Abstract: 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.

Abstract: A filtration unit for the selective elimination of a target substance from a biological fluid comprising an external envelope, wherein the envelope encloses a filtering medium comprising: an upstream structure for eliminating at least the target substance comprising a stack of layers that are arranged to allow the flow of fluid through the layers in one direction comprising a non-woven material, and particles interposed between at least some of the layers, wherein the particles have an affinity for the target substance; and a downstream structure for retaining the particles comprising at least one layer of porous material.

Abstract: A filter and filter material for providing or treating potable water is provided. The filter includes a housing having an inlet and an outlet, a filter material disposed within the housing, the filter material formed at least in part from a mixture of a plurality of mesoporous and microporous activated carbon particles. Preferably, at least some of the mesoporous activated carbon filter particles are coated with a cationic polymer, and even more preferably, at least some of the particles are coated with a cationic polymer and silver or a silver containing material. Kits comprising filters and information relating to the reduction, killing or removal of bacteria, viruses, microbials, and TTHM are also provided.

Abstract: A novel composite of glass fiber paper and reinforcing material that is useful for high speed manufacturing of devices comprising it is disclosed. The composite is formed by pressing into a glass fiber paper, having multimodal (at least bi-modal) composition, a hydrophilic reinforcing material. The composite has anisotropic separation properties that are particularly useful for preparing a fluid fraction from whole blood. The preferred glass fiber paper comprises glass fibers such that there are a plurality of short fibers (6) having large diameters and long fibers (2) with smaller diameters. The preferred glass fiber paper also exhibits partial ordering. There are many more of the long fibers (2) with smaller diameters than of the short fibers (6) having large diameters. Also disclosed are several blood separator device designs for efficiently separating the fluid fraction of blood from whole blood using the composite.

Abstract: In a device and a process for continuous solid/liquid separation (filtration) of solid-liquid suspensions on moving filters, for example on rotating drum filters or belt filters, the active filtering layer contains a woven fabric material composed of synthetic fibres, which has an enhanced filtrate permeability and also an enhanced thermal stability with improved dimensional stability, and also improved mechanical strength compared with polypropylene fibres.

Abstract: A fiber material web of pulp fibers is made by pulp fibers being calendered and spot-connected or linearly connected without a binder in pressurized areas by fusion of the fiber bodies with generation of an embossed patter. The pulp fibers are chemically treated pulp fibers. The fiber material web is suitable for use in sanitary articles and as a filter material.

Abstract: Provided is a disposable multi-layered filtration device for the separation of blood plasma which can be applied to a biochip and appropriate for disposal uses. The filtration device for the separation of blood plasma includes: an upper substrate including a blood inlet; an intermediate substrate including a filtering unit for extracting blood plasma from blood flowing through the blood inlet; and a lower substrate including an air outlet, wherein the upper substrate, the intermediate substrate, and the lower substrate are stacked and adhered.

Abstract: Reactive geocomposite mats, and their method of manufacture, for treating contaminants in soil or water that allow the passage of essentially non-contaminated water therethrough. The geocomposite mat includes a pre-formed woven or non-woven geotextile, having a thickness of about 6 mm to about 200 mm, and having, a porosity sufficient to receive a powdered or granular contaminant-reactive material, contaminant-sorptive material, or a contaminant-neutralizing material (hereinafter collectively referred to as “contaminant-reactant material” or “contaminant-reactive material”) throughout its thickness, or in any portion of the thickness across its entire major surface(s). The powdered or granular contaminant-reactive material is disposed within the pores of the previously formed, high loft geotextile mat to surround the fibers, e.g.

Abstract: The invention concerns the production of filter materials for the purification and disinfection of water, water solutions and other liquids, as well as for sterilizing filtration of injections and other solutions, for concentration of biomolecules in physiological liquids, concentration and extraction of viruses, preparation of apyrogenic water, in biocatalytic diaphragm reactors. The invention solves the problems of a new filter material production, characterized by high sorption properties, high retention efficiency of submicron electronegative particles, microorganisms, submicron non-polar particles and chemical contaminations, and, at the same time, characterized by low hydrodynamic resistance. A base of filter material is the nonwoven organic synthetic polymeric fabric, modified by the aluminum hydroxide particles, fixed to the surface of base fibers for improvement of its sorption properties and for making it positively charged.

Abstract: A process and apparatus for removing elements is described herein.

Abstract: In the filtration of fluid materials, the removal of particulate from the moving stream requires substantial pressure to maintain flow and substantial capacity for removing particulate. The filters of the invention are rugged, high wet strength materials having a basis weight, permeability and efficiency suitable to obtain substantial reduction in particulate loading from liquid streams without plugging or mechanical failure. In particular, the filters of the invention permit the removal of substantial proportions of particulate from non-aqueous streams including lubricant oils, hydraulic fluids and other contaminated streams.

Abstract: There is disclosed a method of controlling pore size in a porous material comprising the steps of: providing a porous material comprising a plurality of interconnected auxetic fibres; and applying a tensile or compressive load to the porous material so as to vary the pore size of the porous material in order to produce a desired effect.

Abstract: A filter and filter media configured and arranged for placement in a fuel stream is disclosed. The filter and filter media allow for filtering of liquid fuels, such as diesel fuel. In certain embodiments the filter media includes a media fiber (such as glass) and a binder fiber (such as bicomponent) that combine to create a media structure having low solidity and relatively low compressibility, and which contain a pore structure that avoids premature fouling of the filter by fuel degradation products.

Abstract: A method for electrospraying nanosized metal or metal oxide particles onto a substrate. A metal oxide deposited fibrous material comprising a substrate, fibers and metal oxide particles may be made using the method. The material may be a flexible and porous fibrous matrix on which metal oxide particles may be uniformly deposited on a surface thereof. In an exemplary embodiment, the invention is directed to an electrospun nanofibrous material on which electrosprayed photocatalytic metal oxide particles are uniformly deposited without agglomeration.

Abstract: A filter medium comprises a modified cross-section fiber (A) having a fiber diameter between 40 and 70 ?m, an extremely fine fiber (B) having a fiber diameter of more than 5 ?m and no more than 10 ?m and a modified cross-section fiber (C) having a fiber diameter between 15 and 30 ?m, the content of the extremely fine fiber (B) is between 3 and 10% by mass, and the content of the modified cross-section fiber (C) is between 5 and 15% by mass based on 100% by mass of total the fibers in the filter medium.

Abstract: In the filtration of fluid materials, the removal of particulate from the moving stream requires substantial pressure to maintain flow and substantial capacity for removing particulate. The filters of the invention are rugged, high wet strength materials having a basis weight, permeability and efficiency suitable to obtain substantial reduction in particulate loading from liquid streams without plugging or mechanical failure. In particular, the filters of the invention permit the removal of substantial proportions of particulate from non-aqueous streams including lubricant oils, hydraulic fluids and other contaminated streams.

Abstract: A separation membrane complex where a carbon membrane is formed directly on a porous body (surface layer) and an intermediate layer has a thickness of 10 to 100 ?m can be used as a filter having improved flux and selectivity in comparison with a conventional one.

Abstract: An apparatus, system and method to facilitate fluid flow across a filter. The apparatus includes a filtration layer coupled to a support layer to form a composite filter. The support layer includes a hydroentangled cellulosic material forming a plurality of apertures. The apertures form channels to facilitate fluid flow across the filter while the support layer provides structural support to the filtration layer to enable lateral flow while preventing pleat deformation and collapse.

Abstract: The present invention relates to a ceramic filter device for molten metal filtration comprising a major ceramic phase and a minor carbon phase bonded by phosphate bond, a method for producing such filter devices, and the use of such filter devices for the filtration of molten steel.

Abstract: Disclosed are coalescers, systems, and methods for coalescing a mixture of two phases, namely a continuous phase and a dispersed phase. The disclosed coalescers, systems, and methods include or utilize one or more layers of media material having a distinct mean pore size and wettability. The disclosed coalescers, systems, and methods are effective for removing the dispersed phase from the mixture.

Abstract: Separation media, separation modules and methods are provided for separating water from a water and hydrocarbon emulsion and include a fibrous nonwoven coalescence layer for receiving the water and hydrocarbon emulsion and coalescing the water present therein as a discontinuous phase to achieve coalesced water droplets having a size of 1 mm or greater, and a fibrous nonwoven drop retention layer downstream of the coalescence layer having a high BET surface area of at least 90 m2/g or greater sufficient to retain the size of the coalesced water droplets to allow separation thereof from the hydrocarbon.

Abstract: A filter and filter material for providing or treating potable water is provided. The filter includes a housing having an inlet and an outlet, a filter material disposed within the housing, the filter material formed at least in part from a mixture of a plurality of mesoporous and microporous activated carbon particles. Preferably, at least some of the mesoporous activated carbon filter particles are coated with a cationic polymer, and even more preferably, at least some of the particles are coated with a cationic polymer and silver or a silver containing material. Kits comprising filters and information relating to the reduction, killing or removal of bacteria, viruses, microbials, and TTHM are also provided.

Abstract: A fluidic device containing a flow through chamber comprising an inlet port, an outlet port, and a fluid permeable, compressible matrix located in the chamber between said inlet port and said outlet port, and said compressible matrix having a higher flow resistance at higher compressions and a plurality of flow paths leading from said inlet port to said outlet port through said matrix comprising shorter and longer length flow paths, wherein said matrix is compressed in at least one dimension, being more strongly compressed along the shorter length flow paths than along the longer length flow path.

Abstract: Hydrogen generator coupled to or integrated with a fuel cell for portable power applications. Hydrogen is produced via thermocatalytic decomposition (cracking, pyrolysis) of hydrocarbon fuels in oxidant-free environment. The apparatus can utilize a variety of hydrocarbon fuels, including natural gas, propane, gasoline, kerosene, diesel fuel, crude oil (including sulfurous fuels). The hydrogen-rich gas produced is free of carbon oxides or other reactive impurities, so it could be directly fed to any type of a fuel cell. The catalysts for hydrogen production in the apparatus are carbon-based or metal-based materials and doped, if necessary, with a sulfur-capturing agent. Additionally disclosed are two novel processes for the production of two types of carbon filaments, and a novel filamentous carbon product.

Abstract: Acid-neutralizing filter media includes filter media fibers in combination with a strong base of small particle size and high surface area attached to and immobilized on the filter media fibers, and methodology therefore.

Abstract: A novel composite of glass fiber paper and reinforcing material that is useful for high speed manufacturing of devices comprising it is disclosed. The composite is formed by pressing into a glass fiber paper, having multimodal (at least bi-modal) composition, a hydrophilic reinforcing material. The composite has anisotropic separation properties that are particularly useful for preparing a fluid fraction from whole blood. The preferred glass fiber paper comprises glass fibers such that there are a plurality of short fibers (6) having large diameters and long fibers (2) with smaller diameters. The preferred glass fiber paper also exhibits partial ordering. There are many more of the long fibers (2) with smaller diameters than of the short fibers (6) having large diameters. Also disclosed are several blood separator device designs for efficiently separating the fluid fraction of blood from whole blood using the composite.

Abstract: The present invention discloses a membrane, optionally for use in sewage treatment. The membrane comprises a support membrane having a gas face biolayer on a gas face of the membrane and/or in the support membrane near the gas face, and a liquid face biolayer on a liquid face of the membrane and/or in the support membrane near the liquid face.

Abstract: An integrally formed multi-component structure is disclosed, the multi-component structure comprising a plurality of components, at least one of which is a three-dimensional bonded fiber fluid transmissive component comprised of a plurality of polymeric fibers bonded to each other at spaced apart contact points, the fibers collectively defining tortuous fluid flow paths, and wherein each component has an interface with at least one other component.

Abstract: An aggregate-removing filter material efficiently removes aggregates that are contained in a blood product for transfusion and may cause transfusion reactions without clogging, and exhibits excellent quality stability, and a blood product filtration method uses a filter apparatus that includes the aggregate-removing filter material and a leukocyte-removing filter material. The aggregate-removing filter material includes short fibers having a fineness of 0.7 to 4.0 dtex and a fiber length of 1 to 80 mm, and a ground fabric that includes long fibers, a fiber axis of the long fibers being oriented in a planar direction of the ground fabric, the short fibers being entangled with the ground fabric so that the aggregate-removing filter material has a total weight per unit area of 10 to 80 g/m2, and a layer of the short fibers forming a three-dimensional structure.

Abstract: The present invention is a reclamation unit (1) for a liquid comprising a housing (4) with a detachable upper (2) and lower (3) part in which the lower part (3) is connected with a base part (13). The lower part (3) comprises at least one heating unit (17) and inlets (14) and outlets (15,34). The upper part (2) encloses at least one filter unit (8). The lower part (3) and the base part (13) form an evaporation chamber (27), wherein the connection between the lower part (3) and the base part (13) includes a separator plate (19) which guides the liquid from the filter unit (8) onto side walls (37) of the evaporator chamber (27). The heating unit (17) protrudes into the evaporator chamber (27) with no conductive contact to the side walls (37).

Abstract: Reactive geocomposite mats, and their method of manufacture, for treating contaminants in sediment, soil or water that allow the passage of essentially non-contaminated water therethrough. The geocomposite mat includes a pre-formed woven or non-woven geotextile, that is needlepunched to an outer geotextile sheet layer to provide a high loft, structurally secured, pre-formed geotextile having a thickness of about 6 mm to about 200 mm, and having, a porosity sufficient to receive a powdered or granular contaminant-reactive material, contaminant-sorptive material, or a contaminant-neutralizing material (hereinafter collectively referred to as “contaminant-reactant material” or “contaminant-reactive material”) throughout its thickness, or in any portion of the thickness across its entire major surface(s). The powdered or granular contaminant-reactive material is disposed within the pores of the previously formed, high loft geotextile mat to surround the fibers, e.g.

Abstract: The fiber webs described herein may be incorporated into filter media and filter elements. The fiber webs may exhibit a low surface electrical resistivity. The fiber webs may also be sufficiently flexible and/or deformable so that they may be processed to include a series of waves (also known as flutes) that extend along the cross-machine direction.

Abstract: A method of treating low-pressure untreated drinking water includes providing a low-pressure water filter device, running low-pressure untreated drinking water from a source of low-pressure untreated drinking water through a low-pressure water filter of the low-pressure water filter device, removing bacteria and viruses from the low pressure untreated drinking water at a level of Filter Bacteria Log Removal of greater than about 2 logs and a Filter Viruses Log Removal of greater than about 1 log, and filling a storage housing with treated drinking water at greater than about 5 mL/min. The low-pressure water filter device may include a connector for connecting to an untreated drinking water source, a low-pressure water filter comprising mesoporous activated carbon particles and a storage housing. The average fluid contact time with the low-pressure water filter may be greater than about 2 seconds.

Abstract: Millimeter to nano-scale structures manufactured using a multi-component polymer fiber matrix are disclosed. The use of dissimilar polymers allows the selective dissolution of the polymers at various stages of the manufacturing process. In one application, biocompatible matrixes may be formed with long pore length and small pore size. The manufacturing process begins with a first polymer fiber arranged in a matrix formed by a second polymer fiber. End caps may be attached to provide structural support and the polymer fiber matrix selectively dissolved away leaving only the long polymer fibers. These may be exposed to another product, such as a biocompatible gel to form a biocompatible matrix. The polymer fibers may then be selectively dissolved leaving only a biocompatible gel scaffold with the pores formed by the dissolved polymer fibers.

Abstract: The disclosure relates to composite nonwoven fibrous webs including a population of sub-micrometer fibers having a median diameter less than one micrometer (?m), and a population of microfibers having a median diameter of at least 1 ?m. At least, one of the fiber populations is oriented, and each composite nonwoven fibrous web has a thickness and exhibits a Solidity of less than 10%. The disclosure also relates to methods of making composite nonwoven fibrous webs, and articles including composite nonwoven fibrous webs made according to the methods. In exemplary applications, the articles may be used as gas filtration articles, liquid filtration articles, sound absorption articles, surface cleaning articles, cellular growth support articles, drug delivery articles, personal hygiene articles, or wound dressing articles.

Abstract: Filter media, including those suitable for hydraulic applications, and related components, systems, and methods associated therewith are provided. The filter media described herein may include two or more layers, at least one of the layers having a relatively high percentage of microglass fibers. Additionally, the filter media may be designed such that the ratio of average fiber diameters between two layers is relatively small, which can lead to a relatively low resistance ratio between the layers. The filter media has desirable properties including high dirt holding capacity with low basis weight and a low resistance to fluid flow. The media may be incorporated into a variety of filter element products including hydraulic filters.

Abstract: A filter comprises a pad (1) of non-woven fibrous material, the pad having a substantially solid edge (13) of consolidated pad material which has been softened and subsequently hardened. The filter can be manufactured by providing a pad (1) of non-woven fibrous material, treating a peripheral region of the pad so as to form around the pad an edge of consolidated material (13) which has been softened, and subsequently allowing the edge of consolidated material to harden.

Abstract: Provided is an agglomeration for neutralizing acid mine drainage which includes a neutralizer and binder component consisting of steel slag in an amount of 75% to 95% by weight of the agglomeration, a sodium carbonate selected from the group consisting of soda ash and pulp liquor in an amount of 0.5% to 25% of the agglomeration, and, optionally, a lime component selected from the group consisting of limestone sand and slag. Further included is a dissolution control and filtration component consisting of an organic material in an amount of 0.24% to 15% by weight of the agglomeration selected from the group consisting of recycled newsprint, sphagnum peat moss, and sawdust. Next is a dispersant and neutralizer component consisting of a surfactant in an amount of 0.01% to 0.075% by weight of the agglomeration. The agglomeration may further comprise an oxidation component such as calcium peroxide, potassium permanganate, and hydrogen peroxide.

Abstract: The invention relates to a filter for the separation of leukocytes from whole blood, comprising a hydrophobic support material and a polymeric coating material, whereby the surface of the filter has a critical surface wetting tension in the range 50 to 80 dyn/cm and the polymeric coating material may be obtained by polymerisation reaction of mixtures comprising hydrophobic and hydrophilic monomers. The invention further relates to a method for production of said filter and devices for the separation of leukocytes from whole blood and the use of the filter.

Abstract: An immiscible lipophilic or hydrophilic liquid phase separated respectively from a continuous hydrophilic phase or a lipophilic phase liquid. Fibers having hydrophilic and hydrophobic properties are mixed, layered, etc., and formed into a filter. The separation mechanism involves capture of small droplets of the immiscible phase, coalescence of the small droplets into larger droplets as the immiscible liquid flows through the fiber filter, and release of the large immiscible droplets from the filter. With respect to separation of a hydrophilic immiscible fluid such as water in a lipophilic continuous fluid such as oil, the hydrophobic fibers will cause small water droplets to migrate towards the hydrophilic fibers whereby large droplets are formed on hydrophilic surface.

Abstract: A filter made of specifically arranged filaments. The filter has an upstream side where fluid enters and a downstream side where fluid exits. The filaments are greatest in diameter near the upstream side wherein the filaments continuously and gradually decrease in thickness toward the downstream side. The pores or spaces between the filaments are largest near the upstream side and decrease gradually toward the downstream side. This allows various size particles to become entrained in the filter in an evenly distributed manner.

Abstract: A multi-faceted family of non-woven webs that can take the form of a filter media, an adaptable forming process and a machine capable of making the range of media are disclosed. The filter medium can have a first surface and a second surface defining a thickness. The medium can comprise a region having a gradient. Such a gradient is formed by having a medium wherein the concentration of a fiber, a property or other component varies from one surface to the next surface. The gradient region of the media can comprise the entire thickness of the medium or can comprise a region that comprises a portion of the media thickness. The media are characterized by the presence of a continuous change of the fiber concentration or property within the region. A non-woven web can also be made comprising a planar fiber structure having a gradient. Such a web can comprise fibers having diameters that can range from 1 to 40 microns and a second fiber having a diameter that can range from 0.5 microns to about 5 microns.

Abstract: A multi-layer filter media including at least one layer of melt-blown fiber filter media and at least one layer of electrospun nanofiber filter media is provided. The multi-layer filter media of the present invention is configured such that the at least one layer of the melt-blown fiber filter media is on the upstream and the at least one electrospun nanofiber filter media is positioned downstream of the at lest one melt-blown fiber filter media.

Abstract: Disclosed is a method of providing potable water that includes providing a filter, passing water through the filter, and removing bacteria and viruses from the water with the filter. The filter comprises a housing having an inlet and an outlet and a filter material disposed within the housing, the filter material formed at least in part from a plurality of filter particles consisting of mesoporous activated carbon wherein at least a portion of the plurality of filter particles is at least partially coated with silver or a silver-containing material. A sum of mesopore and macropore volumes of the filter particles may be between about 0.2 mL/g and about 2 mL/g, wherein mesopore means an intra-particle pore having a diameter between 2 nm and 50 nm, and macropore means an intra-particle pore having a diameter greater than 50 nm, a total pore volume of the filter particles is greater than about 0.

Abstract: Disclosed is a method of providing potable water that includes providing a filter, passing water through the filter, and removing bacteria and viruses from the water with the filter. The filter comprises a housing having an inlet and an outlet and a filter material disposed within the housing, the filter material formed at least in part from a plurality of mesoporous wood activated carbon filter particles and particles selected from the group consisting of mesoporous wood activated carbon filter particles coated entirely with a cationic polymer, mesoporous wood activated carbon filter particles partially coated with a cationic polymer, and mixtures thereof. A sum of mesopore and macropore volumes of the filter particles may be between about 0.2 mL/g and about 2 mL/g, wherein mesopore means an intra-particle pore having a diameter between 2 nm and 50 nm, and macropore means an intra-particle pore having a diameter greater than 50 nm, a total pore volume of the filter particles is greater than about 0.

Abstract: Disclosed is a method of providing potable water that includes providing a filter, passing water through the filter, and removing bacteria and viruses from the water with the filter. The filter comprises a housing having an inlet and an outlet and a filter material disposed within the housing, the filter material formed at least in part from a plurality of filter particles consisting of mesoporous activated carbon. A sum of mesopore and macropore volumes of the filter particles may be between about 0.2 mL/g and about 2 mL/g, wherein mesopore means an intra-particle pore having a diameter between 2 nm and 50 nm, and macropore means an intra-particle pore having a diameter greater than 50 nm, a total pore volume of the filter particles is greater than about 0.4 mL/g and less than about 3 mL/g, and a ratio of the sum of the mesopore and macropore volumes to the total pore volume of the filter particles is greater than about 0.3.

Abstract: It is intended to provide a polymer for coating a leukocyte removal filter material which is excellent in the capability of removing leukocytes. It is further intended to provide a filter whereby both of leukocytes and platelets can be highly efficiently removed from a blood product containing leukocytes and platelets. The above objects can be achieved by using a polymer for coating a leukocyte removal filter material which comprises a unit originating in a hydrophobic polymerizable monomer, a unit originating in a polymerizable monomer containing a basic nitrogen-containing part, and a unit originating in a polymerizable monomer containing a protonic neutral hydrophilic part.

Abstract: A filter and filter material for providing or treating potable water is provided. The filter includes a housing having an inlet and an outlet, a filter material disposed within the housing, the filter material formed at least in part from a mixture of a plurality of mesoporous and microporous activated carbon particles. Preferably, at least some of the mesoporous activated carbon filter particles are coated with a cationic polymer, and even more preferably, at least some of the particles are coated with a cationic polymer and silver or a silver containing material. Kits comprising filters and information relating to the reduction, killing or removal of bacteria, viruses, microbials, and TTHM are also provided.

Abstract: A tufted nonwoven includes a face material which tufts a bonded nonwoven having a mixture of a plurality of bicomponent filaments 1 with a plurality of bicomponent filaments 2. At least bicomponent filaments 1 have component 11 and component 12. Component 11 exhibits a melting temperature Tm(11), and component 22 of the bicomponent filaments 2 exhibits a melting temperature Tm(22). Component 12 exhibits a melting temperature Tm(12), and component 21 of the second bicomponent filaments exhibits a melting temperature Tm(21), and Tm(12) is higher than Tm(21). The melting temperatures of components 11 and 22 and the melting temperatures of components 12 and 21 obey a relationship in which Tm(11) and Tm(22)>Tm(12)>first Tm(21) and optionally wherein the face material is bonded to bicomponent filaments 2 by a solidified melt of component 21. Also described are a bonded nonwoven and methods for their manufacture.

Abstract: A filter comprising a polymer material comprising a polymer matrix such as polyacrylonitrile containing dispersed metal oxide particles. The metal oxide particles are for example ferric oxide particles, and the polymer material contains generally 0.25-3% by weight of these particles. The filters are resistant to thermo-oxidation and have reduced shrinkage or degradation.