Abstract: A method for filtering liquids having a dielectric constant less than 10 is disclosed. The method includes the step of filtering a liquid through a porous layer of an electret, the electret consisting of a fibrous sheet having a surface charge density of at least 5.times.10.sup.-11 coulombs/cm.sup.2, wherein on the upstream side of the electret is laminated another porous layer having at least a porosity or an average fiber diameter greater than that of the electret layer. The upstream layer may consist of either a fibrous electret layer, or an uncharged fibrous layer.

Abstract: An apparatus for the separation of blood components, specifically for the removal of white blood cells and blood platelets from blood comprises a tubular housing providing at one end thereof with a blood inlet and at the other end thereof with a blood outlet and an aggregate layer of fibers capable of sequestering white blood cells and blood platelets packed in the housing. The aggregate layer of fibers comprises a blood inlet side layer of a bulk density of not less than 0.16 g/cm.sup.3 and less than 0.21 g/cm.sup.3 and a blood outlet side layer of a bulk density of not less than 0.21 g/cm.sup.3 and not more than 0.23 g/cm.sup.3 and is packed in a ratio in the range of 0.04 to 0.09 g per ml of the flow volume of blood under treatment.

Abstract: Devices for the depletion of leukocytes in blood products, preferably comprising an upstream porous element including means for removal of gels, at least one intermediate porous element including means for removal of microaggregates, and a downstream element including means for removal of leukocytes by both adsorption and filtration, preferably with at least one of the elements having been modified to a CWST in excess of 53 dynes/cm.

Abstract: An instrument for separation of liquid from solid material comprising: a volume filtration layer having a void volume of not less than 90% which is composed of fibrous material; and a pressure-resistant housing having a liquid entrance and a liquid exit which encases said volume filtration layer therein in such a manner that the side face of the volume filtration layer is tightly arranged in contact with an inner face of the housing so as to prevent passage of the solid material along the interface between the side face of the volume filtration layer and the inner face of the housing.

Abstract: A filter medium for filtration of a fluid to flow therethrough from an upstream side to a downstream side thereof, said filter medium comprising a substrate having a density gradient wherein the density is high on the upstream side and low on the downstream side of the substrate.

Abstract: An apparatus for the recovery of cell material from body fluids is described which consists of a filter with a filter material arranged in one or more layers and not soluble in cell-fixing liquids, such as isopropanol. The filter material consists of a single textured or crimped filament yarn. Preferably, the filaments of the filament yarn are made of synthetic polymers. In contrast to the known apparatus, consisting essentially of a filter cartridge which contains as filter material synthetic fibers dissolvable in alcohol or in an alcohol-water mixture, the use of the apparatus of this invention produces a cell sample which is not interspersed with particles of the filter material. Besides, the present invention permits to achieve very low cell losses, and cell damage does not occur. Body fluids from which cell material may be recovered with the apparatus according to this invention are for example, urine, liquor, pleural effusions or fluids from the abdomen area.

Abstract: A fluid filter element comprises a first filtering medium and a second filtering medium. The first filtering medium includes a nonwoven batt having a marginal edge portion circumscribing the main body portion of the batt in which the fibers are stiffened to provide a support and sealing structure. The second filtering medium includes a nonwoven batt which has been welded into a convoluted drape and which has a circumferential edge portion which provides a supported and sealing structure. The circumferential edge portion is sealed to the marginal edge portion when the fluid filter element is assembled.

Abstract: A filter unit for removing leukocytes from a leukocyte-containing suspension, comprising a container provided with at least one inlet conduit means and at least one outlet conduit means, the container having a main filter packed therein in the form of a non-woven fabric which comprises fibers of an average diameter of from 0.3 .mu.m to less than 3 .mu.m and which has a bulk density of from 0.01 g/cm.sup.3 to 0.7 g/cm.sup.3, and which has an average distance between two adjacent fibers defined by the following equation (1) of from 0.5 .mu.m to 7.0 .mu.m: ##EQU1## wherein y is the average distance between two adjacent fibers in micron; x is the average diameter of fibers in microns; .rho. is the density of the fibers in g/cm.sup.3 ; D is the bulk density of the filter in g/cm.sup.3 ; and .pi. is a circular constant.

Abstract: A method for making a precision wound tubular shaped filter cartridge wherein a filter medium comprising a roving is wound about a central foraminous core to provide a base inner and an outer helical winds of roving each provided with pluralities of both axial and circumferential flow passages wherein the circumferential flow passages of the inner and outer wind are radially aligned at the interface of the winds to provide unrestricted flow paths between the inner and outer wind.

Abstract: A multilayer filter material is described which comprises a coarse and a fine filter layer, while the individual filter layers contain a share of natural fibres and are interconnected with each other on the paper machine, without the use of a bonding agent, whereby the coarse filter layer consists of a mixture of natural and synthetic fibres and at least one part of said synthetic fibres is structured, and synthetic fibres lying on the surface of the coarse filter layer protrude from the plane of the filter material.Moreover a process for the manufacture of the multilayer filter material and its use is described.The inventive multilayer filter material is distinguished against comparable conventional filters by an increased service life and a better degree of separation.

Abstract: A method for in-line filtration of flowing liquids wherein composite filtering of mechanical entrapment type and of absorptive character is implemented in relative measures adapted to meet both flow rate and contaminant filtration requirements. The invention effects jointly operative steps of mechanical and absorptive oil-based contaminant removal with accommodation of desired flow rate of automotive coating liquid by a practice wherein these two filtration techniques are effected concurrently throughout a length of conduit assigned to filtering. The invention is practiced through the use of a fibrous body, comprised in first part of oil-absorptive fiber and in second part of fibrous matter substantially non-absorptive to oil contaminants, the second part fibrous matter being arranged to selectively entrap oil contaminants and prevent absorption thereof by such oil-absorptive fiber.

Abstract: Synthetic, organic, polymeric membranes were prepared from polyethylenimine for use with pervaporation apparatus in the separation of ethanol-water mixtures. The polymeric material was prepared in dilute aqueous solution and coated onto a polysulfone support film, from which excess polymeric material was subsequently removed. Cross-links were then generated by limited exposure to toluene-2,4-diisocyanate solution, after which the prepared membrane was heat-cured. The resulting membrane structures showed high selectivity in permeating ethanol or water over a wide range of feed concentrations.

Abstract: A tubular filter which is primarily intended for filtration of liquid flowing substantially radially towards the interior of the filter. The filter comprises two layers (10, 11) of mineral wool. An interior layer (10) has the fibres oriented substantially concentrically to the tube axis and an outer filter layer (11) of mineral wool has the fibres oriented substantially radially to the tube axis. The material of the tubular filter must be arranged so that its density increases from the outer portion of the tubular filter towards its inner portion.

Abstract: A filter element and method for making it include the steps of providing a pleated paper filtering media and providing a batt-like filtering media containing thermoplastic fibers which is slightly larger than the pleated paper filtering media. A ring-shaped die is used in a press to apply heat and pressure to the edges of the batt-like filtering media while accommodating the rest of the batt-like filtering media in the aperture of the die. Accordingly, a stiffened wall is provided which circumscribes the pleated paper filtering media. The pleated paper filtering media is attached to the stiffened, fluid-impermeable wall to provide a fluid-impermeable seal therebetween. A perimetrically-extending flange gasket is simultaneously formed around the edge of the batt-like media, so that the latter can be sealingly engaged in an air cleaner housing.

Abstract: A fluid filter and method for its manufacture in which an air laid batt is formed consisting of a randomly arrayed mixture of thermoplastic fibers and fibers which are not thermoplastic. The batt is cut into sections and is formed into cup-shaped articles in a heated mold. Accordingly, depending upon the degree of heat and pressure applied, the articles can be made of varying densities, to thereby provide articles of larger or smaller permeability and stiffness. The articles are then nested together to form a fluid filter in which fluid flows through the article of lowest density to remove the larger particles entrained in the fluid first, and then flows through articles of progressively higher density to remove progressively smaller particles. At least some of the particles have been heated and/or compressed sufficiently to be structurally self-supporting, thereby providing a filter article which does not need metallic centertube supports, etc., for structural rigidity.

Abstract: A composite tube of a heat-sealable non-woven material comprises an inner and an outer tube of non-woven, each of said tubes being provided with a longitudinal seal obtained by ultrasonic sealing, the outer and inner tube being fixed with respect to each other by adhesive spots. The inner side of the inner non-woven tube is coated with a membrane for membrane filtration.The seal formed by ultrasonic sealing in the outer tube does not extend to the inner side of the inner tube and preferably the seals in the outer and inner tube are staggered with respect to each other.The composite tube is formed by first forming the inner tube, applying spots of an adhesive upon the outer side of the inner tube, and subsequently applying the outer tube onto the inner tube. During the step of forming the longitudinal seal by ultrasonic sealing in the outer tube it is avoided that the seal as formed extends toward the inner side of the inner tube.

Abstract: A filter device is provided with a multi-layer filter which includes a central highly absorbent layer which expands in the presence of moisture and positioned between an outer layer of absorbent paper and an inner layer of fiber glass adjacent to an inner ply. The filter is longitudinally pleated.

Abstract: A method and apparatus for removing dissolved solids from a liquid which utilizes the technique of reverse osmosis (RO). The liquid to be treated is directed into a pressure vessel which contains a plurality of filter elements positioned therein. The filter elements have a layer of hollow RO fibers around a center core area such that the liquid flows in a direction from the outside of the filter elements towards the center core areas. Pure permeate liquid permeates into the center bores of the fibers and concentrate liquid passes into the center core areas. The permeate liquid from the center bores passes into longitudinally extending permeate collection channels which communicate with the center bores over substantially the entire length of the layers of hollow RO fibers. Various structural embodiments of the filter elements are disclosed.The method and apparatus provide for the backwashing of the filter elements when they become fouled.

Abstract: A self-supporting tubular fibrous filter element consists of elongated fibers compacted in a direction parallel to the central axis of said tubular element to have a substantially constant density throughout the length and thickness of the tube with a majority of the fibers in parallel to one another in a circumferential direction about the said axis. When required, a perforated cylindrical support sheet is molded into at least one cylindrical face of the element.

Abstract: A cartridge filter for gases and liquids having a filter element clamped between an upper and lower cover. The filter includes a profile ring composed of a sealing compound which is firmly connected to the upper end face and an identical and corresponding profile ring firmly connected to the lower end face of the filter element. Sealing rings are embedded in the profile rings. The covers each includes one circumferential groove engaging around the sealing rings in a claw-like manner.

Abstract: A supporting web of synthetic fibers in which a permanently magnetic powder s embedded is used to hold fine magnetic particles in a matrix for interaction with dissolved or dispersed substances present in a liquid or gas flowing through the matrix. The magnetic force in the supporting web produced by the embedded powder lends flow resistance to the adhering particle matrix making it possible to use smaller particles effectively. Catalytic effects can be produced if the magnetic particles are coated with a nonmagnetic material having a catalytic effect for the dissolved or suspended substance, as the costing does not interfere with the tenacity of the magnetically supported matrix. A matrix with particles of a ferrimagnetic compound are useful for removal of metal ions and metal complex ions from water solution as for example uranium.

Abstract: A filter vessel primarily for use in filtering a fluid passed through the vessel under pressure. The housing is provided by an upstanding, circumferential sidewall open at its upper end. The housing supports a reticulated basket for restraining and suspending a filter bag therein. A collar is mounted around the sidewall in the vicinity of the upper end and in cooperative arrangement with a sealing cap installed over and clearing the upper end to provide a discrete liquid flow path for fluid entering through an inlet port in the collar. The fluid path extends substantially uninterrupted from the inlet port, around the sidewall and over the upper end below the cap and, thereafter, into the filter bag over substantially the entire perimetric entrance to the basket.

Abstract: A permselective membrane comprising a thin permselective film of a polymeric material, said polymeric material being prepared by cross-linking a polyaddition product between a polyepoxy compound and a polyamino compound having at least two amino groups capable of reacting with epoxy groups with a polyfunctional compound selected from the group consisting of aromatic, heterocyclic and alicyclic compounds containing at least two functional groups selected from acid halide, sulfonyl halide, isocyanate and acid anhydride groups; and a process for producing the same. The permselective membrane of this invention is especially useful for desalination of saline or brackish water by reverse osmosis.

Abstract: A fiber bed element and process for removing aerosols from gas streams wherein a bed of fibers is packed to a desired packing density between two foraminous screens. A substantial portion of the fibers in the bed are positioned in a generally parallel arrangement such that the element can be mounted in an operative position with such substantial portion of the fibers extending in a generally vertical direction to enhance drainage of collected aerosols from the element to thereby allow-operation at even high bed velocities with reduced re-entrainment of collected liquid and thereby increase the total collection efficiency of the element. In the process, the bed element is mounted such that the parallel fibers extend in a generally vertical direction and the gas to be treated is passed through the bed at a predetermined velocity.

Abstract: A cell for coalescing oil droplets dispersed in a water emulsion including an elongated perforated tube core into which the emulsion is injected, layers of oleophilic plastic covered metal mat wound about the core through which the emulsion is forced to pass, the fibers of the metal mat being covered by oleophilic plastic such as vinyl, acrylic, polypropylene, polyethylene, polyvinyl chloride, the metal being in the form of layers of expanded metal or metal fibers, either aluminum or stainless steel. In manufacturing the cell a helix wound wire is formed around the cylindrical plastic coated metal to retain it in place and resist pressure drop of fluid flowing through the metal fibers. In addition, the preferred arrangement includes the use of an outer sleeve formed of a mat of fibrous material such as polyester fibers, acrylic fibers, modacrylic fibers and mixtures thereof.

Abstract: A method and apparatus of producing a filter medium of a relatively strong substrate and a fibrous felt layer bonded to the substrate by needle punching the felt through the substrate and fusing the fibers protruding through the perforations to the substrate and each other.

Abstract: A supporting web of synthetic fibers in which a permanently magnetic powder s embedded is used to hold fine magnetic particles in a matrix for interaction with dissolved or dispersed substances present in a liquid or gas flowing through the matrix. The magnetic force in the supporting web produced by the embedded powder lends flow resistance to the adhering particle matrix making it possible to use smaller particles effectively. Catalytic effects can be produced if the magnetic particles are coated with a nonmagnetic material having a catalytic effect for the dissolved or suspended substance, as the coating does not interfere with the tenacity of the magnetically supported matrix. A matrix with particles of a ferrimagnetic compound are useful for removal of metal ions and metal complex ions from water solution as for example uranium.

Abstract: A filter element that is particularly suitable for filtration of blood is made by compacting a mixture of fibers that is non-injurious to blood and one component of which has a lower softening temperature than the other component or components at a temperature sufficient to soften said fiber component and thereby bind the various fiber components together to form a stable and substantially uniform filter element.

Abstract: A filter cartridge assembly is formed of a series of stacked disc members interlocking with one another and held in compression by a preload force exerted through respective end members at opposite ends of the assembly. Each of the disc members is provided with a series of raised surfaces -- bosses, for positioning filter media thereon and providing fluid flow paths for the filtrate to pass through openings in the disc members into a central passage and out of the cartridge. Cooperating raised edge surfaces adjacent to the outer and inner periphery, engage and seal the filter media under a compressive load along the surfaces adjacent the outer and inner edges of the media, when the respective disc members are in stacked relationship and the media is sandwiched between neighboring discs.

Abstract: An improved filter of the cartridge type having concentric inner and outer filter elements is disclosed. The elements are formed of non-woven polypropylene fibers. In a preferred embodiment the outer element is formed of a laminate including a supporting layer of a continuous filament and a filtering layer of randomly oriented polypropylene fibers. The outer element is pleated and the space between the elements is filled with particulate, activated charcoal. The axial ends of the filter components are encapsulated in plastisol end caps to secure them together, and to form a sealable working surface to be engaged by the filter housing.

Abstract: A media for filtering blood consisting of a layer of fibers having a thickness of at least 0.015 inches. The fibers in the layer are interlocked with one another by frictional entanglement and the layer may have a larger pore opening size on one surface than on the opposite surface.

Abstract: Filter tubes or cartridges are provided comprising a plurality of paper filter sheets of differing pore size, arranged in sequence of fluid flow therethrough according to decreasing pore size, and formed in a concentric corrugated tubular configuration, with at least one foraminous relatively rigid support externally of the outermost and/or internally of the innermost sheet member of the filter tube, in corrugated supporting juxtaposition thereto.

Abstract: A horizontal soil drainage system consisting of a nonwoven three-dimensional mat of a plurality of looped, intersecting and substantially amorphous filaments of melt-spun synthetic polymers bonded together at their intersections, at least one of the outer surfaces of said mat having a lower cross-sectional porosity than the center zone of said mat.