High Content And Good Elasticity
- Jul 09, 2018 -

In the spinning process, spandex Stretch is an important process parameter, which affects the elasticity of the covered yarn and the fabric, and affects the elongation of the covered yarn. Uniformity and creep properties. The pre-draw ratio of spandex is too small, and the advantage of elastic fabric fabric elasticity is not fully utilized. When the drafting is too high, the spinning is difficult, and the yarn breaks easily, and the product quality decreases. In addition, the percentage of spandex yarn also affects. The covered yarn has high elasticity, high content and good elasticity. In the case of a certain size of the spandex yarn, the draw ratio is increased, and the percentage of the spandex yarn is lowered, that is, the pre-draw ratio of the spandex is inversely proportional to the percentage of the spandex.

The elongation of the air-coated yarn increases with the increase of the pre-draw ratio of the spandex. After the drafting reaches a certain value, the shrinkage of the spandex yarn causes the outer fiber to be curled; the pre-draw ratio is appropriately increased, and the spandex is increased. The percentage is reduced and the outer fiber is highly curled. However, when the drafting is too large, the deformation amplitude of the spandex yarn is close to the critical value of the deformation, which will lower the strength of the covered yarn, but it is advantageous for the coated yarn to be evenly dried.

In addition to the spanning draw ratio requirement of the mechanical covering yarn in the air-coated yarn, an important process parameter is the twist, which affects the quality of the yarn, the strength and the uniformity of the strand. Increasing the twist can increase the cohesion between the outer fiber and the spandex, so that the covered yarn is strongly enhanced. The degree of twist is too low, the outer fiber is loose, affecting the coating effect, and the core is exposed, so the twist of the mechanical coating should be high. However, the degree of twist is too high, the fabric feels hard and the drape is poor. Generally, the twist is changed according to the change of the denier of the yarn and the style requirements of the fabric. For example, the N40D+20D machine package has a twist of about 600捻, while the N70D+40D or T150D+40D machine has a twist control of 480. It’s ok. The elongation of the bag is also mainly determined by the performance of the spandex core wire. The twist is too large, the outer fiber is too tightly coated, and the elastic effect of the spandex is not fully exerted, so that the elongation is lowered. As the twist increases, the evenness of the strip improves. When the twist is too small, the outer fiber is loose. During the spinning process, the fiber slightly moves along the axial direction of the yarn due to friction or the like, so the strip is deteriorated.


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