Simple understanding of yarn

Yarn is divided into: ① short fiber yarn, which is made by spinning short fibers (natural short fibers or chemical fiber cut fibers), and is divided into ring spun yarn, free end spun yarn, self twisted yarn, etc. ② Continuous filament, such as natural silk and synthetic filament, with or without twist, smooth filament or deformed filament, etc Short fiber and continuous filament combination yarn, such as polyester cotton filament core-spun yarn. Thread is made by combining and twisting two or more strands of single yarn.

There are various ways to express the fineness of yarn, such as number, metric count, English count, denier count, etc. (see count). The twist of the yarn is represented by the number of twists per meter or inch. The direction of twisting back is divided into S twisting and Z twisting. Within a certain twist range, the strength of the yarn increases with the increase of twist. The twist direction of single yarn and the twist direction of ply yarn are selected based on the purpose of the ply yarn. Usually, single yarn and ply yarn are twisted in the opposite direction, i.e. ZS or SZ. There is an optimal ratio of twist between single yarn and ply yarn, within which the strength of the ply yarn increases with the increase of twist, but decreases when the critical value is exceeded. The properties of fibers and spinning methods play a decisive role in the performance of yarns. During the twisting process of ring spun yarn, due to the transfer of fibers, the fibers are transferred repeatedly from the inner layer to the outer layer of the yarn, and then from the outer layer to the inner layer. The fibers are spiral shaped around the axis of the yarn, and the spiral radius alternately increases or decreases along the axis. At this point, the longer fibers tend more towards the axis of the yarn, while the shorter fibers tend more towards the outer layer of the yarn. Fine fibers tend towards the axis of the yarn, while coarse fibers tend towards the outer layer of the yarn. Fibers with lower initial modulus are mostly located in the outer layer, while fibers with higher initial modulus are mostly located in the inner layer. Reasonable selection of fibers with different properties can spin different styles of yarn, adapt to different fabric uses or improve wearing performance. Due to the fact that chemical fibers can be arbitrarily selected in length, fineness, and cross-sectional shape, it is advisable to use slightly thicker and shorter chemical fibers mixed with cotton for outerwear fabrics to increase the woolly texture on the surface of the yarn. Underwear fabrics should be made of slightly thinner and longer synthetic fibers, with cotton fibers placed on the outer layer of the yarn to improve moisture absorption and comfort. Free end spinning includes yarns spun by airflow spinning, electrospinning, eddy current spinning, etc. Due to less inward fiber transfer during twisting, the yarn core is relatively tight and loose compared to the outer layer, with a loose structure, poor fiber straightness, poor fiber adhesion, low yarn strength, but good dyeing and wear resistance. Self twisted yarn, also known as self twisted yarn, is a type of yarn that uses twist rollers to produce periodic forward and reverse false twist on the strands, resulting in periodic no twist points on the yarn, resulting in low strength. Generally, it is woven after being folded into strands.

Filament yarn is a bundle made up of filaments (such as natural silk, synthetic silk, or rayon) that are combined together; Mainly including polyester filament, viscose filament, nylon filament, etc.

Fancy yarn mainly manifests as changes in the appearance or color of the yarn. There are mainly wrapping, core wrapping, bamboo knots, big belly, colored dots, waveforms, braids, towels, circles, knots, feathers, toothbrushes, centipedes, ribbons, Duan dyeing, Chenille, and so on.