Mechanism of softener in dyeing and finishing

Softener is a kind of chemical substance that can change the static and dynamic friction coefficient of fiber. When the coefficient of static friction is changed, it feels smooth and easy to move on the fiber or fabric; When the coefficient of dynamic friction is changed, the fine structure between the fiber and the fiber is easy to move each other, that is, the fiber or fabric is easy to deform.

In the dyeing and finishing process, in order to make the fabric have a smooth and soft feel, the substance added to improve the quality of the finished product is called softener.

Then the mechanism of softener finishing is reflected in the following aspects:

1, can reduce the surface tension of the fiber

Textile fiber is composed of linear polymer material larger than the surface, the shape is very slender, the flexibility of the molecular chain is also better. When the surfactant (or softener) is added to the finishing solution, because the surfactant is prone to directional adsorption on the interface (textile fiber and finishing solution), the interfacial tension of the fiber is reduced, and the work required to expand the surface area is reduced, so that the fiber becomes easy to expand the surface and extend its length. The result is a fluffy, plump fabric with a soft feel.

2, reduce the friction coefficient of the fiber

A thin layer of surfactant (or softener) is adsorbed on the surface of the fiber, and the hydrophobic groups are neatly arranged outwardly. In this way, friction occurs between hydrophobic groups that slide against each other, and the longer the hydrophobic group, the easier it is to slide. The friction coefficient of the fiber is reduced. Reduce the friction resistance between the fibers or between the fibers and the human body to obtain a soft feel. The appropriate reduction of the friction coefficient can also make the fabric easy to slide when the yarn is subjected to external force, so that the stress is dispersed, the tearing strength is improved, or the fiber that is subjected to tension during the processing is easy to return to the relaxed state, and the fabric becomes fluffy.

Rapid permeants are anionic surfactants. It is used as a fast penetrating agent for fabric in printing and dyeing industry, that is, fast and uniform. Also used as emulsifier, detergent, surfactant and so on.