Hairiness
The term, Hairiness in a spun yarn means, fibers which are protruding from the outer surface of the yarn. Hairiness Index in a yarn corresponds to the total length of protruding fibers within the measurement field of 1cm length of the yarn.
Major factors influencing Yarn Hairiness
There are number of factors influencing yarn hairiness from Speed Frame to Winding. I like to focus mainly on Ring Spinning Department.
Damaged Rings and Worn –out Ring Travellers.
Replace the damaged rings and match the perfect ring traveller which suits to the rings , materials , spindle speed etc.,
Prolonged usage of Ring Travellers.
Fix the optimum ring traveller life based on ring condition, spindle speed , yarn count & material.
Very light or very heavy Ring Traveller Numbers.
Choose the optimum traveller Number. The optimum traveller no. has to be assessed by Trial & Error method only.
Yarn clearance between ring and ring traveller is lesser than required.
Increase the yarn clearance by trying a high bow traveller. But please ensure that the high bow height ring traveller is not affecting your spindle speed. In general terms , low bow height ring traveller is suitable for high speed and a high bow height traveller reduces the stability of ring travellers while running.
Wire cross section of ring traveller should be used as per the material spun.
Ring Traveller manufactures are offering various wire profiles based on the material spun. In general sharper edges of a wire section reduces the yarn hairiness.
Traveller loading – i.e. Fluff accumulation on ring traveller.
More traveller loading increases the weight of ring travellers – Abnormal weight of ring travellers results in high yarn tension which leads to high hairiness.
Diameter of the full cop touches with the Ring Traveller while running.
Reduce the Cop Diameter with respect to ring diameter. Normally 3mm difference between Ring Diameter and Cop Diameter.
Spacer Size plays an important role in yarn hairiness.
Normally, technicians prefer thinner spacer to reduce the U% & Imperfections. But a thinner spacer may result in higher hairiness. Optimum Spacer can result in average quality and hairiness.
Yarn Twist
Lesser TPI reduces the control of short fibers from the core of the yarn. So, higher twist in the yarn may reduce the yarn hairiness.
Spinning Geometry
A higher lappet height from top of the cop leads to more yarn tension and it results in more yarn hairiness. Reducing the lappet height may result in lesser yarn hairiness, but please ensure that the yarn should not touch the top of the cop.
Using lesser ring dia and lesser lift reduces yarn hairiness significantly. More significance noticed when the spindle speed is constant.
Higher width of spinning triangle gives more time for fibers to get into the yarn strand and which gives lesser hairiness. Spinning Triangle varies based on winding angle and front roller offset.
Damaged suction tubes and snail wires may result in higher hairiness. Some recent study shows that, Ceramic based snail wires gives consistent Hairiness or say hairiness CV% between the spindles.
These are all the major factors which are directly influencing the yarn hairiness in ring spinning department. In addition, Roving Hank, Simplex spacer size, Cone Winding speed, Yarn Tension & Waxing method in winding also has great importance in controlling the yarn hairiness.
