Wedge welders are smaller hand-held machines that weld two overlapped sheets of material. The welder heats the interface between the two materials with a heated metal “Wedge” and then presses the materials together to form a weld. The thermoplastic materials are then fused at the molecular level.
Wedge welders run at a comparatively high speed between clean, overlapped material and are used for the long straight welds. More complicated work such as curves or attaching pipe boots should not be done with a wedge-welder; detail work like this should be done with extrusion or hot-air gun .

Arian weld