Introduction and main classification of textile printing and dyeing auxiliaries

As we all know, cotton, hemp, wool, silk, man-made fibers and synthetic fibers are not suitable for further textile processing after being formed, and surfactants are also required , emulsifier, antistatic agent, sizing agent and a series of auxiliaries can be processed to obtain the required yarn or silk, and when further processed into weaving or textiles, certain textile printing and dyeing auxiliaries are also required. Finally, bleaching, dyeing, printing, finishing and processing are required to appear in the consumer market. And each step requires the use of various auxiliaries, especially for wool, rayon and synthetic fibers, which have many varieties, large quantities, and high requirements.

The auxiliaries required in the textile printing and dyeing process are various, and the number of varieties is extremely large. The most influential ones include the following categories: The processing aids before silk, this part belongs to the polymer material additives, here Kaiyin Chemical will not discuss it. Auxiliaries for each cleaning process; such as cleaning agents, refining agents, scouring agents, etc.; as well as auxiliary agents required for post-spinning drawing, drawing, twisting, reeling, spinning, weaving and other processes , are generally called oil agents, called textile oil agents or fiber oil agents, and the other is auxiliary agents in the process of exhaust dyeing and printing. They are called printing and dyeing auxiliary agents, such as diffusing agents, penetrating agents, dispersing agents, and leveling agents. There are also additives specially added to textiles with special properties such as softness, antifouling, antistatic, fire prevention, flame retardant, etc., called finishing agents.

Fiber oil

Synthetic fiber is a hydrophobic polymer substance, and oil must be used in spinning and textile processing. Synthetic fiber oils are generally composed of soft smoothing agents to improve friction characteristics, antistatic agents to eliminate static electricity, emulsifiers to ensure stable emulsions, and antioxidants to reduce knots and increase thermal stability.

Smoothing agent

Synthetic fiber finishes rarely consist of one material with a single chemical structure. Instead, various base materials (surfactants, mineral oils, higher alcohols, fatty acid esters, etc.) are compounded according to their respective characteristics according to certain requirements and purposes.

Mineral oil has been used for a long time. When using it, it should be noted that the friction coefficient increases with the increase of viscosity, and the viscosity has a linear relationship with the molecular weight of mineral oil. Therefore, it should be Consider using a lower molecular weight mineral oil as a smoothing agent.

The smoothness of fatty acid esters increases with the increase of molecular weight, but attention should be paid to the volatility of esters when using them.

Mineral oils and fatty acid esters have a smoothing effect due to the nearly straight-chain aliphatic hydrocarbon structure in the molecule. Therefore, for surfactants The water-increasing base should have the same chemical structure as the above-mentioned mineral oil and fatty acid ester. When the surfactant attaches a thin layer on the surface of the fiber, the linear water-increasing bases are arranged neatly outward, and friction occurs between the water-increasing base layers sliding against each other. The longer the water-reinforcing base, the less likely it is to hang, and it is easier to slide. Therefore, the number of carbon atoms of the surfactant used as a smoothing agent is usually C16 and C18. In principle, the water-reinforcing surfactants with branched chains or benzene rings are not suitable as components of smoothing agents.

In the filament oil agent, vegetable oil and mineral oil were used at first, and now, fatty acid monoalcohol ester, fatty acid polyol ester, polyol monobasic acid ester, etc. are also used. Recently, some surfactants have become important smoothing agents for filament oils, such as trimethylolpropane fatty acid esters, pentaerythritol fatty acid esters, sorbitol fatty acid esters and other propylene oxide copolymers in fatty acid polyol esters. substances, alkyl polyol esters, etc.

Short fiber oil commonly used surfactants with smoothing effect include alkyl phosphate, alkyl sulfate, fatty acid polyoxyethylene ether, alkylphenol poly Oxyethylene ether, fatty acid polyethylene glycol ester, polyoxyethylene castor oil, hexane oxide-propylene oxide copolymer, alkyl polyol ester, etc.