Abstract: A method for stabilizing yarns made from polyacrylonitrile using chemical stabilization reactions, including: generating a field of high-frequency electromagnetic waves in an application space of an applicator, which has areas with minimum electric field strength and areas with maximum electric field strength, the maximum electric field strength in the application space being in a range from 3 to 150 kV/m; continuously supplying a precursor yarn based on a polyacrylonitrile polymer into the application space, and conveying the precursor yarn through the application space and through the field of the high-frequency electromagnetic waves; introducing a process gas into the application space and conveying the process gas through the application space with a flow rate of at least 0.1 m/s relative to the precursor yarn being conveyed through the application space, wherein a temperature of the process gas is in a range between 150 and 300° C.

Abstract: A process for continuous production of carbon fibres whereby stabilised precursor fibres are carbonised and graphitised with the help of high-frequency electromagnetic waves, characterised in that the stabilised precursor fibres are continuously conveyed, as the inner conductor of a coaxial conductor consisting of an outer and an inner conductor, through the coaxial conductor and a treatment zone; that the stabilised precursor fibres are irradiated in the treatment zone with high-frequency electromagnetic waves that are absorbed by the precursor fibres, which are thereby heated and converted into carbon fibres; and that the stabilised precursor fibres or carbon fibres are conveyed under an inert gas atmosphere through the coaxial conductor and the treatment zone.