Working principle and structure of medical mask

Working principle of medical mask filter material

1. Diffusion deposition: Brownian motion of particles diffuses into the filter fiber and is absorbed by the attraction of molecules. It is the easiest to capture small-scale particles, fine fibers and particles moving at low speed.

2. Retention and deposition: The larger particles moving with the air flow are retained by the mechanical screening effect of the filter material. The ratio of particle diameter to membrane fiber diameter affects the interception efficiency.

3. Inertial deposition: When the particles pass through the curved mesh channel of the filter material, the particles are separated from the airflow and hit the filter fiber due to the inertial effect, and are trapped by the molecular gravity. The large particles, high density, and fast speed have good interception effect.

4. Electrostatic attraction deposition: the deposition of particles generated by the electrostatic action of the filter fiber.

The smaller the particles, the stronger the deposition effect of 1, 4 and the larger the particles, the better the effect of 2, 3, so the particles that are not smaller are more difficult to filter. Synthesizing the synergistic effect of various filtration mechanisms, the range of the most easily penetrated particle size of ordinary mechanical filter materials is 0.1m ~ 0.3m.

Product structure

Medical masks are generally composed of the following materials:

Main filter material: such as polypropylene meltblown cloth. Other materials: metal (for nose clips), stains, elastic materials (for mask bands), etc.

Medical masks generally have the following forms:

According to the shape of the mask, it can be divided into plane, duckbill, arch or folding. According to the way of wearing, it can be divided into earhook type, strap type or headband type.