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Different classification standards of filter media for bag filter
There are many types of filter materials for bag filter. Bag filter is widely used in China. Different technologies and methods will use different filter materials for filtration. The filter materials of manufacturers on the market can be roughly classified according to the following methods: 1. , Classification according to the material of the filter bag: 1. Synthetic fiber filter material: filter material processed and manufactured with synthetic fiber as raw material, referred to as synthetic fiber filter material. 2. Glass fiber filter material: filter material processed and manufactured with glass fiber as raw material, referred to as glass fiber filter material. 3. Composite filter material: a filter material composed of two or more fibers. 4. Other filter materials: filter materials made of fiber materials other than synthetic fibers and glass fibers (such as ceramic fibers, metal fibers, carbon fibers, rock fibers, etc.). 2. According to the structure According to the different structure, the filter material can be divided into woven cloth, needle felt, surface filter material, etc. (1) Woven fabric Woven fabric is a fabric made by continuously interlacing warp and weft yarns at right angles according to certain rules. Its basic structure has three kinds of plain weave, twill weave and satin weave. In order to improve the performance of the woven filter material, the weft double or double layer structure is often used. For a long time, woven cloth was the only filter material structure that could be selected, and the appearance of needle felt gradually relegated it to a secondary position. (2) Needle-punched felt Needle-punched felt is a filter material made by laying fibers on the bottom two sides, or completely using fibers to form by needle punching, and then post-processing. It does not go through the textile process, so it is also called non-woven fabric or non-woven fabric. The post-treatment of the needle-punched filter material mainly includes heat setting, singeing, hot melt calendering, etc., and some also need to eliminate static electricity, hydrophobicity, acid and alkali resistance, oil repellency, resin covering and other treatment processes. The pores of the needled felt are formed between single fibers, so there are multiple layers of pores in the thickness direction, the porosity can reach 70-80, and the pores are uniform. In contrast, the porosity of woven fabrics is formed between the yarns, there is no hierarchy in the thickness direction, the porosity is 30 to 40, and it is about half of that of needled felt. Therefore, under the same filtration speed, the pressure loss of the needled felt is lower than that of the woven fabric, and the dust removal efficiency of the needled felt is also higher than that of the woven fabric. (3) Surface filter material Surface filter material refers to the filter material in which the dust including fine dust particles is almost completely blocked on its surface and cannot penetrate into its interior. Based on the theory that the dust layer is beneficial to filtration, a layer of microporous film is artificially attached to the surface of the common filter material to improve the dust removal efficiency. Therefore, the film on the filter surface is also called the artificial dust layer. The advantage is that a thin layer of dust with good ventilation can be formed on the surface of the membrane at the beginning of the filter material work, which can not only ensure high dust removal efficiency, but also ensure low operating resistance.
1. ISO 5402-1: Specifies the flexometer method for testing leather flex resistance under repeated bending.
2. ISO 17694: Defines test methods for footwear upper and lining flex resistance, simulating real-world bending stress to assess long-term durability.
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