Hydrophilic Coating: Improving Cleanability
Hydrophilic coatings possess properties that improve cleanability and provide antifouling effects. Why do hydrophilic coatings contribute to better cleanability and antifouling? What is the mechanism behind this?
About Hydrophilicity, Water Repellency, and Hydrophobicity
Hydrophilicity
The hydrophilicity of surfaces such as metals means that water molecules tend to spread evenly across the surface. On a hydrophilic metal surface, water droplets spread out and form a uniform water film over the entire surface.
Water Repellency
On a water-repellent metal surface, water droplets form spheres and slide off the surface as if repelled.
Hydrophobicity
Hydrophobicity is intermediate between hydrophilicity and water repellency. On a hydrophobic metal surface, water droplets tend to form spheres, but not as strongly as on water-repellent surfaces.
Improvement of Cleanability by Hydrophilic Coating
Unlike water-repellent or hydrophobic surfaces, hydrophilic-coated metal surfaces allow water droplets to spread out and form a film. This spread water penetrates between the metal surface and attached dirt, lifting and washing it away. For example, when hydrophilic coatings are applied to building exteriors or car bodies, rainwater spreads across the surface, washing away dirt and maintaining the aesthetic appearance. In manufacturing plants, applying hydrophilic coatings to metal containers that are difficult to clean can improve cleanability by allowing effective dirt removal with just rinsing or light wiping, thereby improving cleanability.
Furthermore, hydrophilic coatings can potentially reduce the amount of detergents or solvents used during cleaning. Since water works effectively on hydrophilic surfaces, simple cleaning methods using water can achieve satisfactory results. This approach is environmentally friendly and enhances the efficiency of cleaning tasks.
Hydrophilic coatings are widely used in various applications such as buildings, automobiles, and kitchen utensils. We recommend hydrophilic coatings for improving cleanability and reducing environmental impact in manufacturing processes.
