Abstract: Solvent-resistant polybenzimidazole membranes, methods of making them and crosslinking them and composite membranes and hollow fiber membrane modules from them are disclosed.

Abstract: The invention relates to a spinneret for spinning thermoplastics. Said spinneret comprises a central polymer inlet channel, a filter assembly (2), consisting of one or more filter plates of various filtration grades, a spinneret plate (3) and a housing (1) which receives and tightly surrounds the filter assembly (2) and the spinneret plate (3). The selection of suitable materials and tolerances for the individual parts of the spinneret enables the sealing effect to be achieved at operating temperature by the increased expansion of the internal components, in relation to the external housing.

Abstract: Structural supports for elements, particularly supports for filtration materials and membranes, and methods of manufacturing such supports are disclosed. The membrane support structure includes one or more tapered through-holes that enable a much larger area of the membrane to be exposed to fluid flow, thereby enhancing separation processes and membrane efficiency. In addition, through-holes having smaller openings on one side of the structure produce improved support and mechanical stability/rigidity. Thus, the structural support increases the surface area of the membrane through which filtration may take place, yet preserves the mechanical strength and stability of the support structure.

Abstract: There is provided a leukocyte filter comprising: a prefilter portion; and a membrane filter portion downstream of the prefilter portion, the membrane filter portion having a pore size distribution having a median pore size between 3 and 12 microns and having at least 40% of the pore volume being constituted by pores having a pore cross section diameter of between 3 and 10 microns and having at least 5% of the pore volume being constitutted by pores having a pore cross section diameter larger than 10 microns. In a preferred embodiment, no more than 60% of the pore volume is constituted by pores having a pore cross section diameter larger than 10 microns. In another preferred embodiment, the membrane filter portion is characterized in that no more than 30% of the pore volume is constituted by pores having a pore cross section diameter less than 3 microns.

Abstract: The filter device contains a stack of filter rings (2), preferably consisting of plastic. Each filter ring (2) contains a number of cams (3) which are distributed evenly over the face, and diametrically opposed recesses. When the cams (3) and the recesses of adjacent filter rings (2) lie flush on top each other, a gap (7) is formed between them. The gap openings of the filter element (8), which consists of several filter rings (2) layered on top of each other, can be cleaned efficiently by means of a back-flow device comprising nozzle bodies (70). The characteristics of the filter can be altered by selecting a filter gap with different filter rings and different filter stack heights.

Abstract: A filter for filtering blood includes a coiled core with a hollow center. The core has only two layers that are coiled atop one another, the two layers being a blood filter layer and a spacer layer where blood flows more easily through the spacer layer than through the filter layer. An outer side of one of the spacer layer, and the filter layer defines an outer circumference of the core. The filter and spacer layers are coiled so that both sides of the filter layer directly contact respective sides of the spacer layer. A casing for the core has a blood inlet in fluid communication with the outer circumference of the core and a blood outlet in fluid communication with the hollow center. Blood entering the inlet travels to the outlet within the spacer layer and transversely across the filter and spacer layers.

Abstract: A screen material having a flexible member. The screen material includes closely spaced filter wires supported by a plurality of support members. A stranded cable is used as the support members to provide flexibility to the screen material. The filter wires are welded to the members and define filter gaps between adjacent filter wires to allow liquid and small particles to pass through, while retaining particles too large to fit through the filter gaps.

Abstract: Apparatus for chromatography, featuring a composite chromatography column including a tubular member having an inlet end and an outlet end, where the tubular member includes an innermost first layer comprised of a first material and a second layer comprised of a second material. The chromatography apparatus can also include a first intermediate layer formed from a third material, where at least a portion of the first intermediate layer is disposed between the innermost first layer and the second layer. A second intermediate layer formed from a fourth material, can further be included in the chromatography apparatus, where at least a portion of the second intermediate layer is disposed between the innermost first layer and the second layer. A portion of the second intermediate layer can be disposed between the second layer and the first intermediate layer.

Abstract: A filter element (10) having a supporting body (11) around which a filter medium (12) is wound. The filter medium (12) is a weldable material and is sealingly affixed to the supporting body (11) two radial weld seams (18) and/or a longitudinal weld seam (19). The welding of the filter medium (12) onto the supporting body (11) eliminates the need to produce prefabricated tubes of filter medium, and enables the filter medium to be processed directly from a roll.

Abstract: Spent pyrophoric reaction catalyst from a reaction mixture is removed safely, cheaply, and rapidly using a single plate pressure filter. After hydrogenation, the reaction mixture is decanted, the desired hydrogenation product is removed, and catalyst-rich material which settles at the bottom of the vessel is delivered to a single plate pressure filter fitted with a filter bag 40 of permeable material. The spent catalyst is retained in the filter bag 40 and stored under water awaiting recovery. The filter apparatus 1 comprises a container having a domed base 2, a generally cylindrical sidewall 3 terminating in an upper rim 4 closed by a lid 5 having lifting lugs 6. The lid 5 is fixed in pressure-tight engagement with the sidewall 3 by flange engaging screw clamps 7 and an embedded polytetrafluoroethene gasket 8. The filter bag 40 is held in position by a band 11 and may be readily released for removal of the spent catalyst material. The bag 40 may be reused.

Abstract: A combined filter for removing an aqueous fluid and entities, such as bacteria, existing in such aqueous fluid, from a nonaqueous fluid is described. The combined filter consists of a hydrophilic filter and a hydrophobic filter that are arranged in fluid communication and serially to be placed along the flow path of a fluid. The hydrophilic filter and the hydrophobic filter may touch one another or be located some distance from one another. Also, a structure may be inserted into the space between the hydrophilic filter and the hydrophobic filter that will maintain the space between the hydrophilic filter and the hydrophobic filter without significantly restricting the flow of fluid. And, in one embodiment, the combined filter may be composed simply of material having both hydrophilic and hydrophobic characteristics on the molecular level. Preferably, however, the filters and spacing structure are contained within an encasement having an inlet and an outlet.

Abstract: Devices, systems and methods for treating a biological fluid are provided comprising placing the fluid in contact with a complement filter capable of depleting at least one complement fragment from the fluid while at least one component of the biological fluid is being stored.

Abstract: The invention includes a filtration unit for the selective deleukocytation of a fluid containing blood platelets such as blood or a blood component. The unit includes a medium for deleukocytation by adsorption and/or filtration of the leukocytes. The medium is formed by at least one layer of non-woven polyurethane fabric which has been treated by gas plasma.

Abstract: A braided strainer for a draw line, and method of forming same. The strainer comprises a frame in the form of a pair of spaced planar plates, one being a solid end plate and the other having a control aperture. A plurality of spaced, parallel rods of similar length are positioned near the peripheries of the plates and secured and extending between the plates. A plurality of cylindrical walls of braided strands of strainer medium, are provided, the braided cylindrical walls having similarly spaced rod-receiving holes extending longitudinally in spaced fashion through the strands of strainer medium. These walls are contiguously stacked on the plates to extend between them. The plate having the central aperture permits flow of fluid drawn through the cylindrical walls during operation of the strainer. That plate has associated with it a connector to releasably secure the strainer to a mating connector on a free end of the draw line.

Abstract: Sulfonamide polymer matrices and their various uses are disclosed. Among the uses is the configuration of the matrix with a porous support membrane to form a semipermeable membrane of the invention. The matrix of the invention is ultrathin, dense and substantially free of defects. The matrix configuration as the semipermeable membrane shows improved permeate flux and retention values.

Abstract: The invention relates to a filtration device for deep-bed filtration which is easier to handle and enables filter modules(s) to be changed and disposed of easily. The filtration device has a casing with at least one filter module inserted in the casing with filter elements made from deep-bed filter materials stacked on top of each other. The filter elements have at least one internal structure formed by a perforation wherein the boundary surface of the perforation formed by the deep-bed filter materials creates a through-flow surface for filtrates or non-filtrates. At least one end plate has at least one inlet and/or outlet.

Abstract: A filter for removing leukocytes from blood comprises a filter media enclosed in a housing. The filter media includes a main filter region comprising a porous membrane structure extending between first and second skin surfaces. The porous membrane structure is formed by intersecting cells having a range of diameters. The cells adjacent to the first skin surface have diameters generally smaller than the diameters of the cells adjacent to the second skin surface. The first skin surface includes an open area defined by pores, which are formed by the intersection of cells with the first skin surface. The majority of the open area is defined by pores having a diameter of between about 12 &mgr;m and 28 &mgr;m.

Abstract: The present invention provides porous media or membranes having a surface coating that includes a first coating of a cross-linked terpolymer and a second coating comprising a copolymer or a terpolymer modified with a hydrophilic or hydrophobic functional group which has a superior combination of properties, including heat stable biomolecule resistant adsorptive properties, resistance to strong alkaline solutions, and low levels of extractable matter.

Abstract: A plasma- or serum-collecting device with simple structure and easy to handle is provided. The device comprises a vacuum blood-drawing tube accommodating a blood-filtering unit, wherein the vacuum tube contains a space above the blood-filtering unit to preserve blood to be filtered and a partition wall under the blood-filtering unit to keep a backspace at reduced pressure, and the blood-filtering unit contains a communicating needle to break the partition wall at the bottom.

Abstract: A hydrogen permselective membrane, a method of forming a permselective membrane and an apparatus comprising a permselective membrane, a porous substrate and an optional intermediate layer are described. Using chemical vapor deposition (CVD) at low reactant gas concentration, high permselectivities are achieved with minimal reduction in hydrogen permeance.

Abstract: The invention is directed to a microbiological interception enhanced filter medium, preferably having an adsorbent prefilter located upstream from the filter medium. Preferably, the prefilter is adapted to remove natural organic matter in an influent prior to the influent contacting the microbiological interception enhanced filter medium, thereby preventing loss of charge on the filter medium. The microbiological interception enhanced filter medium is most preferably comprised of fibrillated cellulose fibers, in particular, lyocell fibers. At least a portion of the surface of the at least some of the fibers have formed thereon a microbiological interception enhancing agent comprising a cationic metal complex. A filter medium of the present invention provides greater than about 4 log viral interception, and greater than about 6 log bacterial interception.

Abstract: A blood collection system has a container for holding blood and a filter communicating with the container, mutually arranged for handling as a unit. The filter (20) contains a fibrous filter medium (28) housed within two flexible sheets (32, 34) of plastic. A first seal (36) joins the sheets (32, 34) directly to the filter medium (28) inboard of the peripheral edge (40) of the filter medium (28), and a second seal (38) joins the sheets (32, 34) outboard of the peripheral edge (40) of the filter medium (28). A region (42) of the filter medium (28) extends between the first and second seals (36, 38) to cushion contact with the filter housing during handling.

Abstract: The invention is directed to a microbiological interception enhanced filter medium, preferably having an adsorbent prefilter located upstream from the filter medium. Preferably, the prefilter is adapted to remove natural organic matter in an influent prior to the influent contacting the microbiological interception enhanced filter medium, thereby preventing loss of charge on the filter medium. The microbiological interception enhanced filter medium is most preferably comprised of fibrillated cellulose fibers, in particular, lyocell fibers. At least a portion of the surface of the at least some of the fibers have formed thereon a microbiological interception enhancing agent comprising a cationic metal complex. A filter medium of the present invention provides greater than about 4 log viral interception, and greater than about 6 log bacterial interception.

Abstract: The invention is directed to a microbiological interception enhanced filter medium, preferably having an adsorbent prefilter located upstream from the filter medium. Preferably, the prefilter is adapted to remove natural organic matter in an influent prior to the influent contacting the microbiological interception enhanced filter medium, thereby preventing loss of charge on the filter medium. The microbiological interception enhanced filter medium is most preferably comprised of fibrillated cellulose fibers, in particular, lyocell fibers. At least a portion of the surface of the at least some of the fibers have formed thereon a microbiological interception enhancing agent comprising a cationic metal complex. A filter medium of the present invention provides greater than about 4 log viral interception, and greater than about 6 log bacterial interception.

Abstract: The invention is directed to a microbiological interception enhanced filter medium, preferably having an adsorbent prefilter located upstream from the filter medium. Preferably, the prefilter is adapted to remove natural organic matter in an influent prior to the influent contacting the microbiological interception enhanced filter medium, thereby preventing loss of charge on the filter medium. The microbiological interception enhanced filter medium is most preferably comprised of fibrillated cellulose fibers, in particular, lyocell fibers. At least a portion of the surface of the at least some of the fibers have formed thereon a microbiological interception enhancing agent comprising a cationic metal complex. A filter medium of the present invention provides greater than about 4 log viral interception, and greater than about 6 log bacterial interception.

Abstract: An annular space or inlet chamber 24 between the filter element 16 and housing of a liquid filter is viewable such that an operator can see the level of liquid in the inlet chamber as an indication of when to replace the filter element: the higher the liquid level, the greater the pressure drop across the filter element. A change interval plugging indicator includes a porous outer wrap 50 that traps gas in an upper section 23 of the inlet chamber below a designated release pressure and releases trapped gas upon attainment of the release pressure causing a rapid rise in liquid level within the housing and corresponding to a desired terminal pressure. The indicator prevents premature plugging indication otherwise indicated by a slowly rising liquid in the chamber. Accurate and reliable calibration is enabled by separating the filtering and indicating functions.

Abstract: A device for filtering a liquid, in particular for filtering a polymer plastic melt, has a housing which includes an inlet channel, a connecting channel situated in a shaft and a discharge channel, as seen in the flow direction of the liquid to be filtered, where the connecting channel has at least two filters arranged side by side and aligned across the flow direction of the liquid in the connecting channel, and the shaft is mounted in a bore in the housing so that it is axially displaceable and is liquid-tight, so that by axial displacement of the shaft, the two filters can be moved between a filtration position in which the inlet channel is connected to the discharge channel through the connecting channel, and an externally accessible cleaning position in which the connection from the inlet channel to the discharge channel is interrupted, and vice versa.

Abstract: The invention is directed to a microbiological interception enhanced filter medium, preferably having an adsorbent prefilter located upstream from the filter medium. Preferably, the prefilter is adapted to remove natural organic matter in an influent prior to the influent contacting the microbiological interception enhanced filter medium, thereby preventing loss of charge on the filter medium. The microbiological interception enhanced filter medium is most preferably comprised of fibrillated cellulose fibers, in particular, lyocell fibers. At least a portion of the surface of the at least some of the fibers have formed thereon a microbiological interception enhancing agent comprising a cationic metal complex. A filter medium of the present invention provides greater than about 4 log viral interception, and greater than about 6 log bacterial interception.

Abstract: The present invention provides a convenient way to filter water in a body of water. The invention combines an encloseable container with an internal pump producing cyclonic action, with two different types of filters. One type of filtering consists of layers of varied porosity, one layer filtering only very fine debris, while the other layers blocking progressively large debris. The other type of filtering involves stacked discs placed to aid in further filtering of the water in the chamber of the cylinder. Water flows around the bottom disc, through holes in the second disc, and around the third disc before approaching the stacked filters of varied porosity. An internal ultra-violet light helps control algae in the water.

Abstract: A filter unit for removing leukocytes from a leukocyte-containing suspension by passing the suspension through a filter unit. The filter unit may comprise a main filter for blocking the leukocytes and a post-filter for preventing leakage of the leukocytes having a higher median pore size than the main filter and placed downstream of the main-filter.

Abstract: There is provided a leukocyte filter comprising: a prefilter portion; and a membrane filter portion downstream of the prefilter portion, the membrane filter portion having a pore size distribution having a median pore size between 3 and 12 microns and having at least 40% of the pore volume being constituted by pores having a pore cross section diameter of between 3 and 10 microns and having at least 5% of the pore volume being constituted by pores having a pore cross section diameter larger than 10 microns. In a preferred embodiment, no more than 60% of the pore volume is constituted by pores having a pore cross section diameter larger than 10 microns. In another preferred embodiment, the membrane filter portion is characterized in that no more than 30% of the pore volume is constituted by pores having a pore cross section diameter less than 3 microns.

Abstract: A modular system for putting together different sized filter elements, especially filter elements having different lengths, more particularly filter devices for hydraulic fluids, comprising a support tube that defines an inner cavity in the corresponding filter element, said tube being surrounded by a filter mat that is substantially cylindrical and that matches the different dimensions and having passages to let the fluid pass through. The filter elements also contain at least one coupling member enabling connection on the end side of a corresponding support tube to an additional support tube having a location on the end side for interacting with and locking on the coupling member. Each coupling member is embodied as an attachment plug element with a crown consisting of interspaced tabs extending in axial direction and hooks for snapping on the location of the attached support tube.

Abstract: The invention is directed to a microbiological interception enhanced filter medium, preferably having an adsorbent prefilter located upstream from the filter medium. Preferably, the prefilter is adapted to remove natural organic matter in an influent prior to the influent contacting the microbiological interception enhanced filter medium, thereby preventing loss of charge on the filter medium. The microbiological interception enhanced filter medium is most preferably comprised of fibrillated cellulose fibers, in particular, lyocell fibers. At least a portion of the surface of the at least some of the fibers have formed thereon a microbiological interception enhancing agent comprising a cationic metal complex. A filter medium of the present invention provides greater than about 4 log viral interception, and greater than about 6 log bacterial interception.

Abstract: According to the present invention there is provided a ceramic foam filter for molten metal filtration comprising a preferably substantially flat inlet portion, an intermediate portion and an outlet portion that incorporates an undulating surface defined by smoothly transitioned peaks and valleys. Making the outlet portion or surface irregular as described herein provides paths for entrapped air to escape or vent during start-up, thereby significantly reducing or eliminating the need for potentially harmful corrective action, such as rapping, to achieve a rapid filter star-tup.

Abstract: A filter aid, in particular for filtering beverages by means of precoated filters, comprises a mixture of exclusively natural components, e.g. cellulose components. The filter aid is made only of sustainable raw materials and can be degraded almost totally in a natural way.

Abstract: A filter for removing leukocytes from blood comprises a filter media enclosed in a housing. The filter media includes a main filter region comprising a porous membrane structure extending between first and second skin surfaces. The porous membrane structure is formed by intersecting cells having a range of diameters. The cells adjacent to the first skin surface have diameters generally smaller than the diameters of the cells adjacent to the second skin surface. The first skin surface includes an open area defined by pores, which are formed by the intersection of cells with the first skin surface. The majority of the open area is defined by pores having a diameter of between about 12 &mgr;m and 28 &mgr;m.

Abstract: Described is a method of isolating cell components, such as nucleic acids, from natural sources by filtering a sample of the digested natural sources such as cells or cell fragments. The method is characterized in that the sample is passed through a filter, the pore size of which decreases in the direction of flow of the sample through the filter.

Abstract: A disposable filter cartridge, in which the entire filter cartridge is disposable. The filter cartridge includes a tubular filter element substantially permanently retained to a lid such that the filter element cannot be removed from the lid without extreme force. The filter element includes a ring of filter media having ends potted in cup shaped end caps. The lid includes a central hub that is inserted through the opening in on of the end caps and ultrasonically deformed or flared radially outward to provide a lip that engages the top end cap for axial retention. The filter element is free floating and can be moved or tilted a small degree axially and can also be freely rotated relative to the lid.

Abstract: The present invention is directed to a filtration unit intended to allow the removal of leukocytes from a fluid such as blood or a blood component. The filtration unit contains a porous element comprising a medium for the removal of leukocytes by adsorption and filtration of the leukocytes. The medium comprises a number of layers of a first type which are formed from at least one porous non-woven material. At least one layer has been pressed by calendering prior to the stacking thereof. The at least one calendered layer is disposed on the downstream side of the stack. The medium also comprises at least one non-calendered layer. The present invention is also directed to a bag-based system comprising the filtration unit. The system is in particular arranged for the sterile and closed-circuit filtration of the fluid.

Abstract: A wedge wire for use in a wire type screen for screening papermaker's stock is formed with an elongated body (12) having an enlarged head (20) at the inlet surface of the screen. The head (20) is formed with tapered walls (30, 33) that cooperate to define grooves (28) at the inlet surface between adjacent elements including an upstream wall (30) and a downstream wall (33). A radiused protuberance or projection (37) defines one wall of a screening slot (15), with a wall surface (22) of an adjacent wedge wire element. The slot wall formed by the projection (37) is free of sharp edges and is limited in length, in the direction of flow through the slot (15), not substantially exceeding the gap width of the slot. The upstream wall (30) defining the groove (28) provides protection for the slot (15) against impact and damage by contaminants that may be contained in the papermaker's stock. The slot (15) is free of sharp corners so as not to impede flow through the slot.

Abstract: A selective membrane having a high fouling resistance. In one embodiment, the selective membrane is a composite polyamide reverse osmosis membrane in which a hydrophilic coating has been applied to the polyamide layer of the membrane, the hydrophilic coating being made by (i) applying to the membrane a quantity of a polyfunctional epoxy compound, the polyfunctional epoxy compound comprising at least two epoxy groups, and (ii) then, cross-linking the polyfunctional epoxy compound in such a manner as to yield a water-insoluble polymer.

Abstract: A screen assembly for a vibratory shaker, the screen assembly including at least two screening members, and the at least two screen members connected by sewing material. In one aspect of such a screen assembly the sewing material is thread in a stitch pattern across the at least two screening members, a pattern of expandable material on and corresponding to the stitch pattern, and the thread passing through holes in the pattern of expandable material, the expandable material expanded within the holes following extraction of a needle therefrom, the needle used to apply the sewing material, to inhibit tearing of either of the at least two screening members between holes.

Abstract: A composite filter medium for removing at least 99.95 percent of particulates of a size in the 3 to 4 micron range and dissolved chemical contaminants from a fluid and filters of various configurations employing the composite filter medium are disclosed. The composite filter medium comprises an adsorbent layer containing an adsorbent agent and a hydrophilic particulate intercepting layer disposed adjacent to the adsorbent layer. The composite medium has a mean flow pore diameter of about 1 to 10 microns, a bubble point of about 3 to 15 microns and an air permeability of about 0.5 to 7 liters per minute/cm2 with a pressure drop of about 0.1 bar.

Abstract: The present invention relates to a silicone-coated organic solvent resistant polyamide composite nanofiltration membrane and a method for preparing the same. More particularly, the present invention relates to a nanofiltration composite membrane that is not only rejection rate superior but also organic solvent stable and flux excellent, prepared by coating with silicone during the process of interfacial polymerization of polyamide on the surface of porous support; and a method for producing it.

Abstract: A solid-liquid separating apparatus including a strainer of a cylindrical shape. The strainer is comprised of circular ring members arranged side by side with gaps in between and disposed inside an accommodating section the device casing. The circular ring members comprise end-part circular ring members at both ends of the strainer and a plurality of intermediate circular ring members disposed between the end-part circular ring members and have inward projections projecting from their inner circumferential surfaces. A plurality of lateral bridge members are installed between the end-part circular ring members, and these bridge members have engaging parts that engage with the respective inward projections of the intermediate circular ring members so as to hold the intermediate circular ring members.

Abstract: The present invention relates to a super water-repellent organic/inorganic composite material, more particularly to a new-concept super water-repellent organic/inorganic composite material with superior separation property having skin layer chemically immobilized with functional polymer on the porous inorganic support surface with fractal surface structure and pores of nanometers to micrometers, using grafting-from surface polymerization method.

Abstract: Devices, systems and methods for treating a biological fluid are provided comprising placing the fluid in contact with a complement filter capable of depleting at least one complement fragment from the fluid while at least one component of the biological fluid is being stored.

Abstract: Colander apparatus for straining and rinsing including a first rim portion and a second rim portion hingedly movable about an axis between a generally coplanar position and a collapsed or folded position wherein the rim portions are generally parallel or oriented at a small acute angle one to the other, the first and second rim portions when in the generally coplanar position defining a bowl opening. The colander apparatus further includes a bowl portion integrally formed with, attached to or otherwise supported by the first and second rim portions around the bowl opening in spanning relation thereto, the bowl portion including a plurality of openings therethrough.

Abstract: A high capacity leukocyte depletion filtration media incorporates a high specific surface area components with a matrix of fibers, yielding a filtration medium that removes leukocytes by at least 99.99%. The filtration medium uses a significantly low weight ratio of high specific surface area components to the matrix of fibers. The high specific area creates a multitude of adhesion sites for leukocytes while the low weight ratios allow good filtration flow rates. The filtration medium is incorporated into a filter device for removing leukocytes from biological fluids.

Abstract: A vertically extending support for supporting a plurality of stacked discs includes an elongated extruded plastic pipe having a bottom end attached to a cap and a top end receiving a molded plastic coupling therein. The molded plastic coupling is provided with a threaded end for threadably connecting to a threaded portion of a handle.