Mask filter material is a subdivision of air filter material. Since SARS in 2003, masks(Medical Face Mask Wholesale) equipped with filter materials based on melt-blown technology have quickly replaced the mainstream status of gauze masks(Dustproof Face Mask Supplier) due to their obvious protective effect.

The core technical principle of melt-blown cloth is ultrafine fiber and electrostatic electret. The filtering mechanism mainly depends on interception, gravity sedimentation, inertial collision, Brownian motion, and electrostatic adsorption. When the air particles pass through the filter layer, the three-dimensional network structure formed by the melt-blown fibers will hinder the air flow, so that the air flow changes the speed of movement and the direction of travel numerous times and bypasses the fibers. The finer the fiber diameter, the greater the probability of particles colliding with the fiber due to mechanical reasons, so that more particles are retained on the surface of the fiber, thereby playing a better filtration effect, that is, the higher the filtration efficiency. The average fiber diameter of melt-blown fibers is 2~5 microns, and the new technology can make it reach 0.5~3 microns, which is generally called nanometer level. Therefore, one of the characteristics of high-quality melt-blown filter materials is ultra-fine fibers And the arrangement is randomly distributed, the specific surface area is large, the void is small, and the void rate is high. However, the mechanical barrier effect is relatively poor for particles with a particle size of less than 1um, and small particles are easy to enter the lungs and cause more harm to the human body. Therefore, the filtration of small particles cannot be ignored. It is a good way to improve the filtration efficiency of filter media by using electrostatic adsorption. At present, the most common method to achieve electrostatic adsorption is to use a high-voltage corona charging method to carry out electrostatic electret on the melt-blown cloth. Generally, there is no product that has been electret, its filtration efficiency is only about 30%, then after we elect the pole, the efficiency can reach more than 90%. At the same time, the durability and stability of the electric field generated by the electret depends mainly on the level of electret technology. Taking into account the high filtration efficiency and low resistance itself is contradictory, because the fiber diameter fine mechanical filtration effect is also accompanied by an increase in resistance, so while completing the melt-blown ultrafine fiber preparation technology, the long-term electret preparation technology is The key to producing high-quality meltblown fabrics is high-efficiency low-resistance meltblown technology.

Based on the development of high-efficiency and low-resistance melt-blown technology, the technological progress of masks has become more significant. The N95 of NIOSH 42 CFR84 in the United States requires that the filtering efficiency of the mask is ≥95.0%, the inhalation resistance ≤350Pa, and the exhalation resistance ≤250Pa; while the GB/T 32610 "Technical Specifications for Daily Protective Masks" issued by China in 2016, the filtration efficiency ≥ At 95.0%, inhalation resistance ≤ 175 Pa and expiratory resistance ≤ 145 Pa are required; when the filtration efficiency ≥ 95.0% is specified in GB/T 38880 "Children's Mask Technical Specifications" released on May 6, 2020, the resistance is adopted according to the child's breathing characteristics Test at 45L/min, inhalation resistance and exhalation resistance are required to be ≤45Pa. It can be seen from the change of standards that the technological advancement level of masks and melt-blown preparation technology in our country has developed rapidly.

Children's metabolism is strong, and their metabolic level and oxygen demand are close to those of adults. Due to its physiological characteristics, children's lung volume and tidal volume are smaller than adults. In order to meet the needs of metabolism, the body can only be satisfied by increasing the respiratory rate, so the younger the age, the faster the respiratory rate. In addition, children's internal respiratory resistance is greater than that of adults, so under the premise of ensuring a protective effect, in order to allow children to enjoy relative comfort when wearing masks(3 Ply Face Mask Manufacturer), reducing inhalation resistance is the most important requirement for children's masks. It is the development of high-efficiency and low-resistance melt-blown technology that enables the masks that meet the national standard of children to ensure high efficiency, while the ventilation performance is significantly better than that of adult masks, making it easier for children to breathe when wearing them.