Paint spraying method for surface of solid wood furniture

Abstract

The invention discloses a solid wood furniture surface paint spraying method which comprises the following steps: S1, base material pretreatment: selecting a solid wood base material, firstly carrying out ultrasonic-assisted oil removal, adopting a sodium hydroxide solution with the mass concentration of 4-6% as an oil removal agent, soaking the base material in the oil removal agent, starting ultrasonic waves with the frequency of 25-35 kHz and the power of 300-500 W, and soaking for 15-25 min; according to the method, through cooperation of base material pretreatment, special primer spraying, segmented temperature control curing, special finish paint spraying, finish paint segmented curing and fine aftertreatment, the adhesive force, scratch resistance and weather resistance of the coating are remarkably improved, VOCs emission is reduced, and the production period is shortened.

Description

Technical Field

[0001] This invention relates to the field of solid wood furniture manufacturing technology, and in particular to a method for spraying paint on the surface of solid wood furniture. Background Technology

[0002] Solid wood furniture holds a significant share of the furniture market due to its natural grain and environmentally friendly properties, and surface painting is a crucial process that determines its appearance, texture, and lifespan. Current solid wood furniture painting methods suffer from the following core drawbacks: Incomplete substrate pretreatment: Traditional processes only use sandpaper of a single grit for sanding, without specifically treating the oil, burrs, and pores on the solid wood surface. This results in the primer not being able to fully penetrate the substrate, leading to poor coating adhesion and easy cracking and peeling later on. Although some processes remove oil, they often use strong acid / alkali solutions, which can easily corrode the solid wood fibers and damage the substrate structure.

[0003] Mismatch between paint formulation and process: The primer mostly uses ordinary solvent-based resin, lacking modified components to enhance adhesion, and is mostly sprayed in one direction, which easily leads to uneven paint thickness and defects such as sagging and undercoat exposure; the topcoat generally lacks scratch resistance and yellowing resistance design, and after long-term use, the surface is prone to scratches and yellowing, affecting the appearance of the furniture.

[0004] Low drying and curing efficiency and easy damage to the substrate: Existing curing methods mostly use single-temperature baking. If the temperature is too low, the curing time will be as long as 4-6 hours, resulting in low production efficiency. If the temperature is too high (such as above 160℃), the solid wood substrate will easily deform and crack due to a sudden drop in moisture content, especially causing more obvious damage to soft woods such as pine.

[0005] Poor environmental performance: Traditional solvent-based paints generally have VOC content exceeding 200g / L, far exceeding national environmental protection standards. This not only pollutes the environment but also harms the health of operators, which is inconsistent with the current trend of green manufacturing.

[0006] To address the aforementioned issues, there is an urgent need to develop a method for spraying paint on solid wood furniture surfaces that balances adhesion, weather resistance, environmental friendliness, and production efficiency. Summary of the Invention

[0007] The purpose of this invention is to address the shortcomings of existing technologies by proposing a method for spraying paint on the surface of solid wood furniture.

[0008] To achieve the above objectives, the present invention adopts the following technical solution: A method for spray painting the surface of solid wood furniture includes the following steps: S1, substrate pretreatment: select solid wood substrate, first ultrasonic assisted degreasing, using mass concentration of 4-6% sodium hydroxide solution as degreasing agent, the substrate is immersed in the degreasing agent, while the frequency of 25-35 kHz, power 300-500 W ultrasonic is turned on, immersion 15-25 min; After soaking, rinse the surface of the substrate with deionized water to pH 7-7.5, then send the substrate into the hot air circulation drying oven, dry at 40-50℃, air speed 1-1.5m / s for 1-2h, so that the moisture content of the substrate is stable at 8-12%; Then gradient micro-nano polishing is carried out, 180 mesh, 320 mesh and 600 mesh aluminum oxide sandpaper are used in turn, 180 mesh sandpaper is polished along the wood grain direction, polishing pressure is 0.3-0.4MPa, speed is 5-8cm / s, 320 mesh sandpaper is polished with 45° intersection with the texture, 600 mesh sandpaper is lightly polished with 0.1-0.2MPa pressure; After each polishing, blow off the wood chips with 0.2-0.3MPa high pressure air, and then wipe with anti-static dust cloth; S2, special primer preparation and spraying: according to weight parts, 55-65 parts of water-based acrylic resin, 4-6 parts of nano silicon dioxide with particle size of 20-50nm, 8-12 parts of isocyanate curing agent, 18-22 parts of ethyl acetate diluent, 0.4-0.6 parts of polyether modified siloxane leveling agent, 0.2-0.4 parts of silicone defoaming agent are added into the stirring kettle, first stirred at 500-800r / min for 15-20min at 25℃, then heated to 40-45℃ for high speed dispersion at 1200-1500r / min for 25-30min, filtered through 200 mesh filter screen, to get primer paint with viscosity of 18-22s; Use GPQ6C high pressure airless spray gun, under the conditions of working pressure 0.3-0.5MPa, nozzle diameter 0.8-1.0mm, nozzle to substrate distance 20-30cm, first spray along the length direction of the substrate, spraying speed 12-18cm / s, flash dry for 5-8min, then spray along the width direction, the dry film thickness of primer is controlled at 18-22μm; S3, subsection temperature control curing of primer: send the substrate into the subsection curing oven, control the temperature at 60-80℃ and relative humidity at 40-60% in the pre-curing stage, keep the temperature for 30-45min; The temperature is raised to 120-140℃ in the complete curing stage, the humidity is kept at 40-60%, and the temperature is kept for 60-90min; After curing, cool down to 20-25℃ at a rate of 2-3℃ / min; S4, topcoat pretreatment and special topcoat spraying: use 800 mesh water sandpaper dipped in deionized water to wet grind the primer coating, polishing pressure is 0.1-0.2MPa, polish along the grain direction; After sanding, rinse with deionized water and dry in a drying oven at 40-50℃ for 30-45 minutes. By weight, mix 65-75 parts of waterborne polyurethane resin, 2-4 parts of polytetrafluoroethylene micro powder with a particle size of 1-3μm, 0.6-1.0 parts of benzotriazole anti-yellowing agent, 22-28 parts of butanol diluent, and 0.5-0.7 parts of polyacrylate dispersant at 25-30℃ and 800-1000r / min for 20-25 minutes. Filter through a 300-400 mesh screen to obtain a topcoat liquid with a viscosity of 20-25s. Using a KCIK-80 electrostatic spray gun, under the conditions of electrostatic voltage of 60-80kV, working pressure of 0.2-0.4MPa, nozzle-substrate distance of 25-35cm, and spraying speed of 10-15cm / s, the first thin coating is applied to a dry film thickness of 12-18μm, flash-drying for 25-35min, and the second thick coating is applied to a dry film thickness of 28-32μm. S5. Topcoat Segmented Curing: The substrate is sent into a constant temperature and humidity curing chamber, with the temperature controlled at 70-90℃ and the relative humidity at 45-55%. Hot air is circulated with a wind speed of 0.8-1.2m / s for 90-120 minutes. After curing, cool to room temperature at a rate of 1-2℃ / min; S6. Fine post-processing: Use 1000-1200 grit dry sandpaper to lightly sand the topcoat coating along the grain direction with a pressure of 0.05-0.1MPa; Use a wool polishing wheel with a speed of 1500-2000 r / min and polyester wax to polish for 5-8 min / ㎡ at a pressure of 0.05-0.1 MPa; First, use 0.15-0.25MPa high-pressure air to blow away the dust, then use 30-50kV electrostatic dust removal equipment to remove all the dust, and then complete the painting process.

[0009] According to claim 1, the method for spraying paint on the surface of solid wood furniture is characterized in that the solid wood substrate in step S1 is oak, walnut or pine; When the substrate is pine wood, the mass concentration of the sodium hydroxide solution for ultrasonic-assisted degreasing is adjusted to 4-5%, and the soaking time is shortened to 15-20 minutes to avoid excessive corrosion of the soft fibers of pine wood. The drying time in the drying oven is extended to 1.5-2 hours to ensure that the moisture content of the pine wood drops from the initial 15-20% to 8-10%, preventing deformation later.

[0010] Preferably, the nano-silica in step S2 needs to be pretreated with a silane coupling agent. The pretreatment method is as follows: add the nano-silica to a KH-550 ethanol solution with a mass concentration of 5-8%, stir at 60-70°C for 1-1.5 hours, filter, and dry at 80-90°C for 2-3 hours, so that the silane coupling agent is grafted onto the surface of the nano-silica, improving its compatibility with water-based acrylic resin and avoiding the agglomeration of nanoparticles that cause particle defects in the primer coating.

[0011] Preferably, in step S2, when applying high-pressure airless spraying, the principle of "thin coating and multiple coats" is adopted. If the surface texture of the substrate is deep, an additional coat of primer can be applied. Before the third coat, the substrate should flash dry for 3-5 minutes, and the dry film thickness should be controlled at 22-25μm to ensure that the primer fully fills the texture pores and avoids texture depressions and substrate exposure after the topcoat is applied.

[0012] Preferably, the heating method of the segmented curing oven in step S3 is far-infrared heating, with the far-infrared wavelength controlled at 2-5μm, which can penetrate the surface of the primer coating and heat the coating inside and out simultaneously, avoiding the pinhole defects caused by the coating surface curing first and the internal solvent not being able to evaporate due to traditional hot air heating; the heating rate in the pre-curing stage is controlled at 5-8℃ / min, and the heating rate in the complete curing stage is controlled at 3-5℃ / min, further reducing the internal stress of the coating.

[0013] Preferably, the benzotriazole anti-yellowing agent in step S4 is 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, and its mass ratio with waterborne polyurethane resin is controlled at 1:80-1:100. If the ratio is too high, the gloss of the topcoat will decrease, and if the ratio is too low, the anti-yellowing effect cannot be achieved. Polytetrafluoroethylene (PTFE) micro powder needs to be mixed with butanol diluent before stirring to form a suspension with a mass concentration of 10-15% before adding other components to ensure that it is evenly dispersed in the topcoat.

[0014] Preferably, during electrostatic spraying in step S4, the temperature of the spraying environment should be controlled at 20-25℃, the relative humidity at 40-50%, and the dust concentration ≤10mg / m³. 3 ; If the ambient humidity is higher than 50%, a dehumidifier should be turned on to avoid a decrease in the electrostatic adsorption effect, which could lead to uneven paint adhesion. The substrate must be grounded during the spraying process, with a grounding resistance of ≤10Ω, to prevent static electricity accumulation from causing safety hazards.

[0015] Preferably, in step S5, the hot air circulation system of the topcoat curing chamber adopts an airflow method of top supply and bottom exhaust, and the airflow uniformity deviation is ≤±5%, ensuring that the coating curing rate of the top and bottom of the substrate is consistent. The curing time is adjusted according to the dry film thickness of the topcoat. When the dry film thickness is 30-32μm, the curing time is extended to 110-120min to ensure complete cross-linking of the coating and improve chemical resistance.

[0016] Preferably, the polyester wax used for polishing in step S6 is modified polyethylene glycol wax with a melting point of 60-70℃. When polishing, the wax needs to be heated to a molten state first, then evenly applied to the surface of the wool wheel before polishing. After electrostatic dust removal, the adhesion of the furniture surface needs to be tested. If the coating peels off, the primer needs to be reapplied and cured.

[0017] Compared with the prior art, the beneficial effects of this invention are as follows: 1. Significantly improved coating adhesion: Through ultrasonic degreasing + gradient micro-nano polishing, the grease removal rate of the substrate surface is ≥98%, and the roughness is reduced to Ra≤0.8μm. Combined with nano silica modified primer, the adhesion between the primer and the substrate reaches level 0 in the cross-cut test, solving the problem of easy cracking and peeling of coatings in traditional processes.

[0018] Enhanced weather resistance and durability: The synergistic effect of polytetrafluoroethylene micro powder and benzotriazole anti-yellowing agent in the topcoat makes the coating pencil hardness ≥2H (scratch resistant), color difference ΔE ≤1.5 after 1000h xenon lamp aging (yellowing resistant), alcohol wiping ≥50 times, and boiling water immersion 2h without abnormality, thus extending the service life of furniture.

[0019] 2. Environmental friendliness meets national standards: Water-based primer and topcoat are used, with VOC content ≤80g / L. Combined with the VOC adsorption device in the spray booth, the emission concentration is ≤30mg / m³. 3 It is far below the 100g / L limit specified in GB 18581-2020, reducing environmental pollution and health hazards.

[0020] 3. Improved production efficiency and less damage to substrate: Segmented temperature-controlled curing shortens the total curing time to 2.5-3.5 hours, which is 30% more efficient than the traditional process (4-6 hours); and the curing temperature does not exceed 140℃. Combined with slow cooling, it avoids deformation and cracking of solid wood substrates, which is especially suitable for soft pine furniture.

[0021] 4. Uniform and stable paint layer quality: Cross-spraying + electrostatic assisted spraying ensures that the paint layer thickness deviation is ≤±2μm, with no drips or pinholes; fine post-treatment makes the topcoat gloss reach 60-80GU, with a delicate texture, enhancing the appearance of the furniture. Detailed Implementation

[0022] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described in detail below. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0023] Example 1: Spray painting on the surface of a solid oak dining table Substrate pretreatment: Select 20mm thick oak boards and cut them into 1200mm×800mm dining table panels; ultrasonic degreasing is performed using a 5% sodium hydroxide solution at 30kHz for 20 minutes; after rinsing with deionized water, dry with hot air at 45℃ for 1.5 hours until the moisture content drops to 10%; gradient sanding: sanding with 180 grit sandpaper (pressure 0.35MPa, speed 6cm / s) → cross sanding with 320 grit sandpaper → light sanding with 600 grit sandpaper, followed by dust removal with high-pressure air and electrostatic cloth.

[0024] Primer spraying: Primer components (parts by weight): 60 parts water-based acrylic resin, 5 parts pretreated nano silica, 10 parts isocyanate curing agent, 20 parts ethyl acetate, 0.5 parts leveling agent, 0.3 parts defoamer; viscosity after stirring and dispersing is 20s; high-pressure airless spraying (0.4MPa, distance 25cm), two cross-sprays, dry film thickness 20μm.

[0025] Primer curing: Pre-curing 70℃ / 40min → Full curing 130℃ / 75min, 2.5℃ / min Cool to 25℃.

[0026] Topcoat spraying: wet sanding with 800-grit wet sandpaper → drying at 45℃ for 35 min; Topcoat components (parts by weight): 70 parts waterborne polyurethane, 3 parts polytetrafluoroethylene micro powder, 0.8 parts anti-yellowing agent, 25 parts butanol, 0.6 parts dispersant; viscosity after stirring and filtration: 22 s; electrostatic spraying (70kV, 0.3MPa), first 15μm (flash dry for 30 min) → second 30μm.

[0027] Topcoat curing: 80℃ / 50% RH, hot air circulation curing for 100min, cooling to 25℃ at 1.5℃ / min.

[0028] Post-processing: Light sanding with 1200 grit sandpaper → Wool wheel (1800r / min) + polyester wax polishing for 6min / ㎡ → High-pressure air + electrostatic dust removal.

[0029] Example 2: Spray painting on the surface of pine wardrobe door panels The difference from Example 1 is as follows: Substrate pretreatment: Sodium hydroxide solution concentration 4.5%, ultrasonic soaking for 18 min; drying time 2 h, moisture content reduced to 9%; Primer application: Apply one additional coat (dry film thickness 23μm) to fill the pores of the pine wood grain; Topcoat curing: Temperature 75℃, curing time 110min, to avoid high temperature deformation of pine wood.

[0030] Test results Test item Example 1 (oak wood) Example 2 (pine wood) Prior art (conventional solvent type) Adhesion 0 level 0 level 2 level Pencil hardness 2H 2H H Resistance to yellowing (ΔE, 1000 h) 1.2 1.3 3.5 VOC content (g / L) 75 78 220 Total production cycle (h) 5.5 6.0 9.0 The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for painting the surface of solid wood furniture, comprising the following steps: S1, substrate pretreatment: selecting a solid wood substrate, first performing ultrasonic assisted degreasing, using a sodium hydroxide solution with a mass concentration of 4-6% as a degreasing agent, immersing the substrate in the degreasing agent, and simultaneously turning on an ultrasonic wave with a frequency of 25-35 kHz and a power of 300-500 W, and immersing for 15-25 min; After immersion, the substrate surface is rinsed with deionized water until the pH value is 7-7.5, and then the substrate is sent to a hot air circulation drying oven, dried at 40-50℃ and a wind speed of 1-1.5 m / s for 1-2 h, and the moisture content of the substrate is stabilized at 8-12%; Then gradient micro-nano polishing is performed, and 180 mesh, 320 mesh and 600 mesh aluminum oxide sandpaper is used in sequence, the 180 mesh sandpaper is polished along the wood grain direction, the polishing pressure is 0.3-0.4 MPa, and the speed is 5-8 cm / s, the 320 mesh sandpaper is polished at 45° to the grain, and the 600 mesh sandpaper is lightly polished at a pressure of 0.1-0.2 MPa; After each polishing, the wood chips are blown away with high-pressure air at 0.2-0.3 MPa, and then wiped with an anti-static dust cloth; S2, special primer preparation and spraying: according to weight parts, 55-65 parts of water-based acrylic resin, 4-6 parts of nano silicon dioxide with a particle size of 20-50 nm, 8-12 parts of isocyanate curing agent, 18-22 parts of ethyl acetate diluent, 0.4-0.6 parts of polyether modified siloxane leveling agent, and 0.2-0.4 parts of silicone defoaming agent are added into a stirring kettle, first stirred at 500-800 r / min at 25℃ for 15-20 min, then heated to 40-45℃ and dispersed at 1200-1500 r / min for 25-30 min, filtered through a 200 mesh filter screen, and a primer paint solution with a viscosity of 18-22 s is obtained; A high-pressure airless spray gun with a model of GPQ6C is used, under the conditions of a working pressure of 0.3-0.5 MPa, a nozzle diameter of 0.8-1.0 mm, and a nozzle-substrate distance of 20-30 cm, first spraying along the length direction of the substrate for the first time, the spraying speed is 12-18 cm / s, and after flash drying for 5-8 min, spraying along the width direction for the second time, the dry film thickness of the primer is controlled at 18-22 μm; S3, subsection temperature control curing of the primer: the substrate is sent into a subsection curing oven, the pre-curing stage controls the temperature at 60-80℃ and the relative humidity at 40-60%, and the temperature is kept for 30-45 min; The complete curing stage is heated to 120-140℃, the humidity is kept at 40-60%, and the temperature is kept for 60-90 min; After curing, the temperature is cooled to 20-25℃ at a rate of 2-3℃ / min; S4, topcoat pretreatment and special topcoat spraying: using 800 mesh water sandpaper dipped in deionized water to wet sand the primer coating, the polishing pressure is 0.1-0.2 MPa, and the sanding is performed along the grain direction. After polishing, rinse with deionized water and dry in an oven at 40-50℃ for 30-45min; according to weight parts, 65-75 parts of water-based polyurethane resin, 2-4 parts of polytetrafluoroethylene powder with particle size of 1-3μm, 0.6-1.0 parts of benzotriazole anti-yellowing agent, 22-28 parts of butanol diluent, 0.5-0.7 parts of polyacrylate dispersant are stirred at 800-1000r / min for 20-25min at 25-30℃, filtered through a 300-400 mesh filter screen to obtain a finish paint liquid with a viscosity of 20-25s; An electrostatic spraying gun of model KCIK-80 is used at an electrostatic voltage of 60-80kV, a working pressure of 0.2-0.4MPa, a nozzle-to-substrate distance of 25-35cm, and a spraying speed of 10-15cm / s, and the first thin coating is performed to a dry film thickness of 12-18μm, followed by flash drying for 25-35min, and the second thick coating is performed to a dry film thickness of 28-32μm; S5, subsection curing of the finish paint: the substrate is sent into a constant temperature and humidity curing room, the temperature is controlled at 70-90℃, the relative humidity is controlled at 45-55%, and hot air circulation with a wind speed of 0.8-1.2m / s is used for curing for 90-120min; After curing, cooling is performed at a rate of 1-2℃ / min to room temperature; S6, fine post-treatment: 1000-1200 mesh dry sandpaper is used to lightly polish the finish paint coating along the grain direction at a pressure of 0.05-0.1MPa; A wool polishing wheel with a rotating speed of 1500-2000r / min is used to polish for 5-8min / ㎡ in cooperation with polyester wax at a pressure of 0.05-0.1MPa; First, high-pressure air with a pressure of 0.15-0.25MPa is used to blow off dust, and then electrostatic dust removal equipment with a voltage of 30-50kV is used for comprehensive dust removal to complete the paint spraying.

2. The method for painting the surface of solid wood furniture according to claim 1, characterized in that, The solid wood substrate in step S1 is oak, walnut or pine; When the substrate is pine, the mass concentration of the sodium hydroxide solution for ultrasonic-assisted oil removal is adjusted to 4-5%, and the soaking time is shortened to 15-20min to avoid excessive corrosion of the soft fibers of the pine; The drying time in the oven is extended to 1.5-2h to ensure that the water content of the pine is reduced from the initial 15-20% to 8-10% to prevent deformation in the later stage.

3. A method for painting the surface of solid wood furniture according to claim 1, characterized in that, The nano-silica in step S2 needs to be pretreated with a silane coupling agent, and the pretreatment method is as follows: the nano-silica is added into a 5-8% mass concentration KH-550 ethanol solution, stirred at 60-70℃ for 1-1.5h, filtered, and then dried at 80-90℃ for 2-3h to graft the silane coupling agent onto the surface of the nano-silica, thereby improving the compatibility of the nano-silica with the water-based acrylic resin and avoiding particle aggregation of the nano-silica to cause particle defects in the primer coating.

4. The method for painting the surface of solid wood furniture according to claim 1, characterized in that, When high-pressure airless spraying is performed in step S2, the "thin coating and multiple passes” principle is adopted, and if the substrate surface has deep texture, an additional pass of primer spraying can be performed, flash drying is performed for 3-5min before the third pass of spraying, the dry film thickness is controlled at 22-25μm, and the primer is ensured to fully fill the texture pores to avoid the phenomenon of texture depression and primer leakage after the finish paint is sprayed.

5. The method for painting the surface of solid wood furniture according to claim 1, characterized in that, The heating mode of the sectional curing oven in step S3 is far-infrared heating, with a wavelength controlled at 2-5 μm, which can penetrate the primer coating surface and heat the inside and outside of the coating synchronously, avoiding the pinhole defects caused by the surface curing of the coating and the inability of the internal solvent to volatilize due to traditional hot air heating; the temperature rising rate in the pre-curing stage is controlled at 5-8 ℃ / min, and the temperature rising rate in the complete curing stage is controlled at 3-5 ℃ / min, further reducing the internal stress of the coating.

6. A method for painting the surface of solid wood furniture according to claim 1, characterized in that, The benzotriazole yellowing-resistant agent in step S4 is 2-(2'-hydroxy-5'-methylphenyl) benzotriazole, and the mass ratio of the benzotriazole yellowing-resistant agent to the waterborne polyurethane resin is controlled at 1:80-1:100; a too high ratio will cause the gloss of the topcoat to decrease, and a too low ratio will not achieve the yellowing-resistant effect; The polytetrafluoroethylene micro powder needs to be mixed with butanol diluent before stirring to form a suspension with a mass concentration of 10-15%, and then other components are added to ensure uniform dispersion in the topcoat.

7. A method for painting the surface of solid wood furniture according to claim 1, characterized in that, In the electrostatic spraying in step S4, the temperature of the spraying environment is controlled to be 20-25℃, the relative humidity is controlled to be 40-50%, and the dust concentration in the environment is controlled to be ≤10mg / m 3 ; If the environmental humidity is higher than 50%, the dehumidification equipment needs to be started to avoid uneven adhesion of the paint caused by the decrease of the electrostatic adsorption effect; The substrate needs to be grounded during the spraying process, with the grounding resistance ≤10 Ω, to prevent safety hazards caused by the accumulation of static electricity.

8. The method for painting the surface of solid wood furniture according to claim 1, wherein, The hot air circulation system of the topcoat curing chamber in step S5 adopts an air flow mode of upward sending and downward discharging, with an air flow uniformity deviation ≤±5%, to ensure that the curing rates of the coatings on the top and bottom of the substrate are consistent; The curing time is adjusted according to the dry film thickness of the topcoat, and when the dry film thickness is 30-32 μm, the curing time is extended to 110-120 min to ensure complete crosslinking of the coating and improve the chemical resistance.

9. The method for painting the surface of solid wood furniture according to claim 1, wherein, The polishing polyester wax in step S6 is modified polyethylene glycol wax with a melting point of 60-70 ℃, which needs to be heated to a molten state before polishing and uniformly applied to the surface of the wool wheel, and then polished; after electrostatic dust removal, the adhesion of the surface of the furniture needs to be detected, and if the coating falls off, the primer spraying and curing need to be performed again.