Production of highly crimped polyester yarn

Claim 1

IN THE PROCESS OF PREPAING MULTIFILAMENT YARN OF FILAMENTS WHICH CRIMP DUE TO ASYMMETRIC SHRINKAGE PROPERTIES WHEN HEAT-RELAXED, WHEREIN SAID ASYMMETRIC SHRINKAGE PROPERTIES ARE IMPARTED BY PASSING THE FILAMENTS UNDER TENSION IN CONTACT WITH A HARD SURFACE TO MODIVY THE FILAMENTS ALONG THEIR LENGTHS; THE IMPROVEMENTS FOR PROVIDING BETTER CRIMPING PROPERTIES IN POLYESTER YARN AND HIGHER PROCESSING SPEEDS, WHEREIN THE IMPROVEMENTS COMPRISE PASSING DRAWN FILAMENTS OF A SINGLE POLYESTER COMPOSITION AT HIGH SPEED IN FRICTIONAL CONTACT WITH AN UNHEATED NONMETALLIC PIN FOR A DISTANCE OF 0.5 TO 15 MILLIMETERS AT A TENSION CHANGE OVER THE PIN OF 0.2 TO 1.5 GRAMS PER DENIER TO MODIFIY THE FILAMENTS SUBSTANTIALLY CONTINUOUSLY ON PIN-CONTACTING SIDES, THE SUM OF THE LENGTHS OF DISCONTINUTIES IN THE MODIFIED PORTION WHICH ARE MORE THAN 2 MILLIMETERS LONG BEING LESS THAN 5 PERCENT OF THE FILAMENTS LENGTH, AND THEN IMPARTING A RANDOM THREE-DIMENSIONAL, CURVILINEAR, CONFIGURATION CONTINOUSLY ALONG THE MODIFIED FILAMENTS BY (A) FEEDING THE FILAMENTS AT HIGH SPEED INTO A JETTED STREAM OF COMPRESSIBLE FLUID HEATED TO A TEMPERATURE WHICH WILL PLASTICIZE THE FILAMENTS WITHOUT CAUSING FUSION BETWEEN FILAMENTS, AND (B) IMPINGING THE FILAMENTS IN A PLASTICIZED CONDITION ON A MOVING SURFACE TO SEPARATE THE FILAMENTS FROM THE HEATED FLUID AND CONVEY THE FILAMENTS ON THE MOVING SURFACE FOR COOLING IN A SUBSTANTIALLY TENSIONLESS STATE.