Nonwoven multilayer structures having at least two nanofiber layers are described herein. The nonwoven multilayer structure may have two nanofibers layers that have different properties from each other, such as fiber diameter. One nanofiber layer may be produced by an electrospinning process, while another nanofiber layer may be produced by a melt blown process.

The present invention provides a filter material comprising an antistatic substrate having a predefined antistatic capacity, and one or more layers of nanofibers applied on the substrate. The one or more layers of nanofibers may be fabricated to have gradient structure in various parameters including thickness of nanofiber layer, nanofiber pore size, nanofiber diameter, nanofiber content and the like to suit different filtration applications. The present invention also provides a face mask comprising the filter material and a method for making the filter material.

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.

The invention relates to a polymeric fabric comprising an outer functional layer having hydrophobic and oleophobic characteristics made of a first compound, and a second functional layer having hydrophobic characteristics made of a second compound, wherein the first and the second compound differ from each other. Further the outer functional layer at least partly coats the second layer. Additionally, the invention relates to a method of producing a polymeric fabric and an apparatus for producing a polymeric fabric.

Provided is an antiviral filter medium. An antiviral filter medium according to one embodiment of the present invention includes a first member provided with an antiviral coating layer formed of fibers and including, on part or all of the outer surface of the fibers, an antiviral fusion protein in which an antiviral motif is bound to an adhesive protein. Accordingly, the antiviral filter medium exhibits antiviral properties, is excellent in filtration efficiency and ventilation amount (or flow rate), and has low pressure loss. In addition, the antiviral filter medium is characterized in that the coating layer exhibiting antiviral properties retains adhesiveness for a long period of time after being attached to the surface. Moreover, the antiviral filter medium can retain antiviral activity for a long time without loss of the antiviral activity due to external conditions during production, storage, and use.

Filter media comprising a pre-filter layer and related components, systems, and methods associated therewith are provided. In some embodiments, the pre-filter layer may be designed to impart desirable properties to the filter media, such as a high gamma and/or long service life, while having relatively minimal or no adverse effects on another property of the filter media that is important for a given application. For instance, a pre-filter layer may be used to improve the upstream removal of fine particulate matter, which may clog a downstream efficiency layer comprising submicron fibers and reduce filtration performance. The pre-filter layer may be configured to increase service life and/or increase the gamma of the filter media. Filter media, as described herein, may be particularly well-suited for applications that involve filtering air, though the media may also be used in other applications.

Disclosed is a porous support including fine porous structures formed between nanofibers, wherein the fine porous structures have a porosity of 50% to 90%, a pore size of 0.01 μm to 10 μm and an air permeability of 0.01 to 7 sec/100 cc.Math.air, and the porous support has a thickness of 5 μm to 50 μm, a method of manufacturing the same and a reinforced membrane including the same.

Embodiments of the present disclosure generally relate to coated substrates having, e.g., anti-viral properties, to articles including the coated substrates, and to processes for making such coated substrates and articles. In an embodiment, a mask for preventing infection by a virus is provided. The mask includes a coated substrate having a breathing resistance (95 L/min, EN 149:2001) of about 6 mbar or less and a water droplet absorption time of less than about 5 seconds. The coated substrate includes a non-woven fabric having a weight of about 120 g/m.sup.2 or less according to ASTM D3776, and mineral oxide particles, iron oxide particles, or both, coupled to at least a portion of the non-woven fabric.

A face mask is disclosed. The face mask includes a mask pad adapted to cover a nose and a mouth of a wearer and allows a passage of air therethrough to the wearer and restricts a passage of microbes. The mask pad has at least a surface protected by a sulfonated polymeric layer for killing at least 90% microbes within 120 minutes of contact with at least a surface of the face mask. The sulfonated polymeric layer consists essentially of a sulfonated polymer, the sulfonated polymer being selected from the group of perfluorosulfonic acid polymers, polystyrene sulfonates, sulfonated block copolymers, sulfonated polyolefins, sulfonated polyimides, sulfonated polyamides, sulfonated polyesters, sulfonated polysulfones, sulfonated polyketones, sulfonated poly(arylene ether), and mixtures thereof.

A filtering film includes a porous substrate and a membrane disposed on the porous substrate. The membrane includes a plurality of fibers of one or more bio-degradable materials. The fibers have an average diameter of about 50 nm to about 3 μm. The one or more bio-degradable materials has a melt flow index of at least 5 g/10 min at 210° C. at a load of 2.16 kg.