According to the filter medium, it can be divided into:

1. Air filter

Make the polluted air be cleaned to the state needed for production and life, that is to say, make the air reach a certain degree of cleanliness.

2. Liquid filters

Make the contaminated liquid be cleaned to the state needed in production and life, that is to say, make the liquid achieve a certain degree of cleanliness.

3. Network filter

By setting up to block junk information, the information appearing on the computer screen can meet the requirements as far as possible. The principle of same absorption separates light of different colors

4. Light filter

Absorb some unwanted light.