标签： powder coating innovation

Impact of Dispersion on UV Coating Performance

To investigate the influence of vapor-phase nanomaterial dispersion on UV coating performance, the technical team at BLUETEE conducted extensive research focusing on dispersion time and equipment rotation speed to find the optimal parameters. They studied how different dispersion levels affect UV coatings’ viscosity, thixotropy, particle condition, gloss, haze, light transmittance, pencil hardness, and abrasion resistance. Their findings confirm that the degree of dispersion of vapor-phase nanomaterials significantly impacts the performance of UV coatings. A proper dispersion process can fully utilize the advantages of vapor-phase nanomaterials and enhance the overall performance of powder coating formulations.

UV coatings, cured by UV radiation, are known for their fast curing speed, energy-saving advantages, room-temperature processing, reduced environmental impact, smaller production footprint, and improved product performance.

Key Properties of Vapor-Phase Silica and Alumina

Vapor-phase silica is a critical fine inorganic material characterized by extremely small particle size, high specific surface area, strong surface adsorption, high surface energy, high chemical purity, and excellent dispersibility. It offers superior thickening, thixotropic behavior, reinforcement, and stability in formulations. In UV-curable coatings, vapor-phase silica improves thickening, matting, hardness, and especially enhances abrasion resistance.

Similarly, vapor-phase nano alumina is another important ultrafine inorganic material widely used in powder coating applications to improve flowability. It forms a movable layer on the surface of powder particles, preventing moisture absorption and caking. Additionally, due to its positive triboelectric properties, it improves spraying efficiency and enhances powder adhesion rates.

Optimal Dispersion Parameters for Vapor-Phase Nanomaterials

Initially, the BLUETEE technical team incorporated hydrophilic vapor-phase silica HL-200 into UV coatings at a fixed dosage, and performed dispersion using a high-speed mixer at 500r/min, 1000r/min, 2000r/min, and 3000r/min for 30 minutes. Viscosity and thixotropy were then tested for each group. Results showed that as dispersion intensity increased, the UV coating viscosity and thixotropic index steadily rose, reaching optimal values at 3000r/min — with viscosity reaching 4543Pa·s and thixotropic index reaching 5.

However, as the dispersion speed continued to increase, the rate of viscosity and thixotropy growth slowed and eventually plateaued. Beyond a critical point, higher speeds no longer significantly affected the thickening and thixotropic behavior, and both properties stabilized.

Further experiments involved coating and curing the UV formulations. Observations showed that when the dispersion speed was below 1000r/min, the surface of the cured film exhibited obvious graininess and roughness. At speeds above 2000r/min, the film became notably smoother and more uniform.

Therefore, to achieve optimal viscosity, thixotropy, and particle conditions, dispersion speeds must be set above 2000r/min for at least 30 minutes.

Comparative Analysis of Different Nanomaterials

Additionally, BLUETEE conducted comparative experiments by adding 1.5% of different nano powders (blank control, HL-200, a competitor’s hydrophilic silica, and vapor-phase nano alumina Aluna-100) into UV coatings. They evaluated gloss, haze, transmittance, pencil hardness, and abrasion resistance.

The results indicated that both HL-200 and the competing product had a minimal impact on transmittance while effectively improving pencil hardness. Differences in matting, hardness, and wear resistance between the two were not significant. Notably, although vapor-phase silica decreased gloss, Aluna-100 had less impact on gloss while significantly enhancing pencil hardness and abrasion resistance.

Conclusion: The Critical Role of Dispersion in Powder Coating

In conclusion, vapor-phase nanomaterials such as vapor-phase silica and vapor-phase nano alumina have demonstrated significant application value in powder coating and UV-curable coatings. However, the dispersion quality of these nanomaterials is critical to realizing their full benefits.

Proper dispersion ensures uniform distribution of nanoparticles within the coating matrix, enhancing viscosity, thixotropy, particle smoothness, gloss, transmittance, hardness, and wear resistance. In contrast, poor dispersion can lead to viscosity issues, surface defects, reduced gloss, lower transmittance, and unstable mechanical properties.

Thus, it is essential to focus on dispersion technology when applying vapor-phase nanomaterials in powder coating. Choosing the right dispersing equipment and techniques can unlock the full performance potential of nanomaterials and promote the advancement of the powder coating and UV coatings industry.