Abstract: The mold process of plastic auto boxes, including fill time, injection pressure, melt front temperature, cavitation, and weld line location were analyzed by Moldflow software. According to the simulation, a three-plate submarine gate injection mold was designed. The application of molds showed that the design was reasonable. Smooth motion and high-dimensional accuracy were realized.One may find no burr, weld marks, air pockets, and other defects on the surface of the parts.

Key words: injection molding, Moldflow, submarine gate, welding marks, cavitation