Analysis of the main causes of yellowing of cotton fabric:

1. Fiber degradation: degradation of the fiber caused by heat, light, other radiation, chemicals and biological action.

2. Additives: yellowing and shade change caused by softeners, oils, lubricants, resins, fluorescent brightening agents and metal compounds.

3. Atmospheric pollutants: yellowing caused by nitrogen oxides, sulfur dioxide and ozone.

4. Transferred contaminants: the original yellow colorants are transferred to the fabric from contacting paper, cardboard, plastic film or plastic bags and the pumice used in stone washing.

5. Consumer contaminants: residues from perspiration and from home washing and bleaching.

During storage, phenolic yellowing is the most common. Phenolic compounds or butylated hydroxytoluene (BHT) transfer from packaging materials such as cardboard, paper or plastic film onto the fabric during storage, and nitro compounds formed by the action of nitrogen oxides on these colorants cause yellowing. Proper packaging with low-phenol materials, adequate ventilation during storage, and control of temperature and humidity help prevent the problem. Choosing additives with low yellowing tendency and keeping the fabric clean before finishing also reduce the risk.