The elastic fiber is mainly spandex, and there are also a small amount of other fibers, such as elastic polyester.
Usually spandex has 20D, 30D, 40D, 70D, 105D, 140D specifications, knitted 30 is used more, woven 40D is used more, if the elasticity is better, use 70D.
If the dyeing is successful once, then the quality of the spandex is better or the difference is not obvious; if you want to repair the color, the elastic damage of the spandex with good quality will be less.
Spandex is generally transparent, white, black, and colored.
The application of spandex in fabrics includes three types: bare silk, network and twisting. The twisting is divided into two types: spandex and filament yarns and spandex and short fiber yarns, and the spandex core-spun yarn is directly added when spinning.
The elasticity of the fabric has no absolute relationship with the spandex content. For example, NR grosgrain has good elasticity, but the spandex content is not high. This has something to do with the composition of the fabric, the organizational structure and the dyeing process. Finishing can also destroy stretch, such as fluffing.
Spandex will be colored when dyed with disperse dyes and acid dyes, so many times we see spandex as reddish-brown. That means disperse or acid dyes are used for dyeing.