Abstract: Cylindrical fibrous structures comprising a fibrous mass of nonwoven, synthetic, polymeric microfibers wherein the microfibers are substantially free of fiber-to-fiber bonding and secured to each other by mechanical entanglement of intertwining, the fiber structure having a substantially constant voids volume over at least a substantial portion of the structure and, preferably, a graded fiber diameter structure, both as measured in the radial direction. The structures are particularly useful as depth filters.

Abstract: A self-cleaning system and method for dispersing aggregates in a fluid medium is provided. The system is comprised of first and second members operatively associated to form an internal chamber and having an inlet to the chamber for admitting the fluid to be treated. At least one of the members is biased toward the other whereby the introduction of a fluid medium to be treated into the chamber under an operating pressure in the range of from about 50 to about 1,000 psid (3.5 to 70.3 kg/cm.sup.2) provides an elongated orifice between the first and second members having a transverse dimension or width of from about 1 to about 1,500 micrometers for egress of the fluid medium. As the fluid passes through the elongated orifice, aggregates contained therein are dispersed. The system is self-cleaning by virtue of the biased nature of at least one of the members toward the other, thereby providing longer onstream operation and requiring less servicing.

Abstract: Filter media comprised of charge modified, resin coated inorganic microfibers are prepared by mixing inorganic microfibers with an aqueous solution of a water soluble, noncolloidal cationic thermosetting binder resin to form a dispersion, following which a precipitating agent is added to precipitate the binder resin and coat the microfibers. The coated microfibers may be used in the dispersed or suspended form as a filter aid. Preferably they are formed into a filter sheet which is then dried and cured to form a filter sheet of narrowly distributed pore size, pore sizes as small as one-half micron, and having a positive zeta potential in alkaline media. Glass is the preferred microfiber and polyamine-epichlorohydrins the preferred resins. By providing the normally negative zeta potential microfibers with a positive zeta potential the binder resins used to coat the microfibers substantially enhance particulate removal capabilities of the microfiber filter sheet.

Abstract: A filter cartridge is provided comprising, in combination:(1) a filter sheet material formed in a tube open at at least one end;(2) a support such as an internal core or external sheath disposed in supporting relation to and substantially coextensive with the tube and supporting the filter sheet material of the tube;(3) the support having one end at the open end of the tube formed in a castellated configuration in which at least some of the castellations define grooves therebetween, preferably having reentrant sides; and(4) at least one end cap attached to and extending across the open end of the tube of filter sheet material, and having embedded therein at least the castellated end of the support, with end cap material extending into and substantially filling the grooves, thereby fixedly attaching the end cap to the support in a leak-tight seal.

Abstract: A microporous filter system comprises two types of hydrophilic, microporous filter media operating in series. The two filter media have opposite zeta potentials with the upstream or first filter medium preferably having the positive zeta potential and the downstream or second filter having the negative zeta potential. The first filter medium typically has an absolute pore rating of from about 0.1 to about 1.0 micrometer and the second or downstream filter medium typically has an absolute pore rating of from about 0.02 to about 0.1 micrometer. The downstream or second filter has a finer absolute pore rating than the upstream or first filter. Fluids contaminated with ultrafine particles can be purified with an essentially absolute efficiency to remove 99.99 percent or more of the particulate matter in the contaminated fluid. The filter system finds particular use in the preparation of ultrapure effluent water of near theoretical resistivity and in the removal of bacteria and endotoxins to form sterile fluids.

Abstract: A corrugated cylindrical filter element is provided having an external spiral tape support, comprising a corrugated filter sheet material in the form of a cylinder having an end cap at each end of the cylinder sealingly bonded to the filter sheet material at that end, the corrugations of the filter sheet material having a tendency to become distorted and displaced with respect to each other under the conditions to which the material is subjected in use, and a relatively narrow strip to continuous high-modulus fiber-reinforced synthetic plastic tape spirally wound around the cylinder, spanning the corrugations and extending between each end and bonded to the end cap and to the tips of the corrugations in a manner to prevent distortion and displacement thereof.

Abstract: A disposable unitary filter assembly is provided for filtering pharmaceutical and other fluid materials without danger of contaminating downstream effluent in the event of leakage of unfiltered fluid material past a filter seal, comprising, in combination, a filter housing of plastic material comprising first and second housing parts; the first housing part having a first fluid chamber open at one side, a fluid port opening into the fluid chamber, and a peripheral sealing surface extending in at least two planes at an angle to each other of from 30.degree. to 150.degree.; the second housing part having a second fluid chamber open at one side, a fluid port opening into the fluid chamber and a peripheral sealing surface extending in at least two planes at an angle to each other of from 30.degree. to 150.degree.

Abstract: A process is provided for preparing skinless hydrophilic alcohol-insoluble polyamide membranes by preparing a solution in a polyamide solvent of an alcohol-insoluble polyamide resin having a ratio CH.sub.2 :NHCO of methylene CH.sub.

Abstract: A process is provided for preparing skinless liquophilic alcohol-insoluble polyamide membranes by preparing at a first temperature a solution in a polyamide solvent having a temperature coefficient of solubility within the range from about 0.01 to about 5 weight percent per degree Centigrade of an alcohol-insoluble polyamide resin having a ratio CH.sub.2 :NHCO of methylene CH.sub.

Abstract: An end cap coupler system for linking one end-capped filter cartridge to another at the end cap thereof or to another functional member is provided, comprising, in combination:(1) first and second attaching members, each having first and second opposed faces,(a) a first face of each attaching member facing one end of a filter cartridge or another functional member; and(b) a second face of each attaching member being adapted for closely-abutting contact with the second face of the other attaching member;(2) an outer periphery of the second face terminating in an outwardly extending flange, the flange of each member being adapted for closely-abutting contact when the second faces of each member are in closely-abutting contact;(3) at least two intermeshing clamping channel members having channel sides shaped to embrace the abutting flanges of the attaching members and spaced apart sufficiently to engage the flanges and clamp the attaching members together; each channel member having intermeshing locking means en

Abstract: Tubular filter elements are provided having an improved side seam seal which can be bonded to end caps in a leak-tight manner and can be formed of a thermoplastic material which is the same plastic material as the end caps and/or of the filter elements, improving the bonding of the side seam seal to the end caps and filter elements.

Abstract: Filter elements and filter assemblies are provided for use at any operating temperatures, having the filter elements disposed in sealing relationship in a leak-tight seal formed at such operating temperature by thermal expansion of at least two sealing components. Thus, at a lower or higher temperature, such as normal atmospheric temperature, the sealing components are contracted, and release the filter elements from sealing engagement, for removal and replacement, while at the selected operating temperature such sealing components are expanded, to form a thermal leak-tight seal therebetween.

Abstract: A corrugated tubular filter element is provided, resistant to corrugation collapse under high differential pressure, although formed of filter sheet material susceptible to such collapse, comprising, in combination, filter sheet material enclosed in a dual layer of more open foraminous sheet material and formed in a closed corrugated configuration having axial corrugation folds arranged in groups with adjacent side surfaces in supporting contact with each other; and, interposed between said groups, solid wedge support elements extending axially of the corrugation folds from end to end of the element having side surfaces in supporting contact with external side surfaces of the end folds of each group, substantially filling the spaces between the end folds of adjacent groups, and confining the folds of each group in substantially parallel array against lateral movement; and a foraminous support sheath disposed at least one of externally and internally of the filter sheet material in supporting contact with adja

Abstract: A process is provided for the continuous production of modular tubular filter elements using nonwoven webs in cylindrical or sheet form spun from thermoplastic fibers, spinning the fibers continuously from a melt onto a rotating internal tubular core for the filter element, serving as a mandrel, and winding them up on the core to form a wound tube.

Abstract: A process is provided for the continuous production of modular tubular filter elements using nonwoven webs in cylindrical or sheet form spun from thermoplastic fibers, spinning the fibers continuously from a melt onto a rotating internal tubular core for the filter element, serving as a mandrel, and winding them up on the core to form a wound tube.

Abstract: A demister assembly is provided for removing and reclaiming liquids from gases, and particularly engine lubricating oil aerosols from leakage air in gas turbine engines. When in series connection to an air vent line from a gas turbine engine, the demister strips out oil from the air before it is vented overboard while producing a moderate noise reduction and imposing only slightly higher back pressure on the system.By increasing in number selected demister components, the noise reduction can be significantly increased with minimal increase in back pressure, combining a silencer function with the demister function.

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 process is provided for the continuous production of nonwoven webs in cylindrical or sheet form from thermoplastic fibers, spinning the fibers continuously from a melt onto a rotating mandrel and winding them up on the mandrel to form a generally spirally wound cylinder. Density of the wound cylinder is controlled by controlling the distance between the rotating mandrel and the orifices of the spinning die through which the molten polymeric material is spun. If the spinning of the fibers is continuous, the cylinder can be formed in a continuous length. Control of the spinning rate in relation to the diameter and rate of rotation of the mandrel and the rate of advance of the cylinder on the mandrel controls the thickness of the cylinder. The cylinder can be drawn off the mandrel and used as a cylinder, or either slit lengthwise and opened out, or collapsed onto itself, for use as a sheet. The process is particularly adapted for forming filter elements.

Abstract: A process is provided for the continuous production of nonwoven webs in the form of a flexible tube from thermoplastic fibers, spinning the fibers continuously from a melt onto a rotating mandrel and continuously withdrawing the web from the mandrel in the form of a flattened tube. Density of the web is controlled by controlling the distance between the rotating mandrel and the orifices of the spinning die through which the molten polymeric material is spun, and by controlling the diameter of the fibers. If the spinning of the fibers is continuous, the flattened tubular web can be formed in a continuous length. Control of the spinning rate in relation to the diameter of the mandrel and the rate of withdrawal of the tubular web from the mandrel controls the thickness of the web. The web drawn off the mandrel can be used as a tube, or slit lengthwise and opened out, or collapsed onto itself, for use as a double layer sheet.