Definition - What does Extrusion Welding mean?
Extrusion welding is a technique used to join thermoplastics and composites. The process involves using a welding machine that heats and melts a plastic filler material while simultaneously heating the base material to be welded. The pressurized molten filler plastic is extruded from the machine on to the surface of the base material. The two molten plastics (the filler and the base material) are allowed to cool to form a permanent bond.
Trenchlesspedia explains Extrusion Welding
Extrusion welding is typically done on thermoplastics due to their response to heating. Unlike other types of plastics which burn when heat is applied, thermoplastics liquefy and harden again upon cooling.
Extrusion welding is typically used to join components such as tanks and pipes. In trenchless construction, sections of thermoplastic (most often polyethylene) can be extrusion welded together to form a monolithic pipe structure to be inserted into the host pipe for rehabilitation.
In other applications, extrusion welding is ideal for applications that require lengthy welds to be made in a single run. Although most commonly done on HDPE sheets, extrusion welding can be performed on other thermoplastics such as polyvinyl chloride (PVC), polypropylene (PP), and polyvinylidene fluoride (PVDF).