Photocuring printing equipment for embossment printing, embossment printing method and controller
By staggering the varnish and white ink printheads, a high-stack base printing layer is constructed, solving the problems of insufficient number of white ink printheads and high maintenance costs in UV printers, improving printing efficiency and embossing effect, and achieving synergistic optimization of cost and efficiency.
Patent Information
- Application Number
- CN202511625487.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-07
- Publication Date
- 2026-01-16
AI Technical Summary
Existing UV printers suffer from low efficiency and high costs in embossing printing due to insufficient white ink printheads. Furthermore, white ink is prone to sedimentation, causing printhead clogging and increasing maintenance costs.
The system employs an alternating arrangement of varnish and white ink printheads. The varnish printheads construct the baseline printing layer, while the layered design of the white base layer reduces the number of white ink printheads. The varnish printheads and curing device are used to achieve pre-curing and leveling treatment, forming a baseline printing layer with a high degree of stacking.
It reduces initial investment and maintenance costs, improves printing efficiency and embossing effect, ensures finished product quality, and achieves synergistic optimization of cost and efficiency.
Smart Images
Figure CN121340803A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] Embodiments of the present application relate to the technical field of printing equipment, in particular to a relief printing light-curing printing equipment, a relief printing method and a controller. BACKGROUND
[0002] A UV (Ultraviolet) printer is a digital printing device taking UV curing ink as the core and instantly curing the ink through a UV lamp, which can realize high-precision pattern printing on the surface of various materials. At present, the UV printer is widely used in relief printing scenes such as oil painting and Braille, aiming to enhance the three-dimensionality, texture and touch of the printed piece. The existing conventional printing process is as follows: first, white ink is used to form a relief base by stacking, and then color patterns are printed on the surface of the white ink stacking layer.
[0003] However, this process has significant technical contradictions: if the number of white ink nozzles configured is small, the white ink stacking efficiency is low, resulting in long overall printing cycle and low efficiency; if the number of white ink nozzles is increased to improve efficiency, the user's equipment procurement cost and daily consumable use cost will be greatly increased.
[0004] At the same time, white ink is prone to precipitation due to its own material properties, and long-term use can cause nozzle blockage, increase equipment maintenance frequency, and increase user's use risk and operation cost, which is difficult to meet the production demand of high efficiency and low cost. SUMMARY
[0005] An object of embodiments of the present application is to provide a relief printing light-curing printing equipment, a relief printing method and a controller to solve the technical problem that relief printing cannot coexist with high efficiency and low cost in the related art.
[0006] In a first aspect, embodiments of the present application provide a relief printing light-curing printing equipment, comprising: a first gloss oil nozzle, a second gloss oil nozzle, a white ink nozzle, a color ink nozzle, a first curing device, a second curing device and a controller. The first gloss oil nozzle, the second gloss oil nozzle, the white ink nozzle and the color ink nozzle are sequentially arranged in the printing head along a first direction for sequentially spraying corresponding gloss oil and ink, and the first direction is the direction of the printing medium. The first curing device is arranged on both sides of the first gloss oil nozzle for curing the gloss oil sprayed by the first gloss oil nozzle. The second curing device is arranged on both sides of the white ink nozzle and the color ink nozzle for curing the gloss oil sprayed by the second gloss oil nozzle, the white ink sprayed by the white ink nozzle and the color ink sprayed by the color ink nozzle. The controller is electrically connected to the first varnish printhead, the second varnish printhead, the white ink printhead, the color ink printhead, the first curing device, and the second curing device, respectively. The controller is configured to: Based on the first part of the nozzle in the first varnish nozzle, varnish is sprayed onto the printing medium, and the first curing device is controlled to irradiate it to obtain pre-cured varnish; Based on the second part of the nozzle in the first varnish nozzle and the second varnish nozzle spraying varnish onto the pre-cured varnish, after the varnish flows level, a high stacking degree reference printing layer is obtained. The white ink nozzle sprays white ink onto the reference printing layer, and the second curing device is controlled to irradiate it to obtain a white underlayer; The colored ink is sprayed onto the white substrate by the ink nozzle, and the second curing device is controlled to irradiate it to obtain a colored relief image.
[0007] Optionally, the first varnish printhead and the second varnish printhead are staggered in the second direction, the white ink printhead and the color ink printhead are staggered in the second direction, the first varnish printhead and the white ink printhead are in the same column in the second direction, the second varnish printhead and the color ink printhead are in the same column, and the second direction is perpendicular to the first direction.
[0008] Optionally, the first varnish nozzle and the first curing device have an overlap of a first preset length in the first direction, where the first preset length is the step length of the printing medium when the print head moves once in the second direction.
[0009] Optionally, the lengths of the first varnish nozzle and the second varnish nozzle in the first direction are equal to a preset multiple of the first preset length.
[0010] Optionally, the first curing device and the second curing device are spaced apart by a second preset length in the first direction, and the total length of the second preset length and the first preset length is equal to the total length of the first varnish nozzle and the second varnish nozzle in the first direction.
[0011] Optionally, the length of the second curing device in the first direction is equal to the total length of the white ink nozzle and the color ink nozzle in the first direction.
[0012] Optionally, the first curing device and the second curing device may be separate or integrated segmented LED lights.
[0013] Optionally, the first and second varnish printheads use a large-dot inkjet method to spray varnish.
[0014] Secondly, embodiments of this application provide an embossing printing method, applied to the photopolymerization printing equipment described above, the method comprising: The varnish is sprayed onto the printing medium based on the first part of the nozzle in the first varnish nozzle, and the first curing device is controlled to irradiate the varnish to obtain pre-cured varnish. Based on the second part of the nozzle in the first varnish nozzle and the second varnish nozzle spraying varnish onto the pre-cured varnish, after the varnish flows level, a high stacking degree reference printing layer is obtained. The white ink nozzle sprays white ink onto the reference printing layer, and the second curing device is controlled to irradiate it to obtain a white underlayer; The colored ink is sprayed onto the white substrate by the ink nozzle, and the second curing device is controlled to irradiate it to obtain a colored relief image.
[0015] Thirdly, embodiments of this application provide a controller, which includes a memory and a processor. The memory is connected to the processor, and the processor is used to execute one or more computer programs stored in the memory. When the processor executes the one or more computer programs, it causes the controller to implement the relief printing method as described above.
[0016] The embodiments of this application achieve the following technical effects: In the photopolymer printing equipment for relief printing provided in this application embodiment, a base printing layer is constructed by adding varnish nozzles. Combined with the subsequent layered design of the white underlayer, multiple technical benefits are achieved. The base printing layer provides a uniformly adhered substrate for the white underlayer, reducing the number of white ink nozzles required. This eliminates the need for stacking multiple sets of white ink nozzles, directly reducing initial equipment investment costs. Simultaneously, the reduced number of white ink nozzles lowers the frequency of nozzle cleaning and replacement, as well as consumable consumption, significantly reducing long-term maintenance costs. Furthermore, the base printing layer allows for higher stacking density, enhancing the three-dimensionality of the relief image. While improving the relief effect, printing efficiency remains unaffected, achieving synergistic optimization of cost, efficiency, and finished product quality. Attached Figure Description
[0017] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0018] Figure 1 This is a schematic diagram of the structure of a photopolymerization printing device for relief printing provided in an embodiment of this application; Figure 2 This is a schematic diagram of the layout of a nozzle and a curing device provided in an embodiment of this application; Figure 3 A schematic diagram of the motion of a photopolymerization printing device for relief printing provided in this application embodiment; Figure 4 A schematic flowchart of an embossing printing method provided in an embodiment of this application; Figure 5 This is a schematic diagram of the structure of a controller provided in an embodiment of this application. Detailed Implementation
[0019] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.
[0020] It should be noted that, unless there is a conflict, the various features in the embodiments of this application can be combined with each other, all of which are within the protection scope of this application. Furthermore, although functional modules are divided in the device schematic diagram and a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in a different order than the module division in the device or the order in the flowchart. Moreover, the terms "first," "second," and "third" used in this application do not limit the data or execution order, but only distinguish identical or similar items with essentially the same function and effect.
[0021] Please see below. Figure 1 , Figure 1 This is a schematic diagram of the structure of a photopolymer printing device for relief printing provided in an embodiment of this application. The photopolymer printing device 100 for relief printing includes a first varnish printhead 11, a second varnish printhead 12, a white ink printhead 13, a color ink printhead 14, a first curing device 15, a second curing device 16, and a controller 17. The controller 17 is electrically connected to the first varnish printhead 11, the second varnish printhead 12, the white ink printhead 13, the color ink printhead 14, the first curing device 15, and the second curing device 16.
[0022] The first varnish nozzle 11 includes a nozzle body. The nozzle body has a spray surface on the side facing the printing medium. Multiple nozzles are arranged in a linear array of multiple columns. The columns are parallel and equally spaced. The nozzles in the same column are evenly distributed along the direction of travel of the printing medium. Each nozzle is connected to an external varnish storage device through a varnish supply channel inside the nozzle body. Varnish is sprayed onto the printing medium through the nozzle.
[0023] Similarly, the second varnish nozzle 12 includes a nozzle body, and the nozzle body has a spray surface on the side facing the printing medium. Multiple nozzles are arranged in a linear array of multiple columns, with parallel columns and equal spacing between them. The nozzles in the same column are evenly distributed along the direction of travel of the printing medium. Each nozzle is connected to an external varnish storage device through a varnish supply channel inside the nozzle body. Varnish is sprayed onto the printing medium through the nozzle.
[0024] The white ink printhead 13 includes a printhead body, inside which is a white ink delivery chamber that communicates with an external white ink storage tank. The printhead body has a jetting end face on the side facing the printing medium, and multiple nozzles are arranged on the jetting end face in an equidistant linear array. The columns are parallel and equally spaced. Adjacent nozzles in the same column are equally spaced along the direction of travel of the printing medium. The diameter of each nozzle is uniform. The inlet end of the nozzle is connected to the white ink delivery chamber through a diversion channel inside the printhead body. The outlet end is polished to form a smooth jetting nozzle to avoid white ink residue clogging.
[0025] The color ink printhead 14 includes a printhead body with independent multi-component color delivery chambers inside. Each color delivery chamber is connected to an external color ink storage device for the corresponding color (such as cyan, magenta, yellow, and black). The printhead body has an ejection end face facing the printing medium, with multiple nozzles arranged in a staggered linear array. The columns are staggered but equally spaced, and adjacent nozzles within the same column have equal center-to-center spacing. The inlet of each nozzle is connected to the corresponding color delivery chamber via an independent microchannel, and the outlet is laser-polished to form a conical ejection nozzle, ensuring uniform atomized ink droplets during ink ejection. The color ink printhead 14 can also be composed of multiple separate printhead bodies arranged in combination for different colors.
[0026] The first varnish nozzle 11, the second varnish nozzle 12, the white ink nozzle 13, and the color ink nozzle 14 are sequentially arranged inside the print head along a first direction for sequentially spraying corresponding varnish and ink. The first direction is the direction of travel of the printing medium. Specifically, in the direction of travel of the printing medium, the first varnish nozzle 11, the second varnish nozzle 12, the white ink nozzle 13, and the color ink nozzle 14 are sequentially arranged inside the print head. The first varnish nozzle 11 and the second varnish nozzle 12 are used to spray varnish, the white ink nozzle 13 is used to spray white ink, and the color ink nozzle 14 is used to spray ink of different colors.
[0027] The first curing device 15 includes two independent LEDs, symmetrically distributed along a second direction, and respectively positioned on both sides of the first varnish nozzle 11. The second direction is perpendicular to the first direction, i.e., perpendicular to the direction of travel of the printing medium. Each LED is a strip-shaped light source structure, the length of which is adapted to the width of the nozzle array of the first varnish nozzle, ensuring that the irradiation range completely covers all nozzle spray areas. Both LEDs are equipped with independent power adjustment modules, allowing for light power adjustment to achieve ultraviolet light irradiation at different power levels.
[0028] It should be noted that the printhead reciprocates in the second direction. During this movement, the controller 17 controls each printhead and each curing device to perform corresponding printing operations. For example, if the second direction is defined as the left-right direction, when the print table moves to the right, after the first varnish printhead 11 sprays varnish, the controller 17 will control the left-side LED light to immediately irradiate and cure it. When the print table moves to the left, after the first varnish printhead 11 sprays varnish, the controller 17 will control the right-side LED light to immediately irradiate and cure it. This ensures that the area sprayed by the first varnish printhead 11 is irradiated by the first curing device 15, avoiding areas that cannot be irradiated and forming curing blind spots when only one side is set.
[0029] The second curing device 16 includes two independent LEDs symmetrically distributed along a second direction, positioned on either side of the white ink printhead 13 and the color ink printhead 14, respectively. The second direction is perpendicular to the first direction, i.e., perpendicular to the direction of travel of the printing medium. Each LED is a strip-shaped light source, its length adapted to the width of the nozzle array of the white ink printhead 13 and the color ink printhead 14, ensuring complete coverage of all nozzle spray areas. Both LEDs are equipped with independent power adjustment modules, allowing for light power adjustment to achieve different levels of ultraviolet light irradiation. The second curing device 16 is used to cure the inks sprayed from the second varnish printhead 12, the white ink printhead 13, and the color ink printhead 14.
[0030] It should be noted that the printhead reciprocates in the second direction. During this movement, the controller 17 controls each printhead and each curing device to perform corresponding printing operations. For example, if the second direction is defined as the left-right direction, when the print table moves to the right, after the white ink printhead 13 sprays white ink or the color ink printhead 14 sprays color ink, the controller 17 will control the left-side LED light to immediately irradiate and cure the ink. When the print table moves to the left, after the white ink printhead 13 sprays white ink or the color ink printhead 14 sprays color ink, the controller 17 will control the right-side LED light to immediately irradiate and cure the ink. This ensures that the area where the white ink printhead 13 sprays white ink or the color ink printhead 14 sprays color ink is irradiated by the second curing device 16, avoiding areas that cannot be irradiated and forming curing blind spots when only one side is set up.
[0031] The controller 17 is configured to perform relief printing based on the first varnish printhead 11, the second varnish printhead 12, the white ink printhead 13, the color ink printhead 14, the first curing device 15, and the second curing device 16.
[0032] Specifically, the controller 17 controls the first part of the nozzles in the first varnish nozzle 11 to spray varnish onto the printing medium. It should be noted that the first curing device 15 is located on both sides of the first varnish nozzle 11, with an overlapping portion. The first part of the nozzles consists of multiple rows of nozzles on the first varnish nozzle 11 along the length of the overlap with the first curing device 15 in the first direction. After spraying is complete, the controller 17 immediately controls the first curing device 15 to irradiate, achieving pre-curing of the varnish. Pre-curing involves prematurely and incompletely curing the sprayed varnish. By controlling the degree of curing, it achieves a state where the surface is initially set while retaining some internal fluidity, rather than directly completing full curing. The first curing device 15 can be power-adjusted. For example, using a medium-power mode allows for precise control of the varnish curing progress, achieving pre-cured varnish. This prevents the varnish from spreading and deforming due to excessive fluidity, providing a stable underlying support for subsequent varnish stacking.
[0033] The controller 17 controls the second part of the nozzles in the first varnish nozzle 11 and the second varnish nozzle 12 to spray varnish onto the pre-cured varnish. After the varnish has leveled, a high-density base printing layer is obtained. Specifically, the second part of the nozzles is the remaining part of the nozzles in the first varnish nozzle 11 after removing the first part of the nozzles. After the controller 17 controls the second part of the nozzles in the first varnish nozzle 11 to spray varnish onto the pre-cured varnish, it then controls the second varnish nozzle 12 to spray varnish. Leveling is the process by which the varnish naturally diffuses due to its own fluidity, filling the gaps between adjacent varnish dots to form a varnish stack layer with uniform thickness and a smooth surface. After the varnish has leveled, a base printing layer is obtained.
[0034] It should be noted that the varnish sprayed by the second part of the nozzle in the first varnish nozzle 11 and the varnish sprayed by the second varnish nozzle 12 is not immediately irradiated after spraying to achieve timely curing. Instead, the varnish is allowed to flow and level naturally. This results in a higher stacking height than immediate curing. In addition, the leveling process allows the varnish sprayed by the first varnish nozzle 11 and the varnish sprayed by the second varnish nozzle 12 to fully blend during the flow, forming a continuous single varnish stack layer, rather than two independent structures. This improves the structural stability of the base printing layer and avoids delamination during subsequent curing or printing.
[0035] The controller 17 controls the white ink printhead 13 to spray white ink onto the reference printing layer and controls the second curing device 16 to irradiate it, thus obtaining a white underlayer. Specifically, the controller 17 controls the white ink printhead 13 to spray white ink onto the reference printing layer, and immediately after spraying is completed, controls the second curing device 16 to irradiate it, thus obtaining a white underlayer. The second curing device 16 can adjust the light power; for example, using a high-power mode for irradiation can cure the varnish and white ink, preventing the white ink from penetrating into the reference printing layer and affecting the structure, while also providing a stable surface for subsequent spraying of colored inks.
[0036] The controller 17 controls the inkjet head 14 to spray colored ink onto the white substrate and controls the second curing device 16 to irradiate it, thus obtaining a colored embossed image. Specifically, the controller 17 divides the colored pattern to be printed into several pixel units, each unit corresponding to a set of nozzles on the inkjet head. A single set of nozzles includes CMYK four-color nozzles, such as cyan, magenta, yellow, and black. After obtaining the white substrate, the controller 17 controls each set of nozzles to spray the corresponding color ink according to the colored pattern. The single spray volume and spray frequency of the nozzles can be adjusted to regulate the color density. After spraying is completed, the controller immediately controls the second curing device 16 to irradiate the ink, thus curing it and obtaining the colored embossed image.
[0037] This application embodiment achieves multiple technical benefits by adding a varnish printhead to construct a baseline printing layer, which, in conjunction with the subsequent layered design of the white base layer, realizes multiple technical benefits. Specifically, the baseline printing layer provides a uniform adhesion substrate for the white base layer, reducing the number of white ink printheads required. This eliminates the need for stacking multiple sets of white ink printheads, directly reducing initial equipment investment costs. Simultaneously, the reduced number of white ink printheads decreases the frequency of printhead cleaning and replacement, as well as consumable consumption, significantly reducing long-term maintenance costs. Furthermore, the baseline printing layer allows for higher stacking density, enhancing the three-dimensionality of the embossed image. While improving the embossing effect, it ensures that printing efficiency is not affected, achieving synergistic optimization of cost, efficiency, and finished product quality.
[0038] In some embodiments, please refer to Figure 2 , Figure 2 This is a schematic diagram of the layout of a printhead and curing device provided in an embodiment of this application. The first varnish printhead 11 and the second varnish printhead 12 are staggered in the second direction, and the white ink printhead 13 and the color ink printhead 14 are staggered in the second direction. The first varnish printhead 11 and the white ink printhead 13 are in the same column in the second direction, and the second varnish printhead 12 and the color ink printhead 14 are in the same column. The second direction is perpendicular to the first direction.
[0039] Specifically, in Figure 2In the diagram, the y-direction represents the first direction, i.e., the direction of travel of the printing medium, and the x-direction represents the second direction, which is perpendicular to the first direction, i.e., the printing width direction. The first varnish printhead 11, the second varnish printhead 12, the white ink printhead 13, and the color ink printhead 14 are arranged in four rows sequentially in the first direction, and in two columns in the second direction. The first varnish printhead 11 and the white ink printhead 13 are in the same column in the second direction, and the second varnish printhead 12 and the color ink printhead 14 are in the same column. The first varnish printhead 11 and the second varnish printhead 12 form an alternating layout in the second direction, as do the white ink printhead 13 and the color ink printhead 14.
[0040] In some embodiments, the first varnish nozzle 11 and the first curing device 15 have an overlap of a first preset length in the first direction, where the first preset length is the step length of the printing medium when the print head moves once in the second direction.
[0041] For details, please continue reading. Figure 2 The first curing device includes two LEDs, respectively positioned on both sides of the first varnish nozzle 11. The first varnish nozzle 11 and the LEDs overlap by a first preset length in the direction of travel of the printing medium. The first preset length is set as the step length of the printing medium when the print head moves once in the second direction. For details, please refer to [link to relevant documentation]. Figure 3 The printhead 31 reciprocates in the second direction. During this movement, the controller 17 controls each nozzle and curing device to perform corresponding printing operations, and the printing medium gradually moves along the first direction on the print table 32. It can be understood that each time the printhead 31 moves in the second direction, the printing medium moves a first preset length in the first direction. In this embodiment, the first preset length is set in the range of 15-25 mm.
[0042] It should be noted that the first part of the nozzles refers to the multiple rows of nozzles that overlap with the first curing device 15 in the first direction. Therefore, the length of the first part of the nozzles in the first varnish nozzle 11 in the first direction is equal to a first preset length. Setting the length of the overlap to the first preset length ensures that when the print head moves once in the second direction, the irradiation range of the first curing device 15 synchronously covers the varnish just sprayed by the first part of the nozzles in the first varnish nozzle 11 during this movement, allowing the varnish to be immediately irradiated and cured, avoiding varnish diffusion due to curing delay. Furthermore, the overlapping portion is for pre-curing the varnish; in this embodiment, this overlapping portion is defined as a pre-cured section.
[0043] In some embodiments, the length of the first varnish nozzle 11 and the second varnish nozzle 12 in the first direction is equal to a first preset length that is a preset multiple thereof.
[0044] Specifically, the preset multiple is set to 3, that is, the length of the first varnish nozzle 11 and the second varnish nozzle 12 in the first direction is equal to 3 times the first preset length. The first preset length is set as the step length of the printing medium when the print head moves once in the second direction. In this embodiment, the first preset length is set in the range of 15-25mm.
[0045] In some embodiments, the first curing device 15 and the second curing device 16 are spaced apart by a second preset length in the first direction, and the total length of the second preset length and the first preset length is equal to the total length of the first varnish nozzle 11 and the second varnish nozzle 12 in the first direction.
[0046] For details, please continue reading. Figure 2 The first varnish nozzle 11 and the second varnish nozzle 12 are arranged sequentially in the first direction, while the first curing device 15 and the second curing device 16 are arranged at intervals in the first direction. The first curing device 15 and the second curing device 16 are spaced apart by a second preset length in the first direction. The total length of the second preset length and the first preset length is equal to the total length of the first varnish nozzle 11 and the second varnish nozzle 12 in the first direction. It can be understood that the length of the first varnish nozzle 11 and the second varnish nozzle 12 in the first direction is equal to 3 times the first preset length, that is, the total length of the first varnish nozzle 11 and the second varnish nozzle 12 in the first direction is 6 times the first preset length. Therefore, the second preset length is equal to 5 times the first preset length.
[0047] It should be noted that when the printing medium moves within the second preset length, the controller 17 controls the second part of the nozzles of the first varnish nozzle 11 and the second varnish nozzle 12 to spray varnish onto the pre-cured varnish. At this time, curing does not occur immediately; instead, the sprayed varnish is allowed to naturally level out. In this embodiment, the portion characterized by the second preset length is defined as the leveling section. The pre-curing section pre-cures the varnish sprayed from the first part of the nozzles in the first varnish nozzle 11, i.e., the varnish surface is shaped, resulting in pre-cured varnish. The leveling section follows the pre-curing section, allowing the varnish sprayed from the second part of the nozzles in the first varnish nozzle 11 and the varnish sprayed from the second varnish nozzle 12 to naturally level out, preventing the pre-cured varnish from forming layers with subsequent varnish due to complete curing. The flow allows the two layers of varnish to fully fuse, forming a continuous, seamless reference printing layer, providing a uniform adhesion surface for subsequent white ink spraying.
[0048] The leveling section does not undergo curing. The varnish can be layered to the designed thickness with the support of the pre-cured varnish, usually achieving a higher degree of layering than direct irradiation curing. Natural leveling also allows the varnish to be evenly distributed, avoiding localized excessive thickness that could lead to cracking after curing, or excessive thinness that would affect the three-dimensionality of the relief. At the same time, the evenly layered varnish can buffer the pressure of subsequent white and colored inks, reducing the risk of ink layer peeling off and improving the structural stability and durability of the relief artwork.
[0049] In some embodiments, the length of the second curing device 16 in the first direction is equal to the total length of the white ink nozzle 13 and the color ink nozzle 14 in the first direction.
[0050] For details, please continue reading. Figure 2 The second curing device 16 includes two LEDs, respectively positioned on either side of the white ink nozzle 13 and the color ink nozzle 14, for curing the white and color inks. The length of the second curing device 16 in the first direction is equal to the total length of the white ink nozzle 13 and the color ink nozzle 14 in the first direction. The irradiation range of the second curing device 16 completely covers all the spray areas of the white ink nozzle 13 and the color ink nozzle 14, preventing the white and color inks from failing to cure in a timely manner.
[0051] In some embodiments, the first curing device 15 and the second curing device 16 employ separate or integrated segmented LED lights. For example, if separate LED lights are used, the first curing device 15 includes two independently controlled LED light source modules, mounted on both sides of the first varnish nozzle 11 via adjustable brackets. The light power of each light source module can be independently adjusted, and its irradiation range is perfectly matched to the length of the pre-cured section of the first varnish nozzle 11, ensuring that only the varnish in the pre-cured section is cured, avoiding interference with the flowability of the varnish in the leveling section. The second curing device 16 includes four or eight LED light source modules, evenly divided into two groups and arranged on both sides of the white ink nozzle 13 and the colored ink nozzle 14. The LED light source modules on each side are spliced to form a continuous irradiation band. In the first direction, the LED light source module closer to the white ink nozzle 13 cures the white ink, and the LED light source module closer to the colored ink nozzle 14 cures the colored ink. The light power of each light source module can be independently adjusted, allowing for independent control to meet the curing intensity requirements of different ink layers.
[0052] In some embodiments, the first varnish printhead 11 and the second varnish printhead 12 use a large-dot inkjet method to spray varnish. Specifically, in the embodiments of this application, both the first varnish printhead 11 and the second varnish printhead 12 use a pure large-dot inkjet method to spray varnish. The pure large-dot inkjet method uses only the "large dot" ink droplet volume to spray ink during printing, without mixing medium and small dots.
[0053] It should be noted that the first varnish printhead 11 and the second varnish printhead 12 use a large-dot inkjet method to spray varnish, which can deposit a thicker varnish layer in one go, providing sufficient varnish for subsequent varnish leveling. Understandably, if the amount sprayed in a single pass is too small, complete leveling may not be achieved in the leveling stage, resulting in gaps between varnish dots and easily causing orange peel texture, poor gloss, and other defects. Furthermore, to cover the same area on the printing media, the large-dot inkjet method requires fewer spray passes, reducing the number of reciprocating movements of the printhead and improving varnish printing efficiency.
[0054] In order to improve the stacking effect of ink aggregation, in this embodiment, the varnish is usually selected as a type with a higher viscosity, such as 16-20cp. Driving the first varnish nozzle 11 and the second varnish nozzle 12 to spray a single large varnish droplet is less burdensome than frequently driving the first varnish nozzle 11 and the second varnish nozzle 12 to spray multiple small varnish droplets, which helps to maintain the stability of the nozzle and reduce the risk of clogging.
[0055] In another aspect of this application, this application provides an embossing printing method applied to the photopolymerization printing equipment described above. The method includes the following steps: S41: Based on the first part of the nozzle in the first varnish nozzle, varnish is sprayed onto the printing medium, and the first curing device is controlled to irradiate the varnish to obtain pre-cured varnish.
[0056] S42: Based on the second part of the nozzle in the first varnish nozzle and the second varnish nozzle, varnish is sprayed onto the pre-cured varnish. After the varnish flows level, a high stacking degree reference printing layer is obtained.
[0057] S43: White ink is sprayed onto the reference printing layer by a white ink nozzle, and the second curing device is controlled to irradiate it to obtain a white underlayer.
[0058] S44: Based on the inkjet nozzle spraying colored ink onto a white substrate and controlling the second curing device to irradiate it, a colored relief image is obtained.
[0059] In step S41, the controller controls the first portion of the nozzles in the first varnish nozzle to spray varnish onto the printing medium. It should be noted that the first curing device 15 is located on both sides of the first varnish nozzle 11, with an overlapping portion. The first portion of the nozzles consists of multiple rows of nozzles on the first varnish nozzle 11 along the length of the overlap with the first curing device 15 in the first direction. After spraying is complete, the controller immediately controls the first curing device 15 to irradiate the varnish, achieving pre-curing. Pre-curing involves prematurely and incompletely curing the sprayed varnish. By controlling the degree of curing, it achieves a preliminary surface shaping while retaining some internal fluidity, rather than directly completing full curing. The first curing device 15 can be power-adjusted. For example, using a medium-power mode allows for precise control of the varnish curing progress, achieving pre-cured varnish and preventing it from spreading and deforming due to excessive fluidity, thus providing a stable underlying support for subsequent varnish stacking.
[0060] In step S42, the controller 17 controls the second part of the nozzles in the first varnish nozzle 11 and the second varnish nozzle 12 to spray varnish onto the pre-cured varnish. After the varnish has leveled, a high-stack reference printing layer is obtained. Specifically, the second part of the nozzles is the remaining part of the nozzles in the first varnish nozzle 11 after removing the first part of the nozzles. After the controller 17 controls the second part of the nozzles in the first varnish nozzle 11 to spray varnish onto the pre-cured varnish, it then controls the second varnish nozzle 12 to spray varnish. Leveling is the process by which the varnish naturally diffuses due to its own fluidity, filling the gaps between adjacent varnish dots to form a varnish stack layer with uniform thickness and a smooth surface. After the varnish has leveled, the reference printing layer is obtained. The surface of this reference printing layer is not cured, has high surface smoothness, is soft, and has a certain viscosity. When white ink is printed on it later, the white ink droplets adhere well to it, and the white underlayer formed by the white ink droplets has good stability after curing. It should be noted that the varnish sprayed by the second part of the nozzle in the first varnish nozzle 11 and the varnish sprayed by the second varnish nozzle 12 is not immediately irradiated after spraying to achieve timely curing. Instead, the varnish is allowed to flow and level naturally, resulting in a higher stacking height than when cured immediately. In addition, the leveling process allows the varnish sprayed by the first varnish nozzle 11 and the varnish sprayed by the second varnish nozzle 12 to fully blend during the flow, forming a continuous single varnish stack layer, rather than two independent structures. This improves the structural stability of the base printing layer and avoids delamination during subsequent curing or printing.
[0061] In step S43, the controller 17 controls the white ink nozzle 13 to spray white ink onto the reference printing layer and controls the second curing device 16 to irradiate it, thus obtaining a white underlayer. Specifically, the controller 17 controls the white ink nozzle 13 to spray white ink onto the reference printing layer, and immediately after spraying is completed, controls the second curing device 16 to irradiate it, thus obtaining a white underlayer. The second curing device 16 can adjust the light power; for example, using a high-power mode for irradiation can achieve curing of the varnish and white ink, preventing white ink from penetrating into the reference printing layer and affecting the structure, while also providing a stable surface for subsequent spraying of colored inks.
[0062] It should be noted that white ink is prone to sedimentation and clogging, and ink splatter during printing can affect the image quality. In contrast, varnish is a transparent liquid, does not easily precipitate, and ink splatter is not observable and does not affect the final image quality. This application's embodiment first uses varnish for printing to obtain a high-density base printing layer, which is more cost-effective and produces better image quality than the traditional method of directly using white ink for stacking.
[0063] In step S44, the controller 17 controls the inkjet head 14 to spray colored ink onto the white substrate and controls the second curing device 16 to irradiate it, thereby obtaining a colored embossed image. Specifically, the controller 17 divides the colored pattern to be printed into several pixel units, each unit corresponding to a set of nozzles on the inkjet head. A single set of nozzles includes CMYK four-color nozzles, such as cyan, magenta, yellow, and black. After obtaining the white substrate, the controller 17 controls each set of nozzles to spray the corresponding color ink according to the colored pattern. The single spray volume and spray frequency of the nozzles can be adjusted to regulate the color density. After spraying is completed, the second curing device 16 is immediately controlled to irradiate the ink, thereby curing the colored ink and obtaining a colored embossed image.
[0064] It should be noted that in the above embodiments, there is no necessarily a certain order between the steps. Those skilled in the art can understand from the description of the embodiments of this application that the above steps may have different execution orders in different embodiments, that is, they may be executed in parallel or in turn, etc.
[0065] See Figure 5 , Figure 5 This is a schematic diagram of a controller provided in an embodiment of this application. The controller includes one or more processors 51 and a memory 52. The memory 52 is connected to one or more processors 51, for example, via a bus.
[0066] Processor 51 is configured to support the controller in performing the corresponding functions in the methods described in the above method embodiments. The processor may be a central processing unit (CPU), a network processor (NP), a hardware chip, or any combination thereof. The aforementioned hardware chip may be an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a combination thereof. The aforementioned PLD may be a complex programmable logic device (CPLD), a field-programmable gate array (FPGA), a generic array logic (GAL), or any combination thereof.
[0067] Memory 52 is used to store program code, etc. Memory 52 may include volatile memory (VM), such as random access memory (RAM); memory may also include non-volatile memory (NVM), such as read-only memory (ROM), flash memory, hard disk drive (HDD), or solid-state drive (SSD); memory 52 may also include combinations of the above types of memory.
[0068] The memory 52 can be used to store non-volatile software programs, non-volatile computer-executable programs, and modules, such as the program instructions / modules corresponding to the relief printing method in the embodiments of this application. The processor executes the relief printing method by running the non-volatile software programs, instructions, and modules stored in the memory.
[0069] The memory 52 may include a program storage area and a data storage area, wherein the program storage area may store the operating system and at least one application program required for a function. The one or more modules are stored in the memory 52 and, when executed by the one or more processors 51, perform the relief printing method in any of the above method embodiments.
[0070] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. The storage medium can be a magnetic disk, optical disk, read-only memory (ROM), or random access memory (RAM), etc.
[0071] The above-disclosed embodiments are merely preferred embodiments of this application and should not be construed as limiting the scope of this application. Therefore, any equivalent variations made in accordance with the claims of this application shall still fall within the scope of this application.
Claims
1. A relief-printed light-cured printing apparatus, characterized by, The application relates to a printing head and a printing method. The first gloss oil spray head, the second gloss oil spray head, the white ink spray head and the color ink spray head are sequentially arranged in a first direction in the printing head, and are used for sequentially spraying corresponding gloss oil and ink, wherein the first direction is the running direction of a printing medium. The first curing device is arranged on both sides of the first gloss oil spray head, and is used for curing the gloss oil sprayed by the first gloss oil spray head. The second curing device is arranged on both sides of the white ink spray head and the color ink spray head, and is used for curing the gloss oil sprayed by the second gloss oil spray head, the white ink sprayed by the white ink spray head and the color ink sprayed by the color ink spray head. The controller is electrically connected with the first gloss oil spray head, the second gloss oil spray head, the white ink spray head, the color ink spray head, the first curing device and the second curing device, and is configured to: The first part of the first gloss oil spray head sprays gloss oil on the printing medium, and the first curing device is controlled to irradiate, so that pre-cured gloss oil is obtained. The second part of the first gloss oil spray head and the second gloss oil spray head spray gloss oil on the pre-cured gloss oil, and after the gloss oil is leveled, a reference printing layer with high stacking degree is obtained. The white ink spray head sprays white ink on the reference printing layer, and the second curing device is controlled to irradiate, so that a white bottom layer is obtained. The color ink spray head sprays color ink on the white bottom layer, and the second curing device is controlled to irradiate, so that a color relief picture is obtained. The first gloss oil spray head and the second gloss oil spray head are staggered in a second direction, the white ink spray head and the color ink spray head are staggered in the second direction, the first gloss oil spray head and the white ink spray head are in the same column in the second direction, the second gloss oil spray head and the color ink spray head are in the same column, and the second direction is perpendicular to the first direction.
2. The light-curing printing apparatus according to claim 1, wherein The first gloss oil spray head and the first curing device have a first preset length of overlapping part in the first direction, and the first preset length is the stepping length of the printing medium when the printing head moves once in the second direction.
3. The light-curing printing apparatus according to claim 2, wherein The length of the first gloss oil spray head and the second gloss oil spray head in the first direction is equal to the first preset length of a preset multiple.
4. The light-curing printing apparatus according to claim 3, wherein The first curing device and the second curing device are spaced apart by a second preset length in the first direction, and the total length of the second preset length and the first preset length is equal to the total length of the first gloss oil spray head and the second gloss oil spray head in the first direction.
5. The light-curing printing apparatus according to claim 4, wherein The length of the second curing device in the first direction is equal to the total length of the white ink spray head and the color ink spray head in the first direction.
6. The light-curing printing apparatus according to claim 5, wherein The first curing device and the second curing device adopt a split type or an integrated segmented type LED lamp.
7. The light-curing printing apparatus according to claim 1, wherein The first gloss oil spray head and the second gloss oil spray head adopt a large dot inkjet mode to spray gloss oil.
8. The light-curing printing apparatus according to claim 1, wherein The application is applied to the light curing printing device in any one of claims 1-8, and the method comprises:
9. A relief printing method characterized by, spraying the photo-oil on the printing medium based on a first part of the nozzles in the first photo-oil head, and controlling the first curing device to irradiate the photo-oil, to obtain a pre-cured photo-oil; spraying the photo-oil on the pre-cured photo-oil based on a second part of the nozzles in the first photo-oil head and the second photo-oil head, and obtaining a reference printing layer with high stacking after the photo-oil is leveled; spraying the white ink on the reference printing layer based on the white ink head, and controlling the second curing device to irradiate, to obtain a white base layer; spraying the color ink on the white base layer based on the color ink head, and controlling the second curing device to irradiate, to obtain a color relief picture.
10. A controller characterized by comprising: The controller comprises a memory and a processor, the memory is connected to the processor, the processor is used to execute one or more computer programs stored in the memory, and the processor makes the controller realize the method in claim 9 when executing the one or more computer programs.