| 摘要 |
<p>PURPOSE:To obtain easily a resin pipe having a hollow rib that is seamless and uniform in thickness all round the surface by projecting the resin extruded from an extruder from starting as a hollow-ribbed resin pipe through the main slit and subsidiary slits of a rotary mold. CONSTITUTION:The resin 29' extruded continuously from an extruder 20 is revolved by the revolution of a rotary mold 21 in the peripheral direction while protruding. A hollow rib part 29b passing through a plurality of subsidiary slits 34 connected around the main slit 22 is provided spirally on the outer periphery of the annular part 29a that this protruded resin pipe 29 passes through the main slit 22 of the rotary mold 21. The resin pipe 29 protruded from the rotary mold 21 is brought into a negative pressure tank 24 from a rotary charging hole 25 rotating in the reverse direction to the rotary direction of the rotary mold 21 and at a speed equal to that of the rotary mold and subjected to sizing through the water. In this case, since the resin pipe is sucked radially by a suction hole 25b provided on the barrel of the rotary charging mouth piece 25, it does not deform. Thereafter, the resin pipe is extracted from a rotary extracting hole 26 and taken up by a resin pipe take-up unit 28.</p> |
