| 摘要 |
A method or apparatus for joining polyolefin articles such as pipes, tubes or conduits by fusion bonding, in which the surfaces of the articles are raised to the fusion temperature (eg 150{C to 250{C) in a time of less than one minute (eg 10 to 30 seconds), and in which there is interposed between the surfaces to be joined a polyolefin film of a thickness less than 50 microns. The articles may be made of a material having a melt flow index of less than 0.2 and may be cross linked, such as crosslinked polyethylene. The heating may be carried out by infra red heaters or a mirror plate. The surfaces of the articles may be raised to different temperatures. The film may be substantially un-crosslinked. The articles may be of dissimilar polyolefin composition. |
