For a good filter material of 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 breathing resistance is small; third, the user feels comfortable. There are a variety of materials for dust-proof mask filter materials, including ordinary fabrics, animal hair, non-woven fabrics, etc. In the national standard is a very popular activated carbon felt material.
The structure of gauze mask has poor tightness with human face. Many fine particles that do great harm to us will enter the respiratory tract and lung through the gap between the mask and the face. The filter material is usually made of mechanical fabric. To achieve high dust prevention efficiency, the method is to increase the thickness, and the negative effect of increasing the thickness is to make the user feel great respiratory resistance, I don't feel comfortable. The non-woven fabric after electrostatic treatment can not only block the large dust particles, but also the static charge attached to its surface can absorb the fine dust by electrostatic attraction, so as to achieve high dust resistance efficiency. However, the thickness of the filter material is very thin, which greatly reduces the breathing resistance of the user and feels comfortable, thus achieving the three necessary conditions for a good filter material mentioned above. With a good filter material and scientifically designed mask structure, a suitable mask is formed.
Fit effect
Masks must be of the right size and worn in the right way for them to work. The masks sold 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 protective effect. The user should press the wire on the mask on the bridge of the nose, and then spread the whole mask along the bridge of the nose, so as to play an effective role. Children can wear rectangular surgical masks, because it has no fixed shape, if well bound, can be close to the child's face. The cup-shaped mask should be made sure that the density of the mask is enough after sticking on the face, and the air will not leak out. When wearing a cup-shaped mask, cover the mask with both hands and try to blow. Check whether there is air leakage from the edge of the mask. If the mask is not tight, you should readjust the position before wearing it.
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