the liquid further advance to a friction type false twisting apparatus 7 which performs false twisting of the filament yarns from the false twister 7 the processed composite filament yarn is fed to and wound on a take up unit 9 details of the false twisting apparatus 7 are depicted in fig2 the false twister 7 is comprised of a first endless flat surfaced belt 13 trained around operating pulleys 11 and 12 and a second endless flat surfaced belt 16 trained around pulleys 14 and 15 the belts 13 and 16 cross each other at a suitable angle u03b8 and are engaged in surface to surface relation with each other in the intercrossing area designated 17 as viewed in fig3 the filament yarns 2 travelling through the intercrossing area 17 are applied not only with a twisting action but with an advancing action in accordance with the movement of the belts 13 and 16 referring to fig4 there is shown an example of the liquid applier 6 which employs a generally u shaped pipe 20 and a casing 23 the u shaped pipe 20 is mounted to the casing 23 in such a manner as to have its base portion 21 oriented vertically as illustrated the bottom or outer part of the wall of the base portion 21 is cut away or removed while the casing 23 is formed with vertically aligned upper and lower slits 24 and 25 a liquid as typified by water or water coluble oil is supplied at a small rate from an upper end or inlet 26 of the pipe 20 so that it flows down along the inner surface of the pipe 20 and then out of the pipe 20 through a lower end or outlet 22 meanwhile the filament yarns 2.