Yarn twist index and its calculation-twist degree and twist angle
If one end of the fiber sliver is controlled and held, and the other end rotates around its own axis, a spinning yarn can be formed. This process is called twisting. For short fiber yarns, twisting is a necessary means for spinning yarns to obtain strength and other properties. For filament yarns and kimono threads, twisting creates a tight structure that is not easily damaged by lateral external forces. Twisting can also form textured yarn and fancy yarn. The amount and direction of twisting not only affect the feel and appearance of the fabric, but also affect the intrinsic quality of the fabric. The indicators indicating the degree of twist in spinning yarn include twist degree, twist angle, twist width and twist coefficient. The indicator indicating the direction of twisting is the twist direction. (1) Twist The number of twists per unit length of spinning yarn is called twist. The two cross sections of the spinning yarn produce an angular displacement of 360°, which is called a twist, which is commonly known as a turn. The unit of twist varies with the linear density of the spun yarn. The unit of twist Ttex in the Tex system is twist/10cm, which is usually used for cotton spinning yarn; the unit of twist Tm in the metric system is twist/m, Usually used to indicate the degree of twist of combed wool yarn and chemical fiber filament. The degree of twist of carded wool yarn can be expressed by either the Tex system twist or the metric count system twist. The unit of twist Te in the British alphanumeric system is twist/inch. (2) Twist angle Before twisting, the fibers in the spinning yarn are parallel to each other. After twisting, the fibers are tilted. The greater the twisting degree of the spinning yarn, the greater the fiber tilt. Therefore, the twist angle β can be used to express the degree of twisting by using the tilt angle of the fiber in the spinning yarn. The twist angle β refers to the angle between the surface fiber and the yarn axis, as shown in Figure 2-10, and is calculated by formula (2-15). The twist angle β can be used to indicate the degree of twist of spun yarns of different thicknesses. Two spun yarns with the same twist have different twisting degrees due to different thicknesses. The thicker fiber has a larger twisting degree and a larger twist angle β. Direct measurement of the twist angle requires a microscope, and the eyepiece phase objective micrometer is used to measure it, which is inconvenient and difficult to measure and accurate. Therefore, when necessary in practice, use formula (2-15) to calculate.
AAANHJJGHSFW
Extendedreading:https://www.yingjietex.com/product/400D-Polyester-Yarn-Dye-Punctate-Plain-OXFORD-Fabric.html
Extendedreading:
Extendedreading:
Extendedreading:
Extendedreading:
Extendedreading:
Extendedreading:
Extendedreading:
Extendedreading:
Extendedread
