Abstract: A fuel-filtering device includes a filter body in a bag form and a spacing member arranged in the filter body to maintain the bag form. The filtering device is attached to a fuel suction port located inside a fuel tank such that an inner space of the filter body communicates with the fuel suction port. The filter body is formed of at least two laminated filter layers, which includes an outside filter layer formed of a woven mesh and an inside filter layer formed of a non-woven fabric. Alternatively, the filter body includes an upper surface section and a lower surface section, and at least the lower surface section of the filter body has an inner layer formed of a mesh and an outer layer formed of a non-woven fabric.

Abstract: A filter media product and method of making the same wherein at least two independent filter media thicknesses of differing coarse and fine pore sizes are held in face-to-face relationship with the pore sizes being so calculated that the overall average pore size of successive thicknesses is smaller than the pore size of the finest fiber thickness.

Abstract: A fluid filtering member is provided with three layers including a dense layer having first and second surfaces and performing a filtering function, and a pair of rough layers respectively connected to both surfaces of the dense layer and functioning as a passage. A V-shaped member is formed by connecting edge portions of two sheets of materials to one another. The V-shaped member may be formed either by folding a single sheet of material in a longitudinal direction or by connecting edge portions of two lapped sheets of materials in a longitudinal direction. When the V-shaped bodies are rolled, the rough layer at an opening edge of one V-shaped member is connected to the rough layer at an opening edge of an adjacent V-shaped member by heat-welding to form the fluid filtering member. The fluid filtering member can simplify the manufacturing process and can decrease the manufacturing cost. Further, the fluid filtering member can improve durability and reliability the fluid filtering member.

Abstract: A filter is composed of filter media having the following characteristics in combination: a) the filter media has a greater affinity for the filtered fluid than for contaminants in the fluid, and wherein the work of adhesion between the filter media and the contaminants is less than the work of adhesion between the filter media and fluid, and wherein the filter media is preferentially wetted by the fluid relative to the contaminants; b) the filter media is composed of fibers having a defined surface area ratio facilitating fewer attachment sites for contaminants, and, in the case of cleanable reusable filters, facilitating cleansing backwash of the cleanable reusable filter by cleansing fluid along a reverse flow backflush path; c) the filter media has a thickness of 0.025 to 0.075 inch, 0.7 to 2.

Abstract: A separator cartridge comprises a support screen comprising a substantially rigid reinforced plastic cylinder including an inner first major surface and an outer second major surface, a first nonwoven polymer layer adhered to the inner first major surface of the support screen, a second nonwoven polymer layer adhered to the outer second major surface of the support screen, and a polymeric screen contacting and frictionally engaging the second nonwoven polymer layer, the polymeric screen including a hydrophobic coating.

Abstract: A filter media system, which is capable of operating in the microfiltration regime, offers: low cost, durability, high temperature and chemical resistance, no particulation, mechanical strength, separation efficiency, and biocompatibility. The present invention provides a filter media system comprising a fibrous substrate of at least one of carbon and ceramic fibers, wherein an array of carbon or ceramic fiber whiskers have been grown onto the fibrous substrate, without prior densification of the fibrous substrate. A process for manufacturing a filter media system wherein a carbon fiber is treated with a solution of metal catalyst salt, heated in hydrogen at elevated temperatures to reduce the metal salt to metal, and whisker growth is initiated on the surfaces of the metal deposited carbon fibers by decomposition of low molecular weight hydrocarbon gas at elevated temperature is also provided.

Abstract: A multi-layer filter element for filtering fluids, in which a plurality of layers of filter media follow each other in succession in the direction of flow through the filter. All of the individual filter layers are preferably made of synthetic fibers, especially polyester fibers. The successive filter layers exhibit an increasing degree of filter fineness in the direction of flow through the filter, and the filter material contains at least one filter layer arranged on the inflow side of the filter which is composed of a meltblown fiber nonwoven web, especially a polyester fiber web.

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 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 filter element according to the present disclosure includes a plurality of longitudinally extending pleats including outwardly radiating primary pleats and inwardly radiating secondary pleats, with at least one secondary pleat positioned between two adjacent primary pleats. Each primary pleat has a predetermined radial height, and each secondary pleat has a radial height that is less than the radial height of each primary pleat and different from the radial height of at least one other secondary pleat. A filter element according to the present disclosure provides greater filter area, an increased overall filter density, and access to more radial flow paths at the outer diameter of the filter element.

Abstract: An improved fluid separating device for filtering a second fluid from a first fluid. The improved fluid separating device comprises a first layer of filter media comprising a sintered matrix of first fibers. A second layer of filter membrane comprises a matrix of second fibers. A third layer of filter media comprises a sintered matrix of third fibers. The first, second and third layers are formed into a lamination with the second layer being interposed between the first and third layers. The second layer has a pore size substantially less than the pore size of the first and third layers for enabling the second fluid to pass through the second layer and for inhibiting the first fluid from passing through the second layer for separating the second fluid from the first fluid. The improved fluid separating device is suitable for separating a gas from a liquid as well as separating a gas from a dissimilar gas.

Abstract: A filter medium is formed by preparing a pH 3-5 aqueous suspension of cellulose fibers in a pulper or beater with a concentration of between 3% and 5%. A pH 2.8-3.8 aqueous suspension of glass fibers is prepared in a pulper or beater with a fiber concentration of between 0.5% and 1.2%. A first pulp consisting exclusively of cellulose fibers is prepared, to which a moisture-resistant resin is added. A second pulp is prepared consisting of cellulose fibers and glass fibers in proportions of between 30% and 70%, to which a moisture-resistant resin is added. Two superposed layers of the pulps are formed by methods used in paper manufacture. The two layers are collected on a layer of material able to absorb water. The two superposed layers of pulp are pressed to a pressure of between 0.1 and 1 kg/cm2. The resultant sheet is dried to a moisture content of 1%. The dried material is impregnated with a 50 wt % solution of acrylic latex, and dried again. The dried material is then wound on a reel.

Abstract: The present invention pertains to a filter medium including an airlaid composite, which is made of pulp fibers, at least about 2% by weight bicomponent fiber, and moisture. This airlaid composite is unique in that, when used as a filter medium, it exhibits advantageous filtering properties as well as physical strength. The bicomponent fibers of the present invention include a first polymer component and a second polymer component, and the first polymer component melts at a temperature lower than the melting temperature of the second polymer component. Mixing of the pulp fibers with the bicomponent fibers is done in such a way that the fibers are evenly dispersed in the airlaid composite. This airlaid composite is then heated such that at least a portion of the first polymer component of the bicomponent fiber is melted, which bond the bicomponent fibers to many of the pulp and other bicomponent fibers when cooled.

Abstract: A leukocyte-removing filter medium which comprises a matrix and ultra-fine fibers having a fiber diameter of less than 1.0 &mgr;m and not less than 0.01 &mgr;m which contains ultra-fine fibers in an amount of less than 50 wt % and not less than 0.1 wt %, the degree of curvature of the ultra-fine fibers being 1.2 or more, and/or the ultra-fine fibers form pores having a roundness of 1.7 or less.

Abstract: A filter media system, which is capable of operating in the microfiltration regime, offers: low cost, durability, high temperature and chemical resistance, no particulation, mechanical strength, separation efficiency, and biocompatibility. A filter media system is comprised of a carbon or ceramic composite substrate which contains a carbon or ceramic matrix reinforced with carbon or ceramic fibers. The composite has an array of carbon or ceramic fiber whiskers grown onto its surface or in its bulk. A process is provided for manufacturing the filter media system wherein a carbon fiber is disposed in a matrix deposited by a CVI or LPI process, at temperatures of about 900 to about 1200° C. to achieve a weight gain of about 10 to 200% (the ceramic matrix is deposited by a CVI process from an aqueous slurry or by use of a preceramic polymer). This composite is treated with an aqueous solution of metal catalyst salt and is then heated in hydrogen at elevated temperatures to reduce the metal salt to metal.

Abstract: The present invention provides a plasma separation filter capable of easily, speedily and safely separating plasma from a small quantity of blood without damaging blood cell components in the blood. The plasma retains the same protein concentration as in the blood. The present invention also provides a method using such a filter and an apparatus comprising such a filter. The filter of the present invention comprises a micro fiber medium formed of micro fibers with an average hydraulic radius of 0.5 &mgr;m to 3.0 &mgr;m. Such a micro fiber medium is placed in a container having an inlet and an outlet so that a ratio (L/D) of a blood flow passage length (L) to a blood flow passage diameter (D) is 0.15 to 6. The present invention provides such a filter, a plasma separation method using the filter, and a plasma separation apparatus comprising the filter. The present invention can significantly contribute to promote the automation and enhance speediness and safety in clinical tests.

Abstract: A cartridge filter having a cylindrical filter element, which is pleated parallel to its axis and is made of a layered non-woven unitary fabric. The fabric is permeable by air flow in the radial direction and is used in fresh air-supply filtration with initial pressure losses of less than 300 Pa at air flow rates through the filter medium of less than 250 m.sup.3 /m.sup.2 h. The non-woven fabric has a mass per unit area of 100 to 500 g/m.sup.2, and a thickness of 1.5-7.0 mm mm. It is made of layered staple fibers of a titer of 0.1 to 50 decitex, which are bonded by a thermally softened binding agent. A bottom layer bordering on the downstream side is contained in the non-woven fabric, having a thickness of 10 to 60% of the overall thickness, and is compressed two to ten times as much as a top layer bordering on the upstream flow side having a thickness of 10-60% of the overall thickness. One or more intermediate layers link the top and bottom layers to one another.

Abstract: A leukocyte-removing filter material is described, which includes a porous element having fine pores of an average pore diameter of not less than 1.0 .mu.m but less than 100 .mu.m and a fiber structure composed of a plurality of fibers having an average fiber diameter of not less than 0.01 .mu.m but less than 1.0 .mu.m kept on the porous element. The porosity of the filter material is not less than 50% but less than 95%, and the proportion of the fiber structure to the filter material is not less than 0.01% by weight but less than 30% by weight. The ratio between the average pore diameter of the porous element and the average fiber diameter of the fiber structure is not less than 2 but less than 2,000 and the above fiber structure forms a reticulate structure. A process for producing the leukocyte-removing fiber material and an apparatus for removing leukocyte using the above fiber material are also described.

Abstract: A method correlates average fiber diameter with performance for a complex filtration media comprising a matrix of fibers having a fibrillated component with a diameter so small (e.g., less than 0.01 microns), that cannot be physically measured with accuracy. The method manufactures a selected matrix, derives the number average diameter of the fibers according to prescribed steps, some of which do not require actual physical measurements, and observes a performance characteristic. The method repeats the foregoing steps for different matrixes, yielding different number average diameters. The method expresses change in the selected performance characteristic as a function of change in number average diameter of the matrices.

Abstract: The subject matter of the present invention is a device for purifying lightly laden water containing particles and/or fatty matter and/or microorganisms in suspension. The device of the invention is a filter comprising a grid (1) on which is placed a filter element (3) consisting of at least one sheet based on fibers and filled with organic and/or inorganic powders. The invention finds its application in all the industries which consume water and especially the crude oil processing industries and the chemical, papermaking and agri-foodstuffs industries.

Abstract: A filter includes a center layer of carbon cloth interposed between two layers of filter material whose edges are welded together to provide not only a filter edge substantially free of carbon particles, but also an effective barrier to the migration of carbon particles from the filter's interior to its exterior. A filter pouch, encapsulating the carbon filter, includes a layered structure welded together proximate its edges. The filter pouch is also suitable for use with a desiccant filter.

Abstract: The present invention provides a method and apparatus for separating a blood sample having a volume of up to about 20 milliliters into cellular and acellular fractions. The apparatus includes a housing divided by a fibrous filter into a blood sample collection chamber having a volume of at least about 1 milliliter and a serum sample collection chamber. The fibrous filter has a pore size of less than about 3 microns, and is coated with a mixture including between about 1-40 wt/vol % mannitol and between about 0.1-15 wt/vol % of plasma fraction protein (or an animal or vegetable equivalent thereof). The coating causes the cellular fraction to be trapped by the small pores, leaving the cellular fraction intact on the fibrous filter while the acellular fraction passes through the filter for collection in unaltered form from the serum sample collection chamber.

Abstract: The present invention is related to a composite microporous polyolefin membrane having a high separation, a high flux and a high strength, comprising a microporous layer, b-layer, providing a reinforcing function, the b-layer being stacked on at least one surface of a microporous layer, a-layer, providing a separate function, wherein micropores in a-layer and b-layer are mutually interconnected inside of the layer and also between layers, thereby forming micropores connected from one surface of the membrane to the other surface thereof, and the ratio of the mean distance Da between microfibril bundles of micropores existing in a-layer to the mean distance Db between microfibril bundles of micropores existing in b-layer is in the range of 1.3.ltoreq.Db/Da.ltoreq.15, and furthermore all of the inner and the outer surfaces of the composite membrane and the surface inside of micropores are coated by a thin film of a hydrophilic copolymer.

Abstract: Melt-blown fibrous webs having a uniform structure for use in processing biological fluids are disclosed.

Abstract: A composite filter media includes a fibrous filtration layer of randomly oriented fibers and one or more pleatable stiffening layers which enable the composite filter media to be pleated and hold or retain its pleats. The pleatable stiffening layer(s) may enhance the dirt holding capacity of the composite filter media especially when positioned upstream of the fibrous filtration layer. The composite filter media may also include a flexible covering layer which functions to block the loss of fibers from the fibrous filtration layer. Preferably, the mean fiber diameter of the fibers in fibrous filtration layer increases and the density of the fibrous filtration layer decreases throughout the thickness of the fibrous filtration layer from one major surface to the other major surface of the fibrous filtration layer.

Abstract: An apertured film extruded from a crystalline, thermoplastic, extrudable fluoroplastic material. The film includes spaced-apart strand segments defining apertures therebetween and has at least 10 strand segments per inch. The film has a thickness of 2-12 mils and a Frazier air permeability number in the range of 200-2,000. The invention includes a process for preparing an apertured thermoplastic film by a single-sided embossing method. The process includes the steps of extruding in the machine direction, a film of a molten, crystalline, thermoplastic, extrudable, fluoroplastic material. The molten extruded film is passed in the machine direction through the nip of two metal rollers. One of the rollers has a substantially smooth surface, having a convex configuration as viewed from a direction substantially parallel to the axis of the roll, such that the diameter in the center of the roll is in the range of 8-12 mils greater than the diameter at the ends of the roller for a 40 inch roller.

Abstract: Multilayered filter material is provided with at least two layers having different filter properties (coarse filter layer and fine filter layer), for which the separation ratio of the coarse filter layer is selected depending on the number of layers of the filter material as well as the total separation ratio of the complete filter material. The separation ratio of the first layer is proportioned such that at least 20% of the total particles are filtered out by it. The first layer has a porosity of at least 95%. For the remaining filtration of the fine particles, at least one fine filter layer is present, which has a porosity of somewhat greater than 85%.

Abstract: An air filtration media is formed of a blanket of fibers, preferably glass fibers, bonded together at their points of intersection with a binder. The blanket has a weight between about 2.5 and about 4.0 grams per square foot and the average diameter of the fibers in the blanket is within a range from 3.0 .times.10.sup.-5 to 4.1.times.10.sup.-5 inches. The blanket has an average air filtration efficiency of at least 80% and the pressure drop across the thickness of the blanket is no greater than 0.30 inches of water. The blanket can be used alone; with a permeable backing sheet; or with a second layer or blanket of filtration media, as part of a dual-phase or multi-phase air filtration media.

Abstract: A filter element (10) comprises a porous, thick-walled, integral, self-supporting, resin impregnated and bonded fibrous, tubular filter structure (11) having a hollow core (15); an inner shell (20) of a first large pore size porous media adjacent the hollow core and forming the majority of the filter structure; and an outer shell (21) of a second small pore size porous media, finer than the first porous media and adjacent the inner shell, the first and second porous media being resin impregnated and bonded.

Abstract: A leukodepletion filter is provided including glass fiber filter pads and non-woven polyester fiber filter pads sealed within a filter housing. The filter is designed such that a fluid, such as whole blood, packed red blood cells, platelets or plasma, is conducted through the glass fiber filter pads before the non-woven polyester fiber filter pads. A method is further provided for leukodepleting a body fluid by filtering the body fluid through glass fiber filter pads and also filtering the body fluid through non-woven polyester fiber filter pads. After filtering, the body fluid is collected.

Abstract: An in-tank fuel filter includes a body comprising layers of spun bonded and melt blown filtration media and a fitting for mounting the filter to an in-tank fuel pump inlet. An outer layer of the body is preferably spun bonded material which exhibits good abrasion resistance. One or more inner layers of melt blown filtration media define smaller pore sizes and thus exhibit smaller particle filtration capability. The mounting fitting is made of a fuel compatible material and may either be a multiple part device or be in-situ molded on the filter body. A separator may be disposed in the interior of the filter to prevent its collapse and improve fuel withdrawal through the mounting fitting.

Abstract: A low-cost portable water treatment device having a low-cost replaceable filter. The device includes a housing having an inlet, an outlet and a water filtration chamber. The replaceable filter is disposed in the water filtration chamber and comprises a disk having a compressible peripheral portion. The device includes a mechanism for compressing the peripheral portion to seal the filter and a mechanism for forcing contaminated water through the filter and out the outlet. The device also includes a storage compartment for a spare filter. Methods for manufacturing the low-cost filter and for sealing the filter in the device are disclosed.

Abstract: The present invention provides an apparatus for separating a relatively large volume of blood into cellular and acellular fractions without the need for centrifugation. The apparatus comprises a housing divided by a fibrous filter into a blood sample collection chamber having a volume of at least about 1 milliliter and a serum sample collection chamber. The fibrous filter has a pore size of less than about 3 microns, and is coated with a mixture of mannitol and plasma fraction protein (or an animal or vegetable equivalent thereof). The coating causes the cellular fraction to be trapped by the small pores, leaving the cellular fraction intact on the fibrous filter while the acellular fraction passes through the filter for collection in unaltered form from the serum sample collection chamber.

Abstract: The present invention provides a method of preparing a support for a filtration medium comprising passing a sheet of nonwoven fibrous polymeric material having first and second sides through a calender which comprises a nondeformable roll and a resilient roll, the nondeformable roll being maintained at a temperature below the melting temperature of the material, so as to increase the smoothness of the first side of the material which contacted the resilient roll. A filtration medium support material prepared in accordance with the method of the present invention, as well as a filter comprising a filtration medium and that filtration medium support material, are also provided by the present invention.

Abstract: There is provided a fiber bed for removing liquid aerosols and soluble solids from a gas stream in a fiber bed mist eliminator. The fiber bed is in the form of a flexible mat having a void fraction of greater than about 0.89 and greater than about 700 net collection targets. The mat includes a layer of collecting fibers having an average fiber diameter between about 1 and about 5 .mu.m. The collecting fibers are stabilized by a plurality of stabilizing fibers which penetrate into and are disposed interstitially within the collecting fiber layer. The improved fiber bed of the present invention is field-replaceable and, by utilizing fibers having a small average diameter, the thickness of the fiber bed may be reduced.

Abstract: A high efficiency leucocyte-depletion filter for use with packed red cell concentrate derived from freshly drawn blood comprises a fibrous filter medium with a pore size of from about 0.5 to less than 3.6 .mu.m and a CWST of from 53 to about 80. The filter is preferably used in conjunction with a gel prefilter and, optionally, a microaggregate filter so as to minimize clogging. In a preferred embodiment, the voids volume is about 60% to about 85%.

Abstract: Insolubilized enzyme particulates are located on the upstream surface of a filtration layer of a filtering element which can be used in a cartridge filter. Employed in a recycling flow reaction system at relatively high flux rates, the cartridges are useful for conducting catalyzed chemical reactions of dissolved solutes, for example, esterifications, isomerizations, oxidations, reductions, and cyclizations.

Abstract: There is provided a multi-ply filter laminate/composite for manufacturing vacuum cleaner filter bags comprising at least one ply of filter paper and at least one ply of fine fiber web, wherein at least one ply of fine fiber web does not cover the whole width of the ply of filter paper bonded to it and thus there are formed one or two edge strip blanks on at least one ply of filter paper.

Abstract: The invention provides processing donated blood, particularly a platelet-containing solution such as platelet-containing plasma, involving separating blood into a red cell containing sediment layer and a supernatant layer, and passing the supernatant layer through a filter until the filter is blocked, thereby leaving platelets to be harvested. The preferred filter comprises a porous medium having a plurality of zones of progressively increasing density.

Abstract: A high efficiency leucocyte-depletion filter for use with packed red cell concentrate derived from freshly drawn blood comprises a fibrous filter medium with a pore size of from about 0.5 to less than 3.6 .mu.m and a CWST of from 53 to about 80. The filter is preferably used in conjunction with a gel prefilter and, optionally, a microaggregate filter so as to minimize clogging. In a preferred embodiment, the voids volume is about 60% to about 85%.

Abstract: A method for removing leukocytes from a leukocyte-containing blood product, include subjecting a leukocyte-containing blood product to a first stage leukocyte-removing treatment to remove at least 60% of all leukocytes contained in the leukocyte-containing blood product, thereby obtaining a leukocyte-depleted blood product, and passing the leukocyte-depleted blood product through a microfilter element to perform a second stage leukocyte-removing treatment, the microfilter element having a non-woven or a woven fabric including fibers having an average diameter of from 0.3 to 1.6 .mu.m. A filter system for removing leukocytes from a leukocyte-containing blood product, to includes a first filter element for the first stage and a second filter element for the second stage, wherein the first filter element communicates with the second filter element and is positioned upstream of the second filter element with respect to a direction in which a leukocyte-containing blood product is to be flowed.

Abstract: A two-layered filter medium for liquid filtration comprises a support composed of organic fibers of 7 .mu.m or more in diameter and basis weight of 30-150 g/m.sup.2, and a filtering layer composed of three kinds of organic fibers different in diameter, a part or all of the kind of organic fibers having the largest diameter being a fibrous organic binder.

Abstract: A device for separating plasma from blood is provided comprising a synthetic polymeric fibrous structure having a CWST in excess of 65 dynes/cm, the structure having a first region for receiving a blood sample and a second region for accumulating plasma.

Abstract: A high efficiency leucocyte-depletion filter for use with packed red cell concentrate derived from freshly drawn blood comprises a fibrous filter medium with a pore size of from about 0.5 to less than 3.6 .mu.m and a CWST of from 53 to about 80. The filter is preferably used in conjunction with a gel prefilter and, optionally, a microaggregate filter so as to minimize clogging. In a preferred embodiment, the voids volume is about 60% to about 85%.

Abstract: Disclosed is a filtration process for the removal of undesired substances from dry cleaning fluids. Illustratively, a cylindrically-shaped batt of a long-fiber synthetic washable fabric filter is attached to a spoke-like rigid frame and the fabric-frame assembly is placed into a filter housing having a fluid collecting center rod. Contaminated dry cleaning fluid is introduced to the housing, passed inwardly through the fabric, and a contaminant free permeate is collected by the fluid collecting center rod.

Abstract: Red Blood Cells (RBC's) are removed from whole blood samples by contacting the whole blood sample with a solution containing an acid selected from the group consisting of acetic acid, citric acid, ascorbic acid, lactic acid, maleic acid, malic acid, and malonic acid. The agglutinated RBC's are then removed from the resultant suspension by procedures of filtration, centrifugation or decantation, leaving an essentially RBC-free serum or plasma sample.

Abstract: In a process for the manufacture of a filter for liquid or gaseous media, especially for exhaust gases of combustions engines, the filter is formed from one or several filter plates out of a mesh, network, reticulation or fabric of metal wires. The filter body of a plurality of layers or plies of wires is brought between the electrodes of a resistance welding unit and subsequently a resistance welding is performed for partial connection of the wires to one another by spot welding.

Abstract: Filter cartridge elements are provided with a spiral wrapping made from a thermoplastic polymer to give stability against inside-out flow and to protect the filtration medium. The spiral wrapping is attached to underlying turns of the wrap and to the surface of the filter cartridge by fusion bonding.

Abstract: A method of producing a closed end seamless liquid pervious article, such as filter bags, by rotating a mandrel in the flow path of a quanity of melted micro-woven filaments to collect the filaments upon the mandrel in multiple layers.

Abstract: A liquid filtering device for separating leukocytes from blood to produce concentrated red cells, for example, includes a housing having a liquid inlet port and a liquid outlet port and providing a flow passage from the liquid inlet port to the liquid outlet port, a partition plate fixedly disposed in the housing, a first filter element disposed in the housing in an upstream position with respect to the flow passage, and a second filter element disposed in the housing in a downstream position with respect to the flow passage, the second filter element being made of a material having a larger filtration resistance than the first filter element. The second filter element has an outer peripheral edge fixed directly to the partition plate in a liquidtight manner in surrounding relation to the first filter element.