A fine automatic spraying process method for microcrystalline electromagnetic stove panel

Abstract

The application provides a fine automatic spraying process method for a microcrystalline electromagnetic oven panel, establishes and executes a dynamic quality control system with "atomization state prediction-key parameter cooperative locking-exceptional state closed loop reset" as the main line, and sequentially comprises the following steps: S1. Production preparation and parameter cooperative setting; S2. Fine adjustment of the medicine water system and pressure cooperation; S3. Quantitative image-based atomization quality online calibration and closed loop feedback; S4. Automatic spraying and online inspection; S5. Anti-damage directional flow based on a special fixture; S6. System state consistency intelligent recovery method based on process data backtracking. The stability, consistency and anti-interference ability of the spraying process are fundamentally improved, and continuous production with high quality and high yield is realized.

Description

Technical Field

[0001] This invention relates to the field of surface treatment technology, specifically to a refined automatic spraying process for microcrystalline induction cooker panels, and more particularly to an automated spraying system and method integrating dynamic quality control. Background Technology

[0002] As a core material for high-end induction cooker panels, microcrystalline glass requires an anti-fingerprint (AF) coating to improve aesthetics, ease of cleaning, and scratch resistance. Currently, the industry commonly uses automated spraying processes for AF coating. However, in actual large-scale production, this process faces a series of persistent technical challenges, severely restricting product yield and production stability.

[0003] First, the instability of atomization is the core pain point. The atomization quality of the spray gun is affected by various factors such as air pressure, paint viscosity, temperature, and equipment wear, resulting in slow drift. Traditional methods rely on operator experience for offline manual adjustments (such as spraying on a glass plate for observation), which is not only inefficient and inconsistent in standards, but also cannot achieve real-time monitoring and closed-loop correction during production, leading to poor coating uniformity and microscopic defects such as "snowflake spots" and "orange peel texture".

[0004] Secondly, there is a lack of systematic coordination among process parameters. Key parameters such as preheating temperature, spraying speed, line conveyor speed, and solvent flow rate are usually set and monitored independently. However, these parameters collectively determine the spreading, wetting, and solvent evaporation kinetics of the solvent on the glass-ceramic surface. Isolated parameter control results in a narrow process window, poor adaptability to environmental and material fluctuations, and a high susceptibility to macroscopic defects such as poor flow or leveling due to improper parameter matching.

[0005] Furthermore, the recovery process after production anomalies is often crude and uncontrollable. After unexpected interruptions such as power outages or emergency shutdowns, the traditional approach is often to simply remove or re-coat and re-bake the products in the interrupted area. This ignores the complex impact of the interruption on system thermal balance, material continuity, and the product's "thermal history." In particular, for products remaining in the oven, their curing process has been interrupted; re-baking using standard procedures may result in insufficient curing or over-baking, creating hidden quality risks and causing significant waste.

[0006] Finally, there is insufficient protection for the irregularly shaped structure of the microcrystalline panel during transfer. The coating on the edges of the panel, such as openings and button holes, is not cured after spraying. During the transfer between processes, the edge coating is easily damaged by manual handling or bumps from ordinary jigs. In addition, inconsistent placement orientation may affect the uniformity of the baking heat field.

[0007] Therefore, existing technologies lack a systematic solution that integrates process parameter prediction and collaborative locking, online atomization state calibration and closed-loop feedback, and intelligent recovery from abnormal interruptions. There is an urgent need for a refined, automated spraying process method that can ensure coating quality stability across the entire chain, from "source prediction, process control, and abnormal reset." Summary of the Invention

[0008] To overcome the shortcomings of existing technologies, this invention provides a refined automated spraying process for microcrystalline induction cooker panels. This invention aims to establish and implement a dynamic quality control system based on "atomization state prediction - key parameter collaborative locking - abnormal state closed-loop reset." Through multi-parameter collaboration, online image calibration, and data-driven recovery mechanisms, it fundamentally improves the stability, consistency, and anti-interference capabilities of the spraying process, achieving high-quality, high-yield continuous production.

[0009] This invention provides a refined automatic spraying process method for microcrystalline induction cooker panels. It establishes and executes a dynamic quality control system based on "atomization state prediction - key parameter collaborative locking - abnormal state closed-loop reset." This system relies on an integrated platform of Manufacturing Execution System (MES) and Programmable Logic Controller (PLC) / Distributed Control System (DCS), and all key process data form a traceable process data package. The system includes the following steps in sequence:

[0010] S1. Production preparation and parameter coordination settings:

[0011] a. Verify order and product information through the MES system and retrieve the corresponding process formula;

[0012] b. Set baking parameters: The baking temperature for the first AF coating is 180℃±10℃, and the time is 30min±3min;

[0013] c. Check and adjust the main air pressure to 0.6-0.8 MPa;

[0014] d. Multi-parameter coordinated setting of the spraying line: To accurately control the spreading kinetics and solvent evaporation rate of the chemical on the microcrystalline glass surface and avoid "snowflake" defects, the following parameters need to be coordinated, locked, and dynamically compensated:

[0015] Panel preheating temperature: Preheat the panel to 50±5℃. This temperature range has been experimentally verified to effectively reduce the surface tension of the microcrystalline glass, increase surface energy, and reduce the contact angle of the solvent by approximately 15%-25%, thereby promoting rapid spreading. Preferably, the preheating temperature setting can be dynamically compensated according to the ambient humidity. For every 10% increase in ambient humidity above the standard value (50%RH), the preheating temperature setting is increased by 1-2℃ to stabilize the solvent evaporation rate.

[0016] AP Axis Movement Speed: The automatic spraying (AP) axis movement speed is controlled at 850±50 mm / s. This speed is matched with the preset chemical flow rate (S2d). Through a calculation model of the area covered per unit time (coverage = flow rate / (speed × spray width)), the theoretical deviation of the chemical deposition per unit area is ensured to be less than ±3%. After changing paint batches or major maintenance, online calibration is required: spray a test panel at a fixed AP speed, measure the actual deposition per unit area, and then reverse-calibrate the flow meter display value to ensure consistency between the theoretical model and the actual result.

[0017] The conveyor speed is set at 0.9 ± 0.1 meters per minute. This speed, in conjunction with the aforementioned preheating temperature, determines the dwell time of the panel in the spraying area, thus confining the solvent evaporation process within the "optimal evaporation window."

[0018] S2. Fine-tuning and pressure coordination of the medicine system:

[0019] a. Add the specified type of AF coating to the pressure tank and set the automatic replenishment amount to 5kg per cycle;

[0020] b. Dual-tank pressure stabilization system: To ensure absolute stability of liquid supply and suppress pressure pulsation, differentiated pressure settings are adopted for the main and backup tanks.

[0021] b1. The pressure of the main drug tank is set to 0.15±0.05 MPa to provide a stable basic fluid flow.

[0022] b2. The pressure of the backup medicine tank is set to 0.20±0.05 MPa as a high-pressure compensation source. When the system detects that the pressure drop in the main tank exceeds the set threshold of 0.02 MPa, it automatically switches or mixes the liquid supply to ensure that the pressure fluctuation at the spray gun inlet is less than ±0.01 MPa.

[0023] c. Spray gun parameter scaling: For AF coatings with a specific viscosity (35-45 cP at 25℃), set the spray gun shut-off pressure to 0.40±0.05 MPa and the atomizing pressure to 0.20±0.05 MPa, maintaining a fixed ratio of approximately 2:1. This ratio produces a suitable atomized particle size distribution (Dv50 approximately 20-40 μm) and a stable atomization cone angle (approximately 60°-80°) for this type of fluid. Set the spray gun spacing to ≥150 mm to avoid fog field interference.

[0024] d. Flow monitoring and calibration: The flow rate of the medicine in each spray gun is precisely adjusted to 30±4 ml / min, and real-time visual monitoring and recording are performed using a high-precision transparent flow meter.

[0025] S3. Online calibration and closed-loop feedback of fogging quality based on quantized images:

[0026] After each shift begins, critical component replacement, or system recovery from an outage, an online atomization quality calibration procedure is performed, converting offline atomization status detection into automatic calibration signals for online process parameters. The system supports two calibration modes:

[0027] Rapid calibration mode: Compare the features of the spot image generated by the current test spray with the template image stored from the last qualified calibration. If the image similarity is >95% and the key process parameters have not changed, the calibration is deemed to have passed.

[0028] Deep calibration mode: Activated when changing paint, gun cap, or when quick calibration fails; specifically: place a standard A4-sized yellow colorimetric plate in a fixed position below the spray gun; the colorimetric plate is for single use or driven by an automatic paper feeding mechanism to ensure a clean area is used for each calibration.

[0029] Start the spray gun and perform a short test spray (0.5 seconds).

[0030] Images of fogged spots on a colorimetric plate are acquired using an industrial image sensor, and the distribution of spot diameter and spatial density is analyzed in real time by an algorithm. The acceptable standard is that the spot diameter is concentrated in the range of 0.5-2.0mm, and the distribution density difference within the effective area of ​​the plate is ≤10%.

[0031] Closed-loop feedback: If the analysis results are not up to standard, the control system automatically generates adjustment instructions and feeds them back to the atomizing air pressure or flow regulating valve in S2. Within the safe range (air pressure ±0.02 MPa, flow rate ±2 ml / min), automatic fine-tuning is performed. The system cyclically executes the "test spray-collection-analysis-adjustment" process until the image features meet the preset standards.

[0032] S4. Automated spraying and online inspection:

[0033] a. The calibrated spray gun system and the panel to be coated will be put into automatic spraying operation. The coating thickness will be between 3-5μm through precise path control of the AP axis.

[0034] b. After spraying, the machine vision system performs online automatic visual inspection in the high-light inspection section, focusing on checking for macroscopic defects such as color difference, stripes, and snowflake patterns. The results are then uploaded to the MES system.

[0035] S5. Damage-resistant directional transfer based on modular fixtures:

[0036] The design utilizes a modular turnover fixture; the fixture is equipped with an adjustable adaptive contouring block, the position of which can be quickly adjusted and locked according to the contour of the non-painted support area of ​​different panel models, and the pneumatic interface is a standard part; the fixture pneumatically clamps and rotates the panel with the painted surface facing upwards and the opening markings facing a uniform and fixed direction, avoiding manual contact with the painted surface and ensuring consistent baking heat field conditions.

[0037] S6. Intelligent recovery method for system state consistency based on process data backtracking:

[0038] When production is interrupted unexpectedly, the following intelligent recovery process will be executed:

[0039] a. Interruption point data acquisition: After power is restored, the system automatically reads and records the actual temperature curve inside the baking oven, the position of the product in the spraying machine, and the final stable pressure value of the chemical system from the PLC / DCS at the time of the interruption, and stores them in the MES.

[0040] b. Product Status Classification and Handling:

[0041] b1. Products that are stuck in the painting area should be sent out and then put back into the starting point of the production line.

[0042] b2. For products stuck in the baking oven, calculate their thermal history based on the recorded temperature curve; the system dynamically generates a compensatory baking scheme according to the following strategies: a conservative strategy of extending the standard holding time by 20% is preferred; the heating rate adjustment scheme based on the thermal history deviation model is only activated when the interruption occurs during the heating stage and the calculation shows that the core temperature of the product has exceeded 80% of the glass transition temperature (Tg) of the coating.

[0043] c. System parameter consistency reconfirmation: After completing product handling, perform a two-level recovery confirmation:

[0044] Level 1 Confirmation: The system automatically checks whether the real-time readings of key sensors (main air pressure, panel preheating temperature, main medicine tank pressure) are within the standard range set by S1 and S2.

[0045] Level 2 confirmation: The atomization quality must be recalibrated online via S3 (fast calibration mode should be activated first).

[0046] Formal processing can only resume after both levels of confirmation have been passed.

[0047] The beneficial effects of this invention are as follows:

[0048] 1. Through S3's online image calibration and closed-loop feedback, the difficult-to-quantify "atomization state" is transformed into measurable and adjustable process parameters, achieving a consistent "zeroing" of the production starting state and curbing quality variation from the source.

[0049] The system achieves systematic coordination and dynamic compensation of parameters: S1 emphasizes the physical correlation between preheating temperature, AP speed and linear speed, and introduces environmental humidity compensation and model calibration process, making the process window wider and the anti-interference ability stronger.

[0050] 2. S6's data-backtracking-based compensation baking strategy balances processing effectiveness and operational risks, avoiding the blind spots of traditional methods. The tiered recovery confirmation mechanism improves recovery efficiency while ensuring safety.

[0051] 3. The modular fixture design of the S5 reduces tooling costs and shortens product changeover time. End-to-end MES integration enables data traceability, providing a data foundation for continuous process optimization.

[0052] 4. This invention systematically solves the problems of stability, uniformity and consistency in AF spraying of microcrystalline panels through a self-consistent dynamic quality control system, which is expected to significantly reduce the defect rate and improve production efficiency and product yield. Detailed Implementation

[0053] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.

[0054] The method described in this invention is applicable to modern production lines equipped with automatic spraying systems (including AP axes), preheating devices, baking ovens, MES and PLC / DCS control systems.

[0055] Implementation example: Take the AF1 DB301G-10% coating for spraying a certain model of microcrystalline induction cooker panel as an example.

[0056] Production Start-up: The operator selects the corresponding product formula on the MES terminal, and the system automatically loads the parameter settings for step S1 (preheating 50℃, AP speed 850mm / s, line speed 0.9m / min, etc.).

[0057] System Calibration: Perform S3 depth calibration. Place a new yellow colorimetric plate, spray the spray gun for 0.5 seconds, and image analysis shows a spot density difference of 15% (>10% standard). The system automatically adjusts the atomizing pressure by +0.01 MPa, and performs another test spray analysis. The density difference decreases to 8%, and the calibration is passed. Parameters and qualified image templates are stored in the system.

[0058] Normal production: After preheating, the panels enter the spraying area, where spray guns spray according to the calibrated settings and the S4 path. Flow meters monitor in real time, and a dual-tank pressure system provides stable liquid supply. After spraying, the panels are fixed by modular fixtures and flow in a uniform direction to the high-intensity light inspection section. After machine vision inspection confirms no defects, they are sent to the baking oven.

[0059] Anomaly Recovery: Assume a brief power outage occurs after 2 hours of production. After system recovery: Automatically read the interruption data: The temperature curve of a certain area inside the baking oven shows an interruption at the 120℃ heat preservation section.

[0060] Product handling: Panels stuck in the spraying area are brought back online. Panels stuck in the oven are determined by the system to have entered the heat preservation stage, and a strategy of "extending the standard heat preservation time by 20%" is adopted for compensatory baking.

[0061] System verification: Level 1 verification found that all sensor readings were normal; Level 2 verification initiated S3 rapid calibration, and the similarity to the template before the interruption reached 97%, so it passed directly. Subsequently, the production line resumed fully automated operation.

[0062] Throughout the process, all set parameters, calibration results, interruption data, compensation schemes, and test results are uploaded to the MES database in real time, forming a complete digital process archive.

[0063] The embodiments described above merely illustrate the preferred implementation of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A refined automatic spraying process for microcrystalline induction cooker panels, characterized in that, Establish and implement a dynamic quality control system based on "atomization state prediction - key parameter collaborative locking - abnormal state closed-loop reset", which includes the following steps: S1. Production preparation and parameter setting: Verify information and set baking parameters, main air pressure, panel preheating temperature, AP axis moving speed and conveyor speed in a coordinated manner; S2. Fine-tuning and pressure coordination of the chemical system: When adding paint, a dual-tank pressure coordination system is used to stabilize the liquid supply. The shut-off air pressure of the spray gun and the atomizing air pressure are set to maintain a ratio of approximately 2:1, and the flow rate of the chemical is monitored and adjusted. S3. Online calibration and closed-loop feedback of atomization quality based on quantitative images: After the start of the shift, replacement of parts or resumption of interruption, the system performs test spraying, collects and analyzes atomization spot images, and automatically adjusts the atomization pressure or flow rate if the atomization status does not meet the standard until the atomization status meets the standard. S4. Automated spraying and online inspection: Spraying is performed using a calibrated system, and online defect inspection of the coating is conducted. S5. Damage-proof directional transfer based on dedicated clamps: The panel is held and transferred in a fixed posture using clamps; S6. Intelligent recovery method for system state consistency based on process data backtracking: After the interruption is recovered, the interruption data is collected, the affected products are classified and dealt with, and the system parameters are reconfirmed before production is resumed.

2. The refined automatic spraying process method for microcrystalline induction cooker panels according to claim 1, characterized in that, In S1, the panel preheating temperature is set to 50±5℃, and this setting is dynamically compensated according to the ambient humidity: for every 50%RH 10% increase in ambient humidity above the standard value, the preheating temperature setting is increased by 1-2℃.

3. The refined automatic spraying process method for microcrystalline induction cooker panels according to claim 1, characterized in that, In S1, the AP axis moving speed and the chemical flow rate are matched by a unit time coverage area calculation model. After changing the paint batch or major maintenance, an online calibration process is performed: the test plate is sprayed at a fixed AP speed, and the flow meter display value is calibrated by measuring the actual deposition amount per unit area.

4. The refined automatic spraying process method for microcrystalline induction cooker panels according to claim 1, characterized in that, The online calibration step in S3 supports two modes: Quick calibration mode: Compare the current test spray image with the template image stored from the last successful calibration. If the similarity is >95% and the key parameters have not changed, then it passes. Depth calibration mode: Activated when changing paint, gun cap or when rapid calibration fails, to execute a complete calibration process including closed-loop feedback adjustment; the depth calibration uses a disposable or automatically fed yellow colorimetric plate.

5. The refined automatic spraying process method for microcrystalline induction cooker panels according to claim 1, characterized in that, In the S3 depth calibration mode, the qualified standard is: the diameter of the atomized spots is concentrated in the range of 0.5-2.0mm, and the distribution density difference in the effective area of ​​the plate surface is ≤10%.

6. The refined automatic spraying process method for microcrystalline induction cooker panels according to claim 1, characterized in that, The dedicated turnover fixture in S5 is modularly designed, and the position of its contoured support block can be quickly adjusted and locked according to the contour of the non-painted support area of ​​different panel models.

7. The refined automatic spraying process method for microcrystalline induction cooker panels according to claim 1, characterized in that, In S6, the method for handling products stuck in the baking oven is as follows: calculate their thermal history based on the recorded interruption point temperature curve, and prioritize the strategy of extending the standard holding time by 20% for compensatory baking; only when the interruption occurs during the heating stage and the core temperature of the product has exceeded 80% of the glass transition temperature (Tg) of the coating, will the heating rate adjustment scheme based on the thermal history deviation model be activated.

8. The refined automatic spraying process method for a microcrystalline induction cooker panel according to claim 1, characterized in that, The system parameter consistency reconfirmation in S6 is a two-level confirmation: Level 1 Confirmation: Automatically checks whether the real-time readings of key sensors are within the standard range; Secondary confirmation: Recalibrate the atomization quality online via S3; Production can only resume after both levels of confirmation have been passed.

9. A refined automatic spraying process method for a microcrystalline induction cooker panel according to claim 1, characterized in that, In the dual-tank pressure stabilization system, the pressure of the main tank is set to 0.15±0.05 MPa, and the pressure of the backup tank is set to 0.20±0.05 MPa. When the system detects that the pressure drop of the main tank exceeds 0.02 MPa, it automatically switches or mixes the liquid supply to ensure that the pressure fluctuation at the spray gun inlet is less than ±0.01 MPa.

10. A refined automatic spraying process method for a microcrystalline induction cooker panel according to claim 1, characterized in that, The method relies on an integrated platform of manufacturing execution system and programmable logic controller / distributed control system. All key process data are automatically uploaded to the MES database to form a traceable process data package.