Causes of yellowing of spandex fabric
01 Because spandex molecular chains all contain 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.
02 Spandex In order to improve the running performance during spinning, silicone oil lubricants and other additives are used in the weaving process. These additives will naturally degrade over time causing the fibers to yellow.
03 Spandex is not resistant to ultraviolet rays and easily yellows after prolonged sunlight exposure, but it will not cause immediate loss of strength. Polyether spandex is more yellowing than polyester spandex. When spandex is subjected to dry heat treatment, if it is too long or the temperature is too high, it will also cause yellowing and loss of strength and elasticity. This is due to the soft segment of the polyether spandex. Caused by oxidation. Certain nitrogen oxides, sulfur oxides, aldehydes, and fumes in the atmosphere can also cause yellowing of spandex and affect the appearance of finished products. Certain unsaturated oils, unsaturated fatty acids, and certain fats in skin secretions have an extraction effect on some stabilizers in spandex filaments, which will increase the sensitivity of spandex to photooxidation, and make spandex more yellowing after sun exposure. .
04 Spandex will also yellow if exposed to chemicals containing available chlorine, so it is best to cover it with polyethylene film during storage.
05 In addition, spandex itself is not easy to color, that is, conventional dyes cannot color spandex. Therefore, after the fabric is dyed and the reduction cleaning is not sufficient, the so-called yellowing phenomenon will also occur.