Polycarbonate sheets can block UV radiation, but this depends on whether or not they have been specially treated with UV resistant coatings or additives. Here's how it works:
1. UV protection in polycarbonate itself
Polycarbonate sheets have a certain degree of UV resistance on their own, which stems from their molecular structure. However, without special treatment of polycarbonate sheet in the long-term natural environment, especially long time subjected to ultraviolet radiation, will gradually appear degradation phenomenon. Under the continuous action of ultraviolet rays, the chemical bonds in the molecular structure of the plate will be broken and reorganized, resulting in the deterioration of the physical properties of the plate, the most intuitive manifestation is the yellowing. The original transparent plate gradually lose the sense of transparency, yellow color, seriously affecting its aesthetics and light transmittance. At the same time, the plate will also become brittle, toughness decreased significantly, in the impact of external forces, more likely to crack.
Nowadays, most of the polycarbonate panels used outdoors, such as common multi-layer roof panels, greenhouse panels, etc., will be coated on one or both sides with a UV-resistant layer. This coating is like putting on a layer of strong protective armor for the sheet, which can effectively absorb or reflect UV rays and avoid UV rays acting directly on the sheet body, thus greatly protecting the material from UV damage and significantly extending the service life of the sheet. Take high quality polycarbonate sheet for greenhouse as an example, after the treatment of anti-UV coating, the normal service life can be as long as 10 to 15 years.
2. Blocking UV Rays for People/Objects Behind the Sheet
UV-coated polycarbonate sheets are excellent at blocking harmful UV rays, blocking up to 99% of the passage of UVA and UVB rays, two of the most harmful UV rays to people and objects. This makes them ideal for a wide range of applications.
Greenhouses: While moderate exposure to visible light is essential for plant growth, excessive UV rays can harm plants by inhibiting photosynthesis and affecting the balance of plant hormones. Polycarbonate panels coated with an anti-UV coating not only effectively block most UV rays, creating a safe light environment for plant growth, but also allow sufficient visible light to pass through to meet the photosynthesis needs of plants, helping them to thrive.
Skylight / Window Application: In indoor spaces, furniture and flooring are exposed to sunlight for long periods of time and are prone to discoloration due to UV radiation. Polycarbonate sheets installed on skylights or windows can block out UV rays, protect interior decorations, keep furniture and floors in their original color and texture, and extend their service life.
Outdoor Signs / Displays: Outdoor signs and displays are exposed to wind and sun for a long time, and ultraviolet rays are one of the important factors leading to their color degradation. Adopting polycarbonate sheets coated with anti-ultraviolet rays as the protective panel can effectively prevent the color from fading gradually due to ultraviolet rays, ensuring that the signboards and displays always maintain eye-catching and vivid colors, and enhancing their visual effect and commercial value.
Key considerations
Check the "UV Protection" label: When shopping for polycarbonate panels, be sure to carefully check for the "UV Protection" label, which visually indicates that the panels have a clear UV resistance rating. Different applications require different levels of UV protection. For example, UV-protected panels used in medical settings usually require a higher level of protection than panels used for general outdoor shading. Only by specifying the UV protection level of the panels can we ensure that they provide the best possible protection in the respective scenario.
Installation points for single-sided and double-sided coatings: Polycarbonate panels with single-sided or double-sided coatings should be installed with the coated side facing outwards. The coated side is usually clearly identified by the manufacturer during the production process. If installed incorrectly, with the uncoated side facing outwards, the UV resistance of the sheet will be greatly reduced, failing to effectively protect the sheet body and objects behind it, and may also lead to premature aging and damage to the sheet.
Service life considerations: high-quality UV coating in the harsh environment of direct sunlight, can still maintain excellent protective performance, the service life of up to 10 years or more. However, this is not absolute, the actual service life will be affected by environmental factors, the frequency of use of panels and other factors. For example, in tropical coastal areas with high temperatures, high humidity and extremely high UV intensity, the service life of the panels may be relatively shorter. Overall, however, the protective advantages over uncoated panels are still significant.
Comparison with other materials
Glass: Glass does have some ability to block some UV rays. However, glass itself is heavy, and in some buildings or applications where there are strict weight limitations, the use of glass can add to the structural burden. And glass texture fragile, once subjected to external impact, such as falling objects impact, it is easy to break, there are greater security risks.
Acrylic: acrylic material in its natural state can block some of the ultraviolet rays, but its impact resistance compared to polycarbonate sheet is obviously insufficient. In the outdoor environment, the acrylic sheet is more likely to be ruptured and damaged due to wind, foreign body impact, etc., affecting its protective effect on ultraviolet rays and normal use.