Description of printing and dyeing pretreatment agent: In compounding, according to the requirements of each factory, such as alkali resistance, permeability, whiteness, capillary effect, etc.
For example, in the preparation of penetrating agent, some requirements are higher alkali resistance (such as mercerizing penetrating agent), some requirements are general alkali resistance (below 509/L NaoH), and sometimes requirements are good acid resistance (wool carbonization penetrating agent), should be different in the selection of raw materials. In the preparation of scouring agents, some have better alkali resistance (caustic soda and additives are mixed together in a high tank). In general, the requirement of alkali resistance is lower when it is used directly in rolling trough.
Generally speaking, alkyl alcohol phthalide amine, alkyl polyoxyethylene ether, sodium secondary alkyl sulfonate, sodium 2-olenyl sulfonate and other additives can withstand about 10 rabbits/LNa0H. They are not suitable for preparing mercerizing penetrant and alkali-resistant scouring agent, while sodium alkyl sulfonate and fatty alcohol polyoxyethylene are unsuitable for preparing mercerizing penetrant and alkali-resistant scouring agent. Sodium ether sulfate, sodium alkyl sulfate, alkyl sulfur (phosphoric) acid phenolic salts, etc. can resist high strength alkali.
In the preparation of scouring agent, its main purpose is to remove wax, pectin, protein, organic impurities in cotton fibers. Adding surfactant mainly with caustic soda is beneficial to the adsorption, wetting, penetration, acceleration of emulsification and dispersion of wax, and to keep it dispersed and suspended and washed away by water. According to research, cotton wax can be removed no matter what kind of surfactant is used (usually without cationic surfactant).
Therefore, the complex of anionic and nonionic surfactants is usually used, and its CMC and HLB values should be taken into account when compounding, so that the HLB values are close to each other. Among them, C13-16 is the best carbon chain for anionic surfactants and C:2-14 is the best carbon chain for nonionic surfactants. For example, the scouring agent composed of ASA60 (HLB 13.0), sodium hexadecyl sulfonate (HLB 12.08) and AEO-6 (HLB 12.12) has good application effect.
