Views: 0 Author: Site Editor Publish Time: 2021-06-01 Origin: Site
How to improve the wet rubbing fastness of reactive dye deep and dense fabrics is a matter of great concern to dyeing and finishing technicians. It is also one of the trade technical barriers that must be overcome to improve the quality of textiles and export textiles and clothing, and has become a hot spot for everyone. By using wet rubbing fastness improver, make your fabric coloring stronger.
This passage is going to talk about the following questions of the wet rubbing fastness improver:
(1) Why to use the wet rubbing fastness improver?
(2) What is the principle of the wet rubbing fastness improver?
(3) What is the color fastness?
The main reasons for the unqualified wet rubbing fastness of reactive dye deep and dense textiles are: the floating color transfer of water-soluble dyes and the mechanical friction transfer of colored fiber particles (10-40 nanometers).
The wet rubbing fastness of dyed cloth refers to the rubbing of a wet white cloth with a sample of dyed cloth under specified conditions. The degree of staining on the white cloth is compared with the standard gray staining sample card, that is, dye molecules and colored fiber particles. The degree of transfer to the test white cloth through interface contact. With the same fabric, the same dye and the same pre-treatment and dyeing process, the darker the color, the worse the wet rubbing fastness.
The water-soluble gene in the reactive dye molecule is beneficial to the dissolution and dyeing of the dye, but it becomes an unfavorable factor for the wet rubbing fastness of the dyed fabric. Due to the presence of the aqueous medium on the wet white cloth, the reactive dyes tend to leave the fabric and enter the aqueous medium. Therefore, the dry rubbing fastness of the same reactive dyestuff can reach 4-5, while the wet rubbing fastness is 2-3
Level is also difficult to achieve.
The floating color on reactive dyes is the main reason for the unqualified wet rubbing fastness of dark and dense fabrics. The floating dyes of reactive dyes include: dyes that have been adsorbed on the fiber without participating in the covalent reaction with the fiber, partially hydrolyzed dyes and vinyl sulfone-based dyes after the sulfate ester has been eliminated. The total amount of floating dyes can be the difference between the final dye uptake rate E and the final fixation rate F in the SERF value of the characteristic value of dyeing with reactive dyes is displayed as the EF value. Therefore, it is necessary to select reactive dyes with less floating color after dyeing to facilitate the removal of floating color; that is, the lower the E-F value, the less the floating color amount. If the fixation rate is high, most of the dyes are fixed to the fiber after dyeing, and the amount of floating color can be greatly reduced.
Dyeing fastness is the quality requirement for dyed and printed fabrics. In the process of taking or processing, the dyes on dyed and printed textiles undergo various factors to maintain their original color to varying degrees. The performance is called dye fastness. Dyeing fastness is related to fiber type, yarn structure, fabric structure, printing and dyeing method, dye type and external forces. According to the different nature of the external factors that the dye is subjected to on the fabric, there are various corresponding color fastnesses, such as light fastness (sunlight), washing fastness, rubbing (dry and wet color fastness), Color fastness to perspiration (acid, alkali), color fastness to ironing (hot pressing), color fastness to chlorine
G swimming pool water), color fastness to saliva, composite color fastness to perspiration, and sublimation fastness of disperse dyes and milling on wool fabrics. Reactive dyes form chemical bonds with fibers in the form of covalent bonds.