Insulated copper wires are used in windings for electric motors, generators and transformers. The automotive industry’s entry into electric mobility has created new challenges for manufacturers of enameled wire.
However, in large transformers (e.g., in power stations), enamel insulated rectangular wires have been preferred for decades, because they significantly improve power density and efficiency. The enamel-insulation is very thin with a layer thickness of 50 to 150 μm. The lacquer is applied in 10 to 20 layers, i.e., the individual layer might be just 5 μm. While the bare wire passes a lacquer bath and a calibration nozzle, spare lacquer is stripped off . Repeated passaging in a hot-air oven burns in the layer.