A FINITE-ELEMENT ANALYSIS OF RUBBER COEXTRUSION USING A POWER-LAW MODEL

A finite element method to simulate coupled thermal viscous coextrusio n is presented, with a power-law viscosity function obtained from visc ometric data on rubber composites. It combines, by successive substitu tion iterations, some well-known schemes, such as streamline integrati on for updating interfaces and Lagrange-Galerkin treatment of the ener gy equation. Some details of the implementation are discussed. The met hod is then applied to a comparison of two pre-forming plates for the dual tuber head extruder of Farrel Corporation. Both the normal stress and the temperature at the interface suggest that the presence of a d eflector deteriorates the adherence properties. This prediction is in agreement with operational experience.