Abstract: A process and apparatus for producing integral interlocking closure film stock useful in making reclosable containers by extruding a film of molten thermoplastic material onto a casting roll, extruding closure elements to contact and join said film at a point between about one inch and about five inches prior to the tangency line of the film on the periphery of the casting roll, partially cooling the closure elements with liquid coolant starting anywhere within the region between the closure element extrusion exits, and the tangency line of a film of molten thermoplastic material and the periphery of the casting roll, and further cooling the closure elements by directing them past additional cooling assemblies. Stripping means are employed to remove liquid coolant from the cooled integral interlocking closure film stock material produced.

Abstract: A method is disclosed for the extrusion of low-density linear polyolefin materials having high viscosities, wherein such materials are continuously fed to and through a rotary extruder having feeding, transition and metering sections which comprises employing, in the extruder screw forming such sections in cooperation with the cylindrical interior of the extruder housing, opened leading edges for the screw flights of said sections; and gall-resistant coated surfaces on the screw flights of said sections.