Why do we need to coat?
Materials that we see around us can be degraded over time. The degradation can be in the form of oxidisation, corrosion, fading, etc. To slow down the degradation process, we try to preserve the materials surface so that it becomes more resistant to the degradation.
Conventional coatings from early times include:
1. Painting: Using brushes to apply the paint on the surface
2. Spray painting: Using spray gun to spray the paint on the surface
3. Dipping: Dipping the surface in the paint or coating materials
4. Flow coating: Placing the materials surface in the flow of paint or coating materials to coat the surface
5. Powder coating: electrostatically charging the powder particles and then spray them on the surface before curing this in the oven
6. Electroplating: utilising electricity to deposit the coating materials on the surface
7. Hot-dip galvanising: Immersing steel or iron in molten zinc to coat the materials
8. Roller coating: Using rollers to apply the coating materials evenly on the surface
9. Curtain coating: Flowing the materials in a curtain like manner so that the surface can be moved through horizontally
10. Chemical Vapour Deposition (CVD): Using chemical gas to deposit thin coating materials on the surface
Each of these technique has seen widespread usage across different industries. Now let’s look at different innovations happening to advance the coating.
1. Eco-Friendly Coatings
New developments are now showcasing new ways to use eco-friendly coatings via water-based solutions, bio-based materials, from bio-based alternatives to low Volatile Organic Compounds (VOCs), which can easily be evaporated and create pollution in the airs. The improvement in performance in these eco-alternatives will not only help address the effectiveness, but will also help reduce the environmental impact as well.
2. Advanced Coating Technologies
New materials and multi-layered coatings are designed to be help increase longevity of the materials and reduce degradation such as corrosion effectively. This is not limited to the formulations of the coat but also extend to the application technologies like the spray and other tools used to apply the coatings so that we can improve the efficiency in the coating process.
3. Self-Healing Coatings
This smart coating technology not only aims to slow down the degradation process but also help heal the surface as well. This novel technique incorporate the nanotechnology and unique polymerisation technology that helps activated the healing process when there are slight damages to the surfaces.
4. Responsive Coatings
Coatings can also be used to respond to external stimuli and adapt. This technology aims to create a coating that can be more responsive to different factors like temperature, UV, or other environmental conditions. This kind of coating will adapt itself to best suit the condition around. They can also be used to signal changes to people working with them as well (ex. heat-responsive coating that might change colour when it is too hot, etc.)
As new technologies emerge, we may see newer ways to preserve the surface with lesser impact to the environment while also extending the life of the surface coating as well. Advancement in coating technology has the potential to impact the overall advancement of material science and also creating new applications for different coated materials.