James L Groff

US Patent:

41451759, Mar 20, 1979

Filed:

Mar 8, 1976

Appl. No.:

5/665000

Inventors:

James Groff - York PA
Stanley Driscoll - York PA

Assignee:

Keltrol Enterprises, Inc. - York PA

International Classification:

B29F 308

US Classification:

425377

Abstract:

An extrusion apparatus especially suitable for the extrusion of ultra high molecular weight polyethylene comprising an elongated die having internal heating and cooling temperature control units. The die comprises one piece straight through construction and incorporates a chamber that is positioned in longitudinal alignment with the die profile zone. The ratio of cross sectional areas of the chamber and of the die profile zone is substantially one to one. A punch forces the polyethylene through the chamber and into the profile zone of the die wherein the resin is cured and extruded to the desired shape. Internal heating passages and cooling passages are positioned within the die to form a temperature gradient wherein the temperature is greatest at a point intermediate the ends of the die. The travel of the extruded shape is retarded by an adjustable clamp exteriorly of the die.