Deformation Analysis of Injection Molded Articles due to In-mold Residual Stress and Cooling after Ejection

사출 성형품의 금형내 잔류응력과 이형후 냉각에 의한 후변형 해석

Deformation analysis of injection molded articles whose geometry is considered as the assembly of the thin flat plates has been conducted. For the in-mold analysis, thermo-viscoelastic stress calculation of rheologically simple amorphous polymer and in-mold deformation calculation considering the in-plane mold constraint has been done. Free volume theory has been used for the non-equilibrium density state by the fast cooling. At ejection, the redistribution of stress together with instantaneous deformation has been considered. During out-of-mold cooling after ejection, thermoelastic model based on the effective temperature has been adopted for the calculation of deformation. Two typical mold geometries are used to test the numerical simulation.