Ink jet printing device

Abstract

The invention discloses an ink jet printing device which comprises a first printing structure and a second printing structure, the first printing structure comprises a first base frame and a first printing roller assembly, the first printing roller assembly is connected with the first base frame, and the first printing roller assembly is suitable for receiving a base material guided out by a front device for spot color printing; the second printing structure is arranged on the downstream of the first printing structure, the second printing structure comprises a second base frame, a second printing roller assembly and an ink jet assembly, the ink jet assembly and the second printing roller assembly are both installed on the second base frame, and the ink jet assembly is used for spraying printing patterns on the second printing roller assembly; the second printing roller assembly can receive a first base material printed by the first printing structure and conduct ink-jet printing, a conventional reel-to-reel intaglio printing unit and a digital ink-jet unit are used for combined printing, spot color printing and digital color overlapping printing can be achieved at the same time, the universality of equipment is improved, and the use amount of ink is reduced; the production cost is reduced and the production efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of printing machinery technology, and more specifically to an inkjet printing apparatus. Background Technology

[0002] Before printing on a conventional roll-to-roll gravure printing press, the colors on the production pattern need to be separated one by one. A corresponding halftone screen is made according to the color pattern. After adjusting the spot color ink, the ink is poured into the ink trough and brought into contact with the halftone screen. After removing the excess ink on the halftone screen with a doctor blade, the remaining ink on the halftone screen is transferred to the substrate. A richly colored pattern is formed by overlaying multiple sets of spot color inks.

[0003] In conventional roll-to-roll gravure printing, screen printing plates are required. These plates are coated with the appropriate spot color ink, and excess ink is scraped off to form the image, which is then transferred to paper. If the image has multiple colors, multiple screen printing plates are needed for overprinting. Furthermore, producing different image orders requires creating different screen printing plates for each image, leading to low production efficiency and fixed production costs. Additionally, screen printing plates have specific size specifications and cannot exceed the outer surface area of ​​the transfer roller; the printed image must be within the specifications of the screen printing plate. When the image size exceeds the specifications of the screen printing plate in any direction, the image needs to be printed using two or more screen printing plates, resulting in relatively high cumulative printing costs and further reduced time efficiency.

[0004] The biggest advantage of digital inkjet printing is that it eliminates the need for screen printing and allows for unlimited length dimensions. However, digital inkjet printers also have significant drawbacks when printing solid colors and spot colors, such as uneven color distribution and misalignment, and they consume relatively more ink. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is that the printing cost of existing printing devices is relatively high, the time efficiency is further reduced, and the ink consumption is large.

[0006] Therefore, the present invention provides an inkjet printing apparatus, comprising:

[0007] A first printing structure, the first printing structure including a first base frame and a first printing roller assembly, the first printing roller assembly being connected to the first base frame, the first printing roller assembly being adapted to receive a substrate exported by a pre-processor for spot color printing;

[0008] The second printing structure is located downstream of the first printing structure. The second printing structure includes a second base frame, a second printing roller assembly, and an inkjet assembly. The inkjet assembly and the second printing roller assembly are both mounted on the second base frame. The inkjet assembly is used to spray a printing pattern onto the second printing roller assembly. The second printing roller assembly can receive the first substrate that has been printed by the first printing structure and perform inkjet printing on it.

[0009] Optionally, the second printing roller assembly described above includes:

[0010] The first printing roller is connected to the first base frame;

[0011] The second printing roller is spaced apart from the first printing roller and rotates in the opposite direction to the first printing roller. The first substrate is passed between the first printing roller and the second printing roller. The second printing roller is used to press the first substrate onto the first printing roller to form the second substrate.

[0012] The inkjet assembly is located at the top of the first printing roller, and the inkjet assembly is used to spray colored ink onto the surface of the first printing roller.

[0013] Optionally, the second printing roller assembly described above further includes:

[0014] A functional film roller, which is connected to the base frame, is used to hold a functional film;

[0015] A coating roller is provided, which is spaced apart from the second printing roller. The coating roller and the first printing roller rotate in the same direction. The second substrate and the functional film layer are interlaced between the coating roller and the second printing roller. The second printing roller is used to press the second substrate and the functional film onto the second printing roller to form a third substrate.

[0016] Optionally, the second printing roller assembly described above further includes:

[0017] The first drying element is located downstream of the inkjet assembly and upstream of the second printing roller, along the rotation direction of the first printing roller. The first drying element is used to dry the ink sprayed by the inkjet assembly onto the surface of the first printing roller.

[0018] A first cleaning component is disposed downstream of the second printing roller and upstream of the inkjet assembly, along the rotation direction of the first printing roller. The first cleaning component is used to clean residual ink on the first printing roller.

[0019] The second drying element is located downstream of the first cleaning element and downstream of the inkjet assembly, along the rotation direction of the first printing roller. The second drying element is used to dry the area on the first printing roller that has been cleaned.

[0020] Optionally, the second printing roller assembly described above further includes:

[0021] The third drying element is located downstream of the first printing roller and upstream of the coating roller, along the rotation direction of the second printing roller. The third drying element is used to dry the second substrate.

[0022] A fourth drying element is located downstream of the second printing roller along the rotation direction of the coating roller, and is used to dry the third substrate.

[0023] Optionally, the second printing structure described above further includes a film-forming assembly connected to the base frame and located downstream of the coating roller, the film-forming assembly being used to separate the functional film on the third substrate.

[0024] Optionally, the inkjet printing apparatus described above further includes: an unwinding machine and a roll tension cutter, wherein the roll tension cutter is located downstream of the unwinding machine and is used to receive the roll material installed on the unwinding machine and to perform roll material correction positioning and tension adjustment.

[0025] Optionally, the inkjet printing apparatus described above further includes: a dust removal structure for removing dust from the roll material; the dust removal structure includes:

[0026] At least two dust removal rollers are provided for receiving the roll material output from the roll material tension cutter; the at least two dust removal rollers respectively remove dust from both sides of the roll material.

[0027] Optionally, the aforementioned dust collection roller includes:

[0028] The dust removal roller body has a plurality of dust removal holes and a receiving cavity inside the dust removal roller body;

[0029] A vibrating roller is fixed inside the receiving cavity, and a dust removal channel is formed between the vibrating roller and the dust removal roller, which communicates with the dust removal hole.

[0030] A suction duct is provided on the dust removal roller body. One end of the suction duct is connected to the dust removal channel, and the other end of the suction duct is adapted to be connected to an exhaust device.

[0031] Optionally, the inkjet printing apparatus described above further includes: a coating printing structure disposed between the dust removal structure and the first printing structure, the coating printing structure being used to coat the substrate with a coating.

[0032] The technical solution provided by this invention has the following advantages:

[0033] 1. The present invention provides a method for preparing a roll substrate. After being fed out by an unwinding machine and undergoing correction, positioning, and tension adjustment by a roll tension cutter, the substrate is placed from above the left dust removal roller to below the right dust removal roller. As the material passes through the dust removal rollers, low-amplitude, high-frequency vibrations remove and dislodge dust from the material surface. The dislodged dust is then discharged through dust removal holes via a dust removal channel inside the dust removal rollers, and static electricity on the material surface is removed. The substrate then enters the first printing unit. The first printing unit on the left prints a single spot color and, through its internal conventional first printing roller assembly, transports the substrate to its internal drying unit for further processing. The roll substrate is then transported to the first printing unit on the right to print a second spot color, forming the first substrate.

[0034] The first substrate is conveyed to the second printing structure via a transfer roller. A computer processor controls the inkjet printing process, spraying the required remaining colors and patterns onto the first printing roller through printheads. The first printing roller rotates to the first drying unit, where the ink on its surface is pre-dried and fixed, reducing ink diffusion and pooling. Simultaneously, the first substrate is conveyed between the first and second printing rollers, and the pre-dried ink is transferred onto the substrate, forming the second substrate. The third drying unit completely dries and cures the front side of the second substrate. Depending on customer requirements, a special functional film is selected and placed on a functional film roller. Simultaneously, the special functional film is introduced onto the surface of a laminating roller. The pressure between the second printing roller and the laminating roller presses the functional film and the second substrate together, achieving lamination or enhancement processes to form the third substrate. The reverse side of the third substrate is then dried and cured by a fourth drying unit, completing the drying and curing process. For some functional films, a functional film peeling device is required to remove excess functional film from the third substrate. After the first printing roller has transferred ink, it continues to rotate to the first cleaning unit, where residual or adhering dirt on the surface of the first printing roller is removed and cleaned. Then, the surface of the first printing roller is dried by the second drying unit before the next digital inkjet printing operation. After completion, the substrate can be conveyed to the rewinder for storage.

[0035] This structure combines conventional roll-to-roll gravure printing units with digital inkjet printing units, enabling both spot color printing and digital overprinting. This provides equipment versatility, reduces ink consumption, lowers production costs, and increases production efficiency. Using in-line lamination or enhancement units allows for simultaneous on-line processing of the substrate, further reducing production costs and improving efficiency.

[0036] 2. This invention provides two dust removal rollers, fixed to the dust removal base in a left-right direction. The roll material, after being corrected and positioned and tensioned by the tension-breaking roller, passes through a transfer roller and is placed from above the left dust removal roller to below the right dust removal roller, ensuring the roll material is tightly adhered to the surface of the dust removal rollers. A low-amplitude, high-frequency ultrasonic vibration generator is installed on the vibrating roller, creating a low-amplitude, high-frequency vibration between the vibrating roller and the dust removal roller. The amplitude is 0.3-2 mm, and the frequency is 30-50 Hz. When the material passes through the dust removal roller, the low-amplitude, high-frequency vibration removes and dislodges dust from the material surface. The dislodged dust is then discharged through dust removal holes located inside the dust removal roller. These dust removal holes are waist-sized, approximately 120 mm long x 5 mm wide, and are evenly distributed on the roller surface, with approximately 12 holes around the circumference. The same material passes through another dust removal roller to remove dust from the other side, allowing for online removal and cleaning of dust and stains on the film material without the glue waste and other material losses associated with traditional dust removal methods. Because the material undergoes ultrasonic vibration and friction, static electricity easily accumulates on its surface. This static electricity can repel ink droplets and affect their accuracy. Therefore, after exiting the roll, it needs to pass through an anti-static device to remove static electricity from the material surface, improving printing quality and accuracy. Through low-amplitude, high-frequency vibration combined with suction, dust can be continuously removed from the roll substrate, reducing operating costs.

[0037] 3. The coating transfer roller and the first printing roller are coated with a coating surface made of lubricating materials such as silicon and fluorine in a certain proportion, so that the surface roughness of the coating transfer roller and the first printing roller reaches RA1.6 and the surface tension of the steel roller surface reaches more than 30mN / m, ensuring that the coating and ink are well transferred to the substrate, guaranteeing the color registration accuracy between the coating and the color group, and improving the stability of continuous printing. Attached Figure Description

[0038] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0039] Figure 1 A schematic diagram of the overall structure of the inkjet printing apparatus provided by the present invention;

[0040] Figure 2 This is a schematic diagram of the dust removal structure provided by the present invention;

[0041] Figure 3 This is a schematic diagram of the structure of the dust removal roller provided by the present invention;

[0042] Figure 4 This is a schematic diagram of the internal structure of the dust removal roller provided by the present invention;

[0043] Figure 5 This is a schematic diagram of the coating printing structure provided by the present invention;

[0044] Figure 6 This is a schematic diagram of the second printing structure provided by the present invention;

[0045] Explanation of reference numerals in the attached figures:

[0046] 1 - Unwinder;

[0047] 2 – Coil tension breaking machine; 21 – Coil tension breaking roller;

[0048] 3 - Dust removal structure; 31 - Dust removal roller; 311 - Dust removal roller body; 312 - Dust removal hole; 313 - Vibrating roller; 314 - Suction duct; 32 - Static elimination structure;

[0049] 4 - Coating printing structure; 41 - Coating printing base frame; 42 - Coating transfer roller; 43 - Coating back pressure roller; 44 - Coating preliminary drying device; 45 - Coating transfer roller cleaning device; 46 - Coating transfer roller drying device; 47 - Coating printing assembly; 48 - Overall coating drying device.

[0050] 5 – First printing structure; 51 – First base frame; 52 – First printing roller assembly;

[0051] 6 – Second printing structure; 61 – Second base frame; 62 – Second printing roller assembly; 621 – First printing roller; 622 – Second printing roller; 623 – First drying component; 624 – First cleaning component; 625 – Second drying component; 626 – Third drying component; 627 – Fourth drying component; 63 – Inkjet assembly; 64 – Functional film roller; 65 – Coating roller; 66 – Film lifting assembly; 67 – Surface temperature control device;

[0052] 7 - Winding machine. Detailed Implementation

[0053] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0054] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0055] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0056] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0057] Example

[0058] This embodiment provides an inkjet printing apparatus, such as... Figures 1 to 6 As shown, it includes: an unwinding machine 1, a roll tension cutter 2, a dust removal structure 3, a coating and printing structure 4, a first printing structure 5, a second printing structure 6, and a rewinding machine 7.

[0059] Unwinder 1 can hold rolled materials. A tension cutter 2 is located downstream of unwinder 1, and is equipped with four tension cutter rollers 21. The substrate on unwinder 1 is sequentially wound onto the four tension cutter rollers 21. For example, the tension cutter 2 has two tension cutter rollers 21 at the upper and lower ends respectively. Figure 1 As shown, a transfer roller is also provided at the lower end. The roll material is inserted from the lower left side of the transfer roller and wound counterclockwise around the transfer roller. It then extends obliquely to the upper right from the right side of the transfer roller and connects to the tension stop roller at the lower left corner. After rotating clockwise, it connects to the tension stop roller at the lower right corner from below. After winding counterclockwise, it connects to the tension stop roller at the upper left corner from below. After winding clockwise, it connects to the tension stop roller at the upper right corner from below and moves towards the dust removal structure 3. The tension stop roller corrects the roll material's alignment and adjusts its tension to meet the needs of subsequent processes.

[0060] like Figure 2As shown, the dust removal structure 3 includes two dust removal rollers 31 fixed on the dust removal base frame and an anti-static structure 32. The dust removal roller 31 includes a dust removal roller body 311, a vibrating roller 313, and a suction pipe 314. The dust removal roller body 311 is a hollow structure, which is a receiving cavity. Several rectangular dust removal holes 312 are opened on the shell of the dust removal roller body 311. The length direction of the dust removal holes 312 is parallel to the axial direction of the dust removal roller 31, so that the dust removal holes 312 can cover most of the width direction of the roll material in the axial direction, thereby improving the dust removal effect. A vibrating roller 313 is installed in the receiving cavity. The central axis of the vibrating roller 313 coincides with the central axis of the dust removal roller 31. An ultrasonic generator is built into the vibrating roller 313. A dust removal channel is formed between the vibrating roller 313 and the dust removal roller 31. The dust removal channel is connected to the dust removal hole 312. The suction pipe 314 is opened on the dust removal roller body 311. One end of the suction pipe 314 is connected to the dust removal channel, and the other end of the suction pipe 314 is suitable for connection to the exhaust device.

[0061] like Figure 3 and Figure 4 As shown, there are two dust removal rollers 31, fixed to the dust removal base in the left and right directions. The roll material, after being corrected and positioned and tensioned by the tension isolation roller, passes through a transfer roller and is placed from above the left dust removal roller 31 to below the right dust removal roller 31, ensuring the roll material is tightly adhered to the surface of the dust removal roller 31. A low-amplitude, high-frequency ultrasonic vibration generator is installed on the vibrating roller 313, causing low-amplitude, high-frequency vibration between the vibrating roller 313 and the dust removal roller 31. The amplitude is 0.3–2 mm, and the frequency is 30–50 Hz. When the material passes through the dust removal roller 31, the low-amplitude, high-frequency vibration removes and dislodges dust from the material surface. The dust is then discharged through the dust removal channel inside the dust removal roller 31 via dust removal holes 312. The dust removal holes 312 are oblong holes, approximately 120 mm long x 5 mm wide, and are evenly distributed on the roller surface, with approximately 12 holes around the circumference. The same material passes through another dust removal roller 31 to remove dust from the other side of the material. This allows for online removal and cleaning of dust and stains on the film material, eliminating the waste of adhesive and other materials associated with traditional dust removal methods. Because the material undergoes ultrasonic vibration and friction, static electricity easily accumulates on its surface. This static electricity can repel ink droplets and affect their accuracy. Therefore, after exiting the roll, it needs to pass through an anti-static device to remove static electricity from the material surface, improving printing quality and accuracy. Through low-amplitude, high-frequency vibration combined with suction, dust can be continuously removed from the roll substrate, reducing operating costs.

[0062] like Figure 5As shown, the coating printing structure 4 is positioned between the dust removal structure 3 and the first printing structure 5. The coating printing structure 4 includes: a coating printing base frame 41, on which a coating transfer roller 42 and a coating back pressure roller 43 are mounted. The coating transfer roller 42 is located above, and the coating back pressure roller 43 is located below. Above the coating transfer roller 42, two coating printing groups 47 are arranged. A coating preliminary drying device 44 is installed on the left side, a coating transfer roller drying device 46 is installed slightly above the right side, and a coating transfer roller cleaning device 45 is installed slightly below the right side.

[0063] After dust removal and static electricity removal, the roll material passes through a transfer roller mounted on the dust removal base and coating inkjet base 41, and is then placed between the coating transfer roller 42 and the coating back pressure roller 43. The coating transfer roller 42 rotates counterclockwise, and the coating back pressure roller 43 rotates clockwise. According to the pattern requirements, the coating is sprayed onto the coating transfer roller 42 through two coating inkjet groups 47 in the areas requiring coating. Then, the coating on the coating transfer roller 42 is preliminarily dried and fixed by the coating preliminary drying device 44. The coating is adhered to the roll material by the clamping force of the coating transfer roller 42 and the coating back pressure roller 43, ensuring that the coating is well transferred to the substrate. This achieves on-demand coating liquid application, reduces coating liquid waste, and ensures that the roll material is clean in areas without patterns. Finally, it is dried by the coating general drying device 48 located on the right side of the coating inkjet base 41. When the coating transfer roller 42 is performing the transfer operation, coating residue will inevitably remain on the surface of the coating transfer roller 42. The coating transfer roller 42 needs to be cleaned. After being cleaned by the coating transfer roller cleaning device 45, it is then dried by the coating transfer roller drying device 46. This ensures that the surface of the steel roller is clean and free from residual coating contamination, thereby improving the stability of continuous printing.

[0064] Downstream of the coating inkjet printing structure 4, two first printing structures 5 are installed. Each first printing structure 5 is a conventional roll-to-roll gravure printing unit, including a first base frame 51 and a first printing roller assembly 52. ​​The first printing roller assembly 52 is connected to the first base frame 51 and is adapted to receive the substrate exported from the pre-installed device for spot color printing. The left-hand first printing structure 5 prints spot color one, and the substrate is then transported through the internal conventional first printing roller assembly 52 to its internal drying unit for processing. The roll-shaped substrate is then further transported to the right-hand first printing structure 5 to print spot color two, forming the first substrate. Two sets of conventional roll-to-roll gravure printing units are configured for printing pattern spot colors, reducing the cost of digital inks and meeting customer color requirements. Furthermore, the screen rollers, ink reservoirs, doctor blade assemblies, and back pressure roller assemblies on the original conventional roll-to-roll gravure printing units are removed, reducing the overall complexity of the device.

[0065] like Figure 6As shown, the second printing structure 6 is located downstream of the first printing structure 5. The second printing structure 6 includes a second base frame 61, a second printing roller assembly 62, and an inkjet assembly 63. Both the inkjet assembly 63 and the second printing roller assembly 62 are mounted on the second base frame 61. The second printing roller assembly 62 includes: a first printing roller 621, an inkjet assembly 63, a second printing roller 622, a functional film roller 64, a coating roller 65, a first drying component 623, a first cleaning component 624, a second drying component 625, a third drying component 626, a fourth drying component 627, and a film lifting assembly 66. All of the above structures are mounted on the second base frame 61. The first printing roller 621 rotates counterclockwise, the second printing roller 622 rotates clockwise, and the laminating roller 65 rotates counterclockwise. The inkjet assembly 63 is located above the first printing roller 621, the second printing roller 622 is located below the first printing roller 621, and the laminating roller 65 is located below the second printing roller 622. The first drying component 623 is located on the left side of the first printing roller 621. Along the rotation direction of the first printing roller 621, the first cleaning component 624 and the second drying component 625 are sequentially arranged on the right side of the first printing roller 621. The third drying component 626 is located on the right side of the second printing roller 622, and the fourth drying component 627 is located on the left side of the laminating roller 65. The film lifting assembly 66 is located on the right side of the laminating roller 65, and the working surface of the film lifting assembly 66 is parallel to the bottom surface of the laminating roller 65.

[0066] The first substrate is conveyed to the second printing structure 6 via a transfer roller. The inkjet assembly 63 is equipped with four ink color groups. A computer processor controls the ink color group printing, spraying the remaining colors and patterns onto the first printing roller 621 through the printhead. The first printing roller 621 rotates to the first drying unit 623, which pre-dries and fixes the ink on its surface, reducing ink diffusion and aggregation. Simultaneously, the first substrate is conveyed between the first and second printing rollers 621 and the pre-dried ink is transferred onto the substrate, forming the second substrate. The third drying unit 626 completely dries and cures the front side of the second substrate. A special functional film is selected according to customer requirements and placed on the functional film roller 64. Simultaneously, the special functional film is placed on the surface of the laminating roller 65 and introduced. The pressure between the second printing roller 622 and the laminating roller 65 presses the functional film and the second substrate together, achieving lamination or enhancement processes to form the third substrate. The fourth drying unit 627 dries and cures the reverse side of the third substrate, completing the drying and curing process. A surface temperature control device 67 is installed on the right side of the coating roller 65. This device ensures a constant surface temperature for the coating roller 65, preventing incomplete coating due to temperature differences. For some functional films, a functional film peeling device is required to remove excess functional film from the third substrate. A front and back ink drying device ensures complete ink drying and curing, reducing ink migration and ensuring safety.

[0067] After the first printing roller 621 has transferred ink, it continues to rotate to the first cleaning unit 624, where residual or adhering dirt on the surface of the first printing roller 621 is removed and cleaned. Then, the surface of the first printing roller 621 is dried by the subsequent second drying unit 625 before the next digital inkjet printing operation. After completion, the substrate can be conveyed to the rewinder 7 for storage. This completes a roll-to-roll gravure printing process combined with digital inkjet printing.

[0068] In this embodiment, the coating transfer roller 42 and the first printing roller 621 are coated with a coating surface made of lubricating materials such as silicon and fluorine in a certain proportion, so that the surface roughness of the coating transfer roller 42 and the first printing roller 621 reaches RA1.6 and the surface tension of the steel roller surface reaches more than 30mN / m, ensuring that the coating and ink are well transferred to the substrate, ensuring the color registration accuracy between the coating and the color group, and improving the stability of continuous printing.

[0069] The specific steps implemented by the inkjet printing apparatus provided in this embodiment are as follows:

[0070] Upon receiving the production pattern, the color composition is analyzed, and the customer's pattern requirements are assigned to the first printing unit, which then prepares for printing. Spot colors one and two are printed on the first printing plate, and a resin halftone plate corresponding to the pattern is created. The remaining colors are inkjet printed using the second printing roller 622. If the customer's pattern requires online lamination or enhancement processing, special ink adhesives are printed using different functional ink groups, and lamination and peeling processes are performed to complete the final product.

[0071] When the roll substrate is fed out by the unwinder 1, after being corrected, positioned, and tensioned by the roll tension cutter 2, it is placed from above the left dust removal roller 31 to below the right dust removal roller 31. As the material passes through the dust removal roller 31, the dust on the surface of the material is shaken off and falls off through the low-amplitude, high-frequency vibration. Then, the fallen dust is discharged through the dust removal hole 312 through the dust removal channel set inside the dust removal roller 31, and the static electricity on the surface of the material is removed. Then it enters the first printing unit. The first printing structure 5 on the left prints spot color one, and the substrate is conveyed to the drying unit inside by the conventional first printing roller assembly 52 for processing. The roll substrate is then conveyed to the first printing structure 5 on the right to print spot color two, forming the first substrate.

[0072] The first substrate is conveyed to the second printing structure 6 via a transfer roller. A computer processor controls the inkjet printing process, spraying the required remaining colors and patterns onto the first printing roller 621 through a printhead. The first printing roller 621 rotates to the first drying unit 623, where the ink on its surface is pre-dried and fixed, reducing ink diffusion and aggregation. Simultaneously, the first substrate is conveyed between the first and second printing rollers 621 and 622, and the pre-dried ink is transferred onto the substrate, forming the second substrate. The third drying unit 626 completely dries and cures the front side of the second substrate. A special functional film is selected according to customer requirements and placed on the functional film roller 64. Simultaneously, the special functional film is placed on the surface of the laminating roller 65 and introduced. The pressure between the second printing roller 622 and the laminating roller 65 presses the functional film and the second substrate together, achieving lamination or enhancement processes to form the third substrate. The fourth drying unit 627 dries and cures the reverse side of the third substrate, completing the drying and curing process. For some functional films, a functional film peeling device is required to peel off the excess functional film from the third substrate. After the first printing roller 621 has transferred the ink, it continues to rotate to the first cleaning unit 624 to remove and clean any remaining or adhered dirt from the surface of the first printing roller 621. Then, the surface of the first printing roller 621 is dried by the second drying unit 625 before the next digital inkjet printing operation. After completion, the substrate can be conveyed to the rewinder 7 for storage.

[0073] Using a combination of conventional roll-to-roll gravure printing units and digital inkjet units enables both spot color printing and digital overprinting, providing equipment versatility and reducing ink consumption. In-line lamination or enhancement units allow for simultaneous on-line processing of substrates, reducing production costs and increasing efficiency.

[0074] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. An inkjet printing apparatus, characterized in that, include: The first printing structure (5) includes a first base frame (51) and a first printing roller assembly (52). The first printing roller assembly (52) is connected to the first base frame (51) and is adapted to receive the substrate exported by the pre-installed device for spot color printing. The second printing structure (6) is located downstream of the first printing structure (5). The second printing structure (6) includes a second base frame (61), a second printing roller assembly (62), and an inkjet assembly (63). The inkjet assembly (63) and the second printing roller assembly (62) are both mounted on the second base frame (61). The inkjet assembly (63) is used to spray the printing pattern onto the second printing roller assembly (62). The second printing roller assembly (62) can receive the first substrate printed by the first printing structure (5) and perform inkjet printing.

2. The inkjet printing apparatus according to claim 1, characterized in that, The second printing roller assembly (62) includes: The first printing roller (621) is connected to the first base frame (51); A second printing roller (622) is provided at a distance from the first printing roller (621). The second printing roller (622) rotates in the opposite direction to the first printing roller (621). The first substrate is passed between the first printing roller (621) and the second printing roller (622). The second printing roller (622) is used to press the first substrate onto the first printing roller (621) to form a second substrate. The inkjet assembly (63) is located at the top of the first printing roller (621) and is used to spray colored ink onto the surface of the first printing roller (621).

3. The inkjet printing apparatus according to claim 2, characterized in that, The second printing roller assembly (62) also includes: A functional film roller (64) is connected to the base frame and is used to hold a functional film. A coating roller (65) is provided at a distance from the second printing roller (622). The coating roller (65) and the first printing roller (621) rotate in the same direction. The second substrate and the functional film layer are interleaved between the coating roller (65) and the second printing roller (622). The second printing roller (622) is used to press the second substrate and the functional film onto the second printing roller (622) to form a third substrate.

4. The inkjet printing apparatus according to claim 2, characterized in that, The second printing roller assembly (62) also includes: The first drying element (623) is located downstream of the inkjet assembly (63) and upstream of the second printing roller (622) along the rotation direction of the first printing roller (621). The first drying element (623) is used to dry the ink sprayed by the inkjet assembly (63) onto the surface of the first printing roller (621). The first cleaning component (624) is located downstream of the second printing roller (622) and upstream of the inkjet assembly (63) along the rotation direction of the first printing roller (621). The first cleaning component (624) is used to clean residual ink on the first printing roller (621). The second drying element (625) is located downstream of the first cleaning element (624) and downstream of the inkjet assembly (63) along the rotation direction of the first printing roller (621). The second drying element (625) is used to dry the area on the first printing roller (621) that has been cleaned.

5. The inkjet printing apparatus according to claim 3, characterized in that, The second printing roller assembly (62) also includes: The third drying element (626) is located downstream of the first printing roller (621) and upstream of the coating roller (65) along the rotation direction of the second printing roller (622). The third drying element (626) is used to dry the second substrate. The fourth drying element (627) is located downstream of the second printing roller (622) along the rotation direction of the coating roller (65), and is used to dry the third substrate.

6. The inkjet printing apparatus according to claim 5, characterized in that, The second printing structure (6) further includes a film-forming assembly (66), which is connected to the base frame and is located downstream of the coating roller (65). The film-forming assembly (66) is used to separate the functional film on the third substrate.

7. The inkjet printing apparatus according to any one of claims 1-6, characterized in that, The inkjet printing apparatus further includes an unwinder (1) and a roll tension cutter (2), wherein the roll tension cutter (2) is located downstream of the unwinder (1) and is used to receive the roll installed on the unwinder (1) and to perform roll alignment, positioning and tension adjustment.

8. The inkjet printing apparatus according to claim 7, characterized in that, The inkjet printing apparatus further includes: a dust removal structure (3), which is used to remove dust from the roll material; the dust removal structure (3) includes: At least two dust removal rollers (31) are used to receive the roll material output from the roll material tension cutter (2); the at least two dust removal rollers (31) respectively remove dust from the front and back sides of the roll material.

9. The inkjet printing apparatus according to claim 8, characterized in that, The dust removal roller (31) includes: The dust removal roller body (311) has a plurality of dust removal holes (312) and a receiving cavity inside the dust removal roller body (311). Vibrating roller (313) is fixed in the receiving cavity. A dust removal channel is formed between the vibrating roller (313) and the dust removal roller (31). The dust removal channel is connected to the dust removal hole (312). A suction duct (314) is provided on the dust removal roller body (311). One end of the suction duct (314) is connected to the dust removal channel, and the other end of the suction duct (314) is adapted to be connected to an exhaust device.

10. The inkjet printing apparatus according to claim 9, characterized in that, The inkjet printing apparatus further includes a coating printing structure (4), which is disposed between the dust removal structure (3) and the first printing structure (5), and is used to coat the substrate with a coating.

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