Numerical study of the effect of operating parameter on rapid heat cycle molding process

Abstract

Recently, rapid heat cycle molding technology has been developed based on the mold heating before each polymer injection stage. For this process, successful heating and cooling phases are of great importance to ensure the cycle productivity and product quality. In this study, a three-dimensional model was developed to investigate the thermal response during the rapid heat cycle molding process. The procedure uses the finite volume method and the fractional area volume obstacle representation to obtain the thermal behavior of both polymer and mold until reaching the regular cyclic regime. The authors’ objective was to determine the operating parameter effect on rapid heat cycle molding process. Thus, four parameters were studied: the heating and cooling temperatures, the heat transfer coefficient of the cooling phase, and the fouling resistance at the channels. To investigate the influence of these parameters on the product quality and the process productivity and profitability, four criteria were selected: cycle time, consumed energy, temperature gap at the surface cavity, and temperature homogeneity in the polymer part. It was found that the operating conditions had a significant effect on the rapid heat cycle molding cycle performance. It was demonstrated that the heating medium temperature affects only the heating time; however, the cooling water temperature affects both heating and cooling times. In particular, the cooling temperature range of 50–60 ℃ reduces the consumed energy compared with the lowest temperatures, without a significant increase in the cycle time.