Numerical Simulation of Co-Injection Molding

2000 ◽  
Author(s):  
James T. Wang

Abstract In the co-injection molding process, two (or more) different polymers are injected into the cavity simultaneously or sequentially. Different properties of these two polymers and their distribution in the cavity greatly affect the applications of this molding process. The skin layer can use special polymers to provide good appearance and texture, strength, chemical resistance, EMI shielding and other functions. The core layer can use recycled or inexpensive materials. Together these can improve part quality and lower the cost. However, due to the dynamic interaction of two polymers in the manufacturing process and their difference in properties, process control becomes more complicated and process design becomes a challenge. The rules used for the traditional injection molding process design may not always be useful for co-injection molding any more. An integrated CAE software has been developed to simulate the co-injection molding process. In this study, the capability and usefulness of the CAE tool will be shown. The control of polymer distribution will be discussed. The effects of polymer properties and their distribution on part quality will also be studied.

1999 ◽  
Author(s):  
Alan M. Tom ◽  
Akihisa Kikuchi ◽  
John P. Coulter

Abstract The current investigation focused on contributing to the development of a novel injection molding process by attempting to understand the scientific relationship that exist between the applied vibrational parameters involved in this process and the effect it has on final product polymeric characterization. Although previous and current attempts at understanding the connection between applied oscillatory or vibrational motion to an injection molding process has shown positive quantitative advantages to final product properties, there still exists a void in the scientific explanation on a molecular level linking these effects. This experimental study, in particular, involved an evaluation on a range of processing conditions applied to Polystyrene and the effects it produced on resultant product quality and polymer properties. Optimal control and mechanical vibrational molding conditions were obtained for Polystyrene. As a result of this, optimal opportunities for initial commercial utilization of the technology can be proposed.


2011 ◽  
Vol 418-420 ◽  
pp. 1194-1201
Author(s):  
He Sheng Liu ◽  
Ai Hua Xiong ◽  
Xing Yuan Huang ◽  
Jia Mei Lai

Based on generalized non-Newtonian fluid with seven parameters Cross-WLF viscosity model and modified 2-double Tait model, the numerical simulation was carried out for the short glass fiber reinforced PP injection molding process of rectangular part. The influence of main process parameters on fiber orientation is investigated. The results show that fiber orientation can be generally divided into three-regional layers in injection molding, that is outer-surface, subsurface and core layer. The degree of fiber orientation in subsurface layer is the highest and that in core layer is the lowest. The influence of fibers interaction coefficient (Ci) and fibers aspect ratio (re) on fiber orientation is significant. There is obvious difference between simulation results and practical results without consideration of Ci. The effect of melt temperature, mold temperature and cooling tubes number on fiber orientation isn’t obvious.


Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3297
Author(s):  
Jinsu Gim ◽  
Byungohk Rhee

The cavity pressure profile representing the effective molding condition in a cavity is closely related to part quality. Analysis of the effect of the cavity pressure profile on quality requires prior knowledge and understanding of the injection-molding process and polymer materials. In this work, an analysis methodology to examine the effect of the cavity pressure profile on part quality is proposed. The methodology uses the interpretation of a neural network as a metamodel representing the relationship between the cavity pressure profile and the part weight as a quality index. The process state points (PSPs) extracted from the cavity pressure profile were used as the input features of the model. The overall impact of the features on the part weight and the contribution of them on a specific sample clarify the influence of the cavity pressure profile on the part weight. The effect of the process parameters on the part weight and the PSPs supported the validity of the methodology. The influential features and impacts analyzed using this methodology can be employed to set the target points and bounds of the monitoring window, and the contribution of each feature can be used to optimize the injection-molding process.


2013 ◽  
Vol 135 (1) ◽  
Author(s):  
Eunyoung Chang ◽  
Seungwon Shin ◽  
Haseung Chung

Injection molding process is a widely used manufacturing technique to massively produce the components of mobile device with various sizes and complicated geometries. However, the final part quality, especially dimension or geometry, referring to the original design specifications is not often acceptable due to various reasons. This study aims at developing the numerical model to predict the final part quality and subsequently identifying the critical reasons for existing problems. moldflow and abaqus software have been simultaneously used to simulate the injection molding process and thermal deformation arising after ejection step from the mold. In order to validate the model, the deformation predicted by the developed model was compared with experimental results, and both results showed good agreement. We also carried out design of experiment (DOE) to investigate the effect of various processing parameters that affect the final deformation of injection molded product. The developed model and information derived from DOE are expected to provide useful resources to the initial stage of mobile device design.


Author(s):  
Supasit Rodkwan ◽  
Rungtham Panyawipart ◽  
Chana Raksiri ◽  
Kunnayut Eiamsa-ard

With a recent growth in the demand of the rubber products globally, the latest technology is adopted to improve the design and manufacturing of those rubber products in term of part quality and production lead time and cost. The cold runner system is one of the technologies which can assist in unfilling part problem and raw material saving. Nevertheless, with the lack of numerical tool with an ability to predict the behavior of rubber during the injection molding process, designers still need to use their experience and trial-and-error method to design the mold and the cold runner system. Therefore, in this research, the use of CAE and a cold runner system is applied to the design and manufacturing of rubber injection molding process with a gasket mold made of SBR as a case study. The empirical and simulated results agree well and the use of raw material in the actual system is decreased by 12% shot weight which can lead to the reduced cost of products. Finally, it can be seen that the use of CAE can assist the mold designers and manufacturers to get better understanding of flow pattern and behavior of rubber during the injection process so the better part quality can be obtained.


1996 ◽  
Vol 36 (11) ◽  
pp. 1477-1488 ◽  
Author(s):  
Suzanne L. B. Woll ◽  
Douglas J. Cooper ◽  
Blair V. Souder

2013 ◽  
Vol 690-693 ◽  
pp. 2772-2775
Author(s):  
Jian Wen Tang

In the injection molding process, CAE technology is used for detailed analysis of the designing of injection mold gate location and number, this method can optimize the pouring system, and change the traditional method which improves the mold structure by mold testing, so the cost of mold design and manufacturing can be reduced.


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