Analysis of polymers flow through dies of forming devices

The steady laminar flow of molten polymer modelled by viscoplastic fluid is considered, through a narrow space between two fixed surfaces of revolution. The problem is described by boundary layer equations. Using the method of averaged inertia one obtains the formulae expressing the pressure distribution. Generally, the flow of viscoplastic fluids given by the nonlinear model of Shulman is considered. The flows of polymers modelled by the viscoplastic fluids of Vočadlo, Herschel - Bulkley, Ostwald - de Waele and Newtonian are discussed in detail. Numerical examples of pressure distributions in the clearance between parallel disks and concentric spherical surfaces are presented.