| 摘要 |
PURPOSE:To make an intermediate layer of a molded body moldable at appropriate positions in parts each in a vertical direction of the molded body, by a method wherein a feed rate of surface layer forming resin through the second resin discharge port is varied at the first and second processes. CONSTITUTION:An intermediate layer forming resin is fed through an extruding machine 19 and enters into a process discharging oxygen barrier layer forming resin through the third resin discharge port 14a. The process possesses the first process forming a part corresponding to a belly part of a preform and the second process forming a part corresponding to the bottom part of the preform. A flow control valve 20 is opened to its full width and a flow rate QS1 of resin flowing through an inner surface layer resin feed passage 15 is increased more than a flow rate QS2 of the resin flowing through an outer surface layer resin feed passage 13, in the first process. A ratio Qr between the flow rates QS1, QS2 of the resin is set up at about 1.6. The ratio Qr is set up at about 0.3 and a position of an oxygen barrier layer is positioned at an inner side of a vessel than the center line of a thickness. |
