In the manufacturing of solar lights, ensuring the durability and longevity of the product is crucial, especially for outdoor applications. A critical aspect of this durability is the quality of the surface treatment applied to the solar lights.
To achieve a high-quality, resilient finish, the process of high-temperature spray curing is employed. This process involves several meticulous steps: pre-treatment, electrostatic spraying, and high-temperature curing. Each stage is essential in enhancing the protective qualities of the surface coating, ensuring that the solar lights withstand harsh outdoor environments.
1. Pre-treatment: Laying the Foundation
The first step in the surface treatment process is pre-treatment. This involves preparing the solar light components to ensure optimal adhesion of the coating material. The pre-treatment process typically includes:
Degreasing: This step removes oils and grease from the surface of the solar lights, which could otherwise hinder the adhesion of the coating.
There are two main methods of degreasing: organic solvent degreasing and chemical degreasing. Organic solvent degreasing uses the dissolving power of organic solvents to remove grease, while chemical degreasing removes grease through chemical reactions. In the surface treatment of solar lamps, chemical degreasing is usually used because it can remove grease more thoroughly and will not pollute the environment.
Rust Removal: Any rust present on the metal parts is thoroughly removed to prevent corrosion from spreading under the coating.
Specific rust removal tools include scrapers, wire brushes, powered sandpaper discs, or hand-grinding wheels. These tools can help remove impurities such as oil, dust, rust, etc. on the surface of the workpiece, providing a clean substrate for subsequent electrostatic spraying.
During the rust removal process, the operator needs to choose the appropriate tools and strength according to the degree of rust on the surface of the workpiece to ensure the rust removal effect while avoiding excessive damage to the substrate.
After rust removal, thorough rinsing with clean water is essential to remove any residue from the rust removal process.
Phosphating: A phosphate layer is applied to the metal surface, providing a rough texture that enhances the adhesion of the subsequent coating layer. This also adds an additional layer of corrosion resistance.
Phosphating involves immersing the solar light components in a solution containing phosphates, which react with the metal surface to form the phosphate layer. The thickness and composition of the phosphate layer can be adjusted by varying the phosphating solution and conditions.
After phosphating, the components are rinsed with clean water to remove any excess solution and then dried to prevent corrosion.
2. Electrostatic Spraying: Applying the Coating
Once the solar light components are pre-treated, they are ready for the electrostatic spraying process. This step involves using electrostatic principles to apply a uniform layer of powder coating to the surface of the components:
Electrostatic Attraction: A high-performance electrostatic spray gun is used to charge the powder particles, which are then attracted to the grounded metal surface of the solar lights. This ensures an even coating distribution, even in hard-to-reach areas.
The coating material used in electrostatic spraying is typically a polymer-based paint or primer, which provides excellent corrosion resistance and durability.
To achieve the best results, the coating material should be applied in multiple layers, with each layer allowed to dry before the next is applied. This ensures that the coating is thick enough to withstand harsh outdoor conditions while maintaining a smooth and even appearance.
Electrostatic spraying offers several key advantages:
- It ensures thorough atomization, resulting in a smooth and aesthetically pleasing coating;
- It provides high material utilization efficiency;
- Minimizes overspray, reducing waste;
- Improves production efficiency;
- Excels at coating complex shapes and edges with uniform coverage.
Solar light, often made from aluminum alloys or steel, requires anti-corrosion treatment. Electrostatic spraying delivers an even, smooth coating with precise thickness control, making it suitable for complex components while reducing pollution and increasing material efficiency.
High-Quality Powder: At our company, we use imported powder coatings from AkzoNobel, a global leader in paints and coatings. AkzoNobel’s powder coatings are renowned for their toughness, durability, and consistent quality worldwide. These coatings are not only safe and environmentally friendly, but they also enhance the protective properties and aesthetics of the solar lights.
The use of such premium powder ensures that the surface treatment results in a finish that is resistant to wear, corrosion, and environmental factors. This high level of protection ultimately extends the lifespan of the product, making it more reliable and long-lasting in outdoor environments.
3. High-Temperature Curing: Solidifying the Coating
The final step in the surface treatment process is high-temperature curing. After the powder coating is applied, the components are placed in a curing oven where they are heated to a predetermined temperature:
Curing Process: The solar light components are typically heated to around 185°C (365°F) and maintained at this temperature for approximately 15 minutes. This high heat causes the powder coating to melt, flow, and then solidify into a smooth, durable finish.
The curing process also helps to remove any volatile organic compounds (VOCs) from the coating material, which can improve the overall quality and environmental performance of the solar lights.
However, this process cannot be applied to ABS plastic solar lamps, which are the most popular in the market, because the heat deformation temperature of ABS plastic is usually between 80 and 118 degrees. If the high-temperature electrostatic spraying temperature reaches or exceeds this range, it will damage ABS plastic.
Therefore, in addition to the fact that the material of ABS plastic solar lamps is easy to age in outdoor environments, the lack of good spray coating protection is also one of the main reasons.
Cooling: After curing, the components are carefully cooled, allowing the coating to harden fully and develop its final protective properties.
4. The End Result: Durable and Aesthetic Solar Lights
The high-temperature spray curing process results in a solar light surface that is not only visually appealing but also highly durable. The treated surfaces are resistant to UV radiation, weathering, corrosion, and physical impacts, ensuring that the solar lights maintain their performance and appearance over time, even in harsh outdoor environments.
The high-temperature spray curing process is a vital aspect of producing high-quality solar lights that can withstand the challenges of outdoor environments. By following this rigorous process and using premium materials like AkzoNobel powder coatings, manufacturers can ensure that their products deliver long-lasting performance and remain an integral part of sustainable and reliable outdoor lighting solutions.
The cost of a good solar light surface treatment can be 50% more expensive than a bad one.
This advanced surface treatment process highlights the importance of combining technical precision with quality materials to produce solar lights that meet the high standards demanded by both the market and the end users.
