The main route of transmission in novel coronavirus is droplet transmission. Wearing a mask can effectively stop the spread of the virus. Masks are an important line of defense for respiratory infectious diseases, which can reduce the risk of novel coronavirus infection. The mask can not only prevent patients from spraying droplets, reduce the number and spraying speed of droplets, but also block droplet nuclei containing viruses and prevent the wearer from inhaling.

Classification of masks

Classification by shape

Masks can be divided into three types according to their appearance: flat, folding and cup. Flat mask is easy to carry, but its sealing is poor; Folding mask is easy to carry; Cup-shaped breathing space is large, but it is inconvenient to carry.

Classified by way of wearing.

Head-mounted: it is suitable for workshop workers who wear it for a long time, and it is more troublesome to wear it. Ear hanging type: easy to wear, suitable for wearing and taking off frequently. Neck-wearing type: S-shaped hook and some soft material connectors are adopted, and the connecting ear strap is converted into a neck strap, which is suitable for wearing for a long time and more convenient for workshop workers to wear safety helmet or protective clothing.

According to the classification of materials used

Gauze masks: At present, gauze masks are still used in some workshops, but the requirements of GB 19084-2003 are low, which does not meet the standards of GB2626-20 19, and can only protect large particles of dust.

Non-woven mask: Most disposable protective masks are made in non-woven mask, mainly by physical filtration and electrostatic adsorption. Cloth mask: The cloth mask only keeps warm, but does not filter tiny particles such as PM.

Paper mask: suitable for food, beauty and other industries, with good air permeability and convenient and comfortable use. The paper used follows GB/T22927-2008 standard. Masks made of other materials, such as new materials for biological protection and filtration.

Classification by scope of application

Medical masks: China is divided into three categories: medical ordinary masks, medical surgical masks and medical protective masks. The protective ability of medical masks in China from high to low is medical protective masks, medical surgical masks and general medical masks.

Particle-proof mask (KN mask): KN is a mask that meets the national standard (GB2626-2006/GB2626-20 19), and it is the particle-proof grade of the mask certified by China, which refers to the filtering ability of the mask to non-oily particles with a diameter of 0.3 micron. ..