Co-Extrusion Die Design
Multilayer polymer sheets or films are often produced from a single manifold die with a feedblock just upstream of the die. The purpose of the feedblock is to combine and form the various layers such that they have a uniform thickness entering the die. The die should be designed to spread the layers to the desired width while maintaining good thickness uniformity at the exit of the die. The design of both the feedblock and the die requires a requires a 3-D flow analysis as demonstrated below.