Manufacturing process of high-definition intaglio roller

Abstract

The invention relates to the technical field of plate roller manufacturing, in particular to a high-definition gravure plate roller manufacturing process which comprises the following steps that S1, a roller body is subjected to machining, degreasing, acid pickling and ultrasonic cleaning treatment; s2, the surface of the roller body is subjected to laser engraving; s3, the engraved roller body is subjected to chromium plating treatment; s4, performing rough grinding, fine grinding and polishing treatment on the chromium-plated roller body; and S5, surface appearance, hardness, plating thickness and printability detection is conducted on the manufactured plate roller, and classification and feedback adjustment are conducted according to detection results. The method has the beneficial effects that the precision of the pit pattern and the thickness of the chromium plating layer can be improved, and the printing effect is improved.

Description

Technical Field

[0001] The invention relates to the technical field of plate roller production, and in particular to a production process of a high-definition gravure plate roller. Background Art

[0002] Gravure printing is widely used in packaging, publishing, decoration, and other fields due to its thick ink layer, bright colors, and high plate durability. The traditional gravure printing roller production process mainly includes roller surface treatment, electroengraving, and chrome plating.

[0003] In the existing technology, when manufacturing gravure printing rollers, the laser power cannot be dynamically adjusted according to the engraving depth requirements, and the engraved pit pattern required for printing is not accurate, which affects the printing effect. When chrome-plating the roller body, the thickness of the chrome-plating layer cannot be predicted, resulting in the chrome-plating layer thickness not meeting the process requirements, thereby affecting the printing effect. Summary of the Invention

[0004] In response to the shortcomings of the existing technology, this application proposes a high-definition gravure roller manufacturing process, which can improve the accuracy of the pit pattern and the thickness of the chrome plating layer and improve the printing effect.

[0005] The following is a technical solution of the present invention, a high-definition gravure printing plate roller manufacturing process, comprising the following steps: S1. Machining, degreasing, pickling and ultrasonic cleaning of the roller body; S2. Laser engraving the roller surface; S3, chrome plating the engraved roller body; S4, performing rough grinding, fine grinding and polishing on the chrome-plated roller body; S5. Test the surface morphology, hardness, coating thickness and printability of the finished plate roller, and classify and make feedback adjustments based on the test results.

[0006] As a preferred solution of the present invention, S1 includes the following steps: S11, turning, grinding and polishing the roller blank; S12. Immerse the roller in a degreasing agent solution at a temperature of 60-80°C for 10-15 minutes, then rinse with clean water; The degreasing agent is a mixed solution of sodium hydroxide, sodium carbonate and surfactant, with concentrations of 20-30g / L, 10-20g / L and 2-5g / L respectively; S13, immersing the roller in a hydrochloric acid solution with a temperature of 20-30°C and a concentration of 15-20% for 5-10 minutes to remove the surface oxide layer; S14. Place the roller in an ultrasonic cleaning tank and clean it for 5-10 minutes at a frequency of 20-40kHz and a power density of 0.5-1.0W / cm². Then rinse it with deionized water and dry it.

[0007] As a preferred solution of the present invention, S2 comprises the following steps: S21. Design printing patterns; S22, setting laser parameters; S23, adjusting the laser power according to the area of the printed pattern; S24, using several laser beams to engrave simultaneously, with the spacing between adjacent laser beams being 0.1-0.5mm; S25. Monitor the engraving process and detect the shape and size of the pit using image recognition technology.

[0008] As a preferred solution of the present invention, in S24, multiple laser beams are used to simultaneously perform engraving, including the following steps: S241, splitting a laser beam into 4-8 parallel laser beams through a beam splitting system to form a beam array, with a spacing between the beams being 0.1-0.5 mm; S242, adopt high-precision synchronous control system to ensure that the switching time error of each beam does not exceed ±1μs; S243, the pattern to be engraved is divided according to the number of light beams, and the pattern is assigned to each light beam for simultaneous engraving. The segmentation algorithm is expressed as follows: In the above formula, is the total pattern area, For the The laser beam is responsible for the engraving area. is the number of beams; S244, the engraving areas of adjacent beams are set to overlap by 5-10%, and the splicing marks are eliminated by optimizing the engraving parameters of the overlapping area.

[0009] As a preferred solution of the present invention, S3 includes the following steps: S31, immersing the engraved roller body in a sulfuric acid solution at a temperature of 40-60°C for activation for 1-3 minutes, with a sulfuric acid mass fraction of 10-20%; S32. Prepare a chromium plating solution with the following ingredients: potassium chromium sulfate 250-350g / L, sulfuric acid 2.5-3.5g / L, catalyst 10-20g / L, process conditions: temperature 50-60°C, cathode current density 30-60A / dm²; S33, electroplating using pulse current, pulse frequency of 100-1000 Hz, duty cycle of 30-70%; S34. During the electroplating process, the distance between the anode and the cathode is dynamically adjusted according to the electric field distribution at each point on the roller surface; S35. After the chrome plating is completed, the roller body is tempered at a temperature of 180-220°C for 2-4 hours to eliminate the stress in the plating layer.

[0010] As a preferred solution of the present invention, S34 includes the following steps: S341. Establish an electric field distribution model for the chrome plating process and predict the current density distribution at each point on the roller surface; S342. Based on the electric field distribution simulation results, the distance between the anode surface and the roller surface varies with position to compensate for the uneven distribution of the electric field. S343. During the electroplating process, the distance between the anode and the roller is adjusted in real time by the servo motor. The distance adjustment expression is as follows: In the above formula, is the real-time distance, is the initial distance, To simulate the current density, is the target current density, is the adjustment factor; S344. The current density sensor arranged in the plating tank monitors the current density distribution on the roller surface in real time, and feeds the data back to the control system to dynamically adjust the anode position.

[0011] As a preferred solution of the present invention, S4 comprises the following steps: S41. Use a grinding wheel with a grit size of 180-240 mesh to coarsely grind the surface of the roller to remove burrs and protrusions generated during the chrome plating process. The grinding pressure is 0.2-0.5 MPa and the grinding speed is 10-20 m / min. S42, using a grinding wheel with a grit size of 400-600 mesh for fine grinding, with a grinding pressure of 0.1-0.3 MPa and a grinding speed of 15-25 m / min; S43. Polish the roller surface using polishing paste and a polishing wheel to make the surface roughness Ra ≤ 0.1 μm, the polishing wheel speed is 1500-3000 r / min, and the polishing pressure is 0.05-0.1 MPa.

[0012] As a preferred solution of the present invention, in S2, the laser generator dynamically adjusts the laser power according to the engraving depth requirement, and the expression is as follows: In the above formula, is the real-time laser power, is the initial power, is the power adjustment factor, The current engraving depth.

[0013] As a preferred solution of the present invention, in S3, based on Faraday's law of electrolysis, the thickness of the chromium plating layer is predicted, and the expression is as follows: In the above formula, is the thickness of the chrome plating layer, is the chrome plating efficiency coefficient, is the current intensity, is the plating time, is the density of chromium, is the valence of chromium, is the Faraday constant.

[0014] As a preferred solution of the present invention, in S5, the quality of the chrome plating layer is evaluated based on the hardness of the plate roller and the thickness of the plating layer, and the expression is as follows: In the above formula, is the hardness value, is the coating thickness, is the coating coefficient, is a constant term.

[0015] The beneficial effects of the present invention are as follows: when manufacturing a gravure printing plate roller, the laser power is dynamically adjusted according to the engraving depth requirement, thereby improving the accuracy of the pit pattern required for engraving and printing; when chrome-plating the roller body, the thickness of the chrome-plated layer is predicted; during the electroplating process, the distance between the anode and the cathode is dynamically adjusted according to the electric field distribution at each point on the roller body surface, thereby ensuring that the thickness of the chrome-plated layer meets the process requirements and improving the printing effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagram of the device for making the present invention Figure 1 ; Figure 2 Schematic diagram of the device for making the present invention Figure 2 ; Figure 3 A diagram showing the steps of the manufacturing process of the present invention; Figure 4 Flowchart of the manufacturing process of the present invention; In the figure: 1. Roller pretreatment module; 11. Machining unit; 12. Degreasing unit; 13. Pickling unit; 14. Ultrasonic cleaning unit; 2. Laser engraving module; 21. Laser generator; 22. Beam shaping unit; 23. Scanning galvanometer; 24. Focusing lens; 25. Control system; 3. Intelligent chrome plating module; 31. Chrome plating tank; 32. Anode device; 33. Cathode device; 34. Power supply unit; 35. Circulation filtration unit; 36. Temperature control unit; 4. Quality inspection module; 41. Surface inspection unit; 42. Hardness inspection unit; 43. Coating thickness inspection unit; 44. Coating thickness inspection unit; 5. Data management and control module; 51. Database server; 52. Process control server; 53. Human-computer interaction interface; 54. Communication network. DETAILED DESCRIPTION

[0017] To make the technical problems solved, the technical solutions adopted, and the technical effects achieved by the present invention more clearly understood, the technical solutions of the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. It is obvious that the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative work shall fall within the scope of protection of the present invention.

[0018] Example 1: like Figure 1 and Figure 2 As shown, a high-definition gravure printing plate roller manufacturing device includes: Roller pretreatment module 1, used for surface treatment of the plate roller substrate; Laser engraving module 2, which uses a high-energy-density laser beam to engrave the roller surface to form the pit pattern required for printing; Intelligent chrome plating module 3, used to plate a uniform and dense chrome layer on the surface of the engraved roller; The quality inspection module 4 is used to inspect the finished plate roller; The data management and control module 5 is responsible for data management, process control and system coordination.

[0019] In this embodiment, the roller pretreatment module 1 is used to perform surface treatment on the plate roller substrate, ensuring its surface is smooth, clean, and has good adhesion. The roller pretreatment module 1 includes a machining unit 11, a degreasing unit 12, a pickling unit 13, and an ultrasonic cleaning unit 14. The machining unit 11 processes the roller to a predetermined size and surface roughness through turning and grinding. The degreasing unit 12 uses a chemical degreasing agent to remove grease and oil from the roller surface. The pickling unit 13 uses an acidic solution to remove oxide layers and rust from the roller surface. The ultrasonic cleaning unit 14 further removes microparticles from the roller surface using the cavitation effect of ultrasound. Machining unit 11, degreasing unit 12, pickling unit 13, and ultrasonic cleaning unit 14 are sequentially connected by conveyor belts, forming a continuous processing line. The roller is automatically transported between the units. In machining unit 11, it undergoes turning, grinding, and polishing. In degreasing unit 12, it is immersed in a degreaser and spray-cleaned. In pickling unit 13, it is soaked in acid, neutralized, and then rinsed with water. In ultrasonic cleaning unit 14, it undergoes ultrasonic cleaning and hot air drying. The degreaser concentration is monitored in real time using acid-base titration. If the concentration decreases, the degreaser is replenished to maintain the degreaser concentration within the set range.

[0020] In this embodiment, the laser engraving module 2 uses a high-energy-density laser beam to engrave the roller surface, forming the desired pit pattern. The laser engraving module 2 comprises a laser generator 21, a beam shaping unit 22, a scanning galvanometer 23, a focusing lens 24, and a control system 25. The laser generator 21 generates a high-energy-density laser beam, selecting lasers of varying wavelengths and powers based on the specific engraving requirements. The beam shaping unit 22 shapes the laser beam into the desired spot shape and energy distribution. The scanning galvanometer 23 controls the laser beam's scanning path and speed across the roller surface. The focusing lens 24 focuses the laser beam onto the roller surface, forming a tiny, high-energy-density spot. The control system 25 precisely controls the laser's on / off, power, and scanning path based on pre-set pattern data. The designed printing pattern is converted into a digital format and imported into the control system 25. Laser parameters such as laser power, scanning speed, and frequency are set based on the desired pattern and roller material. Based on the pattern data, the control system 25 controls the laser beam to scan and engrave the roller surface, forming the pit pattern.

[0021] According to the engraving depth requirements, the laser power is dynamically adjusted. The expression is as follows: In the above formula, is the real-time laser power, is the initial power, is the power adjustment factor, The current engraving depth.

[0022] In this embodiment, the intelligent chrome plating module 3 is used to deposit a uniform, dense layer of chromium on the surface of the engraved roller, improving its hardness, wear resistance, and corrosion resistance. The intelligent chrome plating module 3 comprises a chrome plating tank 31, an anode assembly 32, a cathode assembly 33, a power supply unit 34, a circulating filter unit 35, and a temperature control unit 36. The chrome plating tank 31 holds the chrome plating electrolyte; the anode assembly 32, which uses a lead alloy anode, provides a source of chromium ions; the cathode assembly 33, connected to the roller, serves as the cathode during the plating process; the power supply unit 34 provides direct current to control the current density and plating time; the circulating filter unit 35 maintains the uniformity and cleanliness of the electrolyte; and the temperature control unit 36 controls the electrolyte temperature within an optimal range. The engraved roller undergoes activation treatment to remove the surface oxide layer. The roller is immersed in the chrome plating tank 31 and connected to the power supply unit 34 to deposit a chromium layer on the roller surface. The roller is then removed and cleaned, dried, and polished.

[0023] Based on Faraday's law of electrolysis, the thickness of the chrome plating layer is predicted as follows: In the above formula, is the thickness of the chrome plating layer, is the chrome plating efficiency coefficient, is the current intensity, is the plating time, is the density of chromium, is the valence of chromium, is the Faraday constant.

[0024] In this embodiment, the quality inspection module 4 is used to inspect the finished plate roller to ensure that it meets quality standards. The quality inspection module 4 includes a surface inspection unit 41, a hardness inspection unit 42, a coating thickness inspection unit 43, and a coating thickness inspection unit 44. The surface inspection unit 41 is used to detect the shape, size, and distribution of pits on the plate roller surface; the hardness inspection unit 42 is used to test the hardness of the plate roller surface; the coating thickness inspection unit 43 is used to measure the thickness and uniformity of the chrome plating layer; and the coating thickness inspection unit 44 is used to simulate the printing process and evaluate the printing performance of the plate roller. Each inspection unit is connected to the central control system 25 via a data transmission line, transmitting inspection data in real time to the control system 25 for analysis and processing.

[0025] A mathematical model of hardness and coating thickness is established to evaluate the quality of the chrome plating layer. The expression is as follows: In the above formula, is the hardness value, is the coating thickness, is the coating coefficient, is a constant term.

[0026] In this embodiment, the data management and control module 5 is responsible for data management, process control, and system coordination. The data management and control module 5 includes a database server 51, a process control server 52, a human-machine interface 53, and a communication network 54. The database server 51 stores information such as plate roller design data, process parameters, and test data. The process control server 52 controls the operating parameters and workflow of each module according to preset process rules. The human-machine interface 53 provides an interface between the operator and the system, enabling functions such as parameter setting, status monitoring, and fault alarms. The communication network 54 facilitates data transmission and communication between modules. The database server 51, process control server 52, human-machine interface 53, and the control systems 25 of each module are connected via Industrial Ethernet to form a complete network.

[0027] The operator inputs the plate roller design data and process parameters through the human-computer interaction interface 53; the process control server 52 generates a process plan based on the input data and preset rules; the process control server sends control instructions to each module, monitors the operating status of each module in real time, and makes adjustments based on feedback data; the database server 51 stores various data in the production process and provides data analysis functions.

[0028] Example 2: like Figure 3 and Figure 4 As shown, a high-definition gravure printing plate roller manufacturing process includes the following steps: S1. Machining, degreasing, pickling and ultrasonic cleaning of the roller body; S2. Laser engraving the roller surface; S3, chrome plating the engraved roller body; S4, performing rough grinding, fine grinding and polishing on the chrome-plated roller body; S5. Test the surface morphology, hardness, coating thickness and printability of the finished plate roller, and classify and make feedback adjustments based on the test results.

[0029] In step S1, the roller body is subjected to machining, degreasing, pickling and ultrasonic cleaning, including the following steps: S11, turning, grinding and polishing the roller blank; The outer diameter tolerance of the roller is within ±0.02mm, and the surface roughness Ra≤0.4μm; S12. Immerse the roller in a degreasing agent solution at a temperature of 60-80°C for 10-15 minutes, then rinse with clean water; The degreasing agent is a mixed solution of sodium hydroxide, sodium carbonate and surfactant, with concentrations of 20-30g / L, 10-20g / L and 2-5g / L respectively; S13, immersing the roller in a hydrochloric acid solution at a temperature of 20-30°C for 5-10 minutes to remove the surface oxide layer; The concentration of hydrochloric acid is 15-20%; S14. Place the roller in an ultrasonic cleaning tank and clean it for 5-10 minutes at a frequency of 20-40kHz and a power density of 0.5-1.0W / cm². Then rinse it with deionized water and dry it.

[0030] In step S2, laser engraving is performed on the surface of the roller, including the following steps: S21. Design printing patterns; Convert the printed pattern into a digital format that can be recognized by the laser engraving machine, with a resolution of no less than 2400dpi; S22, setting laser parameters; Set the laser power to 30-100 W, the scanning speed to 500-2000 mm / s, the frequency to 20-100 kHz, and the spot diameter to 20-50 μm; S23, adjusting the laser power according to the area of the printed pattern; During the engraving process, the laser energy is adjusted in real time according to the area of the printed pattern; for dark areas, the laser power is increased by 5-10%; for highlight areas, the laser power is reduced by 5-10%; S24, using several laser beams to engrave simultaneously, with the spacing between adjacent laser beams being 0.1-0.5mm; S25, monitoring the engraving process and detecting the shape and size of the pit using image recognition technology; The engraving process is monitored in real time by a high-speed camera, and the shape and size of the pits are detected using image recognition technology. When unqualified pits are detected, the laser parameters are adjusted to make corrections.

[0031] In step S24, multiple laser beams are used to simultaneously perform engraving, including the following steps: S241, splitting a laser beam into 4-8 parallel laser beams through a beam splitting system to form a beam array, with a spacing between the beams being 0.1-0.5 mm; S242, using a high-precision synchronous control system 25 to ensure that the switching time error of each light beam does not exceed ±1μs; S243, the pattern to be engraved is divided according to the number of light beams, and the pattern is assigned to each light beam for simultaneous engraving. The segmentation algorithm is expressed as follows: In the above formula, is the total pattern area, For the The laser beam is responsible for the engraving area. is the number of beams; S244, the engraving areas of adjacent beams are set to overlap by 5-10%, and the splicing marks are eliminated by optimizing the engraving parameters of the overlapping area.

[0032] Compared with traditional single-beam engraving, the engraving speed is increased by 3-5 times. At the same time, because each beam is controlled independently, different engraving parameters can be used for different areas, further improving the engraving quality.

[0033] In step S3, the engraved roller body is chrome-plated, which includes the following steps: S31, immersing the engraved roller body in a sulfuric acid solution at a temperature of 40-60°C for activation for 1-3 minutes, with a sulfuric acid mass fraction of 10-20%; S32. Prepare a chromium plating solution with the following ingredients: potassium chromium sulfate 250-350g / L, sulfuric acid 2.5-3.5g / L, catalyst 10-20g / L, process conditions: temperature 50-60°C, cathode current density 30-60A / dm²; S33, using pulse current for electroplating, with a pulse frequency of 100-1000 Hz and a duty cycle of 30-70%, and improving the structure and performance of the chrome plating layer by controlling the on-off of the pulse current; S34. During the electroplating process, the distance between the anode and cathode is dynamically adjusted according to the electric field distribution at each point on the roller surface. For the edge area, the distance between the anode and cathode is reduced by 5-10%; for the center area, the distance is increased by 5-10%; S35. After chrome plating is completed, the roller body is tempered at a temperature of 180-220°C for 2-4 hours to eliminate the internal stress of the coating and improve the hardness and wear resistance of the coating.

[0034] In step S34, during the electroplating process, the distance between the anode and the cathode is dynamically adjusted according to the electric field distribution at each point on the roller surface, including the following steps: S341. Use finite element analysis software to establish the electric field distribution model of the chrome plating process and predict the current density distribution at each point on the roller surface.

[0035] S342. Based on the simulation results of the electric field distribution, a special-shaped anode is designed so that the distance between the anode surface and the roller surface changes with position to compensate for the uneven distribution of the electric field.

[0036] S343. During the electroplating process, the distance between the anode and the roller is adjusted in real time by the servo motor. The distance adjustment expression is as follows: In the above formula, is the real-time distance, is the initial distance, To simulate the current density, is the target current density, is the adjustment factor.

[0037] S344. The current density distribution on the roller surface is monitored in real time by a current density sensor arranged in the plating tank, and the data is fed back to the control system 25 to dynamically adjust the anode position.

[0038] In step S4, the chrome-plated roller body is subjected to rough grinding, fine grinding and polishing, which includes the following steps: S41. Use a grinding wheel with a grit size of 180-240 mesh to coarsely grind the surface of the roller to remove burrs and protrusions generated during the chrome plating process. The grinding pressure is 0.2-0.5 MPa and the grinding speed is 10-20 m / min. S42, use a grinding wheel with a grit size of 400-600 mesh to perform fine grinding to further improve the surface finish, the grinding pressure is 0.1-0.3 MPa, and the grinding speed is 15-25 m / min; S43, polishing the roller surface using a polishing paste and a polishing wheel to a surface roughness Ra ≤ 0.1 μm, with a polishing wheel speed of 1500-3000 r / min and a polishing pressure of 0.05-0.1 MPa; S44. Use a laser roughness meter to test the roller surface to ensure that the surface roughness meets the process requirements. The distance between the test points should not exceed 5mm, and the average value of three measurements should be taken for each test point.

[0039] In step S5, the surface morphology, hardness, coating thickness and printability of the manufactured plate roller are tested, and classification and feedback adjustment are performed based on the test results, including the following steps: S51. Use a 3D laser scanner to scan the roller surface to obtain three-dimensional topography data of the pits. The scanning resolution is not less than 10 μm and the measurement accuracy is ±1 μm. S52. Use Rockwell hardness tester to test the hardness of 10 points evenly distributed on the roller surface. The hardness value should be within the range of 65-75HRC. The indentation spacing of each test point should not be less than 3mm. S53. Use an X-ray fluorescence thickness gauge to test the thickness of the chrome plating layer at different locations on the roller surface. The test points should be no less than 20. The average thickness of the coating should be within the range of 25-35μm, and the thickness deviation should not exceed ±5μm. S54. Under laboratory simulated printing conditions, use the prepared plate roller to conduct printing tests. Evaluation indicators include ink transfer rate, dot reproducibility, printing color difference, etc. The ink transfer rate should be no less than 85%, and the dot gain rate should be within the range of 10-15%. S55. Input the test data into the data analysis system and compare and analyze it with the preset quality standards. If there is no quality problem, the plate roller will be transferred to the qualified product area. If a quality problem is found, the plate roller will be transferred to the unqualified product area, and adjustment suggestions will be generated and fed back to the corresponding process links for optimization.

[0040] In the present invention, when manufacturing a gravure printing plate roller, the laser power is dynamically adjusted according to the engraving depth requirement, thereby improving the accuracy of the pit pattern required for engraving and printing. When chrome-plating the roller body, the thickness of the chrome-plated layer is predicted. During the electroplating process, the distance between the anode and the cathode is dynamically adjusted according to the electric field distribution at each point on the roller body surface, thereby ensuring that the thickness of the chrome-plated layer meets the process requirements and improving the printing effect.

[0041] Although preferred embodiments of the present invention have been described, further changes and modifications may be made to these embodiments by those skilled in the art once the basic inventive concepts are understood. It is apparent that various changes and modifications may be made to the present invention by those skilled in the art without departing from the spirit and scope of the present invention. Thus, the present invention is intended to encompass such changes and modifications as fall within the scope of equivalents of the present invention.

Claims

1. A high-definition gravure printing plate roller manufacturing process, characterized in that: The following steps are involved: S1. Machining, degreasing, pickling and ultrasonic cleaning of the roller body; S2. Laser engraving the roller surface; S3, chrome plating the engraved roller body; S4, performing rough grinding, fine grinding and polishing on the chrome-plated roller body; S5. Test the surface morphology, hardness, coating thickness and printability of the finished plate roller, and classify and make feedback adjustments based on the test results.

2. A high-definition gravure printing plate roller manufacturing process according to claim 1, characterized in that: S1 includes the following steps: S11, turning, grinding and polishing the roller blank; S12. Immerse the roller in a degreasing agent solution at a temperature of 60-80°C for 10-15 minutes, then rinse with clean water; The degreasing agent is a mixed solution of sodium hydroxide, sodium carbonate and surfactant, with concentrations of 20-30g / L, 10-20g / L and 2-5g / L respectively; S13, immersing the roller in a hydrochloric acid solution with a temperature of 20-30°C and a concentration of 15-20% for 5-10 minutes to remove the surface oxide layer; S14. Place the roller in an ultrasonic cleaning tank and clean it for 5-10 minutes at a frequency of 20-40kHz and a power density of 0.5-1.0W / cm². Then rinse it with deionized water and dry it.

3. The process for manufacturing a high-definition gravure printing plate roller according to claim 1, characterized in that: S2 includes the following steps: S21. Design printing patterns; S22, setting laser parameters; S23, adjusting the laser power according to the area of the printed pattern; S24, using several laser beams to engrave simultaneously, with the spacing between adjacent laser beams being 0.1-0.5mm; S25. Monitor the engraving process and detect the shape and size of the pit using image recognition technology.

4. A high-definition gravure printing plate roller manufacturing process according to claim 3, characterized in that: In S24, several laser beams are used to engrave at the same time. The following steps are involved: S241, splitting a laser beam into 4-8 parallel laser beams through a beam splitting system to form a beam array, with a spacing between the beams being 0.1-0.5 mm; S242, adopt high-precision synchronous control system to ensure that the switching time error of each beam does not exceed ±1μs; S243, the pattern to be engraved is divided according to the number of light beams, and the pattern is assigned to each light beam for simultaneous engraving. The segmentation algorithm is expressed as follows: In the above formula, is the total pattern area, For the The laser beam is responsible for the engraving area. is the number of beams; S244, the engraving areas of adjacent beams are set to overlap by 5-10%, and the splicing marks are eliminated by optimizing the engraving parameters of the overlapping area.

5. The process for manufacturing a high-definition gravure printing plate roller according to claim 1, characterized in that: S3 includes the following steps: S31, immersing the engraved roller body in a sulfuric acid solution at a temperature of 40-60°C for activation for 1-3 minutes, with a sulfuric acid mass fraction of 10-20%; S32. Prepare a chromium plating solution with the following ingredients: potassium chromium sulfate 250-350g / L, sulfuric acid 2.5-3.5g / L, catalyst 10-20g / L, process conditions: temperature 50-60°C, cathode current density 30-60A / dm²; S33, electroplating using pulse current, pulse frequency of 100-1000 Hz, duty cycle of 30-70%; S34. During the electroplating process, the distance between the anode and the cathode is dynamically adjusted according to the electric field distribution at each point on the roller surface; S35. After the chrome plating is completed, the roller body is tempered at a temperature of 180-220°C for 2-4 hours to eliminate the stress in the plating layer.

6. A high-definition gravure printing plate roller manufacturing process according to claim 5, characterized in that: S34 includes the following steps: S341. Establish an electric field distribution model for the chrome plating process and predict the current density distribution at each point on the roller surface; S342. Based on the electric field distribution simulation results, the distance between the anode surface and the roller surface varies with position to compensate for the uneven distribution of the electric field. S343. During the electroplating process, the distance between the anode and the roller is adjusted in real time by the servo motor. The distance adjustment expression is as follows: In the above formula, is the real-time distance, is the initial distance, To simulate the current density, is the target current density, is the adjustment factor; S344. The current density sensor arranged in the plating tank monitors the current density distribution on the roller surface in real time, and feeds the data back to the control system to dynamically adjust the anode position.

7. The process for manufacturing a high-definition gravure printing plate roller according to claim 1, characterized in that: S4 includes the following steps: S41. Use a grinding wheel with a grit size of 180-240 mesh to coarsely grind the surface of the roller to remove burrs and protrusions generated during the chrome plating process. The grinding pressure is 0.2-0.5 MPa and the grinding speed is 10-20 m / min. S42, using a grinding wheel with a grit size of 400-600 mesh for fine grinding, with a grinding pressure of 0.1-0.3 MPa and a grinding speed of 15-25 m / min; S43. Polish the roller surface using polishing paste and a polishing wheel to make the surface roughness Ra ≤ 0.1 μm, the polishing wheel speed is 1500-3000 r / min, and the polishing pressure is 0.05-0.1 MPa.

8. The process for manufacturing a high-definition gravure printing plate roller according to claim 1, characterized in that: In S2, the laser generator dynamically adjusts the laser power according to the engraving depth requirements. The expression is as follows: In the above formula, is the real-time laser power, is the initial power, is the power adjustment factor, The current engraving depth.

9. The process for manufacturing a high-definition gravure printing plate roller according to claim 1, characterized in that: In S3, the thickness of the chrome plating layer is predicted based on Faraday's law of electrolysis. The expression is as follows: In the above formula, is the thickness of the chrome plating layer, is the chrome plating efficiency coefficient, is the current intensity, is the plating time, is the density of chromium, is the valence of chromium, is the Faraday constant.

10. The process for manufacturing a high-definition gravure printing plate roller according to claim 1, characterized in that: In S5, the quality of the chrome plating layer is evaluated based on the hardness of the plate roller and the thickness of the coating, and the expression is as follows: In the above formula, is the hardness value, is the coating thickness, is the coating coefficient, is a constant term.

Images