| 摘要 |
PURPOSE:To obtain the title resin pipe free from water leak from the space of the pipe wall, by thickening the outer and inner walls of a double resin pipe and fusing the walls with the intermittent deceleration and stop of the take-off unit. CONSTITUTION:The double resin pipe 5 is extruded from the mold 2, cooled and regulated by the annular space 33 between the sizing dies 31 and 32. The take-off unit 6 is then decelerated or stopped temporarily to thicken the outer and the inner walls of the resin pipe 5 without changing the amount of the molten resin fed from the extruder 1 and extruded through the mold 2; thus fusing the walls. When the speed of the take-off unit 6 is returned to the normal one, the walls are separated from each other to form a double pipe structure. |
