A panel filter includes a first media layer constructed from a first material that is permeable to air and impermeable to particulates of a targeted size or type, a support grid, and a second media layer constructed from a second material that is permeable to air. The second media layer is adhesively coupled to the first media layer without a mechanical seal. When the first media layer and second media layer are coupled, the support grid is retained between the first media layer and the second media layer.

A bio-functional air filter medium is provided with a first filter layer that retains particles and at least one bio-functional carrier coated with or having embedded therein antimicrobial material and an anti-allergenic material. An air filter element having the bio-functional air filter medium is also disclosed. The bio-functional air filter medium is adapted to bind and capture allergens and block metabolism of bacteria while filtering air in high flow, low pressure drop residential or HVAC applications.

In a method for producing a filter medium, at least one substrate layer of a nonwoven comprising cellulose fibers and/or synthetic polymer fibers is provided and a fiber layer of polymer fibers is deposited on the at least one substrate layer. Prior to depositing the fiber layer, a solvent is applied to the at least one substrate layer, wherein a material of the substrate layer and/or a material of the fiber layer is soluble in the solvent. A filter medium produced by the method has material-fused connections at crossing points of the polymer fibers and/or cellulose fibers of the substrate layer with the polymer fibers of the fiber layer.

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 bio-functional air filter medium is provided with a at least one particle filtration layer that retains particles and at least one bio-functional carrier coated with or having embedded therein antimicrobial, anti-viral and anti-allergenic materials. An air filter element having the bio-functional air filter medium is also disclosed. The bio-functional air filter medium is adapted to bind and capture allergens and block metabolism of bacteria, and provide anti-viral activity to effectively inhibit/deactivate viruses, all while filtering air in high flow, low pressure drop residential, HVAC or air purifier applications.

A filtration article including a composite filtration structure, a seal region positioned within the composite filtration structure, and an attachment weld that interconnects the seal region and an outer casing is provided. The composite filtration structure includes a stacked filter material including at least two fluoropolymer membranes and a support layer. The support layer may be formed of a thermoplastic or thermoset polymer. When heated, the polymer in the support layer melts and flows into the fluoropolymer membranes. In exemplary embodiments, the polymer is imbibed through the thickness of the fluoropolymer membranes. The attachment weld may be positioned at any location within the seal region so long as the attachment weld is positioned a distance from the outer periphery of the composite filtration structure. The filtration article is small in size, is lightweight, and may be used as a sterilizing grade filter. Methods of producing the filtration article also provided.

Thermoplastic bicomponent binder fiber can be combined with other media, fibers and other filtration components to form a thermally bonded filtration media. The filtration media can be used in filter units, such as breather caps. Such filter units can be placed in the stream of a mobile fluid and can remove a particulate and/or fluid mist load from the mobile stream. The unique combination of media fiber, bicomponent binder fiber and other filtration additives and components provide a filtration media having unique properties in filtration applications.

An air filter for automobiles includes, a main filter and a prefilter, wherein the prefilter comprises a nonwoven synthetic fiber having an average density of 0.01 to 0.5 g/cm.sup.3 and a moisture absorbent is adsorbed to the prefilter.

A droplet coalescing filter cartridge is provided. The filter cartridge includes an outer filter tube and an inner filter tube disposed within the outer filter tube, and is configured to provide parallel filtration of a fluid flow. The filter includes a depth media configured to coalesce fine droplets or aerosols from an air flow. The filter cartridge is suitable for use in a coalescing filter assembly including the filter cartridge and a secondary filter element.

A filter, a method of operating and a method of making is provided. The filter includes multiple filter layers in plurality with the structural integrity of the filter as a whole. The layers are perforated to allow any type of filtering such as but not limited to osmosis filtering, reverse osmosis filtering, static filtering, and sifting or sieve-like filtering effect as the media being filtered passes through the layers as the outermost layer collects most debris. The layers further have an adhesive relationship with each other layer and an optional base layer, so that each layer may be individually removed and the one beneath is exposed as a cleaner filter surface.