The wedge is a heated metal blade that the machine drives between the two overlapped sheets, melting their surfaces just ahead of the pinch rollers. Crews say running the wedge for making fusion seams and treat wedge temperature and speed as the two settings they adjust most. Dirt or moisture between the sheets, or a worn wedge, shows up as cold spots and weak peels.
Bump the wedge up ten degrees and slow it down a hair, the peels are coming off the inside track.
Also heard as
- wedge welder
- hot wedge
- the wedge
Related terms
Fusion weld
Geomembrane seam made by melting the facing surfaces of two overlapped sheets and pressing them together.
Trial weld
Short test seam made on scrap geomembrane before production welding to prove the machine settings and the operator.
Burn-through
Hole or severe thinning in a geomembrane where a welder ran too hot or stopped on the sheet.
Seamer
Welding technician who makes and repairs geomembrane seams on a liner crew.