Textile yellowing causes and solutions

what are the causes of textile yellowing?

Light yellowing:

Light yellowing refers to textile clothing due to sunlight or ultraviolet light irradiation, causing molecular oxidation and cleavage reaction and make the surface of the clothing yellowing. Light yellowing in light-coloured clothing, bleaching treatment fabrics, whitening treatment fabrics in the most common. After the fabric is exposed to light, light energy is transmitted to the fabric dyes, resulting in the cleavage of the dye conjugates, thus causing light discolouration and yellowing of the fabric surface. Among them, visible light and ultraviolet light are the main factors that cause azo dyes and phthalocyanine dyes to discolour the fabric.

Phenol yellowing:

Phenol yellowing is generally caused by NOX and phenolic compounds through the contact transfer of fabric surface yellowing, the main reaction substance is usually packaging materials containing antioxidants, such as butylphenol (BHT). Clothing and footwear in the factory after a long period of packaging and transport, packaging materials in the BHT will react with the NOX in the air, thus causing yellowing of clothing.

Oxidative yellowing:

Oxidative yellowing refers to the yellowing of fabrics produced by the atmosphere or oxidation of other substances. Textile and clothing in the dyeing and finishing usually use reducing dyes or additives, in contact with oxidising gases, redox effect and yellowing.

Whitening agent yellowing:

Brightener yellowing mainly occurs in light-coloured fabrics, when the surface of the garment residual brightener because of long storage and migration, resulting in excessive local brightener, and produce clothing yellowing.

Softeners and other finishing agents yellowing:

Clothing in the finishing process used in the softening additives, when subjected to heat, light and other conditions, the cations will be oxidised, resulting in fabric softening parts of the yellowing.

How to prevent textile yellowing?

1. for the need to use fluorescent whitening agent varieties, choose to various conditions of yellowing small whitening agent.

2. in the fabric finishing shaping, the temperature should not be too high, high temperature will make the fabric surface dyes or auxiliaries oxidation cracking, which in turn causes the fabric yellowing. 

3. softeners and other finishing additives before using the test of yellowing performance, choose low yellowing additives models. 

4. in the packaging storage, transport process, the use of BHT content of lower packaging materials, and try to keep the storage, transport environment to maintain room temperature and ventilation to avoid phenol yellowing. 

5. according to the different causes of yellowing use anti-yellowing agent, the use of anti-yellowing agent. According to different causes of yellowing, use anti-yellowing agent, generally divided into antioxidant yellowing agent and anti-phenol yellowing agent.

Edit by Edie

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