Only effectively intercept dust particles, without the formation of the airflow too much resistance. Messy interwoven fibers form numerous particle barrier, wide space between the fibers allow airflow smoothly.
The amount of dust collecting filter unfiltered amount of dust in the air ratio of " filtration efficiency ." Mainly for particles smaller than 0.1цm diffusion , the smaller the particle , the higher the efficiency ; than 0.5цm mainly for inertial motion of particles , the larger particles , the higher the efficiency .

Fiber bypass the airflow , resulting in a slight resistance. Numerous power is the sum of the fiber filter resistance . Filter resistance increases with the gas flow rate increased by increasing the area of ??the filter material , can reduce the relative network speed through the filter , reducing filter resistance .

The dust is captured additional resistance to flow , so the use of gradually increasing resistance of the filter . The dust was captured to form a new obstacle , therefore, a slight improvement in filtration efficiency . Most of the dust is captured in the filter material is gathered on the windward side . Larger filter area , the dust can be accommodated , the more the longer filter life .

The more dust on the filter , the greater the resistance . When the resistance is large enough to allow the design of the extent of the filter on the end of life . If the filter material with electrostatic or dust with static electricity , filter effects can be significantly improved. Changes due to static so that dust trajectories and hit an obstacle , static electricity stick work involved .