2-layer polycarbonate sheet is an extruded twin-wall thermoplastic panel, with two parallel polycarbonate walls connected by vertical internal ribs. The enclosed air tubes in this construction impede heat transmission and reduce panel weight vs solid glass or acrylic options. SINHAI produces these sheets from 100% virgin PC resin or imported SABIC/BAYER resin and co-extrudes them with UV protection on one or both sides. It is available in thicknesses from 3mm to 12mm and is ideal for greenhouse glass, roofing, canopies, skylights and interior walls.
The twin-wall construction is two flat walls joined by vertical ribs which provide channels for air inside of it that serve as thermal insulation. This design makes the panel much lighter than glass, while maintaining structural rigidity.
The panel is rated 250 times more impact resistant than glass and 30 times more than acrylic, a shatterproof glazing alternative that also does not add undue stress to supporting structures.
There are three problems that are common in construction and agriculture. They include controlling energy use in temperature controlled buildings, huge roofs meeting weight constraints and safety hazards from brittle glazing materials.
| Parameter | Detail |
|---|---|
| Product Name | 2-Layer / Twin-Wall Polycarbonate Sheet |
| Structure | Two walls with connecting vertical ribs |
| Thickness Range | 3mm – 12mm |
| Material | 100% virgin PC resin / SABIC / BAYER (customizable) |
| Light Transmission (Clear) | 75% – 82% |
| U-Value | Approx. 3.0 – 3.9 W/m²K (thickness-dependent) |
| Weight per m² | 1.2 – 2.8 kg/m² |
| UV Protection Layer | Co-extruded, 50–109 microns, 1 or 2 faces |
| Operating Temperature | -40°C to +120°C |
| Colors | Transparent, bronze, grey, opal, lake blue, amber, dark blue, silver, orange, yellow, or custom |
| Packaging | PE protective film + wooden pallet |
| Lead Time | 7–15 days (standard orders) |
| Certifications | ISO 9001:2015, CE, RoHS, UDEM |
Thermal Insulation
2-layer polycarbonate sheet has an air gap between the two walls, which slows down the heat transmission. With a U-value of 3.0 – 3.9 W/m2K (depending on thickness), these panels assist to keep constant interior temperatures in greenhouses, warehouses and commercial buildings, which might help to minimise heating and cooling bills over time. This is backed by a 10-year guarantee from Sinhai against yellowing and light loss.
UV Protection, Co-Extruded
Each SINHAI twin-wall sheet has a co-extruded UV protection layer of 50-109 μ thickness on one or both sides. This layer prevents 99% of damaging UV radiation, preventing the resin from photo deterioration, yellowing and brittleness. Panels fitted with the UV face facing the sun appropriately are guarantyd for 10 years against yellowing and loss of light transmission.
Range of thickness for different applications
Canopies, roofing panels and even internal partitions may be manufactured with a single product range, covering the 3mm to 12mm range, greenhouse glazing. Thinner varieties (3-4mm) are better suited for DIY and greenhouse applications. Sheets 6mm and higher perform better as roof sheeting in wind or snow load locations.
Farming Using Light Diffusion
Clear variations transmit 75–82% visible light. The rib structure spreads the light more evenly throughout the surface of the panel, mitigating hot patches that concentrate and may stress crops. This makes the sheet a valuable option for commercial gardening.
Chemical & Fire Resistance
It is resistant to various organic and inorganic acids and is fire resistant according to international standards. Neutral-cure silicone sealants are necessary for installation to prevent stress breaking from mismatched sealant chemistry.
Commercial Greenhouses
The combination of diffused light transmission and heat insulation helps to control nighttime temperatures and minimise overexposure to UV for the crops. These sheets are used in large horticultural businesses to save heating expenses in temperate areas.
Industrial Skylights & North Light
A shatterproof daylighting solution for industrial situations with vibration and impact. Twin-wall panels can withstand heavy wind and snow loads and may let natural light into the structure.
Canopies & Pergolas, Roofing
Panels starting at 1.2 kg/m² impose a minimum strain on support structures. The less weight also makes them economical for carport roofs, sidewalk canopies and residential pergola coverings.
Sound Barriers and Public Structures
The interior rib structure provides acoustical energy absorption. Combined with impact resistance and weathering endurance, this makes the panels appropriate for railway and highway sound barriers that are constantly subjected to cleaning chemicals and environmental stress.
Hallways and Partitions
The 2-layer polycarbonate sheet’s light transmission, thermal isolation and compatibility with CNC cutting for bespoke size make it ideal for indoor and semi-outdoor partition walls.
SINHAI conducts inspection in 3 phases, raw material reception, in process manufacturing and final delivery.
Microscopic cross-section analysis is used to verify the UV Layer Thickness and validate that the co-extrusion fulfils the 50-micron minimum necessary for the 10-year guarantee.
Impact Resistance Falling Dart (ISO 6603) The panel does not break under impact of a falling dart at high velocity.
Yellowing Index (YI) - Determined via accelerated weathering tests (Xenon arc) to monitor colour change over time.
Dimensional Stability is determined by thermal shrinkage tests in the operational range of -40°C to +120°C.
The weight per square metre is used to indicate rib density and structural grade uniformity.
SINHAI offers a variety of processing and customisation choices to meet project needs:
Standard orders usually take 7–15 days to fulfil. For Central Asia clients, the Kashgar manufacturing base provides delivery within around 7 days, with local storage capabilities in Tashkent and Dushanbe to expedite regional fulfilment.
UV side out. Always face the side with the branded protection film, which indicates the UV co-extruded layer, to the sun. Reverse installation will greatly reduce the service life of the panel.
Give room for heat to expand. Polycarbonate expands at 0 . 065mm/meter per degree Celsius . Use large drill holes and H-profile connecting techniques that allow the sheet to move without buckling during temperature fluctuations.
Properly seal the open passages. Use anti-dust vented tape for the bottom edge and solid tape for the top and finish with U-profiles. thus lets the moisture escape, but keeps the dust and insects from getting into the hollow chambers.
Cold curving on site is an option. Minimum bending radius is about 175 times the thickness of the sheet, e.g. 1,050mm for a 6mm sheet.
Do not walk directly on top of the panels. Always use stepping boards across at least 3 purlins to spread the load and prevent point load cracking.
Q1: Will the sheet turn yellow or brittle after a few years outdoors?
A: SINHAI twin-wall sheets include a 50μm co-extruded UV layer that blocks 99% of harmful UV rays, protecting the resin from degradation. A 10-year warranty against yellowing and loss of light transmission applies when the sheet is installed with the UV face toward the sun.
Q2: Which side should face the sun during installation?
A: The side printed with the protective film marking — indicating UV protection — must face the sun. Installing it in reverse will shorten the panel's useful life.
Q3: How do I prevent water and dust from entering the hollow chambers?
A: Use anti-dust vented tape at the bottom edge and solid tape at the top, then seal with U-profiles. This lets moisture escape while blocking dust and insects.
Q4: Is a 4mm sheet strong enough for roofing?
A: A 4mm product works well for small greenhouses or DIY projects. For roofing in areas with wind or snow loads, 6mm or 8mm thickness is recommended to prevent deflection or frame pop-out.
Q5: How does the anti-drip coating work for agricultural use?
A: A hydrophilic coating applied to the interior surface reduces surface tension so condensation flows as a thin film rather than forming droplets that could fall onto crops below.
Q6: What warranty does this product carry?
A: SINHAI provides a 10-year limited warranty against yellowing and light transmission loss for panels with a co-extruded UV protection layer, subject to correct installation.
Do you have more questions about 2-layer polycarbonate sheet? Send your specifications or questions to [email protected] and our team will follow up with pricing and lead time details.
⭐⭐⭐⭐⭐ · August 12, 2026
Central Asia - Uzbekistan Focus (Customization & UV Resistance)
Impressive customization capabilities! We ordered the customized Double‑wall Narrow Grid sheets with Double Circular Edges for our recent urban project in Tashkent. The fit and finish are exceptional. Most importantly, the use of high‑quality 3R virgin raw materials provides the thermal stability and UV protection needed for the intense Uzbek sun. A top‑tier partner for Central Asian infrastructure.
⭐⭐⭐⭐⭐ · July 25, 2026
South America - Corrugated Selection (Volume & Patent)
The best selection of corrugated profiles in the market. Having access to 70+ free molds saved us significant tooling costs. We are extremely pleased with the Trapezoidal 1000 and the 1060 Wave/Trapezoidal sheets in Bronze and Yellow; there is zero color deviation across the entire batch. Furthermore, their Patented Reed Sheets have given our architectural projects a unique, high‑end texture that no other supplier can offer.
⭐⭐⭐⭐⭐ · June 18, 2026
Southeast Asia - Solid Sheet (Durability)
Our go‑to supplier for Solid Polycarbonate Sheets. In the humid and high‑heat environment of Southeast Asia, these solid panels maintain perfect transparency and high impact resistance. The quality of the resin is evident, and the service is always efficient。