What are the mechanical properties of textile fibers?

Twist properties include twist degree, twist coefficient and twist direction.

Twist yarn twist Angle twist for one turn. The number of twist cycles per unit length of yarn is called twist. China's cotton yarn adopts special twist, that is, the number of twist within the length of 10cm. Worsted yarns and chemical filament yarns are of metric twist, that is, the number of twists per meter; There is also a British twist, expressed in revolutions per inch.

Twist coefficient twist cannot be used to compare the degree of twist of yarns of different thicknesses, because, with the same twist, the skewness of the fibers of the coarse yarns is greater than that of the fine yarns. In practical production, twist coefficient is often used to represent the degree of yarn twist. Twist coefficient is the relative value of yarn twist degree based on linear density. It can be used to compare the twist degree of different thick and thin yarns. The twist coefficient is calculated by the twist of the yarn and the linear density of the yarn.

Twist direction twist direction is the direction of inclination of a single yarn after twisting. It is available in Z twist and S twist. After twisting, the twist of the yarn tends to the upper left corner from the lower right corner, and the inclined direction is consistent with the middle part of "S", which is called "S twist" or "smooth twist"; A z-twist or backhand twist in which the yarn twists from the bottom left corner to the top right corner in a direction consistent with the middle of the "Z". General single yarn often USES Z twist, strands use S twist.

The direction of twist of the strand is indicated by the direction of subsequent twisting. For example, a single yarn with a Z twist, an S twist for the first twist, and a Z twist for the second twist, with the twist direction indicated by ZSZ.