| 摘要 |
PROBLEM TO BE SOLVED: To improve a quality of a product by a method wherein a cut end of a synthetic resin film is finished clean while a welded position of a strap handle is not shifted. SOLUTION: When a synthetic resin film-made tube 1 is in a plane double layers state folded up longitudinally, one side is folded into W-figured side edges 4 and 5 by providing a folded-in part 3, thereafter the folded-in ridgeline 6 is cut to be opened, the heat sealed 7 and cut 8 at a specific interval in a direction crossing the longitudinal direction, and an edge is dropped by cutting the W-figured side edges 4 and 5. |
