With the popularization of sunscreen knowledge, more and more people have mastered scientific and effective sunscreen methods. Such as the skin coated with a variety of sun care products, wearing a variety of sun proof clothing and so on.
When the topic turns to physical sunscreen, consumers will still have or less fixed thinking. In summer this season, whether going out for commuting or traveling, physical sunscreen is a convenient, effective and lasting measure.
By measuring the real-time UVA and UVB intensity, the ratio t (λ) of transmission radiation flux and incident radiation flux is calculated, which is the ratio of ultraviolet intensity through clothes and sunlight ultraviolet intensity. The more the value is, the better anti ultraviolet effect will be.
Testing instrument:
One is to detect UVA ultraviolet irradiance meter, which mainly detects the intensity of ultraviolet light in 320-400nm band, and UVA mainly tans people; the other is to detect UVB ultraviolet irradiance meter, which mainly detects the intensity of ultraviolet light in 290-320nm band, and UVB mainly burns people.
Test standard:
In fact, ordinary clothes, how much can also block point UV. However, not all clothes can be called sunscreen clothes.
Anti UV products should be marked on the label:
1. National Standard No.: GB / T 18830 2009;
2. When 40 < UPF ≤ 50, it is labeled as upf40 +. When UPF > 50, it is labeled as UPF50 +.
3. The protection provided by the product may be reduced after long-term use and under tensile or wet conditions.
*According to this standard, when the sample's UPF > 40, and t (UVA) AV
When it is less than 5%, it can be called "anti ultraviolet product"
The sunscreen effect of ordinary sunscreen clothing benefits from the sunscreen coating, but the sunscreen coating will weaken the sunscreen effect with sweat invasion and water washing, which is also a common problem of many poor quality sunscreen clothing.
After that, the relationship between the sunscreen performance and thickness, color and material of clothes is tested and analyzed.
1. Influence of thickness Using the laboratory under the standard environmental conditions, the test equipment yg141d - Ⅱ fabric thickness gauge, one value was measured at the front and the middle part of the back of the garment
(test equipment yg141d - Ⅱ fabric thickness gauge)
The results show that the thicker the fabric thickness is, the better the anti ultraviolet effect is under the same material and color.
But it's not that the thicker the thickness, the worse the wearing experience. It also has something to do with the material behind.
2. The influence of color
Some research results show that wearing dark clothes is cooler than wearing white clothes in summer, but I really don't feel that... Friends who know this can contact us at any time. But according to the contrast, the same material and thickness, it is true that the fabric color is darker, the more obvious the anti ultraviolet effect.
3. Influence of ingredients
The fabric made of nylon has good elasticity, alkali resistance, and very wear-resistant, soft and comfortable feel, but compared with other fabrics, the cost is also the highest; polyester fabric is stiffer, acid resistant and high-temperature resistant than nylon; nylon / polyester components are mixed according to the proportion, and the characteristics are between them. The higher the proportion of nylon, the softer the fabric. Therefore, the sunscreen clothes made of nylon fabric are more soft, light and comfortable.
The principle of anti ultraviolet fabric is to use the ultraviolet absorbent mixed in the fabric to absorb high-energy ultraviolet, and transform it into low-energy heat energy or electromagnetic wave with short wavelength, so as to eliminate the harm of ultraviolet ray to human body and fabric. The use of ultraviolet reflectors can increase the reflection and scattering effect of fabric to ultraviolet ray and prevent it from penetrating the fabric. It has the properties of heat protection, heat insulation and cool touch
