A great share of the loss power dissipated during the operation of electrical machines is caused by the resistance of the copper conductors. One way to reduce copper losses without changing the machine volume is to increase the copper fill factor by means of rectangular conductors. This approach is applied in the case of so-called preformed coils, which are first brought to their final form and subsequently pushed into the stator. there is still no cost-efficient production process suitable for large-scale production for preformed colis with rectangular conductors, however. The goal of the Flexicoil project is to produce cost-efficient preformed coils using forming technologies. A big challenge is the manufacturing of the insulation: classic enameled wires cannot be used here because of the geometry of the coil. An alternative process must yield thin insulating layers and provide good insulating properties so that the advantage of the high copper filling factor is not lost.