Understanding of UV
Understanding of Anti-UV Coating
With a layer of anti-UV coated on the surface during the process of co-extrusion could prolong the lifespan of the sheet. Purpose of the anti-UV coating is to prevent ultraviolet from shining through which could cause the sheet from turning yellowish and ends with crack. Polycarbonate sheet maintains an excellent transparency surface over a period of time compare to others.
The Way of Anti-UV Coating:
QUV Durable Test:
|Production Mode||Yellowish fig.||Years of Yellowish|
|UV W/o anti-UV||Above Δ YI 40||Yellowish in short time|
|UV Stabilize anti-UV||Δ YI 10 ~ 15||2 ~ 3 years|
|UV Coating Normal anti-UV||Δ YI 3~7||3 ~ 5 years|
|UV Coating High Performance anti-UV||Below Δ YI 6||10 years & above|
Polycarbonate sheet with Anti-UV coating not only reduces ultraviolet from transmitting but also protect Polycarbonate sheet against any harmful damage and prolong properties of Polycarbonate Sheet. Surface of the sheet form a protective force against factory pollution, exhaust emission from vehicles, dust and acid rain stain. It enables the sheet to maintain as new as it is.
Co-extrusion with Anti-UV coating on the surface shall effectively blocking harmful ultraviolet rays, protect against ultraviolet from transmitting which cause sheet to crack, turn yellow and effectively maintain physical properties of Polycarbonate.
FAQ: What waviness of UV causes biggest damage to Polycarbonte?
UV-A: 320nm ~ 380nm
-Influence of UV-A on polymer: It might cause some certain polymers to degrade.
-Influence of UV-A on human: In general, there is no harm to human body, but human often expose under the UV-A during the life time. The UV-A permeates deeply and strongly so that skin becomes lack of elasticity easily.
UV-B: 280nm ~ 320nm
-Influence of UV-B on polymer: This is the lowest waviness of sun light, and mainly causes polymers to degrade.
-Influence of UV-B on human: UV-B is strongest during 10 AM to 2 PM. UV-B would make skin rough, sensitive, weak, and even become skin cancer. It's easy to get sunburn because of UV-B.
UV-C: lower than 280nm
-Influence of UV-C on polymer: UV-C would cause some abnormal effects on polymers.
-Influence of UV-C on human: UV-C can destroy microorganism. UV-C is absorbed by ozonosphere while passing the atmosphere. As the results, UV-C wouldn't cause any damage to skin.
Certain waviness which might cause biggest damage:
|Polymer||Certain waviness which might cause biggest damage (nm)|
|Polyvinyl acetate||< 280|
|Polycarbonate (PC)||285, 305, 330, 360|
|PET / PBT||325|
|PA||280 - 290, 300 - 320|
The QUV weather ability test of Polycarbonate boards made by SUN ASIA:
|Ways||The Index Of Yellowing||Useful Life Without Yellowing|
|No Anti-UV||Higher than 40||Yellowing at A Short Time|
|Anti-UV Contain||10 ~ 15||1 ~ 2 Years|
|General Anti-UV Coating||3 ~ 7||3 ~ 5 Years|
|Long-Lasting Anti-UV Coating||Lower than 6||Lower than 10 Years|
Data criterion above is base on 313nm for this test.