The rapid development of industry and human activities have led to the release of large amounts of smoke and dust from various emission sources such as industry, life, transportation and construction. The dramatic increase in atmospheric particulate matter and the deteriorating environment have affected human health. Therefore, people pay more and more attention to the material that can protect dust particles and increase the development and application of such materials. Filtration refers to the separation, capture dispersed in the gas or liquid particulate material in a process. Dust removal purification technology, the level of improvement and the expansion of its scope of application, so that people on the number of dusting textiles, varieties and quality have higher requirements. Therefore, it is more and more important to develop and develop protective textile materials for dust removal.

At present, China's filtration and separation textiles have a wide range of applications, and by the impact of national environmental policies, filtration and separation of the textile industry in recent years continue to maintain rapid growth, including high-temperature filtration textiles growth was significant. Non-woven processing methods and diverse, and in accordance with the density gradient of the filter material need to design the best fiber winding system, production more reasonable and economical. Non-woven filter efficiency and its structure are closely related. Studies have shown that the smaller the porosity of non-woven fabrics, the greater the fiber filling rate, the stronger the interference of particles, the higher the capture efficiency, the better the filtration efficiency.

Needle punched felt as a new non-woven filter material, its unique three-dimensional network structure, uniform pore distribution, reasonable fiber warp system and good filtering performance, coupled with high yield, low cost and so on, and gradually replace the traditional woven and knitted filter material, a filter bag filter mainstream. When the medium flows through the needle felt, the filter mesh porosity enhances the dispersion effect, improve the filtration efficiency. Needle felting can inhibit the penetration of dust particles to the deep, extending service life, but also the rapid formation of dust cake, enhance the role of filtration.
 
in conclusion:
 
(1) The major and minor order of the surface area density of polyester needle felt is the structure of filter felt> the ratio of fiber> the density of needling. In the filter felt structure, the greater the mass fraction of the polyester staple fibers with the smaller linear density is, the smaller the areal density of the polyester composite needle felt is and the smaller the thickness is.
 
(2) The order of primary and secondary mechanical properties of polyester needle felt felt acupuncture density> fiber ratio> filter felt structure. [15% (mass fraction) 0.90 dtex polyester + 35% (mass fraction) 2.20 dtex polyester] / 50% (mass fraction) 2.78 dtex The mechanics of the composite needle punched filter felt The best performance.
 
(3) The order of the primary and secondary factors that affect the permeability of polyester composite needle felt is filter felt structure> needle penetration density> fiber ratio. [35% (mass fraction) 0.90 dtex polyester + 15% (mass fraction) 2.20 dtex polyester] / 50% (mass fraction) 2.78 dtex breathability of composite needled felt at 7 bar / cm² the best.
 
(4) The filtration efficiency of PM25 for all samples reached 100%. When the linear density of the fiber in the polyester composite needle felt is smaller, the filtration efficiency is greater; as the linear density of the fiber is increased, the fiber web is relatively fluffy, the void of the fiber is increased, the power diffusion and inertia are decreased, the filtration efficiency decline.