The role of 3M KN95 face mask and wearing common sense

In 2020, under the unprecedented COVID-19, unprecedented human history has had a strong bond with the mask. This kind of special medical supplies that only a few people would use suddenly became a necessity for the daily life of the public. Masks are currently one of the most powerful weapons against COVID-19.

Among them, the KN95 mask has become a product that everyone wants to buy. So do you know the KN95 mask?

KN95 face mask

KN95 face mask

1.KN95 face mask

1) what is the KN95 face mask?

KN95 masks and N95 masks are actually the same in terms of particle filtration efficiency.

The KN95 mask comes from the Chinese national standard GB2626-2006 “Respiratory protective equipment self-priming filter anti-particulate respirator”, N means Not resistant to oil, can be used to protect non-oily suspended particles; 95 means that the filtration efficiency is greater than or equal to 95%; KN95 means that the filtering performance of non-oily particulate matter reaches more than 95%, which can provide better protection in daily life.

KN95 masks are used in non-medical places to prevent various types of aerosol particles suspended in the air, including dust, smoke, and pathogenic microorganisms such as bacteria and viruses. KN95 masks are mainly of two types: breathing valve and no breathing valve. Among them, the breathing valve-less mask can effectively block the contamination of the surrounding environment by droplet bacteria discharged by the wearer of the mask, and the breathing valve mask does not have this function. So it is best to buy a mask without a breathing valve.

KN95 masks do not have the function of blocking the penetration of body fluids and cannot be used for medical operations, especially high-risk operations such as tracheotomy and tracheal intubation. KN95 masks may not be suitable for some frail or have cardiopulmonary diseases and are also not suitable for patients with respiratory problems with dyspnea.

2) who invented the KN95 face mask?

In 1720, when the outbreak of the French plague in Marseille was the worst, it was necessary to protect yourself by covering your face tightly with a cloth. Because it is too inconvenient to wrap the mouth and nose with cloth, people specially invented a mask similar to a bird’s beak for the doctor. This is probably the original mask.

After the 1870s, scientists gradually realized the existence of bacteria. In the 1890s, German bacteriologist Carl Flugge proposed that tuberculosis is spread in the air by droplets. According to this “saliva droplets are likely to spread disease”, surgeons put on masks for the first time in 1897.

These surgical masks are gradually spreading around the world, but their use is very limited, limited to the surgical room, and their role has been seriously underestimated. Until the autumn of 1910, a terrible plague swept northeast China. For the first time, masks showed their talents in epidemic prevention.

Soon after, in the Spanish influenza pandemic of 1918, people put on masks and further promote them.

In 1972, 3M developed the first KN95 face mask. The predecessor of 3M is actually a mining company. The reason why it actively develops protective masks is that mining workers also need masks to protect, which can reduce the occurrence of occupational pneumoconiosis. “N95” means that these masks can filter out at least 95% of the particles in the air.

3) what material is a KN95 face mask made from?

Masks are usually non-woven materials, all of which are made of polypropylene, and the KN95 face mask is no exception. It is an executive standard for the production of masks. The production materials are also non-woven fabrics, and the raw materials are also polypropylene. There are no other special The material is just a few more layers of filtering than ordinary masks.

Common medical masks are mainly composed of three layers of non-woven fabrics: the inner layer (hygroscopic layer) is a common non-woven fabric; the outer layer (water-blocking layer) is a non-woven fabric with a waterproof treatment, which is mainly used to isolate others from spraying The liquid droplets in the middle; the middle filter layer (core filter layer) is a polypropylene melt-blown nonwoven fabric that has been subjected to electret treatment, generally referred to as SMS structure (S for spunbond layer, M for meltblown layer).

In other words, the mask should be at least 3 layers, that is, 2 layers of Slayer and 1 layer of M layer. As a KN95 mask with a relatively high protection level, it is a 5-layer mask made of polypropylene non-woven SMMMS (2-layer S-layer and 3-layer M-layer) that can filter more than 95% of fine particles.

4)KN95 face mask sizes

The sizing differs with each mask model. Some of the sizing options include small, small/medium, medium, medium/large, and large.

5) KN95 face mask model

The KN95 face mask is divided into cup cover type, folding type, and so on from the appearance. This is mainly because of their different shapes, and their functions are basically the same. For non-oily particles such as bacteria and viruses, they can achieve more than 95% occlusion effect.

3M cup-type masks include: du8210 (8110S), 1860 (1860S), 8247, 9913V, 8822 and 8577, etc.

Folding masks, common 3M folding masks are: 9001 (V), 9002 (V), 9041, 9042, 9021, 9022, 9010, 9501, 9502, 9132, 9320, 9322, 9332 and so on.

The specific model can be found on the 3M official website.

2. The role of KN95 face mask

1) Can wear a KN95 face mask prevents COVID-19?

The new coronavirus can be spread through droplets, and the KN95 mask can protect the droplets well.

Because the droplets are mouth foams flying in the air, the particle size is much larger than the fine dust, the function of the mask is mainly to block rather than a filter.

2) Can KN95 face mask filter pm2.5?

The KN95 face mask can filter particulate matter and pm2.5 in the air.

3. KN95 face mask-wearing common sense

1) How to wear a KN95 face mask?

  • Wash your hands and keep your hands clean;
  • Select the KN95 face mask suitable for your face shape, hold the outer layer of the mask with one hand, and point the metal strip with your fingertips, with the metal strip side facing up, and cover the mouth, nose, and chin with the mask;
  • Pull the upper headband over the top of the head and hang it on the back of the head. Pull the lower headband over the head and hang it under the neck and ears. People with long hair should hang the lower headband under their hair.
  • Use both hands and fingers to move outward from the position of the bridge of the nose while pressing the metal bar, so that the nose is clamped against the bridge of the nose;
  • Check the airtightness every time you wear the N95 mask, and cover the outside of the mask with both hands: if it is a version without a breathing valve, quickly exhale (positive pressure) to check for leaks at the edge of the mask; if it is with a breathing valve Version, you should quickly inhale (negative pressure) to check the leakage.
  • If there is a leak, you need to readjust the position of the nose clip or mask. If you can’t seal it, you should replace the KN95 face mask that is more suitable for the face.
  • When you need to remove the mask, you can first loosen the lower headband hanging around the neck around the top of the head, and then loosen the upper headband hanging on the back of the brain, so that your hands can avoid touching the outside of the mask and reduce contact with germs probability.

2) Can the KN95 face mask be used repeatedly?

In addition to the medical (infected area), 3M masks can be used multiple times until you feel that the breathing resistance is large, or the mask is contaminated.

The frequency of replacement varies from person to person and is mainly related to the concentration of external pollutants. The bigger the dust on the outside and the dirtier the air, the more and faster the sticking to the filter cotton. This naturally has to be changed more diligently.

3) If it is not opened, will the KN95 face mask expire?

The KN95 face mask is one of the anti-particle masks. It has good prevention of droplet infection caused by patients’ body fluids or blood splashes. It has a certain shelf life. Generally, the shelf life of the KN95 face mask is three years. In this process, as long as it is not intentionally destroyed, it can be used.

Generally speaking, the expired KN95 face mask is not recommended to be used again. Because of the expired KN95 face mask, the protective performance of the filter material has been greatly reduced, and it has been unable to effectively block the spread of the virus, and it is easy to increase infection after use. There is a risk of a virus, so once the KN95 face mask expires, it is not recommended to use it again.

4. KN95 face mask cleaning knowledge

1) Can the KN95 face mask be cleaned?

The KN95 face mask cannot be washed with water. The reason is that the electrostatic loading on the filter can absorb extremely small particles. After washing, the mask will destroy the filtering ability of the material, and the tightness cannot be guaranteed, which seriously affects the filtering effect.

A KN95 face mask is a maintenance-free disposable protective mask. The disposable here does not mean that it should be discarded once, but that it can be reused several times, but it cannot be cleaned. It is discarded when the breath is blocked or the mask is dirty. No longer use.

2) How to disinfect the KN95 face mask?

The outbreak of COVID-19 caused a shortage of personal masks and protective equipment. If we strictly follow the one-time abandonment requirements of masks, it is difficult to meet the needs of everyone wearing masks. In addition, if hundreds of millions of masks are discarded every day, it also constitutes a huge potential source of pollution, which can easily lead to the secondary transmission of COVID-19 and other influenza viruses, thereby further aggravating the risk of COVID-19 and other respiratory diseases.

How to disinfect, regenerate, and reuse protective equipment such as masks without reducing protection requirements has become an important and realistic demand?

Two methods are introduced here:

(1) Use an electric hair dryer to clean and disinfect disposable masks:

  • Wrap the used disposable mask in a fresh-keeping bag to prevent the hot air from blowing away the contaminated pathogens, and also to avoid damaging the filter layer of the mask.
  • Turn on the ordinary electric hair dryer of the home to the maximum level of the hot air, and carry out the hot air heating treatment about 10-20 cm above the mask.
  • The experimental data shows that after 1 minute and 30 seconds, the temperature of the tuyere of the electric hair dryer can rise to 70 ℃ and continue to be maintained at this temperature.
  • Continue to blow hot air for 30 minutes to inactivate the virus and restore the mask to the state before it was used. It can be reused again.

(2) Microwave disinfection and regeneration mask

  • Look at the mask to see if there are metal, glue, etc. adhering to the sealing ring. If there is a second step if there is no third step.
  • Disassemble the wire and remove the wire (without damaging the mask structure).
  • Put the mask on the front of the microwave oven, if there is no adhesive such as glue, the maximum power is 700 watts (microwave high fire) for 2 minutes; if there is adhesive such as glue, 300 watts (40% maximum power, microwave medium fire), 4 minutes.
  • Turn on the microwave oven, and after running for 2 minutes, let the mask (temperature about 30 degrees) cool down slightly.
  • Put the back of the mask into the microwave oven, if there is no adhesive such as glue, the maximum power is 700 watts for 2 minutes; if there is adhesive such as 300 watts (medium), 4 minutes.
  • After the radiation is finished, take out the mask. If there is a metal wire, stick it with glue or adhesive tape. The mask is resurrected and can be used again.

It is recommended that the number of mask recycling should not exceed 5 times. Masks of medical personnel who are at high risk of exposure are not recommended for resurrection. The longer the irradiation time, the more complete the virus inactivation, but the risk of filtering changes to the mask increases.

KN95 face mask must be supplied before COVID-19 has been resolved, understand that KN95 face mask can better protect yourself.

I hope the above content about the KN95 face mask can give you some help.

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