Geomembrane is a polymer anti-aging material with high barrier properties, which can withstand various acids and alkalis and can be reused. During the oil drilling process, a large amount of sewage and mud are generated. Geomembranes have been widely used in dam seepage control, channel seepage control, water retaining cofferdams, flood control and emergency response, emergency reinforcement, and repair projects.
In recent years, geomembranes have been used in pre drilling engineering to prevent leakage and prevent soil contamination by petroleum drilling mud materials. The welding quality of geomembrane is a factor that affects its anti-seepage effect. There are two main methods for the construction and welding of geomembrane welding structures. Double seam welding and single seam extrusion welding should comply with the requirements of relevant specifications. The double seam welding machine can complete a set of double seam welding at once, forming a cavity for inflatable leak detection. It can transform the leak detection method of the weld from vacuum method to inflatable method, improving work efficiency. The geotextile membrane is welded on a large area using a double weld welding machine, but for non direct overlapping parts, local repairs, reinforcement treatments, etc., extrusion welding machines are required.
The main welding quality inspection methods for geomembranes include gas leakage detection of thermal bonded double welds, using the inflation (positive pressure) method. The two ends of the entire weld to be tested are temporarily sealed, and a dedicated hollow needle is inserted to connect the air compressor. The vacuum (negative pressure) method is an old and traditional method. Apply soapy water to the weld seam of the geomembrane, seal the five sides of the vacuum box, use a vacuum pump, observe the bubble hole under negative pressure, and it can be detected.
The electric spark detection system uses a plastic film as an insulator. When a hole is scanned or connected to the ground, a bright electric spark is generated. During the engineering acceptance process, whether it is a double weld or a single weld, the strength of the geomembrane weld must be inspected.