Application Methods of UV Coatings for Wood Finishing

1. UV-Cured Putty Paint

UV-cured putty paint is primarily used on wood surfaces with poor smoothness, such as particleboard or fiberboard. Its main purpose is to fill small holes and minor imperfections, sealing the substrate to ensure a smooth surface for subsequent coatings. This prevents unevenness caused by the absorption of decorative coatings into the substrate.

• Key Benefits:

• Fast curing speed

• Provides a dry surface ready for further processing

• Reduces the need for multiple sanding steps, thus enhancing competitiveness

• Application Process:

• First, sand the wood surface with coarse sandpaper to clean and smooth it.

• Apply the putty by scraping or troweling, ensuring an even coat.

• Cure the putty using UV light for 5–6 seconds.

• Sand the cured surface with 280# to 400# sandpaper to improve adhesion for subsequent layers.

• After sanding, proceed with UV primer and topcoat application.

2. UV Primer

UV primers are used on wood surfaces that are relatively smooth. The coating can be applied by brushing, spraying, or curtain coating. The low-viscosity primer can penetrate small pores and enhance the natural beauty of the wood grain through light refraction.

• Key Benefits:

• Preserves and highlights the natural texture of wood

• Provides a solid base for subsequent layers

• Application Process:

• Apply one layer of UV primer using the chosen method (brush, spray, or curtain coating).

• Cure with UV light for 7–8 seconds.

• After curing, sand the surface to improve intercoat adhesion.

• Follow with UV topcoat for a smooth, glossy finish.

3. UV Topcoat

UV topcoats are widely used on natural wood or wood veneers, creating either a high-gloss, closed-grain finish or a matte texture. In addition to aesthetics, the topcoat provides protective properties such as wear resistance, solvent resistance, heat resistance, and resistance to various chemicals.

• Key Benefits:

• Durable protective layer

• High gloss or matte finish options

• Excellent resistance to wear and chemicals

• Application Process:

• The topcoat can be applied by brushing, spraying, or curtain coating.

• Cure with UV light for 8–10 seconds to achieve a perfect finish.

Important Considerations for Wood Coating:

Wood is highly sensitive to humidity and temperature changes, which can cause swelling or shrinkage if not handled properly, potentially leading to cracks. Ideal coating conditions are at 20°C with humidity below 75%, and wood moisture content should be under 20% to ensure optimal results.

This process ensures that wood finishes are both aesthetically pleasing and durable, making UV-cured coatings an ideal choice for high-quality wood finishing.