What are the types of dust bag filter materials?

Fiber filter material. Fiber filter materials have always occupied most of the market of filter materials due to their large surface area, fluffy volume, low price, and easy processing. Among them, non-woven fiber materials have the characteristics of short cloth forming process, low cost and good filtering performance. , Has become the leading product of air filtration materials.　　Composite filter material. The so-called composite filter material is a filter material formed by interlacing different fibers to overcome the performance defects of a single filter material. It has been widely used in flue gas treatment in metallurgy, cement and other industries.　　 Functional filter material. Functional filter materials are air filter materials developed for specific industries (such as high temperature resistance, corrosion resistance, antistatic, water repellency, oil repellency, flame retardancy, removal of harmful gases, etc.), and are increasingly used in industrial flue gas Processing, indoor air purification and other fields. 1. Fiber filter material The main raw materials of fiber filter material are polyester, polypropylene, nylon and many high temperature resistant chemical fiber filter materials such as Nomex, Procon, Torcon, Basfil, P84, etc. [2], as well as inorganic fibers such as glass fiber, ceramic fiber, Metal fiber, etc. At present, my country’s chemical fiber filter materials are mainly polyester woven fabrics and polyester needle-punched felt polyester. Polyester has the advantages of good folding and abrasion resistance. It can withstand an operating temperature of 135°C under dry conditions, but it is continuously above 135°C. Work will harden, fade, and become brittle. Short-term high temperature will also weaken its strength. Therefore, polyester has poor high temperature resistance, low strength, and high elongation. It is not suitable for use under high alkali and high humidity conditions. . In order to solve these problems, some researchers have developed a filter material interwoven with polyester fiber and glass fiber. The filter material interwoven with fibers of different properties can maximize its strengths and avoid weaknesses, and give play to their respective advantages. Glass fiber has the advantages of good high temperature resistance, low elongation, high strength, good corrosion resistance, etc., but at the same time, because the fiber surface is smooth, the diameter is small, and the filtering resistance is small, the filtering efficiency is high. However, the glass fiber has poor bending resistance and abrasion resistance, and it is easy to wear and break due to frequent cleaning during use, which affects the service life. The filter material interwoven with polyester fiber and glass fiber has good performance and has been applied now.　　The weaving method of fiber filter material is organic weaving, knitting and non-woven. Because the fibers of woven fabric and knitted fabric form regularly arranged yarns, the yarns are closely intertwined with each other, and the fibers lack the possibility of forming a labyrinth system. The disorderly distributed fibers in the nonwoven filter material make the carrier phase flow through the filter material. The fiber tortuous system can strengthen the dispersion effect, so that the suspended phase of the particles to be separated has more chances to collide and adhere to the single fiber, so the filtration efficiency of non-woven fabrics is significantly higher than that of woven and knitted fabrics, and it is also The flow rate of the carrier phase can be increased, that is, the filtration process can be accelerated. At present, non-woven products have become the leading products of air filtration materials.　　　　Second, composite filter material 　　 Composite filter material is a hot spot that has emerged in recent years. For example, spunbonded nonwovens are strong, but their uniformity is poor. The composite filter material made by stacking it with meltblown nonwovens can not only overcome the shortcomings of meltblown nonwovens, but also can give full play to the meltblown nonwovens. The woven fabric has the characteristics of excellent filtering performance. SMS composite filter material is made by thermally bonding three layers of spunbonded, meltblown, and spunbonded nonwovens under a certain temperature and pressure. The membrane composite filter material successfully developed in the mid-1990s is to cover woven fabric, non-woven fabric or glass fiber filter material with PTFE. It has high filtration efficiency (the filtration efficiency for submicron dust is above 9919%), low resistance (30% ~ 40% lower than traditional filter media), and long service life (up to 2 ~ 5 times that of traditional filter media). The advantages of high temperature resistance (up to 280 e) and high dust exfoliation rate have been increasingly used in dust removal and purification and air conditioning filtration industries.　　　　 3. Functional filter material 　　 1. High temperature and ultra-high temperature filter material. Mainly used in the treatment of industrial waste gas and dust such as steel, power stations and incineration, mainly including polyphenylene sulfide chemical fiber Ry to n filter material and subphthalamide chemical fiber Nomex filter material, polyphthalimide fiber P84, polytetrafluoroethylene Ethylene Teflon, some metal and ceramic filter materials have also been put into use in recent years. The metal sintered filter material made of metal fiber cotton mesh after high temperature sintering is used in dry smoke conditions, and can withstand high temperatures up to 600 ℃.　　2, corrosion-resistant filter material. The needle-punched viscous filter material made of polyphenylene sulfide fiber has strong room temperature, high temperature acid resistance and normal temperature alkali resistance. It is used to filter high temperature (190℃) smoke from coal-fired boilers, garbage incineration, and power plant fly ash. Ideal filter material for air. The surface treatment of glass fiber can also resist various corrosive media.　　 3. Antistatic filter material and flame retardant filter material. Used to collect industrial dust (such as flour dust, chemical dust, coal dust), usually two methods of antistatic agent and conductive fiber (such as metal wire, carbon fiber, polyester, acrylic) are used to eliminate the static electricity of the filter material. Flame-retardant fiber is a filter material with better flame-retardant properties made of flame-retardant fiber.　　 4. Water and oil repellent filter material. Through the water and oil repellent finishing of the ordinary filter material, the filter material has the characteristics of water and oil repellency. There are two main finishing methods: (1) The reaction method makes the water repellent and certain groups in the fiber macromolecular structure occur. The reaction forms a macromolecular chain, which changes the affinity of the fiber with water and oil, and becomes a water- and oil-repellent type. (2) Coating method: Use a coating method to prevent the filter material from being soaked by water or oil. Membrane filter material and water-repellent treatment on the surface of the filter material have achieved obvious results in solving the problems of anti-condensation and bag sticking.