Filter media comprising fluorinated water-repellent additives and/or water-repellent additives having minimal or no fluorine atoms are generally provided. Filter media disclosed herein may include fluorinated water-repellent additives but not water-repellent additives having minimal or no fluorine atoms, water-repellent additives having minimal or no fluorine atoms but not fluorinated water-repellent additives, or both fluorinated water-repellent additives and water-repellent additives having minimal or no fluorine atoms.

Filter media, filter elements, and methods for filtering an gas stream are described herein. In some embodiments, the filter media may comprise a fiber web comprising a plurality of fibers and having a particular oil repellency level. For instance, in certain embodiments, the surface chemistry of the fiber web may be tailored to impart a particular surface energy density that matches the surface energy density of the fluid (e.g., an oil, a lubricant, and/or a cooling agent) being removed from the gas stream. In some embodiments, the fiber web may be wrapped around a core. For example, the fiber web may be wrapped around the core such that it forms two or more layers around the core. In some cases, the fiber web may be perforated. In certain embodiments, an gas stream comprising a fluid (e.g., an oil, a lubricant, and/or a cooling agent) may be passed through the fiber web, filter media, and/or filter element such that at least a portion of the fluid coalesces on the fiber web. Fiber webs, filter media, and/or filter elements as described herein may be particularly well-suited for applications that involve filtering gas streams containing oil, lubricants, and/or cooling agents (e.g., gas streams generated by a compressor) though the media may also be used in other applications. Advantageously, the fiber webs, filter media, and/or filter elements described herein may significantly reduce or prevent fouling of the filter caused by oil or other liquids.

Filter media including a filtration layer comprising fibers (e.g., synthetic fibers) comprising a flame retardant and related components, systems, and methods associated herewith are provided. In some embodiments, a filtration layer may include a nonwoven web (e.g., wet-laid nonwoven web) comprising fibers including a certain flame retardant that has a relatively low concentration of or is substantially free of certain undesirable and/or toxic components (e.g., halogens). In certain embodiments, the nonwoven web may also comprise a blend of fibers. For instance, in some embodiments, the nonwoven web may also comprise a blend of coarse and fine diameter synthetic fibers that impart beneficial performance properties to the filtration layer. In some embodiments, the filtration layer may be designed to have a desirable flame retardancy (e.g., F1 rating, K1 rating) and performance properties without compromising certain mechanical properties (e.g., pleatability of the media) and/or environmental attributes (e.g., relatively low toxicity). Filter media described herein may be particularly well-suited for applications that involve filtering air, though the media may also be used in other applications.

An exhaust gas purification filter includes a cell assembly including cells each having a quadrangular cross-sectional shape and a partition wall, seal members, and a skin member. The partition wall has a porosity P1 of 50% to 70%, and the skin member has a porosity P2 of 50% to 70%, the porosity P1 and the porosity P2 satisfy a relationship P1<P2. A difference between the porosity P2 and the porosity P1 is 20% or less. The partition wall includes crossing portions, each cell has at least one part of an outer periphery defined by a corresponding one of the crossing portions, the at least one part is rounded to have a radius of curvature R, each cell has a radius r of a hydraulic diameter, the radius of curvature R and the radius r of the hydraulic diameter satisfy a relationship 0.2<R [mm]/r [mm]<1.

The present invention relates to a mask comprising a mask body for covering a wearer's face and wearing straps coupled to both sides of the mask body, the mask body comprising a filter member having: a support layer having a mesh structure; and a filter coating layer formed on the outer surface of the support layer and for filtering contaminants, wherein the filter coating layer is formed from a microfiber web eletrospinned on the support layer.

Filter media, such as electret-containing filtration media for filtering gas streams (e.g., air), are described herein. In some embodiments, the filter media may be designed to have desirable properties such as stable filtration efficiency over the lifetime of the filter media, increased normalized gamma, relatively low pressure drop (i.e. resistance), and/or relatively low basis weight. In certain embodiments, the filter media may be a composite of two or more types of fiber layers where each layer may be designed to enhance its function without substantially negatively impacting the performance of another layer of the media. For example, one layer of the media may be designed to have a relatively low basis weight and/or a relatively high air permeability, and another layer of the media may be designed to have stable filtration efficiency and/or a relatively high efficiency throughout the filter media's lifetime. The filter media described herein may be particularly well-suited for applications that involve filtering gas streams (e.g., face masks, cabin air filtration, vacuum filtration, room filtration, furnace filtration, respirator equipment, residential or industrial HVAC filtration, high-efficiency particulate arrestance (HEPA) filters, ultra-low particular air (ULPA) filters, medical equipment), though the media may also be used in other applications.

The present invention provides compositions comprising cellulose fibers and cellulose ester fibers and wet laid articles made from the compositions, as well as wet laid processes to produce these compositions. More specifically, the present invention provided compositions comprising cellulose fibers and cellulose acetate fibers and wet laid articles made from these compositions as well as wet laid processes to produce these compositions. The present invention also relates to developing a composition, process, wet laid product, or articles exhibiting any one of many desired benefits. The present invention relates a filtration article comprising a wet-laid composition comprising cellulose fibers and staple fibers.

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.

Disclosed herein is a degradable filter structures and protective coverings including degradable filter structures. The filter structures comprise cellulose acetate and optionally plasticizer. The filter structures and protective coverings described herein degrade more rapidly than other known protective coverings.

Filter media comprising polyethersulfone, related components, and related methods are generally described.