MXPA97010301A - Procedure for making metal thread - Google Patents

Abstract

This invention relates to a method for making metallic yarn, which includes: (A) forming metal sheet, (B) cutting said sheet to form at least one strand of wire, and (C) forming said strand of thread to give said strand the desired cross-sectional shape and size. This method is especially suitable for making copper wire, especially copper wire of very fine diameter (for example, about 0.00508 to about 0.508 mm (0.0002 to 0.02 inch

Description

PROCEDURE TO MAKE METALLIC THREAD.

Technical Field This invention relates to a method for making metal wire. More specifically, this invention relates to a method for making metallic yarn through the phases of forming metallic foil, then cutting the foil to form one or more strands of metallic thread, and shaping the strands to give the metallic thread the shape in section and the desired size. This invention is especially suitable for making copper wire. BACKGROUND OF THE INVENTION The conventional method for making copper wire involves the following phases. Electrolytic copper (electrorefined, electroextracted or both) is melted, molded into a bar, and hot-rolled into a rod shape. The rod is then cold worked when it passes through mortise matrices that systematically reduce the diameter while lengthening the yarn. In a typical operation, the rod manufacturer molds the molten electrolytic copper into a substantially trapezoidal cross-sectional bar with rounded edges and a cross-sectional area of about 7 inches square; This bar is passed through a preparatory phase to cut the corners, and then through 12 laminate boxes from which it comes out in the form of a copper rod of 7.93 mm (0.3125 inches) in diameter. The copper rod is then reduced to the desired wire size through standard round mortise matrices. Typically, these reductions occur in a series of machines with a final annealing phase, and in some cases with intermediate annealing steps to soften the worked yarn. The conventional method of producing copper wire consumes considerable amounts of energy and requires a lot of labor and large capital investments. Melting, casting and hot rolling operations subject the product to oxidation and possible contamination with foreign materials, such as refractory and rolling materials, which can then cause problems to the wire drawing machines in general in the form of yarn breaks during stretching. . By virtue of the process of the invention, copper wire is produced in a simplified and less expensive manner compared to the prior art. In one embodiment, the method of the invention utilizes a source of copper, such as copper shot, copper oxide or recycled copper; this procedure does not require the prior art steps of first making copper cathodes, and then hot melting, casting and laminating the cathodes to obtain a copper rod material. SUMMARY OF THE INVENTION This invention relates to a method for making metallic wire, which includes: (A) forming metal sheet; (B) cutting said sheet to form at least one strand of thread; and (C) forming said strand of yarn to give said strand the desired sectional shape and size. This invention is especially suitable for making copper wire, especially copper wire with a very fine or ultra-thin diameter, for example, diameters in the range of about 0.00508 mm to about 0.508 mm (0.0002 to 0.02). inch). BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings, parts and the like are designated by analogous reference numerals. Figure 1 is a flow diagram illustrating an embodiment of the invention, where copper is electrodeposited on a cathode vertically oriented to form copper foil, the sheet is cut and extracted from the cathode in the form of copper wire strand, and the The copper wire is then shaped to give the copper wire the shape in cross-section and the desired sizes. Figure 2 is a flowchart illustrating another embodiment of the invention, where copper is electrodeposited into a cathode horizontally oriented to form copper foil, and then the foil is extracted from the cathode, cut to form one or more strands of yarn coppermade, and the copper wire strands are then shaped to form copper wire with the cross-sectional shape and the desired sizes. Figures 3-20 illustrate cross-sectional shapes of the yarn made according to the invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS The yarn that is made according to the method of the invention can be made of any metal or metal alloy that can be initially transformed into a metal sheet. Examples of such metals include copper, gold, silver, tin, chromium, zinc, nickel, platinum, palladium, iron, aluminum, steel, lead, brass, bronze, and alloys of the foregoing metals. Examples of such alloys include copper / zinc, copper / silver, copper / tin / zinc, copper / phosphorus, chromium / molybdenum, nickel / chromium, nickel / phosphorus, and the like. Copper and copper-based alloys are especially preferred. The metal sheets are made using one of two techniques. Forged or laminated metal sheet is produced by mechanically reducing the thickness of a strip or ingot of the metal by a process, such as lamination. Electrodeposited sheet is produced electrolytically depositing the metal in a cathode drum and then releasing the strip deposited from the cathode. The metal foils typically have nominal thicknesses in the range of from about 0.00508 to about 0.508 mm (0.0002 to 0.02 inch), and in one embodiment from about 0.106 to about 0.355 mm (0.004 to 0.014 inch). The thickness of the copper sheet is sometimes expressed in terms of weight and normally the sheets of the present invention have weights or thicknesses in the order of from about 38.14 to about 4272.1 g / m2 (1/8 to 14 ounces) /square foot). Useful copper sheets are those having weights of from about 915.45 to about 3.051.5 g / m2 (3 to 10 ounces / square foot). Electrodeposited copper sheets are especially preferred. In one embodiment, electrodeposited copper foil is produced in an electroforming stack equipped with a cathode and an anode. The cathode can be mounted vertically or horizontally, and has the shape of a cylindrical mandrel. The anode is adjacent to the cathode and has a curved shape that conforms to the curved shape of the cathode to provide a uniform interval between the anode and the cathode. The interval between the cathode and the anode generally measures from about 0.3 to about 2 centimeters. In one embodiment, the anode is insoluble and is made of lead, lead alloy, or titanium coated with a metal of the platinum family (ie, Pt, Pd, Ir, Ru) or its oxide. The cathode has a smooth surface to receive the electrodeposited copper, and the surface is made, in one embodiment, of stainless steel, chrome-plated stainless steel or titanium. In one embodiment, electro-deposited copper foil is formed on a horizontally mounted rotary cylindrical cathode, and then sheds as a thin sheet when the cathode rotates. Said thin sheet of copper foil is cut to form one or more strands of copper wire, and the copper wire strands are then shaped to obtain the desired cross-sectional shape and size. In one embodiment, copper foil is electrodeposited on a vertically mounted cathode to form a thin cylindrical copper envelope around the cathode. Said cylindrical copper sheath is cut to form a fine strand of copper wire that detaches from the cathode and is then shaped to obtain the desired cross-sectional shape and size. In one embodiment, a copper electrolyte solution flows in the interval between an anode and a cathode, and an electric current is used to apply an effective amount of voltage across the anode and the cathode to deposit copper at the cathode. The electrical current can be direct current or alternating current with DC bias. The flow rate of the electrolyte solution through the interval between the anode and the cathode is generally of the order of about 0, 2 to about 5 meters per second, and in one embodiment about 1 to about 3 meters per second. The electrolyte solution has a concentration of free sulfuric acid in the general range of about 70 to about 170 grams per liter, and in one embodiment about 80 to about 120 grams per liter. The temperature of the electrolyte solution in the electroforming cell is generally in the order of about 25 ° C to about 100 ° C, and in an embodiment of about 40 ° C to about 70 ° C. The concentration of copper ions is generally in the order of about 40 to about 150 grams per liter, and in an embodiment of about 70 to about 130 grams per liter, and in an embodiment of about 90 to about 110 grams per liter. The concentration of free chloride ions is generally up to about 300 ppm, and in one embodiment up to about 150 ppm, and in one embodiment up to about 100 ppm. In one embodiment, the concentration of free chloride ions is up to about 20 ppm, and in one embodiment up to about 10 ppm, and in one embodiment up to about 5 ppm, and in one embodiment up to about 2 ppm, and in one embodiment up to about 1 ppm. In one embodiment, the concentration of free chloride ions is less than about 0.5 ppm, or less than about 0.2 ppm, or less than about 0.1 ppm, and in one embodiment is ceso or substantially zero. The level of impurities is generally not greater than about 20 grams per liter, and is usually not more than about 10 grams per liter. The current density is generally of the order of about 5.35 to about 321 amperes / cm2 (50 to 3000 amperes per square foot), and in an embodiment of about 42.8 to about 192.6 amperes / cm2 (400 to 1800 amps per square foot). In one embodiment, copper is electrodeposited using a vertically mounted cathode that rotates at a tangential velocity of up to about 400 meters per second, and in one embodiment about 10 to about 175 meters per second, and in an embodiment of about 50 to about 75 meters per second, and in one embodiment approximately 60 to approximately 70 meters per second. In one embodiment, the electrolyte solution flows up between the vertically mounted cathode and the anode at a rate of the order of about 0.1 to about 10 meters per second, and in an embodiment of about about 4 meters per second, and in an embodiment of about 2 to about 3 meters per second. During electrodeposition, the electrolyte solution may optionally contain one or more materials containing active sulfur. The term "active sulfur-containing material" refers to materials generally characterized in that they contain a bivalent sulfur atom whose double bonds are directly attached to a carbon atom together with one or more nitrogen atoms also directly attached to the carbon atom. In this group of compounds, the double bond can in some cases exist or alternate between the sulfur or nitrogen atom and the carbon atom. Thiourea is a material that contains useful active sulfur. Thioureas having the nucleus NH- / S = C \ NH- and iso-thiocyanates having the group S = C = N- are useful. Thiosinamine (allyl thiourea) and thiosemicarbazide are also useful. The material containing active sulfur should be soluble in the electrolyte solution and compatible with the other constituents. The concentration of active sulfur-containing material in the electrolyte solution during electrodeposition is in one embodiment preferably up to about 20 ppm, and in the range of about 0.1 to about 15 ppm. The copper electrolyte solution may also optionally contain one or more gelatins. The gelatins that are useful here are heterogeneous mixtures of water-soluble proteins derived from collagen. The animal glue is a preferred gelatin, because it is relatively inexpensive, commercialized and easy to handle. The concentration of gelatin in the electrolyte solution is generally up to about 20 ppm, and in one embodiment up to about 10 ppm, and in an embodiment in the range of about 0.2 to about 10 ppm. The copper electrolyte solution may also optionally contain other additives known in the art to control the properties of the electrodeposited sheet. Examples include saccharin, caffeine, molasses, guar gum, gum arabic, polyalkylene glycols (eg, polyethylene glycol, polypropylene glycol, polyisopropylene glycol, etc.), dithiothreitol, amino acids (eg, proline, hydroxyproline, cysteine, etc.), acrylamide, sulfopropyl disulfide, tetraethylthiuram disulfide, benzyl chloride, epichlorohydrin, chlorohydroxypropyl sulfonate, alkylene oxides (for example, ethylene oxide, propylene oxide, etc.), sulphonium alkane sulfonates, thiocarbamoyl disulfide, selenic acid, or a mixture of two or more of them. In one embodiment, these additives are used in concentrations of up to about 20 ppm, and in one embodiment up to about 10 ppm. In one embodiment, the copper electrolyte solution lacks organic additives. During copper electrodeposition, it is preferred to maintain the applied current density ratio (I) at the diffusion-limited current density (IL) at a level of up to about 0.4, and in an embodiment up to about 0.3 . That is, I / lL is preferably about 0.4 or less, and in one embodiment about 0.3 or less. The applied current density (I) is the number of amperes applied per unit area of the electrode surface. The diffusion-limited current density (lL) is the maximum rate at which copper can be deposited. The maximum deposition rate limits the speed with which copper ions can diffuse to the surface of the cathode to replace those depleted by previous deposition. It can be calculated with the equation t = nFD L ~ d (1-t) The terms used in the above equation and their units are defined below: Symbol Description Units I Current density Amperes / cm2 IL Density of current limited by diffusion Amperes / cm2 n Equivalent load Equivalents / mol F Faraday constant 96487 (Amp) (second) / equivalent C ° Concentration of cupric ions in mass Mol / cm3 D Diffusion coefficient cm2 / second d Thickness of the concentration boundary layer cm t Copper transfer number without dimension The thickness of the boundary layer d is a function of viscosity, diffusion coefficient and flow velocity. In one embodiment, the following parameter values are useful when electroplating copper foil: Parameter Value l (A / cm2) 1.0 n / eq / mol) 2 D (cmVs) 3.5 x 10 s C ° (mol / cm3, Cu +2 (as CuS04)) 1.49 x 10 ~ 3 Temperature (° C) 60 Free sulfuric acid (g / 1) 90 Kinematic viscosity (cm2 / s) 0.0159 Flow rate (cm / s) In one embodiment a rotating cathode is used, and the copper foil is detached from the cathode when it rotates. The sheet is cut using one or more cutting phases to form a plurality of copper strands or strips with cross sections of approximately rectangular shape. In one embodiment, two sequential cutting phases are used. In one embodiment, the sheet has a thickness in the range of about 0.0254 mm (0.001 inch) to about 1.27 mm (0.050 inch), or about 0.101 mm (0.004 inch) to about 0.254 mm (0.010 inch). The sheet is cut into strands having widths of about 6.35 mm (0.25 inch) to about 25.4 mm (1 inch), or about 7.62 mm (0.3 inch) to about 17.78 mm (0.7 inch), or approximately 12.7 mm (0.5 inch). These strands are then cut to widths of about 1 to about 3 times the thickness of the sheet, and in one embodiment the width to thickness ratio is about 1.5: 1 to about 2: 1. In one embodiment, a 170.04 g (6 oz.) Sheet is cut into a strand having a cross section of about 0.203 x 6.35 mm (0.008 x 0.250 inch), and then cut to a cross section of about 0.203 x 0.304 mm (0.008 x 0.012 inch). The strand is then rolled or stretched to give the strand the desired cross-sectional shape and size. In one embodiment, the copper is electrodeposited on a rotating cathode, which has the shape of a cylindrical mandrel, until the copper thickness at the cathode is from about 0.127 mm (0.005 inch) to 1.27 mm (0.050 inch), or about 0.254 mm (0.010 inch) to about 0.762 mm (0.030 inch), or about 0.508 mm (0.020 inch). Then the electro-deposition is interrupted, and the copper surface is washed and dried. A blade is used to cut the copper into a fine copper strand «which then detaches from the cathode. The blade advances along the cathode when it rotates. The blade preferably cuts copper to a depth of about 0.0254 mm (0.001 inch) from the surface of the cathode. The width of the copper strand that is cut is, in one embodiment, from about 0.127 to about 1.27 mm (0.005 to 0.050 inch), or from about 0.254 to about 0.762 mm (0.010 to 0.030 inch), or about 0.508 mm. (0.020 inch). In one embodiment, the copper strand has a square or substantially square cross section of about 0.127 x 0.127 mm (0.005 x 0.005 inch) to about 1.27 x 1.27 mm (0.050 x 0.050 inch), or about 0.254 x 0.254 m (0.010 x 0.010 inch) to about 0.762 x 0.762 mm (0.030 x 0.030 inch), or about 0.508 x 0.508 (0.020 x 0.020 inch). The copper strand is then rolled or stretched to give it the desired cross-sectional shape and size. In general, the metallic thread made according to the invention can have any cross-sectional shape that is conventionally available. These include the cross-sectional shapes illustrated in Figures 3-20. Round cross sections are included (figure 3), squares (figures 5 and 7), rectangles (figure 4), plates (figure 8), ribbed plates (figure 18), tracks (figure 6), polygons (figures 13-16), crosses (figures 9, 11. 12 and 19), stars (figure 10), semicircles (figure 17), ovals (figure 20), etc. The edges of said shapes may be sharp (e.g., Figures 4, 5, 13-16) or rounded (e.g., Figures 6-9, ll, and 12). These yarns can be made using one or a series of turret mills to obtain the desired shape and size. They may have diameters in cross section or major dimensions in the order of about 0.00508 mm to about 0.508 mm (0.0002 to 0.02 inch), and in one embodiment about 0.0254 to about 0.254 mm (0.001 to 0.01) inch), and in an embodiment about 0.254 to about 0.127 mm (0.001 to 0.005 inch). In one embodiment, the wire strands are laminated using one or a series of turret-forming mills, where, in each shaping tube, the strands are passed through two pairs of opposed rigidly formed forming rollers. In one embodiment, said rollers are grooved to produce shapes (e.g., rectangles, squares, etc.) with rounded edges. Motorized turkish mills can be used, where the rollers are driven. The speed of the shank mill can be about 30.48 to about 1524 m per minute (100 to 5000 feet per minute), and in one embodiment about 91.44 to about 457.2 m per minute (300 to 1500 feet) per minute), and in one embodiment approximately 182.88 m per minute (600 feet per minute). In one embodiment, the yarn strands are subjected to sequential passes through three turret mills to convert a yarn of rectanguide cross-section into yarn with square cross-section. In the first, the strands are laminated from a cross section of 0.127 x 0.254 mm (0.005 x 0.010 inch) to a cross section of 0.122 x 0.223 mm (0.0052 x 0.0088 inch). In the second, the strands are laminated from a cross section of 0.122 x 0.223 mm (0.0052 x 0.0088 inch) to a cross section of 0.137 x 0.177 mm (0.0054 x 0.0070 inch). In the third, the strands are laminated from a cross section of 0.137 x 0.177 mm (0.0054 x 0.0070 inch) to a cross section of 0.142 x 0.142 mm (0.0056 x 0.0056 inch). In one embodiment, the strands are subjected to sequential passes through two turret mills. In the first, the strands are laminated from a cross section of 0.203 x 0.254 mm (0.008 x 0.010 inch) to a cross section of 0.220 x 0.236 mm (0.0087 x 0.0093 inch). In the second, the strands are laminated from a cross section of 0.220 x 0.236 mm (0.0087 x 0.0093 inch) to a cross section of 0.228 x 0.288 mm (0.0090 x 0.0090 inch). The strands of thread can be cleaned using chemical, mechanical or electropolishing techniques. In one embodiment, the copper wire strands, which are cut from the copper foil or scratched and detached from the cathode, are cleaned using such chemical, electropolishing or mechanical techniques before arriving at the turret mills for its additional conformation. Chemical cleaning can be carried out by passing the wire through an etching or pickling bath of hot nitric acid or sulfuric acid (for example, approximately 25 ° C to 70 ° C. Electropolishing can be carried out using an electric current and acid Sulfuric Mechanical cleaning can be performed using brushes and the like to remove burrs and similar rough portions from the surface of the yarn In one embodiment, the yarn is degreased with a solution of caustic soda, washed, rinsed, etched with hot sulfuric acid (eg, about 35 ° C), electropule with sulfuric acid, rinses and dries In one embodiment, the wire strands made according to the invention have relatively short lengths (eg, about 152.4 m to about 1524 m (500 at 5000 feet), and in one embodiment approximately 304.8 to 914.4 m (1000 to 3000 feet), and in one embodiment approximately 609.6 m (2000 feet)), and these strands of wire are welded to other strands of thread produced in a similar manner using known techniques (eg, butt welding) to produce strands of thread of relatively long lengths (eg, lengths greater than about 30,480 m (100,000 feet) or more than about 60,960 m (200,000 feet), up to approximately 304,800 m (1,000,000 feet) or more). In one embodiment, the strands of yarn made according to the invention are stretched through a die to obtain strands of round cross section. The matrix can be a run-form matrix (for example, square, oval, rectangle, etc.) to round, where the incoming yarn strand contacts the matrix in the stretching cone along a flat place, and leaves the matrix along a flat place. The included angle of the matrix, in one embodiment, is approximately 8o, 12o, 16o, 24oC or others known in the art. In one embodiment, before stretching, said strands of thread are cleaned and welded (as explained above). In one embodiment, a strand of yarn with square cross section of 0.142 x 0.142 mm (0.0056 x 0.0056 inch) is stretched through a die in a single pass to obtain a yarn of round cross section and a diameter in 0.142 mm (0.0056 inch) cross section (AWG 35). The yarn can then be stretched further through additional dies to reduce the diameter. The drawn wire, especially copper wire, produced according to the method of the invention, has, in one embodiment, a round cross section and a diameter in the range of about 0.00508 mm to about 0.508 mm (0.0002 to 0.02). inch), and in an embodiment of about 0.0254 mm to about 0.254 mm (0.001 to 0.01 inch), and in an embodiment of about 0.0254 mm to about 0.127 mm (0.001 to 0.005 inch). In one embodiment, the wire is coated with one or more of the following coatings: (1) Lead, or lead alloy (80 Pb-20Sn) ASTM B189 (2) Nickel ASTM B355 (3) Silver ASTM B298 (4) Tin ASTM B33 These coatings are applied to (a) preserve the • weldability for wire applications for connections, (b) provide a barrier between the metal and the insulating materials, such as rubber, which would react with the - copper and adhere to it (thus making it difficult to peel the wire insulation to make an electrical connection) or (c) avoid the oxidation of the metal during high temperature service. Tin-lead alloy coatings and pure tin coatings are the most common; Nickel and silver are used for special applications and at high temperature. The metallic thread can be coated by hot dip in a bath of molten metal, electrodeposition or plating. In one embodiment a continuous process is used; this allows coating "in line" after the yarn stretching operation. Twisted yarn can be produced by braiding or guipando several wires to obtain a flexible cable. Different degrees of flexibility can be achieved for a given current driving capacity by varying the number, size and arrangement of the wires. The solid thread, the concentric strand, the cord strand and grouped strand provide increasing degrees of flexibility; In the last three categories, a greater number of finer yarns can provide greater flexibility. The braided thread and the cable can be made in machines called "groupers" or "braiders". Conventional groupers are used to braid small diameter wires (34 AWG to 10 AWG). The individual threads are unwound from coils located along the equipment and are fed on flywheels that rotate around the winding coil to twist the threads. The rotational speed of the arm in relation to the winding speed controls the length of the group. For small portable flexible cables, the wires are usually from 30 to 44 AWG, and there may be up to 30,000 wires in each cable. A tubular grouper can be used, which has up to 18 unwinding coils mounted inside the unit. The thread is unwound from each bobbin, while remaining in a horizontal plane, it is threaded along a tubular barrel and twisted together with other threads by a rotation action of the barrel. At the winding end, the strand passes through a closing die to form the final configuration of the group. The finished strand is wound onto a coil that also remains inside the machine. In one embodiment, the copper wire is coated or covered with an insulation or liner. Three types of insulation or liner materials can be used. These are polymeric, enamel and paper and oil. In one embodiment, the polymers that are used are polyvinyl chloride (PVC), polyethylene, ethylene propylene rubber (EPR), silicone rubber, polytetrafluoroethylene (PTFE) and fluorinated ethylene propylene (FEP). Polyamide coatings are used when fire resistance is of primary importance, as such in yarn bundles for manned spacecraft. Natural rubber can be used. Synthetic rubbers can be used whenever good flexibility is required, such as in welding or mining cables. Many varieties of PVC are useful. These include several that are flame resistant. PVC has good dielectric strength and flexibility, and is especially useful because it is one of the least expensive conventional insulation and lining materials. It is mainly used for communication wire, control cable, construction wire and low voltage power cables. PVC insulation is normally selected for applications that require continuous operation at low temperatures of up to approximately 75 ° C. Polyethylene, because of its low and stable dielectric constant, is useful when better electrical properties are required. Resists abrasion and solvents. It is mainly used for connection wire, communication wire and high voltage cable. Crosslinked polyethylene (XLPE), which is made by adding organic peroxides to polyethylene and then vulcanizing the mixture, produces better heat resistance, better mechanical properties, better aging characteristics, and absence of cracking by environmental stresses. Special compositions can give flame resistance in cross-linked polyethylene. The usual sustained maximum operating temperature is approximately 90 ° C. PTFE and FEP are used to isolate yarn for jet aircraft, wire of electronic equipment and special control cables, where the resistance to heat, resistance to solvents and high reliability are important. These electrical cables can operate at temperatures up to approximately 250 ° C. Said polymeric compounds can be applied onto the yarn using extrusion. Extruders are machines that convert pellets or thermoplastic polymer powders into continuous covers. The insulation compound is loaded into a hopper that feeds it into a long heated chamber. A screw in continuous rotation takes the pellets to the hot zone, where the polymer softens and becomes fluid. At the end of the chamber, the molten compound is expelled by a small die onto the moving wire, which also passes through the hole in the die. As the insulated wire exits the extruder, it is ed by water and wound into coils. The EPR and XLPE liner yarn preferably passes into a vulcanization chamber before ing to complete the crosslinking process. The film-coated yarn, generally thin thread for coils, generally includes a copper wire coated with a thin, flexible enamel film. Said insulated copper wires are used for electromagnetic coils in electrical devices, and must be capable of withstanding high breaking voltages. The temperature bands are of the order of from about 105 ° C to about 220 ° C, depending on the composition of the enamel. Useful enamels are based on polyvinyl acetals, polyesters and epoxy resins. The equipment for coating the thread with enamel is usually designed to simultaneously isolate a large number of threads. In one embodiment, the yarns are passed through an enamel applicator which deposits a liquid enamel of controlled thickness on the yarn. The yarn then passes through a series of furnaces to cure the coating, and the finished yarn is collected on reels. To form a heavy enamel coating, it may be necessary to run the threads through the system several times. Powder coating methods are also useful. These prevent the release of solvents, characteristic of the curing of conventional enamels, and thus facilitate the compliance of OSHA and EPA standards by the manufacturer. Electrostatic sprays, fluidized beds and the like can be used to apply such powder coatings. Referring now to the illustrated embodiments, and initially to Figure 1, a method for making copper wire is described, where copper is electrodeposited on a cathode to form a thin cylindrical copper envelope around the cathode; said cylindrical copper shell is then cut to form a fine strand of copper wire that detaches from the cathode and is then shaped to give the yarn the desired cross-sectional shape and size (e.g., round cross-section with a diameter in cross section from about 0.0058 to about 0.508 mm (0.0002 to 0.02 inch) The apparatus used in this method includes an electroforming cell 10 which includes a tub 12, a cylindrical anode 14 mounted vertically, and a cathode Cylindrical 16 mounted vertically The tank 12 contains electrolyte solution 18. Also included are a cutter 20, a turret shaping mill 22, the matrix 24 and the coil 26. The cathode 16 is shown in transparency immersed in the electrolyte 18 in the tank 12, also shown removed from the tank 12 next to the cutter 20. When the cathode 16 is in the tank 12, the anode 14 and the cathode 16 are mounted coaxially, the cathode 16 being placed within the anode 14. The cathode 16 rotates at a tangential velocity of up to about 400 meters per second, and in one embodiment about 10 to about 175 meters per second, and in one embodiment about 50 to about 75 meters per second, and in one embodiment approximately 60 to approximately 70 meters per second. The electrolyte solution 18 rises between the cathode 16 and the anode 14 at a rate of the order of about 0.1 to about 10 meters per second, and in one embodiment about 1 to about 4 meters per second, and in one embodiment about 2. at approximately 3 meters per second. Voltage is applied between the anode 14 and the cathode 16 to effect electrodeposition of the copper at the cathode. In one embodiment, the current used is direct current, and in one embodiment it is alternating current with DC bias. In electrolyte 18, the copper ions gain electrons on the peripheral surface 17 of the cathode 16, whereby copper metal is electrodeposited in the form of a copper cylindrical shell 28 around the surface 17 of the cathode 16. Electrodeposition of copper at the cathode 16 it proceeds until the thickness of the copper envelope 28 is at a desired level, for example, about 0.127 to about 1.27 mm (0.005 to 0.050 inch). Then the electrodeposition is interrupted. The cathode 16 is withdrawn from the tub 12. The copper casing 28 is washed and dried. The cutter 20 is then activated to cut the copper casing 28 in a fine continuous strand 30. The cutter 20 advances along the screw 32 when the cathode 16 is rotated about its central axis by the support and drive element 34. The rotating blade 35 cuts the copper casing 28 to a depth of about 0.0254 mm (0.001 inch) from the surface 17 of the cathode 16. The wire strand 36, which has a rectangular cross-section, emerges from the cathode 16, it is passed through the shank mill 22, where it is rolled to convert the cross-sectional shape of the wire strand into a square shape. The yarn is then stretched through the die 24, where the cross-sectional shape becomes a round cross-section. The thread is then wound onto a coil 26. The process exhausts copper ions and organic additives from the electrolyte solution 18. These ingredients are continuously filled. The electrolyte solution 18 is taken out of the tank 12 by the line 40 and recirculated through the filter 42, the digester 44 and the filter 46, and then reintroduced into the tank 12 via the line 48. Acid sulfuric from tub 50 is taken to digester 44 through line 52. Copper from source 54 is introduced into digester 44 along path 56. In one embodiment, the copper introduced into digester 44 is shaped of copper shot, copper wire scrap, copper oxide or recycled copper. The copper is dissolved in the digester 44 by the sulfuric acid and air forming a solution that contains copper ions. Organic additives are added to the recirculating solution in line 40 from a tub 58 through line 60. In one embodiment, active sulfur-containing material is added to the recirculating solution in line 48 through line 62 from a cuba 64. The rate of addition of said organic additives is, in one embodiment, in the order of up to about 14 mg / -min / kA, and in one embodiment up to about 0.2 to about 6 mg / min / kA , and in an embodiment from about 1.5 to about 2.5 mg / min / kA. In one embodiment, no organic additives are added. The illustrated embodiment described in Figure 2 is identical to the embodiment described in Figure 1, except that the electroforming stack 10 of Figure 1 has been replaced by the electroforming stack 110 in Figure 2.; tank 12 has been replaced by tank 112; the cylindrical anode 14 has been replaced by the curved anode 114; the vertically mounted cylindrical cathode 16 has been replaced by the horizontally mounted cylindrical cathode 116; and the cutter 20, the screw 32 and the support and drive element 34 have been replaced by the roller 118 and the cutter 120. In the electroforming cell lio a voltage is applied between the anode 114 and the cathode 116 to effect electrodeposition of copper in the cathode. In one embodiment, the current used is direct current, and in one embodiment it is alternating current with DC bias. In the electrolyte solution 18 the copper ions gain electrons on the peripheral surface 117 of the cathode 116, whereby copper metal is electrodeposited in the form of a copper foil layer on the surface 117. The cathode 116 rotates about its axis, and the sheet layer is removed from the surface 117 of the cathode in the form of a continuous sheet 122. The electrolyte is circulated and filled in an identical manner to that described above with respect to the embodiment described in Figure 1. The copper foil 122 detaches from the cathode 116 and passes over the roller 118 a and through the cutter 120, where it is cut into a plurality of continuous strands 124 of copper wire with cross sections of rectangular or substantially rectangular shape. In one embodiment, the copper foil 122 is advanced to the cutter 120 in a continuous process. In one embodiment, the copper foil is detached from the cathode 116, stored as a roll, and then passed through the cutter. The rectangular strands 124 advance from the cutter 120 through the turret mill 22, where they are laminated obtaining strands 126 of square cross sections. The strands 126 are then stretched through the die 24, where they are stretched to form copper wire 128 of round cross section. Copper wire 128 is wound on coil 26. The following examples are given for the purpose of illustrating the invention. EXAMPLE 1 Electrodeposited copper foil with a weight of 1830.9 g / m2 (6 ounces / square foot) is made in an electroforming cell using an electrolyte solution with a copper ion concentration of 50 grams per liter, and a concentration of sulfuric acid of 80 grams per liter. The concentration of free chloride ions is zero, and no organic additives are added to the electrolyte. The sheet is cut, then passed through a hammer mill and then stretched through a die to form copper wire. Example 2 An electrodeposited copper foil sheet is 84 inches wide, 0.203 inches thick and 600 feet long. Using a series of cutters, the sheet is reduced from the original width of 213.36 cm (84 inches) to ribbons of 6.35 mm (0.25 inch) wide. The first cutter reduces the width from 213.36 cm (84 inches) to 60.96 cm (24 inches), the second from 60.96 cm (24 inches) to 5.08 cm (2 inches), and the third from 5.08 cm (2 inches) to 6.35 mm (0.25 inches). The 6.35 mm (0.25 inch) ribbons are cut into ribbons at 0.304 mm (0.012 inch). These ribbons, or cut copper wires, have a cross section of 0.203 x 0.304 mm (0.008 x 0.012 inch). Said copper wire is prepared for forming and shaping operations of the metal. This consists of degreasing, washing, rinsing, pickling, electropolishing, rinsing and drying. The separated strands of wire are welded and wound to unroll for further processing. The strands of thread are clean and without burrs. They conform to round cross section using a combination of rollers and drawing dies. The first pass uses a motorized, miniaturized motorized shaping mill to reduce the side dimension from 0.304 mm (0.012 inch) to about 0.254-279 mm (0.010-0.011 inch). The next pass is through a second turret mill, wherein said dimension is further compressed to approximately 0.203-0.254 mm (0.008-0.010 inch), with a square general cross section. Both passes with compressive, in relation to the aforementioned dimensions, with an increase in the transverse dimension (the dimension in the transverse direction perpendicular to the direction of compression) and an increase in the length of the yarn. The edges are rounded on each pass. The yarn is then passed through a stretching die, where it is rounded and elongated, having a diameter of 0.201 mm (0.00795 inch, AWG 32. An advantage of this invention is that, when the metal sheet, especially copper foil, is produced using electrodeposition, the properties of the wire made from said sheet can be controlled to a large extent by the composition of the electrolyte solution.Thus, for example, electrolyte solutions without organic additives and with a concentration of free lower chloride ions ai ppm, and in a zero or substantially zero embodiment, they are especially suitable for producing ultra-fine copper wire (e.g., AWG 25 to about AWG 60, and in one embodiment AWG 55.) Although the invention has been explained in relation to its preferred embodiments, it is to be understood that its various modifications will be apparent to those skilled in the art after reading the specification. it is to be understood that the invention described herein is intended to cover modifications that fall within the scope of the appended claims.

Claims (30)

1. CLAIMS i. A method for making metal wire, which includes: (A) forming metal sheet; (B) cutting said sheet to form at least one strand of thread; and (C) forming said strand of yarn to give said strand the desired cross-sectional shape and size.
2. 2. The method of claim 1, wherein said metal is selected from the group consisting of copper, gold, silver, tin, chromium, zinc, nickel, platinum, palladium, iron, aluminum, steel, lead, brass, bronze, or an alloy of one or several previous metals.
3. The method of claim 1, wherein said metal is an alloy selected from the group consisting of copper / zinc, copper / silver, copper / tin / zinc, copper / phosphorus, chromium / molybdenum, nickel / chromium and nickel / phosphorus .
4. 4. The method of claim 1, wherein said metal is copper or a copper-based alloy.
5. The method of claim 1, wherein said metal foil is electrodeposited copper foil.
6. 6. The method of claim 1, wherein said metal foil is forged copper foil.
7. The method of claim 1, with the step of cleaning said wire strand from phase (B) before phase (C).
8. The method of claim 5, wherein said sheet is formed in an electroforming stack that includes an anode and a cathode, said cathode being mounted horizontally.
9. The method of claim 5, wherein said sheet is formed in an electroforming stack that includes an anode and a cathode, said cathode being vertically mounted.
10. 10. The method of claim 5, wherein said sheet is formed in an electroforming stack at a cathode during phase (A), and said cutting phase (B) includes cutting said sheet while it is on said cathode to form said thread strand. and removing said strand from said cathode.
11. The method of claim 10, wherein, prior to step (B), said cathode is removed from said electroforming stack.
12. The method of claim 5, wherein said forming step (A) includes flowing an electrolyte solution between an anode and a cathode and applying an effective amount of voltage across said anode and said cathode to deposit sheet cj / and copper in said cathode. / 13.
13. The process of claim 1, wherein said electrolyte solution has a free chloride ion concentration of up to about 5 ppm.
14. The method of claim 12, wherein said electrolyte solution has a free chloride ion concentration of up to about 1 ppm.
15. 15. The method of claim 12, wherein said electrolyte solution has a free chloride ion concentration of zero.
16. 16. The method of claim 12, wherein said electrolyte solution is free of organic additives.
17. The method of claim 12, wherein said electrolyte solution further includes at least one organic additive.
18. 18. The method of claim 17, wherein said organic additive is a gelatin or an active sulfur containing material.
19. The method of claim 17, wherein said organic additive is selected from the group consisting of saccharin, caffeine, molasses, guar gum, gum arabic, polyethylene glycol, polypropylene glycol, polyisopropylene glycol, dithiothreitol, proline, hydroxyproline, cysteine, acrylamide , sulfopropyl disulfide, tetraethylthiuram disulfur, benzyl chloride, epichlorohydrin, chlorohydroxypropyl sulfonate, ethylene oxide, propylene oxide, sulfonium alkane sulfonate, thiocarbamoyl disulfide and selenic acid.
20. 20. The method of claim 12, wherein said electrolyte solution has a concentration of copper ions in the range of about 40 to about 150 grams per liter, a concentration of free sulfuric acid in the range of about 70 to about 170 grams per liter, and a chloride ion concentration up to about 5.ppm.
21. 21. The method of claim 12, wherein the current density during phase (A) is of the order of about 5.35 to about 321 amperes / cm2 (50 to 3000 amperes per square foot).
22. 22. The method of claim 12, wherein the electrolyte flow rate between said anode and said cathode is in the range of about 0.2 to about 5 meters per second.
23. 23. The method of claim 12, wherein I / LL during phase (A) is up to about 0.4.
24. 24. The method of claim 1, wherein said yarn is round in cross section.
25. 25. The method of claim 1, wherein said yarn is square or rectangular in cross section.
26. 26. The method of claim 1, wherein said thread has cross-section in the form of a cross, a star, a semicircle, a polygon, a track, an oval, a plate or a ribbed plate.
27. 27. The method of claim 1, wherein said yarn has a cross section of substantially the form illustrated in any of Figures 3-20.
28. 28. A process for making copper wire, which includes: (A) forming copper foil; (B) cutting said sheet to form at least one strand of copper wire; and (C) forming said copper wire strand to give said strand the desired cross-sectional shape and size.
29. 29. A method of making copper wire, which includes: (A) flowing an electrolyte solution between an anode and a cathode in an electroforming cell and applying an effective amount of voltage through said anode and said cathode to depositing copper at said cathode, said electrolyte solution being characterized by a concentration of free chloride ions of up to about 5 ppm; (B) cutting said copper to form a strand of copper wire and removing said copper strand from said cathode; and (C) forming said copper wire strand to give the copper wire the desired cross-sectional shape and size.
30. 30. A method for making copper wire, which includes: (A) flowing an electrolyte solution between an anode and a cathode in an electroforming stack and applying an effective amount of voltage across said anode and said cathode to deposit copper sheet in said cathode, said electrolyte solution being characterized by a concentration of free chloride ions of up to about 5 ppm; (B) removing said copper sheet from said cathode; (C) cutting said copper sheet to form at least one strand of copper wire; and (D) forming said copper wire strand to give the copper wire the desired cross-sectional shape and size.