Numerical and experimental investigation of polycarbonate vacuum-forming process

This research investigates the influence of process variables on the quality of vacuum-formed thermoplastic products and provides guidelines for polycarbonate (PC) thermoforming optimization. The process variables investigated include: operating temperature, non-uniform temperature of the PC sheet, and applied pressure. A series of thermo-coupled numerical simulations are conducted to examine the quality of the vacuum-formed parts. Three general hyperelastic constitutive models are used to describe the mechanical behavior of PC during the thermoforming process and to examine its reliability. The forming limit and the thickness distribution predicted by the numerical simulations for the axisymmetric vacuum-formed parts are compared with the experimental results of vacuum-forming. Good agreement is found between the numerical simulations and the experimental results. In addition, the effect of temperature on the surface smoothness and the deformation results of the thermoformed parts are discussed. Based on the results of the experiments and numerical analyses, guidelines for the PC thermoforming process are proposed.