Simulation Of Injection Molding And Optimization Of Molding Parameter For The Plastic Part With Complicated Structure

In this paper, injection molding of a notched ejector and a back plate of the washing machine is regarded as the research object, based on numerical simulation software Moldflow/MPI. the study is distributed into the optimization of the structure of the injection mold and the molding parameter to discuss the cause of the molding defects and the way to improve.Taking the notched ejector as the example of non-thin wall plastic part. Beginning with the CAD modeling of the part, the different simulation processes of 3D mesh and 2d mesh were discussed for the part. There are partial thin wall structures on the part where the joint fusion area is apt to form. Orthogonal design of experiment is choosed to optimize the molding parameter to improve the quality of that fusion area. Taking the back plate of the washing machine as the example of the thin wall part. The structure of the injection mold was firstly optimized using CAE technology to decrease the warpage value. A new control method was proposed which based on the PVT properties of the material of the part to control the packing process, making the plastic melt shrinkage at a specific density, thus to control the warpage problem.The study indicated that the 3D mesh, comparing to the 2D mesh, can express the melt front at a more accurate way for the simulation of molding process of the non-thin wall plastic part. As to the fusion area, choosing the proper injection time, relatively higher temperature of the melt and the mold are the way to improve the fusion quality. Concerning to the warpage problem of the thin wall part, using CAE technology to optimize the injection mold structure and setting proper packing profile which is based on the PVT properties of the injetion material are significant to minimize the wapage problem.