| 摘要 |
This invention pertains to draw tape equipment, and methods for incorporating draw tapes into plastic and like bags. In general, a continuous plastic web is slit at a slitting station to form layers, and respective free edges. The web then passes to a hole forming station where holes are punched in the top and bottom layers adjacent the free edges. After the holes are punched, edge regions of the top and bottom layers are separated from each other, followed by forming of hems in the separated layers at hem forming stations arranged in parallel with each other. Concurrent with forming of the hems, continuous draw tapes are fed to the hem forming stations and the hems are formed about the draw tapes. The formed hems, with the draw tapes incorporated therein, optionally pass through first temperature control stations where the temperature of the plastic web is controlled to a desired temperature before hem sealing. The formed hems are then sealed to the main bodies of the respective top and bottom layers. Narrow pressure wheels apply pressure to the hot seals to improve seal quality. The sealed hems optionally pass through second temperature control stations to cool the web. The edge regions of the layers are then rejoined, in face-to-face relationship with each other. |
