There are many types of medical masks. Common medical masks are disposable non-woven masks, gauze masks, and special anti-virus masks.
1. Disposable non-woven masks, with more than three layers, can isolate bacteria and dust, and are disposable, safe and reliable, without the risk of secondary infection.
2. Gauze masks are the type of masks that have been used all the time. Gauze masks are widely used in the field of medical care and scientific research.
3. Anti-virus masks are mainly made of special materials with a filter layer in the middle. Generally, the filter layer is made of activated carbon felt or meltblown cloth. It has the effect of sterilization and sterilization.
According to performance characteristics and scope of application, medical masks can be divided into: medical protective masks, medical surgical masks, and general medical masks.
1. Medical protective masks meet the GB19083-2003 "Technical Requirements for Medical Protective Masks" standard. Important technical indicators include non-oily particle filtration efficiency and airflow resistance:
(1) Filtration efficiency: Under the condition of air flow (85±2) L/min, the filtration efficiency of sodium chloride aerosol with aerodynamic median diameter (0.24±0.06) μm is not less than 95%, which is in line with N95 (or FFP2) and above.
(2) Inhalation resistance: Under the above flow conditions, the inhalation resistance does not exceed 343.2Pa (35mmH2O).
2. Medical surgical masks comply with the YY 0469-2004 "Technical Requirements for Medical Surgical Masks" standard. Important technical indicators include filtration efficiency, bacterial filtration efficiency and respiratory resistance:
(1) Filtration efficiency: under the condition of air flow (30±2) L/min, the filtration efficiency of sodium chloride aerosol with aerodynamic median diameter (0.24±0.06) μm is not less than 30%;
(2) Bacterial filtration efficiency: under specified conditions, the filtration efficiency of Staphylococcus aureus aerosols with an average particle diameter of (3±0.3) μm is not less than 95%;
(3) Respiratory resistance: Under the condition of filtration efficiency and flow rate, the inspiratory resistance does not exceed 49Pa, and the expiratory resistance does not exceed 29.4Pa.
3. Ordinary medical masks meet the relevant registered product standards (YZB), generally lack the filtration efficiency requirements for particles and bacteria, or the filtration efficiency requirements for particles and bacteria are lower than medical surgical masks and medical protective masks.
