Polyurethane (spandex)
Spandex fiber belongs to the polyurethane structure, which is the earliest developed, most widely used and most mature production technology of elastic fiber. With high elongation, low modulus and high elastic recovery rate, the elongation of spandex can reach 400%~800%, and the recovery rate of production 500% is as high as 95%~99%. Spandex also has excellent chemical stability and thermal stability, and spandex has good acid and alkali resistance, sweat resistance, seawater resistance, dry cleaning resistance, and abrasion resistance. However, spandex needs to be coated before it can be used, and it has the disadvantages of not being resistant to chlorine bleaching and easy to relax.
Generally, as long as 2%~10% spandex is added, the underwear can be soft and close, comfortable and beautiful, and the sportswear fit is soft and soft, and the movement is free.
Polyether ester elastane
Polyether ester elastane is an elastane fiber made from polyester and polyether copolymers through melt spinning, and was first produced by Teijin Corporation in Japan in 1990. Polyether ester elastane fibers are structurally similar to polyurethane elastane fibers and also have a "segmental" structural characteristic. The "soft" chain segment is mainly polyether segment, which has good flexibility, long chain, and easy elongation and deformation; The "hard" segment is the polyester segment, which is relatively stiff and easy to crystallize, and the chain is shorter, which acts as a node when the fiber is deformed by force, imparts elastic recovery properties, and determines the strength and heat resistance of the fiber.
Polyether ester elastane fiber not only has high strength, but also good elasticity, at 50% elongation, the elasticity of medium strength elastane fiber has been equivalent to spandex, and the melting point is also higher, blended with PET fiber, can be dyed at 120~130 °C, so polyester fiber can also be processed into elastic textiles. In addition, they have excellent lightfastness, chlorine bleaching resistance, acid and alkali resistance, etc., which are better than ordinary spandex. Due to its good acid and alkali resistance, the fabric composed of it and polyester can also be processed with alkali reduction to improve the drape of the fabric.
This fiber also has the advantages of cheap raw materials, easy production and processing, and is a more promising type of fiber.
Polyolefin Elastane (XLA)
XLA fiber is a polyolefin fiber launched by Dow in the United States, the average crystallinity of the fiber is 14%, the elongation at break is 500%, it can generate recovery, and can withstand high temperature of 220 °C, resistant to chlorine bleaching and strong acid and alkali and other chemical agents, and has strong resistance to ultraviolet degradation. After washing, bleaching, dyeing, coating and bonding, its inherent elasticity is largely unaffected. At the same time, because the elongation force of XLA fiber fabric is less than that of most other stretch fabrics, the shrinkage is more natural and comfortable, which is suitable for use in infant clothing.
In addition, since the main component of XLA is recyclable polyolefins, it will not be suitable for spinning volatile organic compounds during the textile process, and does not contain heavy metals, which will not hinder the recycling of garments.
Composite elastane fiber (T400 fiber)
CONTEX (ST 100 composite elastane, collectively known as T400 elastane in the market) is a new two-component composite elastic fiber made of DuPont Sorona as the main raw material and ordinary PET through advanced composite spinning process; With natural permanent spiral crimp and excellent bulkiness, elasticity, elastic recovery rate, color fastness and particularly soft feel, it can be woven alone, or interwoven with cotton, viscose, polyester, nylon, etc., to form a variety of types of styles. It not only solves many problems such as traditional spandex yarn is not easy to dye, excess elasticity, complex weaving, unstable fabric size, and easy aging during use, but also can be directly woven on air-jet, water-spray, and arrow looms, and does not have to be woven on the machine after being made into covered yarn like spandex, which reduces the cost of yarn and improves the quality uniformity of products.