The coronavirus pandemic turned everything upside downthat the most popular goods in the world were personal protective equipment - hand antiseptics, disposable gloves and face masks. Now they are sold in all stores, in the subway, on the street, countries exchange them, sending entire cargo multi-ton aircraft. For some time there was a strong shortage of masks and respirators, which caused a serious increase in prices for them. And many began to make protective masks on their own, which, although they are not intended for use in a medical institution, can still help when they are in crowded places. But which material is best for making medical masks with your own hands?
To find out, American scientiststested more than 70 combinations of various tissues and materials to find out how a particular material transmits virus-like particles. To do this, they developed a setup that performed in the role of a “man” - it simulated pressure and air flow rate, as in ordinary breathing, while spraying aerosol particles that mimic virus particles. To make the particles better visible later on under a microscope, they were stained with a dye.
What material does not allow viruses
The compressor of the installation forced air into the chamber withaerosol spray, after which air through a narrow passage rushed into a wide chamber. So the particles were evenly distributed throughout the system. At the end of the chamber, the test material was placed, behind which a glass plate was placed, which collected particles that passed through the fabric. Using a microscope and a glass plate, scientists watched the material pass particles, and measured the amount of nanoparticles deposited on the glass plate.
As a result, the mostcommon materials - from jeans and cotton to fabrics based on polypropylene, polyester and polyaramide. Moreover, at first, scientists tested pieces of materials one at a time, and then studied their throughput properties in a "multilayer" mode - placing several pieces on top of each other, including combining different materials.
According to the results of the study, best fromvirus-like particles protect terry cloth, quilted cotton or flannel along with polypropylene, polyester or polyaramide fabric. They can not miss most of the nanoparticles ranging in size from 10 to 200 nanometers, and, according to the researchers, they can cope with this task no worse than medical respirators N95, which are almost consistent with the classification of FFP2. At the same time, FFP2 (medium level of protection) and FFP1 (low level of protection) are not as effective as FFP3. These respirators can already pass the coronavirus, however, the question is the number of viral particles. So, masks with a low level of protection will miss more particles CoVID-19, but most viral particles still remain on the respirator - thereby protecting the airways.
Jeans protect worst of virus particlesfabric, so if you suddenly want to sew yourself a mask of old jeans, it’s best not to. Such material allows almost 17 times more particles to pass through than the N95 mask.
The effectiveness of protective masks
No matter what material you choosefor making a mask, the main rule is that it should fit snugly to the skin of the face, but in no case touch the lips. Otherwise, the degree of protection is greatly reduced, and even if you make a mask of cotton and polyester, but do not place it tightly, the effect will not be better than it is a "denim" protective mask. In addition, studies by American scientists once again prove that it is better to breathe in the mask as little as possible - the more often you breathe, the more particles penetrate the material.
Well, in any case, keep in mind that masks, no matter how effective they are, do not guarantee 100% protection against CoVID-19. And WHO constantly says that the most effective way not to get infected SARS-CoV-2 - This is to wash your hands thoroughly with soap and water and observe social distance. So it’s better to sit at home and read our Telegram chat.
And if you decide to sew a mask, as my colleague did Lyubov SokovikovaIt’s better to do two at once so that you can wear one mask while the second is sterilized.
Regarding flu viruses, homemade masks fromthe materials mentioned may also reduce the risk of infection. Not only that, scientists recently found that rag masks (medical, not home-made) are comparable in effectiveness with N95 respirators.