Welding

Welding - Joining thermoplastic pieces by one of several heat-softening processes. In hot-gas welding, the material is heated by a jet of hot air or inert gas directed from a welding "torch" onto the area of contact of the surfaces which are being welded. Welding operations to which this method is applied normally require the use of a filler rod. In Spin-Welding the heat is generated by friction. Welding also includes heat sealing and the terms are synonymous in some foreign countries including Britain.