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.

The present invention provides a filter material comprising an antistatic substrate having a predefined antistatic capacity, and one or more layers of nanofibers applied on the substrate. The one or more layers of nanofibers may be fabricated to have gradient structure in various parameters including thickness of nanofiber layer, nanofiber pore size, nanofiber diameter, nanofiber content and the like to suit different filtration applications. The present invention also provides a face mask comprising the filter material and a method for making the filter material.

Provided is an antiviral filter medium. An antiviral filter medium according to one embodiment of the present invention includes a first member provided with an antiviral coating layer formed of fibers and including, on part or all of the outer surface of the fibers, an antiviral fusion protein in which an antiviral motif is bound to an adhesive protein. Accordingly, the antiviral filter medium exhibits antiviral properties, is excellent in filtration efficiency and ventilation amount (or flow rate), and has low pressure loss. In addition, the antiviral filter medium is characterized in that the coating layer exhibiting antiviral properties retains adhesiveness for a long period of time after being attached to the surface. Moreover, the antiviral filter medium can retain antiviral activity for a long time without loss of the antiviral activity due to external conditions during production, storage, and use.

An air filter for a fuel cell vehicle may include a first filtration layer formed in a two-layered dust holding structure, a gas adsorption layer formed of amorphous activated carbon, a second filtration layer having amorphous pores formed therein, and a cover layer for maintaining a physical form of the air filter.

A filter medium is provided with a layer (A) provided with non-impregnated active carbon, a layer (B) with a solid carrier material that is impregnated with a permanganate salt, and a layer (C) with alkaline impregnated active carbon. The layer (B) and the layer (C) are arranged such that a gas flowing through the filter medium flows through the layer (B) before flowing through the layer (C). The layer (A) is arranged such that the gas flowing through the filter medium flows through the layer (A) before flowing through the layer (B) or the gas flowing through the filter medium flows through the layer (A) after flowing through the layer (C).

Water impermeable, air permeable membrane assemblies are described herein. In some embodiments, the assemblies include a polymer membrane and at least one support structure. Certain assemblies are configured to provide an acoustic impedance having phase angle of +45 degrees to −45 over a frequency range of 50 to 20,000 Hz.

A process is provided for removing viruses and micro-organisms from building air by inactivation of those biological elements within an HVAC filter having exuding halogenated material therein. The filter for the HVAC systems has the exuded halogenated material applied with a tackified material via a sequential spraying operation prior to heat curing either of those materials. The filter can subsequently be formed with other laminated materials for increased efficiency, and pleated for use in the HVAC system. Both porous and non-porous substrate fibers can serve as the substrate web for the exuded halogenated material, preferably processed as a non-woven web during air filter fabrication

A tetrafluoroethylene polymer is provided in an air filter medium having a pressure loss that can be reduced and made uniform at a plurality of positions. The tetrafluoroethylene polymer may also be provided in an air filter medium, a filter pack, or an air filter unit. The tetrafluoroethylene polymer has drawability and non-melt processability. The tetrafluoroethylene polymer has a ratio S.sub.2/S.sub.1 of 0.60 or more, where S.sub.2 represents an endotherm mJ/mg in a range of T.sub.0° C. or higher and 350° C. or lower, T.sub.0° C. is a temperature 2.5° C. lower than a temperature T.sub.p° C. (340≤T.sub.p≤345) at which a minimum point is given on a heat-of-fusion curve obtained by measuring an unbaked polymer for measurement having no history of heating to a temperature of 300° C. or higher using a differential scanning calorimeter at a temperature-increasing rate of 2° C./min, and S.sub.1 represents an endotherm mJ/mg in a range of 320° C. or higher and T.sub.0° C. or lower.

Filter media comprising adsorptive particles are generally described. In some embodiments, the adsorptive particles are present in a relatively large amount, in a layer discrete from one or more other layers and/or fiber webs also present in the filter media, and/or in a layer that comprises a relatively low amount of fibers. In some embodiments, the filter media further comprises a non-woven fiber web comprising fibers with relatively small diameters.