A nonwoven fabric, including fibers, in which the fibers have an elongational viscosity, as measured under conditions at an elongational strain rate of 2.5×10.sup.2 (1/s) and a temperature of 160° C., of from 430 Pa.Math.s to 1200 Pa.Math.s, and a ratio of the elongational viscosity (Pa.Math.s) to a shear viscosity (Pa.Math.s) of the fiber, as measured under conditions at a shear strain rate of 2.5×10.sup.2 (1/s) and a temperature of 160° C., is from 35 to 65.

Charged polymeric webs, such as electret webs, include a thermoplastic resin and a charge-enhancing additive. The additives are substituted heterocyclic thiolate salts. The heterocyclic thiolate salt has 2 nitrogen groups and a third group that may be an NH, N—NH.sub.2, O, or S group. The substituent group is an aromatic or heterocyclic aromatic group. The electret webs may be a non-woven fibrous web or a film. The electret webs are suitable for use as filter media.

The present invention has an object to provide a blood processing filter that is excellent in the filtration rate. The object can be solved by a blood processing filter comprising a container having an inlet and an outlet for blood, and a filter medium disposed between the inlet and the outlet of the container, wherein the filter medium comprises a filter element, an average thickness of the filter medium is 7 to 12 mm, and a standard deviation in thickness of the filter medium is 0.30 to 0.80 mm.

A method for filtering particulate down to 0.5 micron from cooking oil at a filtration temperature of up to 425° Fahrenheit is provided. The method includes providing a filter having a non-woven panel of randomly oriented fibers of polyphenylene sulfide (PPS) material and exposing the filter to the oil for a period of time while applying a pressure or vacuum to move the oil through the filter for filtering particulate from the cooking oil.

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.

Provided is a filter medium. A filter medium according to an embodiment of the present invention comprises: a first porous support body which has been electrostatically treated; and a nanofiber web which is disposed on one surface of the first support body and formed by accumulating nanofibers. Accordingly, excellent air filtering efficiency is obtained even for fine dust of PM 2.5 or below, and furthermore, deterioration in air filtering efficiency may be prevented or minimized even when usage is extended for a long period of time. Therefore, the filter medium and the composite filter according to an embodiment of the present invention can be widely utilized as media of filters for various air filtering devices.

It is provided that a layered body having excellent absorption speeds of fuel and the like to the filter media. A layered body comprising a first base material and a second base material, wherein the first base material and the second base material are adhered to each other via an adhesive, the first and second base materials each contain a phenol-based resin and an aliphatic hydrocarbon detected during a retention time of 12.0 to 30.0 minutes under pyrolysis-gas chromatography mass spectrometry (PY-GC/MS), and the adhesive contains 65 mol % or more of a butylene terephthalate unit and 5 mol % or more of a butylene isophthalate unit, and has an acid value of not larger than 100 eq/ton, a glass transition temperature of −10 to 60° C., and a specific gravity of not less than 1.20.

The present disclosure provides a filter for removing contaminants from a liquid or gaseous medium including a woven or nonwoven sheet of entangled carbon nanotubes. The present disclosure also provides a method for reducing the concentration of contaminants in a liquid or gaseous medium by contacting the liquid or gaseous medium with the filter.

A method for preparing a composite filter medium (1), comprising a step of forming a first filter medium (8) through deposition of nanofibers (4) on a base fabric (2) through an electrospinning process and a step of covering said filter medium (1) by plasma deposition of a coating (7) on said first filter medium (8) in a vacuum chamber (9). According to the invention, after the electrospinning process and before the plasma deposition of the coating (7), a degassing step of the base fabric (2) and of the nanofibers (4) forming the aforementioned first filter medium (8) is provided inside the same chamber (9). With respect to the known filter media, that of the invention offers the advantage of maintaining the desired level of water and oil repellency, due to the formation of a completely polymerized coating strongly adhering to the surface of the base fabric and of the nanofibers.

The present invention relates to a sheet filter material, in particular having an aerosol filter function and/or a particle filter function, preferably having a protective function against chemical, biological and/or chemical harmful and toxic substances, and to a method for the production thereof. The sheet filter material is particularly suitable for producing protective equipment, protective objects, sports and leisure clothing and filters and filter materials of all types.