摘要:
An electret article can be made by quenching a molten blend containing a polymer and a performance-enhancing additive. The resulting low crystallinity material can be annealed and charged to produce a material for making electret filters having superior oily mist loading performance properties.
摘要:
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.
摘要:
The present invention relates to a method of making a fibrous electret material which includes the steps of (1) forming a fibrous web of nonconductive thermoplastic fibers from a blend of nonconductive thermoplastic resin and an additive which is (a) a thermally stable organic compound or oligomer containing at least one perfluorinated moiety or (b) a thermally stable organic triazine compound or oligomer containing at least one nitrogen atom in addition to those in the triazine group or (c) a combination thereof; (2) impinging jets of water or a stream of water droplets onto the web at a pressure sufficient to provide the web with filtration enhancing electret charge; and (3) drying the web.
摘要:
An oily mist resistant electret filter media is provided. The filter media includes polypropylene electret fibers and a melt processable fluorochemical additive, the additive having a melting point of at least 25.degree. C. and a molecular weight of about 500 to 2500.
摘要:
An oily mist resistant electret filter media is provided. The filter media includes polypropylene electret fibers and a melt processable fluorochemical additive. The additive has a melt temperature of at least 25.degree. C. and a molecular weight of about 500 to 2500. Also provided is a method for filtering particulate material from air containing oily aerosol particles.
摘要:
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.
摘要:
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.
摘要:
Fibrous webs comprising a blend of a thermoplastic resin and at least one compound or oligomer which is ##STR1## wherein R.sub.f is a perfluorinated moiety which may contain one or more catenary ether oxygen atoms, Q is a linking group selected from alkylene groups having 1 or 2 carbon atoms, sulfonamido groups or combinations thereof, R is an alkyl group, R.sup.1 is a perfluoroalkyl group, R.sup.2 is an alkyl group which may be straight chain or branched and n is a number of from 2 to 40.
摘要:
An electret article that includes a polymeric material that has electric charge imparted thereto, that has a CF3:CF2 ratio of at least 0.15 and that has a fluorosaturation ratio greater than about 200. The electret article may be in the form of a porous web of polymeric fibers suitable for use as a filter. The inventive electret article is resistant to charge degradation upon exposure to high temperatures for prolonged time periods.