| 摘要 |
An electro fusion element 20 for connecting hollow plastics articles 28, 29 such as pipes, tubes etc, which comprises an annular body member of plastics material and an electrical heating member 25 embedded therein, which may be a spiral wound electrical resistance wire coil. The body member has fusion-bondable surfaces 23, 24 and at least a portion 21 of the body member has been cross linked such that it does not flow, or such that it flows only to a limited extent, when heated to the softening point of the plastics material. The plastics materials from which the various parts are made may be the same or different, such as polyolefins and especially polyethylene which may be cross linked. |
