5 kinds of pretreatment methods for dyeing fabrics to obtain dark colors

1 Strengthen the decontamination treatment of the dyed material

The pre-treatment is sufficient, the fabric wettability is good, the capillary effect is large, and the diffusion ability of the dye molecules to the dyes may be increased, thereby increasing the dye uptake rate. Therefore, the above purposes can be achieved by enhancing the removal of impurities and decontamination of the dyed material.

2 Mercerization of cotton fabrics

After the mercerized cotton fabric, its dye adsorption capacity is obviously improved, and the medium and dark color effect can be obtained more than the non-silk treated cotton fabric, and the surface gloss is improved.

3 Alkaline reduction treatment of polyester fabrics

Polyester macromolecules have high crystallinity, tight fiber structure, high index of refraction and surface reflectivity, and smooth fiber surface. They reflect light mainly by mirrors and are dyed black with disperse dyes because of the large amount of reflected light from the surface of the fabric. Light enters people's sight, so deep black is harder to obtain. After the alkali reduction treatment, the original smooth surface of the polyester turns into a rough surface, forming an irregular concave and convex reflective layer, which is also known as the etching effect, resulting in a certain dark color effect, and after reduced treatment fabric The freedom of movement increased, and the dye's adhesion increased.

4 Application of Low Temperature Plasma Technology

Plasma technology belongs to the method of processing on the surface of the fabric and belongs to the modern dry-cleaning physical processing of the dyeing technology. For example, after plasma-treated polyester fibers are graft-polymerized to form a low-refractive-index film on the surface of the fiber, the dye uptake rate and depth of color can be significantly improved; for example, when the hard-dyeing linen fabric is treated with plasma, the fabric is The capillary effect is 1 to 1.5 times that of the unprocessed one. The amount of dye adsorbed is greatly increased, and it is easily dyed with deep dark color, and the dark color effect is obvious.

5 Ultrasonic processing

Ultrasound is a vibration wave that cannot be perceived by the human ear. The sound wave with a normal frequency of 104 to 109 Hz is called an ultrasonic wave, and the frequency of which is greater than 109 Hz is called a special ultrasonic wave or a microwave ultrasonic wave. After fabric dyed by ultrasonic technology, the degree of fiber concentration has a certain loose, so that the specific surface area of ​​the fiber increases, thereby increasing the adsorption of dye on the fiber, increasing the dyeing rate of the fabric, and achieving the effect of medium and dark colors. . After research, this technology has obvious effects on fleece fibers with flake layer and flax fabric with close surface structure.