PROCESS FOR PRODUCING THERMOPLASTIC FILMS BY BLOWN FILM EXTRUSION AND FILMS PRODUCED THEREBY

摘要

A process for making a thermoplastic film by the blown film extrusion process comprises extruding a molten thermoplastic polymer through a tubular die to form a tube of molten polymer, contacting the inner surface of the tube of molten polymer as it exits the die with an aqueous solution of a water-soluble polysaccharide ether, inflating the tube of molten polymer to form a blown tubular film and then collapsing the blown film to a flat web. The thermoplastic film has on its surface a coating of a water-soluble polysaccharide ether.