Study On Preparation And Properties Of Aramid 1313/PANOF Needle-punched Filter Material

As people's awareness of environmental protection continues to strengthen,China's environmental protection efforts are constantly increasing.Exhaust gas from industrial sectors such as steel,metallurgy and power plants is one of the most important sources of air pollution.The complex components and high temperatures in industrial exhaust gases put high demands on high temperature resistant filter materials.Aramid 1313 fiber has excellent mechanical properties,high temperature resistance and chemical stability.It can work in high temperature and harsh environment for a long time.It is an ideal material for preparing high temperature resistant filter bags.We chose aramid 1313 fiber as the main raw material,by mixing with different proportions of PAN pre-oxidized fiber,using hot rolling and PTFE coating finishing to make aramid1313/PANOF needle-punched filter material with low cost,high filtration efficiency,excellent high temperature resistance and corrosion resistance.According to the practical application conditions of high-temperature flue gas filter materials,this paper designed a series of experiments to analyze the aramid 1313/PANOF needle-punched filter material.Includes basic physical properties,filterability,high temperature resistance,thermal stability and acid and alkali corrosion resistance testing.The high temperature resistance of the filter material was analyzed by measuring the breaking strength retention rate and heat shrinkage rate of the filter material after high temperature treatment,and the corrosion resistance of the filter material was analyzed by observing the surface morphology and break strength retention rate of the filter material after acid and alkali treatment.According to the test results of the physical properties and filtration properties of different mixing ratio filter materials,it was shown that adding PAN pre-oxidation fiber can increase the entanglement degree of the filter material,reduce the pore size and gas permeability of the filter material,increases the filtration resistance,and improves the filtration efficiency of the filter material.With the increase of PAN pre-oxidized fiber content,the tensile properties of the filter material are gradually reduced.The transverse breaking fracture strength of the filter material with PAN pre-oxidized fiber mass ratio of 45%was 29.8 MPa,which is 36%lower than that of the filter material without the addition of pan pre-oxidized fibers.According to the test results of high temperature resistance,thermal stability and acid and alkali resistance of aramid 1313/PANOF needle-punched filter,with the increase of PAN pre-oxidized fiber content,the high temperature resistance,thermal stability and acid and alkali resistance of the filter material were effectively improved.After the filter material was treated at200°C for 100 h,the breaking strength retention rate was still above 90%,and the heat shrinkage rate was about 1.5%.The five kinds of filter materials have good high temperature resistance and are suitable for high temperature environment of 200°C.After treatment at 250°C for 24 h,the transverse breaking strength retention of the filter material with a PANOF mass ratio of 45%was92%,which was 11.3%higher than that of the pure aramid filter.In the thermal performance analysis,it was found that the filter material did not substantially decompose before 400°C.At600°C,the remaining mass of the filter material with a PAN mass fraction of 45%was 54.4%,which was 11%higher than that of the filter material without PAN pre-oxidized fiber.After treatment with H₂SO₄ and NaOH solution,although the fiber surface was eroded and had different degrees of groove cracks,the filter material still had good mechanical properties.In summary,the aramid 1313/PANOF needle-punched filter material prepared in this paper has excellent mechanical properties,filtration properties and high temperature resistance.This filter material is more resistant to strong acid than alkali corrosion.The filter material with PAN pre-oxidized fiber can be used for high temperature about 220°C.In actual production,we can adjust the ratio of aramid 1313 fiber and PAN pre-oxidized fiber to meet the needs of different application environments.