| 摘要 |
In a process for welding plastic tubes and fittings, esp. of PVDF, (i) opposing tube (1,2) ends are butted against each other; (ii) an electrically heated sleeve (3) located over the joint heats each tube (1,2) in an outer area (6) at a specified distance from the butt joint (15) and welds the sleeve (3) to the tubes (1,2); (iii) a more intense htg is produced by the sleeve (3) in an inner area (5) to weld the abutting tube (1,2) ends together and the sleeve (3) to the tubes (1,2). A claimed welding sleeve (3) includes a heating element (4) with higher heat output in the centre (5) area than in the outer (6) areas. Also claimed is an inflation sack of silicone rubber, 1.5-2.5 mm thick for insertion into the tubes during welding to prevent softened plastic flowing inside the tubes (1,2). <IMAGE> |
