| 摘要 |
PROBLEM TO BE SOLVED: To reduce use of materials and to eliminate sealing defects or wrinkles in seaming can-tops by reducing the cutting diameter of a can-top material while the strength of the can-top is maintained, in a thin can-top formed with a reinforcing annular groove. SOLUTION: The chuck wall part 4 situated between the flange curl part 5 and the reinforcing annular groove 3 is composed of an upper wall part 4a extending from the inner edge curved wall part 5a of the flange curl part 5 and a lower wall part 4b continuing to the outer edge of the reinforcing annular groove 3. A bent part 4c dividing the upper and lower wall parts 4a, 4b is situated at the height lower than and close to the sealed part when the can-top 1 is seamed to a can body 10. The lower wall part 4b that is continuous to the upper wall part 4a through the bent part 4c is formed with an inclination gentler in the angel at least by 5 deg. or more compared with the upper wall part 4a.
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