Mask is a sanitary and epidemic prevention product, which is usually worn on the nose and mouth to filter the air entering the nose and mouth to block harmful gases, smells, droplets, viruses and other substances. It is made of gauze or paper. Masks have a certain filtering effect on the air entering the lungs. Wearing a mask has a very good effect when respiratory infectious diseases are prevalent and when working in polluted environments such as dust. Masks can be divided into air filtration masks and air supply masks.