General model of polymer melting in extrusion process
Polimery 2018, No 6, 444
A procedure of general modeling of polymer melting in extrusion process has been presented. The procedure is independent on the type of extrusion, and does not require any knowledge of melting mechanism. The procedure involves modeling the two-phase flow (fluid/solid) as a single-phase flow in which the material, depending on the flow conditions, is solid or fluid. Cross-WLF rheological model has been used, which defines the solid polymer as a high viscosity fluid, while the polymer melt as a low viscosity fluid. The problem has been solved for single screw extrusion process as a three-dimensional, non-isothermal, non-Newtonian flow using CFD (Computational Fluid Dynamics) software. Melting progress is defined by the temperature distribution which determines the regions of solid and fluid.