HDPE Geomembrane Laying
1. Before laying the HDPE geomembrane, the corresponding qualified acceptance document of the civil engineering project shall be supplied.
2. Before the HDPE membrane is cut, should measure its related size accurately, then cut it according to the actual. Generally, it is not appropriate to cut it according to the size of the figure. It should be numbered and recorded on the special form.
3. When laying HDPE geomembrane, the weld should be minimized. Under the premise of ensuring quality, try to save raw materials as much as possible.
4. The width of the joints between the membrane between the membranes generally not less than 10cm.
5. Usually in corners and deformed areas, The joint length should be shortened as far as possible.Except for special requirements, on the slope of the slope gradient more than 1: 6 within 1.5 meters from the top slope or stress concentration area, try not to install weld.
6. In the laying of the HDPE geomembrane, should avoid human folds. When the temperature is low, should try to tighten as much as possible.
7. After complete the laying of HDPE membrane, should try to reduce walking and moving tools on the membrane surface. Any object that can cause harm to the HDPE geomembrane should not be placed on the membrane or carried on the membrane.
Welding of Geomembrane
1. The welding process of welder is divided into: adjust pressure, set temperature, set speed, weld seam, lap check, install film into machine, start motor, pressure welding.
2. The joint shall not have oil, dust, HDPE geomembrane lap surface should not be filled with sand and other debris, if have debris, must clean up before welding.
3. At the beginning of daily welding, a 0.9mm × 0.3mm sample must be welded at the scene. The width of the overlap not less than 10cm, and the peeling and cutting test are performed on tensile machines. After the sample is qualified, the speed, pressure and temperature adjusted at that time can be used for formal welding.During the welding process, it is necessary to pay attention to the running condition of the welder at any time, and fine-tune the speed and temperature according to the actual situation on site.
4. The welds shall be neat and beautiful, without sliding welding or jumping.
5. When the length of geomembrane is not enough, the long splicing is needed. The transverse weld should be welded first, and then the longitudinal seam should be welded.The transverse welds with a distance of more than 50cm should form a T-shape and should not cross.
6. The welded seam of the adjacent geochemical membrane should be mixed as possible. The nodes formed between the membrane block should be T -shaped to minimize the cross type. The vertical mold is enhanced by the squeezing welding machine at the intersection of the weld.
7. It is not allowed to press the dead fold when welding film, when laying the HDPE geomorphology, When laying HDPE geomembrane, according to the local temperature change range and HDPE geomembrane performance requirements, the expansion deformation caused by temperature change should be reserved.
8. When the temperature of the hand-held welder is lower than 200℃, it is necessary to use a clean cloth or cotton yarn to dust off the welding, and if necessary, it should be repolished, and do not rub it by hand.
9. When the joint has condensation, moisture, sediment and other effects, welding after treatment.
10. Welding shall not be performed during periods of rain or when joints are damp, dewy, or heavy sand, except when protective measures are taken.
11. When the temperature is lower than 5℃, according to the specification requirements should not be performed, if necessary, the welding machine should be preheated before welding.
12. In 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 film surface.
13. Geomembrane should be powered by generators with good voltage stabilization performance during welding. In special cases, the voltage regulator must be used when using local power consumption.
