Method and apparatus for sealing flanges and deforming profiles of plastic zipper

摘要

A method of manufacture involves the following steps: extruding a first zipper strip comprising a first zipper flange and a first closure profile; extruding a second zipper strip comprising a second zipper flange and a second closure profile that is interlockable with the first closure profile; interlocking the first and second closure profiles; and welding the first and second zipper flanges together in a first zone and welding the first and second closure profiles together in a second zone by applying energy to both zones in one operation or in separate operations. A generally T-shaped zone of fusion is formed. The second zone forms the top of the T shape, while the first zone forms the stem of the T shape. The first zone forms respective flange seals, while the second zone forms either back-to-back preseals or back-to-back slider end stops when the zipper is cut, depending on whether the zipper is sliderless or slider-actuated.