Cationic Dyes Used in the Textile Industry
Dyes are used for coloring the thread or fabrics in the textile industry. Cationic dyes are quite common.
What are cationic dyes? They are known as basic dyes also.
These are synthetic dyes that are basic, and when dissolved in the water, they form a colored cationic salt.
The salt causes a reaction with the anionic site on the surface of the substrate.
Cationic dyes are preferred due to their bright shades and high tinctorial properties.
Use of cationic dyes
Since they are applied on a substrate that has an ionic characteristic, the dyes form the electrostatic attraction.
The positive charge is on the basic dye molecule called chromophore. On the basic side of the isoelectric points the reaction happens.
Therefore, it is not suitable for cotton fabrics. First, the cotton doesn’t offer sufficient affinity or substantivity. Also, the structure of the cotton fabric is not smooth.
Basic dyes are more suitable for silk, wool, and modified acrylic fibers. Cationic dyes are used for coloring paper also.
They work as strong coloring agents. The basic, positive radical is the fundamental dying stuff here.
To take up of the dye to the fiber; acetic acid is used to the dyebath.
Modified Basic Dyes
They are developed based on the basic chemistry of cationic dyes. These dyes have more extended molecular structure than the “basic” basic dyes. Hence, their properties are significantly different (and better).
Due to the longer molecular structure, they have more comprehensive coverage and sustainability. Improved lightfastness is a distinguishable characteristic.
Hence, modified cationic dyes are found suitable for a variety of dying applications.
The shade range is quite widespread, and even a few florescent colors are also available. Since the solubility is excellent in water, application of cationic color is not a difficult thing. It is required to add glacial acetic acid to improve the solubility.
As far as exhaustion is concerned, the cationic dyes show variable rates. The exhaustion characteristic is decided by the “K value”.
The higher is the value, the slower the exhaustion is. It means the K value 5 denotes the slowest exhaustion and 1 indicates the fastest exhaustion. When different shades are created, dyes of similar K value are chosen.
Due to its high affinity for silk and wool, the cationic dyes are most suitable. The affinity for cellulose is low. Hence, it is not an ideal dye for cotton fabric. To dye cellulose, it needs to be treated using mordanting agents.
If you are looking for dyes and chemicals manufacturers in india then Sagar Colour Co. is one of the foremost acrylic dyes, cationic dyes and textile chemicals manufacturers in Gujarat as well as other parts of India.