Why do cotton clothes fade easily?  What is the working mechanism of fixing agent?

Textiles woven from natural fibers are more susceptible to fading than textiles woven from chemical fibers, especially synthetic fibers.  That is, cotton, hemp, silk, wool textiles than nylon, polyester, acrylic and so on easily fade.  Especially with silk and cotton fabrics easily fade;  Second, the color is more dense textiles, colorful textiles easy to fade.  That is to say, black, dark, big red, brilliant green, bright blue, brilliant purple and so on easy to fade;  While the light and some darker colors of textiles are not easy to fade.

Pure cotton and other cellulose fibers are usually dyed with direct dyes, acid dyes and other anionic water-soluble dyes, such as complete color spectrum, bright color.  However, since the dye has a water-soluble group in its structure, the dye is hydrophilic, and when washed, the color on the clothes tends to fade and fade.  The process of fading can make clothes look old;  At the same time, dye hydrolysis into the dye solution will reverse on cotton clothes, stained, color phenomenon.

Solid color

Now manufacturers to solve this problem, usually through fixation processing.  Fixation, as the name implies, is to improve the color fastness of fabrics;  And can improve all kinds of dyeing fastness additives called fixation agent.  So how can manufacturers solve the problem of fading and staining cotton clothes from the source?

Working mechanism of fixing agent

Firstly, dyes are dyed on different fibers, and the dyeing mechanism and dyeing fastness are different, so the fixing agent mechanism and application of the fixing agent are also different.

1, utilizing cationic groups such as quaternary ammonium salt or tertiary amine salt in the molecule of the fixing agent to be combined with ionic bonds of the anionic groups in the ionic dye structure to enable the dye and the fixing agent to form insoluble color blocks to be deposited on the fiber, thereby improving the color fastness of the dye on the fabric.

And 2, crosslinking the reactive group in the fixing agent molecule with the reactive group on the dye molecule and the hydroxyl group on the cellulose molecule to reduce the water solubility of the dye.

3. improving the dyeing fastness of the fabric by using the film-forming performance of the fixing agent on the fabric.  During the high-temperature drying process of the fabric treated by the fixing agent, the reactive coupling groups on the fixing agent molecules are automatically crosslinked into macromolecules, a protective film with certain strength is formed on the surface of the fabric and the fiber, and the dye is coated on the fiber, so that the dye is not easy to fall off.

Types of fixing agents

According to the principle of fixing agent, we can classify two kinds of fixing agent: reactive fixing agent and non-reactive fixing agent.

Reactive fixation agent is to introduce reactive groups into the molecules of the fixation agent, usually epoxy group, this kind of fixation agent can form covalent bond with some groups in the fiber dye molecules, is more advantageous to improve the dyeing fastness.

Non - reactive fixation agent refers to two types of film formation and blocking water-soluble groups on the surface of fiber, which are mainly divided into cationic fixation agent and resin fixation agent.

18 - 03 - 23. jpg

Daily washing protection act

1, the use of nursing laundry detergent: laundry detergent is easier to rinse, not easy to fade, do not hurt the hand, to prevent static electricity;  Laundry detergent generally contains softener, so softer than washing powder washed out, comfortable, bright as new.

2, reverse air method: the clothes in reverse air, can prevent ultraviolet rays directly irradiated most of the fabric and fade, especially for some dark clothes is particularly effective.  Colorful clothes try to dry them in a dark and ventilated place.

3, black, red and blue and other easily fading clothes, it is best to separate soaking and cleaning.

Cotton quality clothes want not easy to fade, it is best to choose high-priced clothes.  The fabric of medium and high price clothes will basically have fixed color, color and luster of the clothes will be more durable, more beautiful, and more comfortable to wear at the same time.

With the development of science and technology, famous clothing manufacturers often choose some dyes which are closer to natural components to dye.  The dye has poor fastness, but is harmless to human body and environment - friendly.

This kind of clothes should not be soaked for a long time, stacked, also can't wash with higher temperature.  At present, non - azo dyes are mainly used.  In this kind of dye printing and dyeing of textiles, some varieties of dyeing fastness is poor, whether dyed fabrics or printed fabrics will appear in the wash fading phenomenon.  This kind of clothes are mostly cotton fiber fabric, containing cotton fiber blended fabric or containing viscose fiber fabric, and mostly summer clothes or close to the body to wear clothes, women's clothing is more common.  This kind of laundry washing should choose neutral detergent, washing operation process must be continuous, fast, unfavorable soak in water or stacked, more do not use higher temperature washing.

The above describes the classification of fixing agent, let's say, how to reduce the production cost of printing and dyeing factory, we recommend the use of: jun chemical dyeing and fixation bath acid fixing agent, can be dyeing, fixation synchronization, for printing and dyeing enterprises to reduce a production process.  Can effectively reduce the production time, reduce the cost of washing and the like.

More printing and dyeing knowledge, please collect our website: jy 956. com