Anti-seepage performance of geomembrane
The composite geomembrane uses plastic film as an impermeable board and is compounded with non-woven fabric. Its anti-seepage effect lies in the anti-seepage performance of the plastic film, that is, relying on the non-water absorption of the plastic film to decorate and cut off the safe passage of sand and soil penetration. At present, polyethylene (PVC) and high-pressure polyethylene (PE) are key plastic films for seepage prevention in the world.
They are soft raw materials for polymer chemistry, with small specific gravity, strong ductility, high comprehensive deformability, corrosion resistance, cold resistance, and good cold resistance. Non-woven fabric is also a chemical material of polyester staple fiber, which has high compressive strength and ductility according to needle punching or thermal bonding.
After blending with plastic film, it not only expands the compressive strength and puncture resistance of the high-quality LDPE geomembrane but also expands the friction resistance with the sand surface because the surface of the non-woven fabric is not smooth, which is beneficial to the stability and protection of the composite geomembrane. Layer thickness. In addition, they have good corrosion resistance to bacteria and oxidation and are not afraid of corrosion by acids, alkalis, and acid salts.
The service life of composite geomembrane mainly depends on whether the plastic film loses its anti-seepage, waterproof and fireproof functions. According to the working experience of this project, 0.3mm thick polyethylene film with thickener can reach 40-50 years under cold water standards and 30-40 years under wastewater standards. The service life of the composite geomembrane can consider the service life stipulated by the dam anti-seepage.