Analysis of Residual Stresses in Blow Molded Polyethylene Terephthalate Bottles Using Creep Model

Abstract In this paper, the residual stress in polyethylene terephthalate (PET) bottles, which was processed using blow-molding, was analyzed theoretically and numerically. First, the process of blow-molding was analyzed theoretically, which had considered both blowing process and curing of the polymer. The creep model was used to describe the relation between the deformation and the pressure in the blowing process, and thermo-chemical model was used to describe the curing process of the PET bottle. Then, a simulation was carried out using ABAQUS based on the creep model and thermo-chemical curing model. The deformation, residual stresses, heat flux vector and strain of the PET bottle during the blow-molding process were obtained. Finally, the effect of loading path on the residual stress was analyzed numerically, which shows that the longer the pressure was applied, the larger the residual stress.