Process for texturing polyester yarn

Claim 1

In the process for producing textured polyester yarn wherein synthetic linear ethylene terephthalate polymer is meltspun into filaments at 3000 to 5000 yards per minute to form a yarn characterized by a break elongation of 70 to 180 percent, by a birefringence value of at least 0.025, and by polyester which is less than 30 percent crystalline and has a relative viscosity of at least 18, and the yarn is drawn and textured in a draw-twist zone of a false-twist texturing machine with a heater temperature of at least 180°C; the improvement which comprises draw-texturing the yarn at 1.3 to 2.0 draw ratio and 20 to 70 turns per inch twist in said draw-twist zone, feeding the yarn from the drawtwist zone to an air jet at 8 to 35 percent overfeed without additional heating, jet-texturing the yarn with the air jet to form crunodal surface loops in the yarn, and packaging the resulting textured yarn at a package speed (P) greater than the takeup speed (T) from the air jet, the value of ##EQU3## being from -1 to -10 percent.