Application of Polycarbonate Hollow Sheet in Light-Shielding Canopies at Tunnel Exits
Polycarbonate Hollow Sheet is applied to light-shielding canopies at highway tunnel exits. Do you know the function of the canopies at highway tunnel exits? They are not designed for rainproofing, but for light shielding. Tunnels are fitted with LED lighting which provides insufficient brightness. When vehicles drive into tunnels, drivers will experience a brief visual shift from bright light to dim darkness. Canopies installed at tunnel entrances can effectively weaken natural light. Sunshade structures are erected outside the entrances and exits of highway tunnels to reduce light intensity.
Do you know the purpose of canopies at highway tunnel portals?
Their core function is not rain sheltering, but light attenuation.
Since tunnels are illuminated by LED lights with inadequate brightness, drivers will undergo a short visual transition from bright to dark when entering tunnels. The canopies built at tunnel openings can gradually and effectively soften light contrast. These light-shielding structures are constructed outside road tunnel portals to lower the brightness of natural daylight.
What covering materials are suitable for arched tunnel light-shielding canopies?
For arched tunnel light-shielding canopies, 3–5 mm solid polycarbonate sheets or 8–10 mm Polycarbonate Hollow Sheets deliver the optimal light reduction effect. Among them, 8–10 mm Polycarbonate Hollow Sheets cut down construction costs and shorten construction cycles.
Tunnel light attenuation canopies operate outdoors for long periods under extreme cold or high-temperature environments. Therefore, Aoz Polycarbonate Hollow Sheets with a co-extruded 50-micron UV protective layer are recommended. Such sheets can resist ultraviolet radiation, effectively block UV rays, improve outdoor weather resistance and extend the service life of the panels.
Design Concept of Light-Shielding Canopies
The light-shielding canopy should create a gradual light transition from dark to bright, which can be realized by adopting Polycarbonate Hollow Sheets with different light transmittance. For bronze Polycarbonate Hollow Sheets, buyers can request manufacturers to supply three variants with different transmittance levels, with gradient transmittance set at 50%, 60% and 70% respectively.
The length of the light-shielding canopy shall be designed based on local sunshine diagrams. The solar altitude angle and solar azimuth angle are used to calculate the required length and terminal inclination angle of the canopy.
