| 摘要 |
PROBLEM TO BE SOLVED: To provide a manufacturing method for a blow molded article which can form a rib that maintains stably a high quality of an outward appearance and that extends to the design surface side from the bottom side, partitions the inside of a hollow part and ensures a prescribed rigidity, adopting a relatively simple method of manufacture. SOLUTION: A parison 2 extruded from a die 1 is held in by a blow mold 4 and, by closing the mold, a sealed parison 2a is formed in a cavity C. In succession, compressed air is blown into a hollow part S of the sealed parison to press the parison on a mold face 43, so as to shape it into a hollow molded article 3a. After passing of the time when crystallization of a surface layer portion 30 of a design surface of the hollow molded article being in contact with the mold face 43 is almost ended, a slide core 5 is advanced into the hollow part S of the hollow molded article 3a of which the most part is still in a softened state, so as to make a portion of the article 3a extend to the design surface side from the bottom side so that the rib 33 partitioning the inside of the hollow part S be formed. |
