1.What is the technical principle behind self-cleaning coatings?
Superhydrophobic (Lotus Leaf Effect)
Principle: Through nanotechnology, a microscopic rough structure is constructed on the coating surface, resulting in an extremely large water contact angle (typically >150°). Water droplets form spherical shapes on the surface and roll off very easily.
Superhydrophobic (Lotus Leaf Effect)
Principle: Through nanotechnology, a microscopic rough structure is constructed on the coating surface, resulting in an extremely large water contact angle (typically >150°). Water droplets form spherical shapes on the surface and roll off very easily.
2.How effective is the self-cleaning coating?
Superhydrophobic (Lotus Leaf Effect):
Strong Water Repellency: Rainwater quickly rolls off the surface, carrying away dry dirt such as dust and pollen.
Anti-Adhesion: Oily stains also have difficulty wetting and penetrating the surface.
Aided Cleaning: This is the technology used in the mainstream "self-cleaning" color-coated steel sheets on the market; more accurately, it's "easy to clean" or "aids in cleaning."
Photocatalytic (TiO₂ effect) effects:
Organic matter decomposition: Decomposes organic matter into harmless substances such as carbon dioxide and water.
Superhydrophilicity: After the photocatalytic reaction, the surface becomes superhydrophilic, allowing water to spread evenly to form a water film rather than water droplets, thus washing away decomposed dirt and some inorganic dust.
Limitations: Dependent on light exposure; effectiveness weakens on backlit surfaces; primarily effective against organic stains; maintaining long-term durability and catalytic efficiency are key technical challenges.
3.What are the core features and advantages of self-cleaning color-coated coils?
Significantly Reduced Maintenance Costs: Surface dust and rain stains are more easily washed away by rainwater, reducing the frequency and cost of manual cleaning.
Long-Term Preservation of Building Aesthetics: Effectively alleviates localized color differences caused by dust accumulation and rain streaks, keeping the building's appearance looking new for longer.
Superior Overall Performance: The self-cleaning function is an added bonus; the substrate and coating itself still retain all the advantages of color-coated steel coils: excellent weather resistance (UV resistance, chalking resistance), corrosion resistance, mechanical strength, and a wide range of color choices.
Environmentally Friendly: Reduces the use of cleaning water and chemical cleaning agents.
4.What are the main application scenarios?
Large public buildings: Exterior walls and roofs of airports, stadiums, and exhibition centers.
High-rise building curtain walls: High cleaning costs highlight the value of self-cleaning functionality.
Low-slope or complex roof designs: Areas with good rainwater runoff resistance.
Areas with heavy rainfall or severe air pollution: They function more effectively in these situations.
5.What are the key points for selection and verification?
Quantitative testing reports are required: Don't rely solely on advertising claims; third-party testing reports are mandatory. Key indicators include:
Water contact angle test: A value greater than 150° generally indicates excellent superhydrophobic properties.
Stain resistance test: Simulates the residue rate after rainwater or standard cleaning following dirt adhesion.
Weather resistance test: Crucial! Self-cleaning functionality must be effective over a long period. Data on the retention rate of hydrophobic angle or easy-cleaning properties after accelerated aging tests (such as QUV thousands of hours) are required. Functional durability should match the weathering life of the coating itself.