How to lay and weld HDPE geomembrane？
Geomembrane laying process
1. Before laying HDPE geomembrane, the corresponding acceptance certificate of civil engineering should be issued.
2. Before cutting the HDPE geomembrane, you should accurately measure its relevant size, and then cut it according to the actual size. Generally, it is not suitable to cut according to the size shown in the figure. It should be numbered one by one and recorded in detail on the special form.
3. When laying HDPE geomembrane, the welding seams should be minimized, and raw materials should be saved as much as possible under the premise of ensuring quality. At the same time, it is easy to ensure the quality.
4. The overlapping width of the joint between the membrane and the membrane is generally not less than 10cm, and the direction of the welding seam is usually arranged parallel to the maximum slope, that is, arranged along the slope direction.
5. Usually in corners and deformed areas, the length of the joint should be shortened as much as possible. Except for special requirements, on slopes with a slope greater than 1:6, within 1.5 meters from the top slope or the stress concentration area, try not to set up welds.
6. During the laying of HDPE geomembrane, artificial wrinkles should be avoided. When the temperature is low, it should be stretched as far as possible and paved flat.
7. After the laying of HDPE geomembrane is completed, walking and moving tools on the membrane surface should be minimized, and any objects that can cause harm to the anti-seepage membrane should not be placed or carried on the membrane to avoid damage to the geomembrane applications. Accidental damage to the membrane.
HDPE geomembrane welding
1. The welding process of the hot wedge welding machine is divided into: adjusting the pressure, setting the temperature, setting the speed, welding seam lap inspection, loading film into the machine, starting the motor, and pressurized welding.
2. There should be no oil or dust at the joints, and the overlapping section of the HDPE textured geomembrane for landfill should not contain debris such as sediment. If there are debris, it must be cleaned before welding.
3. At the beginning of welding every day, a sample of 0.9mm×0.3mm must be welded on site first, and the lap width is not less than 10cm, and the peeling and shearing test is carried out on site with a tensile machine. After the sample is qualified, it can be adjusted at that time. Good speed, pressure, temperature make exactly the welding. The date, time and ambient temperature should be marked on the sample. During the welding process of the hot wedge welding machine, it is necessary to pay attention to the operation of the welding machine at any time, and to fine-tune the speed and temperature according to the actual situation on site.
4. The welding seam is required to be neat and beautiful, and there must be no slip welding or jumping away.
5. When the length of the hdpe geomembrane liners is not enough, long-term splicing is required. The transverse welds should be welded first, and then the longitudinal seams should be welded. The distance between the transverse welds is greater than 50cm, and they should be T-shaped without crossing.
6. Adjacent properties of geomembrane cover welds should be staggered and overlapped as much as possible. The joints formed between the membrane blocks should be T-shaped, and the cross-shaped should be minimized. The intersection of the longitudinal mold and the weld should be strengthened by extrusion welding.
7. Do not press out dead folds when welding the film. When laying geomembrane types, according to the range of local temperature changes and the performance requirements of HDPE geomembrane, reserve the amount of expansion and contraction deformation caused by temperature changes.
8. When the temperature of the welding machine indicated by the temperature control of the portable welding machine is lower than 200°C, dust it off with a clean cloth or cotton yarn before welding, and re-grind if necessary, and do not wipe it by hand.
9. When the joints are affected by condensation, moisture, sediment, etc., weld them after treatment.
10. Welding cannot be carried out during the rainy period or when there is moisture, dew, or heavy sand on the joints, except for taking protective measures.
11. When the temperature is lower than 5°C, construction should not be carried out according to the requirements of the specification. If construction is necessary, the welding machine should be preheated before welding.
12. During the welding process of the extrusion welding machine, the slider of the gun head should be checked frequently, and the slider should be replaced in time when the wear is serious, so as not to damage the membrane surface.
13. geomembrane uses welding should be powered by a generator with good voltage stabilization performance. In special cases, when using local electricity, a voltage stabilizer must be used.
We adhere to the principle of teamwork and finally, the company of Tinhy Geosynthetics was founded in 2002. From then on, we have been focusing on the production of various geosynthetic items, including Geomembranes, Geotextiles, Geogrids, Drainage boards, Geosynthetic Clay Liners(GCL), etc.
In recent years, our team has accomplished a great number of projects related to Agriculture, Mining, Aquaculture, Oil & Gas both from home and abroad. As the sustainable development of Tinhy Geosynthetics, a skillful qualified welders team has gradually been built and recognized by worldwide customers. By far, we have 55 welders being verified by the International Association of Geosynthetics Installers(IAGI) providing quality welding service all over the world. We are ready to help you with the project of waste landfills, tailings dams, anti-seepage of reservoirs, and river courses.