For the filter material of a good protective mask, the following three conditions should be met. One is that the filter efficiency is high when the mask is in good contact with the user's face, the other is low breathing resistance, and the third is that the user feels comfortable.
There are many kinds of materials for the filter materials of dust-proof masks, including ordinary fabrics, animal hair, and non-woven fabrics. Very popular in the national standard is an activated carbon felt material.