Introduction to the protection principle of KN95 protective masks

KN95 protective masks use mineral fibers, natural fibers or synthetic fibers to filter particulate matter. There are five mechanisms by which filter fibers filter particulate matter in the air, and they can work together.

Sedimentation: large particulate matter settles on the filter material under the influence of gravity in the airflow, and is separated from the airflow;

Inertial impact: When the particles in the air flow bypass the filter fiber that is blocked in front of the air flow, the higher-quality particles will deviate from the direction of the air flow due to the inertia, and hit the filter fiber to be filtered;

Interception: The particles are located on the streamline closest to the filter material in the airflow, and the particles are "scraped" and intercepted by the filter material because the radius of the particles is larger than the distance between the streamline and the filter material;

Diffusion: Affected by the thermal movement of air molecules, extremely tiny particles are impacted by air molecules, constantly changing the direction of motion, showing Brownian motion, and randomly contacting the filter fibers to be filtered;

Electrostatic effect: If the filter material fiber has weak static electricity, no matter whether the particles in the airflow are electrostatically charged or not, when they are close to the filter material fiber, they are easily attracted by static electricity and be filtered. The electrostatic effect can help the filter material without increasing the airflow. Improve filtration efficiency under the premise of resistance.