Disperse dyeing mainly involves dyeing polyester fibers under high temperature and pressure. Although the molecules of dispersed dyes are small, it cannot be guaranteed that all dye molecules will enter the interior of the fibers during dyeing. Some dispersed dyes will adhere to the surface of the fibers, causing poor fastness. Reduction cleaning is used to damage the dye molecules that have not entered the interior of the fibers, improve color fastness, and other functions.

   In order to fully remove floating colors and residual oligomers on the surface of polyester fabrics, especially in medium and dark color dyeing, and improve dyeing fastness, reduction cleaning is usually required after dyeing. Blended fabrics generally refer to yarns made from a mixture of two or more components, thus possessing the advantages of these two components. Moreover, more characteristics of one component can be obtained by adjusting its proportion.

   Blending generally refers to short fiber blending, where two types of fibers with different compositions are mixed together in the form of short fibers. For example, polyester cotton blended fabric, also commonly known as T/C, CVC.T/R, etc. It is woven from a blend of polyester staple fibers and cotton or synthetic fibers. It has the advantage of having the appearance and feel of all cotton fabric, weakening the chemical fiber luster and chemical fiber feel of polyester fabric, and improving the level.

   Improved color fastness. Due to the high temperature dyeing of polyester fabric, the color fastness is higher than that of whole cotton. Therefore, the color fastness of polyester cotton blended fabric is also improved compared to that of whole cotton. However, to improve the color fastness of polyester cotton fabric, it is necessary to undergo reduction cleaning (also known as R/C), followed by post-treatment after high-temperature dyeing and dispersion. Only after performing a reduction cleaning can the desired color fastness be achieved.

   Short fiber blending enables the characteristics of each component to be evenly utilized. Similarly, blending of other components can also leverage their respective advantages to meet some functional, comfort, or economic requirements. However, in high-temperature dispersion dyeing of polyester cotton blended fabrics, due to the blending of cotton or rayon fibers, the dyeing temperature cannot be higher than that of polyester fabrics. However, when polyester cotton or polyester cotton artificial fiber cloth is stimulated by strong alkali or insurance powder, it will cause a significant decrease in fiber strength or tearing force, and it is difficult to achieve product quality in the subsequent stages.