Analysis of numerical modeling strategies to improve the accuracy of polymer injection molding simulations

The present study addresses the capacity of the generalized Hele-Shaw (GHS) approximation and a full 3D Newtonian approach (GNF) to predict flow features of molten polymers in injection molding. The numerical solutions are compared with experimental data for a single-cavity mold. Evolution of the flow front and quan-titative global measures for the numerical simulations, such as the mass-filling fraction and time efficiency, are assessed based on experimental results for the ABS polymer. The global differences between the GHS and GNF solution approaches are discussed based on evolution of local flow velocities, viscosities and pressure. The study shows that the maximum differences in the time efficiency (with respect to experiments) for the GHS and GNF approximations were 8.9% and 3.4%, respectively. The results indicate that both approximations yield good predictions for the present test case; however, the GNF approach provides greater accuracy when computing the flow characteristics during mold-filling stage.