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 filter element comprises one or more several tubular filter media element segments, which may be pleated filter media ring segments. One or more heat activated disks are used to connect each tubular filter media element segments together and/or to connect tubular filter media element segments with one or more end cap supports. The heat activated disks are solid in form for assembly with tubular filter media ring segment and then heat activated to bond with tubular filter media ring segments. Multiple end caps can be simultaneously bonded to one or more tubular filter media element segments if a filter stack assembly of component are heated together, such as in an oven. Filter media may also be simultaneously cured. Heat activated disks may be used as pleat stabilizers and/or for and/or as part of end caps.

A porous composite structure including a substrate including a plurality of nanostructures; a particle layer disposed on a surface of the substrate; and a liquid, a method of preparing the porous composite structure, an article including the porous composite structure, and an air purifier including the porous composite structure.

Articles comprising binders, cross-linking agents and/or other components, and related methods are generally disclosed.

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.

A respiration filtering face mask that can be washed and sterilized by common means and reused repeatedly comprised of a filtering component that is a laminate of at least one layer of particle filtering material and at least one layer of a microbe killing metallic woven cloth laminated together by adhesive or fusible material in a manner that allows low resistance to air flow, cut to a shape that is folded into a modified cone, a padding filled gasket that is continuously sealed to the outer edge of the filter cone, harness straps that are elastic and user adjustable for length and tension, and an attached shield to prevent fogging of eye ware. A method for making said anti-microbial filter and respiration filtering face mask.

Disclosed here is a composite filter media having at least one nanofiber layer bonded to a substrate layer, the at least one nanofiber layer optionally having a plurality of nanofibers having a geometric mean diameter of less than or equal to 0.5 μm, the at least one nanofiber layer having a thickness of about 1-100 μm.

Described are multi-layer filters of a type commonly known as “depth filters” and related devices and methods, with the filters containing a layer that includes polyaramid fiber, synthetic filter aid, and polymeric binder.

The invention relates to a filtering material permeable to air and impermeable to oral, nasal and/or ocular human liquid aqueous excretions, comprising at least one bundle, referred to as a hydrophobic bundle, of at least two hydrophobic sheets which are superimposed and each formed by porous paper, having a gsm substance less than 30 g/m.sup.2, each hydrophobic sheet being formed by cellulose fibres, referred to as cross-linked cellulose fibres, which are connected to each other by hydrogen bonds and by covalent bonds which are formed with at least one group of cross-linking atoms, characterised in that at least some of the hydroxyls of the cross-linked cellulose fibres which are not engaged in hydrogen bonds and which are accessible to the gases form a covalent bond with an acyl group with a hydrophobic chain.