Abstract: A method of making a respirator, which method includes placing an electret in a respirator body that is adapted to fit over the nose and mouth of a wearer. The electret is disposed in the respirator body such that air passes through it before being inhaled by a respirator wearer. The electret includes a nonwoven web that has fluorinated polymeric microfibers and that has at least about 25% atomic fluorine as detected by ESCA and a CF3:CF2 ratio of at least about 0.45.

Abstract: Electret filter media comprising a nonwoven web of thermoplastic nonconductive microfibers having trapped charge, said charge provided by (1) subjecting the nonwoven web to a corona treatment, followed by (2) impingement of jets of water or a stream of water droplets on the web at a pressure sufficient to provide the web with filtration enhancing electret charge and (3) drying the web. This electret filter media may be used in a respiratory mask to provide extraordinarily good filtration properties.

Abstract: An electret is described that includes a surface modified polymeric article having surface fluorination produced by fluorinating the polymeric article.

Abstract: An electret is described that includes a plasma surface modified polymeric article having plasma surface fluorination produced by fluorinating the polymeric article.

Abstract: An electret is described that includes a surface modified polymeric article having surface fluorination produced by fluorinating the polymeric article.

Abstract: An electret is described that includes a surface modified polymeric article having surface fluorination produced by fluorinating the polymeric article.

Abstract: An electret is described that includes a surface modified polymeric article having surface fluorination produced by fluorinating the polymeric article.

Abstract: A method of charging fibrous webs with nonaqueous polar liquids. A web 20 that contains nonconductive fibers is wetted with a nonaqueous polar liquid 14. The web 20 is then substantially dried 22 to provide a fibrous electret web. The fibrous electret web can be used as a filter in a filtration face mask 40 that is adapted to cover the nose and mouth of the wearer. The present method has the advantage over known charging methods in that the nonaqueous liquid requires less energy for drying than is required for aqueous liquids. Additionally, many filter webs can be directly wetted with nonaqueous liquids, which cannot be easily wetted with aqueous liquids.

Abstract: An apparatus for charging fibers that contain a nonconductive polymer. A polar liquid 32, 34 is sprayed onto free-fibers 24, and the free-fibers 24 are then collected to form an entangled nonwoven fibrous web 25 that may contain a portion of the polar liquid. The nonwoven web 25 is then dried 38. By applying an effective amount of polar liquid 32, 34 onto the nonconductive free-fibers 24 before forming the nonwoven web 25, followed by drying 38, the individual fibers 24 become charged. The apparatus can enable the fibers 24 to be charged during web manufacture without subsequent processing.

Abstract: An electret is described that includes a surface modified polymeric article having surface fluorination produced by fluorinating the polymeric article.

Abstract: An electret is described that includes a surface modified polymeric article having surface fluorination produced by fluorinating the polymeric article.

Abstract: An electret is described that includes a surface modified polymeric article having surface fluorination produced by fluorinating the polymeric article.

Abstract: An electret is described that includes a surface modified polymeric article having surface fluorination produced by fluorinating the polymeric article.

Abstract: A method and apparatus for charging fibers that contain a nonconductive polymer. A polar liquid 32, 34 is sprayed onto free-fibers 24, and the free-fibers 24 are then collected to form an entangled nonwoven fibrous web 25 that may contain a portion of the polar liquid. The nonwoven web 25 is then dried 38. By applying an effective amount of polar liquid 32, 34 onto the nonconductive free-fibers 24 before forming the nonwoven web 25, followed by drying 38, the individual fibers 24 become charged. The method and apparatus enable the fibers 24 to be charged during web manufacture without subsequent processing.

Abstract: This invention provides fluorochemical compounds comprising: a fluorochemical oligomeric portion comprising an aliphatic backbone with a plurality of pendant fluoroaliphatic groups, each fluoroaliphatic group having a fully fluorinated terminal group and each independently linked to a carbon atom of the aliphatic backbone through an organic linking group; an aliphatic moiety; and a linking group which links the fluorochemical oligomeric portion to the aliphatic moiety. The fluorochemical compounds are useful as topical treatments for fibrous substrates such as textiles and fabrics, and as polymer melt additives to provide desirable oil-, water and stain repellency to shaped articles such as fibers.

Abstract: A compound comprising wherein R2 is an alkyl group which may be straight chain or branched and n is a number of from 2 to 40.

Abstract: A method of removing particulate solid or liquid aerosol from a gas, which method comprises the step of: passing a particulate solid or liquid aerosol containing gas through an electret filter that comprises a polymer and a performance enhancing additive, wherein the electret filter has a thermally stimulated discharge current (TSDC) spectrum exhibiting a peak having a width at half height of less than about 30° C., as measured by TSDC test procedure 3.

Abstract: Novel electret articles containing a polymer and a performance-enhancing additive can be identified by their thermally stimulated conductivity characteristics or their filtration properties. Electret articles such as nonwoven filter webs and respirators exhibit superior oily mist loading performance, low penetration and a small pressure drop.

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.

Abstract: An electret filter media, and mask, that is made of a nonwoven web of thermoplastic microfibers. The thermoplastic microfibers are of substantially the same composition, are nonconductive, and have an effective fiber diameter less than about 15 micrometers. The nonwoven web also has sufficient unpolarized trapped charge to exhibit an initial filtration quality factor of at least 0.31 when measured under the DOP Penetration and Pressure Drop Test.