Abstract: A composite filter media for a vacuum cleaner comprising a first filtration layer comprising a slit film having a plurality of continuous electrostatically-charged polyolefin filaments disposed substantially parallel to each other along their lengths; and a second filtration layer comprising a high-efficiency filtration media selected from wet-laid filter paper, dry-laid filter paper, and nonwoven filter media; wherein said first filtration layer is disposed in series with said second filtration layer, with respect to an air flow direction through said vacuum cleaner, to form a composite.

Abstract: A composite filter media for a vacuum cleaner comprising a first filtration layer comprising a slit film having a plurality of continuous electrostatically-charged polyolefin filaments disposed substantially parallel to each other along their lengths; and a second filtration layer comprising a high-efficiency filtration media selected from wet-laid filter paper, dry-laid filter paper, and nonwoven filter media; wherein said first filtration layer is disposed in series with said second filtration layer, with respect to an air flow direction through said vacuum cleaner, to form a composite.

Abstract: The present invention is drawn to an improved electrostatic filter medium comprising a web of electret fibers which have been treated with fluorine-containing plasmas at a deposition amount of about 0.03 g/m2 to about 1.5 g/m2; rinsing; and drying prior to being electrically charged. The present invention is further drawn to a method of producing non-woven webs which have been treated with a fluorine-containing plasma at a deposition amount of about 0.03 g/m2 to about 1.5 g/m2; rinsed; and dried prior to electrostatically charging the web.

Abstract: The present invention is drawn to an improved electrostatic filter medium comprising a web of electret fibers which have been treated with fluorine-containing plasmas at a deposition amount of about 0.03 g/m2 to about 1.5 g/m2; electrostatically charged; rinsed; and dried. The present invention is further drawn to a method of producing non-woven webs which have been treated with a fluorine-containing plasma at a deposition amount of about 0.03 g/m2 to about 1.5 g/m2; electrostatically charged; rinsed; and dried.