| 摘要 |
PROBLEM TO BE SOLVED: To control the distortion of a container, in particular, its central portion so as to prevent the central portion in the bottom of the container from cracking resulting from the internal pressure of a content containing carbon dioxide after being filled by cooling the outer surface in the bottom of the container by a bottom mold and cooling at least the inner surface of the central portion in the bottom of the container by cooling air after performing biaxial oriented blow molding on a preform to manufacture the container. SOLUTION: A preform is oriented in the radial direction by blow air, almost at the same time when the preform is extended in the axial direction, and the biaxial oriented blow molding is performed to manufacture a container V. The outer surface in the bottom of the container V is cooled by a bottom mold 2 where cooling water is circulated through a cooling water passage 3. The inner surface of the central portion C in the bottom of the container V is cooled by blowing the cooling air from cooling air holes 6 in the front end portion of an oriented rod 5. This results in the cooling of the thick portion formed in the central portion C in the bottom of the container V from the inner and outer surfaces at the time of the biaxial oriented blow molding, so as to control the distortion in the bottom V of the container, in particular, the central portion C in the bottom, caused by the shrinkage after the biaxial oriented blow molding. |
