A method of filling a weld seam of a metal can

Abstract

The present application relates to a kind of packaged inkjet method, especially a kind of metal can weld seam filling method, comprising the following steps: moving metal can and keeping metal can not rotating;After identifying the coating mark on metal can, inkjet head is moved to inkjet coating position;Inkjet head moves to carry out inkjet coating.The metal can weld seam filling method provided by the present application keeps metal can not rotating when conveying metal can, carries out inkjet coating to weld seam after detecting coating mark, can not only coat single color, but also can realize color coating, and can form integral with the printing area of metal can, improve the aesthetic sense of product.

Description

Technical Field

[0001] This invention relates to an inkjet printing method for packaging, and more particularly to a method for filling weld seams in metal cans. Background Technology

[0002] Metal cans, often called three-piece cans, are widely used due to their high barrier properties, airtightness, and attractive appearance. The can body is made by rolling and welding iron plates, resulting in weld seams. These weld seams require surface treatment to prevent rusting. Currently, the main method to address rust is by spraying or roller coating a transparent anti-rust layer, followed by high-temperature curing to form a stable anti-rust layer. However, this method only achieves a transparent anti-corrosion layer, has a limited color range, and cannot create a seamless integration with the printed areas on the can body. Summary of the Invention

[0003] To address the issues of the aforementioned single-color spray coating and its inability to form a unified whole with the printed area, this invention provides a method for filling weld seams in metal cans. The specific technical solution is as follows:

[0004] A method for filling weld seams in a metal can includes the following steps: moving the metal can while keeping it stationary; identifying a recoating mark on the metal can and moving an inkjet head to the inkjet recoating position; and performing inkjet recoating after the inkjet head has been moved.

[0005] Preferably, inkjet feathering zones are provided at both ends of the printing area of ​​the metal can, and the inkjet feathering zones are covered during inkjet recoating.

[0006] Furthermore, when recoating the inkjet feathered area, the inkjet head also uses a feathering method for recoating.

[0007] Preferably, the touch-up marking is located in the weld area. The width of the inkjet feathering zone is 0.5~10mm.

[0008] Preferably, the inkjet recoating quality is tested after the inkjet recoating is completed, and the position of the inkjet recoating is adjusted according to the recoating quality.

[0009] Furthermore, a detection camera is used to detect the quality of the inkjet recoating.

[0010] Preferably, when moving and keeping the metal can from rotating, the metal can is moved from both sides by a can-feeding timing belt, and the metal can is pressed onto the can-feeding timing belt by a magnet.

[0011] Furthermore, the can-feeding timing belt is limited and supported by a sliding groove.

[0012] Preferably, a recognition camera or photoelectric sensor is used when identifying the repainted markings.

[0013] Preferably, the weld seam is cleaned before inkjet coating.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] The present invention provides a method for filling weld seams in metal cans. When the metal can is being transported, it is kept stationary. After a repair marking is detected, the weld seam is inkjet-coated. This method can repair with a single color or a color, and can also form an integral whole with the printed area of ​​the metal can, thus improving the aesthetics of the product. Attached Figure Description

[0016] Figure 1 This is a flowchart of the present invention;

[0017] Figure 2 This is a schematic diagram of the metal can in its unfolded state;

[0018] Figure 3 This is a front view of a metal can weld filling device;

[0019] Figure 4 This is a top view of a metal can weld filling device;

[0020] Figure 5 A side view of a metal can weld filling device;

[0021] Figure 6 This is a cross-sectional view of the can-feeding device. Detailed Implementation

[0022] The present invention will now be further described with reference to the accompanying drawings.

[0023] Example 1

[0024] like Figure 1 As shown, a method for filling weld seams in a metal can includes the following steps:

[0025] Move the metal can 9 while keeping it stationary;

[0026] After identifying the recoating mark 94 on the metal can 9, the inkjet head 22 is moved to the inkjet recoating position;

[0027] The inkjet head 22 moves to the rear to perform inkjet recoating.

[0028] When moving and keeping the metal can 9 stationary, the metal can 9 is moved from both sides by the can-feeding timing belt 13, and the metal can 9 is pressed onto the can-feeding timing belt 13 by the magnet 14. The can-feeding timing belt 13 is limited and supported by the sliding groove 121.

[0029] The touch-up marking 94 is placed in the weld area 92 or the printing area 91. The touch-up marking 94 is identified using a recognition camera.

[0030] Both ends of the printing area 91 of the metal can 9 are provided with inkjet feathering areas 93, which are covered during inkjet recoating. The width of the inkjet feathering area 93 is 0.5~10mm. When recoating the inkjet feathering area 93, the inkjet head 22 also uses the feathering method for recoating. That is, the inkjet feathering area 93 of the printing area 91 gradually fades towards the weld seam area 92, while during inkjet recoating, it gradually fades from the weld seam area 92 towards the inkjet feathering area 93. After the two overlap, a complete print is formed, making the color consistent and reducing color difference.

[0031] Clean the weld seams before inkjet coating to ensure the adhesion of the touch-up ink to the substrate of the can.

[0032] like Figure 2 As shown, both ends of the metal can 9 are provided with welding areas, and two touch-up markings 94 are located within the weld seam area 92. The printing area 91 has inkjet feathering areas 93 at both ends.

[0033] It is applicable not only to the weld treatment of small-capacity metal cans, but also to the weld treatment of large-capacity metal cylinders.

[0034] After inkjet coating is completed, post-processing is performed according to the needs of the ink to achieve ink curing, which can be achieved by UV curing or drying.

[0035] It can be used for both metal cans and metal cylinders.

[0036] Example 2

[0037] like Figure 1 As shown, based on the above embodiments, in order to further improve the quality of inkjet recoating and achieve seamless integration between inkjet recoating and the original printing, the inkjet recoating quality is detected after completion, and the position of the inkjet recoating is adjusted according to the quality, so that the inkjet recoated color blocks are seamlessly connected with the original printed color blocks. A detection camera is used to detect the inkjet recoating quality.

[0038] The following equipment is used to implement the above solution:

[0039] like Figures 3 to 6 As shown, a metal can weld filling device includes a can feeding device 1, an inkjet device 2, a moving device 3, a position acquisition device 4, and a detection device 5.

[0040] A can-feeding device 1 is mounted on the frame 10 and located on one side of the resistance welding can machine. The can-feeding device 1 is used to transport the welded metal cans 9. A moving device 3 is mounted on the frame 10 and located on one side of the can-feeding device 1. An inkjet device 2 is mounted on the moving device 3 and located above the can-feeding device 1. The inkjet device 2 is used to apply inkjet coating to the weld seam of the metal can 9. The moving device 3 is used to align the inkjet device 2 with the weld seam. A position acquisition device 4 is mounted on the inkjet device 2 and located at the inlet end of the inkjet device 2. It is used to control the position of the inkjet device 2 via the moving device 3. A detection device 5 is mounted on the inkjet device 2 and located at the outlet end of the inkjet device 2. The detection device 5 is connected to the moving device 3 and is used to detect the accuracy of the inkjet coating and correct errors in real time.

[0041] Specifically, the can feeding device 1 includes a can feeding guide rail 11, a can feeding timing belt 13, a timing belt drive device, and a magnet 14. The can feeding guide rail 11 is fixed to the top of the frame 10 and two are symmetrically arranged. Sliding plates 12 are symmetrically mounted on both sides of the can feeding guide rail 11. Two sliding grooves 121 are symmetrically arranged on each sliding plate 12, with the grooves 121 extending along the length of the sliding plate 12 and their width matching that of the can feeding timing belt 13. Several adsorption holes 122 are arrayed along the center line of the sliding plate 12. The magnet 14 is installed within the adsorption holes 122 and located between the two sliding grooves 121. The can feeding timing belt 13 is slidably inserted into the sliding grooves 121, achieving limiting of the bottom and sides of the can feeding timing belt 13. The sliding plates 12 are made of engineering plastic, which reduces friction, does not affect the movement of the can feeding timing belt 13, and simultaneously achieves limiting of the can feeding timing belt 13. The synchronous belt drive includes a driving pulley 15, a driven pulley 16, and a motor. The motor is mounted on the can-feeding guide rail 11. The driving pulley 15 and the driven pulley 16 are rotatably mounted at both ends of the can-feeding guide rail 11 and are positioned opposite to the sliding groove 121. The can-feeding synchronous belt 13 is fitted onto the driving pulley 15 and the driven pulley 16. The motor is connected to the driving pulley 15 and drives the can-feeding synchronous belt 13 to rotate. A servo motor is used to ensure control accuracy. When conveying the metal can 9, both sides of the metal can 9 abut against the two side conveyor belts 13. In other words, the four belts clamp the metal can 9 from both sides, causing it to move. Magnets 14 further press the metal can 9 together by magnetic force, thus maintaining the position between the metal can 9 and the conveyor belts 13 and preventing rotation during movement. This eliminates the torsion caused by the conveyor belts 13, preserving the original position of the weld and ensuring the accuracy of inkjet coating. It also prevents weld misalignment due to rotation, which could lead to substandard inkjet coating. Magnets 14 also eliminate the gap between the conveyor belts 13 and the metal can 9, solving the problem of the conveyor belts 13 failing to press the metal can 9 firmly. Excessive pressure between the can-feeding timing belt 13 and the metal can 9 can cause deformation of the metal can 9. This is because the two ends of the metal can 9 are not sealed at this time, and the metal can 9 is cylindrical. The sides of the metal can 9 are easily deformed under pressure. Magnets 14 attract the metal can 9 from both sides, ensuring that the metal can 9 is pressed firmly onto the can-feeding timing belt 13 and moves with it, while simultaneously preventing deformation. This perfectly solves the problem of movement and rotation of the metal can 9. Magnets 14 can be strong magnets, and at least two magnets 14 must remain attached to the metal can 9 during movement. Magnets 14 do not contact the metal can 9, thus preventing damage to the printing on the surface of the metal can 9.

[0042] The sliding plate 12 supports the can feeding timing belt 13 to prevent the can feeding timing belt 13 from shifting under pressure, thereby avoiding the positional deviation of the metal can 9. It can keep the metal can 9 moving on the same axis, ensuring the accuracy of the subsequent inkjet coating position and improving the quality of inkjet coating.

[0043] The can feeding guide rail 11 can be mounted on the top of the frame 10 via the screw slide table 17 to achieve precise position adjustment, thereby aligning the axis of the can feeding guide rail 11 with the axis of the resistance welding can machine, achieving seamless connection of the metal can 9 conveying.

[0044] The can feeding device 1 may also include a lower support roller 17, which is mounted on top of the frame 10 and located between the two can feeding guide rails 11, below the metal can 9, to support the metal can 9 from the bottom and further improve the positional accuracy of the metal can 9. The lower support roller 17 can be installed as needed and can be used when the metal can 9 is heavy.

[0045] The moving device 3 includes a first linear module 31 and a second linear module 33. The first linear module 31 is mounted on the top of the frame 10 and is located below the can feeding guide rail 11, and is vertically arranged with respect to the can feeding guide rail 11. The first linear module 31 is horizontally mounted. The second linear module 33 is mounted on the first slide 32 of the first linear module 31 and is vertically arranged. The second linear module 33 is located on one side of the can feeding guide rail 11.

[0046] The inkjet unit 2 includes an inkjet cartridge 21 and an inkjet head 22. The inkjet cartridge 21 is mounted on the second slide 34 of the second linear module 33. The inkjet head 22 is mounted on the inkjet cartridge 21 and is arranged along the feeding direction of the can feeding guide rail 11. The inkjet head 22 is an existing mature product and is a color inkjet recoating head. The number of inkjet heads 22 is set as needed, but not less than one. When it is necessary to further increase the production speed of the metal can 9, multiple inkjet heads 22 can be set to perform recoating simultaneously. The ink used for inkjet printing is also an existing mature product, which can achieve both color inkjet recoating and rust prevention.

[0047] The position acquisition device 4 includes a position recognition camera. The recognition camera is used to identify the recoating mark 94 on the metal can 9. When the recoating mark 94 is identified, the inkjet device 2 is controlled to spray ink according to the can feeding speed.

[0048] The inspection device 5 includes an inspection camera. The inspection camera is used to detect and correct the accuracy of the inkjet coating in real time. If the inkjet quality is unqualified, it can be transmitted to the back-end via the control system to reject the defective products. It can also correct errors based on the accuracy of the color filling, feeding back the deviation to the moving device 3 to adjust the position of the inkjet head 22, ensuring accurate color filling and thus forming an integrated pattern. This ensures a seamless connection of the color blocks, allowing the inkjet-coated color blocks at the weld seam to perfectly align with the graphics on both sides, preventing misalignment. The inspection camera is also connected to a display via the control system to show the inspection status in real time.

[0049] It also includes a cleaning device 6, which ensures the adhesion of the complementary ink to the substrate of the can. The cleaning device 6 includes a plasma cleaning device, which is located above the can feeding guide rail 11 and at the feed end of the inkjet device 2. It is used to clean the weld seam and ensure that the ink can be stably and reliably adsorbed on the surface of the weld seam.

[0050] After the metal can 9 is welded on the resistance welding can machine, it enters between two can feeding guide rails 11. The can feeding synchronous belt 13 drives the metal can 9 to move towards the inkjet head 22. The magnet 14 controls the metal can 9 not to rotate. When the recognition camera detects the pre-printed recoating mark 94 on the metal can 9, the moving device 3 controls the inkjet device 2 to move to the inkjet recoating position. Then, inkjet recoating is performed according to the delay. During inkjet recoating, ink is sprayed along the weld seam. After the inkjet recoating of the entire weld seam is completed, the detection camera detects the quality of the inkjet recoating. If the quality of the inkjet recoating is unqualified, it can be transmitted to the back end through the control system to reject unqualified products. The quality feedback of the inkjet recoating can also be fed back to the moving device 3 to adjust the position of the inkjet head 22, so that the pattern is integrated and the weld seam is quickly sprayed to complete the rust prevention treatment of the weld seam.

[0051] The technical principles of the present invention have been described above with reference to specific embodiments. These descriptions are merely for explaining the principles of the invention and should not be construed as limiting the scope of protection of the invention in any way. Based on this explanation, those skilled in the art can readily conceive of other specific embodiments of the invention without inventive effort, and these embodiments will all fall within the scope of protection of the claims of the present invention.

Claims

1. A method of filling a weld seam of a metal can, characterized by, The method comprises the following steps: Moving the metal can (9) and keeping the metal can (9) from rotating; Moving the inkjet head (22) to the inkjet filling position after recognizing the filling mark (94) on the metal can (9); Moving the inkjet head (22) to the inkjet filling position after recognizing the filling mark (94) on the metal can (9); When moving and keeping the metal can (9) from rotating, the metal can (9) is moved by the can conveying synchronous belt (13) from both sides of the metal can (9), and the metal can (9) is pressed on the can conveying synchronous belt (13) by the magnet (14); The filling method is filled by the metal can welding seam filling device, which comprises a can conveying device, an inkjet device, a moving device, a position acquisition device and a detection device; The can conveying device is installed on the rack and located on one side of the resistance welding can machine, and is used for conveying the welded metal can; the moving device is installed on the rack and located on one side of the can conveying device (1), the inkjet device is installed on the moving device and located above the can conveying device (1), and the inkjet device is used for inkjet filling of the welding seam of the metal can; the moving device is used for aligning the inkjet device with the welding seam; The position acquisition device is installed on the inkjet device and located at the feeding end of the inkjet device, and is used for controlling the position of the inkjet device by the moving device; the detection device is installed on the inkjet device and located at the discharging end of the inkjet device, and is connected with the moving device, and is used for real-time detection of the precision and error correction of the inkjet filling; Both ends of the printing area (91) of the metal can (9) are provided with inkjet feathering areas (93), and the inkjet filling covers the inkjet feathering areas (93) during inkjet filling.

2. A method of filling a weld seam of a metal can according to claim 1, characterized in that, The inkjet head (22) also adopts the feathering method for filling when filling the inkjet feathering area (93).

3. A method of filling a weld seam of a metal can according to claim 1, characterized in that, The width of the inkjet feathering area (93) is 0.5-10mm.

4. The method of claim 1, wherein After the inkjet filling is completed, the inkjet filling quality is detected, and the position of the inkjet filling is adjusted according to the filling quality.

5. A method of filling a weld seam of a metal can according to claim 4, characterized in that, The detection camera is used for detecting the inkjet filling quality.

6. A method of filling a weld seam of a metal can according to claim 1, wherein The can conveying synchronous belt (13) is limited and supported by the sliding groove (121).

7. A method of filling a weld seam of a metal can according to any one of claims 1 to 5, characterized in that, The recognition camera or the photoelectric sensor is used for recognizing the filling mark.

8. A method of filling a weld seam of a metal can according to any one of claims 1 to 5, characterized in that, The welding seam is cleaned before inkjet filling.

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