Multilayer film manufacture utilizing scrap resin

Abstract From the Canadian patent

A novel system for producing film by extruding and/or casting at least two layers of resin such as, polyacrylonitrile homopolymer or interpolymers. The system provides for co-extruding a continuous multi layer film with contiguous or tandem dies from a first supply of homogeneous resin solution and a second supply of non-homogeneous redissolved resin scrap. The film may be cast onto a smooth cooled drum surface to form substantially continuous adjacent layers from two or more resin supplies. By stripping the film from the drum as a continuous film strip and stretching the film an oriented structure is provided. Scrap resin such as, selvage trimmed from the stretched film or mill scrap is …