PROCESS FOR PRODUCING METALLO-POLYMER TUBING AND A DEVICE FOR CARRYING OUT THE SAME

摘要

The invention concerns the continuous production of metallo-polymer tubing for use in hostile environments under pressure. The aim of the invention is to improve both the mechanical properties of the tubing and the quality of the inner surface. The process for producing the tubing in question involves winding reinforcing coils (3, 3a) onto the elements of the longitudinal unit (2), welding them to those elements to match the winding using contact-roller electrodes (4, 4a) which turn about the axis of the reinforcing coil, and introducing the reinforcing body thus obtained into a moulding cavity into which molten polymer is simultaneously poured. The welding current at each contact-roller electrode is adjusted independently. The device used in producing the tubing comprises: an extruder with a tip (9) carrying direct-current and on which are mounted a mandrel with guide grooves for the longitudinal unit, and a cooled core; a housing (12) with drum (14) on which are mounted spools (16, 16a) for the transverse unit, deflecting rollers for the winding of the reinforcing coils, contact-roller electrodes for welding the latter and a feed commutator (20); an immobile sleeve (21) inside the drum which together with the core forms the moulding cavity; and a mechanism for feeding the finished pipe. The feed commutator is in the form of insulated sections matching the number of electrodes.