Extrusion die design for viscoplastic fluids

Abstract We propose to apply two approaches to analyze the design and performance of extrusion dies that deliver wide and thin uniform sheets and films of fluids with yield stress. The first approach is based on the one‐dimensional lubrication approximation and the second approach is the three‐dimensional finite element simulation. The performance of a T‐die and a coat‐hanger die has been under investigation. The effects of two dimensionless groups, the Reynolds number Re and the Bingham number Bi, on lateral flow uniformity have been examined. Several design variations, such as opening the end of the manifold and inserting a choker bar into a die, have also been studied. © 1994 John Wiley & Sons, Inc.