Pandemic coronavirus demonstrated a problem of total shortage of certified means of protection, and raised the question of adequate replacement. In fact, from a practical point of view to provide the whole population with protective masks medical or industrial grade is simply inefficient. They must not only produce according to strict standards, but also to educate the population to use them properly, otherwise they will be no good.
As a consequence, the focus has shifted from medical masks and industrial respirators to a simple improvised masks that one can make himself. But how to ensure that they were effective against viruses?
Let’s start with the fact that the size of the coronavirus of about 0.08 micrometer and the distance between the threads in a rag mask about 1000 times (from 0.1 to 1 mm). So “efficiency” in this case means not the ability to capture viral particles. In fact, efficiency in this matter means the ability to reduce the distance that your breath can spread from the body. If you want to protect yourself from the virus – you still need sertifitsirovanna protection class FFP2 (often referred to as N95 masks). But massive buying of such masks creates scarcity for those who really need doctors and rescuers. So the usual improvised mask is still the best solution.
To understand how far a particular mask allows you to extend your breath, try a simple test – try to blow out a candle in front of his face. First examine the distance and the force of exhalation, which is required to do, and then proceed to the testing of various materials and – more importantly – the number of desired layers. The mask, which makes you exert more effort just to blow out a candle that will impede the movement of viral particles directly into the face of your interlocutor. Without much more sophisticated equipment to conduct more reliable tests will not succeed.
Source — The Conversation