Study on Computer Simulation of Co-injection Molding

The co-injection molded parts can be produced by the combination of two types of plastic materials,such as using the skin material to achieve required surface properties,while using the core material to obtain sufficient mechanical properties or to reduce cost.Because the molding factors are numerous and the molding mechanism is complex,core melt may break through skin melt in molding,and waster may be produced.In this paper,barrel product,which was used as the model,was tested by orthogonal test method and simulation software MPI.Process parameters' effect on breakthrough of core melt was studied,and optimum process parameters were obtained.The result shows that injection temperature of core melt is the main factor of the breakthrough of core melt.Next factor is the injection rate of core melt,and the injection rate of skin melt,while mold temperature,and injection temperature of skin melt have light influence on the breakthrough of core melt.