An HDPE landfill liner is the barrier between buried waste and the soil and groundwater below it. It sits under heavy fill for many years, in contact with aggressive liquids. So the sheet must resist puncture, tear, chemical attack and slow cracking under stress. This guide explains how to read a textured geomembrane data sheet, and how Target approaches landfill and pond lining work in Egypt.
Contents
- What a landfill liner must resist
- Why textured HDPE on slopes?
- Two textured HDPE geomembranes
- Choosing HDPE landfill liner thickness
- Welding and quality checks
- Execution steps for an HDPE landfill liner
- Common mistakes
- FAQ
- Conclusion
What a landfill liner must resist
A landfill liner works under conditions that few other membranes face. First, waste and cover soil press stones and debris into the sheet. Next, rainwater passing through the waste becomes leachate, a liquid loaded with dissolved chemicals. Finally, the liner must keep its properties for the full life of the cell.
Each of these risks has a matching line in a geomembrane data sheet:
- Puncture and tear cover stones and site damage.
- Tensile strength and elongation cover settlement and stretching.
- Carbon black content protects the polymer from sunlight while exposed.
- OIT and stress-crack tests indicate long-term durability.
Leachate ponds
Leachate collected from the cells usually goes to a lined pond or tank. In practice, the same HDPE sheet types serve here too. However, a pond liner often stays exposed above the liquid line. For this reason, the carbon black content and the aging tests on the data sheet deserve extra attention.
Why textured HDPE on slopes?
Landfill cells have side slopes. Smooth plastic, on the other hand, offers little friction. As a result, soil and protection layers can slide over a smooth sheet. By contrast, textured geomembrane has a rough surface that improves grip with the soil and geotextiles on either side.
The Solmax data sheet for GSE HD Texture lists an asperity height of 0.40 (ASTM D7466) for every thickness. The sheet labels this column “mil (mm)”, so confirm the unit with the supplier before using it in a specification. Meanwhile, Hyma GEO HD Textured, from Egyptian maker Hyma Plastic, comes as single- or double-textured liners.
Two textured HDPE geomembranes
GSE HD Texture (Solmax). GSE describes it as a textured high-density polyethylene geomembrane for applications that need chemical resistance and durability. Its sheet states that GSE HD is produced at GSE Lining Technology-Egypt in 6th of October City.
Hyma GEO HD Textured. According to its data sheet, it contains 97–97.5% polyethylene, 2–3% carbon black, and traces of antioxidants and heat stabilisers. In addition, Hyma states that its specifications meet or exceed GRI GM13.
Overall, both sheets list density of at least 0.94 g/cm³ and carbon black of 2–3%. Likewise, both report OIT above 100 minutes (ASTM D3895) and stress-crack resistance above 500 hours (ASTM D5397).
The Hyma sheet adds high-pressure OIT of at least 400 minutes (ASTM D5885). It also lists oven-aged OIT retention of at least 55% after 90 days at 85 °C.
Choosing HDPE landfill liner thickness
The designer or the permit sets the minimum thickness. Even so, the data sheet shows how strength grows with thickness. The values below are minimum averages from the GSE HD Texture sheet.
| Core thickness (ASTM D5994) | Strength at break (N/mm) | Tear (N, ASTM D1004) | Puncture (N, ASTM D4833) |
|---|---|---|---|
| 0.75 mm (30 mil) | 8 | 93 | 200 |
| 1.00 mm (40 mil) | 10 | 125 | 267 |
| 1.50 mm (60 mil) | 16 | 187 | 400 |
| 2.00 mm (80 mil) | 21 | 249 | 534 |
| 2.50 mm (100 mil) | 26 | 311 | 667 |
Hyma’s sheet covers 1.00 to 2.50 mm, with the same tear and puncture values at each matching thickness. The puncture test follows ASTM D4833, so you can compare products on the same basis.
Besides break strength, both sheets list strength at yield. In the GSE sheet it starts at 11 N/mm for 0.75 mm and reaches 37 N/mm for 2.50 mm. Elongation at yield is 12% for every thickness. These values help when you study expected settlement, because the sheet stretches long before it breaks.
Roll sizes, however, differ between the two makers. GSE lists 7.0 m wide rolls, while Hyma lists widths of about 5.8, 6 or 7 m.
Welding and quality checks
Note that the data sheets cover the sheet itself, not the seams. Seam methods and test frequencies come from the project specification and the liner installer’s quality plan. Still, a few principles always apply.
- Check each roll’s label and thickness against the approved submittal.
- Weld in dry conditions, on clean and dry overlaps.
- Run trial welds at the start of each shift and test them.
- Test every field seam, then record and repair any failure.
- Keep traffic off the exposed liner, and cover it with the specified protection layer.
GSE notes that its NCTL value for the textured sheet comes from tests on smooth samples. Therefore, ask the supplier for the full certificate set for your order.
It also helps to record roll numbers, seam locations and repairs on an as-built panel drawing. This drawing eases the consultant’s review and helps the landfill owner with any later extension or inspection.
What to ask the supplier
Before approving an HDPE landfill liner, ask for documents that match the order, not only a brochure. A short checklist helps:
- The data sheet for the exact thickness and texture (single or double).
- Roll certificates showing thickness, density and carbon black results.
- OIT and stress-crack results, with the test methods named.
- Roll dimensions, so you can plan panel layout and seam count.
Also, check that both texture type and thickness appear on each roll label. This simple step prevents mix-ups on large sites.
Execution steps for an HDPE landfill liner
Target supplies and installs geomembranes as part of its polyethylene sheets scope. For example, a typical cell or pond sequence looks like this:
- Survey the subgrade and remove stones, roots and sharp objects.
- Compact and trim the base and slopes to the design levels.
- Excavate anchor trenches at the slope crests.
- Place any underlying geotextile or clay layer from the design.
- Deploy textured rolls down the slope, not across it.
- Weld overlaps and test the seams.
- Backfill the anchor trenches.
- Cover the liner with protection and drainage layers.
For related work, see our infrastructure waterproofing projects.
Common mistakes
- Rough subgrade. A single sharp stone can puncture the sheet under load.
- Comparing sheets on different tests. Always match the ASTM method and the thickness.
- Using smooth sheet on steep slopes. The cover soil may slide.
- Welding wet or dirty overlaps. Seam quality drops quickly.
- Leaving the liner exposed too long. Wind and site traffic cause damage.
FAQ
What thickness should an HDPE landfill liner have?
In short, your designer or the environmental permit sets it. The data sheets then show puncture and tear values for each thickness.
What does OIT mean on a geomembrane data sheet?
Oxidative induction time indicates how much antioxidant protection remains in the polymer. Both sheets list more than 100 minutes.
Is HDPE geomembrane made in Egypt?
Yes. The GSE sheet states that GSE HD is produced in 6th of October City, and Hyma Plastic is also an Egyptian manufacturer.
Can the same liner serve a leachate pond?
Leachate and storage ponds use the same sheet types. For decorative or irrigation ponds, read our guide to pond and lake lining.
When is double-sided texture useful?
When soil or geotextile touches both faces of the sheet on a slope, double texture adds grip on both sides. If one face rests on a flat surface, single texture may be enough. In every case, the slope stability check in the design settles the choice.
Conclusion
An HDPE landfill liner must resist load, chemicals and time. Textured HDPE adds grip on slopes, and the data sheet shows how thickness drives puncture and tear values. Above all, good subgrade work and tested seams matter just as much as the sheet.
Target supports landfill and lining projects in Egypt, with occasional regional work. Contact our team to review your liner specification and installation plan.
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