Multi-stage electrostatic dust collection and self-cleaning method for printing-down machine

Abstract

The invention discloses a multi-stage electrostatic dust collection and self-cleaning method for a printing down machine, which comprises the following steps of: dynamically pre-collecting dust, analyzing the characteristics of a material by terahertz spectrum, and generating turbulent flow by bionic fish scale-shaped flow deflectors; carrying out gradient electrostatic adsorption, and carrying out multi-stage electric field polarization, charging, particle adsorption, dust collection pole plate sensing monitoring, pulse blowback and polarity switching self-cleaning; activating plasma, generating radio frequency by a double-frequency generator to resonate with microwave, injecting mixed gas to activate, and monitoring spectrum in real time; intelligent vacuum suction, sensing and height adjustment of a silica gel suction nozzle, particle adhesion reduction through ultrasonic waves, temperature control through a micro-channel and vacuum degree adjustment through a variable frequency pump are achieved; and when the supercritical CO2 is used for cleaning and the efficiency is reduced, liquid CO2 is injected, supercritical fluid is formed through temperature rise and pressure rise, an auxiliary agent is added, stubborn pollutants are removed by virtue of a pulsed electric field, and CO2 is recycled. According to the invention, material self-adaptive processing, tracing and 5G remote operation and maintenance are realized through a terahertz spectrum analysis and control system, the quality control and fault response speed is improved, and the overall technical index reaches a leading level.

Description

Technical Field

[0001] This invention relates to the field of dust removal technology for plate exposure machines, and more particularly to a multi-stage electrostatic dust removal and self-cleaning method for printing plate exposure machines. Background Technology

[0002] In the printing plate-making process, the precise removal of dust particles is crucial for ensuring plate quality. Traditional single-stage dust removal technologies (such as cyclone dust collectors and single electrostatic adsorption) struggle to address the challenge of submicron-level contamination: when particle size is less than 5μm, dust removal efficiency is generally below 70%, and drops even further to below 50% in the 0.1-1μm range, resulting in dot distortion exceeding 3% and persistently high scrap rates during plate exposure. One packaging and printing company, using traditional electrostatic dust collectors to process PET film, experienced a 5.2% scrap rate due to 0.5μm toner residue, resulting in annual losses exceeding 2 million yuan. Furthermore, traditional airflow dust collectors consume up to 12.5 kWh / hour and have poor adaptability to curved materials (such as flexographic rollers), with dust uniformity deviations exceeding ±15%.

[0003] Systemic deficiencies exist in equipment maintenance and pollution control. After 48 hours of continuous operation, traditional dust collection plates experience a more than 30% decrease in electric field strength due to dust accumulation, requiring manual disassembly and cleaning. Each maintenance session takes over 4 hours, and annual maintenance costs account for 40% of the equipment investment. In one newspaper printing workshop, the failure to clean the plates in a timely manner led to a sharp drop in electrostatic dust removal efficiency, forcing maintenance shutdowns every two days and a 15% decrease in production efficiency. Simultaneously, the annual disposal volume of hazardous waste generated by solvent cleaning processes (such as cleaning solutions containing benzene compounds) reaches 20 tons, resulting in high environmental compliance costs. Furthermore, solvent residue can easily lead to uneven coating of the photosensitive emulsion on the printing plates, affecting the consistency of printed colors.

[0004] The intelligent and dynamic adaptability capabilities are severely lacking. Existing dust removal systems mostly operate with fixed parameters, failing to adapt to different materials (such as paper, film, and metal plates). When handling high surface energy materials (such as aluminum plates), excessive electrostatic adsorption leads to material damage; when handling low charge mobility materials (such as newsprint), low charging efficiency results in incomplete dust removal. A label printing company experienced dot-matrix smudging in three consecutive batches of printing plates due to a failure to adjust parameters in time when switching materials, resulting in a loss of approximately 80,000 yuan. Furthermore, the lack of real-time monitoring and predictive maintenance functions means there are no warnings before equipment failures, leading to an 8% sudden downtime rate that severely impacts production plans. Summary of the Invention

[0005] The present invention proposes a multi-stage electrostatic dust removal and self-cleaning method for printing plate exposure machines to solve the problems mentioned in the prior art.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a multi-stage electrostatic dust removal and self-cleaning method for a printing plate exposure machine, comprising: Step 1, Dynamic Pre-dust Removal Stage: The material to be exposed is transported to the dust removal chamber, and the adaptive airflow pre-dust removal system is started. The particle distribution on the material surface is detected in real time by a laser particle size analyzer. The turbulent air field generated by the variable frequency fan is adjusted. Vibrating guide vanes driven by piezoelectric ceramics are set in the air field to make the airflow form a biomimetic fish scale scouring path to improve the dust removal efficiency of particles. Step 2, Gradient Electrostatic Adsorption Stage: A three-level gradient electric field design is adopted. First, the material surface is polarized by the primary electric field, then the particles are charged by the intermediate electric field, and finally the particles are adsorbed by the non-uniform electric field. The dust collection plate adopts a micro-nano composite structure with a carbon nanotube array on the surface, which increases the adsorption capacity by 5 times. At the same time, a pulse backflush module is set up to release a high-pressure CO2 pulse every 15 minutes for self-cleaning of the plate. Step 3, Plasma Activation Dust Removal Stage: A dual-frequency plasma generator is used to generate mixed-frequency plasma, forming a high-energy ion cloud on the material surface, causing the chemical bonds of stubbornly adsorbed organic pollutants to break; at the same time, an active gas with an O3 concentration of 10-20 ppm is injected to perform micro-etching activation on the material surface, reducing the adhesion of micro-dust and simultaneously achieving surface hydrophilic modification, reducing the contact angle from 90° to 45°. Step 4, Vacuum Suction Stage: Ultrasonic-assisted vacuum suction technology is adopted. The slit nozzle has an built-in ultrasonic transducer, and the generated standing wave field causes the micro dust particles to resonate and detach. At the same time, the nozzle adopts a deformable flexible structure. The contact force with the material surface is monitored in real time by a pressure sensor. The constant pressure is maintained to achieve seamless suction of curved materials. The vacuum degree can be dynamically adjusted within the range of 0.03-0.12MPa. Step 5, Supercritical CO2 Deep Cleaning Stage: When a decrease in dust collection system efficiency is detected, the system automatically switches to supercritical cleaning mode: the pressure in the dust removal chamber is increased to 8 MPa, the temperature is controlled at 35°C, liquid CO2 is injected and heated to the critical point to form a supercritical fluid that circulates and cleans the entire system; surfactants are added to the supercritical CO2 to generate 10 through the Venturi effect. 6 Pa cavitation microjets perform non-destructive cleaning of micro / nano structured plates, and the CO2 is recovered after depressurization separation.

[0007] Furthermore, it also includes: Before step one, a terahertz spectroscopy analysis module is set up to perform composition analysis on the printing material and establish a material property database. During the dust removal process, the central control system dynamically adjusts the parameters of each stage according to the material properties: for high surface energy materials, the electric field strength in step two is increased; for low charge mobility materials, the plasma treatment time is increased in step three.

[0008] In the gradient electric field system of step two, a quantum tunneling enhanced electrode design is adopted: a 5nm thick boron nitride quantum dot layer is deposited on the electrode surface, which improves the electron emission efficiency by utilizing the quantum tunneling effect and reduces the operating voltage; the dust collection plate adopts a capacitive self-cleaning structure, which uses electrostatic repulsion to make the adsorbed particles automatically fall into the collection tank by periodically changing the polarity of the plate, without the need for external mechanical vibration.

[0009] Furthermore, it also includes: In the plasma activation process of step three, microwave plasma resonance technology is introduced: the plasma resonance frequency of the material is found by frequency scanning, and the plasma density generated in the resonance state is increased by 5 times, and the energy utilization rate is improved; at the same time, the plasma generator has a built-in optical emission spectrum monitoring module to analyze the plasma composition in real time and automatically adjust the gas ratio to achieve targeted removal of different pollutants.

[0010] In the vacuum suction system of step four, magnetorheological fluid sealing technology is adopted. The edge of the suction nozzle is filled with magnetorheological fluid, and the viscosity of the fluid is adjusted by the external magnetic field strength to form a dynamic sealing boundary. At the same time, a microchannel condensation system is set inside the suction nozzle. When high-temperature materials are detected, 10°C coolant is introduced for heat exchange to prevent sealing failure caused by thermal expansion.

[0011] Furthermore, it also includes: In the supercritical CO2 cleaning stage of step five, pulsed electric field enhancement technology is combined: during the supercritical fluid circulation process, a pulsed electric field with a frequency of 1-10kHz and a field strength of 5kV / cm is applied to destroy the molecular structure of stubborn pollutants using the electroporation effect; at the same time, the cleaning system adopts a modular design to realize the replacement of cleaning modules with different functions.

[0012] Throughout the dust removal process, a holographic particle image velocimetry (PIV) system is set up to monitor the airflow field distribution in real time. The flow field data is analyzed through deep learning algorithms to dynamically optimize the guide vane angle and fan speed. At the same time, surface potential dynamic compensation technology is adopted, which uses an array of surface potential sensors to monitor the surface charge distribution of materials in real time. When a local potential anomaly is detected, the discharge parameters of the ion fan bar are automatically adjusted.

[0013] Furthermore, it also includes: In each of steps one through five, an online Raman spectroscopy detection module is set up to analyze the composition and concentration of residual pollutants on the material surface in real time; when the concentration of a specific pollutant exceeds a threshold, a targeted treatment procedure is automatically triggered.

[0014] After the supercritical cleaning in step five, a low-temperature plasma drying technology is used to reduce the chamber pressure to 0.1 MPa and introduce an Ar / O2 mixed gas to generate low-temperature plasma. The high-energy particles in the plasma break the hydrogen bonds between water molecules to achieve drying. During the drying process, the material temperature is monitored in real time by infrared thermal imaging to prevent deformation caused by local overheating.

[0015] Furthermore, it also includes: A quality traceability system is set up to record complete data for each dust removal process, including operating parameters, pollutant detection results, and equipment status, forming an unalterable digital twin archive. At the same time, the dust removal effect is analyzed in real time through edge computing units to establish a predictive maintenance model, provide early warning of potential faults, and automatically generate maintenance work orders. It also supports 5G remote control, allowing operators to obtain the equipment's operating status in real time through augmented reality devices for remote operation and maintenance.

[0016] Compared with existing technologies, the beneficial effects of this invention are: The dynamic pre-dust removal stage adopts a biomimetic fish scale airflow design, which enables a 98.2% removal rate for particles larger than 30μm, laying the foundation for subsequent fine dust removal. Gradient electrostatic adsorption combined with quantum tunneling electrodes and carbon nanotube plates increases the removal rate of 0.5μm particles to 99.95%, and the overall dust removal efficiency reaches 99.98%. The plate-making scrap rate is reduced from 3.2% to 0.08%. After application, a large printing company saves more than 5 million yuan in waste plate costs annually.

[0017] Significant reductions in energy consumption and maintenance costs have been achieved. Dual-frequency plasma resonance technology reduces processing power by 30%, and the intelligent vacuum suction system, aided by ultrasound, lowers energy consumption to 2.7 kWh / hour, resulting in an overall system energy consumption reduction of 35.2% compared to traditional solutions. Supercritical CO2 cleaning technology achieves a 99% CO2 recovery rate with no hazardous waste emissions, saving 1.4 million yuan in annual environmental costs. Capacitive self-cleaning plates and predictive maintenance systems extend the maintenance cycle from once a week to once a month, reducing maintenance hours by 87.5%. After implementation, a newspaper group reduced its annual operation and maintenance costs by 800,000 yuan.

[0018] The system significantly enhances intelligence and adaptability. The terahertz spectroscopy analysis module matches material characteristics in real time and automatically adjusts parameters such as electric field strength and plasma power, keeping dust removal efficiency fluctuations within ±1.5% when switching between PET film and newsprint. The blockchain quality traceability system ensures tamper-proof recording of data throughout the entire process, and the 5G remote operation and maintenance function reduces fault response time from 4 hours to 20 minutes. A packaging and printing company used this system to remotely optimize dust removal parameters, increasing product yield to 99.92% and shortening order delivery cycles by 25%, demonstrating the integrated advantages of "high efficiency, low consumption, and intelligence." Attached Figure Description

[0019] Figure 1 This is a schematic block diagram of the multi-stage electrostatic dust removal and self-cleaning method for printing plate exposure machines proposed in this invention; Figure 2 This is a schematic diagram of the supercritical CO2 cleaning cycle energy efficiency of the multi-stage electrostatic dust removal and self-cleaning method for printing plate exposure machines proposed in this invention. Figure 3 This is a schematic diagram comparing the full life cycle costs of the multi-stage electrostatic dust removal and self-cleaning method for printing plate making machines proposed in this invention. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0022] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. Furthermore, the terms "installed," "connected," and "linked" should be interpreted broadly; for example, they may refer to a fixed connection, a detachable connection, or an integral connection; they may refer to a mechanical connection or an electrical connection; they may refer to a direct connection or an indirect connection through an intermediate medium; and they may refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. The invention will now be described in further detail with reference to the accompanying drawings.

[0023] Reference Figures 1 to 3 Detailed Implementation of a Multi-stage Electrostatic Dust Removal and Self-cleaning Method for Printing Plate Exposure Machines This invention relates to a multi-stage electrostatic dust removal and self-cleaning method for printing plate exposure machines, aiming to solve problems such as incomplete dust removal and complex equipment maintenance in existing technologies. The invention will be described in detail below with reference to specific embodiments.

[0024] I. Dynamic Pre-dust Removal Stage When the material to be exposed (such as PET film, paper, etc.) is conveyed to the entrance of the dust removal chamber via a conveyor belt, the terahertz spectral analysis module (model: TAS7500TS, Advantest, Japan) is first activated to scan the material surface. This module emits terahertz waves with frequencies of 0.1-10 THz and, based on the material's absorption characteristics for terahertz waves of different frequencies, quickly analyzes parameters such as material composition, thickness, and surface roughness, and transmits the data to the central control system (based on an Intel Xeon E5-2620v4 processor) in real time.

[0025] The central control system automatically matches the material type and adjusts the subsequent dust removal parameters based on a preset material property database. For example, for PET film (surface energy approximately 42 mN / m), the system sets the speed of the variable frequency fan (model: EBM-PAPSTR4D630-AF04-05) in the first-stage airflow pre-dust removal device to 2800 rpm, generating an initial wind speed of 18 m / s; for paper (surface energy approximately 35 mN / m), the speed is adjusted to 2500 rpm, and the wind speed is 15 m / s.

[0026] The airflow pre-dust removal device employs a two-stage flow guidance design: the airflow generated by the main fan first forms an initial laminar flow through an arc-shaped guide plate, and then passes through a piezoelectric ceramic-driven vibrating guide vane (model: PZT-5H, Morgan Advanced Materials, USA). The guide vane vibrates slightly at a frequency of 200Hz, creating a biomimetic fish-scale-like turbulent flow path, effectively improving the scouring ability for particles ≥30μm. In actual tests, for A4 paper with paper scraps of 30-50μm on the surface, the dust removal efficiency at this stage can reach 98.2%, an improvement of 15.3% compared to the traditional linear airflow design.

[0027] Meanwhile, the laser particle size analyzer (model: Mastersizer3000, Malvern Panalytical, UK) monitors the particle concentration and particle size distribution in the exhaust airflow in real time. When the detected particle concentration exceeds 10mg / m³, the system automatically increases the wind speed to 22m / s and increases the vibration frequency of the guide vanes to 300Hz to ensure the stability of the pre-dust removal effect.

[0028] II. Gradient Electrostatic Adsorption Stage After entering the gradient electric field region, the material first passes through a primary electric field of ±5kV (composed of stainless steel plates with a thickness of 0.5mm and a spacing of 50mm). This electric field has a relatively low strength and its main function is to polarize the material surface, creating conditions for subsequent particle charging. Experimental data show that after treatment with the primary electric field, the electrostatic adsorption force on the material surface can be reduced by approximately 30%.

[0029] Subsequently, the material is subjected to an intermediate electric field region of ±15 kV. This region employs a serrated edge electrode design, with a 5 nm thick boron nitride quantum dot layer (prepared via chemical vapor deposition) deposited on the electrode surface. The quantum dot layer utilizes the quantum tunneling effect, increasing electron emission efficiency to twice that of conventional electrodes while reducing the operating voltage to 70% of that of conventional electrodes, significantly reducing energy consumption. In this electric field, particles with a diameter of 10–30 μm are effectively charged and adsorbed onto dust collection plates with opposite charges.

[0030] Finally, the material was subjected to a nanoscale non-uniform electric field of ±30 kV. This electric field consisted of micro / nanostructured electrodes spaced only 0.5 mm apart, with the electrode surfaces covered by an array of carbon nanotubes (approximately 20 nm in diameter and 10 μm in length). The carbon nanotube array significantly enhanced the non-uniformity of the electric field, causing the electric field strength to reach 10 kV in localized regions. 6 With a V / m or higher, it can effectively adsorb submicron particles with a particle size ≤10μm.

[0031] The dust collection plates employ a capacitive self-cleaning structure, with a built-in pressure sensor (model: MPX5050DP, NXP, USA) that monitors the thickness of micro-dust accumulation on the plate surface in real time. When the detected accumulation thickness reaches 0.5mm, the system automatically switches the plate polarity (frequency 1Hz), using electrostatic repulsion to cause the adsorbed particles to fall into the bottom collection tank. Simultaneously, a pulse backflushing module is activated every 15 minutes, releasing a high-pressure CO2 pulse (pressure 0.8MPa) through a precision solenoid valve (model: ParkerSeries9) to further remove stubborn particles remaining on the plate surface.

[0032] Actual test data shows that for printed circuit boards with toner particles of average size 5μm distributed on the surface, the number of residual particles is reduced to 0.2 particles / cm² after the gradient electrostatic adsorption stage. 2 The dust removal efficiency reaches 99.8%, which is 23.5% higher than that of traditional single-stage electrostatic precipitator technology.

[0033] III. Plasma Activation Dust Removal Stage After the material enters the plasma processing area, a dual-frequency plasma generator (model: DienerPico, Germany) first generates radio frequency plasma at a frequency of 13.56 MHz to form an initial ion cloud environment. Subsequently, a 2.45 GHz microwave plasma is superimposed, and frequency scanning technology is used to find the material's plasma resonant frequency (e.g., the resonant frequency of PET film is approximately 2.47 GHz). In the resonant state, the plasma density can be increased to 5 times that of the conventional state, reaching 1 × 10⁻⁶. 11 cm -3 It significantly enhances the activation ability of stubborn pollutants.

[0034] Simultaneously, the system injects an Ar / O2 / N2 mixed gas into the plasma region via a mass flow controller (model: BronkhorstF-201CV), with the gas ratio dynamically adjusted according to the material type and contaminant characteristics. For example, to remove organic ink contaminants, the gas ratio is set to Ar:O2:N2=7:2:1; for removing metal particulate contaminants, the gas ratio is adjusted to Ar:O2:N2=8:1:1.

[0035] Under the influence of plasma, stubborn contaminants on the material surface undergo chemical bond breakage and oxidative decomposition reactions. For example, hydrocarbons in organic inks are oxidized into CO2 and H2O, and a loose oxide layer forms on the surface of metal particles, reducing their adhesion to the material surface by more than 80%. Simultaneously, the high-energy particles in the plasma micro-etch and activate the material surface, reducing the surface contact angle from the initial 90° to 45°, significantly improving the surface hydrophilicity of the material, which is beneficial for subsequent cleaning and drying processes.

[0036] The optical emission spectrum monitoring module (model: OceanInsightHR4000) analyzes plasma composition and intensity in real time to ensure the stability of plasma treatment results. When a decrease in plasma intensity or abnormal composition is detected, the system automatically adjusts the power supply and gas flow rate to ensure consistent treatment results.

[0037] Actual test data shows that for printed aluminum plates with stubborn UV ink, after plasma activation treatment, the ink residue was reduced by more than 95%, and the surface tension increased from the original 30mN / m to 50mN / m, which significantly improved the uniformity of photosensitive emulsion coating in the subsequent exposure process.

[0038] IV. Intelligent Vacuum Suction Stage After the material enters the vacuum suction area, the slit-type suction nozzle (made of silicone with a Shore A30 hardness) monitors the contact force with the material surface in real time via a pressure sensor (model: Honeywell SSC), and dynamically adjusts the nozzle height via a servo motor (model: Panasonic MINASA6) to maintain a constant contact pressure of 0.5-1N. For planar materials, the nozzle remains horizontal; for curved materials (such as cylindrical printing rollers), the nozzle automatically adapts to the curved shape through a flexible hinge structure to ensure a seamless fit.

[0039] The suction nozzle incorporates a built-in 1-3MHz ultrasonic transducer (model: KAIJO4012E) to generate a standing wave field with a sound pressure level ≥120dB. The ultrasonic vibrations cause the micro-dust particles to resonate, effectively reducing the adhesion between the particles and the material surface, and significantly improving suction efficiency. For example, for TiO2 particles with a diameter of 1μm, the suction efficiency can be increased from 85% to over 98% with ultrasonic assistance.

[0040] Meanwhile, the microchannel condensation system inside the nozzle monitors the material surface temperature in real time. When processing high-temperature materials (such as printed paper that has just undergone a drying process, with a surface temperature of about 70°C), the system introduces 10°C coolant into the microchannel through a micro-peristaltic pump (model: IsmatecRegloICC). The coolant circulates inside the nozzle, reducing the material surface temperature to below 40°C through heat exchange. This effectively prevents the gap between the nozzle and the material from increasing due to thermal expansion, ensuring that the sealing efficiency remains above 99.9%.

[0041] The vacuum suction system uses a variable frequency vacuum pump (model: Edwards nXDS10i), and the vacuum level is dynamically adjusted according to the material type and contaminant characteristics. For light particles (such as paper scraps and fibers), the vacuum level is set to -0.05MPa; for heavy particles (such as metal shavings and glass powder), the vacuum level is increased to -0.1MPa. Simultaneously, a particulate matter concentration monitoring module (model: TSI DustTrakDRX8533) monitors the particulate matter concentration in the exhaust airflow in real time. When the detected concentration exceeds 5mg / m³, the secondary filtration system (using a HEPA H13 high-efficiency filter) is automatically activated to perform secondary filtration of the exhaust airflow, ensuring that the final particulate matter concentration in the exhaust gas is below 0.1mg / m³. 3 It meets environmental protection requirements.

[0042] Actual test data shows that for flexible printed circuits with carbon black particles of average size 0.5 μm distributed on the surface, the number of residual particles is reduced to 0.05 particles / cm² after intelligent vacuum suction treatment. 2 The dust removal efficiency reaches 99.95%, which is 18.7% higher than that of traditional vacuum suction technology.

[0043] V. Supercritical CO2 Deep Cleaning Stage When the system has been running for a certain period of time (e.g., 8 hours of continuous operation) or when the dust removal efficiency is detected to drop below 95%, the supercritical CO2 deep cleaning program is automatically triggered. First, the material conveying system is shut down, and the dust removal chamber is sealed. Then, liquid CO2 is injected into the chamber from the storage tank using a high-pressure pump (model: Haskel DSTV-22), while the electric heating system (model: Watlow F4T) is activated to raise the chamber temperature to 35°C and the pressure to 8 MPa, bringing the CO2 to a supercritical state.

[0044] Supercritical CO2 has a density similar to that of a liquid and a diffusion coefficient similar to that of a gas, giving it an extremely strong ability to dissolve pollutants. In this case, injecting 5% of an environmentally friendly surfactant (mainly composed of alkyl glycoside APG) into the supercritical CO2 using a precision metering pump (model: LewaEcoflow) further enhances its ability to dissolve and disperse stubborn pollutants.

[0045] During the supercritical fluid circulation process, a pulsed electric field with a frequency of 5 kHz and a field strength of 5 kV / cm (generated by a high-voltage pulse generator, model: FIDGmbHHPG10-10000) is applied to the system. The pulsed electric field generates an electroporation effect in the supercritical fluid, which disrupts the molecular structure of stubborn pollutants (such as polymers, greases, etc.), making them easier to dissolve by supercritical CO2.

[0046] The cleaning system adopts a modular design, allowing for quick replacement of cleaning modules to meet different cleaning needs. For example, for cleaning microporous materials (such as ceramic anilox rollers), a dedicated module with fine nozzles, only 0.1mm in diameter, is used to clean deep into the micropores; for cleaning precision optical components (such as laser imagesetter lenses), a dedicated cleaning fluid module with low surface tension is used to avoid damage to the optical surfaces.

[0047] After the cleaning process lasts for 20 minutes, the system slowly reduces the chamber pressure to 4 MPa through a pressure-reducing valve, at which point the CO2 turns into a liquid state. The liquid CO2, carrying dissolved pollutants, passes through a separation tower (filled with activated carbon adsorbent). The pollutants are adsorbed onto the activated carbon, while the pure CO2 is compressed back into liquid by a compressor and returned to the storage tank for recycling. The CO2 recovery rate is ≥99%.

[0048] Finally, the chamber was dried using low-temperature plasma drying technology. The chamber pressure was reduced to 0.1 MPa, and an Ar / O2 mixed gas (4:1 ratio) was introduced. The plasma generator was then activated to produce low-temperature plasma (temperature controlled at 40-50℃). The high-energy particles in the plasma broke the hydrogen bonds between water molecules, causing the moisture to evaporate rapidly. An infrared thermal imager (model: FLIRT1030sc) monitored the internal temperature distribution of the chamber in real time to ensure uniform drying and prevent thermal damage to the equipment. After the drying process lasted for 10 minutes, the internal humidity of the chamber dropped below 10%, and the system returned to normal operation.

[0049] Actual test data shows that after supercritical CO2 deep cleaning, the overall dust removal efficiency of the dust removal system is restored to over 99.8%, the adsorption capacity of the dust collection plates is restored to 98% of the initial state, and the equipment maintenance cycle is extended from once a week to once a month, which significantly reduces equipment maintenance costs and downtime.

[0050] VI. Central Control System and Quality Traceability System The entire dust removal process is managed by a central control system based on an industrial-grade PLC (Siemens S7-1500) and an industrial PC (Advantech IPC-610L). The system adopts a redundant design, with the main controller and the backup controller synchronizing data in real time. When the main controller fails, the backup controller automatically switches over to take over, ensuring uninterrupted system operation.

[0051] The central control system collects data from various sensors in real time through distributed I / O modules (model: Wago750 series) and dynamically adjusts the operating parameters of each actuator according to preset control algorithms. For example, it automatically adjusts parameters such as fan speed, electric field strength, and plasma power based on the particle distribution on the material surface; and it automatically triggers maintenance reminders and fault alarms based on the equipment operating status.

[0052] Simultaneously, the system is equipped with a holographic particle image velocimetry (PIV) system (model: TSIPIVview2C) to monitor the airflow field distribution in real time. A high-speed camera (model: PhotronFastcamSA-Z) captures the trajectory of tracer particles in the airflow at a speed of 1000 frames per second, and the measurement area is illuminated by a laser sheet light source (model: NewWaveSoloPIV). The acquired image data is analyzed by a dedicated algorithm to obtain the velocity field and vorticity field information of the airflow. Based on this information, the central control system uses a deep learning algorithm (based on the TensorFlow framework) to optimize the guide vane angle and fan speed, making the airflow field more uniform and stable, and improving dust removal efficiency.

[0053] The quality traceability system, based on blockchain technology (using the Hyperledger Fabric platform), records complete data for each dust removal process, including material information, operating parameters, pollutant detection results, and equipment status. This data is encrypted and stored in a distributed ledger, forming an immutable digital twin archive. Operators can scan the QR code on the material using a barcode scanner (model: Honeywell Xenon 1900) to retrieve the dust removal history of that batch of materials in real time, achieving full traceability of product quality.

[0054] The edge computing unit (model: Intel NUC11 Pro) analyzes dust removal performance data in real time to build a predictive maintenance model. By analyzing equipment vibration data (collected by accelerometer model: PCB352C22), temperature data (collected by infrared temperature sensor model: Raytek MX4), and energy consumption data, the system can provide early warning of potential faults up to 72 hours in advance and automatically generate maintenance work orders to be sent to the mobile terminals of maintenance personnel (supporting Android and iOS applications).

[0055] In addition, the system supports 5G remote control (using Huawei's 5G industrial module ME909s-821). Operators can use AR glasses (model: Microsoft HoloLens2) to obtain real-time 3D visualization information of the equipment's operating status for immersive remote operation and maintenance. For example, when equipment malfunctions, remote experts can use AR glasses to guide on-site personnel in repair operations, improving troubleshooting efficiency.

[0056] Practical application data shows that after adopting the multi-stage electrostatic dust removal and self-cleaning method of the present invention, the dust removal efficiency of the printing plate exposure machine is increased from 90% of the traditional method to more than 99.95%, the plate exposure scrap rate is reduced from the original 3% to less than 0.1%, the equipment maintenance cost is reduced by 60%, and the energy consumption is reduced by 35%. It significantly improves the quality and production efficiency of printing plate exposure, and has good economic and social benefits.

[0057] Technical effect data comparison

[0058] This invention achieves significant breakthroughs in several key indicators through innovative multi-stage dust removal and self-cleaning technologies. The improved dust removal efficiency is primarily due to the synergistic effect of gradient electrostatic adsorption and plasma activation technologies, enabling the system to efficiently capture submicron-sized particles and significantly reduce the plate exposure scrap rate. The extended equipment maintenance cycle is achieved through supercritical CO2 deep cleaning and an intelligent predictive maintenance system, reducing manual intervention and downtime. Reduced energy consumption is attributed to the quantum tunneling enhancement electrode and adaptive control system, which optimizes energy utilization efficiency. The significant reduction in micro-dust emission concentration meets stringent environmental protection requirements, demonstrating the technology's green characteristics. Improved plasma treatment efficiency and supercritical CO2 recovery rate further enhance the system's stability and sustainability. Improved surface tension and electrostatic residual potential directly improve the quality and reliability of the plate exposure process. In summary, this invention represents a qualitative leap in dust removal efficiency, operating costs, environmental performance, and process stability, exhibiting significant technological advantages and market competitiveness.

[0059] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A multi-stage electrostatic dust removal and self-cleaning method for a printing plate exposure machine, characterized in that, include: Step 1, Dynamic Pre-dust Removal Stage: The material to be exposed is transported to the dust removal chamber, and the adaptive airflow pre-dust removal system is started. The particle distribution on the material surface is detected in real time by a laser particle size analyzer. The turbulent air field generated by the variable frequency fan is adjusted. Vibrating guide vanes driven by piezoelectric ceramics are set in the air field to make the airflow form a biomimetic fish scale scouring path to improve the dust removal efficiency of particles. Step 2, Gradient electrostatic adsorption stage: A three-level gradient electric field design is adopted. First, the material surface is polarized by the primary electric field, then the particles are charged by the intermediate electric field, and finally the particles are adsorbed by the non-uniform electric field. The dust collection plate adopts a micro-nano composite structure with a carbon nanotube array covering the surface, which increases the adsorption capacity by 5 times. It is also equipped with a pulse backflush module that releases a high-pressure CO2 pulse every 15 minutes to self-clean the plate. Step 3, Plasma Activation Dust Removal Stage: A dual-frequency plasma generator is used to generate mixed-frequency plasma, forming a high-energy ion cloud on the material surface, causing the chemical bonds of stubbornly adsorbed organic pollutants to break; at the same time, an active gas with an O3 concentration of 10-20 ppm is injected to perform micro-etching activation on the material surface, reducing the adhesion of micro-dust and simultaneously achieving surface hydrophilic modification, reducing the contact angle from 90° to 45°. Step 4, Vacuum Suction Stage: Ultrasonic-assisted vacuum suction technology is adopted. The slit nozzle has an built-in ultrasonic transducer, and the generated standing wave field causes the micro dust particles to resonate and detach. At the same time, the nozzle adopts a deformable flexible structure, and the contact force with the material surface is monitored in real time by a pressure sensor. The constant pressure is maintained to achieve seamless suction of curved materials. The vacuum degree can be dynamically adjusted within the range of 0.03-0.12MPa.

2. The multi-stage electrostatic dust removal and self-cleaning method for a printing plate exposure machine according to claim 1, characterized in that, Also includes: Step 5, Supercritical CO2 Deep Cleaning Stage: When a decrease in dust collection system efficiency is detected, the system automatically switches to supercritical cleaning mode: the pressure in the dust removal chamber is increased to 8 MPa, the temperature is controlled at 35°C, liquid CO2 is injected and heated to the critical point to form a supercritical fluid that circulates and cleans the entire system; surfactants are added to the supercritical CO2 to generate 10 through the Venturi effect. 6 Pa cavitation microjets are used to perform non-destructive cleaning of micro-nano structured plates, and CO2 is recovered by depressurization separation after cleaning. Before step one, a terahertz spectroscopy analysis module is set up to perform composition analysis on the printing material and establish a material property database. During the dust removal process, the central control system dynamically adjusts the parameters of each stage according to the material properties: for high surface energy materials, the electric field strength in step two is increased; for low charge mobility materials, the plasma treatment time is increased in step three.

3. The multi-stage electrostatic dust removal and self-cleaning method for a printing plate exposure machine according to claim 1, characterized in that, Also includes: In the gradient electric field system of step two, a quantum tunneling enhanced electrode design is adopted: a 5nm thick boron nitride quantum dot layer is deposited on the electrode surface, which improves the electron emission efficiency by utilizing the quantum tunneling effect and reduces the operating voltage; the dust collection plate adopts a capacitive self-cleaning structure, which uses electrostatic repulsion to make the adsorbed particles automatically fall into the collection tank by periodically changing the polarity of the plate, without the need for external mechanical vibration.

4. The multi-stage electrostatic dust removal and self-cleaning method for a printing plate exposure machine according to claim 1, characterized in that, Also includes: In the plasma activation process of step three, microwave plasma resonance technology is introduced: the plasma resonance frequency of the material is found by frequency scanning, and the plasma density generated in the resonance state is increased by 5 times, and the energy utilization rate is improved; at the same time, the plasma generator has a built-in optical emission spectrum monitoring module to analyze the plasma composition in real time and automatically adjust the gas ratio to achieve targeted removal of different pollutants.

5. The multi-stage electrostatic dust removal and self-cleaning method for a printing plate exposure machine according to claim 1, characterized in that, Also includes: In the vacuum suction system of step four, magnetorheological fluid sealing technology is adopted. The edge of the suction nozzle is filled with magnetorheological fluid, and the viscosity of the fluid is adjusted by the external magnetic field strength to form a dynamic sealing boundary. At the same time, a microchannel condensation system is set inside the suction nozzle. When high-temperature materials are detected, 10°C coolant is introduced for heat exchange to prevent sealing failure caused by thermal expansion.

6. The multi-stage electrostatic dust removal and self-cleaning method for a printing plate exposure machine according to claim 2, characterized in that, Also includes: In the supercritical CO2 cleaning stage of step five, pulsed electric field enhancement technology is combined: during the supercritical fluid circulation process, a pulsed electric field with a frequency of 1-10kHz and a field strength of 5kV / cm is applied to destroy the molecular structure of stubborn pollutants using the electroporation effect; at the same time, the cleaning system adopts a modular design to realize the replacement of cleaning modules with different functions.

7. The multi-stage electrostatic dust removal and self-cleaning method for a printing plate exposure machine according to claim 1, characterized in that, Also includes: Throughout the dust removal process, a holographic particle image velocimetry (PIV) system is set up to monitor the airflow field distribution in real time. The flow field data is analyzed through deep learning algorithms to dynamically optimize the guide vane angle and fan speed. At the same time, surface potential dynamic compensation technology is adopted, which uses an array of surface potential sensors to monitor the surface charge distribution of materials in real time. When a local potential anomaly is detected, the discharge parameters of the ion fan bar are automatically adjusted.

8. The multi-stage electrostatic dust removal and self-cleaning method for a printing plate exposure machine according to claim 1, characterized in that, Also includes: In each of steps one through five, an online Raman spectroscopy detection module is set up to analyze the composition and concentration of residual pollutants on the material surface in real time; when the concentration of a specific pollutant exceeds a threshold, a targeted treatment procedure is automatically triggered.

9. The multi-stage electrostatic dust removal and self-cleaning method for a printing plate exposure machine according to claim 1, characterized in that, Also includes: After the supercritical cleaning in step five, a low-temperature plasma drying technology is used to reduce the chamber pressure to 0.1 MPa and introduce an Ar / O2 mixed gas to generate low-temperature plasma. The high-energy particles in the plasma break the hydrogen bonds between water molecules to achieve drying. During the drying process, the material temperature is monitored in real time by infrared thermal imaging to prevent deformation caused by local overheating.

10. The multi-stage electrostatic dust removal and self-cleaning method for a printing plate exposure machine according to claim 1, characterized in that, Also includes: A quality traceability system is set up to record complete data for each dust removal process, including operating parameters, pollutant detection results, and equipment status, forming an unalterable digital twin archive. At the same time, the dust removal effect is analyzed in real time through edge computing units to establish a predictive maintenance model, provide early warning of potential faults, and automatically generate maintenance work orders. It also supports 5G remote control, allowing operators to obtain the equipment's operating status in real time through augmented reality devices for remote operation and maintenance.

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