| 摘要 |
PROBLEM TO BE SOLVED: To facilitate opening by pulling of tear strips, while securing a pressure resistance of a cardboard box.SOLUTION: A cardboard box is opened by applying cut-lines 11 of liner cut in parallel to a corrugated fiberboard and forming a tear strip 12 sandwiched by the cut-lines 11, and then pulling the tear strip 12 from a cut starting part 13 and cutting the corrugated fiberboard. Stepwise crushed parts 14 crushing a core of the corrugated fiberboard are intermittently arranged vertically only along the cut-lines 11 positioning on the lower part among the cut-lines 11 arranged in upper and lower parts of the tear strip 12. An end side 14a, which is positioned on the terminal side of the tear strip 12 among end sides forming the circumference of each stepwise crushed part 14, is to be directed from the upper part of cut-line 11 to the diagonally downward from the starting-edge side of the tear strip to the terminal side thereof. A portion between the stepwise crushed parts 14 serves as a rib in the stacking, and the tear direction is corrected to the lower direction by the end side 14a of the stepwise crushed part 14 in the opening. |
