Calendering of coextruded polymer structures

Abstract : The velocity and pressure fields that form within the gap of a calender are calculated with onedimensional and two-dimensional isothermal monolayer models. The one-dimensional model simplifies the momentum balance and the continuity equation by the lubrication approximation. Pressure and velocity fields are obtained analytically with this calculation. The velocity and pressure fields are numerically calculated with a two-dimensional model based on Forge®2005. Forge®2005 is based on a Finite Element Method. The pressure field is determined by the gap height, the circumferential speed of the rolls and the rheological behaviour of the polymer. The one and two-dimensional pressure fields are compared.