Abstract: A process for removing anionic contaminants from an aqueous fluid having a pH up to about 12, the fluid being passed through a filter media whereby the contaminants are electrokinetically captured and adsorbed onto the media, such a media comprising cellulose 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. One 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. A portion of the epoxy groups on the organic polymer are bonded to the secondary charge modifying agent.

Abstract: A process for removing particulate contaminants from a fluid is disclosed, the fluid being passed through a filter media comprising cellulose 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. One 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. A portion of the epoxy groups on the organic polymer are bonded to the secondary charge modifying agent.

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 cylindrical 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 edges by the liquid being filtered.

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: 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 filter media sheet comprising fine particulate and a self-bonding matrix of cellulose fiber, the surfaces of at least one of which are modified with a polyamido-polyamine epichlorhydrin cationic resin, the matrix incorporating beaten cellulose fiber to provide a Canadian Standard Freeness of less than 600 ml.

Abstract: The present invention sets forth an improved cell type filter cartridge in which the individual cells contain a separator disc having stiffening members formed at the central aperture of the cell and connected to a plurality of the separating ribs in spaced relation to each other. The coaction of the two or more discs with the separator ribs provides for a rigid, box-like structure of the ribs to impart a substantial cantilevered strength to the ribs. Additionally, at least one of the stiffening discs is positioned at or near the ends of the separator ribs to act as a load-bearing surface to prevent media intrusion of the filtering medium and thereby maintain the area of the flow path of the filtered liquid as it passes through the central aperture of the disc.

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 cylindrical filter element. Such a combination provides a means for determinging whether there is leakage past the sealing edges by the discoloration of the sealing gasket area between the concentric sealing edges by the liquid being filtered.

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 cylindrical 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 edges by the liquid being filtered.

Abstract: A process is provided for for cationically charge modifying a microporous filter membrane, wherein the membrane is a substantially symmetrical isotropic, hydrophilic, organic polymeric microporous filter membrane, preferably nylon, having a microstructure throughout the membrane. The process comprises bonding a primary charge modifying amount of a water soluble cationic charge modifying agent to substantially all of the membrane microstructure, without substantial pore size reduction or pore blockage. The charge modifying agent is a reaction product of a polyamine with epichlorohydrin, the reactive product having (i) tertiary amine or quaternary ammonium groups, and (ii) epoxide groups along a polyamine chain, the epoxide groups capable of bonding to the microstructure of the membrane.

Abstract: A cationic charge modified microporous membrane comprising a hydrophilic organic polymeric microporous membrane and a cationic charge modifying agent bonded to substantially all of the wetted surfaces of the membrane, the charge modifying agent being an epichlorohydrin modified polyamide having tertiary amine or quaternary ammonium groups. A secondary charge modifying agent may be employed selected from: (i) aliphatic polyamines having at least one primary amine or at least two secondary amines; and (ii) aliphatic amines having at least one secondary amine and a carboxyl or hydroxyl substituent. Processes for producing and using the membrane are also described.

Abstract: A cationic charge modified microporous membrane comprising a hydrophilic organic polymeric microporous membrane and a cationic charge modifying agent bonded to substantially all of the wetted surfaces of the membrane, the charge modifying agent being an epichlorohydrin modified polyamide having tertiary amine or quaternary ammonium groups. A secondary charge modifying agent may be employed selected from: (i) aliphatic polyamines having at least one primary amine or at least two secondary amines; and (ii) aliphatic amines having at least one secondary amine and a carboxyl or hydroxyl substituent. Processes for producing and using the membrane are also described.

Abstract: Process for production of anionically charged filter media sheet including pretreatment of filter elements with cationic charge modifier, preferably, employing inorganic colloidal silica charge modifiers. The resulting filters are used for the removal of haze or haze formers from beverages.

Abstract: Particulate filter aid coated with a sufficient amount of melamine formaldehyde cationic colloid to render the anionic surface of the filter aid electropositive. Preferred filter aids are diatomaceous earth, perlite and defibered cellulose. The filter aid is used in a filter bed for filtering submicronic contaminants.

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 cationic charge modified microporous membrane, process for producing said membrane and use thereof are provided. The membrane comprises a hydrophilic organic polymeric microporous membrane and a charge modifying amount of a primary cationic charge modifying agent bonded to substantially all of the wetted surfaces of the membrane. The primary charge modifying agent if a water soluble organic polymer having a molecular weight greater than about 1000 wherein each monomer thereof has at least one epoxide group capable of bonding to the surface of the membrane and at least one tertiary amine or quaternary ammonium group. Preferably, a portion of the epoxy groups on the organic polymer are bonded to a secondary charge modifying agent selected from the group consisting of:(i) aliphatic amines having at least one primary amine or at least two secondary amines; and(ii) aliphatic amines having at least one secondary amine and a carboxyl or hydroxyl substituent.

Abstract: A molecular separation chromotography column for effecting the differential distribution, between two phases, of the components of a sample flowing therethrough. The column contains a substantially homogeneous solid stationary phase which comprises a porous matrix of fiber having particulate immobilized therein, wherein at least one of said fiber or particulate is effective for molecular separation. The column is characterized by a reduced pressure drop, increased axial dispersion, more uniform peak shapes and better separations at high sample loading.

Abstract: A filter media sheet comprising fine particulate and a self-bonding matrix of cellulose fiber, the surfaces of at least one of which are modified with cationic colloidal silica.

Abstract: A method for preparing an improved filter medium of enhanced electrokinetic capture potential for contaminated liquids having suspended therein electro-negative particles of about 0.1 to 0.7 micron diameter. The method comprises forming a filter medium from a dispersion of negatively charged particulate material for filtration and a sufficient amount of fibers to form a matrix of self-bonding fibers. The surface of the particulate has been modified with a melamine formaldehyde cationic colloid.