There are two basic methods of dyeing fabrics:
1. Pad-batch method of dyeing fabrics
It consists in treating the material in a dyeing bath for a specific time, under certain conditions and with the use of chemical auxiliaries. After the end of the process, the product is washed to remove residual fabric dye and residual chemicals.
2. Continuous and semi-continuous method of dyeing fabrics
The straightened textile product is immersed in a bath (or applied by spraying or in the form of a foam), decoupled, and then by a thermal method (steam or air), the connection of the fabric dye with the fiber is fixed and the washing is carried out to remove the dye residues and detergent residues. auxiliary.
Dyeing of fabrics made of cellulose fibers:
Most often, reactive dyes are used to dye fabrics. Direct, vat and sulfur dyes are used much less frequently. Auxiliaries used in the dyeing process of cellulose fibers. Auxiliaries for washing after dyeing. Auxiliaries used for fixing colors.
Agents for dyeing natural fabrics:
Woolen fiber products are dyed batchwise.
The following groups of dyes for fabrics are used:
- metal complex 1: 1 and 1: 2
Auxiliaries for dyeing fabrics used in the dyeing of wool fibers. Acids or acidifying agents to obtain the appropriate pH of the environment. Levelling agents to obtain adequate uniformity of dyeing
Agents for dyeing synthetic fibers:
Fabric dyes are used: acid, metal complex, reactive and suspension dyes in the periodic dyeing method.
The auxiliaries used for dyeing synthetic fabrics:
- pH regulators for the precise regulation of the acidity of the bath
- compensation agents
- color fastness improvers
Dyeing polyester fibers requires the use of high-temperature methods or the so-called carriers.
Disperse dyes are used. Dyeing is performed mainly by the batch method or, less frequently, in the case of fabrics by the continuous method (Thermosol).
Auxiliaries used for dyeing synthetic fabrics are:
- agents allowing to obtain the appropriate pH 4-5.
- agents that facilitate diffusion of the dye into the fiber
- leveling agents to improve the uniformity of coloring
- dispersing agents that facilitate the preparation of the dye and prevent its migration during drying
- reducing and auxiliary agents to remove non-fiber dye residues.
Dyeing is carried out by the batch method using disperse dyes for light shades and cationic dyes, which can be applied in a continuous or batch method.
Auxiliaries for dyeing the PAN fiber:
- bath acidulants
- agents delaying the sorption of cationic dyes (retarding agents)
- dispersing agents