Quadrant Epp Ag

Wesley Allen Kohler

Joseph V Gregg

Lyle D Berning

Wide panels of UHMWPE having exceptional flatness and surface quality are ram extruded through a slit die equipped with a plurality of individually adjustable cooling zones proximate the panel exit slit and transverse to the machine direction, which cool the panel while the panel is restrained by a back pressure device and preferably a vertical movement restraint. The process is robust and can be run for long product campaigns.

Production of UHMWPE sheet materials

UHMWPE panels of large width may be ram extruded from a slit die in a stable process, by restraining a panel which exits the die below the crystalline melt temperature against movement away from the die by a back pressure device, so as to exert a back pressure between the back pressure device and the die, the back pressure device preferably constructed of a plurality of differentially adjustable elements so as to be able to compensate for changes in processing characteristics over time. Vertically restraining UHMWPE panels as they further cool also greatly improves product characteristics.

UHMWPE panels of large width may be prepared by a continuous ram extrusion process by employing a slit die which preferably narrows from both sides in a direction transverse to the machine direction, and/or which employs a plurality of transversely positioned cooling zones located on the top and the bottom of the die, proximate the exit thereof. The panel exits the die at a temperature lower than the crystalline melt temperature.

Wide panels of UHMWPE having exceptional flatness and surface quality are ram extruded through a slit die equipped with a plurality of individually adjustable cooling zones proximate the panel exit slit and transverse to the machine direction which cool the by a back pressure device and preferably a vertical movement restraint. The process is robust and can be run for long product campaigns.

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Ossian, IN, United States of America

Wesley Allen Kohler