Process parameters optimization in pressure vibration injection molding

Abstract

Plastic injection molding (PIM) is a major manufacturing technology to produce plastic products for high product quality and high productivity. The process parameters such as the melt temperature, the packing pressure and the cooling time affect the product quality and productivity, and thus it is important to determine the optimal process parameters. Recently, the pressure vibration injection molding (PVIM), which vibrates the pressure during the filling and packing phases, has attracted attention. The mechanical properties, the viscosity and the shear stress are mainly discussed through the experiment in the literature, but the period and amplitude of pressure vibration are rarely discussed. In this paper, the process parameters optimization in PVIM is performed for a thin-plate product. The warpage and the cycle time are simultaneously minimized for high product quality and high productivity. The numerical simulation in PIM is so intensive that sequential approximate optimization using radial basis function network is adopted. It is clarified though that numerical result that the PVIM makes the distribution of shear stress and pressure uniform, and thus the warpage is well reduced. Thus, the PVIM is an effective approach for warpage reduction and short cycle time.