How to dye reactive dyes?
When reactive dyes are dyed, they can be dyed directly on the cloth. At the same time, because of its good diffusion ability, it is easy to diffuse the dye into the fiber. However, since it has not chemically reacted with the fiber at this time, it is easy to remove most of the dye with water. Washing off, therefore, an alkaline agent must be used to promote a chemical reaction between the dye and the fiber to fix the dye on the fiber. The former is called dyeing, and the latter is called fixation.
Second, the operating process of reactive dyes
Reactive dyes can be dyed with jig dyeing and pad dyeing according to different dyeing requirements.
The jig dyeing process is suitable for small batch and multi-variety production. It is easy to dye, flexible in turnover, and can dye light, medium and dark colors. Due to the different types of dyes, the directness to the fiber is also different, so the dyeing conditions, fixing temperature, alkali dosage and electrolyte dosage are also different.
The reactive dye jig dyeing operation is to wash the scoured fabric back and forth with hot water at 80～90℃ for 3 times, then walk a few times in cold water until it is close to the dyeing temperature, add the dissolved dye and dye it for 2 to 3 times, and put the electrolyte into it. Then dye it for 3 to 4 coats, and dye it for 5 to 6 coats with the reinforcement dye.
2. Pad dyeing
The pad dyeing of reactive dyes is divided into one-bath and two-bath methods.
One-bath method: Put the dye and alkali agent together. The alkali agent used is baking soda. After rolling, after steaming or baking, the baking soda decomposes sodium formate, which increases the pH value, which is beneficial to dye fixation, X type Reactive dyes usually use the one-bath method.
Two-bath method: After padding the dye solution, padding the fixing solution containing the alkali agent, and then steaming and fixing the color, the alkali agent used can be soda ash or trisodium phosphate, or baking soda can be added to the first bath. Add soda ash during two-bath fixation.