Abstract: Based on Moldflow software, the filling, packing, cooling, and warping of a front bumper was simulated using a scaled down model. The used material was high impact polypropylene K9015 provided by Yangzi Petrochemical. The reason causing warping was explored with two injection schemes. It showed that the injection times was the same for two schemes. When the three gates were located on the same side of the product, better quality of appearance and more accurate assembly were obtained. Both schemes caused large warpage, however, which could be reduced by optimizing the packing curve.

Key words: Moldflow, automobile bumper, simulation analysis, injection molding