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

사출 성형품의 금형내 잔류음력과 이형후 냉각에 의한 후변형 해석

  • Published : 2002.02.01

Abstract

Deformation analysis of injection molded articles whose geometry is considered as the assembly of thin flat plates has been conducted. For the in-mold analysis, thermo-viscoelastic stress calculation of thermo-rheologically simple amorphous polymer and in-mold deformation calculation considering the in-plane mold constraint have been done. Free volume theory has been used to represent the non-equilibrium density state during the fast cooling. At ejection, instantaneous deformation takes place due to the redistribution of in-mold residual stress. During out-of-mold cooling after ejection, thermoelastic model based on the effective temperature has been adopted for the calculation of out-of-mold deformation. In this study, emphasis is also made on the treatment with regard to lateral constraint types during molding process. Two typical mold geometries are used to test the numerical simulation modeling developed in this study.

Keywords

Deformation;Shrinkage;Warpage;Residual Stress;Injection Molding

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