z.; Vastesson, A.; Carlborg, C. F.; van der Wijngaart, W.; Haraldsson, T.

    2015-07-01

    In this article, we present OSTE+RIM, a novel reaction injection molding (RIM) process that combines the merits of off-stoichiometric thiol–ene epoxy (OSTE+) thermosetting polymers with the fabrication of high quality microstructured parts. The process relies on the dual polymerization reactions of OSTE+ polymers, where the first curing step is used in OSTE+RIM for molding intermediately polymerized parts with well-defined shapes and reactive surface chemistries. In the facile back-end processing, the replicated parts are directly and covalently bonded and become fully polymerized using the second curing step, generating complete microfluidic devices. To achieve unprecedented rapid processing, high replication fidelity and low residual stress, OSTE+RIM uniquely incorporates temperature stabilization and shrinkage compensation of the OSTE+ polymerization during molding. Two different OSTE+ formulations were characterized and used for the OSTE+RIM fabrication of optically transparent, warp-free and natively hydrophilic microscopy glass slide format microfluidic demonstrator devices, featuring a storage modulus of 2.3?GPa and tolerating pressures of at least 4?bars.

  13. Simulation and experiment research on the proportional pressure control of water-assisted injection molding

    Science.gov (United States)

    Zhou, Hua; Chen, Yinglong; Zhang, Zengmeng; Yang, Huayong

    2012-05-01

    Water-assisted injection molding (WAIM), a newly developed fluid-assisted injection molding technology has drawn more and more attentions for the energy saving, short cooling circle time and high quality of products. Existing research for the process of WAIM has shown that the pressure control of the injecting water is mostly important for the WAIM. However, the proportional pressure control for the WAIM system is quite complex due to the existence of nonlinearities in the water hydraulic system. In order to achieve better pressure control performance of the injecting water to meet the requirements of the WAIM, the proportional pressure control of the WAIM system is investigated both numerically and experimentally. A newly designed water hydraulic system for WAIM is first modeled in AMEsim environment, the load characteristics and the nonlinearities of water hydraulic system are both considered, then the main factors affecting the injecting pressure and load flow rate are extensively studied. Meanwhile, an open-loop model-based compensation control strategy is employed to regulate the water injection pressure and a feedback proportional integrator controller is further adopted to achieve better control performance. In order to verify the AMEsim simulation results WAIM experiment for particular Acrylonitrile Butadiene Styrene (ABS) parts is implemented and the measured experimental data including injecting pressure and flow rate results are compared with the simulation. The good coincidence between experiment and simulation shows that the AMEsim model is accurate, and the tracking performance of the load pressure indicates that the proposed control strategy is effective for the proportional pressure control of the nonlinear WAIM system. The proposed proportional pressure control strategy and the conclusions drawn from simulation and experiment contribute to the application of water hydraulic proportional control and WAIM technology.

  14. Properties of high density polyethylene – Paulownia wood flour composites via injection molding

    Science.gov (United States)

    Paulownia wood (PW) flour is evaluated as a bio-based fiber reinforcement. Composites of high density polyethylene (HDPE), 25% by weight of PW, and either 0% or 5% by weight of maleated polyethylene (MAPE) were produced by twin screw compounding followed by injection molding. Molded test composite...

  15. Short-term and long-term behavior of PP-polymer nanocomposites produced by injection molding compounding

    Science.gov (United States)

    Battisti, M. G.; Guttmann, P.; Chitu, L.; Friesenbichler, W.

    2015-05-01

    There are only few investigations considering the impact of nanoscale fillers on the mechanical und thermo-mechanical properties of polymers. Particularly there is a lack of results regarding long term creep behavior of Polypropylene-based polymer nanocomposites (PNCs). Therefore, the objective of this study is to determine the influence of nanofiller content on the mechanical and thermo-mechanical behavior of Polypropylene-based PNCs. Processing of the test specimens was carried out using the Polymer NanoComposite Injection Molding Compounder (PNC-IMC). In comparison to the conventional compounding process, in which the compound must be pelletized and fed into the injection molding machine for the second plasticizing process, injection molding compounding combines these two processing steps. Material compounding and subsequent injection molding are done directly with only one plasticizing process, using a heated melt pipe and a melt accumulator for melt transfer from the compounder to the injection molding machine. The PNCs were produced in the 3-in-1 process at the PNC-IMC, where all components (polymer, compatibilizer, nanofiller) were added simultaneously into the compounder. Furthermore, the polymer melt was treated using elongational flow generating devices for better intercalation and exfoliation of the nanofillers. Tensile tests were made to characterize the short-term-mechanical properties. Tensile creep tests show the influence of nanofillers on the long-term-creep-performance and dynamic mechanical tests (DMA) were performed to investigate the thermo-mechanical behavior. Both, the improvements in the mechanical and thermo-mechanical properties in comparison to the pure polypropylene are shown and give an excellent overview of possibilities and limitations of the PNCs. Further research will focus on the detailed understanding of the different mechanisms of property improvement of layered silicates in polymer. By using small angle X-ray scattering exfoliation and intercalation of the layered silicates in the polymer matrix will be verified.

  16. Cytocompatibility of titanium metal injection molding with various anodic oxidation post-treatments

    International Nuclear Information System (INIS)

    Metal injection molding (MIM) is a near net shape manufacturing method that allows for the production of components of small to moderate size and complex shape. MIM is a cost-effective and flexible manufacturing technique that provides a large innovative potential over existing methods for the industry of implantable devices. Commercially pure titanium (CP-Ti) samples were machined to the same shape as a composite feedstock with titanium and polyoxymethylene, and these metals were injected, debinded and sintered to assess comparative biological properties. Moreover, we treated MIM-Ti parts with BIOCOAT®, BIODIZE® and BIOCER®, three different anodic oxidation techniques that treat titanium using acid, alkaline and anion enriched electrolytes, respectively. Cytocompatibility as well as morphological and chemical features of surfaces was comparatively assessed on each sample, and the results revealed that MIM-Ti compared to CP-Ti demonstrated a specific surface topography with a higher roughness. MIM-Ti and BIOCER® samples significantly enhanced cell proliferation, cell adhesion and cell differentiation compared to CP-Ti. Interestingly, in the anodization post-treatment established in this study, we demonstrated the ability to improve osseointegration through anionic modification treatment. The excellent biological response we observed with MIM parts using the injection molding process represents a promising manufacturing method for the future implantable devices in for the future implantable devices in direct contact with bones. - Highlights: ? Metal injection molding technique gives titanium a specific surface roughness. It enhances the biological response. ? Anodic oxidation method adds Ca, P, and Mg ions on the surface, promoting the cell adhesion. ? Cytocompatibility analyses show an increased cell adhesion and proliferation on MIM-Ti compared to pure titanium.

  17. Cytocompatibility of titanium metal injection molding with various anodic oxidation post-treatments

    Energy Technology Data Exchange (ETDEWEB)

    Demangel, Clemence; Auzene, Delphine [CRITT-MDTS, ZHT du Moulin Leblanc, 3, Bd Jean Delautre 08000 Charleville-Mezieres (France); Vayssade, Muriel [Universite de Technologie de Compiegne, UMR 7338 Biomecanique-Bioingenierie, BP 20529 60205 Compiegne Cedex (France); Duval, Jean-Luc, E-mail: jean-luc.duval@utc.fr [Universite de Technologie de Compiegne, UMR 7338 Biomecanique-Bioingenierie, BP 20529 60205 Compiegne Cedex (France); Vigneron, Pascale; Nagel, Marie-Daniele [Universite de Technologie de Compiegne, UMR 7338 Biomecanique-Bioingenierie, BP 20529 60205 Compiegne Cedex (France); Puippe, Jean-Claude [Steiger Galvanotechnique, Route de Pra de Plan, 18 CH-1618 Chatel-St-Denis (Switzerland)

    2012-10-01

    Metal injection molding (MIM) is a near net shape manufacturing method that allows for the production of components of small to moderate size and complex shape. MIM is a cost-effective and flexible manufacturing technique that provides a large innovative potential over existing methods for the industry of implantable devices. Commercially pure titanium (CP-Ti) samples were machined to the same shape as a composite feedstock with titanium and polyoxymethylene, and these metals were injected, debinded and sintered to assess comparative biological properties. Moreover, we treated MIM-Ti parts with BIOCOAT Registered-Sign , BIODIZE Registered-Sign and BIOCER Registered-Sign , three different anodic oxidation techniques that treat titanium using acid, alkaline and anion enriched electrolytes, respectively. Cytocompatibility as well as morphological and chemical features of surfaces was comparatively assessed on each sample, and the results revealed that MIM-Ti compared to CP-Ti demonstrated a specific surface topography with a higher roughness. MIM-Ti and BIOCER Registered-Sign samples significantly enhanced cell proliferation, cell adhesion and cell differentiation compared to CP-Ti. Interestingly, in the anodization post-treatment established in this study, we demonstrated the ability to improve osseointegration through anionic modification treatment. The excellent biological response we observed with MIM parts using the injection molding process represents a promising manufacturing method for the future implantable devices in direct contact with bones. - Highlights: Black-Right-Pointing-Pointer Metal injection molding technique gives titanium a specific surface roughness. It enhances the biological response. Black-Right-Pointing-Pointer Anodic oxidation method adds Ca, P, and Mg ions on the surface, promoting the cell adhesion. Black-Right-Pointing-Pointer Cytocompatibility analyses show an increased cell adhesion and proliferation on MIM-Ti compared to pure titanium.

  18. Injection-molded Cr3C2/Al2O3 components

    International Nuclear Information System (INIS)

    The Injection molding of Cr3C2/Al2O3 composites was studied. The optimized processing parameters were developed. By controlling the content and particle size of Cr3C2, the strength, toughness and electrical conductivity of alumina were substantially improved. The effects of Cr3C2 additives and sintering environment on the microstructure and phase stability were investigated. Prototype complex-shaped valves and blades were demonstrated. Copyright (1998) AD-TECH - International Foundation for the Advancement of Technology Ltd

  19. Simulação do processo de injeção de polipropileno isotático (iPP utilizando um modelo de cinética de cristalização quiescente Simulation of injection molding process of isotactic polypropylene (iPP using a quiescent crystallization kinetics model

    Directory of Open Access Journals (Sweden)

    Marcos A d'Ávila

    1997-12-01

    Full Text Available Este trabalho concentrou-se na simulação das fases de preenchimento e resfriamento do processo de injeção do polipropileno isotático. Foi utilizado um modelo matemático baseado nas equações de conservação onde foi considerada a cinética de cristalização quiescente como termo fonte na equação da energia. Os parâmetros do modelo de cinética de cristalização, assim como os do modelo de viscosidade, foram obtidos experimentalmente. Para a solução das equações governantes foi utilizado o método dos volumes finitos. Como resultados foram obtidos os campos de temperatura, pressão, velocidade, taxa de cisalhamento e cristalinidade em diferentes condições de processamento.This work is concerned with the simulation of the filling and cooling stages of the injection molding process of an isotactic polypropylene (iPP. A mathematical model based on the conservation equations was used. A crystallization kinetics model was considered as a source term in the energy equation. The parameters of the crystallization kinetics model, as well as the viscosity model, were obtained by experimental techniques. For the solution of the governing equations the finite volume method was employed. Temperature, pressure, velocity, shear rate and crystalinity profiles under different processing conditions were obtained.

  20. Simulação do processo de injeção de polipropileno isotático (iPP) utilizando um modelo de cinética de cristalização quiescente / Simulation of injection molding process of isotactic polypropylene (iPP) using a quiescent crystallization kinetics model

    Scientific Electronic Library Online (English)

    Marcos A, d' Ávila; Carlos H, Ahrens; Rosario E. S, Bretas.

    1997-12-01

    Full Text Available Este trabalho concentrou-se na simulação das fases de preenchimento e resfriamento do processo de injeção do polipropileno isotático. Foi utilizado um modelo matemático baseado nas equações de conservação onde foi considerada a cinética de cristalização quiescente como termo fonte na equação da ener [...] gia. Os parâmetros do modelo de cinética de cristalização, assim como os do modelo de viscosidade, foram obtidos experimentalmente. Para a solução das equações governantes foi utilizado o método dos volumes finitos. Como resultados foram obtidos os campos de temperatura, pressão, velocidade, taxa de cisalhamento e cristalinidade em diferentes condições de processamento. Abstract in english This work is concerned with the simulation of the filling and cooling stages of the injection molding process of an isotactic polypropylene (iPP). A mathematical model based on the conservation equations was used. A crystallization kinetics model was considered as a source term in the energy equatio [...] n. The parameters of the crystallization kinetics model, as well as the viscosity model, were obtained by experimental techniques. For the solution of the governing equations the finite volume method was employed. Temperature, pressure, velocity, shear rate and crystalinity profiles under different processing conditions were obtained.

  1. MECHANICAL PROPERTIES OF INJECTION-MOLDED FOAMED WHEAT STRAW FILLED HDPE BIOCOMPOSITES: THE EFFECTS OF FILLER LOADING AND COUPLING AGENT CONTENTS

    OpenAIRE

    Fatih Mengeloglu; Kadir Karaku?

    2012-01-01

    This study investigated the effect of filler loading and coupling agent contents on the densities and mechanical properties of injection-molded foamed biocomposites. Biocomposite pellets were manufactured using wheat straw flour, maleic anhydrite grafted polyethylene (MAPE), paraffin wax, and high-density polyethylene (HDPE) with an extrusion process. Pellets and the chemical foaming agent (azodicarbonamide) were dry-mixed and foamed in an injection-molding machine. Densities and mechanical p...

  2. Design of Multimodel based MPC and IMC control schemes applied to injection molding machine

    OpenAIRE

    Kanaga Lakshmi; D. Manamalli; M. Mohamed Rafiq

    2014-01-01

    Good control of plastic melt temperature for injection molding is very important in reducing operator setup time, ensuring product quality, and preventing thermal degradation of the melt. The controllability and set points of barrel temperature also depend on the precise monitoring and control of plastic melt temperature. Motivated by the practical temperature control of injection molding, this paper proposes MPC and IMC based control scheme. A robust system identification and control methodo...

  3. Design Optimization of Stationary Platen of Plastic Injection Molding Machine Using FEA

    OpenAIRE

    Dheeraj Mandliya*1; Yogesh Agrawal2; G.V.R.Seshagiri Rao

    2014-01-01

    Plastic are certainly most versatile of all known materials today and have therefore, established themselves in enviable position from where are not even possible to replaced. Injection molding machine is one of the most widely used method of conversion of plastic into various end products application to wide range of plastic materials from plastic commodity to specialty engineering plastic.In injection molding machine stationary platen play a very important role. During the p...

  4. Transcription of Small Surface Structures in Injection Molding - an Experimental Study

    DEFF Research Database (Denmark)

    ArlØ, Uffe Rolf; Kjær, Erik Michael

    2001-01-01

    The ability to replicate the surface roughness from mold wall to the plastic part in injection moldning has many functional and cosmetic important implications from medical use to designer products. Generally the understanding of surface transcription i.e the the replication of the surface structure from the mould to plastic part, also relates to micro injection moulding and moulding of parts with specific micro structures on the surface such as optical parts. The present study concerns transcription of surface roughness as a function of process parameters. The study is carried out with a polystyrene part, process parameters at typical levels and a rough spark eroded mould surface with Ra=12.6 micro meters.

  5. Numerical modeling of magnetic induction and heating in injection molding tools

    DEFF Research Database (Denmark)

    Guerrier, Patrick; Hattel, Jesper Henri

    2013-01-01

    Injection molding of parts with special requirements or features such as micro- or nanostructures on the surface, a good surface finish, or long and thin features results in the need of a specialized technique to ensure proper filling and acceptable cycle time. The aim of this study is to increase the temperatures as close as possible to the cavity surface, by means of an integrated induction heating system in the injection molding tool, to improve the fluidity of the polymer melt hereby ensuring that the polymer melt will continue to flow until the mold cavity is completely filled. The presented work uses numerical modeling of the induction heating in the mold to investigate how the temperature in the mold will be distributed and how it is affected by different material properties.

  6. Reducción del Tiempo de Ciclo de Inyección de Termoplásticos con el uso de Moldes con Tratamiento Superficial por Nitruración / Cycle Time Reduction of Thermoplastic Injection using Nitriding Treatment Surface Molds

    Scientific Electronic Library Online (English)

    Emerson J, Corazza; Carlos M, Sacchelli; Cintia, Marangoni.

    Full Text Available Se presenta un estudio sobre la transferencia de calor en un molde, comparando los ensayos de inyección utilizando moldes con y sin tratamiento superficial de nitruración. Simulaciones del proceso se realizaron con el uso de Asistencia Computacional a Ingeniería (CAE) para determinar los parámetros [...] iniciales que se aplicaron en los ensayos reales en moldes instrumentados de acero P20 (con y sin tratamientos), inyectados con el polímero poliestireno cristal. Los resultados indicaron una reducción del tiempo de enfriamiento y del tiempo de proceso en el molde con el tratamiento, debido a una mejora en la conductividad térmica. Abstract in english A study on the heat transfer in a mold, comparing experimental injection tests using a mold with and without surface treatment (nitriding) is presented. Process simulations were carried out using Computer Aided Engineering tools (CAE) for the estimation of the initial parameters to be applied in the [...] tests in instrumented P20 steel injection molds with the polymer crystal polystyrene. Results indicated a reduction of cooling time and of the time of the process in the mold with treatment, due to an increase of the thermal conductivity.

  7. Optimization of injection molded parts by using ANN-PSO approach

    Directory of Open Access Journals (Sweden)

    R. Spina

    2006-02-01

    Full Text Available Purpose: The aim of the work was the optimization of injection molded product warpage by using an integrated environment.Design/methodology/approach: The approach implemented took advantages of the Finite Element (FE Analysis to simulate component fabrication and investigate the main causes of defects. A FE model was initially designed and then reinforced by integrating Artificial Neural Network to predict main filling and packing results and Particle Swarm Approach to optimize injection molding process parameters automatically.Findings: This research has confirmed that the evaluation of the FE simulation results through the Artificial Neural Network system was an efficient method for the assessment of the influence of process parameter variation on part manufacturability, suggesting possible adjustments to improve part quality.Research limitations/implications: Future researches will be addressed to the extension of analysis to large thin components and different classes of materials with the aim to improve the proposed approach.Originality/value: The originality of the work was related to the possibility of analyzing component fabrication at the design stage and use results in the manufacturing stage. In this way, design, fabrication and process control were strictly links.

  8. Design Optimization of Stationary Platen of Plastic Injection Molding Machine Using FEA

    Directory of Open Access Journals (Sweden)

    Dheeraj Mandliya*1

    2014-05-01

    Full Text Available Plastic are certainly most versatile of all known materials today and have therefore, established themselves in enviable position from where are not even possible to replaced. Injection molding machine is one of the most widely used method of conversion of plastic into various end products application to wide range of plastic materials from plastic commodity to specialty engineering plastic.In injection molding machine stationary platen play a very important role. During the process generally compressive stress generates at particular regions. As load varies with fast rate there is chance to failure of tie bar rod. Due to heavy mould shape, size of platen also change, that’s increase its weight as well as stress level at certain region and this is not good in practice . This leads to failure of platen or failure of tie rod due to stretching by nut and platen. This create loss of money (Production stop, man (injured due to accident, and material (increase inventory cost. The aim of this project is study about those areas where stress can affect the failure of tie bar due to heavy weight of stationary platen the deflection or misalignment with movable platen. Finally redistribution of stress sothat uniforme stress achive (optimization of platen. This project is including Finite Element Analysis and Design Optimization of a Typical Structural Component of a Plastic Injection Molding Machine. The aim of project is to optimize a typical structural component (stationary platen by using finite element analysis after checking induced stresses with allowable design stress. Hence design modification of platen is carried out to achieve good strength and cost effectiveness.

  9. Enteric-coating of pulsatile-release HPC capsules prepared by injection molding.

    Science.gov (United States)

    Macchi, E; Zema, L; Maroni, A; Gazzaniga, A; Felton, L A

    2015-04-01

    Capsular devices based on hydroxypropyl cellulose (Klucel® LF) intended for pulsatile release were prepared by injection molding (IM). In the present work, the possibility of exploiting such capsules for the development of colonic delivery systems based on a time-dependent approach was evaluated. For this purpose, it was necessary to demonstrate the ability of molded cores to undergo a coating process and that coated systems yield the desired performance (gastric resistance). Although no information was available on the coating of IM substrates, some issues relevant to that of commercially-available capsules are known. Thus, preliminary studies were conducted on molded disks for screening purposes prior to the spray-coating of HPC capsular cores with Eudragit® L 30 D 55. The ability of the polymeric suspension to wet the substrate, spread, start penetrating and initiate hydration/swelling, as well as to provide a gastroresistant barrier was demonstrated. The coating of prototype HPC capsules was carried out successfully, leading to coated systems with good technological properties and able to withstand the acidic medium with no need for sealing at the cap/body joint. Such systems maintained the original pulsatile release performance after dissolution of the enteric film in pH 6.8 fluid. Therefore, they appeared potentially suitable for the development of a colon delivery platform based on a time-dependent approach. PMID:25585355

  10. Development and Design of Binder Systems for Titanium Metal Injection Molding: An Overview

    Science.gov (United States)

    Wen, Guian; Cao, Peng; Gabbitas, Brian; Zhang, Deliang; Edmonds, Neil

    2013-03-01

    Titanium metal injection molding (Ti-MIM) has been practiced since the late 1980s. Logically, the Ti-MIM practice follows the similar processes developed for the antecedent materials such as stainless steel and ceramics. Although Ti-MIM is a favorite research topic today, the issue of convincing the designers to use Ti injection-molded parts still exists. This is mainly because of the concern about contamination which seems unavoidable during the Ti-MIM process. Much information about the binder formulation, powder requirements, debinding, and sintering is available in the literature. There are several powder vendors and feedstock suppliers. However, most of the binders in the feedstock are proprietarily protected. The disclosed information on the binders used for formulating powder feedstock is very limited, which in turn discourages their adoption by engineering designers. This overview intends to discuss some of major binder systems for Ti-MIM available in the literature. It serves to provide a guideline for the Ti-MIM practitioners to choose a suitable powder feedstock.

  11. Crystallization kinetics and morphology of PBT/MMT and PTT/MMT nanocomposites during injection molding

    International Nuclear Information System (INIS)

    This work had as main objective to study the crystallization of nanocomposites of poly(butylene terephthalate) (PBT) and poly(trimethylene terephthalate) (PTT) with a montmorillonite nanoclay (MMT) using an on-line optical monitoring system during the injection molding and to characterize the morphologies of the injection samples by polarized light optical microscopy (PLOM), wide angle X-ray diffraction (WAXS) and differential scanning calorimetry (DSC). The optical system allowed to analyze the crystallization process by the changes of the optical properties during the solidification of the materials. It was concluded that the MMT lamellae accelerated the overall crystallization of the polymers. By PLOM, it was observed that the nanoclay caused qualitative changes on the morphology of the PTT (polymer with slow crystallization kinetics). The crystallinity indexes were not affected by the addition of the MMT; however, by WAXS it was shown that the nanocomposites had a higher orientation degree. (author)

  12. Effect of injection molded micro-structured polystyrene surfaces on proliferation of MC3T3-E1 cells

    Directory of Open Access Journals (Sweden)

    G. Lucchetta

    2015-04-01

    Full Text Available In this work, osteoinductive micro-pillared polystyrene surfaces were mass-produced for bone replacement applications, by means of the micro injection molding process. Firstly, the molding process parameters were optimized with a two-level, three-factor central composite face-centered plan to increase the quality of polystyrene micro pillars replication and to maximize the pillars height uniformity over the molded part. Secondly, osteoblastic MC3T3-E1 cells adhesion and proliferation on the replicated substrates were assessed as a function of micro topography parameters, such as pillars diameter, aspect ratio and spacing. Cell morphology and proliferation were evaluated through MTS test after 1, 3 and 7 days from seeding. The experimental results showed that cells adhesion and proliferation is more positively promoted on micro-pillared surfaces compared to flat surfaces, but no correlations were observed between cell proliferation and pillar diameter and spacing.

  13. (The control of microstructures during consolidation and injection molding of colloidal dispersions)

    Energy Technology Data Exchange (ETDEWEB)

    1991-01-01

    The existing three-year grant pertaining to The control of micro-structures during consolidation and injection molding of colloidal dispersions'' began July 1, 1988 as a continuation of a previous grant. The overall effort seeks to answer fundamental questions relevant to the colloidal processing of submicron particles leading to ceramic materials for strutural, electronic, or optical applications. At the outset two distinct projects were envisioned, an exploration of the ultrasonic enhancement of disorder-order transitions and a detailed study of injection molding of very dense dispersion, with each weighted toward experiments but with theoretical components. As the effort evolved the focus shifted in response to the interests of the students attracted to the project, the identification of interesting related problems through technical meetings, and different insights gained during participation in a DOE sponsored workshop. The scope that has emerged encompasses: completion of research begun during the first grant period on disorder-order transitions occurring during sedimentation, the consolidation of flocculated dispersions via filtration and the assembly of nanometer-sized particle into dense packings.

  14. Mechanical properties of the weld line defect in micro injection molding for various nano filled polypropylene composites

    International Nuclear Information System (INIS)

    Research highlights: ? PP/CNFs and PP/TiO2 composites with relative high loading fractions (10, 20, 30 and 35 wt%) were fabricated by inner melt mixing process. Micro tensile test samples were formed by injection molding combined with variotherm process for all composites. ? The morphological properties of all nano composites were characterized by WXRD, whose results imply the adding nano fillers did not change the crystal form of PP, but the crystallites size and distance between lattices of crystals were changed with various nano fillers and loading fractions. ? DSC analysis show that due to the nucleating function of nano fillers, the peak temperature of crystallization was increased and the peak temperature of crystallization melting was decreased by adding the nanofillers. ? The flow ability of nano composites was tested by high pressure single capillary rheometer and the results demonstrate that nano fillers increased the viscosity of PP matrix. ? Based on these significant information and analysis foundation of the nano filled composites, the micro weld line samples were formed by injection molding process and characterized by tensile test method. From the achieved results, it can be found that in general, for functional nano filled polymer composites, the mechanical property of micro weld lines were obviously influenced by nano fillers' shape and loading fractions. ? The E modulus of micro weld line was increased due to loading CNFs in Peased due to loading CNFs in PP matrix, while the elongation of the micro tensile samples with weld line is considerably decreased comparing with those of unfilled PP samples. The detrimental tensile strength of micro weld lines were observed when CNFs contents increasing, except for at a 10 wt%. ? For TiO2 nano particles filled PP, due to the poor dispersion of nano particles, at low loading fraction of 10 wt%, the E modulus and tensile strength of micro weld lines were decreased by filling nano particles, but when the loading fraction is increased to 30%, the E modulus and tensile strength of micro weld line were increased again compared with the low loading level. ? Finally, an empirical prediction equation for micro injection molded weld line strength of nano PP composites was proposed for higher nano filler loading fraction than 10 wt%. - Abstract: The nano filled functional polymer materials have been widely processed with micro injection molding technology for micro electromechanical systems (MEMS) fabrication. As the unfavorable defect in micro injection molding parts, weld line brings reduced mechanical and physical properties, especially for nano filled composites. In this study, polypropylene (PP) was compounded respectively with carbon nano fibers (CNFs) and TiO2 nano particles at various weight fractions (10, 20, 30, 35 wt%) through co-screws internal mixing. The morphological, thermal and rheological properties of nano composites were characterized by wider angle X-ray diffraction (WXRD), different scanning calorimeter (DSC) and high pressure capillary rheometer. Additionally, under the constant setting of injection molding process parameters in injection molding machine, micro tensile samples with weld lines for each nano filled PP composite were produced. The tensile tests were served as the characterizing method for weld line mechanical properties. The results show that when the CNFs is filled higher than 10 wt%, the tensile strength of samples with weld lines made of nano composites become lower than neat PP. While the raising CNFs content contributes to the improved E modulus of micro injection molded weld lines. Additionally, with the increasing fraction of CNFs in PP, the weld line area's elongation percent is decreased. Whereas for case of TiO2, the 10 wt% is the threshold for micro injection molded weld line tensile strength turning from decrease trend to increase. The same as CNFs, elongation of micro weld line samples were in general lower than neat PP as well, due to the addition of TiO2 nano particles.

  15. Efeito do processamento em misturas de alumina/ligantes orgânicos usadas na moldagem por injeção em baixa pressão / Effect of processing variables in alumina/organic binders mixtures used in low-pressure injection molding

    Scientific Electronic Library Online (English)

    P . A., Ourique; A., Susin Neto; S. G., Echeverrigaray; R. C. D., Cruz; J. E., Zorzi.

    2013-03-01

    Full Text Available A moldagem por injeção em baixa pressão (MIBP) é uma técnica que já vem sendo empregada na produção de peças cerâmicas com formas e geometrias complexas. A homogeneidade da mistura de ligantes orgânicos e pós cerâmicos é um fator determinante que deve ser controlado para minimizar a formação de impe [...] rfeições no processamento de feedstocks para MIBP. Defeitos típicos de processamento por MIBP, como bolhas de ar e aglomerados, geram gradientes de densidade nas misturas que, após conformação, possuem poucas possibilidades de remoção. Essas imperfeições comprometem o desempenho dos produtos obtidos por essa técnica. Este trabalho está focado na avaliação dessas heterogeneidades e como elas podem ser correlacionadas com a variação da densidade aparente e com o comportamento reológico dessas misturas. Para tanto, aluminas submicrométricas, como recebida e desaglomerada, foram adicionadas a uma mistura fundida de ligantes a base de parafinas, ceras e aditivos e processada em dois tipos diferentes de misturadores, com e sem o auxílio de vácuo. Foi observada a presença de aglomerados existentes na alumina como recebida, possivelmente gerados durante a etapa de calcinação. Também foi observado que o tipo de misturador e a aplicação ou não de vácuo durante a etapa final do processamento têm grande influência no tempo de mistura necessário para reduzir a viscosidade do feedstock para a injeção. Abstract in english The low-pressure injection molding (LPIM) is a technique already being used in the production of ceramic parts with complex shapes and geometries. The homogeneity of the mixture of organic binder and ceramic powder is a determining factor which must be controlled to minimize defects formation while [...] feedstock processing to LPIM. Typical defects of LPIM processing, such as air bubbles and agglomerates, generate density gradients in the mixtures, which, after shaping, have little possibility of removal. These imperfections compromise the performance of the products obtained by this technique. This work is focused on the evaluation of these inhomogeneities and how they can be correlated with density variation and the rheological behavior of these mixtures. Therefore, submicrometer aluminas, as received and deagglomerated, were added to a molten mixture of paraffin based binders, waxes and additives and processed in two different mixers, with and without vacuum. The presence of alumina agglomerates was observed in the powder as received, possibly generated during the calcination step. It was also observed that the type of mixer and vacuum application or not during the final processing step, has a major influence on the mixing time required to reduce the viscosity of the feedstock for injection.

  16. Efeito do processamento em misturas de alumina/ligantes orgânicos usadas na moldagem por injeção em baixa pressão Effect of processing variables in alumina/organic binders mixtures used in low-pressure injection molding

    Directory of Open Access Journals (Sweden)

    P . A. Ourique

    2013-03-01

    Full Text Available A moldagem por injeção em baixa pressão (MIBP é uma técnica que já vem sendo empregada na produção de peças cerâmicas com formas e geometrias complexas. A homogeneidade da mistura de ligantes orgânicos e pós cerâmicos é um fator determinante que deve ser controlado para minimizar a formação de imperfeições no processamento de feedstocks para MIBP. Defeitos típicos de processamento por MIBP, como bolhas de ar e aglomerados, geram gradientes de densidade nas misturas que, após conformação, possuem poucas possibilidades de remoção. Essas imperfeições comprometem o desempenho dos produtos obtidos por essa técnica. Este trabalho está focado na avaliação dessas heterogeneidades e como elas podem ser correlacionadas com a variação da densidade aparente e com o comportamento reológico dessas misturas. Para tanto, aluminas submicrométricas, como recebida e desaglomerada, foram adicionadas a uma mistura fundida de ligantes a base de parafinas, ceras e aditivos e processada em dois tipos diferentes de misturadores, com e sem o auxílio de vácuo. Foi observada a presença de aglomerados existentes na alumina como recebida, possivelmente gerados durante a etapa de calcinação. Também foi observado que o tipo de misturador e a aplicação ou não de vácuo durante a etapa final do processamento têm grande influência no tempo de mistura necessário para reduzir a viscosidade do feedstock para a injeção.The low-pressure injection molding (LPIM is a technique already being used in the production of ceramic parts with complex shapes and geometries. The homogeneity of the mixture of organic binder and ceramic powder is a determining factor which must be controlled to minimize defects formation while feedstock processing to LPIM. Typical defects of LPIM processing, such as air bubbles and agglomerates, generate density gradients in the mixtures, which, after shaping, have little possibility of removal. These imperfections compromise the performance of the products obtained by this technique. This work is focused on the evaluation of these inhomogeneities and how they can be correlated with density variation and the rheological behavior of these mixtures. Therefore, submicrometer aluminas, as received and deagglomerated, were added to a molten mixture of paraffin based binders, waxes and additives and processed in two different mixers, with and without vacuum. The presence of alumina agglomerates was observed in the powder as received, possibly generated during the calcination step. It was also observed that the type of mixer and vacuum application or not during the final processing step, has a major influence on the mixing time required to reduce the viscosity of the feedstock for injection.

  17. Micro Injection Molding of Thin Walled Geometries with Induction Heating System

    DEFF Research Database (Denmark)

    Menotti, Stefano; Hansen, Hans NØrgaard

    2014-01-01

    To eliminate defects and improve the quality of molded parts, increasing the mold temperature is one of the applicable solutions. A high mold temperature can increase the path flow of the polymer inside the cavity allowing reduction of the number of injection points, reduction of part thickness and moulding of smaller and more complex geometries. The last two aspects are very important in micro injection molding. In this paper a new embedded induction heating system is proposed and validated. An experimental investigation was performed based on a test geometry integrating different aspect ratios of small structures. ABS was used as material and different combinations of injection velocity, pressure and mold temperature were tested. The replicated test objects were measured by means of an optical CMM machine. On the basis of the experimental investigation the efficacy of the embedded induction heating system with respect to improvement of replication quality, reduction of injection pressure and injection velocity as well as reduction of cycle time has been verified.

  18. Mold

    Centers for Disease Control (CDC) Podcasts

    2011-05-02

    This podcast answers a listener's question about the risks associated with mold after a natural disaster or severe weather.  Created: 5/2/2011 by National Center for Environmental Health (NCEH).   Date Released: 5/2/2011.

  19. Acoustic Emission Detection of Macro-Cracks on Engraving Tool Steel Inserts during the Injection Molding Cycle Using PZT Sensors

    Directory of Open Access Journals (Sweden)

    Aleš Han?i?

    2013-05-01

    Full Text Available This paper presents an improved monitoring system for the failure detection of engraving tool steel inserts during the injection molding cycle. This system uses acoustic emission PZT sensors mounted through acoustic waveguides on the engraving insert. We were thus able to clearly distinguish the defect through measured AE signals. Two engraving tool steel inserts were tested during the production of standard test specimens, each under the same processing conditions. By closely comparing the captured AE signals on both engraving inserts during the filling and packing stages, we were able to detect the presence of macro-cracks on one engraving insert. Gabor wavelet analysis was used for closer examination of the captured AE signals’ peak amplitudes during the filling and packing stages. The obtained results revealed that such a system could be used successfully as an improved tool for monitoring the integrity of an injection molding process.

  20. A wide variety of injection molding technologies is now applicable to small series and mass production

    International Nuclear Information System (INIS)

    Micro plastic parts open new fields for application, e. g., to electronics, sensor technologies, optics, and medical engineering. Before micro parts can go to mass production, there is a strong need of having the possibility for testing different designs and materials including material combinations. Hence, flexible individual technical and technological solutions for processing are necessary. To manufacture high quality micro parts, a micro injection moulding machine named formicaPlast based on a two-step plunger injection technology was developed. Resulting from its design, the residence time and the accuracy problems for managing small shot volumes with reproducible high accuracy are uncompromisingly solved. Due to their simple geometry possessing smooth transitions and non adherent inner surfaces, the plunger units allow to process 'all' thermoplastics from polyolefines to high performance polymers, optical clear polymers, thermally sensitive bioresorbables, highly filled systems (the so-called powder injection molding PIM), and liquid silicon rubber (LSR, here with a special kit). The applied platform strategy in the 1K and 2K version allows integrating automation for assembling, handling and packaging. A perpendicular arrangement allows encapsulation of inserts, also partially, and integration of this machine into process chains. Considering a wide variety of different parts consisting of different materials, the high potential of the technology is demonstrated. Based on challenging industrial parts from electronic applications (2K micro MID and bump mat, where both are highly structured parts), the technological solutions are presented in more detail

  1. A wide variety of injection molding technologies is now applicable to small series and mass production

    Energy Technology Data Exchange (ETDEWEB)

    Bloß, P., E-mail: bloss@kuz-leipzig.de, E-mail: juettner@kuz-leipzig.de, E-mail: jacob@kuz-leipzig.de, E-mail: loeser@kuz-leipzig.de, E-mail: michaelis@kuz-leipzig.de, E-mail: krajewsky@kuz-leipzig.de; Jüttner, G., E-mail: bloss@kuz-leipzig.de, E-mail: juettner@kuz-leipzig.de, E-mail: jacob@kuz-leipzig.de, E-mail: loeser@kuz-leipzig.de, E-mail: michaelis@kuz-leipzig.de, E-mail: krajewsky@kuz-leipzig.de; Jacob, S., E-mail: bloss@kuz-leipzig.de, E-mail: juettner@kuz-leipzig.de, E-mail: jacob@kuz-leipzig.de, E-mail: loeser@kuz-leipzig.de, E-mail: michaelis@kuz-leipzig.de, E-mail: krajewsky@kuz-leipzig.de; Löser, C., E-mail: bloss@kuz-leipzig.de, E-mail: juettner@kuz-leipzig.de, E-mail: jacob@kuz-leipzig.de, E-mail: loeser@kuz-leipzig.de, E-mail: michaelis@kuz-leipzig.de, E-mail: krajewsky@kuz-leipzig.de; Michaelis, J., E-mail: bloss@kuz-leipzig.de, E-mail: juettner@kuz-leipzig.de, E-mail: jacob@kuz-leipzig.de, E-mail: loeser@kuz-leipzig.de, E-mail: michaelis@kuz-leipzig.de, E-mail: krajewsky@kuz-leipzig.de; Krajewsky, P., E-mail: bloss@kuz-leipzig.de, E-mail: juettner@kuz-leipzig.de, E-mail: jacob@kuz-leipzig.de, E-mail: loeser@kuz-leipzig.de, E-mail: michaelis@kuz-leipzig.de, E-mail: krajewsky@kuz-leipzig.de [Kunststoff-Zentrum in Leipzig gGmbH (KuZ), Leipzig (Germany)

    2014-05-15

    Micro plastic parts open new fields for application, e. g., to electronics, sensor technologies, optics, and medical engineering. Before micro parts can go to mass production, there is a strong need of having the possibility for testing different designs and materials including material combinations. Hence, flexible individual technical and technological solutions for processing are necessary. To manufacture high quality micro parts, a micro injection moulding machine named formicaPlast based on a two-step plunger injection technology was developed. Resulting from its design, the residence time and the accuracy problems for managing small shot volumes with reproducible high accuracy are uncompromisingly solved. Due to their simple geometry possessing smooth transitions and non adherent inner surfaces, the plunger units allow to process 'all' thermoplastics from polyolefines to high performance polymers, optical clear polymers, thermally sensitive bioresorbables, highly filled systems (the so-called powder injection molding PIM), and liquid silicon rubber (LSR, here with a special kit). The applied platform strategy in the 1K and 2K version allows integrating automation for assembling, handling and packaging. A perpendicular arrangement allows encapsulation of inserts, also partially, and integration of this machine into process chains. Considering a wide variety of different parts consisting of different materials, the high potential of the technology is demonstrated. Based on challenging industrial parts from electronic applications (2K micro MID and bump mat, where both are highly structured parts), the technological solutions are presented in more detail.

  2. Injection Molding of Titanium Alloy Implant For Biomedical Application Using Novel Binder System Based on Palm Oil Derivatives

    OpenAIRE

    Ibrahim, R.; Azmirruddin, M.; Jabir, M.; Ismail, M. R.; Muhamad, M.; Awang, R.; Muhamad, S.

    2010-01-01

    Problem statement: Titanium alloy (Ti6Al4V) has been widely used as an implant for biomedical application. In this study, the implant had been fabricated using high technology of Powder Injection Molding (PIM) process due to the cost effective technique for producing small, complex and precision parts in high volume compared with conventional method through machining. Approach: Through PIM, the binder system is one of the most important criteria in order to successfully fabricate the implants...

  3. Injection molding of ultra-fine Si3N4 powder for gas-pressure sintering

    Science.gov (United States)

    Yang, Xian-feng; Yang, Jiang-hong; Xu, Xie-wen; Liu, Qi-cheng; Xie, Zhi-peng; Liu, Wei

    2015-06-01

    The ceramic injection molding technique was used in the gas-pressure sintering of ultra-fine Si3N4 powder. The feedstock's flowability, debinding rate, defect evolution, and microstructural evolution during production were explored. The results show that the solid volume loading of less than 50vol% and the surfactant mass fraction of 6wt% result in a perfect flowability of feedstock; this feedstock is suitable for injection molding. When the debinding time is 8 h at 40°C, approximately 50% of the wax can be solvent debinded. Defects detected during the preparation are traced to improper injection parameters, mold design, debinding parameters, residual stress, or inhomogeneous composition distribution in the green body. The bulk density, Vickers hardness, and fracture toughness of the gas-pressure-sintered Si3N4 ceramic reach 3.2 g/cm3, 16.5 GPa, and 7.2 MPa·m1/2, respectively.

  4. Aplikasi Rekayasa Mutu untuk Mengurangi Cacat pada Mesin Injection Molding

    Directory of Open Access Journals (Sweden)

    Glenn Eko Yulianto

    1999-01-01

    Full Text Available The imperfect combustion process will be a problem in the development effort of diesel engine's performance. Nonhomogen air-fuel mixing process is one of the factors which cause the imperfect combustion. By heating up the diesel fuel up to a certain temperature before it goes through the high pressure injection pump will lower its density and viscosity. Therefore, when injected in the combustion chamber, it will formed smaller droplets of fuel spray which result in a more homogenious air-fuel mixture. Also by using higher temperature will make the diesel fuel easier to ignite in order to compensate the limited time which is available in high speed operating conditions. Diesel fuel heating can improve the combustion process to increase the power and decrease the fuel consumption optimally. Abstract in Bahasa Indonesia : Tidak sempurnanya proses pembakaran merupakan masalah yang akan dijumpai dalam usaha peningkatan kinerja motor diesel. Proses pencampuran udara dan bahan bakar yang kurang baik menjadi salah satu faktor penyebab ketidak sempurnaan tersebut. Dengan melakukan pemanasan terhadap solar sampai temperatur tertentu sebelum masuk ke dalam pompa tekanan tinggi akan menyebabkan penurunan density dan viskositas solar, sehingga bila diinjeksikan ke dalam ruang bakar akan membentuk butiran kabut bahan bakar yang lebih halus yang akan menyebabkan proses pencampuran bahan bakar dan udara menjadi lebih homogen. Disamping itu, dengan temperatur yang lebih tinggi akan membuat solar menjadi lebih mudah terbakar sehingga dapat mengimbangi singkatnya waktu yang tersedia untuk pembakaran pada putaran tinggi. Pemanasan solar dapat dipergunakan sebagai salah satu cara untuk menyempurnakan proses pembakaran sehingga dihasilkan peningkatan daya dan penurunan konsumsi bahan bakar yang optimal. Kata kunci : peningkatan daya, penurunan konsumsi bahan bakar, motor diesel, proses pembakaran

  5. High quality ion channels recordings on an injection molded polymer chip

    DEFF Research Database (Denmark)

    Tanzi, Simone

    2013-01-01

    In this thesis we demonstrate high quality recordings of the ion channel activity across the cell membrane in a biological cell by employing the so called patch clamping technique on an injection molded polymer microfluidic device. Such recordings are traditionally made using glass micropipettes, or in recent years using consumable microfluidic chips of high costs. The patch clamping method is widely used both in fundamental studies of electrophysiology of living cells and tissue and in drug discovery. The findings of this work will allow direct recordings of ion channel activity to be made using the cheapest materials and production platform to date, and with the potential for very high throughput. The employment of cornered apertures for cell capture allowed the fabrication of devices without through holes via a process comprising master origination by dry etching in a silicon substrate, electroplating in nickel, and injection molding of the final part. A thorough characterization of the patching orifices by means of SEM and AFM showed high replication accuracy through the fabrication process. The most critical device parameters were identified as the length of the patching capillaries and the very low surface roughness inside of the capillaries. The cross-sectional shape of the cornered apertures was found to be less critical, as apertures with different profiles were tested with cells and showed the same ability to form tight seals with cells with negligible leak currents. The ability to form high resistance seals in the GOhm range, the so called gigaseals, is demonstrated with a success rate of 15%. The devices were functionally tested with Human Embryonice Kidney (HEK) cells expressing voltage-gated sodium channels and benchmarked against a commercial state-of-the-art system for automated ion channel recordings. These experiments considered current-voltage relationships for activation and inactivation of the sodium channels and their sensitivity to a local anesthetic, lidocaine. Both IVs and lidocaine does response curves obtained from the injection molded polymer device were in excellent agreement with data obtained from the commercial system.

  6. Mejora de la etapa de llenado en moldes de inyección de plástico usando vibración / Improvement Performance of the Filling Step in Injection Mold through Vibration

    Scientific Electronic Library Online (English)

    J.P., Benítez-Rangel; L.A., Morales-Hernández; M., Trejo-Hernández.

    2012-12-01

    Full Text Available El presente trabajo muestra la mejora de flujo que tiene la etapa de llenado del proceso de inyección de plásticos, debida a la excitación del polímero a través de vibración. Dicho proceso, puede resumirse en tres etapas principales que son: el llenado, el empaquetado y el enfriamiento. El proceso d [...] e llenado es el paso en el que se pueden cambiar una gran cantidad de propiedades, tanto mecánicas como estéticas del producto terminado. El objetivo de esta investigación es mostrar que el llenado del molde mejora adicionando vibración, sin tener que agregar aditivos químicos. Para ello, se llevó a cabo el diseño y fabricación de un molde experimental, en el cual se acondicionó un mecanismo de vibración que permitió demostrar las ventajas de la vibración en dicho proceso. Además, se propuso una metodología heurística para la elaboración de las pruebas que reveló una mejora en el llenado con frecuencias cercanas a los 3 Hz. Abstract in english This paper shows the flow improvement in the filling step of the polymer injection process due to the polymer excitation though vibration. This process can be split up into three main steps: filling, pocking and cooling. Several mechanical and aesthetic properties of the finished product can be chan [...] ged in the filling step. The objective of this investigation is to demonstrate the improvement in the filling mold under vibration without adding chemical products. To reach this result, an experimental mold was designed and manufactured in which a vibration device was coupled; it was possible to demonstrate the vibration advantage through this process. Moreover, a heuristic methodology was proposed for the experiment which shows an improvement in the filling process with frequencies close to 3 Hz.

  7. Nanoimprint Molds with Circumferentially Aligned Patterns Fabricated by Liftoff Process

    Science.gov (United States)

    Okada, Takeru; Fujimori, Jiro; Iida, Tetsuya

    2011-12-01

    A liftoff process was used to fabricate nanoimprint molds with dense patterns below 50 nm pitch. Circumferentially aligned patterns were defined by electron-beam lithography (EBL) using an electron-beam recorder with a rotary stage. Undercut profiles suitable for liftoff were fabricated by etching multilayered resist systems that use a hydrogen silsesquioxane (HSQ) layer as an etching mask for the underlying resin, and liftoff was performed by dissolving the HSQ layer on an insoluble resin layer. By using an undercut profile that was formed in a trilayered stack after EBL, a mold with high-density (42 nm pitch) and large-area (2.5 in.) pillar patterns was fabricated. Quartz replica molds were also fabricated by the liftoff process combined with UV nanoimprint. It was possible to fabricate molds with both a positive tone and a negative tone, and the fabrication of a replica mold with pillar patterns (49 nm pitch) was demonstrated.

  8. Process-induced damage evolution and management in resin transfer molding of composite panels

    Science.gov (United States)

    Kuan, Yean-Der

    2000-10-01

    Woven fiber composites made by resin transfer molding process are currently used as the primary and secondary load bearing structures in automotive and aircraft industries. A variety of defects could be evolved during the injection stage and the curing stage of the process. Improper injection conditions or unsound tool design would result in process induced damage in the form of dry spots, incomplete filling, or displacement of the fiber. In the curing stage, the process parameters of heating and cooling rates, and the temperature level at each element of the curing cycle have direct effects on the development of internal residual stresses, and shape distortion due to warpage. The work in this dissertation aims at developing numerical models to predict, characterize, and minimize process-induced damage during both the injection stage and curing stage in RTM process for woven-fiber composites. A control volume technique based on the finite difference method is used to characterize the flow behavior in resin transfer molding (RTM) of composite structures. Resin flow through fiber mats is modeled as a two-phase flow through porous media. Experimental results on flow behavior of EPON 826 epoxy resin into irregular mold cavity with fiberglass mats agree well with the present numerical simulation. Parametric analysis of several case studies using developed model illustrates the effectiveness of the flow model in investigating the flow pattern, mold filling time, dry spots formulation, and pressure distribution inside the mold. A numerical model describing the evolution of process-induced damage during curing in molded composite panels was developed. The effects of thermo-mechanical and thermo-chemical responses of the material on the evolution of damage during resin transfer molding of the panels are quantified. The developed numerical model in conjunction with an optimization module based on Simulated Annealing (SA) scheme form a useful tool for conducting a parametric design analysis for characterization and management of process-induced damage in composite panels. Experimental investigation of resin transfer molding of composite panels made of epoxy resin (EPON 826) and eight-harness graphite fiber mats, indicates that low cure temperature, moderate heating rate and high rate of cooling after cure would minimize damage during curing. Furthermore the experimental measurements are in agreement with the degree of damage predicted by the numerical models and hence verifying the effectiveness of these models. The models and methods developed in the present work are of broader applicability to process design and optimization of resin transfer molding of composite structures.

  9. Fabrication and characterization of injection molded multi level nano and microfluidic systems

    DEFF Research Database (Denmark)

    Matteucci, Marco; Christiansen, Thomas Lehrmann

    2013-01-01

    We here present a method for fabrication of multi-level all-polymer chips by means of silicon dry etching, electroplating and injection molding. This method was used for successful fabrication of microfluidic chips for applications in the fields of electrochemistry, cell trapping and DNA elongation. These chips incorporate channel depths in the range between 100nm and 100?m and depth to width aspect ratios between 1/200 and 2. Optimization of the sealing process of all-polymer COC microfluidic chips by means of thermal bonding is also presented. The latter includes comparing the bonding strength of UV-treated foils and presentation of a simple model for estimating the delamination pressure. With UV surface treatments, foils of 100?m thickness were found to withstand pressures up to 9atm in Ø4mm cylindrical inlets when thermally bonded to micropatterned substrates of 2mm thickness.

  10. PP-polymer nanocomposites with improved mechanical properties using elongational flow devices at the injection molding compounder

    Science.gov (United States)

    Battisti, M. G.; Friesenbichler, W.

    2014-05-01

    Numerous researches have been done in the field of improving PP by adding nanofillers. Consistently good scientific results and positive industrial feedback were reached; however, the industrial interest is still low due to the high technological and financial risks and too less benefit. Our experiments, using the worldwide unique Polymer NanoComposite Injection Molding Compounder (PNC-IMC) which combines the two processing steps of compounding and injection molding, showed an impressive increase of both mechanical and thermal properties, but more or less in the same range than in other publications. Thus we tried to improve the materials by using elongational flow generating devices for better intercalation and exfoliation of nanofillers in the polymer melt. This paper will give an overview on our first investigations, carried out on both a high pressure capillary rheometer (HPCR) and the injection molding machine (IMM) focusing on the mechanical properties. The PNCs were produced at the PNC-IMC with the 3in1 process. After the treatment in the HPCR the material was crushed, plates were prepared using a hydraulic vacuum press and tensile bars were milled, respectively tensile bars were produced with the IMM. The Young's modulus was successfully slightly improved. Thus future research will focus on both, the mechanism of improvement and the implementation of several of these devices into the PNC-IMC.

  11. A Novel Injection-Molded Capsular Device for Oral Pulsatile Delivery Based on Swellable/Erodible Polymers

    OpenAIRE

    GAZZANIGA, ANDREA; Cerea, Matteo; Alberto COZZI; Foppoli, Anastasia; Maroni, Alessandra; ZEMA, LUCIA

    2011-01-01

    The feasibility of injection molding was explored in the preparation of a novel capsular device for oral pulsatile/delayed delivery based on swellable/erodible polymers. For this purpose, a mold intended to be coupled with a bench-top injection-molding press was designed. This was expected to enable the preparation of matching capsule cap and body items within a single manufacturing cycle and the selection of differing shell thicknesses (300, 600, and 900 ?m). Hydroxypropylcellulose (Klucel...

  12. Hot mold casting process of ancient East India and Bangladesh

    Directory of Open Access Journals (Sweden)

    Barnali Mandal

    2010-05-01

    Full Text Available Ancient casting process for production of brass or bronze utensils and icons were made in hot molds using clay molded investment casting or piece mold process, as presumed by archaeologists. Piece mold process is still traditionally practiced in many parts of Eastern India and Bangladesh along with investment casting process. Incidentally, Bengal artisans are more accustomed to piece mold process unlike tribal artisans who practiced investment casting process. This piece mold casting process has been reconstructed to get the idea of metal characteristics in order to investigate ancient casting process of Bengal and Bangladesh. The characterization of ancient archaeo-metal products come to a type of cast Cu-Sn-Zn-Pb type quaternary alloy produced by a slow freezing process. Though these alloys physically differ from the traditional cast alloy of binary Cu-Zn type brass, the physical characteristics are similar to the binary cast alloy character. This investigation throws light on the similarity of the production processes by which ancient artisans probably produced cast metal products.

  13. All-in-polymer injection molded device for single cell capture using multilevel silicon master fabrication

    DEFF Research Database (Denmark)

    Tanzi, S.; Larsen, S.T.

    2012-01-01

    This work demonstrates a novel all-in-polymer device for single cell capture applicable for biological recordings. The chip is injection molded and comprises a "cornered" (non planar) aperture. It has been demonstrated how cornered apertures are straightforward to mold in PDMS [1,2]. In this study we demonstrate cornered apertures made in a thermoplastic polymer. One of the advantages of cornered apertures is the ease of microscopy under a standard inverted optical microscope, when using transparent materials. After the part is injection molded, the sealing of the chip is performed by thermal bonding to a polymer foil, so the complete device results from only two parts. It differs from similar devices in the novel material and fabrication platform that enables high reproducibility and inexpensive mass production. Optimization of the fabrication scheme has been carried out in order to avoid defects during demolding. Capturing of single PC12 cells has been demonstrated.

  14. CO-INJECTION RESIN TRANSFER MOLDING FOR OPTIMIZATION OF INTEGRAL ARMOR

    Science.gov (United States)

    To address the cost and performance barriers which hinder the introduction of composite materials for combat ground vehicle applications, Co-Injection Resin Transfer Molding (CIRTM) and Diffusion Enhanced Adhesion (DEA) have been recently invented and developed at the Army Resear...

  15. Low Speed Technology for Small Turbine Development Reaction Injection Molded 7.5 Meter Wind Turbine Blade

    Energy Technology Data Exchange (ETDEWEB)

    David M. Wright; DOE Project Officer - Keith Bennett

    2007-07-31

    An optimized small turbine blade (7.5m radius) was designed and a partial section molded with the RIM (reaction-injection molded polymer) process for mass production. The intended market is for generic three-bladed wind turbines, 100 kilowatts or less, for grid-assist end users with rural and semi-rural sites, such as the farm/ranch market, having low to moderate IEC Class 3-4 wind regimes. This blade will have substantial performance improvements over, and be cheaper than, present-day 7.5m blades. This is made possible by the injection-molding process, which yields high repeatability, accurate geometry and weights, and low cost in production quantities. No wind turbine blade in the 7.5m or greater size has used this process. The blade design chosen uses a RIM skin bonded to a braided infused carbon fiber/epoxy spar. This approach is attractive to present users of wind turbine blades in the 5-10m sizes. These include rebladeing California wind farms, refurbishing used turbines for the Midwest farm market, and other manufacturers introducing new turbines in this size range.

  16. Injection molding of nanopatterned surfaces in the sub-micrometer range with induction heating aid

    DEFF Research Database (Denmark)

    Menotti, Stefano; Hansen, Hans NØrgaard

    2014-01-01

    Replication of sub-micrometer structures by injection molding leads to special requirements for the mold in order to ensure proper replica and acceptable cycle time. This paper investigates the applicability of induction heating embedded into the mold for the improvement of nanopattern replication. A tool insert having a surface containing functional geometries in the sub-micrometer range was produced using aluminum anodization and nickel electroplating. In order to provide elevated mold temperatures necessary for the complete replica of the pattern, a new mold setup was developed, which allows rapid heating of the cavity wall using an induction heating system. Temperature was measured using a thermocouple placed in the mold insert. The system was used to heat up the cavity wall with heating rates of up to 10 K/s. Acrylonitrile butadiene styrene (ABS) and polycarbonate (PC) were used as materials, and heating parameters were investigated after a preliminary optimization with standard heating conditions. The replicated surfaces were quantitatively characterized by atomic force microscopy using specific three-dimensional surface amplitude parameters and qualitatively inspected by scanning electron microscopy. The experimental results show that the use of the induction heating system is an efficient way for improving nanoreplication.

  17. EXTRUDED AND INJECTION MOLDED BIOPOLYMERS: PROPERTIES OF POLYLACTIC ACID PLA/SUGAR-BEET PULP BLENDS, AND WHEY PROTEIN/CORN GLUTEN MEAL (CGM)

    Science.gov (United States)

    In this study, processing techniques for extruded foods and non-foods using new and novel ingredients, to create unique bio-polymer blends, are emphasized. Our team in the Center of Excellence for Extrusion and Polymer Rheology (CEEPR) has recently used extrusion processing and injection molding (I...

  18. Powder Injection Molding - An innovative manufacturing method for He-cooled DEMO divertor components

    International Nuclear Information System (INIS)

    At Karlsruhe Institute of Technology (KIT), a He-cooled divertor design for future fusion power plants has been developed. This concept is based on the use of modular cooling fingers made from tungsten and tungsten alloy, which are presently considered the most promising divertor materials to withstand the specific heat load of 10 MW/m2. Since a large number of the finger modules (n > 250,000) are needed for the whole reactor, developing a mass-oriented manufacturing method is indispensable. In this regard, an innovative manufacturing technology, Powder Injection Molding (PIM), has been adapted to W processing at KIT since a couple of years. This production method is deemed promising in view of large-scale production of tungsten parts with high near-net-shape precision, hence, offering an advantage of cost-saving process compared to conventional machining. The complete technological PIM process for tungsten materials and its application on manufacturing of real divertor components, including the design of a new PIM tool is outlined and, results of the examination of the finished product after heat-treatment are discussed. A binary tungsten powder feedstock with a solid load of 50 vol.% was developed and successfully tested in molding experiments. After design, simulation and manufacturing of a new PIM tool, real divertor parts are produced. After heat-treatment (pre-sintering and HIP) the successful finished samples showed a sintered density of approximatel showed a sintered density of approximately 99%, a hardness of 457 HV0.1, a grain size of approximately 5 ?m and a microstructure without cracks and porosity.

  19. Predictive Engineering Tools for Injection-molded Long-Carbon-Fiber Thermoplastic Composites - FY 2014 Third Quarterly Report

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Ba Nghiep; Sanborn, Scott E.; Mathur, Raj N.; Sharma, Bhisham; Sangid, Michael D.; Wang, Jin; Jin, Xiaoshi; Costa, Franco; Gandhi, Umesh N.; Mori, Steven; Tucker III, Charles L.

    2014-08-15

    This report describes the technical progresses made during the third quarter of FY 2014: 1) Autodesk introduced the options for fiber inlet condition to the 3D solver. These options are already available in the mid-plane/dual domain solver. 2) Autodesk improved the accuracy of 3D fiber orientation calculation around the gate. 3) Autodesk received consultant services from Prof. C.L. Tucker at the University of Illinois on the implementation of the reduced order model for fiber length, and discussed with Prof. Tucker the methods to reduce memory usage. 4) PlastiComp delivered to PNNL center-gated and edge-fan-gated 20-wt% to 30-wt% LCF/PP and LCF/PA66 (7”x7”x1/8”) plaques molded by the in-line direct injection molding (D-LFT) process. 5) PlastiComp molded ASTM tensile, flexural and impact bars under the same D-LFT processing conditions used for plaques for Certification of Assessment and ascertaining the resultant mechanical properties. 6) Purdue developed a new polishing routine, utilizing the automated polishing machine, to reduce fiber damage during surface preparation. 7) Purdue used a marker-based watershed segmentation routine, in conjunction with a hysteresis thresholding technique, for fiber segmentation during fiber orientation measurement. 8) Purdue validated Purdue’s fiber orientation measurement method using the previous fiber orientation data obtained from the Leeds machine and manually measured data by the University of Illinois. 9) PNNL conducted ASMI mid-plane analyses for a 30wt% LCF/PP plaque and compared the predicted fiber orientations with the measured data provided by Purdue University at the selected locations on this plaque. 10) PNNL put together the DOE 2014 Annual Merit Review (AMR) presentation with the team and presented it at the AMR meetings on June 17, 2014. 11) PNNL built ASMI dual domain models for the Toyota complex part and commenced mold filling analyses of the complex part with different wall thicknesses in order to support part molding. 12) Toyota and Magna discussed with PNNL on tool modification for molding the complex part. Toyota sent the CAD files of the complex part to PNNL to build ASMI models of the part for mold filling analysis to provide guidance to tooling and part molding.

  20. Progress in modeling long glass and carbon fiber breakage during injection molding

    Science.gov (United States)

    Chen, Hongyu; Cieslinski, Mark; Baird, Donald G.

    2015-05-01

    This work is concerned with the modeling of in-machine fiber breakage during injection molding. A lab-scale single screw extruder is used to evaluate fiber breakage in the screw. Our experiments show that as the initial glass fiber pellets length is reduced relative to the channel width, the overall percent of breakage is reduced. We believe that the ratio of initial pellet length to the screw channel width, or diameter, is an important parameter determining the percent of fiber breakage. Data have been fit using an exponential decay model with a kinetic decay constant and a critical length value. This empirical model has been tested on an injection molding machine with a screw 1.6 times larger than that of our single screw extruder. The predicted average fiber length leaving the nozzle shows reasonable agreement with the measured value. For the injection molded end-gated-plaque produced by the same machine, additional fiber breakage has been observed in the runner. A hydrodynamic force based breakage model is combined with mold filling simulation to simulate the fiber breakage in the runner. For carbon fibers, similar breakage trends were observed in the single screw extruder indicating the applicability of our empirical model to carbon fiber.

  1. Experimental Study of Fiber Length and Orientation in Injection Molded Natural Fiber/Starch Acetate Composites

    DEFF Research Database (Denmark)

    Peltola, Heidi; Madsen, Bo

    2011-01-01

    Composite compounds based on triethyl citrate plasticized starch acetate and hemp and flax fibers were prepared by melt processing. Plasticizer contents from 20 to 35 wt% and fiber contents of 10 and 40 wt% were used. The compounded composites were injection molded to tensile test specimens. The effect of processing, melt viscosity and fiber type on the fiber length was investigated. The lengths of fully processed fibers were determined by dissolving the matrix and measuring the length of the remaining fibers by microscope analysis. A clear reductive effect of the processing on the fiber length was noticed. A reduction of fiber length along the increasing fiber content and the decreasing plasticizer content was also detected. This reduction originated from the increasing shear forces during compounding, which again depended on the increased viscosity of the material. Hemp fibers were shown to remain longer and fibrillate more than flax fibers, leading to higher aspect ratio. Thus, the reinforcement efficiencyof hemp fibers by the processing was improved, in contrast with flax fibers. In addition, the analysis of fiber dispersion and orientation showed a good dispersion of fibers in the matrix, and a predominant orientation of the fibers in the melt flow direction.

  2. Determination of Optimal Manufacturing Parameters for Injection Mold by Inverse Model Basing on MANFIS

    Directory of Open Access Journals (Sweden)

    Chong-Ching Chang

    2010-03-01

    Full Text Available Since plastic products are with the features as light, anticorrosive and low cost etc., that are generally used in several of tools or components. Consequently, the requirements on the quality and effectiveness in production are increasingly serious. However, there are many factors affecting the yield rate of injection products such as material characteristic, mold design, and manufacturing parameters etc. involved with injection machine and the whole manufacturing process. Traditionally, these factors can only be designed and adjusted by many times of trial-and-error tests. It is not only waste of time and resource, but also lack of methodology for referring. Although there are some methods as Taguchi method or neural network etc. proposed for serving and optimizing this problem, they are still insufficient for the needs. For the reasons, a method for determining the optimal parameters by the inverse model of manufacturing platform is proposed in this paper. Through the integration of inverse model basing on MANFIS and Taguchi method, inversely, the optimal manufacturing parameters can be found by using the product requirements. The effectiveness and feasibility of this proposal is confirmed through numerical studies on a real case example.

  3. Unique opportunities in powder injection molding of refractory and hard materials

    International Nuclear Information System (INIS)

    Powder injection molding (PIM) is a relatively new manufacturing process for the creation of complicated net-shapes outside the range usually possible via powder metallurgy technologies. This new process is now in production at more than 550 sites around the world. Although a small industry, PIM will soon pass $1 billion dollars (USA) in annual sales. This presentation overviews the PIM process, some of the new developments and some of the successes that have occurred with both refractory metals and hard metals. Example applications are seen in medical and dental devices, industrial components, wristwatches, jet engines, firearms, automotive components, and even hand tools. To help establish the novel growth opportunities, PIM is compared to other fabrication routes to better understand the design features arising with this new approach, providing a compelling case for substantial opportunities in the refractory and hard materials. Illustrations are provided of several components in production. New opportunities abound for the technology, since it eliminates the shape complexity barrier associated with die compaction and the cost of machining associated with complicated or dimensionally precise components. Further, a relative cost advantage exists for refractory and hard materials because PIM can use the same powders at the same prices as employed in alternative processes. Future successes will occur by early identification of candidate materials and designs. Early examples include tungsten heavy alloy components now reaching production rates of six million per month. (author)

  4. The manufactoring of a two–layered injection mold by welding

    Directory of Open Access Journals (Sweden)

    A. Košnik

    2011-10-01

    Full Text Available The article presents the technology of deposit cladding different materials, using the injection molds for thermoplastic as a case study. The aim of the study is to surface weld to the working surface of the mold a different material with corresponding physical properties. Steel (1.1141 and a copper alloy were used as the base, onto which different materials were surface-welded. Tungsten inert gas (TIG welding was employed to make molds inserts. An analysis of cross-sectioned specimens was made by optical microscopy, and chemical and hardness profiles were measured too. The thermal conductivity of base and cladded layer was also tested. Finally, a thermal fatigue test was employed to investigate the thermal fatigue properties of such surfaces.

  5. Optimizing the Filling Time and Gate of the Injection Mold on Plastic Air Intake Manifold of Engines

    OpenAIRE

    Shiqiang Zhang

    2013-01-01

    In order to acquire the best filling time, Mold trial is made by setting different injection time, or Mold flow software is used to analyze data recorded by computer. Whether doing successive trials or being simulated point by point, is very tedious. A new method is put forward-seeking the minimum of curve being simulated by Lagrange interpolation. The minimum of the curve is the best filling time. This method can improve the efficiency of the simulation analysis. The software Mold flow...

  6. Microwaves energy in curing process of water glass molding sands

    Directory of Open Access Journals (Sweden)

    Granat K.

    2007-01-01

    Full Text Available This work presents the results of investigation of microwave heating on hardening process of water glass molding sands. Essential influence of this heating process on basic properties such as: compression, bending and tensile strength as well as permeability and abrasion resistance has been found. It has been proved, that all investigated sorts of sodium water glass with a module between 2.0 and 3.3 can be used as a binder of molding sands in microwave curing process. It has been found during analysis of research results of sands with 2.5 % water glass addition that they are practically the same as in case of identical molding sands dried for 120 minutes at the temperature of 110°C, used for comparative purposes. Application of microwave curing of molding sands with water glass, however, guarantees reduction of hardening time (from 120 to 4 minutes as well as significant reduction of energy consumption. Attempts of two stage hardening of the investigated water glass molding sands have also been carried out, that is after an initial hardening during a classical CO2 process (identical sands have also been tested for comparison after CO2 blowing process and additional microwave heating. It has been found that application of this kind of treatment for curing sands with 2.5 % sodium water glass content and module from 2.0 up to 3.3 results in the improvement of properties in comparison to classical CO2 process.

  7. A X-ray study of ?-phase and molecular orientation in nucleated and non-nucleated injection molded polypropylene resins

    International Nuclear Information System (INIS)

    The development of alpha- and beta-phases and the molecular orientation of injection molded disks of two isotactic polypropylene (i-PP) resins were studied by wide angle X-ray diffraction (WAXD) and pole figures. A nucleated (NPP) and non-nucleated (HPP) polymers were analyzed. The main proposal of this article was the comprehensive study of the interrelations between the processing conditions, phase contents and PP alpha-phase molecular orientation of injection molded PP resins. In both resins, it was observed that the alpha-phase was present in all regions along the thickness while the beta-phase was present mainly in the external layers, decreasing from the surface to the core; however this last phase was present in a very small amount in the NPP resin. For both polymers, the orientation of the macromolecules c-axis was higher along the flow direction (RD) than along the transverse direction (TD). The b-axis of the PP alpha-phase molecules was oriented to the thickness direction (ND). The orientation of the c-axis along RD and b-axis along ND of the NPP samples was considerably higher than of the HPP samples, due to the NPP faster crystallization kinetics. For both polymers, the most influential processing parameters on the molecular orientation were the mold temperature and flow rate. The results indicate that, as the mold temperature increased, the characteristic molecular orientation of PP alpha-phase, with c-axis along RD and b-axis along ND, decreased. With inRD and b-axis along ND, decreased. With increase in the flow rate an increase of the c-axis molecular orientation of the samples along RD was observed. (author)

  8. A X-ray study of ?-phase and molecular orientation in nucleated and non-nucleated injection molded polypropylene resins

    Scientific Electronic Library Online (English)

    Marcia Maria, Favaro; Marcia Cristina, Branciforti; Rosario Elida Suman, Bretas.

    Full Text Available The development of ? and ?-phases and the molecular orientation of injection molded disks of two isotactic polypropylene (i-PP) resins were studied by wide angle X-ray diffraction (WAXD) and pole figures. A nucleated (NPP) and non-nucleated (HPP) polymers were analyzed. The main proposal of this art [...] icle was the comprehensive study of the interrelations between the processing conditions, phase contents and PP ?-phase molecular orientation of injection molded PP resins. In both resins, it was observed that the ?-phase was present in all regions along the thickness while the ?-phase was present mainly in the external layers, decreasing from the surface to the core; however this last phase was present in a very small amount in the NPP resin. For both polymers, the orientation of the macromolecules c-axis was higher along the flow direction (RD) than along the transverse direction (TD). The b-axis of the PP ?-phase molecules was oriented to the thickness direction (ND). The orientation of the c-axis along RD and b-axis along ND of the NPP samples was considerably higher than of the HPP samples, due to the NPP faster crystallization kinetics. For both polymers, the most influential processing parameters on the molecular orientation were the mold temperature and flow rate. The results indicate that, as the mold temperature increased, the characteristic molecular orientation of PP ?-phase, with c-axis along RD and b-axis along ND, decreased. With increase in the flow rate an increase of the c-axis molecular orientation of the samples along RD was observed.

  9. Evolução da morfologia de fases de blendas PA6/AES em extrusora de dupla rosca e moldagem por injeção / Evolution of phase morphology of PA6/AES blends during the twin screw extrusion and injection molding processes

    Scientific Electronic Library Online (English)

    Adriane, Bassani; Elias, Hage Jr; Luiz A., Pessan; Ana V, Machado; José A., Covas.

    2005-07-01

    Full Text Available A evolução da morfologia de fases em blendas não reativas e reativas de poliamida-6 com copolímero de acrilonitrila/EPDM/estireno (AES) em uma extrusora de rosca dupla co-rotacional foi investigada. A evolução da morfologia de fases ao longo da extrusora de rosca dupla foi monitorada através da cole [...] ta de pequenas amostras em válvulas no barril da extrusora e caracterização por microscopia eletrônica de transmissão (MET). Foram utilizados como compatibilizantes reativos os copolímeros metacrilato de metila-co-anidrido maleico (MMA-MA) e metacrilato de metila-co-metacrilato de glicidila (MMA-GMA). Os grupos anidrido maleico e epóxi nos copolímeros podem reagir com os grupos finais de cadeia da poliamida durante o processamento no estado fundido e melhorar a interação na interfase do sistema PA6/AES. A blenda PA6/AES não compatibilizada apresentou uma morfologia grosseira de fases onde a fase AES não está bem dispersa na matriz de PA6 devido à falta de interações adequadas entre os componentes da blenda. A adição do compatibilizante MMA-GMA não proporcionou boa dispersão de fases e não melhorou as propriedades mecânicas da blenda, provavelmente porque as possíveis reações no sistema são lentas e podem não ocorrer na extrusora. Por outro lado, a blenda compatibilizada com o copolímero MMA-MA apresentou uma excelente resistência ao impacto à temperatura ambiente e uma diminuição na temperatura de transição dúctil-frágil. As partículas de AES apresentam-se muito mais refinadas e sofrem uma redução significativa em seu tamanho já no início do processo de extrusão. A morfologia observada nas amostras injetadas apresentou uma boa correlação com as propriedades mecânicas obtidas. Abstract in english The evolution of phase morphology in non-reactive vs reactive blends with polyamide and ethylene-propylene-diene elastomer grafted with styrene-acrylonitrile copolymer (AES) in a co-rotating twin-screw extruder was investigated. The morphological evolution of these blends along a twin-screw extruder [...] was monitored by quickly collecting small samples from the melt at specific extruder barrel locations and characterizing them with a transmission electron microscope (TEM). The copolymers methyl methacrylate-co-maleic anhydride (MMA-MA) and methyl methacrylate-co-glycidyl methacrylate (MMA-GMA) were used as compatibilizing agents. The maleic anhydride and the epoxy groups of the copolymers can react with the polyamide end groups during melt processing and improve the interphase interaction in the PA6/AES system. The uncompatibilized blends showed a coarse phase morphology where the AES phase is not well dispersed in the PA6 matrix due to lack of adequate interaction between the components. The addition of MMA-GMA compatibilizer neither promoted good phase dispersion or improved the mechanical properties of the blends, probably because the possible reactions are very slow and may not occur inside the extruder. On the other hand, the addition of the MMA-MA copolymer promotes better impact strength and good phase dispersion in the blend. The AES particles undergo significant reduction in the first stages of the mixture inside the extruder. The morphology observed for the injection molded specimens was correlated with the mechanical properties.

  10. Evolução da morfologia de fases de blendas PA6/AES em extrusora de dupla rosca e moldagem por injeção Evolution of phase morphology of PA6/AES blends during the twin screw extrusion and injection molding processes

    Directory of Open Access Journals (Sweden)

    Adriane Bassani

    2005-07-01

    Full Text Available A evolução da morfologia de fases em blendas não reativas e reativas de poliamida-6 com copolímero de acrilonitrila/EPDM/estireno (AES em uma extrusora de rosca dupla co-rotacional foi investigada. A evolução da morfologia de fases ao longo da extrusora de rosca dupla foi monitorada através da coleta de pequenas amostras em válvulas no barril da extrusora e caracterização por microscopia eletrônica de transmissão (MET. Foram utilizados como compatibilizantes reativos os copolímeros metacrilato de metila-co-anidrido maleico (MMA-MA e metacrilato de metila-co-metacrilato de glicidila (MMA-GMA. Os grupos anidrido maleico e epóxi nos copolímeros podem reagir com os grupos finais de cadeia da poliamida durante o processamento no estado fundido e melhorar a interação na interfase do sistema PA6/AES. A blenda PA6/AES não compatibilizada apresentou uma morfologia grosseira de fases onde a fase AES não está bem dispersa na matriz de PA6 devido à falta de interações adequadas entre os componentes da blenda. A adição do compatibilizante MMA-GMA não proporcionou boa dispersão de fases e não melhorou as propriedades mecânicas da blenda, provavelmente porque as possíveis reações no sistema são lentas e podem não ocorrer na extrusora. Por outro lado, a blenda compatibilizada com o copolímero MMA-MA apresentou uma excelente resistência ao impacto à temperatura ambiente e uma diminuição na temperatura de transição dúctil-frágil. As partículas de AES apresentam-se muito mais refinadas e sofrem uma redução significativa em seu tamanho já no início do processo de extrusão. A morfologia observada nas amostras injetadas apresentou uma boa correlação com as propriedades mecânicas obtidas.The evolution of phase morphology in non-reactive vs reactive blends with polyamide and ethylene-propylene-diene elastomer grafted with styrene-acrylonitrile copolymer (AES in a co-rotating twin-screw extruder was investigated. The morphological evolution of these blends along a twin-screw extruder was monitored by quickly collecting small samples from the melt at specific extruder barrel locations and characterizing them with a transmission electron microscope (TEM. The copolymers methyl methacrylate-co-maleic anhydride (MMA-MA and methyl methacrylate-co-glycidyl methacrylate (MMA-GMA were used as compatibilizing agents. The maleic anhydride and the epoxy groups of the copolymers can react with the polyamide end groups during melt processing and improve the interphase interaction in the PA6/AES system. The uncompatibilized blends showed a coarse phase morphology where the AES phase is not well dispersed in the PA6 matrix due to lack of adequate interaction between the components. The addition of MMA-GMA compatibilizer neither promoted good phase dispersion or improved the mechanical properties of the blends, probably because the possible reactions are very slow and may not occur inside the extruder. On the other hand, the addition of the MMA-MA copolymer promotes better impact strength and good phase dispersion in the blend. The AES particles undergo significant reduction in the first stages of the mixture inside the extruder. The morphology observed for the injection molded specimens was correlated with the mechanical properties.

  11. Moldagem por injeção da PA 6.6 em moldes de estereolitografia metalizados com Ni-P pelo processo electroless / Injection molding of PA 6.6 in stereolithography moulds coated with electroless Ni-P

    Scientific Electronic Library Online (English)

    Diovani C., Lencina; Carlos H., Ahrens; Gean V., Salmoria; Fernando H., Lafratta.

    2007-06-01

    Full Text Available A fabricação de moldes por técnicas de prototipagem rápida, como a estereolitografia (SL), é considerada uma importante tecnologia no auxílio ao desenvolvimento de produtos de plástico moldados por injeção. Embora esta tecnologia se mostre vantajosa, a vida útil dos moldes pode ser bastante reduzida [...] em decorrência, por exemplo, de forte adesão entre o polímero injetado e o material do molde SL. Neste trabalho é investigado o uso da técnica de recobrimento metálico com Ni-P por deposição electroless sobre moldes de injeção, fabricados por SL com a resina DSM SOMOS 7110®. Foram comparados resultados de moldagem de PA6.6 em moldes fabricados com e sem recobrimento metálico evidenciando a possibilidade de utilizar a técnica de metalização como alternativa para a moldagem deste material em moldes SL, uma vez que a vida útil foi superior. Abstract in english Manufacturing of moulds by rapid prototyping processes, such as stereolithography (SL), is considered an important technology to aid the development of injection moulding plastic products. Although this technology shows significant advantages, the lifetime of moulds may be drastically be reduced due [...] to strong adhesion between the injected polymer and the material of the SL mould. This work investigates the use of Ni-P metal coating obtained by electroless deposition on SL moulds manufactured with the resin DSM SOMOS 7110. Specimens of PA6.6 have been injected into SL moulds manufactured with and without metal coating. The results showed that the electroless metal coating process can be an appropriate alternative to allow moulding of small series of PA6.6 parts in SL moulds.

  12. Microwaves energy in curing process of water glass molding sands

    OpenAIRE

    Granat K.; Nowak D.; Pigiel M.; Stachowicz M.; Wikiera R.

    2007-01-01

    This work presents the results of investigation of microwave heating on hardening process of water glass molding sands. Essential influence of this heating process on basic properties such as: compression, bending and tensile strength as well as permeability and abrasion resistance has been found. It has been proved, that all investigated sorts of sodium water glass with a module between 2.0 and 3.3 can be used as a binder of molding sands in microwave curing process. It has been found during...

  13. Inexpensive 3dB coupler for POF communication by injection-molding production

    Science.gov (United States)

    Haupt, M.; Fischer, U. H. P.

    2011-01-01

    POFs (polymer optical fibers) gradually replace traditional communication media such as copper and glass within short distance communication systems. Primarily, this is due to their cost-effectiveness and easy handling. POFs are used in various fields of optical communication, e.g. the automotive sector or in-house communication. So far, however, only a few key components for a POF communication network are available. Even basic components, such as splices and couplers, are fabricated manually. Therefore, these circumstances result in high costs and fluctuations in components' performance. Available couplers have high insertion losses due to their manufacturing method. This can only be compensated by higher power budgets. In order to produce couplers with higher performances new fabrication methods are indispensable. A cheap and effective way to produce couplers for POF communication systems is injection molding. The paper gives an overview of couplers available on market, compares their performances, and shows a way to produce couplers by means of injection molding.

  14. Carbon Nanotubes Reinforced Copper Matrix Nanocomposites via Metal Injection Molding Technique

    OpenAIRE

    Norani M. Mohamed; Faiz Ahmad; Ali S. Muhsan; Putri S.M.BT M. Yusoff; M.R. Raza

    2012-01-01

    New thermal management solutions are required to provide cost-effective means of dissipating heat from next generation microelectronic devices. In this paper, fabrication of heat sink nanocomposite made of copper reinforced by multiwalled carbon nanotubes up to 10 Vol. % using metal injection molding technique is presented. A mixture of Cu-MWNTs was compounded using internal mixer machine for homogenous dispersion of the solid powder in the binder. To ensure a flow able feedstock during...

  15. Forehead Augmentation with a Methyl Methacrylate Onlay Implant Using an Injection-Molding Technique

    Directory of Open Access Journals (Sweden)

    Dong Kwon Park

    2013-09-01

    Full Text Available Background The forehead, which occupies about one third of the face, is one of the majordeterminants of a feminine or masculine look. Various methods have been used for the augmentationof the forehead using autologous fat grafts or alloplastic materials. Methylmethacrylate(MMA is the most appropriate material for augmentation of the forehead, and we have usedan injection-molding technique with MMA to achieve satisfactory results.Methods Under local anesthesia with intravenous (IV sedation, an incision was made onthe scalp and a meticulous and delicate subperiosteal dissection was then performed. MMAmonomers and polymers were mixed, the dough was injected into the space created, andmanual molding was performed along with direct inspection. This surgery was indicated forpatients who wanted to correct an unattractive appearance by forehead augmentation. Everypatient in this study visited our clinics 3 months after surgery to evaluate the results. Wejudged the postoperative results in terms of re-operation rates caused by the dissatisfactionof the patients and complications.Results During a 13-year period, 516 patients underwent forehead augmentation with MMA.With the injection-molding technique, the inner surface of the MMA implant is positionedclose to the underlying frontal bone, which minimizes the gap between the implant and bone.The borders of the implant should be tapered sufficiently until no longer palpable or visible.Only 28 patients (5.4% underwent a re-operation due to an undesirable postoperative appearance.Conclusions The injection-molding technique using MMA is a simple, safe, and ideal methodfor the augmentation of the forehead.

  16. Microengineering of Metals and Ceramics: Part I: Design, Tooling and Injection Molding; Volume 3: Advanced Micro & Nanosystems

    Science.gov (United States)

    Baltes, Henry; Brand, Oliver; Fedder, Gary K.; Hierold, Christofer; Korvink, Jan G.; Tabata, Osamu; Löhe, Detlef; Haußelt, Jürgen

    2005-09-01

    Microstructures, electronics, nanotechnology - these vast fields of research are growing together as the size gap narrows and many different materials are combined. Current research, engineering sucesses and newly commercialized products hint at the immense innovative potentials and future applications that open up once mankind controls shape and function from the atomic level right up to the visible world without any gaps. In this volume, authors from three major competence centres for microengineering illustrate step by step the process from designing and simulating microcomponents of metallic and ceramic materials to replicating micro-scale components by injection molding.

  17. Evaluation of hot-melt extrusion and injection molding for continuous manufacturing of immediate-release tablets.

    Science.gov (United States)

    Melocchi, Alice; Loreti, Giulia; Del Curto, Maria Dorly; Maroni, Alessandra; Gazzaniga, Andrea; Zema, Lucia

    2015-06-01

    The exploitation of hot-melt extrusion and injection molding for the manufacturing of immediate-release (IR) tablets was preliminarily investigated in view of their special suitability for continuous manufacturing, which represents a current goal of pharmaceutical production because of its possible advantages in terms of improved sustainability. Tablet-forming agents were initially screened based on processability by single-screw extruder and micromolding machine as well as disintegration/dissolution behavior of extruded/molded prototypes. Various polymers, such as low-viscosity hydroxypropylcellulose, polyvinyl alcohol, polyvinyl alcohol-polyethylene glycol graft copolymer, various sodium starch glycolate grades (e.g., Explotab(®) CLV) that could be processed with no need for technological aids, except for a plasticizer, were identified. Furthermore, the feasibility of both extruded and molded IR tablets from low-viscosity hydroxypropylcellulose or Explotab(®) CLV was assessed. Explotab(®) CLV, in particular, showed thermoplastic properties and a very good aptitude as a tablet-forming agent, starting from which disintegrating tablets were successfully obtained by either techniques. Prototypes containing a poorly soluble model drug (furosemide), based on both a simple formulation (Explotab(®) CLV and water/glycerol as plasticizers) and formulations including dissolution/disintegration adjuvants (soluble and effervescent excipients) were shown to fulfill the USP 37 dissolution requirements for furosemide tablets. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 104:1971-1980, 2015. PMID:25761921

  18. Wall-slip of highly filled powder injection molding compounds: Effect of flow channel geometry and roughness

    International Nuclear Information System (INIS)

    The paper deals with the rheological behavior of highly filled compounds proceeded via powder injection molding (PIM) and applied in many sectors of industry (automotive, medicine, electronic or military). Online rheometer equipped with slit dies varying in surface roughness and dimensions was applied to investigate the wall-slip as a rheological phenomenon, which can be considered as a parameter indicating the separation of compound components (polymer binder and metallic powder) during high shear rates when injection molded

  19. Wall-slip of highly filled powder injection molding compounds: Effect of flow channel geometry and roughness

    Energy Technology Data Exchange (ETDEWEB)

    Hausnerova, Berenika; Sanetrnik, Daniel [Dept. of Production Engineering, Faculty of Technology, Tomas Bata University in Zlin, nám. T.G. Masaryka 5555, 760 01 Zlín, Czech Republic and Centre of Polymer Systems, University Institute, Tomas Bata University in Zlin, Nad Ovc (Czech Republic); Paravanova, Gordana [Centre of Polymer Systems, University Institute, Tomas Bata University in Zlin, Nad Ovcírnou 3685, 760 01 Zlín (Czech Republic)

    2014-05-15

    The paper deals with the rheological behavior of highly filled compounds proceeded via powder injection molding (PIM) and applied in many sectors of industry (automotive, medicine, electronic or military). Online rheometer equipped with slit dies varying in surface roughness and dimensions was applied to investigate the wall-slip as a rheological phenomenon, which can be considered as a parameter indicating the separation of compound components (polymer binder and metallic powder) during high shear rates when injection molded.

  20. Eliminating weldlines of an injection-molded part with the aid of high-frequency induction heating

    International Nuclear Information System (INIS)

    High-frequency induction is an efficient way to heat mold surface by non-contact electromagnetic induction. It has been recently applied to injection molding because of its capability to heat and cool mold surface rapidly. This study applies high-frequency induction heating to eliminate weldlines in an injection-molded plastic part. To eliminate or reduce weldlines, the mold temperature at the corresponding weld locations should be maintained higher than the glass transition temperature of the resin material. Through 3 s of induction heating, the maximum temperature of 143 .deg. C is obtained on the mold surface around the elliptic coil, while the temperature of the mold plate is lower than 60 .deg. C. An injection molding experiment is then performed with the aid of induction heating, and the effect of induction heating conditions on the surface appearance of the weldline is investigated. The weldline on the heated region is almost eliminated, from which we can obtain the good surface appearance of the part

  1. Thermal and mechanical behavior of injection molded Poly(3-hydroxybutyrate)/Poly(epsilon-caprolactone) blends

    Scientific Electronic Library Online (English)

    Marcia Adriana Tomaz, Duarte; Roberson Goulart, Hugen; Eduardo Sant' Anna, Martins; Ana Paula Testa, Pezzin; Sérgio Henrique, Pezzin.

    2006-03-01

    Full Text Available Aiming the development of high-performance biodegradable polymer materials, the properties and the processing behavior of poly(3-hydroxybutyrate), P(3HB), and their blends with poly(epsilon-caprolactone), PCL, have been investigated. The P(3HB) sample, obtained from sugarcane, had a molecular weight [...] of 3.0 x 10(5) g.mol¹, a crystallinity degree of 60%, a glass transition temperature (Tg), at - 0.8 °C, and a melting temperature at 171 °C. The molecular weight of PCL was 0.8 x 10(5) g.mol-1. Specimens of 70/30 wt. (%) P(3HB)/PCL blends obtained by injection molding showed tensile strength of 21.9 (± 0.4) MPa, modulus of 2.2 (± 0.3) GPa, and a relatively high elongation at break, 87 (± 20)%. DSC analyses of this blend showed two Tg´s, at - 10.6 °C for the P(3HB) matrix, and at - 62.9 °C for the PCL domains. The significant decrease on the Tg of P(3HB) evidences a partial miscibility of PCL in P(3HB). According to the Fox equation, the new Tg corresponds to a 92/8 wt. (%) P(3HB)/PCL composition.

  2. Surface Hardening of Powder Injection Molded 316L Stainless Steels Through Low-Temperature Carburization

    Science.gov (United States)

    Cheng, Li-Hui; Hwang, Kuen-Shyang

    2013-02-01

    The surface hardness of powder injection molded (PIM) 316L is generally low due to the inherited austenitic structure and large grains induced during high-temperature sintering. To increase the surface hardness and the wear resistance, low-temperature carburization (LTC) was applied to PIM 316L. With carburization at 773 K (500 °C) for 24 hours, the resulting hardness at the surface increases from 160 to 810 HV due to the "colossal" supersaturation of interstitial carbon and M5C2 carbide, and the corrosion resistance is not deteriorated. The carburized depth is about 40 ?m, and the carbon content in this layer is about 3.25 wt pct or 13.5 at. pct, which causes lattice expansion of the austenite. When the carburization temperature increases to 823 K (550 °C), or the carburization time increases to 72 hours, chromium carbides are observed and the corrosion resistance is impaired. One distinct advantage of applying LTC to PIM 316L is that no acid cleaning process is required, unlike for wrought counterparts, because of the clean surface of the sintered materials.

  3. Structural scheme optimization design for the stationary platen of a precision plastic injection molding machine

    Science.gov (United States)

    Ren, Bin; Zhang, Shuyou; Tan, Jianrong

    2014-07-01

    The current development of precision plastic injection molding machines mainly focuses on how to save material and improve precision, but the two aims contradict each other. For a clamp unit, clamping precision improving depends on the design quality of the stationary platen. Compared with the parametric design of stationary platen, structural scheme design could obtain the optimization model with double objectives and multi-constraints. In this paper, a SE-160 precision plastic injection molding machine with 1600 kN clamping force is selected as the subject in the case study. During the motion of mold closing and opening, the stationary platen of SE-160 is subjected to a cyclic loading, which would cause the fatigue rupture of the tie bars in periodically long term operations. In order to reduce the deflection of the stationary platen, the FEA method is introduced to optimize the structure of the stationary platen. Firstly, an optimal topology model is established by variable density method. Then, structural topology optimizations of the stationary platen are done with the removable material from 50%, 60% to 70%. Secondly, the other two recommended optimization schemes are given and compared with the original structure. The result of performances comparison shows that the scheme II of the platen is the best one. By choosing the best alternative, the volume and the local maximal stress of the platen could be decreased, corresponding to cost-saving material and better mechanical properties. This paper proposes a structural optimization design scheme, which can save the material as well as improve the clamping precision of the precision plastic injection molding machine.

  4. Injection Molding of Titanium Alloy Implant For Biomedical Application Using Novel Binder System Based on Palm Oil Derivatives

    Directory of Open Access Journals (Sweden)

    R. Ibrahim

    2010-01-01

    Full Text Available Problem statement: Titanium alloy (Ti6Al4V has been widely used as an implant for biomedical application. In this study, the implant had been fabricated using high technology of Powder Injection Molding (PIM process due to the cost effective technique for producing small, complex and precision parts in high volume compared with conventional method through machining. Approach: Through PIM, the binder system is one of the most important criteria in order to successfully fabricate the implants. Even though, the binder system is a temporary, but failure in the selection and removal of the binder system will affect on the final properties of the sintered parts. Therefore, the binder system based on palm oil derivative which is palm stearin had been formulated and developed to replace the conventional binder system. Results: The rheological studies of the mixture between the powder and binders system had been determined properly in order to be successful during injection into injection molding machine. After molding, the binder held the particles in place. The binder system had to be removed completely through debinding step. During debinding step, solvent debinding and thermal pyrolysis had been used to remove completely of the binder system. The debound part was then sintered to give the required physical and mechanical properties. The in vitro biocompatibility also was tested using Neutral Red (NR and mouse fibroblast cell lines L-929 for the direct contact assay. Conclusion: The results showed that the properties of the final sintered parts fulfill the Standard Metal Powder Industries Federation (MPIF 35 for PIM parts except for tensile strength and elongation due to the formation of titanium carbide. The in vitro biocompatibility on the extraction using mouse fibroblast cell line L-929 by means of NR assays showed non toxic for the sintered specimen titanium alloy parts.

  5. Optimization of injection molding process parameters by a hybrid of artificial neural network and artificial bee colony algorithm / Optimización de los parámetros del proceso de inyección de plásticos a través de un híbrido de redes neuronales artificiales y el algoritmo de la colonia artificial de abejas

    Scientific Electronic Library Online (English)

    Alejandro, Alvarado Iniesta; Jorge L., García Alcaraz; ManuelIván, Rodríguez Borbón.

    2013-06-01

    Full Text Available Este estudio presenta un híbrido de redes neuronales artificiales con el algoritmo de la colonia artificial de abejas para optimizar los parámetros del proceso de inyección de plásticos con el objetivo de minimizar la deformación en productos plásticos. Una red neuronal de propagación hacia adelante [...] es empleada para obtener una relación matemática entre los parámetros del proceso y el objetivo a optimizar. El algoritmo de la colonia artificial de abejas es usado para encontrar el conjunto óptimo de valores de los parámetros que resultarían en la solución óptima. Un caso experimental es presentado acoplando simulaciones de Moldflow junto con los esquemas mencionados con el fin de validar el enfoque propuesto. La temperatura del plástico, temperatura del molde, presión de empaque, tiempo de empaque, y tiempo de enfriamiento son consideradas como las variables de diseño. Los resultados revelan que el enfoque propuesto puede eficientemente apoyar a ingenieros a determinar los parámetros óptimos y alcanzar ventajas competitivas en términos de calidad y costos. Abstract in english This paper presents a hybrid of artificial neural networks and artificial bee colony algorithm to optimize the process parameters in injection molding with the aim of minimize warpage of plastic products. A feedforward neural network is employed to obtain a mathematical relationship between the proc [...] ess parameters and the optimization goal. Artificial bee colony algorithm is used to find the optimal set of process parameters values that would result in the optimal solution. An experimental case is presented by coupling Moldflow simulations along with the intelligent schemes in order to validate the proposed approach. Melt temperature, mold temperature, packing pressure, packing time, and cooling time are considered as the design variables. Results revealed the proposed approach can efficiently support engineers to determine the optimal process parameters and achieve competitive advantages in terms of quality and costs.

  6. Implementation of Molding Constraints in Topology Optimization

    DEFF Research Database (Denmark)

    Marx, S.; Kristensen, Anders Schmidt

    2009-01-01

    In many cases the topology optimization method yield inadmissible solutions in respect to a particular manufacturing process, e.g. injection molding. In the present work it is chosen to focus on the most common injection molding parameters/factors determining the quality of the mold geometry, i.e. uniform thickness, filling of the die and ejection of the molded item, i.e. extrusion. The mentioned injection mold parameters/factors are introduced in the topology optimization by defining a centerline of the initial domain and then penalize elements in respect to the distance to the defined centerline of the domain.

  7. Influência do desempenho térmico de moldes fabricados com compósito epóxi/alumínio nas propriedades de pp moldado por injeção Thermal behavior of epoxy/aluminum rapid tooling composite during injection molding of polypropylene

    Directory of Open Access Journals (Sweden)

    Gean V. Salmoria

    2008-09-01

    Full Text Available O surgimento das tecnologias de prototipagem rápida (RP e de ferramental rápido (RT tem despertado interesse da indústria de moldes de injeção. O vazamento de termofixos com cargas metálicas possibilita a construção de moldes usando materiais compósitos, os quais apresentam maior resistência que os utilizados por outras técnicas RT. Neste trabalho foi estudado o comportamento térmico de moldes fabricados em epóxi/alumínio durante a injeção de polipropileno através de avaliações da estrutura e de propriedades mecânicas utilizando difração de raio X e ensaios de dureza e de tração. Os corpos-de-prova injetados no molde em compósito epóxi/alumínio apresentaram pequenas diferenças no grau de cristalinidade das superfícies analisadas e propriedades mecânicas semelhantes aos corpos-de-prova injetados em molde de aço. O estudo mostrou um razoável desempenho térmico do molde compósito durante a injeção de polipropileno evidenciando a viabilidade de utilização destes moldes na produção de pequenas séries de protótipos e de produtos neste termoplástico.rapid prototyping (RP and rapid tooling (RT technologies are gaining increasing importance in the injection molding industry. Casting of resin/metal composites allows the construction of molds with greater resistance than those manufactured by other RT techniques such as Stereolithography. In this work, the thermal behavior of molds manufactured in epoxy/aluminum during the injection molding of polypropylene specimens was investigated. Structural and mechanical characterization of the molded specimens included X ray analysis, hardness and tensile testing. The samples presented small differences in the degree of crystallinity and similar mechanical properties in comparison with samples injected into steel molds. This study showed a reasonable thermal performance of the epoxy/aluminum mold during the injection molding of polypropylene, thus demonstrating the viability of using these molds to produce a few number of prototypes or products with this thermoplastic.

  8. Influência do desempenho térmico de moldes fabricados com compósito epóxi/alumínio nas propriedades de pp moldado por injeção / Thermal behavior of epoxy/aluminum rapid tooling composite during injection molding of polypropylene

    Scientific Electronic Library Online (English)

    Gean V., Salmoria; Carlos H., Ahrens; Felix A. Y., Villamizar; Aurélio da C., Sabino Netto.

    2008-09-01

    Full Text Available O surgimento das tecnologias de prototipagem rápida (RP) e de ferramental rápido (RT) tem despertado interesse da indústria de moldes de injeção. O vazamento de termofixos com cargas metálicas possibilita a construção de moldes usando materiais compósitos, os quais apresentam maior resistência que o [...] s utilizados por outras técnicas RT. Neste trabalho foi estudado o comportamento térmico de moldes fabricados em epóxi/alumínio durante a injeção de polipropileno através de avaliações da estrutura e de propriedades mecânicas utilizando difração de raio X e ensaios de dureza e de tração. Os corpos-de-prova injetados no molde em compósito epóxi/alumínio apresentaram pequenas diferenças no grau de cristalinidade das superfícies analisadas e propriedades mecânicas semelhantes aos corpos-de-prova injetados em molde de aço. O estudo mostrou um razoável desempenho térmico do molde compósito durante a injeção de polipropileno evidenciando a viabilidade de utilização destes moldes na produção de pequenas séries de protótipos e de produtos neste termoplástico. Abstract in english rapid prototyping (RP) and rapid tooling (RT) technologies are gaining increasing importance in the injection molding industry. Casting of resin/metal composites allows the construction of molds with greater resistance than those manufactured by other RT techniques such as Stereolithography. In this [...] work, the thermal behavior of molds manufactured in epoxy/aluminum during the injection molding of polypropylene specimens was investigated. Structural and mechanical characterization of the molded specimens included X ray analysis, hardness and tensile testing. The samples presented small differences in the degree of crystallinity and similar mechanical properties in comparison with samples injected into steel molds. This study showed a reasonable thermal performance of the epoxy/aluminum mold during the injection molding of polypropylene, thus demonstrating the viability of using these molds to produce a few number of prototypes or products with this thermoplastic.

  9. Estudo de caso de peça moldada pelo processo de injeção-compressão para termoplásticos utilizando análise computacional Study of injection-compression molded part using CAE analysis

    Directory of Open Access Journals (Sweden)

    Thyago M. Kiam

    2007-03-01

    Full Text Available O processamento de termoplásticos através do processo de injeção representa o principal método de fabricação de peças plásticas. Limitações do processo de injeção convencional, principalmente quanto à matéria-prima e configuração e funcionamento das máquinas disponíveis, tornam inviável a produção de produtos com grande área projetada e pequena espessura, como janelas automotivas e alguns tipos de lentes. Paralelamente, o processo de injeção evolui continuamente e há uma série de novas tecnologias geradas a partir do processo original, dentre elas o processo de injeção-compressão. No presente trabalho, utilizando análise computacional, estudou-se a produção de lentes de policarbonato através de dois processos distintos: injeção convencional e processo de injeção-compressão. A seqüência de estudos envolveu basicamente os seguintes pontos: estudo do padrão de preenchimento com conseqüente otimização do processo de injeção-compressão quanto à formação de linha de emenda; estudo da janela de processo para ambos os casos e comparação de alguns parâmetros principalmente tensão de cisalhamento e força de fechamento, por se tratarem de fatores limitantes na produção de peças com grande área projetada. Os resultados para o caso estudado comprovam grande vantagem na utilização do processo de injeção-compressão.The injection-molding of thermoplastics is the main process used in the production of plastics parts. There are some limitations in the conventional injection process, specially related to raw materials, machines configuration and operation, which hamper fabrication of thin parts with large areas such as car windows and lenses. On the other hand, the process has been improved continuously with several new technologies, going beyond the conventional injection molding process, including the "injection-compression" process. In this paper, using CAE (computer aided engineering technology, the author studied the production of PC lens by both processes: conventional injection molding and injection-compression molding. The studies were basically conducted in the following sequence: flow pattern study and optimization of the injection-compression process focusing on the weld line size, molding window study for both cases and comparison of several parameters, particularly shear stress and clamp force - as they are key parameters for the production of large-area parts. The results confirm the advantages of the injection-compression process.

  10. Estudo de caso de peça moldada pelo processo de injeção-compressão para termoplásticos utilizando análise computacional / Study of injection-compression molded part using CAE analysis

    Scientific Electronic Library Online (English)

    Thyago M., Kiam; Nilson C., Pereira.

    2007-03-01

    Full Text Available O processamento de termoplásticos através do processo de injeção representa o principal método de fabricação de peças plásticas. Limitações do processo de injeção convencional, principalmente quanto à matéria-prima e configuração e funcionamento das máquinas disponíveis, tornam inviável a produção d [...] e produtos com grande área projetada e pequena espessura, como janelas automotivas e alguns tipos de lentes. Paralelamente, o processo de injeção evolui continuamente e há uma série de novas tecnologias geradas a partir do processo original, dentre elas o processo de injeção-compressão. No presente trabalho, utilizando análise computacional, estudou-se a produção de lentes de policarbonato através de dois processos distintos: injeção convencional e processo de injeção-compressão. A seqüência de estudos envolveu basicamente os seguintes pontos: estudo do padrão de preenchimento com conseqüente otimização do processo de injeção-compressão quanto à formação de linha de emenda; estudo da janela de processo para ambos os casos e comparação de alguns parâmetros principalmente tensão de cisalhamento e força de fechamento, por se tratarem de fatores limitantes na produção de peças com grande área projetada. Os resultados para o caso estudado comprovam grande vantagem na utilização do processo de injeção-compressão. Abstract in english The injection-molding of thermoplastics is the main process used in the production of plastics parts. There are some limitations in the conventional injection process, specially related to raw materials, machines configuration and operation, which hamper fabrication of thin parts with large areas su [...] ch as car windows and lenses. On the other hand, the process has been improved continuously with several new technologies, going beyond the conventional injection molding process, including the "injection-compression" process. In this paper, using CAE (computer aided engineering) technology, the author studied the production of PC lens by both processes: conventional injection molding and injection-compression molding. The studies were basically conducted in the following sequence: flow pattern study and optimization of the injection-compression process focusing on the weld line size, molding window study for both cases and comparison of several parameters, particularly shear stress and clamp force - as they are key parameters for the production of large-area parts. The results confirm the advantages of the injection-compression process.

  11. Microstructural study of duplex stainless steels obtained by powder injection molding

    International Nuclear Information System (INIS)

    Highlights: • The microstructural evolution of sintered PIM duplex stainless steels was studied. • A destabilization of austenite occurs after sintering at high temperature. • Electron backscatter diffraction (EBSD) revealed a remaining of 0.5% of austenite. • Ferrite content was also determined employing a magnetic method. -- Abstract: This experimental work is focused on the study of microstructural evolution during sintering of duplex stainless steels (DSS) obtained by powder injection molding (PIM). Ferritic 430L and austenitic 316L stainless steel powders were previously premixed in a 50/50 volume ratio and afterward they were sintered in low vacuum at different temperatures for 1 h. Microstructural analysis of sintered samples was conducted by means of scanning electron microscopy (SEM) and a compositional analysis of the alloying elements along different phases was performed by energy dispersive analysis of X-rays (EDS). Phase transformations were evaluated by X-ray diffraction (XRD) experiments, and the magnetic phase content was measured with a ferritoscope. The intensity of the main austenite diffraction peak decreases as sintering temperature increases to finally disappear in the sample sintered at 1100 °C. This destabilization of the austenite is probably related to a high Nickel diffusion detected from austenite to ferrite particles. Moreover, electron backscatter diffraction (EBSD) data were collected to quantify microstructural properties. Several EBSD pattern maps were acquired in order to define the amount of austenite phase. Due to the advantages of this technique a 0.5% of austenite could be detected after sintering at 1200 °C. After sintering process, the austenite content in sintered duplex stainless steels obtained through this processing route was lower than expected. Finally, Bain mechanism was proposed as an explanation to this phase transformation takes place. EBSD technique has been proved to be the most suitable to monitor the microstructure of sintered DSS

  12. Microstructural study of duplex stainless steels obtained by powder injection molding

    Energy Technology Data Exchange (ETDEWEB)

    Sotomayor, M.E., E-mail: msotomay@ing.uc3m.es [Materials Science and Engineering Department, Carlos III University of Madrid, Avda. Universidad 30, 28911 Leganés (Spain); Kloe, R. de, E-mail: rene.de.kloe@ametek.nl [EDAX B. V., PO Box 4144, 5004 JC Tilburg (Netherlands); Levenfeld, B., E-mail: bll@ing.uc3m.es [Materials Science and Engineering Department, Carlos III University of Madrid, Avda. Universidad 30, 28911 Leganés (Spain); Várez, A., E-mail: alvar@ing.uc3m.es [Materials Science and Engineering Department, Carlos III University of Madrid, Avda. Universidad 30, 28911 Leganés (Spain)

    2014-03-15

    Highlights: • The microstructural evolution of sintered PIM duplex stainless steels was studied. • A destabilization of austenite occurs after sintering at high temperature. • Electron backscatter diffraction (EBSD) revealed a remaining of 0.5% of austenite. • Ferrite content was also determined employing a magnetic method. -- Abstract: This experimental work is focused on the study of microstructural evolution during sintering of duplex stainless steels (DSS) obtained by powder injection molding (PIM). Ferritic 430L and austenitic 316L stainless steel powders were previously premixed in a 50/50 volume ratio and afterward they were sintered in low vacuum at different temperatures for 1 h. Microstructural analysis of sintered samples was conducted by means of scanning electron microscopy (SEM) and a compositional analysis of the alloying elements along different phases was performed by energy dispersive analysis of X-rays (EDS). Phase transformations were evaluated by X-ray diffraction (XRD) experiments, and the magnetic phase content was measured with a ferritoscope. The intensity of the main austenite diffraction peak decreases as sintering temperature increases to finally disappear in the sample sintered at 1100 °C. This destabilization of the austenite is probably related to a high Nickel diffusion detected from austenite to ferrite particles. Moreover, electron backscatter diffraction (EBSD) data were collected to quantify microstructural properties. Several EBSD pattern maps were acquired in order to define the amount of austenite phase. Due to the advantages of this technique a 0.5% of austenite could be detected after sintering at 1200 °C. After sintering process, the austenite content in sintered duplex stainless steels obtained through this processing route was lower than expected. Finally, Bain mechanism was proposed as an explanation to this phase transformation takes place. EBSD technique has been proved to be the most suitable to monitor the microstructure of sintered DSS.

  13. Mechanical Properties of Injection Molded B 4C-C Ceramics

    Science.gov (United States)

    Schwetz, Karl A.; Sigl, Lorenz S.; Pfau, Lothar

    1997-10-01

    Various mechanical properties of carbon-doped boron carbide ceramics, prepared by the fabrication route, injection molding/pressureless sintering/post-hot isostatic pressing (HIP) were investigated as a function of the sintering temperature and the carbon additive level used. An optimum combination of mechanical properties (flexural stregth, fracture toughness, Young's modulus, Knoop's hardness) is thus obtained with 100% dense and very fine grained materials (mean grain size 1-4 ?m) which were sintered at temperatures from 2150 to 2175°C and post-HIPed at 2050°/200 MPa Ar, having an approximate final composition of 96 B4C-4C (wt%).

  14. High-Temperature Oxidation Behavior of Two Nickel-Based Superalloys Produced by Metal Injection Molding for Aero Engine Applications

    Science.gov (United States)

    Albert, Benedikt; Völkl, Rainer; Glatzel, Uwe

    2014-09-01

    For different high-temperature applications like aero engines or turbochargers, metal injection molding (MIM) of superalloys is an interesting processing alternative. For operation at high temperatures, oxidation behavior of superalloys produced by MIM needs to match the standard of cast or forged material. The oxidation behavior of nickel-based superalloys Inconel 713 and MAR-M247 in the temperature interval from 1073 K to 1373 K (800 °C to 1100 °C) is investigated and compared to cast material. Weight gain is measured discontinuously at different oxidation temperatures and times. Analysis of oxidized samples is done via SEM and EDX-measurements. MIM samples exhibit homogeneous oxide layers with a thickness up to 4 µm. After processing by MIM, Inconel 713 exhibits lower weight gain and thinner oxide layers than MAR-M247.

  15. Rotational Molding Process Technician. Instructional Program Package.

    Science.gov (United States)

    El Paso Community Coll., TX.

    This curriculum package contains materials developed through a partnership of the Association of Rotational Molders, El Paso Community College (Texas), and the College of DuPage (Illinois). The materials, which were developed during a 2-day DACUM (Developing a Curriculum) process, are based on national skill standards and designed for…

  16. DNA barcoding via counterstaining with AT/GC sensitive ligands in injection-molded all-polymer nanochannel devices.

    Science.gov (United States)

    Østergaard, Peter Friis; Matteucci, Marco; Reisner, Walter; Taboryski, Rafael

    2013-02-21

    Nanochannel technology, coupled with a suitable DNA labeling chemistry, is a powerful approach for performing high-throughput single-molecule mapping of genomes. Yet so far nanochannel technology has remained inaccessible to the broader research community due to high fabrication cost and/or requirement of specialized facilities/skill-sets. In this article we show that nanochannel-based mapping can be performed in all polymer chips fabricated via injection molding: a fabrication process so inexpensive that the devices can be considered disposable. Fluorescent intensity variations can be obtained from molecules extended in the polymer nanochannels via chemical counterstaining against YOYO-1. In particular, we demonstrate that the counterstaining induced fluorescent intensity variations to a large degree appear to be proportional to the theoretically computed sequence-maps of both local AT and GC variation along DNA sequences. PMID:23314250

  17. DNA barcoding via counterstaining with AT/GC sensitive ligands in injection-molded all-polymer nanochannel devices

    DEFF Research Database (Denmark)

    Østergaard, Peter Friis; Matteucci, Marco

    2013-01-01

    Nanochannel technology, coupled with a suitable DNA labeling chemistry, is a powerful approach for performing high-throughput single-molecule mapping of genomes. Yet so far nanochannel technology has remained inaccessible to the broader research community due to high fabrication cost and/or requirement of specialized facilities/skill-sets. In this article we show that nanochannel-based mapping can be performed in all polymer chips fabricated via injection molding: a fabrication process so inexpensive that the devices can be considered disposable. Fluorescent intensity variations can be obtained from molecules extended in the polymer nanochannels via chemical counterstaining against YOYO-1. In particular, we demonstrate that the counterstaining induced fluorescent intensity variations to a large degree appear to be proportional to the theoretically computed sequence-maps of both local AT and GC variation along DNA sequences.

  18. Gas Atmosphere Formed in Casting by Full Mold Process

    Directory of Open Access Journals (Sweden)

    Mocek J.

    2014-10-01

    Full Text Available A test mold was designed to investigate the full mold process. Pressure changes in a gap developing between the pattern made of foamed polystyrene and the raising column of liquid alloy were determined. Studies were conducted pouring molds with cast iron and with AK11 silumin. It was found that pressure is significantly higher in the case of cast iron, due to a higher rate of pattern decomposition and more advanced dissociation of hydrocarbons. The increase in pressure was observed to have no significant effect on changes in the pouring rate as it was compensated by higher metallostatic pressure. The increase of pressure occurs immediately after the start of pouring, it reaches a maximum and then stabilizes or decreases smoothly as a result of the drop in metallostatic pressure. The temperature of pouring has a significant effect on the decomposition rate of hydrocarbons evolving from the metal. During pouring of cast iron, the presence of hydrogen was revealed. It was particularly evident across the gas-permeable coating, where the concentration has exceeded 40%. Hydrogen precipitation was accompanied by an evolution on the casting surface of considerable amounts of pyrolytic carbon. It was found that gases forming in the gap were totally free from oxygen.

  19. Injection molded chips with integrated conducting polymer electrodes for electroporation of cells

    International Nuclear Information System (INIS)

    We present the design-concept for an all polymer injection molded single use microfluidic device. The fabricated devices comprise integrated conducting polymer electrodes and Luer fitting ports to allow for liquid and electrical access. A case study of low voltage electroporation of biological cells in suspension is presented. The working principle of the electroporation device is based on a focusing of the electric field by means of a constriction in the flow channel for the cells. We demonstrate the use of AC voltage for electroporation by applying a 1 kHz, ±50 V square pulse train to the electrodes and show delivery of polynucleotide fluorescent dye in 46% of human acute monocytic leukemia cells passing the constriction.

  20. Internal stresses analysis in electroformed nickel shells for thermoplastics injection mold core (rapid tooling)

    International Nuclear Information System (INIS)

    This study deals with a research field started at the LFI laboratorio de Fabricacion Integrada) of the ULPGC (Universidad de Las Palmas de Gran Canaria). Its aim is to analyse and propose improvements in the electroformed nickel cores manufacture. The main application of these cores is to be used as plastic injection molds. It has been considered an important part of this study taking under consideration internal stresses that appear in the nickel electroformed core. These stresses play a determinant role towards reaching a dimensional and resistant quality standard of the shells, which will be later transformed into cores. The investigation includes not only a theoretic study but also an experimental one. the testing method has the remarkable advantage of a wide industrial application because of its simplicity, low cost and reproducibility of the electrolytic bath actual conditions. (Author) 7 refs

  1. Qualification Methods of Al2O3 Injection Molding Raw Materials

    Science.gov (United States)

    Egész, Á.; Gömze, L. A.

    2015-04-01

    For producing ceramic arc tube parts (plugs), there are used two different major components for producing injection molding raw material (feedstock): high purity alumina powder as the main component, and an organic paraffin wax as a binder material. It is expressly important to know the material, physical and chemical properties of these components, since mainly these have effect on the homogenity of feedstock, and therefore on the quality of end product. In this research, both of the main components and the moldable raw material was investigated by visual, physical, and thermal methods. As most important and main statement, the researchers found that the dynamic viscosity of raw material depends more on the applied temperature, than on the deformation speed gradient. Applied analitycal methods were laser granulometry, sieve analysis, differential thermal analysis and rheology analysis.

  2. Injection Molding of Polystyrene Matrix Composites Filled with Vapor Grown Carbon Fiber

    Science.gov (United States)

    Enomoto, Kazuki; Yasuhara, Toshiyuki; Ohtake, Naoto; Kato, Kazunori

    Vapor grown carbon fiber (VGCF) is a kind of carbon nanotube (CNT), which has outstanding properties such as high mechanical strength and high electrical conductivity. In this study, injection molding properties of polystyrene (PS) filled with VGCF and evaluation of mechanical and electrical properties are discussed in comparison with composites in which conventional carbon fillers were filled. As a result, volume resistivity of VGCF/PS composites dropped significantly between VGCF concentration of 3 and 4vol.%. Resistivity of the composites filled with VGCF was 1.2×102?·cm when VGCF concentration was 11.6vol.%. The resistivity was significantly lower than that of composites which were filled with conventional carbon fillers. The elastic modulus slightly increases with increasing VGCF concentration, whereas the tensile strength slightly decreases in the VGCF concentration in the range from 0 to 12vol.%.

  3. Biodegradability of injection molded bioplastic pots containing polylactic acid and poultry feather fiber.

    Science.gov (United States)

    Ahn, H K; Huda, M S; Smith, M C; Mulbry, W; Schmidt, W F; Reeves, J B

    2011-04-01

    The biodegradability of three types of bioplastic pots was evaluated by measuring carbon dioxide produced from lab-scale compost reactors containing mixtures of pot fragments and compost inoculum held at 58 °C for 60 days. Biodegradability of pot type A (composed of 100% polylactic acid (PLA)) was very low (13 ± 3%) compared to literature values for other PLA materials. Near infrared spectroscopy (NIRS) results suggest that the PLA undergoes chemical structural changes during polymer extrusion and injection molding. These changes may be the basis of the low biodegradability value. Biodegradability of pot types B (containing 5% poultry feather, 80% PLA, 15% starch), and C (containing 50% poultry feather, 25% urea, 25% glycerol), were 53 ± 2% and 39 ± 3%, respectively. More than 85% of the total biodegradation of these bioplastics occurred within 38 days. NIRS results revealed that poultry feather was not degraded during composting. PMID:21320772

  4. INJECTION MOLDING AND STRUCTURAL ANALYSIS IN METAL TO PLASTIC CONVERSION OF BOLTED FLANGE JOINT BY CAE

    Directory of Open Access Journals (Sweden)

    Marian Blaško

    2014-12-01

    Full Text Available Many metal parts in various applications are being replaced by plastic parts. There are several reasons for that depending on actual application - minimize part cost, enhance corrosion resistance, integrating more components into one part etc. Most important steps of metal to plastic conversion are material selection and design of plastic part. Plastic part has to withstand the same load as metal part. To fulfill this requirement fiber reinforced engineering plastics are often used. Also it is convenient to substitute heavy wall sections with ribbed structure to increase load-carrying ability of part and decrease cycle time, eliminate voids, sink marks etc. Mechanical properties of such part could be highly affected by fiber orientation. Results of fiber orientation from injection molding filling analysis can be used in stress analysis for better prediction of part response to mechanical load. Such coupled analysis is performed here in this case study on bolted flange joint.

  5. Three-Dimensional Numerical Simulation of Mold Filling Process in Compression Resin Transfer Molding

    Science.gov (United States)

    Yang, Bo; Jin, Tianguo; Li, Jianguang; Bi, Fengyang

    2015-04-01

    Compression resin transfer molding (CRTM) is an effective process for the manufacturing of composite parts with large size and high fiber content, while the existence of open gap, the dynamically changing dimensions of cavity geometry and the deformation of preform during filling process bring great difficulties to the three-dimensional simulation of resin flow in CRTM. In order to develop a convenient and efficient three-dimensional simulation approach for CRTM filling process, a unified mathematical model for resin flow in both open gap and preform is established instead of considering the gap as high permeability preform, then the analysis of the clamping force and stress distribution are presented. In order to avoid direct solving the coupled equations of resin flow and cavity deformation, volume of fluid (VOF) multiphase flow technology and dynamic mesh model are applied to track the resin flow front and update the cavity geometry during filling simulation, respectively. The master-slave element method is used to modify the amount of resin release and ensure the resin mass conservation. The validity of the numerical approach is verified by comparison with analytical and experimental results, three-dimensional simulation examples are also presented.

  6. MECHANICAL PROPERTIES OF INJECTION-MOLDED FOAMED WHEAT STRAW FILLED HDPE BIOCOMPOSITES: THE EFFECTS OF FILLER LOADING AND COUPLING AGENT CONTENTS

    Directory of Open Access Journals (Sweden)

    Fatih Mengeloglu,

    2012-06-01

    Full Text Available This study investigated the effect of filler loading and coupling agent contents on the densities and mechanical properties of injection-molded foamed biocomposites. Biocomposite pellets were manufactured using wheat straw flour, maleic anhydrite grafted polyethylene (MAPE, paraffin wax, and high-density polyethylene (HDPE with an extrusion process. Pellets and the chemical foaming agent (azodicarbonamide were dry-mixed and foamed in an injection-molding machine. Densities and mechanical properties of the foamed biocomposites samples were measured and analyzed using central composite design (CCD. The results showed that both filler loading and coupling agent contents affected the density and mechanical properties of foamed biocomposites. Densities in the range of 0.57 to 0.81 gr cm-3 were achieved. Best results were obtained when less than 20% wheat straw flour and 1% coupling agent content were used. The flexural modulus and tensile modulus of foamed biocomposites were improved with increasing filler loading. However, flexural strength, tensile strength, elongation at break, and impact strength values were diminished. The tensile strength of the biocomposites was positively affected by CA contents, but other mechanical properties were not affected by it. Overall, injection molded foamed biocomposites with moderate mechanical properties were produced.

  7. Optimization of powder injection molding of feedstock based on aluminum oxide and multicomponent water-soluble polymer binder.

    Czech Academy of Sciences Publication Activity Database

    Hausnerová, B.; Marcaníková, L.; Filip, Petr; Sáha, P.

    2011-01-01

    Ro?. 51, ?. 7 (2011), s. 1376-1382. ISSN 0032-3888 R&D Projects: GA ?R GA103/08/1307 Institutional research plan: CEZ:AV0Z20600510 Keywords : powder injection molding * viscosity * thermogravimetric analysis Subject RIV: BK - Fluid Dynamics Impact factor: 1.302, year: 2011

  8. Modeling of process-induced residual stresses and resin flow behavior in resin transfer molded composites with woven fiber mats

    Science.gov (United States)

    Golestanian, Hossein

    This research focuses on modeling Resin Transfer Molding process for manufacture of composite parts with woven fiber mats. Models are developed to determine cure dependent stiffness matrices for composites manufactured with two types of woven fiber mats. Five-harness carbon and eight-harness fiberglass mats with EPON 826 resin composites are considered. The models presented here take into account important material/process parameters with emphasis on; (1) The effects of cure-dependent resin mechanical properties, (2) Fiber undulation due to the weave of the fiber fill and warp bundles, and (3) Resin interaction with the fiber bundles at a microscopic scale. Cure-dependent mechanical properties were then used in numerical models to determine residual stresses and deformation in the composite parts. The complete cure cycle was modeled in these analyses. Also the cool down stage after the composite cure was analyzed. The effect of 5% resin shrinkage on residual stresses and deformations was also investigated. In the second part of the study, Finite Element models were developed to simulate mold filling in RTM processes. Resin flow in the fiber mats was modeled as flow through porous media. Physical models were also developed to investigate resin flow behavior into molds of rectangular and irregular shapes. Silicone fluids of 50 and 100 centistoke viscosities as well as EPON 826 epoxy resin were used in the mold filling experiments. The reinforcements consisted of several layers of woven fiberglass and carbon fiber mats. The effects of injection pressure, fluid viscosity, type of reinforcement, and mold geometry on mold filling times were investigated. Fiber mat permeabilities were determined experimentally for both types of reinforcements. Comparison of experimental and numerical resin front positions indicated the importance of edge effects in resin flow behavior in small cavities. The resin front positions agreed well for the rectangular mold geometry.

  9. Research of thermal response simulation and mold structure optimization for rapid heat cycle molding processes, respectively, with steam heating and electric heating

    International Nuclear Information System (INIS)

    The dynamic mold temperature control system is the key of rapid heat cycle molding (RHCM) technology because it significantly affects the stability of the process, productivity and the quality of the final polymer part. For this reason, the approaches and techniques for dynamic mold temperature control were discussed in this study and two different dynamic mold temperature control methods, respectively, with steam heating and electric heating were found to be very feasible in mass production. The methods and principles of mold design for the two RHCM technologies were also discussed and then several different kinds of mold structures were designed. By constructing the corresponding thermal response analytical models for these RHCM molds, the temperature responses of the molding systems in the heating and cooling process of RHCM were simulated and studied. The effects of the mold design parameters such as the insulation layer between mold plate and mold inert, and mold material, on thermal response efficiency and temperature uniformity of the two RHCM processes were analyzed based on the simulation results. The results show that the insulation layer can increase the upper limit temperature of RHCM with steam heating and improve the heating speed of RHCM with electric heating. It can also greatly decrease the energy consumption of the two RHCM processes. The heating efficiency of RHCM with steam heating can be effectively improved by increasing the thermal conductivity of the cavity/core material, while the situation is diametrically opposite for RHCM with electric heating. Therefore, we acquired an optimized mold design principle and method for RHCM with steam heating and electric heating, respectively. Finally, a new electric heating mold with a cooling plate was proposed to enhance the cooling efficiency. The thermal response of this new electric heating mold was also simulated. The simulation results show that the cooling plate can significantly improve the cooling and heating efficiency.

  10. Hybrid tooling technologies and standardization for the manufacturing of inserts for micro injection molding

    DEFF Research Database (Denmark)

    Tosello, Guido; Fillon, Bertrand

    2007-01-01

    This paper is based on the European Platform’s activities within the 4M Network of Excellence “Multi-Material Micro Manufacturing”. To overpass limitations of the current existing micro tooling capabilities, a new generation of micro hybrid tooling technologies for micro replication was developed. A metrological approach was applied to standardize the employed tooling processes (micro milling, µEDM, laser micromachining, electrochemical µ-milling). The micro tools were then tested with different polymers (PP, PP + nano fillers, PC, COC). The paper provides a comparison of these technologies concerning obtainable feature sizes, surface finish, and aspect ratios of both micro tools and micro molded parts.

  11. Rubber molds for investment casting

    International Nuclear Information System (INIS)

    The main objective of the project is to investigate different types of molding rubbers used for investment casting. The level of shape complexity which can be achieved by using these rubber molds is also studied. It was almost impossible to make complex shapes molds using metal molds, in that cases rubber molds are very important because they arc flexible and give accurate and precise part dimensions. Turbine blades are hi-tech components with air-foil geometries that have close dimensional tolerances. They are made of super-alloys and manufactured by investment casting. The final blade profile depends upon the dimensional accuracy in each of the processing steps. In the present work experimental study for the production of high quality low cost castings of turbine blades using rubber molds and injected wax patterns is presented. Natural Rubber molds and wax patterns from these molds were made. Different types of molding rubbers were studied including natural rubber, silicone rubber and liquid silicone rubber. It was found that by using rubber molds we can make most complex shape with very less finishing required. The shrinkage was 12% as compared to original master pattern. Rubber molds were made using laboratory hot press. Three layers of rubber above and below the master pattern. After that vulcanization was done by giving temperature and pressure. (author)

  12. Phenolic Molding Compounds

    Science.gov (United States)

    Koizumi, Koji; Charles, Ted; de Keyser, Hendrik

    Phenolic Molding Compounds continue to exhibit well balanced properties such as heat resistance, chemical resistance, dimensional stability, and creep resistance. They are widely applied in electrical, appliance, small engine, commutator, and automotive applications. As the focus of the automotive industry is weight reduction for greater fuel efficiency, phenolic molding compounds become appealing alternatives to metals. Current market volumes and trends, formulation components and its impact on properties, and a review of common manufacturing methods are presented. Molding processes as well as unique advanced techniques such as high temperature molding, live sprue, and injection/compression technique provide additional benefits in improving the performance characterisitics of phenolic molding compounds. Of special interest are descriptions of some of the latest innovations in automotive components, such as the phenolic intake manifold and valve block for dual clutch transmissions. The chapter also characterizes the most recent developments in new materials, including long glass phenolic molding compounds and carbon fiber reinforced phenolic molding compounds exhibiting a 10-20-fold increase in Charpy impact strength when compared to short fiber filled materials. The role of fatigue testing and fatigue fracture behavior presents some insight into long-term reliability and durability of glass-filled phenolic molding compounds. A section on new technology outlines the important factors to consider in modeling phenolic parts by finite element analysis and flow simulation.

  13. Determinação da redução da resistência à tração em corpos de prova com Weld Line / Determination of reduction of the weld line strength in injection molded

    Scientific Electronic Library Online (English)

    R.P., Bom; A.F., Kalin.

    2008-06-01

    Full Text Available Neste trabalho objetivou-se determinar a redução da resistência à tração de corpos de prova com linhas de solda. Os corpos de prova ASTM foram moldados pelo processo de injeção com diferentes temperaturas de plastificação (180 ºC a 280 ºC). O material utilizado foi o polímero termoplástico Polystyro [...] l 158 K da Basf. Este estudo relaciona as linhas de solda em produtos moldados por injeção com a redução da resistência mecânica devido a fragilização na região da linha de solda. Para o desenvolvimento deste trabalho foi projetado e desenvolvido um molde de injeção com uma cavidade em forma de corpo de prova com canal de ataque pelas extremidades. Desta forma no momento da junção dos fluxos obtêm-se uma linha de solda no centro do corpo de prova. Os parâmetros do processo de injeção foram determinados a partir de um aplicativo comercial. A temperatura do molde e o tempo de injeção permaneceram constantes. O tempo de solidificação do material foi determinado analiticamente, considerando-se o centro do corpo de prova como referência. Foram injetados dez corpos de prova em cada uma das temperaturas. Foi observada de forma clara a existência de linhas de junção no centro da peça e as condições de processo utilizadas não permitiram a formação de linha de solda fria. Após a realização dos ensaios de tração, foi determinado que a tensão de ruptura decresce nas seguintes condições: com a diminuição da temperatura de injeção e do tempo de solidificação e com o aumento da trinca. A ruptura sempre ocorreu na linha de solda. Abstract in english In this paper, the purpose is to determine the weld line strength in injection molded samples. The ASTM standard dogbone-shaped samples were molded over a range of melt temperatures (180 ºC up to 280 ºC). The plastic used was a commercial grade of polystyrene (PS), BASF Polystyrol 158K. This study l [...] inks weld lines in parts by injection molding with mechanical strength reduction due to embrittling effect in weld-line region. A single-cavity mold double-gated was used to generate ASTM D638 Type I tensile specimens. The double-gated and runner allow the parts to be molded with weld line. The injection process parameters were determined by imputing resin, machine and geometry information into a CAE software package. The mold temperature and fill time were maintaining the same. The frozen time was determined by analytic equation, which considers the center of the thickness as reference. For each melt temperature 10 samples were tested. The weld line was clearly noted in the centre of the samples and the process condition set avoided the cold weld line. By the strength tests were possible to realize that lower the injection temperature lower the frozen time and higher the length of the crack. Then low injection temperature leads to low maximum strength. The fracture always occurs in the weld line.

  14. A high volume precision compression molding process of glass diffractive optics by use of a micromachined fused silica wafer mold and low Tg optical glass

    Science.gov (United States)

    Yi, A. Y.; Chen, Y.; Klocke, F.; Pongs, G.; Demmer, A.; Grewell, D.; Benatar, A.

    2006-10-01

    Recent advances in compression molding of glass optical elements for mass production offer the potential of extending this technology to elements with micro and nano scale features. In this research, glass diffractive optical elements (DOEs) with lateral features in the order of 10 µm and vertical height of 330 nm were fabricated using a fused silica glass mold and a special low Tg (glass transition temperature) glass material K-PG325. Molded DOEs were studied using an atomic force microscope (AFM) and scanning electron microscope (SEM) to evaluate the glass molding process capability. Optical testing of the molded DOEs was a further demonstration of the effectiveness of the molding process for high volume micro and diffractive optical component fabrication. The combination of two high-precision, high-volume processes, i.e., semiconductor batch process for optical mold making and glass molding for DOE replication, is an effective alternative manufacturing method for high-quality, low-cost optical components. The reported experiment is a detailed illustration of the glass molding process capability. With further process optimization a robust manufacturing process can be developed for mass production of diffractive and micro glass optical elements.

  15. Effect of boron addition on injection molded 316L stainless steel: mechanical, corrosion properties and in vitro bioactivity.

    Science.gov (United States)

    Bayraktaroglu, Esra; Gulsoy, H Ozkan; Gulsoy, Nagihan; Er, Ozay; Kilic, Hasan

    2012-01-01

    The research was investigated the effect of boron additions on sintering characteristics, mechanical, corrosion properties and biocompatibility of injection molded austenitic grade 316L stainless steel. Addition of boron is promoted to get high density of sintered 316L stainless steels. The amount of boron plays a role in determining the sintered microstructure and all properties. In this study, 316L stainless steel powders have been used with the elemental NiB powders. A feedstock containing 62.5 wt% powders loading was molded at different injection molded temperature. The binders were completely removed from molded components by solvent and thermal debinding at different temperature. The debinded samples were sintered at different temperature for 60 min. Mechanical property, microstructural characterization and electrochemical property of the sintered samples were performed using tensile testing, hardness, optical, scanning electron microscopy and electrochemical corrosion experiments. Sintered samples were immersed in a simulated body fluid (SBF) with elemental concentrations that were comparable to those of human blood plasma for a total period of 15 days. Both materials were implanted in fibroblast culture for biocompatibility evaluations were carried out. Results of study showed that sintered 316L and 316L with NiB addition samples exhibited high mechanical and corrosion properties in a physiological environment. Especially, 316L with NiB addition can be used in some bioapplications. PMID:23114463

  16. Bi-composite sandwich moldings : processing, mechanical performance and bioactive behaviour

    OpenAIRE

    Sousa, R.A; Oliveira, A. L.; R. L. Reis; Cunha, A.M.; Bevis, M. J.

    2003-01-01

    Two composite systems composed of high-density polyethylene (HDPE) filled with hydroxyapatite (HA) and carbon fiber (C fiber) were compounded in a co-rotating twin screw extruder and subsequently molded in a two component injection molding machine in order to produce test bars with a sandwich-like morphology. These moldings are based on a HDPE/HA composite outer layer and a HDPE/C fiber composite core. The mechanical performance of the obtained specimens was assessed by tensile and impact tes...

  17. Survey of molds, yeast and Alicyclobacillus spp. from a concentrated apple juice productive process

    OpenAIRE

    de Cássia Martins Salomão, Beatriz; Muller, Chalana; do Amparo, Hudson Couto; de Aragão, Gláucia Maria Falcão

    2014-01-01

    Bacteria and molds may spoil and/or contaminate apple juice either by direct microbial action or indirectly by the uptake of metabolites as off-flavours and toxins. Some of these microorganisms and/or metabolites may remain in the food even after extensive procedures. This study aim to identify the presence of molds (including heat resistant species) and Alicyclobacillus spp., during concentrated apple juice processing. Molds were isolated at different steps and then identified by their macro...

  18. Measurement Of Thermal Contact Resistance Between The Mold And The Polymer For The Stretch-blow Molding Process

    Science.gov (United States)

    Bordival, M.; Schmidt, F. M.; Le Maoult, Y.; Coment, E.

    2007-04-01

    In the stretch-blow molding process, the heat transfer between the polymer and the mold is of prime interest. Although the time of contact is very short (typically around 0.5 s), the heat transfer affects the mechanical properties of the bottle, and the quality of final parts. In order to model heat transfers at the interface, a classical approach — generally adopted in numerical softwares — is to impose the heat flux density boundary condition thanks to a parameter called Thermal Contact Resistance (TCR). This paper focuses on describing the experimental method developed in order to measure evolution of this thermal parameter (TCR) versus time, as well as results obtained on the CROMeP blowing machine. In this study, a mold has been instrumented with two different sensors. The first probe allows to estimate the heat flux density and temperature at the mold surface temperature, using a linear inverse heat condution problem (Function Specification Method). The second device is used to measure the surface temperature of the PET during the blowing. This measurement is non intrusive, and can be applied within an industrial environment during the blowing step. In addition, air pressure inside the preform is also measured during the blowing. This work is part of the European project "APT_PACK" (Advanced knowledge of Polymer deformation for Tomorrow's PACKaging).

  19. Trial production of titanium orthodontic brackets fabricated by metal injection molding (MIM) with sintering.

    Science.gov (United States)

    Deguchi, T; Ito, M; Obata, A; Koh, Y; Yamagishi, T; Oshida, Y

    1996-07-01

    Safety and esthetics are two indispensable factors to consider when fabricating orthodontic brackets. However, these factors are not easily achieved when conventional techniques (including forging and casting) are used in the mass production of titanium brackets, albeit the brackets exhibit excellent biocompatibility. In the present study, orthodontic brackets were manufactured by metal powder injection molding with sintering. Brackets with three different base designs were made and subjected to compression shear tests for evaluation of their bonding strength to enamel substrate. The shapes given to the dimple of the base were spherical, oval, and grooved. The maximum shear forces for each type were 11.1 kgf, 7.6 kgf, and 18.5 kgf, respectively. The bonding strengths of the titanium bracket were equivalent to those obtained with conventional stainless steel brackets. Moreover, uniform distribution of Vickers hardness values (average, 240 +/- 40 Hv) measured at three locations indicated that the titanium bracket was uniformly sintered. Accordingly, titanium brackets thus fabricated exhibit a potential for clinical application. PMID:8876601

  20. Thermal shock behavior of tungsten based alloys manufactured via powder injection molding

    International Nuclear Information System (INIS)

    The focus of this work is to address mechanical strength and recrystallization resistance through thermal shock investigation of newly developed fine grained tungsten base materials (i.e., pure tungsten and two doped tungsten-grades incorporating either 1 or 5 vol%Y2O3 produced via powder injection molding (PIM)). Therefore, repetitive ELM (edge localized mode)-like loads (n = 100) were applied by means of an electron beam at various temperatures between RT and 400 °C (673 K) with a pulse duration of 1 ms and an absorbed power density of up to 1.13 GW/m2. The microstructural properties, e.g. grain size, and Y2O3-particle distribution, were correlated with crack formation at a certain temperature, the crack propagation direction towards the bulk material and the amount of plastic deformation/surface roughening at higher temperatures. Thereby, it was shown that W–1 vol%Y2O3 outperformed all other investigated grades and reference materials from literature

  1. Injection molding of ceramic filled polypropylene: The effect of thermal conductivity and cooling rate on crystallinity

    Energy Technology Data Exchange (ETDEWEB)

    Suplicz, A.; Szabo, F.; Kovacs, J.G., E-mail: kovacs@pt.bme.hu

    2013-12-20

    Highlights: • BN, talc and TiO{sub 2} in 30 vol% were compounded with polypropylene matrix. • According to the DSC measurements, the fillers are good nucleating agents. • The thermal conductivity of the fillers influences the cooling rate of the melt. • The higher the cooling rate is, the lower the crystallinity in the polymer matrix. - Abstract: Three different nano- and micro-sized ceramic powders (boron-nitride (BN), talc and titanium-dioxide (TiO{sub 2})) in 30 vol% have been compounded with a polypropylene (PP) matrix. Scanning electron microscopy (SEM) shows that the particles are dispersed smoothly in the matrix and larger aggregates cannot be discovered. The cooling gradients and the cooling rate in the injection-molded samples were estimated with numerical simulations and finite element analysis software. It was proved with differential scanning calorimetry (DSC) measurements that the cooling rate has significant influence on the crystallinity of the compounds. At a low cooling rate BN works as a nucleating agent so the crystallinity of the compound is higher than that of unfilled PP. On the other hand, at a high cooling rate, the crystallinity of the compound is lower than that of unfilled PP because of its higher thermal conductivity. The higher the thermal conductivity is, the higher the real cooling rate in the material, which influences the crystallization kinetics significantly.

  2. Thermal shock behavior of tungsten based alloys manufactured via powder injection molding

    Energy Technology Data Exchange (ETDEWEB)

    Pintsuk, G., E-mail: g.pintsuk@fz-juelich.de [Forschungszentrum Jülich, EURATOM-Association, D-52425 Jülich (Germany); Blagoeva, D. [Nuclear Research and Consultancy Group, P.O. Box 25, 1755 ZG Petten (Netherlands); Opschoor, J. [ECN, Energy research Centre of the Netherlands, P.O. Box 1, 1755 ZG Petten (Netherlands)

    2013-11-15

    The focus of this work is to address mechanical strength and recrystallization resistance through thermal shock investigation of newly developed fine grained tungsten base materials (i.e., pure tungsten and two doped tungsten-grades incorporating either 1 or 5 vol%Y{sub 2}O{sub 3} produced via powder injection molding (PIM)). Therefore, repetitive ELM (edge localized mode)-like loads (n = 100) were applied by means of an electron beam at various temperatures between RT and 400 °C (673 K) with a pulse duration of 1 ms and an absorbed power density of up to 1.13 GW/m{sup 2}. The microstructural properties, e.g. grain size, and Y{sub 2}O{sub 3}-particle distribution, were correlated with crack formation at a certain temperature, the crack propagation direction towards the bulk material and the amount of plastic deformation/surface roughening at higher temperatures. Thereby, it was shown that W–1 vol%Y{sub 2}O{sub 3} outperformed all other investigated grades and reference materials from literature.

  3. Thermal shock behavior of tungsten based alloys manufactured via powder injection molding

    Energy Technology Data Exchange (ETDEWEB)

    Pintsuk, G. [Forschungszentrum Juelich, EURATOM-Association, D-52425 Juelich (Germany); Blagoeva, D. Nuclear Research and Consultancy Group NRG, PO Box 25, 1755 ZG Petten (Netherlands)); Opschoor, J. [Energy research Centre of the Netherlands ECN, P.O. Box 1, 1755 ZG Petten (Netherlands)

    2013-11-15

    The focus of this work is to address mechanical strength and recrystallization resistance through thermal shock investigation of newly developed fine grained tungsten base materials (i.e., pure tungsten and two doped tungsten-grades incorporating either 1 or 5 vol%Y2O3 produced via powder injection molding (PIM)). Therefore, repetitive ELM (edge localized mode)-like loads (n = 100) were applied by means of an electron beam at various temperatures between RT and 400C (673 K) with a pulse duration of 1 ms and an absorbed power density of up to 1.13 GW/m{sup 2}. The microstructural properties, e.g. grain size, and Y2O3-particle distribution, were correlated with crack formation at a certain temperature, the crack propagation direction towards the bulk material and the amount of plastic deformation/surface roughening at higher temperatures. Thereby, it was shown that W-1 vol%Y2O3 outperformed all other investigated grades and reference materials from literature.

  4. Injection molding of ceramic filled polypropylene: The effect of thermal conductivity and cooling rate on crystallinity

    International Nuclear Information System (INIS)

    Highlights: • BN, talc and TiO2 in 30 vol% were compounded with polypropylene matrix. • According to the DSC measurements, the fillers are good nucleating agents. • The thermal conductivity of the fillers influences the cooling rate of the melt. • The higher the cooling rate is, the lower the crystallinity in the polymer matrix. - Abstract: Three different nano- and micro-sized ceramic powders (boron-nitride (BN), talc and titanium-dioxide (TiO2)) in 30 vol% have been compounded with a polypropylene (PP) matrix. Scanning electron microscopy (SEM) shows that the particles are dispersed smoothly in the matrix and larger aggregates cannot be discovered. The cooling gradients and the cooling rate in the injection-molded samples were estimated with numerical simulations and finite element analysis software. It was proved with differential scanning calorimetry (DSC) measurements that the cooling rate has significant influence on the crystallinity of the compounds. At a low cooling rate BN works as a nucleating agent so the crystallinity of the compound is higher than that of unfilled PP. On the other hand, at a high cooling rate, the crystallinity of the compound is lower than that of unfilled PP because of its higher thermal conductivity. The higher the thermal conductivity is, the higher the real cooling rate in the material, which influences the crystallization kinetics significantly

  5. Quality Prediction Model of Injection-Molded Rib Design using Back-Propagation Network

    Directory of Open Access Journals (Sweden)

    Tian-Syung Lan

    2009-01-01

    Full Text Available In this study, an analytical model of a rectangular thermoplastic ABS (Acrylonitrile Butadiene Styrene plastic cover with rib of a given thickness (2.8 mm was introduced and the dimensions as well as width of the rib were selected as the control factors for simulation. Additionally, the deflection under a constant force of 150 Newton at the back centre of the cover was defined as quality characteristic. Moreover, the L9(34 orthogonal array for four factors and three levels from Taguchi method was additionally considered to layout the 34 = 81 sets of full simulations. By commencing the BPN (Back-Propagation Network to learn the selected 45 sets of simulated results. The remaining 36 sets of simulated results are then employed to verify and construct a quality predictor of rib design. Considering the learning rate as 1 and momentum factor as 0.5, the results of 20000 times of BPN training through a hidden layer indicated that the accuracy of deflection prediction reached 95.87%. In this study, the full FEM (Finite Element Method simulated results from the 81 sets of combinations layout by Taguchi method are learned and verified by BPN for the design of injection-molded rib. It is shown that the quality of a plastic rib can surely be effectively found with the proposed economic and prospective BPN. This study exactly contributes an economical technique to the quality prediction of rib design for plastic injection industry in minimizing the development period of a new product.

  6. Optimizing the fabrication process of a high-efficiency blazed grating through diamond scribing and molding

    International Nuclear Information System (INIS)

    This paper presents the experimental investigation of an optimal hot embossing process to prevent the nanoscale thermal deformation of microstructures replicated from the electroless Ni mold fabricated by the diamond tool-interfered scribing method. A polymer-based PMMA was replicated from the mold with the blazed profile: period 2.0 µm and depth 0.2 µm. The molding conditions, the applying pressure (Pm), molding temperature (Tm) and demolding temperature (Td) were chosen as experiment parameters. In terms of the quality of surface smoothness, profile, sharp edge, surface roughness and optical performance of the replica, the conditions, Pm = 0.9 MPa, Tm = 150 °C and Td = 20 °C, showed a best results. From optical testing, diffraction efficiency of the replica was measured, 87.6%, and the replica molded in other conditions showed a noticeable efficiency drop due to the molding error.

  7. Constante de mola de molas cerâmicas injetadas a baixa pressão / Spring constant of low-pressure injection molded ceramic springs

    Scientific Electronic Library Online (English)

    R. A., Barbieri; J. E., Zorzi.

    2011-12-01

    Full Text Available A dificuldade de usinagem de peças cerâmicas já sinterizadas é muito grande, principalmente devido à dureza e fragilidade destes materiais, o que implica em altos custos de produção. Por isso, grandes esforços tem sido feitos no sentido de melhorar os processos de conformação a verde existentes, ou [...] criar novos processos que permitam a obtenção de peças cada vez mais próximas do formato final desejado. Produzir peças cerâmicas com formatos complexos, livres de defeitos, é uma tarefa que implica em grandes dificuldades. Molas cerâmicas possuem formatos extremamente difíceis de serem moldados e, conseqüentemente, atualmente são produzidas comercialmente molas cerâmicas pelo processo de usinagem, geralmente a um custo elevado. Uma alternativa para a produção de molas cerâmicas é a moldagem por injeção em baixa pressão. Para o desenvolvimento de molas cerâmicas para aplicações tecnológicas, é necessário, além de obter peças íntegras e livres de defeitos, aferir algumas de suas propriedades, como a constante de mola. Uma vez que estas molas encontram aplicação em altas temperaturas, torna-se imprescindível realizar a medida da resistência imposta pela mola à deformação elástica em diferentes temperaturas. Para tanto, este trabalho propõem a montagem de um sistema para a medição da constante de mola de molas cerâmicas injetadas a baixa pressão, tanto à temperatura ambiente como em altas temperaturas, usando o método dinâmico da excitação por impulso para medir a frequência de vibração da mola suspensa no interior de um forno. Para ilustrar a aplicação desta técnica são apresentados resultados obtidos para uma mola helicoidal de alumina, da temperatura ambiente até 1100 ºC. Abstract in english The machining of sintered ceramic parts is a difficult process, mainly due to the hardness and brittleness of these materials, which implies in high production costs. Therefore, great efforts have been made to improve the forming processes of green ceramics, or create new processes to obtain the nea [...] r net shape parts. The production of ceramic parts with complex shapes, free of defects, is a task that involves great difficulties. Ceramic springs exhibits shapes extremely difficult to be molded and therefore are currently commercially produced mainly by machining, a process which is difficult and expensive. An alternative for the production of ceramic springs is by low-pressure injection molding. For the development of ceramic springs for technological applications, it is required in addition to getting parts intact and free of defects, to measure some of its properties, including the spring constant. Since these springs are usually applied at high temperatures, it becomes important to carry out the measurement of resistance imposed by the spring to elastic deformation at different temperatures. Accordingly, in this work we describe the assembly of an experiment for the measurement of the spring constant of low-pressure injection molded ceramic springs, both at ambient temperature and at high temperatures, using the dynamic impulse excitation method to measure the frequency of vibration of a suspended spring inside a furnace. Results are presented for a helical spring of alumina from room temperature to1100 ºC to illustrate the application of this technique.

  8. Tool steel quality and surface finishing of plastic molds

    Directory of Open Access Journals (Sweden)

    Rafael Agnelli Mesquita

    2010-01-01

    Full Text Available Plastic industry is today in a constant growth, demanding several products from other segments, which includes the plastic molds, mainly used in the injection molding process. Considering all the requirements of plastic molds, the surface finishing is of special interest, as the injected plastic part is able to reproduce any details (and also defects from the mold surface. Therefore, several aspects on mold finishing are important, mainly related to manufacturing conditions - machining, grinding, polishing and texturing, and also related to the tool steel quality, in relation to microstructure homogeneity and non-metallic inclusions (cleanliness. The present paper is then focused on this interrelationship between steel quality and manufacturing process, which are both related to the final quality of plastic mold surfaces. Examples are discussed in terms of surface finishing of plastic molds and the properties or the microstructure of mold steels.

  9. Microstructure and mechanical properties of high Nb containing TiAl alloy parts fabricated by metal injection molding

    International Nuclear Information System (INIS)

    Metal injection molding (MIM) process was applied to fabricate parts of high Nb containing TiAl alloys with a nominal composition of Ti-45Al-8.5Nb-0.2W-0.2B-0.02Y (at.%), and the effects of sintering parameters on their microstructures and mechanical properties, as well as the fractographies after tensile tests were investigated. Results show that for sintering of the alloy in vacuum, effective densification took place in the temperature range 1460-1480 deg. C. Sintering at too high a temperature or too long a time will result in distortion or warpage of the sintered body or coarsening of the lamellar colony. When the optimum sintering parameters (1480 deg. C, 2 h) were chosen, the alloy with the relative density of 96.2% was obtained. The microstructure was homogenous and fine-grained near lamellar structure, consisting of ?2/? lamellar colonies with an average size of 60 ?m, small amounts of ? phase, few boride rods and yttrium oxide precipitates. Its compressive strength, compressibility, ultimate tensile strength and plastic elongation were 2839 MPa, 34.9%, 382 MPa and 0.46%, respectively. At tensile tests, translamellar fracture was the predominant mode and the microcracks often originated from pores and the interfaces of borides/matrix and ? phase/matrix.

  10. Effect of mixing on the rheology and particle characteristics of tungsten-based powder injection molding feedstock

    Energy Technology Data Exchange (ETDEWEB)

    Suri, Pavan; Atre, Sundar V.; German, Randall M.; Souza, Jupiter P. de

    2003-09-15

    This study investigates the effect of mixing technique and particle characteristics on the rheology and agglomerate dispersion of tungsten-based powder injection molding (PIM) feedstock. Experiments were conducted with as-received (agglomerated) and rod-milled (deagglomerated) tungsten powder mixed in a paraffin wax-polypropylene binder. Increase in the mixing shear rate decreased the agglomerate size of the agglomerated tungsten powder, decreased the viscosity, and improved the flow stability of the feedstock, interpreted as increased homogeneity of the feedstock. Higher solids volume fraction, lower mixing torques, and improved homogeneity were observed with deagglomerated tungsten powder, emphasizing the importance of particle characteristics and mixing procedures in the PIM process. Hydrodynamic stress due to mixing and the cohesive strength of the tungsten agglomerate were calculated to understand the mechanism of deagglomeration and quantify the effect of mixing. It was concluded that deagglomeration occurs due to a combination of rupture and erosion with the local hydrodynamic stresses exceeding the cohesive strength of the agglomerate.

  11. Effect of mixing on the rheology and particle characteristics of tungsten-based powder injection molding feedstock

    International Nuclear Information System (INIS)

    This study investigates the effect of mixing technique and particle characteristics on the rheology and agglomerate dispersion of tungsten-based powder injection molding (PIM) feedstock. Experiments were conducted with as-received (agglomerated) and rod-milled (deagglomerated) tungsten powder mixed in a paraffin wax-polypropylene binder. Increase in the mixing shear rate decreased the agglomerate size of the agglomerated tungsten powder, decreased the viscosity, and improved the flow stability of the feedstock, interpreted as increased homogeneity of the feedstock. Higher solids volume fraction, lower mixing torques, and improved homogeneity were observed with deagglomerated tungsten powder, emphasizing the importance of particle characteristics and mixing procedures in the PIM process. Hydrodynamic stress due to mixing and the cohesive strength of the tungsten agglomerate were calculated to understand the mechanism of deagglomeration and quantify the effect of mixing. It was concluded that deagglomeration occurs due to a combination of rupture and erosion with the local hydrodynamic stresses exceeding the cohesive strength of the agglomerate

  12. Integrated polymer-based Mach-Zehnder interferometer label-free streptavidin biosensor compatible with injection molding.

    Science.gov (United States)

    Bruck, R; Melnik, E; Muellner, P; Hainberger, R; Lämmerhofer, M

    2011-05-15

    We report the development of a Mach-Zehnder interferometer biosensor based on a high index contrast polymer material system and the demonstration of label-free online measurement of biotin-streptavidin binding on the sensor surface. The surface of the polyimide waveguide core layer was functionalized with 3-mercaptopropyl trimethoxy silane and malemide tagged biotin. Several concentrations of Chromeon 642-streptavidin dissolved in phosphate buffered saline solution were rinsed over the functionalized sensor surface by means of a fluidic system and the biotin-streptavidin binding process was observed in the output signal of the interferometer at a wavelength of 1310nm. Despite the large wavelength and the comparatively low surface sensitivity of the sensor system due to the low index contrast in polymer material systems compared to inorganic material systems, we were able to resolve streptavidin concentrations of down to 0.1?g/ml. The polymer-based optical sensor design is fully compatible with cost-efficient mass production technologies such as injection molding and spin coating, which makes it an attractive alternative to inorganic optical sensors. PMID:21420847

  13. Diseño de un molde de inyección con un sistema de cavidades intercambiables y deslizantes / DESIGN OF INJECTION MOULD WITH A SYSTEM OF INTERCHANGEABLE AND SLIDING CAVITIES

    Scientific Electronic Library Online (English)

    María V, Candal; María I, Hernández.

    2011-03-01

    Full Text Available El presente trabajo tuvo como objetivo principal diseñar un molde de inyección de probetas normalizadas, destinadas a ensayos mecánicos, utilizando un sistema novedoso de cavidades intercambiables y deslizantes. El diseño que se propone se basa en el uso de insertos o postizos, para el moldeo indivi [...] dualizado de diferentes probetas. Actualmente, existe la tendencia a diseñar moldes con postizos intercambiables que ofrecen facilidades para la obtención de probetas diversas, con la característica de fijarse al sistema de placas mediante tornillos. Al estar sujetos de esa forma, presentan dificultades importantes al momento de montarlos y desmontarlos, para un cambio rápido de cavidades de moldeo. Para ello se requiere de un gran esfuerzo manual e inversión de tiempo. Partiendo de esa experiencia y de las tendencias recientes en la industria a usar moldes con sistemas de cambio rápido, el presente trabajo plantea el diseño con un sistema de postizos intercambiables y deslizantes, bajo las especificaciones de las normas ASTM 6141 e ISO 294-1. Con tal fin, se han diseñado dos postizos, uno para la inyección de probetas tipo halterio y otro para barras rectangulares, las cuales pueden usarse en múltiples ensayos mecánicos (tracción, flexión e impacto). Para modelar y validar el molde diseñado y los postizos propuestos se usaron los programas Pro/ENGINEER y C-MOLD. Se formularon dos propuestas preliminares, considerando los dos movimientos posibles de los postizos en el sistema de placas de la máquina de inyección: vertical y horizontal. La evaluación comparativa de los pros y los contras de cada molde favoreció al sistema horizontal, debido a sus facilidades de manipulación y garantías para inmovilizar los postizos Abstract in english The main aim of this work was the design of an injection mould with the purpose of preparing test specimens, using a new system of interchangeable and sliding cavities. The proposed mould is able to hold inserts able to, manufacture the individualized test specimen by injection moulding. Nowadays, t [...] he trend toward the design of moulds with interchangeable cavities intended for easing the process of obtaining diverse plastic parts in the same mould, present the characteristic of fixing the system of plates by means of several screws. This system presents important drawback, at the moment of a rapid change of them, like the trend of having to make a great manual effort and to spend considerable amount of time. The present work presents the design of a mould with sliding and interchangeable cavities, under ASTM 6141 and ISO 294-1 norms. The design of two interchangeable and sliding cavities is developed: one with the purpose of producing tensile test specimen and the other for manufacturing rectangular bars (for flexion or impact tests). In order to shape and validate the designed mold and the proposed cavities, the Pro/ENGINEER and C-MOLD software were used. Two preliminary designs were formulated considering horizontal or vertical possible movements of the interchangeable cavities in the system of plates of the injection mould. The comparative evaluation of the advantages and disadvantages of every mould favoured the horizontal system, due to its operational facility associated with the guaranty of an easy manipulation and immobilization of cavities

  14. Thermal and mechanical properties of injection molded recycled high density polyethylene blends with virgin isotactic polypropylene

    International Nuclear Information System (INIS)

    Highlights: ? Recycled high density polyethylene and isotactic polypropylene blends have been prepared by melt compounding. ? Thermal study showed that iPP is not well dispersed into the rHDPE matrix. ? Tensile testing shows that there is strong correlation between the thermal properties and the tensile behavior of rHDPE/ipp blends. - Abstract: Polymer blending has become an important field in polymer research and especially in the area of recycling. In this research the target was to reduce the polymer waste problem. Therefore, recycled high density polyethylene (rHDPE) and virgin isotactic polypropylene (vPP) blends containing upto 30 wt% of vPP have been prepared by melt compounding method using injection molding at 220 °C. The thermal properties, thermal degradation and the mechanical properties of the polymer blends were studied using differential scanning calorimetry (DSC), Thermogravimetric analysis (TGA), and tensile testing method. DSC study shows that in all the blends there are two melting peaks, one around the melting temperature of rHDPE and another one around the melting point of vPP, indicating that vPP is not well dispersed into the rHDPE matrix. The changes in the heat of fusion for the rHDPE/iPP polymer blends versus vPP content suggests that incorporating vPP affects the crystallinity of the system. TGA analysis of the polymer blends shows that parts of rHDPE with 95/5 upto 80/20 of vPP are mostly stable composition which brings about valuable stabilization to the rHDPE. Tensile testing shows that there is strong correlation between the thermal properties and the tensile behavior of rHDPE/vpp blends

  15. Tribological and mechanical performance evaluation of metal prosthesis components manufactured via metal injection molding.

    Science.gov (United States)

    Melli, Virginia; Juszczyk, Mateusz; Sandrini, Enrico; Bolelli, Giovanni; Bonferroni, Benedetta; Lusvarghi, Luca; Cigada, Alberto; Manfredini, Tiziano; De Nardo, Luigi

    2015-01-01

    The increasing number of total joint replacements, in particular for the knee joint, has a growing impact on the healthcare system costs. New cost-saving manufacturing technologies are being explored nowadays. Metal injection molding (MIM) has already demonstrated its suitability for the production of CoCrMo alloy tibial trays, with a significant reduction in production costs, by holding both corrosion resistance and biocompatibility. In this work, mechanical and tribological properties were evaluated on tibial trays obtained via MIM and conventional investment casting. Surface hardness and wear properties were evaluated through Vickers hardness, scratch and pin on disk tests. The MIM and cast finished tibial trays were then subjected to a fatigue test campaign in order to obtain their fatigue load limit at 5 millions cycles following ISO 14879-1 directions. CoCrMo cast alloy exhibited 514 HV hardness compared to 335 HV of MIM alloy, furthermore it developed narrower scratches with a higher tendency towards microploughing than microcutting, in comparison to MIM CoCrMo. The observed fatigue limits were (1,766 ± 52) N for cast tibial trays and (1,625 ± 44) N for MIM ones. Fracture morphologies pointed out to a more brittle behavior of MIM microstructure. These aspects were attributed to the absence of a fine toughening and surface hardening carbide dispersion in MIM grains. Nevertheless, MIM tibial trays exhibited a fatigue limit far beyond the 900 N of maximum load prescribed by ISO and ASTM standards for the clinical application of these devices. PMID:25577214

  16. Analysis of Optimal Injection Moulding Process Parameters for Thin-Shell Plastic Product Using Response Surface Methodology

    OpenAIRE

    Awang Bono; Jumat Sulaiman; S. Rajalingam

    2014-01-01

    The injection molding process is used to produce thin-walled plastic products for a wide variety of applications. However, the difficulty in adjusting optimum process parameters setting may cause defects on injected moulded parts such as shrinkage. A study was conducted for the determination of the optimal injection moulding process parameters which will minimize the shrinkage defect on a thin-shell plastic product for cell phone housing component. The machine process setting in use currently...

  17. A novel injection-molded capsular device for oral pulsatile delivery based on swellable/erodible polymers.

    Science.gov (United States)

    Gazzaniga, Andrea; Cerea, Matteo; Cozzi, Alberto; Foppoli, Anastasia; Maroni, Alessandra; Zema, Lucia

    2011-03-01

    The feasibility of injection molding was explored in the preparation of a novel capsular device for oral pulsatile/delayed delivery based on swellable/erodible polymers. For this purpose, a mold intended to be coupled with a bench-top injection-molding press was designed. This was expected to enable the preparation of matching capsule cap and body items within a single manufacturing cycle and the selection of differing shell thicknesses (300, 600, and 900 ?m). Hydroxypropylcellulose (Klucel(®) EF, LF, and GF) was employed as the release-controlling polymer in admixture with polyethylene glycol 1500 (10%, w/w) as the plasticizer. After preliminary trials aimed at the setup of operating conditions, Klucel(®) EF and LF capsule shells with satisfactory technological properties were manufactured. The performance of capsular devices filled with a tracer drug powder was studied by means of a modified USP31 disintegration apparatus. Typical in vitro delayed release patterns were thereby obtained, with lag time increasing as a function of the wall thickness. A good correlation was found between the latter parameter and t (10%), i.e., the time to 10% release, for both polymer grades employed. On the basis of the overall results, the investigated technique was proven suitable for the manufacturing of an innovative pulsatile release platform. PMID:21267684

  18. Bi-composite sandwich moldings: processing, mechanical performance and bioactive behavior.

    Science.gov (United States)

    Sousa, R A; Oliveira, A L; Reis, R L; Cunha, A M; Bevis, M J

    2003-05-01

    Two composite systems composed of high-density polyethylene (HDPE) filled with hydroxyapatite (HA) and carbon fiber (C fiber) were compounded in a co-rotating twin screw extruder and subsequently molded in a two component injection molding machine in order to produce test bars with a sandwich-like morphology. These moldings are based on a HDPE/HA composite outer layer and a HDPE/C fiber composite core. The mechanical performance of the obtained specimens was assessed by tensile and impact testing. The fracture surfaces were observed by scanning electron microscopy (SEM) and optical reflectance microscopy was used to characterize the morphology within the moldings. In order to study the bioactivity of the molded specimens, the samples were immersed for different periods of time up to 30 days in a simulated-body fluid (SBF) with an ion composition similar to human blood plasma. After each immersion period, the surfaces of the specimens were characterized by SEM. The chemical composition and the structure of the deposited films were studied by electron dispersive spectroscopy (EDS) and thin-film X-ray diffraction (TF-XRD). The evolution of the elemental concentrations in the SBF solution was determined by induced coupled plasma emission (ICP) spectroscopy. Bi-composite moldings featuring a sandwich-like morphology were successfully produced. These moldings present a high stiffness as a result of the C fiber reinforcement present in the molding core. Furthermore, as a result of the HA loading, the sandwich moldings exhibit a clear in vitro bioactive behavior under simulated physiological conditions, which indicates that an in vivo bone-bonding behavior can be expected for these materials. PMID:15348441

  19. Moldagem por injeção de pós cerâmicos: remoção da parafina e do polipropileno utilizados como veículo orgânico / Ceramic injection molding: removal of pafafin and polypropylene used as organic binder

    Scientific Electronic Library Online (English)

    Ricardo V. B., Oliveira; Eduardo A., Pinheiro; Valdir, Soldi; Alfredo T. N., Pires; Márcio C., Fredel.

    2004-09-01

    Full Text Available A moldagem por injeção de pós cerâmicos tem se tornado um processo altamente atrativo por aliar a versatilidade e a produtividade da moldagem por injeção convencional às propriedades inerentes aos materiais cerâmicos. A remoção do ligante, usado como veículo orgânico nesse processo, é uma das etapas [...] críticas para a produção de peças cerâmicas sem defeitos. Neste trabalho avaliou-se a influência da geometria das peças injetadas na remoção do ligante, tanto por imersão em solvente como por decomposição térmica. Alumina em pó foi misturada fisicamente a um ligante composto por polipropileno [PP], parafina [PW] e ácido esteárico [AE]. As peças com diferentes geometrias foram mantidas imersas em hexano, secas sob vácuo e acompanhada a variação de massa devido à solubilização do PW e AE. A determinação da porosidade das peças, realizada por meio das isotermas de adsorção/desorção de nitrogênio, mostrou um aumento de porosidade de 0,5% volume para aproximadamente 20% volume após a imersão em solvente. A remoção térmica do PP remanescente produziu hidrocarbonetos alifáticos e compostos insaturados, determinados e quantificados por espectroscopia de infravermelho, que permearam a estrutura porosa da peça. A geometria das peças tem grande influência na remoção do ligante, podendo afetar não só a qualidade do produto final, mas também as etapas subseqüentes do processo. Abstract in english Powder injection molding [PIM] has become highly attractive as it combines the versatility and productivity of conventional injection molding processes with the intrinsic properties of metallic and ceramic materials. The removal of organic binder, used as vehicles during the process, is one of the m [...] ost critical stages in the production of ceramic devices in this process. In this work, the influence from the geometry of the injected part on the removal of the organic binder was evaluated for both solvent immersion and thermal degradation processes. Alumina powder was mixed with an organic binder, comprising polypropylene [PP], paraffin wax [PW] and stearic acid [SA], and injection molded in different geometries. Immersion of ceramic parts in hexane induced the solubilization of PW and SA, confirmed by weight variation. Parts porosity, determined through nitrogen adsorption isotherm, showed an increase from 0.5 v% before immersion to ca. 20 v% after immersion. PP burnout produced aliphatic hydrocarbons and unsaturated compounds that flow through a porous structure produced in early stages of this process. Parts geometry plays an important role in binder removal, affecting the quality of the sintered part as well as the remaining stages of the process.

  20. Moldagem por injeção de pós cerâmicos: remoção da parafina e do polipropileno utilizados como veículo orgânico Ceramic injection molding: removal of pafafin and polypropylene used as organic binder

    Directory of Open Access Journals (Sweden)

    Ricardo V. B. Oliveira

    2004-09-01

    Full Text Available A moldagem por injeção de pós cerâmicos tem se tornado um processo altamente atrativo por aliar a versatilidade e a produtividade da moldagem por injeção convencional às propriedades inerentes aos materiais cerâmicos. A remoção do ligante, usado como veículo orgânico nesse processo, é uma das etapas críticas para a produção de peças cerâmicas sem defeitos. Neste trabalho avaliou-se a influência da geometria das peças injetadas na remoção do ligante, tanto por imersão em solvente como por decomposição térmica. Alumina em pó foi misturada fisicamente a um ligante composto por polipropileno [PP], parafina [PW] e ácido esteárico [AE]. As peças com diferentes geometrias foram mantidas imersas em hexano, secas sob vácuo e acompanhada a variação de massa devido à solubilização do PW e AE. A determinação da porosidade das peças, realizada por meio das isotermas de adsorção/desorção de nitrogênio, mostrou um aumento de porosidade de 0,5% volume para aproximadamente 20% volume após a imersão em solvente. A remoção térmica do PP remanescente produziu hidrocarbonetos alifáticos e compostos insaturados, determinados e quantificados por espectroscopia de infravermelho, que permearam a estrutura porosa da peça. A geometria das peças tem grande influência na remoção do ligante, podendo afetar não só a qualidade do produto final, mas também as etapas subseqüentes do processo.Powder injection molding [PIM] has become highly attractive as it combines the versatility and productivity of conventional injection molding processes with the intrinsic properties of metallic and ceramic materials. The removal of organic binder, used as vehicles during the process, is one of the most critical stages in the production of ceramic devices in this process. In this work, the influence from the geometry of the injected part on the removal of the organic binder was evaluated for both solvent immersion and thermal degradation processes. Alumina powder was mixed with an organic binder, comprising polypropylene [PP], paraffin wax [PW] and stearic acid [SA], and injection molded in different geometries. Immersion of ceramic parts in hexane induced the solubilization of PW and SA, confirmed by weight variation. Parts porosity, determined through nitrogen adsorption isotherm, showed an increase from 0.5 v% before immersion to ca. 20 v% after immersion. PP burnout produced aliphatic hydrocarbons and unsaturated compounds that flow through a porous structure produced in early stages of this process. Parts geometry plays an important role in binder removal, affecting the quality of the sintered part as well as the remaining stages of the process.

  1. Die-sinking electrical discharge machining of a high-strength copper-based alloy for injection molds

    Directory of Open Access Journals (Sweden)

    F. L. Amorim

    2004-06-01

    Full Text Available High-strength copper alloys are used as materials for injection molding tools or as cores and inserts in steel molds because of their high thermal conductivity, corrosion and wear resistance. Unfortunately, there is little technological knowledge on the electrical discharge machining (EDM of copper-beryllium ASTM C17200 alloy. In this work, rough and finish machining conditions were tested using copper and tungsten-copper as materials for the electrodes. Cross-sectional micrographic and hardness examinations as well as surface roughness measurements were also carried out on workpieces after machining in order to study the thermally affected zones. Appropriate parameters settings for EDM of the investigated alloy are suggested.

  2. Die-sinking electrical discharge machining of a high-strength copper-based alloy for injection molds

    Scientific Electronic Library Online (English)

    F. L., Amorim; W. L., Weingaertner.

    2004-06-01

    Full Text Available High-strength copper alloys are used as materials for injection molding tools or as cores and inserts in steel molds because of their high thermal conductivity, corrosion and wear resistance. Unfortunately, there is little technological knowledge on the electrical discharge machining (EDM) of copper [...] -beryllium ASTM C17200 alloy. In this work, rough and finish machining conditions were tested using copper and tungsten-copper as materials for the electrodes. Cross-sectional micrographic and hardness examinations as well as surface roughness measurements were also carried out on workpieces after machining in order to study the thermally affected zones. Appropriate parameters settings for EDM of the investigated alloy are suggested.

  3. Analysis of the resin transfer molding (RTM) process for FRP and its process simulation fundamentals

    Science.gov (United States)

    Caba, S.; Koch, M.

    2015-05-01

    The industrialization of the resin transfer molding process is a major objective in reducing production cost for FRPs thus making it more competitive for use in large scale applications. Normally, shorter cycle times run into the risk of quality inconsistencies. The creation of voids is influenced by various process parameters, such as mold temperature, resin flow rate and fiber volume content. With knowledge of the effects of these parameters on the process, a specific approach to reducing void content is made while reducing processing time. In order to achieve this objective, in particular, capillary forces and its influence on impregnation of the fiber bundle were examined. A DOE approach was chosen to lead to the determination of interactions. The results target at a pre-determination of required process parameter to obtain consistent part quality with reduced cycle time.

  4. Modeling of Initial Mold Filling in Uphill Teeming Process Considering a Trumpet

    OpenAIRE

    Tan, Zhe

    2012-01-01

    The flow pattern in the uphill teeming process has been found to be closely related to the quality of ingots and further to affect the yield of ingot production, which is crucial for the steel making process. The formation of non-metallic inclusion and entrapment of mold flux has been considered to be affected by the flow pattern in the gating system and molds by many previous researchers. The aim of this study is to investigate the flow pattern of steel in the gating system and molds during ...

  5. Moldes de ABS construídos pelo processo de modelagem por fusão e deposição para injeção de PP e PEBD PP and LDPE injection in ABS molds built with fused deposition modeling

    Directory of Open Access Journals (Sweden)

    José A. Foggiatto

    2004-12-01

    Full Text Available Os processos de prototipagem rápida (Rapid Prototyping - RP e ferramental rápido (Rapid Tooling - RT surgiram para reduzir os tempos de desenvolvimento de produtos na fase de projeto diminuindo a necessidade de retrabalhos e, conseqüentemente, antecipando a entrada de novos produtos no mercado. Neste trabalho foi utilizada uma das tecnologias de prototipagem rápida, denominada Modelagem por Fusão e Deposição (FDM, na construção de moldes em ABS com o objetivo de investigar sua aplicação na moldagem por injeção de termoplásticos. Amostras das peças injetadas foram submetidas a ensaios de difração de raios X, dureza Shore D e tração. Os resultados mostraram a viabilidade de fabricar pequenos lotes de peças em PEBD e PP com propriedades mecânicas bastante similares às encontradas em peças moldadas em moldes metálicos.Rapid Prototyping and Rapid Tooling are aimed at reducing the development time of products in the design phase by minimizing re-workings and, consequently, reducing the time to launch new products. In this work one of the technologies of rapid prototyping, called Fused Deposition Modeling (FDM, was used in the construction of ABS molds with the objective of investigating its application in the injection molding of thermoplastics. Specimens of the molded parts were characterized with X-ray diffraction, Shore D hardness and tensile tests. The results demonstrated the viability to manufacture small batches of LDPE and PP parts with mechanical properties similar to those molded parts in metallic molds.

  6. Moldes de ABS construídos pelo processo de modelagem por fusão e deposição para injeção de PP e PEBD / PP and LDPE injection in ABS molds built with fused deposition modeling

    Scientific Electronic Library Online (English)

    José A., Foggiatto; Carlos H., Ahrens; Gean V., Salmoria; Alfredo T. N., Pires.

    2004-12-01

    Full Text Available Os processos de prototipagem rápida (Rapid Prototyping - RP) e ferramental rápido (Rapid Tooling - RT) surgiram para reduzir os tempos de desenvolvimento de produtos na fase de projeto diminuindo a necessidade de retrabalhos e, conseqüentemente, antecipando a entrada de novos produtos no mercado. Ne [...] ste trabalho foi utilizada uma das tecnologias de prototipagem rápida, denominada Modelagem por Fusão e Deposição (FDM), na construção de moldes em ABS com o objetivo de investigar sua aplicação na moldagem por injeção de termoplásticos. Amostras das peças injetadas foram submetidas a ensaios de difração de raios X, dureza Shore D e tração. Os resultados mostraram a viabilidade de fabricar pequenos lotes de peças em PEBD e PP com propriedades mecânicas bastante similares às encontradas em peças moldadas em moldes metálicos. Abstract in english Rapid Prototyping and Rapid Tooling are aimed at reducing the development time of products in the design phase by minimizing re-workings and, consequently, reducing the time to launch new products. In this work one of the technologies of rapid prototyping, called Fused Deposition Modeling (FDM), was [...] used in the construction of ABS molds with the objective of investigating its application in the injection molding of thermoplastics. Specimens of the molded parts were characterized with X-ray diffraction, Shore D hardness and tensile tests. The results demonstrated the viability to manufacture small batches of LDPE and PP parts with mechanical properties similar to those molded parts in metallic molds.

  7. Desenvolvimento de liga sinterizada de níquel por moldagem de pós por injeção / Development of sintered nickel alloy by powder injection molding

    Scientific Electronic Library Online (English)

    Moisés Luiz, Parucker; Aloisio Nelmo, Klein; Roberto, Binder.

    2014-09-01

    Full Text Available A moldagem de pós por injeção é um processo de fabricação de elevada produtividade que possibilita obter componentes de geometria complexa, estreita precisão dimensional e boas propriedades mecânicas. Neste processo, uma mistura de uma determinada quantidade de pós e ligantes orgânicos (polímeros, c [...] eras e óleos) é obtida por meio de uma massa de injeção (feedstock) o qual tem características reológicas adequadas para promover a injeção desta massa em uma cavidade de um molde. A produção de ligas de níquel por meio deste processo é uma alternativa para produção de produtos que requerem aplicações avançadas onde se exige resistência a corrosão e oxidação, resistência mecânica a altas temperaturas e baixo coeficiente de atrito. Neste trabalho apresentamos um estudo das propriedades microestruturais e mecânicas de uma liga de níquel (Ni-Fe-Cr-P) processada via moldagem de pós por injeção, utilizando pós de níquel carbonila com e sem a presença de fase líquida durante a sinterização. Os resultados foram comparados com a mesma liga processada por compactação de pós. Os resultados demonstraram a necessidade de maior quantidade de matéria orgânica para o desenvolvimento da massa de injeção (feedstock: 15% m/m de polímero) para os tipos de pós metálicos utilizados (níquel carbonila do tipo INCO 123) se comparado ao feedstock de ligas comerciais que normalmente utilizam uma quantidade menor de matéria orgânica (feedstock: 9% m/m de polímero). A maior quantidade de matéria orgânica necessária para a preparação do feedstock deve-se a morfologia dos pós empregados (superficie rugosa - tipo spiky) que promove retenção de carbono durante o processo de extração, ocasionando a necessidade de otimização do ciclo de extração térmica e sinterização. Ciclos mais lentos e a baixa temperatura promoveram a total retirada dos ligantes. A liga de Ni-Fe-Cr-P injetada apresentou contração de aproximadamente 50%, além de elevado teor de poros quando comparado ao material compactado, o que influenciou as propriedades mecânicas e dureza aparente do material. Abstract in english The powder injection molding is a manufacturing process that allows high productivity to obtain complex geometry components, dimensional accuracy and good mechanical properties. In this process, a mixture of a quantity of powders and organic binders (polymers, waxes, oils) is obtained through inject [...] ion of a mass (feedstock) which has rheological properties suitable for promoting the injection of this mass in a cavity of a mold. The production of nickel alloy by this process is an alternative to production of products that require advanced applications, which require resistance to corrosion and oxidation, mechanical strength at high temperatures and low coefficient of friction. This paper we present the study of the microstructural and mechanical properties of a nickel alloy (Ni-Fe-Cr-P) processed by powder injection molding, using carbonyl nickel powders with and without the presence of liquid phase during sintering. The results are compared with the alloy processed by powder compaction. The results demonstrate the need for increased amount of organic matter for developing the injection mass (feedstock: 15 wt.% polymer) for the types of metallic powders used (nickel INCO type 123 carbonyl) compared to commercial alloy feedstock typically use a smaller amount of organic matter (feedstock: 9 wt.% polymer). The largest quantity of organic matter needed for the preparation of the feedstock due to the morphology of the powders used (spiky) which promoted carbon retention during the extraction process, resulting in the need to optimize the extraction cycle and thermal sintering. Slower cycles and low temperature promoted the complete extraction of the ligands. The Ni-Fe-Cr-P alloy injected showed shrinkage of approximately 50%, and high levels of pores as compared to the compacted material, which influenced the mechanical properties and apparent hardness of the material.

  8. Effect of mold rotation on inclusion distribution in bearing steel during electroslag remelting process

    OpenAIRE

    Chang Lizhong; Shi Xiaofang; Wang Runxi

    2014-01-01

    To remove the inclusions in the ingots by conventional electroslag remelting (ESR), the bearing steel was prepared using ESR process but with mold rotation in this study. Experimental results show a reduction in amount of large inclusions when the mold rotation rate is 6 r·min-1, and the inclusions are uniformly distributed in the ESR ingot. As comparison with the electroslag ingots of conventional ESR (stationary mold), the portion of the Al2O3 inclusions smaller than 1 ?m in size increase...

  9. Fabrication of combined-scale nano- and microfluidic polymer systems using a multilevel dry etching, electroplating and molding process

    DEFF Research Database (Denmark)

    Tanzi, Simone; Østergaard, Peter Friis

    2012-01-01

    Microfabricated single-cell capture and DNA stretching devices have been produced by injection molding. The fabrication scheme employed deep reactive ion etching in a silicon substrate, electroplating in nickel and molding in cyclic olefin polymer. This work proposes technical solutions to fabrication challenges associated with chip sealing and demolding of polymer high-volume replication methods. UV-assisted thermal bonding was found to ensure a strong seal of the microstructures in the molded part without altering the geometry of the channels. In the DNA stretching device, a low aspect ratio nanoslit (1/200) connecting two larger micro-channels was used to stretch a 168.5 kbp DNA molecule, while in the other device single-HeLa cells were captured against a micro-aperture connecting two larger microfluidic channels. Different dry etching processes have been investigated for the master origination of the cell-capture device. The combination of a modified Bosch process and an isotropic polysilicon etch was found to ensure the ease of demolding by resulting in slightly positively tapered sidewalls with negligible undercut at the mask interface.

  10. Liquid composite molding-processing and characterization of fiber-reinforced composites modified with carbon nanotubes

    Science.gov (United States)

    Zeiler, R.; Khalid, U.; Kuttner, C.; Kothmann, M.; Dijkstra, D. J.; Fery, A.; Altstädt, V.

    2014-05-01

    The increasing demand in fiber-reinforced plastics (FRPs) necessitates economic processing of high quality, like the vacuum-assisted resin transfer molding (VARTM) process. FRPs exhibit excellent in-plane properties but weaknesses in off-plane direction. The addition of nanofillers into the resinous matrix phase embodies a promising approach due to benefits of the nano-scaled size of the filler, especially its high surface and interface areas. Carbon nanotubes (CNTs) are preferable candidates for resin modification in regard of their excellent mechanical properties and high aspect ratios. However, especially the high aspect ratios give rise to withholding or filtering by fibrous fabrics during the impregnation process, i.e. length dependent withholding of tubes (short tubes pass through the fabric, while long tubes are restrained) and a decrease in the local CNT content in the laminate along the flow path can occur. In this study, hybrid composites containing endless glass fiber reinforcement and surface functionalized CNTs dispersed in the matrix phase were produced by VARTM. New methodologies for the quantification of the filtering of CNTs were developed and applied to test laminates. As a first step, a method to analyze the CNT length distribution before and after injection was established for thermosetting composites to characterize length dependent withholding of nanotubes. The used glass fiber fabric showed no perceptible length dependent retaining of CNTs. Afterward, the resulting test laminates were examined by Raman spectroscopy and compared to reference samples of known CNT content. This Raman based technique was developed further to assess the quality of the impregnation process and to quantitatively follow the local CNT content along the injection flow in cured composites. A local decline in CNT content of approx. 20% was observed. These methodologies allow for the quality control of the filler content and size-distribution in CNT based hybrid composites.

  11. Silane based coating of aluminium mold

    DEFF Research Database (Denmark)

    Cech, Jiri Technical University of Denmark,

    A method of preparing an aluminum mold for injection molding is provided, the method comprises the steps of providing an aluminum mold having a least one surface, subjecting the at least one surface to a gas or liquid phase silane to thereby form an anti-stiction coating, the anti-stiction coating comprising a chemically bonded monolayer of silane compounds on the at least one surface wherein the silane is a halogenated silane. The at least one surface coated with the anti-stiction coating may be configured to withstand an injection molding process at a pressure above 100 MPa. Furthermore, a mold having at least one closed cavity is provided, at least one surface of the at least one cavity being an aluminium surface coated with a silane based coating layer. The silane based anti-stiction coating improves the anti-stiction properties of the mold which may allow for molding and demolding of structures which would otherwise be difficult to mold. The resistance of the coated aluminium mold is significantly improved by applying a silane-based coating layer.

  12. Embedded fiber optic sensors for monitoring processing, quality and structural health of resin transfer molded components

    International Nuclear Information System (INIS)

    Due to their small size and flexibility fiber optics can be embedded into composite materials with little negative effect on strength and reliability of the host material. Fiber optic sensors such as Fiber Bragg Gratings (FBG) or Etched Fiber Sensors (EFS) can be used to detect a number of relevant parameters such as flow, degree of cure, quality and structural health throughout the life of a composite component. With a detection algorithm these embedded sensors can be used to detect damage in real time while the component remains in service. This paper presents the research being conducted on the use of fiber optic sensors for process and Structural Health Monitoring (SHM) of Resin Transfer Molded (RTM) composite structures. Fiber optic sensors are used at all life stages of an RTM composite panel. A laboratory scale RTM apparatus was developed with the capability of visually monitoring the resin filling process. A technique for embedding fiber optic sensors with this apparatus has also been developed. Both FBGs and EFSs have been embedded in composite panels using the apparatus. EFSs to monitor the fabrication process, specifically resin flow have been embedded and shown to be capable of detecting the presence of resin at various locations as it is injected into the mold. Simultaneously these sensors were multiplexed on the same fiber with FBGs, which have the ability to measure strain. Since multiple sensors can be multiplexed on a single fiber the number of ingresxed on a single fiber the number of ingress/egress locations required per sensor can be significantly reduced. To characterize the FBGs for strain detection tensile test specimens with embedded FBG sensors have been produced. These specimens have been instrumented with a resistive strain gauge for benchmarking. Both specimens and embedded sensors were characterized through tensile testing. Furthermore FBGs have been embedded into composite panels in a manner that is conducive to detection of Lamb waves generated with a centrally located PZT. To sense Lamb waves a high speed, high precision sensing technique is required to acquire data from embedded FBGs due to the high velocities and small strain amplitudes of these guided waves. A technique based on a filter consisting of a tunable FBG was developed. Since this filter is not dependant on moving parts, tests executed with this filter concluded with the detection of Lamb waves, removing the influence of temperature and operational strains. A damage detection algorithm was developed to detect and localize cracks and delaminations.

  13. Embedded fiber optic sensors for monitoring processing, quality and structural health of resin transfer molded components

    Science.gov (United States)

    Keulen, C.; Rocha, B.; Yildiz, M.; Suleman, A.

    2011-07-01

    Due to their small size and flexibility fiber optics can be embedded into composite materials with little negative effect on strength and reliability of the host material. Fiber optic sensors such as Fiber Bragg Gratings (FBG) or Etched Fiber Sensors (EFS) can be used to detect a number of relevant parameters such as flow, degree of cure, quality and structural health throughout the life of a composite component. With a detection algorithm these embedded sensors can be used to detect damage in real time while the component remains in service. This paper presents the research being conducted on the use of fiber optic sensors for process and Structural Health Monitoring (SHM) of Resin Transfer Molded (RTM) composite structures. Fiber optic sensors are used at all life stages of an RTM composite panel. A laboratory scale RTM apparatus was developed with the capability of visually monitoring the resin filling process. A technique for embedding fiber optic sensors with this apparatus has also been developed. Both FBGs and EFSs have been embedded in composite panels using the apparatus. EFSs to monitor the fabrication process, specifically resin flow have been embedded and shown to be capable of detecting the presence of resin at various locations as it is injected into the mold. Simultaneously these sensors were multiplexed on the same fiber with FBGs, which have the ability to measure strain. Since multiple sensors can be multiplexed on a single fiber the number of ingress/egress locations required per sensor can be significantly reduced. To characterize the FBGs for strain detection tensile test specimens with embedded FBG sensors have been produced. These specimens have been instrumented with a resistive strain gauge for benchmarking. Both specimens and embedded sensors were characterized through tensile testing. Furthermore FBGs have been embedded into composite panels in a manner that is conducive to detection of Lamb waves generated with a centrally located PZT. To sense Lamb waves a high speed, high precision sensing technique is required to acquire data from embedded FBGs due to the high velocities and small strain amplitudes of these guided waves. A technique based on a filter consisting of a tunable FBG was developed. Since this filter is not dependant on moving parts, tests executed with this filter concluded with the detection of Lamb waves, removing the influence of temperature and operational strains. A damage detection algorithm was developed to detect and localize cracks and delaminations.

  14. Embedded fiber optic sensors for monitoring processing, quality and structural health of resin transfer molded components

    Energy Technology Data Exchange (ETDEWEB)

    Keulen, C; Rocha, B; Suleman, A [University of Victoria, Department of Mechanical Engineering, PO Box 3055, Stn. CSC, Victoria, B.C., V8W 3P6 (Canada); Yildiz, M, E-mail: suleman@uvic.ca [Sabanci University, Faculty of Engineering and Natural Sciences, Orhanli - Tuzla, 34956, Istanbul (Turkey)

    2011-07-19

    Due to their small size and flexibility fiber optics can be embedded into composite materials with little negative effect on strength and reliability of the host material. Fiber optic sensors such as Fiber Bragg Gratings (FBG) or Etched Fiber Sensors (EFS) can be used to detect a number of relevant parameters such as flow, degree of cure, quality and structural health throughout the life of a composite component. With a detection algorithm these embedded sensors can be used to detect damage in real time while the component remains in service. This paper presents the research being conducted on the use of fiber optic sensors for process and Structural Health Monitoring (SHM) of Resin Transfer Molded (RTM) composite structures. Fiber optic sensors are used at all life stages of an RTM composite panel. A laboratory scale RTM apparatus was developed with the capability of visually monitoring the resin filling process. A technique for embedding fiber optic sensors with this apparatus has also been developed. Both FBGs and EFSs have been embedded in composite panels using the apparatus. EFSs to monitor the fabrication process, specifically resin flow have been embedded and shown to be capable of detecting the presence of resin at various locations as it is injected into the mold. Simultaneously these sensors were multiplexed on the same fiber with FBGs, which have the ability to measure strain. Since multiple sensors can be multiplexed on a single fiber the number of ingress/egress locations required per sensor can be significantly reduced. To characterize the FBGs for strain detection tensile test specimens with embedded FBG sensors have been produced. These specimens have been instrumented with a resistive strain gauge for benchmarking. Both specimens and embedded sensors were characterized through tensile testing. Furthermore FBGs have been embedded into composite panels in a manner that is conducive to detection of Lamb waves generated with a centrally located PZT. To sense Lamb waves a high speed, high precision sensing technique is required to acquire data from embedded FBGs due to the high velocities and small strain amplitudes of these guided waves. A technique based on a filter consisting of a tunable FBG was developed. Since this filter is not dependant on moving parts, tests executed with this filter concluded with the detection of Lamb waves, removing the influence of temperature and operational strains. A damage detection algorithm was developed to detect and localize cracks and delaminations.

  15. In-Situ Real Time Monitoring and Control of Mold Making and Filling Processes: Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Mohamed Abdelrahman; Kenneth Currie

    2010-12-22

    This project presents a model for addressing several objectives envisioned by the metal casting industries through the integration of research and educational components. It provides an innovative approach to introduce technologies for real time characterization of sand molds, lost foam patterns and monitoring of the mold filling process. The technology developed will enable better control over the casting process. It is expected to reduce scrap and variance in the casting quality. A strong educational component is integrated into the research plan to utilize increased awareness of the industry professional, the potential benefits of the developed technology, and the potential benefits of cross cutting technologies.

  16. Characterization of thermoplastic polyurethane/polylactic acid (TPU/PLA) tissue engineering scaffolds fabricated by microcellular injection molding

    Energy Technology Data Exchange (ETDEWEB)

    Mi, Hao-Yang [National Engineering Research Center of Novel Equipment for Polymer Processing, South China University of Technology, Guangzhou (China); Department of Mechanical Engineering, University of Wisconsin–Madison, WI (United States); Salick, Max R. [Department of Engineering Physics, University of Wisconsin–Madison, WI (United States); Jing, Xin [National Engineering Research Center of Novel Equipment for Polymer Processing, South China University of Technology, Guangzhou (China); Department of Mechanical Engineering, University of Wisconsin–Madison, WI (United States); Jacques, Brianna R. [Department of Biology, University of Wisconsin–River Falls, WI (United States); Crone, Wendy C. [Department of Engineering Physics, University of Wisconsin–Madison, WI (United States); Peng, Xiang-Fang, E-mail: pmxfpeng@scut.edu.cn [National Engineering Research Center of Novel Equipment for Polymer Processing, South China University of Technology, Guangzhou (China); Turng, Lih-Sheng, E-mail: turng@engr.wisc.edu [Department of Mechanical Engineering, University of Wisconsin–Madison, WI (United States)

    2013-12-01

    Polylactic acid (PLA) and thermoplastic polyurethane (TPU) are two kinds of biocompatible and biodegradable polymers that can be used in biomedical applications. PLA has rigid mechanical properties while TPU possesses flexible mechanical properties. Blended TPU/PLA tissue engineering scaffolds at different ratios for tunable properties were fabricated via twin screw extrusion and microcellular injection molding techniques for the first time. Multiple test methods were used to characterize these materials. Fourier transform infrared spectroscopy (FTIR) confirmed the existence of the two components in the blends; differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) confirmed the immiscibility between the TPU and PLA. Scanning electron microscopy (SEM) images verified that, at the composition ratios studied, PLA was dispersed as spheres or islands inside the TPU matrix and that this phase morphology further influenced the scaffold's microstructure and surface roughness. The blends exhibited a large range of mechanical properties that covered several human tissue requirements. 3T3 fibroblast cell culture showed that the scaffolds supported cell proliferation and migration properly. Most importantly, this study demonstrated the feasibility of mass producing biocompatible PLA/TPU scaffolds with tunable microstructures, surface roughnesses, and mechanical properties that have the potential to be used as artificial scaffolds in multiple tissue engineering applications. - Highlights: • Microcellular injection molding was used to fabricate tissue engineering scaffolds. • TPU/PLA tissue engineering scaffolds with tunable properties were fabricated. • Multiple test methods were used to characterize the scaffolds. • The biocompatibility of the scaffolds was confirmed by fibroblast cell culture. • Scaffolds produced have the potential to be used in multiple tissue applications.

  17. Characterization of thermoplastic polyurethane/polylactic acid (TPU/PLA) tissue engineering scaffolds fabricated by microcellular injection molding

    International Nuclear Information System (INIS)

    Polylactic acid (PLA) and thermoplastic polyurethane (TPU) are two kinds of biocompatible and biodegradable polymers that can be used in biomedical applications. PLA has rigid mechanical properties while TPU possesses flexible mechanical properties. Blended TPU/PLA tissue engineering scaffolds at different ratios for tunable properties were fabricated via twin screw extrusion and microcellular injection molding techniques for the first time. Multiple test methods were used to characterize these materials. Fourier transform infrared spectroscopy (FTIR) confirmed the existence of the two components in the blends; differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) confirmed the immiscibility between the TPU and PLA. Scanning electron microscopy (SEM) images verified that, at the composition ratios studied, PLA was dispersed as spheres or islands inside the TPU matrix and that this phase morphology further influenced the scaffold's microstructure and surface roughness. The blends exhibited a large range of mechanical properties that covered several human tissue requirements. 3T3 fibroblast cell culture showed that the scaffolds supported cell proliferation and migration properly. Most importantly, this study demonstrated the feasibility of mass producing biocompatible PLA/TPU scaffolds with tunable microstructures, surface roughnesses, and mechanical properties that have the potential to be used as artificial scaffolds in multiple tissue engineering applications. - Highlights: • Microcellular injection molding was used to fabricate tissue engineering scaffolds. • TPU/PLA tissue engineering scaffolds with tunable properties were fabricated. • Multiple test methods were used to characterize the scaffolds. • The biocompatibility of the scaffolds was confirmed by fibroblast cell culture. • Scaffolds produced have the potential to be used in multiple tissue applications

  18. Interface conditions of two-shot molded parts

    Energy Technology Data Exchange (ETDEWEB)

    Kisslinger, Thomas, E-mail: thomas.kisslinger@pccl.at [Polymer Competence Center Leoben GmbH, 8700 Leoben (Austria); Bruckmoser, Katharina, E-mail: katharina.bruckmoser@unileoben.ac.at; Resch, Katharina, E-mail: katharina.resch@unileoben.ac.at [Department of Polymer Engineering and Science, Chair of Materials Science and Testing of Polymers, Montanuniversitaet Leoben, 8700 Leoben (Austria); Lucyshyn, Thomas, E-mail: thomas.lucyshyn@unileoben.ac.at, E-mail: guenter.langecker@unileoben.ac.at; Langecker, Guenter Ruediger, E-mail: thomas.lucyshyn@unileoben.ac.at, E-mail: guenter.langecker@unileoben.ac.at; Holzer, Clemens, E-mail: clemens.holzer@unileoben.ac.at [Department of Polymer Engineering and Science, Chair of Polymer Processing, Montanuniversitaet Leoben, 8700 Leoben (Austria)

    2014-05-15

    The focus of this work is on interfaces of two-shot molded parts. It is well known that e.g. material combination, process parameters and contact area structures show significant effects on the bond strength of multi-component injection molded parts. To get information about the bond strength at various process parameter settings and material combinations a test mold with core back technology was used to produce two-component injection molded tensile test specimens. At the core back process the different materials are injected consecutively, so each component runs through the whole injection molding cycle (two-shot process). Due to this consecutive injection molding processes, a cold interface is generated. This is defined as overmolding of a second melt to a solidified polymer preform. Strong interest lies in the way the interface conditions change during the adhesion formation between the individual components. Hence the interface conditions were investigated by computed tomography and Raman spectroscopy. By analyzing these conditions the understanding of the adhesion development during the multi-component injection molding was improved.

  19. Extruded/injection-molded composites containing unripe plantain flour, ethylene vinyl-alcohol and glycerol: Evaluation of color, mechanical property and biodegradability

    Science.gov (United States)

    Extruded/injection-molded composites were produced from plantain flour blended with ethylene vinyl-alcohol (EVA) and glycerol. Scanning electron microscopy showed composites had a smooth surface and excellent compatibility between plantain flour, EVA and glycerol. The impact of increased plantain fl...

  20. Simulative design and process optimization of the two-stage stretch-blow molding process

    Science.gov (United States)

    Hopmann, Ch.; Rasche, S.; Windeck, C.

    2015-05-01

    The total production costs of PET bottles are significantly affected by the costs of raw material. Approximately 70 % of the total costs are spent for the raw material. Therefore, stretch-blow molding industry intends to reduce the total production costs by an optimized material efficiency. However, there is often a trade-off between an optimized material efficiency and required product properties. Due to a multitude of complex boundary conditions, the design process of new stretch-blow molded products is still a challenging task and is often based on empirical knowledge. Application of current CAE-tools supports the design process by reducing development time and costs. This paper describes an approach to determine optimized preform geometry and corresponding process parameters iteratively. The wall thickness distribution and the local stretch ratios of the blown bottle are calculated in a three-dimensional process simulation. Thereby, the wall thickness distribution is correlated with an objective function and preform geometry as well as process parameters are varied by an optimization algorithm. Taking into account the correlation between material usage, process history and resulting product properties, integrative coupled simulation steps, e.g. structural analyses or barrier simulations, are performed. The approach is applied on a 0.5 liter PET bottle of Krones AG, Neutraubling, Germany. The investigations point out that the design process can be supported by applying this simulative optimization approach. In an optimization study the total bottle weight is reduced from 18.5 g to 15.5 g. The validation of the computed results is in progress.

  1. Investigations on Void Formation in Composite Molding Processes and Structural Damping in Fiber-Reinforced Composites with Nanoscale Reinforcements

    Science.gov (United States)

    DeValve, Caleb Joshua

    Fiber-reinforced composites (FRCs) offer a stronger and lighter weight alternative to traditional materials used in engineering components such as wind turbine blades and rotorcraft structures. Composites for these applications are often fabricated using liquid molding techniques, such as injection molding or resin transfer molding. One significant issue during these processing methods is void formation due to incomplete wet-out of the resin within the fiber preform, resulting in discontinuous material properties and localized failure zones in the material. A fundamental understanding of the resin evolution during processing is essential to designing processing conditions for void-free filling, which is the first objective of the dissertation. Secondly, FRCs used in rotorcraft experience severe vibrational loads during service, and improved damping characteristics of the composite structure are desirable. To this end, a second goal is to explore the use of matrix-embedded nanoscale reinforcements to augment the inherent damping capabilities in FRCs. The first objective is addressed through a computational modeling and simulation of the infiltrating dual-scale resin flow through the micro-architectures of woven fibrous preforms, accounting for the capillary effects within the fiber bundles. An analytical model is developed for the longitudinal permeability of flow through fibrous bundles and applied to simulations which provide detailed predictions of local air entrapment locations as the resin permeates the preform. Generalized design plots are presented for predicting the void content and processing time in terms of the Capillary and Reynolds Numbers governing the molding process. The second portion of the research investigates the damping enhancement provided to FRCs in static and rotational configurations by different types and weight fractions of matrix-embedded carbon nanotubes (CNTs) in high fiber volume fraction composites. The damping is measured using dynamic mechanical analysis (DMA) and modal analysis techniques, and the results show that the addition of CNTs can increase the material damping by up to 130%. Numerical simulations are conducted to explore the CNT vibration damping effects in rotating composite structures, and demonstrate that the vibration settling times and the maximum displacement amplitudes of the different structures may be reduced by up to 72% and 50%, respectively, with the addition of CNTs.

  2. High solid loading aqueous base metal/ceramic feedstock for injection molding

    Science.gov (United States)

    Behi, Mohammad

    2001-07-01

    Increasing volume fraction of metal powder in feedstock provided lower shrinkage. Reduction of the shrinkage results in better dimensional precision. The rheology of the feedstock material plays an important role to allowing larger volume fractions of the metal powder to be incorporated in the feedstock formulations. The viscosity of the feedstock mainly depends on the binder viscosity, powder volume fraction and characteristics of metal powder. Aqueous polysaccharide agar was used as a baseline binder system for this study. The effect of several gel-strengthening additives on 1.5wt% and 2wt% agar gel was evaluated. A new gel-strengthening additive was found to be the most effective among the others. The effect of other additives such as glucose, sucrose and fructose on viscosity of baseline binder and feedstock was investigated. Two new agar based binder compositions were developed. The use of these new binder formulations significantly improved the volume fraction of the metal powder, the stability of the feedstock, and reduced the final shrinkage of the molded articles. Two types of 17-4PH stainless steel metal powders, one gas atomized and, the other water atomized, were used for this research.

  3. Survey of molds, yeast and Alicyclobacillus spp. from a concentrated apple juice productive process.

    Science.gov (United States)

    de Cássia Martins Salomão, Beatriz; Muller, Chalana; do Amparo, Hudson Couto; de Aragão, Gláucia Maria Falcão

    2014-01-01

    Bacteria and molds may spoil and/or contaminate apple juice either by direct microbial action or indirectly by the uptake of metabolites as off-flavours and toxins. Some of these microorganisms and/or metabolites may remain in the food even after extensive procedures. This study aim to identify the presence of molds (including heat resistant species) and Alicyclobacillus spp., during concentrated apple juice processing. Molds were isolated at different steps and then identified by their macroscopic and microscopic characteristics after cultivation on standard media at 5, 25 and 37 °C, during 7 days. Among the 19 isolated found, 63% were identified as Penicillium with 50% belonging to the P. expansum specie. With regards to heat resistant molds, the species Neosartorya fischeri, Byssochlamys fulva and also the genus Eupenicillium sp., Talaromyces sp. and Eurotium sp. were isolated. The thermoacidophilic spore-forming bacteria were identified as A. acidoterrestris by a further investigation based on 16S rRNA sequence similarity. The large contamination found indicates the need for methods to eliminate or prevent the presence of these microorganisms in the processing plants in order to avoid both spoilage of apple juice and toxin production. PMID:24948913

  4. Survey of molds, yeast and Alicyclobacillus spp. from a concentrated apple juice productive process

    Scientific Electronic Library Online (English)

    Beatriz de Cássia Martins, Salomão; Chalana, Muller; Hudson Couto do, Amparo; Gláucia Maria Falcão de, Aragão.

    Full Text Available Bacteria and molds may spoil and/or contaminate apple juice either by direct microbial action or indirectly by the uptake of metabolites as off-flavours and toxins. Some of these microorganisms and/or metabolites may remain in the food even after extensive procedures. This study aim to identify the [...] presence of molds (including heat resistant species) and Alicyclobacillus spp., during concentrated apple juice processing. Molds were isolated at different steps and then identified by their macroscopic and microscopic characteristics after cultivation on standard media at 5, 25 and 37ºC, during 7 days. Among the 19 isolated found, 63% were identified as Penicillium with 50% belonging to the P. expansum specie. With regards to heat resistant molds, the species Neosartorya fischeri, Byssochlamys fulva and also the genus Eupenicillium sp., Talaromyces sp. and Eurotium sp. were isolated. The thermoacidophilic spore-forming bacteria were identified as A. acidoterrestris by a further investigation based on 16S rRNA sequence similarity. The large contamination found indicates the need for methods to eliminate or prevent the presence of these microorganisms in the processing plants in order to avoid both spoilage of apple juice and toxin production.

  5. Rapid fabrication of molds by mechanical micromilling: process development

    Science.gov (United States)

    Friedrich, Craig R.; Kikkeri, Bharath

    1995-09-01

    At the macroscale, the milling process is very versatile and capable of creating 3D features and structures. Adaptation of this process at the microscale could lead to the rapid and direct fabrication of micromolds and masks to aid in the development of microcomponents. This task has been undertaken and results of the process indicate it can become an increasingly useful method. The micromilling process is currently characterized by milling tools with a diameter as small as 22 micrometers. The micromilling process can create trench-like features with vertical sidewalls and good smoothness. External corners are sharp and stepped features can be machined simply by programming those shapes. The process is direct and therefore dimensional errors do not accumulate as can occur with serial fabrication processes.

  6. Improvement of the Dimensional Stability of Powder Injection Molded Compacts by Adding Swelling Inhibitor into the Debinding Solvent

    Science.gov (United States)

    Fan, Yang-Liang; Hwang, Kuen-Shyang; Su, Shao-Chin

    2008-02-01

    Defects are frequently found in powder injection molded (PIM) compacts during solvent debinding due to the swelling of the binders. This problem can be alleviated by adjusting the composition of the debinding solvent. In this study, 10 vol pct swelling inhibitors were added into heptane, and the in-situ amounts of swelling and sagging of the specimen in the solvent were recorded using a noncontacting laser dilatometer. The results show that the addition of ethanol, 2-propanol, 1-butanol, and 1-pentanol reduced the amounts of swelling by 31, 21, 17, and 11 pct, respectively. This was because the small molecule alcohols, which do not dissolve paraffin wax (PW) or stearic acid (SA) in the binder system, could diffuse easily into the specimen and increased the portion of the swelling inhibitor inside. The amount of the extracted PW and SA also decreased, but only by 8.3, 6.1, 4.3, and 2.4 pct, respectively. The solubility parameters of 1-bromopropane (n-PB) and ethyl acetate (EA) are between those of heptane and alcohols, and they also yielded a slight reduction in the amounts of swelling by 6 and 11 pct, respectively. These results suggest that to reduce defects caused by binder swelling during solvent debinding, alcohols with high solubility parameters can be added into heptane without sacrificing significantly on the debinding rate.

  7. AKUMULASI LISTRIK STATIS PADA GELAS PLASTIK PRODUKSI MESIN INJECTION MOLDING: PENGARUH KELEMBABAN UDARA, TEMPERATUR, DAN BAHAN ADITIF

    Directory of Open Access Journals (Sweden)

    Ratnawati Ratnawati

    2014-12-01

    Full Text Available Akumulasi listrik statis pada gelas polipropilena hasil produksi mesin injection molding dapat menyebabkan gelas memiliki gaya elektrostatik dan tidak dapat turun secara gravitasi. Masalah ini menghambat aplikasi gelas pada mesin pengisian air minum dalam kemasan (AMDK. Penelitian ini bertujuan untuk mengetahui pengaruh kelembaban udara, temperatur, dan penambahan bahan aditif TiO2 terhadap potensial listrik permukaan gelas polipropilena. Hasil penelitian menunjukkan bahwa potensial listrik permukaan dipengaruhi oleh kelembaban udara ruang produksi, temperatur, dan penambahan TiO2. Potensial listrik permukaan semakin kecil dengan naiknya kelembaban udara. Setelah kelembaban mencapai 68% potensial listrik permukaan cenderung konstan. Ditinjau dari beda potensial (DV antara permukaan dua gelas, kelembaban optimum adalah 67-68%, yang ditandai dengan beda potensial yang paling rendah. Beda potensial ? 5,2 kV menyebabkan gelas cepat turun, beda potensial 5,2 kV < DV ? 6,7 kV menyebabkan gelas turun dengan lambat, dan DV ? 6,7 kV menyebabkan gelas sangat lambat turun atau menempel. Potensial listrik turun dengan naiknya temperatur. Potensial listrik statis permukaan hanya sedikit turun akibat penambahan 0,75% berat TiO2. Hasil penelitian ini juga menunjukkan bahwa penggunaan gelas dengan potensial listrik permukaan rendah dapat menaikkan kecepatan mesin pengisian AMDK menjadi 220-250 rpm dan 140-160 rpm, masing-masing untuk mesin pengisian gelas 180 ml dan 225 ml.

  8. Mould temperature control during injection moulding process

    Science.gov (United States)

    Postawa, Przemyslaw; Stachowiak, Tomasz

    2015-05-01

    Mould temperature is one of the most important parameter in injection moulding process of thermoplastic polymers in particular semi crystalline polymers. There are a lots of methods of control mould temperature but it is not simple and easy to measure heat transfer precisely. Injection moulds have usually a large mass and this is equal also to large heat capacity of tools and its thermal inertia. Measuring temperature by using contact equipment causes a lot of mistakes, because that method is based on heat transfer between thermocouple and measured area of mould. Result of research of 3 different method of temperature control of mould surface were present in the publication. For this purpose a special experimental mould was made. Mould has eight independent cooling circuits which were connected to the thermo controller Wittmann with two circuits. The main aim of research was to determine the effect of normal process of injection moulding on temperature changing in different area of mould. Under the cavity 4 thermocouple were placed and connect to the recorder what gave a possibility of uploading data during injection process. For that research mould temperature was change in many different layouts. Data and sequences of changes in temperature collected during tests gave very interesting result for discussion. Furthermore use of differences in temperature profile of the mould causes different temperature profile recorded during injection moulding. Tests were made by using fallowing equipment: Krauss Maffei injection moulding machine KM65-C4 and thermo controller Wittmann TPplus2, Shini Rotameter, infrared camera TESTO-890 and thermocouple signal recorder with 4 thermocouples of diameter 1mm located in injection mould 3mm under cavity surface. Draft of experimental mould and thermocouple location were presented in the article, and results of research as a drafts and charts of temperature changing in different area of mould were included.

  9. Predictive Engineering Tools for Injection-Molded Long-Carbon-Fiber Thermoplastic Composites - FY 2014 First Quarterly Report

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Ba Nghiep; Sanborn, Scott E.; Simmons, Kevin L.; Mathur, Raj N.; Sangid, Michael D.; Jin, Xiaoshi; Costa, Franco; Gandhi, Umesh N.; Mori, Steven; Tucker III, Charles L.

    2014-02-19

    The CRADA between PNNL, Autodesk, Toyota and Magna has been effective since October 28th, 2013. The whole team including CRADA and subcontract partners kicked off the project technically on November 1st, 2013. This report describes work performed during the first quarter of FY 2014. The following technical progresses have been made toward project milestones: 1) The project kickoff meeting was organized at PlastiComp, Inc. in Winona on November 13th, 2013 involving all the project partners. During this meeting the research plan and Gantt chart were discussed and refined. The coordination of the research activities among the partners was also discussed to ensure that the deliverables and timeline will be met. 2) Autodesk delivered a research version of ASMI to PNNL for process modeling using this tool under the project. PNNL installed this research version on a PNNL computer and tested it. Currently, PNNL is using ASMI to prepare the models for PlastiComp plaques. 3) PlastiComp has compounded long carbon-fiber reinforced polypropylene and polyamide 6,6 compounds for rheological and thermal characterization tests by the Autodesk laboratories in Melbourne, Australia. 4) Initial mold flow analysis was carried out by PlastiComp to confirm that the 3D complex part selected by Toyota as a representative automotive part is moldable. 5) Toyota, Magna, PlastiComp and PNNL finalized the planning for molding the Toyota 3D complex part. 6) Purdue University worked with PNNL to update and specify the test matrix for characterization of fiber length/orientation. 7) Purdue University developed tools to automate the data collection and analysis of fiber length and orientation measurements. 8) Purdue University designed and specified equipment to replace the need for equipment using the technology established by the University of Leeds at General Motors.

  10. Simulation and Injection Molding of Ring-Shaped Polymer Bonded Nickel Braze Metal Composite Preforms Based on Rheological and Thermal Analyses

    Directory of Open Access Journals (Sweden)

    Stefan Kirchberg

    2013-04-01

    Full Text Available Rheological and thermal properties of LD-PE and LD-PE + 65 vol% Ni composite were examined by viscosity, pvt and thermal conductivity measurements at a wide range of shear rate, temperature and pressure. The typical shear-thinning viscosity of LD-PE polymer melt was enhanced up to four times by adding 65 vol% Ni braze metal particles. LD-PE show increasing specific volume versus temperature, decreasing with pressure and braze particle filler content. Variation of specific volume of LD-PE was reduced to 5% by admixing 65 vol% rigid Ni braze metal particles. Thermal conductivity of LD-PE was increased up to 15 times in the composite, reduced by decreasing pressure at temperature exceeding 80?. Furthermore, thermal analysis was performed in modulated DSC to determine the specific heat capacity in wide temperature range. Viscosity and pvt-data were fitted using Cross-WLF equation and 2-domain Tait-pvt model, respectively. Simulation of LD-PE and LD-PE + 65 vol% Ni composite was performed based on rheological and thermal properties to define processing parameters. Simulation and injection molding of ring-shaped LD-PE + 65 vol% Ni composite braze metal preforms were performed successfully.

  11. Thermal Analysis (Differential Scanning Calorimetry And Thermogravimetric Analysis) Of SEBS Blends For Injection Molding

    OpenAIRE

    Juárez Varón, David; Ferrándiz Bou, Santiago; Peydro Rasero, Miguel Ángel; Sánchez Caballero, Samuel

    2013-01-01

    Thermal analysis (DSC: Differential Scanning Calorimetry and TGA: Thermogravimetric Analysis) of SEBS blends have been studied in this paper. SEBS blends were made using two transparent SEBS commercial grades with extreme hardness values. The first thermal property determined in SEBS blends was the evaluation of the thermal degradation at high temperatures (DSC). Another thermal property of the SEBS blends consists in knowing the degradation process of the blend (TGA). It should be emphasi...

  12. Analysis of rocket engine injection combustion processes

    Science.gov (United States)

    Salmon, J. W.

    1976-01-01

    A critique is given of the JANNAF sub-critical propellant injection/combustion process analysis computer models and application of the models to correlation of well documented hot fire engine data bases. These programs are the distributed energy release (DER) model for conventional liquid propellants injectors and the coaxial injection combustion model (CICM) for gaseous annulus/liquid core coaxial injectors. The critique identifies model inconsistencies while the computer analyses provide quantitative data on predictive accuracy. The program is comprised of three tasks: (1) computer program review and operations; (2) analysis and data correlations; and (3) documentation.

  13. Finite Element Analysis Of Reciprocating Screw For Injection Moulding Machine

    OpenAIRE

    VIKAS.R.RAJORIA, PROF.P.K.JADHAO

    2013-01-01

    Injection moulding machine is the most commonly used manufacturing process for the fabrication of plastic parts. The plastic being melted in injection molding machine and then injected into the mould. The barrel contains reciprocating screw for injecting the material into the mould and the material is also melted into the barrel. This project deals with, the solution of problem occurred for reciprocating screw of Injection molding machine. It identifies and solves the problem by using the mod...

  14. DATA MINING BASED KNOWLEDGE DISCOVERY FOR QUALITY PREDICTION AND CONTROL OF EXTRUSION BLOW MOLDING PROCESS

    Directory of Open Access Journals (Sweden)

    E.V.Ramana

    2013-05-01

    Full Text Available In practice, when quality of products fall below the expected level, causal relationships between process variables and product defects are investigated. Quality improvement and control activities in product manufacturing include identifying the factors that significantly affect quality, modeling relationships between input attributes and target attribute (yield, quality, performance index etc and predicting quality levels of given input attributes. Data mining tools have created new ways of extracting useful knowledge from existing manufacturing process databases. This paper proposed data mining based knowledge discovery approach from Extrusion Blow Molding process database making use of Microsoft Clustering, Naïve Bayes and Decision Trees algorithms available in SQL Server 2008. Data mining models have been created using these algorithms from extrusion blow molding process data set of a typical product (Gum Bottle. These models were trained based on database containing historical process data. The objective of this study was to apply the discovered process knowledge to set optimum process parameters resulting in high quality products, increased output and reduction of scrap.

  15. Injection molded component

    Science.gov (United States)

    James, Allister W; Arrell, Douglas J

    2014-09-30

    An intermediate component includes a first wall member, a leachable material layer, and a precursor wall member. The first wall member has an outer surface and first connecting structure. The leachable material layer is provided on the first wall member outer surface. The precursor wall member is formed adjacent to the leachable material layer from a metal powder mixed with a binder material, and includes second connecting structure.

  16. Water treatment processes for oilfield steam injection

    Energy Technology Data Exchange (ETDEWEB)

    Shannon, A.; Pauley, J.C. [Chevron Canada Ltd., Vancouver, BC (Canada)

    2009-07-01

    Various water treatment processes are used within the oilfield industry. Processes tend to be common within one region of the world, but different between regions due to untreated water characteristics and treated water quality requirements. This paper summarized Chevron's view of water treatment requirements and processes for oilfield steam injection. It identified water treatment systems that have been used at thermal projects, where they are most commonly utilized, their purpose, and the limits of each process. The advantages and disadvantages of different water treatment systems were also reviewed. The paper focused on the treatment of fresh waters, low-TDS produced waters, high-hardness waters, and high-silica produced waters. Challenges and opportunities were also identified. It was concluded that the challenges created by high-silica, or by high-hardness produced waters lead to more costly processes. 25 refs., 5 tabs., 4 figs.

  17. Observation of the Mold-Filling Process of a Large Hydro-Turbine Guide Vane Casting

    Science.gov (United States)

    Kang, Jinwu; Long, Haimin; Li, Yongjie; You, Rui; Hao, Xiaokun; Nie, Gang; Wang, Tianjiao; Zhang, Chengchun

    2015-02-01

    The mold-filling process has a determining effect on the quality of castings, and it has always been a hot but difficult research topic. The authors developed a wireless monitoring system for the mold-filling process of castings based on a contact time method and an observation system based on heat-resistant high-speed cameras. By using these two systems, the filling process of a turbine guide vane casting with a stepped gating system was investigated. The filling profile of the casting was recorded, and the filling time of nine typical positions was acquired. These results show that at the beginning, the liquid steel flowed out from the top ingate, which was designed to be the last to fill. The numerical simulation of the filling of the guide vane was performed, and the outflow from the top ingate were predicted. Finally, the gating system of the casting was improved with enlarged sprue. The new design features bigger sprue to ingate ratio; therefore, it could avoid the overflow from the top ingate and realize stable filling.

  18. Interphase formation of a resin transfer molded silica-phenolics composites subjected to dynamic impregnation process

    International Nuclear Information System (INIS)

    In this study interphase formation of a resin transfer molded (RTMed) silica-phenolics composites subjected to dynamic impregnation process was investigated. The solvent effect on the interphase formation of silica fiber-phenolics composites was evaluated. UV-vis spectra, XPS and electron paramagnetic resonance (EPR) techniques were used to characterize the competitive adsorption of the components of phenolics solution onto silica reinforcement surfaces. Interlaminar shear strength (ILSS) and void content of silica-phenolics composites were also measured. It has been found that phenolics forms distribution gradient over RTM mold with respect to isomeric composition under the effect of solvent, which result, to varying extent, in the inhomogeneity of void content and thus ILSS of a final product. For the first time, it has been shown that the RTM process of silica-phenolics composites is highly solvent-dependent. Our work gives an insight into the role of organic solvent in a RTM solution impregnation processing and provides useful information and trends relating microscopic to macroscopic behavior

  19. Large Eddy Simulation of Transient Flow, Solidification, and Particle Transport Processes in Continuous-Casting Mold

    Science.gov (United States)

    Liu, Zhongqiu; Li, Linmin; Li, Baokuan; Jiang, Maofa

    2014-07-01

    The current study developed a coupled computational model to simulate the transient fluid flow, solidification, and particle transport processes in a slab continuous-casting mold. Transient flow of molten steel in the mold is calculated using the large eddy simulation. An enthalpy-porosity approach is used for the analysis of solidification processes. The transport of bubble and non-metallic inclusion inside the liquid pool is calculated using the Lagrangian approach based on the transient flow field. A criterion of particle entrapment in the solidified shell is developed using the user-defined functions of FLUENT software (ANSYS, Inc., Canonsburg, PA). The predicted results of this model are compared with the measurements of the ultrasonic testing of the rolled steel plates and the water model experiments. The transient asymmetrical flow pattern inside the liquid pool exhibits quite satisfactory agreement with the corresponding measurements. The predicted complex instantaneous velocity field is composed of various small recirculation zones and multiple vortices. The transport of particles inside the liquid pool and the entrapment of particles in the solidified shell are not symmetric. The Magnus force can reduce the entrapment ratio of particles in the solidified shell, especially for smaller particles, but the effect is not obvious. The Marangoni force can play an important role in controlling the motion of particles, which increases the entrapment ratio of particles in the solidified shell obviously.

  20. Moldagem por injeção em baixa pressão de peças complexas de cerâmicas avançadas produzidas com pós submicrométricos Low-pressure injection molding of complex parts of advanced ceramic produced with fine powder

    Directory of Open Access Journals (Sweden)

    J. E. Zorzi

    2004-09-01

    Full Text Available A moldagem por injeção em baixa pressão (MIBP tem constituído, nos últimos anos, uma excelente alternativa para a produção de pequenos lotes de peças cerâmicas diversificadas e com formas complexas. Esta técnica de conformação é relativamente simples e barata, mas apresenta diversos problemas na etapa de extração dos ligantes, principalmente quando o pó cerâmico é muito fino e as peças possuem grande seção transversal. Neste trabalho é descrita uma metodologia específica para a produção de peças cerâmicas por moldagem por injeção a baixa pressão de alumina submicrométrica (0,4 mim, incluindo a formulação da mistura para injeção, bem como detalhes do processo de extração dos ligantes orgânicos utilizados na moldagem. Para o desenvolvimento deste processo fez-se necessário (i entender melhor o processo de MIBP, (ii desenvolver a formulação da mistura de pó cerâmico e aditivos orgânicos, (iii confeccionar moldes adequados para a injeção a baixas pressões e (iv otimizar os parâmetros de injeção. A metodologia desenvolvida neste trabalho, possibilita a confecção de peças cerâmicas complexas, com seção transversal relativamente grande, permitindo uma produção robusta de pequenos lotes de peças cerâmicas diversificadas com ótima qualidade e excelente reprodutibilidade.In the past years, low-pressure injection molding (LPIM has been a good alternative for the production of small batches of diversified complex shapes ceramic parts. This molding technique is relatively simple and cheap, but presents several problems related to debinding, especially for fine ceramic particle, and large cross-section ceramic pieces. In this work, we present a metodology for the production of ceramic parts based on the LPIM of submicrometer-sized alumina powder (0.4 mum. The binder formulation is described, as well as the details of the debinding stage. For the development of this process it was necessary (i to achieve a better understanding of the LPIM process, (ii develop the binder formulation and to find the better proportion for the binder plus ceramic powder mixture, (iii to prepare molds suitable for LPIM and (iv to optimize the injection parameters. The procedure here reported makes it possible to produce complex shape ceramic parts, with relatively large cross-section, allowing the robust production of small batches of diversified ceramic parts, with high quality and excellent reproducibility.

  1. Moldagem por injeção em baixa pressão de peças complexas de cerâmicas avançadas produzidas com pós submicrométricos / Low-pressure injection molding of complex parts of advanced ceramic produced with fine powder

    Scientific Electronic Library Online (English)

    J. E., Zorzi; C. A., Perottoni; J. A. H. da, Jornada.

    2004-09-01

    Full Text Available A moldagem por injeção em baixa pressão (MIBP) tem constituído, nos últimos anos, uma excelente alternativa para a produção de pequenos lotes de peças cerâmicas diversificadas e com formas complexas. Esta técnica de conformação é relativamente simples e barata, mas apresenta diversos problemas na et [...] apa de extração dos ligantes, principalmente quando o pó cerâmico é muito fino e as peças possuem grande seção transversal. Neste trabalho é descrita uma metodologia específica para a produção de peças cerâmicas por moldagem por injeção a baixa pressão de alumina submicrométrica (0,4 mim), incluindo a formulação da mistura para injeção, bem como detalhes do processo de extração dos ligantes orgânicos utilizados na moldagem. Para o desenvolvimento deste processo fez-se necessário (i) entender melhor o processo de MIBP, (ii) desenvolver a formulação da mistura de pó cerâmico e aditivos orgânicos, (iii) confeccionar moldes adequados para a injeção a baixas pressões e (iv) otimizar os parâmetros de injeção. A metodologia desenvolvida neste trabalho, possibilita a confecção de peças cerâmicas complexas, com seção transversal relativamente grande, permitindo uma produção robusta de pequenos lotes de peças cerâmicas diversificadas com ótima qualidade e excelente reprodutibilidade. Abstract in english In the past years, low-pressure injection molding (LPIM) has been a good alternative for the production of small batches of diversified complex shapes ceramic parts. This molding technique is relatively simple and cheap, but presents several problems related to debinding, especially for fine ceramic [...] particle, and large cross-section ceramic pieces. In this work, we present a metodology for the production of ceramic parts based on the LPIM of submicrometer-sized alumina powder (0.4 mum). The binder formulation is described, as well as the details of the debinding stage. For the development of this process it was necessary (i) to achieve a better understanding of the LPIM process, (ii) develop the binder formulation and to find the better proportion for the binder plus ceramic powder mixture, (iii) to prepare molds suitable for LPIM and (iv) to optimize the injection parameters. The procedure here reported makes it possible to produce complex shape ceramic parts, with relatively large cross-section, allowing the robust production of small batches of diversified ceramic parts, with high quality and excellent reproducibility.

  2. An Empirical Model for Resin Viscosity During Cure in Vacuum Infusion Molding Process

    Science.gov (United States)

    Yang, Jinshui; Xiao, Jiayu; Zeng, Jingcheng; Peng, Chaoyi; Feng, Xuebin; Hou, Binbin

    2012-06-01

    The rheological behaviors of a low viscosity epoxy resin system (RIMR135/RIMH137) for vacuum infusion molding process (VIMP) were studied with viscosity experiments. And an empirical model has been developed to predict the viscosity of the resin system during curing at low extents of cure, which is of significance during the mould filling stage in VIMP. Good agreement is observed between the experimental data and the model predicted viscosity. The processing windows of the resin system for VIMP can be predicted by the proposed models. The results show that the optimum processing temperature range of RIMR135/RIMH137 epoxy resin system for VIMP is from 25°C to 45°C, at which the resin system can maintain the viscosity less than 500 mPa·s for 75 min at least.

  3. Selected methods of modelling of polymer during the injection moulding process

    Directory of Open Access Journals (Sweden)

    J. Koszkul

    2007-09-01

    Full Text Available Purpose: The purpose of present paper was presenting chosen results of investigations on polymer flow during mould cavity filling phase of injection process. Advancement in the simulation software make possible to model more phenomena occurring during polymer flow in injection molding process.Design/methodology/approach: The results of computer simulations of injection process have been compared with the results of video recording for the plastic flow during filling phase. For the simulating investigations a professional computer software Moldflow Plastics Insight ver. 6.1. has been employed. A specialized injection mould which enables observation and registration of the plastic flow during processing has been employed. The mould enables direct monitoring of the course of phenomena inside the mould cavity in two planes. To record the flow, a digital video camera has been employed. As an example the issue of stream flow (jeting have been described.Findings: The results of the investigations enabled documenting of specific phenomena which occur during plastics or their composites injection process. The registered video sequences have been compared with the results of numerical calculations and then it was estimated to what degree the computer simulation of injection process may be useful in practice.Research limitations/implications: The camera enabled to register the flows with the rate of 25 fps. This reduced the scope of the investigations, since at higher plastic flow speeds the registered image became less clear. The investigations were performed on a wide scale, however, only chosen results have been presented.Practical implications: Deep understanding of the phenomena which occur during filling the injection mould may lead to more effective design of the processing tools and shortening of the time for implementation and production time.Originality/value: The transparent sight-glasses have been used, made of a material called Zerodur® which is characterized by the coefficient of thermal expansion close to zero.

  4. Simulation of the Two Stages Stretch-Blow Molding Process: Infrared Heating and Blowing Modeling

    International Nuclear Information System (INIS)

    In the Stretch-Blow Molding (SBM) process, the temperature distribution of the reheated perform affects drastically the blowing kinematic, the bottle thickness distribution, as well as the orientation induced by stretching. Consequently, mechanical and optical properties of the final bottle are closely related to heating conditions. In order to predict the 3D temperature distribution of a rotating preform, numerical software using control-volume method has been developed. Since PET behaves like a semi-transparent medium, the radiative flux absorption was computed using Beer Lambert law. In a second step, 2D axi-symmetric simulations of the SBM have been developed using the finite element package ABAQUS registered . Temperature profiles through the preform wall thickness and along its length were computed and applied as initial condition. Air pressure inside the preform was not considered as an input variable, but was automatically computed using a thermodynamic model. The heat transfer coefficient applied between the mold and the polymer was also measured. Finally, the G'sell law was used for modeling PET behavior. For both heating and blowing stage simulations, a good agreement has been observed with experimental measurements. This work is part of the European project ''APTPACK'' (Advanced knowledge of Polymer deformation for Tomorrow's PACKaging)

  5. Simulation of the Two Stages Stretch-Blow Molding Process: Infrared Heating and Blowing Modeling

    Science.gov (United States)

    Bordival, M.; Schmidt, F. M.; Le Maoult, Y.; Velay, V.

    2007-05-01

    In the Stretch-Blow Molding (SBM) process, the temperature distribution of the reheated perform affects drastically the blowing kinematic, the bottle thickness distribution, as well as the orientation induced by stretching. Consequently, mechanical and optical properties of the final bottle are closely related to heating conditions. In order to predict the 3D temperature distribution of a rotating preform, numerical software using control-volume method has been developed. Since PET behaves like a semi-transparent medium, the radiative flux absorption was computed using Beer Lambert law. In a second step, 2D axi-symmetric simulations of the SBM have been developed using the finite element package ABAQUS®. Temperature profiles through the preform wall thickness and along its length were computed and applied as initial condition. Air pressure inside the preform was not considered as an input variable, but was automatically computed using a thermodynamic model. The heat transfer coefficient applied between the mold and the polymer was also measured. Finally, the G'sell law was used for modeling PET behavior. For both heating and blowing stage simulations, a good agreement has been observed with experimental measurements. This work is part of the European project "APT_PACK" (Advanced knowledge of Polymer deformation for Tomorrow's PACKaging).

  6. Resin Flow Behavior Simulation of Grooved Foam Sandwich Composites with the Vacuum Assisted Resin Infusion (VARI Molding Process

    Directory of Open Access Journals (Sweden)

    Yibo Wu

    2012-07-01

    Full Text Available The resin flow behavior in the vacuum assisted resin infusion molding process (VARI of foam sandwich composites was studied by both visualization flow experiments and computer simulation. Both experimental and simulation results show that: the distribution medium (DM leads to a shorter molding filling time in grooved foam sandwich composites via the VARI process, and the mold filling time is linearly reduced with the increase of the ratio of DM/Preform. Patterns of the resin sources have a significant influence on the resin filling time. The filling time of center source is shorter than that of edge pattern. Point pattern results in longer filling time than of linear source. Short edge/center patterns need a longer time to fill the mould compared with Long edge/center sources.

  7. Efecto del proceso de transformación sobre el coeficiente de endurecimiento por deformación en polímeros / Effect of the molding process on the strain hardening index by deformation in polymers

    Scientific Electronic Library Online (English)

    Rosa, Morales; María, Candal; Jennifer, Robles.

    2009-12-01

    Full Text Available El objetivo principal de este trabajo fue analizar el comportamiento del coeficiente de endurecimiento por deformación (Gp) en materiales plásticos, para diferentes condiciones de inyección y velocidades de deformación durante el ensayo mecánico. Se inyectaron probetas tipo I de Polietileno de Alta [...] Densidad (PEAD 2811) modificando las variables del proceso de inyección (presión, velocidad y temperatura de inyección). Se evaluaron las propiedades tensiles y se determinaron los parámetros mecánicos (Módulo de Young, Esfuerzo y Deformación a la fluencia y Gp). Se encontró que el Gp disminuye con la presión de inyección y se mantiene constante al incrementar la temperatura de inyección, sin embargo, con la velocidad de inyección presenta una dualidad de comportamientos, es decir a bajas velocidades de ensayo aumenta, mientras que a altas velocidades disminuye el coeficiente. También se obtuvo que a medida que la velocidad de deformación aumenta el Gp disminuye Abstract in english The main objective of this study was to analyze the behavior of the strain hardening coefficient (Gp) in plastic materials, for different injection molding conditions and the strain rate during a mechanical test. Test specimen type I of High Density Polyethylene (HDPE 2811) was injected under differ [...] ent process conditions (injection pressure, injection temperature and injection velocity). The tensile properties were evaluated and the mechanical parameters (Young modulus, yield stress, yield strain and Gp) were determined. Gp decreases with injection pressure, and remains constant by increasing injection temperature; however, with injection velocity, it presents a mixed behaviour. A low velocity generated an increase of the Gp and a high velocity decreases the Gp. Also, the Gp decreases with an increase in the strain rate

  8. Nanopatterning planar and non-planar mold surfaces for a polymer replication

    DEFF Research Database (Denmark)

    Cech, Jiri; Pranov, Henrik

    2013-01-01

    We present a novel process to create nanopatterns on planar and non-planar polymer replication tools, such as metallic molds for an injection molding. Such tools with nanopatterned cavities then allow affordable mass production of nanopatterned polymer parts with inherent advanced functionalities such as low reflectivity or color effects, self cleaning, superhydrofobicity, antifouling, etc, all created in a single injection molding cycle. Presented process is based on the classic cleanroom microfabrication of micro/nano patterns, nickel electroplating and template removal to form a flexible, freestanding nickel foil with a reversed pattern. This foil is then used either as a direct master for polymer replication or as a master for an extremely high pressure embossing of such master onto a metallic injection mold cavity surface coated with special coating, which, when cured, forms robust and hard, glass-like material. We have demonstrated nanopattern transfer on both planar and non-planar geometries and our nanopatterned mold coating can sustain more than 10.000 injection molding cycles. We can coat our nanopatterned mold surfaces with a monolayer of perfluorosilane to further reduce surface energy and sticktion and to facilitate de-molding of plastic parts.1 This allows forming of affordable plastic parts with advanced functionality.

  9. Heat-radiation combination for control of mold infection in harvested fruits and processed cereal foods

    International Nuclear Information System (INIS)

    A combination of mild heat and low dose irradiation was found to extend the shelf-life of fresh fruits and processed cereal foods by controlling mold infection. Chapaties (Indian unleavened bread) and bread slices packed in polycell pouches, subjected to 50 krad followed by dry heat (650C) were free from mold and shelf-stable for 10 weeks at ambient temperature (28-320C). Inoculated pack studies confirmed the efficiency of the treatment. No immediate changes in organoleptic attributes were discernible even after exposure to 100 krad. The quality deterioration in sliced bread stored for 2 1/2 months has been attributed to natural staling rather than radiation. Hot water dip (500C for 5 min) followed by 150 krad irradiation extended the shelf-life of fresh figs by 3-4 days at 28-320C and 8-10 days at 150C. Regardless of the sequence of treatments, combination of heat and 100 krad extended the shelf-life of grapes both at ambinet and refrigerated storage. In mangoes, heat followed by 50 krad was effective in controlling anthracnose and stem-end rot whereas in bananas irradiated for delayed ripening, hot water treatment can be used as a supplementary process to control stem-end rot. Quality of combination treated fruits was comparable to normally ripened fruits. In vitro studies with fungal pathogens isolated from the above fruits and cereal foods revealed that the synergistic effect of heat-radiation combination depe effect of heat-radiation combination depends on the sequence of treatments which varied with respect to different pathogens studied. Some biochemical aspects of combination treated fruits is discussed. (F.J.)

  10. Os efeitos no empacotamento de peças injetadas para diferentes espessuras de canais de ataque (gate) tipo filme / The effects of injection molding packing for different thickness of film type gates

    Scientific Electronic Library Online (English)

    Altair Carlos da, Cruz; Ricardo Pedro, Bom.

    Full Text Available Este trabalho tem como objetivo determinar a variação da massa de corpos de prova fabricados pelo processo de moldagem por injeção. A partir de equações que tratam da solidificação de placas, foi correlacionado o tempo de solidificação do canal de ataque com o tempo de início de estabilização da mas [...] sa do corpo de prova obtido na cavidade do molde de injeção. Para o desenvolvimento experimental foi utilizado o copolímero estireno-acrilonitrila (SAN). Para a realização dos corpos de prova, foi necessário secar o material, fixar alguns parâmetros de processo, tais como pressão de injeção, tempo de injeção, temperatura nos diferentes estágios e temperatura do molde. Os parâmetros variáveis foram o tempo e a pressão de recalque. Com os corpos de prova prontos, suas massas foram determinadas, inicialmente, para o conjunto corpo de prova e canais de distribuição; em seguida, para o corpo de prova individualmente, sendo este previamente separado dos canais de distribuição. A variação da massa dos corpos de prova para as diferentes pressões de recalque e seus respectivos desvios-padrão foram representadas graficamente em função da variação do tempo de recalque. A massa do corpo de prova começou a estabilizar a partir de um certo tempo. Este tempo foi determinado graficamente e ficou coerente com os resultados dos tempos calculados a partir de equações que tratam do resfriamento de placas. Abstract in english The aim of his study is to determine the model test bulk used by the injection molding process. The mathematical model governing by the plate solidification will indicate the solidification time of the gate together with the beginning of the stabilization of the cavity bulk. In this test a styrene-a [...] crylonitrile copolymer (SAN) will be used. In order to develop the model tests, the material had to be dried to establish some parameters like: injection pressure, injection time, temperature of the different stages as well as moulding temperature. The variable parameters were the time and the discharge pressure. As the model tests were fully develoved, bulks were determined, first for the mould cavity and branches and next for the single cavity which was separated from the branches. The variation of the cavity bulk for the different discharge pressures and the standard deviation were graphically represented due to the time deviation of the discharge. The results showed that the time the bulk cavity begins to stabilize matches the calculated time, for the non-flow temperature, as well as the glass part temperature, the discharge pressure.

  11. Processamento de placa espessa de compósito através de moldagem por transferência de resina / Processing of thick composite plate by resin transfer molding process

    Scientific Electronic Library Online (English)

    Wanderley F. de, Amorim Júnior; Gustavo Queiroz, Chaves; Verônica M. A., Calado; Fernando Luiz, Bastian.

    2006-09-01

    Full Text Available Devido às suas elevadas propriedades mecânicas específicas, os materiais compósitos estão enfrentando demandas novas, onde a capacidade de produção em massa a um custo mais acessível se tornou indispensável. A Moldagem por Transferência de Resina ou RTM (Resin Transfer Molding) constitui um promisso [...] r processo de fabricação de materiais compósitos. O objetivo deste trabalho é o estudo experimental do processo de infusão durante a fabricação de placa espessa por RTM. Os materiais usados nos experimentos foram: tecido de fibra de vidro e resina éster-vinílica com catalisador Butanox e acelerador CoNaP. As placas de material compósito eram constituídas de 32 camadas de fibra de vidro com espessura de 25,4 mm. Dois tipos de experimentos foram realizados: o primeiro para medir a influência do sistema de injeção de resina no processamento e o segundo para medir a influência da quantidade de resina presente no reservatório de injeção. Nos processamentos realizados, o sistema de injeção de resina alterou o tempo de preenchimento da preforma. A variação na quantidade de resina no reservatório não só alterou os tempos de preenchimento como impediu o preenchimento da preforma em um dos processamentos realizados. Não foi possível impedir o fenômeno de race-tracking. Baseando-se nos experimentos realizados, pode-se concluir que: o sistema de injeção de resina é importante no real entendimento do processamento por RTM e que a quantidade de resina no reservatório de injeção pode influenciar o processamento por RTM. Abstract in english Because of their high specific mechanical properties, composite materials are facing new demands, where the large scale production capacity with low cost became important. Resin Transfer Molding (RTM) constitutes a promising process of composite materials manufacturing. The objective of this work is [...] an experimental study of the infusion process during the manufacture of thick plate by RTM.The materials used in the experiments were: fiber glass fabric and vinylester resin with Butanox initiator and CoNaP accelerator. The preform had 32 layers of fiber glass reinforcements whose dimension was approximately 25,4 mm thick. Two types of experiments were carried out: the first one, to measure the influence of the resin injection system on the processing and the second one, to measure the influence of the amount of resin in the reservoir on the injection processing. By the experiments, we could conclude that the resin injection system and the variation of the amount of resin modified the fulfilling time of the preform and prevented the fulfilling of the preform in the experiments. It was not possible to prevent the phenomenon of race-tracking. The resin injection system and the variation of the amount of resin in the reservoir of injection influence RTM processes.

  12. EVALUATION OF POLLUTION PREVENTION OPTIONS TO REDUCE STYRENE EMISSIONS FROM FIBER-REINFORCED PLASTIC OPEN MOLDING PROCESSES

    Science.gov (United States)

    Pollution prevention (P2) options to reduce styrene emissions, such as new materials, and application equipment, are commercially available to the operators of open molding processes. However, information is lacking on the emissions reduction that these options can achieve. To me...

  13. Hot press molding process for pyramid-type glass optical multiplexer

    Science.gov (United States)

    Ko, Myeong-Jin; Park, Soon-Sub

    2014-12-01

    By developing a pyramid-shaped reflector, we were able to remove the optical filter that causes the decline in light efficiency in existing systems. A pyramid-type glass optical multiplexer (MUX) can be designed for beam coupling efficiency >60% in a combined module. The module was designed and optimized using CODE V, which utilizes nonlinear curve fitting numerical analysis. Based on optical design data, aspheric grinding paths were developed using ULG APS software. Tungsten carbide optical MUX mold cores were fabricated with an ultraprecision grinding machining device [ULG-100C(H3)] and optimum grinding machining of optical surface roughness (99.985%. A pyramid-type glass optical MUX molding technique was developed using an optical mold design, ultraprecision grinding machining technology, and a hot press molding system.

  14. Process for the production of prismatic graphite molded articles for high temperature fuel elements

    International Nuclear Information System (INIS)

    Prismatic graphite molded objects for high temperature fuel elements are prepared by producing the outer geometry and the holes for cooling channels and for receiving fuel and fertile materials in the formation of the carbon object

  15. Silicon micro-mold

    Science.gov (United States)

    Morales, Alfredo M. (Livermore, CA)

    2006-10-24

    The present invention describes a method for rapidly fabricating a robust 3-dimensional silicon-mold for use in preparing complex metal micro-components. The process begins by depositing a conductive metal layer onto one surface of a silicon wafer. A thin photoresist and a standard lithographic mask are then used to transfer a trace image pattern onto the opposite surface of the wafer by exposing and developing the resist. The exposed portion of the silicon substrate is anisotropically etched through the wafer thickness down to conductive metal layer to provide an etched pattern consisting of a series of rectilinear channels and recesses in the silicon which serve as the silicon micro-mold. Microcomponents are prepared with this mold by first filling the mold channels and recesses with a metal deposit, typically by electroplating, and then removing the silicon micro-mold by chemical etching.

  16. Influence of Rubber Concentration on Angular deformation in Injection Molded Parts of Talc and Rubber Filled Polypropylene

    Science.gov (United States)

    Takahara, Tadayoshi; Koyama, Kiyohito

    The most popular resin material for automotive plastic parts is polypropylene, which includes talc for stiffness and heat-resistance and rubber for impact-resistance. The anisotropic thermal expansion coefficient is well documented for talc reinforced polypropylene, but there are very few technical papers for warpage. Therefore, using this kind of material and molding with an L-shaped cross section, the influence of rubber concentration on corner deformation was discussed in this study. The results of this study are as follows 1) L-shaped cross section specimens show that the corner deformation increases linearly in proportion to the increase of rubber concentration. 2) Plane shape specimens show that the shrinkage rates in the planar direction decrease linearly and the shrinkage rates in the thickness direction increase linearly. 3) The strains in each rubber concentration are calculated using Hooke's Law. This force that induces corner deformation is assumed as the shrinkage difference between the planar and thickness directions. The tendencies of calculated strains are qualitatively consistent with measured corner deformations. 4) The reason why corner deformation decreases linearly to rubber concentration is due to the fact that the shrinkage difference between the planar and thickness directions increases and the fact that the flexural modulus decreases linearly.

  17. Investigation of the shear thinning behavior of epoxy resins for utilization in vibration assisted liquid composite molding processes

    Science.gov (United States)

    Meier, R.; Kirdar, C.; Rudolph, N.; Zaremba, S.; Drechsler, K.

    2014-05-01

    Efficient production and consumption of energy are of greatest importance for contemporary industries and their products. This has led to an increasing application of lightweight materials in general and of Carbon Fiber Reinforced Plastics (CFRP) in particular. However, broader application of CFRP is often limited by high costs and manual labor production processes. These constraints are addressed by Liquid Composite Molding (LCM) processes. In LCM a dry fibrous preform is placed into a cavity and infiltrated mostly by thermoset resins; epoxy resins are wide spread in CFRP applications. One crucial parameter for a fast mold filling is the viscosity of the resin, which is affected by the applied shear rates as well as temperature and curing time. The work presented focuses on the characterization of the shear thinning behavior of epoxy resins. Furthermore, the correlation with the conditions in vibration assisted LCM processes, where additional shear rates are created during manufacture, is discussed. Higher shear rates result from high frequencies and/or high amplitudes of the vibration motions which are created by a vibration engine mounted on the mold. In rheological investigations the shear thinning behavior of a representative epoxy resin is studied by means of rotational and oscillatory experiments. Moreover, possible effects of shear rates on the chemical curing reaction are studied. Here, the time for gelation is measured for different levels of shear rates in a pre-shearing phase. Based on the rheological studies, the beneficial effect of vibration assistance in LCM processes with respect to mold filling can further be predicted and utilized.

  18. Molded optics design and manufacture

    CERN Document Server

    Schaub, Michael

    2007-01-01

    While several available texts discuss molded plastic optics, none provide information on all classes of molded optics. Filling this gap, Molded Optics: Design and Manufacture presents detailed descriptions of molded plastic, glass, and infrared optics. Since an understanding of the manufacturing process is necessary to develop cost-effective, producible designs, the book extensively covers various manufacturing methods, design guidelines, trade-offs, best practices, and testing of critical parameters. It also discusses topics that often arise when designing systems with molded optics, such as

  19. Mold Heating and Cooling Pump Package Operator Interface Controls Upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Josh A. Salmond

    2009-08-07

    The modernization of the Mold Heating and Cooling Pump Package Operator Interface (MHC PP OI) consisted of upgrading the antiquated single board computer with a proprietary operating system to off-the-shelf hardware and off-the-shelf software with customizable software options. The pump package is the machine interface between a central heating and cooling system that pumps heat transfer fluid through an injection or compression mold base on a local plastic molding machine. The operator interface provides the intelligent means of controlling this pumping process. Strict temperature control of a mold allows the production of high quality parts with tight tolerances and low residual stresses. The products fabricated are used on multiple programs.

  20. MOLD POLLUTION

    Science.gov (United States)

    Mold pollution is the growth of molds in a building resulting in a negative impact on the use of that structure. The negative impacts generally fall into two categories: destruction of the structure itself and adverse health impacts on the building's occupants. It is estimated...

  1. Analysis of Optimal Injection Moulding Process Parameters for Thin-Shell Plastic Product Using Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Awang Bono

    2014-01-01

    Full Text Available The injection molding process is used to produce thin-walled plastic products for a wide variety of applications. However, the difficulty in adjusting optimum process parameters setting may cause defects on injected moulded parts such as shrinkage. A study was conducted for the determination of the optimal injection moulding process parameters which will minimize the shrinkage defect on a thin-shell plastic product for cell phone housing component. The machine process setting in use currently caused shrinkage where variations in the dimensions of the length and width below the specification limit. Therefore the experiment is needed to identify the optimal process parameters that could be set to maintain the length and width dimensions closest to the target value with smallest possible variation. The process parameters selected in this study are the mould temperature, injection pressure and screw rotation speed. The Response Surface Method (RSM of analysis was used for the determination of the optimal moulding process parameters. The significant factors affecting the responses were identified from ANOVA. Statistical results and analysis are used to provide better interpretation of the experiment. Verification runs with the optimal process parameter setting found by RSM determined that the shrinkage defect can be minimized.

  2. Moulded interconnect device fabrication by two shot molding and lasert induced selective activation

    DEFF Research Database (Denmark)

    Sun, Jie

    2008-01-01

    This report on the project “Molded Interconnect Device (MID) by two shot injection molding and laser induced selective activation” has been submitted to fulfil the requirements for the master project at department of Manufacturing Engineering and Management of Technical University of Denmark (IPL-DTU). MID is defined as an injection molded plastic substrate with electrical infrastructures on the surface and integrates both mechanical and electrical functionalities on the single device. This paper describes many aspects of MID such as the background information, manufacturing process chain, comparative process analysis, applications and specially two shot injection molding and laser induced selective activation in the MID area. There is also an experimental part which contains fabrication of a MID demonstrator, selective metallization as well as characterization. The realization of molded interconnect device was achieved with two innovative processes such as two shot injection molding which combines platetableand none-platetable thermoplastics, and laser induced selective activation which uses a laser to draw circuit on the thermoplastic surface containing laser sensitive additive. Different material combinations such as PEI (GE Ultem 1000) +PPO (GTX 810) and PEEK (Victrex 150GL30) +PPO (GTX 810) were investgated which can be selected electroless plating for metallization. Several plastics such as PC (GE Lexan 500R) and PEEK (Victrex 150GL30) were applied to the laser induced activation and reacted differently with the diverse structure.

  3. Fabrication of balloon-expandable self-lock drug-eluting polycaprolactone stents using micro-injection molding and spray coating techniques.

    Science.gov (United States)

    Liu, Shih-Jung; Chiang, Fu-Jun; Hsiao, Chao-Ying; Kau, Yi-Chuan; Liu, Kuo-Sheng

    2010-10-01

    The purpose of this report was to develop novel balloon-expandable self-lock drug-eluting poly(?-caprolactone) stents. To fabricate the biodegradable stents, polycaprolactone (PCL) components were first fabricated by a lab-scale micro-injection molded machine. They were then assembled and hot-spot welded into mesh-like stents of 3 and 5 mm in diameters. A special geometry of the components was designed to self-lock the assembled stents and to resist the external pressure of the blood vessels after being expanded by balloons. Characterization of the biodegradable PCL stents was carried out. PCL stents exhibited comparable mechanical property to that of metallic stents. No significant collapse pressure reduction and weight loss of the stents were observed after being submerged in PBS for 12 weeks. In addition, the developed stent was coated with paclitaxel by a spray coating technique and the release characteristic of the drug was determined by an in vitro elution method. The high-performance liquid chromatography analysis showed that the biodegradable stents could release a high concentration of paclitaxel for more than 60 days. By adopting the novel techniques, we will be able to fabricate biodegradable drug-eluting PCL stents of different sizes for various cardiovascular applications. PMID:20496003

  4. Predictive Engineering Tools for Injection-Molded Long-Carbon-Fiber Thermoplastic Composites - FY 2015 First Quarterly Report

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Ba Nghiep; Fifield, Leonard S.; Kijewski, Seth A.; Sangid, Michael D.; Wang, Jin; Jin, Xiaoshi; Costa, Franco; Tucker III, Charles L.; Mathur, Raj N.; Gandhi, Umesh N.; Mori, Steven

    2015-01-29

    During the first quarter of FY 2015, the following technical progress has been made toward project milestones: 1) Autodesk delivered a new research version of ASMI to PNNL. This version includes the improved 3D fiber orientation solver, and the reduced order model (ROM) for fiber length distribution using the proper orthogonal decomposition (POD) implemented in the mid-plane, dual-domain and 3D solvers. 2) Autodesk coordinated a conference paper with PNNL reporting ASMI mid-plane fiber orientation predictions compared with the measured data for two PlastiComp plaques. This paper was accepted for presentation at the 2015 Society for Plastics Engineers (SPE) ANTEC conference. 3) The University of Illinois (Prof. Tucker) assisted team members from Purdue with fiber orientation measurement techniques, including interpretation of off-axis cross sections. 4) The University of Illinois assisted Autodesk team members with software implementation of the POD approach for fiber length modeling, and with fiber orientation modeling. 5) The University of Illinois co-authored in the SPE ANTEC paper, participated with the team in discussions of plaque data and model results, and participated in the definition of go/no-go experiments and data. 6) Purdue University (Purdue) conducted fiber orientation measurements for 3 PlastiComp plaques: fast-fill 30wt% LCF/PP center-gated, fast-fill 50wt% LCF/PA66 edge-gated and fast-fill 50wt% LCF/PA66 center-gated plaques, and delivered the fiber orientation data for these plaques at the selected locations (named A, B, and C) to PNNL. However, the data for the fast-fill 50wt% LCF/PA66 edge-gated plaque exhibited unusual variations and could not be used for the model validation. Purdue will re-measure fiber orientation for this plaque. 7) Based on discussions with the University of Illinois Purdue explained the ambiguity in the measurements of the fiber orientation components. 8) PNNL discussed with team members to establish a go/no-go decision plan for the project and submitted the established plan to DOE. 9) PNNL performed ASMI mid-plane analyses for the fast-fill center-gated 30wt% LCF/PP and 50wt% LCF/PA66 plaques and compared the predicted fiber orientations with the measured data provided by Purdue at Locations A, B, and C on these plaques. 10) Based on discussions with the University of Illinois and Autodesk, PNNL proposed a procedure to adjust fiber orientation data for Location A of the center-gated plaques so that the data can be expressed and interpreted in the flow/cross-flow direction coordinate system. 11) PNNL tested the new ASMI version received from Autodesk, examined and discussed 3D fiber orientation predictions for PlastiComp plaques. 12) PlastiComp, Inc. (PlastiComp), Toyota Research Institute North America (Toyota) and Magna Exteriors and Interiors Corp. (Magna) participated in discussions with team members on the go/no-go plan and the issues related to fiber length measurements. Toyota continued the discussion with Magna on tool modification for molding the complex part in order to achieve the target fiber length in the part.

  5. Predictive Engineering Tools for Injection-Molded Long-Carbon-Fiber Thermoplastic Composites - Second FY 2015 Quarterly Report

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Ba Nghiep [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Fifield, Leonard S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kijewski, Seth A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Sangid, Michael D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Wang, Jin [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Costa, Franco [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Tucker, III, Charles L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Mathur, Raj N. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Gandhi, Umesh N. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Mori, Steven [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-05-19

    During the second quarter of FY 2015, the following technical progress has been made toward project milestones: 1) Autodesk reviewed 3D fiber orientation distribution (FOD) comparisons and provided support on improving accuracy. 2) Autodesk reviewed fiber length distribution (FLD) data comparisons and provided suggestions, assisted PNNL in FOD and FLD parameter settings optimization, and advised PNNL on appropriate through thickness thermal conductivity for improved frozen layer effect on FOD predictions. Autodesk also participated in project review meetings including preparations and discussions towards passing the go/no-go decision point. 3) Autodesk implemented an improved FOD inlet profile specification method through the part thickness for 3D meshes and provided an updated ASMI research version to PNNL. 4) The University of Illinois (Prof. C.L. Tucker) provided Autodesk with ideas to improve fiber orientation modeling 5) Purdue University re-measured fiber orientation for the fast-fill 50wt% LCF/PA66 edge-gated plaque, and delivered the fiber orientation data for this plaque at the selected locations (named A, B, and C, Figure 1) to PNNL. Purdue also re-measured fiber orientation for locations A on the fast-fill 30wt% LCF/PP and 50wt% LCF/PA66 center-gated plaques, which exhibited anomalous fiber orientation behavior. 6) Purdue University conducted fiber length measurements and delivered the length data to PNNL for the purge materials (slow-fill 30wt% LCF/PP and 30wt% LCF/PA66 purge materials) and PlastiComp plaques selected on the go/no-go list for fiber length model validation (i.e., slow-fill edge-gated 30wt% LCF/PP and 30wt% LCF/PA66 plaques, Locations A, B, and C). 7) PNNL developed a method to recover intact carbon fibers from LCF/PA66 materials. Isolated fibers were shipped to Purdue for length distribution analysis. 8) PNNL completed ASMI mid-plane analyses for all the PlastiComp plaques defined on the go/no-go list for fiber orientation (FO) model validation and compared the predicted fiber orientations with the measured data provided by Purdue at Locations A, B, and C on these plaques. The 15% accuracy criterion based on evaluation of tensile and bending stiffness was used to assess the accuracy in fiber orientation predictions. 9) PNNL completed ASMI mid-plane analyses for all the PlastiComp plaques defined on the go/no-go list for fiber length distribution (FLD) model validation and compared the predicted length distributions with the measured data provided by Purdue at Locations A, B, and C on these plaques. The 15% accuracy criterion based on evaluation of tensile and bending stiffness was used to assess the accuracy in fiber orientation predictions. 10) PNNL tested the new ASMI version received from Autodesk in March 2015, examined and discussed 3D fiber orientation predictions for PlastiComp plaques. 11) PlastiComp, Inc. (PlastiComp), Toyota Research Institute North America (Toyota) and Magna Exteriors and Interiors Corporation (Magna) participated in discussions with team members on the go/no-go plan. Toyota continued the discussion with Magna on tool modification for molding the complex part in order to achieve the target fiber length in the part.

  6. Injection

    International Nuclear Information System (INIS)

    The author presents an introduction to beam injection. Especially considered are single-turn injection, multi-turn injection, H- charge-exchange injection, and injection from a cyclotron into a synchrotron. Finally some novel injection schemes are briefly mentioned. (HSI)

  7. Determinação e análise de parâmetros para o desenvolvimento de um processo de decoração de peças plásticas através da injeção sobre tecido / Determination and analysis of parameters for the development of a process for decoration plastic parts by injection on fabrics

    Scientific Electronic Library Online (English)

    Cristiano, Linck; Carmen Iara Walter, Calcagno; João Antônio Pinto de, Oliveira.

    2015-02-01

    Full Text Available O processo de injeção sobre tecidos, utilizado na indústria automotiva, é caracterizado por modificações no processo de injeção convencional e possibilita o desenvolvimento de novos produtos com características diferenciadas. Devido às dificuldades de processamento, e tendo em vista as necessidades [...] de adaptação dos parâmetros de injeção quando essa é feita sobre tecidos, foi desenvolvida uma metodologia de determinação e análise de parâmetros de processo que possibilitaram o desenvolvimento desta técnica. Os testes foram realizados inicialmente em uma indústria produtora de peças automotivas e a metodologia adotada foi repetida em uma instituição de ensino. Verificou-se, então, que controlando os parâmetros de injeção e fechamento do molde, foi possível obter, em ambos os casos, peças conforme as especificações de qualidade requeridas. Abstract in english The injection molding process on fabrics used in the automotive industry is characterized by changes in conventional injection molding process and enables the development of new products with different characteristics. Due to processing difficulties, and considering the need for adaptation of inject [...] ion parameters when it is done on fabrics, a method for determining and analyzing the process parameters was developed so that technique could be put into practice. Initially tests were conducted in an industry producing automotive parts and the method adopted was replicated in an educational institution. Then, it has been found, that through controlling the injection and mold closing parameters, it was possible to obtain, parts conforming to quality specifications required in both cases.

  8. PENGEMBANGAN PROSES COMPRESSION MOLDING DALAM PEMBUATAN EDIBLE FILM DARI TEPUNG KORO PEDANG (Canavalia ensiformis L. [Development of Compression Molding Process for Edible Films Production from Canavalia ensiformis (L. Flour

    Directory of Open Access Journals (Sweden)

    Triana Lindriati1*

    2011-06-01

    Full Text Available Edible Films based on Canavalia Ensiformis flour could be made using compression molding process. This research was to investigate temperature (120oC, 130oC, 140oC and pressure ( 0.845 Mpa, 1.690 Mpa, 2.540 Mpa effect on the properties of the film. The compression-molding pressure significantly affected the film’s thickness, lightness, tensile strength, elongation and Water Vapor Transmition Rate (WVTR. Meanwhile molding temperature only affected film’s elongation (P<0.05 over the range of conditions studied. Increase in compaction pressure resulted in decreased thickness, tensile strength, elongation with increase in lightness (L* and WVTR. Increasing the molding temperature decreased elongation. Flexible, light-yellow edible films could be produced at a processing temperature of 140oC and compaction pressure of 0.845 Mpa. The films thickness was 0.302 mm; lightness (L* was 68.557, tensile strength was 4.091 Mpa, elongation was 37.547 % and WVTR was 0.001 mg/m2.det.

  9. Chemorheology of in-mold coating for compression molded SMC applications

    Science.gov (United States)

    Ko, Seunghyun; Straus, Elliott J.; Castro, Jose M.

    2015-05-01

    In-mold coating (IMC) is applied to compression molded sheet molding compound (SMC) exterior automotive or truck body panels as an environmentally friendly alternative to make the surface conductive for subsequent electrostatic painting operations. The coating is a thermosetting liquid that when injected onto the surface of the part cures and bonds to provide a smooth conductive surface. In order to optimize the IMC process, it is essential to predict the time available for flow, that is the time before the thermosetting reaction starts (inhibition time) as well as the time when the coating has enough structural integrity so that the mold can be opened without damaging the part surface (cure time). To predict both the inhibition time and the cure time, it is critical to study the chemorheology of IMC. In this paper, we study the chemorheology for a typical commercial IMC system, and show its relevance to both the flow and cure time for the IMC stage during SMC compression molding.

  10. Mold Allergy

    Science.gov (United States)

    ... to build a natural immunity to the trigger. Mobile Pollen/Mold App now available! Visit pollen.aaaai.org from your ... Slides: Immunotherapy: Alternative Routes » Teaching Slides: Immunotherapy: Changing ...

  11. Process development for the reactive injection moulding of caprolactam intermediates

    OpenAIRE

    Berg, Lars Fredrik

    2011-01-01

    In order to fulfil the need for efficient large volume capable production technologies for high performance composite structures, a new processing technology has been developed. The process is based on the injection moulding technology but differs from this known processing technology by enabling the production of continuous fibre reinforced high performance composites with fibre volume contents of over 40 % by volume. The processing technology enables the processing of very low viscosity pol...

  12. Investigation of cyclic solvent injection process for heavy oil recovery

    Energy Technology Data Exchange (ETDEWEB)

    Ivory, J.; Chang, J.; Coates, R.; Forshner, K. [Alberta Research Council, Edmonton, AB (Canada)

    2009-07-01

    Numerical and experimental studies of a cyclic solvent injection (CSI) process were presented. The study formed part of a larger research program investigating the use of solvents as a follow-up process in Cold Lake and Lloydminster reservoirs pressure-depleted using cold heavy oil production with sand (CHOPS). The CSI process consisted of a primary production process followed by 6 solvent injection cycles using 28 per cent propane and 72 per cent carbon dioxide (CO{sub 2}). Results of the experiments demonstrated a recovery rate of 50 per cent using the CSI process. A numerical model was developed to represent the physical characteristics of the experiments. Non-equilibrium rate equations were used to simulate the delay in the solvent reaching equilibrium concentration as it dissolved or exsolved in the oil in response to pressure and gas phase composition changes. A history match of the primary production portion of the experiment was then obtained using a foamy oil model. The history match was used validate the numerical model of the CSI process. The study showed that the quantity of gas injected in an injection period was insensitive to oil phase diffusion coefficients, but sensitive to solvent solubility in oil, dissolution rates and gas phase relative permeability. It was concluded that gas injections are also sensitive to molar densities in the oil phase and capillary pressure. 20 refs., 40 figs.

  13. Predictive Engineering Tools for Injection-Molded Long-Carbon-Fiber Thermoplastic Composites - FY13 Fourth Quarterly Report

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Ba Nghiep; Simmons, Kevin L.

    2013-12-02

    This quarterly report summarizes the status of the project planning to obtain all the approvals required for a Cooperative Research and Development Agreement (CRADA) with Autodesk, Inc., Toyota Motor Engineering and Manufacturing North America (Toyota), and Magna Exterior and Interiors Corporation (Magna). The final CRADA documents processed by PNNL’s Legal Services were submitted to all the parties for signatures.

  14. Geothermal injection treatment: process chemistry, field experiences, and design options

    Energy Technology Data Exchange (ETDEWEB)

    Kindle, C.H.; Mercer, B.W.; Elmore, R.P.; Blair, S.C.; Myers, D.A.

    1984-09-01

    The successful development of geothermal reservoirs to generate electric power will require the injection disposal of approximately 700,000 gal/h (2.6 x 10/sup 6/ 1/h) of heat-depleted brine for every 50,000 kW of generating capacity. To maintain injectability, the spent brine must be compatible with the receiving formation. The factors that influence this brine/formation compatibility and tests to quantify them are discussed in this report. Some form of treatment will be necessary prior to injection for most situations; the process chemistry involved to avoid and/or accelerate the formation of precipitate particles is also discussed. The treatment processes, either avoidance or controlled precipitation approaches, are described in terms of their principles and demonstrated applications in the geothermal field and, when such experience is limited, in other industrial use. Monitoring techniques for tracking particulate growth, the effect of process parameters on corrosion and well injectability are presented. Examples of brine injection, preinjection treatment, and recovery from injectivity loss are examined and related to the aspects listed above.

  15. Predictive Engineering Tools for Injection-Molded Long-Carbon-Fiber Thermoplastic Composites - FY13 Third Quarterly Report

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Ba Nghiep; Simmons, Kevin L.

    2013-08-06

    This quarterly report summarizes the status for the project planning to obtain all the approvals required for a Cooperative Research and Development Agreement (CRADA) with Autodesk, Inc., Toyota Motor Engineering and Manufacturing North America (Toyota), and Magna Exterior and Interiors Corporation (Magna). The CRADA documents have been processed by PNNL Legal Services that is also coordinating the revision effort with the industrial parties to address DOE’s comments.

  16. MODELING OF ELECTRONIC GASOLINE INJECTION PROCESSES IN TWO STROKE ENGINE

    Directory of Open Access Journals (Sweden)

    Hraivoronskyi, Y.

    2013-06-01

    Full Text Available Basic provision of the processes developed mode, occurring in ignition fuel system with electronically controlled two stroke engine with positive ignition are given. Fuel injection process’ calculation results for the case of placing fuel injector into intake system presented.

  17. Influence of the stretch blow molding processing parameters on PET bottles properties / Influence of the stretch blow molding processing parameters on PET bottles properties

    Directory of Open Access Journals (Sweden)

    Maja RUJNI?-SOKELE

    2008-04-01

    Full Text Available U radu je prikazana analiza utjecajnih faktora u postupku izradbe boca od poli(etilen-tereftalata za pakiranje jestivog ulja – injekcijskom razvla?nom puhanju. Razmatran je utjecaj pogonski prilagodljivih parametara izradbe na ?imbenike koji su važni za izradbu PET boca za pakiranje jestivog ulja, obujam i naknadno stezanje boca. Primjenom centralno kompozitnog plana pokusa odre?eni su faktori koji utje?u na obujam i naknadno stezanje PET boca. / The paper deals with the analysis of the influencing factors in the procedure of manufacturing poly(ethylene terephthalate bottles for packaging of table oil - injection stretch blow moulding. The influence of individual manufacturing parameters on the quality guidelines important in the making of PET bottles for table oil packaging, final volume, and post-shrinkage have been studied. The influencing factors have been determined which affect the volume and shrinkage of PET bottles by using the central composite design.

  18. Micro Injection Moulding Challenges Connected to the Realisation of Process Chains for Micro Injection Moulding

    DEFF Research Database (Denmark)

    Hansen, Hans NØrgaard

    2004-01-01

    The incorporation of micro and nano technology into the products of the future is an area of increasing interest. The ideas for new products based on this technology often take their starting point in specific scientific fields whereas the subsequent design and product development not necessarily is based on a systematic approach including manufacturing processes and production system capabilities. The process chain associated with micro and nano injection moulding usually comprises silicon or photoresist mastering, electroforming and polymer processing. However, other tooling technologies such as micro milling can be used for certain geometries. The paper describes the challenges connected with realisation of two different process chains for micro injection moulding based on two specific cases.

  19. Molds in the Environment

    Science.gov (United States)

    ... on Facebook Tweet Share Compartir Molds in the Environment What are molds? What are some of the ... molds found? Molds are found in virtually every environment and can be detected, both indoors and outdoors, ...

  20. New mold manufacturing techniques

    Science.gov (United States)

    Hall, Chris; Tricard, Marc; Murakoshi, Hiroshi; Yamamoto, Yoshihiro; Kuriyama, Kunitaka; Yoko, Hiroyoshi

    2005-08-01

    Typically, optical molds have been made from silicon carbide (SiC) or tungsten carbide (WC). Magnetorheological Finishing (MRF) polishing results of SiC and WC molds will be reviewed. Impressive figure corrections have been demonstrated on both types of materials. The roughness performance of CVD-SiC, WC and binderless WC will be compared. However, the hardness and polycrystalline nature of these materials make them difficult to manufacture. In this paper we report positive initial results using an alternate mold material, glassy carbon. Test samples have been ground, pre-polished and finish polished to a 38 nm surface figure peak-to-valley (PV) and a 6 Å rms surface roughness, with improved cycle times versus SiC and WC. Glassy carbon is a promising mold material candidate as an amorphous material of lower hardness. The lower hardness leads to more effective diamond grinding process and results in a better surface rms roughness following MRF. After reviewing key material properties of glassy carbon material, this paper will describe some collaborative activities between Toshiba Machine Co., Ltd. and QED Technologies (QED) to manufacture representative examples of glassy carbon. Details of the grinding, pre-polishing and final polishing process will be provided along with the resultant metrology results after key steps. Molding experiments based on these developments will also be presented.

  1. Improving the accuracy of micro injection moulding process simulations

    DEFF Research Database (Denmark)

    Marhöfer, David Maximilian; Tosello, Guido

    Process simulations in micro injection moulding aim at the optimization and support of the design of the mould, mould inserts, the plastic product, and the process. Nevertheless, dedicated software packages for micro injection moulding are not available. They are developed for macro plastic parts and are therefore limited in the capability of modelling the polymer flow in micro cavities. Hence, new strategies for comprehensive simulation models which provide more precise results open up new opportunities and will be discussed. Modelling and meshing recommendations are presented, leading to a multi-scale mesh of all relevant units of the injection moulding system. The implementation of boundary conditions, e.g. machine and venting, and results illustrating their importance on the simulation accuracy are presented.

  2. Application of Soft Computing for the Prediction of Warpage of Plastic Injection

    OpenAIRE

    Vijaya Kumar Reddy; J.Suresh Kumar; B. Sidda Reddy; Padmanabhan, G.

    2009-01-01

    This paper deals with the development of accurate warpage prediction model for plastic injection molded parts using softcomputing tools namely, artificial neural networks and support vector machines. For training, validating and testing of thewarpage model, a number of MoldFlow (FE) analyses have been carried out using Taguchi’s orthogonal array in the designof experimental technique by considering the process parameters such as mold temperature, melt temperature, packing pressure,packing t...

  3. Impact of physical properties of biodiesel on the injection process in a common-rail direct injection system

    International Nuclear Information System (INIS)

    This paper presents the influence of biodiesel fuel properties on the injection mass flow rate of a diesel common-rail injection system. Simulations are first performed with ISO 4113 diesel fuel on a four-cylinder common-rail system to evaluate a single and triple injection strategies. For each injection strategy, the impact of modifying a single fuel property at a time is evaluated so as to quantify its influence on the injection process. The results show that fuel density is the main property that affects the injection process, such as total mass injected and pressure wave in the common-rail system. The fuel's viscosity and bulk modulus also influence, but to a lessen degree, the mass flow rate of the injector notably during multiple injection strategies as individual properties change the fuel's dampening property and friction coefficient.

  4. Mold Growth

    Science.gov (United States)

    NASA

    2012-06-26

    In this activity learners observe mold growth on different types of bread by measuring and recording the growth rate. Educators can use this activity to introduce a challenge astronauts face while in space: no refrigeration. This lesson plan includes discussion questions, extensions, and black-line masters.

  5. Embranquecimento do polipropileno isotático injetado contendo TiO2 como pigmento / Whitening mechanism in injection molded polypropylene with TiO2 as pigment

    Scientific Electronic Library Online (English)

    Dênison R. J., Maia; Marco-Aurelio, De Paoli.

    2000-12-01

    Full Text Available Descrevemos neste trabalho as causas e o mecanismo do embranquecimento de peças de polipropileno isotático injetado. Para isto foram injetados corpos de prova e placas com e sem estabilizantes. As amostras foram envelhecidas por exposição ambiental e em equipamento de envelhecimento acelerado (Weath [...] erometer). Foi feito o acompanhamento visual das peças para que pudessem ser caracterizadas quando começassem a embranquecer. A caracterização foi feita através de espectroscopia FT-IR por reflectância, Microscopia eletrônica de varredura, Microfluorescência de raios-X, Reflectância de luz e Microanálise de energia dispersiva (EDS) da superfície. Os espectros de infravermelho mostraram o aparecimento de diversos produtos de degradação como cetonas, aldeídos, ácidos carboxílicos, ésteres, perésteres e alfa-cetoésteres. Quando as amostras começaram a embranquecer foi verificada a formação de fissuras superficiais e o aumento da reflectância de luz para todos os comprimentos de onda do espectro. Concomitantemente foi verificado que a composição de superfície não é alterada pelo envelhecimento. A superfície não apresenta grande quantidade de partículas de TiO2 expostas. Conclui-se que o embranquecimento das peças é devido ao fissuramento superficial que aumenta a quantidade de luz refletida na superfície e não pela migração do pigmento. Abstract in english We studied in this work the whitening mechanism in injection molded polypropylene (PP), a problem usually manifested in car parts and particularly in car bumpers. For the development of this work we had samples (plaques and test samples) with and without antioxidants and ultraviolet stabilizers. The [...] se samples had been already aged by natural and artificial (Weatherometer equipment) exposure. In the natural aging samples were collected when the material started to whiten, after 3190, 4320 and 6190 h of exposure. In the artificial aging samples were collected after 415, 515 and 3000 h of exposure. The samples were characterized by visual observation, infrared spectroscopy, scanning electron microscopy, surface total light reflectance and titanium mapping in the samples cross section by X-ray microfluorescence and X-ray difraction of the TiO2 used in the formulation. When the samples start to whiten we observe the evolution of surface fissures which increase the surface roughness. This is followed by an increase in the total light reflection by the surface for all wavelengths. We observed that titanium is almost homogeneously distributed along samples cross section. In addition, we did not observe high concentration of exposed TiO2 on the surface. We conclude that the whitening phenomenon is a consequence of surface fissures evolution, which provides higher surface roughness and is followed by a higher surface diffuse light reflectance.

  6. Casting process modeling using ProCAST and CAST2D -- Mold filling, solidification and structural response

    Energy Technology Data Exchange (ETDEWEB)

    Stein, W.; Shapiro, A.B.

    1992-04-01

    Correctly modeling the fluid flow and heat transfer during the filling of a mold with a molten fluid is important in predicting the quality of a cast part. Determining the dynamics of the flow and the free surface shape during filling are essential in establishing the temperature gradients in the melt and in the mold. After filling the mold, solidification may be greatly affected by natural convection effects. Further, correctly modeling the physics across the solidifying part-mold interface is crucial in predicting the part final shape. Most metals undergo a volume change on solidification (e.g. aluminum-6.6%) and shrinkage on cooling. As the cast metal shrinks, it pulls away from the mold wall creating a gap. This gap affects the thermal contact resistance between the part and mold. The thermal contact resistance increases as the gap widens. This directly affects the cooling rate and ultimately the final cast shape, stress state, and quality of the cast part.

  7. Sol-gel concave micro-lens arrays fabricated by combining the replicated PDMS soft mold with UV-cured imprint process

    Science.gov (United States)

    Zhang, Xuehua; Que, Wenxiu; Chen, Jing; Hu, Jiaxing; Gao, Tianxi; Liu, Weiguo

    2013-11-01

    Photosensitive TiO2/organically modified silane organic-inorganic hybrid thin films were synthesized by combining a low-temperature sol-gel process with a spin-coating method. Optical transmittance properties and the photochemical activities of the planar hybrid films were characterized by UV-Visible spectroscopy and Fourier transform infrared spectroscopy. Advantages for fabrication of the concave micro-lens arrays (MLAs) based on the photosensitive hybrid films were demonstrated by using the replicated polydimethylsiloxane (PDMS) soft mold as the imprint mold and a UV soft imprint technique. Morphological and surface profile properties of the master, the PDMS soft molds and the as-fabricated sol-gel concave MLAs were observed by scanning electron microscopy and laser confocal scanning microscopy. Contact angles of water on the PDMS soft molds baked at different temperatures were studied. Optical imaging properties of the as-fabricated concave MLAs were confirmed by a self-made optical test system. Results indicate that the as-prepared photo-patternable hybrid materials have great applicability for the fabrication of photonic components, thus providing an effective method to fabricate concave MLAs based on the as-synthesized hybrid films by combining the UV-cured imprint technique with the replicated PDMS soft mold, which has advantages of simplicity, cost-effective and mass production and potential application in industry production.

  8. Molding and casting process of a depleted uranium shield for a multipurpose type B (U) transport package of radioactive substances

    International Nuclear Information System (INIS)

    Anticipating future demand for transport of radioisotopes, a high performance transport package (BU-MAN) with a gamma barrier built in depleted uranium (DU) has been designed by the Radioisotope and Radiation Program (P4) of CNEA in 2003. The shield is a hollow cylinder of approximately 173 mm outside diameter, 223 mm in height, a cylindrical hollow interior 63 mm diameter and 166 mm in height, and a cylindrical plug 58 mm diameter and 57 mm height. Its total weight is 84 Kg. In the period 2004-2006 the Special Alloys Group (DM-GIDAT-GAEN-CNEA) has conducted several developments in order to obtain the mentioned shield, including a manufacturing test casting SAE 1010 in a sand mold. The confirmation of its properties, mechanical and gamma shield are being evaluated by licensing tests of the whole package. In this paper we show all metallurgical processes involved to get the shield in metallic DU. (author)

  9. Texturing of HTSC materials during molding

    International Nuclear Information System (INIS)

    HTSC-ceramics texturing processes at the stages of cold and hot molding are studied. It is shown that in HTSC materials based on bismuth compounds and YBa2Cu3Ox, texture is formed under cold molding. It is easily destroyed under hot molding due to the occurrence of recrystallization process in a plastically deformed briquet. Texturing degree of hot-molded YBa2Cu3Ox ceramics can be increased by a short-term heating prior to hot molding up to temperature close to peritectic melting. 4 refs.; 3 figs

  10. Processamento de laminados de compósitos poliméricos avançados com bordas moldadas Processing of advanced structural polymeric composite laminates with molded edges

    Directory of Open Access Journals (Sweden)

    Geraldo M. Cândido

    2000-03-01

    Full Text Available Técnicas que contribuem para melhorar a qualidade dos compósitos produzidos por laminação manual e cura em autoclave e/ou visando à redução no custo de processamento têm sido intensamente pesquisadas. Uma das maneiras de se obter esse ganho de produtividade é eliminar operações de usinagem da borda por meio da técnica de fabricação de laminados com bordas moldadas. Neste trabalho é apresentada uma revisão da tecnologia de fabricação de peças estruturais de compósitos poliméricos avançados, com ênfase na produção de laminados com bordas moldadas. Exemplos deste tipo de acabamento são mostrados utilizando laminados cruzados simétricos [(0,90/0]s e [(0,90/90]s, fabricados com fita unidirecional contínua e tecido bidirecional de carbono, pré-impregnados com resina epóxi. O arranjo de fibras e resina na região da borda livre de todos os corpos-de-prova foi analisado usando um microscópio óptico. Foi observado que as fibras longitudinais (a 0° podem se mover lateralmente na direção da borda moldada sob ação da pressão aplicada durante a cura. Bolsas de resina pura podem ser formadas nessa região dependendo da seqüência de empilhamento do laminado.Manufacturing techniques that improve the quality and/or reduce the cost of advanced composites structures produced by vacuum bag and cure in autoclave have been intensely investigated. One way to obtain a gain in productivity is to produce laminates with molded edges. This work presents a literature review of the fabrication process of structural parts of advanced polymeric composites, with emphasis in the manufacturing of laminates with molded edges. As an example of this type of edge finishing, symmetric cross ply laminates [(0,90/0]s and [(0,90/90]s were manufactured with pre-impregnated unidirectional tape and fabric. The arrangement of fibers and resin near the free edge of all specimens were analyzed using an optical microscope. It was observed that longitudinal fibers in the laminate (fibers at 0° may move laterally towards the molded edge under the action of the pressure applied during cure. Pockets of pure resin may be formed at this region depending on the laminate stacking sequence.

  11. Influência da cera de carnaúba no comportamento reológico de misturas usadas na moldagem por injeção em baixa pressão / Influence of carnauba wax in the feedstock rheology used in low-pressure injection molding

    Scientific Electronic Library Online (English)

    P. A., Ourique; R. C. D., Cruz; J. E., Zorzi.

    2015-03-01

    Full Text Available A moldagem por injeção em baixa pressão (MIBP) tem algumas vantagens sobre outros métodos de conformação de peças cerâmicas com formas complexas. Dentre as vantagens estão os menores custos na produção de lotes pequenos e médios e o menor desgaste de moldes e equipamento. Neste trabalho, foi estudad [...] o o efeito de um dos aditivos orgânicos usados na MIBP, a cera de carnaúba, no comportamento reológico da mistura (feedstock). O pó cerâmico utilizado foi uma alumina, com tamanho de partícula em torno de 0,4 ?m. Com adições de 5% e 10% em peso de cera de carnaúba no veículo orgânico a viscosidade diminui significativamente, sendo bem mais acentuada com 10%, enquanto que, acima deste valor (15%), a viscosidade diminui, mas esta redução é menos pronunciada. Em contrapartida, em feedstocks sem a cera de carnaúba (0%), a viscosidade é tão elevada que praticamente inviabiliza a injeção em baixas pressões. Abstract in english The low-pressure injection molding (LPIM) has some advantages over other methods of forming ceramic parts with complex shapes. Among the advantages are the lower costs in the production of small and medium lots and less wear of molds and equipment. In this work, the effect of an organic additive use [...] d in LPIM been studied, carnauba wax, on the rheology of the mixture (feedstock). The ceramic powder used was alumina with particle size of about 0.4 micrometers. With additions of 5wt% and 10wt% of carnauba wax in the organic vehicle, viscosity decreases significantly, being much more pronounced at 10%, while above this value (15%), the viscosity decrease, but this reduction is less pronounced. In contrast, in feedstock without carnauba wax (0%), the viscosity is so high that the injection almost impossible at low pressures.

  12. Selección de Resinas de Poliéster Insaturado para Procesos de Transferencia de Resina en Molde Cerrado / Selection of Unsaturated Polyester Resins for Closed Resin Transfer Moulding Processes

    Scientific Electronic Library Online (English)

    Leyla Y., Jaramillo-Zapata; Iván D., Patiño-Arcila.

    2012-06-01

    Full Text Available En este artículo se analizan tres tipos de resinas poliéster insaturado comerciales de amplio uso en el mercado nacional y se evalúa su conveniencia de uso en procesos de transferencia de resina en molde cerrado (RTM), de acuerdo con criterios de viscosidad y reactividad. Se compara la viscosidad de [...] las resinas entre 15 y 50°C, así como la reactividad mediante curvas de curado a temperatura ambiente, con porcentajes de catalizador del 1, 1.5 y 2%. De acuerdo con los resultados se determinó que algunas de las resinas son susceptibles de uso en procesos RTM, por su apropiada viscosidad, estabilidad en la reactividad y su velocidad de curado. Estas características son de gran importancia al momento de seleccionar las resinas poliéster insaturado, de acuerdo con las condiciones del proceso en molde cerrado. Abstract in english In this paper three commercial unsaturated polyester resins of wide use in Colombia are analyzed and it is evaluated the convenience of their use in resin transfer molding processes according to viscosity and reactivity criteria. The resin viscosities are compared between 15 and 50°C, in the same wa [...] y as the reactivity by mean of the curing curves at room temperature, using catalyst at 1, 1.5 and 2%. In agreement with the results, it was determined that some resins are suitable for RTM process, because of their appropriate viscosity, consistent reactivity and curing velocity. These features are of great importance in the unsaturated polyester resin selection, according to conditions of closed mold processes.

  13. Microstructured metal molds fabricated via investment casting

    International Nuclear Information System (INIS)

    This paper describes an investment casting process to produce aluminum molds having integrated microstructures. Unlike conventional micromolding tools, the aluminum mold was large and had complex curved surfaces. The aluminum was cast from curved microstructured ceramic molds which were themselves cast from curved microstructured rubber. The aluminum microstructures had an aspect ratio of 1:1 and sizes ranging from 25 to 50 µm. Many structures were successfully cast into the aluminum with excellent replication fidelity, including circular, square and triangular holes. We demonstrate molding of large, curved surfaces having surface microstructures using the aluminum mold.

  14. Polyamide from lactams by reactive rotational molding via anionic ring-opening polymerization: Optimization of processing parameters

    Directory of Open Access Journals (Sweden)

    N. Barhoumi

    2013-01-01

    Full Text Available A reactive rotational molding (RRM process was developed to obtain a PA6 by activated anionic ring-opening polymerization of epsilon-caprolactam (APA6. Sodium caprolactamate (C10 and caprolactam magnesium bromide (C1 were employed as catalysts, and difunctional hexamethylene-1,6-dicarbamoylcaprolactam (C20 was used as an activator. The kinetics of the anionic polymerization of !-caprolactam into polyamide 6 was monitored through dynamic rheology and differential scanning calorimetry measurements. The effect of the processing parameters, such as the polymerization temperature, different catalyst/activator combinations and concentrations, on the kinetics of polymerization is discussed. A temperature of 150°C was demonstrated to be the most appropriate. It was also found that crystallization may occur during PA6 polymerization and that the combination C1/C20 was well suited as it permitted a suitable induction time. Isoviscosity curves were drawn in order to determine the available processing window for RRM. The properties of the obtained APA6 were compared with those of a conventionally rotomolded PA6. Results pointed at lower cycle times and increased tensile properties at weak deformation.

  15. Cavity air flow behavior during filling in microinjection molding

    DEFF Research Database (Denmark)

    Griffiths, C.A.; Dimov, S.S.

    2011-01-01

    Process monitoring of microinjection molding (?-IM) is of crucial importance in understanding the effects of different parameter settings on the process, especially on its performance and consistency with regard to parts' quality. Quality factors related to mold cavity air evacuation can provide valuable information about the process dynamics and also about the filling of a cavity by a polymer melt. In this paper, a novel experimental setup is proposed to monitor maximum air flow and air flow work as an integral of the air flow over time by employing a microelectromechanical system gas sensor mounted inside the mold. The influence of four ?IM parameters, melt temperature, mold temperature, injection speed, and resistance to air evacuation, on two air flow-related output parameters is investigated by carrying out a design of experiment study. The results provide empirical evidences about the effects of process parameters on cavity air evacuation, and the influence of air evacuation on the part flow length. © 2011 American Society of Mechanical Engineers.

  16. Simplified mold filling simulation in resin transfer molding

    Science.gov (United States)

    Cai, Zhong

    1992-01-01

    A simplified mold filling simulation is developed to estimate the process variables for resin transfer molding (RTM) of structural composite parts. This approach uses very limited calculations and needs only microcomputer facilities. Resin flow in RTM processes is considered to follow Darcy's law. Both Newtonian fluid and power-law fluid are studied. Mold sections are decomposed as a combination of simple geometry shapes, such as rectangular, circular, trapezoid, spheric or conic sections. Closed form solutions are derived for each of these simplified shapes. The total mold filling time can then be estimated, as well as the required inlet pressure or flow rate. Compared with more sophisticated simulation programs, the computer time and user interface effort are greatly reduced.

  17. Model optimization for mould filling analysis with application CAE package C-Mold

    OpenAIRE

    J. Nabialek; J. Koszkul

    2006-01-01

    Purpose: The simulation of mould filling in injection process has been presented. The methodology and sources of errors during preparation of simulation has been presented. Design/methodology/approach: The tensile test specimen has been used as a model. The experimental verification of numerical simulations of different FEM models reflecting different injection conditions has been performed. For the simulation investigations a professional computer CAE software C-Mold ver. 99.1. has been empl...

  18. Evaluation of wear during the injection process with the use of optical profilometry

    Science.gov (United States)

    Hernández, P.; Díaz, M.; Covelo, E.; Ares, E.

    2012-04-01

    This article deals with the study of wear of non-conventional materials in the plastic injection industry, particularly in inserts for reusable injection molds. A methodology for the analysis of wear is proposed using new measurement parameters. Superficial parameters like roughness average (Ra) have proven not to be quite effective for this purpose. Therefore new coefficients are suggested, as the Minimum Wear Area (MWA), which takes advantage of the collected data and appears to be a better choice for wear characterization. A Polyamide with 30% load of fiberglass has been injected into two cavities manufactured in different material (aluminum and brass) and with the same geometry, in which the wear at different points has been evaluated. We have used interferometry and an optical microscope as measurement tools. Finite element analysis and simulation software has also been used.

  19. Influence of calcium carbonate and slip agent addition on linear medium density polyethylene processed by rotational molding

    Scientific Electronic Library Online (English)

    Marina I., Baumer; Janaina L., Leite; Daniela, Becker.

    2014-02-01

    Full Text Available In this paper, the influence of calcium carbonate and slip agent on linear medium density polyethylene (LMDPE) processed by rotational molding was evaluated. LMDPE was dry blended with different CaCO3 masterbatch ratios, erucamide slip agent and then extruded, micronized and rotomolded. The powder s [...] amples were characterized using MFI (Melting flow index), dry flow and bulk density. The characterization of rotomolded samples properties was performed by DSC (Differential scanning calorimetry), microscopy analysis, izod impact and tensile test. The results pointed out that the CaCO3 addition modifies the bulk density compared to neat LMDPE, but did not significantly affect the dry flow and MFI. The erucamide addition decreased the dry flow and increased the bulk densities. The porosity degree data showed that CaCO3 addition in the LMDPE increased the quantity of pores. The DSC results showed no significant difference in the crystallinity degree. The behavior of porosity led to a decrease in the mechanical properties of LMDPE with the CaCO3 addition.

  20. Chalcogenide-mold interactions during precision glass molding (PGM) of GeAsSe glasses

    Science.gov (United States)

    Gleason, B.; Wachtel, P.; Musgraves, J. D.; Steinkopf, R.; Eberhardt, R.; Richardson, K.

    2013-09-01

    Five chalcogenide glasses in the GeAsSe ternary glass system were melted, fabricated into flats, and molded between planar, uncoated, binderless WC molds using a laboratory-scale precision glass molding machine. The five glasses originate at the binary arsenic triselenide (As40Se60) and are modified by replacing As with Se in 5 mol% increments, or by locking the As:Se ratio and adding Ge, also in 5 mol% increments. The glasses are separated into two groups, one for the Ge-free compositions and the other for the Ge-containing compositions. This effort analyzes the differences between the Ge-containing and the Ge-free glasses on the post-molded glass and mold surface behavior, as well as the mold lifetime. Fabrication features, such as scratch and/or dig marks were present on the glass and mold surfaces prior to the PGM process. White light interferometry analysis of the surfaces shows an overall reduction in the RMS roughness of the glass after molding, and an increase of the roughness of the molds, after 15 molding cycles. After molding, the quantity of observable defects, primarily deposits and dig marks are increased for both the glass and mold surfaces. Deposits found on the WC molds and glasses were analyzed using Electron Dispersive X-ray Spectroscopy (EDS) and showed no evidence of being due to material transfer between the WC molds and the glass constituents. In general the main observable difference in the analysis of the two post molded sets, despite the changes in chemistry, is the quantity of molding induced defects near the edge of the GeAsSe samples.

  1. P80 SRM low torque flex-seal development - thermal and chemical modeling of molding process

    Science.gov (United States)

    Descamps, C.; Gautronneau, E.; Rousseau, G.; Daurat, M.

    2009-09-01

    The development of the flex-seal component of the P80 nozzle gave the opportunity to set up new design and manufacturing process methods. Due to the short development lead time required by VEGA program, the usual manufacturing iterative tests work flow, which is usually time consuming, had to be enhanced in order to use a more predictive approach. A newly refined rubber vulcanization description was built up and identified on laboratory samples. This chemical model was implemented in a thermal analysis code. The complete model successfully supports the manufacturing processes. These activities were conducted with the support of ESA/CNES Research & Technologies and DGA (General Delegation for Armament).

  2. Characterization of the level fluctuations in a physical model of the steel continuous casting mold through image processing

    Scientific Electronic Library Online (English)

    J.R., Miranda-Tello; F., Sánchez-Rangel; C.A., Real-Ramírez; G., Khatchatourov; J.A., Aragón-Lezama; L.F., Hoyos-Reyes; E.A., Andrade-González; J.I., González-Trejo.

    2012-04-01

    Full Text Available In this work is characterized the periodic behavior of the liquid level inside a scaled cold-model of the mold section of a steel continuous casting machine, which uses water as working fluid. The models are designed in order to simulate the dynamic forces acting on the molten steel inside a mold of [...] continuous casting. The force magnitude can induce choppy flow, waves and vortex formation in the mold. The experimental model uses a closed-loop hydraulic configuration. In the mold, the inlet and the outlet water flow rates are the same. This configuration resembles a perfect control of the liquid level inside the water model. A high-speed video camera was used to get several video clips of the movement of the water level profile. Several techniques were tested in order to obtain the best lighting conditions for recording the water movement. The edge-detection technique of Sobel was used to determine the profile of the liquid level in each one of the images recorded. The analysis of the dynamic behavior of the water profile showed that the fluctuations of the liquid level inside the mold have a complex structure, which is repeated over large time periods.

  3. Permeability characterization and quality control of reinforcement in resin transfer molding by the gas flow method

    Science.gov (United States)

    Opperer, Jeremy G.

    Resin transfer molding (RTM) requires the permeation of a viscous fluid through a mold enclosed preform. The in-plane flow pattern, rate of flow, and gate pressures are essential to the design of an efficient RTM process. This information can be calculated using Darcy's Law, which is dependent on the constituent material properties, fluid viscosity and preform permeability. Established methods and databases are available to determine viscosity, however, there are no established procedures for quantifying RTM preform permeability. This work discusses previous techniques for permeability estimation using liquid flow methods. Problems associated with such approaches are addressed and experienced firsthand, through laboratory experimentation. A gas flow method (GFM) for permeability measurement is introduced. It is proven to be robust and facilitates the rapid acquisition of permeability data without contaminating the material while it is in the mold. The feasibility of this method is demonstrated using a mold with multiple ports for gas injection and pressure measurement, and yielded consistent and reliable results. The GFM is applied to determine the quality of fibrous preforms in an RTM mold prior to resin injection. Defects resulting from preform misplacement, accidental inclusions, material preparation, etc., are quantified. Unintentional permeability variations, due to such defects, can result in defective part production and excessive part scrapping. Pressure profiles generated during steady-state gas flow are affected by such variations. To determine the anomaly type, location, and severity, a multivariate statistical approach called discriminant analysis (DA) is applied to compare measured quantities from a test preform with quantities obtained from known groups. The tested preform is then classified into a defect free group or any one of several groups associated with specific types of defects, such as inclusions, shear, and race tracking. Application of this process has been accomplished on an unmodified industrial mold used to fabricate composite curved I-Beam stiffeners. The GFM for RTM preform quality control can be used to optimize industrial RTM processes with minimal inconvenience to mold operators.

  4. DATA MINING BASED KNOWLEDGE DISCOVERY FOR QUALITY PREDICTION AND CONTROL OF EXTRUSION BLOW MOLDING PROCESS

    OpenAIRE

    E.V.Ramana; P. Ravinder Reddy

    2013-01-01

    In practice, when quality of products fall below the expected level, causal relationships between process variables and product defects are investigated. Quality improvement and control activities in product manufacturing include identifying the factors that significantly affect quality, modeling relationships between input attributes and target attribute (yield, quality, performance index etc) and predicting quality levels of given input attributes. Data mining tools have created new ways of...

  5. Rapid tooling for functional prototyping of metal mold processes. CRADA final report

    Energy Technology Data Exchange (ETDEWEB)

    Zacharia, T.; Ludtka, G.M.; Bjerke, M.A.; Gray, W.H.

    1997-12-01

    The overall scope of this endeavor was to develop an integrated computer system, running on a network of heterogeneous computers, that would allow the rapid development of tool designs, and then use process models to determine whether the initial tooling would have characteristics which produce the prototype parts. The major thrust of this program for ORNL was the definition of the requirements for the development of the integrated die design system with the functional purpose to link part design, tool design, and component fabrication through a seamless software environment. The principal product would be a system control program that would coordinate the various application programs and implement the data transfer so that any networked workstation would be useable. The overall system control architecture was to be required to easily facilitate any changes, upgrades, or replacements of the model from either the manufacturing end or the design criteria standpoint. The initial design of such a program is described in the section labeled ``Control Program Design``. A critical aspect of this research was the design of the system flow chart showing the exact system components and the data to be transferred. All of the major system components would have been configured to ensure data file compatibility and transferability across the Internet. The intent was to use commercially available packages to model the various manufacturing processes for creating the die and die inserts in addition to modeling the processes for which these parts were to be used. In order to meet all of these requirements, investigative research was conducted to determine the system flow features and software components within the various organizations contributing to this project. This research is summarized.

  6. Roughness measurement of hole processing surface for mold steel using white light interferometer

    International Nuclear Information System (INIS)

    In this study, NIMAX material has been processed using the three dimensional measuring instrument and white light interferometer. They were tested to roundness and surface roughness and results are as follows: As for a cutting characteristic, it indicated that F4 showed a lower result than 2F showed due to the high hardness of the material and showed a good result when spindle rotation speed and tool feed were low. As for the measurement of roundness through 3 Dimensional measuring machine, it indicated that 4F showed a good result like the condition of cutting component and that roundness showed a good result when spindle rotation speed of 1,700 rpm and tool feed speed of 85 mm/min were applied. As for the surface roughness of processing surface, Surface roughness showed better 4F than 2F and conditions of spindle rotation speed 1,700 rpm, tool feed rate 55 mm/min showed good results in the Ra 0.4025 ?m

  7. Comparative description of structure and properties of Ti-6Al-4V titanium alloy for biomedical applications produced by two methods: conventional (molding and innovative (injection ones

    Directory of Open Access Journals (Sweden)

    J. Klimas

    2013-12-01

    Full Text Available Purpose: In paper characterized two methods produced titanium alloy: hitherto used in industry – conti-casting and innovative method of obtaining solid amorphous alloy by injection casting. The results of studies comparing the structure and properties of the alloy Ti-6Al-4V produced by both methods. Design/methodology/approach: Test samples were titanium alloy Ti-6Al-4V produced by two methods: conventional and injection. To achieve the objective pursued performed the following tests: microstructure observation was carried out, the analysis of mechanical properties (microhardness and corrosion resistance tests were performed in Ringer’s liquid, which simulates the human body fluids. Findings: Microstructural study allowed to observe that titanium alloy T-6Al-4V produced by conventional method has crystalline ordered structure which is characteristic for materials obtained by drawing, with oriented grains and elongated in the direction of drawing. Same alloy produced by injection casting has amorphous structure with occurrences of the single-crystal seeds, that kind of structure has lack of order and regularity. The microhardness study showed, that titanium alloy Ti-6Al-4V produced by drawing has a hardness of less than twice for the same alloy produced by the injection. The corrosion tests conducted in an environment that simulates human body fluids, revealed showed that the materials made by injection have significantly corrosion potential than alloy obtained by drawing. Originality/value: The paper presents a comparative study of titanium alloy produced by drawing and massive amorphous alloy produced by unconventional method – injection casting. By the results proved that the alloy produced by injection has much better properties than alloy produced by drawing.

  8. Process Condition Monitoring of Micro Moulding Using a Two-plunger Micro Injection Moulding Machine

    DEFF Research Database (Denmark)

    Tosello, Guido; Hansen, Hans NØrgaard

    2010-01-01

    The influence of micro injection moulding (µIM) process parameters (melt and mould temperature, piston injection speed and stoke length) on the injection pressure was investigated using Design of Experiments. Direct piston injection pressure measurements were performed and data collected using a micro injection moulding machine equipped with a two-pluger injection unit. Miniaturized dog-bone shaped speciments on polyoxymethylene (POM) were moulded over a wide range of processing cpnditions in order to characterize the process and assess its capability. Experimental results obtained under diferent processing conditions were evaluated to correlate the process parameter levels influence on the selected responses, considering both average values (for processes characterization) and standard derivations (for process robustness assessment).

  9. IC chip stress during plastic package molding

    Energy Technology Data Exchange (ETDEWEB)

    Palmer, D.W.; Benson, D.A.; Peterson, D.W.; Sweet, J.N.

    1998-02-01

    Approximately 95% of the world`s integrated chips are packaged using a hot, high pressure transfer molding process. The stress created by the flow of silica powder loaded epoxy can displace the fine bonding wires and can even distort the metalization patterns under the protective chip passivation layer. In this study the authors developed a technique to measure the mechanical stress over the surface of an integrated circuit during the molding process. A CMOS test chip with 25 diffused resistor stress sensors was applied to a commercial lead frame. Both compression and shear stresses were measured at all 25 locations on the surface of the chip every 50 milliseconds during molding. These measurements have a fine time and stress resolution which should allow comparison with computer simulation of the molding process, thus allowing optimization of both the manufacturing process and mold geometry.

  10. Numerical simulation in steam injection process by a mechanistic approach

    Energy Technology Data Exchange (ETDEWEB)

    De Souza, J.C.Jr.; Campos, W.; Lopes, D.; Moura, L.S.S. [Petrobras, Rio de Janeiro (Brazil)

    2008-10-15

    Steam injection is a common thermal recovery method used in very viscous oil reservoirs. The method involves the injection of heat to reduce viscosity and mobilize oil. A steam generation and injection system consists primarily of a steam source, distribution lines, injection wells and a discarding tank. In order to optimize injection and improve the oil recovery factor, one must determine the parameters of steam flow such as pressure, temperature and steam quality. This study focused on developing a unified mathematical model by means of a mechanistic approach for two-phase steam flow in pipelines and wells. The hydrodynamic and heat transfer mechanistic model was implemented in a computer simulator to model the parameters of steam injection while trying to avoid the use of empirical correlations. A marching algorithm was used to determine the distribution of pressure and temperature along the pipelines and wellbores. The mathematical model for steam flow in injection systems, developed by a mechanistic approach (VapMec) performed well when the simulated values of pressures and temperatures were compared with the values measured during field tests. The newly developed VapMec model was incorporated in the LinVap-3 simulator that constitutes an engineering supporting tool for steam injection wells operated by Petrobras. 23 refs., 7 tabs., 6 figs.

  11. QUANTIFYING INDOOR MOLDS

    Science.gov (United States)

    There is growing awareness that indoor molds/fungi may be connected to such conditions as asthma, allergies, hemorrhaging, chronic rhinosinusitis, memory loss, and a symptom complex called sick-building-syndrome. In addition, molds cause frequently fatal nosocomical infections. ...

  12. LC/MARC on MOLDS; An Experiment in Computer-Based Interactive Bibliographic Storage, Search, Retrieval, and Processing

    OpenAIRE

    Atherton, Pauline; Miller, Karen B.

    2013-01-01

    A project at Syracuse University utilizing MOLDS, a generalized computer-based interactive retrieval program, with a portion of the Library of Congress MARC Pilot Project tapes as a data base. The system, written in FORTRAN, was used in both a batch and an on-line mode. It formed part of a computer laboratory for library science students during 1968-1969. This report describes the system and its components and points out its advantages and disadvantages.

  13. Large-scale micro- and nanopatterns of cu(in,ga)se2 thin film solar cells by mold-assisted chemical-etching process.

    Science.gov (United States)

    Wang, Yi-Chung; Cheng, Hsiang-Ying; Yen, Yu-Ting; Wu, Tsung-Ta; Hsu, Cheng-Hung; Tsai, Hung-Wei; Shen, Chang-Hong; Shieh, Jia-Min; Chueh, Yu-Lun

    2015-04-28

    A reactive mold-assisted chemical etching (MACE) process through an easy-to-make agarose stamp soaked in bromine methanol etchant to rapidly imprint larger area micro- and nanoarrays on CIGS substrates was demonstrated. Interestingly, by using the agarose stamp during the MACE process with and without additive containing oil and triton, CIGS microdome and microhole arrays can be formed on the CIGS substrate. Detailed formation mechanisms of microstructures and the chemical composition variation after the etching process were investigated. In addition, various microand nanostructures were also demonstrated by this universal approach. The microstructure arrays integrated into standard CIGS solar cells with thinner thickness can still achieve an efficiency of 11.22%, yielding an enhanced efficiency of ?18% compared with that of their planar counterpart due to an excellent absorption behavior confirmed by the simulation results, which opens up a promising way for the realization of high-efficiency micro- or nanostructured thin-film solar cells. Finally, the complete dissolution of agarose stamp into hot water demonstrates an environmentally friendly method by the mold-assisted chemical etching process through an easy-to-make agarose stamp. PMID:25769317

  14. Simulation on Gas Injection Refining Process with Mechanical Stirring

    OpenAIRE

    Zhang Ting’an; Zhang Junhua; Zhao Hongliang; Shao Pin; Liu Yan

    2012-01-01

    Basing on the new method of in-situ desulfurization with gas injection and mechanical stirring, the effect of bubble dispersion and disintegration of three type impellers are numerically simulated by commercial CFD software Ansys Fluent 12.0. Numerical simulations of three-dimensional multiphase turbulence in gas injection and mechanical stirring are performed by adopting unsteady SM method coupled with Eulerian multiphase model and two-phase turbulence model. The information of gas-liquid fl...

  15. Determination of application possibilities of microwave heating in the curing process of water glass molding sands with fluid esters. Part 1

    Directory of Open Access Journals (Sweden)

    K. Granat

    2009-01-01

    Full Text Available This article presents results of the experimental trial of combination of the chemical method of water glass molding sands’ curing, used in foundry industry, with an innovative microwave heating. The research objective was to indicate at new areas of microwave energy application. The sands prepared, according to recommendations for curing technology, with the use of ethylene glycol diacetate, have been subject to microwave influence. The attempt at determination of microwave influence on qualitative changes of the binding bridges created during the curing process concerned such parameters as: bending and tensile strength, permeability as well as wear resistance. Moreover,we also determined the influence of microwave curing on the phenomena accompanying the process as well as bond stability (storage time of the prepared molding and core sands. It has been found, basing on the result analysis, that the innovative microwave heating might constitute a very good supplementation of the ester curing method. The advantages of the combined chemical and microwave gelation process include, among others, improvement of the described resistance and technological parameters as well as significant decrease of preparation time of foundry moulds and cores. The subject discussed in this article will be continued in its second part.

  16. Molding of Aluminum Foams by Using Hot Powder Extrusion

    Directory of Open Access Journals (Sweden)

    Yoshitaka Tanino

    2012-06-01

    Full Text Available In order to form aluminum foams directly from powder, a combined process of hot powder extrusion and molding is proposed. Aluminum powder mixed with a foaming agent is extruded into the mold through the die heated to a temperature higher than the melting point, and the mold is filled with the aluminum foam. When a stainless steel pipe is used for a simple mold, an aluminum foam bar is obtained of which the relative density varies between 0.2 and 0.3. The molding of aluminum foam by using three types of mold shape shows the influence of gravity and friction. The effect of gravity is significant when a large step exists at the connection between the mold inlet and the die outlet, and friction is dominant in cases where foam is mold in a narrow space.

  17. Injection process of the Cornell Electron Storage Ring CESR

    International Nuclear Information System (INIS)

    The injection system for the Cornell Electron Storage Ring CESR is presented. The design of the beam transport system between the Wilson Electron Synchrotron and CESR is discussed, including calculations of the transport optics and possible injection errors. The vernier phase compression technique used to shorten the positron accumulation time is discussed. Crucial to this technique is the trajectory length of positrons that are extracted from CESR, allowed to circulate in the synchrotron, and reinjected into CESR. This length is calculated in detail. Estimates are included for the beam filling time. Results from beam tests are compared with these calculations

  18. Injection process of the Cornell Electron Storage Ring (CESR)

    International Nuclear Information System (INIS)

    The injection system for the Cornell Electron Storage Ring CESR is presented. The design of the beam transport system between the Wilson Electron Synchrotron and CESR is discussed, including calculations of the transport optics and possible injection errors. The vernier phase compression technique used to shorten the positron accumulation time is discussed. Crucial to this technique is the trajectory length of positrons that are extracted from CESR, allowed to circulate in the synchrotron, and reinjected into CESR. This length is calculated in detail. Estimates are included for the beam filling time. Results from beam tests are compared with these calculations

  19. Fabrication of silicon molds for polymer optics

    DEFF Research Database (Denmark)

    Nilsson, Daniel; Jensen, SØren

    2003-01-01

    A silicon mold used for structuring polymer microcavities for optical applications is fabricated, using a combination of DRIE (deep reactive ion etching) and anisotropic chemical wet etching with KOH + IPA. For polymer optical microcavities, low surface roughness and vertical sidewalls are often needed. This is achieved by aligning the mold precisely to the [110] direction of a silicon (100) wafer and etching very close to the (110) surfaces using a DRIE Bosch process. The surface roughness of the sidewalls is then removed with a short etch in KOH + IPA. To achieve this, the parameters for DRIE and KOH + IPA etch have been optimized. To reduce stiction between the silicon mold and the polymers used for molding, the mold is coated with a teflon-like material using the DRIE system. Released polymer microstructures characterized with AFM and SEM are also presented.

  20. Evaluation of Process Cooling in Subsea Separation, Boosting and Injection Systems (SSBI)

    OpenAIRE

    Gyllenhammar, Svenn Emil

    2012-01-01

    The next generation of subsea process systems will combine the subsea gas compression technology currently under qualification with the previously developed subsea processing technologies, including separation, multiphase pumping and produced water re-injection. These systems will benefit from process cooling. This paper is an evaluation of the use of process cooling in subsea separation, boosting and injection (SSBI) systems including compression. Fouling is the biggest uncertainty, and pote...

  1. The MOLD expert of VAI - A mold monitoring system for best casting performance

    International Nuclear Information System (INIS)

    The increasing demand for higher quality products of the clients each year needs a better understanding of the continuous casting process to fulfill also in the future these requirements to be competitive on the steel market. Based on these strong economic boundary conditions the VAI MOLD EXPERT is able to cover these requirements. The VAI's MOLD EXPERT enables deep insight into the process behavior of the mold package and will be used in an advanced stage to partly control the casting machine with the goal of stable operation and high quality product. In the first step the MOLD EXPERT is a tool to acquire, store, compress and visualize measurement data of the mold/oscillator, with the advantage of gathering all data in one system. In the second step, these data are interpreted via mathematical models which are linked together to make comparisons to adaptive limits and setpoints. The benefit of the MOLD EXPERT is manifold. For the metallurgists new insight into the continuous casting process are given which results in a better interpretation of the whole casting process. New casting practices and alarm limits will be derived from the MOLD EXPERT. These results will increase the operational process stability and the product quality continuously. For the operators an on-line visualization is available to get a better support and to cast permanently with the optimal parameters. The modular hard- and software concept of MOLD EXPERT is shown and the different packages - moT is shown and the different packages - mold thermic, mold oscillation, casting powder, mold level, steel flow, narrowface taper - including visualization monitors will be described in detail. (author)

  2. Advanced information processing system: Fault injection study and results

    Science.gov (United States)

    Burkhardt, Laura F.; Masotto, Thomas K.; Lala, Jaynarayan H.

    1992-01-01

    The objective of the AIPS program is to achieve a validated fault tolerant distributed computer system. The goals of the AIPS fault injection study were: (1) to present the fault injection study components addressing the AIPS validation objective; (2) to obtain feedback for fault removal from the design implementation; (3) to obtain statistical data regarding fault detection, isolation, and reconfiguration responses; and (4) to obtain data regarding the effects of faults on system performance. The parameters are described that must be varied to create a comprehensive set of fault injection tests, the subset of test cases selected, the test case measurements, and the test case execution. Both pin level hardware faults using a hardware fault injector and software injected memory mutations were used to test the system. An overview is provided of the hardware fault injector and the associated software used to carry out the experiments. Detailed specifications are given of fault and test results for the I/O Network and the AIPS Fault Tolerant Processor, respectively. The results are summarized and conclusions are given.

  3. Estimation of radiation dose received by the radiation worker during 18F FDG injection process

    International Nuclear Information System (INIS)

    The radiation dosimetric literature concerning the medical and non-medical personnel working in nuclear medicine departments are limited, particularly radiation doses received by radiation worker in nuclear medicine department during positron emission tomography (PET) radiopharmaceutical injection process. This is of interest and concern for the personnel. To measure the radiation dose received by the staff involved in injection process of Fluorine-18 Fluorodeoxyglucose (FDG). The effective whole body doses to the radiation workers involved in injections of 1511 patients over a period of 10 weeks were evaluated using pocket dosimeter. Each patient was injected with 5 MBq/kg of 18F FDG. The 18F-FDG injection protocol followed in our department is as follows. The technologist dispenses the dose to be injected and records the pre-injection activity. The nursing staff members then secure an intravenous catheter. The nuclear medicine physicians/residents inject the dose on a rotation basis in accordance with ALARA principle. After the injection of the tracer, the nursing staff members flush the intravenous catheter. The person who injected the tracer then measures the post-injection residual dose in the syringe. The mean effective whole body doses per injection for the staff were the following: Nurses received 1.44 ± 0.22 ?Sv/injection (3.71 ± 0.48 nSv/MBq), for doctors the dose values were 2.44 ± 0.25 ?Sv/injection (6.29 ± 0.49 nSv/MBq) and forection (6.29 ± 0.49 nSv/MBq) and for technologists the doses were 0.61 ± 0.10 ?Sv/injection (1.58 ± 0.21 nSv/MBq). It was seen that the mean effective whole body dose per injection of our positron emission tomography/computed tomography (PET/CT) staff who were involved in the 18F-FDG injection process was maximum for doctors (54.34% differential doses), followed by nurses (32.02% differential doses) and technologist (13.64% differential doses). This study confirms that low levels of radiation dose are received by staff during 18F-FDG injection and these values can be used as a reference to allay any anxiety in the radiation workers. (author)

  4. An easy mold

    International Nuclear Information System (INIS)

    This book deals with an easy mold, which introduces what is a mold kinds and classification of mold. It gives descriptions of easy theories such as basic knowledge on shearing work, clearance, power for punching and shear angle, basic knowledge for bending such as transform by bending, the minimal bending radius, spring back, the length of material, flexural strength for bending, fundamental knowledge for drawing work with transform of drawing and limitation of drawing.

  5. Simulation on Gas Injection Refining Process with Mechanical Stirring

    Directory of Open Access Journals (Sweden)

    Zhang Ting’an

    2012-12-01

    Full Text Available Basing on the new method of in-situ desulfurization with gas injection and mechanical stirring, the effect of bubble dispersion and disintegration of three type impellers are numerically simulated by commercial CFD software Ansys Fluent 12.0. Numerical simulations of three-dimensional multiphase turbulence in gas injection and mechanical stirring are performed by adopting unsteady SM method coupled with Eulerian multiphase model and two-phase turbulence model. The information of gas-liquid fluid flow, velocity, turbulent kinetic energy and the power consumption are investigated and the results show that the SSB impeller can make bubbles get best dispersion and disintegration?and its power consumption is lower than VB impeller. The disk on the impeller blades can weaken the swirl flow in the upper zone of the impeller. Therefore, the bubble residence time is extended, and the bubble dispersing zone is also increased.

  6. CALCIUM-BASED SORBENTS IN THE LIMB (LIMESTONE INJECTION MULTISTAGE BURNER) PROCESS

    Science.gov (United States)

    The paper discusses EPA research on dry sorbent injection, which began in the late 1960s and early 1970s, and which will be demonstrated as the limestone injection multistage burner (LIMB) process at Ohio Edison's Edgewater plant in 1987. The effect and interrelationship of funda...

  7. Bioglass 45S5 transformation and molding material in the processing of biodegradable poly-DL-lactide scaffolds for bone tissue engineering

    Science.gov (United States)

    Abdollahi, Sara

    When bone is damaged, a scaffold can temporarily replace it in the site of injury and incite bone tissue to repair itself. A biodegradable scaffold resorbs into the body, generating non-toxic degradation products as new tissue reforms; a bioactive scaffold encourages the surrounding tissue to regenerate. In the present study, we make composite biodegradable and bioactive scaffolds using poly-DL-lactide (PDLLA), a biodegradable polymer, and incorporate Bioglass 45S5 (BG) to stimulate scaffold bioactivity. BG has an interesting trait when immersed in body fluid, a layer of hydroxycarbonate apatite, similar to the inorganic component of bone, forms on its surface. It is of utmost importance to understand the fate of BG throughout the scaffold’s processing in order to assess the scaffold’s bioactivity. In this study, the established different stages of BG reactivity have been verified by monitoring pH during BG dissolution experiments and by conducting an elemental analysis using inductively coupled plasma optical emission spectroscopy (ICP-OES). The composite scaffolds are synthesized by the solvent casting and particulate leaching technique and their morphology assessed by scanning electron microscopy (SEM). To understand the transformations occurred in BG during scaffold synthesis, BG as received, as well BG treated in acetone and water (the fluids involved in scaffold processing) are characterized by Fourier transform infrared (FTIR), and x-ray photoelectron spectroscopy (XPS). The results are then compared with BG extracted from scaffolds after processing. BG has been determined to start reacting during the scaffold processing. In addition, its reactivity is influenced by BG particle size. The study suggests that the presence of the polymer provides a reactive environment for BG due to pH effects. Teflon molds in scaffold fabrication are inert and biocompatibile, but their stiffness presents a challenge during de-molding. Silicone-based and polyurethane molds are attractive because they are flexible. However, there is a possibility that silicone leaches either from the material itself or the agents used to enhance their performance onto the scaffold. The second study in this thesis focuses on different types of such flexible substrates (Sil940, polyurethane, polyether, polydimethylsiloxane). The presence of Si in PDLLA films prepared on each material is inspected using XPS. Films made on all four materials are found to contain Si, indicative of the dissolution of part of the substrate in the film. However, silicon in the Si-containing catalysts used in the synthesis of polyethers is not transferred to samples, when the polyether substrate is plasma coated.

  8. Molding of Aluminum Foams by Using Hot Powder Extrusion

    OpenAIRE

    Yoshitaka Tanino; Masanori Shiomi

    2012-01-01

    In order to form aluminum foams directly from powder, a combined process of hot powder extrusion and molding is proposed. Aluminum powder mixed with a foaming agent is extruded into the mold through the die heated to a temperature higher than the melting point, and the mold is filled with the aluminum foam. When a stainless steel pipe is used for a simple mold, an aluminum foam bar is obtained of which the relative density varies between 0.2 and 0.3. The molding of aluminum foam by using thre...

  9. Effects of gas injection condition on mixing efficiency in the ladle refining process

    Science.gov (United States)

    Pan, S.-M.; Chiang, J.-D.; Hwang, W.-S.

    1997-02-01

    The aim of this research was to investigate the effects of injection condition on the mixing efficiency of the gas injection treatment of the ladle refining process in steelmaking. A water modeling approach was employed. A NaCl solution was injected into the vessel and the electric conductivity value of the water solution was measured to represent the concentration of the additive. The results of this investigation reveal that up to a certain level, mixing efficiency is improved as the gas flow rate increases. Off- center injection is better than centerline injection. However, the injection lance should not be too close to the wall. Also, mixing efficiency is improved when the submerged depth of the immersion lance increases. The immersion hood has a optimal size as far as mixing efficiency is concerned. A larger or smaller hood would reduce its efficiency. The submerged depth of the immersion hood should be kept to a minimum to improve mixing efficiency.

  10. Avaliação do comportamento térmico por DSC na região da pele e do núcleo de amostras injetadas de nanocompósitos de poliamida 6/argila organofílica Polyamide 6/organoclay nanocomposites: evaluation of thermal behavior of injection molded samples by DSC

    Directory of Open Access Journals (Sweden)

    Renê A. da Paz

    2010-01-01

    Full Text Available Nanocompósitos de poliamida 6/argila organofílica foram preparados pelo método de intercalação por fusão. A argila foi tratada com o sal quaternário de amônio (Cetremide visando-se à obtenção da argila organofílica (OMMT. Esta foi caracterizada por fluorescência de raio X (FRX, Espectroscopia no Infravermelho (FTIR e Difração de Raio X (DRX. Os resultados dessas análises evidenciaram incorporação do sal entre as camadas da argila, tornando-a organofílica. Os nanocompósitos foram obtidos em extrusora de rosca dupla corrotacional, com 3% em peso de argila, e estes foram posteriormente injetados. A caracterização dos nanocompósitos por DRX mostrou uma estrutura esfoliada e/ou parcialmente esfoliada. As análises por Calorimetria Exploratória Diferencial (DSC foram realizadas nas regiões da pele (superfície e do núcleo (centro dos corpos de prova e, mostraram as fases cristalinas ? e ? na pele e apenas a fase ? no núcleo e que o grau de cristalinidade na pele foi menor do que no núcleo.Polyamide 6/organoclay nanocomposites were prepared using the melt intercalation technique. The clay was treated with a quaternary ammonium salt (Cetremide to obtain the organoclay (OMMT, which was characterized with X ray fluorescence (XRF, Infrared Spectroscopy (FTIR and X ray diffraction (XRD. The results of these analyses showed the incorporation of the salt in the clay structure, confirming the organophilization. The nanocomposites were obtained in a co-rotational twin screw extruder with 3 wt. (% of clay, and then the pellets were injection molded. The characterization by XRD of the nanocomposites showed an exfoliated and/or partially exfoliated structure. The analysis by DSC were made in the skin and core regions of the samples, showing the ? and ?-crystalline forms in the skin and only the ?-form in the core region. The degree of crystallinity in the skin was lower than in the core.

  11. Avaliação do comportamento térmico por DSC na região da pele e do núcleo de amostras injetadas de nanocompósitos de poliamida 6/argila organofílica / Polyamide 6/organoclay nanocomposites: evaluation of thermal behavior of injection molded samples by DSC

    Scientific Electronic Library Online (English)

    Renê A. da, Paz; Amanda M. D., Leite; Edcleide M., Araújo; Tomas J. A., Melo; Luiz A., Pessan.

    Full Text Available Nanocompósitos de poliamida 6/argila organofílica foram preparados pelo método de intercalação por fusão. A argila foi tratada com o sal quaternário de amônio (Cetremide) visando-se à obtenção da argila organofílica (OMMT). Esta foi caracterizada por fluorescência de raio X (FRX), Espectroscopia no [...] Infravermelho (FTIR) e Difração de Raio X (DRX). Os resultados dessas análises evidenciaram incorporação do sal entre as camadas da argila, tornando-a organofílica. Os nanocompósitos foram obtidos em extrusora de rosca dupla corrotacional, com 3% em peso de argila, e estes foram posteriormente injetados. A caracterização dos nanocompósitos por DRX mostrou uma estrutura esfoliada e/ou parcialmente esfoliada. As análises por Calorimetria Exploratória Diferencial (DSC) foram realizadas nas regiões da pele (superfície) e do núcleo (centro) dos corpos de prova e, mostraram as fases cristalinas ? e ? na pele e apenas a fase ? no núcleo e que o grau de cristalinidade na pele foi menor do que no núcleo. Abstract in english Polyamide 6/organoclay nanocomposites were prepared using the melt intercalation technique. The clay was treated with a quaternary ammonium salt (Cetremide) to obtain the organoclay (OMMT), which was characterized with X ray fluorescence (XRF), Infrared Spectroscopy (FTIR) and X ray diffraction (XRD [...] ). The results of these analyses showed the incorporation of the salt in the clay structure, confirming the organophilization. The nanocomposites were obtained in a co-rotational twin screw extruder with 3 wt. (%) of clay, and then the pellets were injection molded. The characterization by XRD of the nanocomposites showed an exfoliated and/or partially exfoliated structure. The analysis by DSC were made in the skin and core regions of the samples, showing the ? and ?-crystalline forms in the skin and only the ?-form in the core region. The degree of crystallinity in the skin was lower than in the core.

  12. Moulded interconnect device fabrication by two shot molding and lasert induced selective activation

    OpenAIRE

    Sun, Jie; Hansen, Hans Nørgaard

    2009-01-01

    This report on the project “Molded Interconnect Device (MID) by two shot injection molding and laser induced selective activation” has been submitted to fulfil the requirements for the master project at department of Manufacturing Engineering and Management of Technical University of Denmark (IPL-DTU). MID is defined as an injection molded plastic substrate with electrical infrastructures on the surface and integrates both mechanical and electrical functionalities on the single device. Th...

  13. Molded ultra-low density microcellular foams

    International Nuclear Information System (INIS)

    Ultra-low density (< 0.01 g/cc) microcellular foams were required for the NARYA pulsed-power-driven x-ray laser development program. Because of their extreme fragility, molded pieces would be necessary to successfully field these foams in the pulsed power accelerator. All of the foams evaluated were made by the thermally induced phase separation technique from solutions of water soluble polymers. The process involved rapidly freezing the solution to induce the phase separation, and then freeze drying to remove the water without destroying the foam's structure. More than sixty water soluble polymers were evaluated by attempting to make their solutions into foams. The foams were evaluated for shrinkage, density, and microstructure to determine their suitability for molding and meeting the required density and cell size requirements of 5.0 mg/cc and less than twenty ?meters. Several promising water soluble polymers were identified including the polyactylic acids, guar gums, polyactylamide, and polyethylene oxide. Because of thier purity, structure, and low shrinkage, the polyacrylic acids were chosen to develop molding processes. The initial requirements were for 2.0 cm. long molded rods with diameters of 1.0, 2.0. and 3.0 mm. These rods were made by freezing the solution in thin walled silicon rubber molds, extracting the frozen preform from the mold, and then freeze drying. Requirements for half rods and half annuli necessitated using aluminum molds. Again we successfully molded these shapes. Our best efforts to date involve molding annuli with 3.0 mm outside diameters and 2.0 mm inside diameters

  14. Comparación de Deformaciones de un Aforador Determinadas por Simulación del Proceso de Inyección con Valores del Proceso Real Comparison of Gauge Deformation Determined by Simulation of the Injection Process With Real Process Values

    Directory of Open Access Journals (Sweden)

    Alfredo Padilla

    2006-01-01

    Full Text Available Se ha realizado un estudio comparativo entre las deformaciones reales de una pieza industrial obtenida por inyección y los desplazamientos obtenidos por simulación empleando C-MOLD, con el objeto de verificar la utilidad predictiva de herramientas de simulación de procesos. La pieza seleccionada es un aforador, fabricado en poliamida 6/10 con un 50% de fibra corta de vidrio, que presenta suaves rechupes en las zonas laterales como principal defecto. La simulación del proceso se realizó con las condiciones empleadas por el fabricante y, posteriormente, se optimizó para máquinas de inyección Engel 125 y 175. Con los parámetros óptimos de proceso se fabricaron piezas y se midieron las deformaciones en puntos situados en dos ejes paralelos a la dirección longitudinal de la pieza. Estas deformaciones se compararon con los valores de desplazamiento obtenidos por simulación encontrándose una coincidencia excelente entre ambos, excepto en las zonas próximas a los extremos de la pieza.A comparative study between the actual deformation of a real industrial part obtained by injection moulding and the displacement in the same simulated part has been performed using C-MOLD, with the objective of verifying the predictive capabilities of process simulation tools. The selected part is a gauge, made of polyamide 6/10 reinforced with 50% of fibber glass, that presents soft sink marks in the lateral areas as main defects. Process simulation was initially performed using the process conditions used by the manufacturer and, in a later stage, those conditions were optimised for Engel 125 and 175 injection machines. Using the optimum process parameters a set of parts was manufactured and the deformations were measured in several points located along two parallel longitudinal axis. These deformations were compared with displacement values obtained from simulation. Excellent agreement between the two sets of values was found except in the most external regions of the part.

  15. Development of Processes for Natural Gas Drying :Further exploring the TEG Injection Concept

    OpenAIRE

    Bra?then, Audun

    2008-01-01

    This paper treats further development of the TEG injection process described in Bråthen (2007). An introduction to separation technology, conventional glycol regeneration and compact mixing is presented, as these are important parts of the alternative dehydration concept. Advantages, disadvantages and operational problems are pointed out, before the problems with the TEG injection process is described. Using hot stripping gas for regeneration of the TEG is one of the suggested improvem...

  16. Development of Processes for Natural Gas Drying : Further exploring the TEG Injection Concept

    OpenAIRE

    Bra?then, Audun

    2008-01-01

    This paper treats further development of the TEG injection process described in Bråthen (2007). An introduction to separation technology, conventional glycol regeneration and compact mixing is presented, as these are important parts of the alternative dehydration concept. Advantages, disadvantages and operational problems are pointed out, before the problems with the TEG injection process is described. Using hot stripping gas for regeneration of the TEG is one of the suggested improvements, ...

  17. Characterization of thermo-rheological behavior of polymer melts during the micro injection moulding process

    OpenAIRE

    Zhang, Nan; Gilchrist, M.D.

    2012-01-01

    In-line process monitoring and rheological characterization can help to understand the behaviour of polymer melt flows during manufacture and to make injection moulding a measurable process for manufacturing high quality parts. This work developed an in-line rheology measurement system using a slit die attached to a micro injection moulding machine. A series of dumbbell mould inserts was used to form the slit die with thickness ranging from 600 ?m to 200 ?m. Two combined pressure and temper...

  18. Characterization of structural relaxation in As2Se3 for analysis of lens shape change in glass press mold cooling and post-process annealing

    Science.gov (United States)

    Koontz, Erick; Wachtel, Peter; Musgraves, J. David; Richardson, Kathleen

    2013-09-01

    This study explores the structural relaxation behavior of As2Se3 by thermo mechanical analysis in order to characterize and eventually predict volume change in As2Se3 upon relaxation during cooling after precision glass molding (PGM) and annealing. A vertical beam of As2Se3 was placed in a thermo mechanical analyzer (TMA) and fully relaxed at a given temperature. The temperature was then quickly changed a given amount and the 1-D relaxation of the beam was measured until it reached equilibrium at the new temperature. The resultant curve was then fit with a Prony series which captured the relaxation data. The mathematical representation of the relaxation is then analyzed as a function of time, temperature, and quench rate and can be used to predict one dimensional (1-D) length change upon relaxation. A maximum of three terms is needed to describe the relaxation behavior and that number declines with an increase in temperature. This decay of the number of Prony terms needed to describe relaxation points to a structure that relaxes with less complexity as it approaches Tg. These trends can be converted to 3-D due to the amorphous and therefore typically isotropic nature of As2Se3 glass. This volume change information as a function of vital processing parameters can then be used to predict the change in shape of a work piece during cooling or post process annealing within a precision molding cycle. The mathematical representation of volume relaxation can then be applied to finite element models (FEM) of As2Se3 lenses or other optical elements.

  19. Improved Processing of Titanium Alloys by Metal Injection Moulding

    Science.gov (United States)

    Sidambe, A. T.; Figueroa, I. A.; Hamilton, H.; Todd, I.

    2011-12-01

    The commercially pure (CP-Ti) and Ti6Al4V (Ti-64) powders with powder size of sub 45-micron were mixed with a water soluble binder consisting of a major fraction of Polyethylene Glycol (PEG), a minor fraction of Polymethylmethacrylate (PMMA) and some stearic acid as surfactant. The pelletised mix was injection-moulded into standard tensile bar specimens and then subjected solvent debinding by water leaching and thermal debinding in an argon atmosphere. The titanium compacts were then subjected to sintering studies using the Taguchi method. The results of the oxygen impurity levels of the sintered parts are presented in this paper. Titanium parts conforming to Grade 2 requirements were achieved for CP-Ti whilst those conforming to Grade 5 were achieved for Ti-64.

  20. Improved Processing of Titanium Alloys by Metal Injection Moulding

    International Nuclear Information System (INIS)

    The commercially pure (CP-Ti) and Ti6Al4V (Ti-64) powders with powder size of sub 45-micron were mixed with a water soluble binder consisting of a major fraction of Polyethylene Glycol (PEG), a minor fraction of Polymethylmethacrylate (PMMA) and some stearic acid as surfactant. The pelletised mix was injection-moulded into standard tensile bar specimens and then subjected solvent debinding by water leaching and thermal debinding in an argon atmosphere. The titanium compacts were then subjected to sintering studies using the Taguchi method. The results of the oxygen impurity levels of the sintered parts are presented in this paper. Titanium parts conforming to Grade 2 requirements were achieved for CP-Ti whilst those conforming to Grade 5 were achieved for Ti-64.

  1. Practical aspects of steam injection processes: A handbook for independent operators

    Energy Technology Data Exchange (ETDEWEB)

    Sarathi, P.S.; Olsen, D.K.

    1992-10-01

    More than 80% of the total steam injection process operating costs are for the production of steam and the operation of surface and subsurface equipment. The proper design and operation of the surface equipment is of critical importance to the success of any steam injection operation. However, the published monographs on thermal recovery have attached very little importance to this aspect of thermal oil recovery; hence, a definite need exists for a comprehensive manual that places emphasis on steam injection field practices and problems. This handbook is an attempt to fulfill this need. This handbook explores the concept behind steam injection processes and discusses the information required to evaluate, design, and implement these processes in the field. The emphasis is on operational aspects and those factors that affect the technology and economics of oil recovery by steam. The first four chapters describe the screening criteria, engineering, and economics of steam injection operation as well as discussion of the steam injection fundamentals. The next four chapters begin by considering the treatment of the water used to generate steam and discuss in considerable detail the design, operation and problems of steam generations, distribution and steam quality determination. The subsurface aspects of steamflood operations are addressed in chapters 9 through 12. These include thermal well completion and cementing practices, insulated tubulars, and lifting equipment. The next two chapters are devoted to subsurface operational problems encountered with the use of steam. Briefly described in chapters 15 and 16 are the steam injection process surface production facilities, problems and practices. Chapter 17 discusses the importance of monitoring in a steam injection project. The environmental laws and issues of importance to steam injection operation are outlined in chapter 18.

  2. Flow-Injection Responses of Diffusion Processes and Chemical Reactions

    DEFF Research Database (Denmark)

    Andersen, Jens Enevold Thaulov

    2000-01-01

    The technique of Flow-injection Analysis (FIA), now aged 25 years, offers unique analytical methods that are fast, reliable and consuming an absolute minimum of chemicals. These advantages together with its inherent feasibility for automation warrant the future applications of FIA as an attractive tool of automated analytical chemistry. The need for an even lower consumption of chemicals and for computer analysis has motivated a study of the FIA peak itself, that is, a theoretical model was developed, that provides detailed knowledge of the FIA profile. It was shown that the flow in a FIA manifold may be characterised by a diffusion coefficient that depends on flow rate, denoted as the kinematic diffusion coefficient. The description was applied to systems involving species of chromium, both in the case of simple diffusion and in the case of chemical reactions. It is suggested that it may be used in the resolution of FIA profiles to obtain information about the content of interference’s, in the study of chemical reaction kinetics and to measure absolute concentrations within the FIA-detector cell.

  3. Diagnosis parameters of mold filling pattern for optimization of a casting system

    Directory of Open Access Journals (Sweden)

    Jun-Ho Hong

    2012-11-01

    Full Text Available For optimal design of a gating system, the setting of diagnosis parameters is very important. In this study, the permanent mold casting process was selected because most of the other casting processes have more complicated factors that influence the mold filling pattern compared to the permanent mold casting process, such as the surface roughness of mold, gas generation from the mold wash and binder of sand mold, and the gas permeability through a sand mold, etc. Two diagnosis parameters (flow rate difference and arrival time difference of molten metal flow pattern in the numerical simulation are suggested for design of an optimum casting system with a permanent mold. The results show that the arrival time difference can be used as one important diagnosis parameter of the complexity of the runner system and its usefulness has been verified via making aluminum parts using permanent mold casting (Fig. 9.

  4. Effect analysis for compensating viscosity fluctuations by means of a self-optimising injection moulding process

    Science.gov (United States)

    Hopmann, Ch.; Weber, M.; Reßmann, A.

    2015-05-01

    As the conventional control of the injection moulding process is based on machine variables which cannot compensate process fluctuations, a constant part quality cannot be guaranteed. The aim of the self-optimising processing method is to compensate the effects of process fluctuations, to ensure a repeatable forming of the moulded part and therefore achieve a constant part quality. The so called pvT-optimisation allows, in combination with a closed-loop cavity pressure control, a systematic consideration of variable boundary conditions of the process. In addition, the effort required for setting up the process can be significantly reduced. The pvT-optimised processing method enables the compensation of thermal disturbances and pressure fluctuations. Additionally, the influence of variations in material viscosity on the process variables, caused by the usage of recycled material, is addressed. Changing temperature and pressure of the material during the process compensates for the variations in material viscosity. An effect analyses of the influence of viscosity-relevant process parameters such as melt temperature, mould temperature and injection velocity on quality criteria such as part weight is conducted. The effect analysis shows a strong correlation between injection velocity and the weight. Thus, the part weight can be controlled by adapting the injection velocity.

  5. Competing atomic processes in Ba and Sr injection critical velocity experiments

    Science.gov (United States)

    Newell, P. T.; Torbert, R. B.

    1985-01-01

    The critical ionization velocity effect requires a superthermal electron population to ionize through collisional impact. Such superthermal electrons can however lose energy to competing atomic processes, as well as to ionization, thus limiting the efficiency of the effect. Considering Ba and Sr magnetospheric injection experiments designed to test the CIV theory, it is found that in both cases roughly 60 percent of the superthermal electron energy is lost on exciting line radiation. Moreover, energy loss to background neutral oxygen places a strict limit on the injected cloud densities for which critical velocity effects are possible; a finding which explains the consistently negative