| 摘要 |
The U shaped reinforcing strips are continuously sealed onto the edges of a continuously moving film whereby the strips are continuously separated from film wider than the width of two strips, is folded over and then applied to the cut edges of the film acc. to parent patent, in which two adjacent strips are cut out of the middle of the upper and lower walls of a tube, they are folded into U shapes and then applied to the cut edges of the remaining half tubes. |
