Analysis of the principle of yellowing of spandex fabrics

Spandex is a kind of fiber commonly used in our life. The most prominent feature is good elasticity, and it has the advantages of low fineness, large elastic modulus (elongation at break can reach 400%-800%) and small proportion. Spandex is a commonly used fiber variety in our life. The most prominent feature is good elasticity, and it has the advantages of low fineness, large elastic modulus (elongation at break can reach 400%-800%), and small specific gravity. Spandex can be blended with wool, cotton, polyester, acrylic, viscose and other textile fibers to make the fabric soft, elastic and comfortable to wear. It is widely used in fitness clothes, swimming suits, jeans, tights, underwear, one-piece In clothing and intimate underwear, spandex fabrics are more popular among women because women's clothing has higher requirements for close-fitting. Since the molecular chain of spandex contains a large number of reactive groups such as amino groups, it is easy to turn yellow during high temperature setting or storage, which affects the quality of finished products, especially fluorescent whitening fabrics and light-colored fabrics. In order to improve the running performance of spandex during spinning, silicone oil lubricants and other auxiliaries are used in the weaving process. These additives naturally degrade over time causing the fibers to yellow. In addition, spandex itself is not easy to color, that is, conventional dyes cannot color spandex, so after the fabric is dyed, if the reduction and cleaning are insufficient, the so-called yellowing phenomenon will also occur. Best-selling black spandex filament --- dope dyeing technology: Black spandex is a widely used variety in clothing fabrics. In recent years, the domestic black spandex filament production capacity has been continuously expanded, and the product performance has been continuously improved. The black spandex filament directly spun through special processes such as dope dyeing or online addition not only has a more uniform and lasting black effect, higher color fastness and excellent washing resistance, but also saves the dyeing process of the fiber. Energy consumption in the dyeing process, reducing environmental pollution.