Research On High-gloss Double-injection Molding Technology Based On Multi-gates Sequence Control

As the latest injection molding technology, high gloss double-injection molding technology developed on double color injection molding and high gloss injection technology.The goal is to produce the plastic products with high quality.At present,this technology has been widely used in white household electrical appliance industry.Although double color high gloss products can be produced nowdays,the yield in actual production is low,and still have defects which are difficult to overcome,because of the lack of theory support of corresponding double color high gloss forming.According to this current situation,basic research about theoretical model,structure of products and mould, gating system and parameter optimization is carried on,in order to be the theoretical guidance for the structure design of double color high gloss products and its mould, molding process parameter etc.The mumerical simulation technology of double color high gloss molding is studied.Based on the process characters of double color high gloss molding, reasonable reduction and hypothesis are made. The mathematical model of filling process in double color high gloss molding is deduced,based on the basic melt flow control equations and boundary conditions.According to traditional injection molding,the high gloss double-injection molding technology is studied,based on double color injection molding and high gloss injection technology. According to the basic requirements of structure design of double-injection and high gloss injection molding,general principles and the matters needing attention about the structure design of double color high gloss products and its mould is studied.Gating system of double color high gloss TV front shell with hot runner valve gate sequence control is built.According to the comparative analysis on the use before&after of hot runner valve gate sequence control,it is found that the molding using this method not only can remove weld line,also can improve the process conditions,and decrease energy cost.Take the TV front shell forming by high gloss double-injection as an example, and using sink index and volumetric shrinkage as the optimization objective, multi-objective process optimization is studied by orthogonal experiment and analysis of range to get optimal combination for the improvement of the quality of products. Last, the optimal combination is used in experiment which verify the accuracy of the optimization analysis.