result of the limitation of the length of the heating plate the looping angle and thus the increase of the tensile force are technically limited to ranges which are given by the technology of false twist texturing thus for example when processing a polyamide yarn e g nylon 6 or nylon 6 6 having a denier of between about 15 to 44 dtex after false twist crimping and drawing thereof the length l between the ends of the heating plate should preferably be between about 0 8 and 1 6 meters and the ratio r l should preferably be between about 0 8 and 4 4 when processing a polyester yarn having a denier between about 55 to 500 dtex after false twist crimping and drawing thereof the length l should preferably be between about 1 6 and 2 2 meters and the ratio r l should preferably be between 0 8 and 3 2 it will be possible to obtain the specified small heater lengths only when the curvature of the heating plate is selected such that the specified quotients q r l is satisfied this means that a lower range of radii of curvature for the heating plate exists in which the necessary heating plate length is only insignificantly influenced by the respective radius.