General principles of polymer processing modeling

Abstract Specific rheological and thermal properties of molten polymers and their consequences on the numerical simulation of forming processes are first reviewed. The strong coupling between flow kinematics and material temperature is pointed out. According to geometrical specificities, to the type of deformation the material is submitted to and to thermal conditions, continuum mechanics and energy balance equations can be simplified and more or less sophisticated rheological equations can be used. Finally, these considerations are applied to the modeling of steady extrusion and fiber spinning and of unsteady molding processes.