1. Structure of medical mask
Medical masks generally consist of a mask face and a tightening strap. The tightening strap is usually elastic and integral. However, some masks use manual tethering to strengthen the fit of the face and increase the protective effect. The mask face generally has three layers: inner, middle and outer. The inner layer is usually made of skin-friendly materials such as ordinary hygienic gauze or non-woven fabrics to prevent allergies. The middle layer is an isolation filter layer. Generally, an ultra-fine polypropylene fiber meltblown material layer is used. The layer is generally made of ultra-thin polypropylene melt-blown material and other special materials. The outer layer and the middle layer have their main protective barriers. After a certain period of use, the middle layer and the outer layer will gradually lose their protective effect, so this disposable mask should be worn After a certain period of time, it should be replaced in time to ensure the protective effect.
Second, the main classification of medical masks
1. Medical protective mask
Medical protective masks are the masks with the highest protection level. Common medical N95 masks are medical protective masks, which can filter particles with aerodynamic diameter of 0.075m¡À0.020m to more than 95%. Under normal circumstances, when properly worn, it can isolate most of the germs and viruses in the air, and it has a good protective effect for doctors and other personnel who directly contact the patient for a long time at close range.
2. Medical surgical mask
Medical surgical masks are not as effective as medical protective masks, but they can still block most bacteria and some viruses. Medical surgical masks require that the filtration efficiency of bacteria can reach more than 95% (different from N95-0.075m for aerodynamic diameter The filtration efficiency of particles of ¡À0.020m reaches more than 95%).
3. Ordinary medical mask
Ordinary medical masks are mainly used to block the exhaled breath from the mouth and nasal cavity, and have a certain protective effect against cross infection in ordinary environments. It is generally used for one-time hygiene care in general medical environments. The protection level is the lowest among medical masks. But in daily protection, it can play a certain protective effect when the personnel is not too dense.
3. Notes on the use of medical masks
1. Wash your hands before wearing a mask. Avoid wearing your hands and other contaminants on the inside of the mask during the mask wearing process.
2. Wearing a mask should pay attention to the upper, lower, inner and outer, and the upper side has a nose clip formed of a metal or other material fixing bar. Pressing against the nose can enhance the airtightness.
3. When the following situations occur, the mask needs to be replaced in time: the respiratory impedance increases significantly, the breathing is not smooth, the mask is damaged, etc., the mask cannot fully fit the face, the mask is contaminated (such as blood stains, droplets and other foreign objects) Contaminated), the mask has been used for more than the recommended duration, etc.