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US 5,328,653 AGranted
Process of making heat-sealable oriented web
AssigneeMinnesota Mining and Manufacturing Company
InventorsPatrick D. Hyde, Andrew J. Ouderkirk
Life of this patent
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Abstract
A heat-sealable oriented film or layer of a semi-crystalline thermoplastic polymer. The film has a thin, heat-sealable layer of the same thermoplastic polymer having a different heat-seal temperature, which layer is heat-sealable without requiring fusion of the entire film. There is also provided a method for producing the claimed heat-sealable film.
Claims17
A process for forming a heat sealable surface layer or region on an oriented film or film layer of crystalline or semi-crystalline polymer comprising the steps of:
- (a) providing an oriented film or film layer of a crystalline or semi-crystalline polymer.
- (b) contacting at least a region of one outer surface of said oriented film or film layer with a heated textured surface at a temperature above the melting point of said oriented polymer for a time sufficient to treat a layer of said film to a thickness of no greater than 15 microns and at a pressure sufficient to ensure substantially continuous contact between the film and the heated textured surface.
Dependencies are inferred from the claim text.