Interpretation of Anti - ultraviolet Performance of Textiles

In recent years, due to the destruction of the ozone layer, reaching the surface of the radiation is increasing, excessive ultraviolet light on the human eye, skin and immune system caused some damage, so the anti-ultraviolet light of textile increasingly attention. The market has more and more anti-UV products, the performance of the pros and cons, a direct impact on the interests of consumers.
When ultraviolet rays are irradiated onto the fabric, a portion is absorbed, a portion of the fibers that penetrate the fabric (including from the voids of the fabric), and a portion of which is reflected. Through the fabric of the more ultraviolet, the greater the harm caused by the human body. Therefore, the main way to improve the performance of UV protection is to enhance the fabric of ultraviolet absorption and reflection ability, thereby reducing its throughput, usually there are three ways:1) coating on the surface of the fabric;2) blended in the fabric into the anti-UV additives;3) anti-ultraviolet dyeing and finishing fabric finishing;
The method of assessing the UV resistance of fabrics is usually spectrophotometrically. An ultraviolet spectrophotometer was used as a radiation source, and the sample was irradiated with a light beam scattered by a monochromator. The radiation flux in each direction of the fabric was collected by an integrating sphere to calculate the ultraviolet transmittance. At present, the standard of this method is AATCC 183, AS / NZS 4399, BS EN 13758 and so on.
The UV resistance of fabrics is generally evaluated by UPF and UVA transmittance.1) UPF - The ratio of the UV light-permeation effect calculated when the protective article is not used and the UV-based toner effect actually calculated using the protective article. It is more and more used at home and abroad to evaluate the performance of anti-ultraviolet film fabric indicators.2) UPA transmittance - ratio of long-wave ultraviolet transmittance flux to long-wave ultraviolet radiation flux without sample.The factors that affect the UV resistance of textiles are:1) fiber type, usually polyester and wool anti-ultraviolet performance better than cotton fabric;2) fabric structure, the more compact fabric, the less the UV, the better the UV resistance;3) fabric color, the general dark fabric than the light-colored fabric through the UV less, the UPF value is higher.