Abstract: In a method of insulating an electrical conductor, the conductor passes upwardly through a coating fluid and a die means which is carried in a vertical position by a supporting fluid force. This force is provided by the supporting force of the fluid or a magnetic force which holds the die in suspension. Freedom for horizontal movement of the die is provided to enable it to move in a manner corresponding to any lateral movement of the conductor, this die movement being controlled by hydrodynamic forces between conductor and die to maintain the concentricity of a fluid layer formed on the conductor.

Abstract: An insulated wire having excellent heat resistance, abrasion resistance and flexibility can be prepared by coating on an electric conductor directly or via another insulating material a polyamide-imide resin composition prepared by reacting an aromatic diisocyanate and a tricarboxylic acid anhydride in the presence of a basic solvent while adjusting the resin content at 40% by weight or more, and adding to the reaction system a lactam in an amount of 0.1 to 1.0 mole per mole of the aromatic diisocyanate, and if necessary, an alcohol and/or an oxime in an amount of 0.01 to 0.5 mole per mole of the aromatic diisocyanate before, during or after the above-mentioned reaction to mask terminal functional groups and to make the reduced viscosity of the composition 0.1 to 0.27, and baking the resin composition.

Abstract: A method of making a cellulose-free electrical winding having a tubular configuration in which layers of insulating resin and conductors are alternately disposed in a concentric pattern, with opposite edges of the conductor turn layers being coated with overlapping layers of resin. The resin is applied as a liquid in thin layers as the winding is being formed, and the liquid resin is instantly gelled to provide mechanical support for the next winding layer.

Abstract: A process for polymer coating electrical conductors comprises dissolving a polymer in a volatile solvent to provide a solution of the polymer. The solution is maintained in a container provided with an outlet orifice at its lower end. The conductor to be coated is drawn through the solution and out of the bottom orifice which is sized to receive the conductor and the desired wall thickness of the coating. After the coated conductor leaves the orifice, it is passed through a heating chamber to evaporate the volatile solvent.

Abstract: A corona-resistant wire enamel composition is described comprising a polyimide, polyamide, polyester, polyamideimide, polyesterimide, or polyetherimide resin and from about 1% to about 35% by weight of dispersed alumina particles of a finite size less than about 0.1 micron, the alumina particles being dispersed therein by high shear mixing. A method of providing corona resistant one and two-stage insulations for an electrical conductor employing the above compositions and an electrical conductor insulated with a one or two-stage coating of the wire enamel compositions are also disclosed.

Abstract: A low mechanical noise coaxial cable for suppressing noise due to mechanical movement of the cable wherein the cable includes a central conductor, a dielectric surrounding the conductor, electrical shielding embedded in conductive material surrounding the dielectric and preferably, jacketing structure holding the above recited elements in place.

Abstract: Improved enamels and insulated electrical articles produced therefrom are described. The enamels are composed of solutions of curable resin which have been modified to contain nylon polymer. This polymer facilitates application of the enamel to a metallic conductor so as to produce an especially smooth and desirable insulation coating.

Abstract: Disclosed is a UV-curable coating composition and method of preparing it, a method of coating a conductor with it, and the resulting coated conductor. The composition comprises about 20 to about 40% by weight of an acrylated epoxy which is the reaction product of an epoxy resin and an acrylate adduct. The acrylate adduct is the reaction product of an acrylate which may be either 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxyethyl methacrylate or mixture thereof, and either an anhydride or a diisocyanate. The anhydride may be phthalic anhydride, maleic anhydride, trimellitic anhydride, or mixtures thereof. The diisocyanate can be toluene diisocyanate, 4,4'-diisocyanato diphenyl methane, or mixtures thereof. The composition also includes about 4 to about 15% by weight of an acrylated blocked isocyanate which is the reaction product of caprolactam and an acrylated isocyanate.

Abstract: A high solids content, relatively low viscosity, organic solvent solution of polyester magnet wire enamel is described. The enamel is a tris (hydroxy-ethylisocyanurate) polyester having a ratio of hydroxyl to carboxyl groups of 1.65 to 2.0:1 and a hydroxyl number of 216 to 316. Such enamels are produced with solids contents of about 50 to about 70% by weight and viscosity less 1,500 cps at 200.degree. F. The method of making such enamel by reacting a glycol, tris (hydroxy-ethylisocyanurate), and an aromatic diacid or diester in the presence of a titanate catalyst is also described.

Abstract: An enameled wire having resistance to overload which comprises an electric conductor and a baked wire enamel coat is disclosed. The wire enamel coat is applied to the conductor through a die from wire enamel comprising a silicone resin having incorporated therein 50 to 200 phr of particles of an inorganic tabular crystalline material that have a maximum average particle size not greater than 80.mu., an average not greater than 40.mu. and an average aspect ratio between 30 and 100 and which react with the silicone resin at elevated temperatures to become a ceramic and which have been surface-treated with a coupling agent, a surface active agent or a coating agent. The tabular crystals in the wire enamel coat are orientated parallel to the surface of the conductor. The enamel coat has good adhesion to the conductor and will not easily crack or peel off the conductor even when subjected to high temperatures and adverse physical stress.

Abstract: Temperature monitoring of electrically conductive wire during heating in which the current in the wire in the heating zone is measured and the voltage at the downstream end portion of the zone is measured, signals corresponding to the measured values then being combined to produce a resultant signal corresponding to the resistance of the wire at the downstream end portion of the heating zone. The resistance value corresponds to the temperature of the heated wire. Apparatus includes current and voltage measuring means located in the appropriate positions to enable temperature monitoring, and means to combine voltage signals which correspond to the measured values and to produce a combined signal representative of wire resistance after heating.

Abstract: Build control means is provided by which the characteristics of a cloud of electrostatically charged particles can readily be altered, so as to produce an optimal deposit upon any of a variety of workpieces. The means described offers a high degree of flexibility of application for the apparatus in which it is employed, and is particularly adapted for use in coating electrical conductors of rectangular cross section.

Abstract: An improved multilayer electric cable is disclosed having a conductive core, an extruded strand shield (ESS) layer, an insulating layer of polymeric insulation material surrounding the core and coaxial therewith, a semi-conductive insulation shield (EIS) layer strippably bonded to the insulation layer surrounding it and coaxial therewith and, preferably, a plurality of axially extending drain wires disposed within the semiconductive EIS layer. The semi-conductive EIS layer is formed of a copolymer of an ethylene/alkylacrylate/monoalkyl ester of 1,4-butenedioic acid copolymer, conductive carbon black, and a peroxide curing agent and preferably also a copolymer of ethylene and propylene or a copolymer of ethylene, propylene and an unconjugated diene. The semi-conductive EIS layer is applied by extrusion at elevated temperature in a dry gas atmosphere.

Abstract: A process for manufacturing a polyester resin insulated wire involves coating a resin consisting essentially of a saturated substantially linear polyester resin prepared by reacting (i) an aromatic dicarboxylic acid or a dicarboxylic acid in which an aliphatic dicarboxylic acid is substituted for part of the aromatic dicarboxylic acid, and (ii) an aliphatic diol or an aromatic diol on a conductor having a copper surface without use of a solvent, and then heating the coated conductor in oxygen or an oxygen-containing gas at a temperature higher than the melting point of said linear polyester resin to permit cross-linking in the coated resin.

Abstract: An improved multilayer electric cable is disclosed having a conductive core, an extruded strand shield (ESS) layer, an insulating layer of polymeric insulation material surrounding the core and coaxial therewith, a semiconductive insulation shield (EIS) layer strippably bonded to the insulation layer surrounding it and coaxial therewith and, preferably, a plurality of axially extending drain wires disposed within the semiconductive EIS layer. The semiconductive EIS layer is formed of a copolymer of an ethylene/acrylate/monoalkyl ester of 1,4-butenedioic acid copolymer, conductive carbon black, a peroxide curing agent and polyethylene or polyethylene copolymer. The semiconductive EIS layer is applied by extrusion at elevated temperature in a dry gas atmosphere.

Abstract: Electrical coating compositions comprise blended polyesterimides and from 1 to 20 percent by weight of total solids of an ester terminated amide imide. Such compositions provide insulation coatings on electrical conductors which have superior smoothness, even after high speed coating operations.

Abstract: Method and apparatus for filling a cable core unit with powder in a fluidized bed in which the unit is vibrated laterally by introducing energy pulsations into the bed, the pulses being transmitted as successive waves through the powder particles to transfer the energy to the unit and set up the vibration. In preferred constructions, the pulsations are set up by a reciprocating piston means disposed beneath the upper surface of the powder. There may be two or more piston means spaced in the feed path direction for the unit or a single piston extending.

Abstract: A wire or other core is enclosed by two concentric extruded layers, at least one of which is of crystallizable polymeric material, by extruding the layers in succession around but spaced from the core. The first and second layers are brought into thermal and mechanical engagement with each other before the first contacts the core, and the relative thermal capacities of the parts and the temperatures of the layers as they are brought into engagement are such that as the second layer cools and increases in strength and the first layer is heated by thermal transfer from the second layer and decreases in strength, a region of least overall yield strength is formed at a position where the temperature of at least one of the parts (being made of a crystallizable polymeric material) is at a temperature between its glass transition temperature and its crystalline melting point.

Abstract: A magnet wire having a nylon outer coating is described which is capable of power insertion into coil slots in a locking wire size range by virtue of a specific lubricant outer coating. The external lubricant comprises a mixture of paraffin wax and hydrogenated triglyceride. An internal lubricant composition comprised of esters of fatty alcohols and fatty acids and/or hydrogenated triglyceride can be added to the nylon coatings to provide greater ease of insertability.

Abstract: A method of improving the physical and electrical properties of polymer insulation coated electrical conductors is described. A non-ionic surfactant added to an organic solvent solution of insulation polymer followed by coating the solution on the wire, drying and curing, has been found to produce a coated magnet wire with improved concentricity and smoothness, therefore resulting in improvement in other wire properties as well.

Abstract: A bondable electrical conductor is made of an adherent insulating resinous first layer, directly covered by an adhesive layer consisting essentially of the uncatalyzed mixture of epoxy resin, having an epoxy equivalent weight of from about 250 to about 750, and a phenoxy resin.

Abstract: A heat-resistant insulated electric wire and cable which comprises an electric conduction; the first coating layer thereon consists of a mixture of a binder and a finely ground and unmelted inorganic substance; and the second organic insulating coating layer formed on the first coating layer. Said heat-resistant insulated electric wire can advantageously be used for a coil of a magnet or a motor.

Abstract: A water soluble composition including an amine or ammonium salt of a polyimide precursor which is obtained by the reaction steps of: reacting a tetracarboxylic compound and a diamine in about equimolar amounts in a water miscible organic solvent to obtain the polyimide precursor; and reacting the polyimide precursor with ammonia, or an aqueous solution of ammonia, or a primary or secondary aliphatic amine in an amount sufficient to neutralize the free carboxyl groups of the polyimide precursor.A process of coating and a substrate are also disclosed.

Abstract: An electromagnetic coil for high temperature and high radiation application in which glass is used to insulate the electrical wire. A process for applying the insulation to the wire is disclosed which results in improved insulation properties.

Abstract: A tinned conductor is advanced through each of a plurality of successively smaller die openings in a drawing apparatus to reduce the diameter of the tinned conductor after which it is annealed. After the tinned conductor has been annealed, it is moved through the opening of a die which is slightly smaller than the final die opening in the drawing apparatus. This reconfigures any of the tin coating that may have reflowed during annealing and formed protrusions to remove any such protrusions and form an essentially smooth surface. As a result, the adhesion of a subsequently extruded plastic covering to the tinned conductor is controlled to be within a predetermined range and to be substantially uniform along the length of the conductor.

Abstract: A method is disclosed for substantially reducing shrink back of thermosetting materials from electrical cable. The method comprises reheating the cable, after curing of the thermosetting material and cooling of the cable, to a temperature below the melting point of the thermosetting material.

Abstract: A process and apparatus for filling multi-conductor cables, particularly a telecommunication cable with several insulated wires surrounded by a covering and a sheath, with a mixture of powders which expand with the absorption of moisture. The conductors are fed in spaced relation into the entrance of a casing having an interior, frusto-conical wall which decreases in diameter from its entrance to its exit. The exit is small in diameter compared to the entrance so that the conductors converge as they pass from the entrance to the exit. Intermediate the entrance and the exit, the conductors are subjected to the powders which are caused to follow a helicoidal course by a screw which directs them toward the exit. Due to the shape of the casing wall, the powders are forced toward the conductors.

Abstract: A method of coating products such as metallic coil formers and wire containing the components of an intermetallic superconductive compound in which the coating is flexible at room temperatures but which has good insulating properties after heat treatment, the coating comprising a mixture of sodium silicate, chalk and China clay which reacts on heat treatment to form an insulating ceramic but which is flexible when merely dried.

Abstract: Heat treating stranded together conductors in a reeled condition by passing electrical current along a path through some of the conductors in one direction around the reel and then through other conductors in the opposite direction around the reel. In preferred methods, the current is passed in one direction through one half of the conductors and then in the opposite direction through the other half.

Abstract: Improved enamels and insulated electrical articles produced therefrom are described. The enamels are composed of solutions of curable resin which have been modified to contain nylon polymer. This polymer facilitates application of the enamel to a metallic conductor so as to produce an especially smooth and desirable insulation coating.

Abstract: Provision of a protective cover for a fibrous layer of insulation on a conductor by forming an inner layer of the protection cover by depositing a polymeric based composition without creating a crushing effect, and then, in tandem, hardening the inner layer and applying a second coat by extrusion. The inner layer absorbs the crushing forces of extrusion to protect the fibrous layer during addition of the second layer. The inner layer is preferably formed by electrostatic deposition coating and prevents pinhole formation in the second layer.

Abstract: A process for producing a crosslinked polyethylene insulated cable having an outer semiconductive layer which comprises providing an internal semiconductive layer, and an electrically insulating layer on an electrical conductor in conventional manner, coating by extrusion a resin composition comprising 100 parts by weight of an ethylene/vinyl acetate copolymer having a vinyl acetate content of at least about 55% by weight and about 5 to about 100 parts by weight of carbon black and a crosslinking effective amount of a crosslinking agent on said electrically insulating layer and heating said coated composition to at least about 230.degree. C. to crosslink said resin composition is disclosed. This process assures high production speed.When the ethylene/vinyl acetate copolymer used has a vinyl acetate content of at least about 80% by weight the outer semiconductive layer can easily be peeled off by hand.

Abstract: A novel method for manufacturing magnet wire in a continuous process by which coatings of a flowable resin material may be applied concentrically to a moving elongated filament in thicknesses of about 16 mils or less. The filament can be a bare copper or aluminum conductor having round or rectangular configuration or an insulated conductor upon which a top or an intermediate coat of material is desirably applied. Coatings of one-half and one mil also can be applied by the method of the invention. By the method of the invention, magnet wire can be manufactured by continuously drawing the wire to size, annealing the wire, if necessary, insulating the wire with one or more coats of flowable resin material, curing the resin material, and spooling the wire for shipment, without interruption at speeds limited only by the filament pay-off and take-up devices used. The invention utilizes the flowable resin material to center the filament in a die, the size of the die controls the thickness of the coat to be applied.

Abstract: Hot-melt electrical coating compositions comprise high solids content polyesterimides prepared to an acid number of less than 6-7 in the presence of a monoether or monoester of a glycol or polyglycol and reacted hot with a blocked polyisocyanate. Such virtually solventless compositions provide insulation coatings on electrical conductors which have superior flexibility, especially after aging.

Abstract: A magnet wire having a polyamide-imide outer coating is described which is capable of multiple winding power insertion into coil slots without damage by virtue of an improved lubricant outer coating. The lubricant comprises a mixture of oleic acid, beeswax, fluorocarbon surfactant and paraffin wax.

Abstract: Disclosed are very fine wires, of the order of 3-6.times.10.sup.-6 m diameter, having cross sections which are uniform within .+-.3%. A common drawn tungsten wire is electrolytically etched to a fine diameter, of the order of 2-4.times.10.sup.-6 m. The variations in cross sectional area along the etched wire are eliminated by selectively vapor depositing tungsten on the surface while using resistance heating. The very fine uniform wires enhance the performance of devices such as fluidic angular rate motion sensors.

Abstract: A method of impregnating a cable with a water impenetrable and water repellent sealing material comprising passing the cable axially through a pipe having open ends such that the pipe and cable form an annular gap along the length of the pipe. The gap is relatively thin compared to the diameter of the cable. A heated flowable sealing material is injected under pressure into the gap at an intermediate position between the open ends of the pipe so that the sealing material will flow inwardly into the cable during passage thereof through the pipe while the excess material travels axially along the cable in the gap and freely flows axially outwards from the ends of the pipe for collection and recirculation. The solidified filling material forms a solid barrier protecting the cable against penetration of water.

Abstract: A high strength, lightweight composite wire is made by intercalating grape fiber with a material that will impart high electrical conductivities to the fiber. The intercalated fiber is coated with a wetting agent and the coated intercalated graphite fiber then placed in a molten bath of magnesium or a low melting magnesium alloy. A composite wire is then produced by extrusion through a suitable die.

Abstract: A method and apparatus for retarding electrochemical tree-type decomposition of polyolefin electrical insulation by saturating the insulation with a liquid having high resistivity and a low dielectric constant. The insulation of cables which have already been in service is dried prior to being saturated with the liquid. One embodiment of the invention provides a continuing supply of liquid to the cable after it has been buried underground.

Abstract: A method and apparatus are disclosed by which electrical conductor cable can be produced utilizing electrostatic coating means, which method and apparatus are highly convenient, uncomplicated and economical to carry out. An outstanding and unique feature of the cable produced in accordance herewith resides in the presence of a web portion of reduced cross-section connecting the individual conductors, by which manual severence of one from another is facilitated. Most desirably, the apparatus and method provide means for producing individual insulating coatings on each of the conductors, which means ideally utilizes an electrostatic cloud coating technique.

Abstract: A method for increasing resistance to treeing in a polymeric layer comprising an insulating layer on a metal conductor. Pellets of an organic polymeric material also containing an organo silane treeing inhibitor are exposed to ultraviolet radiation, and pellets having portions fluorescing above a predetermined threshold level are separated from the remainder. The remaining pellets are blended together and applied to a metal conductor to form a coating on the conductor. In a preferred embodiment, the organic polymeric material is high molecular weight polyethylene, and the ultraviolet radiation has a wavelength of about 3000 to 4000 A.

Abstract: A method of insulating an electrical conductor by applying thereto a coating of a polyesterimide resin which can be hardened through its free OH groups from a resin melt at above 100.degree. C., wherein the resin used is solvent-free and has been prepared by esterification or ester-exchange of starting materials for the polyesterimide in the presence of an excess of one or more short-chain diols and subsequent removal of the diol or diols in such a way that the condensation is only effected to an extent such that the Durrans softening point of the unhardened resin is not above 150.degree. C. (preferably not above 100.degree. C.) and the viscosity of the molten resin at 180.degree. C. is not above 5000 (preferably not above 1000) mPa s (cP). This process avoids the disadvantages encountered when a solvent is present in the insulating bath.

Abstract: This invention relates to a process control system and method of controlling a chemical vapor deposition (CVD) process where a coating is deposited on a substrate heated by passing a current through the substrate to create a heating zone. The control system relies on detecting a signal induced on the coated substrate outside of the heating zone and using the induced signal to control one or more process parameters.

Abstract: Certain thallous and cesium halides, either used alone or in combination with other ceramic materials, are provided in cryogenic applications such as heat exchange material for the regenerator section of a closed-cycle cryogenic refrigeration section, as stabilizing coatings for superconducting wires, and as dielectric insulating materials. The thallous and cesium halides possess unusually large specific heats at low temperatures, have large thermal conductivities, are nonmagnetic, and are nonconductors of electricity. They can be formed into a variety of shapes such as spheres, bars, rods, or the like and can be coated or extruded onto substrates or wires.

Abstract: A magnet wire having a nylon outer coating is described which is capable of power insertion into coil slots in a locking wire size range by virtue of a specific lubricant outer coating. The lubricant comprises a mixture of paraffin wax, hydrogenated triglyceride and ester lubricant composition comprising esters of fatty alcohols and fatty acids. An internal ester lubricant composition comprised of esters of fatty alcohols and fatty acids and/or an internal hydrogenated triglyceride lubricant composition can be added to the nylon coatings to further improve ease of insertability.

Abstract: A magnet wire having a polyamide-imide outer coating is described which is capable of multiple winding power insertion into coil slots without damage by virtue of an improved lubricant outer coating. The lubricant comprises a mixture of oleic acid, beeswax, fluorocarbon surfactant and paraffin wax.

Abstract: A magnet wire having a polyamide-imide outer coating is described which is capable of power insertion into coil slots in a locking wire size range by virtue of a specific lubricant outer coating. The external lubricant comprises a mixture of paraffin wax, hydrogenated triglyceride and an ester lubricant composition comprised of esters of fatty alochols and fatty acids. An internal ester lubricant composition comprised of esters of fatty alcohols and fatty acids can be added to the polyamide-imide coatings to further improve ease of insertability.

Abstract: A method of and an apparatus for producing an electrical conductor wire, especially a profiled heavy wire wherein the wire to be coated is guided subsequently through applying means, calibrating means and through a hardening chamber in which the individual layers of varnish are exposed to ultraviolet radiation of different intensity of irradiation. The layers which are applied onto the conductor wire in superposing manner have different properties wherein the wire is running through the apparatus after each occurring application of varnish.

Abstract: A method of applying substantially consistent and uniform coatings of a corrosion preventive compound to metallic cable lengths is disclosed which involves the immersion of the cable into a liquid coating compound of controlled viscosity followed by wiping the cable with a compound-containing material upon withdrawal of the cable from the compound.

Abstract: A method and apparatus for forming an electrically conductive layer on a corrosion-resistant layer which covers a cable. The cable is passed through a powder accumulating tank in which are mixed an electrically conductive powder and binder powder so as to allow the mixed powder to initially adhere to the surface of the cable. The mixed powder is then pressed against the surface of the cable first at a cable outlet of the powder accumulating tank and then with a powder applying device in which an endless powder applying belt or cloth is rotated around the cable at a rotational speed dependent upon the linear speed of the cable. The surface of the cable is then heated to melt the binder powder and cause the electrically conductive powder to yet more firmly adhere to the surface of the cable. The cable is then cooled and wound.