Disclosed are exemplary embodiments of woven filtration fabrics that include core-sheath spun yarns in either or both of the warp and weft directions.

Problem: The present invention allows a fiber sheet to be densely charged with electric charge and provides an electret fiber sheet that has excellent dust-collecting characteristics. Solution: The electret fiber sheet according to the present invention is an electret fiber sheet in which the relationship between a* and b* measured by a spectrophotometer when a red positive charge toner and a blue negative charge toner are attached to the sheet satisfies the expression: [12{(b*)(a*)}.sub.Ave50].

A polymer, applications thereof, and method of making a nanofiber nonwoven product is disclosed which includes: providing a spinnable polyamide polymer composition comprising a solution of a polyamide in a suitable solvent, wherein the polyamide has a Relative Viscosity of from 30-300; a basis weight greater than 1 gm/m.sup.2, solution-spinning the polyamide polymer composition into a plurality of nanofibers having an average fiber diameter of less than 1 micron (1000 nanometers); and forming the nanofibers into said nonwoven product which thereby has an average nanofiber diameter of less than 1 micron (1000 nanometers). Preferably, the nonwoven product is solution-spun from a process selected from (i) centrifugal spinning using a rotating spinneret or (ii) 2-phase propellant-gas spinning including extruding the polyamide polymer composition in liquid form with pressurized gas through a fiber-forming channel. Suitable solvents include formic acid, sulfuric acid, trifluoroacetic acid, hexafluoroisopropanol (HFIP) and phenols including m-cresol.

A washing apparatus for a 3D-printed article is provided for the removal of support material from the article. The apparatus includes a glove isolation cabinet with a liquid-discharging nozzle to enable an operator to spray an article with a washing liquid, and a drain. A first filter arrangement receives liquid discharged from the cabinet. The washing liquid drains through the first filter arrangement under the influence of gravity but the first filter arrangement is located in a trough in which washing liquid that has passed through the first filter arrangement accumulates whereby, in use, one or more filters of the first filter arrangement are submerged to ensure filtered-out residue remains submerged in the washing liquid. A pump is provided to pump liquid that has passed through the first filter arrangement through a second filter arrangement adapted to filter out solid material equal to or greater than 5 m in size.

An internal combustion engine including a urea-water solution injection in the exhaust system, includes at least one urea-water solution tank, at least one pump, at least one intake line leading to the pump, at least one urea-water solution metering valve which is connected to the pump with the aid of a pressure line, and at least one return line which leads from the pump to the urea-water solution tank and at whose end opposite to the pump a filter element is situated, as well as at least one urea-water solution sensor situated in the urea-water solution tank.

A filter formed essentially from a staple fiber is provided. A nonwoven staple fiber is compressed in to a mat or sheet of selected porosity. The mat or sheet does not include a binder or bicomponent fibers. The staple fibers may be heat treated. The sheet is formed into a selected geometric shape and the staple fibers are thermally fused to bind the staple fibers into a porous filter element. The preferred shape is a helically wound tube or plural sheets, each sheet being self-overlapped and compressed to overlap another sheet. Each sheet is preferably heated and compressed individually and the sheets may be selected to have different porosities and densities.

Articles and methods involving filter media are generally provided. In certain embodiments, the filter media includes at least a first layer, a second layer, and an adhesive resin positioned between the first layer and the second layer. In some embodiments, the first layer may be a pre-filter layer or a support layer. The second layer may, for example, comprise fibers formed by a solution spinning process and/or may comprise fine fibers. In some embodiments, the adhesive resin may be present in a relatively low amount and/or may have a low glass transition temperature. The filter media as a whole may have one or more advantageous properties, including one or more of a high stiffness, a high bond strength between the first layer and the second layer, a high gamma, and/or a low increase in air resistance after being subjected to an IPA vapor discharge. The filter media may be, for example, a HEPA filter and/or an ULPA filter.

A filter mesh is provided that has warp threads and weft threads which are crosswise interwoven and together form a filter cloth having one side facing a filter cake when being in a position of use and one side facing a filtrate drain side. At least some of the warp threads are made of an ultra-high molecular weight polyethylene. For example, at least 25% of the warp threads are made of ultra-high molecular weight polyethylene.

Porous and/or curved nanofiber bearing substrate materials are provided having enhanced surface area for a variety of applications including as electrical substrates, semipermeable membranes and barriers, structural lattices for tissue culturing and for composite materials, production of long unbranched nanofibers, and the like. A method of producing nanofibers is disclosed including providing a plurality of microparticles or nanoparticles such as carbon black particles having a catalyst material deposited thereon, and synthesizing a plurality of nanofibers from the catalyst material on the microparticles or nanoparticles. Compositions including carbon black particles having nanowires deposited thereon are further disclosed.

A method for removing retroviruses from liquid samples and a nanofiber containing liquid filtration medium that simultaneously exhibits high liquid permeability and high microorganism retention is disclosed. Retroviruses are removed from a liquid by passing the liquid through a porous nanofiber containing filtration medium having a retrovirus LRV greater than about 6, and the nanofiber(s) has a diameter from about 10 nm to about 100 nm. The filtration medium can be in the form of a fibrous electrospun polymeric nanofiber liquid filtration medium mat.