Process for treating yarns, filaments and fibers

Claim 1

A METHOD OF PRODUCING A UNIFORMLY CRIMPED, HEAT SET YARN OF THERMOPLASTIC SYNTHETIC LINEAR POLYMER WHICH COMPRISES PROVIDING A SUPPLY OF SAID YARN IN THE UNCRIMPED, NON-HEAT SET STATE, PASSING SAID YARN CONTINUOUSLY FROM SAID SUPPLY INTO THE NIP OF A PAIR OF INTERNALLY HEATED, DRIVEN CRIMPING ROLLS MAINTAINED AT A TEMPERATURE SUFFICIENT TO HEAT SAID YARN TO A TEMPERATURE AT LEAST EQUAL TO THE SECOND TRANSITION POINT OF THE POLYMER AND BELOW THE TACK POINT THEREOF, MAINTAINING THE YARN BETWEEN SAID ROLLS FOR A PERIOD OF TIME SUFFICIENT TO SIMULTANEOUSLY CRIMP AND HEAT SET THE SAME, THE HEAT SET BEING SUCH THAT THE POLYMER, UPON COOLING, SHOWS SUBSTANTIALLY NO SHRINKAGE AFTER IMMERSION IN HOT WATER FOLLOWED BY DRYING IN THE SLACK CONDITIONS, DISCHARGING SAID YARN FROM THE CRIMPING ROLLS IN THE HOT PLASTIC STATE AND ALLOWING THE DISCHARGED YARN TO COOL AND SET INTO THE CRIMPED PATTERN OF SAID ROLLS WHILE SAID YARN IS IN A PREDOMINANTLY UNSUPPORTED, ESSENTIALLY SLACK-FREE STATE AND UNDER NEGLIGIBLE TENSION, TAKING UP SAID COOLED, SET YARN AT A RATE EQUAL TO THE RATE AT WHICH IT IS DISCHARGED FROM THE CRIMPING ROLLS, MEASURING THE TENSION ON SAID YARN THROUGHOUT THE COOLING AND SETTING THEREOF BETWEEN ITS POINT OF DISCHARGE AND TAKEUP, ADJUSTING THE TAKEUP PATH AND THE DISTANCE OF TAKEUP TO COMPENSATE FOR ANY INCREASE IN TENSION ON THE YARN AS IT IS BEING COOLED AND SET, AND THEREAFTER COLLECTING THE COOLED AND CRIMPED MATERIAL FROM SAID TAKEUP UNDER TENSION, THE HEAT SETTING TREATMENT WITH SAID CRIMPING ROLLS CONSTITUTING THE SOLE ESSENTIAL HEATING TREATMENT BETWEEN SAID CRIMPING AND COOLING OPERATIONS.

Claim 2

A METHOD OF PRODUCING A UNIFORMLY CRIMPED, HEAT SET YARN OF THERMOPLASTIC SYNTHETIC LINEAR POLYMER WHICH COMPRISES PROVIDING A SUPPLY OF SAID YARN IN THE UNCRIMPED, NON-HEAT SET STATE, PASSING SAID YARN CONTINUOUSLY FROM SAID SUPPLY INTO THE NIP OF A PAIR OF INTERNALLY HEATED, DRIVEN CRIMPING ROLLS MAINTAINED AT A TEMPERATURE SUFFICIENT TO HEAT SAID YARN TO A TEMPERATURE AT LEAST EQUAL TO THE SECOND TRANSITION POINT OF THE POLYMER AND BELOW THE TACK POINT THEREOF, MAINTAINING THE YARN BETWEEN SAID ROLLS FOR A PERIOD OF TIME SUFFICIENT TO SIMULTANEOUSLY CRIMP AND HEAT SET THE SAME, THE HEAT SET BEING SUCH THAT THE POLYMER, UPON COOLING, SHOWS SUBSTANTIALLY NO SHRINKAGE AFTER IMMERSION IN HOT WATER FOLLOWED BY DRYING IN THE SLACK CONDITIONS, DISCHARGING SAID YARN FROM THE CRIMPING ROLLS IN THE HOT PLASTIC STATE AND ALLOWING THE DISCHARGED YARN TO COOL AND SET INTO THE CRIMPED PATTERN OF SAID ROLLS WHILE SAID YARN IS IN A PREDOMINANTLY UNSUPPORTED, ESSENTIALLY SLACK-FREE STATE AND UNDER NEGLIGIBLE TENSION, TAKING UP SAID COOLED, SET YARN AT A RATE EQUAL TO THE RATE AT WHICH IT IS DISCHARGED FROM THE CRIMPING ROLLS, MEASURING THE TENSION ON SAID YARN THROUGHOUT THE COOLING AND SETTING THEREOF BETWEEN ITS POINT OF DISCHARGE AND TAKEUP, ADJUSTING THE TAKEUP PATH AND THE DISTANCE OF TAKEUP TO COMPENSATE FOR ANY INCREASE IN TENSION ON THE YARN AS IT IS BEING COOLED AND SET, AND THEREAFTER COLLECTING THE COOLED AND CRIMPED MATERIAL FROM SAID TAKEUP UNDER TENSION, THE HEAT SETTING TREATMENT WITH SAID CRIMPING ROLLS CONSTITUTING THE SOLE ESSENTIAL HEATING TREATMENT BETWEEN SAID CRIMPING AND COOLING OPERATIONS.