The fineness of the classical yarn has a variety of methods, such as number, metric number, imperial number, and denier (see count). The fineness of the classical yarn is expressed by the number of minutes per meter or per inch. The direction of the return is divided by S and Z. In a certain range of degrees, the yarn strength increases with the degree of warp. The direction of the single yarn and the alignment of the strands are selected according to the use of the strands. Usually the single yarn and the Strand line adopt opposite direction, namely ZS or SZ. Single yarn and strands of the degree of the best ratio, in this range, the strength of the strands along with the increase in the number of strands, more than the critical value when the strength of the strand decreased.
Fiber properties and spinning methods play a decisive role in the performance of classical yarns. Ring yarn in the process, due to the transfer of fiber, from the classic yarn to the outer layer, and then from the outside to the inner layer, many times repeatedly transferred, the fiber around the yarn axis is spiral, spiral radius along the axis alternately increase or decrease. At this time the length of the fiber more tend to the axis of the yarn, the shorter the length of the fibers tend to the outer layer of the yarn. Fineness of fine fiber tends to yarn axis, and fineness of coarse fibers tends to the outer layer of the yarn. The fibers with smaller initial modulus are more in the outer layer, and the fibers with large initial modulus are more in the inner layers. Reasonable selection of different properties of the fiber, can be spun into different styles of classic yarn, to adapt to different fabric use or improve the performance.
Because the chemical fiber can choose the length, fineness and the fiber cross-section shape, the coat fabric should choose the fiber slightly coarse, the length is slightly shorter the chemical fiber and the cotton blended, to increase the wool type feeling of the yarn surface. The fabric of the underwear should be slightly thinner and longer in length, so as to improve the moisture absorption and wear comfort of the cotton fiber in the outer layer of the classical yarn. Free end spinning includes airflow spinning, electrostatic spinning, Eddy spinning, such as spinning yarn, because of the increase in fiber transfer less, yarn core and the outer layer, the internal tight outside loose, the structure is loose, the fiber straightness is poor, the fiber cohesion is poor, the yarn strength is low, but the dyeing and wear resistance is good. Spin spinning yarn is also called the yarn, is the use of rubbing roll to produce a periodic positive and negative to the false, yarn on the occurrence of periodic no point, and thus the strength of the lower, general joint-stock line after weaving.