| 摘要 |
PROBLEM TO BE SOLVED: To provide a manufacturing method for a packaging bag, by which a fastener can be attached easily and beautifully.SOLUTION: A sheet material 1 is continuously drawn and on one surface 1a, a chuck tape male part 2 and female part 3 are juxtaposed and fused. Then, on a widthwise center line between the chuck tape male part 2 and female part 3, a grooved tearing line 5 is formed in the sheet material 1. Next, the sheet material 1 is folded along the tearing line 5 such that the one surface 1a is oriented outside. Then, a reverse folding guide roller is brought into contact with the sheet material 1 from the one surface 1a side of a folded part, and also a pair of reverse folding guide members are brought into contact with the sheet material from the other surface side. The sheet material 1 is folded along two mountain-folding parts and one valley-folding part, thereby forming a folded part with an M-shaped cross-section having a first sheet part, second sheet part, third sheet part, and fourth sheet part in order. In the folded part, a fastener is formed such that the chuck tape male part 2 and female part 3 are opposite each other so as to be fittable and the second sheet part and third sheet part are mutually sealable. Also, a tearing line is disposed nearer to the bag inside than to the fastener.SELECTED DRAWING: Figure 1 |
