| 摘要 |
PROBLEM TO BE SOLVED: To improve the accuracy of folding position of a bag making paper and permit the coping with respective paper qualities by a method wherein the paper is folded by a roller conveyor along a folding line and a turning line while the central part of the turning line of the bag making paper, folded along the folding line, is pinched from both sides of up and down to set the posture of the bag making paper under the process of transferring to a folding work unit. SOLUTION: A paper tube forming device 4 is provided with a first folding process unit 42, folding a bag making paper by roller conveyors 41, connected in series, while pinching the same from a folding line and a turning line, and a second folding process unit, folding the bag making paper along the folding line. The second folding process unit is provided with roller conveyors, having the same constitution substantially as that of the first folding process unit 42, a second folding work unit, turning the bag making paper through double turnings in accordance with the folding line and bonding the folded paper, and a posture setting and transferring means, setting the posture of the bag making paper under transferring to the second folding work unit while pinching the same from up and down under a condition that the central part of the left and right turning lines of the bag making paper is provided with a length in the transferring direction of the same. |
