Pressure prediction verification studies using 3D CAE injection molding simulation software

The purpose of this study was to evaluate how changes of the 3D mesh affected the accuracy of the simulation results when compared to experimental cavity pressures collected from an instrumented family mold. The number of elements on the 3D mesh was changed and the runner was modeled using 1D and 3D elements. Parts were molded for PP and ABS at six different processing conditions, changing melt temperature and injection flow rate. Short shots were collected and flow simulations were completed with and without cooling analysis. Molded short shorts were in agreement with the simulation results. However, the non-uniform temperature distribution inside the cavity extended the PP fill time. Representing the runner as 1D for the ABS provided better predictions while modeling the runners as 3D for the PP displayed better results. Results showed that PP requires more elements in the mesh than ABS. Hence, ABS analysis times are shorter.