What chemicals are used in denim washing?（1）

The purpose of garment washing is to enhance the stability of garment. By washing water, you can shrink in advance, so that the size is stable. The second is to enhance the beauty of clothing, through different washing methods, you can wash a variety of effects of color and texture, and deeply loved by people, so that the added value of clothing increases. So what chemicals are used in the washing process?

First, acid, alkali and salt

1. Acetic acid: Acetic acid is commonly used to adjust the pH in the process of clothing washing, or it is used to remove cloth wool and hair together with acid cellulase.

2, oxalic acid: oxalic acid can be used to clean rust spots on clothing, but also to wash the residual potassium permanganate liquid on clothing, or used for clothes after rinsing bleaching.

3, caustic soda (sodium hydroxide) : caustic soda can not contact with the skin, will be seriously burned. Caustic soda can make all kinds of animal fibers such as silk, wool completely dissolved; Generally used for cooking cotton and other natural fibers, can remove impurities in the fibers, can also be used for mercerizing cotton fibers, clothing washing as a desizing agent, bleaching alkali agent, wash light color effect is stronger than soda ash.

4, soda ash: some clothes, need to be washed through the light color, you can add soda ash cooking. It can be used to adjust the pH of solution.

5, Yuanming powder: commonly known as glauber's glass. Can be used as direct dyes, reactive dyes, sulfide dyes and other dyeing cotton dyeing agent, these dyes are specially easy to dissolve in the configuration of the dye solution, but not easy to dye cotton fibers. Because the dye is not easy to suck up, the foot water remains more dye. The solubility of dye in water can be reduced by adding the powder, thus increasing the coloring ability of dye. So the amount of dye can be reduced, and dyed color is deepened, improve the dyeing rate and color depth.

6, sodium chloride: salt is commonly used to replace the sodium powder for direct, active, vulcanization and other dyes dyeing dark dyeing agent, every 100 copies of salt is equivalent to anhydrous sodium powder 100 or 227 copies of crystal powder.

Second, water softener, PH regulator

1, sodium hexametaphosphate: is a good water softener. Can save dye and soap, to achieve the effect of water purification.

2. Disodium hydrogen phosphate: In clothing washing, it is usually used in combination with sodium dihydrogen phosphate to adjust the PH value of neutral cellulase

3. Trisodium phosphate: Generally used as hard water softener, descaling agent and metal cleaner. Used as a calcining aid for cotton cloth, the caustic soda in the calcining liquid can not be consumed by hard water, and promote the calcining effect of caustic soda on cotton cloth.

Third, bleach

1. Sodium hypochlorite: sodium hypochlorite bleaching generally needs to be carried out under alkaline conditions. At present, this bleaching method is almost gradually phased out.

2, hydrogen peroxide: usually fabric adopts hydrogen peroxide bleaching temperature requirements in 80-100℃, high requirements for equipment, cost than sodium hypochlorite bleaching, suitable for advanced and high quality products.

3, potassium permanganate: potassium permanganate has special strong oxidation, oxidation ability is stronger in acidic solution, is an excellent oxidant and bleaching agent. In clothing washing, used for color removal and bleaching, such as spray PP (monkey), hand sweeping PP (monkey), stir-fry PP (pickling, stir-fry snow), is one of the most important chemicals.

4. Reducing agent

1, baking soda: commonly known as Hai Bo. In clothing washing, clothes rinsed by sodium hypochlorite should be bleached with baking soda. This is because baking soda has a strong reducing property, can be chlorine gas and other substances reduction.

2, insurance powder: commonly known as low sodium sulfite, is a strong reducing agent, used for staining stripping, PH value at 10 when the most stable.

3. Sodium metabisulfite: due to its low price, it is widely used in the clothing washing industry for neutralization after potassium permanganate bleaching.

Fifth, biological enzymes

1, deplasmic enzyme: denim clothing contains a lot of starch or denatured starch slurry. The depulsification function of depulsification enzyme is that it can catalyze the hydrolysis of large molecular chains of starch, and generate some low molecular compounds with relatively small molecular weight, low viscosity and high solubility. The purpose of depulsification is achieved by removing the hydrolyzed products through washing. Amylase can also remove mixed pulp, which is usually dominated by starch. Deplasmosis is characterized by its high conversion power to starch, which can completely destroy starch without damaging cellulose, which is a special advantage of enzyme specificity. It can provide a comprehensive desizing function, to help the stability and fluency of clothing after treatment.

2. Cellulase: cellulase is selectively used for cellulose fibers and cellulose fiber derivatives, which can improve the surface properties and color of textiles, produce the effect of imitation old, and can remove the dead cotton and fluff on the surface of the fabric; It can degrade cellulose fibers and make the fabric feel soft and comfortable. Cellulase is soluble in water, and has good compatibility with wetting agent and cleaning agent, but the effect of reducing agent, oxidant and enzyme will be reduced. Cellulase can be divided into acidic cellulase and neutral cellulase according to the PH value of water bath in the washing process.

3, laccase: laccase is a kind of copper-containing polyphenol oxidase, can catalyze the REDOX reaction of phenolic substances. It can be used to decolorize denim indigo dye. Laccase can catalyze the oxidation of insoluble indigo dye, make indigo molecules decompose, play the role of fading, so as to change the appearance of indigo dyed denim. The application of laccase in denim washing has two aspects: (1) to replace or partially replace cellulase for enzyme washing. ② Rinse instead of sodium hypochlorite.

Using the specificity and efficiency of laccase to indigo dye, rinsing can achieve the following effects: ① give the product a new appearance, a new style and a unique finishing effect. (2) Enhance the degree of grinding products, to provide a rapid grinding process. Maintain the best strong denim finishing process. Easy to manipulate, good reproducibility. ⑤ Green production.