| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a container lid suitable for integrally forming an extensible cylindrical part at a part of the container lid of a container for microwave oven cooking. <P>SOLUTION: A primary molded article 40 of which a portion other than a cylindrical part 47 serving as the extensible cylindrical part 9 is of the same shape as the container lid 3 of a final molded article is molded out of thermoplastic resin. A lid top plate part 41 and an opening part flange 43 in the primary molded article 40 left as it is as the part of the container lid 3 are mechanically held from both sides and placed in a thermal deformation prevented state thermally intercepted from both sides. In this state, only the cylindrical part 47 is heated. The cylindrical part 47 after heated is biaxially extended to form a bellows-like extensible cylindrical part 9, thus obtaining the container lid 3 integrally formed with the extensible cylindrical part 9 causing neither thermal deformation nor thermal deterioration. <P>COPYRIGHT: (C)2011,JPO&INPIT |
