On the viscosity of yarn

The twist of a yarn refers to the number of twists per unit length. Twist has a twist direction, including "S" twist and "Z" twist. Twist generally refers to the number of twists per meter, and the twist of wool yarn varies with the number of yarns. In order to compare the twist of wool yarn and yarn with different counts, the concept of "twist coefficient" is commonly used. The selection of "twist coefficient" generally refers to pure wool being greater than blended yarn, blended yarn being greater than chemical fiber yarn, high short wool content being greater than low short wool content, and fine yarn count being greater than coarse yarn count.

Yarn twist test

1 Overview

Short fibers need to be twisted in order to be spun into yarn, while long fibers also need to be twisted in order to facilitate processing or improve compactness. Twist has a direct impact on the structure, physical properties, fabric style, and clothing performance of the yarn. It is the main basis for evaluating product grade. The testing methods for yarn twist include direct counting method and untwisting and twisting method. The untwisting and twisting method can be further divided into: untwisting and twisting A method, untwisting and twisting B method, and triple untwisting and twisting method. The direct counting method is applicable to short fiber single yarn, twisted multifilament, stranded wire, and cable; The untwisting and twisting method is applicable to single yarns of cotton, wool, silk, hemp and their blended fibers.

2 Purpose and Requirements

By testing the yarn twist, understand the basic structure and working principle of the yarn twist tester, master the operating methods and sampling requirements of the instrument, and understand the meaning of various indicators.