Abstract: A filter element adapted to be sealingly clamped in a filter housing. The element comprises a porous hollow cylindrical integral self-supporting bonded fibrous structure. The structure has thermally melt bonded to at least one end thereof, a thermoplastic polymer closed cell foam sealing gasket. The gasket is adapted to provide a sealing surface between the end of the cartridge and the sealing edge of the filter housing. In a preferred embodiment, the sealing edges of the filter housing used in conjunction with the aforedescribed filter element comprises at least two circular sealing edges concentric to the axis of the cylinder filter element. Such a combination provides a means for determining whether there is leakage past the sealing edges by the discoloration of the sealing gasket area between the concentric sealing edge by the liquid being filtered.

Abstract: A chromatography column for effecting chromatographic separation of at least two components of a sample flowing through the column. The column comprises a housing and at least one solid stationary phase within the housing. The stationary phase has chromatographic functionality and is effective for chromatographic separation. Means are provided for distributing the sample through the stationary phase and for collecting the sample after the sample has flowed through the stationary phase. The stationary phase comprises:(a) a plurality of layers of swellable fibrous matrix in sheet form having chromatographic functionality and being effective for chromatographic separation; and(b) a spacer means between each layer for permitting controlled swelling thereof and enhancing the distribution of sample flowing through the stationary phase.

Abstract: The media comprises cellulosic fiber and silica based particulate or fiber filter elements and a charge modifying amount of a cationic charge modifying system bonded to the surfaces thereof.A component of the charge modifying system is a primary charge modifying agent characterized as a water soluble organic polymer capable of being adsorbed into the filter elements and having a molecular weight greater than about 1000. Each monomer of the polymer can have at least one epoxide group capable of bonding to the surface of the filter elements and at least one quaternary ammonium group. Preferably, the primary charge modifying agent is a polyamido-polyamine epichlorohydrin resin, a polyamine epichlorohydrin resin, or a resin based upon diallylnitrogen-containing materials reacted with epichlorohydrin. A portion of the epoxy groups on the organic polymer are bonded to the secondary charge modifying agent.

Abstract: A filter element comprising a hydrophilic organic polymeric microporous filter membrane having a preformed substantially non-porous sealing area and a filter housing having, preferably, a hydrophobic thermoplastic sealing surface in thermoplastic sealing relationship with the sealing area. Preferably, the filter membrane is a pleated cylindrical membrane and the housing includes endcaps thereto. The preferred membrane is nylon. The preferred pleated cylindrical membrane is produced from an elongated porous filtration area longitudinally bordered by substantially non-porous sealing areas. Such a membrane may be produced by a specific casting method or collapsing the pores along the longitudinal borders of the filtration area. The filter element is particularly useful for the filtration of aqueous liquids, particularly parenteral or body liquids.

Abstract: A modified microporous membrane comprising an organic polymeric microporous membrane having microporous surfaces and having hydroxyl, mercapto, carboxyl, or amino functionality on the surfaces modified by a reactive modifying polymer having a polymer chain and having along the polymer chain epoxy or epithio functional groups capable of reacting with the functionality on the surface of the membrane and terminal neutral chemical functionality. The preferred reactive modifying polymer is made from a free radical polymerization of:(a) a polymerizable compound containing an epoxy or epithio group capable of direct covalent coupling to the surface functionalities of the microporous membrane and a vinyl group capable of free radical polymerization; and(b) ##STR1## wherein R.sub.1 is an alpha, beta ethylenically unsaturated polymerizable radical of two or three carbon atoms;R.sub.2 is an alkyl substituent of two to five carbon atoms having a terminal hydroxyl functionality or (R.sub.3 O).sub.n H,wherein R.sub.

Abstract: A process for surface modifying skinless hydrophilic microporous membrane having an internal microstructure throughout said membrane and a surface modifying amount of surface modifying agent bound thereto without substantial pore reduction of pore blockage involves the steps of providing a dope solution of a membrane forming polymer in a solvent system comprising a mixture of at least one solvent and one non-solvent for the polymer, and a membrane surface modifying agent, and combining said dope solution with sufficient additional non-solvent for the polymer to precipitate said membrane from said dope solution.

Abstract: A method is provided of manufacturing a skinless, nylon microporous hollow fiber membrane. The method comprises the steps of providing a nylon polymer dope solution and a quench liquid capable of solidifying and forming micropores in an extruded nylon polymer dope solution to produce a skinless, microporous nylon membrane. The quench liquid is placed into a vessel and a tube is provided which has a top and a bottom outlet. The bottom outlet of the tube is partially submerged in the quench liquid, the tube vertically extending therefrom. A spinneret is provided which has an outlet adjacent the top of the tube. The chemical quench liquid is raised in the tube until it is in substantial contact with the spinneret outlet. The nylon polymer dope solution is extruded in the form of a hollow fiber through the spinneret outlet directly into the quench liquid.

Abstract: According to the present invention, a locking means is provided for a filter cartridge and head unit. This locking means comprises a spring driven plunger, which preferably is supported by the head and comprises at least one detent, which preferably is disposed in the cartridge in the top wall upper surface thereof, whereby inadvertent disengagement of the cartridge from the head is prevented by engagement of the plunger and the detent, and whereby replacement of the cartridge is permitted by first lifting the plunger before rotating the cartridge through a requisite 90 degrees for disengagement thereof. By using the spring driven plunger and cooperating detent, the problem is avoided of a person, or a child, being able to inadvertently disengage the securing tabs from the securing tab receptacles.

Abstract: An ion-exchange media comprising a modified polysaccharide material and a modified silica material, said modified materials comprising a polysaccharide and silica materials covalently bonded to a synthetic polymer, said synthetic polymer comprising a copolymer made from a polymerization of:(a) a polymerizable compound having a chemical group capable of covalently coupling, directly or indirectly, to said materials; and(b) a polymerizable compound containing (i) an ionizable chemical group or (ii) a chemical group capable of transformation to an ionizable chemical group.The media is used to selectively remove heavy metal contaminants from aqueous solutions containing said contaminants.

Abstract: A filter element containing a hydrophilic nylon microporous filter membrane having a preformed substantially non-porous sealing area of non-porous tape heat sealed to the membrane and a filter housing having preferably a hydrophobic thermoplastic sealing surface in thermoplastic sealing relationship with the sealing area. Preferably, the filter membrane is a pleated cylindrical membrane and the housing includes endcaps thereto. The preferred pleated cylindrical membrane is produced from an elongated porous filtration area longitudinally bordered by the substantially non-porous sealing areas. Such a membrane may be produced by applying a heat sealable non-porous tape along the longitudinal borders of the filtration area. The filter element is particularly useful for the filtration of aqueous liquids, particularly parenteral or body liquids.

Abstract: A process for the cross-flow filtration of a liquid comprising circulating the liquid tangential to a charge modified organic polymeric microporous filter membrane. Preferably, the membrane comprises an organic polymeric microporous filter membrane which has a micro-structure throughout the membrane and an amount of a charge modifying agent bound to substantially all of the membrance micro-structure without substantial pore size reduction or pore blockage.The process may be used for the filtration of liquids, particularly parenteral or biological liquids contaminated with charged particulate and for plasmapheresis, particularly in the form of hollow fiber tubes.

Abstract: A cell-type filter cartridge is disclosed having netting thereon, as well as a method for producing same. Briefly stated, the surface area of filter material exposed to unfiltered fluid has disposed thereon a netting thereby preventing flaking, cracking and the like of filter media during backflow or cleaning operations. The netting is secured to the cell by a molded circumferential retainer and a circumferential centrally disposed ring.

Abstract: A filter apparatus for a home reverse osmosis water system is provided. The apparatus has a head, which has a forward flow inlet port for connection to a reverse osmosis water unit, and which has a reverse flow outlet port for connection to a water service faucet. The apparatus also has a cartridge, which has a twist-on securing means for connection to the head, a filter assembly for filtering forward fluid flow and for filtering reverse fluid flow, and a combination inlet and outlet port for connection to a pressurized water tank. The filter assembly has a primary filter unit, which is disposed in a cartridge primary chamber, and a secondary filter unit, which is disposed in a cartridge secondary chamber, and a valve means, e.g.