| 摘要 |
A thermoplastic pipes reinforced with a wire framework by extrusion moulding, comprises transverse spiral reinforcement (3) coiled onto longitudinal reinforcing strings (2) arranged along the circumference of the fixed welding electrode (4), said reinforcement being welded to the longitudinal reinforcing strings with the help of the rotating welding device (5), following which the welded wire framework (2, 3) is introduced into the moulding cavity (6), whereto is simultaneously fed thermoplastic material being extruded. The transverse spiral reinforcement comprises at least two reinforcing spirals coiled in one direction with mutual central symmetrical shift by the coiling phase. In this case welding is effected with a plurality of roller electrodes (8a, 8b) distributed along the circumference of the roller welding device. <IMAGE> |
