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Sample records for injection molding process

  1. Bubble growth in mold cavities during microcellular injection molding processes

    Bubble nucleation and growth are the key steps in polymer foam generation processes. The mechanical properties of foam polymers are closely related to the size of the bubbles created inside the material, and most existing analysis methods use a constant viscosity and surface tension to predict the size of the bubbles. Under actual situations, however, when the polymer contains gases, changes occur in the viscosity and surface tension that cause discrepancies between the estimated and observed bubble sizes. Therefore, we developed a theoretical framework to improve our bubble growth rate and size predictions, and experimentally verified our theoretical results using an injection molding machine modified to make microcellular foam products

  2. Bubble growth in mold cavities during microcellular injection molding processes

    Moon, Yong Rak [University of Toronto, Toronto (Canada); Lee, Kyoung Soo; Cha, Sung W. [Yonsei University, Seoul (Korea, Republic of)

    2009-12-15

    Bubble nucleation and growth are the key steps in polymer foam generation processes. The mechanical properties of foam polymers are closely related to the size of the bubbles created inside the material, and most existing analysis methods use a constant viscosity and surface tension to predict the size of the bubbles. Under actual situations, however, when the polymer contains gases, changes occur in the viscosity and surface tension that cause discrepancies between the estimated and observed bubble sizes. Therefore, we developed a theoretical framework to improve our bubble growth rate and size predictions, and experimentally verified our theoretical results using an injection molding machine modified to make microcellular foam products

  3. Process and part filling control in micro injection molding

    Tosello, Guido; Hansen, Hans Nørgaard; Schoth, Andreas

    2008-01-01

    The influence of process parameters on μ-injection molding (μIM) and on μ-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...... injection speed in one of the most influencing process parameters on the μIM process and on the μ-parts filling....

  4. Fractal phenomena in powder injection molding process

    郑洲顺; 曲选辉; 李云平; 雷长明; 段柏华

    2003-01-01

    The complicated characteristics of the powder were studied by fractal theory. It is illustrated that powder shape, binder structure, feedstock and mold-filling flow in powder injection molding process possess obvious fractal characteristics. Based on the result of SEM, the fractal dimensions of the projected boundary of carbonylic iron and carbonylic nickel particles were determined to be 1.074±0.006 and 1.230±0.005 respectively by box counting measurement. The results show that the fractal dimension of the projected boundary of carbonylic iron particles is close to smooth curve of one-dimension, while the fractal dimension of the projected boundary of carbonylic nickel particle is close to that of trisection Koch curve, indicating that the shape characteristics of carbonylic nickel particles can be described and analyzed by the characteristics of trisection Koch curve. It is also proposed that the fractal theory can be applied in the research of powder injection molding in four aspects.

  5. Rapid control of mold temperature during injection molding process

    Liparoti, Sara; Titomanlio, Giuseppe [Department of Industrial Engineering, University of Salerno Via Giovanni Paolo II, 132, 84084 Fisciano (Italy); Hunag, Tsang Min; Cakmak, Mukerrem [Department of Polymer Engineering, The University of Akron, Akron, OH 44325 (United States); Sorrentino, Andrea [Institute for Polymers, Composite and Biomaterials (IPCB) - CNR, P. Enrico Fermi 1, 80055 Portici (Italy)

    2015-05-22

    The control of mold surface temperature is an important factor that determines surface morphology and its dimension in thickness direction. It can also affect the frozen molecular orientation and the mold surface replicability in injection molded products. In this work, thin thermally active films were used to quickly control the mold surface temperature. In particular, an active high electrical conductivity carbon black loaded polyimide composites sandwiched between two insulating thin polymeric layers was used to condition the mold surface. By controlling the heating time, it was possible to control precisely the temporal variation of the mold temperature surface during the entire cycle. The surface heating rate was about 40°C/s and upon contact with the polymer the surface temperature decreased back to 40°C within about 5 s; the overall cycle time increased only slightly. The effect on cross section sample morphology of samples of iPP were analyzed and discussed on the basis of the recorded temperature evolution.

  6. Research on machine vision system of monitoring injection molding processing

    Bai, Fan; Zheng, Huifeng; Wang, Yuebing; Wang, Cheng; Liao, Si'an

    2016-01-01

    With the wide development of injection molding process, the embedded monitoring system based on machine vision has been developed to automatically monitoring abnormality of injection molding processing. First, the construction of hardware system and embedded software system were designed. Then camera calibration was carried on to establish the accurate model of the camera to correct distortion. Next the segmentation algorithm was applied to extract the monitored objects of the injection molding process system. The realization procedure of system included the initialization, process monitoring and product detail detection. Finally the experiment results were analyzed including the detection rate of kinds of the abnormality. The system could realize the multi-zone monitoring and product detail detection of injection molding process with high accuracy and good stability.

  7. Observation of the polymer melt flow in injection molding process using co-injection molding technique

    Chen, S.C.; Hsu, K.F.; Huang, J.S. (Chung Yuan Univ., Chung-Li (Taiwan, Province of China). Mechanical Engineering Dept.)

    Studies of the polymer melt flow in injection molding process have been carried out by co-injection molding technique using alternating sequence of transparent and colored PMMA resin. Simulations are also developed to predict the melt front advancements for both skin and core melts. Fountain flow effect is evident in all case studies. During the packing process, the polymer melt flows significantly with the increased packing pressure due to the compressible nature of the melt and the flow concentrates around cavity location near gate area. That the polymer melt flows across the weld line around the gap center in the packing stage was also observed. Although numerical simulations show fair consistence with experimental results in both skin and core material distribution, edge effect remains to be taken into account to improve the simulation accuracy.

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

    Arlø, Uffe Rolf; Hansen, Hans Nørgaard; Kjær, Erik Michael

    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...

  9. Mathematical modeling of the process of filling a mold during injection molding of ceramic products

    Kulkov, S. N.; Korobenkov, M. V.; Bragin, N. A.

    2015-10-01

    Using the software package Fluent it have been predicted of the filling of a mold in injection molding of ceramic products is of great importance, because the strength of the final product is directly related to the presence of voids in the molding, making possible early prediction of inaccuracies in the mold prior to manufacturing. The calculations were performed in the formulation of mathematical modeling of hydrodynamic turbulent process of filling a predetermined volume of a viscous liquid. The model used to determine the filling forms evaluated the influence of density and viscosity of the feedstock, and the injection pressure on the mold filling process to predict the formation of voids in the area caused by the shape defect geometry.

  10. Rapid control of mold temperature during injection molding process: Effect of packing pressure

    Liparoti, Sara; Sorrentino, Andrea; Titomanlio, Giuseppe

    2015-12-01

    A thorough analysis of the effect of operative conditions of injection molding process on the morphology distribution inside the obtained molded is performed, with particular reference to semi- crystalline polymers. In particular, fully characterized injection molding tests are presented using an isotactic polypropylene, previously carefully characterized as far as most of properties of interest. The effects of mold temperature and packing conditions are analyzed. The mold temperature was controlled by a thin heating device, composed by polyimide as insulating layer and polyimide loaded carbon black as electrical conductive layer, that is able to increase temperature on mold surface in few seconds (70°C/s) by joule effect and cool down soon after. The shear layer thickness in the molded is reduced in the samples produced at high mold temperatures, that means high electrical power and long heating time, and this reduction is more significant at lower packing pressures, indeed, at 360bar as packing pressure and 20s as heating time the shear layer disappear. The resulting morphology was analyzed by optical microscope.

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

    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.

  12. Validation of precision powder injection molding process simulations using a spiral test geometry

    Marhöfer, Maximilian; Müller, Tobias; TOSELLO, Guido; Islam, Aminul; Hansen, Hans N.; Piotter, Volker

    2015-01-01

    Like in many other areas of engineering, process simulations find application in precision injection molding to assist and optimize the quality and design of precise products and the molding process. Injection molding comprises mainly the manufacturing of plastic components. However, the variant of precision powder injection molding for the production of metallic and ceramic micro parts raises more and more interest though. Consequently, in the entire field the demand for simulation tools inc...

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

    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.

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

    J. Tepić

    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.

  15. A senior manufacturing laboratory for determining injection molding process capability

    Wickman, Jerry L.; Plocinski, David

    1992-01-01

    The following is a laboratory experiment designed to further understanding of materials science. This subject material is directed at an upper level undergraduate/graduate student in an Engineering or Engineering Technology program. It is assumed that the student has a thorough understanding of the process and quality control. The format of this laboratory does not follow that which is normally recommended because of the nature of process capability and that of the injection molding equipment and tooling. This laboratory is instead developed to be used as a point of departure for determining process capability for any process in either a quality control laboratory or a manufacturing environment where control charts, process capability, and experimental or product design are considered important topics.

  16. Numerical simulation of tungsten alloy in powder injection molding process

    ZHENG Zhen-xing; XIA Wei; ZHOU Zhao-yao; ZHU Quan-li

    2008-01-01

    The flow behavior of feedstock for the tungsten alloy powder in the mold cavity was approximately described using Hele-Shaw flow model. The math model consisting of momentum equation, consecutive equation and thermo-conduction equation for describing the injection process was established. The equations are solved by the finite element/finite difference hybrid method that means dispersing the feedstock model with finite element method, resolving the model along the depth with finite difference methpd, and tracking the movable boundary with control volume method, then the pressure equation and energy equation can be resolved in turn. The numerical simulation of the injection process and the identification of the process parameters were realized by the Moldflow software. The results indicate that there is low temperature gradient in the cavity while the pressure and shear rate gradient are high at high flow rate. The selection of the flow rate is affected by the structure of the gate. The shear rate and the pressure near the gate can be decreased by properly widening the dimension of the gate. There is a good agreement between the process parameters obtained by the numerical simulation and the actual ones.

  17. Experimental Investigation of Comparative Process Capabilities of Metal and Ceramic Injection Molding for Precision Applications

    Islam, Aminul; Giannekas, Nikolaos; Marhöfer, David Maximilian;

    2016-01-01

    The purpose of this paper is to make a comparative study on the process capabilities of the two branches of the powder injection molding (PIM) process—metal injection molding (MIM) and ceramic injection molding (CIM), for high-end precision applications. The state-of-the-art literature does not...... discussion presented in the paper will be useful for thorough understanding of the MIM and CIM processes and to select the right material and process for the right application or even to combine metal and ceramic materials by molding to produce metal–ceramic hybrid components....

  18. Modeling and flow analysis of pure nylon polymer for injection molding process

    Nuruzzaman, D. M.; Kusaseh, N.; Basri, S.; Oumer, A. N.; Hamedon, Z.

    2016-02-01

    In the production of complex plastic parts, injection molding is one of the most popular industrial processes. This paper addresses the modeling and analysis of the flow process of the nylon (polyamide) polymer for injection molding process. To determine the best molding conditions, a series of simulations are carried out using Autodesk Moldflow Insight software and the processing parameters are adjusted. This mold filling commercial software simulates the cavity filling pattern along with temperature and pressure distributions in the mold cavity. In the modeling, during the plastics flow inside the mold cavity, different flow parameters such as fill time, pressure, temperature, shear rate and warp at different locations in the cavity are analyzed. Overall, this Moldflow is able to perform a relatively sophisticated analysis of the flow process of pure nylon. Thus the prediction of the filling of a mold cavity is very important and it becomes useful before a nylon plastic part to be manufactured.

  19. OPTIMIZATION OF INJECTION MOLDING PROCESS BASED ON NUMERICAL SIMULATIONAND BP NEURAL NETWORKS

    王玉; 邢渊; 阮雪榆

    2001-01-01

    Plastic injection molding is a very complex process and its process planning has a direct influence on product quality and production efficiency. This paper studied the optimization of injection molding process by combining the numerical simulation with back-propagation(BP) networks. The BP networks are trained by the results of numerical simulation. The trained BP networks may:(1) shorten time for process planning;(2) optimize process parameters;(3) be employed in on-line quality control;(4) be integrated with knowledge-based system(KBS) and case-based reasoning(CBR) to make intelligent process planning of injection molding.

  20. Gate design in injection molding of microfluidic components using process simulations

    Marhöfer, D. M.; Tosello, G.; Islam, A.;

    2015-01-01

    Just as in conventional injection molding of plastics, process simulations are an effective tool in the area of micro injection molding. They are applied in order to optimize and aid the design of the micro plastic part, the mold and the actual process. Available simulation software is actually...... made for macroscopic injection molding, but by means of the correct implementation and modelling strategy it can also be applied to micro plastic parts, as it is shown in the presented work. Process simulations are applied to two microfluidic devices (a micro distributor and a micro mixer) which shall...... be manufactured by micro injection molding. One of the main goals of the simulations is the investigation of the filling of the parts. Great emphasis is also on the optimization of selected gate designs for both parts which was successfully carried out. The paper describes how the two devices were...

  1. Improved silicon carbide for advanced heat engines. I - Process development for injection molding

    Whalen, Thomas J.; Trela, Walter

    1989-01-01

    Alternate processing methods have been investigated as a means of improving the mechanical properties of injection-molded SiC. Various mixing processes (dry, high-sheer, and fluid) were evaluated along with the morphology and particle size of the starting beta-SiC powder. Statistically-designed experiments were used to determine significant effects and interactions of variables in the mixing, injection molding, and binder removal process steps. Improvements in mechanical strength can be correlated with the reduction in flaw size observed in the injection molded green bodies obtained with improved processing methods.

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

    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

  3. Validation of precision powder injection molding process simulations using a spiral test geometry

    Marhöfer, Maximilian; Müller, Tobias; Tosello, Guido;

    2015-01-01

    Like in many other areas of engineering, process simulations find application in precision injection molding to assist and optimize the quality and design of precise products and the molding process. Injection molding comprises mainly the manufacturing of plastic components. However, the variant of...... precision powder injection molding for the production of metallic and ceramic micro parts raises more and more interest though. Consequently, in the entire field the demand for simulation tools increases constantly, too. The present work reports the material characterization of feedstocks which are used for...... powder injection molding. This characterization includes measurements of rheological, thermal, and pvT behavior of the powder-binder-mixes. The acquired material data was used to generate new material models for the database of the commercially available Autodesk Moldflow® simulation software. The...

  4. Processing study of injection molding of silicon nitride for engine applications

    Rorabaugh, M. E.; Yeh, H. C.

    1985-01-01

    The high hardness of silicon nitride, which is currently under consideration as a structural material for such hot engine components as turbine blades, renders machining of the material prohibitively costly; the near net shape forming technique of injection molding is accordingly favored as a means for component fabrication. Attention is presently given to the relationships between injection molding processing parameters and the resulting microstructural and mechanical properties of the resulting engine parts. An experimental program has been conducted under NASA sponsorship which tests the quality of injection molded bars of silicon nitride at various stages of processing.

  5. Numerical Simulation of Injection Molding Cooling Process Based on 3D Surface Model

    CUIShu-biao; ZHOUHua-min; LIDe-qun

    2004-01-01

    The design of the coohng system of injection molds directly affects both productivity and the quality of the final part. Using the cooling process CAE system to instruct the mold design, the efficiency and quality of design can be improved greatly. At the same time, it is helpful to confirm the cooling system structure and optimize the process conditions. In this paper, the 3D surface model of mold cavity is used to replace the middle-plane model in the simulation by Boundary Element Method, which break the bottleneck of the application of the injection molding simulation softwares base on the middle-plane model. With the improvements of this paper, a practical and commercial simulation software of injection molding cooling process named as HsCAE3D6.0 is developed.

  6. Comparative analysis of different process simulation settings of a micro injection molded part featuring conformal cooling

    Marhöfer, D. M.; Tosello, G.; Hansen, H. N.

    2015-01-01

    Process simulations are applied in all fields of engineering in order to support and optimize the design and quality of products and their manufacturing processes. Micro injection molding is not an exception in this regard. Simulations enable to investigate the process and the part quality. In the...... reported work, process simulations using Autodesk Moldflow Insight 2015® are applied to a micro mechanical part to be fabricated by micro injection molding and with over-all dimensions of 12.0 × 3.0 × 0.8 mm³ and micro features (micro hole, diameter of 580 μm, and sharp radii down to 100 μm). Three...... implementation of the actual mold block, conventional cooling, and conformal cooling. In the comparison, characteristic quality criteria for injection molding are studied, such as the filling behavior of the cavity, the injection pressure, the temperature distribution, and the resulting part warpage...

  7. Processing development of Si3N4 components by injection molding

    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)

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

    Tosello, Guido; Hansen, Hans Nørgaard; Dormann, B.;

    2010-01-01

    A newly developed μ-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 μ-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...

  9. Dimensional Accuracy Optimization of the Micro-plastic Injection Molding Process Using the Taguchi Design Method

    Chil-Chyuan KUO

    2015-07-01

    Full Text Available Plastic injection molding is an important field in manufacturing industry because there are many plastic products that are produced by injection molding. However, the time and cost required for producing a precision mold are the most troublesome problems that limit the application at the development stage of a new product in precision machinery industry. This study presents an approach of manufacturing a hard mold with microfeatures for micro-plastic injection molding. This study also focuses on Taguchi design method for investigating the effect of injection parameters on the dimensional accuracy of Fresnel lens during plastic injection molding. It was found that the dominant factor affecting the microgroove depth of Fresnel lens is packing pressure. The optimum processing parameters are packing pressure of 80 MPa, melt temperature of 240 °C, mold temperature of 90 °C and injection speed of 50 m/s. The dimensional accuracy of Fresnel lens can be controlled within ±3 μm using the optimum level of process parameters through the confirmation test. The research results of this study have industrial application values because electro-optical industries are able to significantly reduce a new optical element development cycle time.

  10. Gate Design in Injection Molding of Microfluidic Components Using Process Simulations

    Marhöfer, David Maximilian; Tosello, Guido; Islam, Aminul;

    2016-01-01

    Just as in conventional injection molding of plastics, process simulationsare an effective and interesting tool in the area of microinjection molding. They can be applied in order to optimize and assist the design of the microplastic part, the mold, and the actual process. Available simulation...... software is however actually made for macroscopic injection molding. By means of the correct implementation and careful modeling strategy though, it can also be applied to microplastic parts, as it is shown in the present work. Process simulations were applied to two microfluidic devices (amicrofluidic...... this design in practiceas actual steel mold. Additionally, the simulation results were critically discussed and possible improvements and limitations of the gained results and the deployed software were described. Ultimately,the simulation results were validated by cross-checking the flow front...

  11. Neural Network Approach to Predict Melt Temperature in Injection Molding Processes

    2000-01-01

    Among the processing conditions of injection molding, temperature of the melt entering the mold plays a significant role in determining the quality of molded parts. In our previous research, a neural network was developed to predict, the melt temperature in the barrel during the plastication phase. In this paper, a neural network is proposed to predict the melt temperature at the nozzle exit during the injection phase. A typical two layer neural network with back propagation learning rules is used to model the relationship between input and output in the injection phase. The preliminary results show that the network works well and may be used for on-line optimization and control of injection molding processes.

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

    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.

  13. Relationship between Microcellular Foaming Injection Molding Process Parameters and Cell Size

    HU Guang-hong; JIANG Chao-dong; CUI Zhen-shan

    2008-01-01

    In order to study the relationship between the main process parameters and the cell size, the mathematical model of cell growth of microcellular foaming injection process is built. Then numeric simulation is employed as experimental method, and the Taguchi method is used to analyze significance of effect of process parameters on the cell size. At last the process parameters are focused on melt temperature, injection time, mold temperature and pre- filled volume. The significance order from big to small of the effect of each process parameters on cell size is melt temperature, pre-filled volume, injection time, and mold temperature. On the basis of above research, the effect of each process parameter on cell size is further researched.Appropriate reduction of the melt temperature and increase of the we-filled volume can optimize the cell size effectively, while the effects of injection time and mold temperature on cell size are less significant.

  14. Microcellular Injection Molding Using Helium

    In comparison with conventional foaming process microcellular injection molding process has advantages such as small bubble size, the removal of sink mark, scale reliability, and weight lightening. So microcellular injection molded parts are applied to electrical product and automobile part. Conventional microcellular foaming process used carbon dioxide and nitrogen as a foaming agent. And it has been never researched and applied about microcellular injection molding process using helium. In this paper, we did a microcellular injection molding process using helium based on previous research result and made samples. From this we can certificate the possibility of microcellular continuous process using helium. Helium is lighter and faster in diffusion than carbon dioxide or nitrogen so through this technique, it can be solved the problem such as spray or labeling

  15. Scratch tests on micro-structured polymer surfaces produced by injection molding and reaction processes

    This work focuses on the mechanical behavior of micro surface structures (molded both in the injection and reaction injection processes) in scratch tests using rounded cone indenters of different sizes. The interest in polymeric micro surface structures has increased in diagnostics, mass storage or optical fields as well as in the production of miniaturized devices such as micro-electro-mechanical systems (MEMS) in which surface properties are essential. Using replication technologies like the injection molding process, such structures can be molded on a mass-production scale with low production costs at the same time. However, if the molded features are not protected, their surfaces are more sensitive compared to their unstructured surface and their functional loss is often a crucial factor. Therefore, the damage mechanisms of random and periodic structures at different length scales below 5 µm are investigated using an AFM and a SEM taking into account different materials and their structures

  16. Gate design in injection molding of microfluidic components using process simulations

    Marhöfer, David Maximilian; Tosello, Guido; Islam, Aminul;

    Process simulations are an effective design and optimization tool in conventional as well as micro injection molding (μIM). They can be applied to optimize and assist the design of the micro part, the mold, the micro cavity and the μIM process. Available simulation software is however developed for...... design with regard to moulding process window, polymer flow, and part quality. This finally led to an optimization of the design and the realization as actual steel mold. Additionally, the simulation results were critically discussed and possible improvements and limitations of the gained results and the...... deployed software are presented. Ultimately, the simulation results were validated by comparing the flow pattern behavior of the polymer flow predicted by the simulation with the actual flow front at different time steps. These were realized by molding short shots with the realized molds and were compared...

  17. Design and fabrication of optical homogenizer with micro structure by injection molding process

    Chen, C.-C. A.; Chang, S.-W.; Weng, C.-J.

    2008-08-01

    This paper is to design and fabricate an optical homogenizer with hybrid design of collimator, toroidal lens array, and projection lens for beam shaping of Gaussian beam into uniform cylindrical beam. TracePro software was used to design the geometry of homogenizer and simulation of injection molding was preceded by Moldflow MPI to evaluate the mold design for injection molding process. The optical homogenizer is a cylindrical part with thickness 8.03 mm and diameter 5 mm. The micro structure of toroidal array has groove height designed from 12 μm to 99 μm. An electrical injection molding machine and PMMA (n= 1.4747) were selected to perform the experiment. Experimental results show that the optics homogenizer has achieved the transfer ratio of grooves (TRG) as 88.98% and also the optical uniformity as 68% with optical efficiency as 91.88%. Future study focuses on development of an optical homogenizer for LED light source.

  18. Numerical simulation method for weld line development in micro injection molding process

    XIE Lei; ZIEGMANN Gerhard; JIANG Bing-yan

    2009-01-01

    In order to reduce the "trial-mold" risk and cost, numerical simulation method was applied to micro injection molding weld line development investigation. The micro tensile specimen which has the size of 0.1 mm (depth)×0.4 mm (width)× 12 mm(length) in test area was selected as the objective part, and polypropylene (PP) as the experimental material. Respectively with specific commercial software (Mold Flow~(R)) and general computational fluid dynamic (CFD) software (Comsol ~(R)Multiphysics), the simulation experiments for development of weld line in micro injection molding process were executed and the real comparison experiments were also carried out. The results show that during micro injection molding process, the specific commercial software for normal injection molding process is not valid to describe the micro flow process, the shape of flow front in micro cavity flowing which is important in weld line developing study and the contact angle clue to surface tension are not able to be simulated. In order to improve the simulation results for micro weld line development, the general CFD software, which is more flexible in user defining function, is applied. The results show better effects in describing micro fluid flow behavior. As a conclusion, as for weld line forming process, the numerical simulation method can give a characteristic analysis results for processing parameters optimizing in micro injection molding process; but for both kinds of softwares quantitative analysis cannot be obtained unless the boundary condition and micro fluid mathematic model are improved in the future.

  19. Dimensional Accuracy Optimization of the Micro-plastic Injection Molding Process Using the Taguchi Design Method

    Chil-Chyuan KUO; Hsin-You LIAO

    2015-01-01

    Plastic injection molding is an important field in manufacturing industry because there are many plastic products that are produced by injection molding. However, the time and cost required for producing a precision mold are the most troublesome problems that limit the application at the development stage of a new product in precision machinery industry. This study presents an approach of manufacturing a hard mold with microfeatures for micro-plastic injection molding. This study also focuses...

  20. Cycle Time Reduction in Injection Molding Process by Selection of Robust Cooling Channel Design

    Muhammad Khan; S. Kamran Afaq; Nizar Ullah Khan; Saboor Ahmad

    2014-01-01

    Cycle time of a part in injection molding process is very important as the rate of production and the quality of the parts produced depend on it, whereas the cycle time of a part can be reduced by reducing the cooling time which can only be achieved by the uniform temperature distribution in the molded part which helps in quick dissipation of heat. Conformal cooling channel design is the solution to the problem which basically “conforms” to the shape of cavity in the molds. This paper describ...

  1. Injection Molding of High Aspect Ratio Nanostructures

    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....

  2. Three-Dimensional Simulation And Design Sensitivity Analysis Of The Injection Molding Process

    Ilinca, Florin; Hétu, Jean-François

    2004-06-01

    Getting the proper combination of different process parameters such as injection speed, melt temperature and mold temperature is important in getting a part that minimizes warpage and has the desired mechanical properties. Very often a successful design in injection molding comes at the end of a long trial and error process. Design Sensitivity Analysis (DSA) can help molders improve the design and can produce substantial investment savings in both time and money. This paper investigates the ability of the sensitivity analysis to drive an optimization tool in order to improve the quality of the injected part. The paper presents the solution of the filling stage of the injection molding process by a 3D finite element solution algorithm. The sensitivity of the solution with respect to different process parameters is computed using the continuous sensitivity equation method. Solutions are shown for the non-isothermal filling of a rectangular plate with a polymer melt behaving as a non-Newtonian fluid. The paper presents the equations for the sensitivity of the velocity, pressure and temperature and their solution by finite elements. Sensitivities of the solution with respect to the injection speed, the melt and mold temperatures are shown.

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

    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.

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

    Østergaard, Peter Friis; Matteucci, Marco; Marie, Rodolphe;

    2012-01-01

    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...

  5. Influence of process parameters on the weld lines of a micro injection molded component

    Tosello, Guido; Gava, Alberto; Hansen, Hans Nørgaard;

    2007-01-01

    The insufficient entanglement of the molecular chains and the stress amplification at the v-notch of a weld line compromise the mechanical strength of a plastic product, also in the micro scale. To investigate the influence of process parameters on the weld lines formation, a special micro cavity...... influenced by mold temperature and injection speed....

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

    Gava, Alberto; Tosello, Guido; Lucchetta, Giovanni;

    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...

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

    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.

  8. Injection Molding of Plastics from Agricultural Materials

    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.

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

    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.

  10. Determination of injection molding process windows for optical lenses using response surface methodology.

    Tsai, Kuo-Ming; Wang, He-Yi

    2014-08-20

    This study focuses on injection molding process window determination for obtaining optimal imaging optical properties, astigmatism, coma, and spherical aberration using plastic lenses. The Taguchi experimental method was first used to identify the optimized combination of parameters and significant factors affecting the imaging optical properties of the lens. Full factorial experiments were then implemented based on the significant factors to build the response surface models. The injection molding process windows for lenses with optimized optical properties were determined based on the surface models, and confirmation experiments were performed to verify their validity. The results indicated that the significant factors affecting the optical properties of lenses are mold temperature, melt temperature, and cooling time. According to experimental data for the significant factors, the oblique ovals for different optical properties on the injection molding process windows based on melt temperature and cooling time can be obtained using the curve fitting approach. The confirmation experiments revealed that the average errors for astigmatism, coma, and spherical aberration are 3.44%, 5.62%, and 5.69%, respectively. The results indicated that the process windows proposed are highly reliable. PMID:25321095

  11. Injection molding ceramics to high green densities

    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.

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

    Ana Elduque; Carlos Javierre; Daniel Elduque; Ángel Fernández

    2015-01-01

    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 mo...

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

    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.

  14. Characterization of Injection Molded Structures

    Sun, Ling; Søgaard, Emil; Andersen, Nis Korsgaard;

    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...... understand structure-properties relationship of the injection molded polymer samples. These results are very important in optimizing injection molding parameters....

  15. Comparison of rheological analytic model with numerical simulation in powder injection molding filling process

    刘跃军; 李祥刚; 黄宇刚; 魏珊珊; 曾广胜

    2008-01-01

    Mathematical model of filling disk-shaped mold cavity in steady state was studied.And the mathematical model under vibration field was developed from the model in steady state.According to the model of filling disk-shaped mold cavity in steady state,the filling time,the distribution of velocity field and the pressure field were obtained.The analysis results from rheological analytic model were compared with the numerical simulation results using Moldflow software in the powder injection molding filling process.Through the comparison,it is found that it is unreasonable to neglect the influence of temperature when calculated the pressure changing with the time at the cavity gate,while it can be neglected in other situations such as calculating the distribution of the velocity fields.This provides a theoretical reference for the establishment of correct model both in steady state and under vibration force field in the future.

  16. Analysis of Injection Molding Process Based on MoldFlow/MPI for Large Plastic Pallet%基于MoldFlow/MPI的大型塑料托盘注射成型分析

    段贤勇

    2012-01-01

    运用MoldFlow/MPI模块对大型塑料托盘注射成型过程进行模流分析,预测了可能出现的注射短射等缺陷,根据分析结果,提出了工艺优化方案,从而缩短模具设计制造周期。%Used MoldFlow/MPI to analyze the mold flow for the large plastic pallet molding process, and predict the possible injection molding defects such as injection molding short shot. According to the analysis, it gives process optimization to reduce the mold design and manufacture cycle.

  17. Functional nanostructures on injection molded plastic

    Johansson, Alicia Charlotte; Søgaard, Emil; Andersen, Nis Korsgaard;

    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...

  18. Model predictive control of servo motor driven constant pump hydraulic system in injection molding process based on neurodynamic optimization

    Yong-gang PENG; Jun WANG; Wei WEI

    2014-01-01

    In view of the high energy consumption and low response speed of the traditional hydraulic system for an injection molding machine, a servo motor driven constant pump hydraulic system is designed for a precision injection molding process, which uses a servo motor, a constant pump, and a pressure sensor, instead of a common motor, a constant pump, a pressure pro-portion valve, and a flow proportion valve. A model predictive control strategy based on neurodynamic optimization is proposed to control this new hydraulic system in the injection molding process. Simulation results showed that this control method has good control precision and quick response.

  19. Injection molding of metal powders

    The powder Injection Moulding (PIM) process is a viable and competitive commercial technique for producing complex-shaped parts of various materials in high volumes. PIM based on a new binder system and using a Co-Cr-Mo alloy powder as a test material, has been described. The binder comprises a major fraction of polyethylene glycols (PEGs) of various molecular weights and a minor fraction of very finely dispersed poly methyl methacrylate (PMMA) incorporated in the form of an emulsion. Various processing stages of the PIM process, i.e., feedstock preparation, injection molding, de binding and sintering have been discussed. (author)

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

    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 μ-CT. The simulation results showed a good agreement with experiment results.

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

    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 μ-CT. The simulation results showed a good agreement with experiment results

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

    Nguyen Thi, T. B.; Yokoyama, A.; Ota, K.; Kodama, K.; Yamashita, K.; Isogai, Y.; Furuichi, K.; Nonomura, C.

    2014-05-01

    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 μ-CT. The simulation results showed a good agreement with experiment results.

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

    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

  4. Optimization of injection molding process for car fender in consideration of energy efficiency and product quality

    Hong Seok Park

    2014-10-01

    Full Text Available Energy efficiency is an essential consideration in sustainable manufacturing. This study presents the car fender-based injection molding process optimization that aims to resolve the trade-off between energy consumption and product quality at the same time in which process parameters are optimized variables. The process is specially optimized by applying response surface methodology and using nondominated sorting genetic algorithm II (NSGA II in order to resolve multi-object optimization problems. To reduce computational cost and time in the problem-solving procedure, the combination of CAE-integration tools is employed. Based on the Pareto diagram, an appropriate solution is derived out to obtain optimal parameters. The optimization results show that the proposed approach can help effectively engineers in identifying optimal process parameters and achieving competitive advantages of energy consumption and product quality. In addition, the engineering analysis that can be employed to conduct holistic optimization of the injection molding process in order to increase energy efficiency and product quality was also mentioned in this paper.

  5. Relationship between processing and mechanical properties of injection molded high molecular mass polyethylene + hydroxyapatite composites

    Reis, R.L.; Cunha, A.M.; Oliveira, M.J.; Campos, A.R. [Dept. of Polymer Engineering, University of Minho, Guimaraes (Portugal); Bevis, M.J. [Wolfson Center for Materials Processing, Brunel Univ., Uxbridge (United Kingdom)

    2001-04-01

    We apply a macromolecular-orientation approach to produce high molecular weight polyethylene (HMWPE) + hydroxyapatite (HA) ductile composites with the stiffness and strength within the range of human cortical bone. Our composites are produced with different amounts (10 to 50% by weight) of the reinforcement by two procedures: bi-axial rotating drum and twin screw extrusion (TSE). The processing is by conventional injection molding and by Scorim (shear controlled orientation in injection molding) under a wide range of processing windows. Tensile testing is performed and the corresponding performance related to the morphology evaluated by polarized light microscopy and scanning electron microscopy. The control of the processing parameters led to significant improvements of the tensile properties. Compounding by TSE and then processing by Scorim produces the maximum modulus of 7.4 GPa and the ductility as high as 19%, for the HA weight fraction of 30%. These mechanical properties match those of bone, and were obtained with much smaller amounts of HA reinforcement then has been previously reported in literature. Our PE + HA composites present the additional benefit of being ductile even for 50% HA amounts. The use Scorim is a unique way of inducing anisotropy to thick sections and to produce very stiff composites that may be used in biomedical applications with important mechanical loads. This fact, combined with the bioactive behavior of the HA phase, makes our composite usable for orthopedic load-bearing implants. (orig.)

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

    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

  7. Polyamide 6 - long glass fiber injection moldings

    Bijsterbosch, H.; Gaymans, R.J.

    1995-01-01

    The injection molding ability of long glass fiber reinforced polyamide pellets was studied. The injection moldable materials were produced by a melt impregnation process of continuous fiber rovings. The rovings were chopped to pellets of 9 mm length. Chopped pellets with a variation in the degree of impregnation and fiber concentration were studied. The injection molded samples were analyzed for fiber concentration, fiber length, and fiber orientation. Dumbbell-shaped tensile bars were made t...

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

    2013-01-01

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

  9. Surface microstructure replication in injection molding

    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...... 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...... 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...

  10. Effect of Functional Nano Channel Structures Different Widths on Injection Molding and Compression Molding Replication Capabilities

    Calaon, M.; Tosello, G.; Garnaes, J.;

    The present study investigates the capabilities of the two employed processes, injection molding (IM) and injection compression molding (ICM) on replicating different channel cross sections. Statistical design of experiment was adopted to optimize replication quality of produced polymer parts wit...

  11. Electronic packaging materials prepared by powder injecting molding and pressure infiltration process

    2007-01-01

    AlSiCp (65 vol.% SiC) electronic packaging materials were manufactured by powder injection molding (PIM) and pressure infiltration process in order to obtain near net-shaped parts. SiCp preformed compacts obtained by pre-sintering process at 1150 K have high strength and good appearance, and the ratio of open porosity to total porosiry is nearly 98%. The relative density of composites is bigger than 99%. The thermal conductivity of AlSiCp composites fabricated by this method is 198 W·m-1·K-1, and the coefficient of thermal expansion (CTE) is 8.0 × 10-6/K (298 K).

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

    Søgaard, Emil; Andersen, Nis Korsgaard; Taboryski, Rafael;

    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...

  13. Injection Compression Molding of Replica Molds for Nanoimprint Lithography

    Keisuke Nagato

    2014-03-01

    Full Text Available As a breakthrough in the cost and durability of molds for nanoimprint lithography (NIL, replica molds are fabricated by injection compression molding (ICM. ICM is commonly used for optical disks such as DVDs or Blu-ray disks and is also a practical fabrication method for nanostructures. In this paper, I successfully demonstrated the fabrication of cycloolefin polymer replica molds with structures smaller than 60 nm by ICM. Furthermore, ultraviolet (UV-NIL using these replica molds was demonstrated. UV-cured resist was replicated over an area of 60 mm diameter. The degree of replication by UV-NIL in the first usage of each replica mold had good repeatability. Because ICM is a high-throughput, low-cost process, the replica mold can be disposed of after a certain time for UV-NIL. This method leads to a high-integrity UV-NIL process of patterned media because multiple large-area replica molds can be fabricated simultaneously.

  14. Particle Image Velocimetry During Injection Molding

    Bress, Thomas; Dowling, David

    2012-11-01

    Injection molding involves the unsteady non-isothermal flow of a non-Newtonian polymer melt. An optical-access mold has been used to perform particle image velocimetry (PIV) on molten polystyrene during injection molding. Velocimetry data of the mold-filling flow will be presented. Statistical assessments of the velocimetry data and scaled residuals of the continuity equation suggest that PIV can be conducted in molten plastics with an uncertainty of +/-2 percent. Simulations are often used to model polymer flow during injection molding to design molds and select processing parameters but it is difficult to determine the accuracy of these simulations due to a lack of in-mold velocimetry and melt-front progression data. Moldflow was used to simulate the filling of the optical-access mold, and these simulated results are compared to the appropriately-averaged time-varying velocity field measurements. Simulated results for melt-front progression are also compared with the experimentally observed flow fronts. The ratio of the experimentally measured average velocity magnitudes to the simulation magnitudes was found on average to be 0.99 with a standard deviation of 0.25, and the difference in velocity orientations was found to be 0.9 degree with a standard deviation of 3.2 degrees. formerly at the University of Michigan.

  15. Polyamide 6 - long glass fiber injection moldings

    Bijsterbosch, H.; Gaymans, R.J.

    1995-01-01

    The injection molding ability of long glass fiber reinforced polyamide pellets was studied. The injection moldable materials were produced by a melt impregnation process of continuous fiber rovings. The rovings were chopped to pellets of 9 mm length. Chopped pellets with a variation in the degree of

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

    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.

  17. Powder Injection Molding of Titanium Components

    Simmons, Kevin L.; Nyberg, Eric A.; Weil, K. Scott; Miller, Megan R.

    2005-01-01

    Powder injection molding (PIM) is a well-established, cost-effective method of fabricating small-to-moderate size metal components. Derived from plastic injection molding and employing a mixture of metal powder and plastic binder, the process has been used with great success in manufacturing a wide variety of metal products, including those made from stainless steel, nickel-based superalloys, and copper alloys. Less progress has been achieved with titanium and other refractory metal alloys because of problems with alloy impurities that are directly attributable to the injection molding process. Specifically, carbon, oxygen, and nitrogen are left behind during binder removal and become incorporated into the chemistry and microstructure of the material during densification. Even at low concentration, these impurities can cause severe degradation in the mechanical properties of titanium and its alloys. We have developed a unique blend of PIM constituents where only a small volume fraction of binder (~5 – 10 vol%) is required for injection molding; the remainder of the mixture consists of the metal powder and binder solvent. Because of the nature of decomposition in the binder system and the relatively small amount used, the binder is eliminated almost completely from the pre-sintered component during the initial stage of a two-step heat treatment process. Results will be presented on the first phase of this research, in which the binder, injection molding, de-binding and sintering schedule were developed. Additional data on the mechanical and physical properties of the material produced will be discussed.

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

    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...

  19. Experimental and Numerical Investigation of the Effect of Process Conditions on Residual Wall Thickness and Cooling and Surface Characteristics of Water-Assisted Injection Molded Hollow Products

    Hyungpil Park

    2015-01-01

    Full Text Available Recently, water-assisted injection molding was employed in the automobile industry to manufacture three-dimensional hollow tube-type products with functionalities. However, process optimization is difficult in the case of water-assisted injection molding because of the various rheological interactions between the injected water and the polymer. In this study, the boiling phenomenon that occurs because of the high melt temperature when injecting water and the molding characteristics of the hollow section during the water-assisted injection process were analyzed by a water-assisted injection molding analysis. In addition, the changes in the residual wall thickness accompanying changes in the process conditions were compared with the analysis results by considering water-assisted injection molding based on gas-assisted injection molding. Furthermore, by comparing the cooling characteristics and inner wall surface qualities corresponding to the formation of the hollow section by gas and water injections, a water-assisted injection molding technique was proposed for manufacturing hollow products with functionality.

  20. Dynamic of taking out molding parts at injection molding

    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.

  1. Nonlinear Modeling of a High Precision Servo Injection Molding Machine Including Novel Molding Approach

    何雪松; 王旭永; 冯正进; 章志新; 杨钦廉

    2003-01-01

    A nonlinear mathematical model of the injection molding process for electrohydraulic servo injection molding machine (IMM) is developed.It was found necessary to consider the characteristics of asymmetric cylinder for electrohydraulic servo IMM.The model is based on the dynamics of the machine including servo valve,asymmetric cylinder and screw,and the non-Newtonian flow behavior of polymer melt in injection molding is also considered.The performance of the model was evaluated based on novel approach of molding - injection and compress molding,and the results of simulation and experimental data demonstrate the effectiveness of the model.

  2. Powder injection molding of pure titanium

    GUO Shibo; DUAN Bohua; HE Xinbo; QU Xuanhui

    2009-01-01

    An improved wax-based binder was developed for powder injection molding of pure titanium. A critical powder loading of 69 vol.% and a pseudo-plastic flow behavior were obtained by the feedstock based on the binder. The injection molding, debinding, and sintering process were studied. An ideal control of carbon and oxygen contents was achieved by thermal debinding in vacuum atmosphere (10-3 Pa). The mechanical properties of as-sintered specimens were less than those of titanium made by the conventional press-sintering process. Good shape retention and ±0.04 mm dimension deviation were achieved.

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

    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.

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

    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.

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

    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......-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...... 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...

  6. Nanostructuring steel for injection molding tools

    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. (paper)

  7. Finger-powered microfluidic systems using multilayer soft lithography and injection molding processes.

    Iwai, Kosuke; Shih, Kuan Cheng; Lin, Xiao; Brubaker, Thomas A; Sochol, Ryan D; Lin, Liwei

    2014-10-01

    Point-of-care (POC) and disposable biomedical applications demand low-power microfluidic systems with pumping components that provide controlled pressure sources. Unfortunately, external pumps have hindered the implementation of such microfluidic systems due to limitations associated with portability and power requirements. Here, we propose and demonstrate a 'finger-powered' integrated pumping system as a modular element to provide pressure head for a variety of advanced microfluidic applications, including finger-powered on-chip microdroplet generation. By utilizing a human finger for the actuation force, electrical power sources that are typically needed to generate pressure head were obviated. Passive fluidic diodes were designed and implemented to enable distinct fluids from multiple inlet ports to be pumped using a single actuation source. Both multilayer soft lithography and injection molding processes were investigated for device fabrication and performance. Experimental results revealed that the pressure head generated from a human finger could be tuned based on the geometric characteristics of the pumping system, with a maximum observed pressure of 7.6 ± 0.1 kPa. In addition to the delivery of multiple, distinct fluids into microfluidic channels, we also employed the finger-powered pumping system to achieve the rapid formation of both water-in-oil droplets (106.9 ± 4.3 μm in diameter) and oil-in-water droplets (75.3 ± 12.6 μm in diameter) as well as the encapsulation of endothelial cells in droplets without using any external or electrical controllers. PMID:25102160

  8. Injection molding as a one-step process for the direct production of pharmaceutical dosage forms from primary powders.

    Eggenreich, K; Windhab, S; Schrank, S; Treffer, D; Juster, H; Steinbichler, G; Laske, S; Koscher, G; Roblegg, E; Khinast, J G

    2016-05-30

    The objective of the present study was to develop a one-step process for the production of tablets directly from primary powder by means of injection molding (IM), to create solid-dispersion based tablets. Fenofibrate was used as the model API, a polyvinyl caprolactame-polyvinyl acetate-polyethylene glycol graft co-polymer served as a matrix system. Formulations were injection-molded into tablets using state-of-the-art IM equipment. The resulting tablets were physico-chemically characterized and the drug release kinetics and mechanism were determined. Comparison tablets were produced, either directly from powder or from pre-processed pellets prepared via hot melt extrusion (HME). The content of the model drug in the formulations was 10% (w/w), 20% (w/w) and 30% (w/w), respectively. After 120min, both powder-based and pellet-based injection-molded tablets exhibited a drug release of 60% independent of the processing route. Content uniformity analysis demonstrated that the model drug was homogeneously distributed. Moreover, analysis of single dose uniformity also revealed geometric drug homogeneity between tablets of one shot. PMID:27012981

  9. Wavelet Packet Decomposition to Characterize Injection Molding Tool Damage

    Tomaž Kek

    2016-02-01

    Full Text Available This paper presents measurements of acoustic emission (AE signals during the injection molding of polypropylene with new and damaged mold. The damaged injection mold has cracks induced by laser surface heat treatment. Standard test specimens were injection molded, commonly used for examining the shrinkage behavior of various thermoplastic materials. The measured AE burst signals during injection molding cycle are presented. For injection molding tool integrity prediction, different AE burst signals’ descriptors are defined. To lower computational complexity and increase performance, the feature selection method was implemented to define a feature subset in an appropriate multidimensional space to characterize the integrity of the injection molding tool and the injection molding process steps. The feature subset was used for neural network pattern recognition of AE signals during the full time of the injection molding cycle. The results confirm that acoustic emission measurement during injection molding of polymer materials is a promising technique for characterizing the integrity of molds with respect to damage, even with resonant sensors.

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

    Tosello, Guido; Gava, Alberto; Hansen, Hans Nørgaard;

    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....

  11. Progress in Titanium Metal Powder Injection Molding

    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.

  12. Numerical Analysis of Mold Deformation Including Plastic Melt Flow During Injection Molding

    Jung, Joon Tae; Lee, Bong-Kee [Chonnam National University, Gwangju (Korea, Republic of)

    2014-07-15

    In the present study, a numerical analysis of an injection molding process was conducted for predicting the mold deformation considering non-Newtonian flow, heat transfer, and structural behavior. The accurate prediction of mold deformation during the filling stage is important to successfully design and manufacture a precision injection mold. While the local mold deformation can be caused by various factors, a pressure induced by the polymer melt is considered to be one of the most significant ones. In this regard, the numerical simulation considering both the melt filling and the mold deformation was carried out. A mold core for a 2D axisymmetric center-gated disk was used for the demonstration of the present study. The flow behavior inside the mold cavity and temperature distribution were analyzed along with the core displacement. Also, a Taguchi method was employed to investigate the influence of the relevant parameters including flow velocity, mold core temperature, and melt temperature.

  13. Evolution of Surface Texture and Cracks During Injection Molding of Fiber-Reinforced, Additively-Manufactured, Injection Molding Inserts

    Hofstätter, Thomas; Mischkot, Michael; Pedersen, David Bue;

    2016-01-01

    This paper investigates the lifetime and surfacedeterioration of additively-manufactured, injection-moulding inserts. The inserts were produced using digital light processing and were reinforcedwith oriented short carbon fibers. Theinserts were used during injection molding oflow......-density polyethylene until their failure. The molded products were used to analyse the development of the surface roughness and wear. By enhancing the lifetime of injection-molding inserts,this work contributes to the establishment of additively manufactured inserts in pilot production....

  14. Porous media heat transfer for injection molding

    Beer, Neil Reginald

    2016-05-31

    The cooling of injection molded plastic is targeted. Coolant flows into a porous medium disposed within an injection molding component via a porous medium inlet. The porous medium is thermally coupled to a mold cavity configured to receive injected liquid plastic. The porous medium beneficially allows for an increased rate of heat transfer from the injected liquid plastic to the coolant and provides additional structural support over a hollow cooling well. When the temperature of the injected liquid plastic falls below a solidifying temperature threshold, the molded component is ejected and collected.

  15. Analysis of batch-related influences on injection molding processes viewed in the context of electro plating quality demands

    Siepmann, Jens P.; Wortberg, Johannes; Heinzler, Felix A.

    2016-03-01

    The injection molding process is mandatorily influenced by the viscosity of the material. By varying the material batch the viscosity of the polymer changes. For the process and part quality the initial conditions of the material in addition to the processing parameters define the process and product quality. A high percentage of technical polymers processed in injection molding is refined in a follow-up production step, for example electro plating. Processing optimized for electro plating often requires avoiding high shear stresses by using low injection speed and pressure conditions. Therefore differences in the material charges' viscosity occur especially in the quality related low shear rate area. These differences and quality related influences can be investigated by high detail rheological analysis and process simulation based on adapted material describing models. Differences in viscosity between batches can be detected by measurements with high-pressure-capillary-rheometers or oscillatory rheometers for low shear rates. A combination of both measurement techniques is possible by the Cox-Merz-Relation. The detected differences in the rheological behavior of both charges are summarized in two material behavior describing model approaches and added to the simulation. In this paper the results of processing-simulations with standard filling parameters are presented with two ABS charges. Part quality defining quantities such as temperature, pressure and shear stress are investigated and the influence of charge variations is pointed out with respect to electro plating quality demands. Furthermore, the results of simulations with a new quality related process control are presented and compared to the standard processing.

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

    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. (paper)

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

    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. (paper)

  18. 模具温度对注塑成型加工的影响及其冷却探析%Research on Influence of Mold Temperature and Cooling in Injection Molding Process

    李谟树

    2011-01-01

    针对注塑成型的技术要求,分析模具温度的冷却过程和决定模具温度冷却效果的影响因素,以及冷却系统的散热与功能参数的计算方法,对于优化模具结构设计、提升注塑成型加工的效益具有重要意义.%Mold temperature of the cooling process and the effect factors of mold temperature were analyzed based on technical requirements for injection molding process. The calculation of cooling system and functional parameters was of great importance to optimize design of the cooling system and injection molding process.

  19. Injection molding of micro patterned PMMA plate

    Yeong-Eun YOO; Tae-Hoon KIM; Tae-Jin JE; Doo-Sun CHOI; Chang-Wan KIM; Sun-Kyung KIM

    2011-01-01

    A plastic plate with surface micro features was injection molded to investigate the effect of pressure rise of melt on the replication of the micro structures. Prism pattern, which is used in many optical applications, was selected as a model pattern. The prism pattern is 50 μm in pitch and 108° in the vertical angle. The overall size of the plate was 335 mm×213 mm and the thickness of the plate varied linearly from 2.6 mm to 0.7 mm. The prism pattern was firstly machined on the nickel plated core block using micro diamond tool and this machined pattern core was installed in a mold for injection molding of prism patterned plate. Polymethyl methacrylate (PMMA) was used as a molding material. The pressure and temperature of the melt in the cavity were measured at different positions in the cavity and the replication of the pattern was also measured at the same positions. The results show that the pressure or temperature profile through the process depends on the shape and the size of the plate. The replication is affected by the temperature and pressure profiles at the early stage of filling, which is right after the melt reaches the position to be measured.

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

    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...... trichloro-silane based coating deposited on aluminum or its alloys by molecular vapor deposition. We have 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...... 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...

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

    Hobæk, Thor Christian; Matschuk, Maria; Kafka, Jan;

    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...

  2. Multi-height structures in injection molded polymer

    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...

  3. Smart plastic functionalization by nanoimprint and injection molding

    Zalkovskij, Maksim; Thamdrup, Lasse Højlund; Smistrup, Kristian;

    2015-01-01

    In this paper, we present a route for making smart functionalized plastic parts by injection molding with sub-micrometer surface structures. The method is based on combining planar processes well known and established within silicon micro and sub-micro fabrication with proven high resolution and...... high fidelity with truly freeform injection molding inserts. The link between the planar processes and the freeform shaped injection molding inserts is enabled by the use of nanoimprint with flexible molds for the pattern definition combined with unidirectional sputter etching for transferring the...... pattern. With this approach, we demonstrate the transfer of down to 140 nm wide holes on large areas with good structure fidelity on an injection molding steel insert. The durability of the sub-micrometer structures on the inserts have been investigated by running two production series of 102,000 and 73...

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

    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

  5. Nanostructuring steel for injection molding tools

    Al-Azawi, A.; Smistrup, Kristian; Kristensen, Anders

    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...... 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...

  6. Shape retention of injection molded stainless steel compacts

    LI Yi-min; K.A.Khalil; HUANG Bai-yun

    2005-01-01

    The effects of the binder composition, the powder loading, the thermal properties of feedstocks, and the injection molding parameters on the compact shape retention for metal injection molding 17-4PH stainless steel were investigated. The high-density polyethylene is more effective than ethylene vinyl acetate as a second component of the wax-based binder to retain compact shape due to its higher pyrolytic temperature and less heat of fusion. The compact distortion decreases with increasing the powder loading, molding pressure and molding temperature. There exists an optimal process combination including the powder loading of 68%, molding pressure of 120 MPa and molding temperature of 150 ℃. Under this process condition, the percentage of distorted compacts is the lowest.

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

    Tosello, Guido; Costa, F.S.; Hansen, Hans Nørgaard

    2011-01-01

    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......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...

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

    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.

  9. Development and Characterization of a Metal Injection Molding Bio Sourced Inconel 718 Feedstock Based on Polyhydroxyalkanoates

    Alexandre Royer; Thierry Barrière; Jean-Claude Gelin

    2016-01-01

    The binder plays the most important role in the metal injection molding (MIM) process. It provides fluidity of the feedstock mixture and adhesion of the powder to keep the molded shape during injection molding. The binder must provide strength and cohesion for the molded part and must be easy to remove from the molded part. Moreover, it must be recyclable, environmentally friendly and economical. Also, the miscibility between polymers affects the homogeneity of the injected parts. The goal of...

  10. Nanostructuring steel for injection molding tools

    Al-Azawi, A.; Smistrup, Kristian; Kristensen, Anders

    2014-01-01

    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...

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

    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.

  12. Innovative use of wood-plastic-composites (WPC) as a core material in the sandwich injection molding process

    Moritzer, Elmar; Martin, Yannick

    2016-03-01

    The demand for materials based on renewable raw materials has risen steadily in recent years. With society's increasing interest for climate protection and sustainability, natural-based materials such as wood-plastic-composites (WPC) have gained market share thanks to their positive reputation. Due to advantages over unreinforced plastics such as cost reduction and weight savings it is possible to use WPC in a wide area of application. Additionally, an increase in mechanical properties such as rigidity and strength is achieved by the fibers compared to unreinforced polymers. The combination of plastic and wood combines the positive properties of both components in an innovative material. Despite the many positive properties of wood-plastic-composite, there are also negative characteristics that prevent the use of WPC in many product areas, such as automotive interiors. In particular, increased water intake, which may result in swelling of near-surface particles, increased odor emissions, poor surface textures and distortion of the components are unacceptable for many applications. The sandwich injection molding process can improve this situation by eliminating the negative properties of WPC by enclosing it with a pure polymer. In this case, a layered structure of skin and core material is produced, wherein the core component is completely enclosed by the skin component. The suitability of WPC as the core component in the sandwich injection molding has not yet been investigated. In this study the possibilities and limitations of the use of WPC are presented. The consideration of different fiber types, fiber contents, skin materials and its effect on the filling behavior are the focus of the presented analysis.

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

    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.

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

    Hayashi, Hidetomo; Mori, Tomoki [Advanced Polymeric Nanostructured Materials Engineering, Graduate School of Engineering, Toyota Technological Institute, Hisakata 2-12-1, Tempaku, Nagoya 468-8511 (Japan); Okamoto, Masami, E-mail: okamoto@toyota-ti.ac.jp [Advanced Polymeric Nanostructured Materials Engineering, Graduate School of Engineering, Toyota Technological Institute, Hisakata 2-12-1, Tempaku, Nagoya 468-8511 (Japan); Yamasaki, Satoshi; Hayami, Hiroshi [Polymer Materials Technology R and D Department Electronics and Materials R and D Laboratories, Sumitomo Electric Industries, Ltd., Shimaya, Konohana-ku, 1-1-3, Osaka, 554-0024 (Japan)

    2010-01-01

    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.

  15. An Integrated Approach Linking Process to Structural Modeling With Microstructural Characterization for Injections-Molded Long-Fiber Thermoplastics

    Nguyen, Ba Nghiep; Bapanapalli, Satish K.; Smith, Mark T.; Kunc, Vlastimil; Frame, Barbara; Norris, Robert E.; Phelps, Jay; Tucker III, Charles L.; Jin, Xiaoshi; Wang, Jin

    2008-09-01

    The objective of our work is to enable the optimum design of lightweight automotive structural components using injection-molded long fiber thermoplastics (LFTs). To this end, an integrated approach that links process modeling to structural analysis with experimental microstructural characterization and validation is developed. First, process models for LFTs are developed and implemented into processing codes (e.g. ORIENT, Moldflow) to predict the microstructure of the as-formed composite (i.e. fiber length and orientation distributions). In parallel, characterization and testing methods are developed to obtain necessary microstructural data to validate process modeling predictions. Second, the predicted LFT composite microstructure is imported into a structural finite element analysis by ABAQUS to determine the response of the as-formed composite to given boundary conditions. At this stage, constitutive models accounting for the composite microstructure are developed to predict various types of behaviors (i.e. thermoelastic, viscoelastic, elastic-plastic, damage, fatigue, and impact) of LFTs. Experimental methods are also developed to determine material parameters and to validate constitutive models. Such a process-linked-structural modeling approach allows an LFT composite structure to be designed with confidence through numerical simulations. Some recent results of our collaborative research will be illustrated to show the usefulness and applications of this integrated approach.

  16. The Simulation and Optimization of Aspheric Plastic Lens Injection Molding

    WEN Jialing; WEN Pengfei

    2005-01-01

    For the purpose of reducing the volumetric shrinkage and volumetric shrinkage variation, the process in injection molding of aspheric plastic lens was simulated, and several process parameters which include holding pressure, melt temperature, mold temperature, fill time, holding pressure time and cooling time were optimized by using an orthogonal experimental design method. Finally, the optimum process parameters and the influence degree of process parameters on the average volumetric shrinkage and the volumetric shrinkage variation are obtained.

  17. Two component micro injection molding for MID fabrication

    Islam, Mohammad Aminul; Hansen, Hans Nørgaard; Tang, Peter Torben

    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...

  18. Recent Developments and Trends in Powder Injection Molding

    Hermina Wang

    2000-01-01

    Injection molding is a productive and widely used technology for shaping plastics. The use of this shaping technique to metal and ceramics powders is termed powder injection molding (PIM). This process combines a certain quantity of a polymer with a metallic or ceramic powder to form a feedstock that can be molded. After shaping, the polymeric binder is extracted and the powder is sintered. When proper powder size or/and its distribution are used, sintered densities of 95% or more, often to near-theoretical densities, are reached and the mechanical properties are, therefore, generally superior to those of traditional PM parts.

  19. Injection molding of bushes made of tribological PEEK composites

    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. Residual stress distribution in injection molded parts

    P. Postawa

    2006-08-01

    Full Text Available Purpose: The paper presents the results of the investigations of influence of the amorphous polystyrene (PSprocessing on the diversity of the internal stresses observed in the injection moulded piece.Design/methodology/approach: For the tests, the standardized mould piece designed for the investigations ofthe processing shrinkage of thermoplastics materials has been used. The samples have been prepared using theDesign of Experiment (DoE theory.The state of internal stresses has been analysed by means of photoelastic method (used stress viewer equipmenton the basis of the layout and size of the isochromatics (fields with the same colour, which determine the mouldpiece’s areas where the same value for the difference of main tensions. In the article the results of investigationsof influence of 5 chosen processing parameters such as injection temperature Tw, mould temperature Tf,clamping pressure pd, cooling time tch and the injection speed vw on the changes in isochromatics layout as adeterminant for diversity of internal stresses in injection moulded pieces have been presented.Findings: The performed investigations of the influence of injection conditions on the state of internal stressesreached for injection mould pieces were to determine the parameters of injection at which the achieved state ofthe stresses in the mould piece (described by the difference of main tensions will show the lowest values.Practical implications: Effects of examinations of influence of processing conditions on residual stress ininjection molded parts (presented in the article could find practical application in polymer industry, both smalland large enterprises.Originality/value: New approach to fast estimation of value of residual stresses were present in the paper.

  1. CAE for Injection Molding — Past, Present and the Future

    Wang, Kuo K.

    2004-06-01

    It is well known that injection molding is the most effective process for mass-producing discrete plastic parts of complex shape to the highest precision at the lowest cost. However, due to the complex property of polymeric materials undergoing a transient non-isothermal process, it is equally well recognized that the quality of final products is often difficult to be assured. This is particularly true when a new mold or material is encountered. As a result, injection molding has often been viewed as an art than a science. During the past few decades, numerical simulation of injection molding process based on analytic models has become feasible for practical use as computers became faster and cheaper continually. A research effort was initiated at the Cornell Injection Molding Program (CIMP) in 1974 under a grant from the National Science Foundation. Over a quarter of the century, CIMP has established some scientific bases ranging from materials characterization, flow analysis, to prediction of part quality. Use of such CAE tools has become common place today in industry. Present effort has been primarily aimed at refinements of many aspects of the process. Computational efficiency and user-interface have been main thrusts by commercial software developers. Extension to 3-dimensional flow analysis for certain parts has drawn some attention. Research activities are continuing on molding of fiber-filled materials and reactive polymers. Expanded molding processes such as gas-assisted, co-injection, micro-molding and many others are continually being investigated. In the future, improvements in simulation accuracy and efficiency will continue. This will include in-depth studies on materials characterization. Intelligent on-line process control may draw more attention in order to achieve higher degree of automation. As Internet technology continues to evolve, Web-based CAE tools for design, production, remote process monitoring and control can come to path. The CAE

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

    Yossathorn Tanetrungroj; Jutarat Prachayawarakorn

    2015-01-01

    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 n...

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

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

    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...

  4. Residual stresses in injection molded shape memory polymer parts

    Katmer, Sukran; Esen, Huseyin; Karatas, Cetin

    2016-03-01

    Shape memory polymers (SMPs) are materials which have shape memory effect (SME). SME is a property which has the ability to change shape when induced by a stimulator such as temperature, moisture, pH, electric current, magnetic field, light, etc. A process, known as programming, is applied to SMP parts in order to alter them from their permanent shape to their temporary shape. In this study we investigated effects of injection molding and programming processes on residual stresses in molded thermoplastic polyurethane shape memory polymer, experimentally. The residual stresses were measured by layer removal method. The study shows that injection molding and programming process conditions have significantly influence on residual stresses in molded shape memory polyurethane parts.

  5. Single gate optimization for plastic injection mold

    LI Ji-quan; LI De-qun; GUO Zhi-ying; LV Hai-yuan

    2007-01-01

    This paper deals with a methodology for single gate location optimization for plastic injection mold. The objective of the gate optimization is to minimize the warpage of injection molded parts, because warpage is a crucial quality issue for most injection molded parts while it is influenced greatly by the gate location. Feature warpage is defined as the ratio of maximum displacement on the feature surface to the projected length of the feature surface to describe part warpage. The optimization is combined with the numerical simulation technology to find the optimal gate location, in which the simulated annealing algorithm is used to search for the optimum. Finally, an example is discussed in the paper and it can be concluded that the proposed method is effective.

  6. Injection molding of iPP samples in controlled conditions and resulting morphology

    Sessa, Nino; De Santis, Felice; Pantani, Roberto

    2015-12-01

    Injection molded parts are driven down in size and weight especially for electronic applications. In this work, an investigation was carried out on the process of injection molding of thin iPP samples and on the morphology of these parts. Melt flow in the mold cavity was analyzed and described with a mathematical model. Influence of mold temperature and injection pressure was analyzed. Samples orientation was studied using optical microscopy.

  7. Injection molding of iPP samples in controlled conditions and resulting morphology

    Sessa, Nino, E-mail: ninosessa.ns@gmail.com; De Santis, Felice, E-mail: fedesantis@unisa.it; Pantani, Roberto, E-mail: rpantani@unisa.it [Department of Industrial Engineering, University of Salerno, 84084 Fisciano (Italy)

    2015-12-17

    Injection molded parts are driven down in size and weight especially for electronic applications. In this work, an investigation was carried out on the process of injection molding of thin iPP samples and on the morphology of these parts. Melt flow in the mold cavity was analyzed and described with a mathematical model. Influence of mold temperature and injection pressure was analyzed. Samples orientation was studied using optical microscopy.

  8. Injection molding of iPP samples in controlled conditions and resulting morphology

    Injection molded parts are driven down in size and weight especially for electronic applications. In this work, an investigation was carried out on the process of injection molding of thin iPP samples and on the morphology of these parts. Melt flow in the mold cavity was analyzed and described with a mathematical model. Influence of mold temperature and injection pressure was analyzed. Samples orientation was studied using optical microscopy

  9. Modelling and monitoring in injection molding

    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...

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

    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.

  11. Two-component co-injection and transfer molding and gas-assisted injection molding of polymers: Simulation and experiment

    Li, Chengtao

    Two-component molding is a novel process for manufacturing polymer products with a sandwich structure or a hollow structure. Typically, two different materials are injected or transferred into a mold sequentially or simultaneously. The skin is generally a prime polymer with required surface and bulk properties for intended use. The core can be solid, foam or gas. Obtaining a uniform encapsulated structure is difficult and there are no science-based rules for optimization of process setup. Thus, a physical model and process simulations have been developed based on the kinematics and dynamics of a moving interface, and Hele-Shaw approximation. The model has incorporated temperature and shear rate dependences of viscosity of both skin and core component into the transient interface evolution. Based on the developed model, simulations have been carried out to study flow rate controlled simultaneous co-injection molding of thermoplastics, pressure-controlled sequential transfer molding of rubber compounds, and gas-assisted injection molding (GAIM). The simulation results were compared with the experimental data, and in general, good agreement was found between the predicted and experimentally measured interface distribution in moldings. For simultaneous co-injection molding, it is found that material pairs with a broad range of viscosities may be utilized. Breakthrough phenomena are mainly determined by the volume of melt of initial single phase injection and rheological properties of material combinations. When the core has a lower viscosity than the skin, or the volume of initial injection of skin melt is smaller, breakthrough is very likely. However, the breakthrough can be eliminated by controlling injection rate of the skin and core melts. For sequential transfer molding, it is found that the rubber distribution in moldings are dominated by the rheological properties of components and the volume fraction transferred, but independent of the gate pressure. When the

  12. Investigation of micro-injection molding based on longitudinal ultrasonic vibration core.

    Qiu, Zhongjun; Yang, Xue; Zheng, Hui; Gao, Shan; Fang, Fengzhou

    2015-10-01

    An ultrasound-assisted micro-injection molding method is proposed to improve the rheological behavior of the polymer melt radically, and a micro-injection molding system based on a longitudinal ultrasonic vibration core is developed and employed in the micro-injection molding process of Fresnel lenses. The verification experiments show that the filling mold area of the polymer melt is increased by 6.08% to 19.12%, and the symmetric deviation of the Fresnel lens is improved 15.62% on average. This method improved the filling performance and replication quality of the polymer melt in the injection molding process effectively. PMID:26479615

  13. Precision replication of co-molded meso and micro optics through injection molding

    Gill, David Dennis

    The objective of the research is to extend the limits of current optical production techniques for complex, thermally-stable, precise optical components produced in large volume. Injection molding is a high volume process, but is not well understood on this scale. Additionally, polymer can be formed into complex and intricate shapes, but the high coefficient of thermal expansion has prevented the widespread use of polymer for precision optics. For injection molding to become a viable process for the production of meso and micro optics, it is necessary for these challenges to be addressed. The goals of this research address the aforementioned challenges on two fronts (1) injection molding of polymer lenses, and (2) molding of polymer elements directly onto stable substrates. The first is through an increased understanding of the injection molding process in the replication of micro optics. Precision molds were produced with optical features of varying size, shape, step height, and aspect ratio. These features included spherical and fresnel lenses, blaze diffraction grating, and wedding cake. The pitch of the features was as small as 10mum and step heights as small as 1.25mum. A screening design of experiment was performed to discover the molding factors (process variables) with the greatest effect on the replication of micro optics. These experiments showed mold temperature and screw rotation speed to have the greatest effects on the accurate replication of meso and micro optics. The second challenge, the thermal instability of polymer lenses, has been addressed through research of the co-molding these optics directly onto thermally stable substrates. Challenges included the modification of properties at the polymer-substrate interface, the large mismatch in coefficients of thermal expansion between the polymer and the substrate, and mold design factors for using a brittle substrate material in the mold. In the experiments, interface adhesion was found to be

  14. Effect of reprocessing cycles on the degradation of polypropylene copolymer filled with talc or montmorillonite during injection molding process

    Mechanical recycling of polymeric materials is a favorable technique resulting in economic and environmental benefits, especially in the case of polymers with a high production volume as the polypropylene copolymer (PP). However, recycling by reprocessing techniques can lead to thermal, mechanical or thermo-oxidative degradation that can affect the structure of the polymer and subsequently the material properties. PP filled with montmorillonite (MMT) or talc are widely produced and studied, however, its degradation reactions by reprocessing cycles are poorly studied so far. In this study, the effects of reprocessing cycles in the structure and in the properties of the PP/MMT and PP/Talc were evaluated. The samples were mixed with 5% talc or MMT Cloisite C15A in a twin-screw extrusion. After extrusion, this filled material was submitted to five reprocessing cycles through an injection molding process. In order to evaluate the changes induced by reprocessing techniques, the samples were characterized by DSC, FT-IR, Izod impact and tensile strength tests. The study showed that Young modulus, elongation at brake and Izod impact were not affected by reprocessing cycles, except when using talc. In this case, the elongation at brake reduced until the fourth cycle, showing rigidity increase. The DSC results showed that melting and crystallization temperature were not affected. A comparison of FT-IR spectra of the reprocessed indicated that in both samples, between the first and the fifth cycle, no noticeable change has occurred. Thus, there is no evidence of thermo oxidative degradation. In general, these results suggest that PP reprocessing cycles using MMT or talc does not change the material properties until the fifth cycle

  15. Effect of reprocessing cycles on the degradation of polypropylene copolymer filled with talc or montmorillonite during injection molding process

    Demori, R.; Mauler, R. S., E-mail: raquel.mauler@ufrgs.br [Chemistry Institute, Federal University of Rio Grande do Sul, UFRGS, Av. Bento Gonçalves, 9500, Porto Alegre, 91501-970 (Brazil); Ashton, E.; Weschenfelder, V. F.; Cândido, L. H. A.; Kindlein, W. [Laboratory of Design LDSM, Federal University of Rio Grande do Sul, UFRGS (Brazil)

    2015-05-22

    Mechanical recycling of polymeric materials is a favorable technique resulting in economic and environmental benefits, especially in the case of polymers with a high production volume as the polypropylene copolymer (PP). However, recycling by reprocessing techniques can lead to thermal, mechanical or thermo-oxidative degradation that can affect the structure of the polymer and subsequently the material properties. PP filled with montmorillonite (MMT) or talc are widely produced and studied, however, its degradation reactions by reprocessing cycles are poorly studied so far. In this study, the effects of reprocessing cycles in the structure and in the properties of the PP/MMT and PP/Talc were evaluated. The samples were mixed with 5% talc or MMT Cloisite C15A in a twin-screw extrusion. After extrusion, this filled material was submitted to five reprocessing cycles through an injection molding process. In order to evaluate the changes induced by reprocessing techniques, the samples were characterized by DSC, FT-IR, Izod impact and tensile strength tests. The study showed that Young modulus, elongation at brake and Izod impact were not affected by reprocessing cycles, except when using talc. In this case, the elongation at brake reduced until the fourth cycle, showing rigidity increase. The DSC results showed that melting and crystallization temperature were not affected. A comparison of FT-IR spectra of the reprocessed indicated that in both samples, between the first and the fifth cycle, no noticeable change has occurred. Thus, there is no evidence of thermo oxidative degradation. In general, these results suggest that PP reprocessing cycles using MMT or talc does not change the material properties until the fifth cycle.

  16. Residual stresses in injection molded products

    Jansen, K. M. B.

    2015-12-01

    During the molding process residual stresses are formed due to thermal contraction during cooling as well as the local pressure history during solidification. In this paper a simple analytical model is reviewed which relates residual stresses, product shrinkage as well as warpage to the temperature and pressure histories during molding. Precise excimer laser layer removal measurements were performed to verify the predicted residual stress distributions. In addition, detailed shrinkage and warpage measurements on a large series of polymers and for different molding conditions were performed and are shown to compare well with the model predictions.

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

    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.

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

    Calaon, Matteo; Tosello, Guido; Hansen, Hans Nørgaard;

    2012-01-01

    In today´s industry, applications involving surface patterning of sub-μm to nanometer scale structures have shown a high growth potential. To investigate the injection molding capability of replicating sub-μm 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...

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

    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.

  20. An investigation into the injection molding of PMR-15 polyimide

    Colaluca, M. A.

    1984-01-01

    The chemorheological behavior of the PRM-15 molding compounds were characterized, the range of suitable processing parameters for injection molding in a reciprocating screw injection molding machine was determined, and the effects of the injection molding processing parameters on the mechanical properties of molded PMR-15 parts were studied. The apparatus and procedures for measuring viscosity and for determining the physical response of the material during heating are described. Results show that capillary rheometry can be effectively used with thermosets if the equipment is designed to overcome some of the inherent problems of these materials. A uniform temperature was provided in the barrel by using a circulating hot oil system. Standard capillary rheometry methods can provide the dependence of thermoset apparent viscosity on shear rate, temperature, and time. Process conditions resulting in complete imidization should be carefully defined. Specification of controlled oven temperature is inadequate and can result in incomplete imidization. For completely imidized PMR-15 heat at 15 C/min melt flow without gas evolution occurs in the temperature range of 325 C to 400 C.

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

    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.

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

    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.

  3. Rapid and low-cost prototyping of medical devices using 3D printed molds for liquid injection molding.

    Chung, Philip; Heller, J Alex; Etemadi, Mozziyar; Ottoson, Paige E; Liu, Jonathan A; Rand, Larry; Roy, Shuvo

    2014-01-01

    Biologically inert elastomers such as silicone are favorable materials for medical device fabrication, but forming and curing these elastomers using traditional liquid injection molding processes can be an expensive process due to tooling and equipment costs. As a result, it has traditionally been impractical to use liquid injection molding for low-cost, rapid prototyping applications. We have devised a method for rapid and low-cost production of liquid elastomer injection molded devices that utilizes fused deposition modeling 3D printers for mold design and a modified desiccator as an injection system. Low costs and rapid turnaround time in this technique lower the barrier to iteratively designing and prototyping complex elastomer devices. Furthermore, CAD models developed in this process can be later adapted for metal mold tooling design, enabling an easy transition to a traditional injection molding process. We have used this technique to manufacture intravaginal probes involving complex geometries, as well as overmolding over metal parts, using tools commonly available within an academic research laboratory. However, this technique can be easily adapted to create liquid injection molded devices for many other applications. PMID:24998993

  4. 注塑机工艺参数的智能设置与优化%Intelligent setting and optimization of process parameters for injection molding machine

    赵朋; 周华民; 李阳; 李德群

    2009-01-01

    针对工艺人员的试模思路,混合使用实例推理、代理模型和模糊推理技术,建立一种描述注塑机工艺参数设置与优化全过程的混合智能模型.首先采用实例推理技术模拟工艺人员设置初始工艺参数时的"借鉴"思维,在实例推理失败的情况下,采用代理模型模拟工艺人员的"直觉"思维设置初始工艺参数,然后将初始参数用于试模,最后利用模糊推理技术实现工艺人员不断修正缺陷、优化工艺参数的思维过程.基于上述智能模型开发出了相应的软件系统,并通过与控制器的通讯实现与注塑机的集成,实际案例验证表明该系统正确有效,可应用于实际生产.%Based on the molding operator's thought during the molding trial-runs, a hybrid intelligent model employing case-based reasoning, surrogate model and fuzzy inference was constructed. First, the idea of case-based reasoning was adopted for the initial process parameters setting, which simulated the molding operator's behavior that one often recalls previous cases and sets the initial process parameters of the current one by referring to the previous ones. If the case-based reasoning failed to set the initial process parameters, a surrogate model was applied to determine the initial process parameters, which imitated a skilled operator's "know-how" and intuitive sense acquired through long-term experience. Then, the molding trial would be run on the molding machine. Finally, a fuzzy inference based on expert knowledge was developed for correcting defects and optimizing process parameters during the molding trial run until the part quality was found satisfactory. A corresponding intelligent system was developed to be integrated with injection machine by communicating with the controller, and experimental studies showed that the intelligent system could be used in a shop-floor production environment.

  5. Residual stresses in injection molded products

    Jansen, K.M.B.

    2015-01-01

    During the molding process residual stresses are formed due to thermal contraction during cooling as well as the local pressure history during solidification. In this paper a simple analytical model is reviewed which relates residual stresses, product shrinkage as well as warpage to the temperature

  6. The Facility and Process Technics of Polyethylene Rotational Molding

    LI BaiShun

    2001-01-01

    @@ 1. Introduction Rotational molding is the process by which hollow plastic parts are formed. It mainly processes the product which Injection molding and Blow molding can not process medium-sized, large-sized and super large-sized plastic parts. The technics may turn out a tub, dustbin, stock tank, sailboat. The research institute of Lanzhou introduces a suit of RS-16 Rotational Molding Machine from Germany Reinhadt Co. on 1990. It mainly put up experiment and smallscale production. RS-16 rotational molding machine is a single arm and di-axial equipment. It is consisting of a gas heated sintering oven, cooling chamber, mouldcarrying carriage and a controlling unit.

  7. Injection molded self-cleaning surfaces

    Søgaard, Emil

    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......° 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....

  8. Investigation of the adhesion interface obtained through two-component injection molding

    Fetecau, Catalin; Stan, Felicia; Dobrea, Daniel

    2011-01-01

    In this paper we study the interface strength obtained through two-component (2C) injection molding of LDPE-HDPE polymers. First, numerical simulation of the over-molding process is carried out using Moldflow technology. Second, butt-joint specimens were produced by over-molding under different process condition, and tested. Two injection sequences were considered, injection of LDPE on HDPE polymer, and HDLE on LDPE, respectively. To investigate the effects of the mold surface roughness on the polymers adhesion at interface, different inserts with different roughness are employed.

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

    Highlights: ► We present novel and highly useful results on FDTS monolayer coating of aluminum. ► The coating is particularly applicable for coating of prototyping injection molding tools, which often are made of Al. ► We have demonstrated that the coating prevails in injection molding conditions and that the coating will prevent wear of the tools. - Abstract: We have characterized perfluorodecyltrichlorosilane (FDTS) molecular coating of aluminum molds for polymer replication via injection molding (IM). X-ray photoelectron spectroscopy (XPS) data, sessile drop contact angles with multiple fluids, surface energies and roughness data have been collected. Samples have been characterized immediately after coating, after more than 500 IM cycles to test durability, and after 7 months to test temporal stability. The coating was deposited in an affordable process, involving near room temperature gas phase reactions. XPS shows detectable fluorine presence on both freshly coated samples as well as on post-IM samples with estimated 30 at.% on freshly coated and 28 at.% on post-IM samples with more than 500 IM cycles with polystyrene (PS) and ABS polymer.

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

    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

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

    Jensen, Marie Pødenphant; Marie, Rodolphe; Olesen, Tom;

    2014-01-01

    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...

  12. Characterization methods of nano-patterned surfaces generated by induction heating assisted injection molding

    Tang, Peter Torben; Ravn, Christian; Menotti, Stefano;

    2015-01-01

    An induction heating-assisted injection molding (IHAIM) process developed by the authors is used to replicate surfaces containing random nano-patterns. The injection molding setup is developed so that an induction heating system rapidly heats the cavity wall at rates of up to 10◦C/s. In order to...

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

    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.

  14. Fabrication of injection molded sintered alpha SiC turbine components

    Storm, R. S.; Ohnsorg, R. W.; Frechette, F. J.

    1981-01-01

    Fabrication of a sintered alpha silicon carbide turbine blade by injection molding is described. An extensive process variation matrix was carried out to define the optimum fabrication conditions. Variation of molding parameters had a significant impact on yield. Turbine blades were produced in a reasonable yield which met a rigid quality and dimensional specification. Application of injection molding technology to more complex components such as integral rotors is also described.

  15. Prediction of stiffness from orientation data of glass reinforced injection moldings

    Neves, N. M.; Pouzada, A. S.

    1999-01-01

    The complex thermo-mechanical process developing in injection molding leads to through-thickness and point to point variation of fiber orientation. It is not economically viable to characterize experimentally the variation of fiber orientation. Thus, efforts have been put into modeling the fiber orientation in injection molding. Some commercially available programs already allow the prediction of fiber orientation distribution in moldings. If the fiber orientation fiel...

  16. Drag material change in hot runner injection molding

    蒋炳炎; 黄伯云

    2001-01-01

    Quick material change is often encountered for the different colors or kinds of polymer in hot runner injecting molding process. Time-costing and incompleteness of material change process often affects the quality and productivity of products. In the practical production, multi-injection or white material as the transition material is often adopted for quick material change. Based on the rheological behavior of the new and the previous plastic melt, the researches on the related problems were carried out. The concept of drag material change was originally presented. The physical and mathematical model on the simultaneous flow process of the new and the previous plastic melt in hot runner were built up, which can well explain the influence of the injection speed, pressure, viscosity difference, temperature and mold structure on the drag material change efficiency. When temperature in different position in the mold was increased and adjusted, the viscosity difference between the two kinds of melt can be controlled. Therefore the material change ability can be greatly improved during the whole material change process, getting rid of more and more difficult changing in the late stage.

  17. Research in manufacturing of micro-structured injection molded polymer parts

    Lucyshyn, Thomas; Struklec, Tobias; Burgsteiner, Martin; Graninger, Georg; Holzer, Clemens

    2015-12-01

    An overview of current research results is given for the topic of injection molding of micro-structured polymer parts regarding filling behavior and demolding process of micro-structures as well as the production of micro-structures on curved surfaces. In order to better understand how micro-structures are formed during the filling stage of injection molding, a study was performed on a test part with micro-channels placed parallely and perpendicularly to flow direction. Short shots with a highly fluent Polypropylene grade were injection molded with the melt front stopping in the structure fields. The melt and mold temperature, the injection rate as well as the use of a variotherm heating system were varied in a systematic Design of Experiments. The shape of the flow front was investigated with the optical measurement system Alicona InfiniteFocus. The data gained was analyzed with Matlab scripts and provided the needed distance to completely fill the structures as a reference value. The next topic covers the demolding step, which is a crucial process step in injection molding of micro-structured parts as the successfully replicated structures often get destroyed in the following demolding step. In order to evaluate the influence of the four aspects polymer, mold surface (coatings), structure (geometry and placement) and process settings on the demolding behavior, an injection mold with integrated measurement system was built, which makes it possible to measure the demolding force respectively a demolding energy under process conditions. These values can be used to quantitatively compare the impact of the above mentioned influencing factors on demolding. Finally, a concept to produce micro-structures on curved surfaces with injection molding is shown: A flat metal premaster structure is used to produce an elastomeric polymer (dimethylsiloxane) master in a casting process. This master is fixed in a conventional injection mold and a thermoplastic polymer is replicated

  18. Comparison of injection molding and injection/compression molding for the replication of microstructure

    Hong, Seokkwan; Hwang, Jeongho; Kang, Jeongjin; Yoon, Kyunghwan

    2015-11-01

    Because of increasing interest in the functional surfaces including micro- or nano-patterns, the mass production of such surfaces has been actively researched. Both conventional injection molding (CIM) and injection/compression molding (ICM) of micro-patterns were investigated in the present study. The molding subject is a multi-scale structure that consists of a macro-scale thin plate and micro-scale patterns formed regularly on its surface. The transcription ratios of micro pattern made by CIM and ICM for different flow length were experimentally measured, and the origin of the obtained results was identified through numerical analysis. It was found that the cavity pressure and polymer temperature are the most important factors for micro-pattern filling; in particular, the polymer temperature is the key factor determining the transcription ratio. It was also found that the difference in CIM and ICM micro-pattern transcription ratios originates from the differences in the cavity pressure history if other molding conditions are the same.

  19. Optomechanical details in injection-molded assemblies

    Hebert, Raymond T.

    1995-12-01

    With the advent of low-cost electro-optic components such as LEDs, laser diodes and CCD imaging devices, the cost and performance demands now fall upon the optical subsystems in order to achieve realistic marketing targets for many emerging commercial and consumer products. One of the many benefits of injection-molded plastic optics is the diversity of features that are available to the design team. Once designed and incorporated into the tooling, many features are virtually free in high-volume production. These features can include mechanical details as well as optical functions. Registration features can be included for precisely positioning optical elements to one another or to other assemblies such as printed circuit boards or housings. Snaps, compression features, spring-loading elements, standoffs, self-tapping screws or ultrasonically weldable features can greatly facilitate ease of assembly.

  20. Investigation of interfacial fracture behavior on injection molded parts

    Fischer, Matthieu; Ausias, Gilles; Kuehnert, Ines

    2016-03-01

    In this study the interfacial morphology of different polymers joined by various assembly injection molding (AIM) technologies were discussed. Melt streams were injected successively using tools with core-back or rotation techniques. To compare bulk specimen strength and weld line strength, the fracture behavior of different specimen scales and thin sections were investigated. An in-situ SEM tensile test and a new thin section testing device which is used in polarized (transmitted) light microscopy were used to observe specimen failure. The effects of processing on spherulitic structures were linked to bonding strength and mechanical properties.

  1. Injection molding of thermoplastic elastomers for microstructured substrates

    Birkar, Smita

    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.

  2. Injection-compression and co-injection moldings of amorphous polymers: Viscoelastic simulation and experiment

    Kim, Nam Hyung

    Injection-compression molding (ICM) and co-injection molding have gained increasing importance in manufacturing of polymer products. Scientific understanding of these processes is presently limited and no attempts have been made to simulate co-injection molding using a viscoelastic model. In addressing this issue, the present study provides results of comprehensive viscoelastic simulations and experimental investigations of the residual stresses and birefringence in center-gated disk moldings of amorphous polymers obtained by ICM and sequential co-injection molding (SCIM) at various processing conditions. The governing equations for viscoelastic simulation of ICM and SCIM processes were derived using a nonlinear viscoelastic model. The equations were solved using a hybrid control volume/finite element/finite difference method. In general, residual stresses and birefringence in moldings arise from the flow- and thermally-induced contributions. To consider the thermal contribution, simulations and experimental study of birefringence in freely quenched multi-layered plates were carried out. The flow- and thermally-induced stresses were simulated using nonlinear and linear viscoelastic theories, respectively. The overall residual birefringence in moldings was obtained by summation of the flow- and thermally-induced birefringence contributions calculated using the stress-optical rule and photoviscoelastic constitutive equation, respectively. The numerical results were found to be in fair agreement with experimental data on the distribution of residual birefringence, Deltan, and average transverse birefringence, , of the ICM made from polycarbonate (PC) and polystyrene (PS). It was found that the melt temperature and compression stroke strongly affected the residual birefringence in ICM, while the mold temperature had less effect. The numerical and experimental results of the gapwise distribution of the residual birefringence, Delta n, and interface of the SCIM were

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

    Guerrier, Patrick; Tosello, Guido; Hattel, Jesper Henri

    2014-01-01

    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...

  4. Using multi-objective evolutionary algorithms in the optimization of polymer injection molding

    Fernandes, Célio Bruno Pinto; Pontes, A.J.; Viana, J.C.; Gaspar-Cunha, A.

    2009-01-01

    A Multi-objective optimization methodology has been applied in the optimization of polymer injection molding process. This allowed the optimization of the operating conditions of the process from mold flow simulations, taking into consideration the existence of 5 criteria simultaneously, such as temperature dif-ference on the molding at the end of filling, the maximum pressure, the pressure work, the volumetric shrinkage and the cycle time. The results produced shown that the proposed methodo...

  5. Rheological properties of granulometric mixtures for powder injection molding

    Resende, L.M. [Dept. of Mechanical Engineering, Univ. Federal de Santa Catarina Florianopolis (Brazil); Dept. of Materials Engineering, Ponta Grossa State Univ., Ponta Grossa PR (Brazil); Klein, A.N.; Prata, A.T. [Dept. of Mechanical Engineering, Univ. Federal de Santa Catarina Florianopolis (Brazil)

    2001-07-01

    Powder injection molding (PIM) combines benefits from both powder metallurgy, regarding the accurate control of microstructure and chemical composition, and the injection molding regarding the feasibility of tridimensional shapes. Obtaining parts with complex geometry and tight dimensional control has proven to be a high technology process. There are many advantages of using PIM; however, some processing difficulties do exist, especially related to the powder-to-binder ratio, that has a direct impact on dimensional distortions, microstructural homogeneity, injectability, and processing time. In this way, the task of establishing an optimum relationship between powder and binder plays an important role on the process quality. One of the alternatives for optimizing the amount of powder in the mixture, keeping appropriate viscosity levels needed during injection, is in the use of powders with multimodal distributions. In the present work, powders with mono and bimodal granulometric distributions were investigated with respect to their rheological properties and parameters for binder remotion. Iron spherical powder was used with medium sizes of 1 {mu}m and 7 {mu}m. (orig.)

  6. Evaluation of stability for monolayer injection molding tools coating

    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....... 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....

  7. Applications of thin carbon coatings and films in injection molding

    Cabrera, Eusebio Duarte

    conductive top layer. For many years, in-mold coating (IMC) has been commercially applied to Sheet Molding Compound (SMC) compression molded parts, as an environmentally friendly approach to improve its surface quality and provide the required conductivity for electrostatic painting using carbon black (CB). Such process can also be applied to injection molding for creating a top conductive layer. Increasing the amount of CB will increase the surface conductivity of the coated part, thus improving the paint transfer efficiency. However the CB levels needed to achieve the conductivity levels required for achieving EMI shielding would make the coating viscosity too large for proper coating. Nanopaper based composites are excellent candidates for EMI shielding because of the nanopaper's high concentration of carbon nanofibers (CNFs) (~2 wt% to 10 wt% depending on nanopaper/thermoplastic thickness and 71wt.% to 79wt.% in the nanopaper itself after resin infusion) and high conductivity of the nanopaper. Instead of premixing nanoparticles with IMC coating, nanopapers enable the use of low viscosity IMC without CB coating to impregnate the CNF network in order to reach high electrical conductivity and EMI shielding values. (Abstract shortened by UMI.).

  8. Stochastic resin transfer molding process

    Park, M

    2016-01-01

    We consider one-dimensional and two-dimensional models of stochastic resin transfer molding process, which are formulated as random moving boundary problems. We study their properties, analytically in the one-dimensional case and numerically in the two-dimensional case. We show how variability of time to fill depends on correlation lengths and smoothness of a random permeability field.

  9. Tool application CAD / CAM for design and construction of a prototype of plastic injection mold

    Albert Miyer Suárez Castrillón

    2015-11-01

    Full Text Available The study, development and production of injection molds comes with the implementation of CAD and CAM tools available on the market; using these tools, a prototype injection mold for thermoplastic materials was designed and built, based on a mold is injection in the laboratory of the University of Pamplona, in which a couple of modifications were made in order to experiment with its design. The prototype was manufactured through a 3D scan of the original mold to provide the CAD / CAM files with the simulated 3D printing technique for performing an experimental study with the prototype for adjusting temperature and pressure sensors and for coatings metallic materials for use in the injection molding process.

  10. Capabilities Of Micro Powder Injection Molding For Microparts Manufacturing

    Kong, X.; Barriere, T.; Gelin, J. C.

    2011-01-01

    The Micro-PIM processing technology satisfies the increasing demand in terms of smaller parts and miniaturization. Research works in this area have been carried out at FEMTO-ST Institute by performing the injection molding with 316L stainless steel fine powders and polymer binders. Several formulations with different proportion of powders and binders as well various polymers have been tested, and then a well adapted one has been selected. The process to select the well adapted formulation and the rheological characteristics of the feedstock realized according with the selected formulation are also detailed. Several test specimens have been successfully manufactured.

  11. Effects of mold geometry on fiber orientation of powder injection molded metal matrix composites

    Ahmad, Faiz, E-mail: faizahmad@petronas.com.my; Aslam, Muhammad, E-mail: klaira73@gmail.com; Altaf, Khurram, E-mail: khurram.altaf@petronas.com.my; Shirazi, Irfan, E-mail: irfanshirazi@hotmail.com [Mechanical Engineering Universiti Teknologi PETRONAS Malaysia (Malaysia)

    2015-07-22

    Fiber orientations in metal matrix composites have significant effect on improving tensile properties. Control of fiber orientations in metal injection molded metal composites is a difficult task. In this study, two mold cavities of dimensions 6x6x90 mm and 10x20x180 mm were used for comparison of fiber orientation in injection molded metal composites test parts. In both mold cavities, convergent and divergent flows were developed by modifying the sprue dimensions. Scanning electron microscope (SEM) was used to examine the fiber orientations within the test samples. The results showed highly aligned fiber in injection molded test bars developed from the convergent melt flow. Random orientation of fibers was noted in the composites test bars produced from divergent melt flow.

  12. Effects of mold geometry on fiber orientation of powder injection molded metal matrix composites

    Fiber orientations in metal matrix composites have significant effect on improving tensile properties. Control of fiber orientations in metal injection molded metal composites is a difficult task. In this study, two mold cavities of dimensions 6x6x90 mm and 10x20x180 mm were used for comparison of fiber orientation in injection molded metal composites test parts. In both mold cavities, convergent and divergent flows were developed by modifying the sprue dimensions. Scanning electron microscope (SEM) was used to examine the fiber orientations within the test samples. The results showed highly aligned fiber in injection molded test bars developed from the convergent melt flow. Random orientation of fibers was noted in the composites test bars produced from divergent melt flow

  13. Fabrication of micro gear wheels by micropowder injection molding

    Haiqing Yin; Xuanhui Qu; Chengchang Jia

    2008-01-01

    The micropowder injection molding technology was investigated to fabricate the microsized gear wheels on a conventional injection molding machine. The feedstock comprised of carbonyl ferrum powder and a wax-based thermoplastic binder. Microinjection molding was fulfilled at about 423 K under 100 MPa. The heating system was applied to the die to improve the fluidity of the feedstock and subsequently the cooling system was used to enhance the strength of the green compacts after injection by decreasing the temperature of the die. The gear wheels were realized successfully with their addendum circle diameter ranging from 800 to 200 m and with the center hole as small as 60 μtm.

  14. Fabrication of sinterable silicon nitride by injection molding

    Quackenbush, C. L.; French, K.; Neil, J. T.

    1982-01-01

    Transformation of structural ceramics from the laboratory to production requires development of near net shape fabrication techniques which minimize finish grinding. One potential technique for producing large quantities of complex-shaped parts at a low cost, and microstructure of sintered silicon nitride fabricated by injection molding is discussed and compared to data generated from isostatically dry-pressed material. Binder selection methodology, compounding of ceramic and binder components, injection molding techniques, and problems in binder removal are discussed. Strength, oxidation resistance, and microstructure of sintered silicon nitride fabricated by injection molding is discussed and compared to data generated from isostatically dry-pressed material.

  15. Development of Integrated Simulation System for Plastic Injection Molding

    CHENGXue-wen; LIDe-qun; ZHOUHua-min

    2005-01-01

    Numerical simulation of injection molding have had success in predicting the behavior of polymer melt in extremely complicated geometries. Most of the current numerical solutions are based on finite-element/finite-difference/boundary-element/volume-control methods and the surface model. This paper discusses the development of an integrated CAE system for injection molding in detail, and presents the mathematics for numerical simulation of filling, packing,cooling, stress and warpage in injection molding. The developed system named as HsCAE3D is introduced at the end.

  16. Injection molded polymeric hard X-ray lenses

    Stöhr, Frederik; Simons, Hugh; Jakobsen, Anders Clemen;

    2015-01-01

    etching profile and were removed after DRIE. By electroplating, an inverse nickel sample was obtained, which was used as a mold insert in a commercial polymer injection molding machine. A prototype lens made of polyethylene with a focal length of 350 mm was tested using synchrotron radiation at photon...

  17. An X-ray Scattering Study of Water-Conditioned Injection- Molded Starch during Isothermal Heating

    Cagiao, M.E.; Bayer, R. K.; Rueda, D. R.; Baltá Calleja, F. J.

    2003-01-01

    The in situ structure variation of injection molded starch (as processed and after water conditioning)during heat treatment was investigated by means of wideangle X-ray scattering using synchrotron radiation. Results confirm that the crystal structure of potato starch is destroyed after injection molding, while as-processed corn starch preserves some degree of crystallinity. This residual crystallinity in corn starch is related to the crystalline Vh form,made of complexes of amylose with l...

  18. Foam injection molding of elastomers with iron microparticles

    Volpe, Valentina; D'Auria, Marco; Sorrentino, Luigi; Davino, Daniele; Pantani, Roberto

    2015-12-01

    In this work, a preliminary study of foam injection molding of a thermoplastic elastomer, Engage 8445, and its microcomposite loaded with iron particles was carried out, in order to evaluate the effect of the iron microparticles on the foaming process. In particular, reinforced samples have been prepared by using nanoparticles at 2% by volume. Nitrogen has been used as physical blowing agent. Foamed specimens consisting of neat and filled elastomer were characterized by density measurements and morphological analysis. While neat Engage has shown a well developed cellular morphology far from the injection point, the addition of iron microparticles considerably increased the homogeneity of the cellular morphology. Engage/iron foamed samples exhibited a reduction in density greater than 32%, with a good and homogeneous cellular morphology, both in the transition and in the core zones, starting from small distances from the injection point.

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

    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.

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

    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

  1. Cooling simulation of plastic injection molding

    2001-01-01

    Analyses the cooling of mold and plastic part during injectionmolding and the continued cooling of plastic part after being ejected from mold using the heat transfer theory and Boundary Element Method (BEM) to predict the temperature distribution in both mold and plastic part,and presents the experiments carried out with plates of ABS (Acrylonitrile-Butadiene-Styrene) to verify the validity of the cooling analysis software used to simulate the temperature distribution in ABS plate parts, and concludes that the analysis software agree qualitatively well with actual experimental findings.

  2. Comparison of two setups for induction heating in injection molding

    Menotti, Stefano; Hansen, Hans Nørgaard; Bissacco, Giuliano;

    2015-01-01

    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 and two different coil setups were tested and compared. An experimental investigation was performed...... based on a test geometry integrating different aspect ratios of small structures. Acrylonitrile butadiene styrene (ABS) was used as material, and different mold temperatures were tested. The replicated test objects were measured by means of an optical coordinate measuring machine (CMM). On the basis of...

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

    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 properties of dielectromagnets. A result of mixture composition on magnetic properties of injection molded dielectromagnets is shown. (author)

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

    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 was used as the molding material and the design of experiment approach was adopted to systematically and statistically investigate the relationship between machine parameters, real process conditions and replication quality. The peak cavity pressure and temperature were selected as process characteristic values to describe the real process conditions that the material experienced during the filling process. The experiments revealed that the replication of ridges, including feature edge, profile and filling height, was sensitive to the flow direction; cavity pressure and temperature both increased with holding pressure and mold temperature; replication quality can be improved by increasing cavity pressure and temperature within a certain range. The replication quality of micro/nano features is tightly related to the thermomechanical history of material experienced during the molding process. In addition, the longevity and roughness of the BMG insert were also evaluated based on the number of injection molding cycles. (paper)

  5. Effect of injection-molding-induced residual stress on microchannel deformation irregularity during thermal bonding

    Micro injection molding offers a promising approach to rapidly produce thermoplastic microfluidic substrates in large volumes. Many research works have been focused on the replication fidelity of microstructures by injection molding. However, there has not been any investigation on the effect of molded-in residual stress on microchannel deformation during the subsequent thermal bonding process. These effects could be important, because the residual stress developed due to anisotropic polymer flow orientation and inhomogeneous cooling may lead to abnormal microchannel distortion. In the direct thermal bonding process, asymmetric cross-sectional distortion was observed in well-formed microchannels aligned perpendicular to the polymer melt injection direction. This asymmetric distortion is attributed to the residual stress introduced into the substrates during molding, particularly in the surface region where microchannels are molded. Design of experiment on injection molding was carried out to reduce the residual stress in order to achieve the lowest microchannel deformation irregularity, which is a new term defined in this study. The direct thermal bonding was utilized as a feasible non-destructive indirectly quantitative method to evaluate the effect of residual stress around microchannel regarding deformation irregularity. The dominant molding parameters with positive effects were found to be melt temperature, mold temperature as well as cooling time after packing. The presence of the residual stress was also demonstrated through photoelastic stress analysis in terms of phase retardation. With improved molding condition, the absolute retardation difference around microchannels aligned parallel and perpendicular to the molding direction could be tuned to the same level, which indicates that the molded-in residual stresses have been moderated. (paper)

  6. Injection-Molded Soft Magnets Prepared from Fe-Based Metallic Glass: Mechanical and Magnetic Properties

    Zhong, Tian; Huang, Ran; Huang, Jia; Ouyang, Wei

    2015-10-01

    The injection-molded metallic glass soft magnet is prepared from the powder of melt-spun ribbon of Fe36Co36B20Si4Nb4 glassy alloy and Nylon 6,6 of wt.% from 5 to 20 via the polymer injection molding technology. The product is characterized by the SEM, mechanical, and magnetic test. The results indicate that this type of materials has comparable mechanical properties and morphological feature with the conventional injection-molded NdFeB magnet and exhibits excellent soft magnetic behaviors. The magnetic properties of the injected magnets are compared with the raw metallic glass, solvent-casted resin bonding magnets, and thermal-treated magnets to confirm that the processing temperature of Nylon injection does not affect the magnetism. The injection technology is a practical processing method to be applied on the metallic glass for potential usage.

  7. Optimization of Lens Hood Injection Molding Process%遮光罩注塑成型工艺优化

    陶永亮

    2011-01-01

    Lens hood is manufactured with Bayer copolycarbonate Apec.According to lens hood product features,plastics injection shoot adhesive volume calculation and adjustment is necessary.In order to solve product quality problems,some main points for hood inject%遮光罩采用Bayer公司共聚碳酸酯Apec制造。根据遮光罩产品特点,进行必要注塑成型加工射胶量计算和调整。为了解决产品质量问题,就遮光罩注塑工艺提出一些要点,并对成型工艺进行优化。经生产实践验证,工艺参数设定符合生产需要。

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

    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.

  9. Numerical prediction of flow induced fibers orientation in injection molded polymer composites

    Oumer, A. N.; Hamidi, N. M.; Mat Sahat, I.

    2015-12-01

    Since the filling stage of injection molding process has important effect on the determination of the orientation state of the fibers, accurate analysis of the flow field for the mold filling stage becomes a necessity. The aim of the paper is to characterize the flow induced orientation state of short fibers in injection molding cavities. A dog-bone shaped model is considered for the simulation and experiment. The numerical model for determination of the fibers orientation during mold-filling stage of injection molding process was solved using Computational Fluid Dynamics (CFD) software called MoldFlow. Both the simulation and experimental results showed that two different regions (or three layers of orientation structures) across the thickness of the specimen could be found: a shell region which is near to the mold cavity wall, and a core region at the middle of the cross section. The simulation results support the experimental observations that for thin plates the probability of fiber alignment to the flow direction near the mold cavity walls is high but low at the core region. It is apparent that the results of this study could assist in decisions regarding short fiber reinforced polymer composites.

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

    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 μm and a maximum structural height of 310 μm 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)

  11. Fabrication of low-cost beta-type Ti-Mn alloys for biomedical applications by metal injection molding process and their mechanical properties.

    Santos, Pedro Fernandes; Niinomi, Mitsuo; Liu, Huihong; Cho, Ken; Nakai, Masaaki; Itoh, Yoshinori; Narushima, Takayuki; Ikeda, Masahiko

    2016-06-01

    Titanium and its alloys are suitable for biomedical applications owing to their good mechanical properties and biocompatibility. Beta-type Ti-Mn alloys (8-17 mass% Mn) were fabricated by metal injection molding (MIM) as a potential low cost material for use in biomedical applications. The microstructures and mechanical properties of the alloys were evaluated. For up to 13 mass% Mn, the tensile strength (1162-938MPa) and hardness (308-294HV) of the MIM fabricated alloys are comparable to those of Ti-Mn alloys fabricated by cold crucible levitation melting. Ti-9Mn exhibits the best balance of ultimate tensile strength (1046MPa) and elongation (4.7%) among the tested alloys, and has a Young's modulus of 89GPa. The observed low elongation of the alloys is attributed to the combined effects of high oxygen content, with the presence of interconnected pores and titanium carbides, the formation of which is due to carbon pickup during the debinding process. The elongation and tensile strength of the alloys decrease with increasing Mn content. The Ti-Mn alloys show good compressive properties, with Ti-17Mn showing a compressive 0.2% proof stress of 1034MPa, and a compressive strain of 50%. PMID:26999621

  12. The Facility and Process Technics of Polyethylene Rotational Molding

    LI; BaiShun

    2001-01-01

    1. Introduction Rotational molding is the process by which hollow plastic parts are formed. It mainly processes the product which Injection molding and Blow molding can not process medium-sized, large-sized and super large-sized plastic parts. The technics may turn out a tub, dustbin, stock tank, sailboat.  The research institute of Lanzhou introduces a suit of RS-16 Rotational Molding Machine from Germany Reinhadt Co. on 1990. It mainly put up experiment and smallscale production. RS-16 rotational molding machine is a single arm and di-axial equipment. It is consisting of a gas heated sintering oven, cooling chamber, mouldcarrying carriage and a controlling unit.  ……

  13. Development and evaluation of P/M processing techniques to improve and control the mechanical properties of metal injection molded parts

    Sago, James Alan

    Metal Injection Molding (MIM) is one of the most rapidly growing areas of powder metallurgy (P/M) but the growth of MIM into new markets and more demanding applications is limited by two fundamental barriers, the availability of low cost metal powders and a lack of knowledge and understanding of how mechanical properties, especially toughness, are affected by the many parameters in the MIM process. The goals of this study were to investigate solutions to these challenges for MIM. Mechanical alloying (MA) is a technique which can produce a wide variety of powder compositions in a size range suited to MIM and in smaller batches. However MA typically suffers from low production volumes and long milling times. This study will show that a saucer mill can produce sizable volumes of MA powders in times typically less than an hour. The MA process was also used to produce powders of 17-4PH stainless steel and the NiTi shape memory alloy for a MIM feedstock. This study shows that the MA powder characteristics led to successful MIM processing of parts. Previous studies have shown that the toughness of individual MIM parts can vary widely within a single production run and from one producer to another. In the last part of the study a Design of Experiments (DOE) approach was used to evaluate the effects of MIM processing parameters on the mechanical properties. Analysis of Variance produced mathematical models for Charpy impact toughness, hardness, density, and carbon content. Tensile properties did not produce a good model due to processing problems. The models and recommendations for improving both toughness and reproducibility of toughness are presented.

  14. Metal Injection Molding (MIM of Magnesium and Its Alloys

    Martin Wolff

    2016-05-01

    Full Text Available Current research has highlighted that magnesium and its alloys as biodegradable material are highly suitable for biomedical applications. The new material fully degrades into nontoxic elements and offers material properties matching those of human bone tissue. As biomedical implants are rather small and complex in shape, the metal injection molding (MIM technique seems to be well suited for the near net shape mass production of such parts. Furthermore, MIM of Mg-alloys is of high interest in further technical fields. This study focusses on the performance of MIM-processing of magnesium alloy powders. It includes Mg-specific development of powder blending, feedstock preparation, injection molding, solvent and thermal debinding and final sintering. Even though Mg is a highly oxygen-affine material forming a stable oxide layer on each particle surface, the material can be sintered to nearly dense parts, providing mechanical properties matching those of as cast material. An ultimate tensile strength of 142 MPa, yield strength of 67 MPa, elastic modulus of 40 GPa and 8% elongation at fracture could be achieved using novel organic polymer binders for the feedstock preparation. Thus, first implant demonstrator parts could be successfully produced by the MIM technique.

  15. Correlation between Molding Conditions and Foam Morphology in Microcellular Injection Molding

    Yamada, Takehiro; Murata, Yasuhiko; Yokoi, Hidetoshi

    In this study, a quantitative analysis of foam cell distribution at the cross section of products in microcellular injection molding was conducted concerning the relationship between the mold conditions and laminar morphology. The following results were obtained; (1) The morphology consists of a surface layer (Skin layer I) with silver streaks, a layer (Skin layer II) with no cells inside, and a foam layer (Core layers I, II, III) with many cells of different size. (2) The morphology changes depending on the molding conditions and cavity position. (3) The core layer domain decreases from the gate to the distal end. (4) Injection conditions greatly affect the thickness of Skin layer II. (5) Maximum filling pressure in the mold affects mainly the core layer of the foam morphology.

  16. Injection molded polymeric micropatterns for bone regeneration study.

    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 (μIM) 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 μm diameter pillars with 8, 9, 10 μm 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

  17. POWDER INJECTION MOLDING OF SIC FOR THERMAL MANAGEMENT V

    Valmikanathan Onbattuvelli

    2012-06-01

    Full Text Available Silicon carbide (SiC exhibits many functional properties that are relevant to applications in electronics, aerospace, defense and automotive industries. However, the successful translation of these properties into final applications lies in the net-shaping of ceramics into fully dense microstructures. Increasing the packing density of the starting powders is one effective route to achieve high sintered density and dimensional precision. The present paper presents an in-depth study on the effects of nanoparticle addition on the powder injection molding process (PIM of SiC powder-polymer mixtures. In particular, bimodal mixtures of nanoscale and sub-micrometer particles are found to have significantly increased powder packing characteristics (solids loading in the powder-polymer mixtures. The influence of nanoparticle addition on the multi-step PIM process is examined. The above results provide new perspectives which could impact a wide range of materials, powder processing techniques and applications.

  18. NUMERICAL SIMULATION OF CASTING'S MOLD FILLING PROCESS

    J.X. Zhou; R.X. Liu; L.L. Chen; D.M. Liao; H.S. Wei

    2005-01-01

    Numerical simulation of casting's mold filling process is the main and the most important aspect of the foundry CAE technology. But it is time-consuming; it may take dozens of hours or several days. While with the development of computer hardware, numerical simulation of casting' s mold filling process has made rapid progress. The simulation results, therefore, have become more and more practical. This study tries to find some clues of the computational time of mold filling process. Firstly, this paper introduces mathematic model and the basic route of numerical simulation of casting's mold filling process. Then the computational time of mold filling process has been carefully studied, and some new and useful results have been gained from the study of the computational time. Finally, this paper has given some real applications of numerical simulation of casting's mold filling process.

  19. Fiber-Based, Injection-Molded Optofluidic Systems

    Matteucci, Marco; Triches, Marco; Nava, Giovanni;

    2015-01-01

    We present a method to fabricate polymer optofluidic systems by means of injection molding that allow the insertion of standard optical fibers. The chip fabrication and assembly methods produce large numbers of robust optofluidic systems that can be easily assembled and disposed of, yet allow...... optical fibers in a quick and precise manner, with a lateral alignment accuracy of 2.7 ± 1.8 μm. We report the production, assembly methods, and the characterization of the resulting injection-molded chips for Lab-on-Chip (LoC) applications. We demonstrate the versatility of this technology by carrying...

  20. 3D Fiber Orientation Simulation for Plastic Injection Molding

    Lin, Baojiu; Jin, Xiaoshi; Zheng, Rong; Costa, Franco S.; Fan, Zhiliang

    2004-06-01

    Glass fiber reinforced polymer is widely used in the products made using injection molding processing. The distribution of fiber orientation inside plastic parts has direct effects on quality of molded parts. Using computer simulation to predict fiber orientation distribution is one of most efficient ways to assist engineers to do warpage analysis and to find a good design solution to produce high quality plastic parts. Fiber orientation simulation software based on 2-1/2D (midplane /Dual domain mesh) techniques has been used in industry for a decade. However, the 2-1/2D technique is based on the planar Hele-Shaw approximation and it is not suitable when the geometry has complex three-dimensional features which cannot be well approximated by 2D shells. Recently, a full 3D simulation software for fiber orientation has been developed and integrated into Moldflow Plastics Insight 3D simulation software. The theory for this new 3D fiber orientation calculation module is described in this paper. Several examples are also presented to show the benefit in using 3D fiber orientation simulation.

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

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

    2013-01-01

    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 channe...

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

    A combination of high dielectric permittivity (ε′) and low dielectric loss (tan δ) is required for charge storage applications. In percolative systems such as conductive polymer composites, however, obtaining high ε′ and low tan δ 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 (σ), ε′ and tan δ 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 ε′=68.3 and tan δ =0.05 (at 1.25 vol.% MWCNT), as opposed to ε′=17.8 and tan δ=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

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

    Ameli, A.; Nofar, M.; Saniei, M.; Hossieny, N.; Park, C. B. [Microcellular Plastics Manufacturing Laboratory, Department of Mechanical and Industrial Engineering, University of Toronto, 5 King’s College Road, Toronto, Ontario, Canada M5S 3G8 (Canada); Pötschke, P. [Leibniz-Institut für Polymerforschung Dresden e.V. (IPF), Hohe Strasse 6, D-01069 Dresden (Germany)

    2015-05-22

    A combination of high dielectric permittivity (ε′) and low dielectric loss (tan δ) is required for charge storage applications. In percolative systems such as conductive polymer composites, however, obtaining high ε′ and low tan δ 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 (σ), ε′ and tan δ 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 ε′=68.3 and tan δ =0.05 (at 1.25 vol.% MWCNT), as opposed to ε′=17.8 and tan δ=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.

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

    2011-01-01

    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...

  5. Bio-inspired piezoelectric artificial hair cell sensor fabricated by powder injection molding

    Han, Jun Sae; Oh, Keun Ha; Moon, Won Kyu; Kim, Kyungseop; Joh, Cheeyoung; Seo, Hee Seon; Bollina, Ravi; Park, Seong Jin

    2015-12-01

    A piezoelectric artificial hair cell sensor was fabricated by the powder injection molding process in order to make an acoustic vector hydrophone. The entire process of powder injection molding was developed and optimized for PMN-PZT ceramic powder. The artificial hair cell sensor, which consists of high aspect ratio hair cell and three rectangular mechanoreceptors, was precisely fabricated through the developed powder injection molding process. The density and the dielectric property of the fabricated sensor shows 98% of the theoretical density and 85% of reference dielectric property of PMN-PZT ceramic powder. With regard to homogeneity, three rectangular mechanoreceptors have the same dimensions, with 3 μm of tolerance with 8% of deviation of dielectric property. Packaged vector hydrophones measure the underwater acoustic signals from 500 to 800 Hz with -212 dB of sensitivity. Directivity of vector hydrophone was acquired at 600 Hz as analyzing phase differences of electric signals.

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

    Islam, Aminul; Giannekas, Nikolaos; Marhöfer, David Maximilian;

    2014-01-01

    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....... 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...

  7. DESIGN TECHNOLOGY FOR INJECTION MOLD PARTING SURFACE BASED ON CASES AND KNOWLEDGE

    Yu Tongmin; Li Guanhua; Li Youmin; Lan Jian

    2005-01-01

    On the basis of the comprehensive analysis about the automatic generation of the injection mold parting surface, the parting surface design method which introduces knowledge and casebased reasoning (CBR) into the computer-aided design is described by combining with the actual characteristic in injection mold design, and the design process of case-based reasoning method is also given. A case library including the information of parting surface is built with the index of main shape features. The automatic design of the mold parting surface is realized combined with the forward-reasoning method and the similarity solution procedure. The rule knowledge library is also founded including the knowledge, principles and experiences for parting surface design. An example is used to show the validity of the method, and the quality and the efficiency of the mold design are improved.

  8. Dimensional changes of acrylic resin denture bases: conventional versus injection-molding technique.

    Jafar Gharechahi

    2014-08-01

    Full Text Available Acrylic resin denture bases undergo dimensional changes during polymerization. Injection molding techniques are reported to reduce these changes and thereby improve physical properties of denture bases. The aim of this study was to compare dimensional changes of specimens processed by conventional and injection-molding techniques.SR-Ivocap Triplex Hot resin was used for conventional pressure-packed and SR-Ivocap High Impact was used for injection-molding techniques. After processing, all the specimens were stored in distilled water at room temperature until measured. For dimensional accuracy evaluation, measurements were recorded at 24-hour, 48-hour and 12-day intervals using a digital caliper with an accuracy of 0.01 mm. Statistical analysis was carried out by SPSS (SPSS Inc., Chicago, IL, USA using t-test and repeated-measures ANOVA. Statistical significance was defined at P<0.05.After each water storage period, the acrylic specimens produced by injection exhibited less dimensional changes compared to those produced by the conventional technique. Curing shrinkage was compensated by water sorption with an increase in water storage time decreasing dimensional changes.Within the limitations of this study, dimensional changes of acrylic resin specimens were influenced by the molding technique used and SR-Ivocap injection procedure exhibited higher dimensional accuracy compared to conventional molding.

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

    Tanzi, Simone; Matteucci, Marco; Christiansen, Thomas Lehrmann;

    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 u...

  10. PHYSICAL PROPERTIES OF EXTRUDED AND INJECTION MOLDED CORN GLUTEN MEAL

    This study was performed to investigate the compounding of corn gluten meal (CGM) and decanoic acid and to evaluate their mechanical properties. The mixture of CGM and 30% decanoic acid was compounded in a twin screw extruder, followed by injection molding. Scanning electron microscopy (SEM), tens...

  11. Fast prototyping of injection molded polymer microfluidic chips

    Hansen, Thomas Steen; Selmeczi, David; Larsen, Niels Bent

    2010-01-01

    , 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....

  12. Multiobjective Design of Turbo Injection Mode for Axial Flux Motor in Plastic Injection Molding Machine by Particle Swarm Optimization

    Jian-Long Kuo

    2015-01-01

    Full Text Available This paper proposes a turbo injection mode (TIM for an axial flux motor to apply onto injection molding machine. Since the injection molding machine requires different speed and force parameters setting when finishing a complete injection process. The interleaved winding structure in the motor provides two different injection levels to provide enough injection forces. Two wye-wye windings are designed to switch two control modes conveniently. Wye-wye configuration is used to switch two force levels for the motor. When only one set of wye-winding is energized, field weakening function is achieved. Both of the torque and speed increase under field weakening operation. To achieve two control objectives for torque and speed of the motor, fuzzy based multiple performance characteristics index (MPCI with particle swarm optimization (PSO is used to find out the multiobjective optimal design solution. Both of the torque and speed are expected to be maximal at the same time. Three control factors are selected as studied factors: winding diameter, winding type, and air-gap. Experimental results show that both of the torque and speed increase under the optimal condition. This will provide enough large torque and speed to perform the turbo injection mode in injection process for the injection molding machine.

  13. 金刚石/铜基钎料粉末注射成型工艺参数的优化%Optimization of Parameters in Diamonds/Copper Based Brazing Filler Metal Powders Injection Molding Process

    伍俏平; 邓朝晖; 潘占; 张荣辉; 张正

    2012-01-01

    通过正交试验对金刚石/铜基钎料粉末小型薄壁件的注射成型工艺参数进行了优化。结果表明:当模具温度为40℃,注射压力为12MPa,注射温度为150℃,注射流量为20cm^3·S^-1,为最佳工艺参数组合,能获得表面光整、组织均匀的注射生坯;随着注射压力的增大,注射生坯密度增大;注射温度升高,生坯密度降低;注射流量增大,生坯密度先升后降。%Optimization of parameters in the injection molding process of diamonds/copper based brazing niter metal powders was investigated by orthogonal experiments. Results indicate that the optimized combination of parameters was given as following: the mould temperature was 40 ℃; injection pressure was 12 MPa; injection temperature was 150 ℃ and injection flow rate was 20 cm^3 . s 1. And a molded specimen with a smooth surface, uniform microstructure could be achieved under the optimized condition. The density of molded specimens increased with increase of injection pressure, but decreased with increase of injection temperature, and the density increased first and decreased afterwards when the iniection flow rate increased.

  14. FPGA-Based Multiprocessor System for Injection Molding Control

    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.

  15. Microinjection molding of thermoplastic polymers: morphological comparison with conventional injection molding

    Giboz, Julien; Copponnex, Thierry; Mélé, Patrice

    2009-02-01

    The skin-core crystalline morphology of injection-molded semi-crystalline polymers is well documented in the scientific literature. The thermomechanical environment provokes temperature and shear gradients throughout the entire thickness of the part during molding, thus influencing the polymer crystallization. Crystalline morphologies of a high-density polyethylene (HDPE) micromolded part (μpart) and a classical part (macropart) are compared with optical, thermal and x-ray diffraction analyses. Results show that the crystalline morphologies with regard to thickness vary between the two parts. While a 'skin-core' morphology is present for the macropart, the μpart exhibits a specific 'core-free' morphology, i.e. no spherulite is present at the center of the thickness. This result seems to be generated under the specific conditions used in microinjection molding that lead to the formation of smaller and more oriented crystalline entities.

  16. Flexural Properties of Injection-Molded Bamboo/pbs Composites

    Ohkita, Kazuya; Takagi, Hitoshi

    In recent years, from an environmental perspective, there has been increasing interest in the change to a sustainable society. The use of natural-fiber-reinforced biodegradable composites has been proposed as one solution. Bamboo is an often used renewable bio-resource; it has an inherent advantage of rapid growth. Polybutylene succinate (PBS), used as matrix resin, has biodegradable characteristics. This paper describes flexural properties of bamboo/PBS composites prepared by injection molding. The following results were obtained. The flexural modulus was improved with increasing bamboo powder contents when the cylinder temperature of the injection molder was 140°C. However, the flexural strength showed the opposite tendency to be decreased with increasing bamboo powder contents. An SEM photomicrograph of the fracture surface for bamboo/PBS composites showed typical fracture behavior of pull-out fibers without fiber fracture. Furthermore, there was no adhesion of PBS resin on the bamboo fiber surface. Processing conditions affected mechanical properties of bamboo/PBS composites, imparting higher flexural strength and flexural modulus at high cylinder temperatures such as 180°C and 200°C.

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

    Tanzi, Simone

    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......, 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...... 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...

  18. Model evolvement and reuse technology of injection molding machine based on performance knowledge

    Wei Zhe; Feng Yixiong; Tan Jianrong; Wang Jinlong

    2008-01-01

    To illuminate the necessity of model evolvement and reuse, dynamics of injection molding machine's product models are analyzed. The performance knowledge is used to support the model evolvement and reuse. The driven factors of mechanical product model are concluded. The dynamic characteristics of product model are described. The performance knowledge is used to improve specific evolvement process. The upper-layer passing rules are adopted in the mechanical product configuration design. The rules of product model evolvement are investigated. And the model evolvement of injection molding machine has three levels. Practical and effective realization arithmetic is given to realize the performance knowledge reuse. Finally, HT1800X1N series injection molding machines are taken as examples to illuminate that the arithmetic is correct and practical.

  19. Development of plastic pulley by injection molding; Shashutsu keisei ni yoru jushi pulley no kaihatsu

    Yoshizumi, F.; Funatsu, A.; Yazawa, H. [Sumitomo Bakelite Co. Ltd., Tokyo (Japan)

    1997-10-01

    We developed plastic pulley for automobile manufactured by injection molding which will reduce manufacturing cost. We have developed product design, injection molding technology especially to improve mechanical strength and phenolic molding compound with good wear resistance and high mechanical strength. We have established `Injection Compression molding` technology to improve mechanical strength of weld portion. We also developed phenolic molding compound which is composed of one step resin and long organic fiber to obtain good wear resistance and high mechanical strength. Manufacturing cost will be reduced by using injection molding combined with lower material cost of the newly developed compound. 12 figs., 2 tabs.

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

    Christiansen, Alexander Bruun; Højlund-Nielsen, Emil; Clausen, Jeppe Sandvik;

    2013-01-01

    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...... 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...

  1. THERMOSETTING PLASTIC INJECTION MOLDING(1)BASIC THERMOSETTING PLASTIC INJECTION MOLDING%热固性塑料注射成型(一)基本热固性塑料注射成型

    胡海青

    2001-01-01

    论述了热固性塑料注射成型的方法、工艺、设备和模具设计方面的问题。%Molding process,equipment and die of thermosetting plastics for injection molding discussed in the paper.

  2. Evaluation of W-Cu metal matrix composites produced by powder injection molding and liquid infiltration

    The near net shape processing of tungsten-copper metal matrix composites by powder injection molding and liquid copper infiltration was studied in this paper. In this technique, powder injection molded bimetallic components were produced. The component was debinded and subsequently heated to an elevated temperature. This facilitated the sintering of the high melting point metal and the liquidation of the lower melting point for infiltration into the preform of the former. Feasibility of this method in the manufacture of tungsten-copper metal matrix composites with high percentage copper, up to 38 wt.%, was demonstrated and mechanical properties were evaluated in this study

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

    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.

  4. An in-mold packaging process for plastic fluidic devices.

    Yoo, Y E; Lee, K H; Je, T J; Choi, D S; Kim, S K

    2011-01-01

    Micro or nanofluidic devices have many channel shapes to deliver chemical solutions, body fluids or any fluids. The channels in these devices should be covered to prevent the fluids from overflowing or leaking. A typical method to fabricate an enclosed channel is to bond or weld a cover plate to a channel plate. This solid-to-solid bonding process, however, takes a considerable amount of time for mass production. In this study, a new process for molding a cover layer that can enclose open micro or nanochannels without solid-to-solid bonding is proposed and its feasibility is estimated. First, based on the design of a model microchannel, a brass microchannel master core was machined and a plastic microchannel platform was injection-molded. Using this molded platform, a series of experiments was performed for four process or mold design parameters. Some feasible conditions were successfully found to enclosed channels without filling the microchannels for the injection molding of a cover layer over the plastic microchannel platform. In addition, the bond strength and seal performance were estimated in a comparison with those done by conventional bonding or welding processes. PMID:21446432

  5. 电器盖注射模设计%Design of Electrical Cover Injection Mold

    张胜

    2013-01-01

    In this paper,taking the design of electrical injection mold as masterstroke,moulding process,design of mold structure,machining ways of mold parts,general assembly and so on were researched.The paper introduced electrical cover injection mold,which has two-cavity mold with a mold,that is to say,forming a combination of the two shell pieces,and at the same time,briefly described the machining process of inserts.%以电器盖注射模具设计为主线,研究了成型工艺、模具结构设计、模具零件的加工方法及模具的总装配等.介绍了一种电器盖注射模具,该模具采用一模两腔,即一次成型2个壳件的组合,同时,简单介绍了镶件的加工工艺.

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

    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.

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

    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.

  8. SPATIAL HIERARCHY AND INTERFACIAL STRUCTURE IN INJECTION-MOLDED BARS OF POLYPROPYLENE-BASED BLENDS AND COMPOSITES

    Ke Wang; Min Guo; Si Liang; Ping Zhao; Hong Yang; Qin Zhang; Rong-ni Du; Qiang Fu

    2007-01-01

    The hierarchical structure and interfacial morphology of injection-molded bars of polypropylene (PP) based blends and composites have been investigated in detail from the skin to the core. For preparation of injection-molded bars with high-level orientation and good interfacial adhesion, a dynamic packing injection molding technology was applied to exert oscillatory shear on the melts during solidification stage. Depending on incorporated component, interfacial adhesion and processing conditions, various oriented structure and morphology could be obtained. First, we will elucidate the epitaxial behavior between PP and high-density polyethylene occurring in practical molded processing. Then, the shear-induced transcrystalline structure will be the main focus for PP/fiber composites. At last, various oriented clay structures have been ascertained unambiguously in PP/organoclay nanocomposites along the thickness of molded bars.

  9. Metal Injection Molding (MIM of NdFeB Magnets

    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.

  10. Pressureless sintering behavior of injection molded alumina ceramics

    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.

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

    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. Metal Injection Molding (MIM) of Magnesium and Its Alloys

    Martin Wolff; Johannes G. Schaper; Marc René Suckert; Michael Dahms; Frank Feyerabend; Thomas Ebel; Regine Willumeit-Römer; Thomas Klassen

    2016-01-01

    Current research has highlighted that magnesium and its alloys as biodegradable material are highly suitable for biomedical applications. The new material fully degrades into nontoxic elements and offers material properties matching those of human bone tissue. As biomedical implants are rather small and complex in shape, the metal injection molding (MIM) technique seems to be well suited for the near net shape mass production of such parts. Furthermore, MIM of Mg-alloys is of high interest in...

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

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

    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.

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

    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.

  16. Temperature Dependence and Magnetic Properties of Injection Molding Tool Materials Used in Induction Heating

    Guerrier, Patrick; Nielsen, Kaspar Kirstein; Hattel, Jesper Henri

    2015-01-01

    To analyze the heating phase of an induction heated injection molding tool precisely, the temperature-dependent magnetic properties, B–H curves, and the hysteresis loss are necessary for the molding tool materials. Hence, injection molding tool steels, core materials among other materials have, in...

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

    Marhöfer, David Maximilian; Tosello, Guido; Hansen, Hans Nørgaard;

    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...

  18. Damage Modeling Of Injection-Molded Short- And Long-Fiber Thermoplastics

    This article applies the recent anisotropic rotary diffusion - reduced strain closure (ARD-RSC) model for predicting fiber orientation and a new damage model for injection-molded long-fiber thermoplastics (LFTs) to analyze progressive damage leading to total failure of injection-molded long-glass-fiber/polypropylene (PP) specimens. The ARD-RSC model was implemented in a research version of the Autodesk Moldflow Plastics Insight (MPI) processing code, and it has been used to simulate injection-molding of a long-glass-fiber/PP plaque. The damage model combines micromechanical modeling with a continuum damage mechanics description to predict the nonlinear behavior due to plasticity coupled with damage in LFTs. This model has been implemented in the ABAQUS finite element code via user-subroutines and has been used in the damage analyses of tensile specimens removed from the injection-molded long-glass-fiber/PP plaques. Experimental characterization and mechanical testing were performed to provide input data to support and validate both process modeling and damage analyses. The predictions are in agreement with the experimental results.

  19. DAMAGE MODELING OF INJECTION-MOLDED SHORT- AND LONG-FIBER THERMOPLASTICS

    Nguyen, Ba Nghiep; Kunc, Vlastimil; Bapanapalli, Satish K.; Phelps, Jay; Tucker III, Charles L.

    2009-10-30

    This article applies the recent anisotropic rotary diffusion – reduced strain closure (ARD-RSC) model for predicting fiber orientation and a new damage model for injection-molded long-fiber thermoplastics (LFTs) to analyze progressive damage leading to total failure of injection-molded long-glass-fiber/polypropylene (PP) specimens. The ARD-RSC model was implemented in a research version of the Autodesk Moldflow Plastics Insight (MPI) processing code, and it has been used to simulate injection-molding of a long-glass-fiber/PP plaque. The damage model combines micromechanical modeling with a continuum damage mechanics description to predict the nonlinear behavior due to plasticity coupled with damage in LFTs. This model has been implemented in the ABAQUS finite element code via user-subroutines and has been used in the damage analyses of tensile specimens removed from the injection-molded long-glass-fiber/PP plaques. Experimental characterization and mechanical testing were performed to provide input data to support and validate both process modeling and damage analyses. The predictions are in agreement with the experimental results.

  20. Analysis of Incomplete Filling Defect for Injection-Molded Air Cleaner Cover Using Moldflow Simulation

    Hyeyoung Shin

    2013-01-01

    Full Text Available A large-sized cover part for air cleaner was injection molded with ABS resin, and its incomplete filling defect was analyzed using commercial Moldflow software. To investigate the effect of processing temperature on incomplete filling defect, tensile properties, weight loss, and phase separation behavior of ABS resin were evaluated. The tensile properties of dumbbell samples were not changed up to 250°C and decreased significantly thereafter. SEM micrographs indicated no significant changes in the status of polybutadiene rubber phase below 250°C. These different test results indicated that ABS resin little affected the thermal decomposition in processing temperature range. The Moldflow simulation was performed using measured thickness of molded cover and actual mold design with the defects. As expected, the cover part showed unbalanced filling and incomplete sections. To improve these defects, two possible cases of hot runner system have been simulated. When applying modified 5-gate system, the maximum injection pressure was decreased approximately 5.5% more than that of actual gate system. In case of 6-gate system, the maximum injection pressure reduced by 23%, and the injection pressure required to fill is well within the range of the molding equipment. The maximum clamping force of 6-gate system was also significantly reduced than that of actual and 5-gate system.

  1. A review on the importance of surface coating of micro/nano-mold in micro/nano-molding processes

    Micro/nano hot-embossing and injection molding are two promising manufacturing processes for the mass production of workpieces bearing micro/nanoscale features. However, both the workpiece and micro/nano-mold are susceptive to structural damage due to high thermal stress, adhesion and friction, which occur at the interface between the workpiece and the mold during these processes. Hence, major constraints of micro/nano-molds are mainly attributed to improper replication and their inability to withstand a prolonged sliding surface contact because of high sidewall friction and/or high adhesion. Consequently, there is a need for proper surface coating as it can improve the surface properties of micro/nano-molds such as having a low friction coefficient, low adhesion and low wear rate. This review deals with the physical, mechanical and tribological properties of various surface coatings and their impact on the replication efficiency and lifetime of micro/nano-molds that are used in micro/nano hot-embossing and injection molding processes. (topical review)

  2. A review on the importance of surface coating of micro/nano-mold in micro/nano-molding processes

    Saha, Biswajit; Toh, Wei Quan; Liu, Erjia; Beng Tor, Shu; Hardt, David E.; Lee, Junghoon

    2016-01-01

    Micro/nano hot-embossing and injection molding are two promising manufacturing processes for the mass production of workpieces bearing micro/nanoscale features. However, both the workpiece and micro/nano-mold are susceptive to structural damage due to high thermal stress, adhesion and friction, which occur at the interface between the workpiece and the mold during these processes. Hence, major constraints of micro/nano-molds are mainly attributed to improper replication and their inability to withstand a prolonged sliding surface contact because of high sidewall friction and/or high adhesion. Consequently, there is a need for proper surface coating as it can improve the surface properties of micro/nano-molds such as having a low friction coefficient, low adhesion and low wear rate. This review deals with the physical, mechanical and tribological properties of various surface coatings and their impact on the replication efficiency and lifetime of micro/nano-molds that are used in micro/nano hot-embossing and injection molding processes.

  3. Computational simulation and experimental analysis of the mold-filling process in µPIM

    The micro powder injection molding technique has developed in recent years to be a unique method to fabricate miniature components in the large scale. In this paper numerical simulation of the mold filling of a micro-sized cylinder and gearwheel on a substrate was carried out with the ANSYS CFX software. The feedstock consisted of 56 vol% of carbonyl iron powder and a thermoplastic binder. The simulation results found that inhomogeneity greatly influences the shape precision of the molded micro-sized parts, and the gears located far from the gate exhibited better morphology than those near the gate. A difference in shape accuracy was found in different regions of a molded compact due to the variation of the state of the mold filling and the heat exchange between the feedstock and the die wall. The experimental data testified to the validity of the numerical simulation of the mold-filling process in micro powder injection molding.

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

    Menotti, Stefano; Hansen, Hans Nørgaard; Bissacco, Giuliano;

    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...

  5. Atmosphere control during debinding of powder injection molded parts

    Moore, J. A.; Jarding, B. P.; Lograsso, B. K.; Anderson, I. E.

    1995-06-01

    Atmosphere control during debinding of powder injection molded (PIM) parts is an important parameter to consider. Experimental results have shown that a stagnant atmosphere containing volatiles evolved during debinding can cause slumping of the green samples. Removal of volatiles from the sample zone aids debinding and can reduce cycle times and improve sample quality. Residual carbon and oxygen can be controlled during debinding by adjusting the atmosphere composition. This paper presents the results of PIM 70 vol% spherical copper powder and 30 vol% binder. Debinding atmospheres were altered to determine the effect of debinding on the green body and the sintered sample.

  6. Sintering products molded by injecting ceramic and metal powders

    LIU Ping-an; ZENG Ling-ke; LI Xiu-yan

    2005-01-01

    The injection molding products with different volume ratios of ZrO2 ceramic powder to 316L stainless steel powder were prepared. Properties and structure of the products were characterized by X-ray diffraction(XRD),scanning electron microscope(SEM) and transmission electron microscope (TEM). The results show that the compressive stress exists in the products and the bend strength reaches 300 MPa. ZrO2 phase and stainless steel phase are uniform in samples. The toughness of ceramic increases with the increasing the content of stainless steel.Through TEM study of the interface, some crystalline orientation relationships are determined.

  7. Methods of Automatic Parting Mold and Manual Parting Mold for Injection Mold Design Based on UG%基于UG注射模设计的自动分模和手动分模方法

    董海涛

    2012-01-01

    UG software is widely applied in plastic injection mold design,the basic principle of parting mold is introduced in this paper,and the UG application in plastic injection mold design is studied with a concrete case.The process of automatic parting mold and manual parting mold in UG are expatiated,the flexible application of two methods will significantly reduce mold design time and greatly improve the efficiency of injection mold design.%UG软件广泛地应用在注射模设计中,本文介绍了分模原理,并结合实例研究UG软件在注射模设计中的应用。介绍了自动分模和手动分模方法,两种方法的灵活应用可以缩短模具设计周期,提高注射模设计的效率。

  8. Results on powder injection molding of Ni[sub 3]Al and application to other intermetallic compositions

    Cooper, R.M.

    1992-01-01

    Net forming processes are under development to allow affordable production of intermetallic components. Powder injection molding (PIM) mav be employed for the production of complex-shaped intermetallic geometries. Proper choice of powder parameters and processing conditions can lead to the formation of fullv dense structures through pressure-less sintering. In this study, Ni[sub 3]Al with 0.04 wt.-% boron has been successfully injection molded and sintered to full density. A yield strength of 340 MPa, ultimate tensile strength (UTS) of 591 MPa, and 8% elongation were attained for injection molded and sintered tensile bars. Powder characteristics and sintering behavior are given for the nickel aluminide employed in this study to highlight the powder attributes needed for injection molding. Molding parameters, debinding and sintering schedules, along, with mechanical properties are presented to indicate the viability of PIM for intermetallics. This approach based on the understanding of key powder characteristics and use of the reactive synthesis powder process mav be extended to the successful injection molding of other intermetallic systems.

  9. Results on powder injection molding of Ni{sub 3}Al and application to other intermetallic compositions

    Cooper, R.M.

    1992-12-31

    Net forming processes are under development to allow affordable production of intermetallic components. Powder injection molding (PIM) mav be employed for the production of complex-shaped intermetallic geometries. Proper choice of powder parameters and processing conditions can lead to the formation of fullv dense structures through pressure-less sintering. In this study, Ni{sub 3}Al with 0.04 wt.-% boron has been successfully injection molded and sintered to full density. A yield strength of 340 MPa, ultimate tensile strength (UTS) of 591 MPa, and 8% elongation were attained for injection molded and sintered tensile bars. Powder characteristics and sintering behavior are given for the nickel aluminide employed in this study to highlight the powder attributes needed for injection molding. Molding parameters, debinding and sintering schedules, along, with mechanical properties are presented to indicate the viability of PIM for intermetallics. This approach based on the understanding of key powder characteristics and use of the reactive synthesis powder process mav be extended to the successful injection molding of other intermetallic systems.

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

    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.

  11. Micro powder injection molding-large scale production technology for micro-sized components

    YIN HaiQing; JIA ChengChang; QU XuanHui

    2008-01-01

    Micro powder injection molding (μPIM), a miniaturized variant of powder injection molding, has advantages of shape complexity, applicability to many materials and good mechanical properties. Co-injection molding has been realized between metals and ceramics on micro components, which become the first breakthrough within the PIM field. Combined with the prominent characteristics of high features/cost ratio, micro powder injection molding becomes a potential technique for large scale production of intricate and three-dimensional micro components or microstructured components in microsystems technology (MST) field.

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

    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

  13. Anisotropic injection molding of strontium ferrite powder using a PP/PEG binder system

    Lee, S.H.; Jeung, W.Y. E-mail: wyjeung@kistmail.kist.re.kr

    2001-05-01

    In this study, new binder system for anisotropic injection molding of Sr-ferrite was developed and a process for injection molding of Sr-ferrite was optimized. The developed binder system is composed of 30 vol% PP, 60 vol% PEG-20 000 and 10 vol% PEG-4000. The extraction by water was applied to remove the major binder components PEGs and the minor binder component, PP, was subsequently burned out in air. Behaviors of extraction and thermal debinding with time and debinding atmosphere and variations of the magnetic properties with sintering temperature were studied. The sintered magnets made by PIM process showed residual carbon content of 230 ppm and a maximum energy product of 4.2 MGOe.

  14. Fiber-Based, Injection-Molded Optofluidic Systems: Improvements in Assembly and Applications

    Marco Matteucci; Marco Triches; Giovanni Nava; Anders Kristensen; Mark R. Pollard; Kirstine Berg-Sørensen; Taboryski, Rafael J.

    2015-01-01

    We present a method to fabricate polymer optofluidic systems by means of injection molding that allow the insertion of standard optical fibers. The chip fabrication and assembly methods produce large numbers of robust optofluidic systems that can be easily assembled and disposed of, yet allow precise optical alignment and improve delivery of optical power. Using a multi-level chip fabrication process, complex channel designs with extremely vertical sidewalls, and dimensions that range from fe...

  15. Analysis of Incomplete Filling Defect for Injection-Molded Air Cleaner Cover Using Moldflow Simulation

    Hyeyoung Shin; Eun-Soo Park

    2013-01-01

    A large-sized cover part for air cleaner was injection molded with ABS resin, and its incomplete filling defect was analyzed using commercial Moldflow software. To investigate the effect of processing temperature on incomplete filling defect, tensile properties, weight loss, and phase separation behavior of ABS resin were evaluated. The tensile properties of dumbbell samples were not changed up to 250°C and decreased significantly thereafter. SEM micrographs indicated no significant changes ...

  16. THE EXAMINATION OF WELD LINE PROPERTIES IN INJECTION MOLDED PP AND PP COMPOSITES

    Demirer, Ahmet

    2011-01-01

    In this study, the effect of weld lines occurred in injection moulded components on mechanical behaviours of PP and PP with 30% glass fiber (GF) materials has been investigated. Two types of specimens were produced; with and without weld line by using single gate and double gate moulds. The range of process temperatures was varied depending on the type of material. The mold was designed to achieve homogenous cooling with the help of Moldflow software. The bending and tensile tests were carrie...

  17. The Injection Molding Mould Design and Process Control of Super-thin Plastic Packing Box%超薄塑料包装盒注塑模具设计与注塑过程控制

    郭幼丹; 吴春笃; 程晓农

    2011-01-01

    冷热交替循环系统是高精密度超薄塑料包装盒热流道注塑技术的关键技术,是把加热、高温保温、低温冷却三种换热流程置于同一注塑工艺系统内的流体系统,实现快速准确而又均匀传热.研究表明,模具设计的关键是系统各管道应具有相同的传热效率.在模具结构、冷热交替循环系统和传热介质确定的情况下,最佳水流速度只与塑料种类有关,注塑过程温度的控制可以转化为冷热交替循环流体系统水流速度的控制.%The cool-hot alternation cycle system is a key technique of hot flow injection molding of high accuracy super-thin plastic packing box, it is heat, heat preservation, low temperature cooling 3 kinds to change hot the process place in same molding inside system of hydro-system, realization fast accurate and e-quality transmit heat. Research enunciation, each piping of system should have homology of transmit heat an efficiency in mould design. The best current rate relate to plastics category,after the mould structure and cool -hot alternation cycle system and transmit heat medium establish, the molding temperature control can translate into control current rate of cool-hot alternation cycle system.

  18. Dynamic penetration behavior of core-material in multi-cavity co-injection molding

    Huang, Chao-Tsai CT; Yang, Jackie; Chang, Rong-Yeu

    2015-12-01

    Co-Injection Molding and multi-cavity molding are very common processes for plastic manufacturing. These two systems are sometimes combined and applied to some structure products. The core penetration and flow balance control problems are very difficult to manage. The inside mechanism of co-injection multi-cavity system is not fully figured out yet. In this study, we have focused on the penetration phenomena of core-material in a co-injection multi-cavity molding. The dynamic penetration behavior of core is very sensitive to injection flow rate and skin/core ratio. The longest core penetration has been shown to change dramatically from one runner to the other. In addition, the core penetration behavior will display imbalance at the end of filling. The more core ratio it is, the longer core penetration flows through runner to cavity. However, due to the multi-cavity geometrical structure, the balance of the core penetration for multi-cavity is still challenging. Finally, the simulation is validated with some literature. The results showed that both simulation and experiment are in a good agreement in trend

  19. Color measurement of plastics - From compounding via pelletizing, up to injection molding and extrusion

    Botos, J.; Murail, N.; Heidemeyer, P.; Kretschmer, K.; Ulmer, B.; Zentgraf, T.; Bastian, M.; Hochrein, T.

    2014-05-01

    The typical offline color measurement on injection molded or pressed specimens is a very expensive and time-consuming process. In order to optimize the productivity and quality, it is desirable to measure the color already during the production. Therefore several systems have been developed to monitor the color e.g. on melts, strands, pellets, the extrudate or injection molded part already during the process. Different kinds of inline, online and atline methods with their respective advantages and disadvantages will be compared. The criteria are e.g. the testing time, which ranges from real-time to some minutes, the required calibration procedure, the spectral resolution and the final measuring precision. The latter ranges between 0.05 to 0.5 in the CIE L*a*b* system depending on the particular measurement system. Due to the high temperatures in typical plastics processes thermochromism of polymers and dyes has to be taken into account. This effect can influence the color value in the magnitude of some 10% and is barely understood so far. Different suitable methods to compensate thermochromic effects during compounding or injection molding by using calibration curves or artificial neural networks are presented. Furthermore it is even possible to control the color during extrusion and compounding almost in real-time. The goal is a specific developed software for adjusting the color recipe automatically with the final objective of a closed-loop control.

  20. Optimization and evaluation of metal injection molding by using X-ray tomography

    Yang, Shidi [State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083 (China); Zhang, Ruijie [School of Material Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Qu, Xuanhui, E-mail: quxh@ustb.edu.cn [State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083 (China); School of Material Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China)

    2015-06-15

    6061 aluminum alloy and 316L stainless steel green bodies were obtained by using different injection parameters (injection pressure, speed and temperature). After injection process, the green bodies were scanned by X-ray tomography. The projection and reconstruction images show the different kinds of defects obtained by the improper injection parameters. Then, 3D rendering of the Al alloy green bodies was used to demonstrate the spatial morphology characteristics of the serious defects. Based on the scanned and calculated results, it is convenient to obtain the proper injection parameters for the Al alloy. Then, reasons of the defect formation were discussed. During mold filling, the serious defects mainly formed in the case of low injection temperature and high injection speed. According to the gray value distribution of projection image, a threshold gray value was obtained to evaluate whether the quality of green body can meet the desired standard. The proper injection parameters of 316L stainless steel can be obtained efficiently by using the method of analyzing the Al alloy injection. - Highlights: • Different types of defects in green bodies were scanned by using X-ray tomography. • Reasons of the defect formation were discussed. • Optimization of the injection parameters can be simplified greatly by the way of X-ray tomography. • Evaluation standard of the injection process can be obtained by using the gray value distribution of projection image.

  1. Optimization and evaluation of metal injection molding by using X-ray tomography

    6061 aluminum alloy and 316L stainless steel green bodies were obtained by using different injection parameters (injection pressure, speed and temperature). After injection process, the green bodies were scanned by X-ray tomography. The projection and reconstruction images show the different kinds of defects obtained by the improper injection parameters. Then, 3D rendering of the Al alloy green bodies was used to demonstrate the spatial morphology characteristics of the serious defects. Based on the scanned and calculated results, it is convenient to obtain the proper injection parameters for the Al alloy. Then, reasons of the defect formation were discussed. During mold filling, the serious defects mainly formed in the case of low injection temperature and high injection speed. According to the gray value distribution of projection image, a threshold gray value was obtained to evaluate whether the quality of green body can meet the desired standard. The proper injection parameters of 316L stainless steel can be obtained efficiently by using the method of analyzing the Al alloy injection. - Highlights: • Different types of defects in green bodies were scanned by using X-ray tomography. • Reasons of the defect formation were discussed. • Optimization of the injection parameters can be simplified greatly by the way of X-ray tomography. • Evaluation standard of the injection process can be obtained by using the gray value distribution of projection image

  2. Numerical simulation of the filling stage in injection molding based on a 3D model

    GENG Tie; LI De-qun; ZHOU Hua-min

    2005-01-01

    Most injection molded parts are three-dimensional, with complex geometrical configurations and thick/thin wall sections. The change of the thickness of parts has significant influence on flow during injection molding. This paper presents a 3D finite element model to deal with the three-dimensional flow, which can more accurately predict the filling process than a 2. 5D model. In this model, equal-order velocity-pressure interpolation method is successfully employed and the relation between velocity and pressure is obtained from the discretized momentum equation in order to derive the pressure equation. A 3D control volume scheme is employed to track the flow front. The validity of the model has been tested through the analysis of the flow in a cavity.

  3. Porous titanium implants fabricated by metal injection molding

    CHEN Liang-jian; LI Ting; LI Yi-min; HE Hao; HU You-hua

    2009-01-01

    Sodium chloride (NaCl) was added as a space holder in synthesis of porous titanium by using metal injection molding(MIM) method. The microstructure and mechanical properties of porous titanium were analyzed by mercury porosimeter, scanning electron microscope(SEM) and compression tester. The results show that the content of NaCl influences the porosity of porous titanium significantly. Porous titanium powders with porosity in the range of 42.4%-71.6% and pore size up to 300 μm were fabricated. The mechanical test shows that with increasing NaCl content, the compressive strength decreases from 316.6 to 17.5 MPa and the elastic modulus decreases from 3.03 to 0.28 GPa.

  4. Microcellular foam injection molding with cellulose nanofibers (CNFs)

    Ohshima, Masahiro; Kubota, Masaya; Ishihara, Shota; Hikima, Yuta; Sato, Akihiro; Sekiguchi, Takafumi

    2016-03-01

    Cellulose nanofibers (CNFs) nanocomposites polypropylene foams are prepared by microcellular foam injection molding with core-back operation. The modified CNFs were blended with isotactic-polypropylene (i-PP) at different CNFs weight percentages and foamed to investigate the effect of CNFs on cell morphology. CNFs in i-PP increased the elastic modulus and induced a strain hardening behavior. CNFs also shifted the crystallization temperature of i-PP to higher temperature and enhanced crystallization. With these changes in rheological and thermal properties, CNFs could reduce the cell size and increase the cell density of the foams. By adjusting the core-back timing i.e., foaming temperature, the closed cell and the nano-fibrillated open cellular structure could be produced. The flexural modulus and bending strength of foams were measured by three point flexural tester. The flexural modulus and bending strength were increased as the CNFs content in i-PP was increased at any foam expansion ratio.

  5. Particle morphology influence on mechanical and biocompatibility properties of injection molded Ti alloy powder.

    Gülsoy, H Özkan; Gülsoy, Nagihan; Calışıcı, Rahmi

    2014-01-01

    Titanium and Titanium alloys exhibits properties that are excellent for various bio-applications. Metal injection molding is a processing route that offers reduction in costs, with the added advantage of near net-shape components. Different physical properties of Titanium alloy powders, shaped and processed via injection molding can achieve high complexity of part geometry with mechanical and bioactivity properties, similar or superior to wrought material. This study describes that the effect of particle morphology on the microstructural, mechanical and biocompatibility properties of injection molded Ti-6Al-4V (Ti64) alloy powder for biomaterials applications. Ti64 powders irregular and spherical in shape were injection molded with wax based binder. Binder debinding was performed in solvent and thermal method. After debinding the samples were sintered under high vacuum. Metallographic studies were determined to densification and the corresponding microstructural changes. 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. The results show that spherical and irregular powder could be sintered to a maximum theoretical density. Maximum tensile strength was obtained for spherical shape powder sintered. The tensile strength of the irregular shape powder sintered at the same temperature was lower due to higher porosity. Finally, mechanical tests show that the irregular shape powder has lower mechanical properties than spherical shape powder. The sintered irregular Ti64 powder exhibited better biocompatibility than sintered spherical Ti64 powder. Results of study showed that sintered spherical and irregular Ti64 powders exhibited high mechanical properties and good biocompatibility properties. PMID:25201399

  6. 邻苯二甲酸二烯丙酯精密注塑%Precise Injection Molding of Diallyl Phthalate

    李思良; 徐鸣亚

    2012-01-01

    The granular thermosetting plastics are made of diallyl phthalate (DAP) resin milled with fiberglass and inorganic filler. The electronic parts which have high shape accuracy and copper inserts are made of the granular thermosetting plastics by injection molding. The problems which occur at the process of injection molding electronic parts are analyzed. theprecise injection molding technique with injection-compression is put forward to solve the problem.%利用邻苯二甲酸二烯丙酯(DAP)添加玻璃纤维与无机填料等混炼而成的粒状热固性塑料,注塑形状精度要求高、有铜质嵌件的电子零件,针对其注塑过程中所出现的工艺问题进行分析,并提出其注塑-压缩的精密注塑解决方法.

  7. Injection molded nanofluidic chips: Fabrication method and functional tests using single-molecule DNA experiments

    Utko, Pawel; Persson, Karl Fredrik; Kristensen, Anders;

    2011-01-01

    We demonstrate that fabrication of nanofluidic systems can be greatly simplified by injection molding of polymers. We functionally test our devices by single-molecule DNA experiments in nanochannels.......We demonstrate that fabrication of nanofluidic systems can be greatly simplified by injection molding of polymers. We functionally test our devices by single-molecule DNA experiments in nanochannels....

  8. Effect of cross sectional geometry on PDMS micro peristaltic pump performance: comparison of SU-8 replica molding vs. micro injection molding.

    Graf, Neil J; Bowser, Michael T

    2013-10-01

    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). 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 elastomeric room temperature vulcanization (RTV) polymers, as opposed to most other injection molding machines, which are designed for use with thermoplastic polymers. The injection mold's bottom plate was used as a microchannel molding template. The molding template was created by threading a small-diameter wire (150 μm or less) through the injection mold's bottom plate, with subsequent adhesion and smoothing of a thin piece of aluminum foil over the wire-raised injection mold template. When molded against, the template produced a rounded/Gaussian-shaped PDMS microchannel. The design of the injection mold will be presented, along with a direct comparison for micropump performance metrics such as flow rate, valving characteristics, and maximum backpressures attainable for each of the respective micropump channel geometries. PMID:23917263

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

    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...

  10. Low Cost Injection Mold Creation via Hybrid Additive and Conventional Manufacturing

    Dehoff, Ryan R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Watkins, Thomas R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); List, III, Frederick Alyious [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Carver, Keith [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); England, Roger [Cummins, Inc, Knoxville, TN (United States)

    2015-12-01

    The purpose of the proposed project between Cummins and ORNL is to significantly reduce the cost of the tooling (machining and materials) required to create injection molds to make plastic components. Presently, the high cost of this tooling forces the design decision to make cast aluminum parts because Cummins typical production volumes are too low to allow injection molded plastic parts to be cost effective with the amortized cost of the injection molding tooling. In addition to reducing the weight of components, polymer injection molding allows the opportunity for the alternative cooling methods, via nitrogen gas. Nitrogen gas cooling offers an environmentally and economically attractive cooling option, if the mold can be manufactured economically. In this project, a current injection molding design was optimized for cooling using nitrogen gas. The various components of the injection mold tooling were fabricated using the Renishaw powder bed laser additive manufacturing technology. Subsequent machining was performed on the as deposited components to form a working assembly. The injection mold is scheduled to be tested in a projection setting at a commercial vendor selected by Cummins.

  11. Molding Properties of Inconel 718 Feedstocks Used in Low-Pressure Powder Injection Molding

    Fouad Fareh

    2016-01-01

    Full Text Available The impact of binders and temperature on the rheological properties of feedstocks used in low-pressure powder injection molding was investigated. Experiments were conducted on different feedstock formulations obtained by mixing Inconel 718 powder with wax-based binder systems. The shear rate sensitivity index and the activation energy were used to study the degree of dependence of shear rate and temperature on the viscosity of the feedstocks. The injection performance of feedstocks was then evaluated using an analytical moldability model. The results indicated that the viscosity profiles of feedstocks depend significantly on the binder constituents, and the secondary binder constituents play an important role in the rheological behavior (pseudoplastic or near-Newtonian exhibited by the feedstock formulations. Viscosity values as low as 0.06 to 2.9 Pa·s were measured at high shear rates and high temperatures. The results indicate that a feedstock containing a surfactant agent exhibits the best moldability characteristics.

  12. Design of Plastic Injection Mold for the New Switch Cover%新型开关盖注射模设计

    洪晓燕

    2012-01-01

    This paper described design steps of injection mold of a new switch cover, including plastic process analysis, determine of molding project, choice of injection machine, the overall structure design of the mold, molding size calculations and so on.%阐述了新型开关盖注射模的设计步骤,主要包括塑件工艺性分析、成型方案的确定、注塑机的选择与校核、模具的总体结构设计、成型尺寸的计算等方面。

  13. A new route for fibre management in powder injection molded metal matrix composites

    The properties of short fibre reinforced metal matrix composites can be enhanced by controlling the directionality of the fibers. In the reported research, the multiple live feed injection moulding technique was successfully used for controlling the orientation of short fibers in powder injection molded metal matrix composites. A range of heavily loaded short fibre reinforced metal matrix compounds were injection molded by both parameters. The level of fibre orientation achieved in injection molded components was assessed by calculation of the orientation factor. One result of this investigation was identification of the moulding composition to achieve the highest level of fibre orientation in a preferred direction. (author)

  14. OSCILLATORY SHEAR-ACCELERATED EXFOLIATION OF GRAPHITE IN POLYPROPYLENE MELT DURING INJECTION MOLDING

    Nan Li; Wei Cheng; Kun Ren; Feng Luo; Ke Wang; Qiang Fu

    2013-01-01

    In this study,good dispersion status of graphite in a nonpolar,intractable polymer,i.e.polypropylene (PP),was realized in melt processing by using a specific dynamic packing injection molding (DPIM) technique.The exfoliation extent of graphite increased remarkably from the skin zone to the core zone of the molded part,as confirmed by combination of WAXD,SEM and TEM analyses,indicating an accelerated exfoliation occurred during the DPIM processing.This phenomenon is due to decreased melt flow channel and increased melt viscosity as the solidification takes place from the wall into the center,which leads to greatly increased shear force.The good dispersion of graphite results in obvious reinforcements of both tensile strength and impact strength by adding moderate amount of graphite.The present study proposes a promising route for realizing the large-scale fabrication of structural parts of polymer/exfoliated-graphite nanocomposites with excellent mechanical properties.

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

    Micro metal injection molding (μMIM) 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, μMIM is applied to produce 316L stainless steel micro components. Due to highly stringent characteristic of μMIM 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.

  16. HIGH SPEED INJECTION MOLDING OF HIGH DENSITY POLYETHYLENE - EFFECTS OF INJECTION SPEED ON STRUCTURE AND PROPERTIES

    Kun Jiang; Feng Chen; Qiang Fu; Fei-long Yu; Run Su; Jing-hui Yang; Tian-nan Zhou; Jian Gao; Hua Deng; Ke Wang; Qin Zhang

    2011-01-01

    Thin wall samples of high density polyethylene (HDPE) were prepared via injection molding with differentinjection speeds ranging from 100 mm/s to 1200 mm/s. A significant decrease in the tensile strength and Young's moduluswas observed with increasing injection speed. In order to investigate the mechanism behind this decrease, the orientation,molecular weight, molecular weight distribution, melt flow rate, crystallinity and crystal morphology of HDPE werecharacterized using two-dimensional wide-angle X-ray diffraction (2D-WAXD), gel permeation chromatography (GPC),capillary rheometry and differential scanning calorimetry (DSC), respectively. It is demonstrated that the orientation,molecular weight, molecular weight distribution, melt flow rate and crystallinity have no obvious change with increasinginjection speed. Nevertheless, the content of extended chain crystals or large folded chain crystals was found to decreasewith increasing injection speed. Therefore, it is concluded that the decrease in tensile properties is mainly contributed by the reduced content of extended chain crystals or large folded chain crystals. This study provides industry with valuableinformation for the application of high speed injection molding.

  17. Injection molding of micro pillars on vertical side walls using polyether-ether-ketone (PEEK)

    Zhang, Yang; Hansen, Hans Nørgaard; Sørensen, Søren

    2016-01-01

    This paper investigates the replication of microstructures on a vertical wall by PEEK injection molding. A 4-cavity insert was used in the injection molding. Pre-fabricated nickel plates with ø 4 μm micro holes on the surface were glued on vertical walls in the cavities. 3 cavities were coated by...... CrN, TiN and TiB2 respectively, the remaining one was not coated as a reference. The effect of coating was compared via the morphology of the micropillars on the polymer parts. 4000 injection molding cycles were repeated. The roughness of the coated surface was measured. The reasons for the demolding...

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

    Thi, Thanh Binh Nguyen; Morioka, Mizuki; Yokoyama, Atsushi [Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585 (Japan); Hamanaka, Senji; Yamashita, Katsuhisa; Nonomura, Chisato [Research Center, Toyobo Co., LTD, 2-1-1 Katata, Otsu, Shiga 520-0292 (Japan)

    2015-05-22

    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 29{sup th} 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-160α, 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.

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

    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-160α, 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

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

    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-160α, 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.

  1. Three-dimensional numerical modeling of an induction heated injection molding tool with flow visualization

    Guerrier, Patrick; Tosello, Guido; Nielsen, Kaspar Kirstein;

    2016-01-01

    Using elevated mold temperature is known to have a positive influence of final injection molded parts. Induction heating is a method that allow obtaining a rapid thermal cycle, so the overall molding cycle time is not increased. In the present research work, an integrated multi-turn induction...... heating coil has been developed and assembled into an injection molding tool provided with a glass window, so the effect of induction heating can directly be captured by a high speed camera. In addition, thermocouples and pressure sensors are also installed, and together with the high speed videos......, comparison of the induction heating and filling of the cavity is compared and validated with simulations. Two polymer materials ABS and HVPC were utilized during the injection molding experiments carried out in this work. A nonlinear electromagnetic model was employed to establish an effective linear...

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

    Menotti, Stefano; Hansen, Hans Nørgaard; Bissacco, Giuliano;

    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...

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

    Tanzi, S.; Larsen, S.T.; Matteucci, M.; Taboryski, R.

    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 stud...

  4. Injection molded polymer chip for electrochemical and electrophysiological recordings from single cells

    Tanzi, Simone; Larsen, Simon Tylsgaard; Taboryski, Rafael J.

    We present a novel method to fabricate an all in polymer injection molded chip for electrochemical cell recordings and lateral cell trapping. The complete device is molded in thermoplastic polymer and it results from assembling two halves. We tested spin-coated conductive polymer poly(3...

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

    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...

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

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

    2013-01-01

    /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...

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

    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 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.

  8. Effects of process parameters on the molding quality of the micro-needle array

    Qiu, Z. J.; Ma, Z.; Gao, S.

    2016-07-01

    Micro-needle array, which is used in medical applications, is a kind of typical injection molded products with microstructures. Due to its tiny micro-features size and high aspect ratios, it is more likely to produce short shots defects, leading to poor molding quality. The injection molding process of the micro-needle array was studied in this paper to find the effects of the process parameters on the molding quality of the micro-needle array and to provide theoretical guidance for practical production of high-quality products. With the shrinkage ratio and warpage of micro needles as the evaluation indices of the molding quality, the orthogonal experiment was conducted and the analysis of variance was carried out. According to the results, the contribution rates were calculated to determine the influence of various process parameters on molding quality. The single parameter method was used to analyse the main process parameter. It was found that the contribution rate of the holding pressure on shrinkage ratio and warpage reached 83.55% and 94.71% respectively, far higher than that of the other parameters. The study revealed that the holding pressure is the main factor which affects the molding quality of micro-needle array so that it should be focused on in order to obtain plastic parts with high quality in the practical production.

  9. Optimization of injection molding parameters for poly(styrene-isobutylene-styrene) block copolymer

    Fittipaldi, Mauro; Garcia, Carla; Rodriguez, Luis A.; Grace, Landon R.

    2016-03-01

    Poly(styrene-isobutylene-styrene) (SIBS) is a widely used thermoplastic elastomer in bioimplantable devices due to its inherent stability in vivo. However, the properties of the material are highly dependent on the fabrication conditions, molecular weight, and styrene content. An optimization method for injection molding is herein proposed which can be applied to varying SIBS formulations in order to maximize ultimate tensile strength, which is critical to certain load-bearing implantable applications. The number of injection molded samples required to ascertain the optimum conditions for maximum ultimate tensile strength is limited in order to minimize experimental time and effort. Injection molding parameters including nozzle temperature (three levels: 218, 246, and 274 °C), mold temperature (three levels: 50, 85, and 120 °C), injection speed (three levels: slow, medium and fast) and holding pressure time (three levels: 2, 6, and 10 seconds) were varied to fabricate dumbbell specimens for tensile testing. A three-level L9 Taguchi method utilizing orthogonal arrays was used in order to rank the importance of the different injection molding parameters and to find an optimal parameter setting to maximize the ultimate tensile strength of the thermoplastic elastomer. Based on the Taguchi design results, a Response Surface Methodology (RSM) was applied in order to build a model to predict the tensile strength of the material at different injection parameters. Finally, the model was optimized to find the injection molding parameters providing maximum ultimate tensile strength. Subsequently, the theoretically-optimum injection molding parameters were used to fabricate additional dumbbell specimens. The experimentally-determined ultimate tensile strength of these samples was found to be in close agreement (1.2%) with the theoretical results, successfully demonstrating the suitability of the Taguchi Method and RSM for optimizing injection molding parameters of SIBS.

  10. Application of MoldFlow in injection molding%MoldFlow在注塑成型中的应用

    汤宏群; 苏广才

    2003-01-01

    利用MoldFlow对星型注塑件不同浇口位置进行流动模拟分析,预测可能存在的气泡位置和熔接痕位置,确定最佳浇口位置和数目.以此为例说明MoldFlow在注塑成型中应用的好处.

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

    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

  12. Mold temperature measurement for glass-pressing processes

    The largest use of radiation thermometers within Corning Glass Works is for mold temperature measurement for the glass-pressing process. Pressing television panels at today's high quality would be very difficult without a mold temperature measurement system and the computer manipulation of the quality control data to supervise the mold temperature control loop. The most critical part of a television panel is the inside surface curvature. The ideal surface is usually defined as a spherical surface. The tolerance for a normal TV panel is +-0.30 mm (+-0.012 in.). High resolution display panels are more critical, having a dimensional tolerance only one half as large as TV panels. Panel curvature is a direct (but negative) function of mold temperature. Every 10C increase in mold temperature results in the panel center being 0.025 mm (0.001 in.) shorter (flatter). Random dimensional variations within a panel take up most of the dimensional tolerance. The result is that each mold is controlled to its own individual temperature set point, +-10C. Hot panel and cold panel curvature measurements are correlated by a process computer and used to update the mold temperature set points. The same computer adjusts the mold cooling air to maintain the required mold temperatures. From the temperature measurement standpoint, the significant problem is the changing emissivity of the mold surface when the mold is new or reconditioned. The selection of a radiation thermometer with a short wavelength was an obvious choice to minimize the effect of emissivity variations

  13. Local mechanical properties of LFT injection molded parts: Numerical simulations versus experiments

    Desplentere, F.; Soete, K.; Bonte, H.; Debrabandere, E.

    2014-05-01

    In predictive engineering for polymer processes, the proper prediction of material microstructure from known processing conditions and constituent material properties is a critical step forward properly predicting bulk properties in the finished composite. Operating within the context of long-fiber thermoplastics (LFT, length Moldflow Insight 2014 software has been used. In this software, a fiber breakage algorithm for the polymer flow inside the mold is available. Using well known micro mechanic formulas allow to combine the local fiber length with the local orientation into local mechanical properties. Different experiments were performed using a commercially available glass fiber filled compound to compare the measured data with the numerical simulation results. In this investigation, tensile tests and 3 point bending tests are considered. To characterize the fiber length distribution of the polymer melt entering the mold (necessary for the numerical simulations), air shots were performed. For those air shots, similar homogenization conditions were used as during the injection molding tests. The fiber length distribution is characterized using automated optical method on samples for which the matrix material is burned away. Using the appropriate settings for the different experiments, good predictions of the local mechanical properties are obtained.

  14. Thermal characterization of polyhydroxyalkanoates and poly(lactic acid) blends obtained by injection molding

    Loureiro, Nuno Calçada; Ghosh, Satyabrata; Viana, J. C.; Esteves, José Luis

    2015-01-01

    In this work we present the thermal characterization of the full scope of polyhydroxyalcanoate and poly(lactic acid) blends obtain by injection molding. Blends of polyhydroxyalcanoate and poly(lactic acid) (PHA/PLA) were prepared in different compositions ranging from 0–100% in steps of 10%. The blends were injection molded and then characterized by differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and wide angle X-ray diffraction (WAXD). The increment of PHA fractio...

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

    Menotti, Stefano; Hansen, Hans Nørgaard; Bissacco, Giuliano;

    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...

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

    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....

  17. Research on Solvent Debinding Process for Titanium Alloy Injection Molded Compacts%粉末注射成形钛合金溶剂脱脂过程研究

    王家惠; 史庆南; 许国红; 韩波

    2011-01-01

    The solvent debinding process of titanium alloy compacts injected by powder injection molding(PIM) was studied. Effects of debinding temperature, solvent, shape of green parts on binder removal were investigated. The results showed that temperature was the dominant parameter, debinding rate would increase with temperature increase; However, the effect of green parts'shape on debinding rate was not significant. The diffusion active energy of normalheptane is 40.39 kJ · mol- 1 · K- 1, which is higher than methylene chloride (38.41 kJ · mol-1 · K-1 ), The diffusion coefficient of normalheptane is higher than methylene chloride under the same temperature.%研究粉末注射成形(PIM) Ti-6A1-4V注射坯的溶荆脱脂行为,分析了脱脂温度、溶剂种类、注射坯形状对脱脂率的影响.结果表明,脱脂温度对注射坯的溶剂脱脂行为影响显著,随着脱脂温度的升高,脱脂率增加;而注射坯的形状对脱脂率的影响不显著.通过对溶剂脱脂动力学分析表明,正庚烷的活化能为40.39 kJ·mot-1·K-1,大于二氛甲烷的活化能(38.41 kJmot-1·K-1);在相同温度下,正庚烷的扩散系数高于二氛甲烷的.

  18. Numerical Simulation of the Flow Behavior and Breakthrough Phenomenon in Co-Injection Molding

    Ilinca, Florin; Hétu, Jean-François

    2007-05-01

    A study of the flow behavior during sequential co-injection molding is shown using a three-dimensional finite element flow analysis code. Solutions of the non-Newtonian, non-isothermal melt flow are obtained by solving the momentum, continuity and energy equations. Two additional transport equations are solved for tracking polymer/air and skin/core polymers interfaces. The co-injection model is integrated into the NRC's 3D injection molding software. Solutions are shown for the filling of a spiral-flow mould for which experimental measurements are available. The numerical approach predicts the core advance stage during which the core flow front catches up on the skin flow front and the core expansion phase when the flow fronts of core and skin materials advance together without breakthrough. The breakthrough phenomenon is also predicted. The predicted flow front behavior is compared to the experimental observations for various skin/core melt temperature and skin/core viscosity ratio. Simulation results are in good agreement with experimental data and indicate correctly the trends in solution change when processing parameters are changing.

  19. Effect of pressure on viscosity at high shear rates by using an injection molding machine

    Volpe, Valentina; Pantani, Roberto

    2015-12-01

    The difficulties in performing accurate measurements of the effect of pressure on the viscosity of the polymeric materials results in a shortage of relevant experimental data in the literature. In this work, an atactic polystyrene has been characterized to determine the effect of pressure on viscosity during the injection molding process. In particular, the nozzle of the injection molding machine has been modified to host a slit rheometer that allows obtaining in-line rheological measurements by means of two pressure transducers. Slits with two different geometries have been adopted, in order to obtain a wide range of shear rates (102-105 s-1). Experiments have been conducted at increasing injection flow rates, corresponding to different shear rates. By analyzing the measured pressures it has been possible to determine the coefficient β, which describes the effect of pressure on viscosity. Results show that the effect of pressure on viscosity decreases on increasing the shear rate until a plateau is reached at very high shear rates.

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

    Tanzi, S.; Larsen, S.T.; Matteucci, M.;

    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...

  1. Visualization analysis of injection molding phenomena in hot-runner system

    Yokoi, Hidetoshi; Kanetoh, Yoshinori; Takamatsu, Ryohei; Endo, Takumi; Chang, Hao; Chayamichi, Toru

    2016-03-01

    Various unsolved defects are known to occur in hot-runner molds, such as stagnation of resins in the manifold channel, asymmetrical cavity filling behavior, flow marks, gate marks, etc. We have been clarifying the causes of various molding defects specifically using visualization technologies inside mold cavity and manifold. This report introduces and discusses the following topics, particularly focusing on clarifying the behavior of resins; (1) Comparison of the imbalanced cavity filling phenomena in between side-fed and center-fed types of valve-gate hot-runner systems, (2) Visualization analysis of the melt flow behaviors and stagnation phenomena inside hot-runner manifolds, (3) Behavior of each stagnant melt around the valve-pin and inner hot-nozzle surfaces, (4) Void generation phenomena remaining on the surface of the valve-pin tip, (5) Melt temperature distribution on the cavity surface during the filling process, (6) Melt temperature profile inside the flowing melt injected from the valve gate, etc.

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

    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

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

    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.

  4. Influence of the polypropylene structure on the replication of nanostructures by injection molding

    Vera, Julie; Brulez, Anne-Catherine; Contraires, Elise; Larochette, Mathieu; Valette, Stéphane; Benayoun, Stéphane

    2015-11-01

    In this paper, an experimental study of replication by injection molding of sub-micrometer features is presented. Two polypropylenes with different melt flow rates (MFR) were used throughout this study. The used removable mold insert was textured with a femtosecond laser. Replication of these periodic structures, called ripples, is thus investigated. Despite different MFR, we show that the viscosities of the two polymers at the investigated temperatures and injection shear rates are similar. The reproducibility of the injected molded samples and the texture of the mold were analyzed. We propose a specific methodology to quantify the reproducibility quality replicas. The latter introduces morphological parameters such as anisotropy rate, power density, etc. A difference between the two replicas was noticeable. Based on rheological analysis, the viscosity was ruled out as the origin of this difference. Other properties were identified as the source such as the chain length and the stress relaxation time. Their impact on the replication quality was investigated and found interesting.

  5. Magnesium Powder Injection Molding (MIM) of Orthopedic Implants for Biomedical Applications

    Wolff, M.; Schaper, J. G.; Suckert, M. R.; Dahms, M.; Ebel, T.; Willumeit-Römer, R.; Klassen, T.

    2016-04-01

    Metal injection molding (MIM) has a high potential for the economic near-net-shape mass production of small-sized and complex-shaped parts. The motivation for launching Mg into the MIM processing chain for manufacturing biodegradable medical implants is related to its compatibility with human bone and its degradation in a non-toxic matter. It has been recognized that the load-bearing capacity of MIM Mg parts is superior to that of biodegradable polymeric components. However, the choice of appropriate polymeric binder components and alloying elements enabling defect-free injection molding and sintering is a major challenge for the use of MIM Mg parts. This study considered the full processing chain for MIM of Mg-Ca alloys to achieve ultimate tensile strength of up to 141 MPa with tensile yield strength of 73 MPa, elongation at fracture Af of 7% and a Young's modulus of 38 GPa. To achieve these mechanical properties, a thermal debinding study was performed to determine optimal furnace and atmosphere conditions, sintering temperature, heating rates, sintering time and pressure.

  6. 机电一体化在塑料模注射生产中的应用%Mechanical and Electrical Integration Application in the Plastic Injection Mold

    桑玉红; 王明荣

    2011-01-01

    以带金属嵌件塑件注射模为例,设计进程中通过磁力作用解决了金属嵌件的定位问题,可以使用卧式注塑机注射成型,并利用气动元件完成两个模腔交替成型,实现注射过程的自动化,缩短塑件的注射成型周期,从而有效地节约了生产成本,提了高生产效率。%With a metal insert injection mold as an example, the design process through the action of magnetic force to solve the metal insert positioning, can use the horizontal injection molding machines injection molding, and the use of pneumatic components to complete a two mold cavity alternating molding, injection molding process automation, shorten the parts of the molding cycle, thereby effectively saving the cost of production put a high production efficiency.

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

    Peltola, Heidi; Madsen, Bo; Joffe, Roberts;

    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...

  8. 塑料注塑成型技术新进展%New Development of the Technology of Injection Molding of Plastic

    李跃文

    2011-01-01

    In this article, the principle, application, characteristics and new development of gas-assisted injection molding technology, water-assisted injection molding technology, precision injection molding technology, micro-injection molding technology, microcellular injection molding technology, libration injection molding technology, in-mold decoration injection molding technology, co-injection molding technology and injection molding CAE technology were introduced.%介绍了气辅注塑、水辅注塑、精密注塑、微注塑、微孔注塑、振动注塑、模内装饰注塑、共注塑和注塑CAE等技术的原理、特点、应用和新进展.

  9. Influence of surface-modified Ti02 nanoparticles on fracture behavior of injection molded polypropylene

    Hui ZHANG; Zhong ZHANG; Hyung-Woo PARK; Xing ZHU

    2008-01-01

    We prepared surface-modified TiO2 nanopar-ticle (21 nm)/polypropylene nanocomposites using a twin-screw extruder and an injection molding machine. The TEM (transmission electron microscopy) and SEM (scan-ning electron microscopy) images showed homogeneous dispersion of nano-TiO2 at 1 vol.% filler content and weak nanoparticle matrix interfacial adhesion. It was found that the essential work of fracture (EWF) approach, usu-ally characterizing fracture toughness of ductile materials, was no longer applicable to the nanocomposite samples because of the extreme crack blunting and tearing pro-cesses observed in the EWF tests. As an alternative approach, the specific essential work-related yield was used for assessment of the plane-strain toughness, as sug-gested in the literature. The results indicated'that the addition of 1 vol.% nano-TiO2 did not toughen the poly-propylene (PP) matrix at all. On the other hand, it was observed from the EWF tensile curves that the nanopar-ticles enhanced the ductility of the PP matrix greatly, the reason of which was probably ascribed to the high level of molecular orientation of the injection molded samples, as revealed by the polarized optical microscopy (POM). Because of the highly ductile behavior induced by the nanoparticles, the fracture energy achieved two- to three-fold increase, depending on the ligament lengths of the samples. The difference between the toughness and ductility of nanocomposites was discussed.

  10. Rheological and thermal performance of newly developed binder systems for ceramic injection molding

    Hausnerova, Berenika; Kasparkova, Vera; Hnatkova, Eva

    2016-05-01

    In a novel binder system, carnauba wax was considered to replace the synthetic backbone polymers (polyolefins) enhancing the environmental sustainability of Ceramic Injection Molding (CIM) technology. The paper presents comparison of the rheological performance and thermal behavior of the aluminum oxide CIM feedstocks based on a binder containing carnauba wax with those consisting of a commercial binder. Further, acrawax (N, N'-Ethylene Bis-stearamide) has been considered as another possible substitute of polyolefins. For both proposed substitutes there is a significant reduction in viscosity, and in case of carnauba wax based feedstock also in processing temperature, which is essential for injection molding of reactive powders. Thermal characterization comprised analyses of single neat binders, their mixtures and mixtures with aluminum oxide. The presence of powder lowered melting temperatures of all tested binders except of polyolefin. Further depression in melting point of poly(ethylene glycol) is observed in combination with polyolefin in the presence of powder, and it is related to changes in size of the crystalline domains.

  11. Fiber-Based, Injection-Molded Optofluidic Systems: Improvements in Assembly and Applications

    Marco Matteucci

    2015-12-01

    Full Text Available We present a method to fabricate polymer optofluidic systems by means of injection molding that allow the insertion of standard optical fibers. The chip fabrication and assembly methods produce large numbers of robust optofluidic systems that can be easily assembled and disposed of, yet allow precise optical alignment and improve delivery of optical power. Using a multi-level chip fabrication process, complex channel designs with extremely vertical sidewalls, and dimensions that range from few tens of nanometers to hundreds of microns can be obtained. The technology has been used to align optical fibers in a quick and precise manner, with a lateral alignment accuracy of 2.7 ± 1.8 μm. We report the production, assembly methods, and the characterization of the resulting injection-molded chips for Lab-on-Chip (LoC applications. We demonstrate the versatility of this technology by carrying out two types of experiments that benefit from the improved optical system: optical stretching of red blood cells (RBCs and Raman spectroscopy of a solution loaded into a hollow core fiber. The advantages offered by the presented technology are intended to encourage the use of LoC technology for commercialization and educational purposes.

  12. 三种不同类型注塑模具的特点与发展现状%Characteristics and Development Status of Three Different Types of Injection Molds

    冯刚; 张朝阁; 齐继宝; 张亚; 赵加伟

    2013-01-01

    The characteristics of large-scale injection molding,precision injection molding and thin-wall injection molding were analyzed. It was found that due to their different plastic injection molding process,the requests to the mold were also different. While the characteristics and domestic research status of large-scale injection molding,precision injection molding and thin-wall injection molding were introduced.Pointing out that China has big gap with foreign in the injection mold design, manufacturing processes and other aspects.Therefore further innovation is needed.%分析了大型注塑、精密注塑、薄壁注塑的特点,发现由于其注塑工艺不同,对模具的要求也不相同。介绍了大型注塑模具、精密注塑模具、薄壁注塑模具的特点和国内研究现状,指出我国在注塑模具的设计理念、制造工艺等方面与国外还存在很大的差距,需要进一步创新。

  13. A Modified Cost Estimation Formulae for Calculating Manufacturing Cost of Injection Part/Mold

    2002-01-01

    In modern society, a plastic part has its own important position. To the managers and decision-makers in the field of plastic component, how to decide the manufacturing cost of the injection part or injection mold as quickly as possible is most valuable. Cost estimation formulae (CEF) are the most common method to evaluate the cost of injection part/mold, which is similar to our ordinary thinking. In this paper, a CEF method used by Dr. Weiyi Hu in Massachusetts University is first discussed. To the problems existed in the formulae, we propose an improved algorithm. This algorithm can be used to estimate the manufacturing cost of injection part/mold accurately in the early design stage.

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

    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 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

  15. Effect of mold rotation on the bifilar electroslag remelting process

    Xiao-fang Shi; Li-zhong Chang; Jian-jun Wang

    2015-01-01

    A novel electroslag furnace with a rotating mold was fabricated, and the effects of mold rotational speed on the electroslag re-melting process were investigated. The results showed that the chemical element distribution in ingots became uniform and that their com-pact density increased when the mold rotational speed was increased from 0 to 28 r/min. These results were attributed to a reasonable mold speed, which resulted in a uniform temperature in the slag pool and scattered the metal droplets randomly in the metal pool. However, an ex-cessive rotational speed caused deterioration of the solidification structure. When the mold rotational speeds was increased from 0 to 28 r/min, the size of Al2O3 inclusions in the electroslag ingot decreased from 4.4 to 1.9μm. But the excessive mold rotational speed would de-crease the ability of the electroslag remelting to remove the inclusions. The remelting speed gradually increased, which resulted in reduced power consumption with increasing mold rotational speed. This effect was attributed to accelerated heat exchange between the consumable electrode and the molten slag, which resulted from mold rotation. Nevertheless, when the rotational speed reached 28 r/min, the remelting speed did not change because of limitations of metal heat conduction. Mold rotation also improved the surface quality of the ingots by pro-moting a uniform temperature distribution in the slag pool.

  16. Virtual Mold Technique in Thermal Stress Analysis during Casting Process

    Si-Young Kwak; Jae-Wook Baek; Jeong-Ho Nam; Jeong-Kil Choi

    2008-01-01

    It is important to analyse the casting product and the mold at the same time considering thermal contraction of the casting and thermal expansion of the mold. The analysis considering contact of the casting and the mold induces the precise prediction of stress distribution and the defect such as hot tearing. But it is difficult to generate FEM mesh for the interface of the casting and the mold. Moreover the mesh for the mold domain spends lots of computational time and memory for the analysis due to a number of meshes. Consequently we proposed the virtual mold technique which only uses mesh of the casting part for thermal stress analysis in casting process. The spring bar element in virtual mold technique is used to consider the contact of the casting and the mold. In general, a volume of the mold is much bigger than that of casting part, so the proposed technique decreases the number of mesh and saves the computational memory and time greatly. In this study, the proposed technique was verified by the comparison with the traditional contact technique on a specimen. And the proposed technique gave satisfactory results.

  17. Injection molded polymer chip for electrochemical and electrophysiological recordings from single cells

    Tanzi, Simone; Larsen, Simon Tylsgaard; Rafael J. Taboryski

    2011-01-01

    We present a novel method to fabricate an all in polymer injection molded chip for electrochemical cell recordings and lateral cell trapping. The complete device is molded in thermoplastic polymer and it results from assembling two halves. We tested spin-coated conductive polymer poly(3,4-ethylenedioxythiopene) and showed that it can be used as an electrode material for detecting neurotransmitters electrochemically in biosensors.

  18. 托纸板模具设计与模具型芯的数控加工%Injection Mold Design and Movable Mold Core NC Machinlng for Shelf of Printer

    黄富

    2011-01-01

    Taking injection mold design and Movable Mold Core NC machining for the Shelf of a Printer as an example,the thesis thoroughly the technics and process of mold designing and NC machining using UG software.%以一款打印机的托纸板注射模的设计和模具后模的数控加工为例,详尽地介绍了运用UG软件进行注射模设计和数控加工的工艺和步骤.

  19. A novel binder and binder extraction method for powder injection molding of tungsten cemented carbide

    祝宝军; 曲选辉; 陶颖

    2003-01-01

    An improved wax-based multi-component binder and a new debinding method termed high-pressure condensed solvent extraction were developed for powder injection molding of tungsten cemented carbide. The results indicate that a critical powder loading of 65% (volume fraction) and an ideal rheological properties were obtained by the feedstock based on the binder. High debinding rate and specimens with high strength were obtained by the debinding method. Moreover, by making high temperature holding time adjustable, it makes the subsequent thermal degradation process more flexible to debinding atmosphere and carbon content of the as debinded specimens controllable. The transverse rupture strength, hardness and density of the as-sintered specimens made by an optimized PIM process are 2.48Gpa, HRA90 and 14.72g/cm3, respectively. Good shape retention and about 0.02% dimension deviation were achieved.

  20. Development of a plastic injection molding training system using Petri nets and virtual reality

    2006-01-01

    In this study, Virtual Reality (VR)-based plastic injection molding training system (VPIMTS), which can be modeled as an integrated system with a task planning module, an intelligent instruction module, a simulation module, and virtual environment (VE) module, was developed. Presented in this paper are an architecture of VPIMTS, a practical knowledge modelling approach for modelling the training scenarios of the system by using Petri nets formalism and key techniques (FEM, injection molding procedure modelling) which have been developed independently. The utilization of the Petri net model realized the environment where the trainee can behave freely, and also made it possible to equip the system with the function of showing the next action of the trainee whenever he wants. The overall system is a powerful approach for highly improving the trainee's comprehension and injection molding study-efficiency by building digital, intelligent, knowledgeable, and visual aids.

  1. Acoustic emission detection of macro-cracks on engraving tool steel inserts during the injection molding cycle using PZT sensors.

    Svečko, Rajko; Kusić, Dragan; Kek, Tomaž; Sarjaš, Andrej; Hančič, Aleš; Grum, Janez

    2013-01-01

    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. PMID:23673677

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

    Aleš Hančič

    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.

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

    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

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

    Bloß, P.; Jüttner, G.; Jacob, S.; Löser, C.; Michaelis, J.; Krajewsky, P.

    2014-05-01

    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.

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

    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.

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

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

  7. Comparison of several closure approximations for evaluating the thermoelastic properties of an injection molded short-fiber composite

    DRAY, Delphine; Gilormini, Pierre; Regnier, Gilles

    2007-01-01

    The accurate prediction of both the elastic properties and the thermal expansion coefficients is very important for the precise simulation of such processes as injection molding of short-fiber polymer-matrix composites. In this work, a two-step homogenization procedure is applied and compared with experimental values obtained on a polyarylamide/glass fiber composite for a broad range of temperatures. It is observed that the stiffness averaging version of the model surpasses the compliance ave...

  8. Three Dimensional Numerical Simulation Of Gas-Assisted And Co-Injection Molding

    Ilinca, Florin; Hétu, Jean-François

    2004-06-01

    This paper presents an overview of the results obtained at the Industrial Materials Institute (IMI) on the numerical simulation of the gas-assisted injection molding and co-injection molding. For this work, the IMI's three-dimensional (3D) finite element flow analysis code was used. Non-Newtonian, non-isothermal flow solutions are obtained by solving the momentum, mass and energy equations. Two additional transport equations are solved to track polymer/air and skin/core materials interfaces. Solutions are shown for various part geometries. The final shape and depth of the core material is predicted and numerical results compare well with experimental data.

  9. A new binder for powder injection molding titanium and other reactive metals

    Weil, K. Scott; Nyberg, Eric A.; Simmons, Kevin L.

    2006-06-26

    We have developed a new aromatic-based binder for powder injection molding (PIM) reactive metals, such as titanium, zirconium, niobium, tungsten, and molybdenum. Because of careful selection of the binder constituents, thermal removal is readily accomplished at low temperatures and short-times via vacuum sublimation. In this way the binder can be cleanly extracted from the green part prior to sintering to minimize the amount of residual carbon left in the final component. Rheological measurements indicate that powder loadings in the PIM feedstock as high as 67 vol% could be achieved using the new binder system, while still maintaining low mixing torques and injection molding pressures.

  10. An axisymmetrical non-linear finite element model for induction heating in injection molding tools

    Guerrier, Patrick; Nielsen, Kaspar Kirstein; Menotti, Stefano;

    2016-01-01

    To analyze the heating and cooling phase of an induction heated injection molding tool accurately, the temperature dependent magnetic properties, namely the non-linear B-H curves, need to be accounted for in an induction heating simulation. Hence, a finite element model has been developed...... in to the injection molding tool. The model shows very good agreement with the experimental temperature measurements. It is also shown that the non-linearity can be used without the temperature dependency in some cases, and a proposed method is presented of how to estimate an effective linear...

  11. Mold Filling Analysis in Vacuum Infusion Molding Process Based on a High-Permeable Medium

    Yingdan ZHU; Hua TAN; Jihui WANG

    2003-01-01

    The objective of this paper is to understand the flow mechanism through visualization experiments and discuss theinfluence of process parameters on mold filling process. A 2D leakage flow model is developed to simulate the moldingprocess, and the simulation results show good agreement with experiments.

  12. Modeling and Simulation of Fiber Orientation in Injection Molding of Polymer Composites

    Jang Min Park

    2011-01-01

    Full Text Available We review the fundamental modeling and numerical simulation for a prediction of fiber orientation during injection molding process of polymer composite. In general, the simulation of fiber orientation involves coupled analysis of flow, temperature, moving free surface, and fiber kinematics. For the governing equation of the flow, Hele-Shaw flow model along with the generalized Newtonian constitutive model has been widely used. The kinematics of a group of fibers is described in terms of the second-order fiber orientation tensor. Folgar-Tucker model and recent fiber kinematics models such as a slow orientation model are discussed. Also various closure approximations are reviewed. Therefore, the coupled numerical methods are needed due to the above complex problems. We review several well-established methods such as a finite-element/finite-different hybrid scheme for Hele-Shaw flow model and a finite element method for a general three-dimensional flow model.

  13. Development of Al{sub 2}O{sub 3}-30mass%TiC composite materials by powder injection molding process; PIM process ni yoru Al{sub 2}O{sub 3}-30%massTiC fukugo zairyo no kaihatsu

    Miura, H.; Nishida, Y. [Kumamoto University, Kumamoto (Japan). Faculty of Engineering; Kai, Y.; Sakaguchi, S. [Nippon Tungsten Co. Ltd., Fukuoka (Japan)

    2000-05-15

    Al{sub 2}O{sub 3}TiC composite materials for cutting tool have been produced by the powder metallurgy process such as hot pressing and HIP. However, there are still problems in fabricating three dimensional complex shaped components. Powder injection molding (PIM) process may solve those problems because of the near net shape forming with complexity. This study has been performed to determine the production feasibility of Al{sub 2}O{sub 3}-30mass%TiC composite materials by PIM process, and the mechanical properties and microstructures of them. Especially, the effects of binder loading and debinding and sintering conditions on the mechanical properties (hardness and transverse rupture strength) were investigated in detail. Finally, high performance Al{sub 2}O{sub 3}-30mass%TiC composite materials were obtained by the optimized PIM process. (author)

  14. Chemical vapor deposition and analysis of thermally insulating ZrO2 layers on injection molds

    High quality injection molding requires a precise control of cooling rates. Thermal barrier coating (TBC) of zirconia with a thickness of 20-40 μm on polished stainless steel molds could provide the necessary insulating effect. This paper presents results of zirconia deposition on stainless steel substrates using chemical vapor deposition (CVD) aiming to provide the process parameters for the deposition of uniform zirconia films with such a thickness. The deposition was performed with zirconium (IV) acetylacetonate (Zr(C5H7O2)4) as precursor and synthetic air as co-reactant, which allows deposition at temperatures below 600 C. The experiments were carried out in a hot-wall reactor at pressures between 7.5 mbar and 500 mbar and in a temperature range from 450 C to 600 C. Important growth parameters were characterized and growth rates between 1 and 2.5 μm/h were achieved. Thick and well adhering zirconia layers of 38 μm could be produced on steel within 40 h. The transient heat transfer rate upon contact with a hot surface was also evaluated experimentally with the thickest coatings. These exhibit a good TBC performance. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  15. Mold

    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.

  16. Microstructure and mechanical behavior of metal injection molded Ti-Nb binary alloys as biomedical material.

    Zhao, Dapeng; Chang, Keke; Ebel, Thomas; Qian, Ma; Willumeit, Regine; Yan, Ming; Pyczak, Florian

    2013-12-01

    The application of titanium (Ti) based biomedical materials which are widely used at present, such as commercially pure titanium (CP-Ti) and Ti-6Al-4V, are limited by the mismatch of Young's modulus between the implant and the bones, the high costs of products, and the difficulty of producing complex shapes of materials by conventional methods. Niobium (Nb) is a non-toxic element with strong β stabilizing effect in Ti alloys, which makes Ti-Nb based alloys attractive for implant application. Metal injection molding (MIM) is a cost-efficient near-net shape process. Thus, it attracts growing interest for the processing of Ti and Ti alloys as biomaterial. In this investigation, metal injection molding was applied to the fabrication of a series of Ti-Nb binary alloys with niobium content ranging from 10wt% to 22wt%, and CP-Ti for comparison. Specimens were characterized by melt extraction, optical microscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), and transmission electron microscopy (TEM). Titanium carbide formation was observed in all the as-sintered Ti-Nb binary alloys but not in the as-sintered CP-Ti. Selected area electron diffraction (SAED) patterns revealed that the carbides are Ti2C. It was found that with increasing niobium content from 0% to 22%, the porosity increased from about 1.6% to 5.8%, and the carbide area fraction increased from 0% to about 1.8% in the as-sintered samples. The effects of niobium content, porosity and titanium carbides on mechanical properties have been discussed. The as-sintered Ti-Nb specimens exhibited an excellent combination of high tensile strength and low Young's modulus, but relatively low ductility. PMID:23994942

  17. Study on manufacture of 2:17 Sm-Co magnets by powder injection molding

    Manufacture of 2:17 Sm-Co magnets by powder injection molding was investigated. The binder of thermoplastic polymer was selected as the wax-based system including paraffin wax, stearic acid and high density polyethylene. Before mixing with paraffin wax and high density polyethylene, the powder of 5-8 μm was coated by stearic acid. The molding compacts were obtained under 200 without deficits. Solvent debinding and thermal debinding were combined to remove the binder. The basic magnetic characteristics of the specimen were of the same level as those by powder metallurgy technique, which indicated that to fabricate 2:17 Sm-Co magnets by powder injection molding was feasible. (orig.)

  18. On the Injection Molding of Nanostructured Polymer Surfaces

    Pranov, Henrik; Rasmussen, Henrik K.; Larsen, Niels Bent;

    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 r...... mold sub-micrometer surface structures in polymers mainly relates to adhesive energy between polymer and shim......., 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...

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

    Matteucci, Marco; Christiansen, Thomas Lehrmann; Tanzi, Simone;

    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 elongati...

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

    Tang, Peter Torben; Christensen, Thomas R.; Jensen, Martin F.

    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...

  1. Thermal properties of extruded/injection-molded poly(lactic acid) and biobased composites

    In order to determine the degree of compatibility between PLA and different biomaterials (fibers), PLA was compounded with sugar beet pulp and apple fibers. Fibers were added at 85:15 and 70:30 PLA:Fiber. The composites were blended by extrusion followed by injection molding. Differential Scannin...

  2. Elasticity at Large Deformations and High Strain Rates in Injection Molded Polypropylene

    Dijkstra, P.T.S.; Gaymans, R.J.; Dijk, van D.J.; Huetink, J.

    2003-01-01

    The deformation behavior of isotactic polypropylene (PP) as a function of strain rate was investigated at 50°C in uniaxial tension. Injection molded dogbone specimens were tested at high strain rates, E = lo-' - 1@ s-l, and the local deformation in the neck was studied using fast tensile videometry.

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

    Andresen, Kristian; Hansen, Morten; Matschuk, Maria;

    2010-01-01

    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 ce...

  4. SA对Al_2O_3粉体改性作用机制及注射成型工艺研究%Study on the Modification Mechanism of Stearic Acid to Alumina Powder and Process of Ceramic Injection Molding

    陈倩; 雅菁; 周彩楼

    2012-01-01

    In this paper, the effect of adding molde of stearic acid on the injection molding process were studied, the modification mechanism of stearic acid to alumina powder as well as the influence of the performance of the feeding and injection were discussed. In addition, the defects of being easy to the introduction in injection molding products were sum- marized. The results showed that the surface of the alumina powder was firstly modified by stearic acid to reduce the aggre- gates and the compatibility, dispersibility, the uniformity of feedstock and injection property were improved by this process. The density and three-bending strength of the sintered samples were improved.%研究了硬脂酸(SA)的加入方式对注射成型工艺的影响,探讨了SA对氧化铝粉末改性作用机制、对喂料性能和注射性能的影响,并对注射成型工艺过程中容易引起的缺陷进行了分析.结果表明:用球磨法对陶瓷粉末进行表面改性处理,可改善陶瓷颗粒表面、有机黏结剂的相容性及分散性、喂料的均匀性和注射性能,有利于提高注射坯体质量、烧结体的密度和强度.

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

    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.

  6. In-situ Formation of Ti Alloys via Powder Injection Molding

    Simmons, Kevin L.; Nyberg, Eric A.; Weil, K. Scott; Miller, Megan R.

    2005-01-01

    We have developed a unique blend of powder injection molding (PIM) feedstock materials in which only a small volume fraction of binder (< 8%) is required; the remainder of the mixture consists of the metal powder and a solid aromatic solvent. Because of the nature of the decomposition in the binder system and the relatively small amount used, the binder can be completely removed from the molded component during heat treatment. Here, we present results from an initial study on in-situ titanium alloy formation in near-net shape components manufactured by this novel PIM technique.

  7. STRESS ANALYSIS OF INJECTION MOLDED PARTS IN POST-FILLING STAGE

    2000-01-01

    The linear isothermo-viscoelastic constitutive equation is established according to the principle of viscoelastic mechanics. Given the boundary conditions of the temperature field, the linear themo-viscoelastic constitutive equation is established acording to the analysis of the thermorheologically simple. The stress analysis model is constructed on the base of some reasonable hypotheses which consider the restraint conditions of mold and the characteristics of injection molding in the post-filling stage. The mathematical model is calculated by the finite difference method. The results can help to predict the warpage of plastic products.

  8. Evaluation of Mechanical Properties of Injection Molding Composites Reinforced by Bagasse Fiber

    Cao, Yong; Fukumoto, Isao

    BMC (Bulk Molding Compound) is composed of UP (Unsaturated Polyester) resin, glass fibers, and bagasse fibers which have been obtained after squeezing sugar cane. Our purpose is to use the bagasse fibers as reinforcement and filler in BMC to fabricate composites by injection molding and injection compression molding. The mechanical properties of injection molding composites were improved after adding the bagasse fibers. Observing the fracture surface of the tensile test specimen through SEM, we could notice the glass fibers were penetrated into the bagasse fibers longitudinally. Along with UP resin solidifying, the glass fibers were firmly fixed in the bagasse fibers and finally united with them. This phenomenon could bring on the same effect as the glass fibers length was prolonged, so that the adhesion interface between fiber and matrix resin became larger, which leads to the increase in the mechanical properties. Otherwise, it was observed that UP resin sufficiently permeated the bagasse fibers and solidified. This also contributes to enhancing the mechanical properties drastically.

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

    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

  10. DESIGN OF INJECTION MOLD FOR THE PIPE COMBINATION%圆管组合注射模设计

    周铭杰

    2011-01-01

    Based on the analysis of the structure characteristics of the pipe combination, an injection mold for pipe combination was designed. The mold structure and working process for this mold were introduced. The changeable molding parts were used to produce pipes with different length. Submarine gate of submarine push rod and push rod which was installed in the covert of plastic parts were used to ensure the surface quality of the parts. The hydraulic cylinder side core-pulling mechanism was used to carry ont the side core-pulling of long pulling distance. The cooling waterline with baffle was set in side core-pulling mechanism to enhance cooling.%通过对圆管组合结构特点的分析,介绍了圆管组合注射模的结构与工作过程.采用互换成型零部件的方式实现生产不同长度的圆管;采用潜推杆的潜伏式浇口及在塑料件隐蔽处设置推杆保证塑料件的外观;采用液压缸侧抽芯机构实现长抽拔距的侧抽芯;在侧抽芯中开设隔片式冷却水道加强侧抽芯的冷却.

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

    Heidi Peltola

    2011-01-01

    Full Text Available 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 efficiency of 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.

  12. Simulation of polymer removal from a powder injection molding compact by thermal debinding

    Lam, Y. C.; Yu, S. C. M.; Tam, K. C.; Shengjie, Ying

    2000-10-01

    Powder injection molding (PIM) is an important net-shape manufacturing process. Thermal debinding is a common methodology for the final removal of residual polymer from a PIM compact prior to sintering. This process is an intricate combination of evaporation, liquid and gas migration, pyrolysis of polymer, and heat transfer in porous media. A better understanding of thermal debinding could lead to optimization of the process to prevent the formation of defects. Simulation of the process based on an integrated mathematical model for mass and heat transfer in porous media is proposed. The mechanisms of mass transport, i.e., liquid flow, gas flow, vapor diffusion, and convection, as well as the phase transitions of polymer, and their interactions, are included in the model. The macroscopic partial differential equations are formulated by volume averaging of the microscopic conservation laws. The basic equations consist of mass conservation and energy conservation and are solved numerically. Polymer residue, pressure, and temperature distributions are predicted. The importance of the various mass transfer mechanisms is evaluated. The effects of key mass transfer parameters on thermal debinding are discussed. It is revealed from the results that the assumed binder front, which is supposed to recede into the powder compact as removal progresses, does not exist. The mass flux of polymer liquid is of the same order of the mass flux of polymer vapor in the gas phase, and the polymer vapor diffusion in the liquid phase is negligible.

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

    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)

  14. Multiple-Step Injection Molding for Fibrin-Based Tissue-Engineered Heart Valves.

    Weber, Miriam; Gonzalez de Torre, Israel; Moreira, Ricardo; Frese, Julia; Oedekoven, Caroline; Alonso, Matilde; Rodriguez Cabello, Carlos J; Jockenhoevel, Stefan; Mela, Petra

    2015-08-01

    Heart valves are elaborate and highly heterogeneous structures of the circulatory system. Despite the well accepted relationship between the structural and mechanical anisotropy and the optimal function of the valves, most approaches to create tissue-engineered heart valves (TEHVs) do not try to mimic this complexity and rely on one homogenous combination of cells and materials for the whole construct. The aim of this study was to establish an easy and versatile method to introduce spatial diversity into a heart valve fibrin scaffold. We developed a multiple-step injection molding process that enables the fabrication of TEHVs with heterogeneous composition (cell/scaffold material) of wall and leaflets without the need of gluing or suturing components together, with the leaflets firmly connected to the wall. The integrity of the valves and their functionality was proved by either opening/closing cycles in a bioreactor (proof of principle without cells) or with continuous stimulation over 2 weeks. We demonstrated the potential of the method by the two-step molding of the wall and the leaflets containing different cell lines. Immunohistology after stimulation confirmed tissue formation and demonstrated the localization of the different cell types. Furthermore, we showed the proof of principle fabrication of valves using different materials for wall (fibrin) and leaflets (hybrid gel of fibrin/elastin-like recombinamer) and with layered leaflets. The method is easy to implement, does not require special facilities, and can be reproduced in any tissue-engineering lab. While it has been demonstrated here with fibrin, it can easily be extended to other hydrogels. PMID:25654448

  15. Application of Rapid Prototyping and Wire Arc Spray to the Fabrication of Injection Mold Tools (MSFC Center Director's Discretionary Fund)

    Cooper, K. G.

    2000-01-01

    Rapid prototyping (RP) is a layer-by-layer-based additive manufacturing process for constructing three-dimensional representations of a computer design from a wax, plastic, or similar material. Wire arc spray (WAS) is a metal spray forming technique, which deposits thin layers of metal onto a substrate or pattern. Marshall Space Flight Center currently has both capabilities in-house, and this project proposed merging the two processes into an innovative manufacturing technique, in which intermediate injection molding tool halves were to be fabricated with RP and WAS metal forming.

  16. IMPROVE THE KINETIC PERFORMANCE OF THE PUMP CONTROLLED CLAMPING UNIT IN PLASTIC INJECTION MOLDING MACHINE WITH ADAPTIVE CONTROL STRATEGY

    2006-01-01

    The kinetic characteristics of the clamping unit of plastic injection molding machine that is controlled by close loop with newly developed double speed variable pump unit are investigated.Considering the wide variation of the cylinder equivalent mass caused by the transmission ratio of clamping unit and the severe instantaneous impact force acted on the cylinder during the mold closing and opening process, an adaptive control principle of parameter and structure is proposed to improve its kinetic performance. The adaptive correlation between the acceleration feedback gain and the variable mass is derived. The pressure differential feedback is introduced to improve the dynamic performance in the case of small inertia and heavy impact load. The adaptation of sum pressure to load is used to reduce the energy loss of the system. The research results are verified by the simulation and experiment. The investigation method and the conclusions are also suitable for the differential cylinder system controlled by the traditional servo pump unit.

  17. Predictive Engineering Tools for Injection-Molded Long-Carbon-Fiber Thermoplastic Composites - Fourth FY 2015 Quarterly Report

    Nguyen, Ba Nghiep; Fifield, Leonard S.; Wollan, Eric J.; Roland, Dale; Gandhi, Umesh N.; Mori, Steven; Lambert, Gregory; Baird, Donald G.; Wang, Jin; Costa, Franco; Tucker III, Charles L.

    2015-11-13

    During the last quarter of FY 2015, the following technical progress has been made toward project milestones: 1) PlastiComp used the PlastiComp direct in-line (D-LFT) Pushtrusion system to injection mold 40 30wt% LCF/PP parts with ribs, 40 30wt% LCF/PP parts without ribs, 10 30wt% LCF/PA66 parts with ribs, and 35 30wt% LCF/PA66 parts without ribs. In addition, purge materials from the injection molding nozzle were obtained for fiber length analysis, and molding parameters were sent to PNNL for process modeling. 2) Magna cut samples at four selected locations (named A, B, C and D) from the non-ribbed Magna-molded parts based on a plan discussed with PNNL and the team and shipped these samples to Virginia Tech for fiber orientation and length measurements. 3) Virginia Tech started fiber orientation and length measurements for the samples taken from the complex parts using Virginia Tech’s established procedure. 4) PNNL and Autodesk built ASMI models for the complex parts with and without ribs, reviewed process datasheets and performed preliminary analyses of these complex parts using the actual molding parameters received from Magna and PlastiComp to compare predicted to experimental mold filling patterns. 5) Autodesk assisted PNNL in developing the workflow to use Moldflow fiber orientation and length results in ABAQUS® simulations. 6) Autodesk advised the team on the practicality and difficulty of material viscosity characterization from the D-LFT process. 7) PNNL developed a procedure to import fiber orientation and length results from a 3D ASMI analysis to a 3D ABAQUS® model for structural analyses of the complex part for later weight reduction study. 8) In discussion with PNNL and Magna, Toyota developed mechanical test setups and built fixtures for three-point bending and torsion tests of the complex parts. 9) Toyota built a finite element model for the complex parts subjected to torsion loading. 10) PNNL built the 3D ABAQUS® model of the complex ribbed

  18. Influence of the power law index on the fiber breakage during injection molding by numerical simulations

    Desplentere, Frederik; Six, Wim; Bonte, Hilde; Debrabandere, Eric

    2013-04-01

    In predictive engineering for polymer processes, the proper prediction of material microstructure from known processing conditions and constituent material properties is a critical step forward properly predicting bulk properties in the finished composite. Operating within the context of long-fiber thermoplastics (LFT, length > 15mm) this investigation concentrates on the influence of the power law index on the final fiber length distribution within the injection molded part. To realize this, the Autodesk Simulation Moldflow Insight Scandium 2013 software has been used. In this software, a fiber breakage algorithm is available from this release on. Using virtual material data with realistic viscosity levels allows to separate the influence of the power law index on the fiber breakage from the other material and process parameters. Applying standard settings for the fiber breakage parameters results in an obvious influence on the fiber length distribution through the thickness of the part and also as function of position in the part. Finally, the influence of the shear rate constant within the fiber breakage model has been investigated illustrating the possibility to fit the virtual fiber length distribution to the possible experimentally available data.

  19. Development of step for light duty truck by using injection molding of long-fiber reinforced thermoplastics; Chosen`i kyoka jushi no shashutsu keisei ni yoru truck yo step no kaihatsu

    Togo, A.; Yamamura, H.; Yamaguchi, M. [Mitsubishi Motor Corp., Tokyo (Japan); Yoshino, K. [Kawasaki Steel Corp. Tokyo (Japan)

    1997-10-01

    The new step for light duty truck was developed by injection molding of glass long-fiber reinforced polypropylene. Feature of the step is good surface appearance and no post processings, compared with the conventional one press molded with a glass fiber reinforced polypropylene sheet (Stampable sheet). 3 refs., 14 figs., 6 tabs.

  20. MoldFlow软件在梳子注射模结构改进及其成型缺陷分析中的应用%The Application of MoldFlow Software in the Structure Improvement and Analysis of forming Defects of Comb Injection Molding

    陈叶娣

    2012-01-01

    MoldFlow software is applied to improve the mold structure and solve molding defects according to the problems of comb injection molding during trying mold. These will be provided some valuable references. Aunusual power is provided for the wide application of MoldFlow software in the design of injection mold.%根据梳子注射模在试模过程中存在的一些问题,采用MoldFlow软件进行分析,为改进模具结构、解决其成型缺陷提供有价值的参考。

  1. Research cooperation project on the development of easy injection molding control technology for engineering plastics; Engineering plastic no seikei joken kan`i settei gijutsu ni kansuru kenkyu kyoryoku jigyo seika hokokusho

    NONE

    1997-03-01

    In order to enhance the industries which supply assembly parts to Japan`s assembly industries in Thailand, research cooperation project on the plastic parts production technology has started. For the research cooperation, the mold design is effectively conducted using simulation technique of CAE (computer aided engineering), and an international easy injection molding control system is made using the molding support software for injection molding machines. In FY 1996, actual situations of plastic parts and assembly industries in Thailand have been investigated through the cooperation with the counterpart of Thailand. Demand and supply of engineering plastics, receive and inspection of parts, and current circumstances of molding processing makers in Thailand have been grasped. Based on the results of this investigation, proposal of basic plan, time schedule, and delivery plan of molding machines and testing equipment have been discussed, to make the basic plan. 18 refs., 4 figs., 23 tabs.

  2. Indirect three-dimensional printing of synthetic polymer scaffold based on thermal molding process

    One of the major issues in tissue engineering has been the development of three-dimensional (3D) scaffolds, which serve as a structural template for cell growth and extracellular matrix formation. In scaffold-based tissue engineering, 3D printing (3DP) technology has been successfully applied for the fabrication of complex 3D scaffolds by using both direct and indirect techniques. In principle, direct 3DP techniques rely on the straightforward utilization of the final scaffold materials during the actual scaffold fabrication process. In contrast, indirect 3DP techniques use a negative mold based on a scaffold design, to which the desired biomaterial is cast and then sacrificed to obtain the final scaffold. Such indirect 3DP techniques generally impose a solvent-based process for scaffold fabrication, resulting in a considerable increase in the fabrication time and poor mechanical properties. In addition, the internal architecture of the resulting scaffold is affected by the properties of the biomaterial solution. In this study, we propose an advanced indirect 3DP technique using projection-based micro-stereolithography and an injection molding system (IMS) in order to address these challenges. The scaffold was fabricated by a thermal molding process using IMS to overcome the limitation of the solvent-based molding process in indirect 3DP techniques. The results indicate that the thermal molding process using an IMS has achieved a substantial reduction in scaffold fabrication time and has also provided the scaffold with higher mechanical modulus and strength. In addition, cell adhesion and proliferation studies have indicated no significant difference in cell activity between the scaffolds prepared by solvent-based and thermal molding processes. (paper)

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

    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.

  4. Injection molding of silicon carbide capable of being sintered without pressure

    Muller-Zell, A.; Schwarzmeier, R.

    1984-01-01

    The most suitable SiC mass for injection molding of SiC articles (for subsequent pressureless sintering) consisted of beta SiC 84, a wax mixture 8, and polyethylene or polystyrene 8 parts. The most effective method for adding the binders was by dissolving them in a solvent and subsequent evaporation. The sequence of component addition was significant, and all parameters were optimized together rather than individually.

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

    Dong Kwon Park; Ingook Song; Jin Hyo Lee; Young June You

    2013-01-01

    Background The forehead, which occupies about one third of the face, is one of the major determinants of a feminine or masculine look. Various methods have been used for the augmentation of the forehead using autologous fat grafts or alloplastic materials. Methylmethacrylate (MMA) is the most appropriate material for augmentation of the forehead, and we have used an injection-molding technique with MMA to achieve satisfactory results. Methods Under local anesthesia with intravenous (IV) sedat...

  6. Micromechanical Properties of Injection-Molded Starch–Wood Particle Composites

    Ueberschaer, A.; Cagiao, M. E.; Bayer, R. K.; Henning, S; Baltá Calleja, F. J.

    2006-01-01

    The micromechanical properties of injection molded starch–wood particle composites were investigated as a function of particle content and humidity conditions. The composite materials were characterized by scanning electron microscopy and X-ray diffraction methods. The microhardness of the composites was shown to increase notably with the concentration of the wood particles. In addition,creep behavior under the indenter and temperature dependence were evaluated in terms of the indepe...

  7. Uniform Dispersion of Multiwalled Carbon Nanotubes in Copper Matrix Nanocomposites Using Metal Injection Molding Technique

    Ali Samer Muhsan

    2013-01-01

    Full Text Available This work presents a novel fabrication approach of multiwalled carbon nanotubes (MWNTs reinforced copper (Cu matrix nanocomposites. A combination of nanoscale dispersion of functionalized MWNTs in low viscose media of dissolved paraffin wax under sonication treatment followed by metal injection molding (MIM technique was adopted. MWNTs contents were varied from 0 to 10 vol.%. Information about the degree of purification and functionalization processes, evidences on the existence of the functional groups, effect of sonication time on the treated MWNTs, and microstructural analysis of the fabricated Cu/MWNTs nanocomposites were determined using TEM, EDX, FESEM, and Raman spectroscopy analysis. The results showed that the impurities of the pristine MWNTs such as Fe, Ni catalyst, and the amorphous carbon have been significantly removed after purification process. Meanwhile, FESEM and TEM observations showed high stability of MWNTs at elevated temperatures and uniform dispersion of MWNTs in Cu matrix at different volume fractions and sintering temperatures (950, 1000 & 1050°C. The experimentally measured thermal conductivities of Cu/MWNTs nanocomposites showed remarkable increase (11.25% higher than sintered pure Cu with addition of 1 vol.% MWNTs, and slight decrease below the value of sintered Cu at 5 and 10 vol.% MWNTs.

  8. 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

    Diovani C. Lencina

    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.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.

  9. Prediction of fiber orientation in injection-molded parts using three-dimensional simulations

    Wang, Jin; Cook, Peter; Bakharev, Alex; Costa, Franco; Astbury, David

    2016-03-01

    The Folgar-Tucker (F-T) model is widely used in most commercial software packages and research programs to predict the fiber orientation distribution in injection-molded fiber-reinforced composites. However, experimental measurements reveal that the F-T model normally results in much higher fiber alignment than observed because it tends to over-predict the orientation kinetics. The Reduced Strain Closure (RSC) model was developed, based on the F-T model, to capture the slow orientation kinetics in an objective fashion. Previous studies demonstrate that t he RSC model yields good agreement of fiber orientation with experimental measurements in shell element simulations using the Hele-Shaw flow approximation. This paper focuses on the RSC model in three-dimensional finite element simulations. The fiber orientation predictions were compared to the orientation measurements in a number of injection-molded parts of various shapes and dimensions and molded with various injection speeds. The RSC model is able to capture the orientation distribution through the part thickness and the average orientation trends along the flow length without the need to tailor the inlet orientation condition to pre-existing data.

  10. Spray-formed Tooling for Injection Molding and Die Casting Applications

    Mc Hugh, Kevin Matthew

    2000-06-01

    Rapid Solidification Process (RSP) ToolingTM is a spray forming technology tailored for producing molds and dies. The approach combines rapid solidification processing and net-shape materials processing in a single step. The ability of the sprayed deposit to capture features of the tool pattern eliminates costly machining operations in conventional mold making and reduces turnaround time. Moreover, rapid solidification suppresses carbide precipitation and growth, allowing many ferritic tool steels to be artificially aged, an alternative to conventional heat treatment that offers unique benefits. Material properties and microstructure transformation during heat treatment of spray-formed H13 tool steel are described.

  11. Spray-formed tooling for injection molding and die casting applications

    K. M. McHugh; B. R. Wickham

    2000-06-26

    Rapid Solidification Process (RSP) Tooling{trademark} is a spray forming technology tailored for producing molds and dies. The approach combines rapid solidification processing and net-shape materials processing in a single step. The ability of the sprayed deposit to capture features of the tool pattern eliminates costly machining operations in conventional mold making and reduces turnaround time. Moreover, rapid solidification suppresses carbide precipitation and growth, allowing many ferritic tool steels to be artificially aged, an alternative to conventional heat treatment that offers unique benefits. Material properties and microstructure transformation during heat treatment of spray-formed H13 tool steel are described.

  12. Improved silicon carbide for advanced heat engines. II - Pressureless sintering and mechanical properties of injection molded silicon carbide

    Whalen, Thomas J.; Baer, J. R.

    1989-01-01

    The influence on density and strength of pressureless sintering in vacuum and argon environments has been evaluated with injection molded SiC materials. Main effects and two factor interactions of sintering (cycle variables temperature, time, heating rate, and atmosphere) were assessed. An improved understanding of the influence of the processing flaws and sintering conditions has been obtained. Strength and density have improved from a baseline level of 299 MPa (43.3 Ksi) and 94 pct of theoretical density to values greater than 483 MPa (70 Ksi) and 97 pct.

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

    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. PMID:25761921

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

    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.

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

    Hausnerova, Berenika; Sanetrnik, Daniel; Paravanova, Gordana

    2014-05-01

    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.

  16. Evaluation of Micro-drilling Technologies for Metal Injection Molded 420 Stainless Steel

    Silverman, David Elion

    Metal injection molded (MIM) 420 stainless steel is a commonly used material for high-value products such as fuel injector nozzles. However, the trade-offs involved in using different micro-drilling processes on this material are not well-documented in literature. This thesis presents a micro-drilling study of MIM 420 stainless steel using four candidate processes, viz., micro-electrical discharge drilling (micro-EDD), ultrasonically-assisted micro-EDD, micro-mechanical drilling (micro-MD) and ultrasonically-assisted micro-MD. The micro-EDD results shows that the use of ultrasonic vibrations significantly improves the overall process time, spark erosion efficiency and material removal rate of the process. However, this improvement comes at the expense of increased tool wear and surface roughness, especially while machining under high discharge energy conditions. The micro-MD results show that the use of ultrasonic vibrations is beneficial in lowering the thrust force, drilling torque and tool-wear at chipload values greater than the minimum chip thickness of the material. However, the ultrasonic vibrations do not have a notable effect on the surface roughness or on the size of the exit burrs. The results obtained from this study have been used to develop a Likert-type comparison scale to enable application-specific selection of micro-drilling processes for MIM 420 stainless steel. Finally, the benefits of using the ultrasonically-assisted micro-EDD process seen during the laboratory tests at Rensselaer were observed to carry over to the production environment of our NYSERDA funded industrial sponsor.

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

    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

  18. Comparative study of pore structure evolution during solvent and thermal debinding of powder injection molded parts

    Hwang, K. S.; Hsieh, Y. M.

    1996-02-01

    The solvent debinding process has been widely accepted in the powder injection molding (PIM) industry due to its short debinding cycle. In the current study, specimens were immersed in a heptane bath for different lengths of time, and the pore structure evolvement in the compact was analyzed. Mercury porosimetry analyses and scanning electron micrographs showed that the binder extraction started from the surface and progressed toward the center of the compacts. As the debinding contin-ued, the pores grew and were widely distributed in size. This pore structure evolvement was different from that of straight thermal debinding in which the pore size distribution was quite narrow and the mean pore diameter shifted toward smaller sizes as debinding time increased. After the soluble binders were extracted, parts were subjected to a subsequent thermal debinding during which these pores served as conduits for decomposed gas to escape. Concurrently, the remaining binder became fluidlike and was redistributed within the compact due to capillarity. This pore structure, as observed from the mercury intrusion curves, showed a sharp increase in the pore volume at the 0.8-µm size, followed by a series of fine pores, which is different from the pore structure of straight thermal debinding. The difference in the pore structure evolvement between solvent and thermal debinding and its effect on the debinding rate are discussed.

  19. Comparative study of pore structure evolution during solvent and thermal debinding of powder injection molded parts

    Hwang, K.S.; Hsieh, Y.M. [National Taiwan Univ., Taipei (Taiwan, Province of China). Inst. of Materials Science and Engineering

    1996-02-01

    The solvent debinding process has been widely accepted in the powder injection molding (PIM) industry due to its short debinding cycle. In the current study, specimens were immersed in a heptane bath for different lengths of time, and the pore structure evolvement in the compact was analyzed. Mercury porosimetry analyses and scanning electron micrographs showed that the binder extraction started from the surface and progressed toward the center of the compacts. As the debinding continued, the pores grew and were widely distributed in size. This pore structure evolvement was different from that of straight thermal debinding in which the pore size distribution was quite narrow and the mean pore diameter shifted toward smaller sizes as debinding time increased. After the soluble binders were extracted, parts were subjected to a subsequent thermal debinding during which these pores served as conduits for decomposed gas to escape. Concurrently, the remaining binder became fluidlike and was redistributed within the compact due to capillarity. This pore structure, as observed from the mercury intrusion curves, showed a sharp increase in the pore volume at the 0.8-{micro}m size, followed by a series of fine pores, which is different from the pore structure of straight thermal debinding. The difference in the pore structure evolvement between solvent and thermal debinding and its effect on the debinding rate are discussed.

  20. 电加热高光注塑模具设计%Electric Heating High Light Injection Mold Design

    黄元贵

    2011-01-01

    A high gloss injection molding, in mold core equipped with electric heating components, in the mold core with insulation on the tank, while the main body in the mold and the mold core with insulation between the plates, to achieve high optical injection in At the same time, greatly reduce energy consumption. This method and technology is useful in the practical production.%一种高光注塑模具在模芯内设有电加热件,在模芯上设有隔热槽,同时在模具主体与模芯之间设有隔热板,使其在实现高光注塑的同时,大幅地降低了能耗.该工艺方法的设计研究,具有显著的科研和工程实用价值.

  1. The effect of injection molding conditions on the near-surface rubber morphology, surface chemistry, and adhesion performance of semi-crystalline and amorphous polymers

    Weakley-Bollin, Shannon Christine

    This thesis investigated the effect of injection molding processing variables, resin formulation and mold material on the resulting morphology and properties of semi-crystalline and amorphous polymers in parts molded on large presses with fully developed flow. Five different polymer resins and two different coating types were investigated, and the near-surface morphology was found to be dependent on material formulation, processing parameters, and geometry. For painted TPO, changes in the near-surface rubber morphology and surface chemistry based on material and processing conditions had no significant effect on the adhesion performance. For metal plated ABS, the adhesion performance was found to be heavily dependent on the rubber surface morphology, which varied with material formulation and processing conditions. One of the most significant findings was that forged aluminum injection molding tooling had little effect on the surface morphology or adhesion performance of either polypropylene or the two TPO formulations examined, despite the five-fold increase in thermal conductivity over traditional tool steel. Surface chemistry, however, was found to be affected by cooling rate, depending on material formulation. A UV stabilizer additive was found concentrated at 2.5 atomic percent on the surface of the aluminum molded part, but not the steel molded part, demonstrating a possible opportunity for using additives and aluminum tooling to create "designer surfaces". Processing conditions were found to have a competing role in metal plated ABS, where conditions that lowered surface stress and improved adhesion by a factor of 15 also increased the amount of bulk molded-in stress by nearly 7%. Both factors were found to play an important role in adhesion performance due to the effect of surface stress on the quality of the resulting etch structure. The bulk stress must be minimized to due to the large mechanical and thermal mismatch between the polymer and metal layers

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

    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.

  3. Development of production technology by metallic powder injection molding for TiAl-type intermetallic compound with high efficiency

    Since a TiAl-type intermetallic compound has an excellent high temperature strength and corrosion resistance, in addition to light weight, it is expected to be applicable to the engine parts. However, it is difficult for TiAI to produce a part with a complex shape, and considerable cost will be required. In this study, it was tried to develop a technology for producing TiAl products with high density and high efficiency by using metal powder injection molding (MIM) process. Several kinds of TiAI alloy powders made by the self-propagating high temperature synthesis process were mixed with an organic binder, kneaded and then injection-molded into tensile specimens. These compacts were subjected to the treatment for removing the binder and sintering, resulted in a relative density as high as 97 %. By room and high temperature tensile tests, it was found that, Ti-47.4Al-2.6Cr (at%) has the strength and ductility as those of the conventional processed materials. (author)

  4. Influence of the injection-molding parameters on the cellular structure and thermo-mechanical properties of ethylene-propylene block copolymer foams

    Gómez Gómez, Jaime Francisco; Arencón Osuna, David; Sánchez Soto, Miguel; Martínez Benasat, Antonio

    2013-01-01

    Microcellular injection-molding technology is capable of producing lightweight polymeric products. The foam morphology is determined by the injection-molding parameters, and it has been observed that depending on the parameter variations, the cell structure may exhibit substantial morphological differences through the entire section along the melt flow direction of the injected part. The effects of varying injection-molding parameters on foam morphology and thermal mechanical p...

  5. MoldFlow软件在50英寸LED平板电视机后壳注射模设计中的应用%Application of MoldFlow Software in Injection Mold Design for the Back Shell of 50 Inch Panel TV

    陈垂根; 杨海明

    2012-01-01

    运用MoldFlow软件对50英寸LED平板电视机后壳注射成型进行流动模拟分析。通过多种设计方案进行比较和调整,确定最优设计方案。MoldFlow软件的应用缩短了模具制造周期,提高了塑件质量,降低了模具制造成本。%Through using MoldFlow software to analysis on injection flow process of the back shell of 50 Inch LED panel TV.An optimized design scheme was determined after a comparison and modification of various plans.With the use of MoldFlow software,reduced the machining cycle,products quality is improved,and the manufacture cost were reduced too.

  6. Feature-based non-manifold modeling system to integrate design and analysis of injection molding products

    Current CAE systems used for both the simulation of the injection molding process and the structural analysis of plastic parts accept solid models as geometric input. However, abstract models composed of sheets and wireframes are still used by CAE systems to carry out more analyses more efficiently. Therefore, to obtain an adequate abstract model, designers often have to simplify and idealize a detailed model of a part to a specific level of detail and/or abstraction. For such a process, we developed a feature-based design system based on a non-manifold modeling kernel supporting feature-based multi-resolution and multi-abstraction modeling capabilities. In this system, the geometric models for the CAD and CAE systems are merged into a single master model in a non-manifold topological representation, and then, for a given level of detail and abstraction, a simplified solid or non-manifold model is extracted immediately for an analysis. For a design change, the design and analysis models are modified simultaneously. As a result, this feature based design system is able to provide a more integrated environment for the design and analysis of plastic injection molding parts

  7. 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

    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

  8. 高速注塑机注射部件设计及应用%Design and Application of Injection Part of High Speed Injection Molding Machine

    王权

    2011-01-01

    The general design principle of injection part of high speed injection molding machine was presented based on the characteristics of high speed injection molding machine. The related parameters of hydraulic accumulator of injection part were calculated and its hydraulic system principle was analyzed. The development and application of high speed injection molding machine were introduced.%针对高速注塑成型机特点,提出其注射部件的一般设计原则,并对注射部件动力源--蓄能器有关参数进行计算,分析注射部件液压系统原理,同时介绍高速注塑成型机的发展及应用.

  9. Using Direct Metal Deposition to Fabricate Mold Plates for an Injection Mold Machine Allowing for the Evaluation of Cost Effective Near-Sourcing Opportunities in Larger, High Volume Consumer Products

    Duty, Chad E [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Groh, Bill [Radio Systems Corporation, Knoxville, TN (United States)

    2014-10-31

    ORNL collaborated with Radio Systems Corporation to investigate additive manufacturing (AM) of mold plates for plastic injection molding by direct metal deposition. The team s modelling effort identified a 100% improvement in heat transfer through use of conformal cooling lines that could be built into the mold using a revolutionary design enabled by additive manufacturing. Using the newly installed laser deposition system at the ORNL Manufacturing Demonstration Facility (MDF) a stainless steel mold core was printed.

  10. Tool steel quality and surface finishing of plastic molds

    Rafael Agnelli Mesquita; Reinhold Schneider

    2010-01-01

    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, grin...

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

    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

  12. Manufacturing of Injection-Molded NdFeB Magnet with (BH)max111 kJ · m-3

    Duan Bohua; Qu Xuanhui; Xu Zhengzhou; Guo Shibo; Qin Mingli

    2004-01-01

    The bonded NdFeB magnets prepared by injection molding meet with the development tendency of the magnet in small volume, light weight and high performance ,and have a good prospect.In this paper, a modified nylonbased binder was developed for powder injection molding of NdFeB bonded magnets.The effects of pretreatment of NdFeB anisotropic magnetic powder produced with HDDR processing on the anti-oxidation behaviors of powder and the final magnetic properties of the molded bonded magnets were studied.The optimal powder loading of 65 vol% was achieved with the modified binder.It was found that the properties of the bonded magnets were mainly affected by the powder surface pretreatment and the intensity of the applied alignment magnetic field during injection molding for a certain powder.Bonded magnets with remanence of 0.820 T, intrinsic coercivity of 1140.3 kA· m-1 and maximum energy product of 111 kJ · m-3 were produced with the optimal processing.

  13. Compact surface plasmon resonance biosensor utilizing an injection-molded prism

    Chen, How-Foo; Chen, Chih-Han; Chang, Yun-Hsiang; Chuang, Hsin-Yuan

    2016-05-01

    Targeting at a low cost and accessible diagnostic device in clinical practice, a compact surface plasmon resonance (SPR) biosensor with a large dynamic range in high sensitivity is designed to satisfy commercial needs in food safety, environmental bio-pollution monitoring, and fast clinical diagnosis. The core component integrates an optical coupler, a sample-loading plate, and angle-tuning reflectors is injection-molded as a free-from prism made of plastic optics. This design makes a matching-oil-free operation during operation. The disposability of this low-cost component ensures testing or diagnosis without cross contamination in bio-samples.

  14. Chemistry principles for thermoplastic polymer binder formula selection for powder injection molding

    梁叔全; 唐艳; 黄伯云; 李少强

    2004-01-01

    The polymer binder selection is one of the very important aspects for the powder injection molding.However, even nowadays the binder selection is still mainly performed by try and error method. Six commercial or intensive studied binder formulas were analyzed according to state diagram and chemical characteristics of ingredients in each binder formula. In addition, the interactions between the binder components and additives were also taken into account. Based on the analysis, the optimum binder formula was selected and some selection criterions were put forward for the binder and additives.

  15. Ball Pad Mold Electromagnetic Forming Process for Aluminium Alloy Sheet

    Wang, Wen-ping; Wu, Xiang-Dong; Wan, Min; Chen, Xiao-wei; Xiong, Wei-Ren

    2014-01-01

    In order to meet requirements of lightweight technology in the field of aerospace, the new forming technology for aluminium alloy skin parts and integral panel are brought to more attention. Based on the principle of electromagnetic forming (EMF) and energy distribution, a new electromagnetic forming process using ball as pad mold for aluminium alloy sheet forming was suggested and test apparatus was designed. The new method was verified by the finite element simulation and exp...

  16. Research Status and Prospect of Energy-Saving Injection Molding Machine Driving System%注塑机驱动系统节能的研究现状及前景

    冯刚; 张朝阁; 江平

    2014-01-01

    介绍了注塑机工作过程及驱动特点。分析了全液压驱动系统、全电动驱动系统、电液混合驱动系统各自的特点,并归纳了国内外在三种不同驱动系统的注塑机节能的研究现状,对我国注塑机发展方向进行展望。我国全自动注塑机关键零部件同世界先进国家相比,在技术上存在较大的差距,我国注塑机主流仍是液压式注塑机,同时指出必须把节能技术作为提高注塑机技术之一进行创新开拓,才能使我国注塑机不断发展。%The working process and driving characteristics of injection molding machines described. The characteristics of hydraulic drive system,electric drive system and electro-hydraulic hybrid drive system were analysed. And the research present situation of three different energy-saving driving system of injection molding machine was summarized,the development direction of injection molding machine was outlooked. Compared with world’s advanced countries,there is a big gap in technology of key components of automatic injection molding machine,hydraulic injection molding machine is still the mainstream of China’s injection molding machine. Only developing energy efficiency technology as one of injection molding machine technology for innovative development,China’s injection molding machine can evolve.

  17. Implementation of Molding Constraints in Topology Optimization

    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...

  18. Application of Moldflow in Solving Injection Mold Shrinkage and Warpage%Moldflow在解决注塑件收缩翘曲中的应用

    金鹏; 张文建; 何政军; 任雯

    2012-01-01

    以注塑箱体为例,介绍了模流分析软件Moldflow在解决注塑件收缩翘曲中的应用.利用Moldflow的模拟分析功能,通过合理调整保压曲线参数,达到减小由压力分布不均所造成的收缩、翘曲的目的,实现注塑模具的优化设计.%The application of Moldflow solving the shrinkage and warpage in injection molding process was introduced with injection box as an example: By adjusting the pressure curve parameters, using the Moldflow simulation analysis capabilities, the shrinkage and warpage defects caused by the uneven pressure distribution were reduced so the optimization of the injection mold design was realized.

  19. Influence of the Mold Current on the Electroslag Remelting Process

    Hugo, Mathilde; Dussoubs, Bernard; Jardy, Alain; Escaffre, Jessica; Poisson, Henri

    2016-08-01

    The electroslag remelting process is widely used to produce high value-added alloys. The use of numerical simulation has proven to be a valuable way to improve its understanding. In collaboration with Aubert & Duval, the Institute Jean Lamour has developed a numerical transient model of the process. The consumable electrode is remelted within a mold assumed to be electrically insulated by the solidified slag skin. However, this assumption has been challenged by some recent studies: the solidified slag skin may actually allow a part of the melting current to reach the mold. In this paper, the evolution of our model, in order to take into account this possibility, is presented and discussed. Numerical results are compared with experimental data, while several sensitivity studies show the influence of some slag properties and operating parameters on the quality of the ingot. Even, a weakly conductive solidified slag skin at the inner surface of the mold may be responsible for a non-negligible amount of current circulating between the slag and crucible, which in turn modifies the fluid flow and heat transfer in the slag and ingot liquid pool. The fraction of current concerned depends mainly on the electrical conductivities of both the liquid and solidified slag.

  20. 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

    Emerson J Corazza

    2012-01-01

    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.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.

  1. Time-Dependent Properties of Multimodal Polyoxymethylene Based Binder for Powder Injection Molding

    Gonzalez-Gutierrez, Joamin; Stringari, Gustavo Beulke; Zupancic, Barbara; Kubyshkina, Galina; Bernstorff, Bernd Von; Emri, Igor

    Powder injection molding (PIM) is one of the most versatile methods for the manufacturing of small complex shaped components from metal, ceramic or cemented carbide powders for the use in many applications. PIM consists of mixing the powder and a polymeric binder, injecting this mixture in a mold, debinding and then sintering. Catalytic debinding of polyoxymethylene (POM) is attractive since it shows high debinding rates and low risk of cracking. This work examines the possibility of using POM with bimodal molecular mass distribution as the main component of the binding agent by studying its time-dependent properties and comparing them to monomodal POM. Furthermore, possible optimization of the binder formulation was investigated by the addition of shorter polymeric chains (wax) to bimodal POM, as to create a multimodal material. It was observed that the magnitude of the complex viscosity for the commercial bimodal material was more than 2 times lower than for the chemically identical monomodal POM within the investigated frequency range and temperature. Viscosity values were observed to drop as the content of wax was increased, without compromising the binders mechanical properties in solid state. A new formulation of bimodal POM plus 8 wt.% of added wax provided the most appropriate results from investigated combinations. This work has shown how the addition of short polymeric chains in POM influences its time-dependent properties in solid and molten state, which can be an important tool for the optimization of binders designed to be used in PIM technology.

  2. Phase Behaviors in Bi-phase Simulation of Powder Segregation in Metal Injection Molding

    Liu Baosheng; Fan Xiaoxin; Cheng Zhiqiang

    2006-01-01

    Powder segregation induced by mold filling is an important phenomenon that affects the final quality of metal injection molding (MIM). The prediction of segregation in MIM requires a bi-phase flow model to describe distinctly the flows of metallic powder and polymer binder. Viscous behaviors for the flows of each phase should hence be determined. The coefficient of interaction between the flows of two phases should also be evaluated. However, only viscosity of the mixed feedstock is measurable by capillary tests. Wall sticking is supposed in the traditional model for capillary tests, while the wall slip is important to be taken into account in MIM injection. Objective of the present paper is to introduce the slip effect in bi-phase simulation, and search the suitable way to determine the viscous behaviors for each phase with the consideration of wall slip in capillary tests. Analytical and numerical methods were proposed to realize such a specific purpose. The proposed method is based on the mass conservation between the capillary flows in mono-phase model for the mixed feedstock and in bi-phase model for the flows of two phases. Examples of the bi-phase simulation in MIM were realized with the software developed by research team. The results show evident segregation, which is valuable for improving the mould designs.

  3. Effect of Fe3P addition on magnetic properties and microstructure of injection molded iron

    Ma, Jidong; Qin, Mingli; Tian, Lusha; Zhang, Lin; Khan, Dil Faraz; Ding, Xiangying; Qu, Xuanhui; Zhang, Houan

    2016-01-01

    Phosphorus powder was used to improve the performance of iron based alloy products fabricated by metal injection molding. Seven kinds of Fe-xP soft magnetic alloys were formed using carbonyl iron powder and Phosphorus powder as raw materials where x=0-1.2 wt% with 0.2 wt% increment. Samples were sintered in hydrogen atmosphere at the temperature range of 1100-1450 °C for varied times. The effects of sintering temperature and time on the density, microstructure and magnetic properties like magnetic induction, maximum permeability and coercive force of the alloys were examined. The results demonstrated that better magnetic performances of the injection molded Fe-xP alloy is due to increased density of the sintered compacts because of formation of liquid phase at low temperature. For Fe-0.8%P alloy, optimum density 7.84 g/cm3 (relative density 99%) and magnetic induction (B6000) 1.77 T, maximum permeability 17,100 were obtained at sintering temperature 1420 °C while the coercive force was 21 A/m respectively.

  4. Hydrophilic thermoplastic polyurethanes for the manufacturing of highly dosed oral sustained release matrices via hot melt extrusion and injection molding.

    Verstraete, G; Van Renterghem, J; Van Bockstal, P J; Kasmi, S; De Geest, B G; De Beer, T; Remon, J P; Vervaet, C

    2016-06-15

    Hydrophilic aliphatic thermoplastic polyurethane (Tecophilic™ grades) matrices for high drug loaded oral sustained release dosage forms were formulated via hot melt extrusion/injection molding (HME/IM). Drugs with different aqueous solubility (diprophylline, theophylline and acetaminophen) were processed and their influence on the release kinetics was investigated. Moreover, the effect of Tecophilic™ grade, HME/IM process temperature, extrusion speed, drug load, injection pressure and post-injection pressure on in vitro release kinetics was evaluated for all model drugs. (1)H NMR spectroscopy indicated that all grades have different soft segment/hard segment ratios, allowing different water uptake capacities and thus different release kinetics. Processing temperature of the different Tecophilic™ grades was successfully predicted by using SEC and rheology. Tecophilic™ grades SP60D60, SP93A100 and TG2000 had a lower processing temperature than other grades and were further evaluated for the production of IM tablets. During HME/IM drug loads up to 70% (w/w) were achieved. In addition, Raman mapping and (M)DSC results confirmed the homogenous distribution of mainly crystalline API in all polymer matrices. Besides, hydrophilic TPU based formulations allowed complete and sustained release kinetics without using release modifiers. As release kinetics were mainly affected by drug load and the length of the PEO soft segment, this polymer platform offers a versatile formulation strategy to adjust the release rate of drugs with different aqueous solubility. PMID:27113866

  5. Producing Zirconium Diboride Components with Complex, Near-Net Shape Geometries by Aqueous Room-Temperature Injection Molding

    Wiesner, Valerie L.; Youngblood, Jeffrey; Trice, Rodney

    2014-01-01

    Room-temperature injection molding is proposed as a novel, low-cost and more energy efficient manufacturing process capable of forming complex-shaped zirconium diboride (ZrB2) parts. This innovative processing method utilized aqueous suspensions with high powder loading and a minimal amount (5 vol.) of water-soluble polyvinylpyrrolidone (PVP), which was used as a viscosity modifier. Rheological characterization was performed to evaluate the room-temperature flow properties of ZrB2-PVP suspensions. ZrB2 specimens were fabricated with high green body strength and were machinable prior to binder removal despite their low polymer content. After binder burnout and pressureless sintering, the bulk density and microstructure of specimens were characterized using Archimedes technique and scanning electron microscopy. X-Ray Diffraction was used to determine the phase compositions present in sintered specimens. Ultimate strength of sintered specimens will be determined using ASTM C1323-10 compressive C-ring test.

  6. Recycling process of casting molds applying to precision castings

    M. Drajewicz

    2012-12-01

    Full Text Available Purpose: The present work relates to investigations about the possibility of recycling and producing sinters from ceramic molds. These molds are applied for producing precise single crystal casts of nickel based superalloys to elements witch are applied to the hot section of aircraft jet engines.Design/methodology/approach: The processes of milling were carried out using the vibratory mill Herzog HSM 100H and the planetary grinder Pulverisette 7 - Fritsch Company. The measurements of all kinds of powders were conducted by using of the Kamika IPS U Analyzer and Malvern Nanosizer-ZS. To the purpose of analysis of the chemical composition an X-ray microanalysis technique was applied with the dispersion of the energy (EDS using of Thermo and Noran equipment. Findings: On the basis of examinations carried out on the powders before and after processes of milling and after processes of pressing and sintering of powders, it is possible to state that technological processes of reuse and further applying of used molds are possible. Processes of pressing were conducted applying different amounts of powders. Powders were pressed both without the addition as well as with the addition of modifiers which were added to basic powder in appropriate amounts. It was found that processes of pressing and sintering in both cases showed good results. Surfaces of pressed and sintered tablets were smooth and not-delaminated as well as did not shell.Research limitations/implications: Results will be used for future researches among others concerning the research on mechanical and thermal properties.Practical implications: Waste products and their reuse, recycling and especially consolidation of dangerous and hazardous compounds including of ceramic materials from foundry industry, will have an important place in the future on account of problems with their recycling and the storage.Originality/value: Researches on new possibilities of the application and properties of

  7. Optimized Injection Molding of Unfilled and Glass Filled PA6 Gears

    Nik Mizamzul Mehat

    2014-01-01

    Full Text Available Shrinkage behavior is a crucial problem in manufacturing plastic molded gear. This is because it negatively affects the dimensional stability and accuracy of the involute profile, as well as the concentricity, roundness, tooth spacing uniformity, and size of the gear. By integrating the Taguchi robust design, Grey relational analysis, and principal component analysis, we investigated the dimensional stability related to the shrinkage of tooth thickness, addendum circle, and dedendum circle of molded gear via the optimization of processing parameters and glass fiber reinforcement. The results revealed that the optimal combination of the processing parameters of the molded gear to achieve minimum shrinkage is melt temperature of 260°C, packing pressure of 60%, packing time of 5 s, and cooling time of 30 s. The melt temperature showed the highest comparability sequence among the four key process parameters examined, followed by packing pressure, cooling time, and packing time. Meanwhile, the presence of glass fibers induced higher deviations of tooth thickness, addendum circle, and dedendum circle than those of the unfilled polyamide 6 gears.

  8. Temperature and Thermal Stress Distribution for Metal Mold in Squeeze Casting Process

    K.H.Chang; G.C.Jang; C.H.Lee; S.H.Lee

    2008-01-01

    In the squeeze casting process, loaded high pressure (over approximately 100 MPa) and high temperature influence the thermo-mechanical behavior and performance of the used metal mold. Therefore, to safely maintain the metal molds, the thermo-mechanical characteristics (temperature and thermal stress) of metal mold in the squeeze casting must be investigated. In this paper, temperature and thermal stress distribution of steel mold in squeeze casting process were investigated by using a three-dimensional non-steady heat conduction analysis and a three-dimensional thermal elastic-plastic analysis considering temperature-dependent thermo- physical and mechanical properties of the steel mold.

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

    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.

  10. Chemical vapor deposition and analysis of thermally insulating ZrO{sub 2} layers on injection molds

    Atakan, Burak; Khlopyanova, Victoria; Mausberg, Simon; Kandzia, Adrian; Pflitsch, Christian [Thermodynamik (IVG) and Cenide, Universitaet Duisburg-Essen, Lotharstr. 1, 47057 Duisburg (Germany); Mumme, Frank [Kunststoff-Institut Luedenscheid, Karolinenstrasse 8, 58507 Luedenscheid (Germany)

    2015-07-15

    High quality injection molding requires a precise control of cooling rates. Thermal barrier coating (TBC) of zirconia with a thickness of 20-40 μm on polished stainless steel molds could provide the necessary insulating effect. This paper presents results of zirconia deposition on stainless steel substrates using chemical vapor deposition (CVD) aiming to provide the process parameters for the deposition of uniform zirconia films with such a thickness. The deposition was performed with zirconium (IV) acetylacetonate (Zr(C{sub 5}H{sub 7}O{sub 2}){sub 4}) as precursor and synthetic air as co-reactant, which allows deposition at temperatures below 600 C. The experiments were carried out in a hot-wall reactor at pressures between 7.5 mbar and 500 mbar and in a temperature range from 450 C to 600 C. Important growth parameters were characterized and growth rates between 1 and 2.5 μm/h were achieved. Thick and well adhering zirconia layers of 38 μm could be produced on steel within 40 h. The transient heat transfer rate upon contact with a hot surface was also evaluated experimentally with the thickest coatings. These exhibit a good TBC performance. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  11. Visualization analysis of tiger-striped flow mark generation phenomena in injection molding

    Owada, Shigeru; Yokoi, Hidetoshi

    2016-03-01

    The generation mechanism of tiger-striped flow marks of polypropylene (PP)/rubber/talc blends in injection molding was investigated by dynamic visualization analysis in a glass-inserted mold. The analysis revealed that the behavior of the melt flow front correlates with the flow mark generation. The cloudy part in the tiger-striped flow marks corresponded to the low transcription rate area of the melt diverging near the cavity wall, while the glossy part corresponded to the high transcription rate area of the melt converging toward the cavity wall side. The melt temperature at the high transcription rate area was slightly lower than that at the low transcription rate area. These phenomena resulted due to the difference in the temperature of the melt front that was caused by the asymmetric fountain flow. These results suggest the followings; At the moment when the melt is broken near the one side of cavity wall due to piling the extensional strains up to a certain level, the melt spurts out near the broken side. It results in generating asymmetric fountain flow temporarily to relax the extensional front surface, which moves toward the opposite side to form the high transcription area.

  12. The Gate Design of Injection Mold for the Thin Shell Plastic Parts Based on the MoldFlow%基于MoldFlow的薄壳塑件的浇口设计

    陈波

    2012-01-01

    The cover of auto was simulated and analyzed by the means of MoldFlow soflerware, determining the optimal gate location area, and through a variety of programs for contrast, analyzed all sorts of defects on injection molding effects, ultimately determine a reasonable form of the gate.%应用MoldFlow软件对汽车盖板的成型过程进行模拟分析,确定最佳的浇口位置区域,并且通过对多种方案的对比,分析了各种缺陷对注射成型的影响,最终确定合理的浇口形式。

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

    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.

  14. Research on properties of carbon black/polypropylene composites by dynamic injection molding

    Wu, Ming-Chun; He, Guang-Jian; Huang, Zhao-Xia; Zhou, Li-Ying; He, He-Zhi

    2016-03-01

    Polymer composites filled with conductive carbon black (CB) are gaining popularity for electromagnetic shielding applications. Dynamic injection molding method was adopted to study the influences of vibration force field on electrical properties of polypropylene/CB composites. The results showed that the percolation phenomenon of conductivity of composites occurred at 15wt% and the calculated SE was positive correlated with the variation trend of conductivity. The calculated SE of composite was more than 30dB at a CB concentration of 30wt%, which could obtain good shielding effects. The result could offer optimum vibration parameters for producing electromagnetic shielding composites by respectively changing the amplitudes and frequencies of the vibration force field.

  15. Effects of milling and active surfactants on rheological behavior of powder injection molding feedstock

    范景莲; 黄伯云; 曲选辉

    2001-01-01

    The effects of milling and active surfactants on the rheological behavior of powder injection molding feedstock were discussed. The feedstock consists of traditional compositional 90W-7Ni-3Fe powder mixture and a wax based polymer binder. Before mixing feedstock, the powder mixture was milled for different times in a QM-1 high-energy ball mill. The viscosity of the feedstock was examined in a capillary rheometer. The rheological behavior was evaluated from viscosity data. The results show that the feedstock belongs to a pseudoplastic fluid, milling decreases viscosity of the feedstock and the sensitivity of viscosity to shear strain rate. The flowability, rheology and powder loading of this feedstock are improved by milling. Active surfactants such as stearic acid (SA) and di-n-octyl-o-phthalate (DOP) have great influences on the rheological properties of the feedstock. DOP improves the flowability and rheological stability of the feedstock further.

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

    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 1.2×102Ω·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.%.

  17. Injection-molded Sm-Fe-N anisotropic magnets using unsaturated polyester resin

    New injection-molding technology has been developed using an unsaturated polyester (UP) resin in order to produce bonded Sm-Fe-N anisotropic magnets. Sheet magnets of 50 mm x 20 mm x 0.36 mm are successfully made within a cycle time of 90 s. Magnetic properties obtained are almost the same as those obtained in column magnets of φ10 mm x 7 mm. Typical data of magnetic properties are as follows: B r = 0.72 T, H CJ = 796 kA/m and (BH)max 94.7 kJ/m3. The density is 4.79 Mg/m3. The degree of orientation of (0 0 6) is 5.31 calculated using the Wilson formula from X-ray diffraction result. Ring magnets of 7.4 mm x 3.2 mm x 0.3 mm are easily made from sheet magnets

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

    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

  19. Oxide Formation In Metal Injection Molding Of 316L Stainless Steel

    Jang Jin Man

    2015-06-01

    Full Text Available The effects of sintering condition and powder size on the microstructure of MIMed parts were investigated using water-atomized 316L stainless steel powder. The 316L stainless steel feedstock was injected into micro mold with micro features of various shapes and dimensions. The green parts were debound and pre-sintered at 800°C in hydrogen atmosphere and then sintered at 1300°C and 1350°C in argon atmosphere of 5torr and 760torr, respectively. The oxide particles were formed and distributed homogeneously inside the sample except for the outermost region regardless of sintering condition and powder size. The width of layer without oxide particles are increased with decrease of sintering atmosphere pressure and powder size. The fine oxides act as the obstacle on grain growth and the high sintering temperature causes severe grain growth in micro features due to larger amount of heat gain than that in macro ones.

  20. Thermal Properties of Extruded Injection-Molded Polycaprolactone/Gluten Bioblends Characterized by TGA, DSC, SEM and Infrared Photoacoustic Spectroscopy

    In order to determine the degree of compatibility between Polycaprolactone resin (PCL) and vital wheat gluten (VG), PCL was compounded with VG at 90:10, 80:20, 70:30, 60:40, 50:50, and 30:70. The composites were blended by extrusion followed by injection molding. Thermal, morphological, and struct...

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

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

    2011-01-01

    Roč. 51, č. 7 (2011), s. 1376-1382. ISSN 0032-3888 R&D Projects: GA ČR 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

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

    J. Koszkul; J. Nabiałek

    2007-01-01

    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 ...

  3. Development of Data Acquisition System for Foam Injection Molding%发泡注塑过程数据采集系统的研制开发

    郭奕崇; 阎芳; 陈思远

    2013-01-01

    The foam injection molding process with inert gas as foaming agent was introduced briefly. The scheme features of data acquisition system for foam injection molding with LabVIEW software were analyzed. Based on virtual instrument technology,a computer data acquisition system was developed, and the parameters of foam injection molding, including screw displacement,motor power,melt temperature and pressure were acquired with producer-consumer model.%简要介绍了以惰性气体为发泡剂的发泡注塑工艺过程,分析了以LabVIEW为开发平台的发泡注塑过程数据采集系统设计方案的特点.开发了基于虚拟仪器技术的计算机数据采集系统,实现了在“生产者-消费者”模式下对发泡注塑过程各参数,包括螺杆位移、主电机功率、熔体温度和压力等数据的采集.

  4. Analysis of Injection Molding For the Electronic Ballast Pan on Moldflow%基于Moldflow的电子镇流器底壳注射成型分析

    萧时诚; 杨文浩

    2012-01-01

    Analysis was made on (he optimal gate location and flow behavior in insertion molding of electronic ballast pan was simulated by Moldflow and the optimal gak- location was determined. Some possible defects in the products were predicted based on the numerical simulation of the filling time, the location of air pockets, weld line, clamping force curve and front temperature. It was shown that the Moldflow technology in the mold development process for optimizing plastic mold design and optimization of plastic mold injection process parameters, etc. played a significant role.%利用Moldflow软件对电子镇流器底壳注射成型过程中最佳浇口位置和流动情况进行分析,确定了最佳浇口位置.通过对填充时间、气穴、熔接痕、锁模力曲线和流动前沿温度等数值模拟,预测塑件可能出现的缺陷,显示了Moldflow技术在模具开发过程中对于优化塑料注射模设计和优化注射工艺参数等方面所起到的显著作用.

  5. Crack analysis for injection mold made from DIN1.2344 steel%DIN1.2344钢注塑模具的裂纹分析

    段莉萍; 唐家耘

    2014-01-01

    A meso⁃level crack was found on the working surface of mold cavity after the finish machining of injection mold for a lampshade of cars. The injection mold is made of 1.2344 steel. The dye penetrating non⁃destructive testing,chemical composition analysis,macroscopic and microscopic morphology observation of the crack were carried out. The results show that there exist obvious microstructure defects,such as zonal segregation,carbide network and nonmetallic inclusions in the raw materials of mold. The secondary carbide network is formed in the quench cooling process of quenching and high temperature tempering. It is concluded that the obvious microstructure defects of material and a sharp angle in the mold result in the early brittleness cracking.%DIN1.2344钢汽车灯罩注塑模具在最终精加工的型腔工作面发现有微细裂纹。采用着色渗透无损检测、化学成分分析、宏观形貌和微观形貌分析以及能谱分析等方法对裂纹进行研究。结果表明:在模具原材料中存在带状偏析、碳化物网和非金属夹杂物等严重的组织缺陷,模具在调质热处理淬火冷却时也形成二次碳化物网;裂纹的产生主要是由于模具材料中存在非金属夹杂物等严重组织缺陷,模具设计有尖锐角也是导致早期脆性开裂的重要原因。

  6. Vacuum Infusion Molding Process Part 1:VIMP Based on a High-Permeable Medium

    ZHU Ying-dan; WANG Ji-hui; YANG Zui; TAN Hua

    2003-01-01

    The visualization experiments were carried out to investigate the permeability of the high-permeable medium (HPM) and the roles of the peel ply and the HPM in the mold filling.The influence of process parameters on mold filling is discussed.Furthermore,the whole vacuum infusion molding process (VIMP) procedure is introduced in detail taking the manufacture of a model boat for example.

  7. Simulation of Jetting in Injection Molding Using a Finite Volume Method

    Shaozhen Hua

    2016-05-01

    Full Text Available In order to predict the jetting and the subsequent buckling flow more accurately, a three dimensional melt flow model was established on a viscous, incompressible, and non-isothermal fluid, and a control volume-based finite volume method was employed to discretize the governing equations. A two-fold iterative method was proposed to decouple the dependence among pressure, velocity, and temperature so as to reduce the computation and improve the numerical stability. Based on the proposed theoretical model and numerical method, a program code was developed to simulate melt front progress and flow fields. The numerical simulations for different injection speeds, melt temperatures, and gate locations were carried out to explore the jetting mechanism. The results indicate the filling pattern depends on the competition between inertial and viscous forces. When inertial force exceeds the viscous force jetting occurs, then it changes to a buckling flow as the viscous force competes over the inertial force. Once the melt contacts with the mold wall, the melt filling switches to conventional sequential filling mode. Numerical results also indicate jetting length increases with injection speed but changes little with melt temperature. The reasonable agreements between simulated and experimental jetting length and buckling frequency imply the proposed method is valid for jetting simulation.

  8. Design of Injection Mold for Connector Based on MoldFlow Software%基于MoldFlow的接插件注射模设计

    孙立新

    2010-01-01

    通过对接插件的结构和工艺的分析,合理确定了模具抽芯机构的结构,同时应用模流分析软件MoldFlow确定了模具的最佳浇口位置,并对塑件的质量进行了预测.

  9. 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

    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.

  10. Rubber molds for investment casting

    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)

  11. Phenolic Molding Compounds

    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.

  12. Wireless accelerometer network for process monitoring during mold forming in lost foam casting

    Whelan, Matthew J.; Janoyan, Kerop D.

    2006-03-01

    Lost Foam Casting (LFC) enables the production of complex castings while offering the advantages of consolidation of components, reduced machining, and recirculation of the casting mold material. In the process, a replica of the desired product is produced of blown polystyrene, coated in refractory slurry, and cast in a dense, unbonded sand mold. In order for the unbonded sand mold to fill into pattern holes and to provide sufficient confining force to prevent the advancing molten front from penetrating beyond the mold boundaries, the sand mold is produced by an overhead raining and flask vibration schedule that encourages fluidization and subsequent densification. The amplitude, frequency, and duration of the flask vibration as well as the rate of sand filling are critical parameters in achieving quality castings. Currently, many foundries use an often-lengthy trial-and-error process for determining an acceptable raining and vibration schedule for each specific mold and rely heavily on simple measurements and operator experience to control the mold making process on the foundry line. This study focuses on developing a wireless sensor network of accelerometers to monitor vibrational characteristics of the casting flask during the mold making stage of LFC. Transformations in the vibrational characteristics of the flask can provide a "signature" for indicating the condition of the unbonded sand mold. Additionally, the wireless nature of the sensor nodes enables the technology to travel across the foundry floor during the casting cycle eliminating the necessity of routine placement and setup.

  13. Fabrication and characterization of injection molded poly (ε-caprolactone) and poly (ε-caprolactone)/hydroxyapatite scaffolds for tissue engineering

    In this study, poly(ε-caprolactone) (PCL)/sodium chloride (NaCl), PCL/poly(ethylene oxide) (PEO)/NaCl and PCL/PEO/NaCl/hydroxyapatite (HA) composites were injection molded and characterized. The water soluble and sacrificial polymer, PEO, and NaCl particulates in the composites were leached by deionized water to produce porous and interconnected microstructures. The effect of leaching time on porosity, and residual contents of NaCl and NaCl/HA, as well as the effect of HA addition on mechanical properties was investigated. In addition, the biocompatibility was observed via seeding human mesenchymal stem cells (hMSCs) on PCL and PCL/HA scaffolds. The results showed that the leaching time depends on the spatial distribution of sacrificial PEO phase and NaCl particulates. The addition of HA has significantly improved the elastic (E′) and loss moduli (E″) of PCL/HA scaffolds. Human MSCs were observed to have attached and proliferated on both PCL and PCL/HA scaffolds. Taken together, the molded PCL and PCL/HA scaffolds could be good candidates as tissue engineering scaffolds. Additionally, injection molding would be a potential and high throughput technology to fabricate tissue scaffolds. - Highlights: ►PCL/NaCl, PCL/PEO/NaCl and PCL/PEO/NaCl/HA composites were injection molded. ►Leaching time depends on the distribution of PEO phase and NaCl particulates. ►The elastic and loss moduli of PCL/HA scaffolds have significantly improved. ►Human hMSCs have attached, survived and proliferated well on PCL and PCL/HA scaffolds. ►Molded PCL and PCL/HA scaffolds could be good candidates for tissue engineering.

  14. Sintering behavior and mechanical properties of a metal injection molded Ti–Nb binary alloy as biomaterial

    Highlights: • The sintering of the MIM Ti–Nb alloy consists of three steps. • The Nb particles act as diffusion barriers during sintering. • The TiCx only precipitate in the cooling step during sintering. • The TiCx hardly influence the sintering process of MIM Ti–Nb alloy. • The MIM Ti–Nb alloy exhibits high strength, low Young’s modulus but poor ductility. - Abstract: Sintering behavior, microstructure and mechanical properties of a Ti–16Nb alloy processed by metal injection molding (MIM) technology using elemental powders were investigated in this work by optical microscopy, X-ray diffraction (XRD), dilatometer, scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS). It was found that from 700 °C to 1500 °C the homogenization and densification process of MIM Ti–16Nb alloy consisted of three steps, i.e., Ti-diffusion-controlled step, Ti–Nb-diffusion step and matrix-diffusion step. Titanium carbide formation was observed in the samples sintered at 1300 °C and 1500 °C, but not in the ones sintered at 900 °C and 1100 °C. The MIM Ti–16Nb specimens sintered at 1500 °C exhibited a good combination of high tensile strength and low Young’s modulus. However, the titanium carbide particles led to poor ductility

  15. Sintering behavior and mechanical properties of a metal injection molded Ti–Nb binary alloy as biomaterial

    Zhao, Dapeng, E-mail: dpzhao@hotmail.com [College of Biology, Hunan University, 410082 Changsha (China); Helmholtz-Zentrum Geesthacht, Institute of Materials Research, D-21502 Geesthacht (Germany); Chang, Keke [RWTH Aachen University, Materials Chemistry, D-52056 Aachen (Germany); Ebel, Thomas [Helmholtz-Zentrum Geesthacht, Institute of Materials Research, D-21502 Geesthacht (Germany); Nie, Hemin [College of Biology, Hunan University, 410082 Changsha (China); Willumeit, Regine; Pyczak, Florian [Helmholtz-Zentrum Geesthacht, Institute of Materials Research, D-21502 Geesthacht (Germany)

    2015-08-15

    Highlights: • The sintering of the MIM Ti–Nb alloy consists of three steps. • The Nb particles act as diffusion barriers during sintering. • The TiC{sub x} only precipitate in the cooling step during sintering. • The TiC{sub x} hardly influence the sintering process of MIM Ti–Nb alloy. • The MIM Ti–Nb alloy exhibits high strength, low Young’s modulus but poor ductility. - Abstract: Sintering behavior, microstructure and mechanical properties of a Ti–16Nb alloy processed by metal injection molding (MIM) technology using elemental powders were investigated in this work by optical microscopy, X-ray diffraction (XRD), dilatometer, scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS). It was found that from 700 °C to 1500 °C the homogenization and densification process of MIM Ti–16Nb alloy consisted of three steps, i.e., Ti-diffusion-controlled step, Ti–Nb-diffusion step and matrix-diffusion step. Titanium carbide formation was observed in the samples sintered at 1300 °C and 1500 °C, but not in the ones sintered at 900 °C and 1100 °C. The MIM Ti–16Nb specimens sintered at 1500 °C exhibited a good combination of high tensile strength and low Young’s modulus. However, the titanium carbide particles led to poor ductility.

  16. Ceramic micro-injection molded nozzles for serial femtosecond crystallography sample delivery

    Serial femtosecond crystallography (SFX) using X-ray Free-Electron Lasers (XFELs) allows for room temperature protein structure determination without evidence of conventional radiation damage. In this method, a liquid suspension of protein microcrystals can be delivered to the X-ray beam in vacuum as a micro-jet, which replenishes the crystals at a rate that exceeds the current XFEL pulse repetition rate. Gas dynamic virtual nozzles produce the required micrometer-sized streams by the focusing action of a coaxial sheath gas and have been shown to be effective for SFX experiments. Here, we describe the design and characterization of such nozzles assembled from ceramic micro-injection molded outer gas-focusing capillaries. Trends of the emitted jet diameter and jet length as a function of supplied liquid and gas flow rates are measured by a fast imaging system. The observed trends are explained by derived relationships considering choked gas flow and liquid flow conservation. Finally, the performance of these nozzles in a SFX experiment is presented, including an analysis of the observed background

  17. Effects of heat treatment on the properties of powder injection molded AIN ceramics

    DU Xueli; QIN Mingli; Akhtar Farid; FENG Peizhong; QU Xuanhui

    2008-01-01

    The effects of two different heat-treatment atmospheres,nitrogen atmosphere and reducing nitrogen atmosphere with carbon,on the properties of Y2O3-doped aluminum nitride (AlN) ceramics were investigated.The AlN powder as a raw material was synthesized by self-propagating high-temperature synthesis (SHS) and compacts were fabricated by employing powder injection molding technique.The polymer-wax binder consisted of 60 wt.% paraffin wax (PW),35 wt.% polypropylene (PP),and 5 wt.% stearic acid (SA).After the removal of binder,specimens were sintered at 1850℃ in nitrogen atmosphere under atmospheric pressure.To improve the thermal conductivity,sintered samples were reheated.The result reveals that the heat-treatment atmosphere has significant effect on the properties and secondary phase of AlN ceramics.The thermal conductivity and density of AlN ceramics reheated in nitrogen gas are 180 W·m-1 K-1 and 3.28 g,cm-3 and the secondary phase is yttrium aluminate.For the sample reheated in reducing nitrogen atmosphere with carbon,the thermal conductivity and density are 173 W.m-1.K-1 and 3.23 g·cm-3,respectively,and the secondary phase is YN.

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

    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

  19. Ceramic micro-injection molded nozzles for serial femtosecond crystallography sample delivery

    Beyerlein, K. R.; Adriano, L.; Heymann, M.; Kirian, R.; Knoška, J.; Wilde, F.; Chapman, H. N.; Bajt, S.

    2015-12-01

    Serial femtosecond crystallography (SFX) using X-ray Free-Electron Lasers (XFELs) allows for room temperature protein structure determination without evidence of conventional radiation damage. In this method, a liquid suspension of protein microcrystals can be delivered to the X-ray beam in vacuum as a micro-jet, which replenishes the crystals at a rate that exceeds the current XFEL pulse repetition rate. Gas dynamic virtual nozzles produce the required micrometer-sized streams by the focusing action of a coaxial sheath gas and have been shown to be effective for SFX experiments. Here, we describe the design and characterization of such nozzles assembled from ceramic micro-injection molded outer gas-focusing capillaries. Trends of the emitted jet diameter and jet length as a function of supplied liquid and gas flow rates are measured by a fast imaging system. The observed trends are explained by derived relationships considering choked gas flow and liquid flow conservation. Finally, the performance of these nozzles in a SFX experiment is presented, including an analysis of the observed background.

  20. Ceramic micro-injection molded nozzles for serial femtosecond crystallography sample delivery

    Beyerlein, K. R.; Heymann, M.; Kirian, R. [Center for Free-Electron Laser Science, Deutsches Elektronen-Synchrotron, Notkestraße 85, 22607 Hamburg (Germany); Adriano, L.; Bajt, S., E-mail: sasa.bajt@desy.de [Photon Science, Deutsches Elektronen-Synchrotron, Notkestraße 85, 22607 Hamburg (Germany); Knoška, J. [Department of Physics, University of Hamburg, Luruper Chaussee 149, 22607 Hamburg (Germany); Wilde, F. [Helmholtz-Zentrum Geesthacht, Max-Planck-Straße 1, 21502 Geesthacht (Germany); Chapman, H. N. [Center for Free-Electron Laser Science, Deutsches Elektronen-Synchrotron, Notkestraße 85, 22607 Hamburg (Germany); Department of Physics, University of Hamburg, Luruper Chaussee 149, 22607 Hamburg (Germany); Centre for Ultrafast Imaging, Notkestraße 85, 22607 Hamburg (Germany)

    2015-12-15

    Serial femtosecond crystallography (SFX) using X-ray Free-Electron Lasers (XFELs) allows for room temperature protein structure determination without evidence of conventional radiation damage. In this method, a liquid suspension of protein microcrystals can be delivered to the X-ray beam in vacuum as a micro-jet, which replenishes the crystals at a rate that exceeds the current XFEL pulse repetition rate. Gas dynamic virtual nozzles produce the required micrometer-sized streams by the focusing action of a coaxial sheath gas and have been shown to be effective for SFX experiments. Here, we describe the design and characterization of such nozzles assembled from ceramic micro-injection molded outer gas-focusing capillaries. Trends of the emitted jet diameter and jet length as a function of supplied liquid and gas flow rates are measured by a fast imaging system. The observed trends are explained by derived relationships considering choked gas flow and liquid flow conservation. Finally, the performance of these nozzles in a SFX experiment is presented, including an analysis of the observed background.

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

    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

  2. SUPER POLYOLEFIN BLENDS ACHIEVED VIA DYNAMIC PACKING INJECTION MOLDING: MORPHOLOGY AND PROPERTIES

    Yong Wang; Bing Na; Qiang Fu

    2003-01-01

    As a long-term project aimed at developing super polyolefin blends, in this paper we summarize our work on the mechanical reinforcement and phase morphology of polyolefin blends achieved by dynamic packing injection molding (DPIM). The main feature of this technology is that the specimen is forced to move repeatedly in the model by two pistons that move reversibly with the same frequency during cooling, which results in preferential orientation of the dispersed phase as well as the matrix. The typical morphology of samples obtained via DPIM is a shear-induced morphology with a core in the center, an oriented zone surrounding the core and a skin layer in the cross-section areas. Shear-induced phase dissolution at a higher shear rate but phase separation at low shear rates is evident from AFM examination of LLDPE/PP (50/50) blends.The super polyolefin blends having high modulus (1.9-2.2 GPa), high tensile strength (100-120 MPa) and high impact strength (6 times as that of pure HDPE) have been prepared by controlling the phase separation, molecular orientation and crystal morphology.

  3. Foam injection molding of polypropylene/stainless steel fiber composites for efficient EMI shielding

    Ameli, A.; Nofar, M.; Saniei, M.; Wang, S.; Park, C. B.

    2016-03-01

    Lightweight polypropylene/stainless-steel fiber (PP-SSF) composites with 15-35% density reduction were fabricated using foam injection molding and supercritical carbon dioxide (CO2). The electrical percolation threshold, through-plane electrical conductivity, and electromagnetic interference (EMI) shielding effectiveness (SE) of the PP-SSF composite foams were characterized and compared against the solid samples. The effects of the plasticizing gas and the void fraction on fiber breakage and orientation were also investigated. Microstructure characterization showed that the presence of dissolved CO2 decreased fiber breakage by about 30%, and together with foaming action, contributed to less preferential orientation of fibers. Consequently, the percolation threshold decreased up to four folds from 0.85 to 0.21 vol.% as the void fraction increased from 0 to 35%. The specific EMI SE was also significantly enhanced. A maximum specific EMI SE of 75 dB.g-1cm3 was achieved in PP-1.1 vol.% SSF composite foams, which was highly superior to 38 dB.g-1cm3 of the solid PP-1.0 vol.% SSF composites. The results reveal that light and efficient products with a lower fiber content can be developed by foam for EMI shielding applications.

  4. MORPHOLOGY AND MECHANICAL PROPERTIES OF POLY(ETHYLENE-OCTENE) COPOLYMERS OBTAINED BY DYNAMIC PACKING INJECTION MOLDING

    Dong Liang; Li-juan Zhou; Qin Zhang; Feng Chen; Ke Wang; Hua Deng; Qiang Fu

    2012-01-01

    The morphology and mechanical properties of poly(ethylene-octene) copolymers (POE) obtained by dynamic packing injection molding were investigated by mechanical tests,differential scanning calorimetry (DSC),fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM).The mechanical tests found that only POE with low octene content and high molecular weight show apparent response for external shear field.Further investigation has been done by DSC,FT-IR,and SEM in order to make clear the reason of that phenomenon.Finally,the hypothetical mechanism of POE microstructure formation under shear field has been proposed.For POE with low octene content and high molecular weight,orientation degree and mechanical properties both increase substantially under shear field.For POE with low octene content and low molecular weight,orientation degree and crystallinity increase under shear field,but it is not dramatically benefit for the mechanical properties.For POE with high octene content and high molecular weight,the shear field has little effect on the morphology and mechanical properties.

  5. Silane based coating of aluminium mold

    2013-01-01

    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...

  6. Mechanical and Antibacterial Properties of Injection Molded Polypropylene/TiO2 Nano-Composites: Effects of Surface Modification

    Mirigul Altan; Huseyin Yildirim

    2012-01-01

    Polypropylene (PP)/titanium dioxide (TiO2) nano-composites were prepared by melt compounding with a twin screw extruder. Nanoparticles were modified prior to melt mixing with maleic anhydride grafted styreneethylene-butylene-styrene (SEBS-g-MA) and silane. The composites were injection molded and mechanical tests were applied to obtain tensile strength, elastic modulus and impact strength. Antibacterial efficiency test was applied on the injection molded composite plaques by viable cell counting technique. The results showed that the composites including SEBS-g-MA and silane coated TiO2 gave better mechanical properties than the composites without SEBS-g-MA. Antibacterial efficiency of the composites varied according to the dispersion and the concentration of the particles and it was observed that composites at low content of TiO2 showed higher antibacterial property due to the better photocatalytic activity of the particles during UV exposure.

  7. Wall-Slip of Highly Filled Powder Injection Molding Compounds: Effect of Flow Channel Geometry and Roughness

    Hausnerová, Berenika; Sanétrník, Daniel; Paravanová, Gordana

    2014-01-01

    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...

  8. Report on the 18th International Trade Fair of Plastics & Rubber (K2010)——New Technologies for Injection Molding%第十八届国际塑料及橡胶展览会特别报道(K2010)——注射成型新技术

    杨卫民; 王小华; 谢鹏程

    2011-01-01

    On the 18th International Trade Fair of Plastics & Rubber (K2010), global injection molding leading enterprises displayed the latest injection molding technologies and machines,including fully electric injection molding machines, electro-hydraulic injection molding machines,large-scale injection molding machines, micro-injection molding machines, control systems with extended function, etc. The injection molding technologies are developed towards energy-saving,high precision, high efficiency and environmentally-friendly. Total solution with highly integrated and automated characteristics becomes the mainstream of plastics injection molding industry.Development of this solution continuously broadens the applications of injection molding process in packaging, medical and automobile fields.%综述了第十八届杜塞尔多夫国际塑料及橡胶展览中全球各大企业展示的最新注射成型技术及设备.注射成型新设备主要包括全电动注射成型设备、电液混合驱动新设备、大型注射成型设备、微型注射成型设备、扩展功能的控制系统等.塑料注射成型技术正向着节能、精密、高效、环保的方向发展,以产品为中心的高度集成化、自动化的总体解决方案成为行业主流,其在包装行业、医疗行业、汽车行业等领域的应用不断拓宽.

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

    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.

  10. Multi-Objective Optimization Design for Injection Molding Process of Plastic Parts Based on Sequence-Valve%基于顺序阀的塑料制件注塑工艺的多目标优化设计

    朱成兵; 李金国; 刘红

    2013-01-01

    Taking a car dashboard for example,gating system and cooling systen of the hot runner sequential-valve for the dashboard are designed.Orthogonal optimization experimental method and simulation analysis software Moldflow were adapted.Weld line and warpage value,the two main indexes which affect the moulding quality of dashboard,are simulated and optimized in different sequence-valve opening time and process parameters.By range analysis of this two indexes,the degree of influence caused by open time,melt temperature,packing pressure and packing time of each sequence-valve on weld line and warpage value is determined.Using the integrated balance method,finally the best opening time and combination process parameters are achieved.Test results show that there are no obvious weld line on surface of parts,and warpage value meets the assembly requirements.%以某汽车仪表盘为例,设计了仪表盘的热流道顺序阀浇注系统和冷却系统.运用正交优化试验法结合Moldflow模拟分析软件,在不同顺序阀的开启时间和工艺参数条件下,对影响仪表盘注射成型质量的熔接痕和翘曲值标进行模拟优化,通过对这2个指标的极差分析,确定各顺序阀的开启时间和熔体温度、保压压力、保压时间对熔接痕和翘曲值的影响程度,并运用综合平衡法,综合评判最终获取最佳阀开启时间和组合工艺参数.试模结果表明,制件表面无明显熔接线且翘曲值符合装配要求.

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

    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

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

    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

  13. Optimization of Injection Molding Parameters for HDPE/TiO2 Nanocomposites Fabrication with Multiple Performance Characteristics Using the Taguchi Method and Grey Relational Analysis

    Hifsa Pervez

    2016-08-01

    Full Text Available The current study presents an investigation on the optimization of injection molding parameters of HDPE/TiO2 nanocomposites using grey relational analysis with the Taguchi method. Four control factors, including filler concentration (i.e., TiO2, barrel temperature, residence time and holding time, were chosen at three different levels of each. Mechanical properties, such as yield strength, Young’s modulus and elongation, were selected as the performance targets. Nine experimental runs were carried out based on the Taguchi L9 orthogonal array, and the data were processed according to the grey relational steps. The optimal process parameters were found based on the average responses of the grey relational grades, and the ideal operating conditions were found to be a filler concentration of 5 wt % TiO2, a barrel temperature of 225 °C, a residence time of 30 min and a holding time of 20 s. Moreover, analysis of variance (ANOVA has also been applied to identify the most significant factor, and the percentage of TiO2 nanoparticles was found to have the most significant effect on the properties of the HDPE/TiO2 nanocomposites fabricated through the injection molding process.

  14. 注射模型腔强度计算%Strength Calculation of Injection Mold Cavity

    陶永亮; 刘昌华

    2012-01-01

    大型塑料模具型腔侧壁强度是模具设计中的一项重要工作。通过对蓄电池槽模具型腔受力分析,根据模具型腔的强度,危险截面校核,变形量验证等进行了计算,对型腔设计中不足之处,提出了型腔凹模锁模块结构设计,能防止型腔的变形,并进行了验证,保证了模具型腔设计的安全、可靠、经济。%Large plastic mold cavity wall strength is in the design of die an important job. Through to the battery tank mold cavity stress analysis, according to the strength of the mold cavity, check the dangerous section, validation of deformation calculation, in the design of cavity deficiency, Put forward the concave mold cavity lock module structure, can prevent deformation of the cavity, and to the test, for the mold cavity design, ensure that the design of the mold safe, reliable, economic.

  15. Camera Cover Injection Mold Design Based on Pro/E-EMX%基于Pro/E-EMX的摄像头盖注塑模设计

    黄薇; 葛正浩; 刘韦华; 陈伟博

    2011-01-01

    Aiming at the structure and characteristics of the camera cover,the 3D design of injection mold had been carried out based on Pro/Engineer 4.0 and EMX 5.0 platform. Using the unique mold design module in pro/E software.combined with Plastic Advisor to conduct the simulation of plastic flow process, it could effectively prevent or reduce the molding defects of plastic parts,shorten design cycle and reduce costs.%针对摄像头盖的结构和特点,以Pro/Engineer 4.0及EMX 5.0软件为平台对其进行了注塑模的3D设计.利用Pro/E软件中特有的模具设计模块,并结合Plastic Advisor(塑料顾问)模拟塑料流动过程,可以有效地防止或降低塑件的成型缺陷,大大缩短设计周期,降低成本.

  16. Tool steel quality and surface finishing of plastic molds

    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.

  17. 注塑成型工艺参数对PP塑料梳成型缺陷的影响研究%EFFECT OF INJECTION MOLDING PARAMETERS ON THE MOLDING DEFECTS OF PLASTIC COMB OF PP

    陈叶娣

    2011-01-01

    针对聚丙烯(PP)塑料梳的主要成型缺陷,分析了缺陷产生的原因,然后根据现有条件主要通过调整PP塑料梳的注射成型工艺参数消除了缺陷,为解决类似制品的成型缺陷提供一定的借鉴.%According to the main injection molding defects of plastic comb of PP, the causes of the defects were analyzed.Then the defects were eliminated by mainly adjusting injection molding parameters of plastic comb of PP according to the current conditions and this could provide some references for solving injection molding defects of similar plastic parts.

  18. Selected Issues Concerning Degradation of Material in the Production of Injection Molded Plastic Components

    Jałbrzykowski Marek

    2016-09-01

    Full Text Available This paper presents the problem of thermal degradation of thermoplastic materials processed using the injection method. Attention was paid to the issue of the optimal selection of a dye for modifying the base materials. For the selected materials and dyes, derivatograph tests were performed in order to assess their thermal characteristics and breakdown kinetics. Additionally, tribological tests and microscope observations of selected samples were performed. The obtained test results suggest a diverse level of thermal processes in the analyzed materials. This is crucial for the appropriate selection of dyes for plastic materials. As it turned out, the tribological properties of materials can also influence the technological quality of the injected alloy.

  19. Numerical simulation on weld line development of injection molding in mold cavity with inserts%带嵌件型腔内熔接过程的数值模拟研究∗

    李强; 李五明

    2016-01-01

    A gas-liquid two-phase model for a viscoelastic fluid is proposed and used to simulate and predict the behavior of melt welding in injection molding process, in which the extended pom-pom (XPP) model and cross-WLF viscosity model combined with Tait state equation are used to describe the constitutive relationship and viscosity change of the viscoelastic melt in this paper, respectively. Meanwhile, the coupled level-set and volume-of-fluid (CLSVOF) method is employed to capture the melt front, and the immersed boundary method is applied to the simulation of the polymer melt flows with the aid of a shaped level-set function to describe and treat the irregular mold cavities. A finite volume method on non-staggered grid is used to solve the mass, momentum, and energy conservation equations. Firstly, the benchmark problem of the single shear flow is simulated to verify the validity of the CLSVOF method. Then, the non-isothermal filling process of the viscoelastic fluid based on the XPP model in a mold with square inset is simulated, and the behavior of the weld line devolopment in the filling process is shown and compared with the experimental result. Finally, it is to simulate the evolution processes of the melt front interface and weld line in a mold with the circular notched inset;and the linear stress-optical rule is adopted to calculate the flow-induced birefringence. Numerical results show that the numerical model proposed in this paper can be employed to simulate the non-isothermal filling process in complex mold cavity and to capture the weld line automatically. Because of the complexity of polymer melt flows, the flow-induced stress increases quickly near the weld line region and then decreases gradually until reaching the mold cavity wall. The maximum value of the flow-induced stress appears at some point after the insert. The distributions of physical quantities, such as pressure and temperature in the mold, are given during the mold filling process. Moreover

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

    Chang Lizhong; Shi Xiaofang; Wang Runxi; Cong Junqiang; Li Tao

    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 smal er than 1 μm in size increase from 38% to 41.4%, whereas that of the SiO2 inclusions increases from 48% to 74% in the ingots when mold rotation is applied. This phenomenon is caused by the decrease in metal droplet size, resulting in large contact area between the slag pool and metal droplets in ESR process with mold rotation. Moreover, the metal droplets have relatively long movement routes, leading to long metal contact time between the slag pool and metal droplets when a relative motion between the consumable electrodes and mold is present. However, when the mold rotation rate is increased to 45 r·min-1, inclusion removing effect decreases. An excessive rotation rate causes wild motion in the slag pool, which drives the molten metal droplets to move violently, and as a result, the slag is entrapped into the metal pool, decreasing the ability of slag absorbing inclusions.

  1. Predictive engineering tools for injection-molded long-carbon-fiber thermoplastic composites - FY 2015 third quarterly report

    Nguyen, Ba Nghiep [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Fifield, Leonard S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Mori, Steven [MAGNA Exteriors and Interiors Corp. Aurora, ON (Canada); Gandhi, Umesh N. [Toyota Research Institute North America, Ann Arbor, MI (United States); Wang, Jin [Autodesk, Inc., Ithaca, NY (United States); Costa, Franco [Autodesk, Inc., Ithaca, NY (United States); Wollan, Eric J. [PlastiComp, Inc., Winona, MN (United States); Tucker, III, Charles L. [Univ. of Illinois at Urbana-Champaign, Urbana, IL (United States)

    2015-07-01

    During the third quarter of FY 2015, the following technical progress has been made toward project milestones: 1) Magna oversaw the tool build and prepared the molding plan for the complex part of Phase II. 2) PlastiComp hosted a visit by Magna and Toyota on April 23rd to finalize the molding scope and schedule. The plan for molding trials including selection of molding parameters for both LFT and D-LFT for the U-shape complex part was established. 3) Toyota shipped the U-shape complex part tool to Magna on May 28th, 2015. 4) Plasticomp provided 30wt% LCF/PP and 30wt% LCF/PA66 compounded pellets to Magna for molding the complex part. 5) Magna performed preliminary molding trials on June 2nd, 2015 to validate wall thickness, fill profile, tool temperature and shot size requirements for the complex part. 6) Magna performed the first complex part run on June 16th and 17th, 2015 at Magna’s Composite Centre of Excellence in Concord, ON, Canada. Dale Roland of Plasticomp, and Umesh Gandhi of Toyota also attended the molding. 7) Magna discussed and finalized the plan with PNNL and the team for cutting samples from molded parts at selected locations for fiber orientation and length measurements. 8) Magna provided the computer-aided design (CAD) files of the complex parts with and without ribs to PNNL and Autodesk to build the corresponding ASMI models for injection molding simulations. Magna also provided the actual parameters used. 9) Plasticomp’s provided knowledge and experience of molding LCF materials essential to the successful molding of the parts including optimization of fill speed, tool temperatures, and plasticizing conditions for the 30wt% LCF/PP and 30wt% LCF/PA66 materials in both rib and non-rib versions. 10) Magna molded additional parts for evaluation of mechanical property testing including torsional stiffness on June 29th and 30th, 2015 at Magna’s Composite Center of Excellence. 11) Toyota began preparation for the torsion test of the specimens

  2. 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

    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

  3. Study on Numerical Simulation of Mold Filling and Solidification Processes under Pressure Conditions

    2002-01-01

    The mold filling and solidification simulation for the high pressure die casting (HPDC) and Iow pressure die casting(LPDC) processes were studied. A mathematical model considering the turbulent flow and heat transfer phenomenonduring the HPDC process has been established and parallel computation technique was used for the mold fillingsimulation of the process. The laminar flow characteristics of the LPDC process were studied and a simplified modelfor the mold filling process of wheel castings has been developed. For the solidification simulation under pressureconditions, the cyclic characteristics and the complicated boundary conditions were considered and techniques toimprove the computational efficiency are discussed. A new criterion for predicting shrinkage porosity of Al alloy underIow pressure condition has been developed in the solidification simulation process.

  4. Influence of binder composition on the rheological behavior of injection-molded microsized SiC suspensions

    Shubin Ren; Xinbo He; Xuanhui Qu; Islam S. Humail; Yanping Wei

    2008-01-01

    The influence of four kinds of binders consisting of paraffin wax (PW), random-polypropylene (RPP), high-density poly-ethylene (HDPE), and stearic acid (SA) on the theological behavior of injection-molded SiC feedstocks was investigated over a tem-perature range of 150℃ to 180℃ and a shear rate range of 4 s-1 to 1259 s-1. The results showed that all the feedstocks exhibited pseudoplastic flow behavior. The wax-based binder of multipolymer components (PW-RPP-HDPE) exhibited better comprehensive rheological properties compared with the binder of monopolymer components (PW-RPP or PW-HDPE). The addition of 5wt% SA to the binder could reduce the viscosity of the feedstock but enhance the rbeological stability by improving the wettability between the binder and the SiC powder. The binder of 65wt% PW + 15wt% HDPE + 15wt% RPP + 5wt% SA was found to be a better binder for microsized SiC injection molding.

  5. Numerical simulation of fiber interaction in short-fiber injection-molded composite using different cavity geometries

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

    2016-03-01

    The theoretical fiber-interaction model for calculating the fiber orientation in the injection molded short fiber/thermoplastic composite parts was proposed. The proposed model included the fiber dynamics simulation in order to obtain an equation of the global interaction coefficient and accurate estimate of the fiber interacts at all orientation states. The steps to derive the equation for this coefficient in short fiber suspension as a function of the fiber aspect ratio, volume fraction and general shear rate are delineated. Simultaneously, the high-resolution 3D X-ray computed tomography system XVA-160α was used to observe fiber distribution of short-glass-fiber-reinforced polyamide specimens using different cavity geometries. The fiber orientation tensor components are then calculated. Experimental orientation measurements of short-glass-fiber-reinforced polyamide is used to check the ability of present theory for predicting orientation. The experiments and predictions show a quantitative agreement and confirm the basic understanding of fiber orientation in injection-molded composites.

  6. EFFECT OF COMPATIBILITY ON PHASE MORPHOLOGY AND ORIENTATION OF ISOTACTIC POLYPROPYLENE (IPP) BLENDS OBTAINED BY DYNAMIC PACKING INJECTION MOLDING

    Jiang Li; Qin Zhang; Cong Wang; Hong Yang; Rong-ni Du; Qiang Fu

    2006-01-01

    The effect of compatibility on phase morphology and orientation of isotactic polypropylene (iPP) blends under shear stress was investigated via dynamic packing injection molding (DPIM). The compatibility of iPP blended with other polymers, namely, atactic polypropylene (aPP), octane-ethylene copolymer (POE), ethylene-propylene-diene rubber (EPDM)and poly(ethylene-co-vinyl acetate) (EVA), have first been studied using dynamic mechanical analysis (DMA). These blends were subjected to DPIM, which relies on the application of shear stress fields to the melt/solid interfaces during the packing stage by means of hydraulically actuated pistons. The phase morphology, orientation and mechanical properties of the injection-molded samples were characterized by SEM, 2D WAXS and Instron. For incompatible iPP/EVA blends, a much elongated and deformed EVA particles and a higher degree of iPP chain orientation were observed under the effect of shear.However, for compatible iPP/aPP blends, a less deformed and elongated aPP particles and less oriented iPP chains were deduced. It can be concluded that the compatibility between the components decreases the deformation and orientation in the polymer blends. This is most likely due to the hindering effect, resulting from the molecular entanglement and interaction in the compatible system.

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

    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

  8. Synchrotron X-ray studies on polyamide composites prepared by reactive injection molding

    Dencheva, Nadya Vasileva; Sampaio Ana Sofia; Oliveira, F. M.; Silva, Cátia Rodrigues da; Ferdov, S.; Pouzada, A. S.; Brito, A. M.; Rocha, A. M.; Denchev, Z.; Funari, S.S.

    2014-01-01

    Semicrystalline polyamide 6 (PA6) and composites on its basis are among the most frequently used polymer materials for highly demanding applications. The performance of these composites depends on the crystalline structure of the PA6 matrix in which two crystalline forms most frequently coexist: α- and γ-polymorphs. This work reports on the crystalline structure of a variety of composite materials produced by in-mold reactive polymerization of caprolactam in specially designed semi-automatic ...

  9. Fabrication of microlens arrays by a rolling process with soft polydimethylsiloxane molds

    In this paper, we present a new roll-to-roll method to fabricate visible light transparent microlens arrays on a glass substrate by using soft and cost-effective polydimethylsiloxane (PDMS) molds. First, we fabricated microlens array master molds by photoresist thermal reflow processes on silicon substrates. We then transferred the pattern to PDMS molds by a spin coater. After making the PDMS molds, we used a two-wheel roll-to-roll printing machine to replicate ultraviolet resin microlens arrays on glass substrates. The PDMS molds can be made easily at a low cost compared with traditional electroplating metal molds. We studied the quality of microlens arrays that were replicated by different rolling pressures of 20, 200 and 500 N cm−2. We also identified the relation between the pressure and the shape of the microlens arrays. The results showed that the best yield rate and replication performance were achieved with a pressure of approximately 200 N cm−2 and 4 min of ultraviolet light exposure

  10. Rapid prototyping of biodegradable microneedle arrays by integrating CO2 laser processing and polymer molding

    Tu, K. T.; Chung, C. K.

    2016-06-01

    An integrated technology of CO2 laser processing and polymer molding has been demonstrated for the rapid prototyping of biodegradable poly-lactic-co-glycolic acid (PLGA) microneedle arrays. Rapid and low-cost CO2 laser processing was used for the fabrication of a high-aspect-ratio microneedle master mold instead of conventional time-consuming and expensive photolithography and etching processes. It is crucial to use flexible polydimethylsiloxane (PDMS) to detach PLGA. However, the direct CO2 laser-ablated PDMS could generate poor surfaces with bulges, scorches, re-solidification and shrinkage. Here, we have combined the polymethyl methacrylate (PMMA) ablation and two-step PDMS casting process to form a PDMS female microneedle mold to eliminate the problem of direct ablation. A self-assembled monolayer polyethylene glycol was coated to prevent stiction between the two PDMS layers during the peeling-off step in the PDMS-to-PDMS replication. Then the PLGA microneedle array was successfully released by bending the second-cast PDMS mold with flexibility and hydrophobic property. The depth of the polymer microneedles can range from hundreds of micrometers to millimeters. It is linked to the PMMA pattern profile and can be adjusted by CO2 laser power and scanning speed. The proposed integration process is maskless, simple and low-cost for rapid prototyping with a reusable mold.

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

    Nguyen, Ba Nghiep [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Fifield, Leonard S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Mathur, Raj N. [PlastiComp, Inc., Winona, MN (United States); Kijewski, Seth A. [Purdue Univ., West Lafayette, IN (United States); Sangid, Michael D. [Purdue Univ., West Lafayette, IN (United States); Wang, Jin [Autodesk, Inc., Ithaca, NY (United States); Jin, Xiaoshi [Autodesk, Inc., Ithaca, NY (United States); Costa, Franco [Autodesk, Inc., Ithaca, NY (United States); Gandhi, Umesh N. [MAGNA Exteriors and Interiors Corp, Aurora, ON (Canada); Mori, Steven [Univ. of Illinois, Champaign, IL (United States); Tucker, III, Charles L.

    2014-09-30

    extract machine purgings (purge materials) from Magna’s 200-Ton Injection Molding machine targeted to mold the complex part. 11) Toyota and Magna discussed with PNNL tool modification for molding the complex part.

  12. 注塑模具厂虚拟布局设计与仿真%Virtual Layout Design and Simulation of Injection Mold Factory

    张冬芹; 祁文军; 孙文磊; 邱清烨

    2012-01-01

    研究传统的设施布置方法——系统布置设计(SLP)和现代物流仿真技术,利用系统布置设计法分析注塑模具厂的工艺及物流,完成工厂总平面布置设计;再利用计算机仿真技术对模具车间的典型作业流程进行建模仿真,使设施布置设计方案可视化,根据仿真结果,分析可能产生的瓶颈问题,对方案进行系统优化.%The traditional facility layout method-SLP (systematic layout planning) and modern logistics simulation technology were researched. The SLP method was used to analyze the process and logistics of injection mold factory to complete the total plant layout design. Then computer simulation technology was used to achieve modeling and simulation for typical processes of mold workshop to realize visualization of facilities layout design scheme. Probable bottlenecks in production was analyzed by the simulation results, therefore the systematic optimization of the scheme was realized.

  13. Unsaturated and Saturated Flow Front Tracking in Liquid Composite Molding Processes using Dielectric Sensors

    Carlone, P.; Palazzo, G. S.

    2015-10-01

    Liquid composite molding processes are manufacturing techniques involving the impregnation and saturation of dry fibrous preforms by means of injection or infusion of catalyzed resin systems. Complete wetting of the reinforcement and reduction of voids are key issues to enhance mechanical properties of the final product, as a consequence on line monitoring and control of resin flow is highly desirable to detect and avoid potentialbet macro- as well as micro-voids. In this paper, parallel-plate dielectric sensors were investigated to track the position of unsaturated as well as saturated flow fronts through dual scale porous media. Sensors configuration was analyzed and improved via electromagnetic (EM) finite element simulations. The effectiveness of the proposed system was assessed in one-dimensional impregnation tests. Good agreement was found between unsaturated front positions provided by the considered system and acquired through conventional visual techniques. An indirect verification strategy, based on CFD and EM simulations of the process, was applied to investigate the reliability of dielectric sensors with respect to saturation phenomena. Obtained outcomes highlighted the intriguing capabilities of the proposed method.

  14. The Effect of Dewaxing and Burnout Temperature in Block Mold Process for Copper Alloy Casting

    S.Z. Mohd Nor

    2015-10-01

    Full Text Available The main objective of this research is to investigate the effect of dewaxing and burnout temperature on the quality of copper alloy casting produced by a low cost block mold that has been developed. In the molding process, two types of silica sand which contains 97.9% silica (SiO2 and 97.2% silica have been used as a refractory material with POP served as a binder. Several mold formulations contained 15-40% plaster of paris (POP, 60-85% silica sand and 35% water had been developed and each formulation had been tested in the process of copper alloy casting. In the dewaxing process, the temperature of 170oC was found appropriate to be used as an initial mold heating temperature and complete wax burnout was effectively achieved with the temperature of 750oC for 5 hours. The insufficient burnout process has produced a defect casting with carbon residue, appeared as a black stain on the surface of the casting. Meanwhile, rapid initial heating had prevented the wax from flowing out smoothly thus, eroded the surface of the mold cavities. This has resulted in deteriorated cavity surface, hence a rough surface of the casting.

  15. Mold Simulator Study of the Initial Solidification of Molten Steel in Continuous Casting Mold. Part I: Experiment Process and Measurement

    Zhang, Haihui; Wang, Wanlin; Ma, Fanjun; Zhou, Lejn

    2015-10-01

    A mold simulator has been successfully used to study the initial solidification behavior of the molten low carbon steel. Coupled with 2D-IHCD calculation and PSD analysis, the variations of the responding temperatures and heat fluxes, as well as the relationship between shell surface profile, heat flux, shell thickness, mold level fluctuation, and the infiltrated slag film, were investigated in this article. The results suggested that the mold high-frequency temperatures and heat fluxes above liquid steel level vary with the oscillation of the mold, and show an opposite variation pattern as those below the shell tip. The formed shell surface profile is directly correlated to the variation of high-frequency heat fluxes, where the formation of oscillation mark is associated with a sudden increase of the heat flux during negative strip time. Mold level fluctuation contributes to the formation of the extra oscillation marks. The growth of shell thickness follows the square root law, and the instantaneous solidification factor is large near the shell tip and becomes small in the area where the deep shell surface depression is formed. The thickness of the slag film in between mold and shell is in the range of 1.4 to 2.46 mm, and the crystallization of mold flux in mold/shell gap is dynamic.

  16. Study on Numerical Simulation of Mold Filling and HeatTransfer in Die Casting Process

    2000-01-01

    A 3-D mathematical model considering turbulence phenomena has been established basedon a computational fluid dynamics technique, so called 3-D SOLA-VOF (Solution Algorithm-Volume of Fluid), to simulate the fluid flow of mold filling process of die casting. In addition, the mathematical model for simulating the heat transfer in die casting process has also been established.The computation program has been developed by the authors with the finite difference method (FDM) recently. As verification, the mold filling process of a S-shaped die casting has been simulated and the simulation results coincide with that of the benchmark test. Finally, as a practical application, the gating design of a motorcycle component was modified by the mold filling simulation and the dies design of another motorcycle component was optimized by theheat transfer simulation. All the optimized designs were verified by the production practice.

  17. Influence of Hygrothermal Aging on Poisson’s Ratio of Thin Injection-Molded Short Glass Fiber-Reinforced PA6

    Thomas Illing

    2016-05-01

    Full Text Available The hygrothermal aging of short glass fiber-reinforced polyamide 6 materials (PA6 GF represents a major problem, especially in thin-walled components, such as in the automotive sector. In this study, therefore, the thickness and the glass fiber content of PA6 GF materials were varied and the materials were exposed to hygrothermal aging. The temperature and relative humidity were selected in the range from −40 °C up to 85 °C, and from 10% up to 85% relative humidity (RH. In the dry-as-molded state, the determined Poisson’s ratio of the PA6 GF materials was correlated with the fiber orientation based on computer tomography (MicroCT data and shows a linear dependence with respect to the fiber orientation along and transverse to the flow direction of the injection molding process. With hygrothermal aging, the value of Poisson’s ratio increases in the flow direction in the same way as it decreases perpendicular to the flow direction due to water absorption.

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

    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.

  19. Moldflow与UG软件在收音机外壳注塑模具设计中的应用%Application of Moldflow and UG Software in Injection Mold Design for Radio Shell

    李金峰

    2015-01-01

    以收音机外壳的注塑模具设计为实例,利用Moldflow软件进行注塑成型分析。并根据分析结果,利用UG软件对收音机外壳注塑模具结构设计。这种设计方法减少了试模次数,降低了开发成本。%Taking an example for the radio shell ,Moldflow software is used to analyze the injection molding process. According to the simulation analysis results ,injection mold is designed by UG software. This method can reduce the number of trial and production costs.

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

    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

  1. Injection Mold Parts Analysis Based on Moldflow%基于Moldflow软件的注塑模件分析

    2013-01-01

    This article using Moldflow software powerful simulation analysis capabilities, visualization capabilities and project management capabilities, to develop and utilize water-saving drip irrigation dripper mold. Moldflow software is used to analyze the dripper gate position,the clamping force,the molding process parameters to achieve the purpose of the rapid development of inserts drippers mold. Using the software can save a lot of manpower and resources,reduce waste of resources,reduce product costs,shorten product development cycles, respond quickly to market demand, and improve the innovative capability and competitiveness of the enterprises.%  利用Moldflow软件具有的强大模拟分析功能、可视化功能和项目管理功能,对节水滴灌用內镶式滴头模具的开发利用。通过Moldflow软件分析滴头浇口位置、锁模力、成型工艺等相关参数,达到快速开发內镶式滴头模具的目的。利用该软件可以节约大量的人力物力,减少资源的浪费,降低产品成本,缩短产品的开发周期,快速响应市场需求,提高企业的创新能力和竞争力。

  2. Use of a Naphthalene-Based Binder in Injection Molding Net-Shape Titanium Components of Controlled Porosity

    Weil, K. Scott; Nyberg, Eric A.; Simmons, Kevin L.

    2005-07-01

    We have recently developed a naphthalene-based binder system for use in powder injection molding (PIM) of ceramic and metallic materials. The use of a binder that can be removed via sublimation offers several unique advantages relative to the typical thermoplastic and/or thermoset binders employed in PIM. One of these is that essentially no volume change takes place during debindering. This offers a relatively facile method of introducing porosity into a net-shape part of potentially complex geometry. In the study described in this paper, the effects of powder loading and subsequent isostatic compaction on the size and amount of porosity in the components produced by this technique were investigated. In general, it was found that the amount of porosity is inversely proportional to the initial concentration of metal powder in the PIM feedstock. Likewise, average pore size displays a similar relationship with powder loading.

  3. Comparison of peri-implant bone formation around injection-molded and machined surface zirconia implants in rabbit tibiae.

    Kim, Hong-Kyun; Woo, Kyung Mi; Shon, Won-Jun; Ahn, Jin-Soo; Cha, Seunghee; Park, Young-Seok

    2015-01-01

    The aim of this study was to compare osseointegration and surface characteristics of zirconia implants made by the powder injection molding (PIM) technique against those made by the conventional milling procedure in rabbit tibiae. Surface characteristics of 2 types of implants were evaluated. Sixteen rabbits received 2 types of external hex implants with similar geometry, either machined zirconia implants or PIM zirconia implants, in the tibiae. Removal torque tests and histomorphometric analyses were performed. The roughness of the PIM zirconia implants was higher than that of machined zirconia implants. The PIM zirconia implants exhibited significantly higher bone-implant contact and removal torque values than the machined zirconia implants (pmold etching technique, can produce substantially rougher surfaces on zirconia implants. PMID:26235717

  4. Influence of the Compacts Homogeneity on the Incidence of Cracks during Thermal Debinding in Ceramic Injection Molding

    Xianfeng Yang; Zhipeng Xie; Yong Huang

    2009-01-01

    During thermal debinding in ceramic injection molding, the inhomogeneity of green body is a key origin of cracks. In this study, the impact of low molecular weight binders on the homogeneity of the green body was investigated. Incidence of cracks during thermal debinding indicated that the volume ratio of wax to stearic acid should be out of high viscosity and incompletely wetting region. In these two formulation regions,typical inhomogeneous microstructures were observed. By mercury intrusion method, it was shown that pore size distribution of the debinded compacts was determined by thermal degradation of low molecular weight binders. A particle-rich region model was established to predict the nucleation of cracks caused by solid loading fluctuation. The criterion of cracks nucleation was that local capillary force from solid loading fluctuation was larger than the suction force from the surroundings.

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

    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

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

    Hopmann, Ch.; Rasche, S.; Windeck, C. [Institute of Plastics Processing at RWTH Aachen University (IKV) Pontstraße 49, 52062 Aachen (Germany)

    2015-05-22

    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.

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

    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

  8. Influencing Factors for the Microstructure and Mechanical Properties of Micro Porous Titanium Manufactured by Metal Injection Molding

    Zhen Lu

    2016-04-01

    Full Text Available Porous titanium is a new structural and functional material. It is widely used in many fields since it integrates the properties of biomaterials with those of metallic foam. A new technology that combines both the preparation and forming of porous materials has been proposed in this paper. Moreover, a new solder was developed that could be employed in the joining of porous materials. Influencing factors for microstructure and mechanical properties of the parent material and joint interface are identified. Metal injection molding (MIM technology was used for fabricating porous materials. The feedstock for injection molding of porous titanium powders was prepared from titanium powders and a polymer-based binder system. In addition, the proportion of powder loading and binders was optimized. Through MIM technology, a porous titanium filter cartridge was prepared. For the purpose of investigating the thermal debinding technology of the filter cartridge, effects of the sintering temperature on the porosity, morphology of micropores and mechanical properties were analyzed. It could be found that when the sintering temperature increased, the relative density, bending and compression strength of the components also increased. Moreover, the porosity reached 32.28% when the sintering temperature was 1000 °C. The microstructure morphology indicated that micropores connected with each other. Meanwhile, the strength of the components was relatively high, i.e., the bending and compression strength was 65 and 60 MPa, respectively. By investigating the joining technology of porous filter cartridges, the ideal components of the solder and pressure were determined. Further research revealed that the micropore structure of the joint interface is the same as that of the parent material, and that the bending strength of the joint interface is 40 MPa.

  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

    Adriane Bassani

    2005-07-01

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

    Tanzi, Simone; Østergaard, Peter Friis; Matteucci, Marco;

    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...

  11. 基于ANSYS Workbench的注胚模腔疲劳寿命研究%Research of Fatigue Life for Injection Molding Cavity Based on ANSYS Workbench

    胡青春; 宋珂; 姜晓平

    2012-01-01

    注胚模具成型聚对苯二甲酸乙二醇酯(PET)瓶坯的一个成型周期分为注塑、保压、冷却阶段,模具受循环载荷影响,其关键零件模腔易出现疲劳破坏.应用ANSYS Workbench (AWB)建立模腔有限元模型,运用传热学理论,完成模腔一个工作周期的温度场,位移场及热应力场的仿真模拟,获得疲劳寿命云图,为注塑模具零件优化设计提供依据.%Embryo injection molding PET perform molding cycle was divided into injection, pressure maintaining and cooling. Influenced by cyclic loading, cavity was prone to have fatigue damage. An analysis method of injection molding cavity fatigue based on ANSYS Workbench (AWB) was proposed to established finite element model of the cavity. A simulation of temperature field, displacement, and thermal stress field and fatigue life for the cavity of a work cycle based on heat transfer theory was completed which provided the basis for the optimization design of the injection mold.

  12. Compensation Method for Die Shift Caused by Flow Drag Force in Wafer-Level Molding Process

    Simo Yeon

    2016-05-01

    Full Text Available Wafer-level packaging (WLP is a next-generation semiconductor packaging technology that is important for realizing high-performance and ultra-thin semiconductor devices. However, the molding process, which is a part of the WLP process, has various problems such as a high defect rate and low predictability. Among the various defect factors, the die shift primarily determines the quality of the final product; therefore, predicting the die shift is necessary to achieve high-yield production in WLP. In this study, the die shift caused by the flow drag force of the epoxy molding compound (EMC is evaluated from the die shift of a debonded molding wafer. Experimental and analytical methods were employed to evaluate the die shift occurring during each stage of the molding process and that resulting from the geometrical changes after the debonding process. The die shift caused by the EMC flow drag force is evaluated from the data on die movements due to thermal contraction/expansion and warpage. The relationship between the die shift and variation in the die gap is determined through regression analysis in order to predict the die shift due to the flow drag force. The results can be used for die realignment by predicting and compensating for the die shift.

  13. Injection Mold Design with Thread Rotating Demoulding Mechanism of Plastic Part with Internal Thread%螺纹旋转脱模内螺纹塑件注塑模设计

    王成

    2013-01-01

    The injection mold with thread rotating demoulding mechanism was designed by taking acrylonitrile-butadiene -styrene plastic bottle cap as example. Without external unscrewing power plant attached to the mold, the plastic part can be automatically rotating demoulded by using opening force of the injection molding machine, so the problems of time-consuming being long and plastic part thread being scuffed when thread was demoulded were solved and the quality of the plastic part was ensured. The gating system, small rod limitting structure and thread rotating demoulding mechanism were designed and analyzed, the overall structure, working process of the mold and demoulding step exploded view were introduced also. The mold has the advantages of simple, compact structure and small size, is suitable for large-scale production.%以ABS塑料瓶盖为例,设计了螺纹旋转脱模内螺纹塑件注塑模.该模具无需外接脱螺纹动力装置,利用注塑机的开模力实现塑件自动旋转脱模顶出,保证了内螺纹塑件的质量,解决了现有技术中螺纹脱模耗时、易拉伤塑件螺纹的问题.对浇注系统、小拉杆限位结构、螺纹旋转脱模结构等进行了设计分析,介绍了模具的整体结构和开、合模工作过程及脱模步骤分解图.该模具结构简单、紧凑、体积小,适用于大批量生产.

  14. Interface conditions of two-shot molded parts

    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

  15. Interface conditions of two-shot molded parts

    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.

  16. 汽车内饰卡扣双物料注射成型模具设计%DESIGN OF TWO MATERIAL INJECTION MOLD FOR SNAP-FIT

    林楷; 陈绮丽; 张婧婧; 敖敬培; 张志添

    2011-01-01

    The two material injection mould process and the structure features of snap-fit were introduced, the mould was designed. In this mould, some special structures, such as delayed mold core pulling, ejection mechanism in order, and hot runner system combined with the general structure of gating system in second injection were used to solve the problem of rotation for cavity. This mould design would improve the bond strength of the two kinds of material and improve the productivity.%介绍双物料多模注射成型工艺及分析汽车卡扣的结构特点,并根据汽车卡扣的结构特点设计了双物料注射成型模具.针对双物料多模注射成型工艺“旋转换腔”的难点,采用延时抽芯和顺序开模机构,二次注射浇注系统采用热流道与普通浇注系统相结合的结构.该模具设计能够较好地改善两种物料的粘结强度、提高生产率.

  17. Optimization of Injection Mold Gate Location of Auto Parts Based on MoldFlow%基于MoldFlow的汽车配件注射模的浇口位置优化

    冯桂香; 金叶明; 蒋飞龙

    2012-01-01

    Based on the analysis of examples to illustrate how to use the professional moldFlow analysis software MoldFlow solve real production problems in the gate location optimization, using MoldFlow software can be detected early in the design stage of the defective product and mold design, timely amendment to optimize designed to ensure the molding quality, shorten the construction period and reduce costs.%通过对实例的分析,说明如何运用专业模流分析软件MoldFlow解决实际生产中浇口位置优化的问题,利用MoldFlow软件能在设计阶段及早发现产品和模具设计的缺陷,及时修正,达到优化设计、保证成型质量、缩短工期、降低成本的目的。

  18. Structural materialization of stainless steel molds and dies by the low temperature high density plasma nitriding

    Aizawa Tatsuhiko; Fukuda Tatsuya; Morita Hiroshi

    2015-01-01

    Various kinds of stainless steels have been widely utilized as a mold substrate material for injection molding and as a die for mold-stamping and direct stamping processes. Since they suffered from high temperature transients and thermal cycles in practice, they must be surface-treated by dry and wet coatings, or, by plasma nitriding. Martensitic stainless steel mold was first wet plated by the nickel phosphate (NiP), which was unstable at the high temperature stamping condition; and, was eas...

  19. Orthogonal ion injection apparatus and process

    Kurulugama, Ruwan T; Belov, Mikhail E

    2014-04-15

    An orthogonal ion injection apparatus and process are described in which ions are directly injected into an ion guide orthogonal to the ion guide axis through an inlet opening located on a side of the ion guide. The end of the heated capillary is placed inside the ion guide such that the ions are directly injected into DC and RF fields inside the ion guide, which efficiently confines ions inside the ion guide. Liquid droplets created by the ionization source that are carried through the capillary into the ion guide are removed from the ion guide by a strong directional gas flow through an inlet opening on the opposite side of the ion guide. Strong DC and RF fields divert ions into the ion guide. In-guide orthogonal injection yields a noise level that is a factor of 1.5 to 2 lower than conventional inline injection known in the art. Signal intensities for low m/z ions are greater compared to convention inline injection under the same processing conditions.

  20. 注塑次数对玻纤增强阻燃PBT性能的影响%Effect of Mold-Injection Times on Properties of Glass Fiber Reinforced Flame Retardant PBT

    张水洞; 黄汉雄

    2011-01-01

    Glass fiber reinforced flame retardant PBT(GFFRPBT) with five times mold-injection was prepared, and the properties and influence factors of GFFRPBT with different mold-injection times including mechanical and thermal were well investigated. The results demonstrate that when GFFRPBT is processed third time, the length of glass fiber and characteristic viscosity of PBT decrease to 590 fim, 0.52, respectively. It also indicates that the trend of the decrease accelerates with more mold-injection times. After second times mold-injection, the notched impact strength, flexural and tensile strength of recycled GFFRPBT (RGFFRPBT-2nd) decrease to 54 J/m, 128 Mpa and 96.1 Mpa, respectively. Thermal stability, maximal crystallization temperature, melting point and hot deformation temperature of RGFFRPBT-2nd are not significant different from those of GFFRPBT. The results illuminate that mechanical and thermal properties of RGFFRPBT-2nd are suitable to use in the electronic and electric field. With the mold-injection times increase, the properties of RGFFRPBT significantly decrease.%通过对五次注塑后的阻燃增强聚对苯二甲酸丁二醇酯(PBT)材料进行性能测试,研究注塑次数对材料的力学性能和热学性能的影响及其变化规律.当注塑次数为三次时,材料的玻纤长度仅为590μm,PBT树脂特性黏度仅为0.52,且随着注塑次数的增加进一步下降.对材料的力学性能、热学性能进行测试,结果发现经过两次注塑后,其缺口冲击强度、弯曲强度和拉伸强度分别为54 J/m、96.1 MPa和128 MPa,力学性能仅小幅度下降,其热学性能也不发生明显变化,满足电子电气领域使用要求.注塑次数超过三次后,材料的力学性能尤其是缺口冲击强度剧烈下降,其热稳定性、结晶温度、熔融温度以及热变形温度也显著下降.