Difference between woven and non woven fabric
Filter fabric is the most diverse and widely used filter media in industry. There are woven and non woven fabric. The composition of the material are natural fibers (cotton, wool, silk, hemp) or synthetic fibers. The filtration function of the filter cloth is determined by the raw materials, fiber weaving and post-treatment processing.
1, According to the nature of the material can be divided into, polyester, polypropylene, nylon, vinylon, cotton, new efficient materials and other filter cloth.
2, There are two types of filter cloth according to the weaving method.
Textile filter cloth: including polyester, polypropylene, nylon, vinylon, cotton, etc. There are several weave patterns of filter fabric, plain, twill, satin, double weave, etc.
Non-woven filter cloth: including Nonwoven fabric, geotextile, filter felt, etc. There are spunbond, needle punching, water weaving, etc.
3, the filament of filter cloth is also divided into three kinds, monofilament, long-fiber compound filament, staple fiber. (The polyester staple fiber series is also divided into large chemical fiber, small chemical fiber)
Non-woven filter cloth in the synthetic fiber polypropylene is the lightest and easy to handle, temperature resistance of 90 ℃, excellent acid and alkali resistance products.
Therefore, it is used in the field of gas-solid and liquid-solid separation where the flue gas temperature is below 100℃ or the acidity and alkalinity are strong. In the field of liquid–solid separation. Polypropylene needle punched filter felts are usually used with liquid-solid separation equipment such as plate and frame filter presses, vacuum suction filters, belt filters and centrifugal filters. It not only has the characteristics of good dimensional stability, high strength and low elongation, but also has smooth surface, pore space and high permeability. So it also has the unique advantages of small vacuum resistance, energy saving, easy to clean, etc.
In mineral processing, coal processing, petroleum, chemical and other industries, need to filter tiny particles and ensure the occasion of filtration. Polypropylene needle felt is far superior to traditional woven filter media. Polypropylene needle felt is generally made of 2.5–6D polypropylene staple fiber as the surface layer, lined with polypropylene yarn or polypropylene high-strength yarn woven into the base fabric, after needle punching reinforcement and calendaring and other post-processing processes. Polypropylene needle punched filter felt is mainly used in the field of liquid-solid separation in metallurgy, mining, petroleum, chemical industry, chemical fiber, medicine, food and other industries.
It is a filter media woven by natural or synthetic fibers. Commonly used materials are cotton, hemp, wool, cocoon silk, asbestos fiber, glass fiber and some synthetic fibers. For example, cotton woven canvas, twill and wool woven tweed, etc. In a broad sense, the filter cloth also includes metal mesh or filter screen (filter screen) included.
Synthetic fibers mainly include polypropylene, polyester, nylon and vinylon, among which polyester and polypropylene are most commonly used for solid-liquid separation, while nylon is widely used in coal washing plants because of its excellent abrasion resistance.
The new high-efficiency filter cloth is mainly used in air filtration and dust removal, dust collection powder to purify the air and protect the environment, and is commonly used in smelters, chemical plants, sugar, dyestuff, medicine, food and other industries.
Filter cloths and screens made of polyester, polypropylene, nylon, vinylon and cotton are widely used in pharmaceutical, chemical, dye, steel, construction, iron treatment, chemical, ceramic, cement, geological and mineral industries.
When filter cloth is used as filter media in centrifuges, the drum is equipped with a metal liner, and the filter cloth is laid on the liner and fixed. Because the filter cloth is soft, and the strength is low, the mesh of the lining should be smaller in order to effectively support the filter cloth and discharge the filtrate smoothly. The filter cloth is required to have sufficient strength, suitable pore size and porosity, corrosion resistance to the material to be treated, and wear resistance. Filter cloth has three kinds of weave, plain, twill and satin, plain weave is the tightest, twill is the second, satin is sparse, porosity increases in turn.
Note: “eye” refers to the number of pores per square inch (1 inch 25.4 mm) screen, 50 eyes means 50 pores per square inch, 500 eyes means 500, the higher the number of eyes, the more pores; in addition to indicating the pores of the screen, it is used together to indicate the particle size that can pass through the screen, the higher the number of eyes, the smaller the particle size. The higher the mesh, the smaller the particle size.