Die assembly providing uniform pressure and flow

Claim 1

A die assembly for extrudable materials comprising: a first member providing an external wall of a continuous cavity for passage of said extrudable material; an entrance port in said first member communicating with said cavity; a second member providing the internal wall of said cavity; bushing means, for directing the flow of extrudable material within said cavity in one axial direction, said bushing means providing an inclined surface continuous with the bottom of said entrance port and rising to an elevated point on said external wall opposite said entrance port; distributor means, interposed within said cavity, for providing a restricted space therein for passage of said extrudable material and having an inclined surface originating at a point proximal said entrance port and terminating at a point opposite said elevated point, the length thereof being defined by the peripheral distance between said two points and the rise thereof being defined by the axial distance between said two points, wherein the ratio of the radial thickness of said restricted space to the radial thickness of said cavity is the same as the ratio of said rise to said length; and a channel formed between said inclined surfaces of said bushing and distributor means through which said extrudable material flows axially and peripherally.