In the hot summer, sunscreen has become a hot topic for people to go out. Compared with sunscreen cosmetics, sun hats, umbrellas, and other sun protection measures, sunscreen clothing with its sun protection ability, long time, large coverage area, easy to carry advantages, etc., become the main means of people travel sunscreen.
1. Sun protection principle of sun protection clothing
According to optical principles, transmittance + reflectivity + absorption = 100%, so the higher the reflectivity and absorption of UV, the lower the transmittance, and the better the sunscreen effect.
Principle
The sun-proof principle of the sun-proof clothes is to protect the fabric from UV rays, that is, to add UV absorbers or UV reflectors to the fabric in various ways to improve the ability of the sun-proof clothes to reflect and absorb UV rays, to block ultraviolet rays through the sun-protective clothing to harm the skin.
UV absorbers
UV absorbers, which selectively absorb UVA and UVB and convert energy to shield UV rays, are most commonly used in the production of Benzophenone and benzotriazoles, its high melting point, toxicity, poor heat resistance, high temperature can be decomposed, there is a certain stimulation to the skin.
Ultraviolet reflectors
UV reflectors, through reflection, refraction of the external part of the UV to achieve the anti-UV effect, with high effect, good safety, long-lasting effect, and so on, in the actual production of metal oxide particles or ceramic powder, such as talcum powder, calcium carbonate, zinc oxide, titanium dioxide, etc.
2. Related standards and major indicators requirements
UPF
UPF (ultraviolet protection factor) is the ratio of the average effect of UV radiation calculated when the skin is unprotected to that calculated when the skin is protected by fabric.
T (UVA) AV
T (Uva) AV refers to the ultraviolet radiation transmission ratio of 315 ~ 400 nm.
The higher the UPF, the lower the UVA, and the better the UV protection of the fabric.
3. Common fabrics for sunscreens
Knitting Fabric
Knitted sunscreen fabric to cotton or polyester-cotton blend-based, with good permeability and comfort, hygroscopicity, but its anti-UV capacity is poor.
Woven Fabric
Woven sun-protective clothing fabrics for nylon, polyester, etc., in the sun-protective clothing market, is the most commonly used, nylon in wear resistance and hygroscopicity, etc., polyester in breathability, contact cool and other comfortableness function has great advantages.
4. Influence of fabric on sun protection performance
The thickness and porosity of the fabric
The thicker the thickness, the tighter the structure, and the smaller the corresponding porosity, the fabric will be the better anti-UV effect
But for sunscreen fabric, first of all, to ensure that both light and thin this feature, you can consider the dense, small pores of the fabric.
The color of the fabric
Color is also an important factor affecting the fabric’s anti-UV performance, after dyeing fabric, which contains part of the dye molecules, dye molecules on the group will enhance the absorption of UV.
The higher the purity, the better the ability to absorb UV rays, so you can choose the preference of relatively dark color sunscreen.
5. Comfort requirements for sun protective clothing
Breathability
Refers to the gas through the performance of fabrics, which directly affects the thermal and wet comfort of sunscreen clothing.
Sunscreen used in summer wear, requires good ventilation, in order to quickly lose heat, and to avoid making people feel hot.
Moisture permeability
It is an important index to evaluate the comfort of sunscreen clothing.
In the hot summer, the human body will produce a certain amount of heat and sweating, sunscreen with good moisture permeability, to avoid people wearing a sultry feeling, sticky feeling.
The air permeability and moisture permeability of sunscreen clothing by density, porosity, the influence of thickness and finishing method, etc.
6. How to choose sunscreen clothing
Nylon and polyester fabrics are most commonly used in the market; preferred fabrics are soft and elastic, lightweight, soft hand feeling, clean and simple, easy to wear, and comfortable; preferred fabrics with fine and solid grain, less light transmission, avoiding purchasing the coating method of sunscreen clothing, its poor permeability, uncomfortable, and easy to peel off the coating after washing, the ability to reduce the sun.
Dark-colored sun-protective clothing reflects ultraviolet rays better than light-colored sun-protective clothing, so when choosing sun-protective clothing, you should choose dark-colored sun-protective clothing, black and red sunscreens work better.
The various styles of sunscreen clothing, can choose high-collar three-dimensional cutting, its more fitting, more protective, more convenient to move; wider brim of the hat design, but also make the face better sunscreen effect. In addition, in order to improve the breathability and perspiration of sunscreen clothing, can choose underarm and back with a small hole design style.
