| 摘要 |
PROBLEM TO BE SOLVED: To facilitate forcible extraction in the inward lip part of a cylindrical molding having the lip part at the opening end fringe. SOLUTION: A thermoplastic resin molding material is injected/packed in a cavity 19 formed by upper and lower molds 10, 11, a core 14, and a core mold 12. After the molding material being cured, the upper mold 10 is opened, and the lower mold 11 and the core 14 are moved relatively to form a space 20, which makes the lower half part of the peripheral surface of the opening end part 13 of the cylindrical molding 1 expandable outward in the diameter direction, between the molding surface 14a of the core 14 and the lower half part of the opening end part. Next, the opening end part 13 of the molding 1 is extracted forcibly while bing expanded/deformed into the space 20, while the core mold 12 is extracted from the molding 1. After the forcible extraction, the opening end part 13 which is expanded temporarily is contracted to be restored to be approximately parallel with the axis.
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