Abstract: To solve the problems of imbalance melt flow in the injection mold combination cavity of the soap box, the Moldflow software was used to perform the numerical simulation for the injection molding process. The initial plan was analyzed from three aspects including filling time, the pressure of velocity/pressure conversion points and the pressure at the injection position to determine the optimization index of the gating system. The size of the runner was optimized by the automatic optimization scheme of flow balance analysis. The results indicated that the unbalance rate of filling time between cavities and pressure unbalance value were less than 5 % and 5 MPa, respectively, after the gating system was optimized. Moreover, the pressure curve at the injection position rose steadily, and the melt flow imbalance were also improved effectively.

Key words: injection molding; numerical simulation; flow balance, optimization design; Moldflow software