Commonly referred to as wedge welding – involves heat-seaming two opposing sheets of liner. The edges of the sheets are inserted into the machine, which in turn applies heat and pressure (via the nib rollers which also drive the machine forward) to create a double-track weld along the length of the sheets. The cavity between the sheets is then sealed at each end and pumped with air until it reaches 2.5 bar. If the air pressure holds without dropping more than the allowable 10% over 5 minutes, the seam is deemed to have passed. If not, any failures in the weld will be repaired by locating the point out of which the air is seeping.
Wedge-welding is recognized as the premier method of welding geomembranes.
Involves adding molten plastic to the original sheet of liner. This method is used for all repairs and detail work such as pipe boots and protrusions.
As well as testing each seam at completion, both the wedge welder and extrusion welder are calibrated at the beginning of each day to ensure they are set to the appropriate speed, temperature and pressure.Samples are cut from the test weld and are pulled apart on a specially designed tensiometer, giving a reading in Newtons indicating the strength of the weld.
Detailed design ensures we select the most efficient method to effectively join the panels, minimising material waste, and ensuring seam integrity.