Paperboard screen printing device

Abstract

The invention belongs to the technical field of silk-screen printing equipment, and particularly relates to a paperboard silk-screen printing device which comprises a silk-screen printing platform, a portal frame, a printing transverse frame, a printing device, a moving mechanism, a split type screen printing plate and a cleaning and air-drying assembly. The moving mechanism drives the split type screen printing plate to be switched between the screen printing station and the cleaning station, and precise dynamic adjustment of the tension of the screen printing plate is achieved through the tension adjusting assembly. The cleaning and air-drying assembly slides along the guide rod to a folded state to conduct infiltration type cleaning on the split type screen printing plate, a double-layer composite structure is adopted, an inner-layer cleaning roller disperses liquid flow to avoid impact damage, and an outer-layer air-drying roller evenly releases hot air. The tension adjusting assembly periodically adjusts the tension of the screen printing plate to enable meshes to expand and contract, the cleaning and air drying assembly outputs ultrasonic waves with different frequencies at different stages, and a breathing type deep cleaning mechanism is achieved. And through the synergistic effect of online cleaning and dynamic tension adjustment, the deep pollution removal rate is increased, and the printing quality of wine packaging is improved.

Description

Technical Field

[0001] This invention belongs to the technical field of screen printing equipment, and in particular relates to a screen printing device for cardboard. Background Technology

[0002] Screen printing is an important printing technology widely used in industries such as wine packaging, electronics, textiles, and advertising. Screen printing primarily utilizes the permeability of the screen mesh to transfer printing ink through the openings onto the substrate, forming patterns or text. In wine packaging screen printing, extremely high requirements are placed on print quality and pattern precision. It is essential to ensure the clarity and consistency of trademarks, text, and decorative patterns to meet the demands of wine packaging in terms of brand image and market competitiveness.

[0003] In the screen printing process for wine packaging, ink is precisely transferred to the cardboard or label through the mesh. However, some ink residue remains on the screen, especially inside the mesh, causing blockages. Because the inks used in wine packaging printing typically have strong adhesion and fast-drying properties, ink residue is more likely to solidify inside the mesh, severely affecting print quality and production efficiency, and even leading to printing defects in batches of products.

[0004] Traditional screen cleaning methods mainly rely on shutdown cleaning, which involves stopping production equipment and removing the screen for manual or mechanical cleaning. This method has several technical problems: First, with the screen tension remaining constant, the cleaning solution cannot penetrate deep into the mesh, resulting in limited effectiveness in cleaning residues of high-viscosity, fast-drying inks used in wine packaging printing. Second, shutdown cleaning leads to a decrease in equipment utilization, which seriously affects production efficiency and delivery time in the mass production of wine packaging. Third, frequent disassembly and reassembly operations can easily cause screen deformation and uneven tension, affecting the accuracy and consistency requirements of wine packaging printing.

[0005] Secondly, during shutdown cleaning, the screen tension is fixed, making it impossible to dynamically adjust the mesh size. The cleaning solution cannot fully penetrate the deep layers of the mesh, resulting in limited cleaning effects on special inks such as metallic inks and UV inks commonly used in wine packaging printing. On the other hand, there is a lack of effective monitoring and adjustment mechanisms for changes in screen tension during the screen printing process. After cleaning, the screen tension often deviates from the process requirements, affecting the quality stability of wine packaging printing. Summary of the Invention

[0006] In view of the technical problems existing in the background art, the present invention provides a paperboard screen printing device.

[0007] To achieve the above objectives, the technical solution provided by this invention is as follows: A paperboard screen printing device includes a screen printing platform, a gantry frame, and a printing crossbeam disposed between the gantry frames. A printing device is slidably connected to the outer end of the printing crossbeam. The device also includes two symmetrically arranged moving mechanisms and a cleaning and drying assembly. The outer ends of the two symmetrically arranged moving mechanisms are fixedly connected to the printing crossbeam. A split screen is provided between the two moving mechanisms. The moving mechanisms drive the split screen to switch between the screen printing station and the cleaning station. The split screen includes an upper screen frame and a lower screen frame. The space between the upper and lower screen frames is provided with several tension adjustment components with fixed spacing. The bottom of the gantry is fixedly connected to a base plate, and the top of the base plate is fixedly connected to several guide rods with opposing supports. The outer ends of the guide rods are slidably connected to the cleaning and drying components. The cleaning and drying components slide along the guide rods to the closed state to perform immersion cleaning on the split screen. The tension adjustment component can periodically adjust the tension of the split screen to expand and contract the mesh, while the cleaning and drying component can output ultrasonic waves of different frequencies at different stages of mesh expansion and contraction.

[0008] Optionally, the moving mechanism includes a guide rail fixedly connected to the outer end of the printing device. The outer end of the guide rail is slidably connected to two nut sliders with a fixed spacing. The outer end of the nut sliders is fixedly connected to a split screen. The inner end of the nut sliders is threadedly connected to a lead screw. The end of the lead screw away from the screen printing platform is fixedly connected to a drive motor. The drive motor is fixedly connected to the guide rail via a mounting plate. The end of the lead screw closer to the screen printing platform is fixedly connected to the guide rail via a mounting plate.

[0009] Optionally, a wire mesh is provided between the upper and lower wire mesh frames. Each of the four sides of the wire mesh is fixedly connected with an independent edge banding strip, which is snapped into the upper and lower wire mesh frames. The inner walls of the upper and lower wire mesh frames are fixedly connected with locking strips, and the outer ends of the locking strips are snapped into limit plates.

[0010] Optionally, stepped countersunk holes are provided on both the upper and lower screen frames, and fastening screws are provided in the stepped countersunk holes. The stepped countersunk holes are arranged alternately with the tension adjustment components. End plates are snapped onto the four sides of both the upper and lower screen frames, and connecting lugs are fixed to the inner walls of the end plates. Fastening screws pass through the connecting lugs. Several leakage holes with fixed spacing are provided at the bottom of the lower screen frame.

[0011] Optionally, the tension adjustment assembly includes an adjustment rod fixedly connected to the edge sealing strip, and the adjustment rod passes through the limiting plate. The outer end of the limiting plate is fixedly connected to a first encapsulation shell. The inner wall of the first encapsulation shell is provided with an adjustment piezoelectric stack. The adjustment piezoelectric stack is electrically connected to the control system through a wire. The top of the adjustment piezoelectric stack is fixedly connected to an adjustment ring. The inner wall of the adjustment ring is fixedly connected to the outer wall of the adjustment rod. The top of the adjustment ring is fixedly connected to an electromagnetic shielding layer. The outer end of the electromagnetic shielding layer is fixedly connected to a second encapsulation shell. The inner wall of the second encapsulation shell is provided with a detection piezoelectric stack. The detection piezoelectric stack is electrically connected to the control system through a wire. The top of the detection piezoelectric stack is fixedly connected to a detection ring. The adjustment rod passes through the adjustment piezoelectric stack, the adjustment ring, the electromagnetic shielding layer, and is fixedly connected to the bottom end of the detection ring in sequence.

[0012] Optionally, the cleaning and drying assembly includes an L-shaped support plate that is slidably connected to the guide rod, a sealing cover that is fixedly connected to the bottom end of the L-shaped support plate, and a sealing strip that is fixedly connected to the bottom end of the sealing cover.

[0013] Optionally, the sealed cover contains several cleaning and drying cylinders with fixed spacing. Each cleaning and drying cylinder includes an outer drying cylinder and an inner cleaning cylinder. Several cleaning nozzles are fixedly connected to the outer end of the inner cleaning cylinder, and the cleaning nozzles penetrate the outer drying cylinder. A cleaning liquid inlet pipe is fixedly connected to the end of the outer drying cylinder closest to the gantry frame. The cleaning liquid inlet pipe communicates with the inner cleaning cylinder and is fixedly connected to a delivery pump via a pipe. A hot air inlet pipe is fixedly connected to the end of the outer drying cylinder furthest from the gantry frame. The hot air inlet pipe communicates with the outer drying cylinder and is fixedly connected to a fan via a pipe. A first lifting cylinder is fixedly connected to the top of the sealed cover. The first lifting cylinder is fixedly connected to a support plate at the outer end of the gantry frame. Several air outlets are opened on the outer wall of the outer drying cylinder.

[0014] Optionally, the cleaning and drying assembly also includes a cleaning tank. A flexible airbag ring is fixedly connected to the outer wall of the cleaning tank. The outer wall of the flexible airbag ring is in close contact with the inner wall of the split mesh screen. Several ultrasonic transducers are fixedly connected to the bottom of the cleaning tank. The ultrasonic transducers are electrically connected to the control system via wires. A waterproof layer is fixedly connected to the outer wall of the ultrasonic transducers. Several drainage holes are opened at the bottom of the cleaning tank and are arranged laterally offset from the waterproof layer. Two opposing guide rails are fixedly connected to the bottom of the cleaning tank. A sealing plate is slidably connected to the outer end of the guide rails. A switch hole is opened at the top of the sealing plate and is arranged longitudinally offset from the drainage holes. A miniature cylinder is fixedly connected to the outer end of the sealing plate.

[0015] Optionally, a connecting plate is fixedly connected to the outer end of the cleaning tank, a liquid collecting hopper is fixedly connected to the outer end of the connecting plate, a liquid collecting trough is fixedly connected to the bottom end of the liquid collecting hopper, a hot air outlet pipe is fixedly connected to the outer end of the liquid collecting hopper, an installation plate is fixedly connected to the outer end of the liquid collecting hopper, the installation plate is slidably connected to the guide rod, the top end of the installation plate is fixedly connected to the micro cylinder through the fixing plate, and the micro cylinder passes through the liquid collecting hopper, and a second lifting cylinder is fixedly connected to the bottom end of the installation plate.

[0016] The present invention has the following advantages and beneficial effects: In this invention, a moving mechanism drives a split-type screen to switch between the screen printing station and the cleaning station, achieving true online cleaning and avoiding production efficiency losses caused by downtime cleaning. In the cleaning state, the tension adjustment component enables periodic dynamic adjustment of the screen tension, causing the mesh openings to constantly change between expansion and contraction, forming a "breathing" active cleaning mechanism. During the mesh opening expansion stage, the increased tension enlarges the mesh size, and with the help of low-frequency ultrasound, the cleaning fluid can deeply penetrate into the mesh openings, effectively dissolving the high-viscosity, fast-drying ink residues used in wine packaging printing. During the mesh opening contraction stage, the decreased tension shrinks the mesh openings, creating a squeezing effect. Combined with the strong cavitation effect of high-frequency ultrasound, it forcefully extrudes the solidified metallic inks, UV inks, and other special inks from within the mesh openings. This dynamic cleaning mechanism solves the technical problem of limited cleaning effect in traditional fixed-tension cleaning and improves the deep contamination removal rate.

[0017] To address the technical problems of lacking an effective monitoring and adjustment mechanism for screen tension changes during screen printing, and the frequent deviation of screen tension from process requirements after cleaning, this invention achieves real-time monitoring and precise adjustment of screen tension during screen printing through a closed-loop control system that detects and adjusts the piezoelectric stack. When a deviation from the set value is detected, the system automatically performs fine-tuning compensation, ensuring high-precision and stable screen tension during wine packaging printing. After cleaning, a tension reset mechanism ensures that the screen tension is accurately restored to the process requirements, solving the technical problem of screen tension deviation from process requirements affecting the stability of printing quality after cleaning. Attached Figure Description

[0018] Figure 1 This is an overall structural diagram of the paperboard screen printing device in this invention; Figure 2 This is a diagram showing the cleaning status of the mesh screen in this invention; Figure 3 This is a diagram showing the screen printing state of the cardboard in this invention; Figure 4 This is a structural diagram of the moving mechanism in this invention; Figure 5 This is a diagram of the split-type screen structure in this invention; Figure 6 for Figure 2 A magnified view of a section at point A in the middle; Figure 7 for Figure 3 A magnified view of a section at point B in the middle; Figure 8 This is a structural diagram of the cleaning and drying component in this invention; Figure 9 This is a partial view of the cleaning and drying component in the present invention. Figure 1 ; Figure 10 This is a partial view of the cleaning and drying component in the present invention. Figure 2 ; Figure 11 This is a structural diagram of the cleaning air drying cylinder in this invention; Figure 12 This is a partial view of the cleaning and drying component in the present invention. Figure 3 ; Figure 13 This is a structural diagram of the cleaning tank in this invention; Figure 14 for Figure 3 A magnified view of a section at point C; Figure 15 This is a diagram showing the sealing state of the cleaning tank in this invention; Figure 16 This is a diagram showing the drainage status of the cleaning tank in this invention.

[0019] Reference numerals: 1. Screen printing platform; 2. Gantry frame; 3. Printing crossbeam; 4. Printing device; 5. Moving mechanism; 501. Guide rail; 502. Nut slider; 503. Lead screw; 504. Drive motor; 6. Split screen; 601. Upper screen frame; 602. Lower screen frame; 603. Screen; 604. Edge sealing strip; 605. Clip; 606. Limiting plate; 607. Stepped countersunk hole; 608. End plate; 609. Connecting lug; 610. Leakage hole; 7. Cleaning and drying assembly; 701. L-shaped support plate; 702. Sealing cover; 703. Drying outer cylinder; 704. Cleaning inner cylinder; 705. Cleaning nozzle; 706. Cleaning fluid inlet pipe; 707. Hot air inlet pipe 708. First lifting cylinder; 709. Air outlet; 8. Tension adjustment assembly; 801. Adjusting rod; 802. First encapsulation housing; 803. Adjusting piezoelectric stack; 804. Adjusting ring; 805. Electromagnetic shielding layer; 806. Second encapsulation housing; 807. Detection piezoelectric stack; 808. Detection ring; 9. Base plate; 10. Guide rod; 11. Cleaning tank; 12. Flexible airbag ring; 13. Ultrasonic transducer; 14. Waterproof layer; 15. Drain hole; 16. T-shaped guide rail; 17. Sealing plate; 18. Switch hole; 19. Miniature cylinder; 20. Connecting plate; 21. Liquid collection hopper; 22. Liquid collection tank; 23. Hot air outlet pipe; 24. Mounting plate; 25. Second lifting cylinder. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments.

[0021] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0022] Example 1 like Figures 1-3 As shown, a paperboard screen printing device includes a screen printing platform 1, a gantry frame 2, a printing crossbar 3, a printing device 4, a moving mechanism 5, a split screen 6, and a cleaning and drying assembly 7.

[0023] The screen printing platform 1 is horizontally positioned to support the cardboard packaging of the wine products to be printed. The gantry frame 2 includes two vertical columns, and the printing crossbeam 3 is positioned between the two columns of the gantry frame 2. The gantry frame 2 can drive the printing crossbeam 3 to move up and down. The printing device 4 is slidably connected to the outer end of the printing crossbeam 3. The printing device 4 can drive the printing crossbeam 3 to move left and right for screen printing operations. The outer end of the printing crossbeam 3 is fixedly connected to two symmetrically arranged moving mechanisms 5. A split screen 6 is provided between the two moving mechanisms 5. The moving mechanisms 5 provide support for the split screen 6 while driving the split screen 6 to switch between the screen printing station and the cleaning station, realizing the function of cleaning without disassembling the equipment. After the moving mechanisms 5 drive the split screen 6 from the screen printing station to the transition area, it moves to the cleaning station for cleaning and drying. After completion, it returns to the screen printing station, forming a complete work cycle.

[0024] like Figures 4-6As shown, the split-type screen printing plate 6 includes an upper screen frame 601 and a lower screen frame 602. Several tension adjustment components 8 with fixed spacing are provided in the interlayer space between the upper screen frame 601 and the lower screen frame 602. A base plate 9 is fixedly connected to the bottom end of the gantry frame 2, and several symmetrically arranged guide rods 10 are fixedly connected to the top end of the base plate 9. The tension adjustment components 8 can detect and adjust the tension of the split-type screen printing plate 6 in real time during the screen printing process. The cleaning and drying component 7 is located at the cleaning station behind the gantry frame 2. When the mesh of the split-type screen printing plate 6 becomes clogged, the moving mechanism 5 drives the split-type screen printing plate 6... Moved to the cleaning station, the cleaning and drying component 7 slides along the guide rod 10 to the closed state, sealing and surrounding the split mesh screen 6 to form a closed cleaning space for immersion cleaning. During cleaning, the tension adjustment component 8 periodically adjusts the tension of the split mesh screen 6, causing the mesh to expand and contract in a "breathing" motion. The cleaning and drying component 7 works in conjunction with the mesh changes, outputting low-frequency ultrasonic waves during the mesh expansion phase to promote deep penetration of the cleaning fluid, and outputting high-frequency ultrasonic waves during the mesh contraction phase to forcefully expel contaminants, achieving efficient deep cleaning and avoiding problems such as mesh clogging and incomplete cleaning.

[0025] The moving mechanism 5 includes a guide rail 501 fixedly connected to the outer end of the printing device 4. Two fixed-distance nut sliders 502 are slidably connected to the outer end of the guide rail 501. The outer end of the nut sliders 502 is fixedly connected to the split screen 6. The inner end of the nut sliders 502 is threadedly connected to a lead screw 503. A drive motor 504 is fixedly connected to the end of the lead screw 503 away from the screen printing platform 1. The drive motor 504 is electrically connected to the control system through wires. The drive motor 504 is fixedly connected to the guide rail 501 through a mounting plate. The other end of the lead screw 503 is also fixedly connected to the guide rail 501 through a mounting plate. The lead screw 503 is rotatably connected to the mounting plate through bearings. When the split screen 6 moves, the drive motor 504 drives the nut sliders 502 to slide along the guide rail 501, further driving the split screen 6 to move and complete the switching between screen printing and cleaning.

[0026] The split-type screen 6 includes an upper screen frame 601 and a lower screen frame 602. A wire mesh 603 is positioned between the two frames. Each of the four sides of the wire mesh 603 is fixedly connected to an independent edge sealing strip 604, facilitating assembly and adjustment of the wire mesh tension. The edge sealing strip 604 engages with the upper screen frame 601 and the lower screen frame 602, facilitating positioning during installation. The inner walls of both the upper screen frame 601 and the lower screen frame 602 are fixedly connected to retaining strips 605. The outer ends of the retaining strips 605 engage with limiting plates 606, providing installation positions for the limiting plates 606. Both the upper screen frame 601 and the lower screen frame 602 have stepped countersunk holes 607. The stepped countersunk hole 607 is equipped with a fastening screw for fastening the upper screen frame 601 and the lower screen frame 602. The stepped countersunk hole 607 and the tension adjustment component 8 are arranged alternately to ensure that they do not interfere with each other. The four sides of the upper screen frame 601 and the lower screen frame 602 are all snapped with end plates 608. The inner wall of the end plate 608 is fixed with a connecting lug 609. The fastening screw passes through the connecting lug 609 and the end plate 608 is fixed by the fastening screw to prevent it from falling off. At the same time, the outer wall of the end plate 608 is fixedly connected to the nut slider 502. The bottom end of the lower screen frame 602 is provided with several drainage holes 610 with fixed spacing to drain the cleaning liquid that overflows during cleaning.

[0027] Example 2 like Figure 5 - Figure 7 As shown, the tension adjustment assembly 8 includes an adjustment rod 801 fixedly connected to the sealing strip 604. The adjustment rod 801 passes through the limiting plate 606 and is used to transmit tension force. The outer end of the limiting plate 606 is fixedly connected to a first encapsulation shell 802. The inner wall of the first encapsulation shell 802 is provided with an adjustment piezoelectric stack 803. The adjustment piezoelectric stack 803 adopts a multi-layer stacked PZT ceramic structure. The adjustment piezoelectric stack 803 is electrically connected to the control system through a highly flexible shielded wire. The top of the adjustment piezoelectric stack 803 is fixedly connected to an adjustment ring 804. The inner wall of the adjustment ring 804 is fixedly connected to the outer wall of the adjustment rod 801.

[0028] An electromagnetic shielding layer 805 is fixedly connected to the top of the adjusting ring 804. The electromagnetic shielding layer 805 can prevent the adjusting signal from interfering with the detection signal and ensure detection accuracy. A second encapsulation shell 806 is fixedly connected to the outer end of the electromagnetic shielding layer 805. A detection piezoelectric stack 807 is provided on the inner wall of the second encapsulation shell 806. The detection piezoelectric stack 807 also adopts a multi-layer stacked PZT ceramic structure. The detection piezoelectric stack 807 is electrically connected to the control system through a highly flexible shielded wire. A detection ring 808 is fixedly connected to the top of the detection piezoelectric stack 807. The adjusting rod 801 passes through the adjusting piezoelectric stack 803, the adjusting ring 804, the electromagnetic shielding layer 805 and is fixedly connected to the bottom of the detection ring 808.

[0029] During tension detection, the tension of the screen 603 is transmitted to the adjusting rod 801 through the sealing strip 604. The adjusting rod 801 transmits the force to the detection ring 808. The pressure of the detection ring 808 directly acts on the detection piezoelectric stack 807. The detection piezoelectric stack 807 generates a corresponding electrical signal according to the pressure it receives. The control system monitors this signal in real time and calculates the current screen tension value.

[0030] When the tension of the wire mesh 603 is detected to be lower than the set threshold, the control system calculates the required adjustment amount based on the tension value detected by the piezoelectric stack 807 and gives a corresponding drive signal. The drive signal acts on the adjusting piezoelectric stack 803 to produce a precise displacement. The extension of the adjusting piezoelectric stack 803 drives the adjusting ring 804 to move outward. The adjusting ring 804 drives the adjusting rod 801 to move outward. The adjusting rod 801 pulls the sealing strip 604, thereby increasing the tension of the wire mesh 603. Conversely, when the tension is too high and exceeds the set threshold, the adjusting piezoelectric stack 803 receives a contraction signal, produces an inward displacement, releases the tension on the adjusting rod 801, and thus reduces the tension of the wire mesh 603.

[0031] The adjustment and testing processes form a mutually reinforcing closed-loop control system. The piezoelectric stack 807 continuously monitors the adjustment effect. When the tension reaches the set value, the control system stops the adjustment action to ensure the tension of the screen 603 is stable during the screen printing process.

[0032] Each of the four sides of the screen is equipped with several tension adjustment components 8. The control system can independently control each component to achieve a uniform distribution of screen tension. When the tension in a certain area is too low, the tension adjustment component 8 in that area will automatically compensate, while other areas will remain stable, ensuring the consistency of overall printing quality.

[0033] Example 3 like Figures 8-12 As shown, the cleaning and drying assembly 7 includes an L-shaped support plate 701 that is slidably connected to the guide rod 10. A sealing cover 702 is fixedly connected to the bottom end of the L-shaped support plate 701. The sealing cover 702 is provided with a number of cleaning and drying cylinders with fixed spacing. The cleaning and drying cylinders include an outer drying cylinder 703 and a cleaning inner cylinder 704. The two adopt a concentric circle structure, and the diameter of the outer drying cylinder 703 is larger than the diameter of the cleaning inner cylinder 704.

[0034] Several cleaning nozzles 705 are fixedly connected to the outer end of the inner cleaning cylinder 704. The cleaning nozzles 705 penetrate the outer drying cylinder 703. A cleaning liquid inlet pipe 706 is fixedly connected to the end of the outer drying cylinder 703 near the gantry 2. The cleaning liquid inlet pipe 706 is connected to the inner cleaning cylinder 704. The cleaning liquid inlet pipe 706 is fixedly connected to the delivery pump through a pipe. The delivery pump delivers the cleaning liquid into the inner cleaning cylinder 704, and then sprays it out through the cleaning nozzles 705 to act on the wire mesh 603.

[0035] A hot air inlet pipe 707 is fixedly connected to the end of the drying outer cylinder 703 away from the gantry frame 2. The hot air inlet pipe 707 is connected to the drying outer cylinder 703. Several air outlets 709 are opened on the outer wall of the drying outer cylinder 703. The hot air inlet pipe 707 is fixedly connected to the fan through the pipe and is equipped with an electric heater to provide hot air. After the wire mesh 603 is cleaned, the fan sends hot air into the drying outer cylinder 703 through the hot air inlet pipe 707, and then enters the cleaning tank 11 through the air outlets 709 to dry the wire mesh 603. A first lifting cylinder 708 is fixedly connected to the top of the sealing cover 702. The first lifting cylinder 708 is a double-acting cylinder that can drive the sealing cover 702 to move up and down along the guide rod 10. The first lifting cylinder 708 is fixedly connected to the support plate at the outer end of the gantry frame 2.

[0036] The inner cleaning cylinder 704 disperses the large flow of cleaning fluid into multiple small flow nozzles, effectively avoiding the impact damage to the wire mesh caused by concentrated liquid flow, and preventing mesh deformation and structural damage; the outer drying cylinder 703 achieves uniform release of hot air through arrayed air outlets 709, ensuring that all parts of the wire mesh are heated evenly, and avoiding material aging and shrinkage deformation caused by local overheating.

[0037] The cleaning and drying assembly 7 also includes a cleaning tank 11. A flexible airbag ring 12 is fixedly connected to the outer wall of the cleaning tank 11. The flexible airbag ring 12 is made of silicone. The outer wall of the flexible airbag ring 12 is in close contact with the inner wall of the split mesh plate 6 to prevent overflow during immersion cleaning.

[0038] like Figure 14 As shown, several ultrasonic transducers 13 are fixedly connected to the bottom of the cleaning tank 11. The ultrasonic transducers 13 are piezoelectric ceramic transducers with adjustable operating frequency and are evenly distributed in a matrix. The ultrasonic transducers 13 are electrically connected to the control system through wires. A waterproof layer 14 is fixedly connected to the outer wall of the ultrasonic transducers 13. The waterproof layer 14 is made of polyurethane material to prevent cleaning liquid from entering the ultrasonic transducers 13.

[0039] like Figure 13 As shown, the bottom of the cleaning tank 11 has several drainage holes 15 that are laterally offset from the waterproof layer 14. The bottom end of the cleaning tank 11 is fixedly connected to two opposing guide rails 16. The guide rails 16 are precision linear guide rails. The outer end of the guide rails 16 is slidably connected to a sealing plate 17. The top end of the sealing plate 17 has a switch hole 18 that is longitudinally offset from the drainage holes 15. The outer end of the sealing plate 17 is fixedly connected to a miniature cylinder 19. The miniature cylinder 19 is used to drive the sealing plate 17 to slide along the guide rail 16 and control the alignment and offset of the drainage holes 15 and the switch hole 18.

[0040] like Figure 12As shown, a connecting plate 20 is fixedly connected to the outer end of the cleaning tank 11, and a liquid collecting hopper 21 is fixedly connected to the outer end of the connecting plate 20. The liquid collecting hopper 21 has a conical structure, and a liquid collecting trough 22 is fixedly connected to the bottom end of the liquid collecting hopper 21. A hot air outlet pipe 23 is fixedly connected to the outer end of the liquid collecting hopper 21, and an mounting plate 24 is fixedly connected to the outer end of the liquid collecting hopper 21. The mounting plate 24 is slidably connected to the guide rod 10. The top end of the mounting plate 24 is fixedly connected to a micro cylinder 19 through a fixing plate, and the micro cylinder 19 passes through the liquid collecting hopper 21. A second lifting cylinder 25 is fixedly connected to the bottom end of the mounting plate 24. The second lifting cylinder 25 is a double-acting cylinder that can drive the mounting plate 24 to slide up and down along the guide rod 10.

[0041] like Figure 4 , Figure 8 and Figures 9-16 As shown, when the mesh is clogged, the moving mechanism 5 moves the split screen 6 to the cleaning station. The first lifting cylinder 708 drives the upper part of the cleaning and drying assembly 7 to move downward along the guide rod 10, and makes the sealing strip at the bottom of the sealing cover 702 tightly contact the screen frame 601 to form a seal. At the same time, the second lifting cylinder 25 drives the lower part of the cleaning and drying assembly 7 to move downward along the guide rod 10, so that the cleaning tank 11 is embedded in the lower screen frame 602. Meanwhile, the flexible airbag ring 12 tightly contacts the inner wall of the lower screen frame 602 to form a seal and prevent the cleaning liquid from overflowing. After the upper and lower parts are closed, the control system... The drive pump delivers the cleaning fluid through the cleaning fluid inlet pipe 706 to the inner cleaning cylinder 704. The fluid is then sprayed out through the cleaning nozzle 705 onto the wire mesh 603 until the fluid level covers the wire mesh 603, at which point the delivery stops. When a small amount of cleaning fluid overflows through the gap between the upper screen frame 601 and the lower screen frame 602, the cleaning fluid flows into the lower screen frame 602 and into the collection hopper 21 through the leakage hole 610 on the lower screen frame 602. Before this, the micro cylinder 19 drives the sealing plate 17 to slide along the guide rail 16, causing the switch hole 18 and the drain hole 15 to be misaligned to form a seal and prevent the cleaning fluid from leaking.

[0042] Subsequently, the control system drives the ultrasonic transducer 13 to output ultrasonic waves that act on the cleaning tank 11. The ultrasonic waves are then transmitted to the cleaning fluid through the cleaning tank 11 to further clean the wire mesh 603. During the cleaning of the wire mesh, the tension adjustment component 8 changes the tension force periodically according to a preset program. Each cycle includes an expansion phase and a contraction phase. Expansion phase: The control system simultaneously drives all adjustable piezoelectric stacks 803 to elongate, increasing the tension of the adjusting rod 801, which increases the tension of the wire mesh 603. At this time, the wire mesh 603 is further stretched, and the mesh size is expanded, creating favorable conditions for the deep penetration of the cleaning fluid. Simultaneously, low-frequency ultrasonic waves, with their gentle cavitation effect combined with the expanded mesh, allow the cleaning fluid to penetrate into every corner of the mesh.

[0043] Shrinkage phase: The control system drives all adjustable piezoelectric stacks 803 to shrink, releasing the tension of the adjusting rod 801, which reduces the tension of the screen 603. At this time, the screen is relatively loose, the mesh size is reduced, and a strong squeezing effect is generated. Combined with the strong cavitation effect of high-frequency ultrasound, the contaminants and ink residues in the mesh are forcefully squeezed out.

[0044] Through this periodic tension adjustment, the mesh constantly changes between expansion and contraction, forming a dynamic cleaning mechanism similar to "breathing". This mechanical "pumping" action, combined with the physical cleaning of ultrasound, results in high cleaning efficiency and good deep cleaning effect.

[0045] After cleaning, the miniature cylinder 19 drives the sealing plate 17 to slide along the guide rail 16, controlling the drain hole 15 to align with the switch hole 18, draining the sewage in the cleaning tank 11 and collecting it in the collection hopper 21 and collection tank 22. After the sewage is drained, the fan sends hot air into the hot air inlet pipe 707 and discharges it through the air outlet on the drying outer cylinder 703. The hot air dries the screen 603 evenly to avoid affecting the screen printing efficiency. After drying, the cleaning and drying components return to the initial position, and the moving mechanism 5 drives the split screen 6 back to the screen printing station for screen printing.

[0046] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A screen printing apparatus for cardboard, comprising a screen printing platform (1), a gantry frame (2), and a printing crossbeam (3) disposed between the gantry frame (2), wherein a printing device (4) is slidably connected to the outer end of the printing crossbeam (3), characterized in that: It also includes two symmetrically arranged moving mechanisms (5) and a cleaning and drying assembly (7). The outer ends of the two symmetrically arranged moving mechanisms (5) are fixedly connected to the printing frame (3). A split screen (6) is provided between the two moving mechanisms (5). The moving mechanisms (5) drive the split screen (6) to switch between the screen printing station and the cleaning station. The split screen (6) includes an upper screen frame (601) and a lower screen frame (602). The space between the upper screen frame (601) and the lower screen frame (602) is provided with a number of tension adjustment components (8) distributed at fixed intervals. The bottom end of the gantry (2) is fixedly connected to a base plate (9). The top end of the base plate (9) is fixedly connected to a number of symmetrically arranged guide rods (10). The outer end of the guide rods (10) is slidably connected to the cleaning and drying component (7). The cleaning and drying component (7) slides along the guide rods (10) to the closed state to perform immersion cleaning on the split screen (6). The tension adjustment component (8) can periodically adjust the tension of the split screen (6) to make the mesh expand and contract, and the cleaning and drying component (7) can output ultrasonic waves of different frequencies at different stages of mesh expansion and contraction.

2. The paperboard screen printing device according to claim 1, characterized in that: The moving mechanism (5) includes a guide rail (501) fixedly connected to the outer end of the printing device (4). The outer end of the guide rail (501) is slidably connected to two nut sliders (502) with a fixed spacing. The outer end of the nut sliders (502) is fixedly connected to the split screen (6). The inner end of the nut sliders (502) is threadedly connected to a lead screw (503). The end of the lead screw (503) away from the screen printing platform (1) is fixedly connected to a drive motor (504). The drive motor (504) is fixedly connected to the guide rail (501) through a mounting plate. The end of the lead screw (503) close to the screen printing platform (1) is fixedly connected to the guide rail (501) through a mounting plate.

3. The paperboard screen printing device according to claim 1, characterized in that: A wire mesh (603) is provided between the upper frame (601) and the lower frame (602). Each of the four sides of the wire mesh (603) is fixedly connected with an independent edge banding strip (604), and the edge banding strip (604) is snapped into the upper frame (601) and the lower frame (602). Each of the inner walls of the upper frame (601) and the lower frame (602) is fixedly connected with a locking strip (605), and the outer end of the locking strip (605) is snapped into a limiting plate (606).

4. The paperboard screen printing device according to claim 3, characterized in that: Both the upper screen frame (601) and the lower screen frame (602) are provided with stepped countersunk holes (607), and fastening screws are provided in the stepped countersunk holes (607). The stepped countersunk holes (607) are arranged alternately with the tension adjustment component (8). End plates (608) are snapped onto the four sides of the upper screen frame (601) and the lower screen frame (602). Connecting lugs (609) are fixed on the inner wall of the end plates (608), and fastening screws pass through the connecting lugs (609). Several leakage holes (610) with fixed spacing are provided at the bottom of the lower screen frame (602).

5. A paperboard screen printing device according to claim 4, characterized in that: The tension adjustment assembly (8) includes an adjustment rod (801) fixedly connected to the sealing strip (604), and the adjustment rod (801) passes through the limiting plate (606). The outer end of the limiting plate (606) is fixedly connected to a first encapsulation shell (802). The inner wall of the first encapsulation shell (802) is provided with an adjustment piezoelectric stack (803). The adjustment piezoelectric stack (803) is electrically connected to the control system through a wire. The top of the adjustment piezoelectric stack (803) is fixedly connected to an adjustment ring (804). The inner wall of the adjustment ring (804) is fixedly connected to the outer wall of the adjustment rod (801). An electromagnetic shielding layer (805) is fixedly connected to the top of the ring (804). A second encapsulation shell (806) is fixedly connected to the outer end of the electromagnetic shielding layer (805). A detection piezoelectric stack (807) is provided on the inner wall of the second encapsulation shell (806). The detection piezoelectric stack (807) is electrically connected to the control system through a wire. A detection ring (808) is fixedly connected to the top of the detection piezoelectric stack (807). The adjusting rod (801) passes through the adjusting piezoelectric stack (803), the adjusting ring (804), the electromagnetic shielding layer (805), and is fixedly connected to the bottom end of the detection ring (808).

6. The paperboard screen printing device according to claim 1, characterized in that: The cleaning and drying assembly (7) includes an L-shaped support plate (701) that is slidably connected to the guide rod (10). A sealing cover (702) is fixedly connected to the bottom end of the L-shaped support plate (701), and a sealing strip is fixedly connected to the bottom end of the sealing cover (702).

7. A paperboard screen printing apparatus according to claim 6, characterized in that: The sealing cover (702) contains several cleaning and drying cylinders with fixed spacing. Each cleaning and drying cylinder includes an outer drying cylinder (703) and an inner cleaning cylinder (704). Several cleaning nozzles (705) are fixedly connected to the outer end of the inner cleaning cylinder (704), and the cleaning nozzles (705) penetrate the outer drying cylinder (703). A cleaning liquid inlet pipe (706) is fixedly connected to the end of the outer drying cylinder (703) near the gantry (2). The cleaning liquid inlet pipe (706) communicates with the inner cleaning cylinder (704) and passes through... The drying outer cylinder (703) is fixedly connected to the conveying pump via a pipeline. A hot air inlet pipe (707) is fixedly connected to the end of the drying outer cylinder (703) away from the gantry frame (2). The hot air inlet pipe (707) is connected to the drying outer cylinder (703). The hot air inlet pipe (707) is fixedly connected to the fan via a pipeline. A first lifting cylinder (708) is fixedly connected to the top of the sealing cover (702). The first lifting cylinder (708) is fixedly connected to the support plate at the outer end of the gantry frame (2). Several air outlets (709) are opened on the outer wall of the drying outer cylinder (703).

8. A paperboard screen printing apparatus according to claim 6, characterized in that: The cleaning and drying assembly (7) also includes a cleaning tank (11). A flexible airbag ring (12) is fixedly connected to the outer wall of the cleaning tank (11). The outer wall of the flexible airbag ring (12) is in close contact with the inner wall of the split mesh screen (6). Several ultrasonic transducers (13) are fixedly connected to the bottom of the cleaning tank (11). The ultrasonic transducers (13) are electrically connected to the control system through wires. A waterproof layer (14) is fixedly connected to the outer wall of the ultrasonic transducers (13). Several drainage holes (15) are opened at the bottom of the cleaning tank (11) and are arranged laterally offset from the waterproof layer (14). Two T-shaped guide rails (16) are fixedly connected to the bottom end of the cleaning tank (11). A sealing plate (17) is slidably connected to the outer end of the T-shaped guide rails (16). A switch hole (18) is opened at the top of the sealing plate (17) and is arranged longitudinally offset from the drainage hole (15). A miniature cylinder (19) is fixedly connected to the outer end of the sealing plate (17).

9. A paperboard screen printing apparatus according to claim 8, characterized in that: The outer end of the cleaning tank (11) is fixedly connected to a connecting plate (20), the outer end of the connecting plate (20) is fixedly connected to a liquid collecting hopper (21), the bottom end of the liquid collecting hopper (21) is fixedly connected to a liquid collecting tank (22), the outer end of the liquid collecting hopper (21) is fixedly connected to a hot air outlet pipe (23), the outer end of the liquid collecting hopper (21) is fixedly connected to an mounting plate (24), the mounting plate (24) is slidably connected to a guide rod (10), the top end of the mounting plate (24) is fixedly connected to a micro cylinder (19) through a fixing plate, and the micro cylinder (19) penetrates the liquid collecting hopper (21), the bottom end of the mounting plate (24) is fixedly connected to a second lifting cylinder (25).

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