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what is the working mechanism of the fixing agent? how to solve the problem of discoloration and staining of cotton clothes?

release date：2020.09.17 pageviews：13

natural fibres in textiles lose colour more easily than chemical fibres.that is, cotton, hemp, silk, wool textiles than nylon, dacron, acrylic, and so on easy to fade.to solve this problem is certainly indispensable color fixing agent, solid color, as the name suggests is to improve the color fastness of the fabric;and can improve all kinds of dyeing fastness of the assistant called fixing agent.so, what is the working mechanism of fixative?how to solve the problem of color fading and staining from the source of cotton clothes?

from the fixing agent principle, we can distinguish the fixing agent mainly divided into two categories: reactive fixing agent and non-reactive fixing agent.reactive color fixing agent refers to the introduction of reactive groups into the molecules of color fixing agent, commonly used is epoxy group, this kind of color fixing agent can form a covalent bond with some groups in the fiber dye molecules, which is more beneficial to the improvement of color fastness.nonreactive color fixing agent refers to two kinds of film forming and water-soluble group blocking on the fiber surface. its main types are cationic color fixing agent and resin color fixing agent.

what is the working mechanism of fixing agent?firstly, dyes are dyed on different fibers with different dyeing mechanism and fastness, so the fixing mechanism and application of the fixing agent are also different.

1. the cationic groups such as quaternary ammonium salt or tertiary amine salt in the color fixing agent are used to bond with ionic groups in the ionic structure of the dye, so that the dye and the fixing agent form an insoluble color block to settle on the fiber, so as to improve the color fastness of the dye on the fabric.

2. the dye water solubility is reduced by cross-linking reactive groups in the dye molecules with reactive groups on the dye molecules and hydroxyl groups on the cellulose molecules.

3. use the film forming performance of fixing agent on the fabric to improve its dyeing fastness.in the high-temperature drying process of the fabric treated with color fixing agent, the reaction groups on the color fixing agent molecules crosslink themselves into macromolecules, forming a protective film with certain strength on the surface of the fabric and fiber, and covering the dye on the fiber, making it difficult for the dye to fall off.