SBM Simulation of PET Bottles Using Newtonian Fluid Method in ANSYS Polyflow

Abstract

Background/Objectives: The rational assumption of the viscosity of the preform, which is difficult to obtain an accurate value, and the simulation using a Newtonian fluid model rather than a visco-elasto-plasticity, make it easy to check the molding behavior of PET bottles in the field.

Methods/Statistical analysis: Except for the viscosity coefficient, the variables are configured as if they were actual. Viscosity coefficients are performed at 50,000 intervals from 50,000 cps to 250,000 cps. At this time, SBM is divided into stretch and blowing phases, and each process operates in order of 0.1 second. The lateral thickness of the bottle obtained by this simulation is compared with the distribution of the lateral thickness of the actual bottle.

Findings: In the SBM process, the viscosity of the preform was confirmed to be less than 50,000 cps. In addition, when focusing on the lateral thickness of the bottle, the thickness distribution of the simulation and the actual thickness distribution of the bottle does not show a big difference. Therefore, the simulation using the Newtonian fluid method used in this study is expected to be suitable for field application. As the computing power evolves, more simulations can be performed in a shorter time, so it is expected that a variety of variables can be set in the field to understand molding behavior.

Improvements/Applications: By simulating the viscosity coefficients of the preforms in the field, it is possible to find suitable assumptions and to perform simulations in the production of other shaped products.

Keywords: Ansys Polyflow, Molding Behavior, Newtonian fluid, SBM, Viscosity.