Flocculation and rapid sepn. sepn. of liq. suspensions

摘要

Polyolefin film with a mat finish comprises at least two coextruded layers; an upper mat finish layer comprising high density polyethylene, polypropylene or blends thereof and a second layer comprising low density polyethylene, linear low density polyethylene or blends thereof. The film is prepd. by coextrusion of an external layer comprising high density polyethylene, polypropylene or blends thereof and an internal layer comprising low density polyethylene, linear low density polyethylene or blends thereof. The extrusion process comprises passage of the coextruded layers from feed zone to an extruder die through temp. control zones where the external layer passing through the temp. control zones from the feed zone is heated more rapidly to a higher temp. than the corresp. internal layer in the corresp. temp. control zone