Patent attributes
This invention discloses a novel process for manufacturing very thin freestanding polymeric films with the steps of supplying a molten film layer stream and a molten assist layer stream by a first extruder and second extruder; intimately contacting the film layer stream and the assist layer stream in coplanar fashion; extruding the film layer stream and the assist layer stream through a planar coextrusion die lip; stretching the multilayer melt curtain; cooling the multilayer film; delaminating the assist layer or layers from the film layer; and transporting the film layer to downstream processing operations. This process allows manufacturing of very thin freestanding films made from amorphous polymers, highly filled films made from amorphous, semi crystalline, or crystalline polymers, chemically cross linked films, and films with diffused addenda that would normally cause undesirable reactions in an extrusion environment.
