Method for manufacturing an electrical insulator

The present invention relates to a method for producing an electric isolator in which a hydrophobic plasma-polymer coating is applied on the moulded part of the isolator. The plasma-polymer coating is obtained by activating a plasma in a working gas which is non-polar or contains non-polar groups at a working pressure of between 1 . 10 and 5 . 10 mbar. The electric power yield per chamber volume ranges from 0.5 to 5 kW/m , while the gas flow per chamber volume ranges from 10 to 1000 sccm/m . It is thus possible to obtain a hydrophobic plasma-polymer coating having a quality that does non depend on the material used for the moulded part.