| 摘要 |
PURPOSE:To suppress the heat generated from a molten resin and to prevent bubbles from becoming unstable and the generation of melt fracture, by guiding bubbles, which were emitted from the ring shaped emitting orifice of an inflation film molding die, to the downstream direction without almost changing the diameter thereof and contacting the same with the outer peripheral surface having a diameter almost equal to that of the bubbles and having a length about 2-3 times said diameter, from the downstream position spaced apart by the dimension 0.5-3 times said diameter from the position of the ring shaped emitting orifice. CONSTITUTION:A lower stabilizing body 13a is provided at a position spaced apart by the dimension corresponding to 1/2 of a diameter D- the distance almost equal to the diameter D from a ring shaped emitting orifice 12 and an upper stabilizing body 13b is fixed to a core rod 11 so that the lower end thereof is allowed to be spaced apart by the dimension 2-3 times the diameter D from the emitting orifice 12. A molten resin is emitted so as to set the emitting amount thereof/1cm in the circumferential direction of the emitting orifice 12 to 2-4 kg/h and a blow ratio is set to 4-7 and the bubbles 15 immediately after emission are contacted with the lower stabilizing body 13a at first and subsequently contacted with the upper stabilizing body 13b to perform molding so that a neck height H is set to 8-12 times the dimeter D. |
