How much do you know about KN95 masks?

1. What is a KN95 mask?

KN95 is a Chinese standard mask. It is a type of mask with particle filtering efficiency in our country. Because the new coronavirus is mainly transmitted through droplets, N95 means that it can filter 95% of the particles in the air.

The filtration capacity of KN95 is better than ordinary masks and medical masks. If ranked according to the priority of the wearer's own protection function, the KN95 mask has the highest protection ability.

2. The specific structure of KN95 mask

Medical masks and protective masks are non-woven materials, composed of oriented or random fibers, usually in a multilayer structure, mainly composed of three layers, usually called SMS structure. At present, the highest number of layers in China is 5 layers, that is, SMMMS. The KN95 mask with higher protection level has 5 layers, 2 layers of meltblown cloth + 3 layers of non-woven fabric, which can filter more than 95% of fine particles.

3. How long can KN95 masks be used?

Compared with other types of masks, the price of KN95 masks is relatively high. Many friends have questions, can I reuse KN95 masks? No problem at all.

Some researchers have conducted related studies on the protection efficiency and wearing time of KN95 masks. The results showed that: KN95 mask was worn for 2 days, the filtration efficiency remained above 95%, and the respiratory resistance did not change much. After 3 days, the filtration efficiency dropped to 94.7%.

The application time of KN95 will vary according to different environments. For example, in the case of direct contact with bacteria and viruses, it usually lasts 6 to 8 hours, not more than 8 hours. If used for general protection, the mask should be discarded when it comes in contact with blood or droplets. If the mask is damaged, it should be discarded. When breathing resistance increases, it should be discarded. If this is not the case, the general reference is to use two per week, if the maximum is one, use five working days.

4. Precautions for wearing KN95 masks

1. Wash your hands before wearing a mask, or avoid touching the inside of the mask while wearing a mask to reduce the possibility of mask contamination.

2. Distinguish the inside, outside, top and bottom of the mask; the printed side of the KN95 mask faces outward; one end of the metal strip/sponge strip is on the top.

3. Do not squeeze masks, including KN95 masks, which isolate the virus on the surface of the mask. If you squeeze the mask with your hands, there is still a chance of infection.

4. Make sure that the mask fits closely to the face. The simple test method is: After putting on the mask, exhale forcefully to prevent air from leaking from the edge of the mask.