Drying method and system for acrylic plate processing

Abstract

The invention relates to the technical field of acrylic plate drying, in particular to a drying method and system for acrylic plate processing. The method comprises the following steps: step 1, pretreatment and parameter acquisition: cleaning the surface of a high-precision optical acrylic plate, spraying an anti-moisture absorption coating, and synchronously acquiring the thickness, the initial humidity distribution and the light transmittance reference value of the plate; step 2, dynamic zoning and humidity-temperature coordinated regulation and control; step 3, staged stress collaborative drying; and 4, post-treatment balancing: standing the plate until the environment temperature is balanced, and maintaining trace airflow circulation to inhibit humidity rebound. Through accurate humidity gradient and temperature control, deformation and stress concentration in the acrylic plate machining process can be effectively reduced, and the optical performance and physical stability of a final product are improved. Meanwhile, the accuracy and controllability of the drying process are greatly improved through the multi-sensor configuration and data fusion method of the system, the possible quality problem is avoided, and the production efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of drying acrylic plates, and in particular to a drying method and system for processing acrylic plates. Background Art

[0002] High-precision optical acrylic sheets (such as light guide plates, optical lenses, AR / VR display panels, etc.) have strict requirements on transmittance, refractive index uniformity and surface flatness, and their optical properties are easily affected by environmental humidity. During the processing, insufficient moisture absorption or drying of the sheet will lead to the following problems: Light transmittance attenuation: Residual moisture forms micron-level scattering centers inside the board, causing diffuse reflection of light and reducing light transmittance (especially significant impact on the visible light band of 400-700nm wavelength); Refractive index fluctuation: After moisture absorption, the distribution of hydrogen bonds between acrylic resin molecular chains changes, causing local refractive index differences, resulting in imaging distortion or optical path deviation; Surface microstructure degradation: Non-uniform shrinkage caused by humidity gradients can form microcracks on the nanoimprinted or coated surface, exacerbating light scattering and increasing reflectivity.

[0003] The current drying technology for high-precision optical sheets still has the following bottlenecks: (1) Static humidity field control defects: The traditional process uses a constant humidity field for drying, which cannot adapt to the spatial differences in the thickness and moisture absorption characteristics of the board. For example, the existing technology controls the humidity through uniform hot air circulation, but the edge area loses heat faster, and the actual humidity is significantly higher than the center area, resulting in the light transmittance of the edge of the board being lower than the set percentage compared to the center area, which cannot meet the full-area consistency requirements of optical devices.

[0004] (2) Lack of optical performance monitoring: The existing technology relies on humidity sensors or timing control to determine the drying endpoint, and lacks online monitoring of optical parameters such as transmittance and surface morphology. Summary of the invention

[0005] In order to solve the above problems, the present invention provides a drying method and system for processing acrylic plates, wherein a drying method for processing acrylic plates comprises the following steps: Step 1: Pretreatment and parameter collection: Clean the surface of the high-precision optical acrylic plate and spray an anti-hygroscopic coating, and simultaneously collect the plate thickness, initial humidity distribution and transmittance reference value; Step 2: Dynamic zoning and humidity-temperature coordinated control: According to the thickness and initial humidity distribution data, the drying area is divided into multiple independent sub-areas, and a humidity gradient target value decreasing from the edge to the center is generated. Dynamic humidity regulation is achieved by injecting mixed gas and independent temperature control of the sub-areas; Step 3: Stress-coordinated drying in stages: Rapid dehumidification, homogenization humidity control and final drying calibration are performed in sequence. Internal stress is eliminated through gradient heating, dynamic orientation of guide plates and cooling reverse airflow. The endpoint judgment must simultaneously meet the humidity standard deviation, transmittance deviation and temperature uniformity thresholds. Step 4: Post-treatment balance: Leave the board to balance to ambient temperature and maintain a small amount of air circulation to suppress humidity rebound.

[0006] Preferably, the specific operations of step 1 include: Ultrasonic cleaning and nitrogen purging were used to remove surface impurities and droplets, and the cleaning time was a function of the plate thickness; The surface of the anti-hygroscopic coating is scanned in real time by a laser interferometer. If the local thickness deviation is detected to exceed the set threshold, an offset of the correction path is generated. The offset is calculated by the area and position coordinates of the deviation area. Four sets of high-precision humidity sensors are arranged in the drying box, located at set distances above, below, on the left and on the right of the board, to collect initial humidity distribution data and calculate the standard deviation; Use a non-contact laser thickness gauge to scan the thickness data at intervals along the length of the plate. The scanning interval is dynamically determined by the ratio of the plate area to the thickness. After eliminating the edge distortion data, the average thickness value is calculated. The initial transmittance is measured by a spectrophotometer under a standard light source. During the measurement, the surface of the plate is at a set angle to the light source. The allowable error of the transmittance reference value is dynamically determined by the target optical performance index.

[0007] Preferably, the generation logic of the humidity gradient target value in step 2 includes: If the standard deviation of the initial humidity distribution exceeds the set threshold, the humidity target value of the edge area is set to a set ratio of the humidity in the central area, and the ratio is dynamically determined by the experimental fitting curve of thickness and moisture absorption rate of the board; The mixed gas is a mixture of dry nitrogen and controllable steam in proportion. The mixing ratio is dynamically adjusted according to the difference between the current humidity and the target humidity. The greater the difference, the higher the proportion of nitrogen. The temperature setting value calculation formula for independent heating of each sub-zone is: the difference between the target humidity and the current humidity multiplied by the thickness correction coefficient, and the correction coefficient is generated by the mapping relationship between the humidity difference and the deformation of the plate in the historical production data.

[0008] Preferably, the staged stress-coordinated drying in step 3 includes: Rapid dehumidification stage: start the high wind speed circulation mode, the air flow speed is controlled by the difference ratio between the initial humidity and the target humidity, the greater the difference, the higher the wind speed; the temperature rises in steps, and the temperature rise amplitude in each stage is determined by the inverse product of the current humidity gradient and the thickness, and the humidity gradient is calculated by the ratio of the humidity difference between adjacent sub-areas to the distance; Homogenization and humidity control stage: When the overall humidity of the board drops to the preset critical value, it switches to low wind speed constant temperature mode, and the guide plate switches to horizontal oscillation mode. The oscillation frequency increases linearly with the rate of humidity decrease, and the frequency increase is determined by the product of the rate change amplitude and the thickness; Final drying calibration stage: turn off the heating element and turn on the cooling system. The cooling wind speed is adjusted proportionally according to the thickness. The greater the thickness, the lower the wind speed. The cooling airflow direction is set at an angle opposite to the airflow direction in the drying stage. The reverse angle is determined by the output value of the residual stress distribution model. The model is constructed through the mapping relationship between thickness and historical stress concentration areas.

[0009] Preferably, the method for suppressing local overheating in the rapid dehumidification stage comprises: The temperature distribution on the plate surface is monitored in real time by an infrared thermal imager. If a local temperature mutation area is detected, that is, a continuous area where the temperature change rate exceeds the set threshold, the heating power of the corresponding sub-area is immediately reduced to a set proportion of the initial value, and local airflow acceleration is triggered; The local airflow acceleration time is a function of the area of ​​the mutation region. After the acceleration time is over, the temperature rise amplitude is restored to a set proportion of the original calculated value. The proportion value is determined by the product of the duration and area of ​​the mutation region. If the same sub-zone triggers overheat suppression twice in succession, the temperature of the sub-zone will be locked and an alarm will be triggered.

[0010] Preferably, the oscillation frequency control logic of the homogenization and humidity control stage includes: The initial value of the oscillation frequency is determined by the product of the plate thickness and the current humidity drop rate; The humidity drop rate is monitored in real time. If the rate increases, the oscillation frequency increases in linear proportion to the rate change amplitude. The deformation rate is monitored by an array of strain gauges attached to the diagonal of the plate. If the deformation rate exceeds a threshold, the oscillation frequency is immediately switched to a fixed value, which is determined by the ratio of the deformation rate to the thickness, until the deformation rate returns to below the threshold.

[0011] Preferably, the cooling airflow reverse control in the final drying calibration stage includes: The cooling airflow direction is set at an opposite angle to the airflow direction in the drying stage, and the reverse angle is determined by the output value of the thickness and residual stress distribution model; During the cooling process, the temperature gradient data of the plate surface is collected in real time. If the gradient exceeds the threshold, the reverse angle is adjusted to a set ratio of the current angle. The ratio value is calculated by the area of ​​the gradient exceeding the threshold. A small amount of inert gas is mixed into the cooling air flow, and the proportion of the inert gas is dynamically adjusted by the ratio of the ambient humidity to the moisture absorption rate of the board.

[0012] Preferably, the static balancing method in step 4 comprises: The rest time is obtained by multiplying the ratio of the thickness to the cooling rate by a thermal expansion coefficient correction factor, which is generated by fitting the experimental data of the thermal expansion coefficient of the material; The speed of the trace airflow during the static period is the set ratio of the maximum wind speed in the drying stage, and the ratio value is determined by the ratio of the ambient humidity to the moisture absorption rate of the board; If the local humidity rebound is detected to exceed the threshold during the static process, a short-term high-speed airflow cycle is triggered, and the cycle time is determined by the product of the humidity exceeding the standard and the area of ​​the rebound area.

[0013] Preferably, the multi-parameter joint logic for endpoint determination includes: Collect four sets of humidity sensor data in real time, remove outliers that deviate from the mean beyond the set range, and then calculate the standard deviation; The deviation between the real-time measured value of light transmittance and the reference value must be less than the allowable error, which is dynamically determined by the product of thickness and target light transmittance; The uniformity of the temperature distribution displayed by infrared thermal imaging must satisfy that the standard deviation is less than a threshold value, and the threshold value is generated by the mapping relationship between the plate thickness and the target optical performance.

[0014] Accordingly, an embodiment of the present invention further provides a drying system for processing acrylic plates, which is used to run a drying method for processing acrylic plates according to an embodiment of the present invention, comprising: Preprocessing module: Equipped with ultrasonic cleaning tank, nitrogen purge nozzle and anti-hygroscopic coating spraying device; The spraying device is integrated with a laser interferometer, the optical path of the laser interferometer covers the surface of the plate and is connected to the control module signal for real-time feedback of coating thickness deviation data; The output end of the preprocessing module is connected to the data input interface of the parameter acquisition module.

[0015] Parameter acquisition module: Includes a non-contact laser thickness gauge, four sets of high-precision moisture sensors and a spectrophotometer; The laser thickness gauges are arranged at intervals along the plate conveying track, and their scanning data are transmitted to the control module after edge distortion is eliminated by the filtering unit; The humidity sensors are respectively fixed on the brackets above, below, on the left and on the right of the plate in the drying box, and the sensor group is connected to the control module through a bus; The spectrophotometer is installed at the entrance of the drying box, and its optical probe forms a set angle with the surface of the plate, and the transmittance data is uploaded to the control module in real time; Dynamic control module: It includes a mixed gas injection unit, a zone heating unit and a guide plate driving unit; The mixed gas injection unit is composed of a nitrogen storage tank, a steam generator and a proportional control valve, and the control end of the proportional control valve receives a mixing ratio instruction issued by the control module; The zoned heating unit comprises a plurality of independently temperature-controlled heating sub-zones, each sub-zone is equipped with a temperature sensor and a heater, and the power of the heater is dynamically adjusted by the control module according to the current humidity difference; The deflector driving unit is composed of a servo motor, an angle sensor and a deflector array. The control signal of the servo motor is generated by the adjacent sub-area humidity difference calculation module, and the feedback signal of the angle sensor is transmitted to the control module in real time. Drying execution module: It includes a high-speed circulation fan, a horizontal oscillation mechanism and a cooling system; The speed of the high-speed circulation fan is controlled by the control module according to the initial humidity difference ratio, and its air outlet is connected to the air flow channel of the guide plate array; The horizontal oscillation mechanism is mechanically connected to the guide plate array via an eccentric wheel, and the rotation speed of the eccentric wheel is driven by an oscillation frequency instruction issued by a control module; The cooling system comprises a reverse airflow nozzle and an inert gas mixer, the nozzle angle is adjusted by a servo motor, and the gas proportional valve of the mixer is connected to the control module signal; Control Module: It includes a data fusion unit, a humidity gradient calculation unit and a multi-parameter determination unit; The data fusion unit receives the thickness, humidity and transmittance data from the preprocessing module and the parameter acquisition module, and outputs the data to the humidity gradient calculation unit after removing abnormal values; The humidity gradient calculation unit generates a target gradient curve according to the thickness and the initial humidity distribution, outputs a mixing ratio instruction to the dynamic control module, and sends a sub-area temperature setting value to the sub-area heating unit; The multi-parameter determination unit receives humidity standard deviation, light transmittance deviation and temperature uniformity data in real time, and triggers a drying termination signal when threshold conditions are met at the same time, and the control module turns off the heating unit and starts the cooling system; Connection relationship between modules: The coating thickness deviation data of the pre-processing module is transmitted to the guide plate driving unit of the dynamic control module through the control module; The humidity sensor group data of the parameter acquisition module is processed by the data fusion unit and then input into the humidity gradient calculation unit to generate a mixed gas ratio instruction; The high-speed circulation fan of the drying execution module receives the wind speed command issued by the control module, and the reverse airflow nozzle angle of the cooling system is adjusted by the termination signal of the multi-parameter determination unit; The servo motor control signal of the guide plate driving unit is jointly generated by the humidity gradient calculation unit and the adjacent sub-area humidity difference calculation module, and the angle feedback signal is transmitted back to the data fusion unit of the control module in real time.

[0016] The beneficial effects brought about by the technical solution provided by the embodiment of the present invention include at least: The present invention can make personalized adjustments according to the initial state of the board (such as thickness, humidity, etc.), thereby avoiding the problems of excessive humidity or uneven temperature in traditional methods. Through precise humidity gradient and temperature control, the deformation and stress concentration in the acrylic board processing process can be effectively reduced, and the optical performance and physical stability of the final product can be improved. At the same time, the system's multi-sensor configuration and data fusion method greatly improve the accuracy and controllability of the drying process, avoid possible quality problems, and improve production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 A flowchart of a drying method for processing acrylic plates provided by an embodiment of the present invention; Figure 2 A flowchart of step 1 of a drying method for processing acrylic plates provided in an embodiment of the present invention; Figure 3 This is a structural block diagram of a drying system for acrylic plate processing provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0019] The technical solution of the present invention is described below in conjunction with the accompanying drawings. It is also noted that, in order to make the embodiments more detailed, the following embodiments are the best and preferred embodiments, and those skilled in the art may also adopt other alternatives to implement some known technologies; and the accompanying drawings are only for more specific description of the embodiments, and are not intended to specifically limit the present invention.

[0020] It should be noted that the references to "one embodiment", "embodiment", "exemplary embodiments", "some embodiments" and the like in the specification indicate that the embodiments described may include specific features, structures or characteristics, but not every embodiment may include the specific features, structures or characteristics. In addition, when a specific feature, structure or characteristic is described in conjunction with an embodiment, it should be within the knowledge of a person skilled in the art to implement such feature, structure or characteristic in conjunction with other embodiments (whether or not explicitly described).

[0021] like Figures 1 to 3 As shown, the embodiment of the present invention provides a drying method for processing acrylic plates. In step 1, the surface of the acrylic plate is first cleaned by ultrasonic cleaning and nitrogen purging to remove impurities and droplets on the surface. Then, an anti-hygroscopic coating is sprayed to ensure that the surface of the plate has a moisture-proof function. At the same time, a laser thickness gauge and a humidity sensor are used to monitor the plate in real time to collect the initial thickness, humidity distribution and transmittance reference value of the plate.

[0022] The collected data will be transmitted to the control system to provide basic data support for subsequent humidity and temperature control, and ensure that each acrylic board has consistent initial parameters before processing, avoiding product quality problems caused by uneven processing.

[0023] In step 2, the system divides the drying area into multiple sub-zones according to the thickness and initial humidity distribution of the board, and generates a humidity gradient target value from the edge to the center of the board. The humidity and temperature of each sub-zone will be adjusted by an independently controlled mixed gas injection and temperature control system. The ratio of the mixed gas is dynamically adjusted according to the difference between the current humidity of the board and the target humidity, ensuring that the humidity changes evenly and meets the set target value.

[0024] Dynamic control of the humidity gradient ensures that the board will not be locally over-wet or over-dry during the drying process, avoiding internal stress and deformation caused by uneven humidity distribution. Fine control of this process can improve the uniformity and optical properties of the board.

[0025] In step 3, the process is divided into three stages: rapid dehumidification, homogenization humidity control and final drying calibration. In the rapid dehumidification stage, the moisture on the surface of the board is quickly removed by high wind speed airflow; in the homogenization humidity control stage, the system controls the temperature and humidity in a stable range to ensure that the humidity of the board is gradually balanced; finally, in the final drying calibration stage, the cooling system and reverse airflow adjustment are used to eliminate the residual internal stress to ensure the stability of the board shape and uniform temperature.

[0026] Through humidity control and temperature adjustment at different stages, stress concentration and deformation caused by rapid or uneven changes in temperature and humidity are effectively avoided. This staged control method not only ensures the physical stability of the board, but also improves the light transmittance and optical quality of the product.

[0027] In step 4, after the drying process is completed, the board needs to be left to stand until the ambient temperature is balanced, and the humidity rebound is suppressed by circulating a small amount of airflow. This stage ensures that the board can be stable for a period of time after reaching the target temperature and humidity, avoiding the reabsorption or change of humidity due to changes in the external environment.

[0028] This step further stabilizes the humidity of the board and prevents humidity rebound caused by environmental changes after the drying process, allowing the board to maintain its excellent performance and stability during long-term use.

[0029] Through this series of steps and precise parameter control, it can ensure that every link in the acrylic sheet processing process is fully optimized, thereby effectively improving production stability, efficiency and the quality of the final product.

[0030] In one possible implementation, a combination of ultrasonic cleaning and nitrogen purging is used to thoroughly clean the surface of the acrylic sheet. Ultrasonic cleaning can effectively remove tiny impurities, oil stains and moisture attached to the surface of the sheet, while nitrogen purging can quickly remove droplets remaining on the surface. The cleaning time is dynamically determined according to the thickness of the sheet, which means that thicker sheets require longer cleaning time to ensure that the cleanliness meets the requirements.

[0031] The coordinated use of ultrasonic waves and nitrogen purge can ensure that the surface of the acrylic sheet reaches a highly clean state before drying, thereby reducing quality problems caused by surface impurities during the drying process.

[0032] The surface of the anti-hygroscopic coating is scanned in real time using a laser interferometer to detect the uniformity of the coating thickness. If the local thickness deviation is found to exceed the preset threshold during the scanning process, the system will generate a correction path offset, and the offset is calculated based on the area and position coordinates of the deviation area. Based on this data, the control system will adjust the distribution of the coating or re-apply it.

[0033] This precise scanning and correction mechanism ensures the uniformity of the anti-hygroscopic coating, avoids inaccurate humidity control or inconsistent hygroscopic properties of the board surface caused by uneven coating, and further improves the stability of the drying process.

[0034] Four sets of high-precision humidity sensors are placed in the drying box, located above, below, on the left and right sides of the board and fixed at set distances. These sensors can collect the initial humidity distribution data of each area of ​​the board in real time. The system then calculates the standard deviation based on the humidity data to understand whether the humidity distribution is uniform.

[0035] By accurately monitoring the humidity at different locations of the board, the humidity distribution of the board can be obtained before drying, providing basic data support for subsequent humidity control and avoiding quality problems caused by uneven humidity.

[0036] Use a non-contact laser thickness gauge to scan along the length direction of the sheet to measure the thickness data of the sheet. The scanning interval is dynamically determined according to the ratio of the area to the thickness of the sheet to ensure that sufficient dense thickness data can be obtained on large-area sheets. During scanning, the system will eliminate the distorted data at the edges to ensure the accuracy of the thickness data and calculate the average thickness value of the entire sheet.

[0037] Through high-precision laser thickness measurement technology, the thickness data of the sheet can be obtained in real time, and inaccurate edge data can be eliminated to ensure that the thickness value of each sheet can accurately reflect its actual situation. This provides data support for the temperature and humidity adjustment caused by thickness differences during the subsequent drying process.

[0038] Use a spectrophotometer to measure the initial light transmittance of the acrylic sheet under a standard light source. During measurement, the angle between the surface of the sheet and the light source needs to be maintained within a preset range. The reference value error of the light transmittance is dynamically adjusted according to the target optical performance standard to ensure that the measured light transmittance meets the requirements.

[0039] By accurately measuring the initial light transmittance and setting a reasonable allowable error range, it is ensured that the optical performance of the sheet reaches the design standard. This detection provides a reference basis for maintaining the consistency of the light transmittance during the subsequent drying process.

[0040] In a possible implementation, first, the system measures the initial humidity distribution. If its standard deviation exceeds a preset threshold, it indicates that the humidity distribution is uneven. In order to optimize the humidity gradient during the drying process, the system sets a target humidity value for the edge area of the sheet. Specifically, the humidity target value for the edge area is set to a certain proportion of the humidity in the central area. This proportion is dynamically determined through an experimental fitting curve of the thickness and the moisture absorption rate of the sheet. Based on these data, the humidity distribution characteristics in different thickness regions can be deduced to achieve reasonable humidity control.

[0041] By setting the relative proportion of the humidity target value in the edge area to the humidity in the central area, the humidity distribution of the sheet can be effectively adjusted, avoiding the concentration of humidity in a certain area, which may lead to unstable sheet quality. This regulation of the humidity gradient is particularly important for the drying of large-area sheets, which can ensure uniform drying and reduce deformation and defects.

[0042] During the drying process, the system uses a mixed gas of dry nitrogen and controllable steam as the main drying medium. The proportion of the mixed gas is dynamically adjusted according to the difference between the current humidity and the target humidity. Specifically, when the difference is large, the system increases the proportion of nitrogen because nitrogen has a strong drying effect; when the difference is small, the proportion of controllable steam is increased, and the moistening effect of steam can effectively adjust the humidity.

[0043] By monitoring the humidity difference in real time and adjusting the gas ratio, the system can accurately control the humidity in the drying environment to avoid over-drying or insufficient humidity. This flexible gas ratio adjustment ensures the stability of the drying process and reduces the fluctuation of board quality caused by environmental instability.

[0044] For different plate sub-areas (such as the center area and the edge area), the temperature setting value is calculated based on the difference between the target humidity and the current humidity. The specific calculation formula is: the difference between the target humidity and the current humidity multiplied by the thickness correction factor. This correction factor is generated by the mapping relationship between the humidity difference and the plate deformation in the historical production data. Based on the accumulation of historical data, the correction factor can reflect the response characteristics of different thickness areas to the temperature and humidity differences during the drying process.

[0045] By dynamically calculating the temperature setting value and applying the thickness correction factor, the temperature of different thickness areas can be accurately controlled. This adjustment can effectively control the deformation of the board and avoid quality problems such as warping and cracking caused by excessively high or low temperatures in thicker or thinner areas during the drying process.

[0046] In one possible implementation, the staged stress-coordinated drying in step 3 is dynamically adjusted according to multivariate factors such as humidity, temperature, and thickness through a refined drying control mode, so as to minimize stress concentration and deformation of the board during the drying process.

[0047] Specifically, in the rapid dehumidification stage, the system starts the high wind speed circulation mode. The airflow speed is set by the difference ratio between the initial humidity and the target humidity. The larger the difference, the more obvious the humidity difference, and the system will increase the wind speed to quickly remove surface moisture; conversely, if the humidity difference is small, the wind speed will be reduced to avoid over-drying. During this process, the temperature gradually rises, and the temperature rise is carried out in a step-by-step manner. The temperature rise in each stage is determined by the product of the current humidity gradient and the inverse of the plate thickness. The humidity gradient is calculated by the ratio of the humidity difference and the distance between adjacent sub-areas to ensure that the humidity differences of different thicknesses and areas are effectively eliminated.

[0048] By adjusting the wind speed and temperature rise, the moisture discharge and the evaporation rate of the water on the board surface can be accurately controlled to avoid local overdrying or uneven humidity, and prevent the board from deforming or cracking. The focus of this stage is to quickly and evenly reduce the humidity, laying the foundation for the subsequent homogenization and humidity control stage.

[0049] When the overall humidity of the board drops to a preset critical value, the system automatically switches to low wind speed constant temperature mode. In this mode, the airflow speed is low to avoid excessive airflow causing unnecessary stress on the board surface. The guide plate switches to horizontal oscillation mode, and the oscillation frequency increases linearly according to the humidity drop rate. The frequency increase is related to the product of the humidity drop rate and thickness. That is, when the humidity drop rate is faster, the frequency increase is larger to ensure uniform moisture distribution and avoid uneven stress.

[0050] Through the combination of low wind speed and oscillation mode, the humidity distribution can be evenly adjusted under constant temperature, especially for areas with uneven thickness, to maintain the balance of humidity and temperature and reduce deformation or cracks caused by humidity differences.

[0051] At the end of the drying process, the system turns off the heating element and starts the cooling system for cooling. The cooling air speed is inversely proportional to the thickness of the plate. The thicker the plate, the lower the cooling air speed. The direction of the cooling airflow is set at an angle opposite to the airflow direction during the drying process. The magnitude of this angle is output by the residual stress distribution model, which is constructed by mapping the thickness to the stress concentration area in the historical production data.

[0052] By setting the reverse angle and controlling the cooling speed related to the thickness, the residual stress can be effectively eliminated to avoid the warping or deformation of the plate during the cooling process. The cooling process combines the analysis of the plate thickness and historical stress distribution to make the cooling process more accurate and further improve the final quality of the plate.

[0053] This staged stress-coordinated drying method can significantly improve the quality of acrylic sheets, reduce deformation, cracks and other problems through meticulous process control and dynamic adjustment, and achieve an efficient and high-quality production process.

[0054] In a possible implementation, the local overheating suppression method in the rapid dehumidification stage prevents local overheating through precise temperature control and dynamic adjustment, thereby ensuring uniform temperature distribution during the drying process and avoiding overheating.

[0055] Specifically, first, the temperature distribution on the surface of the acrylic board is monitored in real time through an infrared thermal imager. The system will detect the temperature mutation area, that is, the continuous area where the temperature change rate exceeds the set threshold. This process ensures that the area of ​​abnormal temperature change can be quickly discovered to avoid the occurrence of overheating areas. The infrared thermal imager can monitor the temperature changes at different locations on the surface of the board with high precision, provide temperature data in real time, and provide a basis for subsequent control measures.

[0056] This monitoring process can efficiently and accurately capture abnormal local temperature changes, prevent overheating problems caused by improper temperature control, and avoid damage to the plate caused by excessively concentrated temperatures.

[0057] Furthermore, once a mutation area is detected, the system will immediately reduce the heating power of the area to a set ratio of the initial value and trigger local airflow acceleration at the same time. Specifically, the airflow acceleration time is a function of the area of ​​the mutation area. The larger the area, the longer the airflow acceleration time. Airflow acceleration can accelerate the heat dissipation of the local area and quickly reduce the temperature, thereby preventing local overheating from affecting the board.

[0058] By reducing the heating power and accelerating the airflow, the local temperature can be quickly stabilized, reducing the thermal stress caused by the rapid temperature rise, avoiding local deformation, cracks or uneven drying. This control strategy effectively suppresses the risk of local overheating while maintaining the uniformity of drying of the entire board.

[0059] After the local overheating problem is effectively suppressed, the system will gradually restore the temperature rise to the set ratio of the original calculated value after the accelerated airflow ends. This recovery ratio is determined by the product of the duration and area of ​​the mutation area, that is, the longer the duration and the larger the mutation area, the smaller the recovery ratio, ensuring that new overheating problems will not be caused by too fast recovery.

[0060] This recovery ratio control based on duration and area can smoothly restore the temperature to a predetermined level, avoiding excessive stress concentration or plate deformation caused by a sudden temperature rise after overheating.

[0061] If the same sub-zone triggers overheat suppression operations twice in a short period of time, the system will automatically lock the temperature of the sub-zone and trigger an alarm. At this time, the relevant operators can promptly detect and adjust the equipment parameters or processes to avoid overheating problems in the area again.

[0062] The alarm mechanism can promptly alert operators to abnormal conditions and make adjustments to prevent overheating areas from affecting the overall drying effect. The locking mechanism ensures that the area will not continue to heat for a short period of time, effectively avoiding mistakes in temperature control.

[0063] Through precise temperature monitoring and dynamic control, the local overheating suppression method effectively ensures the temperature uniformity of acrylic sheets during the drying process, improves the quality and production efficiency of the sheets, reduces losses caused by overheating, and improves the reliability and safety of the overall production process.

[0064] In a possible implementation, the oscillation frequency control logic in the homogenization and humidity control stage controls the humidity drop rate and deformation of the board by dynamically adjusting the oscillation frequency, thereby ensuring the uniformity of the drying process and the quality of the board.

[0065] Specifically, the initial value of the oscillation frequency is determined by the product of the thickness of the plate and the current rate of humidity decrease. Specifically, the thicker the plate is, the faster the rate of humidity decrease is, and the initial oscillation frequency should be appropriately reduced; conversely, when the plate is thinner, the rate of humidity decrease is slower, and the oscillation frequency should be appropriately increased.

[0066] By considering the relationship between the thickness of the board and the rate of humidity drop, the system can set an initial reasonable oscillation frequency for each batch of production. In this way, the oscillation frequency can be adjusted according to the characteristics of different boards to ensure the uniformity of the drying process and avoid uneven or too fast humidity drop due to inappropriate frequency, thereby ensuring the quality of the final product.

[0067] During the entire drying process, the system monitors the rate of humidity decrease in real time. If the rate of humidity decrease increases, the oscillation frequency will increase in linear proportion to the humidity change. Specifically, when the humidity decreases rapidly, increasing the oscillation frequency can enhance air flow and improve water evaporation efficiency, thereby accelerating the drying process.

[0068] This mechanism of dynamically adjusting the oscillation frequency can effectively avoid the problem of surface cracking or uneven drying of the board caused by the humidity decreasing too quickly. At the same time, the increase in oscillation frequency can increase the contact frequency between air and the board surface, thereby accelerating the discharge of moisture and improving drying efficiency.

[0069] The system monitors the deformation rate of the plate in real time through an array of strain gauges attached to the diagonal of the plate. If the deformation rate exceeds the set threshold, the system will immediately switch the oscillation frequency to a fixed value. This fixed value is determined by the ratio of the deformation rate to the thickness of the plate. The system will not resume dynamic adjustment of the oscillation frequency until the deformation rate returns to below the threshold.

[0070] When the deformation rate exceeds the threshold, it means that the board may produce stress concentration due to uneven drying, resulting in deformation or cracking. By switching the oscillation frequency to a fixed value, the rapid changes in temperature and humidity during the drying process can be reduced, thereby avoiding further deformation and ensuring the structural stability of the board.

[0071] When the deformation rate returns to below the threshold, the oscillation frequency will return to the dynamic adjustment mode according to factors such as humidity drop rate and sheet thickness. This adjustment ensures that after the deformation problem is suppressed, the system can return to the normal drying rhythm and continue to control humidity.

[0072] This recovery mechanism ensures that when the plate is deformed, the drying process can be slowed down in time to avoid the deformation expansion. When the deformation problem is solved, the oscillation frequency returns to normal regulation, effectively maintaining the continuity and efficiency of the drying process.

[0073] The oscillation frequency control logic effectively controls the rate of humidity decrease and the risk of sheet deformation through precise dynamic adjustment and real-time response, optimizes the drying process of acrylic sheets, improves production efficiency and product quality, and ensures uniform drying and morphological stability of the sheets.

[0074] In a possible implementation, the cooling air flow reverse control mechanism in the final drying calibration stage ensures temperature uniformity during the cooling process and inhibits sheet deformation by dynamically adjusting the air flow direction, angle, and gas composition.

[0075] Specifically, in the cooling stage, the direction of the cooling air flow is set at a reverse angle to the air flow direction in the drying stage. This reverse angle is determined by the output value of the sheet thickness and residual stress distribution model. The residual stress distribution model calculates the stress concentration areas that may cause deformation by analyzing the temperature and humidity changes during the drying process of the sheet, thereby setting an appropriate reverse air flow angle to avoid sheet deformation caused by uneven temperature.

[0076] By setting the reverse angle according to the output value of the residual stress distribution model, it can be ensured that the air flow during the cooling process can effectively counteract the internal stress formed in the sheet during the drying process, reducing the risk of sheet deformation caused by excessive temperature gradient. This dynamic adjustment of air flow reverse control helps to improve the uniformity of the cooling process and ensure the stability of the sheet during the cooling process.

[0077] During the cooling process, the system real-time collects the temperature gradient data on the sheet surface. If it is found that the temperature gradient exceeds the set threshold, the system will adjust the reverse angle of the cooling air flow according to the area of the gradient exceeding the standard area. The adjustment ratio is calculated by the area of the gradient exceeding the standard area, that is, if the temperature non-uniform area is larger, the reverse angle adjustment ratio will be larger, so as to better balance the temperature distribution during the cooling process.

[0078] By real-time monitoring the temperature gradient and adjusting the reverse angle according to the area of the exceeding standard area, the system can accurately control the distribution of the cooling air flow, avoiding stress concentration and deformation caused by excessive local cooling. This step ensures the uniformity of the temperature distribution on the sheet surface during the cooling process and reduces problems such as warping and cracking of the sheet caused by uneven cooling.

[0079] Mix a small amount of inert gas, such as nitrogen or argon, into the cooling air flow to reduce the humidity of the air flow and improve the control accuracy of the cooling process. The proportion of the inert gas is dynamically adjusted by the ratio of the ambient humidity and the moisture absorption rate of the sheet. If the ambient humidity is high, the system will increase the proportion of the inert gas, thereby reducing the condensation of water vapor and improving the cooling efficiency; if the ambient humidity is low, the proportion of the inert gas will be correspondingly reduced.

[0080] The introduction of inert gas can reduce the humidity fluctuation of the air during the cooling process, avoid the condensation of water vapor on the surface of the plate due to excessive humidity, and thus reduce the impact of surface moisture on the plate. The proportion of inert gas is dynamically adjusted according to the changes in ambient humidity and moisture absorption rate, so that the cooling process can adapt to the external environment in real time and maintain the stability and efficiency of the cooling process.

[0081] The reverse control of cooling airflow ensures the temperature uniformity, humidity control accuracy and deformation suppression of the sheet during the cooling process through multi-level adjustment measures, effectively improving the quality and production efficiency of acrylic sheets.

[0082] In one possible implementation, the static balance method in step 4 is intended to optimize the drying process by regulating the static time, trace air flow velocity, and short-term high-speed air flow cycle, thereby ensuring uniform drying of the acrylic sheet and reducing deformation caused by uneven humidity.

[0083] Specifically, the static balance method in step 4 is intended to optimize the drying process by regulating the static time, trace air flow velocity and short-term high-speed air flow cycle, to ensure uniform drying of the acrylic sheet and reduce deformation caused by uneven humidity. Among them, the thermal expansion coefficient correction factor is generated by fitting the experimental data of the thermal expansion coefficient of the material. According to experimental data, the thermal expansion coefficient of the material will affect the dimensional change of the material during temperature changes, thereby affecting the static time. Thicker plates or slower cooling rates will require longer static time to ensure that the temperature of the plate reaches equilibrium and avoid stress during the cooling process.

[0084] By calculating the rest time based on the ratio of thickness to cooling rate, the duration of the rest process can be controlled more accurately. For sheets of different thicknesses and cooling rates, the appropriate rest time ensures that the acrylic sheet can cool down evenly, thereby effectively reducing thermal stress and deformation, and ensuring the quality of the processed sheet.

[0085] During the static period, the speed of the trace airflow is set as a ratio of the maximum wind speed during the drying stage. The ratio is determined by the ratio of the ambient humidity to the moisture absorption rate of the board. If the ambient humidity is high or the moisture absorption rate of the board is fast, the ratio of the trace airflow will be adjusted accordingly to reduce the airflow speed to avoid the fast wind flow causing the surface to dry too quickly, resulting in a large temperature difference between the inside and outside, and increasing the risk of deformation.

[0086] By adjusting the speed of the micro-airflow, the air flow during the static period can be controlled to reduce the difference in surface and internal humidity caused by over-drying. The appropriate airflow speed can promote the uniform evaporation of surface moisture without excessively accelerating the drying process, thereby ensuring the temperature and humidity balance of the board and avoiding warping or cracking due to uneven drying.

[0087] During the static process, if the local humidity rebound is detected to exceed the preset threshold, the system will trigger a short-term high-speed airflow cycle. The duration of this cycle is determined by the product of the humidity exceeding the standard and the area of ​​the humidity rebound area. Specifically, in areas with more severe humidity rebound and larger areas, a longer high-speed airflow cycle will be activated to quickly remove moisture from the area to avoid moisture accumulation and local uneven drying.

[0088] By triggering a short high-speed airflow cycle, local humidity rebound can be effectively controlled to prevent it from affecting the surface of the board. After the area with excessive humidity is treated with a short high-speed airflow, the uniformity of temperature and humidity can be restored, thus ensuring the overall stability of the board during the static period. This process helps to maintain the quality of the board and avoid deformation or uneven drying caused by humidity rebound.

[0089] In one possible implementation, the multi-parameter joint logic for endpoint determination combines humidity sensor data, light transmittance measurement values, and infrared thermal imaging temperature distribution to comprehensively determine whether the drying process has reached the end standard. The collaborative work of these parameters ensures that the quality and performance of the acrylic sheet during the drying process meet the expected requirements.

[0090] Specifically, data from four groups of humidity sensors are collected in real time, and after removing outliers that deviate from the mean value beyond the set range, their standard deviation is calculated. Humidity sensors are used to monitor humidity changes on the surface of acrylic boards. Removing outliers can ensure data accuracy and avoid misjudgments caused by occasional interference or sensor failure.

[0091] The collection of humidity sensor data and the calculation of standard deviation help monitor the drying of the board in real time. The smaller the standard deviation, the more uniform the humidity change and the more stable the drying process. If the standard deviation is large, it means that there is uneven humidity in some parts of the board, which may mean that the drying is not complete and needs to be continued.

[0092] The transmittance of the acrylic sheet is measured in real time and compared with the set reference value. The allowable error range is dynamically determined by the product relationship between the thickness of the sheet and the target transmittance. The transmittance reflects the optical properties of the acrylic sheet. The appropriate transmittance means the degree of drying is appropriate.

[0093] As a key indicator of optical performance, light transmittance directly affects the use effect of the board. By dynamically adjusting the allowable error value and determining the accuracy of the end point judgment according to the thickness of the board and the target light transmittance, it can ensure that the transparency and optical performance of the board remain in an ideal state during the drying process, avoiding light transmittance discrepancies caused by excessive or insufficient drying.

[0094] Infrared thermal imaging technology is used to monitor the temperature distribution of acrylic plates in real time, requiring the standard deviation of the temperature distribution to be less than a set threshold. The threshold is generated by the mapping relationship between the thickness of the plate and the target optical performance. Through infrared imaging, it is possible to quickly determine whether there are local overheating or unheated areas on the plate.

[0095] Temperature uniformity is a critical factor in the drying process. Uneven temperature may cause different drying degrees between the surface and the inside of the board, causing deformation or uneven stress. By controlling the standard deviation not to exceed the set threshold, it can ensure that the temperature of each part of the board is balanced during the drying process, and ultimately achieve good drying results.

[0096] By real-time monitoring of humidity, light transmittance and temperature distribution, combined with multi-parameter joint logic judgment, this method can more accurately control the drying process and ensure high-quality drying of acrylic sheets during processing. This not only improves production efficiency, but also ensures the optical performance and uniformity of the product.

[0097] Accordingly, an embodiment of the present invention further provides a drying system for processing acrylic plates, which is used to run a drying method for processing acrylic plates according to an embodiment of the present invention, comprising: Preprocessing module: Equipped with ultrasonic cleaning tank, nitrogen purge nozzle and anti-hygroscopic coating spraying device; The spraying device is integrated with a laser interferometer, the optical path of the laser interferometer covers the surface of the plate and is connected to the control module signal for real-time feedback of coating thickness deviation data; The output end of the preprocessing module is connected to the data input interface of the parameter acquisition module.

[0098] Parameter acquisition module: Includes a non-contact laser thickness gauge, four sets of high-precision moisture sensors and a spectrophotometer; The laser thickness gauges are arranged at intervals along the plate conveying track, and their scanning data are transmitted to the control module after edge distortion is eliminated by the filtering unit; The humidity sensors are respectively fixed on the brackets above, below, on the left and on the right of the plate in the drying box, and the sensor group is connected to the control module through a bus; The spectrophotometer is installed at the entrance of the drying box, and its optical probe forms a set angle with the surface of the plate, and the transmittance data is uploaded to the control module in real time; Dynamic control module: It includes a mixed gas injection unit, a zone heating unit and a guide plate driving unit; The mixed gas injection unit is composed of a nitrogen storage tank, a steam generator and a proportional control valve, and the control end of the proportional control valve receives a mixing ratio instruction issued by the control module; The zoned heating unit comprises a plurality of independently temperature-controlled heating sub-zones, each sub-zone is equipped with a temperature sensor and a heater, and the power of the heater is dynamically adjusted by the control module according to the current humidity difference; The deflector driving unit is composed of a servo motor, an angle sensor and a deflector array. The control signal of the servo motor is generated by the adjacent sub-area humidity difference calculation module, and the feedback signal of the angle sensor is transmitted to the control module in real time. Drying execution module: It includes a high-speed circulation fan, a horizontal oscillation mechanism and a cooling system; The speed of the high-speed circulation fan is controlled by the control module according to the initial humidity difference ratio, and its air outlet is connected to the air flow channel of the guide plate array; The horizontal oscillation mechanism is mechanically connected to the guide plate array via an eccentric wheel, and the rotation speed of the eccentric wheel is driven by an oscillation frequency instruction issued by a control module; The cooling system comprises a reverse airflow nozzle and an inert gas mixer, the nozzle angle is adjusted by a servo motor, and the gas proportional valve of the mixer is connected to the control module signal; Control Module: It includes a data fusion unit, a humidity gradient calculation unit and a multi-parameter determination unit; The data fusion unit receives the thickness, humidity and transmittance data from the preprocessing module and the parameter acquisition module, and outputs the data to the humidity gradient calculation unit after removing abnormal values; The humidity gradient calculation unit generates a target gradient curve according to the thickness and the initial humidity distribution, outputs a mixing ratio instruction to the dynamic control module, and sends a sub-area temperature setting value to the sub-area heating unit; The multi-parameter determination unit receives humidity standard deviation, light transmittance deviation and temperature uniformity data in real time, and triggers a drying termination signal when threshold conditions are met at the same time, and the control module turns off the heating unit and starts the cooling system; Connection relationship between modules: The coating thickness deviation data of the pre-processing module is transmitted to the guide plate driving unit of the dynamic control module through the control module; The humidity sensor group data of the parameter acquisition module is processed by the data fusion unit and then input into the humidity gradient calculation unit to generate a mixed gas ratio instruction; The high-speed circulation fan of the drying execution module receives the wind speed command issued by the control module, and the reverse airflow nozzle angle of the cooling system is adjusted by the termination signal of the multi-parameter determination unit; The servo motor control signal of the guide plate driving unit is jointly generated by the humidity gradient calculation unit and the adjacent sub-area humidity difference calculation module, and the angle feedback signal is transmitted back to the data fusion unit of the control module in real time.

[0099] The present invention covers any substitution, modification, equivalent method and scheme made on the essence and scope of the present invention. In order to make the public have a thorough understanding of the present invention, specific details are described in detail in the preferred embodiments of the present invention, but those skilled in the art can fully understand the present invention without the description of these details. In addition, in order to avoid unnecessary confusion about the essence of the present invention, well-known methods, processes, procedures, components and circuits are not described in detail.

[0100] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A drying method for acrylic plate processing, characterized in that: The following steps are involved: Step 1: Pretreatment and parameter collection: Clean the surface of the high-precision optical acrylic plate and spray an anti-hygroscopic coating, and simultaneously collect the plate thickness, initial humidity distribution and transmittance benchmark value; Step 2: Dynamic zoning and humidity-temperature coordinated control: According to the thickness and initial humidity distribution data, the drying area is divided into multiple independent sub-areas, and a humidity gradient target value decreasing from the edge to the center is generated. Dynamic humidity regulation is achieved by injecting mixed gas and independent temperature control of the sub-areas; Step 3: Stress-coordinated drying in stages: Rapid dehumidification, homogenization humidity control and final drying calibration are performed in sequence. Internal stress is eliminated through gradient heating, dynamic orientation of guide plates and cooling reverse airflow. The endpoint judgment must simultaneously meet the humidity standard deviation, transmittance deviation and temperature uniformity thresholds. Step 4: Post-processing balance: Let the board stand until the ambient temperature is balanced, and maintain a small amount of air circulation to suppress humidity rebound.

2. The drying method for acrylic plate processing according to claim 1, characterized in that: The specific operations of step 1 include: Ultrasonic cleaning and nitrogen purging were used to remove surface impurities and droplets, and the cleaning time was a function of the plate thickness; The surface of the anti-hygroscopic coating is scanned in real time by a laser interferometer. If the local thickness deviation is detected to exceed the set threshold, an offset of the correction path is generated. The offset is calculated by the area and position coordinates of the deviation area. Four sets of high-precision humidity sensors are arranged in the drying box, located at set distances above, below, on the left and on the right of the board, to collect initial humidity distribution data and calculate the standard deviation; Use a non-contact laser thickness gauge to scan the thickness data at intervals along the length of the plate. The scanning interval is dynamically determined by the ratio of the plate area to the thickness. After eliminating the edge distortion data, the average thickness value is calculated. The initial transmittance is measured by a spectrophotometer under a standard light source. During the measurement, the surface of the plate is at a set angle to the light source. The allowable error of the transmittance reference value is dynamically determined by the target optical performance index.

3. The drying method for acrylic plate processing according to claim 2, characterized in that: The generation logic of the humidity gradient target value in step 2 includes: If the standard deviation of the initial humidity distribution exceeds the set threshold, the humidity target value of the edge area is set to a set ratio of the humidity in the central area, and the ratio is dynamically determined by the experimental fitting curve of thickness and moisture absorption rate of the board; The mixed gas is a mixture of dry nitrogen and controllable steam in proportion. The mixing ratio is dynamically adjusted according to the difference between the current humidity and the target humidity. The greater the difference, the higher the proportion of nitrogen. The temperature setting value calculation formula for independent heating of each sub-zone is: the difference between the target humidity and the current humidity multiplied by the thickness correction coefficient, and the correction coefficient is generated by the mapping relationship between the humidity difference and the deformation of the plate in the historical production data.

4. The drying method for processing acrylic plates according to claim 3, characterized in that: The staged stress-coordinated drying in step 3 includes: Rapid dehumidification stage: start the high wind speed circulation mode, the air flow speed is controlled by the difference ratio between the initial humidity and the target humidity, the greater the difference, the higher the wind speed; the temperature rises in steps, and the temperature rise amplitude in each stage is determined by the inverse product of the current humidity gradient and the thickness, and the humidity gradient is calculated by the ratio of the humidity difference between adjacent sub-areas to the distance; Homogenization and humidity control stage: When the overall humidity of the board drops to the preset critical value, it switches to low wind speed constant temperature mode, and the guide plate switches to horizontal oscillation mode. The oscillation frequency increases linearly with the rate of humidity decrease, and the frequency increase is determined by the product of the rate change amplitude and the thickness; Final drying calibration stage: turn off the heating element and turn on the cooling system. The cooling wind speed is adjusted proportionally according to the thickness. The greater the thickness, the lower the wind speed. The cooling airflow direction is set at an angle opposite to the airflow direction in the drying stage. The reverse angle is determined by the output value of the residual stress distribution model. The model is constructed through the mapping relationship between thickness and historical stress concentration areas.

5. The drying method for processing acrylic plates according to claim 4, characterized in that: The local overheating suppression method in the rapid dehumidification stage comprises: The temperature distribution on the plate surface is monitored in real time by an infrared thermal imager. If a local temperature mutation area is detected, that is, a continuous area where the temperature change rate exceeds the set threshold, the heating power of the corresponding sub-area is immediately reduced to a set proportion of the initial value, and local airflow acceleration is triggered; The local airflow acceleration time is a function of the area of ​​the mutation region. After the acceleration time ends, the temperature rise amplitude is restored to a set proportion of the original calculated value. The proportion value is determined by the product of the duration and area of ​​the mutation region. If the overheat suppression is triggered twice in a row in the same sub-zone, the temperature of the sub-zone will be locked and an alarm will be triggered.

6. The drying method for processing acrylic plates according to claim 4, characterized in that: The oscillation frequency control logic of the homogenization and humidity control stage includes: The initial value of the oscillation frequency is determined by the product of the plate thickness and the current humidity drop rate; The humidity drop rate is monitored in real time. If the rate increases, the oscillation frequency increases in linear proportion to the rate change amplitude. The deformation rate is monitored by an array of strain gauges attached to the diagonal of the plate. If the deformation rate exceeds a threshold, the oscillation frequency is immediately switched to a fixed value, which is determined by the ratio of the deformation rate to the thickness, until the deformation rate returns to below the threshold.

7. The drying method for processing acrylic plates according to claim 4, characterized in that: The cooling airflow reverse control in the final drying calibration stage includes: The cooling airflow direction is set at an opposite angle to the airflow direction in the drying stage, and the reverse angle is determined by the output value of the thickness and residual stress distribution model; During the cooling process, the temperature gradient data of the plate surface is collected in real time. If the gradient exceeds the threshold, the reverse angle is adjusted to a set ratio of the current angle. The ratio value is calculated by the area of ​​the gradient exceeding the threshold. A small amount of inert gas is mixed into the cooling air flow, and the proportion of the inert gas is dynamically adjusted by the ratio of the ambient humidity to the moisture absorption rate of the board.

8. The drying method for processing acrylic plates according to claim 1, characterized in that: The static balancing method in step 4 comprises: The rest time is obtained by multiplying the ratio of the thickness to the cooling rate by a thermal expansion coefficient correction factor, which is generated by fitting the experimental data of the thermal expansion coefficient of the material; The speed of the trace airflow during the static period is the set ratio of the maximum wind speed in the drying stage, and the ratio value is determined by the ratio of the ambient humidity to the moisture absorption rate of the board; If the local humidity rebound is detected to exceed the threshold during the static process, a short-term high-speed airflow cycle is triggered, and the cycle time is determined by the product of the humidity exceeding the standard and the area of ​​the rebound area.

9. The drying method for processing acrylic plates according to claim 1, characterized in that: The multi-parameter joint logic of endpoint determination includes: Collect four sets of humidity sensor data in real time, remove outliers that deviate from the mean beyond the set range, and then calculate the standard deviation; The deviation between the real-time measured value of transmittance and the reference value must be less than the allowable error, which is dynamically determined by the product of thickness and target transmittance; The uniformity of the temperature distribution displayed by infrared thermal imaging must satisfy that the standard deviation is less than a threshold value, and the threshold value is generated by the mapping relationship between the plate thickness and the target optical performance.

10. A drying system for processing acrylic plates, used for running the drying method for processing acrylic plates according to any one of claims 1 to 9, characterized in that: include: Preprocessing module: Equipped with ultrasonic cleaning tank, nitrogen purge nozzle and anti-hygroscopic coating spraying device; The spraying device is integrated with a laser interferometer, the optical path of the laser interferometer covers the surface of the plate and is connected to the control module signal for real-time feedback of coating thickness deviation data; The output end of the preprocessing module is connected to the data input interface of the parameter acquisition module; Parameter acquisition module: Includes a non-contact laser thickness gauge, four sets of high-precision humidity sensors and a spectrophotometer; The laser thickness gauges are arranged at intervals along the plate conveying track, and their scanning data are transmitted to the control module after edge distortion is eliminated by the filtering unit; The humidity sensors are respectively fixed on the brackets above, below, on the left and on the right of the plate in the drying box, and the sensor group is connected to the control module through a bus; The spectrophotometer is installed at the entrance of the drying box, and its optical probe forms a set angle with the surface of the plate, and the transmittance data is uploaded to the control module in real time; Dynamic control module: It includes a mixed gas injection unit, a zone heating unit and a guide plate driving unit; The mixed gas injection unit is composed of a nitrogen storage tank, a steam generator and a proportional control valve, and the control end of the proportional control valve receives a mixing ratio instruction issued by the control module; The zoned heating unit comprises a plurality of independently temperature-controlled heating sub-zones, each sub-zone is equipped with a temperature sensor and a heater, and the power of the heater is dynamically adjusted by the control module according to the current humidity difference; The deflector driving unit is composed of a servo motor, an angle sensor and a deflector array. The control signal of the servo motor is generated by the adjacent sub-area humidity difference calculation module, and the feedback signal of the angle sensor is transmitted to the control module in real time. Drying execution module: It includes a high-speed circulation fan, a horizontal oscillation mechanism and a cooling system; The speed of the high-speed circulation fan is controlled by the control module according to the initial humidity difference ratio, and its air outlet is connected to the air flow channel of the guide plate array; The horizontal oscillation mechanism is mechanically connected to the guide plate array via an eccentric wheel, and the rotation speed of the eccentric wheel is driven by an oscillation frequency instruction issued by a control module; The cooling system comprises a reverse airflow nozzle and an inert gas mixer, the nozzle angle is adjusted by a servo motor, and the gas proportional valve of the mixer is connected to the control module signal; Control Module: It includes a data fusion unit, a humidity gradient calculation unit and a multi-parameter determination unit; The data fusion unit receives the thickness, humidity and transmittance data from the preprocessing module and the parameter acquisition module, and outputs the data to the humidity gradient calculation unit after removing abnormal values; The humidity gradient calculation unit generates a target gradient curve according to the thickness and the initial humidity distribution, outputs a mixing ratio instruction to the dynamic control module, and sends a sub-area temperature setting value to the sub-area heating unit; The multi-parameter determination unit receives humidity standard deviation, light transmittance deviation and temperature uniformity data in real time, and triggers a drying termination signal when threshold conditions are met at the same time, and the control module turns off the heating unit and starts the cooling system; Connection relationship between modules: The coating thickness deviation data of the pre-processing module is transmitted to the guide plate driving unit of the dynamic control module through the control module; The humidity sensor group data of the parameter acquisition module is processed by the data fusion unit of the control module and then input into the humidity gradient calculation unit to generate a mixed gas ratio instruction; The high-speed circulation fan of the drying execution module receives the wind speed command issued by the control module, and the reverse airflow nozzle angle of the cooling system is adjusted by the termination signal of the multi-parameter determination unit; The servo motor control signal of the guide plate driving unit is jointly generated by the humidity gradient calculation unit of the control module and the adjacent sub-area humidity difference calculation module, and the angle feedback signal is transmitted back to the data fusion unit of the control module in real time.

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