Extrusion Blow Molding Simulation using Cross-Section Technique for Complex Shape Bottles

Abstract

This research proposed the blow molding simulation method for determining of a cross-section thickness of bottles. The finite element method (FEM) was employed to simulate the extrusion blow molding process of the complex shape bottles. The full bottle shape of blow molding process had been attempted to simulate with a rectangular shape bottle for comparing with the cross-section technique. Particularly, the physical experiment of the extrusion blow molding process was performed to verify the FEM. The cross-section technique was obtained a deviation result less than the full bottle shape simulation. The average error of full bottle shape simulation was 32.35% while the cross-section simulation obtained an average error of 17.02% when they were compared with the experimental data of the blow molding process. The FEM of blow molding simulation using the cross-section technique which was developed in this research had been found the satisfactory method to determine the initial thickness of the parison flowing through the extrusion die. It was advantaged to shape dies of the extrusion blow molding process in order to achieve the complex shape of bottles.

Local process-dependent structural and mechanical properties of extrusion blow molded high-density polyethylene hollow parts

“…Uncontrollable sagging occurs if the parison becomes longer due to gravity. It is influenced by molecular weight distribution, melt strength, extrusion and ambient temperature, and melt relaxation behavior [2][3][4]. During blowing, the polymer melt is stretched, and an orientation in stretching directions as well as internal stresses after solidification may cause anisotropy, and affect final thermal and mechanical product properties [1].…”