| 摘要 |
A draw tape bag is formed from a plastic web. An edge folding unit, a notching unit, a tape inserting unit, a heat sealing unit and a web folding unit form a compact continuous line in a rectangular path. The hem folder includes a L-shaped plate within the hem to receive a draw tape. The plate is pivotally mounted the tape within the hem. A wheel is rotatably and pivotally mounted for pulling the hem onto the plate. A single strap on a roll has a width equal to both tapes. The roll is driven and the strap passes over a knife to sever the strap from the tapes. A tension control roll is coupled to moving the strap and controls the strap feed to hold a constant tape tension. A folding board includes spaced edge channels in a V-shape for folding the flat web. An air layer is interposed between the web and the folding channels to provide a low friction movement. A bag making machine includes a presealer to form tape edge seals, a cooler for cooling the tape hems and an edge sealer and cutting unit to form the side edges of the bag.
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