It is an electrostatically charged needle-punched felt comprising specific synthetic fibers which are specially prepared and processed at the manufacturing stage, creating a charge transfer between different fibers. Both positive and negative will deposit on the fiber surfaces stably and permanently because the fiber is an extremely effective insulator, however, overall the filter is electrically neutral. This surface charging dramatically enhances the filtration efficiency, by electrostatically attracting the particles to the fiber surface and thereby removing particles from the airstream.

Indeed, non-woven filter media relying on entirely mechanical filtration mechanisms, such as melt-blown and fiberglass filter material, are required to use extremely fine fibers for removing smallest size fraction. These fine fibred filter materials are normally associated with the inherent disadvantages of low dust holding capacity due to surface blinding and high resistance to airflow.

In order to solve the above problems, we have developed this new electrostatically charged needle-punched filter media series. The advantage of its in this respect is that it combines the benefits of ordinary needle-punched filter media, low airflow resistance and high dust holding, whilst offering very high efficiencies against sub-micron particles.