The filter cloth used in medical masks mainly absorbs bacteria and viruses, and blockades pathogens. The dense filter layer uses N95 filter material, which can filter particles and effectively block flying smear, blood, body fluids and secretions. The head band of the medical mask is two long bands passing through the holes on both sides of the mask. The nose is clamped in the center of the upper part of the filter layer and placed between the dense layer and the filter layer. The material is a metal or metal-plastic composite, which has both plasticity and certain strength, and is easy to wear when the nose is sealed. It can be said that medical masks are protective devices to protect the mutual infection between medical staff and patients. Therefore, the bacterial filtration efficiency must be more than 95% in accordance with national requirements, which is an important role of medical masks.
