scholarly journals Numerical simulation for predicting sink marks on injection molding and injection compression molding process

2020 ◽  
Author(s):  
Yen-Chih Chen ◽  
Chih-Chung Hsu ◽  
Chia-Hsiang Hsu
Keyword(s):  
Numerical Simulation ◽  
Injection Molding ◽  
Compression Molding ◽  
Molding Process ◽  
Sink Marks ◽  
Injection Compression Molding

Numerical Simulation and Process Optimization of a 3D Thin-Walled Polymeric Part Using Injection Compression Molding

2021 ◽  
Vol 36 (4) ◽  
pp. 459-467
Author(s):  
D. Sönmez ◽  
A. A. Eker
Keyword(s):  
Numerical Simulation ◽  
Injection Molding ◽  
Process Parameters ◽  
Compression Molding ◽  
Injection Molding Process ◽  
Mold Surface ◽  
Clamping Force ◽  
Molding Process ◽  
Thin Walled ◽  
Injection Compression Molding

Abstract Injection compression molding (ICM) is a hybrid injection molding process for manufacturing polymer products with high precision and surface accuracy. In this study, a 3D flow simulation was employed for ICM and injection molding (IM) processes. Initially, the process parameters of IM and ICM were discussed based on the numerical simulations. The IM and ICM processes were compared via numerical simulation by using CAE tools of Moldflow software. The effect of process parameters of mold surface temperature, melting temperature, compression force and injection time on clamping force and pressure at the injection location of molded 3D BJ998MO Polypropylene (MFI 100) part was investigated by Taguchi analysis. In conclusion, it was found that the ICM has a relatively lower filling pressure than ICM, which results in reduced clamping force for producing a 3D thin-walled polymeric part.

scholarly journals Analysis of Reactive Injection Compression Molding by Numerical Simulations and Experiments

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Giorgio Ramorino ◽  
Silvia Agnelli ◽  
Matteo Guindani
Keyword(s):  
Injection Molding ◽  
Experimental Tests ◽  
Curing Kinetics ◽  
Compression Molding ◽  
Computational Time ◽  
Injection Molding Process ◽  
Molding Process ◽  
Viscosity Models ◽  
Element Simulation ◽  
Injection Compression Molding

Injection compression molding is an injection molding process with the addition of a compression stage after the injection. This process is useful for the injection molding of precision parts. A stable and controlled manufacturing process is needed to guarantee reliability of complex products, and usually process optimization is achieved by experimental and time consuming approaches. However, for being competitive a minimal market time is a very important requirement and computer simulations can help to optimize the process at the only expense of computational time. This paper reports and discusses for the first time the results of a 3D finite element simulation of reactive injection compression molding (RICM) by commercial software for the production of rubber diaphragms. In particular, the stages of mold filling dynamics and material curing are analyzed and the results verified with experimental tests. To get an accurate representation of the process, the rheological behavior, thermal properties, and kinetic behavior during curing of the real rubber compound were described by mathematical models. A differential scanning calorimeter (DSC) and a capillary rheometer are employed to characterize the rubber material in order to achieve an appropriate curing reaction and viscosity models, respectively. The computations are found to be in good agreement with the experimental results, indicating that reliable information on material viscosity and curing kinetics can play a key role in making well-founded predictions and avoiding trial and error methods.

Effect of gas counter pressure on shrinkage and residual stress for injection molding process

2017 ◽  
Vol 37 (5) ◽  
pp. 505-520 ◽  
Author(s):  
Wen-Ren Jong ◽  
Shyh-Shin Hwang ◽  
Ming-Chieh Tsai ◽  
Chien-Chou Wu ◽  
Chi-Hung Kao ◽  
...  
Keyword(s):  
Residual Stress ◽  
Injection Molding ◽  
Flow Direction ◽  
Injection Molding Process ◽  
Molding Process ◽  
Daily Lives ◽  
Counter Pressure ◽  
Packing Pressure ◽  
Sink Marks ◽  
Feedback Data

Abstract Plastic products are common in contemporary daily lives. In the plastics industry, the injection molding process is advantageous for features such as mass production and stable quality. The problem, however, is that the melt will be affected by the residual stress and shrinkage generated in the process of filling and cooling; hence, defects such as warping, deformation, and sink marks will occur. In order to reduce product deformation and shrinkage during the process of molding, the screw of the injection molding machine will start the packing stage when filling is completed, which continuously pushes the melt into the cavity, thus making up for product shrinkage and improving their appearance, quality, and strength. If the packing pressure is too high, however, the internal residual stress will increase accordingly. This study set out to apply gas counter pressure (GCP) in the injection molding process. By importing gas through the ends of the cavity, the melt was exposed to a melt front pressure, which, together with the packing pressure from the screw, is supposed to reduce product shrinkage. The aim was to investigate the impacts of GCP on the process parameters via the changes in machine feedback data, such as pressure and the remaining injection resin. This study also used a relatively thin plate-shaped product and measurements, such as the photoelastic effect and luminance meter, to probe into the impacts of GCP on product residual stress, while a relatively thick paper-clip-shaped product was used to see the impacts of GCP on shrinkage in thick parts. According to the experimental results, the addition of GCP resulted in increased filling volume, improvement of product weight and stability, and effective reduction of section shrinkage, which was most obvious at the point closest to the gas entrance. The shrinkage of the sections parallel and vertical to the flow direction was proved to be reduced by 32% and 16%, respectively. Moreover, observations made via the polarizing stress viewer and luminance meter showed that the internal residual stress of a product could be effectively reduced by a proper amount of GCP.

Study on Optical Properties of Microstructure of Lightguiding Plate for Micro Injection Molding and Micro Injection-Compression Molding

2006 ◽  
Vol 505-507 ◽  
pp. 229-234 ◽  
Author(s):  
Yung Kang Shen ◽  
H.J. Chang ◽  
C.T. Lin
Keyword(s):  
Optical Properties ◽  
Injection Molding ◽  
Digital Camera ◽  
Mold Temperature ◽  
Compression Molding ◽  
Micro Injection Molding ◽  
Melt Temperature ◽  
Packing Pressure ◽  
Injection Compression Molding ◽  
Better Than

The purpose of this paper presents the optical properties of microstructure of lightguiding plate for micro injection molding (MIM) and micro injection-compression molding (MICM). The lightguiding plate is applied on LCD of two inch of digital camera. Its radius of microstructure is from 100μm to 300μm by linearity expansion. The material of lightguiding plate uses the PMMA plastic. This paper uses the luminance distribution to make a comparison between MIM and MICM for the optical properties of lightguiding plate. The important parameters of process for optical properties are the mold temperature, melt temperature and packing pressure in micro injection molding. The important parameters of process for optical properties are the compression distance, mold temperature and compression speed in micro injection-compression molding. The process of micro injection-compression molding is better than micro injection molding for optical properties.

Finite Element Design and Numerical Simulation on Non-Pneumatic Beehive Damping Tire

2011 ◽  
Vol 291-294 ◽  
pp. 418-422
Author(s):  
Ge Gang Zhu ◽  
Chen Xu ◽  
Long Yi ◽  
Ning Li
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Injection Molding ◽  
Simulation Analysis ◽  
Mold Design ◽  
Molding Process ◽  
Improvement Measures ◽  
Quality Issues

The design and numerical simulation and analysis on non-pneumatic beehive damping tire were discussed in this paper by finite element techniques. And use the molding software filling its experimental to analyze the process of injection molding qualities for the reasonable mold design. And the corresponding improvement measures, the rationality of mold design and molding process were arised for quality issues according to the simulation analysis.

The CAE Simulation of the Printer Cover Panel with Gas-Assisted Injection Molding

2012 ◽  
Vol 201-202 ◽  
pp. 808-811
Author(s):  
Guo Qiang Zhang ◽  
Mei Ting Xie ◽  
Wen Juan Wang ◽  
Ji Qiang Zhai
Keyword(s):  
Numerical Simulation ◽  
Injection Molding ◽  
Production Process ◽  
Process Parameters ◽  
Filling Process ◽  
Molding Process ◽  
Computer Aided ◽  
Simulation Results ◽  
Cae Technology ◽  
Cae Simulation

Numerical simulation in the printer cover product molding process with gas assisted injection molding was carried out by means of computer aided engineering. The filling process and surface quality were forecasted. The simulation results provide an important reference for the selection in the production process parameters. Compared with the production molding process and the actual product, CAE technology used in actual production and design is entirely feasible.

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