UV aging belongs to the aging of sunlight irradiation, UV is short for Ultraviolet (ultraviolet), which is usually used to evaluate the aging rate of products under ultraviolet light. Sunlight irradiation aging is the main aging damage of materials used outdoors. For materials used indoors, It can also be subjected to a certain degree of sunlight irradiation aging or aging caused by ultraviolet light from artificial sources (such as ultraviolet lamps, fluorescent lamps in the ultraviolet band, etc.).
The solar radiation is mainly concentrated in the visible part (0.4-0.76 μm), and the wavelength of infrared is larger than that of visible light (> 0.76μm) and less than visible ultraviolet (< 0.4μm) less. In the total radiation energy, the wavelength between 0.15 ~ 4μm accounts for more than 99%, and is mainly distributed in the visible region and the red and ultraviolet region. The visible region accounts for about 50% of the total solar radiation energy, the infrared region accounts for about 43%, the ultraviolet region solar radiation energy is very little, only about 7% of the total.
Ultraviolet light is a general term for radiation in the electromagnetic spectrum with wavelengths ranging from 0.01 to 0.40 microns, which cannot cause human vision. Ultraviolet light is divided into A rays, B rays, and C rays (UVA, UVB, and UVC for short) with wavelength ranges of 400-315nm, 315-280nm, and 280-190nm, respectively.
According to ASTM G154, UV (ultraviolet) cannot simulate the full spectrum of sunlight. Its principle is that for durable materials exposed outdoors, the short wavelength range of ultraviolet light of 300 to 400nm is the most important cause of aging damage.