Wearing a mask is an important and effective way to isolate the virus and protect vulnerable groups. Currently, masks can be used to isolate bacteria and PM2.5 particles in two ways:
(1) Electrostatic adsorption, which is an active isolation method, uses the electrostatic force between the fibers in the middle layer of the mask to adsorb bacteria and tiny particles to achieve isolation and protection;
(2) Physical isolation is a passive isolation method, which uses the small pore structure of the mask itself to block the invasion of bacteria and viruses. The physical isolation method mainly uses the gravity effect, interception effect, diffusion effect, and inertia effect of bacteria and fine particles.
The design requirements of general medical surgical masks can block bacterial aerosol particles larger than 3 microns in diameter, but due to the large pore diameter of the core layer of the mask, the physical isolation of small particles of bacteria and viruses cannot be perfectly achieved. Such masks mainly use electrostatic adsorption Methods. However, as the wearing time increases (such as 1 to 2 hours), the mask becomes wet due to human activities such as breathing of the wearer, and its electrostatic adsorption capacity is weakened, and the isolation effect gradually becomes worse. Therefore, ordinary medical surgical masks cannot achieve long-term effective isolation and protection.
The surge in global demand for masks has become a global topic. The melt blown fabrics known as the mask "heart" originally started at less than $3,000 per ton, and now the price has risen more than $40,000!