Welding is one of the most commonly used and most dependable methods of joining thermoplastic
materials. As with metals, welding of thermoplastics is accomplished by application of localized heat
sufficient to produce fusion of the areas that are to be joined. Several different methods of welding have
been developed, as follows:
o hot-gas welding
o heated-tool welding
o induction welding
o friction welding (also known as spin welding).
The major difference among these various methods of welding is in the method of applying heat to the
materials.