Study on the effects of parameters to PET bottle thickness in blowing process

Abstract

PET bottles are widely used for drinking water. PET bottles’ quality depends on their thickness. The aim of this study is to find design variables and optimal parameters of the stretching blow molding (SBM) process of PET bottles in order to increase the uniformity of bottle thickness by using the simulation technique and Taguchi method. The finite element method is used to predict the results of the SBM process. The Taguchi method is performed with six variables that belong to two main factors, which are temperature positions and parison thickness. Through the analysis process, the optimal parameters are determined and verified, with a minimum objective function result of 0.000265. On the other hand, the temperature at T4 positions and the preform thickness at Th2 sections are the main influences on the uniformity of PET bottle thickness.