Abstract: A piezoelectric fiber optic phase modulator having a mount at a nodal point of the vibratory system of the modulator. The modulator is excited with an electric field applied in a direction parallel to the axis of the modulator or perpendicular to the radial direction of movement of the modulator. In contrast to the mere hollow cylinder modulator of the related art, the modulator of this invention has a web or center structure integral with the inside surface of the cylinder. The modulator here has a rugged mount, low absorption vibration and negligible harmonics at the mount for efficient and high Q functioning, and has rugged electrical connections for dependable operation.

Abstract: A pellicle for use on a photomask reticle in conjunction with deep ultraviolet light wavelengths. The membrane of the pellicle comprises a purified fluoropolymer that has been spin coated on a glass substrate treated with a surface modifier and then separated and mounted on an aluminum frame. The aluminum frame has vents that filter air of contaminants and which allow an equalization of air pressure on both sides of the pellicle membrane when a peel-off backliner is in place on the opposite side of the frame. A permanent bond is made between the membrane and frame and a sticky adhesive is used to keep the backliner on the frame until peel-off. The sticky adhesive is such that the backliner may be re-attached a plurality of times.

Abstract: A process for the production of structural and semi-structural composites formed by compressing planar layers of nonwoven preform materials formed from aqueous blends of reinforcing fibers and thin thermoplastic fluoropolymer flake. The flakes have an irregular periphery with microfibrils extending therefrom, having a Canadian Standard Freeness of from 800 to 883. The planar layers which are unconstrained in the in-plane direction are preconsolidated by heating the layer to above the melting point of the fluoropolymer, the applying pressure normal to the plane of the layer causing the fluoropolymer to flow thus orienting the fibers in the plane of the layer. The composites are useful in applications which require higher strength and/or modulus, and where chemical and/or heat resistance is needed, as in chemical processing.

Abstract: A novel highly diffuse, consistent reflectance, non-thermochromic and desirable and waterproof series of color standards of sintered fluorinated long-chain addition polymer doped with appropriate pigments, and a method of fabricating the same involving packing and compression density control of the pigment/polymer mixture and concentration control of the pigment dopant in the pre-sintering steps.

Abstract: The present invention is directed to a process for making an array of tapered photopolymerized waveguides. A photomask having opaque and transparent regions is placed in substantial contact with a substrate having a substantially uniform thickness of photopolymerizable mixture thereon. The photopolymerizable mixture is then exposed through the transparent regions of the photomask to substantially collimated actinic radiation for a time sufficient to form an array of tapered photopolymerized waveguides. The photomask and photopolymerizable mixture which was not substantially polymerized by the substantially collimated actinic radiation are then removed from the substrate. The tapered waveguides are useful as a display means in direct view devices and projection display devices.

Abstract: According to the present invention, the copolymers of ethylene vinyl alcohol are extruded using extrusion equipment coated with a fluoropolymer. This method improves the processability, alleviates/slows down die buildup, improves the extrudate quality by reducing die lines on surfaces of the extruded product.

Abstract: A dual porosity PTFE tube including an inner surface of expanded PTFE material having a first porosity and an outer surface of expanded PTFE material having a porosity different from that of the inner surface. The preferred method includes the step of forming inner and outer preformed tubular billets of PTFE resin particles mixed with a lubricant; the outer billet is adapted to closely fit around and concentric to the inner billet. Porosity of the inner and outer surfaces is varied by changing, in the respective billets, the lubrication level and/or the PTFE resin characteristic average particle size. The inner billet is placed inside the outer billet, and the two are extruded together, thereby melding the two billets. The extrudate is then longitudinally expanded and sintered. The inner surface of the resulting PTFE tube exhibits a different porosity than the outer surface of the tube; the porosities of the inner and outer surfaces are both within a range of about 0.10-200.mu..

Abstract: The invention provides a process for preparing a gas-diffusion electrode for metal-air batteries and fuel cells of the type having a blocking layer formed from a precursor containing carbon black and particulate hydrophobic polymeric binders, comprising heating the carbon black at a temperature of about 400.degree.-1,200.degree. C. for a period of about 1-10 hours in a reducing environment, prior to the formation of the precursor, whereby hydrophilic centers in the pre-treated carbon black are minimized without increasing its corrosivity/surface area and thereby increasing the stability in concentrated KOH at high-cell operating temperatures of a blocking layer formed from the pre-treated carbon black.

Abstract: A method of forming porous articles with a varying pore distribution by extrusion from a billet with a varying lubricant distribution. A single-polymer polytetrafluoroethylene is extruded and then stretched and sintered to provide a differential porous PTFE structure composed of fibers and nodes connected to one another by these fibers. The microfibrous structure has a portion within the cross-section that possesses a different pore size, accompanied by a different node and fiber geometry, than adjacent areas within that cross section. In a vascular graft, the pores taper inwardly, providing a fluid-tight lumen wall structure that prevents leakage, yet promotes cellular ingrowth and natural tissue regeneration. A node structure of radially-oriented plates provides flexibility, suture strength, and enhanced protection against collapse.

Abstract: A process for producing a polytetrafluoroethylene molded article by isostatic molding is disclosed, the isostatic molding being conducted under a high pressure of from 1,500 to 10,000 kg/cm.sup.2. The resulting molded article is isotropic as regards coefficient of thermal expansion and exhibits improved frictional resistance.

Abstract: A new porous polytetrafluoroethylene (PTFE) and a process for the production thereof is provided. Both the PTFE and the process excel by the fact that polytetrafluoroethylene is radiation-chemically degraded, the degraded polytetrafluoroethylene is mixed with a high-molecular emulsion polymerisate of polytetrafluoroethylene and the mixture is extruded, stretched and may additionally be sintered.

Abstract: A new porous polytetrafluoroethylene (PTFE) and a process for the production thereof is provided. Both the PTFE and the process excel by the fact that polytetrafluoroethylene is radiation-chemically degraded, the degraded polytetrafluoroethylene is mixed with a high-molecular emulsion polymerisate of polytetrafluoroethylene and the mixture is extruded, stretched and may additionally be sintered.

Abstract: Methods of compression molding powdered polytetrafluoroethylene resins to produce composite articles of manufacture having at least two distinct layers of two types of PTFE resin are disclosed. A first layer of resin, preferably including a filler, is placed in a compression mold and partially compressed at a relatively low pressure. A second layer of resin, preferably virgin resin, is then added to the mold and both layers are simultaneously fully compressed. After compression, the resulting composite preform is preferably sintered and coined to create a finished PTFE material or product. In a preferred embodiment, the partial compression step is performed at pressures of less than 500 psi. It has been found that modified PTFE resins provide improved resistance to cold flow and also provide better binding between filled and unfilled (virgin) layers and thus are used in certain preferred embodiments.

Abstract: A method for making an optical fiber bundle which, in one aspect, includes bending each of a plurality of optical fibers to form a bend therein and then suspending the fibers over a suspension member; holding the fibers taut under tension; applying potting material to the fiber bends and curing it; and removing the fibers from the suspension member.

Abstract: Using an unsintered or sintered polytetrafluoroethylene yarn as at least part of warp and/or filling, a seamless tubular fabric is constructed. This construction is made by circular weaving or by inserting the filling into the warp prepared in the form of a hank or skein.

Abstract: Particles of a fine powder of a thermoplastic synthetic resin (host powder) having a suitable broad range between its initial glass transition temperature (initial T.sub.g) and its final T.sub.g, are partially coated with an anti-caking coating powder (coating powder) by blending at an elevated temperature to form "mottled" particles. The elevated temperature is defined in relation to the initial and final T.sub.g s as: (initial T.sub.g -20).degree. C. but below the final T.sub.g. Mottled particles, without being encapsulated, have the unique ability to maintain their individual particulate characteristics at a temperature at least 10.degree. C. above the initial T.sub.g of the uncoated host powder, and flow freely under applied pressure. Such pressure is applied by a rolling drum which spreads the mottled particles onto a target bed where they are selectively sintered With a controlled high energy beam, usually a laser beam.

Abstract: A process for the manufacture of tubes made of fluoro resin, especially of polytetrafluoroethylene, which can be employed especially as corrosion-resistant coatings for piping components, in particular those made of steel, for conveying chemical products.

Abstract: A method to produce nonlinear optical microcomponents is described which employs hitherto not yet used material combinations. Not only waveguide structures are produced by means of X-ray depth lithography, but also microcell structures, into which materials having nonlinear optical properties are introduced. The microstructure is produced as a positive mold part, from which there is subsequently generated, by means of electroforming, a mold insert, a negative of which is made using a polymer material. After the molding operation the microstructure is applied to a substrate, and nonlinear optical material, covered by a cover plate if needed or desired, is introduced into the microcell structure.

Abstract: A finished ophthalmic lens is made by using a pre-manufactured lens or lens wafer as a part of a mold for making the finished lens. A polymerizable lens material is injected between the lens or lens wafer and a conventional mold member and a trio of indexers are used to rotate the conventional mold member relative to the lens wafer, to adjust the spatial relationship between the conventional mold member and the lens or lens wafer, and to control the angular relation between them. The assembly is subjected to irradiation and the radiation cures the polymerizable lens material and fuses it to the lens wafer so that the lens or lens wafer becomes an integral part of the finished lens. A finished lens is made in less than one hour.

Abstract: A flexible, reinforced textile composite material for constructing tensioned fabric structures, e.g. for sheltering from the outdoor environment, is disclosed. The material has a hydrophobic protective film element laminated to the textile composite material to provide enhanced hydrophobicity. In a preferred embodiment, of the invention, one or a mixture of colorants, dyestuffs or biological agents are incorporated into the hydrophobic protective film layer. The textile composite material has particular application as a tensioned architectural element for forming a dome, roof or the like, or as an electromagnetic window or a radome.

Abstract: A polytetrafluoroethylene (PTFE) porous film is formed from a PTFE resin molding powder obtained by suspension polymerization. The film has a porosity of 40 to 80% and a removal ratio of uniform particles having a diameter of 0.2 .mu.m less than 99%, or has a porosity of 40 to 80% and a bubble point of not less than 3 kg/cm.sup.2. This PTFE porous film is obtained by a process of compression-molding a PTFE resin molding powder to prepare a preform, sintering the preform at a temperature not lower than the melting point of the unsintered PTFE, processing the preform into films, then laminating at least two of the obtained films, fusing the films to unite them, and subjecting the obtained film to uniaxial or biaxial stretching at a temperature not higher than a melting point of the sintered PTFE. If desired, the finally obtained film may be subjected to heat setting. In the PTFE porous film of the invention, pores are nearly round and the diameters of the pores are almost uniform.

Abstract: Fluoroelastomers and fluoroplastics are plasticized with high-boiling fluorinated aliphatic cyclic structures to enhance processibility or to improve final properties.

Abstract: A method of manufacturing a molded optical channel waveguide, having a critical internal reflection angle and an exposed surface, and affixing a holographic layer, having gratings formed therein, in overlying relationship with the exposed surface of the optical waveguide. The gratings are positioned to form an angle with the surfaces of the holographic layer such that light rays incident on an upper surface of the holographic layer and substantially normal thereto are diffracted by the gratings into the optical waveguide. Also, light waves travelling within the waveguide emanate outwardly through the holographic layer. Light generators and detectors are mounted to supply light to and receive light from the holographic layer.

Abstract: A method for surface modification of a fluorine resin by irradiating the surface of the fluorine resin containing a heat-resistant light-absorbing polymeric material and/or a light-absorbing material is with laser light. Surface properties of the fluorine resin molded articles, particularly adhesion and wetting properties, can be greatly improved by a simple operation with high efficiency.

Abstract: A method for making a particulate filled polymeric matrix composite film includes mixing a polymeric matrix material with a dispersion of particulate filler in a carrier liquid to form a casting composition and adjusting the viscosity of the casting composition to retard separation of the particulate filler from the composition. A layer of the viscosity-adjusted casting composition is cast on a substrate and the layer is consolidated to form the particulate filled polymer matrix composite film. Films made by the method include very thin, e.g. less than 1.0 mil, fluoropolymeric matrix films highly filled with very small diameter, preferably spherical, particles for use as, e.g. dielectric substrate materials in laminar electrical circuits.

Abstract: The invention provides a single pass wet fabrication process for preparing a gas diffusion electrode for metal-air batteries and fuel cells comprising:a) preparing an active-layer forming dispersion containing catalyzed carbon black, hydrophilic fluorinated polymer and particulate hydrophobic fluorinated polymer in a liquid medium;b) preparing a blocking-layer forming dispersion containing carbon black and particulate hydrophobic polymeric binders in a liquid medium;c) filtering a first of the layer forming dispersions though filtering means to deposit a first layer of damp solids mass;d) filtering a second of the layer forming dispersions through the first deposited damp solids mass before the drying or sintering of the first deposited damp solids mass in order to deposit a second layer of damp solids mass thereon in such a manner that lower components of the second layer of damp solids mass are intermixed with upper components of the first layer of deposited damp solids mass;e) drying and compressing the co

Abstract: A method is proposed for the preparation of a resin membrane suitable for use, for example, as a covering pellicle of a photolithographic mask for patterning of semiconductor devices in the electronic industry. The method comprises the steps of: (a) coating a continuous-length substrate with a solution of the resin by using a roller coater to form a coating layer of the resin solution; (b) drying the coating layer by evaporating the solvent to form a dry resin film on the substrate surface; and (c) peeling the resin film from the surface of the substrate, preferably, in water.

Abstract: This invention provides for a continuous PTFE fiber having on its surface a substantially round profile and a single spiralling seam formed from a continuous sheet of polytetrafluoroethylene which is helically rolled and self-adhered. The PTFE sheet may include microporous PTFE as well as expanded microporous PTFE. The PTFE sheet may be filled with particulate fillers or coated with polymeric coatings prior to the formation of the inventive fiber. The PTFE sheet may be used to contain various filamentary or sheet-like elements with the inventive fiber.The method for producing the inventive fiber is also disclosed.

Abstract: Disclosed are a porous membrane which is made from a material containing, as its main component, a polytetrafluoroethylene resin, and a method of producing a porous membrane comprising forming a hollow or sheet-like film from a mixture of a polytetrafluoroethylene resin dispersion and a fiber-forming polymer, heat-treating the film at a temperature not lower than the melting temperature of the resin, and removing the fiber-forming polymer. Production of polytetrafluoroethylene porous membranes of a variety of pore sizes and porosities is possible by suitably varying the type and amount of additives added to an original liquid. The membrane finds spreading use in the field of separation in high-temperature and strong decomposing or strong dissolving mediums.

Abstract: A fiber of expanded porous polytetrafluoroethylene in which an amount of a conductive particulate filler is incorporated imparting a measure of conductivity to the fiber is disclosed. The fiber may be twisted along its length. The fiber may be a continuous monofilament fiber, a tow, a staple, or a flock.

Abstract: A surgical suture and a process for producing the same are disclosed, which surgical suture comprising a porous body of polytetrafluoroethylene having an outer circumference that is substantially free of pores, with only the interior being made porous.

Abstract: A method for treating the surface of a thin porous film material of tetrafluoroethylene resin is disclosed, which comprises heating said surface to a temperature higher than the thermal decomposition point of said resin so as to decompose and remove part of said surface. The resulting thin porous film material of tetrafluoroethylene resin has an adhesive surface while retaining the desired pore size, hardness, and degree of penetration of adhesive.

Abstract: A porous material of polytetrafluoroethylene consisting essentially of fibers of polytetrafluoroethylene. The porous material of PTFE is produced by heat-treating a molded article prepared by paste extruding of PTFE fine powder under such a condition that the heat-treated molded article shows at least one endothermic peak which appears between an endothermic peak position of the fine powder and an endothermic peak position of a sintered product thereof on a differential scanning calorimeter chart and then is stretched along at least one direction.

Abstract: A process for producing a multilayer polytetrafluoroethylene porous membrane is disclosed, which process comprises at least two layers having different average pore diameters, the process comprising the steps of: filling the inside of a cylinder of an extruding mold distinctively with at least two kinds of polytetrafluoroethylene fine powders with each of which a liquid lubricant has been mixed; paste-extruding the powders to obtain a multilayer extrudate, which is then optionally rolled; removing the liquid lubricant from the multilayer extrudate or the rolled multilayer extrudate to obtain an unsintered multilayer structure; subsequently heating the unsintered multilayer structure at a temperature not lower than the melting point of sintered polytetrafluoroethylene to obtain a semisintered multilayer structure; and then stretching the semisintered multilayer structure at least monoaxially.

Abstract: A porous PTFE film having a thin thickness and good permeability is produced by coating an emulsion of polytetrafluoroethylene on a substrate surface, in particular, a porous polytetrafluoroethylene substrate which has not been heated at a melting point of unsintered polytetrafluoroethylene or higher, heating the coated substrate at a temperature not lower than a melting point of sintered polytetrafluoroethylene to semi-sinter polytetrafluoroethylene, optionally removing the semi-sintered polytetrafluoroethylene film from the substrate, and then stretching the semi-sintered film at least in one direction.

Abstract: A process for the manufacture of a thin-walled tube of fluorinated resin, particularly polytetrafluoroethylene, in which a ribbon of fluorinated resin obtained by lubricated extrusion and calendaring, is wound into a tube on a mandrel, the winding of the ribbon being performed in a plurality of layers, and the thus-wound ribbon on the mandrel being brought to a temperature above the sintering temperature of the fluorinated resin for sufficient time to produce sintering. The wound tube and the mandrel are cooled; while on the mandrel the thin-walled tube is rolled to elongate the tube, to reduce the thickness of the tube, and to increase the inside diameter of the tube; and then the mandrel within the tube is extracted.

Abstract: A method of forming a hose assembly (10) of the type adapted for carrying fuels and other corrosive fluids. An inner liner (16) of a fluorocarbon material is extruded. The inner liner (16) is then passed through a reservoir containing a dispersion including a fluorocarbon polymer material and a fluid. Glass fibers are then braided about the exterior of the inner liner (16) to form a braided layer (18) having the dispersion thereabout such that the dispersion penetrates the interstitial spaces of the braided layer (18). Subsequently, the assembly (10) is heated to remove the fluid. The assembly is then sintered to cure the fluorocarbon polymer material into a coating dispersed throughout the braided layer (18) and about the inner liner (16).

Abstract: To produce a monoaxially stretched shaped article of polytetrafluoroethylene (PTFE), a pasty mass containing PTFE powder is continuously shaped to a shaped body, which is fed over a plurality of rollers or rolls, heated and stretched. The shaped body is heated to a temperature of between 327.degree. and 450.degree. C. prior to stretching strain, it is sintered simultaneously and is then stretched. This process allows for the production of a monoaxially stretched shaped article of PTFE which has strength values in the stretching direction of at least 500 N/mm.sup.2 and a delivery of between 1.80 and 2.30 g/cm.sup.3.

Abstract: A process for preparing a polytetrafluoroethylene granular powder which comprises agitating primary particles of a finely divided polytetrafluoroethylene powder having an average particle size of not more than 100 .mu.m in an aqueous medium containing no organic liquid to form agglomerates while crushing an agglomerated powder in an apparatus having an agitating mechanism of the aqueous medium and a crushing mechanism of the agglomerates within a temperature range between not less than 20.degree. C. and less than 60.degree. C. According to the present invention, the dense polytetrafluoroethylene granular powder having the excellent electric properties and the high bulk density can be obtained without using the organic liquid which is expensive and whose use is restricted.

Abstract: A molding process for preparing long and thick, large porous PTFE articles comprising preparation steps of a powder for molding which includes a step of gelation of PTFE powder; a pre-forming step by a ram-extrusion; a baking step of the pre-formed article under a non-constrained circumstance; and if necessary, a cooling step; said powder for molding being containing a binder which has a melting point of lower than that of PTFE and does not decompose at a baking temperature of PTFE.

Abstract: A method of making a lightweight hose assembly including a step of extruding the inner liner. A nonmetallic material is then braided about the exterior of the liner. The inner liner and braided layer are then passed through a reservoir containing a solution of the fluorocarbon polymer. The solvent is then removed, leaving a fluorocarbon polymer coating dispersed throughout the braided layer.

Abstract: A polytetrafluoroethylene porous film obtainable by applying an aqueous dispersion of emulsion polymerized polytetrafluoroethylene particles having an average minor particle size of 1 to 500 nm and an average aspect ratio of at least 10 on a substrate, drying the applied dispersion and optionally sintering the dried polytetrafluoroethylene particles on the substrate to obtain the polytetrafluoroethylene porous film, which has a uniform thin thickness.

Abstract: A method for shaping a tetrafluoroethylene resin pipe which comprises:(a) winding a porous sheet of tetrafluoroethylene resin which is not sintered around a mandrel,(b) covering the wound sheet with an elastomeric material,(c) isotactically pressing the wound sheet covered with the elastomeric material,(d) removing the elastomeric material from the wound sheet, and(e) sintering the wound sheet. According to the present invention, a dense tetrafluoroethylene resin pipe having excellent appearance and surface smoothness can be easily obtained, while maintaining the advantages inherent in the conventional winding methods.

Abstract: In accordance with the present invention, there is provided a process for producing polytetrafluoroethylene (PTFE) resin molded articles, wherein an unsintered PTFE resin paste extrusion molded article as extruded from an extrusion machine and inserted into a sintering mold having an inside diameter slightly larger than an outside diameter of said unsintered PTFE resin molded article is sintered at a temperature higher than a melting point of the PTFE resin. In another aspect of the invention, PTFE resin molded articles are produced by a process wherein an unsintered PTFE resin paste extrusion molded article immediately after being extruded from an extrusion machine is sized by means of a sizing die, and the unsintered PTFE molded article thus sized is inserted into a sintering mold having an inside diameter slightly larger than an outside diameter of said unsintered molded article, followed by sintering at a temperature higher than a melting point of the PTFE resin.

Abstract: A polytetrafluoroethylene porous material and a process for producing the same are disclosed, the material comprising a mixture of polytetrafluoroethylene having a number-average molecular weight of 2,000,000 or more and polytetrafluoroethylene having a number-average molecular weight of 1,000,000 or less, the material having been stretched at least uniaxially.

Abstract: A hermetically sealing apparatus comprises: a first seal ring made of a rubber-like resilient material and adapted to seal two members which rotate relative to each other; a second seal ring made of a resin and disposed adjacent to the first seal ring on the atmosphere side; and a backup ring secured to the first seal ring. The backup ring has a flange for clamping both the first and second seal rings. The flange is provided with a plurality of holes in such a manner that a portion of the second seal ring contacting the flange bites into the plurality of holes owing to a molding pressure of the first seal ring.

Abstract: A vascular patch for closing an incision in a blood vessel includes a base layer of expanded polytetrafluoroethylene (PTFE) having an outer coating of an elastomeric, biocompatible material such as polyurethane to minimize suture hole bleeding. Suture guidelines are formed upon the ablumenal side of the PTFE base layer prior to application of the elastomeric coating to facilitate proper and consistent placement of sutures. A colorant is added to the elastomeric coating to identify the ablumenal side of the vascular patch. The vascular patch is made by mounting an expanded PTFE tube upon a mandrel and applying a water based PTFE ink as a helical stripe about the outer surface of the PTFE tube to form the suture guidelines. The striped PTFE tube is then dip-coated or spray-coated with the elastomeric coating to which the colorant has been added. The PTFE tube is slit to form a flat sheet from which vascular patches are cut.

Abstract: A polytetrafluoroethylene porous material and a process for producing the same are disclosed, the material comprising a mixture of polytetrafluoroethylene having a number-average molecular weight of 2,000,000 or more and polytetrafluoroethylene having a number-average molecular weight of 1,000,000 or less, the material having been stretched at least uniaxially.

Abstract: A process for preparing an improved expanded porous polytetrafluorethylene product having a higher density and improved cold flow properties and prepared from a paste formed from a polytetrafluoroethylene resin and a lubricant. The method includes extruding the paste through an extrusion die at a reduction ratio of less than 100, calendering the extrudate, removing the lubricant, and heating the extrudate to a temperature greater than the crystalline melting point of polytetrafluoroethylene but generally below the temperature at which thermal decomposition becomes appreciable while concurrently expanding the extrudate to at least twice its original length.

Abstract: Process of melt extruding through an extrusion die whose surface is coated with one or more metal oxides, M.sub.x O.sub.y, wherein M is a metal selected from the group consisting of Ti, Zr, Cr, Fe, Ni, Pd, Pt, Cu, Ag, Au, Al and Si, and x and y are selected to satisfy the valencies of M, a difficultly-melt-processible polymer containing 0.002-2 parts by weight, based on the weight of the polymer, of at least one melt-processible fluorocarbon polymer processing aid having a fluorine to carbon ratio of at least 1:2 and having metal oxide-reactive sites capable of reacting with or physically associating with the metal oxide of the die surface.