Spandex Covered Yarn (CoveredSpandexYarn)
The spandex-coated yarn is a stretch yarn formed by coating a spandex yarn with a spandex yarn as a core and a filament or a short fiber yarn in a spiral shape.
Classification of spandex covered yarn
First, according to the number of coating layers can be divided into two kinds of single-coated yarn and double-coated yarn, in which the ammonia and polyester are mostly coated in a single package.
Second, according to different equipment can be divided into: mechanical coated yarn and air covered yarn.
Spandex covered yarn features
1. Air-covered yarn (abbreviated as empty bag, abbreviated as ACY) is to draw the outer fiber filament and the spandex wire through a certain type of nozzle, and form a rhythmic network point through the high-compression air jet. Yarn. The fabric feels soft and smooth;
Second, the mechanical covering yarn (referred to as the machine package, abbreviated as SCY) is to continuously rotate the outer fiber filament and wrap it on the core silk spandex which is uniformly drawn, which is twisted and twisted (abbreviated as TPM) ), the fabric style is flat and its main features.
Empty and machine-made yarns have advantages and disadvantages in weaving in downstream weaving mills. Empty bags generally require sizing when warping on an air jet loom, otherwise the fabric is prone to bristles, etc., but beating can be used directly. From the perspective of cost alone, the empty package capacity is much higher than the machine package capacity, so that the price is lower than the machine package, which is convenient to reduce the cost of the downstream weaving factory. Although the machine bag does not expose the core wire, it is generally difficult to produce quality problems in spinning and weaving except for unevenness of the twist, but the output is low, and the price is therefore higher than the empty bag of the same specification by RMB5000/T or more. The price is even higher than the empty package of RMB10000/T of the same specification, thus greatly increasing the cost of using the machine package.
Main process
In the spinning process, the pre-draw ratio of spandex (SpandexStretch) is an important process parameter, which affects the elasticity of the covered yarn (Covered Yarn) and the fabric, and affects the elongation of the covered yarn, and the uniformity of the strip. And creep performance. 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.
The phenomenon that deformation changes with time under constant drawing force is called creep. The conventional covered yarn has the best creep resistance when the spandex yarn is pre-drawn 3.5 times. Specifically, it should be adjusted according to the style of the downstream fabric.
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 为, 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.
Application range
Mainly used in: weaving, stretch denim, webbing, socks, underwear, lace and sporting goods, etc.
Editor in charge: Zhu Ling
Muslim Carpet,Small Muslin Carpet,Soft Muslin Cotton Carpet,Muslin Cotton Carpet
Wenzhou Gangxin textiles co.,Ltd , https://www.gxblanket.com