| 摘要 |
PURPOSE:To uniformly thin the titled sheet in its entirety by folding a strip- shaped sealing material into two in the longitudinal direction so that the upper end side of a mouthpiece appears outside and fitting the folded sealing material to the outer peripheral open part of a double sheet in a state of pinching the upper and lower outer peripheral edges of the double sheet. CONSTITUTION:The mouthpiece 9 having a flange 8 at its lower end is inserted into a hole 11 formed at the central part of the strip-shaped sealing material 10 along arrows in the drawing, and is prevented from slipping off by the flange 8. Next, the strip-shaped sealing material 10 is folded into two along the longitudinal direction as shown by arrows, and fitted to a double sheet 12 in a manner of pinching the outer peripheral edges of the upper sheet 13 and the lower sheet 14, thereby to block the outer peripheral open part of the double sheet 12. A fluorine resin film 15 is inserted into the inner part of the mouthpiece 15. In this state, the strip-shaped sealing material 10 folded into two is heated, and is deposited by welding on the outer peripheral edges of the upper and lower sheets 13 and 14 of the double sheet 12. |
