Patent ID: 7081176

Claim:
A method of attaching a zipper tape in a folded web of bag making film, comprising the following steps: (a) extending a web of bag making film in a machine direction; (b) placing a zipper tape on said web of bag making film, said zipper tape being generally aligned in said machine direction, said zipper tape comprising a first profiled closure element, a first zipper flange connected to said first closure member and having a distal edge, a second profiled closure element that is interlockable with said first closure element, and a second zipper flange connected to said second closure element, folded at a cusp, and having a distal edge confronting and separated by a gap from said distal edge of said first zipper flange; (c) joining a first portion of said second zipper flange to said web of bag making film in a first zone of joinder; (d) folding said web of bag making film so that first and second portions of said web extend upward from said fold with said zipper tape sandwiched therebetween, said fold being placed so that said first zone of joinder is on said first portion of said web; (e) substantially thermally isolating said first portion of said second zipper flange from a second portion of said second zipper flange that opposes said first portion of said second zipper flange; and (f) joining said second portion of said second zipper flange to said second portion of said web in a second zone of joinder by directing thermal energy toward said second portion of said second zipper flange while said first portion of said second zipper flange is substantially thermally isolated therefrom.