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AssigneeAlphacan
InventorsBernard Prevotat, Guillaume Duval
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The invention concerns a continuous manufacturing method which consists in producing a blank (E) by extrusion, bringing said blank to a temperature for molecular orientation, passing said blank around a radial expansion mandrel (12); gauging and cooling while subjecting the blank to axial traction. The radial expansion produced on the mandrel (12) is partial so that the internal diameter (B) of the blank (E), when it leaves the mandrel, is less than the nominal internal diameter (D) of the finished tube, performing an additional radial expansion of the blank, up to its nominal diameter, by internal fluid pressure. In permanent operating conditions, the inner surface of the blank (E) is no longer in contact with the mandrel (12).
A process for the continuous manufacture of plastic pipes with biaxial drawing, in which a tube blank (E) is produced by extrusion, this tube blank is taken to the molecular orientation temperature, this tube blank is made to pass around a radial expansion mandrel (12), the tube blank is sized and cooled while subjecting it to an axial pulling force, characterized in that:
The process as claimed in one of the preceding claims, characterized in that the pulling force on the pipe is exerted at a single point (25) lying downstream of the sizing device and of the cooling device.
A line for the continuous manufacture of plastic pipes with biaxial drawing, comprising:
Dependencies are inferred from the claim text.