The dangers of UV rays to the human body and what kind of protection UV-resistant fabrics can provide us.

The dangers of UV rays to the human body and what kind of protection UV-resistant fabrics can provide us.

The ultraviolet zone of the sun can be divided into three sections. It can be divided into three sections. The wavelength area of ​​400-320nm is called UV-A; the wavelength area of ​​320-280nm is called UV-B; the wavelength area of ​​280-200nm is called UV-C. UV-C has a shorter wavelength, is absorbed in the air, and cannot reach the earth’s surface. Ultraviolet rays account for about 6% of sun exposure, with UV-A accounting for a larger proportion and UV-B accounting for a smaller proportion. UV-A will penetrate beneath the epidermal tissue, causing muscles to lose elasticity, roughening the skin, and causing wrinkles. UV-B can cause skin cancer. Therefore, it is required to effectively shield the short wavelength parts of UV-B and UV-A.
At present, due to the impact of chlorofluorocarbons (ClFCs) on Destruction of the earth’s ozone layer. The ozone concentration of the ozone hole discovered in 1997 was 40% lower than in the 1980s. According to analysis, if the level of the ozone layer is reduced by 1%, the transmission amount of UV-B can be increased by 2%, and the incidence of skin cancer will increase by 0.5-5%. According to statistics, between 1980 and 1996, the number of skin cancer patients doubled. In the United States alone, the number of people increased from 200,000 in 1990 to 1 million in 1996. [6] Therefore, it is very important to carry out UV protection finishing of fabrics, especially UV protection finishing of summer clothing fabrics.
Ultraviolet protective agents can be divided into ultraviolet absorbers and ultraviolet absorbers Shielding agent. The former are mostly organic compounds, while the latter are mostly inorganic compounds. 1) The ultraviolet absorption effect of benzophenone compounds relies on the conversion of ketone and enol forms in the molecular structure, converting the absorbed Complete energy is converted into heat energy. ?Uvinue D-49 (BASF) has multiple hydroxyl groups in its molecular structure and has a high adsorption capacity for cotton fibers. It can be used as a finishing agent for cotton fabrics after masking. After benzophenone compounds are sulfonated, they have the properties of acid dyes and can be used as finishing agents for silk after covering. (2) Benzotriazole compounds, such as 2-(2′-hydroxy-3′-tert-butyl-5′- Methylphenyl)-5-chloro-benzotriazole (Ciba Tinuvin 326), etc., because of their low water solubility, similar structure to disperse dyes, and certain sublimation fastness, they can be used as high-temperature and high-pressure co-bath dyeing of polyester fibers. Use UV protection after finishing. However, benzotriazole compounds absorb slightly near 420nm, so they will cause some color changes. DP-UV[5] developed by Shanghai Printing and Dyeing Research Institute is also estimated to be a benzotriazole compound. (3) The Rayosam series of reactive UV absorbers developed by Swiss Clariant can react with hydroxyl groups on cellulose or amino groups on polyamide fibers. Reaction occurs and the washing fastness is good. Finished fabrics will not change their appearance, feel or breathability. (4) Aliphatic polyol compounds [4] Japanese Shiibo Company product]RICAKGUARD] is a fabric finished with this compound. According to reports, the UV transmittance of the fabric after finishing is only 1.6%, and the UV transmittance after washing 30 times is only 3.4%. It can be used on cotton and polyester/cotton fabrics. The dyeing fastness, air permeability, and hygroscopicity of the fabric after finishing can remain unchanged.

UV shielding agent

Ultraviolet shielding agents are mostly metal oxides with higher refractive index such as zinc oxide, titanium dioxide, etc. The refractive index of zinc oxide is 1.9, and that of titanium dioxide is as high as 2.6. Due to the relatively low refractive index of zinc oxide, the diffusion rate after coating on fabric is also low and the transparency is higher. Japan’s Sumitomo Cement Company has developed ultrafine zinc oxide particles (n-100, n-200). The particles are of hexagonal crystal system. Due to its high crystallinity and small specific surface energy, it is easy to disperse. It can be adsorbed on fabrics in a monodisperse state and has high transparency. Beijing Workwear Institute has tested fabrics treated with zinc oxide, and their UV shielding rate can reach 89%. The UV shielding rate of fabrics treated with titanium dioxide is 84.5%, and it is still 83.6% after five washes. Since inorganic UV shielding agents are heat-resistant and oxidation-resistant, they can be mixed into polyester masterbatch and spun into shielding fibers. Esmer fiber, a product of Kuraray Japan, is one example. Japan Tokai Dye’s [ナウル NEW] is also estimated to be a nano-scale zinc oxide or titanium oxide shielding agent. The nano-scale ceramic cotton textile fabric developed by my country’s Xiamen Huapu High-Tech Industrial Co., Ltd. also has UV resistance, antibacterial and far-infrared heat preservation functions.

Concealed effect

Ultraviolet shielding rate is the current standard for distinguishing the covering effect of domestic products. Level A: The UV shielding rate is above 90%; Level B: The UV shielding rate is above 80%; Level C: The UV shielding rate is above 50%. Generally, it is better to choose level A. The shielding rate is calculated based on the integral value of transmittance in the wavelength range of 280 to 400nm. Tidy up the product after masking for safety.��Since the fabric is mostly used to make summer work clothes after covering, it will be in direct contact with human skin. To this end, it is necessary to strengthen a series of safety tests such as skin allergy tests, acute toxicity tests, and teratogenic tests on the finishing agents after masking. Ensure products are safe for humans and environmentally friendly. Technological masking fabric is made from ordinary fabrics that have been newly masked and sorted. The UV shielding rate of the finished product is ≥80%, which can effectively prevent ultraviolet rays. It is harmless to the human body and is non-toxic, non-irritating and resistant to cleaning. The use of this product has expanded from sun umbrellas to sun hats, work clothes, curtains, construction tents and other fields. Main technical indicators: