The four hollow polycarbonate sheet is a multi-wall structural panel composed of four polycarbonate layers joined by vertical ribbing to create three sealed interior air chambers. Thicknesses are from 8 to 16 mm. It weighs about a tenth of comparable glass, and provides far better thermal and acoustic insulation than twin-wall panels. UV protection is coextruded directly on one or both sides, 50 to 110 microns. Applications for greenhouses, commercial roofs, facades, skylights and noise barriers.
Standard twin-wall sheets have one internal air channel. The four-wall construction produces three sealed chambers across the panel cross section, which more efficiently slows heat transmission in both directions – decreasing heat gain in summer and restricting heat loss in winter.
The extra walls also contribute to the structural depth. This results in a stronger panel that can cover broader gaps between roof supports with less deflection than thinner twin-wall alternatives.
| Parameter | Details |
|---|---|
| Product Name | Four-Wall Hollow Polycarbonate Sheet |
| Thickness Range | 8 mm – 16 mm |
| Wall Structure | 4 walls, 3 sealed air chambers |
| Impact Resistance | 200× stronger than glass |
| UV Protection | UV co-extruded layer, 50–110 microns, 1 or 2 faces |
| Raw Material | 100% virgin PC resin; SABIC / Bayer available; custom options |
| Available Colors | Transparent, Bronze, Grey, Opal, Lake Blue, Amber, Dark Blue, Silver, Orange, Yellow, or custom |
| Standard Applications | Greenhouses, Roofing, Skylights, Facades, Canopies, Pergolas, Sound Barriers |
| Certifications | ISO 9001:2015, CE, RoHS, UDEM |
There are three material classes to suit various project needs and budgets:
UV protection is included in all grades and is applied during co-extrusion, not as a post production surface coating. This also welds the protective layer into the material during manufacture, giving it a higher degree of long-term durability.
Thermal Insulation
The three inner air chambers provide dead-air insulation layers piled across the panel thickness. The four hollow polycarbonate sheet is a viable solution for climate-controlled greenhouses and energy-sensitive roofing projects since it greatly decreases heat transmission compared to twin-wall sheets.
Impact Strength
The multi-wall interior design spreads the impact force over all four levels. The inner chambers are protected from the exterior surface so if the outer surface is hit – say by hail – water cannot penetrate. This feature is of interest in hail prone areas or heavy traffic installations.
Weight
Two persons can carry and place big panels and they are about one eighth the weight of glass. This panel is compatible with standard aluminium profile systems for twin-wall sheets, without any modification.
Soundproofing
Sealed air chambers limit sound transmission through the panel, making this product ideal for highway sound barriers, sports enclosures and industrial partitions.
UV Resistance
The thickness of the co-extruded UV layer is 50 to 110 microns. This thickness is more effective in retarding surface yellowing and deterioration from extended sun exposure than a coating of the same nominal thickness applied after the fact.
Baoding Sinhai enables OEM & ODM manufacture. The options that may be customised include
Each four hollow polycarbonate sheets are sent with PE protective film on both sides. We can print your own logo on the PE film for distributor and project orders.
Panels are palletised on wooden pallets for loading in a container. The Kashgar industrial base lowers overland transportation for orders to Central Asian customers. Support of regional deliveries in Tashkent and Dushanbe. Depending on location and timetable, we may provide sea, truck and air freight solutions.
Q: What is the main thermal advantage of a four-wall sheet over twin-wall in a sunroom?
A: The four-wall structure contains three internal air chambers compared to one in a twin-wall panel. This creates a stronger thermal barrier across the panel thickness, reducing heat gain in summer and heat loss in winter.
Q: Does the additional wall structure affect light transmission?
A: Yes. The extra internal layers reduce direct transparency compared to twin-wall. The result is more uniform light diffusion rather than direct transmission, which also reduces harsh shadows in interior spaces.
Q: Is installation different from twin-wall sheets?
A: The panel is slightly heavier than a twin-wall sheet of the same dimensions but remains well below the weight of glass. It is compatible with the same standard aluminum profile systems used for twin-wall installation.
Q: How does it perform against hail?
A: The multi-layer internal structure absorbs and distributes impact energy. If the outer surface is damaged, the internal chambers are designed to remain sealed, preventing water ingress. This is a practical advantage over twin-wall panels in hail-prone regions.
Q: What purlin spacing applies to a 10 mm four-wall sheet?
A: A 10 mm panel typically supports purlin spacing of 800 mm to 1,000 mm. Final spacing should be determined based on local wind load and snow load design standards.
Q: Which raw material options are available?
A: 100% new virgin PC resin, imported SABIC or Bayer resin, or a custom material blend. All options support UV co-extrusion at 50–110 microns on one or both faces.
Do you have more questions about four hollow polycarbonate sheet? Send your project requirements or sample request to [email protected].
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