| 摘要 |
Infra-red transparent elongate hollow members 1, 2 formed eg of a heat recoverable cross-linked polymeric material and having end portions of different diameters are joined by inserting an end portion 4 of the first member into an end portion 5 of the second member, interposing a layer 3 of infra-red absorptive material between the two end portions, and heating the infrared absorptive layer to the fusion temperature of the polymeric material by the application of infrared energy. The layer may be a coating of un-cross-linked polymer containing a filler of infra-red absorbent material eg carbon black. Heating may be by way of an infra-red source 7 positioned internally or externally of the joint. Internal or external support members 6 may be provided at the joint region during fusion. <IMAGE> |
