a) Fiber supply
d) Package winding
Polyester ring-spun yarn supply, usually in the form of roving and having a hank range from approximately 0.40 to 5.0, is drawn into the drafting system by the rotation of the back rolls. In the drafting zone, the weight per unit length of the input roving is reduced because the surface speed of the front drafting rolls is greater than that of the back rolls. Regular ring frame drafts range up to about 30.
The front rolls deliver a continuous cohesive stream of fibers, which must be twisted immediately into yarn. This transformation is accomplished by the spindle, ring and traveler interactions. The rotation of the spindle causes a twist inserted into the stream of fibers delivered by the front rolls. By passing the yarn under the traveler, the winding is accomplished.
First, it provides a location to wind a package;
Secondly, by rotating the yarn package, the spindle causes twist to be inserted into the strand of yarn being formed at the nip of the front rolls;
Thirdly, the rotation of the package causes the yarn to pull the traveler around the ring. It does not only provide a method of transmitting twist derived from the spindle but also a guide to change the direction of yarn travel so that it approaches the yarn package tangentially, thus being wound onto the package.
Economic limitations on ring spinning are related to power consumption and package size. Power requirements to rotate the package are more significant than insert twists only. In addition, the package size is limited since it must be enclosed in the yarn balloon. Finally, coarse yarn counts and frame down-time doffing must be considered since it increases as coarser yarns are spun.
Spun yarn luster
Luster refers to the light degree reflected from
surfaces of a fiber, the gloss degree or sheen that fiber possesses.
- Full dull