YuanSu is a Wanplas factory that builds plastic film, sheet, and board extrusion lines for clients in more than 60 countries. Geomembrane extrusion sits at the heart of modern civil and environmental construction, from landfill baselines to tunnel waterproofing and reservoir liners. This guide compares the six materials that project engineers ask about most, explains how each one behaves on a flat-die sheet line, and shows which YuanSu line fits your throughput and width targets. Choosing the resin first keeps the rest of the specification, welding plan, and quality control on track.
What a Geomembrane Does on a Construction Site
A geomembrane is a thin, continuous polymeric barrier placed between a contained fluid and the ground beneath it. Its only job is to stop migration: leachate leaving a landfill, brine crossing a canal bank, or rainwater entering a tunnel structure. The barrier works through low permeability, not through strength, so the material and the seams matter more than thickness alone.
Engineers specify geomembranes wherever a project cannot tolerate leakage. Landfills, mining heap leach pads, wastewater ponds, and drinking-water reservoirs all depend on a continuous liner. Secondary containment around fuel tanks and chemical dosing areas uses the same principle at a smaller scale.
The performance of any liner comes from three things working together. The resin must resist the chemistry it contacts, the sheet must stay flat and dimensionally stable, and every field seam must reach the same integrity as the parent sheet. Extrusion quality decides the second and third points before installation even begins.
Material choice sets the ceiling for chemical resistance, temperature range, and weldability. A resin that survives acidic leachate may fail in contact with aromatic fuel, and a sheet that welds cleanly in the factory may split under site welding if the melt window is wrong. That is why the resin decision comes before the machine decision.
YuanSu positions geomembrane and waterproof sheet as one product family because the same flat-die extrusion principle serves both. The difference is the resin recipe and the thickness class, not the underlying line architecture. A Wanplas factory builds the line, but the project defines the polymer.
Design life drives the resin decision as much as chemistry does. A buried landfill liner is specified for decades of service under load, while a temporary dewatering pond may need only a few seasons. Longer service life pushes the specification toward HDPE and away from materials that harden or migrate additive over time.
Sheet texture also matters on slopes. Smooth sheet can slide under cover soil on steep faces, so textured or co-extruded textured HDPE is specified to raise friction at the soil interface. The same flat-die line can deliver textured sheet through a micro-relief roll or a light spray step, and the project engineer should flag that need in the line specification so the right roll surface is ordered.
How Geomembrane Extrusion Turns Resin Into Roll Goods
Geomembrane sheet is made on a flat-die cast extrusion line, not a blown film line, because width and flatness beat bubble stability for thick barriers. Resin plus additive masterbatch feeds a single-screw or twin-screw extruder, melts in the barrel, and is pushed through a wide coat-hanger die onto a polished roll stack.
The extruder plasticizes the blend at a controlled melt temperature. Polyolefins run around 200 to 230 degrees Celsius, while PVC stays lower to avoid degradation. A screen changer filters gel and contamination, and a gear pump can steady the output so sheet gauge stays even across an 8-meter width.
The melt leaves the die as a curtain and contacts the first chill roll. Rapid, even cooling locks molecular orientation and gives the sheet its low haze and flat profile. YuanSu sheet lines hold flatness at or below 0.1 millimeter per meter, which keeps seams aligned during field laying.
Online thickness measurement scans the moving web and feeds a closed-loop control that nudges die-bolt heaters. This is how a line holds plus or minus 2 percent gauge tolerance instead of letting edges drift thick and the center drift thin. Tolerance directly affects how much resin the project wastes.
Multi-layer co-extrusion lets one line put a virgin skin over a filled core. A scrim layer can sit between plies for tear resistance. The same die stack, fed by two or three extruders, builds a barrier that a single resin could not match at the same cost.
Winders and accumulators finish the line. Wide geomembrane needs a surface winder with a reinforced core so the roll survives transport to a remote site. YuanSu integrates the winder, cutter, and edge-trim recovery into one control system for the operator.
Additive dosing runs through a side feeder or a gravimetric blender mounted above the extruder throat. Carbon black for UV protection, antioxidant for thermal stability, and filler for cost control each meter in by weight, and the line control tracks the dose so the recipe repeats shift to shift. A stable dose keeps sheet color and properties uniform across a long production run.
Filled compounds raise the wear load on the screw and barrel. High filler content, common in cost-optimized liner cores, calls for a bimetallic barrel and a hardened screw so the line holds output and gauge as running hours build. YuanSu specifies the screw and barrel package against the filler level the project expects, not only against virgin resin, which protects the line from early wear.
The Top 6 Geomembrane Materials, Ranked by Project Fit
Six resins cover almost every construction geomembrane specification in 2026. They split into polyolefins, PVC, copolymers, and polyolefin blends. Each brings a different balance of chemical resistance, flexibility, weldability, and cost level. The table below gives the headline properties before the material-by-material detail.
Material Property Comparison at a Glance
| Material | Density (g/cm3) | Tensile (MPa) | Elongation | Chemical resistance | Service temp | Cost level |
|---|---|---|---|---|---|---|
| HDPE | 0.94 | 20 to 30 | 600 to 1000 pct | Excellent | -60 to 60 C | Low |
| LLDPE | 0.92 to 0.94 | 18 to 28 | 700 to 1200 pct | Very good | -60 to 55 C | Medium |
| PVC | 1.30 to 1.40 | 12 to 22 | 200 to 400 pct | Good | -20 to 50 C | Medium |
| EVA | 0.93 to 0.95 | 15 to 22 | 500 to 800 pct | Good | -40 to 55 C | Medium-High |
| TPO | 0.90 to 0.94 | 18 to 25 | 400 to 700 pct | Very good | -40 to 70 C | Medium-High |
| PP | 0.90 to 0.91 | 25 to 38 | 400 to 900 pct | Excellent | -20 to 90 C | High |
1. HDPE (High-Density Polyethylene)
HDPE is the default geomembrane for landfills and mining because it shrugs off a very wide range of chemicals. Its high crystallinity gives low permeability and strong stress-crack resistance, which matters under settled waste and loaded liner bases.
The trade-off is stiffness and thermal sensitivity. HDPE expands and contracts with temperature more than flexible resins, so designers add slack and use wider welds. It also needs a rooted ballast or cover because UV slowly embrittles the exposed sheet.
On the line, HDPE is forgiving to extrude. A single-screw machine with a barrier section melts it cleanly, and the weld window is broad enough for thermal wedge and extrusion welding in the field. Black carbon masterbatch is standard for UV protection.
Choose HDPE when the project demands maximum chemical resistance at the lowest resin cost and can accept strict seaming discipline. Landfill baselines, heap leach pads, and wastewater lagoons are its home ground.
2. LLDPE (Linear Low-Density Polyethylene)
LLDPE keeps the chemical resistance of polyethylene but adds far more elongation. That flexibility lets a liner follow ground movement, settlement, and freeze-thaw cycles without tearing. It is the better pick where the subgrade is unstable.
The narrower melt window demands tighter welding control. Line trials on the exact resin grade set the wedge temperature and travel speed so field seams reach the parent sheet strength. Skilled crews handle it without trouble.
Floating covers on potable reservoirs, pond liners on soft soils, and caps over gas-producing waste all favor LLDPE. Its softer hand also drapes better over irregular shapes than rigid HDPE.
Cost sits one step above HDPE because the resin and the welding care cost more. YuanSu lines run LLDPE on the same flat-die architecture as HDPE, often in the same plant that swings between the two by changing screen pack and roll temperature.
3. PVC (Polyvinyl Chloride)
Plasticized PVC geomembrane is flexible straight from the roll and needs no special seaming heat beyond hot-air welding. Crews like it for canals, aquaculture, and decorative water features where speed of laydown matters.
Chemical resistance is good for water and mild acids but weak against hydrocarbons and strong solvents. Aromatic fuels and many oils swell and weaken PVC, so it stays out of refineries and fuel farms. UV stability is a plus because plasticizer packages can be tuned for exposure.
PVC extrudes at lower temperature than polyolefins, which protects the heat stabilizer. The line needs a calm, well-ventilated barrel zone and a precise stabilizer dose, since overheat releases acid that attacks the screw and barrel.
Potable-grade PVC must use certified plasticizers and stabilizers, so request the formulation certification rather than assuming. YuanSu supplies PVC within its PE or PVC waterproof sheet line family when the project scope calls for it.
4. EVA (Ethylene-Vinyl Acetate)
EVA geomembrane is the workhorse of tunnel and subway waterproofing. The vinyl acetate comonomer lowers the melt point and keeps the sheet supple at low temperature, which helps in enclosed, cold structures.
Weldability is a strong point. EVA hot-air welds quickly and bonds to sprayed concrete membranes used in tunnel linings. Elongation stays high enough to absorb joint movement in a moving structure.
Chemical resistance is good for water and salts but not for oil. EVA finds its niche in civil infrastructure rather than harsh industrial containment. Many metro and rail projects specify EVA sheet by name for this reason.
On the line, EVA needs gentle drying and a moderate melt temperature to avoid acetate smell and degradation. YuanSu runs EVA on the same cast sheet platform that serves TPO and PE, with recipe storage for fast grade change.
5. TPO (Thermoplastic Polyolefin)
TPO blends polypropylene with rubber and filler to give a heat-weldable, plasticizer-free sheet. It resists UV, stays flexible, and avoids the long-term hardening that plagues plasticized PVC. Roofing and landfill caps use it heavily.
Chemical resistance sits between HDPE and PVC. TPO handles water, mild acids, and weathering well, which fits exposed caps and covers better than buried baselines. It welds with hot wedge or hot air at a broad, repeatable window.
The resin is friendly to extrude and recycle, with no plasticizer to migrate. That makes TPO a strong choice where sustainability reporting matters, because the sheet keeps its properties instead of leaching additive over time.
Cost is medium-high because the compound costs more than commodity PE. YuanSu includes TPO in its PE or PVC or CPE or TPO or EVA geomembrane and waterproof sheet line, so one platform covers the whole polyolefin-to-TPO range.
6. PP (Polypropylene, Flexible Grade)
Flexible PP geomembrane brings the highest temperature ceiling and excellent resistance to many aggressive chemicals. Chemical plants, brine ponds, and high-heat process containment turn to PP when PE falls short.
The challenge is low-temperature brittleness and a narrower welding window than HDPE. Impact modifiers and careful grade selection keep PP drapable, but field crews need training on the right weld setting.
PP extrudes at a higher melt temperature than PE and needs a robust screw and barrel package. The line must manage the higher enthalpy without overheating the degradation-sensitive resin at the die.
Cost is high, so PP is a targeted solution rather than a default. YuanSu configures PP-capable sheet lines where the project specification names flexible polypropylene as the only material that survives the duty.
Processing Windows and Test References
Each resin welds and tests by its own standard set, so the line specification should name both the processing window and the test method the buyer will use to accept the sheet. The table below pairs a typical extrusion temperature band with the welding method and a common reference test for each material.
| Material | Extrusion temp | Field welding | Common test reference |
|---|---|---|---|
| HDPE | 200 to 230 C | Thermal wedge, extrusion | ASTM D5397, GRI-GM13 |
| LLDPE | 190 to 220 C | Thermal wedge, slower | ASTM D882, GRI-GM17 |
| PVC | 160 to 190 C | Hot-air weld | ASTM D3083 |
| EVA | 170 to 210 C | Hot-air weld | ASTM D1593 type |
| TPO | 190 to 225 C | Hot wedge, hot air | ASTM D6718 |
| PP | 220 to 250 C | Hot wedge, trained crew | ASTM D5397 PP method |
Line trials on the exact resin grade confirm the real window before a project commits to volume. A small trial run on the YuanSu line, using the buyer’s own resin and masterbatch, removes guesswork from both the extrusion setting and the field welding procedure.
Matching Material to Project Scenario
No single resin wins every job. The right call comes from the fluid, the temperature, the subgrade movement, and the welding method available on site. The table maps common scenarios to the material that fits, then to the line width and output you should plan for.
Scenario-to-Material Selection Map
| Project scenario | Best material | Why | Typical thickness |
|---|---|---|---|
| Municipal landfill baseline | HDPE | Max chemical resistance, lowest cost | 1.5 to 2.0 mm |
| Settling pond or soft subgrade | LLDPE | Highest elongation follows movement | 1.0 to 1.5 mm |
| Irrigation canal or aquaculture | PVC | Flexible, fast hot-air weld | 0.75 to 1.5 mm |
| Tunnel or subway waterproofing | EVA | Supple, bonds to sprayed concrete | 1.2 to 2.0 mm |
| Landfill cap or roofing | TPO | UV stable, no plasticizer | 1.0 to 1.5 mm |
| Chemical or brine containment | PP | High temp, aggressive chemical resistance | 1.5 to 3.0 mm |
Width planning follows the seam count. A wider roll means fewer field seams, which lowers leak risk and labor. YuanSu lines reach 8000 millimeters wide, so a large basin can be lined with far fewer joints than a narrow-roll supply allows.
Output planning follows the project schedule. A lining contractor laying thousands of square meters per week needs steady roll supply, so the line output should match the laydown rate plus buffer. Under-specifying output stretches the whole program.
Co-extrusion pays off when one skin must be virgin and the core can carry filler. A reinforced grade with scrim costs less resin per square meter at the same performance, which the selection table below turns into a concrete line recommendation.
Climate and site access also shape the choice. Cold regions favor materials that stay supple below freezing, while hot, exposed sites need UV-stable or covered sheet. Remote sites with limited welding crew skill argue for the material with the broadest, most forgiving weld window, even at a higher resin cost, because field reject rate drives the true installed price more than the roll price does.
YuanSu Geomembrane Extrusion Lines
YuanSu builds geomembrane and waterproof sheet on a flat-die cast platform shared across the PE, PVC, CPE, TPO, and EVA families. Two configurations cover most project specs: a standard single-resin sheet line and a multi-layer co-extrusion line for reinforced or skin-core structures.
PE or PVC or CPE or TPO or EVA Geomembrane and Waterproof Sheet Line
This line is the core offering for contractors who run one or two resins steadily. It pairs a single-screw or twin-screw extruder with a coat-hanger die and a three-roll stack, and it carries the sheet-line features that matter for liners: flatness control and online gauging.
Standard Geomembrane Line Specification
| Parameter | Range | Note |
|---|---|---|
| Product width | 2000 to 8000 mm | Wider roll reduces field seams |
| Sheet thickness | 0.3 to 2.0 mm | Sheet class per line design |
| Output | 400 to 1200 kg/h | By resin and width |
| Screw type | Single or twin-screw | Twin for filled compounds |
| Screw diameter | 130 to 180 mm | Scales with output |
| L/D ratio | 30 to 33 | Good plasticizing and mixing |
| Flatness | Less than or equal to 0.1 mm/m | Keeps seams aligned |
| Layers | 1 to 3 | Co-extrusion ready |
| Drive power | 110 to 250 kW | By configuration |
The line stores recipes for each resin, so a plant that swings from HDPE to TPO changes grade through the human-machine interface instead of re-tuning by hand. Online thickness measurement and multi-layer co-extrusion come as standard sheet-line features.
Multi-Layer Co-Extrusion Geomembrane Line
When the project needs a reinforced or skin-core structure, YuanSu configures a co-extrusion line with two or three extruders feeding one die. A scrim layer sits between polymer plies for tear resistance under puncture loads such as rock cover or root growth.
Reinforced Co-Extrusion Line Specification
| Parameter | Range | Note |
|---|---|---|
| Product width | 4000 to 8000 mm | Large basin coverage |
| Sheet thickness | 1.0 to 3.0 mm | With reinforcement |
| Output | 600 to 1500 kg/h | Higher for thick sheet |
| Extruders | 2 to 3 | Skin plus core plus tie |
| Scrim option | Woven or nonwoven | Tear resistance |
| Layers | Up to 3 | Virgin skin over filled core |
| Thickness control | Online scan | Closed-loop die bolts |
| Drive power | 180 to 320 kW | By layer count |
Both lines share the YuanSu control architecture, so operators move between them with minimal retraining. The Wanplas group supplies matched upstream dosing and downstream winders, which keeps the whole cell under one service umbrella.
Care during changeover keeps the line ready. Purging the barrel and die between resin grades, then running a cleaning compound, prevents cross-contamination that shows up as weak spots in the next roll. YuanSu builds the purge routine into the recipe so operators follow the same steps every time rather than judging by eye.
Selection Guidance and Service Support
The fastest way to size a line is to start from the roll the project needs: material, width, thickness, and weekly area. The table converts those into a recommended YuanSu configuration so the quote stage is short and the engineering is concrete.
Requirement to Line Recommendation
| Requirement | Recommended line | Width | Output |
|---|---|---|---|
| HDPE landfill sheet, 1.5 mm | Standard geomembrane line | 7000 mm | 900 kg/h |
| LLDPE pond liner, 1.0 mm | Standard geomembrane line | 6000 mm | 700 kg/h |
| PVC canal sheet, 1.0 mm | Standard geomembrane line | 4000 mm | 500 kg/h |
| EVA tunnel sheet, 1.5 mm | Standard geomembrane line | 3000 mm | 550 kg/h |
| TPO cap sheet, 1.2 mm | Standard geomembrane line | 5000 mm | 650 kg/h |
| Reinforced PP brine liner, 2.5 mm | Co-extrusion line | 6000 mm | 1200 kg/h |
YuanSu serves the construction and infrastructure segment directly: lighting materials, waterproof materials, and anti-corrosion sheet fall inside its industry solutions. The same line family supports packaging, healthcare, and new-energy customers that need barrier sheet.
Wanplas Shared Service and Support
| Service item | Commitment |
|---|---|
| Free spare parts | USD 500 free parts per year |
| Warranty | Replacement of damaged parts in warranty |
| Installation | Engineer on-site commissioning and trial run |
| Training | Operation and maintenance for your team |
| Open factory | Welcome to visit and audit the plant |
| Quality promise | Refund plus 10 percent if standard fails |
The Wanplas brand backs every YuanSu line with the same promises: free parts, transport guarantee, production capacity guarantee, and quality standards. Buyers get one accountable supplier across the sheet and film range rather than a patchwork of vendors.
Maintenance and Operational Care for Geomembrane Lines
A geomembrane line earns its keep over years of running thick, sometimes filled sheet, so a simple maintenance rhythm protects output and flatness. The wear parts are predictable, and the YuanSu control system logs running hours so the team knows when to inspect rather than waiting for a failure.
Line Care Schedule
| Item | Frequency | Action |
|---|---|---|
| Screw and barrel | Every 2000 hours | Inspect wear, measure clearance |
| Die lip and bolts | Every changeover | Clean, verify heating even |
| Chill rolls | Weekly | Polish, check cooling channels |
| Thickness scanner | Monthly | Calibrate against gauge block |
| Winder core | Every roll change | Check balance and grip |
| Hydraulics and drives | Quarterly | Leak check, lube, torque |
Die-lip care matters most for flatness. A scratched or fouled lip marks every meter of sheet, so operators clean it during each changeover and verify that all die-bolt heaters reach the same temperature. Even heating keeps the edge-to-edge gauge profile straight, which is what the plus or minus 2 percent tolerance depends on.
Chill-roll surface quality decides the sheet finish. Weekly polishing removes residue and keeps heat transfer even, while blocked cooling channels cause hot stripes that show up as uneven thickness. The Wanplas spare-parts policy keeps replacement rolls, screws, and die lips available for the full service life, so a worn part is a planned change, not a line stoppage.
Operator training closes the loop. A team that reads the thickness scan, trusts the recipe storage, and follows the purge routine produces uniform sheet with fewer rejects. YuanSu includes operation and maintenance training during commissioning, and refresher visits keep the standard high as new staff join.
Frequently Asked Questions
What thickness should a geomembrane have for landfill use?
Municipal solid waste landfills normally specify 1.5 mm HDPE as the primary barrier, while critical containment or steep slopes call for 2.0 mm. The extrusion line must hold thickness tolerance within plus or minus 2 percent across the full width.
Can HDPE and LLDPE be welded the same way?
Both polyolefins weld with thermal wedge or extrusion welding, but LLDPE needs lower temperature and slower travel because of its narrower melt window. Line trials on the target resin grade confirm the right welding window before field deployment.
Is PVC geomembrane safe for drinking water?
PVC sheet formulated for potable contact can meet NSF and WRAS type requirements when plasticizer and stabilizer packages are certified. Always request the material certification for the specific formulation rather than assuming generic PVC qualifies.
How wide can an extruded geomembrane roll be?
A flat-die sheet line from YuanSu produces widths up to 8000 mm, which reduces field seams. Wider rolls lower installation labor but need stronger winders and reinforced cores for transport.
Which geomembrane material resists hydrocarbons best?
HDPE and flexible PP lead on resistance to fuels, oils, and many solvents. PVC and EVA degrade faster in contact with aromatic hydrocarbons, so refineries and fuel farms favor polyolefin barriers.
Does YuanSu supply lines for reinforced scrim geomembrane?
Yes. The multi-layer co-extrusion configuration embeds a woven or nonwoven scrim between polymer layers for tear resistance, used in landfill caps and canal liners where puncture load is high.
How long does a geomembrane extrusion line last?
With planned maintenance a YuanSu line runs well beyond a decade. Hardened screws, bimetallic barrels, and the Wanplas spare-parts policy keep wear parts available for the full service life.
What certifications apply to geomembrane sheets?
Common references are GRI-GM test methods, ASTM D methods, ISO 9001 for manufacturing, and CE marking for the European market. Product sheets should list the specific test standard used for each property.
Conclusion
Geomembrane extrusion starts with the resin, not the machine. HDPE leads on cost and chemical resistance, LLDPE follows ground movement, PVC welds fast in canals, EVA suits tunnels, TPO caps roofs, and PP survives aggressive chemical duty. Match the fluid, temperature, and subgrade to the material, then size the line by width, thickness, and weekly area.
YuanSu, a Wanplas factory, builds the flat-die sheet platform that runs all six resins on one architecture, with a co-extrusion option for reinforced liners. Send us your target material, width, thickness, and output, and our team will configure a line, plan the factory layout, and invite you to witness a trial run before shipment.
