E.i. Dupont De Nemours and Company

James E Duncan

Dean H Smiley

A process and apparatus for drawing polyamide yarn in which the yarn having a lubricating finish is drawn while being spirally advanced in frictional contact with the outer surface of a yarn draw assist element. In such process and apparatus, the outer surface of the draw assist element moves at a speed at least 100 times slower than the speed at which the yarn is advanced. From the draw assist element, the yarn directly advances to a roll initial contact location on a pair of space-apart heated rolls and spirally advances on the rolls through at least one wrap in contact with the outwardly-facing surfaces of the heated rolls. The distance that the yarn spirally advances longitudinally in the wrap can be said to define the wrap advance on the rolls. The roll initial contact location of the heated rolls is oscillated by moving the outer surface of the draw assist element in relation to the pair of heated rolls to oscillate the wrap on the rolls a distance which is at least equal to the wrap advance. The process and apparatus advantageously prevent the build-up of deposits on the heated rolls.

Process of drawing yarn using an oscillating draw assist element

A yarn heating element wherein fixed elongated core having a heater therein serves as a support for a sleeve rotatably mounted to and telescoped over the core. The space between the core and sleeve can be varied along their lengths for controlling heat radiated from the core to the shell to control the temperature profile along the length of the shell. Varying the winding density of the heater can serve the same purpose.

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Richmond, VA, United States of America

James E Duncan