It is necessary for the enameled wire to meet the needs of various application and manufacturing skills. The former includes its shape, specification, short-term and long-term operation at high temperatures, as well as severe vibrations in some occasions and centrifugal force at high speeds, corona resistance and breakdown at high voltages, and special atmosphere under electric wires. Chemical resistance, etc.; the latter includes the need to saturate, bend and wear during winding and weaving, as well as swelling and erosion during dipping and drying.
The Enameled Wire can be classified according to its base structure, conductive core and electrical insulation layer. Generally, it is divided into an enameled wire, a wrapped wire, an enamel wrapped wire and an inorganic insulated wire according to the insulation materials and manufacturing methods used for the electrical insulating layer.
Enameled wire. It is made by coating the corresponding paint solution on the outside of the conductor, and then evaporating the solvent and curing and cooling the paint film. The enameled wire can be divided into red polyester enameled wire, polyesterimide enameled wire, polyamideimide enameled wire, polyimide enameled wire, polyesterimide/polyamideimide enameled wire, corona-resistant enameled wire, and oily according to the insulating paint used. Paint, acetal paint, polyurethane enameled wire, etc. Sometimes classified according to the particularity of their use, such as self-adhesive enameled wire, anti-freeze enameled wire.
Wrapped wire an important type of winding wire. In the early stage, cotton yarn and silk, called yarn wrapped wire and silk covered wire, were used in motors and electrical appliances. Due to the large thickness of the insulation and low heat resistance, most of them have been replaced by enameled wires. It was only used as a high frequency winding wire. In the large and medium-sized winding wires, when the heat resistance level is high and the mechanical strength is large, the glass fiber covered wire is also used, and the appropriate adhesive paint is used in the manufacture.
In the wrapped wire, the paper covered wire still occupies the proper orientation, and the electrical wire is mainly used in the oil-immersed transformer. The oil-paper insulation constructed at this time has excellent dielectric function, and is inexpensive and has a long life. In these years, the film is wrapped around the envelope, and the polyester film and the polyimide film are wrapped around the wire.
Recently, there are also mica tape-packed polyesterimide film wrapped copper wire for wind power generation. When the heat resistance grade requirement exceeds the limit of the organic data, the inorganic insulating paint is generally used to coat the electrical wire. The existing inorganic insulated wires can be further classified into glass film wires, oxide film wires, ceramic wires, and the like.