Abstract: A cardiac valve with a support frame having a first end member and a second end member opposing the first end member in a substantially fixed distance relationship, and a cover extending over the support frame to allow for unidirectional flow of a liquid through the valve.

Abstract: Described herein are extrusion processes to produce hollow pellets. Also disclosed are pelletizer devices that can be used to produce the hollow pellets. The processes and devices make use of an extrusion die having a die orifice and an insert that is placed in the die orifice to produce the hollow pellets.

Abstract: Permselective asymmetric membranes suitable e.g. for hemodialysis, hemodiafiltration and hemofiltration of blood, and having improved sieving characteristics providing enhanced removal of middle molecular weight substances, e.g. inflammatory mediators having a molecular weight between 20 and 40 kDa. The membranes comprise polyethersulfone and polyvinylpyrrolidone and are coated with hyaluronic acid or copolymers of 2-methacryloyloxyethyl phosphoryl choline and other vinyl polymerizable monomers. Processes for the preparation of these membranes, devices comprising these membranes, and the use of these membranes in hemodialysis, hemodiafiltration and hemofiltration of blood, as well as in bioprocessing, plasma fractionation and the preparation of protein solutions.

Abstract: A hollow fiber membrane is produced through a thermally induced phase separation process by dissolving a highly hydrophilic polyamide resin in a high-boiling-point solvent such as an aprotic polar solvent at a temperature of not lower than 100° C. The hollow fiber membrane has a membrane surface having a water contact angle of not greater than 80 degrees, and has a water permeability of not less than 100 L/m2·atm·h and a 0.1-?m particle rejection percentage of not less than 90%.

Abstract: Methods of manufacturing a medical article that include radial deformation of a polymer tube are disclosed. A medical article, such as an implantable medical device or an inflatable member, may be fabricated from a deformed tube.

Abstract: Permselective asymmetric membranes suitable e.g. for hemodialysis, hemodiafiltration and hemofiltration of blood, and having improved performance, including improved sieving characteristics, providing enhanced removal of middle molecular weight substances, e.g. inflammatory mediators having a molecular weight between 20 and 40 kDa. The improved sieving characteristics are due to a narrow pore size distribution of the membranes created in the production process. Processes for the preparation of these membranes, devices comprising these membranes, and the use of these membranes in hemodialysis, hemodiafiltration and hemofiltration of blood, as well as in bioprocessing, plasma fractionation and the preparation of protein solutions.

Abstract: A hollow porous membrane with a reduced cost and excellent separation characteristic, water permeability, and mechanical strength and a process of producing the hollow porous membrane with an excellent adhesive property between a support and a porous membrane layer at a low cost are provided. The hollow porous membrane includes a porous membrane layer in which dense layers are disposed in the vicinities of an outer surface and an inner surface. In the process of producing the hollow porous membrane, membrane-forming dopes of a first membrane-forming dope and a second membrane-forming dope, which contain the material of the porous membrane layer and a solvent, are successively applied and stacked onto the outer circumferential surface of a hollow support and the applied membrane-forming dopes are simultaneously coagulated.

Abstract: A hollow fiber membrane is made by covering a tubular supporting structure with a membrane dope and converting the membrane dope into a solid porous membrane wall. Optionally, a textile reinforcing structure in the form of a circular knit may be added around the supporting structure before it is covered in dope. The reinforcing structure thereby becomes embedded in the membrane wall. The supporting structure may be soluble in a non-solvent of the membrane wall, for example water, and may be removed from the membrane. Alternatively, the supporting structure may be porous. A porous supporting structure may be made by a non-woven textile process, a sintering process within an extrusion machine, or by extruding a polymer mixed with a second component. The second component may be a soluble solid or liquid, a super-critical gas, or a second polymer that does not react with the first polymer.

Abstract: A method of manufacturing a hollow fiber spinning nozzle in which supply bores and a nozzle structure connected to these and having a mass discharge opening and a needle with a coagulation agent bore are formed in a base body. At least two plate-shaped bodies structured by means of micro-structure technology are joined together to form the base body.

Abstract: Processes for manufacturing hollow structures such as spars for helicopter rotor blades, fixed wings for aircraft, and other aerostructures can include the provision of a path for gases to exit the material from which the spar is formed as the material is heated and cured, to help eliminate voids within the material caused by the presence of such gases.

Abstract: New fluid separation devices and absorption materials are disclosed. Hollow fibers with an axial capillary slit act as very high efficiency absorption materials, as well as high-surface-area fluid separation devices. The hollow fibers with an axial capillary slit are constructed to preferentially absorb or repel different fluids and arranged to maximize that action over a plurality of fibers to separate different fluids. These separation devices can also function as injection devices and very effective micro-reactors.

Abstract: The invention relates to a microdialysis catheter comprising a multilumen tube (10) and a membrane (11), said tube exhibiting at least two longitudinally arranged inner channels (13,14), said channels extending from a proximal (20) end of the tube to the distal end (21) of the tube, whereat through-holes (12,15) are provided, one from each of said at least two channels to the outside of said tube, said channels (13,14) blocked for passage of liquid distally of the respective through-holes, a tubular membrane (11) arranged circumferentially around the tube (10) such as to cover the at least two through -holes (12,15), said membrane is sealingly fastened (22) to the tube thereby forming a dialysis chamber (18) between the tube and the membrane.

Abstract: A fluorine resin polymer separation membrane and a manufacturing method of the same, which are excellent in a virus-eliminating property, further excellent in water permeability, chemical strength (chemical resistance), physical strength, and an antifouling property, and particularly suitable for practicable use as a filtration membrane for the elimination of viruses, are provided. A fluorine resin polymer separation membrane includes a layer having a three-dimensional network structure and a layer having a spherical structure, in which the layer having a three-dimensional network structure does not substantially contain micro-voids having a void diameter of 5 ?m or more, and the fluorine resin polymer separation membrane has filtration performance represented by the elimination rate of 80% or more of dextran having molecular weight of 75,000. The layer having a three-dimensional network structure is formed by the solidification with a polymer solution containing a fluorine resin polymer and cellulose ester.

Abstract: The process for the preparation of articles from polymer materials having a medicamentous depot effect is performed by mixing the starting materials, shaping the mixture, cross-linking the polymer material at least until a sufficient dimensional stability is reached, performing all the necessary processing work, introducing the article into a protective package, sterilizing the packaged article, optionally with further cross-linking of the polymer material.

Abstract: The present invention provides bimodal polyethylene resins in which the high molecular weight ethylene copolymer component typically has a relatively narrow molecular weight distribution, with short chain branching content being substantially constant across its molecular weight distribution. The resins of this invention are typically characterized by improved toughness and resistance to slow crack propagation properties making them useful for pressure pipe applications.

Abstract: Method for making a hollow body comprising, as sole layer(s), at least one layer L1 consisting of a polyamide composition comprising an aromatic polyamide and an impact modifier, said method comprising extruding the polyamide composition through a die.

Abstract: The present invention is directed to a heat-shrinkable, thermoplastic film or bag which contains at least one homogeneous ethylene alpha-olefin copolymer having a density of at least 0.90 g/cc. Oriented films made in accordance with the present invention exhibit improved optics and improved impact resistance. A homogeneous ethylene alpha-olefin may be present in a monolayer film either alone or in a blend or may be included in one or more layers of a multilayer film in accordance with the present invention.

Abstract: Hollow fiber membranes, such as those used in air separation modules, are generally made from solution spinning. Typically, solvent is present in the bore of the fiber for the spinning process. This solvent, in addition to the solvent already present in the polymer dope solution, may cause voids in the fiber material. By adding citric acid to the polymer dope material, these voids may be reduced or eliminated.

Abstract: A method for forming a resin molded article includes a step of extruding a thermoplastic resin intermittently at a predetermined speed from an extrusion slit, such that the resin droops downward in a shape of a sheet. The method further includes the steps of: feeding the extruded sheet-shaped resin downward by a pair of rollers; and forming the sheet-shaped resin with a mold. In the step of feeding the sheet-shaped resin, one of the rollers is pressed against the other, but not to the extent of crushing the sheet-shaped resin, regardless of the thickness of the sheet-shaped resin. In addition, a surface temperature of each of the rollers is set lower than a temperature of the sheet-shaped resin and within a predetermined temperature range. This method can prevent sliding contact between the rollers and the sheet, while preventing the sheet from being wound around the rollers.

Abstract: A porous membrane, made of polyvinylidene fluoride which is excellent in fractionating capability, permeating capability and physical strength and suitable for use in water treatment such as water purification, preparation of drinking water, preparation of water for industrial use and wastewater treatment, and which can be manufactured inexpensively and easily. The porous membrane has one surface formed with round or oval micropores and the opposite surface formed with substantially slit shaped micropores. The round or oval micropores have an average ratio between the major axis and the minor axis, which is within the range of 1:1 to 5:1, and the substantially slit shaped micropores have an average ratio between the major axis and the minor axis, which is not smaller than 5:1 and the particle cutoff of the membrane is not smaller than 0.2 ?m.

Abstract: A process for manufacturing asymmetric braid reinforced capillary ultra- or micro-filtration membranes (1), including the subsequent steps of pulling a tubular braid (5) through a spinneret (7) and coating the braid with a dope. Prior to the coating step, the braid is impregnated with a non-coagulation liquid, being a liquid which does not cause coagulation of the dope, when brought in contact with the dope. The result is a membrane with an outer skin, i.e. smaller pores near the outside diameter than near the inside diameter, and a coating which is closely arranged around the outside diameter of the braid, without any substantial penetration of the coating into the braid.

Abstract: A method for forming a microporous membrane having a microstructure is described. Dope and coagulant formulations are simultaneously cast, where the coagulant formulation diffuses into the dope formulation through an interface effecting a phase inversion forming a microstructure.

Abstract: The invention relates to a microdialysis catheter comprising a multilumen tube (10) and a membrane (11), said tube exhibiting at least two longitudinally arranged inner channels (13,14), said channels extending from a proximal (20) end of the tube to the distal end (21) of the tube, whereat through-holes (12,15) are provided, one from each of said at least two channels to the outside of said tube, said channels (13,14) blocked for passage of liquid distally of the respective through-holes, a tubular membrane (11) arranged circumferentially around the tube (10) such as to cover the at least two through-holes (12,15), said membrane is sealingly fastened (22) to the tube thereby forming a dialysis chamber (18) between the tube and the membrane.

Abstract: A method for producing an environment protective foamed thermoplastic resin polymer comprises using an extruder with a helical rod to be driven to rotate. The extruder has a feeding section, a melting section, a mixing section and a heating-shaping section formed therein. The method includes a plurality of steps, in which thermoplastic resin is heated, melted in the melting section and moved into the mixing section, and hollow expansion balls are fed into the extruder to be evenly mixed with the melted thermoplastic resin. Then the hollow expansion balls are slightly heated and inflated, and moved into the heating-shaping section, and then the balls are heated at foaming temperature, foamed and inflated. After being injected through a nozzle, the melted thermoplastic resin and the hollow balls become a foamed thermoplastic resin polymer with a preset thickness and shape.

Abstract: Multilayer articles, such as tubing and films, are disclosed which have a soft layer of aliphatic polyurethane and at least one layer of hard aliphatic polyurethane. The articles formed avoid the problem of tackiness when using only a soft aliphatic polyurethane, while maintaining flexibility. The articles are also biocompatible and biostable and are suitable for use in medical applications.

Abstract: A plasma purification membrane and a plasma purification system for treating diseases. The above plasma purification membrane is a hollow fiber plasma purification membrane being made of a hydrophobic polymer and a hydrophilic polymer and having a sponge-like structure wherein the pore size is continuously decreased from the outer surface of the membrane toward the inner surface thereof, characterized in that the break strength of the membrane is 50 kgf/cm2 or more and, in the case of the inner pressure filtration of bovine plasma, the total protein permeability is 50% or more while the immunoglobulin (IgM) permeability is 90% or less.

Abstract: A vinylidene fluoride resin having a weight-average molecular weight as relatively high as 300,000 or higher is mixed with a plasticizer and good solvent for the vinylidene fluoride resin to obtain a composition. A molten extrudate of the composition in a hollow-fiber membrane state is contacted, on its outer side, with a cooling liquid inert to the vinylidene fluoride resin to thereby cool the extrudate. During the solidification, the vinylidene fluoride resin is moderately and mildly crystallized. Thus, a hollow-fiber porous vinylidene fluoride resin membrane is produced which has a high crystallinity represented by an enthalpy of crystal melting 58 J/g or higher. The hollow-fiber porous membrane obtained is excellent in mechanical strength represented by tensile strength and elongation at break and in chemical resistance. It is effectively used as a water microfiltration membrane.

Abstract: The invention relates to a preparation method of exo-pressure type poly(vinylidene fluoride) hollow fiber membrane spinned utilizing an immersion-coagulation method and the product thereof. The invention is performed mainly through the following steps: dissolving and stirring at a certain temperature to obtain a membrane forming solution; by means of a double-tube orifice, spinning the membrane forming solution together with a composite supporting solution which is in the inner tube of the orifice; after a rapid evaporation, performing the two-stage phase-separating coagulations; after a potch, hydrophilizating the resulted phase inversion membrane; thus, obtaining integrally and continuously the exo-pressure type hollow fiber membrane having double barrier layers and a completely spongy supporting layer.

Abstract: A method for producing ceramic micromanufactured items comprises the following stages: a starting material constituting at least a micromanufactured item (1) is prepared and used to from the micromanufactured item (1); said starting material includes at least a pre-ceramic polymer, and the method further comprises a stage in which the inner structure of the starting material is modified, said structure being turned from a polymeric structure to a ceramic structure after the forming stage of said micromanufactured item (1).

Abstract: A mixed matrix membrane for separating gas components from a mixture of gas components is disclosed. The membrane comprises a continuous phase polymer with inorganic porous particles, preferably molecular sieves, interspersed in the polymer. The polymer has a CO2/CH4 selectivity of at least 20 and the porous particles have a mesoporosity of at least 0.1 cc STP/g. The mixed matrix membrane exhibits an increase in permeability of least 30% with any decrease in selectivity being no more than 10% relative to a membrane made of the neat polymer. The porous particles may include, but are not limited to, molecular sieves such as CVX-7 and SSZ-13, and/or other molecular sieves having the required mesoporosity. A method for making the mixed matrix membrane is also described. Further, a method is disclosed for separating gas components from a mixture of gas components using the mixed matrix membrane with mesoporous particles.

Abstract: It is intended to provide a blood purification membrane having excellent performance and showing little elution of blood and little adhesion of blood proteins or platelets. The above object can be achieved by using a moisten membrane, which is free from any membrane pore-sustaining agent and has a high water permeation dose and a large pore size, and lessening the pore size by drying the membrane after desolvation.

Abstract: A hollow fiber microfiltration (MF) membrane is provided. The casting solution used to make this membrane includes a fiber-forming polymer having a degree of polymerization greater than about 1000, a water-soluble polymer, an anhydride with about 2 to 12 carbon atoms, and a solvent. The membrane is formed by mixing and heating these components to form a viscous dope and then extruding the dope through an annular orifice to form a hollow fiber MF membrane. The hollow fiber membrane is then fed through a coagulation bath and two leaching baths. The membrane is especially useful for filtering liquids, such as wine and juice, so as to remove bacteria, gel, and solid particles from the liquids.

Abstract: Hollow fiber membranes having a skinned surface on one diameter, and a porous surface on the opposite diameter are produced from perfluorinated thermoplastic polymers by extruding a heated solution of the polymer having a low critical solution temperature directly into a cooling bath to form the porous membrane by liquid-liquid phase separation. Extrusion can be conducted either vertically or horizontally. The hollow fiber membranes are useful as ultrafiltration membranes and as membrane contactors.

Abstract: An apparatus and method for producing self-texturing hollow fiber that exhibits a desirable tendency to coil rather than to bend sharply or zig-zag. In one embodiment the invention is a spinneret for the production of hollow filament having first and second curved slots where each slot is defined by a first end having a first width and a second end having a second width and where the first and second ends are separated by an intermediate portion possessing a non-uniform width. In another embodiment the invention is a method for of producing generally cylindrical hollow filaments comprising extruding a polymer melt through a spinneret having first and second curved slots where each slot has a first end having a first width and a second end having a second width and where the first and second ends are separated by a intermediate portion possessing a non-uniform width along the continuum defined by the distance between the first end and the second end.

Abstract: A method for manufacturing multiple channel membranes includes extruding a polymer solution through an extrusion nozzle wherein several needles are arranged through which a gas or liquid containing a coagulating agent is injected during extrusion, wherein the outer side of the extruded material is first brought into contact with a mild coagulation agent and subsequently with a strong coagulation agent. By using the method a membrane is obtained having parallel channels extending in extrusion direction, in which an active layer is situated in the channels, whereas the outer surface with respect to the active layer has no or hardly any resistance to flows of liquid. By using the method it is possible to make shapes, such as recessed portions, in the membrane circumference. Also disclosed is the use of such membranes in filtration and separation techniques.

Abstract: Solvent-resistant polybenzimidazole membranes, methods of making them and crosslinking them and composite membranes and hollow fiber membrane modules from them are disclosed.

Abstract: A hollow polyester filament is disclosed that has sufficient openings therein for the hollow filament to substantially fill with water. The polyester filament has a moisture absorption capability of between about 10 and 30 percent by volume.

Abstract: Solvent-resistant polybenzimidazole membranes, methods of making them and crosslinking them and composite membranes and hollow fiber membrane modules from them are disclosed.

Abstract: A hydrophilic membrane that includes a hydrophobic polymer and a water-soluble polymer-metal complex is provided. This membrane is made by heating a mixture of a hydrophobic polymer, a metal compound, and a water-soluble polymer. The water-soluble polymer forms complexes with the metal compound and homogeneously entangles with the dissolved hydrophobic polymer to form a viscous dope. The dope is extruded through an annular orifice to form a hollow fiber. The fiber is put in an environment having a controlled humidity so that it becomes partially solidified, and then, the fiber is put in a coagulation bath. The hollow fiber is formed by phase inversion in the coagulation bath and is collected using a take-up wheel that is partially immersed in a leaching bath.

Abstract: An apparatus and method for producing self-texturing hollow fiber that exhibits a desirable tendency to coil rather than to bend sharply or zig-zag. In one embodiment the invention is a spinneret for the production of hollow filament having first and second curved slots where each slot is defined by a first end having a first width and a second end having a second width and where the first and second ends are separated by an intermediate portion possessing a non-uniform width. In another embodiment the invention is a method for of producing generally cylindrical hollow filaments comprising extruding a polymer melt through a spinneret having first and second curved slots where each slot has a first end having a first width and a second end having a second width and where the first and second ends are separated by a intermediate portion possessing a non-uniform width along the continuum defined by the distance between the first end and the second end.

Abstract: It is an object of the present invention to overcome the problem of fibrillation which is a drawback found in solvent-spun regenerated cellulosic fibers and to thereby provide high-quality regenerated cellulosic fibers. The regenerated cellulosic fibers are produced by the use of a spinning dope of cellulose dissolved in a solvent containing N-methylmorpholine N-oxide under the conditions that the average degree of polymerization of cellulose contained in the spinning dope is held to 400 or lower and 5% to 30% by weight of the cellulose is adjusted to a degree of polymerization of 500 or higher. Thus a pseudo-liquid-crystalline phenomenon can be allowed to occur in the stretched filaments during spinning, so that the resulting regenerated cellulosic fibers have improved resistance to fibrillation as well as improved dyeability and feeling.

Abstract: A fabric material for forming a garment to be worn by a user is provided. The fabric material has a first side and a second side. The fabric material comprises a plurality of fibers with at least a portion of the fibers having at least one open side wherein each fiber directs moisture from the first side of the fabric material to the second side of the fabric material. A method for constructing the fabric material is also provided.

Abstract: Described is a thermoplastic molding composition comprising: a) 0.05 to 1.5 wt. %, with respect to the entire molding composition, of a fatty acid amide ester wax; b) 0.5 to 10 wt. %, with respect to the entire molding composition, of a silica selected from natural silica, synthetic silica and mixtures thereof; c) 0 to 1 wt. %, with respect to the entire molding composition, of a montan wax; and d) at least one thermoplastic elastomer. Also described are a method of preparing the thermoplastic molding composition, and methods of preparing articles from the thermoplastic molding composition.

Abstract: The present invention relates to a method of preparing a coated hollow polymeric tubular member useful in medical devices. The method involves a simple, unique method of simultaneously extruding and coating the polymeric tube.

Abstract: A bitter-tasting water-soluble compound is dissolved in a non-polar substrate, imparting a bitter flavor to the substrate. This bitter flavor discourages rodents from gnawing on an object formed from the treated substrate. Specifically, denatonium benzoate dissolves in molten flexible polyvinyl chloride, imparting a bitter taste to the plastic matrix. Objects formed from this embittered plastic matrix are granted a degree of immunity from the predations of chewing animals; rodents in particular.

Abstract: An unique filtration device (10) which removes acidic contaminants such as H2S and SO2 from a fluid stream through the use of partially hollow wicking fibers (20) impregnated with an effective amount of alkaline-generating chemical compounds, preferably also containing an effective amount of a compound with elements from Group II and Group 6-12 in +2 oxidation state, and most preferably also containing an effective amount of solid fine particles (18). A nonwoven filter mat (12) is formed from a plurality of the elongated fibers (20) each having at least one internal channel (22) connected to the fiber outer surface via an elongated opening (24). The fluid stream containing the acidic gas phase contaminants is directed over the nonwoven filter mat (12) whereby said plurality of small solid particles (18) and reservoir of active chemical reagents disposed in the open channels (22) communicate through the elongated opening (24) with the fluid flow path and absorbs the acidic gas phase contaminants.

Abstract: A porous hollow fiber polyvinylidene fluoride resin membrane, characterized in that the membrane has a unitary three-dimensional network structure entirely composed of a polyvinylidene fluoride resin and has an inside diameter of 1.5-5 mm and a wall thickness of 0.5-2 mm and in that the relationship between membrane bubble point and water flux per unit wall thickness is on or above the curve shown in FIG. 1.

Abstract: A multi-layer tube comprises a metal tube having an outer surface and a zinc layer bonded to the metal tube outer surface, wherein the zinc layer is selected from the group consisting of zinc plating, zinc nickel alloys, zinc cobalt alloys, zinc aluminum alloys, and mixtures thereof. A surface treatment layer is bonded to the zinc layer, wherein the surface treatment layer is selected from the group consisting of a zinc/aluminum/rare earth alloy, phosphate, chromate and mixtures thereof. A first polymeric layer is bonded to the surface treatment layer, wherein the first polymeric layer is selected from the group consisting of a thermoplastic elastomer, an ionomer, a nylon, a fluoropolymer, and mixtures thereof. A second polymeric layer is bonded to the first polymeric layer, wherein the second polymeric layer is selected from the group consisting of a nylon, a thermoplastic elastomer, a fluoropolymer, and mixtures thereof.

Abstract: An anode is embedded in an electrolyte layer applied to the surface of a structure such as a pipe section to provide an ionic conductive path between the anode and structure to supply cathodic protection to the structure, where the natural environment may not provide a continuous electrolyte. The anode is comprised of a material normally used as a cathodic protection anode material, such as, an expanded valve metal mesh or ribbon having either an electrochemically active coating or noble metal coating, or a sacrificial anode metal alloy. The anode material is made continuous from one end of the structure to the other and may be connected to a common bus wire from one end to the other. The anode and structure to be protected are connected using wires to a DC power supply that causes cathodic protection current flow to the structure in the case of an impressed current system. No separate power supply is needed in the case of a galvanic or sacrificial anode system.