Do ordinary sun umbrellas protect against UV rays?

Ultraviolet rays are produced by sunlight. If there is too much exposure to ultraviolet rays, it will be harmful to human health. Therefore, we should be careful not to let too much ultraviolet radiation expose our body to the sun in normal times, so as to avoid causing serious harm to our body. To prevent ultraviolet radiation, you can use methods such as parasols to prevent it. So are parasols UV-proof? Let’s talk about it today.

After the 1990s, anti-UV fabrics suddenly emerged, among which Japanese companies were the most prominent. They successively launched sportswear, shirts, socks, hats, parasols and other products with anti-UV radiation function, which were favored by consumers. Take Australia as an example. It is a country located at low latitudes with strong sunshine. It was the first to develop anti-UV textiles to protect the human body and has brought anti-UV textiles into the commercialization stage. They usually adopt the method of adding anti-UV finishing agents and UV shielding agents. In addition, there are also methods of applying UV absorbers and reflectors to fabrics at the same time to make the protection against UV rays more superior. For example, Unica's Tornado UV first makes fabrics from polyester filaments containing special ceramic powders, and then treats them with UV absorbers. The resulting fabric has a UV shielding rate of up to 97%. In addition, nanotechnology is also applied to anti-UV textiles, such as using the quantum size effect of nanopowders to make their absorption of light of a certain wavelength have a "blue shift phenomenon" and the absorption of various wavelengths have a "broadening phenomenon", resulting in a significant enhancement of the absorption of ultraviolet light, thereby ensuring the product's ultraviolet shielding effect.

Currently, the most commonly used nanomaterials that absorb ultraviolet rays are: 30-40nm TiO2, which has a strong absorption capacity for ultraviolet rays below 400nm; A1203 nanopowder has a strong absorption capacity for ultraviolet rays with a wavelength below 250nm; SiO2 has a reflectivity of up to 95% for ultraviolet rays with a wavelength below 400nm.

The mechanism of anti-ultraviolet radiation finishing of textiles is to apply a substance on the textiles that can reflect and, or strongly and selectively absorb ultraviolet rays, and can convert energy to release or consume energy in the form of heat or other harmless low-energy radiation. After applying these substances, the textiles have no adverse effects on the wearability of the fabrics and meet the requirements for use. Therefore, the anti-UV radiation finishing of textiles has similarities with the light stability of polymers. However, light resistance is to protect polymer compounds from auto-oxidation caused by ultraviolet radiation, which leads to the degradation of polymers and changes in appearance and structural properties; while anti-UV radiation finishing is to protect the human body from damage caused by excessive ultraviolet radiation.

From the perspective of optics, when light hits an object, part of it is reflected from the surface, part of it is absorbed by the object, and the rest passes through the object. However, when light hits fabrics that have been treated with anti-UV radiation, part of it passes through the gaps in the fabric. The UV shielding agent on the fabric either reflects the UV light or selectively absorbs it and converts its energy into low energy and releases it, thereby shielding the UV light.

Inorganic UV shielding agents, also known as UV reflectors, mainly achieve the purpose of protecting against UV radiation by reflecting or refracting incident UV rays. They do not have the function of converting light energy, but only use fine powders such as ceramics or metal oxides to combine with fibers or fabrics to increase the reflection and scattering effect of ultraviolet rays on the fabric surface to prevent ultraviolet rays from passing through the fabric and damaging human skin. These powders include kaolin, calcium carbonate, talc, iron oxide, zinc oxide, lead oxide, etc. According to tests, zinc oxide and lead oxide are the best for reflecting or protecting against ultraviolet rays in the 310-370nm wavelength range, and iron dioxide and kaolin also have certain effects. These inorganic components have certain advantages over organic UV shielding agents. In addition to their superior light resistance and UV protection, they also have outstanding heat resistance. In particular, zinc oxide also has antibacterial and deodorizing functions.

In fact, from the perspective of traditional Chinese medicine, this saying passed down by the ancients has some truth.

Many women who love beauty want to know whether parasols can protect against ultraviolet rays. The above introduction has clearly told you. In addition to using tools such as umbrellas to prevent ultraviolet radiation, you can also develop good habits, such as not going out when the sun is strong, or wearing clothes that prevent ultraviolet radiation. This can also have a good preventive effect.