| 摘要 |
PROBLEM TO BE SOLVED: To effectively reduce a pull-open force for opening a can lid, such as a full-open type can lid, which is broken by pulling the can lid in the reverse initial break direction. SOLUTION: An opening is formed on the easy-openable can lid having superior tear-openability by pressing part of break guide grooves called scores, which are formed on a steel plate, to form an initial break, and then pulling the can lid in the reverse pressed direction to tear the can lid. The scores are formed on the outer surface and inner surface of the can lid, respectively, to be opposite to each other. The groove section of each of two scores is of a curved surface portion having a radius of curvature of 0.1-1.0 mm. The minimum radius of curvature of the curved surface portion of the score formed on the inner surface of the can lid is larger than that formed on the outer surface of the can lid by≥0.05 mm, the depth of the score on the inner surface of the can lid is≥0.01 mm, and the minimum plate thickness of a score machined part is 0.03-0.09 mm. COPYRIGHT: (C)2004,JPO&NCIPI
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