The present invention generally relates to a dual density air filtration media that comprises a plurality of nanofibers layers formed from nanofibers having different fiber diameters. Due to the presence of these multiple nanofiber layers with different nanofiber diameters, the resulting filtration media of the present invention comprises a gradient density. In particular, the present invention uses a novel combination of two or more layers of nanofibers made via an electrospinning process, wherein the nanofiber layers made up from different fiber sizes are strategically applied to a cellulose or synthetic base material or substrate, to thereby maximize the filtration efficiency and dust holding capacity of the resulting filtration media.

A filter may remove PM.sub.2.5 and/or other airborne pollutants, which filter has fibers of an average diameter of no more than 500 nm, the fibers of at least 90 wt. % polyacrylonitrile, relative to all fibers in the filter; and a catalyst of at least 90 wt. % TiO.sub.2, relative to all catalytic metals in the filter, dispersed onto the fibers. The fibers need not be charged. The TiO.sub.2 may be condensed or precipitated onto the fibers out of a liquid containing the TiO.sub.2 and the fibers by simple methods. The catalyst may be activated by UV irradiation to decompose particulate matter having an average particle size of 2.5 μm or less, i.e., PM.sub.2.5, and/or other airborne pollutants from air. Such filters may be implemented around areas of vehicle traffic, e.g., as elements of traffic lights, and may be used to controllably purify polluted air.

The present invention relates to a sheet filter material, in particular having an aerosol filter function and/or a particle filter function, preferably having a protective function against chemical, biological and/or chemical harmful and toxic substances, and to a method for the production thereof. The sheet filter material is particularly suitable for producing protective equipment, protective objects, sports and leisure clothing and filters and filter materials of all types.

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.

In order to address the sustainability and environmental issues associated with conventional HVAC filters, inventive HVAC filters have been developed that are completely biodegradable and compostable and exhibit Minimum Efficiency Reporting Value (MERV) ratings that are superior to conventional HVAC filters. More particularly, it has been discovered that biodegradable electrospun nanofibers can be used to produce biodegradable HVAC filters that exhibit superior filtration performance relative to conventional HVAC filters produced from polypropylene electrostatic media or triboelectric nonwoven media.

A high-adsorption-performance nanofiber filter medium includes a support material and a composite nanofiber filtration layer that includes multiple nanometer composite nanofiber layers deposited and stacked on the support material. The nanometer composite nanofiber layer includes first, second, and third nano-powder composite nanofibers, which are uniformly mixed by means of an airflow or are sequentially laminated to form the nanometer composite nanofiber layer. The nanometer composite nanofiber layer formed through sequential lamination includes first, second, and third nanofiber layers. The first nanofiber layer includes multiple first nano-powder composite nanofibers. The second nanofiber layer is stacked on the first nanofiber layer and includes multiple second nano-powder composite nanofibers. The third nanofiber layer is stacked on the second nanofiber layer and includes multiple third nano-powder composite nanofibers. The composite nanofiber filtration layer is formed of multiple nanometer composite nanofiber layers, so that the high-adsorption-performance nanofiber air filter medium shows improved performance.

A filter element for the filtration of the incoming cabin air of vehicles is disclosed. The filter element can be readily regenerated and reused in a dust-loaded environment. The filer element includes a main body formed from at least one filter medium. The main body has an inflow side and an outflow side. The filter element is used as a regenerable filter element for the filtration of the incoming cabin air in a vehicle which is subjected to elevated dust loading. A coating of nanofibers and/or a diaphragm is arranged on the inflow side of the main body.

A filter cartridge has a filter medium that is formed in such a way that it surrounds a central through-passage, wherein the central through-passage has a first opening and ends at a cartridge base, and wherein the filter medium extends between the first opening and the cartridge base and thereby forms an elongated filter body, which may influence the average ascent speed of air and bring about an optimum filtration operation, wherein the filter medium is rectangular or square-shaped at one end of the filter cartridge and is rounded at the other end.

A high efficiency particulate air filter for the capture of virus particles is disclosed. The filter includes a coform three-dimensional fibrous matrix comprising a population of fibrillated polymeric nanofibers and a population of microparticles homogenously distributed throughout the fibrous matrix. In an embodiment, the microparticles are ion exchange resins. The virus particles are captured by the fibrous matrix and bind to the to the surface of the resins by permanent electrostatic forces and inactivated by the biocidal agent. A process for removing virus particles from an aerosol is also disclosed. The filter provides at least a log.sub.10 reduction value (LRV) greater than 3 for virus particles with a diameter smaller than 0.3 microns with a pressure drop of less than 200 Pascal at an aerosol face velocity of 5.3 cm/s.

Provided are an air permeable vent filter, and a headlight assembly comprising the same. The air permeable vent filter has a body in which a nanofiber web, which comprises a plurality of pores and is formed by accumulating a nanofiber electrospun from a spinning solution in which a polymer material and a solvent are mixed, is spirally wound, and the air permeable vent filter implements an air permeable filter function of allowing air to pass through from one lateral side of the body to the other lateral side and blocking liquids and solids.