Optimizing flow in plastic injection molding

The mold and part design of plastic parts for injection molding is a complicated process, considerations for producing a part ranging from cost and speed of production to structural, ergonomics and aesthetic requirements. One of the routines faced by a designer when designing quality into a part is the process of cavity balancing. This entails controlling the plastic flow in the filling phase such that the melt front reaches the boundaries of the mold at the same time. This is done by adjusting the thicknesses of various sections and can be a tedious trial and error process. In this paper, a method is described whereby the thickness-adjustment process can be automated. An optimization routine is used to generate the thicknesses necessary to balance the mold cavity. The method is implemented on a PC through interfacing of the Fortran code with the commercial software, Moldflow(C). Using the method, good results have been obtained for several basic geometric models. (C) 1997 Elsevier Science S.A.