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5 Pre-treatment Methods For Obtaining Dark Colors On Fabrics

Date:Apr 22, 2020

Dyeing fabrics want to obtain a dark color, the pretreatment for fabric is very important. Can refer to the following points.


1. Strengthen the removal of impurities and dirt

Pre-treatment is sufficient, the fabric has good wettability, and the capillary effect is large. The diffusion ability of the dye molecule to the dye is likely to increase, thereby improving the dyeing rate. Therefore, strengthening the impurity removal and decontamination treatment of the contaminated objects can achieve the above-mentioned objectives.


2. Mercerizing treatment of cotton fabric

The mercerized cotton fabric has significantly improved dye adsorption capacity. Compared with the non-mercerized cotton fabric, it can achieve a medium-dark effect and improved surface gloss.


3. Alkali reduction treatment of polyester fabric

Polyester macromolecules have high crystallinity, tight fiber structure, high refractive index and surface reflectivity, smooth fiber surface, mirror reflection to light, and black dyeing with disperse dyes, because there is a large amount of reflected light from the fabric surface to white Light enters people's sight, so dark black is more difficult to obtain. After the alkali reduction treatment, the original smooth surface of the polyester becomes a rough surface, forming an irregular irregular reflection layer, which is the etching effect we often say, and produces a certain dark effect. After the reduction treatment, the fabric The activity increased spontaneously, and the attached power of the dye increased.


4. Application of low temperature plasma technology

Plasma technology belongs to the method of processing on the surface of the fabric, and it belongs to the dry cleaning physical processing of modern dyeing technology. For example, after the plasma-treated polyester fiber is grafted and polymerized, a low-refractive-index film is formed on the surface of the fiber, which can significantly improve the dyeing rate and color depth. The capillary effect is 1 ~ 1.5 times that of the untreated one, the adsorption capacity of the dye is greatly increased, and it is easy to be dyed in dark and deep colors, and the dark effect is obvious.


5. Ultrasonic technology treatment

Ultrasonic waves are vibration waves that the human ear cannot perceive. Sound waves with a normal frequency of 104 to 109 Hz are called ultrasonic waves, while frequencies greater than 109 Hz are called special ultrasonic waves or microwave ultrasonic waves. After the fabric is treated with ultrasonic technology before dyeing, the degree of fiber concentration is loosened, which increases the specific surface area of the fiber, thereby increasing the fiber's absorption of dye, increasing the dyeing rate of the fabric, and achieving a medium-dark effect . After research, this technology has obvious effect on wool fiber with scale layer and linen fabric with tight surface structure.