As medical workers, medical masks are indispensable two-way protective equipment. Before medical operation, medical masks must be worn, and even medical masks should be worn when ward rounds are required. The protective effect of medical masks is directly related to the selection of medical masks, whether they are correctly worn, and the fitting degree between masks and faces.
Medical masks belong to the second category of medical devices, most of which are self-priming filter masks. The working principle of medical masks is to make the air containing harmful substances filtered through the filter materials of medical masks and then be inhaled or exhaled.
Working principle of medical mask filter material
1. Diffusion deposition: the Brownian motion of particles 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.
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 synergistic effect of these filtration mechanisms, the most easily penetrated particle size range of ordinary mechanical filter media is 0.1m-0.3m.
Product structure
Medical masks are generally composed of the following materials: main filter material: such as polypropylene melt blown cloth, etc. Other materials: metal (for nose clip), dye, elastic material (for mask belt), etc.
Medical masks generally have the following forms: according to the shape of the mask, it can be divided into plane shape, duck beak shape, arch shape or folding type, etc. According to the way of wearing, it can be divided into ear hanging type, bandage type or headband type.
Mastering the correct wearing method of medical masks can avoid gas coming in and out from both sides of nasal bridge, so as to play the filtering and ventilation functions of medical masks, and pay attention to personal safety protection.
