There are many micropores in the internal structure of activated carbon which can form a large specific surface area. These micropores can inhale toxic vapor and gas molecules with different molecular sizes without escaping. The requirements for the treatment and installation of activated carbon are very high. If the treatment is improper or the activated carbon particles are very thick, resulting in the gap between particles, then the toxic gas will penetrate into the respiratory tract from the gap, and will not be absorbed. Therefore, it is very unscientific to change the activated carbon in bags. The activated carbon in a good chemical filter box should be packed tightly, with small particle size and large specific surface area, so that the anti- time will be long, and at the same time, the respiratory resistance should be small and the wearing should be comfortable.
Dust suppression efficiency
The efficiency of respirator is based on its barrier efficiency to fine dust, especially to respirable dust under 2.5 μ M. Because this particle size dust can directly enter the alveoli, which has the greatest impact on human health.
Degree of cohesion
The side leakage prevention design of respirator is to prevent air from passing through the gap between respirator and human face without being inhaled through filtration. Air, like water, flows first where there is little resistance. When the shape of the mask is not close to the face, the dangerous substances in the air will leak into the respiratory tract from the non close place. Well, even if you choose the best filter. It can't protect your health. According to many foreign regulations and standards, workers should regularly test the tightness of masks. The purpose is to ensure that workers choose appropriate size masks and wear them according to the correct procedures.
Filter material of respirator
For a good filter material of the protective mask, the following three conditions should be met: first, the filter efficiency is high when the mask and the user's face are well closed; second, the respiratory resistance is small; third, the user feels comfortable. There are many kinds of filter materials for dustproof masks, including ordinary fabrics, animal hair, non-woven fabrics, etc. A kind of activated carbon felt material is very popular in the national standard.
The mask must be the right size and wear in the right way for it to work. Masks on the market are generally divided into rectangular and cup-shaped. The rectangular mask must have at least three layers of paper structure to have a protective effect. The user should press the wire on the nose bridge of the mask, and then spread the whole mask along the nose bridge, so as to play the role. Let the child wear a rectangular surgical mask, because it has no fixed shape, if well tied, it can close to the child's face. Cup masks should be made sure that the density is enough after the mask is attached to the face, so that the exhaled air will not leak out. When wearing the cup-shaped mask, you can try to blow with your hands covered by the mask to check whether there is air leakage from the edge of the mask. If the mask is not tightly covered, you need to readjust the position before wearing it.
The structure of gauze mask
The structure of gauze mask and the tightness of human face are very poor. Many tiny particles that do great harm to us will enter the respiratory tract and the lungs through the gap between the mask and the face. Its filter materials are generally some mechanical fabrics. The only way to achieve high dust resistance efficiency is to increase the thickness, and the negative effect of increasing the thickness is to let the user feel the respiratory resistance It's very big. I don't feel comfortable. The electrostatically treated non-woven fabric can not only block the large dust particles, but also the static charge attached to the surface of the non-woven fabric can absorb the small dust through the electrostatic attraction, so as to achieve a high dust resistance efficiency. But the thickness of the filter material is very thin, which greatly reduces the user's respiratory resistance and feels comfortable, so as to achieve the three necessary conditions of good filter material mentioned above. With a good filter material and a scientifically designed mask structure, an efficient and high-quality mask is formed.