A medical mask is composed of a mask face and a tension band. The face of the mask is divided into three layers: inner, middle and outer. The inner layer is made of skin-friendly material (normal sanitary gauze or non-woven fabric), and the middle layer is an isolation filter layer (ultra-fine polypropylene). Fiber melt blown material layer), the outer layer is a special material antibacterial layer (non-woven fabric or ultra-thin polypropylene melt blown material layer).

It is understood that the executive standard for medical protective masks is GB 19083-2010; the executive standard for medical surgical masks is YY 0469-2011; the executive standard for disposable medical masks is YY/T 0969-2013. Some products claim to implement the enterprise standard (YZB) formulated by the enterprise itself and are also available for purchase. In principle, the technical requirements of the enterprise standard are not lower than the national standard (GB) or industry standard (YY). (figure 1)

(figure 1)
In addition, the product registration number will be marked on the outer packaging of medical masks that are subject to medical device license supervision according to regulations. The numbering rule is usually: X Machine Note (X is the abbreviation of each province, such as Hubei, Zhejiang, Guangdong, etc.) + registration year +264 (indicating that it belongs to the 64 classification of Class II medical devices) + serial number. Citizens can check and identify them through the website of the State Drug Administration.

If the product name shows "disposable medical mask", "medical surgical mask" or "medical protective mask", then it belongs to the scope of medical mask; if it does not contain the word "medical", it is like "disposable non-woven mask" "Ordinary protective masks" and so on that do not contain the word "medical" are not officially registered medical masks.

The characteristics of medical masks are light, comfortable, odorless, glass-free, non-irritating to the skin, waterproof, and after disinfection, they can kill or remove pathogenic microorganisms on the media to make them harmless; Dust-proof, due to low respiratory resistance and hygienic wearing, it absorbs aerosols, dust, smoke, mist, poisonous gases and poisonous vapors through the filter material, blocking them from being inhaled by people, effectively isolating pollution sources. (figure 2)

(figure 2)

The ordinary mask is a fiber mask, and its flow blocking principle is a mechanical blocking effect. Through this layer by layer mechanical blocking, large particles can be blocked, but particles less than 5 μ m in diameter can not be blocked, let alone PM2.5 particles. However, medical masks and disposable medical masks can block particles larger than 4 μ m in diameter, so ordinary masks can block particles larger than 4 μ M To wear 16 layers to play the effect of medical masks

In addition to higher hygiene requirements, medical protective masks should also have the function of effectively blocking liquid splashes. Due to the possibility of blood or infectious body fluids being splashed during surgery, this kind of splashing has some pressure and is not a normal liquid infiltration. The ability of medical mask materials to block pressured liquids should be relatively high. Only in this way can it be Effectively protect medical staff. (image 3)

(image 3)

Medical masks are generally divided into cotton gauze masks, medical surgical masks, and N95 masks. Their characteristics are Cotton gauze mask. It can prevent some viruses from attacking, but it has poor adhesion to the human face and low anti-virus efficiency.

Medical surgical mask: divided into three layers. Firstly,the outer layer blocks water. Secondly,the middle layer blocks more than 90% of 5μm particles in the air, and the inner layer absorbs moisture.

N95 is certified by the American Institute of Occupational Safety and Health. N refers to non-oily particles, and 95 refers to a filtration rate of 95% under the test conditions specified in the standard, and good adhesion.