The Reason for Turning Yellowing
Clear polycarbonate sheets are popular plastic that featured high impact resistance, lightweight, and high light transmission. It is durable and long-lasting roof material. They are widely used for building cladding, outdoor car shed roofs, and construction daylight roofs. However, polycarbonate sheets will discolor over many years, affecting the sunlight and damaging their appearance. So why does polycarbonate turn yellow and how to solve it?
The serious damage to polycarbonate sheets is UV rays. When polycarbonate sheets are used as glazing roofs, they are completely exposed to the sun and attacked by UV rays. With time, the UV-protected layer of the sheet is reduced by about 5um per year. Finally, the color of the sheet is changed, turning the polycarbonate sheet yellow.
Another reason for turning yellow is that polycarbonate sheets are essentially plastic materials. Over time, the plastic material starts oxidation, resulting in the plastic sheets changing their color much faster. These inherent properties of polycarbonate can also cause the material to turn yellow. The color of the sheet is changed because of the loss of connection between the molecules of polycarbonate. An important thing to keep in mind is that the changing of color is just a visual sign of loss of mechanical properties. The UV radiation causes the plastic to break, crack, shatter or even melt.
Solution of aging yellowing
The UV-protection layer on the polycarbonate sheet is important blocking 99% harmful of UV rays. There are two ways of producing UV-protected polycarbonate sheets. One is a coating on the surface of polycarbonate sheets. This has poor weather resistance and the UV protection layer is easy to be broken greatly reducing the life of polycarbonate. The second way is co-extruded technology. In this way, UV protection is strong and the service life of panels can be extended to more than 10 years.
There are 50um-80um on the UNQ polycarbonate sheets to resist UV rays and co-extrusion production. Guarantee the 10 years long-lasting. UNQ clear polycarbonate sheets can be exposed to the sun and used for pergola roofs, industrial roofs and greenhouse covers. When you are looking for polycarbonate, please select the polycarbonate with UV-protected.
The method of installing a polycarbonate roof is crucial many people don’t know that. At present, polycarbonate hollow wall sheets are mainly single-sided with UV-protected on the market. That requires users to face the UV-protected coating surface in the direction of sunlight during installation. Otherwise, the polycarbonate roof sheets will be invaded by UV rays, causing rapid aging and yellowing, greatly shortening the service life and affecting the light transmittance. When you have received the polycarbonate sheets and are prepared to install them, please read the guide carefully.