What Is a Dust Mask Respirator?

Dust respirator is an indispensable protective article for workers engaged in dust exposure. It is mainly used in working environments containing low concentrations of harmful gases and vapors, and working environments that generate dust. The cartridge contains only adsorbents or sorbents. Some filter boxes are also equipped with a filter layer, which can prevent aerosols at the same time. Some military anti-gas masks are mainly made of activated carbon cloth, or use water- and oil-resistant fabrics as the outer layer, glass fiber filter material as the inner layer, and activated carbon-impregnated polyurethane foam as the bottom layer, which can provide temporary properties when suddenly attacked by poison gas Protection.

Dust respirator is an indispensable protective article for workers engaged in dust exposure. ^[1]

There are many types of dust masks. But their principles are the same: they all use composite filter materials, and the general filter materials are: activated carbon fibers, activated carbon particles, meltblown cloth, non-woven electrostatic fibers, and other special filter materials, which are mainly used to deal with Other special toxic gases or radioactive particles. The classification of dust masks is similar to the classification of other masks, and we can also divide them according to their usage times and appearance.
First, according to the number of uses: It can be divided into: disposable gas and dust respirators, repetitive gas and dust respirators, and recyclable gas and dust respirators.
Second, according to the shape of the points: can be divided into, semi-mask-type full-face flat cup-type duck-bill type and so on.

Duckbill

Duckbill-type dust respirator adopts boat-type design. There are adjustable nose clips on the outside and sponge strips on the inside. The elastic band design is more in line with the requirements of mechanics. It has good sealing performance and can bypass the ears and straddle the head. Ear discomfort caused by wearing a mask for a long time improves the wearing comfort.

The three-dimensional design of the duckbill-type mask makes conversation more convenient, and is particularly suitable for clean rooms, medical use to prevent bacterial and viral infections, and industrial use to block tiny dust. This product is made on a fully automatic production line.

The inner and outer layers are made of soft PP non-woven fabric, which can reduce fiber shedding and increase wearing comfort.

The filter layer is made of high-efficiency meltblown material, which can effectively block dust and air.

1. Personal protective equipment to prevent or reduce dust in the air from entering the human respiratory organs to protect life;

2.Material: Most of the dust masks are two layers inside and outside.

1. The role of the dust mask is to prevent the inhalation of dust. The key to its role is the performance of the filter material, mainly:
   1. The fiber fineness of the filter media is expressed by the fiber diameter and the unit is micrometer. Generally, the diameter of the filter fiber used in dust masks is preferably less than 5 microns. The diameter of polypropylene ultrafine fibers commonly used now is 4.0 microns, and the diameter of perchloroethylene ultrafine fiber filters is less than 2 microns. The drug absorption of fiber is positively related to the dust blocking efficiency, that is, the finer the fiber, the higher the dust blocking efficiency.

   2. Composition of filter material The structure of filter material is related to the manufacturing process of filter material. At present, the forming process of synthetic fiber non-woven filter material mainly includes needle punch method, direct spray method, bonding method, and hot melt method. The hot melt spray molding method is often used, and this method can be used for composite molding of two or more different fiber materials to improve the dust blocking efficiency, which is relatively soft and has good air permeability.

   3. The size of the charge filter belt of the filter material has a positive correlation with the composition efficiency, that is, the larger the amount of electrostatic charge, the higher the dust blocking efficiency.
   When dust passes through the filter, the following happens:
   (1) Collision retention: When the particle diameter of the dust is larger than the gap between the filter media fibers, the dust collides with the surface of the filter media, changes direction due to the reaction of inertia and force, and settles and adheres to the surface layer of the filter media.
   (2) Hook effect: There are burrs on the fiber. When the dust passes through the filter material, it is caught by the burrs on the fiber to prevent the particles from penetrating.
   (3) Multi-layer filtration: The filter material is made of microfibers overlapping each other to form a net, and it has a multi-layered "three-dimensional structure". When the dust passes through the filter material, it is trapped by layers.
   (4) Electrostatic effect: The filter material has a static charge, which has a repulsive effect on the dust particles of quite polarity, while it has an adsorption effect on the dust particles of the opposite sex, that is, trapping dust. ^[4]

   Different dust masks use different filter materials. The filtering effect is related to the particle size on the one hand, and it is also affected by whether the particles contain oil. Dust masks are usually classified according to filtration efficiency and classified as suitable for filtering oily particles. Oil-free particles such as dust, water-based mist, paint mist, oil-free smoke (welding smoke), microorganisms, etc. Although "non-oily particulate" filter materials are more common, they are not suitable for oily particulates, such as oil mist, soot, asphalt smoke, coke oven smoke, and so on. And filter materials suitable for oily particulate matter can also be used for non-oily particulate matter. ^[2]

   First: The dust-proof efficiency of masks must be high. The dust blocking efficiency of a mask is based on its dust blocking efficiency against fine dust, especially respiratory dust below 5 m. The dust blocking principle of general gauze masks is mechanical filtering, that is, when the dust hits the gauze, it will block some large particles of dust in the gauze after layer by layer of blocking. However, fine dust, especially dust smaller than 5 m, will pass through the mesh of gauze and enter the respiratory system. There are some dust masks on the market for sale.The filter material is composed of permanent static charged fibers. Respirable dust smaller than 5 m will be attracted by static electricity and adsorbed on the filter material when it passes through this filter material. It really plays a role in blocking dust.

   Second: The tightness of the mask and face shape is better. When the mask is not tightly attached to the face, dust in the air will enter the respiratory tract through the gaps around the mask. Therefore, people should choose a dust mask suitable for their face shape and wear a dust mask correctly.

   Third: Wear comfortably, including small breathing resistance, light weight, hygienic wear and convenient maintenance, such as wearing arched dust masks.

   There are also particular about wearing masks. The masks on the market are generally divided into rectangular and cup-shaped. When using a rectangular mask, press the wire on the mask against the bridge of the nose, and then spread the entire mask along the bridge of the nose to exert its effectiveness.

   For cup masks, make sure the mask is dense enough to stick to the face, and the exhaled air will not leak out to be effective. When wearing a cup mask, check for air leaking from the edge of the mask. If the mask is not tight, reposition it before wearing it.

   1. First, loosen the headband every 2-4 centimeters, pass your hand through the mask headband, and place the metal nose forward.

   2. Put on the mask and close to the face. The upper end of the mask is placed behind the head, and then the lower end is pulled over the head, placed behind the neck, and adjusted to a comfortable position.

   3. Press the tips of your two fingers along the metal strip of the nose bridge from the middle to the sides and slowly press inward until it is close to the bridge of the nose.

   4. Cover the mask with both hands as much as possible and perform positive and negative pressure tests. (Positive pressure test: cover the mask with both hands and exhale vigorously. If the air overflows from the edge of the mask, it is improperly worn, and the headband and nose bridge must be adjusted again.)

   1. The outer layer of the dust mask often accumulates a lot of dirt, bacteria and other dirt in the outside air, and the inner layer blocks the exhaled bacteria and saliva. Therefore, the two sides of the dust mask cannot be used alternately, otherwise the outer layer will be contaminated. The dirt is sucked into the human body when it is directly close to the face and becomes a source of infection.

   2. When the mask is not worn, it should be folded into a clean envelope, and the side that is close to the nose and nose should be folded inward. Do not put it in your pocket or hang it around your neck.

   Dust masks should be cleaned and disinfected daily. Both gauze masks and air filter masks can be disinfected by heating. The specific approach is:

   1.Cleaning

   Gently rub the gauze mask with warm water and soap first. The bowl-shaped mask can be gently cleaned with a soft brush dipped in detergent, and then washed with water. Please be careful not to rub hard, because if the warp and weft gap of the gauze is too large, it will lose the effect of preventing droplets.

   2. Disinfection

   Soak the cleaned face mask in a 2% peroxyacetic acid solution for 30 minutes or cook in boiling water for 20 minutes or steam in a steamer for 15 minutes, and then air dry for later use. This method is suitable for gauze masks and bowl masks.

   3. Check

   Before using it again, you should carefully check whether the masks and masks are still intact. For gauze masks and masks, you can use the light transmission inspection method, that is, take care of them before the lamp to see if there are obvious light spots, and the middle and edge parts are transparent Is the rate consistent? If in doubt, replace it with a new one. Regardless, masks and masks are generally updated after 3 to 7 times of washing, and masks of particularly good quality can be washed 10 times. Activated carbon adsorption masks should pay attention to periodically replacing the activated carbon interlayer. If the activated carbon interlayer is not replaceable, it must be replaced after 7 to 14 days. This type of mask cannot be reused after cleaning. ^[6]

   The "Occupational Diseases Prevention Law" stipulates that the occupational disease protection supplies provided by employers to workers must meet the requirements for the prevention and treatment of occupational diseases. Similarly, dust masks used by workers engaged in and in contact with dust must also meet the requirements. According to the GB2626-2006 standard for respiratory protective equipment promulgated by the National Quality Supervision, Inspection and Quarantine Bureau and the National Standardization Management Committee, the unit producing dust masks must comply with the law. After obtaining the production and operation license, the production technical specifications of all dust respirators must meet the corresponding standards. This standard specifies the production and technical specifications of respiratory protective equipment, and has strict requirements on the material, structure, appearance, performance, filtration efficiency (dust blocking rate), breathing resistance, detection methods, product identification, and packaging of dust masks. The material of the dust mask must be non-irritating and non-allergenic to the skin, and the filter material is not harmful to the human body. The structure of the dust mask should be convenient to use. The filtering efficiency (dust blocking rate) of the dust mask, the particle diameter is less than 5 microns. The dust rate must be greater than 90%, the dust resistance rate of particles smaller than 2 microns must be greater than 70%, and so on.

   This standard classifies dust respirators into oily dust respirators P and non-oil repellent dust respirators N; according to the performance of the original dust block and the dust block rate, it is divided into KN90, KN95, KN100, KP90, KP95, KP100 class. KP type is suitable for oil-proof dust, such as paraffin wax and jade oil.

   KN type is suitable for preventing non-oily dust, such as table salt and stone ore. The larger the number in the model, the higher the dust resistance rate and the higher the dust safety factor. When you purchase, you need to choose the mask you need for different environmental dust concentrations.

   The GB2626-2006 standard also specifies the standard coefficients of inhalation resistance and exhalation resistance of dust masks. Workers should feel comfortable when wearing dust masks, and can easily exhale and inhale easily without feeling a sense of inadequate breathing. Normally, the breathing rate is 20 times per minute. The constant coefficient of ventilation for exhalation and inspiratory resistance is 85 (± 1) liters / minute. The standard also stipulates that the product identification must be clear and clear, and the identification must be marked- the name and trademark (such as the name "dust mask", the trademark "labor insurance", etc., at a glance); model (such as KN90, KN95, KP100, it is convenient for shoppers to know which masks are oil-resistant and / or non-oil-based dust, and how high the dust blocking rate is; The standard also clearly stipulates: on the smallest sales package, it is marked in Chinese in a clear and durable way, or the following information can be seen through the transparent package: name, trademark; mask type and model; implementation standard number year number, product license Number; production date or batch number, storage life, etc., which helps to know if the product has expired.

   These standards are important. Production units can be manufactured according to uniform requirements, and products can only be sold before they leave the factory if they meet quality standards. According to these standards, the purchaser chooses the required mask according to the type and concentration of dust in the working environment, so that the role of the dust mask can be brought into full play. ^[1]

   1. When we see the name of the dust mask, it is not difficult to see that this mask must be used to prevent dust from entering our respiratory system, so the dust prevention rate of these masks should be quite high, so When choosing a dustproof mask, we should choose a mask with a high dustproof rate.

   2. When choosing a mask, we should look at whether the opening design of the mask matches our face shape. Only those masks that fit the face shape can better match our nose and mouth. The air is isolated, so we should choose masks with a high fit rate to our face.

   3. While the masks have the above two characteristics, they should also look good, and they are convenient to wear, making people feel very comfortable. Only by wearing these masks can we devote ourselves to work and study. Go.

   4. After you use the mask, you can not let the outside of the mask contact the bacteria. This step is very important, because if the outside of the mask is exposed to bacteria, it will directly affect your respiratory system and make it more serious. May affect your life safety.

   Some people are not suitable for wearing masks, so who are they unsuitable for wearing masks? Let's take a look below:

   1. If you have a respiratory disease, or if you have a heart problem, then you are not suitable to wear a mask.

   2. If you are pregnant, then you are not suitable to wear a mask.

   3. If you experience dizziness and difficulty breathing after wearing a mask, or your skin is particularly sensitive, then you are not suitable for wearing a mask.

   Gauze mask can be used for dust protection and comfortable to wear

   1. Non-woven dust mask can be reused after cleaning, which can save costs

   2. As long as you wear a dust mask, you won't get pneumoconiosis

   Experts point out that dust masks are special labor protection products, and the state has special standards for their quality. Gauze masks are only about 10% effective against dust below five micrometers, which is the most harmful to the human body. As a result, they spent money and failed to prevent dust damage. After the dust is captured by the ultra-fine electrostatic fiber cloth, it is extremely difficult to be detached due to washing, and water washing will also destroy the electrostatic suction ability. Therefore, non-woven masks cannot be washed and must be discarded after use. Dust masks have a certain filtering volume. If they exceed their filtering capacity, they cannot be dustproof, and dust masks cannot be dustproof if they are not worn properly.