Precautions for dyeing with acid dyes---Dyeing nylon as an example

Abstract

When using acid dyes for dyeing, you often encounter problems such as color flowers, discoloration, ye

llowish light, and insufficient level dyeing. In addition to poor quality of dyes, improper process operation or failure to handle details are also among the reasons for these problems.

Therefore, taking acid dye dyeing of nylon as an example, we will discuss the dyeing process of acid dyes and the issues that should be paid attention to during production.

Introduction and classification

Acid dyes refer to dye molecules containing acidic groups, also known as anionic dyes, which can combine with amino groups in protein fiber molecules through ionic bonds and are suitable under acidic, weakly acidic or neutral conditions.

Acid dyes have a complete chromatogram and bright colors. The light fastness and wet processing fastness vary greatly with different dye varieties.

Acid dyes are divided into strong acid, weak acid, acid medium, and acid complex dyes according to their chemical structures and dyeing conditions.

Strong acid dyes, the earliest developed acid dyes, require dyeing in a strong acid dye bath. They have a simple molecular structure, low molecular weight, contain sulfonic acid groups or carboxyl groups, and have little affinity for wool. They can be used on wool. It moves evenly and dyes evenly, so it is also called acid leveling dye.

Weak acid dyes can be generated from strong acid dyes by increasing the molecular weight, introducing groups such as aryl sulfone groups or introducing long carbon chains.

Acid mordant dyes are acid dyes that form metal complexes on fabrics after being treated with certain metal salts (such as chromium salts, copper salts, etc.) as mordants.

Acid complex dyes are formed by complexing certain acid dyes with metals such as chromium and cobalt. It is soluble in water, and its dyeing products have excellent lightfastness and lightfastness.

Different types of acid dyes have different dyeing properties due to different molecular structures, and the dyeing methods used are also different.

Nylon dyeing methods and ratios

When dyeing nylon with acid dyes, the composition of the dye liquor is as follows:

Dye x%;

① Acetic acid 1-3%; leveling agent 0.3-0.5%, PH4-61=20;

② Fixing agent 2-4%, HAC 0.5-2%.

There are two dyeing methods: one-bath method and two-bath method. The specific operations are as follows:

1 One-bath method operating curve: PH4-6

                                   Bath ratio 1:20

2 Two-bath method operating curve: ① Dyeing

                                   ② Fixing solution prescription: fixing agent 2-4%, glacial acid 0.5-2%, PH4-5

Nylon dyeing precautions

1 Leveling agent: Its main function is to achieve a uniform dyeing effect, but excessive dosage will cause the color strip to decrease.

2. Glacial acetic acid: adjust the pH value and add it in sequence during dyeing to facilitate leveling.

3 Fixing agent: Acid fixing agent can improve the dyeing fastness of acid dyes.

4 Chemical ingredients: Beat with cold water, dissolve in hot or boiling water, stir thoroughly to dissolve, dilute and filter before use.

5 Adding materials: Pay attention to slow and even feeding to prevent color blooming caused by adding materials too fast.

If you want to know more about dyeing solutions, please contact: info@tiankunchemical.com

Quick Links:

Acid Dyes:https://skygroupchem.com/product/acid-dyes/ 

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