1. Look at the price
Some umbrellas can only shield the sun, and ultraviolet rays will still penetrate the fabric, and only after the sunscreen coating treatment can it have anti-ultraviolet effects. So it's not that parasols can protect against ultraviolet rays. A qualified, anti-ultraviolet sunshade can cost at least 20 yuan. Therefore, the effectiveness of UV protection for umbrellas bought for a few dollars is questionable.
2. Look at the protection level
Only when the UV protection coefficient value is greater than 30, that is, UPF30+, and the long-wave UV transmittance is less than 5%, can it be called a UV protection product; and when UPF>50, it indicates that the product has excellent UV protection performance, and the protection level is marked It is UPF50+. The higher the UPF value, the better its UV resistance.
3. Look at the umbrella fabric
Generally speaking, fabrics with thicker umbrella surfaces and tighter fabrics have better UV resistance. Cotton, silk, nylon, etc. have poor UV resistance, while polyester is better. In addition, the anti-ultraviolet performance is best for satin weave fabrics, followed by twill weave and plain weave, the darker the better.
4. Look at the appearance of the umbrella surface
There are two types of anti-ultraviolet sun umbrellas: glossy and matt. Glossy umbrellas dominate the market and look pretty and lively; the production process of matt umbrellas is relatively complicated, the price is also expensive, and it looks unassuming, giving people a subtle and steady impression. In addition, because the fabric has the characteristics of shrinking, when buying a sun umbrella, the umbrella surface should be large rather than small.