1.What are the operating methods of physical/mechanical cleaning methods?
Wiping Method
Suitable for: Small areas with light oil, grease, or fingerprints.
Instructions: Use a clean, soft, oil-absorbent cloth (such as non-woven fabric or cotton) or specialized industrial wipes dampened with a small amount of denatured alcohol, acetone, or a specialized solvent-based cleaner.
Advantages: Simple, flexible, and low-cost.
Disadvantages: Low efficiency and labor intensity, suitable only for small batches or localized treatments. Caution: Solvents like acetone are highly volatile; use in a well-ventilated area and pay attention to fire safety.
Adsorption Method
Suitable for: Surface oil and excess rust preventative oil.
How to Use: Cover the oily surface with absorbent cotton, oil-absorbing felt, or activated clay, and use the material's adsorption properties to absorb the oil.
Advantages: No damage to the galvanized coating; easy to use.
Disadvantages: Incomplete degreasing; less effective on dried or sticky oil stains.
2.What are the main treatment methods of chemical cleaning?
Alkaline degreasing cleaning, solvent/emulsion cleaning, water-based cleaning agent cleaning
3.What are the operating methods of alkaline degreasing cleaning?
Applicable Applications: Most mineral, animal, and vegetable oils are suitable. This is the most common method in industrial production.
Operation: The galvanized coils are passed through a dedicated cleaning line and sprayed or immersed in a heated alkaline degreaser (primarily composed of sodium hydroxide, sodium carbonate, silicates, phosphates, and surfactants). Rinse with clean water (preferably deionized water) and dry.
Advantages: Thorough cleaning, high efficiency, and suitable for continuous large-scale production.
Disadvantages: Requires a complete set of equipment (cleaning tank, spray system, drying system), resulting in a high investment. The concentration and temperature of the alkaline solution must be strictly controlled, as excessive alkalinity or high temperature can damage the zinc layer, resulting in a darkening of the surface or the formation of "zinc scars."
4.What are the operating methods for solvent/emulsion cleaning?
Suitable for: Heavy oil stains or those difficult to remove with alkaline degreasing.
Instructions:
Solvent-based cleaners: Use hydrocarbon solvents, chlorinated solvents, or other solvents to dissolve the oil by spraying or wiping directly.
Emulsified cleaners: Use a cleaning agent that dissolves oil and mixes with water to form an emulsion, making it easy to rinse away with water.
Advantages: Strong degreasing ability and fast removal speed.
Disadvantages: Most solvents are flammable, toxic, and unfriendly to the environment and operators, requiring specialized ventilation and protective measures. Environmentally friendly water-based cleaners are now preferred.
5.What are the cleaning methods for water-based cleaning agents?
Applications: A common choice for modern environmental protection requirements, it can replace some solvent cleaning methods.
Instructions: Similar to alkaline degreasing, but uses a neutral or slightly alkaline, specialized water-based cleaning agent. Cleaning is performed by spraying, ultrasonication, or immersion, followed by rinsing and drying.
Advantages: Safe, environmentally friendly, non-flammable, and relatively gentle on galvanized coatings.
Disadvantages: Cleaning performance is limited to specific oils and requires a suitable formulation. Subsequent wastewater treatment is required.