In a false twisting process, where a synthetic POY yarn is fed at a given speed to be heated and cooled to be false twisted by friction contact with rotating discs, the take-off speed (Y) is more than 1000 m/min. and the surface speed (D) of the friction discs is raised into a ratio with the take-off speed over the saturation threshold. The friction disc speed (D) is especially more than 2.4 times the yarn take-off speed (Y).
