The clearing is an important step of the film capacitor production process. In case of a weak point in the dielectric, like a reduction of the thickness or a hole in the dielectric, there will be an electric breakdown in that specific area. A key factor for safety is the high efficiency level of self-healing property of polypropylene film. During the production process, the film capacitor is charged to a voltage level that generates locally inside the wound element, voltage discharges between the two plates (wound metallized films) where the dielectric film has some weak points and the dielectric strength is not enough. Thanks to the associated energy, the very thin layer of the zinc metallization will evaporate in the areas around the weak points where the discharges happen. Such metal evaporation will insulate the damaged area because after evaporation there will not be any more metal around the holes facing each other on the two film layers.