The effects of yarn twist and yarn count was studied on hairiness and hair lengths of
polyester-viscose ring spun yarn. Two different types of yarn count with different twist
factors were produced and the hairiness of the yarn and also the friction coefficient of the
yarn against a metal surface were measures. The results showed that by increasing of the
yarn twist, the yarn hairiness is reduced due to more penetration of twist on spinning
triangle and better movement of fibers on body of yarn. The reduction of the yarn longer
hair lengths is more than shorter hair lengths due to increasing of migration of longer
length fibers. The shorter hair length groups in the yarn increases by decreasing of the
yarn count. The effect of yarn twist on friction properties of the yarn was also studied.
The results indicated that the friction coefficient of the yarn against metal surfaces has
not affected by the yarn twist.