The invention discloses a novel method of manufacturing magnet wire in a continuous process. Coatings of a flowable resin material are applied concentrically to a moving elongated filament in thicknesses up to about 16 mils. The filament can be a bare copper or aluminum conductor having round or rectangular configuration, an insulated conductor to which a top or an intermediate coat of the material is desirably applied or a coated conductor upon which the material has been previously cured.
A patented centering device is employed to provide uniform spooling of the coated conductor. By this means the mechanical wear associated with centering dies used in extrusion processes and like devices is eliminated. The coating and spooling operations are carried out continuously in one pass. The filament is fed into the apparatus from a pay-out device, or alternatively it can be supplied from a rolling and drawing operation or from reels.
Most magnet wire is made of copper, which is a highly conductive metal that can be produced in very fine gauges and is very flexible. However, for very high temperature situations, it is often necessary to use a more ductile metal such as aluminum. Stainless steel, nickel or titanium can also be used in very large diameter applications.
In addition to a wide range of insulation material, magnet wire Manufacturers can also offer special alloy conductors and coatings. For example, specialized conductive copper is available for use in applications where corrosion resistance and high temperature performance are required. Additionally, superconducting material can be incorporated into the insulation to help improve the performance of the windings in very high speed motors.
Magnet wire Manufacturers can also provide a variety of surface finishes to the coated conductors. These include bare and 200 or 220 degree C temperature enamels, as well as epoxy, polyester and silicone varnishes. They can also provide a selfbonding layer, which is useful for applications that require bobbinless coils. They can also produce a large variety of special diameters to meet customers’ specifications. This can be important for applications in which the tolerances of bare wire have a direct impact on the overall coil resistance. The tolerances of the insulating material are also important, as they affect the consistency of wound coils. This is particularly critical for very high winding speeds in applications such as traction motors.
