How to prevent "flashing" in cotton nylon dip dyeing?

On the surface, the flashing phenomenon is that the dyed color hue of cotton fiber and nylon fiber is inconsistent, that is, the hue is uneven. The root cause is that some dyed cotton dyes compete with nylon fiber.

In actual production, the dyeing of primary colors and secondary colors can make full use of the characteristics of competitive dyeing, so that cotton fibers and nylon can be dyed with purer colors, flatter hues and better effects. However, it is difficult to dye the same hue on two kinds of fibers at the same time in three colors (such as army green, iron gray, brown), and the phenomenon of flashing is serious. This is the most difficult problem encountered in the dyeing of cotton/brocade blends. , can be solved from the following three aspects.

1. Dye

Generally, the dyes (such as reactive dyes and direct dyes) for dyeing cotton have a certain degree of competition for nylon, and choosing new dyes that do not stain nylon can solve the problem of competition.

2. Additives

In order to prevent competing dyeing of nylon, a special anti-dyeing agent for dyeing cotton/nylon interwoven fabrics can be selected.

3. Craft

Dyeing with reactive dyes generally fixes the color at a pH value above ll. Usually, the best dyeing pH value of acid dyes used for dyeing nylon is 5.5-6.0. That is, dyeing under acidic conditions. The two diametrically opposed process conditions make the reactive dyes that have been dyed on the cotton fibers stripped to varying degrees while dyeing nylon, which brings great difficulties to dithering. Choose neutral dyes with milder dyeing conditions to replace acid dyes. The pH value of neutral dyes is about 6.5, which has little effect on reactive dyes, so that the three colors of army green, iron gray, and brown can be dyed better. Same color effect.