An improved impression wheel for use within respiratory face mask manufacturing machines that includes a first, second, and third series of spaced helicoidal teeth shaped and adapted to more efficiently and securely interconnect respective layers of respiratory face masks.

Articles and methods involving filter media are generally provided. In certain embodiments, a filter media has a design and/or comprises one or more layers that enhances its efficiency and/or performance.

A high filtration filter for filtering aerosols with low pressure drop across the filter and reduced cake formation when the aerosols penetrate through from an upstream side to a downstream side is disclosed. The filter (100) includes a plurality of module layers (110) and a plurality of separators (120). An individual module layer is an electrostatically-charged polyvinylidene fluoride (PVDF) nanofiber mat. The electrostatically-charged PVDF nanofiber mat with charged nanofibers is configured to better capture aerosols. The plurality of module layers and the plurality of separators are alternatingly stacked and connected to one another. Each of the individual module layers has an appropriate fiber basis weight, thereby the aerosols are captured by the charged nanofibers and distributed uniformly across an entire width of the filter from the upstream side (41) to the downstream side (42). The fiber basis weight of nanofibers is selected to minimize the formation of skin leading to formation of a cake layer on the upstream side of the filter module. The filter also carries antimicrobials to disinfect bacteria, viruses, and harmful microbials carried by the trapped aerosols in the filter.

Embodiments include a filter material including an electrospun nanofiber membrane and an active nanomaterial agent incorporated into the electrospun nanofiber membrane, wherein the electrospun nanofiber membrane filters disease-causing agents and the wherein the active nanomaterial agent degrades disease-causing agents. Embodiments further include a face mask and/or respirator including a filter material, wherein the filter material includes an electrospun nanofiber membrane and an active nanomaterial agent incorporated into the electrospun nanofiber membrane, wherein the electrospun nanofiber membrane filters disease-causing agents and the wherein the active nanomaterial agent degrades disease-causing agents.

A nanofiber filter includes: a first support having a front surface and a rear surface opposite to the front surface; a first nanofiber filter layer disposed on the rear surface of the first support; a second nanofiber filter layer disposed on a rear surface of the first nanofiber filter layer; a third nanofiber filter layer disposed on a rear surface of the second nanofiber filter layer; and a second support disposed on a rear surface of the third nanofiber filter layer.

Described here is an air filter comprising a substrate and a network of polymeric nanofibers deposited on the substrate, wherein the air filter a removal efficiency for PM.sub.2.5 of at least 70% when a light transmittance is below 50%. Also described here is an electric air filter comprising a first layer adapted to receive a first electric voltage, wherein the first layer comprises an organic fiber coated with a conductive material. Further described is an air filter for high temperature filtration, comprising a substrate and a network of polymeric nanofibers deposited on the substrate, wherein the air filter has a removal efficiency for PM.sub.2.5 of at least 70% at a temperature of a least 70° C.

An air filter device. The air filter device comprises: a filter medium having an inlet surface for taking in air, and a discharge surface for filtered air. The filter medium having a plurality of air passages for the air to flow therethrough. At least a portion of the inlet surface of the filter medium comprises a sulfonated polymer for killing at least 90% microbes in the air within 120 minutes of contact with the surface of the air passages. The sulfonated polymer is selected from the group of perfluorosulfonic acid polymers, polystyrene sulfonates, sulfonated block copolymers, sulfonated polyolefins, sulfonated polyimides, sulfonated polyamides, sulfonated polyesters, sulfonated polysulfones, sulfonated polyketones, sulfonated poly(arylene ether), and mixtures thereof. The sulfonated polymer has a degree of sulfonation of at least 10%.

Filter media including fibers comprising a matrix polymer and impact modifier, and related methods, are generally described.

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.

Articles and methods relating to filter media are generally provided. In some embodiments, a filter media has an irregular surface structure. For instance, the filter media may comprise a plurality of peaks that are irregular in one or more ways. A ratio of a peak height standard deviation to an average peak height may be greater than or equal to 0.05, and/or a ratio of a peak spacing standard deviation to an average peak spacing may be greater than or equal to 0.08. In some embodiments, a filter media comprises a non-woven fiber web having a layer thickness of greater than 0.3 mm and/or a stiffness of less than or equal to 100 mg.