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 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.

An anti-propylene mask and method for preparation thereof is provided; the anti-propylene mask includes a fiber cloth contact layer, an antistatic non-woven fabric layer and a fullerene/nano titanium dioxide spunbond layer which are arranged in sequence; the fullerene/nano titanium dioxide spunbond layer is made by spun-bonding the modified resin material into a fiber web; the raw materials of modified resin materials include matrix resin, carboxylated fullerene derivatives, nano titanium dioxide, a lubricant, and a coupling agent; the modified resin material is prepared by following method: the carboxylated fullerene derivative is mixed and reacted with the nano titanium dioxide to prepare the carboxylated fullerene derivative-modified nano titanium dioxide, which is then blended and extruded with the remaining components in the raw material, and thus prepared. The mask can prevent propylene from entering the human body through the human respiratory organs and has a good anti-propylene effect.

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.

A spunbond non-woven fabric includes a thermoplastic continuous filament. A CV value of air permeability of the non-woven fabric is 15% or less, bending resistance in a machine direction of the non-woven fabric is 40 mN or more and 80 mN or less, the non-woven fabric includes a projected part and a recessed part, and in a non-woven fabric cross-section, a thickness from one surface to another surface of the projected part is determined to be t.sub.A, a thickness from one surface to another surface of the recessed part is determined to be t.sub.B, and respective distances from one surface of the projected part to one surface of the recessed part are determined to be t.sub.C and t.sub.D (t.sub.C<t.sub.D), and the non-woven fabric has a relation represented by formulas (1) and (2) below:

0.5≤1−t.sub.B/t.sub.A<1.0  (1)

0.65<t.sub.C/t.sub.D<1.0  (2).

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.