I. Principles of action
The decontamination of aqueous cleaning agents is achieved by the wetting, penetration, emulsification, dispersion, solubilisation and other properties of surfactants. The decontamination process can be roughly divided into the following steps:
1. Wetting of the washed substrate and dirt by the detergent solution and penetration between the two interfaces;
2. The surfactants in the detergent emulsify, solubilise and disperse the oily dirt so that the dirt is separated from the solid surface and dispersed or emulsified in the washing medium (usually water);
II. Selection of surfactants
Due to the differences in the cleaning of the substrate, and select the appropriate cleaning agent, cleaning environment is divided into: neutral, acidic, alkaline, the correct selection of surfactants will play an important role in it.
1, pickling process to improve the effect of pickling, that is, to accelerate the dissolution of the oxide layer, delay the corrosion of the acid on the substrate, inhibit the diffusion of hydrogen atoms to the substrate, metal pickling solution is often added to a small amount of surfactant, this is because of the addition of the surfactant will .
2, in the process of alkali washing The main function of surfactants is to reduce surface tension, emulsify and disperse dirt, thus significantly improving cleaning efficiency.
1, adding surfactant can mention increase the emulsification and dispersion of grease.
2, join the machine solvent cleaning process. The main surfactants used are ester, ether and amine ethylene oxide adducts or mixtures of them, but also non-ionic and anionic surfactants can be used in the complex. The choice of surfactant is determined by the type of solvent and the type of cleaner emulsion to be formulated. In addition, certain co-solvents should be added to the solvent-based cleaner to improve solvent solubility (e.g., higher alcohols, glycols, ethylene glycol derivatives, etc.).