Fabrication and evaluation of aramid fiber/polytetrafluoroethylene emulsion/tourmaline particle composite filter media: Filtration performance, thermal behavior, and mechanical property

Abstract

An electrostatically enhanced aramid fiber/polytetrafluoroethylene emulsion/tourmaline particle (AF/PTFE/TM) composite filter media was successfully designed and fabricated by impregnation technology, especially for harsh industrial environment with high temperature. The AF/PTFE/TM composite filter media exhibited the optimum quality factor when the concentration of PTFE emulsion was 10% and the content of TM particles was 12.5 g/cm2. The collection efficiency, pressure drop characteristic, thermal decomposition behavior and kinetics, and tensile strength in machine and cross directions of the composite filter media have been systematically evaluated. Benefiting from the pyroelectricity and piezoelectricity of TM particles, the composite filter media has better collection efficiency with the increase of incoming air temperature. With the increase of flow velocity, the decrease of collection efficiency is smaller than the filter media without TM particles. Meanwhile, the pressure drop across the composite filter media is a little higher than that across the raw filter media. Additionally, it was found PTFE emulsion coating can improve the thermal stability and tensile strength of the composite filter media. TM particles have no negative impact on the thermal behavior of the composite filter media, but slightly attenuates the enhancement in tensile strength. This study provides new insight into the application of TM particles as well as other pyroelectric and piezoelectric materials in industrial filtration.