Under the external condition, as light and chemicals, white or light color material will have surface yellowing. That is called “Yellowing”.
After yellowing, not only the appearance of white fabrics and dyed fabrics is damaged, but also their wearing and using life will be greatly reduced.
What are the reasons for textile yellowing?
Photo-yellowing
Photo-yellowing refers to the surface yellowing of textile clothing caused by molecular oxidative cracking reaction due to sunlight or ultraviolet light. Photo-yellowing is most common in light color clothing, bleached fabrics and whitened fabrics. When the fabric is lighted, the light energy is transferred to the fabric dyes, which causes the dye conjugate to crack and leads to photo-fading. So that the fabric surface appears yellow. Among, visible light and ultraviolet light are respectively the main factors causing fading of fabrics dyed by azo dyes and phthalocyanine dyes.
Phenolic Yellowing
Phenolic yellowing is generally caused by the contact transfer of NOX and phenolic compounds on the fabric surface. The main reactive substances are usually antioxidants in packaging materials, such as butylphenol (BHT). After a long time of packaging and transportation, the BHT in the packaging materials will react with NOX in the air, which will result in yellowing of the clothing.
Oxidative Yellowing
Oxidative yellowing refers to the yellowing of fabric that is oxidized by air or other substances. Generally, during dyeing and finishing process, textile and garment are used reduced dyes or auxiliaries. When they are contact with oxidative gases, there will occur oxidation-reduction, which will cause yellowing.
Whitening Agent Yellowing
Whitening agent yellowing mainly occurs on light color fabrics. When the residual whitening agent on surface of clothing migrates due to long-time storage, it will cause whitening agent on some part is excessive. Therefore, the clothing will become yellow.
Softener Yellowing
In the finishing process, there will use softener in clothing. In the condition of heat and light, the cation in softener will have oxidation, that will lead to fabric yellowing.
How to prevent yellowing of textile?
1.During manufacturing and processing, enterprises should try to minimize the using of whitening agent, which should not exceed the yellowing point of whitening agent.
2.In the finishing process of fabric, the setting temperature should not be too high. High temperature will make the dyes or auxiliaries on the fabric surface oxidize and crack, and then cause the fabric yellowing.
3.In the packaging, storage and transportation please use package materials containing less BHT. Please try to keep the storage and transportation environment ventilated at normal temperature to avoid phenol yellowing.
4.In case of phenolic yellowing due to package material of textile clothing, in order to reduce losses, a certain amount of reducing powder can be scattered on the bottom of the package. And then please seal the carton for 1~2 days and open it and place for 6 hours. After the smell is dissipated, the textile clothing can be re-packed. So the yellowing can be modified to the maximum extent.
5.In daily wear, please pay attention to maintenance, wash frequently and wash lightly. And please do not expose to the sun for a long time.
Wholesale 43512 Anti-oxidation Agent Manufacturer and Supplier | Innovative (textile-chem.com)
Post time: Dec-31-2022