Surface coating of wood furniture is a key process to improve product texture and durability. UV coating technology has become the mainstream choice in modern furniture manufacturing due to its advantages such as "zero VOC emissions", "second-level curing", and "high-hardness coating". For different substrates such as solid wood, MDF, and veneer, as well as diversified product forms such as flat doors, carved cabinets, and special-shaped lines, professional UV coating equipment needs to achieve a three-dimensional balance of "coating precision, curing efficiency, and environmental protection standards". As a manufacturer of coating line equipment, we provide a full-process UV coating solution from primer to topcoat for wood furniture enterprises through customized equipment combinations and process optimization.
Core Equipment System: Customized Configuration for Furniture Forms
The diversity of wood furniture forms determines that UV coating equipment must adopt modular design. Core equipment includes:
UV roller coating line for flat-panel furniture: For flat components such as wardrobe doors and table tops, a combination of "double roller coating + three-lamp curing" equipment is configured. The front putty roller coater adopts rubber + steel roller combination (hardness 60-80 Shore A), achieving uniform application of 10-20μm putty layer at 30-50m/min line speed to fill wood pores; the primer roller coater is equipped with a precision scraper (gap accuracy ±0.01mm) to control dry film thickness at 20-30μm; the topcoat uses a UV shower coater (flow control accuracy ±1ml/min) to ensure high-gloss effect. The curing system adopts a combination of medium-pressure mercury lamps (120-160W/cm) and LED-UV lamps, with total energy reaching 800-1000mJ/cm², realizing instant coating curing (3-5 seconds). The line length is controlled at 15-20m to meet small and medium batch production needs.
UV spraying system for special-shaped furniture: For complex structures such as carvings and arcs, a "6-axis robot + reciprocator" collaborative spraying scheme is adopted. The robot is equipped with a high-pressure airless spray gun (atomization particle size 10-20μm), which identifies the furniture contour through 3D visual scanning (accuracy ±0.5mm) and automatically generates a spraying path. For deep carved areas (depth ≥5mm), it starts pulse spraying mode (frequency 5-10Hz) to ensure sufficient paint penetration; the reciprocator is responsible for touch-up spraying on flat areas, combined with electrostatic assistance (voltage 60-80kV) to increase paint utilization rate to over 75%. The curing area adopts multi-angle UV lamp groups (360° surrounding layout) to solve the problem of shadow curing of special-shaped parts. The lamp distance can be automatically adjusted by a servo motor (range 100-300mm) to adapt to workpieces of different sizes.
Special UV equipment for line furniture: For slender parts such as door frames and decorative strips, a "horizontal conveying + rotating spraying" system is configured. Conveying adopts synchronous belt drive (speed 10-20m/min), and workpieces are fixed by pneumatic fixtures and achieve 360° rotation (rotating speed 30-50r/min); the spraying unit is equipped with 2-4 fan nozzles (angle 60-90°), arranged along the axial direction of the line, and realizes segmented spraying (automatic switching between primer/topcoat) through PLC control; curing adopts a follow-up design where UV lamps move synchronously with the workpiece, avoiding energy waste of traditional curing ovens, reducing energy consumption by 40%.
Process Core: Precise Control of UV Coating Performance
The performance of UV coating equipment is ultimately reflected in coating quality, which requires collaborative control through multiple links:
Coating compatibility design: The equipment must be compatible with UV putty, UV primer, UV topcoat and other coatings with different viscosities (500-5000cP). The paint supply system adopts a variable frequency gear pump (flow range 1-20L/min), combined with a heating and heat preservation device (25-40℃ adjustable) to prevent viscosity fluctuation caused by temperature changes. For matte effect requirements, a powder adding device (addition amount 0.5-2%) can be added to mix UV paint and matting powder online to avoid batch color difference.
Curing energy closed-loop control: The UV lamp group is equipped with an energy monitor (accuracy ±5mJ/cm²) to feedback curing energy in real time and automatically adjust lamp power (10-100% adjustable). For dark wood (such as walnut), a combination process of "infrared preheating (60-80℃) + UV curing" is adopted to solve the problem of ultraviolet absorption by dark coatings, ensuring 100% curing depth (verified by acetone wipe test).
Surface quality optimization: A UV sander (sandpaper grit 400-600) is added after primer curing, adapting to slight unevenness of wood surface through elastic sanding pads (hardness 40-50 Shore A). After sanding, the surface roughness Ra ≤0.8μm; an ion air gun (wind speed 10-15m/s) is configured before topcoat spraying to remove electrostatically adsorbed dust, ensuring no particle defects in the coating (particle count ≤2/m²).
Intelligence and Environmental Protection: Core Demands of Modern Coating
UV coating equipment must balance intelligent production and environmental compliance:
Intelligent control system: Adopting industrial touch screen + PLC architecture, it can store more than 100 process recipes (such as "white paint high gloss", "wood color matte"). During product changeover, parameters are called by scanning codes (changeover time ≤5 minutes). Equipped with online film thickness gauge (accuracy ±1μm) and gloss meter (60° angle), it monitors coating thickness (deviation ≤±2μm) and gloss (range 30-95GU) in real time. Data is automatically uploaded to MES system to realize quality traceability.
Environmental protection and safety design: The spray booth adopts a fully enclosed negative pressure structure (negative pressure 5-10Pa), equipped with paint mist filter cotton (efficiency ≥99%) and activated carbon adsorption device (processing air volume 1000-3000m³/h) to ensure VOC emission concentration ≤20mg/m³. The UV curing area is equipped with an ozone collection system (collection efficiency ≥98%) and ultraviolet protection curtain (light shielding rate ≥99.9%). Operators are equipped with UV dosimeters (range 0-1000mJ/cm²), meeting GB/T 30574 safety standards.
Application Case: UV Coating Upgrade of a Custom Furniture Enterprise
After a medium-sized custom furniture enterprise introduced the "roller coating + spraying" composite UV production line, key indicators improved significantly: coating line speed increased from 5m/min of traditional PU paint to 30m/min, with daily production capacity increased by 5 times; paint utilization rate increased from 50% to 85%, saving about 1.8 million yuan in annual material costs; due to no volatilization of UV paint, the workshop VOC concentration decreased from 200mg/m³ to 15mg/m³, meeting environmental protection requirements. At the same time, the coating hardness increased from 2H to 3H, and the yellowing resistance grade reached △E ≤1 (1000 hours xenon lamp aging), with product premium capacity increased by 20%.
Conclusion
The selection of UV coating equipment for wood furniture must focus on the three cores of "product form - process demand - production capacity planning", achieving flexible production through modular configuration. As equipment manufacturers, we can provide customized solutions according to enterprise product structure (such as mainly flat panels or mostly special-shaped parts) and production capacity scale (500-5000 pieces/day), participating in the whole process from equipment layout to process commissioning, helping enterprises quickly achieve the three goals of "environmental compliance, efficiency improvement, and quality upgrading", and building technical barriers in the wave of furniture industry upgrading.
