| 摘要 |
PURPOSE: To provide a lid wherein sealability can be maintained, the upper lid can be easily removed in use, the adherence or accumulation on the outer periphery of the upper lid skirt of dust or dirt is lessened, there is no possibility of outer lids contacting with one another in the transport, and removal from the mold is ensured even in a high-speed molding. CONSTITUTION: A horizontally split die 33 is provided with a groove 36 having a tapered die face 37 for forming the lower part of a skirt wall in order to form an annularly-shaped groove which permits a tapered surface gradually inclined from at least the deepest part in the thickness direction of the skirt wall toward the lower end of the outer peripheral surface to be formed at the lower part of the outer peripheral surface of the skirt wall 12 of an upper lid 10 in such a manner wherein the difference between the diameter of the deepest part and that of the lower end of the tapered surface is made larger than the contraction quantity after molding of the skirt wall at the lower end of the tapered surface and smaller than the limiting quantity of elastic deformation of the skirt wall. |
