With the outbreak of hazy weather in most areas in recent years, PM2.5 protective masks have become very popular. Many businesses have taken up the idea of PM2.5 and claim that the masks sold have the effect of blocking PM2.5 particles. Experts said that there are a large number of anti-PM2.5 masks on the market. Due to the long-term lack of quality standards for PM2.5 masks, market products are mixed and the quality of adulteration is serious. How to choose protective masks in order to achieve a good protective effect? This also starts with the principle of filtration.
First, the mask filter principle
One of the main factors affecting the level of mask protection is the filtration efficiency of the filter material. Filter media used to filter particles, whether natural or synthetic, filters the airborne particulate matter down into the following five mechanisms:
Second, what kind of masks can achieve the effect of preventing PM2.5?
The above filtering principle tells us that large particles of sand and dust mainly achieve filtration through inertial impact and interception, while small particles are more likely to achieve filtration effects through diffusion and electrostatic effects. Therefore, for particle sizes above 1μm, the effect of interception by the dense fiber network structure of the filter material is obvious, but for the majority of submicron particles in the PM2.5 particle, the interception effect is insignificant. It is more effective to filter and remove by means of particle diffusion principle and electrostatic principle. Therefore, the effective filter material of PM2.5 is often a static-loaded meltblown ultrafine fiber non-woven fabric.
The masks currently available on the market include cotton masks, gauze masks, medical masks, activated carbon masks, and industrial dust masks. How exactly do these masks protect against haze? These numbers tell you the truth:
Third, wear masks pay attention
After reading the above introduction, I believe that everyone has a professional understanding of the filtering and protective effects of various masks. When choosing a mask, choose a mask that has a filtering effect on the particles by a professional protective mechanism. The mask must be matched with your face. Pay attention to the closeness of the face mask, fasten it at the bridge of the nose, and ensure the fit. The better the effect, otherwise no protective effect.
In addition, you cannot wear a mask for a long time. In one aspect, the outer mask adsorbs large contaminant particles, etc., causes an increase in breathing resistance, causing discomfort; on the other hand, air inside the mask will call the adsorbed bacteria, viruses, such as pay attention promptly replaced, will Cause secondary pollution. Therefore, it is not correct to wear a mask throughout the day. If it is to protect the outside from smog pollution, it can be removed indoors. Masks that can be used multiple times should be cleaned and disinfected every day (anti-PM2.5 masks are generally not washable and can only be replaced), hot water wash for a few minutes, and then get sun drying and disinfection.
