Netting type plastic film prodn. - by cutting staggered parallel rows of transverse slits and slightly stretching while warm, so prod. has equal strength

摘要

A perforated plastic film, e.g. a netting type, is produced from thermoplastic film which is extruded with longitudinal slits arranged in parallel rows, those of adjacent rows being staggered, and then heat-shrunk. The slits are actually made transversely to the length of the film, the preferred polymers for which are low density polyethylene and polypropylene. ADVANTAGE - The procedure produces netting or similar with transverse mechanical strength at least as high as that in the longitudinal direction. (3pp Dwg.No.1)