Office furniture board surface treatment process

Abstract

The invention relates to the technical field of surface treatment, in particular to an office furniture board surface treatment process which comprises the following specific steps: A, primer with the solid content of 40-50% is selected as a coating, the primer comprises nanoscale filler, curtain coating is performed in a coating workshop by adopting a curtain coating machine, the primer is filtered by a 100-150-mesh filter screen in a coating pipeline connected with the curtain coating machine, and the coating pipeline is connected with the curtain coating machine; the coating pressure is 0.3-0.5 MPa, and the base material conveying speed is 6-8 m / min; b, after curtain coating, entering a leveling area for leveling for 30-60 seconds, wherein the wind speed of the leveling area is less than or equal to 0.5 m / s; and C, UV curing is conducted through a UV curing machine, the curing parameters are that the wavelength is 365 nm, the energy is 800 mJ / cm to 1200 mJ / cm, the curing time is 10 seconds to 15 seconds, and the coating in the step A is circularly heated to 25 DEG C to 30 DEG C. The purpose of the invention is to solve the problems that in an office furniture board surface treatment process of an existing shower coating machine, a thickening agent in water-based paint is prone to forming flocculent aggregates, and the coating is not prone to falling off. And undispersed matting powder particles in the UV coating are easy to gradually deposit during pumping, so that a nozzle is easy to block.

Description

Technical Field

[0001] The invention relates to the technical field of surface treatment, in particular to a surface treatment process for office furniture panels. Background Art

[0002] The surface of office furniture panels is coated with multiple layers combined with curing to form a protective layer, achieving a customized gloss effect from matte to glossy. It has wear-resistant, scratch-resistant, stain-resistant, anti-corrosive and moisture-proof functions. It adopts a water-based environmentally friendly formula with an E0-level environmentally friendly substrate to meet the requirements of anti-yellowing durability, environmental protection standards and high-end texture. It is suitable for open office areas, conference rooms, executive offices and other scenes. While ensuring easy cleaning and long life, it provides tactile finishes such as mirrors and matte to upgrade the aesthetic experience of office space.

[0003] Among them, curtain coating is used as the core coating technology. The primer layer seals the pores of the substrate, and the topcoat layer shapes the surface texture to achieve uniform coverage of the coating. The water-based UV coating is evenly coated on the surface of the E0-grade substrate through a curtain coating machine to form a wet film of the primer and topcoat, which is then formed into a paint film after UV curing.

[0004] In the existing coating machine's surface treatment process for office furniture panels, the thickener in the water-based paint tends to form flocculent agglomerates, and the undispersed matting powder particles in the UV coating tend to gradually settle during pumping. When there are particles in the coating that exceed 1 / 3 of the nozzle aperture, it directly causes physical blockage, resulting in a sudden increase in local pressure drop.

[0005] The blockage of the coating machine nozzle will lead to a decline in coating quality, resulting in defects such as uneven coating thickness, surface bumps, and orange peel texture, while also causing reduced production efficiency and increased maintenance costs. Summary of the invention

[0006] The purpose of the present invention is to provide a surface treatment process for office furniture panels to solve the problem that in the existing coating machine surface treatment process for office furniture panels, the thickener in the water-based paint is prone to form flocculent agglomerates, and the undispersed matting powder particles in the UV coating are prone to gradually settle during pumping, which easily leads to nozzle clogging.

[0007] To achieve the above object, the present invention provides the following technical solutions: A surface treatment process for office furniture panels, the specific steps are as follows: A. The coating is a primer with a solid content of 40-50%, the primer contains nano-scale fillers, and is curtain coated in a coating workshop using a curtain coating machine. The primer is filtered through a 100-150 mesh filter in a coating pipeline connected to the curtain coating machine. The coating pressure is 0.3-0.5MPa, and the substrate conveying speed is 6-8m / min; B. After the curtain coating, it enters the leveling area and leveling for 30-60 seconds, and the wind speed in the leveling area is ≤0.5m / s; C. Use a UV curing machine for UV curing, the curing parameters are wavelength 365nm, energy 800-1200mJ / cm², and curing time 10-15 seconds.

[0008] Preferably, in step A, the coating flow rate is adjusted to 300-500 ml / min by a gear pump, and the nozzle is 15-20 mm away from the substrate surface.

[0009] Preferably, in step A, the coating is cyclically heated to 25-30°C.

[0010] Preferably, an online particle detection sensor is installed on the paint pipe in front of the filter to detect the concentration of 0.1-100 μm particles in the paint. When the particle concentration is greater than 1000 particles / ml, the sensor sends the detected signal to the controller to trigger the alarm device.

[0011] Preferably, the paint pipeline comprises a main filter channel and a spare filter channel, both of which are equipped with 100-150 mesh filter screens, and an electric switching valve for switching the main filter channel and the spare filter channel is installed on the paint pipeline. When the particle concentration is greater than 1000 particles / ml, the sensor sends the detected signal to the controller to execute the control logic of automatically closing the electric valve of the main filter channel and opening the electric switching valve of the spare filter channel.

[0012] Preferably, the spare filter channel is equipped with an independent circulation pump, and the spare filter channel is pre-filled with primer before switching.

[0013] Preferably, the alarm device includes a red warning light and a buzzer, and the alarm continues until manually reset.

[0014] Preferably, the temperature in the coating workshop is controlled at 21-25° C., and the humidity is controlled at 45-55% RH.

[0015] Preferably, the interval time from curtain coating to UV curing is ≤ 1 minute.

[0016] Compared with the prior art, the present invention has the following beneficial effects: The filter can intercept large particles of impurities in the paint to prevent these impurities from entering the nozzle and causing blockage, ensuring a stable and continuous coating process. When it detects that there are a large number of particles intercepted in the main channel filter, the system will automatically switch to the backup filter channel to continue production, and at the same time remind manual cleaning of the main channel filter. The problem can be handled without shutting down, ensuring that even if the main filter needs maintenance, the production line can continue to operate, greatly reducing downtime caused by equipment failure. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the local structure of the filtration channel of the present invention; Figure 2A flow chart of a process for forming a paint film according to the present invention; Figure 3 The figure is a flow chart of the coating curtain process of the present invention.

[0018] In the figure: 1. Main filter channel; 2. Backup filter channel; 3. Circulation pump; 4. Main storage tank; 5. Electric switching valve. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] See also Figure 1 , the present invention provides a technical solution.

[0021] A surface treatment process for office furniture panels, characterized by: A. Use E0 grade environmentally friendly board with formaldehyde emission ≤ 0.05mg / m³, remove surface burrs through mechanical sanding, use 80-120 mesh sandpaper to improve flatness, and use vacuum adsorption or compressed air to remove surface dust to ensure that no impurities remain.

[0022] B. The coating uses a water-based UV sealing primer with a solid content of 40-50%, containing nano-scale fillers, such as nano-silica fillers, with strong penetration. A curtain coating machine is used in the coating workshop for uniform curtain coating. The nozzle is 0.15mm slit, the coating pressure is 0.3-0.5MPa, and the film thickness is controlled at 15-20μm. After curtain coating, it enters the leveling area and stands for 30-60 seconds to allow the coating to level naturally. The wind speed is ≤0.5m / s to ensure that the substrate pore closure rate is ≥98% (microscope detection) and the orange peel index is ≤3.0 (BYK instrument measurement).

[0023] In step B, adjust the parallelism between the curtain machine scraper and the substrate conveying line with an error of ≤0.1mm. Use a laser calibrator to calibrate daily to ensure that the curtain covers vertically and evenly. Use compressed air to clean the nozzle with a pressure of 0.4-0.6MPa to avoid paint splashing or curtain breakage. The substrate conveying speed is controlled at 6-8m / min (fine-tuned according to film thickness requirements). The curtain machine nozzle is 15-20mm away from the substrate surface to ensure that the curtain is stable and leak-free. The flow rate is adjusted to 300-500ml / min through the gear pump to match the film thickness requirements (15-20μm wet film). The temperature and humidity in the coating workshop are stabilized at 23±2℃ and 50±5%RH to avoid fluctuations in paint viscosity and abnormal leveling.

[0024] In step B, the solid content of the water-based UV sealing primer is 40-50% (detected by a refractometer) and the viscosity is 25±5cps (25°C, Brookfield viscometer). To ensure curtain stability, a 100-150 mesh filter is used to filter the water-based UV sealing primer to remove foreign particles and prevent nozzle clogging. The paint is heated to 25-30°C in a cycle to reduce viscosity and improve fluidity. The paint temperature close to room temperature reduces the temperature difference with the plate, reduces coating shrinkage stress, and enhances adhesion.

[0025] In step B, align the edge of the sheet with the conveyor line to avoid coating deviation (error ≤ 1mm), start the coating machine, and the coating will evenly cover the surface of the substrate in a continuous curtain to form a 15-20μm wet film. Observe the integrity of the curtain. If there is a break or uneven thickness, stop the machine immediately to check the nozzle or coating flow problem.

[0026] In step B, after curtain coating, let it stand for 30-60 seconds to allow the coating to flow smoothly by gravity and eliminate curtain marks. Keep the leveling area windless to avoid airflow interference causing orange peel or shrinkage. After curtain coating, enter the UV curing stage immediately (interval ≤ 1 minute) to avoid wet film contamination or solvent volatilization affecting the curing effect.

[0027] C. Use high-pressure mercury lamp UV curing machine (wavelength 365nm, energy 800-1200mJ / cm²), curing time 10-15 seconds, so that the primer can be quickly cross-linked into a film with a hardness of more than 2H. UV curing does not require traditional drying process, saving energy consumption by about 40%, while reducing VOC emissions, meeting green production requirements.

[0028] Install an online particle detection sensor, including a laser scattering sensor, on the paint pipeline before the filter to detect the concentration of 0.1-100 μm particles in the paint in real time; Pressure sensing modules are installed at the front and rear ends of the filter to detect the filter pressure difference ΔP; The coating pipeline includes a main filter channel 1 and a spare filter channel 2, both of which are equipped with 100-150 mesh filters. The main and spare channels both use 100-150 mesh filters. The filtration efficiency remains consistent after switching, ensuring that there is no difference in the coating appearance; The paint pipeline is equipped with an electric switching valve 5 for switching the main filter channel 1 and the spare filter channel 2, with a response time of ≤2 seconds, to avoid the loss of production capacity caused by the need to shut down and clean the traditional single-channel filter. The electric switching valve 5 has two branch ports connected to the main filter channel 1 and the spare filter channel 2 respectively, and the main port is connected to the main channel of the paint pipeline; When the laser scattering particle sensor detects that the particle concentration in the paint is greater than 1000 particles / ml, or the pressure sensor detects that the pressure difference before and after the filter (ΔP) is greater than 0.2MPa, the sensor transmits the detected analog signal to the programmable logic controller (PLC). After the PLC receives the signal, the trigger condition is met, and the PLC outputs a control signal to trigger the sound and light alarm to sound an alarm, and at the same time executes the control logic of automatically closing the main filter channel 1 electric valve and opening the standby filter channel 2 electric valve. After the switch is completed, the PLC records the switch time and the reason for triggering the switch (such as too high particle concentration or too large pressure difference) in the internal memory.

[0029] The laser scattering sensor has an accuracy of ±5% and a detection flow range of 0.1-1L / min; the filter is made of 316L stainless steel and the surface is electrochemically polished; The standby channel is equipped with an independent circulation pump 3. The standby filter channel 2 is pre-filled with primer before switching, which is conducive to the automatic pre-filling of the standby filter channel 2 to the system pressure, ensuring that the standby system can quickly and smoothly take over the work of the main system when switching, avoiding production abnormalities caused by pressure fluctuations or fluid interruptions. The circulation pump 3 and the electric switching valve 5 are both connected to the main storage tank 4. The circulation pump 3 and the electric switching valve 5 are connected to the same primer supply source main storage tank 4, rather than their own separate storage containers, to reduce the risk of contamination in the intermediate links.

[0030] The controller adopts Siemens S7-1200 PLC; the human-machine interface (HMI) displays the particle concentration curve and switching history records in real time.

[0031] When the main filter channel 1 and the spare filter channel 2 are switched, the residual paint is introduced into the waste tank. The upper and lower ports of the main filter channel 1 and the spare filter channel 2 are detachably connected to the paint pipeline. When the main filter channel 1 and the spare filter channel 2 are switched, the upper and lower ports are disconnected from the paint pipeline to clean the residual paint inside, or replace the filter. The matching flanges are fastened by bolts and a sealing gasket is clamped in the middle for detachable connection. It can also be composed of two semicircular clamps and a sealing gasket, which are fastened by bolts to form a detachable connection structure. Disassembly and assembly are convenient, and only two bolts need to be loosened.

[0032] The alarm device includes a red warning light and a buzzer (≥85dB), which will continue to alarm until manually reset. It will continue to alarm until manually reset, forcing operators to investigate the cause of excessive particles (such as raw material contamination, filter damage, etc.) to avoid recurrence of the problem.

[0033] The specific solution is: install the online particle detection sensor on the paint pipe in front of the filter to ensure that the sensor can accurately detect the paint particles entering the filter, install the alarm device near the operation panel of the curtain machine, install the PLC and HMI in the control cabinet, and connect the signal lines and power lines of sensors, alarm devices, switching valves and other equipment.

[0034] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A surface treatment process for office furniture panels, characterized in that: The specific steps are as follows: A. The coating is a primer with a solid content of 40-50%, the primer contains nano-scale fillers, and is curtain coated in a coating workshop using a curtain coating machine. The primer is filtered through a 100-150 mesh filter in a coating pipeline connected to the curtain coating machine. The coating pressure is 0.3-0.5MPa, and the substrate conveying speed is 6-8m / min; B. After the curtain coating, it enters the leveling area and leveling for 30-60 seconds, and the wind speed in the leveling area is ≤0.5m / s; C. Use a UV curing machine for UV curing, the curing parameters are wavelength 365nm, energy 800-1200mJ / cm², and curing time 10-15 seconds.

2. The surface treatment process of office furniture sheet material according to claim 1, characterized in that: In step A, the coating flow rate is adjusted to 300-500 ml / min by a gear pump, and the nozzle is 15-20 mm away from the substrate surface.

3. The surface treatment process of office furniture sheet material according to claim 1 is characterized in that: In step A, the coating is heated in a circulation manner to 25-30°C.

4. The surface treatment process of office furniture sheet material according to claim 3 is characterized in that: An online particle detection sensor is installed on the paint pipeline in front of the filter to detect the concentration of 0.1-100μm particles in the paint. When the particle concentration is greater than 1000 particles / ml, the sensor sends the detected signal to the controller to trigger the alarm device.

5. The surface treatment process of office furniture sheet material according to claim 4 is characterized in that: The paint pipeline includes a main filter channel and a spare filter channel, both of which are equipped with 100-150 mesh filters. An electric switching valve for switching the main filter channel and the spare filter channel is installed on the paint pipeline. When the particle concentration is greater than 1000 particles / ml, the sensor sends the detected signal to the controller to execute the control logic of automatically closing the main filter channel electric valve and opening the spare filter channel electric switching valve.

6. The surface treatment process for office furniture sheet material according to claim 5, characterized in that: The spare filter channel is equipped with an independent circulation pump, and the spare filter channel is pre-filled with primer before switching.

7. The surface treatment process for office furniture sheet material according to claim 4 is characterized in that: The alarm device includes a red warning light and a buzzer, which will continue to alarm until manually reset.

8. The surface treatment process for office furniture sheet material according to claim 1, characterized in that: The temperature in the coating workshop is controlled at 21-25℃ and the humidity is controlled at 45-55%RH.

9. The surface treatment process for office furniture sheet material according to claim 1, characterized in that: The interval time from curtain coating to UV curing is ≤1 minute.

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