Brief introduction to the production process, characteristics, laying and welding requirements of composite geomembrane

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Brief introduction to the production process, characteristics, laying and welding requirements of composite geomembrane

The composite geomembrane is heated by far infrared in an oven on one side or both sides of the membrane, and the geotextile and the geomembrane are pressed together by a guide roller to form a composite geomembrane. There is also a process of casting a composite geomembrane. Its form is one cloth and one film, two cloths and one film, two films and one cloth, three cloths and two films, etc.

Features

The geotextile is used as the protective layer of the geomembrane to protect the impermeable layer from damage. In order to reduce ultraviolet radiation and increase the aging resistance, the buried method is used for laying.

1. The width of 2 meters, 3 meters, 4 meters, 6 meters and 8 meters is the most practical;

2. High puncture resistance and high friction coefficient;

3. Good aging resistance, adapt to a wide range of ambient temperature;

4. Excellent anti-drainage performance;

5. Applicable to water conservancy, chemical, construction, transportation, subway, tunnel, garbage disposal and other projects

Grassroots processing

1) The base layer on which the composite geomembrane is laid should be flat, and the local height difference should not be greater than 50mm. Remove tree roots, grass roots and hard objects to avoid damage to the composite geomembrane.

Laying of composite geomembrane materials

1) First, check whether the material is damaged or not.

2) The composite geomembrane must be laid according to its main force direction, and at the same time, it should not be pulled too tightly, and a certain amount of expansion and contraction should be reserved to adapt to the deformation of the matrix. .

3) When laying, it should be manually tightened, without wrinkles, and close to the lower bearing layer. It should be compacted at any time with the shop to avoid being lifted by the wind. Construction cannot be carried out when there is standing water or rain, and the bentonite mat laid on the day must be covered with backfill.

4) When the composite geomembrane is laid, there must be a margin at both ends. The margin shall not be less than 1000mm at each end, and shall be fixed according to the design requirements.

5) A certain width of PE film and PET fabric non-adhesive layer (ie, edge rejection) are reserved on both sides of the composite geomembrane. When laying, the direction of each unit of the composite geomembrane should be adjusted to facilitate the two units of the composite geomembrane. welding.

6) For the laid composite geomembrane, there should be no oil, water, dust, etc. at the edge joints.

7) Before welding, adjust the PE single film on the two sides of the seam to make it overlap a certain width. The overlap width is generally 6-8cm and is flat and free of white wrinkles.

Welding;

The composite geomembrane is welded using a double-track welding machine, and the surface of the PE film connected by the heat treatment is heated to melt the surface, and then fused into one body by pressure.

1) Welding bead lap width: 80~100mm; natural folds on the plane and vertical plane: 5%~8% respectively; reserved expansion and contraction amount: 3%~5%; leftover scrap: 2%~5%.

2) The working temperature of hot melt welding is 280~300℃; the traveling speed is 2~3m/min; the welding form is double-track welding.

3) Repair method of damaged parts, cutting materials with the same specifications, hot-melt bonding or sealing with special geomembrane glue.

4) For the connection of non-woven fabrics at the weld bead, the geotextile composite on both sides of the membrane can be welded with a hot air welding gun if it is below 150g/m2, and a portable sewing machine can be used for sewing over 150g/m2.

5) The sealing and water-stop of the underwater nozzle shall be sealed with GB rubber water-stop strip, wrapped with metal and treated with anti-corrosion.

Backfill

1. When backfilling, the backfilling speed should be controlled according to the design requirements and foundation settlement.

2. For the first layer of soil filling on the geosynthetic material, the filling machine can only run along the direction perpendicular to the laying direction of the geosynthetic material, and light-duty machinery (pressure less than 55kPa) should be used for spreading or rolling.


Post time: Sep-22-2022