farmer

Original title: How much do you know about the chemical knowledge of KN95 melt-blown fabric in masks? Small masks also have great knowledge. In the face of the epidemic, masks have become a necessity for everyone. Why do small masks play such an important role? Today, we will use chemical knowledge to bring you a new understanding of masks. Our common masks are ordinary cotton masks, disposable medical masks, surgical mask, N95 masks.. Among them, disposable medical masks and surgical mask can prevent respiratory tract infection to a certain extent, but can not prevent haze; N95 masks can effectively prevent respiratory tract infection and can prevent haze; ordinary cotton masks can not prevent infection because the material itself is not dense enough. Disposable medical mask Expand the full text Disposable medical masks use 2-3 layers of non-woven fabric as the filter material of the mask, mainly to prevent infection between doctors and patients or infection caused by inhalation of bacteria in the environment by medical staff. The outer layer of the mask is water-resistant, which reduces the wearer's exposure to pathogens in the patient's blood or fluids. Medical masks without the words "protection" and "surgery" in their names are all ordinary medical masks. This kind of disposable medical mask is generally not required to have a barrier effect on blood, so it is only used in general medical environment. Nonwoven fabric: It is a kind of fabric formed without spinning and weaving, which is only formed by directional or random arrangement of textile staple fibers or filaments to form a web structure, and then reinforced by mechanical, thermal bonding or chemical methods. Nonwovens break through the traditional textile principle, and have the characteristics of short process flow, fast production speed, high output, low cost, wide use and multiple raw material sources. Medical non-woven products are medical and health textiles made of chemical fibers including polyester, polyamide, polytetrafluoroethylene, polypropylene, carbon fiber and glass fiber. surgical mask Standard surgical mask usually consist of 3-4 layers of non-woven fabrics, and the outer layer is waterproof, which can prevent droplets from entering the mask. The middle layer acts as a filter. The inner layer near the mouth and nose is used to absorb moisture and ensure that the wearer's lips are dry and comfortable. The filter element generally uses superfine fiber as a melt-blown nonwoven material. The superfine fibers are randomly arranged to form a large number of tiny pores. The whole mask adopts folding design to improve the fit between the mask and the wearer's face,3 Ply Disposable Protective Face Mask, which can block more than 90% of particles larger than 5 μm. Superfine fiber: also known as microfiber, fine denier fiber, very fine fiber. Generally, the fiber with a fineness of less than 0.3 denier (diameter of 5 microns) is called superfine fiber. The main ingredients are polyester and nylon. The technical process of the melt-blown non-woven fabric comprises the steps of polymer feeding, melt extrusion, fiber formation, fiber cooling, web formation, and cloth reinforcement. Barrier principle The medical surgical mask is composed of three parts, namely a waterproof layer, a filter layer and a comfort layer from the outside to the inside. When wearing, the white non-woven fabric faces inward and the blue waterproof layer faces outward. Outer layer-waterproof layer. Usually needle-punched cotton, also known as polyester needle-punched felt. Polyester material itself is difficult to absorb water, KN95 Face Mask ,free shipping disposable coverall, and then polyester staple fibers are made into non-woven fabrics by needling, water molecules and droplets with strong polarity are difficult to pass through, while non-polar air can be inhaled smoothly. Middle layer-filter layer. The main material of melt-blown non-woven fabric is polypropylene, which is a kind of ultra-fine fiber cloth with static electricity, which can catch droplets and dust. This layer of non-woven fabric is composed of numerous superfine and electrostatically charged short fibers which are interwoven with each other through mechanical force. Droplets and dust are like walking in a maze in the jungle composed of short fibers. Under the action of electrostatic force and Van der Waals force, most of them stumble and adhere to the dense short fibers, thus playing a very strong adsorption role. Inner layer-comfort layer. The comfort layer is a hot-rolled non-woven fabric, but the moisture absorption and air permeability are much better than the other two layers, which mainly ensures that the nose and mouth are moist and improves the wearing comfort. N95 mask N95 mask is also called medical protective mask. "N" means that the mask is suitable for use in non-oily occasions. "95" means that the mask can filter out more than 95% of the dust with a volume greater than 0.3 μm during use. N95 mask is one of the nine particulate masks certified by NIOSH (National Institute for Occupational Safety and Health), which can prevent droplet transmission. N95 is not a specific product name. As long as the product meets the N95 standard and passes the NIOSH review, it can be called "N95 mask". In particular, it should be reminded that the "bacterial filtration ≥ 95%" indicated in the packaging of some brand masks is not equal to the "N95 protection level". Wherein the mask body is divided into an inner layer, a middle layer and an outer layer, the inner layer is common sanitary gauze or non-woven fabric, the middle layer is a superfine polypropylene fiber melt-blown material layer, and the outer layer is a non-woven fabric or ultrathin polypropylene melt-blown material layer. The high-efficiency medical protective mask has the advantages of strong water repellency and air permeability, remarkable filtering effect on micro-virus aerosol or harmful dust, good overall filtering effect, non-toxic and harmless materials, and comfortable wearing. Polypropylene fiber: Polypropylene fiber is a synthetic fiber spun from isotactic polypropylene obtained by polymerization of propylene. Its trade name in China is polypropylene fiber. Of course, after the mask is produced, there is also analysis and disinfection, which can not be used directly after the machine production and processing! Medical masks are sterilized by ethylene oxide! After sterilization, the residual drugs are released through analysis, and then the safety standards are met! Ethylene oxide: Ethylene oxide, an organic compound with the chemical formula C2H4O, is a toxic carcinogen and was formerly used to make fungicides. Ethylene oxide is flammable and explosive, and is not easy to be transported over long distances, so it has strong regional characteristics. It is widely used in washing, pharmaceutical, printing and dyeing industries. It can be used as the initiator of detergent in chemical industry. Difference between N95 and KN95 The standard of N95 and KN95 is that the filtration efficiency of non-oily particles is greater than 95%. Therefore, in essence, the protective effect of these two masks is the same, but there are differences in certification bodies. N95 is NIOSH certification in the United States, while KN95 is domestic certification, which meets the requirements of GB2626 standard in China. Finally, I would like to remind everyone to pay attention to protection, wear masks, wash hands frequently, ventilate frequently, do not eat together, go out less,KN95 Face Mask with Five Layers, do not spread rumors, do not panic, and overcome the epidemic as soon as possible! Steamed wonderful mask Return to Sohu to see more Responsible Editor:. zjyuan-group.com