| 摘要 |
PROBLEM TO BE SOLVED: To provide a zipper for corrugated board breaking capable of sufficiently suppressing occurrence of surface layer peeling of a corrugated board surface liner and capable of preventing appearance deterioration of a broken end edge.SOLUTION: The double breakable lines 4 are formed by a plurality of unit cuts 6, respectively. The unit cut 6 comprises: a first cut part 6a extending along a break direction; a second cut part 6b extending from the central side between both breakable lines 4 toward the first cut part 6a while inclining, and having an end edge continuing to a starting edge of the first cut part 6a in the break direction; and a third cut part 6c having one end crossing with the first cut part 6a and extending in a direction separating from a position between both breakable lines 4. One end of the third cut part 6c consists in a prescribed distance from the boundary between the first and second cut parts 6a and 6b, and crosses with the first cut part 6a at a position of the side of the second cut part 6b parting from the center of the first cut part 6a in a longitudinal direction.SELECTED DRAWING: Figure 2 |
