A METHOD AND APPARATUS FOR SPIRALLY WINDING A THERMOPLASTIC PROFILE IN THE MANUFACTURE OF WELDED PLASTIC TUBES

A method of spirally winding a thermoplastic profile (1) in the manufacture of welded plastic tubes and a winding apparatus for manufacturing a spirally wound tube. A thermoplastic profile (1) is received on a plurality of sliding members being arranged in an axial direction of the tube (4) to be manufactured and defining an essentially cylindrically shaped winding surface with a diameter essentially corresponding to the inner diameter of the tube (4). The profile (1) is directed along a spiral path (S) towards the previous tum of the profile (1) in order to force opposite edges (1 a, 1 b) of the profile together for welding. The radial position of the sliding member is adjusted to control the tension in the thermoplastic profile (1) and the force with which it constricts itself around the winding surface as defined by the sliding member. Figure 1