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Carbofol® HDPE geomembrane

Naue Carbofol® is a HDPE liner for landfill sealing, mining containment, and groundwater protection.

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  • Close-up of a black Naue Carbofol® geomembrane.
  • Close-up of a Naue Carbofol® geomembrane with embossed surface structure from the top.
  • Close-up of a Naue Carbofol® geomembrane with embossed surface structure from the bottom.
  • Aerial view of a large construction site where workers and machinery install Carbofol® liners and protective nonwoven geotextile for landfill capping.
  • Workers installing Carbofol® liners on the sloped sides of an expansive mininig facility.
  • HDPE geomembrane (GBR-P) for primary containment: landfill, mining, groundwater protection, water conveyance.
  • Flat-die-extruded HDPE barrier. Smooth (s/s) for flat areas; BF/TF embossed for shear transfer on slopes.
  • Carbofol® 406 (s/s, BF/TF) · Carbofol® 612 (DIBt Z-59.21-448, WHG) · Carbofol® + (enhanced OIT/HP-OIT).
  • BAM · DIBt Z-59.21-448 · GRI GM-13 · ASQUAL · DB HPQ · CE (AVCP 2+) · ISO 9001/14001.

Carbofol® is an HDPE geomembrane (GBR-P) for primary containment of leachate, groundwater, and process liquids. Application areas include landfill engineering, mining and tailings storage, groundwater protection, and water conveyance structures. You install it on a prepared, stone-free sub-grade and weld the panels on site. The result: an impermeable barrier that protects soil, groundwater, and surrounding environments from toxic substances. Carbofol® is manufactured exclusively by flat die extrusion and calendering from selected polyethylene resins with density ≥ 0.940 g/cm³. Smooth (s/s) grades are used for flat liner applications. BF/TF embossed grades are used for slope stability applications requiring high interface friction.

Contaminated leachate in landfills and process water in mining must be permanently contained. A single weld failure can result in groundwater contamination, regulatory penalties, and costly remediation. Geomembranes with low Melt Flow Rate (MFR < 1 g/10 min) create narrow welding windows, increasing weld defect risk and slowing installation. Carbofol® solves this with an MFR of 1.0–3.0 g/10 min (190 °C / 5.0 kg). A wider welding window enables faster, more reliable hot-wedge welding. Weld defect rates fall and overall installation time decreases.

Carbofol® geomembranes are CE-marked. Declared durability: 25 years for exposed use (DoP Annex B). Roll widths up to 7.5 m and roll lengths up to 200 m (2.0 mm grades) reduce total weld seam count. Fewer seams mean lower installation costs and less quality-assurance effort. ISO 14001-certified manufacturing is in place.

Carbofol® HDPE 406 BF/TF GM13 meets GRI GM-13 requirements. Standard OIT ≥ 100 min (ASTM D8117) or HP-OIT ≥ 400 min (ASTM D5885). Values are retained after 90-day oven ageing at 85 °C. UV resistance: HP-OIT ≥ 200 min after 1,600 h exposure (ASTM D7238). NCTL stress crack resistance ≥ 500 h (ASTM D5397). Asperity height ≥ 0.9 mm (ASTM D7466). Tensile strength at yield ≥ 37 kN/m (2.5 mm BF/TF) / ≥ 29 kN/m (2.0 mm grades). Density ≥ 0.940 g/cm³ (ASTM D792 / EN ISO 1183). Carbofol® 612 grades hold DIBt approval Z-59.21-448 for German WHG applications. All grades manufactured by flat die extrusion.

Carbofol® HDPE geomembrane function:

  • Barrier

    Barrier

    Carbofol® creates a complete polymeric barrier (GBR-P) against leachate, groundwater, hydrocarbons, acids, bases, and salts.

Carbofol® HDPE geomembrane advantages: installation efficiency and certified performance

  • Safety

    High UV and chemical resistance

    Carbon black 2–3 % (ASTM D4218), dispersion Category 1–2 (ASTM D5596). HP-OIT ≥ 200 min retained after 1,600 h UV exposure (ASTM D7238 + D5885). Density ≥ 0.940 g/cm³ provides chemical resistance.

  • Roll

    Straightforward installation

    Industry-leading roll width up to 7.5 m, lengths up to 200 m (2.0 mm grades). Reduces seam density vs. 5.0 m rolls. Fewer welds mean fewer failure points, and less QA testing.

  • Speed

    Superior weldability

    Welding speed distinctly higher than low-MFR liners (< 1 g/10 min). BF/TF grades uniquely allow heated wedge welding in the structured zone so that no grinding is required.

  • Certificate

    International approvals

    Covers German, European, US, and French regulatory frameworks: BAM, DIBt Z-59.21-448 (WHG DE), GRI GM-13 compliant, ASQUAL (FR), DB HPQ application case 3.12, CE marking (AVCP System 2+), ISO 9001, ISO 14001.

Application areas

Typical applications:

  • Landfill base liner systems: Carbofol® as primary HDPE geomembrane over Bentofix® GCL secondary liner
  • Landfill capping and closure systems: s/s and BF/TF grades as cap sealing element
  • Landfill side slope liners: BF/TF structured variants for enhanced interface friction
  • German DepV landfill engineering: BAM-certified grades meeting LAGA/DepV requirements
  • Intermediate seals separating adjacent waste cells

Carbofol® HDPE geomembranes are the most widely specified primary liner in European landfill engineering. Smooth s/s grades are suitable for slopes up to 1:9. BF/TF structured grades are preferred for steeper slopes. In the composite liner system, Carbofol® is installed over Bentofix® GCL, protected by Secutex® nonwoven (BAM-approved protection nonwoven ≥ 2,000 g/m² required for German landfill Class II). Project references are available from Poland, Germany, Hungary, the Middle East, Africa, and others.

Aerial view of a large construction site where workers and machinery install geomembrane liners and protective nonwoven geotextile for landfill capping.

To the application:

Landfill engineering

Typical applications:

  • Tailings storage facility (TSF) base and side slope liners: GM-13 grades with enhanced OIT
  • Heap leach pad liners: Carbofol® + with HP-OIT ≥ 600 min for acid mine drainage
  • Evaporation ponds and mine water containment
  • Mine closure and recultivation: sealing of tailings ponds with Carbofol® BF/TF for cap stability
  • TSF steep slope applications: BF/TF for demanding interface friction (37 to 45+ degrees)

Carbofol® HDPE 406 BF/TF GM13 meets all GRI GM-13 requirements. OIT ≥ 100 min or HP-OIT ≥ 400 min, retained after ageing and UV. For extreme conditions: Carbofol® + achieves OIT ≥ 200 min and HP-OIT ≥ 600 min simultaneously, exceeding conventional GM-13 thresholds. Naue’s mining experience spans multiple projects like gold mine closure in Hungary, and TSF projects in South-East Europe.

Workers installing geomembrane liners on the sloped sides of an expansive mininig facility.

To the application:

Mining

Technical properties

PropertyUnitCarbofol® HDPE 406 2.5 BF/TF GM13
Dimensions and surface
Thickness, nominalmm2.5 (mean over roll width −5 %; lowest single value of 10 measurements −10 %)
Manufacturing widthm≥ 7.5
Surface, top side / bottom side—BF / TF, structured
Height of surface structuremm≥ 0.9
Mechanical properties
Melt flow rate (190 °C / 5.0 kg)g/10 min≥ 1 and ≤ 3
Tensile strength at yieldkN/m≥ 37
Elongation at yield%≥ 12
Tensile strength at breakkN/m≥ 26
Elongation at break%≥ 100
Tear resistanceN≥ 311
Puncture resistanceN≥ 667
Durability
Stress crack resistance NCTLh≥ 500
Oxidation induction time (OIT), standardmin≥ 100
Oxidation induction time, high pressure (HP-OIT)min≥ 400
Oven ageing 85 °C, after 90 days – OITmin≥ 55
Oven ageing 85 °C, after 90 days – HP-OITmin≥ 320
UV resistance, after 1,600 h – HP-OITmin≥ 200
Carbon black content%2–3
Carbon black dispersionCategory1–2
Declared durability, exposed use (DoP Annex B)years25
Manufacturing and quality assurance
Production method—Flat die extrusion (geomembranes from blown film lines are not admissible)
Factory testing, one certificate per roll (EN 10204)—Thickness, width, density, melt flow rate, carbon black content and dispersion, NCTL, OIT
CE marking, AVCP system—Type 2+, each roll individually identified by a unique serial number
Manufacturer certification—EN ISO 9001 and ISO 14001, product group EPD
Technical illustration of Carbofol® BF/TF production, showing a smooth HDPE geomembrane passing through embossed rollers and emerging with a uniform dimpled surface structure.
Technical illustration of Carbofol® BF/TF production, showing a smooth HDPE geomembrane passing through embossed rollers and emerging with a uniform dimpled surface structure.
Exemplary illustration. Carbofol® BF/TF dimples are moulded directly into the HDPE membrane during production. This creates a homogeneous, one-piece surface structure without an adhesion interface, ensuring uniform asperity distribution and preventing delamination under high shear loads.
Exemplary illustration. Carbofol® BF/TF dimples are moulded directly into the HDPE membrane during production. This creates a homogeneous, one-piece surface structure without an adhesion interface, ensuring uniform asperity distribution and preventing delamination under high shear loads.

HDPE geomembrane BF/TF embossed surface structure

HDPE geomembranes for slope stability must reliably transfer shear forces between the liner and all adjacent layers. Three manufacturing methods exist: embossed (Naue Carbofol®), co-extruded, and sprayed. Each creates visually similar textures. The performance differences are fundamental.

Carbofol® BF/TF uses moulded embossed rollers. These shape dimples directly into the HDPE melt as it exits the flat die. The resulting structure is homogeneous – same resin and masterbatch as the base sheet. No adhesion interface exists between structure and membrane. The dimples cannot delaminate even under high shear loads. Independent testing confirms asperity heights ≥ 0.9 mm (ASTM D7466) across the full roll width, uniformly distributed.

Co-extruded structures apply a secondary HDPE melt via a separate extruder. The bond is not guaranteed to be identical in composition. Shear properties are randomised. Structures can partially detach under high shear loads. Sprayed structures apply HDPE particles with even lower manufacturing control. Certain particles can be peeled off manually. For critical containment on landfill side slopes and mining TSF embankments, embossed BF/TF is the required safety level on steep rock sections.

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Carbofol® HDPE geomembrane projects: sealing case studies

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Frequently asked questions

Carbofol® is Naue’s HDPE geomembrane (GBR-P, density ≥ 0.940 g/cm³) for primary containment in landfill, mining, groundwater protection, and water conveyance. Key differentiators: MFR 1.0–3.0 g/10 min (EN ISO 1133) for a wide welding window vs. competitors with MFR < 1 g/10 min; rolls up to 7.5 m wide and up to 200 m long (2.0 mm grades); embossed BF/TF surface structure; 40+ years of project experience and first BAM-certified HDPE geomembrane in Germany (1989).

Carbofol® pricing depends on grade (406 s/s, BF/TF, GM-13; 612 DIBt; Carbofol® +), thickness (1.5–2.5 mm), and project quantity. The 7.5 m roll width and roll lengths up to 200 m reduce total installed cost by minimising seam length and welding labour. Request a project-specific quote through the contact form below.

Carbofol® is a polymeric geomembrane (GBR-P): a thin, flexible HDPE sheet (density ≥ 0.940 g/cm³) providing primary waterproofing. Bentofix® is a geosynthetic clay liner (GBR-C): a dual-geotextile layer with swellable sodium bentonite acting as a secondary sealing layer. For maximum containment in landfill base liners and mining TSF, both are installed together: Carbofol® (primary) over Bentofix® (secondary), protected by Secutex® nonwoven.

Specify smooth (s/s) for flat liner applications: pond liners, canal liners, tunnel waterproofing, and any application where interface friction is not a design concern. Specify BF/TF where the geomembrane is on an inclined surface and interface shear stability is required. Asperity height ≥ 0.9 mm (ASTM D7466) creates direction-independent shear force transfer. For slopes up to approx. 1:9, smooth Carbofol® can be sufficient. Steeper slopes require BF/TF.

Tensile strength of the parent sheet is important. However, the weld is the most vulnerable zone in any lining system. Welds at too high a temperature (required for low-MFR materials) deplete antioxidants and reduce ductility. Carbofol® MFR 1.0–3.0 g/10 min (EN ISO 1133, 190 °C / 5.0 kg) allows reliable welding at lower temperatures. BF/TF grades uniquely permit heated wedge welding in the structured zone without grinding.

CE marking (AVCP System 2+), ISO 9001, ISO 14001. BAM certification (1989, first BAM-certified geomembrane in Germany). DIBt approval Z-59.21-448 (612 series, WHG Germany). GRI GM-13 compliance (406 BF/TF GM13 grades). ASQUAL (French grades). DB HPQ application case 3.12 (406 F/F DB for Deutsche Bahn). Declared durability: 25 years (DoP Annex B). All grades use flat die extrusion only.

Carbofol® must be installed in Germany by a certified specialist company under the German Water Resources Act (WHG) like Naue, or by certified contractors following Naue’s installation guidelines internationally. Welding follows DVS 2225 standards (DVS 2225-3 for standard, DVS 2225-4 for DB applications). Welder certification per DVS 2212-3. All weld seams tested by air pressure or vacuum test. DIBt geomembranes require flat die extrusion from certified companies only.

Carbofol® is manufactured in thicknesses 1.5 mm to 2.5 mm. Roll width: 7.5 m (min. 5.0 m for 612 grades). Roll lengths (confirmed from data sheets): 406 2.0 s/s: 120 m (~1,680 kg); 406 2.5 BF/TF GM13: 100 m (~1,923 kg); 612 2.0 F/F: 200 m (~1,413 kg). Individual rolls carry unique serial numbers.

EN ISO: EN 1849-2 (thickness), EN ISO 1133 (MFR), EN ISO 1183 (density), EN 14576 / ASTM D5397 (NCTL). ASTM: D6693 (tensile), D4218 (carbon black), D5596 (dispersion), D8117 / D5885 (OIT / HP-OIT), D7238 (UV), D7466 (asperity height), D4833 (puncture), D1004 (tear), D792 / D1505 (density). GRI GM-13 for GM-13 grades. CE marking with AVCP System 2+.

Yes. Naue provides grade selection guidance, shear strength data from in-house large-frame shear testing laboratory, chemical resistance consultation, and specification text support. The Naue Portal includes project planning tools. For any assistance, you can contact Naue engineering via the project enquiry form below.

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