Patent ID: 6540949
Filing Date: 2003-04-01
Classification: B29C,B29K,B32B,C07K,C08J,Y10T

Abstract:
A method of producing a multilayer polyethylene film comprising the steps of:(i) casting a polyethylene sheet comprising: (a) a base layer comprising polyethylene and a cavitating agent, and (b) a layer of a WVTR-controlling material coextensively adherent to a side of the base layer; and (ii) biaxially orienting said polyethylene sheet resulting from step (i) to obtain a WVTR of greater than 0.2 g/100 inch2Â·day in the multilayer polyethylene film; wherein the base layer has a porous microstructure and a WVTR higher than the WVTR of the multilayer polyethylene film.