| 摘要 |
PCT No. PCT/NL95/00099 Sec. 371 Date Nov. 22, 1996 Sec. 102(e) Date Nov. 22, 1996 PCT Filed Mar. 17, 1995 PCT Pub. No. WO95/25628 PCT Pub. Date Sep. 28, 1995A method for manufacturing biaxially oriented tubing from a thermoplastic material. The method includes forcing the tube over a mandrel at an orientation temperature of the plastic material, which mandrel is an expansion part which produces expansion in the circumferential direction of the tube. Downstream of the mandrel an axial pulling force is exerted on the tube, and the biaxially oriented tube is cooled down. At a distance downstream of the mandrel, the tube is drawn through a calibration opening bounded by a calibration device, the calibration opening being such that it produces a reduction in the external dimensions of the tube. Accurate regulation of the external dimensions of the tube is provided by regulating the distance between the mandrel and the calibration device, in particular depending on the external dimensions of the tube measured downstream of the calibration device. |
