| 摘要 |
PURPOSE:To prevent generation of cracks along the groove, effectively, without losing buffer effect by the groove, by making a molecular orientation of polymer, which is formed in the ring-shaped buffer grooved part of the sealed gasket, in radial shape. CONSTITUTION:The sealed gasket 20 for cylindrical alkaline cell is an injection molding product of polypropylene or the like, integratedly formed of the boss part 22, coupling part 26, ring-shaped buffer grooved part 28, and outer cylindrical part 24. The ring-shaped buffer grooved part 28 with a V-shaped sectional area is formed near the surroundings of the coupling part 26. The molecular orientation of polymer in the ring-shaped buffer grooved part 28 is radial like indicated by an arrow a and is perpendicular to the direction of the groove. The fastening force actuating through the surroundings of the sealed gasket 20 is operated to generate cracks along the circular line of the groove in the ring-shaped buffer grooved part 28, however, since the molecular orientation of polymer is perpendicular to the direction of the groove there, the strength, against the force which generates a breaking along the groove, becomes very large, with few cracks being generated. |
