| 摘要 |
<p>Method and device for manufacturing biaxially oriented tubing from thermoplastic material. The method comprises forcing the tube over a mandrel (3) at an orientation temperature of the plastic material, which mandrel comprises an expansion part (5) which produces expansion in the circumferential direction of the tube. Downstream of the mandrel and 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 (12) bounded by calibration means, 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 (3) and the calibration means (12), in particular depending on the external dimensions of the tube measured downstream of the calibration means.</p> |
