Abstract: The flow process in the injection molding of button lid of the automobile inner decoration was simulated using Moldflow. A double surface grid model was formulated based on the body model in the virtue of Pro/E soft. By analyzing the gating location, temperature field and pressure at the gating location，the reasonable pouring system was obtained. The central symmetry layout of the part ensured the pressure center consistency and the uniform distribution of the pressure in the runner. During the moulding, the temperature ranged between 196℃ and 234℃. The highest temperature located at the center of main runner and the lowest temperature at the side of the small flank, which provided a reference for the design of cooling system of the mould.

Key words: button lid, layout, gating location, simulation analysis, injection molding