| 摘要 |
PCT No. PCT/NL95/00160 Sec. 371 Date Jan. 15, 1997 Sec. 102(e) Date Jan. 15, 1997 PCT Filed May 3, 1995 PCT Pub. No. WO95/30533 PCT Pub. Date Nov. 16, 1995A tube is extruded from a thermoplastic material and is then forced over a mandrel at an orientation temperature of the material. The mandrel has an expanding section that expands the tube in its circumferential direction. A tube speed controller upstream of the expanding section of the mandrel exerts an axial force on the tube, and a puller downstream of the mandrel exerts an axial pulling force on the tube. Upstream of the tube speed controller, an outer layer of a wall of the tube is brought to a temperature below the orientation temperature. That outer layer is thick enough to withstand the force exerted by the tube speed controller. |
