This type of plastic welding is a very simple yet versatile process.This process consists of three steps.
- First, a welding plate is heated to the required temperature.
- Second,the work pieces to be joined together are pressed against the heated platen and the plate is removed when the work pieces are sufficiently molten.
- Third, the work pieces are pressed and held together until they cool and a joint is formed between them.
The hot plate used has shape similar to the geometry of the weld joint but more complex shapes can also be used.In order to prevent the adherence of molten plastic to the surface of the plate,it is coated with PTFE,i.e. polytetrafluoroethylene.The plate is heated electrically by resistance heaters.
The hot plate welding has a lot of advantages over other plastic welding processes.The weld produced is of very high quality and strength.This process can weld plastics of very complex geometries.Per cycle, a number of parts can be welded.Also,the nature of the process is very simple and the cost of the equipment is very less and even then it is compatible with most of the thermoplastics.The only problem faced is while joining nylon due to surface oxidation which causes poor joint strength.
As mentioned before this welding type is a very versatile process.Some of the applications are automotive industry where it is used to manufacture of hydraulic fluid reservoirs and battery cases, in the construction of buildings and for the construction of thermoplastic pipes for gas,water and effluents.