| With the fast development of heavy industry, more and more high temperature flue gas pollutants remain in the environment, especially for particles such as dust, sulfuric acid, nitric acid and organic hydrocarbon compounds. Currently many areas are in foggy weather, which lead to many diseases such as cardiovascular diseases and respiratory infections. Disposal of pollutants are also one of the main reasons for this phenomenon. As a result, from the perspective of health and environmental protection,the demand of filtering material also appears more urgent.In recent years, people pay more and more attention to basalt fiber, especially in the field of filter material. Compared with glass fiber, mineral fiber and aramid fiber, basalt fiber has its unique advantages in the aspect of filtering, such as the outstanding mechanical properties, high temperature resistant, acid and alkali resistant and low hygroscopicity. However, because of its large pores, the woven fabric which made by basalt fiber has poor filtration performance. PTFE microporous membrane has high filtering efficiency for tiny particles, smooth surface for easing to clean up the dust, good chemical stability, high and low temperature resistant, good breathability, non-aging, excellent resistance to condensation effect, especially in dusty gas of high density lipoprotein, high humidity and high adhesion dust in environment, it has better effect, but it has poor mechanical properties. The basalt coated filtering material which composited by basalt woven fabric and PTFE microporous not only obtains excellent filtering effect, but also has excellent mechanical performance. It can resist the impact of high temperature dust which with high-speed movement, and the material has long service life.The subject was based on the research of the basalt woven fabric, testing and analyzing the surface, permeability, the function of filter and strength mechanical property of different specification of woven fabric. Then we discussed the laminating process of basalt woven fabric and PTFE microporous membrane, measuring and studying the properties of the tectorial filter material. The main research works are as follows: 1.Use ASL2000-W-E rapier loom to weave11kinds of different specifications basalt woven and observe the surface morphology of the fabric underand Stereo Discovery.V20Zeiss stereoscopic microscope. Test the square meter weight and thickness, then calculate the poriness of the woven fabric. Test the fabric’s air permeability, filtration efficiency and filtration resistance by YG461D digital fabric permeability meter and the SX-L1050filter efficiency test rig. Analyze the relationship between the poriness and air permeability, filtration resistance, filtration efficiency, and test the tensile properties of the fabrics.2.Use two different ways which are glue coated and high temperature hot pressing to make basalt woven laminated with PTFE microporous membrane. Ob serve the changes of surface morphology under Stereo Discovery.V20Zeiss stereoscopic microscope.3.Test the basalt filter material’s thickness of PTFE under JSM-5610LV scanning electron microscope. Measure the basalt material’s aperture size and distribution by filter pore size and its distribution of tester.4.Test the ventilation property, filter efficiency and filtration resistance of the basalt filter material, and compared the filtering quality of the both sides of filter material and basalt woven fabric.5.Heat the basalt tectorial filter material under250℃, analysis the changes about filter efficiency, filtration resistance, ventilation property and weight before and after heat treatment. Study the wear resistance of basalt coated filter material.6. Study and analyze basalt coated filter material’s relationship between structure and the properties of filtration and air permeability.Through testing, analyzing and studying, it shows that the porosity of the basalt woven fabric is larger, especially when using bulky yarn as weft yarn. The larger the porosity, the increaser of the air permeability of basalt woven fabric. Air permeability decreases with the increase of yarn linear density, with the increase of warp/weft density, air permeability is reduced, weft double group of air permeability is greater than2/2twill,2/2twill is greater than plain weave. Basalt woven fabric’s filter efficience for about0.3μm aerosol particle is low. When the porosity increases to a certain value, the filter efficience of basalt woven fabric will tend to zero. The filtration resistance is smaller.After high temperature hot pressing process, the yarn of basalt woven fabric is coated with a layer of PTFE,the thickness of PTFE membrane layer is within24um. The pore size distribution of the basalt coated filter material is uniform and concentrated, the pore size is smaller.Both sides of basalt coated filter material of filter efficiency are good, the filter efficiency of the non-membrane surface is better than the membrane surface, the permeability is good. There is no obvious difference between basalt woven fabric and basalt coated filtering material in the tensile property. After heat treatment under250℃, the filter efficiency of the basalt coated filter material still remains at a high level, the filtration resistance decreases, the permeability rate will increases. Basalt coated filter material has good abrasion resistance, the fastness of PTFE membrane is good.With the increase of film thickness of basalt coated filter material, the filter efficiency and filtration resistance will increase, the permeability rate will decrease; with the increase of the mean pore size, the filter efficiency and filtration resistance will reduce, the permeability rate will increase.The research of this subject has important theoretical guidance and practical application significance for basalt fiber’s application and development in the field of filter material. |
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