Design of coat‐hanger sheeting dies based on ratio of residence times in manifold and slot

Abstract

Abstract A new coat‐hanger die geometry with a uniform flow rate and optional ratio of residence times in manifold and slot is proposed. Such a die will be effective when thermal degradation in the die occurs, especially at die far end. This geometry is easily determined if the flow behavior index n of polymer is assumed. A suitable ratio greater than unity may be taken considering die‐height and cost, because lower height is attained as the ratio increases above unity. An example of a design calculation is shown.