| 摘要 |
PROBLEM TO BE SOLVED: To provide a technology that increases a linear velocity while reliably forming a protrusive structure of a corrugated tube by blow molding.SOLUTION: A narrow slit groove 61 is formed in such a manner as to cross recesses 51, 52 and 54 and a small recess 53, which are formed on a molding surface 501S of a cope 501 of a molding die 50. The narrow slit groove 61 is opened on the bottom surfaces of the recesses 51, 52 and 54 and the small recess 53. Spaces communicating with the outside of the molding die 50 are formed at both the ends of the cope 501, respectively. When a parison 71 is expanded to get into the recesses 51, 52 and 54 and the small recess 53, gas 80 within them is pushed by the parison, and discharged to the outside of the molding die 50 through the narrow slit groove 61. |
