Abstract: Described herein is a thermoplastic core-sheath fiber. The thermoplastic core-sheath fiber comprises a core having a coextensive sheath layer disposed thereon, wherein the core comprises a first polymeric resin and an electrostatic charge enhancing additive, and the sheath layer comprising a second polymeric resin, with the proviso that if the second polymeric resin comprises poly(4-methyl-1-pentene), then the second polymeric resin does not comprise 100 wt % of poly(4-methyl-1-pentene). These thermoplastic core-sheath fibers can be used in filtering applications.

Abstract: A pleated multilayer air filter assembly including a primary filtration layer and a prefilter layer that are bonded to each other and are co-pleated with each other. The primary filtration layer includes meltblown electret fibers. The prefilter layer includes meltspun, spunbonded electret fibers that comprise a radially outer surface comprising polymethylpentene. The ratio of Effective Fiber Diameter of the fibers of the primary filtration layer to Effective Fiber Diameter of the fibers of the primary filtration layer is at least 1.5.

Abstract: A method and system of determining a filter life are disclosed. In examples, a method comprises capturing aerosol particles on a filter and measuring absorbance spectra of the aerosol particles captured on the filter. The method further comprises identifying one or more aerosol particle types based on the measured absorbance spectra and determining a mass accumulation of each of the one or more aerosol particle types based on the measured absorbance spectra and the aerosol particle type. The method further comprises determining a median particle size of each of the one or more aerosol particle types based on the measured absorbance spectra and the aerosol particle type and determining a filter life based on the determined mass accumulation and the determined median particle size of each of the one or more aerosol particle types.

Abstract: A single-layer spunbonded air-filtration web including meltspun autogenously bonded electret fibers with an Actual Fiber Diameter of from 3.0 microns to 9.0 microns. The air-filtration web exhibits a mean flow pore size of from 8.0 to 19 microns and exhibits a ratio of mean flow pore size to pore size range of from 0.55 to 2.5. Also disclosed are methods of making such webs, and methods of using such webs to perform air filtration.

Abstract: A single-layer spunbonded air-filtration web including meltspun autogenously bonded electret fibers with an Actual Fiber Diameter of from 3.0 microns to 15 microns. The air-filtration web exhibits a ratio of mean flow pore size to pore size range of from 0.55 to 2.5. Also disclosed are methods of making such webs, and methods of using such webs to perform air filtration.

Abstract: Polymeric sorbents for aldehydes including formaldehyde and acetaldehyde are provided. More particularly, the polymeric sorbents are sulfonic acid-containing polymeric materials with impregnated urea-based compounds. Additionally, methods of making the polymeric sorbent, methods of sorbing aldehydes (i.e., aldehydes that are volatile under use conditions) on the polymeric sorbents, compositions resulting from the sorption of aldehydes on the polymeric sorbents, and filters containing the polymeric sorbents are provided.

Abstract: An air filter media (10) including a pleated fibrous filtration web (8) with a first major side (2) that includes at least one sorbent-loaded area (26) in which sorbent particles (14) are present on a first major surface (25) of the pleated fibrous filtration web (8), at least some of the sorbent particles (14) being post-pleat-deposited sorbent particles.

Abstract: A sorbent suitable for sorbing aldehydes includes acidified zeolite impregnated with a urea-based compound, the acidified zeolite having a pore opening of 5 ? or greater and a molar ratio of silicate to aluminate of at least 1.1:1. The sorbent may be prepared by impregnating acidified zeolite with a solution of a urea-based compound, where the acidified zeolite includes proton counterions. The sorbent may be supported on a filter support to provide an air filter.

Abstract: An air filter including a filter support that supports polymeric sorbent particles. The polymeric sorbent particles are the reaction product of a hydrolyzed divinylbenzene/maleic anhydride precursor polymeric material with a nitrogen-containing compound, with the nitrogen-containing compound being ionically attached to the hydrolyzed divinylbenzene/maleic anhydride.

Abstract: A sorbent suitable for sorbing aldehydes includes acidified zeolite impregnated with a urea-based compound, the acidified zeolite having a pore opening of 5 ? or greater and a molar ratio of silicate to aluminate of at least 1.1:1. The sorbent may be prepared by impregnating acidified zeolite with a solution of a urea-based compound, where the acidified zeolite includes proton counterions. The sorbent may be supported on a filter support to provide an air filter.

Abstract: An air filter (1) comprises an air filter media (10) with a sorbent-free area (20) that provides a visual filter life indicator zone (30) and with a sorbent-loaded area (26) that provides a visual reference zone (27).

Abstract: An air filter including a filter support that supports polymeric sorbent particles. The polymeric sorbent is the reaction product of a divinylbenzene/maleic anhydride precursor polymeric material with a nitrogen-containing compound.

Abstract: An air filter including a filter support that supports polymeric sorbent particles. The polymeric sorbent is the reaction product of a divinylbenzene/maleic anhydride precursor polymeric material with a nitrogen-containing compound.

Abstract: An air filter media (10) including a pleated fibrous filtration web (8) with a first major side (2) that includes at least one sorbent-loaded area (26) in which sorbent particles (14) are present on a first major surface (25) of the pleated fibrous filtration web (8), at least some of the sorbent particles (14) being post-pleat-deposited sorbent particles.

Abstract: An air filter including a filter support that supports polymeric sorbent particles. The polymeric sorbent particles are the reaction product of a hydrolyzed divinylbenzene/maleic anhydride precursor polymeric material with a nitrogen-containing compound, with the nitrogen-containing compound being ionically attached to the hydrolyzed divinylbenzene/maleic anhydride.

Abstract: An air filter (1) comprises an air filter media (10) with a sorbent-free area (20) that provides a visual filter life indicator zone (30) and with a sorbent-loaded area (26) that provides a visual reference zone (27).

Abstract: The present disclosure relates generally to improved room air purifiers and filtration media for use in room air purifiers. In some embodiments, the room air purifiers and media exhibit excellent filtration of cigarette smoke and/or formaldehyde. Some embodiments include a multilayer filtration media, comprising: a fluorinated electret layer; a sorbent layer adjacent to the fluorinated electret layer; and an optional backing layer having a Gurley stiffness of at least about 200 mg; where the backing layer is not present, at least one of the fluorinated electret layer, the sorbent layer, or the combination of the two layers has a Gurley stiffness of at least about 200 mg. In some embodiments, the filtration media is pleated.