Method of manufacturing a cut pile carpet

Claim 1

A process for manufacturing a cut pile carpet, comprising the steps of: (a) feeding a bulky polyamide multifilament yarn to a device for false twisting and heat setting, so that (i) false twists between 100 twists per meter and 1000 twists per meter are imparted into said bulky yarn, and (ii) while said false twists are maintained in said yarn, said bulky yarn is heat set so that filaments composing said yarn are thermally and partially adhered to each other, said heat set bulky yarn including S twist portions and Z twist portions; (b) taking up said false twisted and heat set yarn while thermal and partial adhesions remain therein, to provide a cohesive bulky synthetic multifilament yarn having alternate twists with S twist portions and z twist portions being distributed randomly along the lengthwise direction of the yarn, with said yarn having a total crimp between 3% and 15%, a coherent factor between 5 and 100, and a latent torque index between 60 twists per meter and 300 twists per meter, and an adherent ratio between 0.5% and 40%; (c) heat relaxation treating said cohesive bulky synthetic multifilament yarn under a constrained condition so that said latent torque index of said cohesive bulky synthetic multifilament yarn is decreased to less than 60 twists per meter; (d) tufting said heat relaxation treated cohesive bulky synthetic multifilament yarn as a pile yarn on a substrate; and (e) cutting the loops of said pile yarn so as to create cut piles.