| 摘要 |
A series of bags are fabricated using a continuous, high-speed bag-forming process in which an elongated section of flattened film tubing is longitudinally conveyed toward a receiving station in which the formed bags are suitable packaged. As the flattened tube is moved toward the receiving station, elongated plastic film tie elements are sequentially formed and welded along relatively large area end portions thereof to at least two layers of a side edge portion of the flattened tube at longitudinally spaced locations thereon adjacent the upper end locations of the individual bags, the resulting free end portions of the tie elements overlying the flattened tube. Each of the resulting integral tie elements may be looped around an upper end portion of its associated bag and then firmly pulled to close the bag, the resulting loop being tightened either by first passing the free end portion of the tie element therethrough or by first passing the free end portion through an aperture formed in the tie element-bag weld area. In either case the relatively large, multiple layer weld area which secures the tie element to a side edge portion of its bag provides sufficient strength so that separation of the tie element from its bag, during tightening of the loop around the upper bag end, is effectively prevented.
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