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US 8,871,011 B2Granted
Electret filter element and method for the manufacture thereof
AssigneeCarl Freudenberg KG
InventorsKlaus Veeser, Martin Krause, Toan-Hieu Giang, Jochen Zabold
Life of this patent
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Abstract
A method for manufacturing an electret filter element includes preparing fibers and producing, by a spray device, a spray mist of fluid droplets which include an electrical charge formed by an electric field between detaching fluid droplets and a counter-electrode. The fibers are passed through the spray mist so as to wet the fibers with the fluid droplets. The fibers are laid down to form a fibrous layer.
Claims20
A method for manufacturing an electret filter element comprising:
- preparing fibers;
- producing, by a spray device, a spray mist of fluid droplets which include an electrical charge formed by an electric field between detaching fluid droplets and a counter-electrode;
- passing the fibers through the spray mist so as to wet the fibers with the fluid droplets;
- and
- laying down the fibers to form a fibrous layer.
2 more elements
An electret filter element, comprising:
- a first fibrous layer including fibers and electrical charges inside the fibers,
- wherein the electrical charges are formed by respective electrical charges of fluid droplets sprayed on the fibers,
- wherein the respective electrical charges are produced by an electric field between detaching fluid droplets and a counter-electrode, and
- wherein at least 60% of the electrical charges of the first fibrous layer carry charges of the same polarity.
1 more element
Dependencies are inferred from the claim text.