The present invention relates to the field of air filtration, in particular to a polytetrafluoroethylene composite filter material and a preparation method and uses thereof. The polytetrafluoroethylene composite filter material comprises a support layer and a polytetrafluoroethylene microporous membrane layer, and the support layer and the polytetrafluoroethylene microporous membrane layer are compounded by an adhesive, wherein the adhesive comprises a two-component polyurethane adhesive, a pore forming agent and an inorganic filler. The present invention adopts a two-component solvent-free polyurethane adhesive, and by adding a low-temperature pore forming agent and an inorganic filler, the pore forming agent forms an irregular pore channel structure at the bonding interface during curing, and the inorganic filler prevents the adhesive from entering the micropores of the polytetrafluoroethylene membrane, so that the air permeability and filtration efficiency of the polytetrafluoroethylene microporous membrane are not affected after compounding; and the prepared polytetrafluoroethylene composite filter material has good air permeability, high peel strength, good filtration efficiency and good barrier effect.

Compositions and articles comprising a non-woven matrix for use as anti-microbial filters are provided. In some embodiments, the non-woven matrix comprises nanofibers suitable for capturing a droplet comprising a microbe (e.g. a virus particle). In some embodiments, the non-woven matrix comprises a biocide suitable for reducing propagation and/or inactivating a microbe.

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.

A filter for filtering particulates from a fluid stream includes a filter element, a first end cap, a second end cap, and a wrap. The end caps are respectively secured to the ends of the filter element to form a fluid tight seal therebetween. At least one of the end caps defines an opening therethrough in fluid communication with the interior passage of the filter element. The wrap is in the form of a strip secured to at least the filter element. The wrap comprises a conductive layer comprising an electrically-conductive material. The wrap is wrapped around the filter element such that at least forty percent of the outer surface area is covered by the conductive layer.

A provided stretched porous polytetrafluoroethylene membrane has a node-fibril structure including a plurality of nodes and a fibril connecting the plurality of nodes. A ratio of an average length of the plurality of nodes in a thickness direction of the stretched porous polytetrafluoroethylene membrane to a thickness of the stretched porous polytetrafluoroethylene membrane is 10% or more. The above stretched porous polytetrafluoroethylene membrane is less likely to suffer breakage. In the above stretched porous polytetrafluoroethylene membrane, assuming that there is a cuboid region having an upper surface and a lower surface respectively positioned at one membrane surface and the other membrane surface of the stretched porous polytetrafluoroethylene membrane, the number of the nodes included in the region may be 4 or less per micrometer thickness, the upper surface and the lower surface each having dimensions of 280 μm×280 μm.

A multi-functional air purification filter includes: a breathable support layer; a mesh layer provided on the breathable support layer; and a filter layer provided on the mesh layer, wherein at least a portion of the multi-functional air purification filter has a plurality of bends, and the mesh layer includes a coating layer of at least one of a photocatalytic material, an adsorption material, or a sterilizing material.

The disclosure relates to a mask including a perforated exterior shell sized to cover the nose and mouth of a user and constructed of one or more fabric layers, and a removable multi-layer nonwoven fabric insert sized to cover the nose and mouth of a user and adapted for abutting contact with the exterior shell, the nonwoven fabric including a layer of a spunbond material and a layer of meltblown material adjacent to the layer of spunbond material.

Air filter media comprising at least one active bead layer comprises an antistatic agent and polyethylenimine coated polymeric beads that can provide better formaldehyde abatement properties than incumbent activated carbon filters and can be prepared by using existing processing facilities for manufacture of incumbent activated carbon filters.

A nuclear fuel assembly bottom end part debris filter has an inlet face (18A) and an outlet face (18B) opposed to the inlet face (18A) and comprises a plurality of filtering structures (50) protruding on the inlet face (18A) of the debris filter (18). Each filtering structure (50) has a structure base (52) and a structure apex (54) spaced along a structure axis (A), and each filtering structure (50) includes blades (56) distributed circumferentially around the structure axis (A). Each blade has one end connected to the structure base (52) and one end connected to the structure apex (54), and each blade (56) delimits a slot (58) with each adjacent blade (56) of the same filtering structure (50).

Articles and methods involving filter media are generally provided. In certain embodiments, the filter media includes at least a first layer, a second layer, and an adhesive resin positioned between the first layer and the second layer. In some embodiments, the first layer may be a pre-filter layer or a support layer. The second layer may, for example, comprise fibers formed by a solution spinning process and/or may comprise fine fibers. In some embodiments, the adhesive resin may be present in a relatively low amount and/or may have a low glass transition temperature. The filter media as a whole may have one or more advantageous properties, including one or more of a high stiffness, a high bond strength between the first layer and the second layer, a high gamma, and/or a low increase in air resistance after being subjected to an IPA vapor discharge. The filter media may be, for example, a HEPA filter and/or an ULPA filter.