ROTORRING MEASUREMENT OF FIBER COHESION AND BULK PROPERTIES OF STAPLE FIBERS

Fiber cohesion and bulk properties and their consistency have a significant influence on yam manufacturing processes and yam quality. These critical properties depend on several staple fiber properties, including staple length, finish type and level fiber geometries, crimp type and level, fiber additives, degree of fiber entanglements, and surface roughness. In order to ensure high processing performance and good yam quality, it is necessary to understand how various staple fiber properties affect fiber cohesion and bulk. A method has been developed using a modified RotorRing instrument to monitor changes in staple fiber cohesion and bulk. The modified RotorRing yields three measurements, fiber-to-metal and fiber-to-fiber opening energy and the bandwidth of the ribbon formed inside the rotor. The method successfully and accurately detects differences in selected nylon and polyester fibers with different crimp/bulk levels, and the correlations between the modified RotorRing and traditional crimp measurements are examined. In addition, differences in crimp/bulk properties induced during the nylon staple processing operation are detected by the modified RotorRing responses. The results indicate that different crimp variables influence the three RotorRing measurements differently, and these independent responses show that the modified RotorRing method is indeed a potential tool for understanding the total effect of crimp variables on fiber cohesion and crimp/bulk and for monitoring the resulting yarn's properties and quality.