This disclosure describes a filtration medium that is preferably glass-free or substantially glass-free. In some embodiments, the filtration medium preferably exhibits capacity and efficiency comparable to or better than similar glass-containing filtration media. The filtration medium includes bicomponent fibers, efficiency fibers (for example, PET fibers), and microfibrillated fibers. The efficiency fibers include fibers having a fiber diameter in a range of 1 micron to 5 microns and fibers having a fiber diameter of at least 0.1 micron and less than 1 micron.

A multi-functional air purification filter includes: a breathable support layer; a mesh layer provided on the breathable support layer; and a filter layer provided on the mesh layer, wherein at least a portion of the multi-functional air purification filter has a plurality of bends, and the mesh layer includes a coating layer of at least one of a photocatalytic material, an adsorption material, or a sterilizing material.

A filter medium is disclosed having a nonwoven layer, which has bicomponent fibres, and a melt-blown layer, which comprises polyester fibres having an average diameter (d1) of less than 1.8 μm. The thickness of the nonwoven layer is less than 0.4 mm at a contact pressure of 0.1 bar. At least 25% of the polyester fibres of the melt-blown layer have a diameter (d) of less than 1 μm.

A rigid, channel-framed, pleated air filter, with a plurality of linear bridging filaments on at least an upstream face of the pleated air filter media of the filter.

The disclosure relates to a mask including a perforated exterior shell sized to cover the nose and mouth of a user and constructed of one or more fabric layers, and a removable multi-layer nonwoven fabric insert sized to cover the nose and mouth of a user and adapted for abutting contact with the exterior shell, the nonwoven fabric including a layer of a spunbond material and a layer of meltblown material adjacent to the layer of spunbond material.

Charged polymeric webs, such as electret webs, include a thermoplastic resin and a charge-enhancing additive. The additives are a mercapto-benzothiazole salts or mercapto-benzoxazole salts. The electret webs may be a non-woven fibrous web or a film. The electret webs are suitable for use as filter media.

Air filter media comprising at least one active bead layer comprises an antistatic agent and polyethylenimine coated polymeric beads that can provide better formaldehyde abatement properties than incumbent activated carbon filters and can be prepared by using existing processing facilities for manufacture of incumbent activated carbon filters.

Charged polymeric webs, such as electret webs, include a thermoplastic resin and a charge-enhancing additive. The additives are substituted benzothiazole compounds or substituted benzoxazole compounds. The substituent groups may be hydroxyl, mercapto, or aromatic groups. The electret webs may be a non-woven fibrous web or a film. The electret webs are suitable for use as filter media.

Charged polymeric webs, such as electret webs, include a thermoplastic resin and a charge-enhancing additive. The charge-enhancing additive is a substituted-benzimidazole compound. The electret webs may be a non-woven fibrous web or a film. The electret webs are suitable for use as filter media.

Charged polymeric webs, such as electret webs, include a thermoplastic resin and a charge-enhancing additive. The charge-enhancing additive is a dual-function charge-enhancing additive that enhances the charge of the electret and also has anti-microbial properties. The additives are substituted-benzimidazole or substituted-benzothiazole compounds. The electret webs may be a non-woven fibrous web or a film. The electret webs are suitable for use as filter media.