Dynamics of solid-state extrusion of viscoelastic cross-linked polymeric materials

A mathematical model for the solid-state extrusion of a compressible polymeric material is developed. The novel feature of the model is the consideration of the actual rheologic behavior of the material and crosslink formation kinetics. Two types of boundary conditions at the press plunger are considered. The system of the governing equations is solved using Lagrangian coordinates. The generalized Maxwell model is used to describe the viscoelastic behavior of the material. The results of numerical experiments discussed in the study show that an unstable material flow can be observed both for high and low extrusion velocities.