Abstract: A bulked polyester continuous filament heteroyarn composed of uncrimped filaments and helically crimped filaments, and having alternating compact and loopy zones. The helically crimped filaments include homofilaments (e.g., false-twist bulked) and heterofilaments.

Abstract: An improved stuffer box crimper and a process employing such apparatus, the process involving feeding a tow of parallel filaments in the form of a sheet of constant thickness into a stuffer box crimper in which a primary crimp is imparted to the filaments by controlling the pressure against which the tow is delivered to the stuffer box and the secondary crimp is imparted to filaments by adjusting the denier per inch width at which the tow is delivered to the stuffer box, the imparted crimp being heat set by heating with a fluid while the tow is in the stuffer box.