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US 5,645,627 AGranted
Charge stabilized electret filter media
AssigneeHollingsworth & Vose Company
InventorsNorman Lifshutz, Richard E. Gahan, Graham C. Stevens
Life of this patent
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Abstract
An electret filter media includes an additive or mixtures thereof that enhance the charge stability of the media. The filter media achieves acceptable alpha values for a range of filtration challenges without significant decay in alpha values over time. Preferred charge additives include fatty acid amides, oleophobic fluorochemical surfactants, and mixtures thereof.
Claims10
A filter media comprising an electret melt-blown polymer fiber web having a charge stabilizing melt-blown additive selected from the group consisting of stearic esters of perfluoroalcohols;
- and mixtures of nonionic fatty acid amides with nonionic, oleophobic fluorochemical surfactants, wherein the melt-blown additive is present at a concentration in the range of about 0.1 to 3.5% by weight to thereby reduce alpha decay in the electret melt-blown polymer fiber web.
Dependencies are inferred from the claim text.