Product

Polyester/PET based punched filter felt is produced with grade polyester staple fibers as raw materials. In addition its unique advantages including high porosity, good air permeability, high dust collection efficiency, long service life and other aspects possessed by common felt type filter cloths, this product has moderate high temperature resistance grade, instantaneous temperature to reach 130℃,medium acid and alkali resistance, it has abrasive resistance. Hence, it is good frequently used category in felt type filter materials. In terms of surface treatment, singeing, calendering or coating and other treatments can be adopted according to different requirements of working conditions.

General industrial dust is easy to cause explosion or fire in case of electrostatic discharge spark or external ignition and other factors, after the concentration reaches certain degree (namely explosion limit). For example, flour dust, chemical dust and coal dust are likely to explode in case of electrostatic discharge. Hence, during production of punched felt, conductive fiber is incorporated to warp of base cloth, or conductive fiber or conductive material is mixed in chemical fiber to reach ideal conductive performance.

At the time of filtering ultra fine dust particle, filter materials are required to have smaller filtration pore diameter as much as possible under the premise of guaranteeing air permeability, thus effectively obstructing and collecting dust particles and controlling shrinkage rate under  limit at the time of certain high temperature. In the production progress of acrylic punched felt, high strength and low elongation industrial filaments are adopted as the base cloths, which could improve the overall tensile strength of filter materials effectively and make them adapt to the flue gas filtration with high air volume. And acrylic punched felt has  Hydrolysis stability.

Nomex, also known as aramid 1313 in China, was invented and put into use by DuPont in the 1960s. It is a good high-temperature resistant and flame retardant fiber. It can maintain about 80% of the original strength at 200℃, and can still maintain 65%-70% of the original strength after continuous use for 100 hours at 260℃. It can form a barrier between the human body and clothing, reduce the effect of heat transfer, provide protection, and can withstand  acids. It also has good stability to alkali. Due to its outstanding performance and broad market prospects, various countries have conducted research and development. It’ s widely used in military industry and filter materials for its heat resistance and electrical performance. The prominent use of filter materials is in the chemical, steel, cement, and asphalt mixing industries, with dust removal and filtration effects.

Glass fiber based punched filter felt is a high temperature resisting filter material with reasonable structure and good performance. It not only has advantages including high temperature resistance corrosion resistance, stable dimension, extremely small elongation shrinkage rate and high strength possessed by glass fiber, but also is a high-speed and efficient temperature filter material due to single fiber borne by felt layer fiber, 3D cellular structure, high porosity and small gas filtration resistance. It can be widely applied to high temperature flue gas filter of chemical, steel, smelting, carbon black, power generation, cement and other industrial furnaces.

FMS high temperature resisting punched felt are blended or laminated by two or more high temperature resistance fibers to realize higher and updated physical and chemical performances. Compared with glass fiber, the abrasion resistance, breaking resistance and peeling strength of filter materials are significantly improved. The filter speed can be over 1.0m/min, with low operation resistance. FMS high temperature resisting punched felt is widely applied to steel, nonferrous metallurgy, chemical, carbon black, building material, power and other industries.

PPS high temperature resistance and acid-alkali resistance punched filter felt is new high temperature resistance filter materials, produced with chemical fibers for polyphenylene sulfide produced by Japan Toray and Japan Toyobo and so on, according to manufacturing process of other high temperature resistance punched felt, PPS fiber has strength completeness retainability and inherent chemical resistance and can keep good filter performance in severe environment to reach ideal service life. PPS has performance in application of the following occasions:
1. Operating temperature 160℃, instantaneous temperature 180℃, limit oxygen index 34-35%.
2. Oxygen content below 15%.
3. Sulfur oxide contained in flue gas.
4. Dusty gas with wet nature in flue gas.

How to prolong service life of filter bags is a key issue attracting long term concern and research of DwHB. Through research and development of filter materials, engineering application experience is continuously summarized and PPS+PTFE blending, PTFE+P84 blending and other varieties of filter bags are innovatively developed in selection of filter bags to be applied to different flue gas working conditions with high oxygen, high sulfur and high temperature. Raw materials are formulated with ingredients of Japan Toray and Japan Torobo, polyphenylene sulfide, Teflon and polyimide based chemical fiber produced in the country and can be used for a long time under 180℃.Combination of them can drastically prolong the service life and environmental effect for high concentration and high humidity dusty gas and high purification is better. The service effect in straw power generation, waste power generation, carbon black plant, steel plant and cement plant with strict requirement for operation condition is better.

PTFE punched felt is a kind of filter material made from PTFE (Teflon fiber) through three-dimensional puncture. PTFE fiber is of macro molecule linear structure and has strong temperature resistance, abrasion resistance, corrosion resistance and chemical stability resistance and can be widely applied to steel, power, glass, chemical, waste incineration and other severe flue gas filter environments. DWHB is a professional manufacturer of PTFE, with the international advanced Andritz PTFE production line, the annual output could reach to 700,000 m2.

P84 high temperature resisting punched filter felt is efficient filter material with high temperature resistance and acid-alkali resistance, developed by the DWHB with other non-woven cloth production technology on the basis of INSPECFI-BERS (polyimide fiber) produced by Austria LENZING Company. DWHB is one of the few manufacturers with capacity to independently develop, design and produce such filter materials at present. With high temperature resistance performance, used for a long time under 260℃, and good chemical resistance, P84 filter materials have very significant filter effect on dusty gas with acid-base nature, highlighting higher dust collection efficiency in waste incineration industry.

Basalt fiber is a super high temperature fiber recently developed by DwHB. With basalt as raw material, it is drawn through high temperature melting. The fiber has high temperature resistance ,  mechanic property, acid resistance, alkali resistance and other properties. Hence, operating temperature of the product could be 250-300℃ and the product has tensile strength. Basalt fiber products are widely applied to high temperature gas filtration, fireproof and flame retardant, composite reinforcement base material, high temperature resistance and ablation resistance fields.

In the field of dust removal and flue gas purification, the temperature resistance of the traditional filter material is no more than 300℃. Under the working condition higher than 300℃, the traditional filter material can not be used because of shrinkage under high temperature. Polypropylene fiber is an intermediate product of carbon fiber, which is partially cyclized black fiber formed by air oxidation at a certain temperature. Its density is about 1.40g/cm3, strength is 1.4cn/dtex, elongation is 23%, modulus is 5GPa, limiting oxygen index is 35 - 60, decomposition temperature is ≥640, moisture remain is 9%, temperature resistance is outstanding, high temperature resistance is up to 300℃, and is fire resistance and non combustion. It is acid resistant, alkali resistant, washing resistant, non-toxic, less smoke. DwHB specializes in the R&D and production of dust removal filter bags. According to the high temperature resistance of pre-oxidized fiber, DwHB select pre-oxidized fiber with glass fiber and basalt base cloth and the temperature resistance effect can reach 350-400℃, meeting the high temperature resistance requirements under special working conditions.