MANUFACTURE OF THERMOPLASTIC RESIN MOLDED PRODUCT

摘要

PROBLEM TO BE SOLVED: To obtain a molded product excellent in heat resistance and appearance and satisfying various physical properties such as shock resistance or the like by subjecting a first molded product obtained by molding a sheet made of a thermoplastic resin to heat shrinkage treatment to form a second molded product and subjecting the second molded product to pressure forming or vacuum forming to obtain a third molded product having capacity smaller than that of the second molded product but larger than that of the third molded product. SOLUTION: A thermoplastic resin sheet is used to mold a first molded product larger than a final shape as a first stage. The first molded product is molded by extending the sheet only by a plug. The first molded product is thermally shrunk at high temp. after the first stage molding to remove orientation crystallization and strain to obtain a second molded product and the thermally shrunk second molded product is subjected to pressure forming and/or vacuum forming to obtain a third molded product. This third molded product is excellent not only in heat resistance but also mechanical strength such as impact resistance or the like.