Abstract: A process of manufacturing micro or nanostructure surfaces or parts formed of PTFE by applying a vacuum to powered or granulated PTFE in a heated compression mold. The process further includes applying a compression anvil within the metallic mold, removing the mold from a heat source and quenching the mold while maintaining the pressure in the mold during quenching. A mold or mold insert may be manufactured from sintered metal, sintered ceramic or sintered stainless steel to allow the vacuum to be applied across a surface holding the micro or nanostructures.

Abstract: A process is disclosed for dispersion spinning non-melt-processible fluoropolymer fiber in which a mixture of an aqueous dispersion of non-melt-processible fluoropolymer particles and an aqueous solution of a matrix polymer is formed. The non-melt-processible fluoropolymer particles have an SSG of less than about 2.40 and comprise a core of high molecular weight polytetrafluoroethylene and a shell of lower molecular weight polytetrafluoroethylene or modified polytetrafluoroethylene. The mixture is extruded into a coagulation bath containing a concentration of ions which coagulate the matrix polymer to form an intermediate fiber structure. The intermediate fiber structure is sintered to decompose the matrix polymer and coalesce the non-melt-processible fluoropolymer particles to form the fiber. The present invention also provides a spinning composition useful for the dispersion spinning of non-melt-processible fluoropolymer fiber.

Abstract: A material comprising aerogel particles and a polytetrafluoroethylene (PTFE) binder is formed having a thermal conductivity of less than or equal to 25 mW/m K at atmospheric conditions. The material is moldable or formable, having little or no shedding of filler particles, and may be formed into structures such as tapes or composites, for example, by bonding the material between two outer layers. Advantageously, composites may be flexed, stretched, or bent without significant dusting or loss of insulating properties.

Abstract: A composition is provided that, in one aspect, may be used in the production of sealing materials, such as gaskets. The composition includes a polytetraflouroethylene matrix and a Boron Nitride filler. In one aspect, the Boron Nitride filler may be provided as a hexagonal, close-packed, Boron Nitride filler that is homogeneously dispersed within the polytetraflouroethylene matrix. In at least one embodiment, the composition is formed by combining quantities of polytetraflouroethylene, Boron Nitride filler, hydrocarbon liquid, and solvent. The liquid and solvent may be removed through various processes prior to sintering the composition to form a full-density, Boron Nitride filled, polytetraflouroethylene matrix that exhibits improved sealability, greater resistance to permeation, and less color contamination.

Abstract: A PTFE-based composite material includes a PTFE major phase filled with a metal oxide minor phase. The major phase is intermixed with the metal oxide minor phase, wherein the minor phase includes a plurality of irregularly shaped metal oxide nanoparticles. The irregularly shaped nanoparticles provide substantial reductions in steady state wear rate over otherwise similar nanocomposites. The metal oxide can comprise aluminum oxide.

Abstract: A material comprising aerogel particles and a polytetrafluoroethylene (PTFE) binder is formed having a thermal conductivity of less than or equal to 25 mW/m K at atmospheric conditions. The material is moldable or formable, having little or no shedding of filler particles, and may be formed into structures such as tapes or composites, for example, by bonding the material between two outer layers. Advantageously, composites may be flexed, stretched, or bent without significant dusting or loss of insulating properties.

Abstract: The subject invention pertains to methods for processing polytetrafluoroethylene (PTFE) resin into highly desirable product forms that fill the needs of the fluoropolymer industry. The subject invention concerns methods for making a multi-directional planar oriented PTFE resin structure. PTFE produced by methods of the present invention will challenge or exceed the capabilities of melt processable resins and accomplish many of the goals not previously realized by the fluoropolymer industry. The subject invention also concerns methods for preparing PTFE resin primary colloidal particles. The subject invention also concerns the PTFE primary colloidal particles produced by the methods and products utilizing the particles.

Abstract: The invention provides an insulated wire having a conductor and an insulator of paste extruded PTFE fine powder around the conductor. The paste extruded insulator has at least one closed continuous longitudinal air channel spaced apart from the conductor. The invention further provides a process for forming an insulator around a conductor by paste extruding lubricated PTFE fine powder in an extrusion device comprising a die, mandrel, and at least one channel-forming member. The die and mandrel form a converging chamber leading to an extrusion orifice and the channel-forming member is positioned in the orifice. The mandrel has a central bore for supplying the conductor. Lubricated PTFE fine powder is forced through the chamber and out of the exit of the orifice as a lubricated green extrudate around the conductor forming an insulator with at least one closed longitudinal air channel spaced apart from the conductor.

Abstract: Disclosed are expanded polytetrafluoroethylene products, such as porous polytetrafluoroethylene tubes, having high axial tear strength and a process for their production. Each expanded polytetrafluoroethylene product has a microstructure, which comprises fibrils and nodes interconnected with each other by the fibrils, and has an axial tear strength of not lower than 6,000 gf/mm as calculated in accordance with the following formula: L/[T×(V/100)] where L (gf) is an axial tear load, T (mm) is a wall thickness, and V (%) is a volume ratio of resin. The process for the production of the expanded polytetrafluoroethylene product includes a high-speed extrusion step.

Abstract: It is an object of the present invention to obtain a PTFE molding excellent in flexing resistance without decreasing the tensile strength and tensile elongation. The present invention is a modified polytetrafluoroethylene molded article obtained by molding a modified polytetrafluoroethylene molding powder, wherein the modified polytetrafluoroethylene molding powder is not melt-moldable, the modified polytetrafluoroethylene constituting the modified polytetrafluoroethylene molding powder contains 0.01 to 1% by mass of a perfluorovinyl ether unit represented by the formula (I): (wherein X is a perfluoroalkyl group containing 1 to 6 carbon atoms or a perfluoroalkoxyalkyl group containing 4 to 9 carbon atoms) and the heat of crystallization thereof is 18.0 to 25.0 J/g as measured using a differential scanning calorimeter, and the modified polytetrafluoroethylene molded article has a heat of fusion of not more than 28 J/g and a flex life of at least 200×104 cycles.

Abstract: A method for making a vascular graft includes providing a PTFE green tube extrudate which is un-sintered, and then initially expanding the un-sintered extrudate to produce an initial node and fibril micro-structure therein. This is followed by heating the extrudate to raise the temperature thereof for a time period of sufficient duration such that the extrudate is partially sintered. The partially sintered extrudate is subsequently expanded to make the vascular graft. The subsequent expansion produces a subsequent node and fibril micro-structure in the vascular graft. An alternative method for making a vascular graft includes providing a PTFE green tube extrudate which is un-sintered, longitudinally expanding the un-sintered extrudate to form an ePTFE tube structure, and radially expanding the un-sintered ePTFE tube structure. ePTFE made according to the method is fabricated into various structures, such as tube structures, filament structures, and sheet structures.

Abstract: A novel densified fluoropolymer article is described which has a water vapor permeation of about 0.015 g-mm/m2/day or less, and preferably has a matrix tensile strength of at least 10,000 psi in two orthogonal directions. The articles are made by compressing expanded porous PTFE at pressures, temperatures and times which result in elimination of the pores, and subsequent stretching above the crystalline melt temperature.

Abstract: A bearing, plastic bearing material, and a method for the production thereof are described. The bearing comprises a continuous consolidated bearing material layer impregnated into a porous layer, which is in turn mounted on a backing material.

Abstract: This invention discloses a fluoroplastic lining manufacture and application technology, and more particularly to a fluoroplastic composite product and its manufacturing method. The product is composed of fiberglass, perfluorinated ethylene-propylene (FEP) and polytetrafluoroethylene (PTFE), wound sequentially on a stainless steel support mold, and then an alkali-free fiberglass strip is wound around an external surface. The product is pressed and sintered at a high-temperature melting condition to permeate the perfluorinated ethylene-propylene (FEP) into gaps on a surface of the fiberglass, and the semi-finished product is taken out from a furnace, and the alkali-free fiberglass strip is removed, and a finished good is formed or cut into plates after demolding. The invention breaks through the technical bottleneck of producing a polytetrafluoroethylene (PTFE) lining for large equipments, reducing the consumption of a large quantity of electric power and coal as well as lowering the transportation cost.

Abstract: A process for dispersion spinning non-melt-processible fluoropolymer fiber in which a mixture of an aqueous dispersion of non-melt-processible polytetrafluoroethylene or modified polytetrafluoroethylene fluoropolymer particles and an aqueous solution of matrix polymer is formed. The non melt-processible particles have an SSG of less than about 2.40. The aqueous dispersion contains an aliphatic alcohol ethoxylate nonionic surfactant having a 20% residuals temperature determined by thermogravimetric analysis (TGA) of less than about 290° C. and is essentially free of surfactants containing aromatic groups. The dispersion has a fluorinated surfactant content of less than about 300 ppm. The mixture is extruded into a coagulation bath containing a concentration of ions which coagulate the matrix polymer to form an intermediate fiber structure. The intermediate fiber structure is sintered to decompose the matrix polymer and coalesce.

Abstract: A process is disclosed for dispersion spinning non-melt-processible fluoropolymer fiber in which a mixture of an aqueous dispersion of non-melt-processible fluoropolymer particles and an aqueous solution of a matrix polymer is formed. The non-melt-processible fluoropolymer particles have an SSG of less than about 2.40 and comprise a core of high molecular weight polytetrafluoroethylene and a shell of lower molecular weight polytetrafluoroethylene or modified polytetrafluoroethylene. The mixture is extruded into a coagulation bath containing a concentration of ions which coagulate the matrix polymer to form an intermediate fiber structure. The intermediate fiber structure is sintered to decompose the matrix polymer and coalesce the non-melt-processible fluoropolymer particles to form the fiber. The present invention also provides for spinning composition useful for the dispersion spinning of non-melt-processible fluoropolymer fiber.

Abstract: Provided is a fluorine substituted oligomeric or polymeric ester including the reaction product of a fluorine substituted acrylate or a fluorine substituted methacrylate; an unsaturated anhydride; and an alkyl acrylate or an alkyl methacrylate. Also provided is a method of making the composition.

Abstract: A material comprising aerogel particles and a polytetrafluoroethylene (PTFE) binder is formed having a thermal conductivity of less than or equal to 25 mW/m K at atmospheric conditions. The material is moldable or formable, having little or no shedding of filler particles, and may be formed into structures such as tapes or composites, for example, by bonding the material between two outer layers. Advantageously, composites may be flexed, stretched, or bent without significant dusting or loss of insulating properties.

Abstract: A material comprising aerogel particles and a polytetrafluoroethylene (PTFE) binder is formed having a thermal conductivity of less than or equal to 25 mW/m K at atmospheric conditions. The material is moldable or formable, having little or no shedding of filler particles, and may be formed into structures such as tapes or composites, for example, by bonding the material between two outer layers. Advantageously, composites may be flexed, stretched, or bent without significant dusting or loss of insulating properties.

Abstract: Moldings of fluoro rubbers produced by crosslinking a tetrafluoroethylene/propylene copolymer or a tetrafluoroethylene/propylene/vinylidene fluoride copolymer, which have metal contents of 1.5% by mass or below in terms of metal elements and are suitable for use applications necessitating clean environment, for example, manufacturing or carrier equipment for semiconductors, manufacturing equipment, carriers, or storage containers for food, or medical supplies.

Abstract: This invention involves forward integration of the art paste extrusion process by adding a step to the processing sequence to change the uniaxially-oriented art form to a desirable planar biaxially-oriented form. This invention also involves the backward integration of the resin preparation to reduce the commercial coagulated dispersion resin particle size (average 500 micron) to the size range of colloidal size particles contained within the original 500 micron particle. In this small particulate form, the polytetrafluoroethylene (PTFE) resin can be blended more homogeneously and extruded with less turbulence in the plug extrusion process, the rheological mechanism of this extrusion process. The size reduction makes processing of micron size fillers possible in up to 90 percent volume of the PTFE resin. This invention also provides a direct and simple method of producing planar biaxially-oriented sheet and a source of resin formulations for fabricating other forms and shapes.

Abstract: A high-performance plain bearing provided with a friction coating including a bronze layer whereof the pores are filled with a PTFE-type fluoroplastic paste filled with molybdenum bisulphide. The production method includes sintering a layer of bronze powder on the metal support of the bearing, a vacuum ionic cleaning, applying a filled fluoroplastic film, passing the component through a die and after sintering the paste, a final pass in the die for final dimensioning. During sintering and passing through the die an anti-adhesive and wear-resistant coating, based on titanium nitride or the like, is applied on the equipment.

Abstract: A method and a device for the production of a ribbon are provided. The method may be performed on a narrow fabric needle loom and may include repeating the following steps: picking a weft thread (4), with (only) one weft needle (1); meshing the weft thread (4), with a catch thread (5), delivered from the side opposite the weft side (weft exit side), by a knitting needle (2) working on the weft exit side; returning the weft needle (1) and wrapping the weft thread (4), with a catch thread (6), delivered from the weft side by a knitting needle working on the weft side. The device may include a narrow fabric needle looms, for production of a ribbon, in particular by the above method. A webbing is also provided that may be produced from the above method.

Abstract: A block-shaped baked molded article having little block deformation amount is obtained in order to reduce a loss of materials until a stable film or sheet can be cut from a block-shaped molded article. After a polytetrafluoroethylene powder is compression-molded to form a preform, the resultant preform is baked while being rotated, thereby to produce a polytetrafluoroethylene molded article.

Abstract: Medical devices having at least a component, such as a catheter balloon, stent cover and vascular graft, formed of ultrahigh molecular weight polyolefin, such as ultrahigh molecular weight polyethylene. The device component is formed from ultrahigh molecular weight polyethylene that has been processed so that it is microporous and has an oriented node and fibril structure. The device component expands compliantly at low strains and are substantially less compliant at higher strains. The invention also comprises methods for making such medical devices, including the steps of compacting a polyethylene powder and deforming it to impart the oriented structure.

Abstract: An auxetic polymeric material is manufactured in a filamentary or fibrous form. The auxetic polymeric material has a negative Poisson ratio so that it has the property of expanding or contracting transversely to a direction in which it is extended or compressed. The process for forming the material involves cohering and extruding heated polymer powder so that the cohesion and extrusion is effected with spinning to produce auxetic filaments. Typically, the power is heated to a temperature sufficient to allow some degree of surface melting yet not high enough to enable bulk melting.

Abstract: A process for extruding of products from fluoropolymers preferably shaped as rods or tubes which have unique physical and other properties resulting from the addition of nanoparticles under unique processing conditions while also utilizing accurate control of processing parameters such as time and temperature and others according to novel methods.

Abstract: The present invention relates to the melt fabrication of fluoropolymer into articles that are useful in semi-conductor manufacture and in transporting liquids, without contaminating the semi-conductor or the liquid with metal contamination arising from metal melt-fabrication equipment. To achieve this result, the article has a smooth surface characterized by an RMS roughness of no greater than 0.20 &mgr;m, so as not to retain metal contaminant.

Abstract: A process for producing unmelted fibrous polytetrafluoroethylene (PTFE) resin from which multi-directional planar oriented structures such as sheets and planar shapes can be readily fabricated. Unfilled forms as well as filled and reinforced products are achievable. Novel composite-plied structures or unsintered sheets can be built by layering two (2) or more sheets containing functional fillers or reinforcements and then sintering said layers to provide a homogenous bond between all layered sheets. True reinforcement of formed fluoropolymer structures can be produced with tensile properties, which exceed the strength of virgin products. Microporous asymmetric membranes, which have decreasing pore size in a series of plies can be readily fabricated.

Abstract: A high density microwall ePTFE structure and a method for making, involving the manipulation of a standard extruded ePTFE graft. The final product has the desired characteristics of high density, reduced wall-thickness, above-average radial strength and enhanced suture retention.

Abstract: A method of forming a polytetraflouroethylene (PTFE) insulation layer over a metallic conductor of a processed product includes the steps of extruding PTFE over a metallic conductor, and heating the PTFE to a temperature substantially below that of the sintering temperature of PTFE to form a sintered PTFE skin over an unsintered PTFE core.

Abstract: A prosthesis, and method for forming same, are provided which includes expanded polytetrafluoroethylene (ePTFE) tubes having angularly offset node and fibril configurations. Also, the node and fibril configurations are angularly offset from the longitudinal axes of the respective tubes, providing resistance against failure in the longitudinal direction.

Abstract: Medical devices such as catheter balloons, stent covers and vascular grafts formed of ultrahigh molecular weight polyethylene. The devices are formed from polyethylene that has been processed so that it is microporous and has an oriented node and fibril structure. The balloons expand compliantly at low strains and are substantially less compliant at higher strains. The invention also comprises methods for making such balloons, including the steps of compacting a polyethylene powder and deforming it to impart the oriented structure.

Abstract: A metal injection-molding feedstock is heated and plasticized. Supercritical carbon dioxide is injected into the feedstock to form micropores when the pressure is reduced and a parts mold is filled. The micropores are retained when the green parts are debindered and sintered.

Abstract: A method of manufacturing PTFE material includes preparing a mixture of PTFE resin powder and a susceptor material which is compacted and sintered by exciting the susceptor material with microwave energy. Preferably, the compaction and sintering of the mixture is carried out in a continuous process and a vacuum is drawn on the mixture in the heating zone to extract any air from the mixture. The sintered mixture may be advanced, preferably continuously, to a cutting zone where the PTFE material may be cut to any desired length preferably while the mixture is still warm to produce anywhere from thin wafer PTFE components to long tubular PTFE hose, or the like.

Abstract: The present invention provides a PFA resin helical blade for use in a compressor, which is superior in dimensional precision and surface smoothness with a superior anti-fatigue property, and a manufacturing method thereof. In a manufacturing method of a compressor-use helical blade of the present invention, a PFA composite resin, which is formed by mixing an inorganic filler with a tetrafluoroethylene/perfluoroalkylvinyl ether copolymer (PFA resin) having a —CH2OH terminal group, which has not been subjected to a stabilizing process, and has fluidity of not ness than 15 g/10 min, is used, and after the resin has been molded into a helical blade through an injection-molding process, the resulting matter is subjected to a heating process at a temperature from 280 to 300° C. for a period from not less than 10 hours to not more than 300 hours.

Abstract: In a method of manufacturing a friction member used for a vibration wave driving apparatus including a vibration member, a contact member which is brought into frictional contact with the vibration member and relatively moved by vibrations produced in the vibration member, and the friction member formed on one of friction portions of the vibration member and contact member, a molded member is formed by compression molding of a fluoroplastic powder and an additive, a sintered member is formed by sintering the molded member, a sheet is formed by cutting the sintered member in the form of a sheet, and a modified layer formed by cutting is removed from the friction surface of the sheet.

Abstract: The present invention provides improved medical introducer devices which incorporate a single or multi-layer PTFE peelable sheath. Devices of the present invention are suitable for use in inserting an ancilliary medical device, e.g., a catheter, guide wire and the like, into a patient. Methods of the present invention also are disclosed which employ a precision sintering process in order to produce sheaths having excellent tear properties and optimal peelability.

Abstract: A PTFE seal and method of fabrication therefor includes preparing a mixture of PTFE resin powder and a susceptor material which is then compacted and sintered by exciting the susceptor material with microwave energy. Preferably, the compaction and sintering of the mixture is carried out in a continuous process and a vacuum is drawn on the mixture in the heating zone to extract any air from the mixture. The sintered mixture is advanced, preferably continuously, to a cutting zone where PTFE wafers are cut from the sintered mixture, preferably while the mixture is still warm.

Abstract: Fluoropolymer materials containing tetrafluoroethylene monomers, such as PTFE, are significantly swollen by supercritical carbon dioxide at high temperatures and pressures. The swollen fluoropolymer is processable by molding, extrusion, and other techniques. In addition, the fluoropolymer may be sintered at significantly lower temperatures compared to a nonswollen fluoropolymer material. The melting temperature of fluorinated polymers containing tetrafluoroethylene and triflouroethylene monomers which are swollen with supercritical carbon dioxide is significantly reduced, thereby permitting manufacturing operations such as extruding and molding to be performed at lower temperatures and with reduced risk of decomposition.

Abstract: In a method of manufacturing a friction member used for a vibration wave driving apparatus including a vibration member, a contact member which is brought into frictional contact with the vibration member and relatively moved by vibrations produced in the vibration member, and the friction member formed on one of friction portions of the vibration member and contact member, a molded member is formed by compression molding of a plastic powder and an additive, a sintered member is formed by sintering the molded member, a sheet is formed by cutting the sintered member in the form of a sheet, and a modified layer formed by cutting is removed from the friction surface of the sheet.

Abstract: Gas-diffusion electrodes containing modified carbon products are described wherein the modified carbon product is a carbon product having attached at least one organic group. The modified carbon product can be used for at least one component of the electrodes such as the active layer and/or the blocking layer. Methods to extend the service life of electrodes as well as methods to reduce the amount of fluorine containing compounds are also described.

Abstract: In an extruder for producing a polytetrafluoroethylene tube having a minimum thickness deviation by extruding a polytetrafluoroethylene paste through an annular portion formed by a core pin (30) and a die orifice (50) around it, the core pin comprises a mandrel connection end (34) which is connected to a mandrel and a die orifice outlet end (36) which is located at a die orifice outlet end, and the core pin has between the ends a portion of which cross-section perpendicular to an axial direction of the core pin has a smaller area than that of a cross-section of each end of the core pin. By using the extruder, the tube having a thickness deviation of not larger than 15% can be obtained.

Abstract: The invention is directed to methods involving rewetting of expandable polymers with a wettable liquid to allow for enhanced expansion at or below room temperature without breakage, and in some cases, allows one to achieve a greater expansion ratio than that allowed at elevated temperatures using known methods. The present invention also allows one to achieve material with unique properties and handling characteristics. These properties included decreased material thickness, increased density, an altered node/fibril morphology, and a more consistent web in the case of flat material. This method is not limited to room temperature conditions and can be applied whenever the expandable polymer material is wet with a wettable liquid, and the expansion is performed at a temperature preferably below the vaporization or boiling points of that liquid.

Abstract: A flat semi-finished product includes a filled fluoroplastics substrate in the form of a sheet, which is coated at least partially on at least one surface with a soft, thin coating of fluoroplastics. The substrate material of the sheet has a Shore-D hardness of at least 65 and the average layer thickness of the thin sheet coating is at most 20 &mgr;m. A component, in particular a flat gasket, is made from the semi-finished product. A process for the production thereof is also provided.

Abstract: A method for producing an electrically conducting melt-processible fluoropolymer comprising pulverizing a composition of (a) carbon aggregate and (b) coagulum particles of aqueous dispersion polymerized melt-processible fluoropolymer, coating the coagulum particle with the disintegrated particles of carbon black. The preferred composition comprises a structured carbon black such as acetylene black and a melt processible fluoropolymer wherein said melt processible fluoropolymer has two crystallization peaks in a DSC cooling curve when allowed to crystallize from a temperature of not less than its melting point at a cooling rate of 12° C./min; and the ratio of the crystallization peak heights (high temperature side peak/low temperature side peak) is 0.65 or greater; and/or the ratio of the high temperature side crystallization peak area to the total area of the crystallization peaks [high temperature side peak area/(high temperature side peak area+low temperature side peak area)] is 0.

Abstract: A method of forming a polytetraflouroethylene (PTFE) insulation layer over a metallic conductor of a processed product includes the steps of extruding PTFE over a metallic conductor, and heating the PTFE to a temperature substantially below that of the sintering temperature of PTFE to form a sintered PTFE skin over an unsintered PTFE core.

Abstract: The present invention provides the use of a mineral oil in a fluoroelastomer composition comprising a fluoroelastomer to improve the flow of said composition during processing to form an article therefrom and/or to improve the release from a mold of a vulcanized article produced from said fluoroelastomer composition. Further provide are a fluoroelastomer composition that includes a mineral oil, a method of making an article therewith and a method of preparing the fluoroelastomer composition.

Abstract: This invention relates to methods for manufacturing large PTFE parts by compression molding followed by sintering. The method comprises layering modified and unmodified PTFE in a mold, and compressing the layers to form a preform part. Once the preform parts are formed, they are assembled such that the areas of preform parts which are to be bonded together are the modified PTFE sections. The parts are then sintered and the modified PTFE sections bond together creating a strong, durable, bond.

Abstract: An method for producing a material useful for forming a component for an electrochemical fuel cell is provided. More particularly, the component is formed of a sheet of a compressed mass of expanded graphite particles. The component is treated with a water resistant additive sufficient to provide utility as a component in an electrochemical fuel cell. Preferably, the water resistant additive is a fluoropolymer material. More preferably, the water resistant additive is a polytetrafluoroethylene material. The treatment preferably occurs by coating and/or impregnating the water resistant material in the sheet of graphite particles.