摘要 |
A string zipper, with no mounting flanges, is welded to bag material for forming zipper bags. The zipper material is fed from a driven unwind and the bag material receives the zipper material. Guides place the zipper material wherever desired with respect to the bag material. The bag material, with the zipper material, is held between continuously moving belts. Stationary heaters are places against the belts, and provide heat through the belts sufficient to weld the bag material to the zipper material. The zipper material is then heated as a preseal before the material is contacted by the side welding blade which completes the seal and separates discrete bags. |