| 摘要 |
PROBLEM TO BE SOLVED: To surely realize the turning-down of a front side tucking-in flap at the making of a bag having a small gore dimension by a method wherein a scoring plate for scoring a bottom return line and another scoring plate for scoring a bottom return line are acted on the sides different from each other or the front and rear sides of a paper cylinder. SOLUTION: A bottom folding scoring device 620 has a scoring blade 621A for scoring a bottom return line L4 by pressing the portion near the bottom of a bag of a paper cylinder T from above and a scoring blade 621B for scoring the bottom return line L5 by pressing the fore side of the bottom return line L4 from below. When the two parallel scores of the bottom return line L4 and the bottom tucking-in line L5 are scored on the paper cylinder T by rotating a lower rotation shaft 624 and an upper rotation shaft 622, the bottom return line L4 is under the state projected toward an underside and the bottom tucking-in line L5 is under the state projected toward a topside. When the paper cylinder T is developed in one plane by folding back the paper cylinder T at the bottom return line L4, a fore bottom tucking-in line is under the state projected toward the underside or the folding of the fore side tucking-in flap is performed by the valley folding in the direction of easy movement. Accordingly, the setting of a folding-back position can be performed precisely at the tucking-in of the fore side tucking-in flap inside. |
