Core material of children's mask high efficiency and low resistance melt blown clothThe core filter material of the mask is melt blown nonwovens, which is located between the inner and outer layers of the mask body. No matter where it is located or what role it plays, the meltblown cloth is worthy of being called the "heart" of the mask.
The mask filter material belongs to the subdivision of air filter material. Since the outbreak of SARS in 2003, masks equipped with filter materials based on melt blown technology have rapidly replaced gauze masks due to their obvious protective effects.
The core technology principle of meltblown cloth is superfine fiber and electrostatic electret. The filtration mechanism mainly depends on interception, gravity sedimentation, inertial collision, Brownian motion and electrostatic adsorption. When the particles in the air pass through the filter layer with the air, the three-dimensional network structure formed by the melt blown fiber will hinder the air flow forward, making the air flow change the speed and direction of movement countless times to bypass the fiber. The smaller the diameter of the fiber, the greater the probability of collision between the particles and the fiber due to mechanical reasons, so that more particles stay on the surface of the fiber, so as to play a better filtering effect, that is, the higher the filtration efficiency. In other words, the average porosity of microfibers in the range of 2 ~ 5 microns can be achieved by the new technology, that is to say, the average porosity of microfibers can reach 2.5 microns, which is one of the characteristics of high-quality fibers. However, the filtration effect of mechanical barrier for particles less than 1 um is relatively poor, and small particles are easy to enter the lung, causing more harm to human body, so the filtration of small particles can not be ignored. It is a good method to improve the filtration efficiency of filter media by using electrostatic adsorption. At present, the most common way to realize electrostatic adsorption is to use high voltage corona charging method to electrostatic electret of melt blown cloth. In general, the filtration efficiency of the product without electret is only about 30%, so the efficiency can reach more than 90% after we are in the pole. At the same time, the persistence and stability of the electric field generated by electret mainly depend on the level of electret technology. It is a contradiction between high filtration efficiency and low resistance, because the fiber diameter is fine and the mechanical filtration effect is good, which brings the rise of resistance. Therefore, while completing the melt blown superfine fiber preparation technology, realizing the long-term electret preparation technology is the key to produce high-quality melt blown cloth, that is, high-efficiency and low resistance melt blown technology.
Based on the development of high efficiency and low resistance melt blown technology, the technical progress of mask is becoming more and more significant. In NIOSH 42 cfr84 of the United States, N95 requires that the filter efficiency of the mask should be greater than or equal to 95.0%, inspiratory resistance should be less than or equal to 350 PA, and exhalation resistance should be less than or equal to 250 Pa; in China's GB / T 32610 "technical specification for daily protective masks" published in 2016, inspiratory resistance should be less than 175 PA and expiratory resistance should be ≤ 145 PA when filtration efficiency is greater than or equal to 95.0% 38880 "technical specification for children's masks" stipulates that when the filtration efficiency is greater than or equal to 95.0%, the resistance shall be tested with 45L / min according to the respiratory characteristics of children, and the inspiratory resistance and expiratory resistance shall be less than 45pa. It can be seen from the standard changes that the technical progress of mask and melt blown technology is developing rapidly in China.
Taeda meltblown fabric,한국 대전 용출 직물,
The metabolism level and oxygen demand of children are close to that of adults. Because of its physiological characteristics, the lung volume and tidal volume of children are smaller than those of adults. In order to adapt to the needs of metabolism, the body only takes to increase the respiratory rate to be satisfied, so the younger the age, the faster the respiratory rate. The most important premise for children to wear the respirator is to ensure that the breathing resistance of children is greater than that of children when wearing masks. It is the development of high-efficiency and low resistance melt blown technology that makes the face mask in line with the national standard of children can ensure high efficiency, and at the same time, its air permeability is much better than that of adult masks, so that children can breathe more smoothly when wearing them.
Since 1992, Dajin new materials has been committed to the research and development and production of melt blown materials, with strong technical strength. Since the outbreak of the epidemic, it has become the first batch of key epidemic prevention material support units designated by the Ministry of industry and information technology, the national development and Reform Commission, and the medical material support group of the joint prevention and control mechanism of the State Council, and fully guarantee the supply of mask filter materials during the period of fighting against the epidemic. At present, the domestic epidemic situation has been greatly alleviated, and Dajin new material is still trying its best to produce high-quality melt blown materials for international epidemic prevention and control and national foreign aid needs; at the same time, Dajin new material is making every effort to produce high-efficiency and low resistance filter materials for children's masks, providing more protection for students who are returning to school, and enabling parents to work more confidently.