| 摘要 |
PURPOSE:To save the operation of plugging pores, and to obtain the title resin pipe suitable for piping, by thickening the outer and inner walls of the pore parts of a pipe having pores arranged parallel to the long direction on the pipe wall with the intermittent deceleration or stop of the take-off unit, and by fusing the walls at an interval. CONSTITUTION:A molten resin is extruded continuously from an extruder through the annular space 24 of the mold 2 into a pipe 5 having the pores 51 parallel to the long direction formed by the pins 27, then fed between the sizing dies 31 and 32. The take-off unit 6 is intermittently decelerated or stopped to stay the pipe 5 in the annular space between the dies 31 and 32, and the surrounding walls of the pores 51 are thickened and brought near each other, thus forming the plugged parts 511 of the pores 51. |
