Magnet wire coating

Poly(amide-imide)s are more easily prepared than polyimides and have better heat stability than polyamides they have found use as magnet wire coatings. 

Magnet Wires. Magnet wines can be classified as coated wines, coated wines with fibrous wrappings, and wines with impregnated fibrous... 

Polyvinyl Aldehyde 1940 H VG VG VG VG Most molding pro-cesses Used for coatings and magnet wire insulation, interlayer of safety glasses... 

Lupinski, J. H., and Gorowitz, B., Powder coating of magnet wire, General Electric Co., Tech. Info. Ser. 79CRD166 (July, 1979)... 

Except for gold and silver, copper is the best metallic electrical conductor and copper wires are commonly used as electrical conductors. They are also used as magnet wires in electric motors, transformers, generators, electromagnets, etc. Copper and aluminum are commonly used for magnet wire because of their good electrical conductivity. Magnet wires are frequently coated by a variety of polymers such as nylon, aramid, polyester, polytetrafluoroethylene, polymide, etc. 

Formulated with pigments, like graphite and carbon black [232] or metal powders [233,234], conductive films were obtained at low cost, used as electromagnetic shielding layers or for capacitive energy-storing inductive coils, when coated on an insulated magnet wire. 

This can be confirmed by simply pressing the tips of an ohmmeter at two points on the surface of any bare ferrite lying around in the lab. Further, if we are trying to rely on the enamel coating of a typical copper magnet wire to protect from shorts, we should know that the coating is considered to be just operational/functional insulation, and is not considered to be even basic insulation. 

Dual Constructions. In addition to the "basic" magnet wire insulations in which the conductor wire is coated with a single enamel, there are a number of cases where two different enamels are used one overcoated over the other. Examples include polyurethane-base insulation overcoated with poly(vinyl butyral) or with nylon, or polyester-base insulation overcoated with nylon or with polyamide imide. 

Miscellaneous Extrusion-Applied Polymers. As mentioned earlier, there is a tendency to develop solventless magnet wire enamel formulations, and extrudable polymer systems would fulfill that requirement. There have been reports about extrusion of thin coatings of polyesters over copper wire. At this point, the state of the art allows extrusion of thin insulating films only with thermoplastic materials. The reliable extrusion of uniform and concentric insulating films of approximately 0.001-0.002 in. wall thickness is already an improvement over the more traditional extrusions of polyethylene, poly(vinyl chloride), and several fluoropolymers in much greater wall thicknesses. Because cross-linked insulation is ultimately required for most magnet wire applications, further materials development needs to be done to provide polymer compositions that are both extrudable as thin films and can be cross-linked in an economical process suitable for large-scale industrial application. 

Polyvinyl formal (PVF) is used to manufacture magnetic wire insulation as well as metal coatings and can linings. The quantities of PVF used are small and thus is a minor use for VAM. 

Electrical conductor wire, printed circuit board coatings, optical fibers, magnetic media, coatings, computer disc clearcoats, coatings for metallized substrates... 

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