Automotive air filters are primarily responsible for removing particulate impurities in the air. Piston-type machinery (internal combustion engines, reciprocating compressors, etc.), if the inhalation of dust and other impurities in the air will aggravate the wear of parts, it must be equipped with air filters. The air filter consists of a cartridge and a shell. The main requirements of the air filter are high filtration efficiency, low flow resistance, continuous use for a long time without maintenance.