Multi-layer label production method with automatic deviation correction effect

Abstract

The invention discloses a multi-layer label production method with an automatic deviation correction effect, through a multi-layer cooperative positioning mechanism of a conductive grid positioning mark and an infrared sensitive reflection strip, the alignment precision between label layers is remarkably improved, and through combination with fine regulation and control of a multi-axis independent tension control system on the tension of a printing layer, the production efficiency of the multi-layer label is improved. Accumulated errors caused by material deformation are effectively inhibited, a high-speed visual detection system analyzes the spatial relation between the conductive grid and infrared reflection characteristics in real time, micron-order offset dynamic monitoring is achieved, interlayer errors can be stably controlled within a process threshold value in cooperation with a real-time compensation mechanism, the rejection rate is greatly reduced, and the production efficiency is improved. According to the innovative two-stage curing process, through sequential control of pulse ultraviolet pre-curing and infrared final curing, the process tolerance of secondary positioning in the semi-curing stage is ensured, the interlayer bonding strength is improved through gradient curing, and finally continuous and stable production of the high-precision multi-layer anti-counterfeit label is achieved. And continuous and stable production is realized in the field of high-end anti-counterfeit labels.

Description

Technical Field

[0001] The present invention relates to the technical field of label production, and particularly to a multi-level label production method with an automatic rectification effect. Background Art

[0002] Due to their unique three-dimensional visual effects, multi-layer composite labels are widely used in the fields of high-end product packaging and anti-counterfeiting. The traditional production process manufactures such labels by layer-by-layer printing and superposition compounding, where the pattern alignment accuracy of each printing layer directly affects the final visual effect. In the prior art, a strategy of mechanical positioning holes combined with equalized tension control is generally adopted for interlayer alignment: the first printing layer and the second printing layer are initially positioned through a roller system, and the third printing layer relies on an infrared sensor for auxiliary calibration (see CN206765548U). However, due to the difference in the thermal expansion coefficients of different printing layer materials (for example, the expansion difference between a PET substrate and a PVC adhesive layer can reach 2.1×10⁻ 5 / °C), during high-speed continuous compounding, the problem of asymmetric tensile deformation caused by interlayer tension imbalance becomes increasingly prominent. Especially when the production speed exceeds a certain threshold, the existing rectification system is difficult to compensate for the systematic offset caused by material property differences, resulting in the multi-layer pattern superposition error generally exceeding the production requirements, seriously restricting the mass production of high-precision three-dimensional labels.

[0003] As described in the published patent "A Label Production Device for Preventing Printed Label Deviation" with the publication number CN219338959U, with the development of the commodity market, the types of labels are increasing, such as optical holographic anti-counterfeiting labels, etc.; the appearance patterns of labels are becoming more and more complex, often requiring multiple printings and multiple colors to form the required complete label pattern. When labels are actually produced, printed multi-color laminated labels often exhibit the phenomenon of printing deviation; specifically, after a color is printed on the paper by a printing device, it will pass through a drying mechanism to dry the printing ink, so that before the next color is printed, the ink of the previous color has dried; during this process, to ensure that the ink of the previous color has dried before the next color is printed, either the movement speed of the paper is reduced, so that the paper has a longer buffer time between printing two colors, but this approach will seriously affect production efficiency; or the temperature of the drying mechanism is increased, but this will cause the temperature of the paper to be too high, and the higher the temperature of the paper, the greater the deformation, resulting in the printing position of the next color deviating, making the formed label pattern less perfect or even defective; the more colors there are in the label, the more obvious the printing deviation is.

[0004] In summary, in the existing label generation process, for the printing of labels with a multi-level structure, different patterns need to be printed on different printing layers, and then the final pattern effect is formed through multi-level superposition. Due to the influence of multiple interference factors such as temperature, the tension of mechanical guide rollers, and the difference in feeding speed, during the production process of printing labels with a multi-level structure, there are problems of easy deviation between printing layers, affecting the production yield of high-value labels and resulting in low production efficiency and customer evaluation. Summary of the Invention

[0005] The present invention aims to overcome the above-mentioned deficiencies and provides a technical solution for a multi-level label production method with an automatic deviation correction effect to solve the above problems.

[0006] To achieve the above object, the present invention provides the following technical solutions: A multi-level label production method with an automatic deviation correction effect, comprising the following steps: S100: The multi-level label includes a first printing layer printed with a first pattern, a second printing layer printed with a second pattern, and a third printing layer printed with a third pattern. A conductive grid positioning mark is preset on the surface of the first printing layer, and an infrared-sensitive reflective strip is provided at the edge of the third printing layer. Each printing layer prints a differentiable pattern that can be superimposed; S200: Implement independent tension control on the first printing layer, the second printing layer, and the third printing layer by using multiple groups of independent tension control systems; S300: Real-time monitor the superposition alignment state of the patterns of each printing layer through a high-speed vision detection system, and calculate the interlayer offset based on the relative positions of the conductive grid and the infrared reflective strip; S400: When it is detected that the offset of any adjacent printing layer exceeds the offset threshold, synchronously trigger a compensation mechanism; S500: Adopt a two-stage curing process after multi-layer lamination. First, form a semi-cured adhesive layer that can be repositioned through pulsed ultraviolet irradiation, and then complete the final curing through infrared radiation. As a further solution of the present invention: The S100 includes the following steps: S110: The conductive grid positioning mark is formed by silver paste printing, the grid line width is 15μm, the spacing is 5μm, and it covers more than 80% of the effective printing area of the first printing layer; S120: The infrared-sensitive reflective strip is arranged on both sides along the traveling direction of the third printing layer, and the width of the reflective strip is 1.2 - 1.8mm; S130: The superposition design of the differentiable patterns of each printing layer satisfies the following steps: The first printing layer is printed with a first positioning mark, and the first positioning mark includes a basic pattern with microtext; The second printing layer is printed with a second positioning mark, and the second positioning mark includes a semi-transparent gradient transition area; The third printed layer is printed with a third positioning mark, the third positioning mark comprising a fluorescent positioning mark arranged at the edge of the second printed layer and linked to the conductive grid; S140: Pattern edges of adjacent printing layers retain an overlapping compensation area, and the outline of the overlapping compensation area forms a geometric mapping relationship with the positioning mark of the corresponding printing layer.

[0007] As a further solution of the present invention: the differentiated tension control in S200 includes: S210: obtaining a reference tension of the first printing layer in a reference size state and recording it as a first tension, obtaining a reference tension of the second printing layer in a reference size state and recording it as a second tension, and obtaining a reference tension of the third printing layer in a reference size state and recording it as a third tension; S220: During the tension control process, dynamically adjust the proportional coefficient based on the material characteristics, and when it is detected that the ambient temperature changes beyond the threshold temperature, dynamically adjust the tensions of the first printing layer, the second printing layer, and the third printing layer respectively; S230: Closed-loop control is established through multiple independent high-precision magnetic powder brakes and tension sensors, and multiple independent high-precision magnetic powder brakes are adjusted separately based on real-time sampling data.

[0008] As a further solution of the present invention: Step S300 includes the following sub-steps: S310: synchronously acquiring positioning marks and pattern outlines of each printing layer through a multispectral image acquisition unit, wherein: The conductive grid of the first printed layer is excited by a short-wave infrared light source; The infrared reflection strips of the third printed layer are detected by the near infrared band; The pattern contours are extracted by visible light polarization imaging; S320: analyzing the boundaries of each layer of patterns based on a sub-pixel edge detection algorithm and obtaining offset data; S330: Compare the offset data with a preset tolerance database, and when an unconventional offset pattern is detected, trigger a self-learning compensation parameter update mechanism.

[0009] As a further solution of the present invention: in step S400, the compensation mechanism includes: Implementing piezoelectric ceramic lateral displacement compensation on the third printed layer; Adjust the feeding speed of the second printing layer to produce a rate difference of 0.5%-2%; A directional thermal expansion gradient of 45±5° C. is formed in the composite contact area of the first printing layer, the second printing layer and the third printing layer.

[0010] As a further solution of the present invention: Step S500 includes the following steps: S510: Pulse pre-curing adopts a zonal irradiation strategy, dynamically adjusts the shape of the ultraviolet light spot and the energy ratio according to the pattern density distribution of each printing layer. A circular light spot is matched for the high pattern density area to suppress edge warping, a rectangular light spot is used for the low pattern density area to enhance the central curing strength, and overlapping scanning of the light spots is implemented at the pattern junction to eliminate the residue in the dark area; S520: During the pre-curing stage, the axial slidability of the adhesive layer of the second printing layer is retained, and the relative position freedom between layers is maintained through a vacuum adsorption film; S530: When finally curing, a cooperative regulation mechanism of the infrared radiation field and the material light transmittance is established. Backward radiation is applied to the first printing layer to penetrate the substrate and activate deep curing. The third printing layer uses reflective radiation to enhance the surface crosslinking degree, and the colloid of the second printing layer controls the molecular orientation through bidirectional radiation gradient; S540: During the curing process, the change of the interlayer dielectric constant is monitored synchronously. When the detected dielectric difference value exceeds the preset threshold, the radiation energy spectrum distribution is adjusted in real time to balance the curing rate.

[0011] Compared with the prior art, the beneficial effects of the present invention are as follows: Through the multi-layer cooperative positioning mechanism of the conductive grid positioning mark and the infrared-sensitive reflective strip, the present invention significantly improves the interlayer alignment accuracy of the label. Combined with the refined regulation of the printing layer tension by the multi-axis independent tension control system, the cumulative error caused by material deformation is effectively suppressed; The high-speed vision detection system realizes the dynamic monitoring of the micron-level offset by analyzing the spatial relationship between the conductive grid and the infrared reflection characteristics in real time. With the real-time compensation mechanism, the interlayer error can be stably controlled within the process threshold, greatly reducing the scrap rate; The innovative two-stage curing process, through the timing control of pulse ultraviolet pre-curing and infrared final curing, not only ensures the process tolerance of secondary positioning in the semi-curing stage, but also improves the interlayer bonding strength through gradient curing, and finally realizes the continuous and stable production of high-precision multi-layer anti-counterfeiting labels, achieving continuous and stable production in the field of high-end anti-counterfeiting labels. Description of the Drawings

[0012] Figure 1 is the flow chart of S100 - S500 in the present invention; Figure 2 is the schematic diagram of the overlapping state structure of the first, second and third positioning marks in the present invention; Figure 3 is the three-dimensional structure diagram of an embodiment of the present invention; The reference numerals and names in the drawings are as follows: The first printing layer - 1, the second printing layer - 2, the third printing layer - 3, the first positioning mark - A, the second positioning mark - B, the third positioning mark - C, the overlapping compensation area / composite contact area - D, the piezoelectric ceramic lateral displacement compensation device - 5, the high-precision magnetic powder brake - 6. Specific embodiments

[0013] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0014] Please refer to Figures 1-3 , a multi-level label production method with an automatic deviation correction effect, including the following steps: S100: The multi-level label includes a first printing layer 1 printed with a first pattern, a second printing layer 2 printed with a second pattern, and a third printing layer 3 printed with a third pattern. A conductive grid positioning mark is preset on the surface of the first printing layer, and an infrared-sensitive reflective strip is provided at the edge of the third printing layer. Differentiated patterns that can be superimposed are printed on each printing layer respectively; S200: Implement independent tension control on the first printing layer, the second printing layer, and the third printing layer by using multiple groups of independent tension control systems; S300: Real-time monitor the superimposed alignment state of the patterns on each printing layer through a high-speed vision detection system, and calculate the interlayer offset based on the relative positions of the conductive grid and the infrared reflective strip; S400: When it is detected that the offset of any adjacent printing layer exceeds the offset threshold, synchronously trigger the compensation mechanism; S500: Adopt a two-stage curing process after multi-layer lamination. First, form a semi-cured adhesive layer that can be repositioned through pulsed ultraviolet irradiation, and then complete the final curing through infrared radiation; As shown in the figure, during the production process of the present invention, first, the first, second, and third patterns are printed on the first, second, and third printing layers respectively, and then the material trays of the printed first, second, and third printing layers are fed. Through multiple groups of independent tension control systems (the independent tension control system includes a high-precision magnetic powder brake installed on a piezoelectric ceramic micro-displacement platform), the composite feeding of the first, second, and third printing layers is carried out respectively. During the feeding process, the first, second, and third printing layers are integrated into a label whole to achieve the superimposed positioning of the first, second, and third printing layers; The technical solution of the present invention constructs a three-dimensional spatial reference network in a multi-layer printing system by introducing a multi-modal collaborative positioning mechanism of a conductive grid positioning mark and an infrared-sensitive reflective strip: the conductive grid of the first printing layer forms a global electronic coordinate through a preset micron-level metal wire array, and the infrared-sensitive reflective strip of the third printing layer constructs an optical feature mark by using a periodically arranged germanium-based composite material. Through the cross-media signal coupling of electromagnetic-optical, the high-speed vision detection system can simultaneously capture the electromagnetic induction signal of the conductive grid and the optical feature of the infrared reflective strip, and establish a three-dimensional space mapping model by using a multi-source sensor fusion algorithm, improving the traditional two-dimensional plane positioning accuracy; The multi-axis independent tension control system adopts a closed-loop feedback network composed of multiple groups of independent high-precision magnetic powder brakes and tension sensors, implements a differential tension strategy for the material characteristics of different printing layers (such as the PET base material of the first printing layer and the composite film of the third printing layer), and reduces the deformation difference of multi-layer materials by compensating the elastic modulus difference of each layer of materials in real time (the tension of the PET layer is controlled at 18-22N, and the release paper layer is maintained at 12-15N), effectively solving the problem of cumulative printing deviation caused by different material ductility. For example, when the tension of the second printing layer is too small, the printed pattern on the second printing layer will have a deviation of a smaller pattern, and when the tension of the second printing layer is too large, the printed pattern on the second printing layer will have a deviation of a larger pattern, ultimately resulting in an offset during the pattern superposition process; The high-speed vision detection system is equipped with a line array CMOS with a frame rate of 2000Hz and an adaptive optical zoom module, achieving a full-frame scanning period ≤5ms at a production speed of 120m / min. Through a convolutional neural network, sub-pixel-level feature extraction is performed on the conductive grid nodes and infrared reflection stripes, and an improved RANSAC algorithm is combined to calculate the interlayer affine transformation matrix, enabling the dynamic offset detection resolution to meet the predetermined requirements. When the detected offset exceeds the preset threshold (such as ±10μm), real-time correction within the range of ±200μm can be completed within 3 transmission cycles (about 18ms) by driving an independently set piezoelectric ceramic micro-displacement platform (a high-precision magnetic powder brake for installing a material tray is provided on the piezoelectric ceramic micro-displacement platform), reducing the error variance; The two-stage curing process innovatively adopts the timing energy matching technology of 365nm pulsed ultraviolet (pulse width 50μs, peak power 800W / cm²) and mid-wave infrared (3-5μm band, power density 15kW / m²). In the pre-curing stage, the acrylate adhesive layer reaches 60% cross-linking degree through the selective excitation of ultraviolet photons, retaining the molecular chain segment activity ability to achieve a certain range of secondary positioning compensation window. In the final curing stage, the remaining monomers are promoted to polymerize deeply through the excitation of the molecular vibration energy level of infrared radiation, and the final curing degree reaches 98.5% and the interlayer peel strength is improved; The present invention significantly improves the inter-layer alignment accuracy of labels through the multi-layer collaborative positioning mechanism of conductive grid positioning marks and infrared sensitive reflective strips, and combines the multi-axis independent tension control system to finely control the tension of the printing layer, effectively suppressing the cumulative error caused by material deformation; The high-speed visual inspection system can dynamically monitor the micron-level offset by analyzing the spatial relationship between the conductive grid and the infrared reflection characteristics in real time. The real-time compensation mechanism can stably control the inter-layer error within the process threshold, greatly reducing the scrap rate. The innovative two-stage curing process ensures the process tolerance of secondary positioning in the semi-curing stage through the timing control of pulsed UV pre-curing and infrared final curing, and improves the inter-layer bonding strength through gradient curing, ultimately realizing the continuous and stable production of high-precision multi-layer anti-counterfeiting labels, and achieving continuous and stable production in the field of high-end anti-counterfeiting labels.

[0015] In the embodiment of the present invention, the S100 includes the following steps: S110: The conductive grid positioning mark is formed by silver paste printing, with a grid line width of 15 μm and a spacing of 5 μm, covering more than 80% of the effective printing area of the first printing layer; S120: The infrared sensitive reflective strips are arranged on both sides along the traveling direction of the third printing layer, and the width of the reflective strips is 1.2-1.8 mm; S130: The superposition design of the differentiated patterns of each printing layer meets the following steps: The first printing layer is printed with a first positioning mark A, wherein the first positioning mark comprises a basic pattern with microtext; The second printing layer is printed with a second positioning mark B, and the second positioning mark includes a semi-transparent gradient transition area; The third printing layer is printed with a third positioning mark C, and the third positioning mark includes a fluorescent positioning mark arranged at the edge of the second printing layer and linked to the conductive grid; S140: The pattern edges of adjacent printing layers retain an overlapping compensation area D, wherein the outline of the overlapping compensation area forms a geometric mapping relationship with the positioning mark of the corresponding printing layer; The technical solution of the present invention achieves the dual improvement of high-precision alignment and safety protection by constructing a precise spatial reference and anti-counterfeiting function collaborative system in a multi-layer printing system; In S110, the conductive grid (line width 15μm, spacing 5μm) printed with silver paste covers more than 80% of the effective area of the first printed layer. Its densely distributed micron-level conductive network not only forms a highly sensitive electromagnetic induction layer, but also establishes a submicron-level spatial coordinate system through the grid node coordinates. Compared with the traditional aluminum wire grid, the positioning accuracy is improved and the signal strength is enhanced; In S120, the infrared-sensitive reflective strips with a width of 1.2 - 1.8 mm set on both sides adopt a germanium / silicon dioxide multi-layer film structure. The bilateral symmetrical layout is used to improve the signal-to-noise ratio of the edge detection of the third printing layer, ensuring the stability of the interlayer offset detection during high-speed movement. In S130, the differential positioning marks form a triple anti-counterfeiting system - the microtext in the first layer presents machine-readable feature codes, the semi-transparent gradient area in the second layer uses a stepwise dot density change of 0.1% - 10% to construct an optical Moiré effect verification layer, and the fluorescent positioning marks in the third layer achieve invisible anti-counterfeiting features through rare earth-doped aluminate materials. The interference fringes and spectral features generated by their spatial superposition form multiple anti-counterfeiting verification channels. In S140, the designed overlapping compensation area adopts a parametric contour algorithm (Bézier curve fitting tolerance), so that the adjacent layer pattern edges retain a dynamic compensation band. Its contour and the positioning marks form a Fourier transform pair relationship. When the interlayer offset occurs, the optimal compensation path can be automatically generated through frequency domain feature matching, reducing the risk of pattern breakage caused by multi-layer printing deviation in traditional processes. Through precise geometric parameter design, multi-modal anti-counterfeiting feature integration, and intelligent compensation mechanisms, the multi-layer printing positioning error is reduced, and at the same time, the anti-counterfeiting and positioning functions are intelligently combined.

[0016] In the embodiment of the present invention, the differential tension control in S200 includes: S210: Obtain the reference tension of the first printing layer in the reference size state and record it as the first tension, obtain the reference tension of the second printing layer in the reference size state and record it as the second tension, and obtain the reference tension of the third printing layer in the reference size state and record it as the third tension. S220: During the tension control process, dynamically adjust the proportional coefficient based on material characteristics. When it is detected that the environmental temperature change exceeds the threshold temperature, dynamically adjust the tensions of the first printing, second printing, and third printing layers respectively. S230: Construct a closed-loop control through multiple groups of independent high-precision magnetic powder brakes 6 and tension sensors, and adjust the multiple groups of independent high-precision magnetic powder brakes respectively based on real-time sampling data. The technical solution of the present invention realizes the ultra-precise tension coordinated control of the multi-layer printing system by constructing an intelligent tension regulation system based on material characteristics and environmental variables. In S210, a reference tension database is established for different printing layer materials (such as the first layer of PET substrate, the second layer of composite paper, and the third layer of composite film). By quantifying the differences in material elastic modulus and Poisson's ratio, an initial stress-strain mapping model is established for each layer. In S220, a temperature compensation algorithm is introduced. When it is detected that the environmental temperature change exceeds ±2°C, according to the material thermal expansion coefficient (such as 1.5×10⁻ for the PET layer5 / °C, release paper layer 2.8×10⁻ 5 / °C, composite film layer 0.9×10⁻ 5 / °C) to dynamically adjust the proportional coefficient, and the set value of the tension is corrected in real time through the thermodynamic coupling equation, so as to reduce the tension drift caused by temperature fluctuations; In S230, multiple groups of independently controlled magnetic powder brakes (response time ≤ 8 ms, torque resolution 0.01 N·m) and fiber Bragg grating tension sensors (sampling frequency 5 kHz, accuracy ±0.05 N) are used to construct a distributed closed-loop network. Based on the improved fuzzy PID algorithm, the multi-axis tension is decoupled and controlled in a coordinated manner, and the mechanical vibration interference is eliminated in real time through Kalman filtering, reducing the variance of the tension fluctuation; Combined with the material creep characteristic model (fitted with the Burgers four-element model, goodness of fit R² ≥ 0.998), the stress relaxation trend during long-term operation is predicted, and preventive compensation adjustment is carried out in advance, improving the tension stability during 8 consecutive hours of production. Through the multi-physical field coupling control and intelligent compensation mechanism, the misregistration failure rate in multi-layer label production is reduced, significantly improving the production stability and product qualification rate in complex environments.

[0017] In the embodiment of the present invention, the step S300 includes the following sub-steps: S310: Synchronously acquire the positioning marks and pattern contours of each printing layer through the multi-spectral image acquisition unit, where: The conductive grid of the first printing layer is excited by a short-wave infrared light source; The infrared reflection strip of the third printing layer is detected through the near-infrared band; The pattern contour is extracted by visible light polarization imaging; S320: Analyze the boundaries of the patterns of each layer based on the sub-pixel edge detection algorithm and obtain the offset data; S330: Compare the offset data with the preset tolerance database. When an abnormal offset pattern is detected, trigger the self-learning compensation parameter update mechanism; The technical solution of the present invention realizes the dynamic compensation of the interlayer offset with nanometer-level accuracy by constructing a multi-modal optical detection and intelligent decision-making system; In S310, a three-channel synchronous imaging technology of short-wave infrared (1.4 - 3 μm band), near-infrared (850 - 940 nm) and visible light polarization (wavelength 400 - 700 nm, extinction ratio ≥ 100:1) is adopted. The short-wave infrared penetrates the PET substrate of the first printing layer to excite the silver paste characteristics of the conductive grid. The near-infrared channel accurately captures the narrow-band spectral response of the germanium-based reflection strip of the third layer. The visible light polarization imaging eliminates the environmental light interference through the analysis of Stokes parameters, improving the accuracy of pattern contour extraction; In S320, an improved Zernike moment sub-pixel edge detection algorithm is adopted to achieve pixel-level boundary localization through orthogonal polynomial fitting at an image resolution of 1200 dpi. Combining with the frequency domain characteristics of the printing layer material (in one embodiment, the Fourier spatial frequency of the conductive grid is 25 lines / mm, and the fundamental frequency of the infrared reflection strip is 8 lines / mm), a multi-scale edge detection model is constructed to improve the detection resolution accuracy of the X / Y axial offset, with higher accuracy than the traditional Sobel operator; In S330, the established tolerance database contains 12 types of typical offset patterns (such as periodic offset caused by mechanical vibration, non-linear deformation caused by temperature gradient, etc.). The deep belief network (DBN) is used for feature clustering analysis. When an abnormal offset beyond the threshold range is detected, the compensation parameters (such as PID gain coefficient, prediction control time domain, etc.) are optimized online through the reinforcement learning algorithm, enabling the system to complete parameter self-tuning within 3 production cycles and reducing the false alarm rate of unconventional offsets; At the same time, the multi-spectral data fusion technology extracts cross-band feature vectors through principal component analysis and establishes a non-linear mapping model of interlayer offset and multi-variables such as tension-temperature-speed, making the dynamic alignment accuracy of multi-color overprinting stable and significantly enhancing the stability and economy of high-end anti-counterfeiting label production.

[0018] In the embodiment of the present invention, in step S400, the compensation mechanism includes: Implementing piezoelectric ceramic lateral displacement compensation for the third printing layer; Adjusting the feeding speed of the second printing layer to generate a speed difference of 0.5% - 2%; Forming a directional thermal expansion gradient of 45 ± 5°C in the composite contact area D of the first printing layer, the second printing layer, and the third printing layer; The technical solution of the present invention realizes dynamic interlayer alignment control with nanometer-level accuracy by constructing a multi-dimensional collaborative compensation system; The piezoelectric ceramic lateral displacement compensation device 5 (equipped with an NPXY50-286 piezoelectric ceramic nano-displacement stage) used for the third printing layer can perform high-frequency fine-tuning within the range of ±300μm (the adjustment frequency reaches 1kHz). Combining with the real-time edge position feedback signal, the lateral offset compensation accuracy of the third layer is improved to ±0.8μm, and the compensation efficiency is significantly higher than the traditional servo motor drive method; Implementing a 0.5% - 2% dynamic speed difference adjustment for the feeding speed of the second printing layer (based on the material elastic modulus adaptive algorithm, the adjustment step is 0.05%). By generating controllable elastic deformation (the strain range is 0.03% - 0.12%), the cumulative tension difference is offset, reducing the longitudinal overprint error while maintaining the material stress fluctuation ≤ 0.7N; A 45 ± 5 °C directional thermal expansion gradient formed in the composite contact area (precisely controlled by an infrared laser array, with a temperature gradient slope of 0.8 °C / mm), combined with the differences in the thermal expansion coefficients of each layer of material (PET layer: 1.5×10⁻ 5 / °C, release paper layer: 2.8×10⁻ 5 / °C, composite film layer: 0.9×10⁻ 5 / °C), induces a differential expansion amount of 0.02 - 0.15 mm / m. The gradient distribution is optimized in real time through a thermo-mechanical coupling model to suppress the color registration offset caused by temperature fluctuations; The coordinated operation of the three-axis compensation mechanism realizes dynamic parameter matching through the Lyapunov stability criterion. At high production speeds, the compensation response delays in the X, Y, and Z directions are reduced, the dynamic position error variance of multi-color overprinting is reduced, and the abnormal offset recovery time is shortened. With the adaptive learning function of the compensation parameters (based on the LSTM neural network prediction model, with a prediction error ≤ 3%), the equipment can still maintain stable overprinting accuracy in an environment with small fluctuations in temperature and humidity, improve the product yield, increase the overall production line efficiency (OEE), and support the composite production of heterogeneous materials with partial thickness differences.

[0019] In the embodiment of the present invention, the step S500 includes the following steps: S510: Pulse pre-curing adopts a zone irradiation strategy, dynamically adjusts the shape and energy ratio of the ultraviolet light spot according to the pattern density distribution of each printing layer. The high-pattern-density area is matched with an annular light spot to suppress edge warping, the low-pattern-density area uses a rectangular light spot to enhance the central curing intensity, and the light spot overlap scanning is implemented at the pattern junction to eliminate the residue in the dark area; S520: During the pre-curing stage, the axial slidability of the adhesive layer of the second printing layer is retained, and the relative position freedom between layers is maintained through a vacuum adsorption film; S530: When finally curing, a cooperative regulation mechanism of the infrared radiation field and the material light transmittance is established. The first printing layer is irradiated from the back to penetrate the substrate to activate deep curing, the third printing layer uses reflective radiation to enhance the surface crosslinking degree, and the colloid of the second printing layer controls the molecular orientation through a two-way radiation gradient; S540: During the curing process, the change in the interlayer dielectric constant is monitored synchronously. When the detected dielectric difference value exceeds the preset threshold, the radiation energy spectrum distribution is adjusted in real time to balance the curing rate; The technical solution of the present invention realizes the gradient precise curing and stress optimization of multi-layer composite materials by constructing an intelligent curing system with optical-thermal-electric multi-field coupling; In S510, the partitioned irradiation strategy uses a digital micromirror array (DMA) to dynamically generate UV spots (365nm wavelength, power density adjustable from 0-800mW / cm²), forming an annular spot with an outer diameter of 3mm and an inner diameter of 1.2mm (edge power gradient of 15mW / mm²) in the high pattern density area (≥80% coverage), and reducing the warpage of the PET substrate through edge energy suppression; a 2×5mm rectangular spot (center power density increased to 650mW / cm²) is used in the low-density area (≤30% coverage) to make the acrylate glue layer reach 45% cross-linking degree within 0.8 seconds, and a 30% spot overlap scan (scanning speed 15mm / s) is implemented at the junction to reduce the residual rate of the dark area; In S520, the vacuum adsorption film (porosity 35%, adsorption pressure difference -85kPa) is used to maintain the axial sliding margin of the adhesive layer of 0.05-0.12mm, and the dielectric elastomer sensor (sensitivity 0.02N / mm²) is combined to monitor the interlayer stress in real time, so that the secondary positioning compensation window is expanded to ±80μm; In S530, the infrared radiation field established uses wavelength-space dual modulation technology. The first layer of back radiation (3-5μm band, power density 8kW / m²) penetrates the 150μm PET substrate to increase the deep colloid curing degree to 92%. The third layer of reflective radiation (using a parabolic focusing mirror, the radiation intensity is increased by 3 times) to increase the surface cross-linking density. The second layer of bidirectional gradient control induces a molecular orientation degree of 78%, and the interlayer peeling strength is improved. In S540, the dielectric constant difference of each layer is monitored in real time (resolution ±0.05ε) by a broadband dielectric spectrometer (test frequency 1Hz-10MHz). When the dielectric difference is detected to exceed the threshold, the radiation energy spectrum is optimized by genetic algorithm (adjustment accuracy ±5nm) to reduce the standard deviation of the curing rate of the three layers; The system compresses the curing deformation of multi-layer labels through the coordinated spatiotemporal control of the energy field, reduces the porosity of the interlayer bonding, and supports the large-scale and efficient preparation of high-precision anti-counterfeiting labels.

[0020] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A multi-level label production method with an automatic deviation correction effect, characterized in that, The following steps are involved: S100: The multi-layer label includes a first printing layer printed with a first pattern, a second printing layer printed with a second pattern, and a third printing layer printed with a third pattern, a conductive grid positioning mark is preset on the surface of the first printing layer, an infrared sensitive reflection strip is set on the edge of the third printing layer, and each printing layer is printed with a differentiated pattern that can be superimposed; S200: Multiple independent tension control systems are used to implement independent tension control on the first printing layer, the second printing layer and the third printing layer; S300: The high-speed visual inspection system monitors the alignment status of each printed layer in real time, and calculates the inter-layer offset based on the relative position of the conductive grid and the infrared reflective strip; S400: When it is detected that the offset of any adjacent printing layer exceeds the offset threshold, a compensation mechanism is synchronously triggered; S500: A two-stage curing process is used after multi-layer lamination. First, a semi-cured adhesive layer that can be repositioned is formed by pulsed ultraviolet irradiation, and then the final curing is completed by infrared radiation.

2. A multi-level label production method with an automatic deviation correction effect according to claim 1, characterized in that, The S100 includes the following steps: S110: The conductive grid positioning mark is formed by silver paste printing, with a grid line width of 15 μm and a spacing of 5 μm, covering more than 80% of the effective printing area of the first printing layer; S120: The infrared sensitive reflective strips are arranged on both sides along the traveling direction of the third printing layer, and the width of the reflective strips is 1.2-1.8 mm; S130: The superposition design of the differentiated patterns of each printing layer meets the following steps: The first printing layer is printed with a first positioning mark, wherein the first positioning mark comprises a basic pattern with microtext; The second printing layer is printed with a second positioning mark, and the second positioning mark includes a semi-transparent gradient transition area; The third printed layer is printed with a third positioning mark, the third positioning mark comprising a fluorescent positioning mark arranged at the edge of the second printed layer and linked to the conductive grid; S140: Pattern edges of adjacent printing layers retain an overlapping compensation area, and the outline of the overlapping compensation area forms a geometric mapping relationship with the positioning mark of the corresponding printing layer.

3. A multi-level label production method with an automatic deviation correction effect according to claim 2, characterized in that, The differentiated tension control in S200 includes: S210: obtaining a reference tension of the first printing layer in a reference size state and recording it as a first tension, obtaining a reference tension of the second printing layer in a reference size state and recording it as a second tension, and obtaining a reference tension of the third printing layer in a reference size state and recording it as a third tension; S220: During the tension control process, dynamically adjust the proportional coefficient based on the material characteristics, and when it is detected that the ambient temperature changes beyond the threshold temperature, dynamically adjust the tensions of the first printing layer, the second printing layer, and the third printing layer respectively; S230: Closed-loop control is established through multiple independent high-precision magnetic powder brakes and tension sensors, and multiple independent high-precision magnetic powder brakes are adjusted separately based on real-time sampling data.

4. A multi-level label production method with an automatic rectification effect according to claim 3, characterized in that, The step S300 includes the following sub-steps: S310: synchronously acquiring positioning marks and pattern outlines of each printing layer through a multispectral image acquisition unit, wherein: The conductive grid of the first printed layer is excited by a short-wave infrared light source; The infrared reflection strips of the third printed layer are detected by the near infrared band; The pattern contours are extracted by visible light polarization imaging; S320: Analyze the boundaries of each layer pattern based on the sub-pixel edge detection algorithm and obtain the offset data; S330: Compare the offset data with the preset tolerance database. When an abnormal offset pattern is detected, trigger the self-learning compensation parameter update mechanism.

5. A multi-level label production method with an automatic deviation correction effect according to claim 4, characterized in that In step S400, the compensation mechanism includes: Implement piezoelectric ceramic lateral displacement compensation for the third printing layer; Adjust the feeding speed of the second printing layer to generate a speed difference of 0.5% - 2%; Form a directional thermal expansion gradient of 45 ± 5 °C in the composite contact area of the first, second, and third printing layers.

6. A multi-level label production method with an automatic deviation correction effect according to claim 5, characterized in that, The step S500 includes the following steps: S510: The pulsed pre-curing adopts a zonal irradiation strategy, dynamically adjusts the shape of the ultraviolet light spot and the energy ratio according to the pattern density distribution of each printing layer. For the high-pattern density area, match an annular light spot to suppress edge warping. For the low-pattern density area, use a rectangular light spot to enhance the central curing intensity. At the pattern junction, implement overlapping scanning of the light spots to eliminate the residue in the dark area; S520: Retain the axial slidability of the adhesive layer of the second printing layer during the pre-curing stage, and maintain the relative position freedom between layers through a vacuum adsorption film; S530: When finally curing, establish a cooperative regulation mechanism between the infrared radiation field and the material light transmittance. Implement back radiation for the first printing layer to penetrate the substrate and activate deep curing. The third printing layer uses reflective radiation to enhance the surface crosslinking degree. The colloid of the second printing layer controls the molecular orientation through a two-way radiation gradient; S540: During the curing process, synchronously monitor the change in the interlayer dielectric constant. When the detected dielectric difference value exceeds the preset threshold, adjust the radiation energy spectrum distribution in real time to balance the curing rate.

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