PREPARATION OF AN END OF A THERMOPLASTICS TUBE MANUFACTURED BY SPIRALLY WINDING A HOLLOW PROFILE

摘要

The invention concerns a method for preparing an end of a thermoplastics tub e (1) manufactured by spirally winding and welding together of a hollow profil e (1a) having a substantially rectangular cross section, and is characterized by the steps as follow: cutting the end of the tube by a planar transversal section; extruding a second hollow profile (2) having a rectangular cross section and an outer shape essentially similar to that of the hollow profile (1a) from which the tube (1) is manufactured; spirally winding the extruded second hollow profile (2) around a drum having a diameter corresponding to inner diameter of the tube (1); cutting a loop (2a) from the second hollow profile (2) in a length corresponding to circumference of the tube end; joining the ends of the loop (2a) to each other, whereby a ring (2b) is achieved having same inner and outer diameters as the spirally wound tube (1 ); placing the ring (2b) against the cut tube end; and welding the ring (2b) to the tube end.