PUNCHING METHOD FOR PROVIDING ELONGATION ALLOWANCE PART AND MAKING WIDTH OF INTERVAL BETWEEN TWO CREASE RULED LINES EQUAL TO INTERVAL OF CORRUGATION TOP PITCH OF DOUBLE-SIDED CARDBOARD SHEET

摘要

PROBLEM TO BE SOLVED: To provide a punching method in which a second longitudinal folding crease ruled line and a fourth longitudinal folding crease ruled line of a double-sided cardboard sheet box can accurately be folded at 180 degrees, regardless of the punching method of the back side punching and the front side punching, and thereby the box bonding failure such as fish tail and second buckling can be prevented.;SOLUTION: In the back side punching, second and fourth longitudinal folding press ruling members are formed by first and second press ruling members, respectively. A face plate 5 for forming an elongation allowance part 23 is provided at the position opposed to the middle of the first and second press ruling members 41, 42. An interval size 43 viewing from the center of the first and second press ruling members is made into the interval equal to the interval of a corrugation top pitch 26. In the front side punching, the second and fourth longitudinal folding press ruling members are formed by a left press ruling member 441 and a right press ruling member 442 respectively, and a press ruling member group 44 comprising a central press ruling member 443 for forming the elongation allowance part. The face plate with a recessed groove strip is provided at the position opposed to the press ruling member group, and the width of the recessed groove strip 55 is made into the interval equal to the interval of the corrugation top pitch.;SELECTED DRAWING: Figure 1;COPYRIGHT: (C)2018,JPO&INPIT