Process and apparatus for forming integral interlocking closure film stock

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.