Polyester needle felt is the main filter material in the bag filter. It is a non-woven needle punching process. The polyester staple fiber is carded and laid on a fine fiber cloth with staggered fibers and uniform gap distribution. The filter material has high strength, good elastic recovery performance, stable fabric size, good wear resistance, large void ratio, good gas permeability, long service life, good dust removal effect, and good mechanical properties at normal temperature (below 130 ° C ). And acid and alkali resistant. Due to the low price of polyester, polyester needle felt is the most cost-effective filter medium at low temperatures.

Polyester needle felts are often mixed with antistatic fibers, singeing, calendering, water-repellent and oil-proof impregnation according to the characteristics of dust from different manufacturers. The polyester needle felts have increased the easy-to-clear ash in the original performance. Dust stripping fast), water and oil proof (anti-condensation), anti-static properties, forming a series of products.

Compared with general woven filter materials, acupuncture filter felts have the following advantages: 1. High porosity and good gas permeability, which can improve equipment load capacity and reduce pressure loss and energy consumption. The needle-punched filter felt is a short-fiber filter cloth with staggered arrangement and uniform pore distribution, and the porosity is more than 70 %, which is double that of the woven filter cloth. Using a needle punch as a filter bag can reduce the size of the bag filter and significantly reduce energy consumption. 2 , the dust emission efficiency is high, and the gas emission concentration is low. Found show that: the filter 325 mesh talc (median diameter 7.5 [mu] m or so) up to the efficiency of 99.9-99.99 % , more than an order of magnitude flannel. Gas emission concentrations can be greatly reduced to national standards. 3 , the surface is heat-treated and singeed or coated, the surface is smooth and smooth, not easy to block, not easy to deform, easy to clean, long service life. The service life of needle felt is generally 1 to 5 times that of woven filter cloth . 4 , chemical stability. It not only filters normal or high temperature gases, but also filters aggressive gases containing acids and bases.