Abstract: This paper reported a case study on influencing factors for structure by taking a 100 mL blown molded medical plastic infusion bottle as a sample. A finite element model was established for the blow molding process of this bottle and then analyzed with Ansys software. For the uneven wall thickness and other defects appearing in the deformation process of the bottle, a mathematical model for the structure of an infusion bottle embryo was established based on a minimum bottle embryo mass, and then it was analyzed and calculated by nonlinear curve fitting using universal global optimization. The optimum value for wall thickness in various parts of the infusion bottle embryo was achieved, and the evenness of wall thickness and the minimum mass of the bottle obtained from blow molding were calculated. Compared with the unoptimized results, the wall thickness evenness was improved, whereas the minimum mass was reduced. In this case, the production cost was reduced due to a decrease in the consumption of PP raw material after optimization.

Key words: blow molding, Ansys software, plastic infusion bottle, nonlinear fitting, structural optimization