The prototype of the air filter is the respiratory protective apparatus used by people to protect breathing. It is recorded as early as
In Rome, First century, people were protected with masks made of coarse hemp when they were purified. During the long time, the air filter has progressed, but it is mainly used as a respiratory protective apparatus for hazardous industries such as the production of hazardous chemicals. 1827 Brown discovered the movement of tiny particles, and people had a further understanding of the mechanism of air filtration.
The rapid development of air filters is closely related to the development of the military industry and the electronics industry. During the First World War, the use of various chemical agents, with asbestos fiber filter paper as the smoke layer of military gas masks emerged. Fiberglass filter media is used for air filtration in October 1940 to obtain patents in the United States. In the 50, the United States made an in-depth study on the production process of fiberglass filter paper, so that the air filter was improved and developed. 60 The generation of HEPA filter, the 70 generation, the use of micro-glass fiber filter paper as the filter media HEPA filter, 013 micron particle size of the efficiency of the filtration of up to 99.9998%. Since the 80-1990s, with the emergence of new test methods, the improvement of the use evaluation and the improvement of the filtration performance requirements, the HEPA filter is found to have serious problems, and the higher performance ULPA filter is produced. Countries are still struggling to study, and it is estimated that more advanced air filters will soon emerge.