| 摘要 |
PURPOSE:To mold the molded object having the peripheral edge of the opening-with high rigidity by a method in which the bottom of the parison having a closed bottom and a nearly U shape in cross section is penetrated with a blow pin, and the opening for blowing is formed on the bottom, and then while the opening edge is folded into the inner part of the parison, the mold clamping and the air blowing by the blow pin are carried out. CONSTITUTION:The parison having a nearly U shape in cross section is extruded in the direction of arrow C. The below pin 7 arranged movably up and down and rotatably is rotated in the direction of arrow C and is simultaneously raised, and then the bottom 6a of the parison 6 is penetrated therewith, thereby forming the opening 10 for blowing. Then, the end of a mouth 2 is made into double structure by folding the opening edge 8 of the parison 6 into the hollow space of the parison 6. In the blow pin 7, a screw thread 7a is formed at the corresponding position of the opening edge 8. The screw thread 7a is brought in close contact with the opening edge 8 of the parison 6 by closing a bottom force in the direction of arrow D, and the screw thread is formed on the opening edge 8. Blowing is carried out by the blow pin 7 and flange-forming part 6a is held between a top force 11a and the bottom force 11b, whereby a flange 6b is formed in the shape folded into double. |
