The method relies on a dedicated plastic extrusion welder that combines two functions in one tool: hot-air preheating and material extrusion. The nozzle first directs heated air onto the surfaces to be joined, bringing them to a molten state, after which the extruder injects molten filler material precisely into the seam.

Because the filler arrives already plasticised, the single-pass approach produces a deep fusion between the weld bead and the parent material rather than a surface bond. The result is a continuous, homogeneous joint that replicates the mechanical behaviour of the surrounding plastic.

The process differs from conventional hot-air welding chiefly in speed, penetration and repeatability, according to technical descriptions of the method.

The process is deployed across several heavy-duty sectors where thick sections and long service life are required.

• Large container fabrication: used for storage tanks and large plastic vessels, meeting the filler-volume demands of thick-walled structures.
• Pipeline engineering: provides reliable sealing and structural strength in municipal and industrial pipe networks.
• Environmental engineering: widely applied to impermeable landfill liners and waterproof roof membranes.
• Water management and agriculture: plays a key role in joining plastic components for land drainage systems, collection pits and irrigation infrastructure.

In each case, the ability to lay down a substantial volume of filler in a single pass shortens installation time while maintaining continuity along long seams.

The technique applies to thermoplastics, principally polypropylene (PP) and high-density polyethylene (HDPE). Before work begins, the filler material must be confirmed as compatible with the parent material so that proper fusion can be achieved.

Consistency depends on strict control of machine settings, including temperature and extrusion rate. Operators are also required to ensure the weld zone is clean and adequately preheated, and to maintain a continuous welding pass in order to avoid defects caused by parameter fluctuation.