Precoating apparatus and printing device

Abstract

This application discloses a pre-coating device and printing equipment, including a support, a pre-coating assembly, and a scraper assembly. The support includes a first side plate and a second side plate disposed opposite to each other. The pre-coating assembly includes a liquid supply pipe, a rubber roller, and a screen roller. The rubber roller is rotatably disposed between the first and second side plates, and the screen roller is rotatably disposed between the first and second side plates, with the rubber roller and screen roller in contact. The liquid supply pipe is disposed between the rubber roller and the screen roller. The scraper assembly includes a support plate, a scraper, and a guide rail. The guide rail is disposed between the first and second side plates, the support plate is disposed on the guide rail, and the scraper is disposed on the support plate, with the scraper used to contact the rubber roller. The liquid supply pipe provides pre-coating liquid to the screen roller and the rubber roller. The screen roller, by rotating, adheres the pre-coating liquid to the rubber roller, and the rubber roller, by rotating, adheres the pre-coating liquid to the paper surface. The scraper, in contact with the rubber roller, squeezes the pre-coating liquid, allowing the pre-coating liquid to adhere more evenly to the rubber roller. This improves the uniformity of the pre-coating liquid and enhances the effect of the pre-coating liquid and ink.

Description

Technical Field

[0001] This application relates to the field of printing technology, and more particularly to a pre-coating device and printing equipment. Background Technology

[0002] With the rapid development of printing technology, digital printing has advantages such as high production speed, no need for plate making, reduced processes, environmentally friendly raw materials, low cost, and wide order range, making digital inkjet printing technology gradually become the mainstream in society. In both traditional and digital printing, pre-coating solutions are often used to achieve better ink effects.

[0003] Currently, pre-coating is mainly done by roller coating. However, due to the characteristics of the roller, uneven pre-coating and varnishing may occur in some areas of the paper. Uneven pre-coating will result in different thicknesses of the paper after pre-coating, thus affecting the printing effect. Uneven varnishing will also cause visual defects in the printed pattern, thus affecting the overall product printing effect. Utility Model Content

[0004] This application aims to provide a pre-coating device and printing equipment, which are designed to reduce uneven pre-coating during pre-coating operations, thereby improving the pre-coating effect.

[0005] In one aspect, this application proposes a pre-coating device, including a support, a pre-coating assembly, and a scraper assembly. Specifically, the support includes a first side plate and a second side plate disposed opposite to each other. The pre-coating assembly includes an inlet pipe, a rubber roller, and a screen roller. The rubber roller is rotatably disposed between the first and second side plates, and the screen roller is rotatably disposed between the first and second side plates. The rubber roller and the screen roller are in contact with each other, and their rotational directions are opposite. The rotation axes of the rubber roller and the screen roller are in the same direction and perpendicular to the first and second side plates. The inlet pipe is disposed between the rubber roller and the screen roller but does not contact them. The scraper assembly includes a support plate, a scraper, and a guide rail. The guide rail is disposed between the first and second side plates, the support plate is disposed on the guide rail, and the scraper is disposed on the support plate. The scraper is used to contact the rubber roller. It should be noted that the opposite rotational directions of the rubber roller and the screen roller mean that their rotational directions must satisfy the opposite movement directions of the contact points (i.e., "opposite rolling").

[0006] In the above scheme, the first and second side plates of the support provide support for the pre-coating assembly and the doctor blade assembly, improving the stability of each component. The liquid supply pipe provides pre-coating liquid to the wire roller and the glue roller. The wire roller, by rotating, adheres the pre-coating liquid to the glue roller, and the glue roller, by rotating, adheres the pre-coating liquid to the paper surface. The doctor blade, by contacting the glue roller, squeezes the pre-coating liquid as the glue roller rotates, allowing the pre-coating liquid to adhere more evenly to the glue roller. Through the cooperation between the doctor blade assembly and the roller, the uniformity of the pre-coating liquid adhered to the paper is improved, enhancing the effect of the pre-coating liquid and ink.

[0007] In some embodiments, the scraper assembly further includes a clamping plate connected to a support plate, with the scraper disposed between the support plate and the clamping plate. The clamping plate is used to press the scraper against the support plate. By using the clamping plate and the support plate to press the scraper together, non-working displacement of the scraper during operation can be reduced, improving the stability of the scraper.

[0008] In some embodiments, the guide rail is rotatably disposed between the first side plate and the second side plate. The scraper assembly further includes a first cylinder, a second cylinder, a first transmission plate, and a second transmission plate. The first cylinder is disposed on the first side plate, the second cylinder is disposed on the second side plate, and the first and second transmission plates are respectively disposed at both ends of the guide rail. The first cylinder is connected to the guide rail through the first transmission plate, and the second cylinder is connected to the guide rail through the second transmission plate. The first cylinder is used to push the first transmission plate to drive the guide rail to rotate, and the second cylinder is used to push the second transmission plate to drive the guide rail to rotate. The first cylinder, the second cylinder, the first transmission plate, and the second transmission plate are disposed at both ends of the guide rail. By using the cylinders to push the transmission plates, the guide rail drives the scraper to rotate, thereby adjusting the angle of the scraper during operation and improving the efficiency of the scraper operation.

[0009] In some embodiments, the scraper assembly further includes a third cylinder disposed on the second side plate and connected to a guide rail. The third cylinder is used to push the guide rail to move axially along the rubber roller. By providing the third cylinder and pushing the guide rail, the guide rail can drive the scraper to move in the axial direction of the rubber roller. This allows for more flexible adjustment of the scraper's working position according to the pre-coating liquid accumulation, thereby improving the scraper's efficiency.

[0010] In some embodiments, the liquid inlet pipe includes a first sub-pipe and a second sub-pipe, which communicate with each other. The first and second sub-pipes are arranged along the axial direction of the rubber roller, and their openings are along the axial direction of the rubber roller but face opposite directions. By providing the first and second sub-pipes with openings along the axial direction of the rubber roller and facing opposite directions, the accumulation of the pre-coating liquid is reduced when it flows to the roller surface through the first and second sub-pipes, resulting in more dispersed and uniform pre-coating liquid and improved working efficiency of the scraper.

[0011] In some embodiments, the pre-coating device further includes a liquid return assembly, which includes a liquid return pipe, a first ink cartridge, and a second ink cartridge. The ink supply pipe, the first ink cartridge, and the second ink cartridge are all connected to the liquid return pipe. The first and second ink cartridges are positioned opposite each other at both ends of the rubber roller. One end of the rubber roller and the screen roller extends into the first ink cartridge, and the other end of the rubber roller and the screen roller extends into the second ink cartridge. By providing the liquid return assembly, the pre-coating liquid flowing from the roller surface is received through the first and second ink cartridges, and then flows back to the roller surface through the liquid return pipe and the ink supply pipe, forming a circulation and improving the utilization rate of the pre-coating liquid.

[0012] In some embodiments, the pre-coating device further includes an adjustment assembly. The adjustment assembly includes an adjustment rod, a first adjustment ring, a second adjustment ring, a first mounting plate, and a second mounting plate. The adjustment rod is rotatably disposed between a first side plate and a second side plate, the first mounting plate is movably disposed on the first side plate, and the second mounting plate is movably disposed on the second side plate. A screen roller is disposed between the first mounting plate and the second mounting plate and connected to both mounting plates. The adjustment rod includes a rod body, a first eccentric wheel structure, and a second eccentric wheel structure, which are disposed opposite to each other at both ends of the rod body. A first adjustment ring is sleeved on the first eccentric wheel structure, and a second adjustment ring is sleeved on the second eccentric wheel structure. The first mounting plate has a first arm and a second arm protruding from it, which are disposed opposite to each other, and the first adjustment ring is disposed between the first arm and the second arm. The second mounting plate has a third arm and a fourth arm protruding from it, which are disposed opposite to each other, and the second adjustment ring is disposed between the third arm and the fourth arm. The first adjusting ring applies force to the first and second arms, causing displacement of the first mounting plate. The second adjusting ring applies force to the third and fourth arms, causing displacement of the second mounting plate. An adjusting assembly is provided, with the screen roller positioned on the first and second mounting plates. The eccentric wheel structure of the adjusting rod pushes the mounting plates, thereby moving the screen roller in a direction perpendicular to the axial direction. This arrangement allows for adjustment of the screen roller's position, improving the efficiency of pre-coating liquid adhesion between the screen roller and the adhesive roller.

[0013] In some embodiments, the adjusting assembly further includes a first adjusting bolt, a second adjusting bolt, a third adjusting bolt, and a fourth adjusting bolt. The first adjusting bolt is adjustablely disposed on the first arm, the second adjusting bolt is adjustablely disposed on the second arm, the third adjusting bolt is adjustablely disposed on the third arm, and the fourth adjusting bolt is adjustablely disposed on the fourth arm. The first and second adjusting bolts are used to contact the first adjusting ring and bear the force exerted by the first adjusting ring. The third and fourth adjusting bolts are used to contact the second adjusting ring and bear the force exerted by the first adjusting ring. By providing adjusting bolts, which bear the force exerted by the adjusting rod on the mounting plate, the minimum and maximum displacement of the mounting plate driving the screen roller can be adjusted by adjusting the length of the adjusting bolts extending towards the adjusting rod, thereby improving the flexibility of the screen roller operation and increasing the efficiency of roller coating.

[0014] In some embodiments, the pre-coating assembly further includes a first drive motor and a second drive motor. The first drive motor is connected to the rubber roller and is used to drive the rubber roller to rotate. The second drive motor is connected to the screen roller and is used to drive the screen roller to rotate. By using the first drive motor and the second drive motor to drive the rubber roller and the screen roller to rotate, the rotational state of the rubber roller and the screen roller, such as the rotational speed, can be controlled more efficiently. This can improve the working efficiency of the rubber roller and the screen roller.

[0015] Secondly, this application provides a printing apparatus including a pre-coating device as described in any embodiment of the first aspect.

[0016] Additional aspects and advantages of the embodiments of this application will be described, shown, or illustrated in part by way of implementation of the embodiments of this application in the following description. Attached Figure Description

[0017] One or more embodiments are illustrated by way of example with reference to the accompanying drawings, which are not intended to limit the embodiments, and elements having the same reference numerals in the drawings are designated as similar elements.

[0018] Figure 1 This is a schematic diagram of the structure of a pre-coating device according to some embodiments of this application; Figure 2 This is a partial enlarged view of section A of the pre-coating device in some embodiments of this application; Figure 3 This is a partial enlarged view of section B of the pre-coating device in some embodiments of this application; Figure 4 This is a cross-sectional view along the roller axis of a pre-coating apparatus according to some embodiments of this application; Figure 5 This is a schematic diagram of the structure of a pre-coating device according to some embodiments of this application; Figure 6 This is a schematic diagram of the structure of a pre-coating device according to some embodiments of this application; Figure 7 This is a schematic diagram of the structure of the scraper assembly in some embodiments of this application; Figure 8 This is a schematic diagram of the structure of the return pipe in some embodiments of this application; Figure 9 This is a schematic diagram of the structure of the adjusting rod in some embodiments of this application; Figure 10 This is a schematic diagram of the structure of the adjustment component portion in some embodiments of this application; Figure 11 This is a schematic diagram of the structure of the adjustment component portion in some embodiments of this application.

[0019] Explanation of reference numerals in the attached drawings: 1. Bracket; 11. First side plate; 12. Second side plate; 2. Pre-coating assembly; 21. Liquid inlet pipe; 211. First sub-pipe; 212. Second sub-pipe; 22. Glue roller; 23. Mesh roller; 24. First drive motor; 25. Second drive motor; 3. Scraper assembly; 31. Support plate; 32. Scraper; 33. Guide rail; 34. Pressing plate; 35. First cylinder; 36. Second cylinder; 37. First transmission plate; 38. Second transmission plate; 39. Third cylinder; 4. Liquid return assembly; 41. Liquid return pipe; 42. First ink cartridge connector; 43. Second ink cartridge connector; 5. Adjustment assembly; 51. Adjustment rod; 511. Rod body; 512. First eccentric wheel structure; 513. Second eccentric wheel structure; 52. First adjusting ring; 53. Second adjusting ring; 54. First mounting plate; 541. First arm; 542. Second arm; 55. Second mounting plate; 551. Third arm; 552. Fourth arm; 56. First adjusting bolt; 57. Second adjusting bolt; 58. Third adjusting bolt; 59. Fourth adjusting bolt. Detailed Implementation

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

[0021] In this application, the reference to "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0022] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0023] The technical features involved in the different embodiments of this application described below can be combined with each other as long as they do not conflict with each other.

[0024] In both traditional and digital printing, the compatibility between ink and paper is crucial. For example, printing requires waterproofing and scratch resistance (i.e., abrasion resistance). However, different types of paper have varying ink compatibility, leading to incompatibility between some inks and papers. This can cause ink pooling, ink dissolving in water droplets, and ink penetrating directly into the paper due to its high absorbency. All of these issues affect print quality. Therefore, pre-coating solutions designed to complement inks have been developed. Furthermore, to enhance the visual appeal of the print, a varnish treatment can be applied to the printed image, improving its waterproof performance and resulting in more vibrant colors.

[0025] However, the combination of pre-coating liquid and paper allows printing inks to be used on a variety of different types of paper. Paper pre-coating equipment is crucial. Currently, pre-coating on the market is mainly done by roller coating. Roller coating mainly involves using a rubber roller to spread the pre-coating liquid or varnish evenly. Due to the characteristics of the rubber roller, uneven pre-coating or varnishing may occur in some areas of the paper. Uneven pre-coating will result in uneven thickness of the paper after pre-coating, which will affect the printing effect and thus affect the overall product printing quality.

[0026] Traditional pre-coating devices typically concentrate the flow of pre-coating liquid or varnish at a certain location, and then allow the pre-coating liquid or varnish to diffuse and flow autonomously. It is then squeezed and tackified through the gap between the rollers. Because the pre-coating liquid or varnish has a certain viscosity, its flow performance is worse than that of water. If used for too long, the pre-coating liquid or varnish will accumulate in a certain location and cannot flow and be replaced, thus affecting the effect of pre-coating or varnishing.

[0027] Firstly, this application proposes a pre-coating device, including a support 1, a pre-coating assembly 2, and a scraper assembly 3. Specifically, please refer to... Figure 1 , Figure 4 as well as Figure 5 The support 1 includes a first side plate 11 and a second side plate 12 disposed opposite to each other. The pre-coating assembly 2 includes an upper liquid pipe 21, a rubber roller 22, and a screen roller 23. The rubber roller 22 is rotatably disposed between the first side plate 11 and the second side plate 12, and the screen roller 23 is rotatably disposed between the first side plate 11 and the second side plate 12. The rubber roller 22 and the screen roller 23 are in contact with each other, and their rotational directions are opposite. The rotation axes of the rubber roller 22 and the screen roller 23 are in the same direction and perpendicular to the first side plate 11 and the second side plate 12. The upper liquid pipe 21 is disposed between the rubber roller 22 and the screen roller 23 but does not contact them. The scraper assembly 3 includes a support plate 31, a scraper 32, and a guide rail 33. The guide rail 33 is disposed between the first side plate 11 and the second side plate 12, the support plate 31 is disposed on the guide rail 33, and the scraper 32 is disposed on the support plate 31. The scraper 32 is used to contact the rubber roller 22. It should be noted that the opposite rotational directions of the rubber roller 22 and the mesh roller 23 mean that their rotational directions must satisfy the opposite movement directions of the contact points (i.e., "rolling against each other").

[0028] For the aforementioned bracket 1, a first side plate 11 and a second side plate 12 are provided to support the rubber roller 22 and the screen roller 23. To better meet the stability requirements, the bracket 1 can be made of high-strength metal materials (such as cast iron or steel), possessing sufficient rigidity and deformation resistance to withstand the weight of the roller itself, printing pressure, and vibration during operation, reducing the impact on printing quality caused by roller parallelism deviation due to bracket 1 deformation. In addition, the first side plate 11 and the second side plate 12 can be detached, which not only improves the dimensional adaptability but also enhances the convenience of maintenance and repair of the bracket 1.

[0029] For the pre-coating component 2 mentioned above, the liquid supply pipe 21 typically delivers the pre-coating liquid to the roller surface via a pump or similar device. The rubber roller 22 is usually made of rubber (such as nitrile rubber, polyurethane, etc.), with a certain degree of elasticity and wear resistance, which allows it to better adhere to the paper surface and improve the clarity of the printed text and images on the substrate. The roller surface of the screen roller 23 can have multiple tiny concave holes, i.e., cells, arranged regularly, which can improve the stability and uniformity of the pre-coating liquid amount.

[0030] The scraper assembly 3 described above can be detachably configured with the guide rail 33, support plate 31, and scraper 32, thereby improving the flexibility of the scraper assembly 3 and allowing the position of the scraper 32 to be set as needed. Alternatively, the guide rail 33, support plate 31, and scraper 32 can be integrated as a single unit, thereby improving the stability of the scraper 32 during operation and reducing the possibility of damage to the scraper 32 during friction with the roller surface.

[0031] In the above scheme, the first side plate 11 and the second side plate 12 of the bracket 1 provide support for the pre-coating assembly 2 and the scraper assembly 3, improving the stability of each component. The liquid supply pipe 21 provides pre-coating liquid to the wire roller 23 and the glue roller 22. The wire roller 23 adheres the pre-coating liquid to the glue roller 22 by rotating, and the glue roller 22 adheres the pre-coating liquid to the paper surface by rotating. The scraper 32 contacts the glue roller 22, so that when the glue roller 22 rotates, the scraper 32 squeezes the pre-coating liquid, allowing the pre-coating liquid to adhere more evenly to the glue roller 22. Through the cooperation between the scraper assembly 3 and the roller, the uniformity of the pre-coating liquid adhered to the paper is improved, thereby improving the effect of the pre-coating liquid and ink.

[0032] In some embodiments, please refer to Figure 4 and Figure 7 The scraper assembly 3 also includes a clamping plate 34, which is connected to the support plate 31. The scraper 32 is disposed between the support plate 31 and the clamping plate 34, and the clamping plate 34 is used to clamp the scraper 32 with the support plate 31. By using the clamping plate 34 and the support plate 31 to clamp the scraper 32, the non-working displacement of the scraper 32 during operation can be reduced, and the stability of the scraper 32 can be improved.

[0033] In some embodiments, please refer to Figure 1The guide rail 33 is rotatably disposed between the first side plate 11 and the second side plate 12. The scraper assembly 3 also includes a first cylinder 35, a second cylinder 36, a first transmission plate 37, and a second transmission plate 38. The first cylinder 35 is disposed on the first side plate 11, the second cylinder 36 is disposed on the second side plate 12, and the first transmission plate 37 and the second transmission plate 38 are respectively disposed at both ends of the guide rail 33. The first cylinder 35 is connected to the guide rail 33 through the first transmission plate 37, and the second cylinder 36 is connected to the guide rail 33 through the second transmission plate 38. The first cylinder 35 is used to push the first transmission plate 37 to drive the guide rail 33 to rotate, and the second cylinder 36 is used to push the second transmission plate 38 to drive the guide rail 33 to rotate. The first cylinder 35, the second cylinder 36, the first transmission plate 37, and the second transmission plate 38 are disposed at both ends of the guide rail 33. By using a cylinder to drive the transmission plate, the guide rail 33 drives the scraper 32 to rotate, thereby adjusting the angle of the scraper 32 during operation and improving the efficiency of the scraper 32 operation.

[0034] In some embodiments, please refer to Figures 1 to 3 The scraper assembly 3 also includes a third cylinder 39, which is disposed on the second side plate 12 and connected to the guide rail 33. The third cylinder 39 is used to push the guide rail 33 to move axially along the rubber roller 22. By setting the third cylinder 39 to push the guide rail 33, the guide rail 33 can drive the scraper 32 to move in the axial direction along the rubber roller 22. This allows for more flexible adjustment of the working position of the scraper 32 according to the pre-coating liquid accumulation, thereby improving the efficiency of the scraper 32.

[0035] In some embodiments, please refer to Figure 6 The liquid inlet pipe 21 includes a first sub-pipe 211 and a second sub-pipe 212, which are connected. The first sub-pipe 211 and the second sub-pipe 212 are arranged along the axial direction of the rubber roller 22, and the openings of the first sub-pipe 211 and the second sub-pipe 212 are along the axial direction of the rubber roller 22 and face opposite directions. By setting the first sub-pipe 211 and the second sub-pipe 212 with openings along the axial direction of the rubber roller 22 and facing opposite directions, the accumulation of the pre-coating liquid when it flows to the roller surface through the first sub-pipe 211 and the second sub-pipe 212 is reduced, the pre-coating liquid is more dispersed and uniform, and the working efficiency of the scraper 32 is improved.

[0036] In some embodiments, please refer to Figure 1 and Figure 8The pre-coating device also includes a liquid return assembly 4, which includes a liquid return pipe 41, a first ink cartridge 42, and a second ink cartridge 43. The upper ink pipe 21, the first ink cartridge 42, and the second ink cartridge 43 are all connected to the liquid return pipe 41. The first ink cartridge 42 and the second ink cartridge 43 are positioned opposite each other at both ends of the rubber roller 22. One end of the rubber roller 22 and the screen roller 23 extends into the first ink cartridge 42, and the other end of the rubber roller 22 and the screen roller 23 extends into the second ink cartridge 43. By setting up the liquid return assembly 4, the pre-coating liquid flowing from the roller surface is received through the first ink cartridge 42 and the second ink cartridge 43, and then flows back to the roller surface through the liquid return pipe 41 and the upper ink pipe 21, forming a cycle and improving the utilization rate of the pre-coating liquid.

[0037] In some embodiments, please refer to Figure 1 as well as Figures 6 to 11 The pre-coating device also includes an adjusting assembly 5. The adjusting assembly 5 includes an adjusting rod 51, a first adjusting ring 52, a second adjusting ring 53, a first mounting plate 54, and a second mounting plate 55. The adjusting rod 51 is rotatably disposed between the first side plate 11 and the second side plate 12. The first mounting plate 54 is movably disposed on the first side plate 11, and the second mounting plate 55 is movably disposed on the second side plate 12. The screen roller 23 is disposed between the first mounting plate 54 and the second mounting plate 55 and connected to both the first mounting plate 54 and the second mounting plate 55. The adjusting rod 51 includes a rod body 511, a first eccentric wheel structure 512, and a second eccentric wheel structure 513. The first eccentric wheel structure 512 and the second eccentric wheel structure 513 are disposed opposite each other at both ends of the rod body 511. The first adjusting ring 52 is sleeved on the first eccentric wheel structure 512, and the second adjusting ring 53 is sleeved on the second eccentric wheel structure 513. The first mounting plate 54 has a first arm 541 and a second arm 542 protruding from it, which are arranged opposite to each other. A first adjusting ring 52 is disposed between the first arm 541 and the second arm 542. The second mounting plate 55 has a third arm 551 and a fourth arm 552 protruding from it, which are arranged opposite to each other. A second adjusting ring 53 is disposed between the third arm 551 and the fourth arm 552. The first adjusting ring 52 exerts a force on the first arm 541 and the second arm 542, causing the first mounting plate 54 to shift. The second adjusting ring 53 exerts a force on the third arm 551 and the fourth arm 552, causing the second mounting plate 55 to shift. An adjusting assembly 5 is provided, and the screen roller 23 is mounted on the first mounting plate 54 and the second mounting plate 55. The eccentric wheel structure of the adjusting rod 51 pushes the mounting plate, thereby driving the screen roller 23 to move in a direction perpendicular to the axial direction. The above settings can adjust the position of the screen roller 23, thereby improving the efficiency of the screen roller 23 and the rubber roller 22 in adhering to the pre-coating liquid.

[0038] In some embodiments, please refer to Figure 10The adjusting assembly 5 also includes a first adjusting bolt 56, a second adjusting bolt 57, a third adjusting bolt 58, and a fourth adjusting bolt 59. The first adjusting bolt 56 is adjustablely disposed on the first arm 541, the second adjusting bolt 57 is adjustablely disposed on the second arm 542, the third adjusting bolt 58 is adjustablely disposed on the third arm 551, and the fourth adjusting bolt 59 is adjustablely disposed on the fourth arm 552. The first adjusting bolt 56 and the second adjusting bolt 57 are used to contact the first adjusting ring 52 and bear the force exerted by the first adjusting ring 52. The third adjusting bolt 58 and the fourth adjusting bolt 59 are used to contact the second adjusting ring 53 and bear the force exerted by the first adjusting ring 52. By setting the adjusting bolts to bear the force exerted by the adjusting rod 51 on the mounting plate, the minimum and maximum displacement of the mounting plate driving the screen roller 23 can be adjusted by adjusting the length of the adjusting bolts extending towards the adjusting rod 51, thereby improving the flexibility of the screen roller 23 during operation and increasing the efficiency of roller coating.

[0039] In some embodiments, please refer to Figure 1 The pre-coating assembly 2 also includes a first drive motor 24 and a second drive motor 25. The first drive motor 24 is connected to the rubber roller 22 and is used to drive the rubber roller 22 to rotate. The second drive motor 25 is connected to the screen roller 23 and is used to drive the screen roller 23 to rotate. By setting the first drive motor 24 and the second drive motor 25 to drive the rotation of the rubber roller 22 and the screen roller 23, the rotational state of the rubber roller 22 and the screen roller 23, such as their speed, can be controlled more efficiently. This can improve the working efficiency of the rubber roller 22 and the screen roller 23.

[0040] In this application, the pre-coating liquid flows through the upper liquid pipe 21 between the rubber roller 22 and the wire roller 23. The rubber roller 22 and the wire roller 23 then rotate and adhere the pre-coating liquid to the paper surface, achieving the effect of varnishing and pre-coating. Simultaneously, the liquid flowing between the rollers flows to both sides, reaching the first ink cartridge 42 and the second ink cartridge, and then is guided back into the upper liquid pipe 21 via the return liquid assembly 4, thus achieving a circulating structure. During operation, the first cylinder 35 and the second cylinder 36 adjust the scraper 32, which evenly distributes the liquid on the roller surface. The scraper 32 is guided by the guide rail 33, and the third cylinder 39 provides power, causing the scraper assembly 32 to move axially along the rubber roller 22. This reduces the accumulation of liquid in one location after being scraped out, which could affect the pre-coating effect, resulting in a more uniform distribution of the scraped liquid on the roller surface, thereby improving the pre-coating or varnishing effect.

[0041] Secondly, this application provides a printing apparatus including a pre-coating device as described in any embodiment of the first aspect.

[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them; under the concept of this application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of this application as described above, which are not provided in detail for the sake of brevity; although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A pre-coating device, characterized in that, include; The bracket includes a first side plate and a second side plate that are disposed opposite to each other; The pre-coating assembly includes a liquid inlet pipe, a rubber roller, and a screen roller. The rubber roller is rotatably disposed between a first side plate and a second side plate, and the screen roller is rotatably disposed between the first side plate and the second side plate. The rubber roller and the screen roller are in contact with each other, and their rotational directions are opposite. The rotation axes of the rubber roller and the screen roller are in the same direction and perpendicular to the first side plate and the second side plate. The liquid inlet pipe is disposed between the rubber roller and the screen roller but does not contact either of them. The scraper assembly includes a support plate, a scraper, and a guide rail. The guide rail is disposed between the first side plate and the second side plate, the support plate is disposed on the guide rail, and the scraper is disposed on the support plate. The scraper is used to contact the rubber roller.

2. The pre-coating device according to claim 1, characterized in that, The scraper assembly further includes a pressing plate, which is connected to the support plate. The scraper is disposed between the support plate and the pressing plate, and the pressing plate is used to press the scraper against the support plate.

3. The pre-coating device according to claim 1, characterized in that, The guide rail is rotatably disposed between the first side plate and the second side plate, and the scraper assembly further includes a first cylinder, a second cylinder, a first transmission plate and a second transmission plate; The first cylinder is disposed on the first side plate, the second cylinder is disposed on the second side plate, the first transmission plate and the second transmission plate are respectively disposed at both ends of the guide rail, the first cylinder is connected to the guide rail through the first transmission plate, and the second cylinder is connected to the guide rail through the second transmission plate. The first cylinder is used to push the first transmission plate to drive the guide rail to rotate, and the second cylinder is used to push the second transmission plate to drive the guide rail to rotate.

4. The pre-coating device according to claim 1, characterized in that, The scraper assembly also includes a third cylinder, which is disposed on the second side plate and connected to the guide rail. The third cylinder is used to push the guide rail to move along the axial direction of the rubber roller.

5. The pre-coating device according to claim 1, characterized in that, The liquid inlet pipe includes a first sub-pipe and a second sub-pipe, which are connected to each other. The first sub-pipe and the second sub-pipe are arranged along the axial direction of the rubber roller, and the openings of the first sub-pipe and the second sub-pipe are along the axial direction of the rubber roller and face opposite directions.

6. The pre-coating device according to claim 1, characterized in that, The pre-coating device further includes a liquid return assembly, which includes a liquid return pipe, a first ink cartridge, and a second ink cartridge. The liquid inlet pipe, the first ink cartridge, and the second ink cartridge are all connected to the liquid return pipe. The first ink cartridge and the second ink cartridge are disposed opposite to each other at both ends of the rubber roller. One end of the rubber roller and the screen roller extends into the first ink cartridge, and the other end of the rubber roller and the screen roller extends into the second ink cartridge.

7. The pre-coating device according to claim 1, characterized in that, The pre-coating device further includes an adjustment assembly; the adjustment assembly includes an adjustment rod, a first adjustment ring, a second adjustment ring, a first mounting plate, and a second mounting plate; The adjusting rod is rotatably disposed between the first side plate and the second side plate; the first mounting plate is movably disposed on the first side plate; and the second mounting plate is movably disposed on the second side plate. The mesh roller is disposed between the first mounting plate and the second mounting plate and is connected to the first mounting plate and the second mounting plate. The adjusting rod includes a rod body, a first eccentric wheel structure, and a second eccentric wheel structure. The first eccentric wheel structure and the second eccentric wheel structure are disposed opposite to each other at both ends of the rod body. The first adjusting ring is sleeved on the first eccentric wheel structure, and the second adjusting ring is sleeved on the second eccentric wheel structure. The first mounting plate has a first arm and a second arm protruding from it, the first arm and the second arm being disposed opposite to each other, and the first adjusting ring being disposed between the first arm and the second arm; the second mounting plate has a third arm and a fourth arm protruding from it, the third arm and the fourth arm being disposed opposite to each other, and the second adjusting ring being disposed between the third arm and the fourth arm; the first adjusting ring is used to exert a force on the first arm and the second arm, causing the first mounting plate to displace; the second adjusting ring is used to exert a force on the third arm and the fourth arm, causing the second mounting plate to displace.

8. The pre-coating device according to claim 7, characterized in that, The adjustment assembly further includes a first adjustment bolt, a second adjustment bolt, a third adjustment bolt, and a fourth adjustment bolt; The first adjusting bolt is adjustablely disposed on the first arm, the second adjusting bolt is adjustablely disposed on the second arm, the third adjusting bolt is adjustablely disposed on the third arm, and the fourth adjusting bolt is adjustablely disposed on the fourth arm. The first adjusting bolt and the second adjusting bolt are used to contact the first adjusting ring and bear the force of the first adjusting ring; the third adjusting bolt and the fourth adjusting bolt are used to contact the second adjusting ring and bear the force of the first adjusting ring.

9. The pre-coating device according to claim 1, characterized in that, The pre-coating assembly also includes a first drive motor and a second drive motor; The first drive motor is connected to the rubber roller and is used to drive the rubber roller to rotate; the second drive motor is connected to the mesh roller and is used to drive the mesh roller to rotate.

10. A printing apparatus, characterized in that, Includes a pre-coating device as claimed in any one of claims 1 to 9.

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