| While industrial production drives economic development,it also brings environmental problems.Bag dust collector is widely used in the field of dust removal.Filter bag is the core component of dust collector,and its performance affects the dust removal effect.The filter bag is made by sewing the filter material with sewing thread,which will change the structure of the filter material and affect its performance.Taking aramid fiber,polyphenylene sulfide /polytetrafluoroethylene(PPS / PTFE)mixed fiber(50/50)and PTFE as the research object,this paper tested the structural morphology,tensile properties,creep properties and filtration properties of the three kinds of high-temperature filter materials after stitching with PTFE sewing thread,and analyzed the performance changes of the three kinds of high-temperature filter materials after stitching.The main research contents and conclusions are as follows:(1)Structural morphology and tensile properties of high temperature filter material before and after stitchingTM3000 scanning electron microscope was used to observe the structure and morphology of three kinds of high-temperature filter materials before and after stitching.The surfaces of aramid filter materials and PPS / PTFE mixed fiber filter materials after singeing and calendaring treatment were produced by Molten Substances.The surface of PTFE filter materials after film coating treatment was smooth,there were obvious holes after PTFE sewing thread was stitched,the surface of filter materials was damaged,and the fibers at the holes of aramid filter materials were obviously broken,the combination of sewing thread and filter material at the suture of PPS / PTFE mixed fiber filter material and PTFE filter material is closer than that of aramid filter material.Yg026h multifunctional electronic fabric strength machine was used to test the tensile properties of three kinds of high-temperature filter materials before and after stitching,and the tensile process and change mechanism of stitched filter materials were analyzed.The meridional breaking strength of aramid filter material,PPS / PTFE mixed fiber filter material and PTFE filter material were 1017.87 n,930.02 n and 846.53 n respectively,which increased by 22.27%,29.51%and 46.59% respectively after suture,and the elongation at break were 67.35%,7.93% and 11.62 respectively,which increased by-24.10%,9.08% and 34.68% respectively after suture;The zonal breaking strength was 1170.96 n,977.10 n and 1013.08 n respectively,which increased by-67.95%,5.94% and-40.48% respectively after suture,and the elongation at break was 53.75%,35.11% and20.76,which increased by-53.22%,3.79% and 25.58% respectively after suture.During the stretching process,the breaking strength and elongation of the stitched filter material change due to the different breaking time of the sewing thread and the filter material.The warp breaking strength increases due to the strength of the sewing thread itself and the shear action between the filter material.In the weft direction,during the stretching process,the sewing thread is gradually embedded into the filter material until the filter material breaks.(2)Tensile and creep properties of stitched high temperature filter materialYG026MB-250 multifunctional electronic fabric strength machine was used to test the tensile creep properties of stitched filter materials.The longitudinal and latitudinal tensile creep properties of stitched aramid filter materials,stitched PPS / PTFE mixed fiber filter materials and stitched PTFE filter materials within 12h(720min)were studied.The initial creep elongation of stitched filter materials was large and gradually decreased with the increase of time.The meridional instantaneous strains of the three stitched high-temperature filter materials were 5.25%,4.20% and5.35% respectively,the zonal instantaneous strain is 8.38%,11.02% and 12.35% respectively,the meridional creep elongation is 2.23%,0.85% and 1.77% respectively,and the zonal creep elongation is 1.06%,1.91% and 3.08% respectively.Then the creep curves are fitted with different functions,and the fitting correlation coefficient R2 is compared and analyzed the creep function equation of the fitting curve is obtained,and the creep mechanism of the suture filter material is explained.(3)Filtration performance of high temperature filter material before and after sutureThe permeability,pore size and filtration performance of the filter material were tested by automatic fabric permeability meter and VDI filter material simulation device.The changes of filtration performance of three kinds of high-temperature filter materials before and after suture were compared and analyzed.The air permeability of aramid filter media,PPS/PTFE hybrid filter media and PTFE filter media were 76.22L/?·s,180.47 L/?·s and 49.54 L/?·s,respectively,and the pore size distribution range was 5.48-49.88?m,4.32-42.21?m,1.03-24.75?m,the pore size distribution of PTFE laminated filter media was concentrated and the average pore size was small,and the average pore size of the aramid filter material and PPS/PTFE mixed fiber filter material treated by burned wool was large and the pore size distribution was relatively dispersed.Approximately a positive and moderate distribution,the coated filter media is more suitable for filtering fine dust,but its breathability is poor.After stitching,the filtration efficiency of aramid filter material,PPS / PTFE mixed fiber filter material and PTFE filter material decreased from 99.9987%,99.9921% and 99.9952% to 99.9770%,99.9886% and 99.9920%;The ash removal time decreases,the average residual resistance increases compared with that before suture,and the resistance increases rapidly,which indicates that to a certain extent,it will increase the mechanical damage of the filter material in the process of use and reduce its service life.However,the effect of suture on PTFE filter material is not obvious.Compared with aramid filter material and PPS / PTFE filter material,it shows excellent ash removal performance. |
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