Precise etching coating device and application thereof on implicit anti-counterfeiting transfer paper

Abstract

The invention relates to the technical field of film coating, in particular to a precise etching film coating device and application of the precise etching film coating device to implicit anti-fake transfer paper.The precise etching film coating device comprises a vacuum film coating mechanism, a flexographic printing mechanism, a film unwinding mechanism and a film winding mechanism; the flexographic printing mechanism is sequentially provided with an ink spraying assembly, an ink feeding roller, an ink transferring roller, a flexographic printing roller and a back pressure roller in the ink transferring direction, and the flexographic printing mechanism adopting the ink steam spraying technology is integrated in the vacuum coating mechanism and located on the upstream of a coating area; according to the invention, ultra-low and high-uniformity ink image-text pre-printing is carried out on the film material in a vacuum environment, seamless connection with the subsequent aluminum plating process is realized, and the problem that the ultra-low ink coating amount is difficult to accurately and uniformly control is solved.

Description

Technical Field

[0001] This invention relates to the field of coating technology, specifically to a precision etching coating device and its application on implicit anti-counterfeiting transfer paper. Background Technology

[0002] In the field of high-end packaging anti-counterfeiting, forming precise and concealed graphics on an extremely thin vacuum-plated aluminum layer is an effective way to achieve implicit anti-counterfeiting. Among existing technologies, the "precision etching coating" process, which combines flexographic printing with vacuum coating, has attracted attention. Its principle is to utilize pre-printed ink (such as perfluoropolyether), which evaporates upon heating during the subsequent high-temperature aluminum plating process, carrying away some of the aluminum vapor. This creates a difference in aluminum layer thickness between the graphic and non-graphic areas, forming a visual "etching" effect.

[0003] However, the implementation of this process faces several challenges: First, the precise control of ultra-low ink coating volume is a difficult problem. Traditional flexographic inking methods (such as anilox rollers or rubber rollers) cannot achieve uniform and stable ink supply at the nanometer level, failing to meet the stringent requirement of producing clear thickness differences on ultra-thin aluminum layers. Second, the formation and consistency of fine graphics are challenging. Ensuring the clarity, uniformity, and edge sharpness of printed lines under extremely low ink volume conditions is extremely difficult, directly affecting the concealment and visibility of the final anti-counterfeiting graphics. Third, the amplitude of the jump (shaking) of each guide roller during the flexographic printing process is difficult to control.

[0004] Existing solutions are mostly simple combinations of printing and coating equipment, lacking targeted design for the aforementioned core issues. This results in poor process stability and insufficient image and text detail, making it difficult to meet the industrialization requirements of high-quality implicit anti-counterfeiting transfer paper. Therefore, there is an urgent need to develop a completely new integrated device and process to overcome the limitations of traditional technologies. Summary of the Invention

[0005] To address the problems existing in the prior art, a precision etching and coating device and its application on implicit anti-counterfeiting transfer paper are provided. By integrating a flexographic printing mechanism using ink vapor spraying technology into the vacuum coating mechanism and placing it upstream of the coating area, ultra-low amount and high uniformity ink pre-printing of the film material is achieved in a vacuum environment, and it is seamlessly connected with the subsequent aluminum plating process, overcoming the problem of difficulty in accurately and uniformly controlling the extremely low ink coating amount.

[0006] To address the problems of existing technologies, this invention provides a precision etching and coating apparatus, comprising: a vacuum coating mechanism having a coating area for a film material to pass through; a flexographic printing mechanism located inside the vacuum coating mechanism and upstream of the coating area, for printing a preset image onto the film surface in ink form before the film material enters the coating area; a film unwinding mechanism and a film winding mechanism, both disposed within the vacuum coating mechanism, wherein the film material released by the film unwinding mechanism passes sequentially through the flexographic printing mechanism and the coating area, and is then wound up by the film winding mechanism; wherein the flexographic printing mechanism is sequentially provided with an ink spraying assembly, an inking roller, and other components along the ink transfer direction. The film unwinding mechanism consists of an ink transfer roller, a flexographic roller, and a back pressure roller. The film material fed out by the film unwinding mechanism is clamped between the flexographic roller and the back pressure roller. The ink spraying assembly sprays ink vapor onto the ink transfer roller. The back pressure roller provides back pressure to keep the film material in contact with the flexographic roller. The ink vapor is evenly distributed by the ink transfer roller and then transferred to the flexographic roller, and transferred to the surface of the film material to form a preset image. When the film material with the preset image passes through the coating area, the ink in the image area is heated and evaporates, while simultaneously carrying away some of the coating vapor. This results in the coating thickness in the corresponding image area being less than that in the adjacent non-printing area, thus revealing the image on the coating of the film material.

[0007] Preferably, the ink spraying assembly includes an ink cartridge and a heating assembly disposed within the ink cartridge. The heating assembly heats the ink to form an ink vapor chamber in the upper part of the ink cartridge. The top of the ink cartridge is provided with ink jet holes arranged at equal intervals along the length direction of the ink roller, and the ink jet holes communicate with the ink vapor chamber.

[0008] Preferably, the ink spraying assembly further includes an inkjet roller rotatably mounted on the top of the ink cartridge and a nozzle switching motor mounted on the ink cartridge and drivenly connected to the inkjet roller. The inkjet roller is hollow and communicates with the ink vapor chamber of the ink cartridge. At least two sets of inkjet nozzles are distributed circumferentially on the inkjet roller. Each set of inkjet nozzles is arranged at equal intervals along the axial direction of the inkjet roller, and the inner diameter of the inkjet nozzles in each set of inkjet nozzles gradually decreases from one set of inkjet nozzles to the adjacent set of inkjet nozzles.

[0009] Preferably, the ink cartridge includes a cartridge body and a cover body disposed on the cartridge body; the top of the cover body has a mounting groove, and the inkjet roller is rotatably disposed in the mounting groove; the two ends of the opening of the mounting groove extend upward to expose a set of inkjet nozzles on the inkjet roller.

[0010] Preferably, the inkjet roller has connecting posts at both ends that penetrate the sidewall of the ink cartridge, one end of which is connected to the nozzle switching motor; each connecting post has a guiding cavity communicating with the inside of the inkjet roller, and a guiding groove is formed on the surface of the connecting post; a vapor channel is provided in the sidewall of the ink cartridge, which is used to connect the ink vapor cavity and the guiding groove.

[0011] Preferably, the flexographic printing mechanism further includes a main frame, and both ends of the ink spraying assembly, the ink feeding roller, the ink transfer roller, and the back pressure roller are movably mounted on the main frame, with the ink spraying assembly moving synchronously with the ink feeding roller.

[0012] Preferably, the main frame is provided with a first lead screw adjusting assembly for driving the ink spraying assembly and the ink roller to move synchronously, a second lead screw adjusting assembly for driving the ink transfer roller to move, and a third lead screw adjusting assembly for driving the back pressure roller to move.

[0013] Preferably, the heating assembly includes at least three sets of heating tubes, with the heating power of the three sets of heating tubes increasing sequentially.

[0014] Preferably, a cooling assembly is provided around the ink cartridge, and a temperature probe is provided inside the ink cartridge.

[0015] The application of a precision etching and coating device on implicit anti-counterfeiting transfer paper includes the following steps: Step 1: Adjust and set the printing parameters of the flexographic printing mechanism to form a preset implicit anti-counterfeiting graphic on the surface of the substrate. Step 2: Start the film unwinding mechanism and the vacuum coating mechanism, so that the printing substrate passes through the flexographic printing mechanism and the coating area in sequence; Step 3: During the movement of the film material, ink vapor is sprayed onto the ink roller through the ink spraying assembly, and then evenly distributed by the ink transfer roller and transferred by the flexographic printing roller to form the hidden anti-counterfeiting graphics on the surface of the film material. Step 4: The film material with the aforementioned implicit anti-counterfeiting graphics enters the coating area for vacuum coating. Step 5: During the coating process, the ink in the graphic area is heated and evaporates, carrying away some of the coating vapor, so that the coating thickness in this area is less than that in the surrounding non-printed areas. Step six: After being wound up by the film winding mechanism, a transfer paper with implicit anti-counterfeiting graphics on its surface is obtained.

[0016] The advantages of this application compared to the prior art are: 1. Traditional mechanical contact ink supply methods struggle to achieve stable nanoscale ink transfer. This application employs ink vapor spraying technology, where heated ink vaporizes and is sprayed non-contactly onto the surface of the ink roller via micro-holes, where it condenses into a uniform ultra-thin film. The coating amount is precisely and digitally controlled by adjusting the heating temperature, vapor pressure, and selecting inkjet nozzle groups with different apertures, fundamentally avoiding the uneven coating problems caused by mechanical fluctuations in traditional methods. 2. To address issues such as uneven edges and broken lines that easily occur under extremely low ink volume, this application employs multiple measures to ensure uniformity: First, the initial ink film formed by vapor condensation inherently possesses excellent uniformity; second, the pressure and spacing between each roller can be precisely adjusted via independent lead screw adjustment components (first, second, and third lead screw adjustment components) to ensure stable and controllable ink distribution and transfer processes; third, the entire printing process is conducted in a vacuum environment, free from dust and airflow interference, ensuring high environmental stability and thus guaranteeing the clarity, uniformity, and edge sharpness of the printed lines. 3. Mechanical vibration and air disturbance are the main causes of guide roller runout in traditional open environments. This application integrates the entire flexographic printing mechanism within the vacuum coating mechanism, thus eliminating air disturbance first. Secondly, it adopts an integrated rigid main frame design, with all key rollers mounted and locked onto the frame via high-precision guide rails and lead screw assemblies, forming a highly rigid, low-vibration unit. With the flexographic roller fixed, the positions of other rollers are adjusted to adapt to the process, preventing instability of the core printing position during adjustment. This effectively suppresses guide roller runout at high speeds, ensuring printing registration and image consistency. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a precision etching and coating device of the present invention and its application on implicit anti-counterfeiting transfer paper; Figure 2 This is a three-dimensional cross-sectional view of a precision etching and coating device of the present invention and its application on implicit anti-counterfeiting transfer paper. Figure 3 This is a cross-sectional view of a precision etching and coating device of the present invention and its application on implicit anti-counterfeiting transfer paper. Figure 4 yes Figure 3 A magnified view of part A; Figure 5 This is a perspective view of a precision etching and coating device of the present invention and its application on implicit anti-counterfeiting transfer paper, showing the flexographic printing mechanism. Figure 6 yes Figure 5 A magnified view of section B; Figure 7 This is a perspective view of a precision etching and coating device of the present invention and its application on implicit anti-counterfeiting transfer paper, including an ink spraying component and an inking roller. Figure 8 This is a perspective view of a precision etching and coating device of the present invention and its application on implicit anti-counterfeiting transfer paper, showing an ink spraying component. Figure 9 This is a cross-sectional view of a precision etching and coating device of the present invention and its application on implicit anti-counterfeiting transfer paper, showing the ink spraying component. Figure 10 This is an exploded perspective view of a precision etching and coating device of the present invention and its application on implicit anti-counterfeiting transfer paper, showing the ink spraying component.

[0018] The diagram is labeled as follows: 11. Coating area; 21. Ink spraying assembly; 211. Ink cartridge; 2111. Ink vapor chamber; 2112. Carton body; 2113. Cover; 2114. Vapor channel; 212. Heating assembly; 213. Inkjet roller; 2131. Inkjet nozzle assembly; 214. Nozzle switching motor; 215. Connecting column; 2151. Conducting cavity; 2152. Conducting groove; 216. Temperature probe; 22. Ink loading roller; 23. Ink transfer roller; 24. Flexographic roller; 25. Back pressure roller; 26. Main frame; 27. First lead screw adjustment assembly; 28. Second lead screw adjustment assembly; 29. ​​Third lead screw adjustment assembly; 3. Film unwinding mechanism; 4. Film winding mechanism; 5. Guide roller. Detailed Implementation

[0019] To further understand the features, technical means, and specific objectives and functions achieved by the present invention, the present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

[0020] like Figures 1 to 3As shown, a precision etching and coating apparatus includes: a vacuum coating mechanism with a coating area 11 for the film material to pass through; a flexographic printing mechanism located inside the vacuum coating mechanism and upstream of the coating area 11, used to print a preset image onto the surface of the film material in ink form before the film material enters the coating area 11; a film unwinding mechanism 3 and a film winding mechanism 4, both located in the vacuum coating mechanism, wherein the film material released by the film unwinding mechanism 3 passes sequentially through the flexographic printing mechanism and the coating area 11, and is then wound up by the film winding mechanism 4; wherein the flexographic printing mechanism is provided with an ink spraying assembly 21, an inking roller 22, an ink transfer roller 23, and a flexographic printing roller 24 sequentially along the ink transfer direction. The film material delivered by the film unwinding mechanism 3 is clamped between the flexographic roller 24 and the back pressure roller 25. The ink spraying assembly 21 sprays ink vapor onto the inking roller 22. The back pressure roller 25 provides back pressure to keep the film material in contact with the flexographic roller 24. The ink vapor is transferred to the flexographic roller 24 after being evenly inked by the ink transfer roller 23, and then transferred to the surface of the film material to form a preset image. When the film material with the preset image passes through the coating area 11, the ink in the image area is heated and evaporates, and at the same time, some of the coating vapor is carried away, resulting in the coating thickness of the corresponding image area being less than that of the adjacent non-printing area, thereby displaying the image on the coating of the film material.

[0021] Among them, the guide roller 5 is used to guide the film material through the flexographic printing mechanism and the vacuum coating mechanism.

[0022] The vacuum coating unit has a coating zone 11 for the continuous passage of the film material. The flexographic printing unit is located inside the vacuum coating unit, upstream of the coating zone 11. Its function is to precisely print pre-set anti-counterfeiting or decorative graphics onto the film surface in the form of an ultra-thin ink layer before the film enters the coating zone 11. The film material conveying system consists of a film unwinding mechanism 3 and a film winding mechanism 4, both of which are located within the vacuum coating unit. During operation, the substrate film released by the film unwinding mechanism 3 passes sequentially through the flexographic printing mechanism for graphic printing, then enters the coating zone 11 for metal vapor deposition, and finally is wound up by the film winding mechanism 4, forming a continuous integrated production process.

[0023] The flexographic printing mechanism is sequentially arranged along the ink transfer path, including an ink spraying assembly 21, an inking roller 22, an inking roller 23, a flexographic roller 24, and a back pressure roller 25. The film material delivered by the film unwinding mechanism 3 is held between the flexographic roller 24 and the back pressure roller 25, which provides back pressure. The ink spraying assembly 21 uses vaporization technology to convert special ink into ink vapor and spray it onto the inking roller 22. The ink vapor condenses on the surface of the inking roller 22 to form liquid ink. This liquid ink is homogenized by the inking roller 23 and stably transferred to the surface of the flexographic roller 24, which has a preset graphic structure. Finally, under the pressure of the back pressure roller 25, it is precisely transferred to the surface of the continuously moving film material, forming an extremely thin and uniform preset graphic.

[0024] The film material carrying the aforementioned pre-set ink graphics then enters the high-temperature coating zone 11. In this zone, the temperature of the evaporated metal (such as aluminum) vapor is extremely high. When the metal vapor reaches the surface of the film material, the low-boiling-point ink in the graphic area is instantly heated and evaporates, carrying away some of the metal vapor that is about to be deposited. In the graphic area with ink, the actual thickness of the final deposited metal coating will be significantly thinner than the surrounding unprinted areas. This optical interference or visual contrast effect caused by the thickness difference ultimately makes the pre-set graphics clearly visible on the seemingly uniform metal coating.

[0025] like Figure 8 As shown, the ink spraying assembly 21 includes an ink cartridge 211 and a heating assembly 212 disposed within the ink cartridge 211. The heating assembly 212 heats the ink to form an ink vapor chamber 2111 in the upper part of the ink cartridge 211. The top of the ink cartridge 211 is provided with ink jet holes arranged at equal intervals along the length direction of the ink roller 22, and the ink jet holes communicate with the ink vapor chamber 2111.

[0026] The ink spraying assembly 21, as the core unit for achieving ultra-low volume and uniform coating, specifically includes an ink cartridge 211 and a heating assembly 212 built into it. The function of the heating assembly 212 is to controllably heat the special ink inside the ink cartridge 211, causing it to vaporize in the upper space inside the ink cartridge 211, thereby forming a stable ink vapor chamber 2111.

[0027] To ensure the directional and uniform delivery of ink vapor from the vapor chamber to the inking roller 22, multiple ink jet holes are provided on the top of the ink cartridge 211. These ink jet holes are arranged at equal intervals along the axial length of the inking roller 22, ensuring the uniformity of ink vapor supply across the entire width of the inking roller 22.

[0028] All inkjet nozzles are directly connected to the ink vapor chamber 2111 below, so that the ink vapor generated by heating can be continuously and stably sprayed onto the surface of the ink roller 22 above through the inkjet nozzles.

[0029] This allows for the replacement of traditional mechanical contact ink supply (such as anilox rollers) with directional jetting, fundamentally solving the problem of uneven and stable transfer of extremely small amounts of ink, and providing a precise material supply basis for achieving the subsequent "etching" effect with nanoscale thickness differences.

[0030] Work environment: 1. Vacuuming process: The vacuum pressure around ink cartridge 211 changes from atmospheric pressure to 0.02 Pa to 0.008 Pa; 2. Vacuuming Process: The temperature of the ink cartridge 211 changes from room temperature to -135℃ (the low-temperature environment inside the vacuum chamber is mainly achieved through an externally connected cryogenic unit. In vacuum coating equipment, cryogenic units (such as cryogenic refrigerators or liquid nitrogen cooling systems) are typically configured. Cooling media is introduced into the cooling plates or components inside the vacuum chamber through cooling pipes, thereby achieving localized or overall low temperatures in a vacuum environment. In this device, cooling components are installed around the ink cartridge (mentioned below in the manual as "the cooling components are connected to the cryogenic unit outside the vacuum chamber through copper pipes"), which can assist in cooling during the vacuuming process. Furthermore, the change in heat conduction under vacuum, combined with the external cryogenic system, allows for process low temperatures of -120℃ to -150℃ in a set area, a common technique in vacuum coating processes.), the ink cartridge 211 has a capacity of no more than 10 liters. When heating begins, high-power heating is used. When the temperature of the perfluoropolyether oil inside the ink cartridge 211 approaches the operating temperature, heating is reduced to a suitable temperature to ensure normal volatilization of the perfluoropolyether (in very small amounts).

[0031] like Figure 4 and Figure 7 As shown, the ink spraying assembly further includes an inkjet roller 213 rotatably mounted on the top of the ink cartridge 211 and a nozzle switching motor 214 mounted on the ink cartridge 211 and drivenly connected to the inkjet roller 213. The inkjet roller 213 is hollow and communicates with the ink vapor chamber 2111 of the ink cartridge 211. At least two sets of inkjet nozzle groups 2131 are distributed circumferentially on the inkjet roller 213. Each set of inkjet nozzle groups 2131 is arranged at equal intervals along the axial direction of the inkjet roller 213, and the inner diameter of the inkjet nozzles included in each set of inkjet nozzle groups 2131 gradually decreases from one set of inkjet nozzle groups 2131 to the adjacent set of inkjet nozzle groups 2131.

[0032] When the inkjet roller 213 rotates, the corresponding inkjet holes rotate in the circumferential direction. Since the cover can only allow one set of inkjet holes to be outside the cover, and the diameter of each set of inkjet holes is different, the ink volume can be adjusted by rotating the position of different inkjet holes (the ink volume control of the ink supply roller 22). The inkjet roller 213 has at least 3 sets of inkjet holes arranged in a regular manner in the width direction. The diameter of the first set of inkjet holes is the smallest (e.g., 2mm), and the spacing between two inkjet holes is 20-30mm. The diameter of the second set of inkjet holes is larger than that of the first set of inkjet holes (e.g., 3mm), and the diameter of the third set of inkjet holes is larger than that of the second set of inkjet holes (e.g., 4mm). The spacing between two inkjet holes in each set of inkjet holes is 20-30mm.

[0033] The inkjet roller 213 is designed as a hollow roller body, and its internal cavity is directly connected to the ink vapor chamber 2111 in the ink cartridge 211, ensuring that ink vapor can enter the interior of the roller body.

[0034] On the circumferential surface of the inkjet roller 213, at least two sets of inkjet nozzle groups 2131 are regularly distributed along its circumference. Each set of inkjet nozzle groups 2131 consists of a series of tiny channels arranged at equal intervals along the axial direction of the inkjet roller 213, ensuring the axial uniformity of the jet.

[0035] The inkjet holes contained in different inkjet hole groups 2131 are designed with different inner diameters, and usually show a pattern of gradually decreasing from one inkjet hole group 2131 to the adjacent inkjet hole group 2131.

[0036] By driving the inkjet roller 213 to rotate through the nozzle switching motor 214, the inkjet nozzle groups 2131 with different apertures can be aligned and connected to the upper ink roller 22 in sequence, thereby quickly and accurately changing the ink vapor jet flow rate without interrupting production or replacing hardware.

[0037] The larger the aperture, the more steam is ejected per unit time, and vice versa. This provides an online, adjustable, and digital means of controlling process parameters to achieve "etching" patterns with different levels of precision and contrast, greatly enhancing the flexibility and adaptability of the equipment and enabling a single unit to meet diverse and customized precision etching production needs.

[0038] like Figure 4 and Figure 10 As shown, the ink cartridge 211 includes a cartridge body 2112 and a cover body 2113 covering the cartridge body 2112; the top of the cover body 2113 is provided with a mounting groove, and the inkjet roller 213 is rotatably disposed in the mounting groove; the two ends of the opening of the mounting groove extend upward to expose a set of inkjet nozzles 2131 on the inkjet roller 213.

[0039] To ensure that ink vapor can be accurately sprayed onto the upper inking roller 22, the opening of the mounting groove is designed with upwardly extending notches at both ends (corresponding to the axial ends of the inkjet roller 213). This ensures that when the inkjet roller 213 rotates in the mounting groove, a set of inkjet orifice groups 2131 (which can be orifice groups of different diameters depending on the rotation position) is always fully exposed to the external space through these upwardly extending notches, and maintains a constant, interference-free spray distance with the surface of the upper inking roller 22.

[0040] This structure provides stable rotational support for the inkjet roller 213 and precisely defines its effective working area (i.e., the range of the exposed inkjet nozzle group 2131), ensuring that the ink vapor jetting path is concentrated, controllable and efficient, avoiding the diffusion and waste of vapor in non-target areas, and further ensuring coating uniformity and process stability.

[0041] like Figure 8 and Figure 9 As shown, the inkjet roller 213 has connecting posts 215 penetrating the sidewall of the ink cartridge 211 at both ends, with one end of the connecting post 215 being drivenly connected to the nozzle switching motor 214; each connecting post 215 has a guiding cavity 2151 communicating with the inside of the inkjet roller 213, and a guiding groove 2152 is formed on the surface of the connecting post 215; a vapor channel 2114 is provided in the sidewall of the ink cartridge 211, which is used to connect the ink vapor cavity 2111 and the guiding groove 2152.

[0042] To ensure that ink vapor can be smoothly introduced from the vapor chamber inside the ink cartridge 211 into the rotating inkjet roller 213, the connecting column 215 is provided with a guiding cavity 2151. This guiding cavity 2151 is directly connected to the hollow interior of the inkjet roller 213, forming the main channel for vapor to enter the roller body.

[0043] Meanwhile, an annular or angled guide groove 2152 is formed on the surface of the connecting post 215. Correspondingly, a dedicated vapor channel 2114 is pre-installed inside the side wall of the ink cartridge 211. After the inkjet roller 213 and its connecting post 215 are installed in place, one end of the vapor channel 2114 is connected to the ink vapor chamber 2111 at the top of the main cavity of the ink cartridge 211, and the other end is aligned with and connected to the guide groove 2152 on the surface of the connecting post 215. This dynamic sealing air supply design ensures that no matter how the inkjet roller 213 rotates under the drive of the motor, the ink vapor can continuously and stably pass through the fixed vapor channel 2114, flow through the guide groove 2152 and the guide chamber 2151 on the connecting post 215, and finally enter the interior of the inkjet roller 213, providing a constant vapor source for the inkjet nozzle assembly 2131 on its surface.

[0044] First, the ink is precisely heated inside the ink cartridge 211, creating an ink vapor chamber 2111 with a certain pressure. The vapor pressure within this chamber is set to be maintained at a level slightly higher than the external vacuum pressure, forming a localized micro-positive pressure zone. Second, after the vapor reaches the inkjet roller 213 from the ink cartridge 211, it is ejected upwards at high speed and in a concentrated manner through tiny inkjet holes (with apertures only on the order of millimeters, as described in the manual, 2 to 4 millimeters). This small-aperture, short-distance directional jetting pattern gives the ink vapor jet high speed and good directionality, effectively penetrating and resisting any vacuum airflow interference in its path, ensuring that the vast majority of it accurately reaches the surface of the inking roller 22 directly above.

[0045] Meanwhile, the inking roller 22 itself operates in a low-temperature environment within the vacuum chamber (e.g., down to -125 degrees Celsius). When high-temperature ink vapor (such as perfluoropolyether, which has a relatively low boiling point) impacts the low-temperature surface of the inking roller 22 at high speed, it immediately condenses, instantly transforming from a gaseous state into an extremely thin liquid oil film, which then firmly adheres to the roller surface. This process is extremely rapid; the ink only enters the subsequent ink-spreading stage after condensation and adhesion, thus physically preventing the vaporized ink from being directly drawn away by the vacuum system.

[0046] The inkjet roller 213 passes through the side wall of the ink cartridge 211 via connecting posts 215 at both ends. The connecting posts 215 have a guide cavity 2151 inside and a ring of guide grooves 2152 on their surface. A vapor channel 2114 is pre-installed in the side wall of the ink cartridge 211. One end of the vapor channel 2114 is connected to the ink vapor cavity, and the other end is aligned with the guide grooves 2152 on the surface of the connecting posts 215.

[0047] When the inkjet roller 213 rotates, the connecting column 215 rotates accordingly, but the vapor channel 2114 always remains connected to the guiding cavity 2151 through the guiding groove 2152, so as to achieve continuous air supply in the rotating state. This is a "groove-cavity docking" dynamic sealing structure, which ensures that ink vapor does not leak and is transported stably.

[0048] like Figure 5 and Figure 6 As shown, the flexographic printing mechanism also includes a main frame 26. The ink spraying assembly 21, the ink feeding roller 22, the ink transfer roller 23, and the back pressure roller 25 are all movably mounted on the main frame 26. The ink spraying assembly 21 moves synchronously with the ink feeding roller 22.

[0049] The main frame 26 provides a stable mounting base for the entire flexographic printing unit. The ink spraying assembly 21, the inking roller 22, the ink transfer roller 23, and the back pressure roller 25 are all designed with adjustable and movable features at both ends.

[0050] These components are mounted on the main frame 26 via slides, guide rails or similar structures, allowing for precise adjustment of their relative positions according to different process requirements (such as changing flexographic rollers 24 of different diameters, adjusting printing pressure, or adapting to film materials of different thicknesses).

[0051] The relative position between the ink spraying assembly 21 and the inking roller 22 is designed to be linked and adjustable, ensuring that they always maintain the preset, optimal spraying distance and relative angle during movement and adjustment. This synchronous movement design ensures that once the optimal steam spraying conditions are set according to a specific job, these conditions will not be disrupted by subsequent overall spacing adjustments to accommodate the flexographic roller 24, thereby maintaining the stability and repeatability of the ultra-low volume ink transfer process, simplifying the equipment calibration process, and improving production changeover efficiency.

[0052] like Figure 5 and Figure 6 As shown, the main frame 26 includes a first lead screw adjusting assembly 27 for driving the ink spraying assembly 21 and the ink roller 22 to move synchronously, a second lead screw adjusting assembly 28 for driving the ink transfer roller 23 to move, and a third lead screw adjusting assembly 29 for driving the back pressure roller 25 to move.

[0053] Multiple sets of lead screw adjustment assemblies are respectively installed on the main frame 26. A first lead screw adjustment assembly 27 is provided to drive the ink spraying assembly 21 and the ink roller 22 to move synchronously. The first lead screw adjustment assembly 27 converts the rotational motion of the servo motor into the linear displacement of the ink spraying assembly 21 and the mounting base of the ink roller 22 as a whole through the lead screw and nut transmission pair, ensuring that the two are synchronized during adjustment and always maintain the predetermined optimal relative position.

[0054] Meanwhile, the main frame 26 is also independently equipped with a second lead screw adjustment assembly 28 for driving the movement of the inking roller 23, and a third lead screw adjustment assembly 29 for driving the movement of the back pressure roller 25. The second lead screw adjustment assembly 28 allows the operator to independently adjust the contact pressure (i.e., ink distribution pressure) between the inking roller 23 and the inking roller 22 and flexographic roller 24. The third lead screw adjustment assembly 29 is used to independently control the pressing pressure (i.e., printing pressure) of the back pressure roller 25 on the flexographic roller 24, which directly affects the integrity, clarity, and registration accuracy of the ink image transfer to the film material.

[0055] These three independent lead screw adjustment assemblies allow operators to finely adjust the relative positions and pressures of the rollers within the printing unit for different specifications of the flexographic rollers 24, different ink properties, and different graphic requirements. This optimizes every step from ink vapor jetting and ink distribution to final impression transfer, ensuring the stability of the entire precision etching printing process and a high degree of consistency in the quality of the resulting images. This modular, independently adjustable design greatly enhances the equipment's process adaptability and operational flexibility.

[0056] like Figure 4 As shown, the heating component 212 includes up to three sets of heating tubes, and the heating power of the three sets of heating tubes increases sequentially.

[0057] The ink cartridge 211 is mounted on the main frame 26 of the ink roller 22, directly below the ink roller 22, and movable with the ink roller 22. The ink roller 22 is rotatably mounted on the main frame 26, which is mounted on the main frame 26 via a linear guide rail. The ink cartridge 211 consists of a cartridge body 2112 and a cover. At least three sets of heating tubes are provided at the bottom of the ink cartridge 211. The first set of heating tubes has a low heating power (e.g., 1 kW), the second set has twice the power of the first set (e.g., 2 kW), the third set has twice the power of the second set (e.g., 8 kW), and so on. The number and power of the heating tubes depend on the size of the ink cartridge 211. The heating tubes are electrically connected to the heating controller and main controller outside the vacuum chamber. Figure 8 As shown, a cooling assembly is provided around the ink cartridge 211, and a temperature probe 216 is provided inside the ink cartridge 211.

[0058] The box 2112 is surrounded by a cooling assembly, which is connected to a cryogenic chamber outside the vacuum chamber via copper pipes. The box 2112 is equipped with at least one temperature probe 216, which is electrically connected to the main controller outside the vacuum chamber to monitor the oil temperature inside the ink cartridge 211. The box 2112 is also equipped with an oil filling hole for adding ink.

[0059] The application of a precision etching and coating device on implicit anti-counterfeiting transfer paper includes the following steps: Step 1: Adjust and set the printing parameters of the flexographic printing mechanism to form a preset implicit anti-counterfeiting graphic on the surface of the substrate. Step 2: Start the film unwinding mechanism 3 and the vacuum coating mechanism, so that the printing substrate passes through the flexographic printing mechanism and the coating area 11 in sequence; Step 3: During the movement of the film material, ink vapor is sprayed upward onto the ink roller 22 by the ink spraying component 21, and then evenly distributed by the ink transfer roller 23 and transferred by the flexographic printing roller 24 to form the hidden anti-counterfeiting graphics on the surface of the film material. Step 4: The film material with the implicit anti-counterfeiting graphics enters the coating area 11 for vacuum coating. Step 5: During the coating process, the ink in the graphic area is heated and evaporates, carrying away some of the coating vapor, so that the coating thickness in this area is less than that in the surrounding non-printed areas. Step six: After being wound up by the film winding mechanism 4, a transfer paper with implicit anti-counterfeiting graphics on its surface is obtained.

[0060] The precision etching and coating method includes the following steps: S1, A release layer is coated on a PET film and dried in an infrared oven to obtain a PET release film; S2, PET release film is molded on a laser holographic molding machine to obtain PET molded film; S3, the PET molding film is in the vacuum coating machine. The operator manually pulls the PET molding film through the film unwinding mechanism 3, the flexographic printing mechanism, the vacuum coating mechanism, and the film winding mechanism 4 in sequence. S4, the flexographic ink perfluoropolyether is injected into the ink cartridge 211 through the ink cartridge 211 filling port, the ink cartridge 211 is sealed, and the vacuum coating mechanism starts to draw a vacuum. S5. While the vacuum coating mechanism is drawing a vacuum, all the heating tubes at the bottom of the ink cartridge 211 start heating. When the temperature inside the vacuum chamber reaches -125℃ (the temperature during vacuum coating) and the oil temperature in the ink cartridge 211 reaches 75℃, the heating tube with the highest heating power is turned off. When the oil temperature inside the ink cartridge 211 reaches 85℃, the heating tube with the second highest heating power is turned off. When the oil temperature inside the ink cartridge 211 reaches 95℃, only the heating tube with the lowest power is left to work. S6, when the ink temperature of ink cartridge 211 reaches 105℃, the inkjet roller 213 is rotated, causing perfluoropolyether vapor to be sprayed onto the surface of ink roller 22 through the ink spray nozzle. The perfluoropolyether vapor liquefies upon cooling on the surface of ink roller 22, forming liquid perfluoropolyether. Thus, the perfluoropolyether is coated onto the surface of ink roller 22. As ink roller 22 rotates, the perfluoropolyether on its surface first passes through ink transfer roller 23, which then transfers ink to flexographic roller 24. Finally, the ink in the image area on flexographic roller 24 is transferred to the PET coated surface (flexographic printing surface) under the action of back pressure roller 25. S7, after the PET molding film is flexographically printed, it directly enters the coating area 11 to evaporate the aluminum layer. When the flexographically printed perfluoropolyether graphic area passes through the coating roller (aluminum vapor deposition position) on the vacuum coating mechanism, the perfluoropolyether on its surface is heated and evaporates instantly. At the same time, it carries away most of the aluminum vapor on its surface, thereby achieving precise etching on the aluminum layer, and finally obtaining a precision etched holographic aluminum transfer film.

[0061] In step S6, ink vapor enters the inkjet roller 213 from the ink vapor chamber via the vapor channel, and is then ejected through the inkjet nozzle group on the surface of the inkjet roller 213. The inkjet roller 213 is located directly below the inking roller 22, and its diameter is much smaller than that of the inking roller 22, so the spray range is concentrated and aimed at the surface of the inking roller. The inkjet roller 213 has multiple sets of inkjet nozzles with different diameters around its circumference. The inkjet roller 213 is rotated to switch nozzle groups only when it is necessary to adjust the ink spray volume. Otherwise, it remains stationary to ensure that the spray position is fixed. In addition, the mounting groove design on the ink cartridge 211 cover 2113 exposes only one set of inkjet nozzles, further constraining the direction of vapor spray and preventing splashing to areas other than the inking roller.

[0062] As a further aspect of the present invention, S6 includes the following steps: S61. During precision etching, the operator observes the etched pattern in real time outside the vacuum chamber. If the etched pattern is too thin (insufficient coating), rotate the inkjet roller 213 to select an inkjet nozzle with a larger diameter (increase coating). If necessary, replace one set of high-power heating tubes or add another set of heating tubes. If the etched pattern is too coarse (excessive coating), rotate the inkjet roller 213 to select an inkjet nozzle with a smaller diameter (decrease coating). If necessary, replace one set of low-power heating tubes or remove one set of heating tubes. S62, once the ink amount on the inking roller 22 is determined, when the inking roller 22 applies greater pressure to the inking roller 23, the amount of ink transferred from the inking roller 22 to the inking roller 23 will increase. Consequently, the amount of ink transferred from the inking roller 23 to the flexographic roller 24 will be greater, resulting in thicker characters after flexographic printing. Conversely, when the inking roller 22 applies less pressure to the inking roller 23, the amount of ink transferred from the inking roller 22 to the inking roller 23 will decrease, resulting in less ink transferred from the inking roller 23 to the flexographic roller 24. Consequently, the characters after flexographic printing will be thinner. S63. When it is found that the flexographic text is uneven in thickness, deformed, or blurry in the left and right (axial direction) directions, it indicates that the pressure applied by the back pressure roller 25 to the flexographic roller 24 is uneven, too low, or too high. At this time, the appropriate pressure on the flexographic roller 24 can be obtained through the third lead screw adjustment assembly 29. When the back pressure roller 25 presses against the flexographic roller 24, the pressure applied by the back pressure roller to the flexographic roller 24 will increase (the text becomes thicker, deformed, and blurry). When the back pressure roller 25 slightly separates from the flexographic roller 24, the pressure applied by the back pressure roller 25 to the flexographic roller 24 will decrease (the text becomes thinner and clearer).

[0063] The above embodiments only illustrate one or more implementations of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of protection of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A precision etching and coating apparatus, characterized in that, include: A vacuum coating mechanism has an internal coating area for the film material to pass through. A flexographic printing mechanism is located inside the vacuum coating mechanism and upstream of the coating area. It is used to print a preset image onto the surface of the film material in ink form before the film material enters the coating area. A film unwinding mechanism and a film winding mechanism are both located in the vacuum coating mechanism. The film material released by the film unwinding mechanism passes sequentially through the flexographic printing mechanism and the coating area, and is then wound up by the film winding mechanism. The flexographic printing mechanism includes, along the ink transfer direction, an ink spraying assembly, an inking roller, an ink transfer roller, a flexographic printing roller, and a back pressure roller. The film material fed by the unwinding mechanism is clamped between the flexographic roller and the back pressure roller. The ink spraying assembly is used to spray ink vapor onto the inking roller. The back pressure roller is used to provide back pressure to keep the film material and the flexographic roller in contact. The ink vapor is transferred to the flexographic roller after being evenly distributed by the inking roller, and then transferred to the surface of the film material to form a preset image. When the film material with the preset image passes through the coating area, the ink in the image area is heated and evaporates, and at the same time, some of the coating vapor is carried away, resulting in the coating thickness of the corresponding image area being less than that of the adjacent non-printing area, thereby revealing the image on the coating of the film material.

2. The precision etching and coating apparatus according to claim 1, characterized in that, The ink spraying assembly includes an ink cartridge and a heating assembly disposed within the ink cartridge. The heating assembly heats the ink to form an ink vapor chamber in the upper part of the ink cartridge. The top of the ink cartridge is provided with ink spray holes arranged at equal intervals along the length of the ink roller, and the ink spray holes communicate with the ink vapor chamber.

3. The precision etching and coating apparatus according to claim 2, characterized in that, The ink spraying assembly further includes an inkjet roller rotatably mounted on the top of the ink cartridge and a nozzle switching motor mounted on the ink cartridge and drivenly connected to the inkjet roller. The inkjet roller is hollow and communicates with the ink vapor chamber of the ink cartridge. At least two sets of inkjet nozzles are distributed circumferentially on the inkjet roller. Each set of inkjet nozzles is arranged at equal intervals along the axial direction of the inkjet roller, and the inner diameter of the inkjet nozzles in each set of inkjet nozzles gradually decreases from one set of inkjet nozzles to the adjacent set of inkjet nozzles.

4. The precision etching and coating apparatus according to claim 3, characterized in that, The ink cartridge includes a cartridge body and a cover covering the cartridge body; the top of the cover has a mounting groove, and the inkjet roller is rotatably disposed in the mounting groove; the two ends of the mounting groove opening extend upward to expose a set of inkjet nozzles on the inkjet roller.

5. The precision etching and coating apparatus according to claim 3, characterized in that, The inkjet roller has connecting posts at both ends that penetrate the side wall of the ink cartridge, and one end of the connecting post is connected to the nozzle switching motor. Each connecting post has a guiding cavity that communicates with the inside of the inkjet roller, and a guiding groove is formed on the surface of the connecting post. A vapor channel is provided in the side wall of the ink cartridge, and the vapor channel is used to connect the ink vapor cavity and the guiding groove.

6. A precision etching and coating apparatus according to any one of claims 3-5, characterized in that, The flexographic printing mechanism also includes a main frame. The ink spraying assembly, the ink feeding roller, the ink transfer roller, and the back pressure roller are all movably mounted on the main frame at both ends. The ink spraying assembly moves synchronously with the ink feeding roller.

7. The precision etching and coating apparatus according to claim 6, characterized in that, The main frame is provided with a first lead screw adjusting assembly for driving the ink spraying assembly and the ink roller to move synchronously, a second lead screw adjusting assembly for driving the ink transfer roller to move, and a third lead screw adjusting assembly for driving the back pressure roller to move.

8. A precision etching and coating apparatus according to any one of claims 2-5, characterized in that, The heating assembly includes at least three sets of heating tubes, with the heating power of the three sets of heating tubes increasing sequentially.

9. A precision etching and coating apparatus according to any one of claims 2-5, characterized in that, A cooling assembly is provided around the ink cartridge, and a temperature probe is provided inside the ink cartridge.

10. The application of a precision etching and coating device on implicit anti-counterfeiting transfer paper, characterized in that, The precision etching and coating apparatus according to any one of claims 1-5 includes the following steps: Step 1: Adjust and set the printing parameters of the flexographic printing mechanism to form a preset implicit anti-counterfeiting graphic on the surface of the substrate. Step 2: Start the film unwinding mechanism and the vacuum coating mechanism, so that the printing substrate passes through the flexographic printing mechanism and the coating area in sequence; Step 3: During the movement of the film material, ink vapor is sprayed onto the ink roller through the ink spraying assembly, and then evenly distributed by the ink transfer roller and transferred by the flexographic printing roller to form the hidden anti-counterfeiting graphics on the surface of the film material. Step 4: The film material with the aforementioned implicit anti-counterfeiting graphics enters the coating area for vacuum coating. Step 5: During the coating process, the ink in the graphic area is heated and evaporates, carrying away some of the coating vapor, so that the coating thickness in this area is less than that in the surrounding non-printed areas. Step six: After being wound up by the film winding mechanism, transfer paper with implicit anti-counterfeiting graphics on its surface is obtained.

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