Friends who have been working in printing and dyeing factories may not have a clear understanding of additives! I always feel that there is too much moisture inside and too many routines! Today, I will popularize the knowledge of classic printing and dyeing auxiliaries to everyone, so that you can open your eyes of wisdom and no longer be blinded!
Whitening agent
1. Fluorescent whitening agent VBL stilbene triazine type, which is an anionic direct dye. The dyeing performance is basically similar to that of direct dyes. You can use salt and Yuanming powder to promote dyeing, and use leveling agent to slow dyeing. It is a light yellow powder with a purple-blue hue. It is soluble in 80 times the amount of soft water. The dissolving water should be in the form of Slightly alkaline or medium-sized. A medium-sized or slightly alkaline PH value of 8-9 is most suitable for the dye bath. It is acid-resistant to PH value 6, alkali-resistant to PH value 11, hard-resistant to 300ppm, not resistant to metal ions such as copper and iron, and can be used with anions. It is mixed with nonionic surfactants, direct and acidic anionic dyes, but it is not suitable to be used in the same bath with cationic dyes, cationic surfactants and synthetic resin primary shrinkage. It is suitable for whitening white or light-colored cellulose products. The dosage should be Appropriate, too much will reduce the whiteness or even turn yellow. It is appropriate not to exceed 0.4% for cellulose fibers.
2. Fluorescent whitening agent VBU stilbene triazine type, light yellow powder, cyan-purple color, soluble in water, anionic, acid-resistant to PH2- -3, alkali resistant to PH10, can be used in the same bath with anionic, nonionic surfactants, cationic dyes, and synthetic resin precondensates, but cannot be used in the same bath with cationic dyes and cationic additives. It is suitable for whitening cellulose fibers. , resin finishing and whitening in the same bath with acidic components.
3. Fluorescent whitening agent DT benzoxazole derivative, resistant to strong acid and alkali, soluble in ethanol, blue-purple color, neutral non-ionic dispersion Yellow-white pulp emulsion can be mixed with water in any proportion. Since polyvinyl alcohol is commonly used as a protective colloid in emulsion products, it condenses with various salts, so it is best to use it in a neutral or slightly acidic bath. DT emulsion It has been mixed with about 0.5% dispersant N. It will settle during storage. It should be stirred thoroughly when using to ensure the concentration. It can be used for bleaching polyester, nylon and other fibers and their blended fabrics. It needs to go through 140-160 degrees. Only 2 minutes of high temperature treatment can give full play to the whitening effect.
4. Fluorescent whitening agent WG yellow powder, the color is blue-green, the aqueous solution is neutral, anionic surfactant, acid-resistant, hard water-resistant, iron and copper have an impact on whiteness It dissolves only after use and is not easy to store. It is used for whitening wool and nylon.
5. Fluorescent whitening agent BCD is a pyrazoline-based, light yellow powder with slightly purple fluorescence. It is insoluble in water and can be evenly dispersed in water to form a stable suspension. It can also be dissolved in ethanol, dimethylformamide, ethylene glycol, ether, etc. It is non-ionic and its 1% aqueous solution is nearly neutral. It is used for whitening white acrylic and brightening light-colored fibers.
Acids
1. The molecular formula of sulfuric acid H2SO4 is colorless or brown Oily liquid, strong oxidant, corrosive machine, extremely water-absorbent, exothermic in large quantities when exposed to water, acid must be added to water when diluting, not the other way around, used as acid dyes, acid mordant dyes, acid chromium compounds Dyeing aids for dyes, wool carbonizing agents, etc.
2. The molecular formula of acetic acid (acetic acid) is CH3COOH, abbreviated as HAC. It is a colorless, transparent and irritating liquid with a freezing point of 14 degrees. It is corrosive and can burn the skin. It is used as a weak acid bath. Dyeing auxiliary for dyes, acidic mordant dyes and neutral complex dyes.
3. The molecular formula of formic acid (formic acid) is HCOOH. It is a colorless, transparent, irritating and smelly liquid. It has a reducing effect and is highly corrosive. It is easy to freeze in cold weather. Formic acid vapor It is flammable and toxic and can be used as an auxiliary agent for acid dyes and acid mordant dyes.
4. The molecular formula of oxalic acid (oxalic acid) is H2C2O4.2H2O. It is white crystal and can decompose into white powder in dry air. It is highly acidic and toxic and is easily decomposed and oxidized. Slightly soluble in cold water, easily soluble in hot water, ethanol and ether, used to remove rust stains.
Alkalis
1. Molecular formula of sodium hydroxide (caustic soda) NaOH, sodium hydroxide content is 95-99.5% solid and 30–45% liquid. Solid sodium hydroxide is white and easily deliquescent. It releases high heat when dissolved in water and is extremely corrosive. It can destroy animal fibers and is harmful to the skin. It can cause severe burns and easily absorb carbon dioxide from the air into sodium carbonate. The container should be sealed and used as a solvent for vat dyes and a cleaning agent for removing the clear color after body dyeing.
2. Sodium carbonate (soda ash) has the molecular formula Na2CO3. Anhydrous sodium carbonate is dark powder or fine granular form. It absorbs moisture and carbon dioxide in the air, agglomerates and generates sodium bicarbonate. , soluble in water, hydrated sodium carbonate has three types: one part water, seven parts water, and ten parts water. Used as wool detergent, direct dye, sulfur dye dyeing auxiliary for cotton and viscose fiber, reactive dye fixing agent, wool carbonization neutralizer.
3. Ammonia is a colorless, transparent or slightly yellow liquid with an irritating odor that can make people cry. It should be stored in a sealed container. It will easily decompose into ammonia gas when heated. Volume expansion can easily burst the container. Be careful not to expose the container containing ammonia to heat or direct sunlight. Used as a washing aidSodium ester sulfonate, anionic surfactant, light yellow to brown viscous liquid, soluble in water, 1% aqueous solution pH to 6.5-7, rapid and uniform penetration, re-wetting, emulsification, good foaming performance, effective It also has a temperature below 40 degrees and a pH value of 5-10. It is not resistant to strong acids, strong alkali, metal salts and reducing agents, and is easily hydrolyzed in an alkali bath above 40 degrees.
3. Penetrating agent EA, penetrating agent JFC, high-grade fatty alcohol polyoxyethylene ether, non-ionic surfactant, light yellow liquid, dissolve in water to form a clear solution, in cold water Its solubility is greater than that in hot water, it has good penetration, wetting and rewetting properties, and has emulsifying and washing effects. It is resistant to acid, alkali, hard water and metal salts. It can be mixed with various surfactants and is also suitable Mixed with synthetic resin primary shrinkage. </p
