Abstract: A method for providing a wide-track integral thermoplastic closure for film or sheet stock. The closure includes ribs on either side of an element of the closure to provide the wide-track effect to assist one in ease of interlocking the closure elements. By varying the thickness of the closure element adjacent the ribs, the spacing of the ribs to provide the desired wide-track feel can be obtained.

Abstract: A method for reducing wax build-up on a sealing equipment where a heated element, such as a hot wire, cuts through and seals adjacent layers of thermoplastic material containing thickened thermoplastic sections. The wax build-up is related to the contact between the cutting and sealing wire and the thermoplastic material. The improvement results from a proper shaping of the cutting and sealing wire, by regulating the rising height and profiling of the wire through the film and thickened sections, and by employing relatively high wire travel speeds whereby it is possible to take advantage of the shrink back characteristics resulting from the orientation already built into the thermoplastic material, so that minimum contact between the wire and the thermoplastic material is realized.