In the textile sector, bleaching processes are applied to all textile products that need to be white or print. The basis of the bleaching processes is the disintegration of the natural dyes, especially in the structure of the natural fibers, and their water-solubility, followed by washing the fabric and removing them from the fibers.

Briefly, the bleaching process aims to produce white fabrics. This process also makes the colors brighter in printing and increases the attractiveness of the fabrics. Bleaching processes are not a cleaning process, contrary to what is believed. It is the process of removing and destroying natural dyes which give the yarn a yellow or brown color by applying an oxidation process.

Oxidizing agents are oxidizing agents and are used more in bleaching processes. In the past, fabrics were spread outdoors and bleached by the effect of sun and air. Generally, the following oxidizing agents are used: hydrogen peroxide, sodium chloride and sodium hypochlorite. In addition, lime cream (calcium hypochlorite) and sodium peroxide is also used.

In particular, raw cotton products need to be bleached to remove the yellow color. In addition, if light colors will be used on the fabrics to be dyed or printed, a very good bleaching process has to be done. Otherwise, light colors cannot be obtained as desired and bright and vivid colors do not appear after dyeing or printing. For this reason, bleaching process is always done in cotton products that will be offered as white. This process also improves the hydrophilicity of the cotton product.

The materials used in the bleaching process react with the color compounds contained in the fiber and make them clean by reducing or oxidizing. In particular, oxidizing agents are used for bleaching cotton products.

Washing fastness with oxidative bleach is determined in accordance with the following standard:

• TS EN ISO 105-C09 / A1 Textiles - Color fastness tests - Part C09: Color fastness to domestic and commercial washing - Oxidant bleaching response using low-temperature bleach activator-added phosphate-free reference detergent