A filtration media including at least a first nonwoven fabric having at least one meltblown layer in provided. The at least one meltblown layer includes a plurality of meltblown fibers having an average diameter from about 1 to about 5 microns. Methods of making a filtration media are also provided. Facemasks including such filtration media are also provided.

A washable, high efficiency mask has a first, inner layer, a second, intermediate layer, and a third, outer layer. The second, intermediate layer is a filter media that achieves the 95% particulate filtration efficiency (PFE)/bacterial filtration efficiency (BFE) filtration. The second, intermediate layer is bonded to a layer adjacent thereto.

A particle filtration system that includes first, second and third filter segments that each include several first, second and third filters. Each first, second and third filter includes a fibrous layer sandwiched between a pair of surface or outer layers. The range of pore sizes of each first, second and third filter varies according to the density of the surface layers relative to the fibrous layers.

A nano silver active filter element comprises a filter element body which comprises sheet filter papers stacked of layered composite structures, the sheet filter papers successively comprises a nano silver antibacterial layer, a filter layer and a protection layer from an air inlet surface to an air outlet surface; the nano silver antimicrobial layer is prepared from phenolic complex fibers loaded with nano silver particles.

An air filter medium includes a first porous PTFE membrane and a second porous PTFE membrane. The air filter medium (10) has a first main surface and a second main surface, and the first porous PTFE membrane and the second porous PTFE membrane are arranged so that an air flow moving from the first main surface to the second main surface passes through the first porous PTFE membrane and subsequently through the second porous PTFE membrane. A thickness of the first porous PTFE membrane is in the range of 4 to 40 μm and a specific surface area of the first porous PTFE membrane is 0.5 m.sup.2/g or less.

The present invention relates to a filter medium being at least formed of a pre-filter substrate laminated with a fine-filter substrate by means of a third binder, wherein the pre-filter substrate comprises synthetic fibers and a first binder, the pre-filter substrate working as a combined surface and depth filter, and the fine-filter substrate comprises at least a second binder and one of synthetic fibers and inorganic fibers.

A system and method for laminating filter media can include applying an adhesive to a layer of the filter media and curing the adhesive. A multilayer filter assembly can include a first and a second layer laminated together using an inorganic adhesive.

The present invention relates to a dust collecting filter and a process for manufacturing the same. Specifically, according to an embodiment of the present invention, the filter medium contained in a dust collecting filter comprises a first nonwoven fabric layer, a porous layer, a second nonwoven fabric layer, and a polypropylene melt-blown layer sequentially laminated, wherein the melt-blown layer has a melt index and a basis weight in specific ranges, and the first nonwoven fabric layer and the second nonwoven fabric layer have a sum of the basis weights in a certain range, whereby it is possible to enhance the sustainability, processability, and bendability of the filter medium, enhance the workability at high temperatures and adhesion, and further enhance the durability and life span characteristics of the filter.

Fibrous filter medium that includes a surface-loading filter layer comprising fine fibers having an average diameter of less than 1 micron; a depth loading filter layer; and a support layer; wherein the layers are configured and arranged for placement in a gas stream with the surface loading filter layer being the most upstream layer.

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.