Twist Liveliness Measurement and Its Application to Predict Fabric Spirality

Abstract

Twist liveliness is the tendency of a spun yarn to twist or untwist spontaneously in an attempt to release the residual torque. Generally, in the textile industry twist liveliness is considered a negative attribute of a spun yarn, which is responsible for many post-spinning problems, such as yarn snarling and fabric spirality. Despite its significance, systematic studies on yarn twist liveliness measurement and particularly its quantitative relationship with fabric spirality, have not been carried out. In the present study, the twist liveliness of 100 % cotton ring yarns were measured using an improved testing methodology and apparatus based on the ISO Standard 03343-1984 where two ends of a known length of yarn are brought together and the number of snarls in the length of yarn is counted. The effects of the measured twist liveliness on the spirality of plain knits have been investigated. Mathematical tools have been used to determine the relationship between the measured twist liveliness and the degree of spirality of pure cotton fabrics. The results of the analyses reveal that the measurement of twist liveliness using the improved testing methodology and apparatus is significant in the prediction of knitted fabric spirality. The results of this work will be of interest to spinners, knitters or researchers investigating methods to monitor yarn twist liveliness and/or control fabric spirality.