# Textile Calculation

Problems and solutions of textile

## Calculation of Draft and Twist in Ring Spinning

Calculation of Draft and Twist in Ring Spinning
S. M. Hossen Uzzal
Production Officer
Monno Fabrics Ltd., Manikgonj
Email: uhossen@gmail.com

Ring Spinning Frame
Ring Spinning Frame is the last stage in the process of conversion of fibers into yarn. The ring spinning machine was first invented in 1828 by the American Thorp. In 1830, another American scientist, Jenk, contributed the traveler rotating on the ring.

Calculation of Draft in Ring Spinning
It is possible to achieve very high range of draft and twist on modern long spinning frames. This is due to the provision of pairs of draft and twist change gears in the mechanism as shown in the figure.

 Gearing Diagram of Modern Ring Spinning Frame
All drafting rollers are of one inch diameter.
Draft between middle roller and back roller:
Draft between front roller and middle roller:
Total Draft between front roller and back roller:
Thus, the range of draft varies from 14.05 to 25.75with the present draft gears. However, it can be further increased by change of Gear H to 150 T in which case the range will increase from 14.05 to 35.115 and if the Gear G is also changed to 24 the range will increase from 14.05 to 70.230.

Calculation of Twist in Ring Spinning
By changing the speed of the main pulley and adjustments in the twist change and auxiliary twist change gears wide range of twist can be achieved.

Turns per inch of 19 to 20 is generally used by the spinners for spinning of 21 Ne warp yarn. In fact the spinners consider the fibre properties of cotton in deciding the twist multiplier for the particular count of yarn to be spun. The main focus is to use optimum twist level so that good quality yarn can be spun at commercially competitive and industrially profitable output rate.