FIBER DAMAGE AT HIGHER ROTOR SPEEDS

The production volume of yarns from man-made fibers using the rotor spinning technology has increased in recent years. Aspects contributing to the increased use of the rotor technology include certain characteristic properties of man-made fibers, namely their strength, cleanliness, and evenness both in length and fineness, as well as the ability to modify these fibers for specific end uses. At higher rotor speeds, man-made fibers are often damaged. As the rotor speed increases, so does the centrifugal force, which deflects the yarn at the doffing tube, creating a normal force that in turn generates a frictional force between the yarn and surface of the doffing tube. This frictional force generates heat and damages fiber surfaces. In order to confirm this theory, polyester/viscose (48/52) blend yarn was rotor spun at 90,000 rpm and optically observed. The frequency of imperfections due to fiber damage was observed, damaged portions were collected, and photographs were taken on a scanning electron microscope.