| 摘要 |
PURPOSE:To eliminate trouble such as the breakaway or the like of parison at pre-blowing by a method wherein the opposing surfaces of pinch bars of a pinching device, which is provided below an injection molder, are formed to be arcuate. CONSTITUTION:The opposing surfaces or the ends of the opposing surfaces of pinch bars 13a and 13b are formed to be arcuate. To the backs of the respective pinch bars, the tips of supporting shafts 14a and 14b are fixed. The supporting shafts 14a and 14b are supported by the supporting bearings 16a and 16b of holders 15a and 15b. The holders 15a and 15b are connected to driving devices so as to contact and separate the pinch bars 13a and 13b in opposite directions. Thus, even when air blowing is performed under the condition that parison is pinched between the pinch bars 13a and 13b, no breakaway or the like occurs at the joint of the parison. As the parison, elastomer containing 50% or more of rubber component can be used. Further, the surface or the whole of the pinch bars 13a and 13b may well be made of elastic body. Thus, the breakage can be prevented from occurring, even when the pinch bars collide with each other. |
