Pick these umbrellas should pay attention to the following three aspects.
First, look at the label. Mainly look at the protection index, that is, UPF and UVA value, only UPF greater than 40, and UVA transmittance of less than 5%, can be called anti-UV products, UPF value is greater, the better anti-UV performance. In general, most of the logo on the market as "UPF50 +", its protective function has been enough.
Second, look at the color. In the case of the same fabric, dark umbrella anti-ultraviolet effect better. Parasol and other umbrellas is the biggest difference between the anti-UV coating, to prevent the penetration of ultraviolet light. UV detection rate of 5% -10%; green, light red, light green, purple, dark green, purple fabric, ultraviolet transmittance of 5% -10%; green, light red, light green , White fabric UV transmittance of 15%.
Third, look at the fabric. Umbrella thick, the fabric of the fabric more anti-ultraviolet performance is better, relative to cotton, silk, nylon and other fabrics, polyester more sunscreen. To know the sun umbrella sunscreen effect, may wish to try the sun. The deeper the shadow, the lower the translucent umbrella sunscreen the best. When purchasing a parasol, be sure to choose a branded product. General manufacturers will be in a number of local use of brand identity, such as umbrella joints and so on. In addition, the rain will corrosion UV coating, it is best to separate the parasols and umbrellas. If the umbrella is dirty, you can rinse with water, or hand rub, otherwise it will affect the effect.
What fabric sunscreen effect?
1, silver plastic coated fabric. Silver tape fabric is not only anti-ultraviolet effect, and the price is relatively cheap. Use the time to pay attention to silver plastic coating do not rain, rain will damage the umbrella coating, reduce sunscreen effect. Use a long time umbrella, silver plastic coating will be aging black, and sometimes you can find a coating of the seal, this is because the climate drying coating shrink, need to replace the new umbrella to ensure sunscreen effect.
2, two new fabrics. TC yarn-dyed fabric is a new type of fabric that can be washed and does not affect the sunscreen effect. Transmittance is not high, the wavelength of 380,300,220 nm of the basic UV can be completely blocked. UV 250-400 nm band most likely to cause human skin and hair and other sunburn, dry. There is also a laser punching fabric, woven by high-density process, the surface of the fabric with a lot of refraction particles, each point will be with the light position of the rotation and change the color, play a role in the scattering of ultraviolet light. These two fabrics have the best UV protection effect, but the price is more expensive.
3, three fashion fabrics. Fat thin silk, looks like lace, ultra-light and very beautiful, but this fabric's high transmittance, sunscreen effect is not good. Satin cloth, is a satin fabric, belonging to the polyester, anti-ultraviolet effect than silver plastic coated fabric weak. There is also a fabric on the market called pearl tape, a certain reflection of the role of ultraviolet light, sunscreen effect is also worse than silver plastic coating fabric. Four kinds of sun umbrellas do not sunscreen if the sun umbrella election is wrong, may be done "useless work"