Study on the Warpage of Plastics Vacuum-Forming Process

Abstract

A series of experiments was carried out to comprehensively study the effect of technological parameters including mold geometry (depths of draw, the shape of impression), initial forming temperature and material properties on the warpage of plastics vacuum-formed parts. During the process of plastics vacuum-forming, the thermoelastic FEM model was adopted to analyze the warpage at the cooling stage and the rigid visco-plastic FEM model was adopted to analyze the deformation at the deforming stage. The 3-D temperature fields are computated using Calerkin FEM code with proper selection of the parison's thermal properties and appropriate disposals of dynamic heat conclusion boundary condition, latent heat and deformation heat. The simulation results of warpage match the experimental results of the sample part quite well.