The smoothness of filter surface has a great influence on the dynamic running resistance of filter media. The initial resistance of filter material is determined by the permeability of filter material itself, while the resistance in operation is much larger than that in initial resistance. The running resistance depends on the smoothness of the surface of the filter, the effect of ash cleaning, and so on. In general, it is hoped that the better the filtration efficiency is, the better the air permeability is, that is, the lower the better the resistance is, because this can save a lot of energy. In the dust remover using air flow back blowing dust, the same pressure and air volume are used in the dust collector. When the flow is used for cleaning, it is better to choose the fabric with larger air permeability when making filter bags than to choose the fabric with less air permeability.

Therefore, under the condition of high filter precision, how to improve the permeability of the filter material and improve the surface finish, reduce the dust adhesion and reduce the running resistance are the first issues to be studied in the filter production plant. The surface resin smooth finishing needle punched filter felt is more than 50% higher than that of the ordinary press finishing filter, and the smoothness of the surface is more smooth than that of the press finishing.

The air permeability of the same accuracy clean filter material determined by laboratory is: burning gas treatment material > easy ash handling filter material > ordinary calender filter material. The actual operation of resistance in ascending order for easy cleaning filter filter press < < singeing common optical filter. Therefore, because of the smooth surface, easy air permeability and low resistance, the needle punched filter felt is a good filter material for industrial dust removal.