A rigid, channel-framed, non-compressible, non-nestable, pleated air filter, comprising: a tightly-pleated air filter media comprised of a nonwoven fibrous web and with an upstream face and a downstream face, wherein the tightly-pleated air filter media comprises a plurality of upstream (and downstream) pleat tips and upstream (and downstream) pleat valleys, the tightly-pleated air filter media comprising a plurality of upstream (and downstream) linear bridging filaments that are at least substantially parallel to each other and are oriented at least substantially orthogonal to the pleat direction and are extrusion-bonded to at least some of the upstream (and downstream) pleat tips, and, a channel frame comprising four major frame portions, with each major frame portion being mounted on one of the four major edges of the pleated air filter media.

Non-halogenated monomers that can be polymerized into flame retardant polymers, and processes to produce the monomers and polymers is provided. In a simplest aspect, there is provided a monomer composition that can comprise a) a group derived from one of a (meth)acrylic acid, (meth)acrylamide, or vinylbenzene, b) a polyphosphate moiety, and c) an amine species. In the monomer composition, the ethylenically unsaturated monomer of (a) is covalently bonded directly or through a linking group to the moiety of b), forming a precursor monomer unit. The amine species of c) is in complex with the precursor monomer unit. The polymer can be a homopolymer of the monomer composition, or a copolymer of the monomer composition having varying a), b) and c). In one embodiment, the polymer can additionally comprise ethylenically unsaturated monomers not covalently bonded to a polyphosphate moiety.

A face mask containing a network of conductive activated carbon meso-fibers crosslinked with a crosslinking agent bonded to a insulative polymeric micro-fiber based purification element. The purification element is captured between two ridged porous elements and contacted to the face by a biocompatible flexible polymeric seal. Optionally the front cover attaches to a main frame of the mask through a system of sliding locks that are coupled with bayonet latch mechanisms. The face mask attaches to the head of a wearer through a harness that couples with the sliding locks or alternatively with a biocompatible adhesive.

Provided are a self-cleaning air filtering material and a preparation method therefor. The air filtering material comprises: a submicron fiber layer (2) at an inflow surface for surface filtration, a supporting area (3) for supporting and a mixed area (5) between the submicron fiber layer (2) and the supporting area (3), wherein the mixed area (5) is formed by contacting and mixing part of the fibers in the submicron fiber layer (2) and the supporting area (3) with each other during the one-step formation of the submicron fiber layer (2) and the supporting area (3) by passing through a double-layer headbox.

Electret webs include a thermoplastic resin and a charge-enhancing additive. The charge-enhancing additive is an arylamino-substituted benzoic acid or an arylamino-substituted benzoic acid salt. The electret webs may be a non-woven fibrous web or a film. The electret webs are suitable for use as filter media.

A substrate for use in a filter media including, for example, in a hydrocarbon fluid-water separation filter; methods of identifying the substrate; methods of making the substrate; methods of using the substrate; and methods of improving the roll off angle of the substrate. In some embodiments, the substrate includes a hydrophilic group-containing polymer or a hydrophilic group-containing polymer coating.

A substrate for use in a filter media including, for example, in a hydrocarbon fluid-water separation filter; methods of identifying the substrate; methods of making the substrate; methods of using the substrate; and methods of improving the roll off angle of the substrate. In some embodiments, the substrate includes a hydrophilic group-containing polymer or a hydrophilic group-containing polymer coating.

Method and systems for filtration of harmful particles are disclosed herein. In one embodiment, a method for making a filtration system for use with a facial covering includes producing a liquid polymerized copper substate, creating a barrier layer by coating a filter media with the liquid copper substrate to coat the filter media with polymerized copper, and binding the barrier layer between two textile layers, wherein each of the two textile layers provides a tortuous path for particles to pass. A filtration system includes a barrier layer including a filter media coated with particulate copper and a polymer.

Provided is a fiber structure which can have both a high filtering efficiency and a small pressure loss. The fiber structure comprises ultrafine fibers having a number average single fiber diameter of 4.5 μm or smaller and non-ultrafine fibers having a number average single fiber diameter of 5.5 μm or larger, wherein the ultrafine fibers and the non-ultrafine fibers are unitedly intermingled, and the fiber structure includes projections on at least one surface thereof. For example, in the fiber structure, the ultrafine fibers may be heat-resistant ultrafine fibers, and the non-ultrafine fibers may be heat-resistant non-ultrafine fibers.

A rigid, channel-framed, pleated air filter, with a plurality of linear bridging filaments on at least an upstream face of the pleated air filter media of the filter.