In order to predict the shrinkage, warpage and mechanical properties of the injection molded parts, a coupled analysis of filling and post-filling process is needed. To simulate the real molding conditions, the effects of phase change and compressibility of the resin were considered in the present investigation. A finite-element/finite-difference hybrid scheme was employed for the present numerical modeling. The melt flow was assumed to follow generalized Hele-Shaw model for a Non-Newtonian fluid. A modified Cross model with either an Arrhenius-type or WLF-type functional form was used for modeling viscosity of the resin. A double-domain Tait equation of state was employed to describe the compressibility of the resin during molding. The energy balance equation including latent-heat dissipation for semicrystalline materials was solved in order to predict the solidified layer and temperature profile. In order to verify the numerical results obtained from the developed program, the simulation results were compared with the experimental results and the available data in the literature. Injection molding experiments were carried out using commercial-grade PP (polypropylen) in the present study. Based on the comparison between experiments and simulations, it was found out the predicted pressure distributions and melt front propagations were accurate. Thus it was concluded that the program developed in this study was proved to be useful in simulations of injection molding process.
