Wire enamels are applied on copper and aluminium round and flat wires used in motors, transformers, generators and electrical measuring instruments. They are cured onto the wires with heat. The resulting coating’s main function is electrical insulation.

Wires Insulated by Enamel

Enameled wires are applied to copper and aluminum wires on up to 30 layers. This process provides electrical insulation and strength windings for short-circuiting. These enameled wires must also have very good chemical and thermal resistances, adhere very well to copper and aluminum wires, and have outstanding mechanical stability.
In some instances, for example when used in inverter-driven electric motors, the appropriate insulation layer should resist possible partial discharges, which can cause the motor to short-circuit and fail.

The wires that are coated vary greatly depending on their use. Some may be smaller than the diameter of a single human hair – in electronic components of watches for instance. But in heavy electric motors in wind generators, the diameter of round or flat wires can measure up to several millimeters.
The wire enamel is applied differently depending on the shape and diameter of the wire to be coated. Horizontal or vertical application or application with molding or with felts, are typical wires coating methods.

Chemically, the wire enamel range consists of polyurethane, polyester, polyesterimide, and polyamide-imide. The range of solids content starts at nearly 8% and ends at 60% (1g/1h/180°C), and the viscosity range is between 30 and 60000 mPas (23°C).