NUMERICAL SIMULATION AND EXPERIMENTAL VERIFICATION OF MELT FRONT ADVANCEMENTS IN COINJECTION MOLDING PROCESS

Abstract

Experimental studies of polymer melt flow in the mold filling stage of the coinjection molding process have been carried out using sequential injection of transparent and colored polystyrene resin. Simulations are also developed to predict the melt front advancements of both skin and core melts. A control volume/finite element method employed within each grid layer of the gapwise direction is applied to trace the melt front advancements for both skin and core materials. Numerical simulations show reasonably good consistency with experimental results in both skin and core material distribution. However, the simulation accuracy can be improved further if edge effect is taken into account using the shape factor as a geometrical correction.