Three‐dimensional finite element analysis of polymer rotational extrusion

Abstract

AbstractA three‐dimensional finite element approach has been employed to model steady, creeping, isothermal helical flows and to study the effect of an imposed rotational field in a wire coating process and a tube extrusion process. It has been shown that the rotational field can affect process characteristics with an underlying viscous character, such as the velocity profile, pressure drop, viscous extrudate swelling, material pathlines, and deformation field. Significant pressure drop reduction may be achieved with implications on the process productivity, pressure drop reduction being most prevalent at low power‐law indices because of the increased nonlinearity in the shear‐thinning viscosity function. Extrudate swelling has been shown to be affected by the rotational field owing to the shear‐thinning nature of polymeric materials. Finally, it has been shown that significant material deformation may result from the imposition of the rotational field.