
Causes of Creasing Or Yellowing of Spandex Fabric
The spandex fabric sent out by the printing and dyeing factory sometimes encounter customer complaints, which are generally nothing more than poor fabric surface effect, horizontal stripes, yellowing of spandex, etc. The raw materials are imported from large factories, the dyeing factories that make the goods are also standardized dyeing factories, and this fabric has been shipped in large quantities, and no customers have reported any problems. To know where these problems come from, we need to first understand the characteristics of spandex.
- Spandex fiber has excellent elasticity, and its elastic elongation is the highest among textile fibers, which can reach 400% to 500%; the elastic recovery rate is also high, which can reach 95% to 99%.
- Spandex is a thermoplastic fiber with a softening point of 160℃, a safe ironing temperature of <150℃, and a heat-setting temperature between 185 and 190℃.
- Spandex is a hydrophobic fiber with low hygroscopicity.
- The relative density of spandex is low, about 1.20, so the texture of the entire spandex is relatively loose.

- The surface friction coefficient of spandex is very large, about 0.7 to 1.30, which is 5 to 7 times the friction coefficient of wool (wool is about 0.14 to 0.17), and 3 to 4 times that of synthetic fibers such as polyester and nylon. Therefore, when spinning spandex yarn, a large amount of silicone emulsion should be used in the spinning oil to facilitate stretching and winding.
- Spandex fabrics are not UV-resistant and tends to turn yellow after long-term exposure to sunlight, but it does not immediately cause strength loss. Polyether spandex is more prone to yellowing than polyester spandex.
Spandex is resistant to dilute acid and alkali at room temperature, and its acid resistance is much better than its alkali resistance; it is resistant to reducing agents and is also resistant to oxidants and bleaches that do not contain effective chlorine.
Why Spandex Fabric Turns Yellow
- 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 shaping or storage, affecting the quality of the finished product, especially the fluorescent whitening fabric and light-colored fabric.
- To improve its running performance during spinning, spandex fabric uses silicone oil lubricants and other additives during the weaving process. These additives will naturally degrade over time and cause the fiber to turn yellow.

- Spandex fabric is not resistant to ultraviolet rays. It is easy to turn yellow after long-term exposure to sunlight, but it will not cause immediate strength loss. Polyether spandex is more prone to yellowing than polyester spandex. When spandex is subjected to dry heat treatment, if the time 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 oxidation of the polyether soft segment. Certain nitrogen oxides, sulfur oxides, aldehydes, and flue gases in the atmosphere can also cause spandex to turn yellow, affecting the appearance of the finished product. Certain unsaturated oils, unsaturated fatty acids, and certain fats in skin secretions can extract certain stabilizers in spandex yarns, which will increase the sensitivity of spandex to photooxidation and make spandex more prone to yellowing after sun exposure.
- Spandex fabric will also turn yellow if it comes into contact with chemicals containing effective chlorine, so it is best to wrap it with polyethylene film during storage.
In addition, spandex itself is not easy to color; conventional dyes cannot color spandex fabrics, so after the fabric is dyed, if the reduction cleaning is not sufficient, the so-called yellowing phenomenon will also occur.
Spandex Fabric Creasing
To improve the running performance of spandex fabric during spinning, silicone oil lubricants, and other additives are used in the weaving process. These additives will naturally degrade over time, causing the fiber to turn yellow and the elasticity of the fabric to decrease. At the same time, spandex-containing fabrics will form a “cold set” during long-term storage, causing permanent wrinkles in the fabric that cannot be eliminated during post-processing. Therefore, in addition to reducing the storage time, it is more important for spandex-containing knitted fabrics to be opened immediately after weaving and then rolled flat to avoid the chance of creases.

Anbu Safety was established in 2008 and is committed to providing customers with different types of safety equipment. It mainly produces safety shoes, work clothes, safety helmets and glasses, and other safety protection equipment. Anbu Safety has its factory and can also provide OEM services for customers, with CE and UL certificates.
Welcome to BOSTON Scrub Factory! BOSTON Scrub is a large-scale modern clothing manufacturer that integrates design, development, production, and sales. It mainly produces and exports medical surgical gowns, medical uniforms, and laboratory work clothes. As a leading manufacturer of medical surgical gowns, BOSTON always adheres to and implements the concept of “quality first, service first”.