In modern engineering projects—spanning water conservancy, environmental protection, transportation, and aquaculture—composite geomembranes have emerged as an indispensable mainstay for seepage control, thanks to their exceptional impermeability, isolation, and reinforcement capabilities. However, amidst the vast array of specifications and price points available on the market, how do you select the material best suited to your project's specific needs? Furthermore, what are the critical considerations during the construction process?

As a leading manufacturer of geotechnical materials within the industry, Longxiang New Materials has compiled this comprehensive and highly detailed guide to assist you in the selection and installation of composite geomembranes.

I. What Is Composite Geomembrane? 

Composite geomembranes are a new type of impermeable material created by bonding geotextiles (such as continuous filament or staple fiber non-woven fabrics) with polymeric materials (such as HDPE membranes) through a thermal lamination process. They combine the tensile strength and puncture-resistant protective properties of geotextiles with the superior impermeability of geomembranes.

Based on specific engineering requirements, these materials are typically categorized into the following two major groups; Longxiang New Materials offers full customization across all specifications:

Reference for Common Specifications (Weight Range):
Standard Total Weight: 300 g/m² – 1500 g/m²

Membrane Thickness Range: 0.2 mm – 1.5 mm

Note: Longxiang New Materials can precisely customize any combination of fabric weight and membrane thickness based on engineering design drawings.

II. Why Choose Longxiang New Materials?

Longxiang New Materials consistently adheres to the following three core standards:

Production Using 100% Virgin Materials—No Recycled Content: We utilize premium-grade, high-density polyethylene (HDPE) virgin resin to ensure our composite geomembranes possess exceptional resistance to aging, acids, and alkalis, boasting a service life exceeding 50 years.

Advanced Thermal Lamination Technology: Delivering High Peel Strength. Longxiang’s production lines employ an intelligent, temperature-controlled thermal lamination process; this ensures a tight, inseparable bond between the fabric and membrane layers, thereby eliminating the common issue of layer separation often encountered in engineering projects.

Comprehensive Testing Documentation: Every product batch shipped from our facility is accompanied by a testing report certifying compliance with national standards (GB/T 17642-2008), thereby meeting the rigorous acceptance criteria required by major municipal and water conservancy projects.

III. Standard Construction Plan and Key Welding Points for Composite Geomembranes

In seepage control engineering, the adage holds true: "materials account for three parts, while construction accounts for seven." Achieving flawless seepage control results is impossible without standardized on-site installation procedures. The following are the benchmark construction steps summarized by the technical team at Longxiang New Materials:

Subgrade Preparation: Before installation, the base surface must be cleared of sharp debris—such as stones, tree roots, and wire—and subsequently leveled and compacted to prevent puncturing of the geomembrane.

Laying and Overlap Allowance: The geomembrane should be laid out naturally and flat; it should not be stretched too tightly. A lap width of 10 cm to 15 cm must be left at the junction of adjacent membrane sheets in preparation for welding.

Core Step: Thermal Fusion Welding:

Main seams should be welded using a dual-track hot-wedge welding machine.

For special areas—such as corners, pipe penetrations, and irregular sections—an extrusion welding gun should be used to perform supplementary welding.

The welding temperature is typically controlled within the range of 280°C to 350°C, with a travel speed of 1.5 m/min to 2.5 m/min (adjusted according to the ambient temperature at the site).

Inspection and Backfilling: Upon completion of welding, an air-pressure integrity test must be conducted (maintaining a test pressure of 0.25 MPa for 5 minutes to verify that there are no leaks). Once confirmed to be leak-free, the protective layer should be laid and the earthworks backfilled in a timely manner.

IV. FAQ

Q1: How much does composite geomembrane cost per square meter?
 

A: The price of composite geomembrane depends on the total unit weight (e.g., 500g/㎡), the thickness of the membrane, whether continuous filament fabric or staple filament fabric is used, and the prevailing market prices for raw materials. Since Longxiang New Materials operates on a direct-from-manufacturer model—eliminating the need for intermediaries—we are able to offer you highly competitive, direct-from-factory wholesale pricing. We invite you to contact our sales engineers to obtain a real-time quote based on current market rates.

Q2: Should I choose a "one-fabric, one-membrane" or a "two-fabric, one-membrane" configuration?
 

A: If your subgrade is exceptionally smooth and level (e.g., fine sandy soil or a base with a concrete cushion layer), a "one-fabric, one-membrane" configuration will suffice to meet your requirements. However, if the subgrade contains a significant amount of gravel or features complex terrain—or if the material will be subjected to heavy loads from above (such as in landfill sites or reservoir dams)—we recommend opting for the "two-fabric, one-membrane" configuration to ensure maximum puncture resistance and safety.

Contact Longxiang New Materials today to receive free samples and a price quote!
 

If you are seeking cost-effective, high-quality composite geomembranes for your engineering project, Longxiang New Materials is ready to provide you with expert technical support.

Official Services: We offer free sample delivery, project budget assessments, and custom specifications tailored to your needs.