Dyes are substances that can make fibers and other materials colored, which are divided into two categories: natural and synthetic. Dyes are substances with colors. But the matter with color is not necessarily a dye.
Definition of dye industry
According to the market survey report of Dyestuff Industry issued by Yubo Market Research Center, dyes are the substances that can make certain colors attached to fibers, and are not easy to fall off and discolor. Dyes are usually soluble in water, and some of them require mordants to make them stick to fibers. Archaeological data show that dyeing technology has been more than 5000 years old in India and the Middle East. Dyes were produced from plants or minerals at that time, and were rarely treated.
Classification of dye industry
According to the properties and application methods of dyes, the dyes can be classified as follows.
By status
Water based color paste oil color paste water color essential oil essence
By purpose
Ceramic pigment pigment pigment textile pigment plastic pigment
By source
Natural dyes: plant dyes animal dyes synthetic dyes (also called artificial dyes) according to usage
According to the properties of dyes and the application methods
Direct dyes insoluble azo dyes reactive dyes reducing dyes soluble reducing dyes sulfurized dyes phthalocyanine dyes oxidation dyes polycondensated dyes disperse dyes acid dyes acid media and acid containing dyes basic and cationic dyes
Direct dyes
Such dyes are named for their direct dyeing on cotton, hemp, silk, wool and other fibers without relying on other chemicals. The method is simple, the chromatogram is complete and the cost is low. But the fastness to washing and sun is poor. If the proper post-treatment method is adopted, the fastness of the finished dyeing products can be improved. Chromium containing gold dye -- qinzhu pigment active dye
Also known as reactive dyes. These dyes are new dyes developed in the 1950s. The molecular structure of the fiber contains one or more active groups, which can react with fibers under appropriate conditions to form covalent bond. It can be used for dyeing cotton, hemp, silk, wool, viscose, nylon, vinylon and other textiles.
Sulfurized dye
Most of these dyes are insoluble in water and organic solvents, but they can be dissolved in alkali sulfide solution, and then they can dye fibers directly. But it is also not suitable for protein fiber because of its strong alkali. The color fastness of these dyes is better than that of the same color spectrum, low price and bright color.
Disperse dyes
The solubility of these dyes is very low in water, and the particles are very fine. They are dispersive in the dye solution, which belongs to non-ionic dyes, mainly used for polyester dyeing, and their dyeing fastness is high.
Acid dyes
These dyes have water-soluble, most of which contain water-soluble genes such as sulfonic group and carboxyl group. Protein fibers can be directly stained in acid, weak acid or neutral medium, but the fastness of wet treatment is poor.
coating
It is suitable for all fibers. Through the attached fibers of resin machinery, dark fabrics will become hard, but the color is very accurate. Most of them have good light fastness and good washing fastness, especially medium and light colors.