Analysis of Meltblown Cloth Filtration Principle1

Meltblown cloth mainly uses polypropylene as the main raw material, and the fiber diameter can reach 1-5 microns. With many voids, fluffy structure and good wrinkle resistance, these ultra-fine fibers with unique capillary structure increase the number and surface area of ​​fibers per unit area, so that the meltblown cloth has good filterability, shielding, heat insulation and oil absorption. . It can be used in air, liquid filter materials, isolation materials, absorbing materials, mask materials, thermal insulation materials, oil absorbing materials and wiping cloths and other fields. Scope of application: (1) Medical and sanitary cloths: surgical gowns, protective clothing, sterilization wraps, masks, diapers, women's sanitary napkins, etc.; (2) Home decoration cloths: wall coverings, tablecloths, bed sheets, bedspreads, etc.; (3) Follow-up cloth: lining, adhesive lining, flakes, shaped cotton, various synthetic leather base cloth, etc.; (4) Industrial cloth: filter material, insulating material, cement packaging bag, geotextile, covering cloth etc.; (5) Agricultural cloth: crop protection cloth, seedling raising cloth, irrigation cloth, thermal insulation curtain, etc; Melt-blown cloth filter material is randomly distributed and bonded together by polypropylene ultra-fine fibers, the appearance is white, smooth and soft, and the material fiber fineness is 0.5-1.0μm, the random distribution of fibers provides more opportunities for thermal bonding between fibers, thus making the meltblown gas filter material have a larger specific surface area, higher porosity (≥75%). After high-pressure electret filtration efficiency, the product has the characteristics of low resistance, high efficiency, and high dust holding capacity. The main material of meltblown non-woven fabric is polypropylene, which is an ultra-fine electrostatic fiber cloth that can capture dust. After the droplets containing pneumonia virus are close to the melt-blown non-woven fabric, they will be electrostatically adsorbed on the surface of the non-woven fabric and cannot pass through. That's how the material keeps germs out. After the dust is captured by the ultra-fine electrostatic fibers, it is extremely difficult to be detached by cleaning, and washing with water will also destroy the electrostatic dust-absorbing ability. Therefore, this mask can only be used once. The melt-blown process is a polymer extrusion non-woven process. As a common way of using PP materials, the melt-blown non-woven fabric produced is commonly known as the heart of the mask. It is the filter layer in the middle of the medical mask, which can filter bacteria and prevent the spread of germs. Its fibers are only one-thirtieth the diameter of a human hair. Although the raw materials are all polypropylene, the production process and performance of the special material for meltblown cloth and other non-woven materials are quite different. The special material for meltblown cloth requires that the raw material must meet the high melt index (>1000g/10min) and molecular weight. narrow distribution.