The air filter material is to electrostatically charge polypropylene fibers during the melt-blown manufacturing process, making them electrostatic electret melt-blown non-woven fabrics (filter paper), with a fiber diameter of 2-5 μm. In addition to using this filter material In addition to the filtration mechanism of traditional air filter materials, the Coulomb force of charged fibers is used to capture particles, so the efficiency increases and the resistance decreases. At present, there are anti-virus functions (including SARS virus) in the world. This filter material is used in 3M surgical masks (N95, N97, N99), and in the anti-SARS air filter launched in the United States in April 2003. due to this It is a kind of filter material with high efficiency, low resistance and low price. Therefore, when this material is used in air filters for general air conditioning and ventilation, when the wind speed on the windward side is 0.5m/s, the filtration efficiency of 0.5μm dust can reach To more than 95%, the air resistance is only 40Pa, which is incomparable to the air filter of the traditional cabinet air conditioner unit (usually nylon mesh). This air filter has been used in large shopping malls, supermarkets, hospital air conditioning systems The system has been used for nearly 10 years, and has been applied to the family, such as the Fairway air purifier, which has achieved good air purification effect. The selection of air filter materials should be based on the filtration requirements used, and the corresponding filter materials with filtration precision and air permeability should be selected to meet the requirements of filtration precision, flow resistance and service life.