Residual stress induced by solidification of thermoviscoelastic melts in the postfilling stage

摘要

Injection moulding is a process where polymer melt is injected into a mould cavity, and solidifies to form a plastic part. Residual stress usually develops daring the solidification of the melt in the postfilling stage. This study use a simple thermoviscoelastic model to calculate the residual stress developed in the postfilling stage. Based on the calculation of the injection moulding process, the temperature and pressure histories in the postfilling stage can be determined, and used to calculate the developed stress field. The model divides the thickness into two regions, liquid and solid. Residual stress calculation is applied in the solid region, while the liquid region is kept at the local melt pressure without any strain.