CAE Optimization and Mold Design of Air Auxiliary Molding of Automobile Door Handle

Abstract

To address the difficulty in forming automobile door handles for partially thick-walled plastic parts, Moldflow is utilized to simulate the Computer-Aided Engineering (CAE) of two molding techniques: conventional injection molding and air-assisted injection molding. The CAE analysis of conventional injection reveals that the main challenge in molding plastic parts is the shrinkage deformation caused by uneven wall thickness, resulting in size control issues and a shrinkage rate exceeding 7.2%. On the other hand, the CAE analysis demonstrates that air-assisted molding can reduce the shrinkage deformation rate to 0.33%. The corresponding air-assisted molding process parameters are as follows: mold temperature of 50℃, melt temperature of 230℃, filling time of 6s; injection pressure in three stages, namely 20MPa for 5s, 20MPa for 2s, and 10MPa for 2s; gas-assisted delay of 2s before injection, with gas injection conducted in three stages at 25MPa for 6s, 15MPa for 3s, and 5MPa for 3s, respectively. Based on these optimized parameters, a two-cavity gas-assisted two-plate plastic mold is designed. The inflatable element utilizes a cylindrical air needle suitable for thick-walled plastic parts, resulting in a simple and practical mold structure with high reliability. This design has significant reference value for future mold designs.