What is leveling agents and its application?
Most leveling agents are water-soluble surfactants. According to the effect of leveling agents on the diffusion and aggregation of dyes, they are mainly divided into two types: fibrophilic leveling agents and dye-philic leveling agents.
Uniform dyeing: When the color depth, shade and brightness of the entire surface of the fabric are consistent, the dyeing can be called uniform dyeing. Most levelling agents are water-soluble surfactants. It can also be expressed as a substance added during the dyeing process of fiber yarn, thread or fabric in order to promote uniform dyeing and not produce color streaks, stains and other defects.
Modern levelling agents have a broader meaning. In addition to levelling in the textile industry, in the coating/coating/printing industries, its meaning is: to make coating/printing more uniform. The coating/printing industry translates it as a leveling agent. Textile auxiliaries are very important to increase the added value of textiles. They can not only functionalize textiles, but also make them high-end and more contemporary. However, the prerequisite for these advantages is that the dyeing of the fabric must be even and very effective. The method is to use the auxiliary agent with slow dyeing or migration effect, that is, the leveling agent to achieve the leveling effect.
Uneven phenomena, such as streaks and dye spots, often appear in dyeing.
On the one hand, the reason is the uneven physical and chemical structure of the fiber, and on the other hand, it is caused by improper pre-treatment and dyeing conditions. In order to achieve the purpose of uniform dyeing of dyes with fast dyeing speed and easy spotting, the following measures can be taken:
(1) Control the dyeing speed
1. Control the heating rate and the instantaneous dyeability of the dye
2. Use leveling agent and retarding agent to keep the dyeing speed of the color matching dyes consistent
3. Control the dye promoter
(2) Make the concentration and temperature of the dye bath uniform, increase the flow of the dye solution, use dyeing machinery with high leveling ability and improve the stability of the solution
1 The easy way is to add leveling agent.
2 As a leveling agent, the condition is: it can make the dye be absorbed by the fiber slowly (has a slow dyeing effect); if the dyeing is not uniform, the dye can be moved from the dark part to the light part (with migration effect); Dyeing fastness. Therefore, the leveling agent should have slow dyeing and migration properties.