| 摘要 |
PROBLEM TO BE SOLVED: To provide a square can lid which is superior in leakage resistance and applicable to such a square can in view of recent trend of a battery can or a case of an electric equipment, increasing volume efficiency by reducing a gap between cans when arranged in parallel by making the radius of the four-corner parts of a square can small. SOLUTION: Before molding into a square can lid 1, a non-stretched polyester coated aluminum sheet as a material is pre-heated and its crystallinity is made into 20-40%. Thereby, even if the radius R of the four-corner parts of the can lid chuck-wall 1w is made 5-10 mm, film wrinkle 1s due to molding is not generated. COPYRIGHT: (C)2007,JPO&INPIT |
