Application of Surfactants in Metal Surface Treatment

Surfactants are used for metal surface cleaning to remove various greases, acids, alkalis, salts, dust, and other solid and liquid contaminants from metal surfaces. Metal cleaners include water-based cleaners, solvent-based cleaners, and alkaline cleaners. Below,let's explore with Qinxiang New Materialsthe applications of surfactants in these cleaning methods:

Water-Based Cleaners

The application principle of surfactants in water-based metal cleaners relies on properties such as wetting, penetration, emulsification, dispersion, and solubilization. These properties weaken or counteract the adhesion of oil stains on metal surfaces. Through mechanical and physical methods, oil stains are accelerated to detach from the metal surface and enter the cleaning solution, where they are emulsified, dispersed, and suspended or solubilized in micelles.

For water-based metal cleaning, inorganic additives are also required, such as corrosion inhibitors, co-solvents, foam stabilizers, defoamers, fillers, etc.

Reference formulation: Nonylphenol polyoxyethylene(20) ether 80%, oleic acid 8%, triethanolamine 8%, boric acid triethanolamide 8%, ethylene glycol monobutyl ether 8%, silicone defoamer 0.2%, water balance, diluted to 5% during use. (Note: The above percentages are by weight.)

Alkaline Cleaners

Surfactants used in alkaline metal cleanersTo enhance the detergency of alkaline cleaners, a small amount of surfactant is added to emulsify mineral oils that cannot undergo saponification into the cleaning solution.• Reference formulation: Alkyl sulfonate 1%, silicon dioxide 3%, thiourea dioxide 5%, sodium tripolyphosphate 40%, sodium carbonate 51%. (Note: The above percentages are by weight, and it is prepared at 10-200 g/l during use.)

Phosphating Treatment

Surfactants in the phosphating process can refine the crystal structure of the phosphate coating, making it dense and providing surface conditioning effects.• Reference formulation: Manganese dihydrogen phosphate 30-40 g/l, zinc dihydrogen phosphate 30-40 g/l, zinc nitrate hexahydrate 80-100 g/l, sodium nitrite 1-2 g/l, sodium nitrate 1 g/l, sodium phosphate dodecahydrate 1.58 g/l, octylphenol polyoxyethylene (7-8) ether 0.5 g/l, sodium bicarbonate 1.58 g/l, pine oil 0.5 g/l, free acidity 3-5 points, total acidity 60-80 points, treatment time 8 min.

Pickling

During the pickling process, a large amount of acid mist is generated, which affects workers' health, pollutes the environment, and corrodes buildings and equipment. To improve the rust removal effect and prevent excessive acid corrosion, surfactants are added to sulfuric acid or hydrochloric acid in the pickling solution. This can suppress acid mist, accelerate the pickling rate, and prevent over-corrosion. Reference formulation: Hydrochloric acid1-10%, nitric acid 1-8%, nonylphenol polyoxyethylene 0.1-20%.

Aboutthe applications of surfactants in metal surface treatment, this concludes the introduction by Qinxiang New Materials. For more information on raw materials for hard metal surface cleaning, please feel free to contact us.~