Welding method of high-density polyethylene impermeable membrane
The construction of an HDPE impermeable membrane is the most important and critical process in the entire accident collection pool. How to control its quality is the key control point of the entire project. Among them, HPDE impermeable materials are accepted (re-inspected), pre-laid, and overlapped. Welding, repairing and testing are the main control points.
HPDE impermeable membrane produced by LDPE geomembrane manufacturers splicing, according to site conditions, construction drawings, material length, and width, using computer-aided design software to simulate splicing on the computer, the purpose is to reduce cross welds and T-welds, and consider the expansion margin caused by temperature changes. Groove construction margin; on the premise of ensuring construction quality, minimize the waste of materials.
There are two welding methods for high-density polyethylene impermeable high quality LDPE geomembrane: double seam heat sealing welding and single seam extrusion welding, using double seam hot air wedge welding machine and Swiss extrusion welding machine respectively.
1. Double seam heat sealing welding machine: Double seam heat sealing welding machine used in the sump project: double seam hot air wedge welding machine, especially used for 1.5 ~ 2.0 mm smooth/double rough high density polyethylene geomembrane double-track heat sealing welding. The double-weld heat-sealing welder is mainly responsible for the longitudinal double-weld welding task of large aircraft.
2. Double welding seam hot-air wedge welding machine: welding seam overlap width: 80 ~ 100 mm; natural wrinkles on the plane and vertical surfaces are 5% to 8% respectively.
The working temperature of hot melt welding is 380~600℃; the driving speed is 2~3m/min; the two layers of high-density polyethylene impermeable film can be welded and melted in 1~2s, and a set of double welds can be completed at once.
The cavity formed by the double weld was used as the carrier of the weld expansion test, and the weld leak test was carried out on the weld in this area.
Extrusion welding machine welding: This project uses an extrusion welding machine to repair and strengthen the parts that do not directly overlap.
1. The working temperature of the extrusion welding machine is 260℃;
2. An automatic wire feeder should be provided when welding, and the welding wire should be made of the same resin as the high-density polyethylene impermeable LDPE geomembrane for sale in the collection tank.
3. When welding, first make sure that the welding surface is dry and clean; then, use an extrusion welding machine to heat and melt the welding wire, and then squeeze and weld to the position that needs to be repaired and connected; finally, the melt of the welding wire and the impermeable membrane body are fused together, To form a whole to achieve the anti-seepage effect.