| 摘要 |
PURPOSE:To enhance the molding accuracy of a flange and increase the yield of a molded product by molding an expanded section by a cavity provided on the mold surface of a blow mold simultaneously with blow molding of a hollow molded product, compressing the end surface of said expanded section by pressure and forming a flange around the end of the expanded section. CONSTITUTION:A preform 10 is set in a blow mold 1 and clamped. After that, air is blown from a blowing core to mold a thin wall cup shaped hollow molded product 11. At that time, a pressing component 4 connected with a piston rod 2 is retracted deep into a cavity 2. Then, part of the preform 10 is pushed into deeper than a step 3 of the cavity 2 by air pressure, and expanded. Before an end face 12a of said expanded section 12 is cooled, the pressing component 4 is pushed out toward the step 3 to form a flange 13. The molding accuracy of the flange is enhanced by thus process, and the yield of the molded product is increased. |
