The inner layer is made of skin-friendly materials such as ordinary sanitary gauze or non-woven fabric to prevent allergies. The middle layer is an isolation filter layer, and the outer layer is made of special materials such as ultra-thin polypropylene meltblown materials. The outer layer and the middle layer have their main protective barrier function. After a certain period of use, the middle and outer layers will gradually lose their protective effect. This disposable mask should be replaced in time to ensure protection.
Second, the main classification of medical masks
1. Medical protective mask
Medical protective masks are the masks with the highest level of protection. Common medical N95 masks are medical protective masks, which can filter particles with an aerodynamic diameter of 0.075m-0.020m, with a filtration efficiency of more than 95%. Under normal circumstances, the correct wearing can isolate most germs and viruses in the air, and provide good protection for doctors and other personnel who have been in close contact with patients for a long time.
2. Medical surgical mask
Although medical surgical masks are not as efficient as medical protective masks, they can still block most bacteria and some viruses. Medical surgical masks require that the filtration efficiency of bacteria can reach more than 95% (unlike N95-different, N95-can filter 95% of particles with an aerodynamic diameter of 0.075 m or more than 0.020 m).
3. Ordinary medical masks
Commonly used medical masks are mainly used to block saliva exhaled from the oral cavity and nasal cavity, and have a certain protective effect on cross-infection in common environments. Generally suitable for disposable health care in general medical environment. Medical masks have the lowest protection level. But in daily protection, the effect can play a certain role when there are few people.