Views: 7 Author: Site Editor Publish Time: 2023-03-17 Origin: Site
Acid dyes refer to a dye that contain acid groups in dye molecules that can be combined with amino groups in protein fiber molecules with ion bonds and applicable under acidic, weak acids or neutral conditions.
Its structure is mainly nitrogen and 为, and a few are aromatum methane structures. Dyes and colors are generally colorful, and they can make other substances clear and firm color in molecular or decentralized state.
The acid dye chromatography is complete and the color is bright.
Compared with direct dyes, the acidic dye structure is simple and lacks a longer common two bonds and the same plane structure. Therefore, it lacks directability to cellulose fiber and cannot be used for dyeing of cellulose fiber.
Different types of acidic dyes, due to different molecular structures, their dyeing performance is also different, and the dyeing methods are also different.
When using acidic dyes in dyeing, we often encounter problems such as color flowers, color variations, yellowish light, and insufficient dyeing. The cause of these problems is that in addition to poor quality of dyes, improper craftsmanship or details of details are not handled, which is also one of the causes.
Next, we take acid -dye dyeing nylon as an example to explore the issues of dyeing in the acid dye and the issues that pay attention to during production.
Under normal circumstances, acid dyes can be divided into three categories: strong acid bath, acid dye H2SO4PH2-4; weak acid bath, acid dye HACPH4-6; neutral bath acid dye NH4ACPH6-7.
In addition to dyeing the nylon, you can also dye wool and silk in the acid or neutral formula. When acting on nylon, you need to use the acidic dye of weak acidic baths. At the same time, it will have the following characteristics:
Fast coloring and poor dyeing, so you need to choose a suitable amount of dyeing;
Poor dyeing fastness (such as soap washing degree) -The requires solid color treatment (especially medium and dark varieties);
Dyeing process: 50-600C start -dye -1000C guarantee -water fixation treatment.
When dyeing with acidic dyes, the composition of the dye solution is: dye X%; ① 1-3%of the acetic acid; 0.3-0.5%average dyes, pH4-61 = 20; .5-2%.
There are two types of dyeing methods and two bath methods. The specific operating curve is as follows:
1) One-bath method operation curve: pH4-6 bath ratio 1:20 2) Two bath operation curve: ① dyeing ② solid solution prescription: 2-4%solid agent, 0.5-2%ice acid, pH4-5 5, pH4-5 5
The role and precautions of the species in the process of dyeing are:
1) Make dyeing agent: The main function of a commonly dye is to make the dyeing effect that walks evenly, but too much dosage will reduce the color bar.
2) Implipate: Implip acetic acid is used to adjust the pH value. The purpose of competing to add during dyeing is conducive to the dyeing.
3) Solved agent: acidic color fixing agent can improve the dyeing fastness of acid dyes.
4) Duration: cold water, dissolved in hot water or boiling water, fully stir, dissolved and dilute, and use it after filtering.
5) Add ingredients: Pay attention to slow, uniformly, and prevent the color of color flowers too fast.