The filter cloth must have suitable pores to allow air to pass smoothly and prevent fine dust from entering the inside of the filter cloth. Once the fine particles of dust enter the filter cloth, it cannot be removed, and the air permeability of the filter cloth is greatly reduced, the dust removal resistance increases, and the filter bag can no longer be used. This is also the reason why the fiber diameter of the filter bag of the dust collector is required to be finer, and the filter cloth is " dense" . Although the price of the filter cloth made of fine fiber is higher, the filter resistance is greater when it is first used, but it is relatively stable throughout the use period and has a long service life. Of course, There are now new materials that prevent dust from entering the inside of the filter cloth without reducing the air permeability, for example, spraying or covering a layer of ultra-thin fluorinated resin microporous film on the surface of the filter bag and the dust contact. Inert resin is completely hydrophobic, smooth surface will not stick to dust, and dust with higher moisture content will also greatly reduce the phenomenon of sticking bags caused by adhesion. It is also possible to spray the surface of the filter bag with a special treatment powder to form a very thin filter cake on the surface, and to make the porosity more uniform and fine. Special processing such as calendering or sintering on the surface of the filter cloth can achieve the same purpose. Three-proof (oil-proof, waterproof, anti-static) filter cloth has been widely used in the dust removal industry of building materials enterprises.
In short, when selecting filter bag materials, it is best to refer to relevant materials or consult professional manufacturers and experts. Now there are many filter bag manufacturers, and there are big differences in varieties and prices. When selecting filter bags, the price, service life and physical properties of the processed materials should be considered comprehensively. Especially when purchasing a dust collector, you cannot simply consider the price, also must consider its configuration and materials. Some filter bags are effective in handling certain types of dust, but may not be optimal for other types of dust. The filter cloth structure can be felt or woven. Most felt products will absorb moisture due to the capillary action between the fibers, but some special felt products such as glass fiber knitted felt can be moisture-proof to a certain extent. The irregular arrangement of felt fibers, uniform pores, at the same time, in order to ensure its strength, the thickness of the filter bag is thicker, and the dust removal efficiency is high. In some important occasions, materials with fine dust are often used, especially filter bags of dust collectors with higher surface air velocity. Woven fiber fabric is woven with spinning yarn. There are pores with various patterns in the spinning room, and the surface is smooth and clean, and it is easy to design a filter cloth that can hold or detach the filter cake. In order to further improve the surface properties, can be sprayed with silicone resin, to obtain a wear-resistant surface, improve the separation of the filter cake or reduce the moisture absorption capacity of the bag. For various chemicals with low melting point and high adhesion, it is best to use woven fiber filter bags.