Electret filters that exhibit increased oily mist resistance
Assignee3M Innovative Properties Company
InventorsAlan D. Rousseau, Marvin E. Jones, Betty Z. Mei
Life of this patent
Estimating the term…
Abstract
The thermally stimulated discharge current of an electret article can be used to identify electret articles that exhibit superior filtration properties. Electret filters that exhibit superior properties not achieved in similarly constructed filters contain fibers that are made from a blend of a polymer and a performance-enhancing additive. The electret filters exhibit an initial detectable DOP penetration of less than 5% and an average Min@Chl of greater than 200 mg DOP as measured by DOP Filter Web Loading Test Procedure 1. These new electrets are particularly useful in a respirator.
Claims19
An electret filter comprising a nonwoven web comprising electret fibers that comprise a polymer and performance-enhancing additive, and wherein the filter exhibits an initial detectable DOP penetration of less than 5% and an average Min@Chl of greater than 200 mg DOP as measured by DOP Filter Web Loading Test Procedure 1.
A respirator containing an electret filter comprising a nonwoven web that contains electret fibers that contain a blend of polymer and a performance-enhancing additive;
- the respirator exhibiting a Min@Chl of greater than 400 mg DOP when testing using the National Institute for Occupational Safety and Health Particulate Filter Penetration Procedure to Test Negative Pressure Respirators Against Liquid Particulates (Procedure APRS-STP-0051-00);
- and wherein the respirator has an exposed surface area of about 180 cm2 or wherein the respirator is tested with the exposed surface area adjusted to be about 180 cm2.
Dependencies are inferred from the claim text.