The textile industry involves processing links such as textiles, fabrics, printing and dyeing. According to the characteristics of different fibers, different types of auxiliary chemicals are needed to improve the quality of textiles, improve processing effects, improve production efficiency, simplify process flow, reduce production costs, and give textiles various excellent application properties. According to the processing steps and uses, these chemicals are collectively referred to as textile dyeing and finishing auxiliaries, which can be divided into three categories: printing and dyeing pretreatment agents, printing and dyeing auxiliaries and finishing agents.

1. Printing and dyeing pretreatment agents

Penetrants, wetting agents, emulsifiers, cleaning agents, etc. are all printing and dyeing pretreatment agents.

Penetrants are chemical substances that can improve the permeability of fiber materials. Its function is to make the texture of fabric fibers more uniform and improve the permeability of dyes, thereby ensuring the quality of dyeing. There are many types of penetrants such as acrylate copolymers, polyvinyl alcohol, and polyethylene glycol.

Wetting agents are surfactants that can reduce the surface tension of water, make it easier for water to contact fibers, and fully soak fabrics, thereby improving the permeability of dyes and dyeing uniformity. There are many types of wetting agents, and the commonly used ones are sodium dodecylbenzene sulfonate, fatty alcohol polyoxyethylene ether, etc.

Emulsifier

Emulsifier is a surfactant that can mix water and oil. In the pre-treatment process of printing and dyeing, it is often used to emulsify oily additives so that they are evenly dispersed in water, which is convenient for contact and mixing with fabrics.

2. Printing and dyeing auxiliaries

Printing and dyeing auxiliaries refer to some chemical substances added during the dyeing process. Their function is to help the dye fix on the fiber and improve the dyeing effect. Printing and dyeing additives can be divided into the following categories according to their functions and uses.

Water softener Water softener is a chemical substance that can convert hard water into soft water. Its main function is to remove metal ions such as calcium and magnesium in water and reduce the generation of scale. In textile printing and dyeing, calcium and magnesium ions in hard water will combine with anions in the dye to form precipitation, thereby affecting the dyeing effect. The use of water softeners can reduce the content of these metal ions, thereby improving the dyeing effect. Commonly used water softeners include EDTA (ethylenediaminetetraacetic acid) and DTPA (diethylenetriaminepentaacetic acid).

Chelating dispersants

A dispersant is a chemical substance that can act as a clamp at the same time. Its main function is to separate metal ions from dyes, thereby avoiding the influence of metal ions on dye fixation and dyeing effects. At the same time, chelating dispersants can also disperse dyes evenly, thereby improving the dyeing effect. Therefore, chelating dispersants are mainly used to treat water quality, prevent the influence of metal ions on dyeing, and improve dyeing effects.

Solvents and cosolvents

Solvents and cosolvents refer to chemical substances that can disperse dyes in solvents. Their function is to disperse dyes evenly, thereby improving dyeing effects. Commonly used solvents include alcohols, ketones, ethers, etc., while cosolvents are of two types: acidic cosolvents and alkaline cosolvents.

Fixing agents and coloring aids

Fixing agents and coloring aids refer to chemical substances that can help dyes fix on fibers, thereby improving color fastness and brightness. Commonly used color fixers include aluminum sulfate, copper sulfate, etc., while color developers include salt developers, amino acid developers, etc.

Printing paste and thickener

Printing paste is a dye used for textile printing, which is characterized by bright color and good color fastness. Thickener is a chemical that can thicken the printing paste, and its function is to make the printing paste have better adhesion and printing performance. Commonly used thickeners include natural gum thickeners, synthetic polymer thickeners, etc.

Adhesives for printing and dyeing

Printing and dyeing glue is a chemical substance that can help keep the pattern clear and avoid dye penetration during the printing and dyeing process. Its function is to form a protective film on the fiber surface so that the dye can only penetrate into the desired area. Commonly used adhesives include natural adhesives, synthetic polymer adhesives, etc.

3. Post-printing and dyeing finishing

Finishing agent

Chemical products used to improve the appearance, touch, shrinkage, appearance stability, life extension, waterproofing, fireproofing, anti-fouling, and mildew resistance of fabrics.

Softener

Softener is a chemical that can make fabrics softer and more comfortable. Its main function is to form a soft film on the surface of the fabric, thereby increasing the feel and comfort of the fabric. Common softeners include fatty acid softeners, fatty amide softeners, etc.

Waterproofing agent

Waterproofing agent is a chemical that can make fabrics waterproof. Its function is to form a waterproof film on the surface of the fabric, so that the fabric has better waterproof function. Commonly used waterproofing agents include fluorocarbon waterproofing agents, silicone oil waterproofing agents, etc.

Anti-oil stain agent

Anti-oil stain agent is a chemical that can prevent fabrics from being contaminated by oil stains. Its function is to form an anti-oil stain film on the surface of the fabric, which can effectively prevent the fabric from being eroded by oil stains. Commonly used anti-oil stain agents include silicone oil anti-oil stain agent, fluorocarbon anti-oil stain agent, etc.

Functional finishing auxiliaries

Functional finishing auxiliaries are chemical products that can provide special functions for fabrics. Its function is to form a special protective film on the surface of the fabric, thereby giving the fabric different properties, such as waterproof, oil-proof, anti-static, UV protection, etc. Nano sunscreens, antibacterial agents, etc. are common functional classification additives.