| 摘要 |
PCT No. PCT/NL95/00100 Sec. 371 Date Nov. 18, 1996 Sec. 102(e) Date Nov. 18, 1996 PCT Filed Mar. 17, 1995 PCT Pub. No. WO95/25627 PCT Pub. Date Sep. 28, 1995Method and device for manufacturing biaxially oriented tubing from thermoplastic material. The method includes forcing the tube over a mandrel at an orientation temperature of the plastic material, which mandrel includes an expansion part which produces expansion in the circumferential direction of the tube, and downstream of the mandrel the exertion of an axial pulling force on the tube, in the course of which the tube encounters a resistance which counteracts the movement of the tube over the mandrel. The method also includes the exertion of an influence sector-wise in an adjustable manner in the circumferential direction of the tube on the resistance which counteracts the movement of the tube over the mandrel. In an advantageous embodiment, the temperature of the plastic material of the tube is influenced sector-wise in an adjustable manner, viewed in the circumferential direction of the tube. The measures according to the invention lead to better control over the manufacture of biaxially oriented tubing. |
