A numerical investigation of the effect of preform length for the fabrication of 1.5Lt PET bottle through the injection stretch blow molding process

Abstract

This study carries the numerical effort for the investigation of effect of preform length on the final product wall thickness distribution. For the investigation, three different preform length cases were taken under consideration. Preform A, preform B and preform C of length 144.75mm, 165.7mm and 186.65mm respectively. All the preforms were stretched up to a same critical point respect to mold length so that the axial deformation during blowing was fair for all the preform cases. Blowing conditions were the same for all cases. The stretching period for each case was set in accordance to the to the limit of critical stretching point. The mass of all preform cases was 58.33grams. It was found that preform B and C result in more uniform thickness distribution. The optimum results are given by preform C, since the resulting product appears the less spots with excess usage of raw material. The heavier bottle bottom region resulting from preform C enhances the steadiness of the bottle.