Process for drawing and crimping yarn

Claim 1

A RAPID INTEGRATED PROCESS FOR THE MANUFACTURE OF CRIMPED FILAMENTS AND FIBERS HAVING LOW SHRINKAGE AND HIGH CRIMP EXTENSION FROM UNDRAWN MELT SPUN POLYESTER FILAMENTS HAVING NATURAL DRAW RATIO AT ROOM TEMPERATURE MAKING THEM CAPABLE OF BEING ELONGATED AT LEAST TWICE THEIR LENGTH, COMPRISING DRAWING THE FILAMENTS 2.5 TO 6 TIMES THEIR LENGTH BETWEEN FEED ROLLS AND DRAW ROLLS, INTRODUCING A TENSION GRADIENT AND LOCALIZING THE DRAW ZONE WITH A SMALL SNUBBING PIN INTERPOSED BETWEEN SAID ROLLS, HEATING THE FILAMENTS IN A FIRST MAINTAINED CLOSE TO AND BEFORE THE SNUBBING PIN, AT A TEMPERATURE BETWEEN 15*C.-45*C. ABOVE THE SECOND ORDER TRANSISITION TEMPERATURE OF THE POLYMER FROM WHICH THE FILAMENTS ARE MADE, PASSING THE HEATED FILAMENTS WITHOUT ALOWING THEM TO COOL SUBSTANTIALLY AND SO THAT STRETCHING IS LIMITED TO LESS THAN 20% AND WITHOUT DRAWING, TO SAID SNUBBING PIN, WHICH IS CAPABLE OF BEING INTERNALLY HEATED AND MAINTAINED AT A SELECTED TEMPERATURE, IN CLOSE PROXIMITY TO SAID FIRST ZONE, MAINTAINING SAID SNUBBING PIN AT TEMPERATURE BETWEEN 85*C. ABOVE THE SECOND ORDER TRANSITION TEMPERATURE AND 30*C. ABOVE THE MELTING TEMPERATURE OF THE FILAMENTS, SAID SNUBBING PIN HAVING A RADIUS OF CURVATURE LESS THAN 6 MM. AND AS SMALL AS IS CONSISTENT WITH MECHANICAL REQUIREMENTS AND PROVIDING A SURFACE AND AN ARC OF CONTACT CAPABLE OF IMPARTING A TENSION GRADIENT SUCH THAT SUBSTANTIALLY ALL THE DRAWING TAKES PLACE ON THE SNUBBING PIN AND BETWEEN IT AND THE DRAW ROLLS BUT CLOSE TO THE SNUBBING PIN AND WITHOUT REACHING THE DRAW ROLLS AND WHILE THE FILAMENTS ARE SPREAD INTO A RIBBON SO THAT THEY BECOME HEATED FROM THE SURFACE OF SNUBBING PIN, WHEN MAKING AN ARC OF CONTACT OF AT LEAST 180* AND UP TO FOUR TURNS AROUND THE PIN, PASSING THE FILAMENTS TO THE DRAW ROLLS ROTATING AT A SPEED TO PROVIDE SUFFICIENT TENSION TO DRAW THE FILAMENTS TO THE REQUIRED DRAW RATIO AND AT A SPEED OF A LEAST 1,000 FT. PER MINUTE, FORWARDING THE FILAMENTS UNDER A TENSION LESS THAN THE DRAWING TENSION, AND SUBSEQUENTLY RELAXING THE FILAMENTS AT LEAST 70% AT ROOM TEMPERATURE, WITHOUT ANY INTERMEDIATE HEATING TO A TEMPERATURE ABOVE THE SECOND ORDER TRANSITION TEMPERATURE TO SHOW THEIR FULL CRIMP OF AT LEAST FOUR CRIMPS PER INCH AND A CRIMP ELONGATION OF AT LEAST 70%, SOLELY AS A RESULT OF SAID DRAWING PROCESS.