Melt blown (MB) fabrics are composed of fine fibers which contribute to high filtration efficiency (FE) and low air flow resistance compared to high efficiency filtration media such as fiber glass paper. Furthermore, MB fabrics are mostly made of polypropylene (PP) polymer, which can be electrostatically charged to enhance the media filtration efficiency without the increase of air flow resistance. However, different charging techniques or charging at different locations on the MB line will contribute to different filtration efficiency. This paper compares the efficiencies of different charging techniques in the MB line.

This paper considers the efficiency of electrostatic charging of water-sprayed fibers during the melt-hiowing process. Two charging methods were used to charge the flbers near the die exit and the fabrics after the collector. Both showed that the charging efficiency was not affected hy the water-spraying process if the amount of spraying was controlled.