People who love beauty, of course, should pay attention to sunscreen in summer. Besides sunscreen, umbrella and other common means, it is also a good way to use clothing and clothing to prevent sun.
However, now there are so many sunscreen clothes, dozens of them and thousands of them. Is it an IQ tax? Is the more expensive the better?
Let's talk about it in detail.
01 Why can clothes protect against sun?
Clothing to preventhuman bodyUV damage plays an important role. In fact, clothing fabrics for daily wear have certain UV protection functions. When ultraviolet rays irradiate the clothing surface, reflection, scattering, absorption, transmission and other phenomena will occurskinThe damage on the surface becomes smaller.
The anti-ultraviolet effect of fabric is closely related to the factors such as fiber material, weaving structure compactness, fabric thickness and weight, color depth and so on. For example, the anti-ultraviolet effect of cotton and silk in natural fibers is general, wool is slightly better, flax is the best, and the anti-ultraviolet effect of polyester (also known as polyester fiber) in chemical fibers is the best; The higher the fabric's weaving structure compactness, the thicker and the lower the penetration rate, the better the anti-ultraviolet effect.
However, the protective effect of daily clothing on ultraviolet radiation is limited, and it is exposed to the strong sun for a long timelightIn the next outdoor scene, we need sunscreen clothes with high UV protection function.
Special sunscreen clothing can reduce the ultraviolet rays that reach the skin surface through the fabric by improving the ability of reflecting, scattering or absorbing ultraviolet rays.
02 How do sunscreen clothes prevent sun?
The fabric of sunscreen clothing generally follows two principles to realize the sunscreen function:
1) Shielding principle: enhance the reflection and scattering effect of the fabric on ultraviolet rays, such as finishing the inner layer of the fabric with shielding agent coating, or adding shielding agent to the fiber of the fabric;
2) Absorption principle: enhance the absorption of ultraviolet rays by the fabric, and convert the energy absorbed by ultraviolet rays into heat energy release or harmless low energyradiationFor example, when dyeing fabrics, choose dyes with good ultraviolet absorption, or finish fabrics with anti-ultraviolet absorbent coating.
So, to what extent can we call sunscreen clothing?
According to the provisions of the national standard GB/T 18830-2009 "Evaluation of Ultraviolet Resistance of Textiles", anti-ultraviolet textiles must reach UPF ＞ 40 and UVA transmittance ＜ 5% before they can be called anti-ultraviolet products. Ultraviolet protection factor (UPF) refers to the ratio of the average effect of ultraviolet radiation calculated when the skin is unprotected and the average effect of ultraviolet radiation calculated when the skin is protected by fabric. The higher the UPF value, the better the anti-ultraviolet performance of the textile. UVA is the part with the longest wavelength in the ultraviolet ray. It has a strong penetrating power. It can directly reach the dermis of the skin and destroy the elastic fiber and collagen fiber. The lower the UVA transmission rate, the better the anti-ultraviolet performance of the textile.
03 Is your sunscreen clothing an IQ tax?
The good news is that people have increased their awareness of sunscreen, and many people will also buy sunscreen clothes. But the price of sunscreen clothing ranges from tens to thousands. How to choose it?
In fact, we just need to identify a sign and consider the price comprehensively.
According to the provisions of the national standard GB/T 18830-2009 "Evaluation of the UV-proof performance of textiles", the UV-proof products should be clearly marked on the products, and the marking content must include the following parts:
"- Standard number, i.e. GB/T 18830-2009;
——When 40 ＜ UPF ≤ 50, it is marked as UPF40+. When UPF ＞ 50, it is marked as UPF50+;
——The protection provided by this product may be reduced after long-term use and under tensile or wet conditions. "
The sunscreen clothes that meet the national standards must have the above marks, which is also the most direct basis for consumers to choose and buy sunscreen clothes.
So, how expensive sunscreen clothes are appropriate? In fact, considering the cost of fabric, design and process as a whole, sunscreen clothing with the above logo and more than 100 yuan can be purchased with confidence, while sunscreen clothing that is too cheap is not recommended. Some sunscreen clothes are sold at a high price, most of which include factors such as brand premium and design style. Under the condition of meeting the national standard, their UV protection functions for skin are not different.
However, we may also have a feeling that it is still a little stuffy to wear the famous brand sunscreen clothes, which is why? In fact, this is mainly determined by the materials and technology, and in fact, the designers have made a lot of efforts.
04 Sunscreen clothes, how can I breathe?
At present, the most common fabric of sunscreen clothing on the market is polyester (also known as polyester fiber), followed by nylon, or the fabric made of polyester and nylon. Usually, a small amount of spandex is added to improve the elasticity of the fabric and improve the comfort of wearing.
Polyester and nylon are the two most common chemical fibers, both of which have outstanding mechanical properties. The woven fabrics have high tensile strength and good wear resistance, and are widely used in the production of outdoor protective clothing. The polyester fabric itself has outstanding anti-ultraviolet ability; In addition, the various anti-ultraviolet treatment technologies of polyester are very mature and have strong moisture absorption and perspiration capacity, making polyester become the preferred material for the production of sunscreen clothing. Nylon has strong hygroscopic and sweat-wicking ability and large thermal conductivity, which can provide obvious instant cool feeling in contact. It is also widely used in sunscreen clothing.
Sunscreen clothing usually adopts a relatively tight woven structure, because the tighter the fabric structure is, the less the UV transmission is. Generally speaking, the structure of woven fabric is more compact than that of knitted fabric. The tight fabric structure, combined with many sunscreen clothes that use fabric coating to improve the anti-ultraviolet performance, will reduce the permeability of the fabric. There are also many sunscreen clothes made of knitted fabric, which has better breathability than woven fabric.
In addition, in the design of sunscreen clothing, some technical treatment will also be used to increase breathability, such as the use of mesh fabric in the armpit and sleeve bottom, which are not exposed to direct sunlight; Other sunscreen clothes are designed as a wide shawl style, which increases the air layer between the sunscreen clothes and the body, which is beneficial to the body's heat dissipation and reduces the feeling of stuffiness when the body is moving.
In addition, when choosing sunscreen clothing, it is recommended to choose sunscreen clothing with cool color fabric as much as possible; When washing the sunscreen clothing, try to wash it gently by hand to avoid damaging the sunscreen finishing effect of the fabric or causing fabric structure relaxation. If after a period of use, the sunscreen clothing has obvious light transmission and loose fabric structure, it should be replaced.
Finally, I would like to remind you that the skin damage caused by ultraviolet rays includes sunburn, sunburn, skin photosensitivity, mainly manifested as skin melanin, redness, swelling and pain, and even seriouswaterBlisters, peeling, severe allergic reactions, etc. The skin exposed to the sun for a long time will also appear obvious aging phenomenon, manifested as the loss of elasticity, the decline of skin barrier function, etc. Because ultraviolet rays do so much damage to the skin, we really can't ignore sunscreen.
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