Patent ID: 9346254
Filing Date: 2016-05-24
CPC Classification: B29C,B32B,Y10T

Claim Text:
1. A process for producing a polymer coated metal substrate comprising the steps of: providing a metal strip as a substrate; providing a polymer film, consisting of one or more layers, for coating onto the substrate; optionally providing an adhesion layer for promoting the adhesion between the substrate and the polymer film; wherein the polymer film consisting of one or more layers is produced by: melting a suitable mixture of polymer granules in one or more extruders to make molten polymer; passing the molten polymer through one or more dies or calendars to form the polymer film consisting of the one or more layers; cooling the extruded polymer film to form a solid polymer film; trimming the edges of the extruded polymer film; reducing the thickness of the solid polymer film by stretching the solid polymer film in a stretching unit by exerting a stretching force only in the longitudinal direction; optionally trimming the edges of the stretched polymer film; laminating the stretched polymer film onto the substrate to produce a polymer-coated substrate; post-heating the polymer-coated substrate to reduce the orientation and crystallinity of the polymer film; cooling the post-heated polymer-coated substrate.