| 摘要 |
PROBLEM TO BE SOLVED: To easily and certainly form the air introducing part to the gap between outer and inner layers without requiring post-treatment. SOLUTION: This parison is constituted so as to be formed by fitting an outer cylinder 2 made of a synthetic resin having a thread 4 provided in the outer peripheral surface of the mouth part 11 thereof and molded into a closed- end cylindrical shape and an inner cylinder 3 made of a flexible synthetic resin freely relaeasable with respect to the outer cylinder 2 molded into a closed-end cylindrical shape wherein an outer flange 5 is provided in the upper end of the mouth part 11. In the case, the groove 7 being the air introducing part 6 to the gap between the outer and inner layers 12, 13 is preliminarily formed to at least one of the mouth part 11 of the outer cylinder 12 and the mouth part 11a of the inner cylinder 3 and the lower parts of the mouth parts 11, 11a of this parison 1 are subjected to biaxial stretch/blow molding. |
