1. Diffusion deposition of medical mask: the particles are moved to the filter fiber by Brownian motion and absorbed by molecular gravity. It is easy to capture small-scale particles, fine fibers and particles with low speed. 2. Retention deposition: the larger particles moving with the air flow are intercepted by the mechanical filtration of the filter material. The ratio of the particle diameter to the diameter of the membrane fiber affects the interception efficiency. 3. Inertia deposition: when the particles pass through the curved network channel of the filter material, the particles will leave the air flow due to the inertial effect, impact the filter fiber, and be intercepted by the molecular gravity. When the particle size is large, the density is high and the velocity is fast, the interception effect is good. 4. Electrostatic attraction deposition: deposition of particles by electrostatic action of filter fibers. The smaller the particle size, the stronger the deposition effect of 1 and 4, and the larger the particle size, the better the effect of 2 and 3. Combined with the synergetic effect of these filtration mechanisms, the common mechanical filter material is easy to penetrate, and the particle size range is 0.1m-0.3m. "Most medical masks are self-priming filter masks. The working principle is that the air containing harmful substances can be filtered through the filter material of the mask before being inhaled or exhaled. The filtration mechanism of mask filter material mainly includes the following (see Fig. 2): 1. Diffusion deposition: the particle Brownian motion diffuses to the filter fiber and is adsorbed by molecular gravity. It is easy to capture small-scale particles, fine fibers and low-speed particles. Masks cover a wide range of places and Bai areas, such as schools, food processing, electronic manufacturing enterprises, etc. These are densely populated places, and viruses are easy to infect. Therefore, when you wear disposable masks, you not only protect yourself, but also protect others, which greatly reduces the spread of viruses and diseases. The main function of disposable medical protective mask is to isolate droplets or blood in the air, and also to isolate body fluids or other secretions in the air, and to absorb dust. It is a very good tool to protect the health of doctors. Generally speaking, disposable medical masks must be strictly tested, and certain medical treatment and maintenance can be used.