Abstract: A hollow fiber separatory device or module is produced by injection molding a thermoplastic potting material around thermoplastic hollow fibers. The thermoplastic hollow fibers are enhanced in order to increase the fibers' ability to withstand the high temperatures inherent in injection molding techniques. Also disclosed is a process for preparing two or more hollow fiber modules whereby the fibers are potted in an hourglass configuration.

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: The present invention provides a supported microporous filtration membrane comprising a porous nonwoven fibrous support material having first and second sides, and a continuous microporous membrane having first and second zones, wherein the first side of the support material is integral with the first zone while not protruding into the second zone, and the first zone has a pore size at least about 50% greater than the pore size of the second zone. A method of preparing such a supported microporous membrane is also provided by the present invention.

Abstract: The present invention provides a method of reducing the butterfat content of a liquid milk product comprising (a) providing a coalescing medium having a critical wetting surface tension of no more than about 50 dynes/cm, preferably a fibrous coalescing medium with an average fiber diameter of up to about 50 microns and a sheet weight of about 5 to about 30 oz/yd.sup.2, (b) passing a liquid milk product containing butterfat through the coalescing medium at a flow rate of about 1 to about 20 gpm/ft.sup.2 coalescing medium surface area to form coalesced butterfat particles and reduced-butterfat content liquid milk product, and (c) separating the coalesced butterfat particles from the reduced-butterfat content liquid milk product.

Abstract: A method for treating raw milk to produce treated milk having a lower bacterial content than the raw milk. The milk is homogenized and within about 5 minutes from the homogenization, subjected to dynamic microfiltration, to yield a filtrate which has a lower bacterial content than the initial raw milk. The resultant milk can be sterile, free from Bacillus cereus bacteria that usually causes degradation of milk quality during refrigerated storage. The milk can be shipped even under non-refrigerated conditions without spoilage, for extended periods of time.

Abstract: The present invention provides a method of pretreating a porous medium for use in filtering a protein-containing fluid, such as milk, beer, wine, or the like, which method comprises contacting a porous medium with an aqueous citrate solution prior to passing the protein-containing fluid through the porous medium.

Abstract: A method for treating raw milk to produce treated milk having a lower bacterial content than the raw milk. The milk is homogenized and, within about 5 minutes from the homogenization, subjected to dynamic microfiltration, to yield a filtrate which has a lower bacterial content than the initial raw milk. When the flow rate of milk through the microfilter drops below a predetermined level, the dynamic microfilter is removed from milk filtration service, flushed with water, and returned to milk filtration service, the steps being repeated as necessary until the membrane cannot be rejuvenated to a minimum filtration capacity, at which time the membrane is subjected to chemical cleaning to essentially restore the original filtration capacity of the membrane.

Abstract: The present invention provides a method of treating a clogged porous medium comprising contacting a porous medium clogged in the course of filtering a protein-containing fluid, such as milk, beer, or wine, with an aqueous citrate solution.

Abstract: A battery separator comprising an ultra-high molecular weight polyethylene microporous membrane radiation grafted with a monomer, the separator having the following properties:(a) a porosity ranging from about 50% to about 95%,(b) an average pore size ranging from about 0.1 to about 20 microns,(c) an electrolytic resistance ranging from about 1 to about 50 m.OMEGA.-in.sup.2,(d) a maximum weight loss of 1% and a change in electrolytic resistance of no greater than 25% after immersion in an aqueous solution of 35% KOH and 5% KMnO.sub.4 at 50.degree. C. for 1 hour,(e) a tensile strength of from about 3.5 to about 5.5 lb/in in both length and width directions,(f) a KOH absorption ratio of from about 5 to about 30,(g) a Gurley air permeability of about 1 to 300 sec/10 ml, and(h) a thickness from about 0.5 mil to about 10 mil.

Abstract: An element for treating a fluid flowing through the element which comprises at least two filter medium layers helically wrapped around a pervious, hollow tube, with the filter medium layers forming an overall graded pore structure for the fluid treatment element and/or at least one diffusion layer positioned between the filter medium layers.

Abstract: A filter medium comprising a microporous polyvinylidene fluoride membrane and a polymer containing positively charged quaternary ammonium groups covalently bonded to the membrane, and a method of using the filter medium to treat a composition, particularly a biological or pharmaceutical composition such as an ophthalmic composition.

Abstract: A PVDF membrane exposed to a quarternary ammonium hydroxide solution retains it hydrophobicity and resistance to corrosive environments, yet spontaneously and completely wets with concentrated sulfuric and nitric acids. The modified membrane is incorporated into filtration devices that are in situ integrity testable in concentrated inorganic mineral acids.

Abstract: A system and method for removing contaminants in a fluid, particularly water from lubricating oil, is provided which may comprise a particulate zeolitic adsorbent in conjunction with a non-porous PTFE barrier that has been modified to be permeable to water and impermeable to oil. Such a system is capable of reducing the level of water in lubricating oil to less than 100 parts per million.

Abstract: A method for treating raw milk to produce treated milk having a lower bacterial content than the raw milk. The milk is homogenized and within about 5 minutes from the homogenization, subjected to dynamic microfiltration, to yield a filtrate which has a lower bacterial content than the initial raw milk. The resultant milk can be sterile, free from Bacillus cereus bacteria that usually causes degradation of milk quality during refrigerated storage. The milk can be shipped even under non-refrigerated conditions without spoilage, for extended periods of time.

Abstract: A process for the preparation of a microporous polymeric membrane is provided which includes polymerizing a polymerizable fluorine-containing monomer in the presence of a microporous polymeric membrane substrate such that the fluorine-containing monomer forms a polymeric superstrate that is permanently chemically bonded to all surfaces of the membrane. A device is also provided for processing fluids which incorporates a microporous polymeric membrane having a CWST of less than about 28 dynes/cm and includes a microporous polymeric membrane substrate formed from a material such as a fluoropolymer and, permanently chemically bonded to all portions of the surface thereof is a superstrate, which may be a polymer or copolymer derived from a monomer(s), having an ethylenically unsaturated group and a perfluoroalkyl group.

Abstract: A hollow fiber separatory device or module is produced by injection molding a thermoplastic potting material around thermoplastic hollow fibers. The thermoplastic hollow fibers are enhanced in order to increase the fibers' ability to withstand the high temperatures inherent in injection molding techniques. Also disclosed is a process for preparing two or more hollow fiber modules whereby the fibers are potted in an hourglass configuration.

Abstract: A method is provided for filtration of particulates from a fluid medium which includes passing the medium through a surface modified, skinless, hydrophilic, microporous, alcohol-insoluble polyamide membrane derived from an alcohol-insoluble hydrophobic polyamide resin having a ratio of CH.sub.2 :NHCO of methylene CH.sub.2 to amide NHCO groups within the range of from about 5:1 to about 7:1. The membrane is characterized by (1) the surface properties thereof being substantially controlled by functional polar groups of a membrane surface-modifying polymer having a molecular weight of 20,000 or greater, (2) the membrane surface-modifying polymer being homogeneously distributed in the membrane, and (3) having the capability of reacting or interacting in a controlled manner with (a) particulate matter in a fluid, (b) non-particulate matter in a fluid, or (c) both (a) and (b).

Abstract: A porous medium having a positive surface change removes heparin from a heparin-containing liquid, without removing other proteinaceous components from the liquid. Methods and devices are disclosed.

Abstract: Microporous membranes having positive zeta potentials in alkaline pH are provided by radiation grafting diallyldimenthylammonium dimethyl ammonium chloride to the surraces of a microporous, polyamide membrane using ionizing radiation. The membranes have particular use in microelectronics manufacture where quick rinse up times with ultrapure water are required.

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.