Metal plate continuous heat transfer printing process and heat transfer printing system

Abstract

The invention relates to the technical field of metal printing, and particularly discloses a continuous heat transfer printing process and a heat transfer printing system for a metal plate. The continuous heat transfer printing process for the metal plate comprises the steps that S1, the metal plate coated with powder is guided into a heating furnace to be heated to the preset temperature, and then the metal plate is guided out of the heating furnace from an outlet of the heating furnace; s2, the heat transfer printing paper and the metal plate are both conveyed around a heat transfer printing roller to be conveyed, the heat transfer printing roller heats the heat transfer printing paper, and the metal plate and the heat transfer printing paper which are conveyed around the heat transfer printing roller and attached to each other are subjected to a heat transfer printing process; and S3, the heat transfer printing paper subjected to the heat transfer printing process is conveyed to a transfer printing paper winding roller to be wound, and the metal plate subjected to the heat transfer printing process is conveyed to a plate winding roller to be wound. According to the scheme, the heating furnace can heat the metal plate coated with powder to the preset temperature, meanwhile, the heat transfer printing paper is independently heated through the heat transfer printing roller, and temperature regulation and control of the heat transfer printing paper and the metal plate do not interfere with each other.

Description

Technical Field

[0001] This application relates to the field of metal printing technology, and in particular to a continuous heat transfer process and system for metal sheets. Background Technology

[0002] Metal sheet heat transfer printing is a process that uses heat transfer to transfer patterns onto the surface of metal sheets (such as steel plates and strips) to beautify the surface of the metal sheet. Its core is to use heat to transfer the pattern on the transfer medium (such as heat transfer paper) to the surface of the metal sheet, thereby meeting the surface appearance requirements of the metal sheet in decorative and functional scenarios.

[0003] During the development of this technology, various technical solutions have emerged. Early traditional heat transfer printing processes involved applying pressure to the outside of the heat transfer paper to make it adhere tightly to the board surface, followed by heating both the paper and the board. Because this process was discontinuous, it was cumbersome and inefficient.

[0004] To address the shortcomings of the aforementioned discontinuous operation, a subsequent solution proposed an improvement: utilizing a heating furnace to achieve continuous heating of the metal sheet and heat transfer paper. In this method, the heating furnace provides a stable heating environment for both the metal sheet and the heat transfer paper. Combined with a traction mechanism, the metal sheet moves continuously, allowing both the metal sheet and the heat transfer paper to simultaneously rotate around the heat transfer roller within the furnace. The heat from the furnace simultaneously acts on both the steel strip and the heat transfer paper, achieving continuous heat transfer operation.

[0005] In practical applications, the continuous heat transfer process using a heating furnace has high requirements for temperature control. It is necessary to ensure that the metal sheet can be effectively heated, while avoiding damage or blurring of the heat transfer paper due to excessive temperature. Summary of the Invention

[0006] In view of this, the purpose of this application is to provide a continuous heat transfer process and system for metal sheets, which solves the problem of high temperature control requirements in existing continuous heat transfer processes for metal sheets.

[0007] To achieve the above-mentioned technical objectives, the first aspect of this application provides a continuous heat transfer process for metal sheets, comprising:

[0008] S1. After the powder-coated metal sheet is introduced into the heating furnace and heated to the preset temperature, it is discharged from the outlet of the heating furnace to the outside of the heating furnace;

[0009] S2. Both the heat transfer paper and the metal sheet are conveyed to the heat transfer roller, so that the heat transfer roller heats the metal sheet and the heat transfer paper, and the metal sheet and the heat transfer paper, which are conveyed around the heat transfer roller and are in contact with each other, undergo a heat transfer process.

[0010] S3. The heat transfer paper after the heat transfer process is conveyed to the transfer paper take-up roller for winding, and the metal sheet after the heat transfer process is conveyed to the sheet take-up roller for winding.

[0011] Furthermore, a flexible pressing component is provided on the outer periphery of the heat transfer roller, and a pressing channel is formed between the flexible pressing component and the heat transfer roller, which is arranged around the outer periphery of the heat transfer roller.

[0012] S2 includes:

[0013] S21. The heat transfer paper and the metal plate are both transferred into the pressing channel, so that the metal plate and the heat transfer paper form a bonding component, and the inner and outer sides of the bonding component respectively abut against the heat transfer roller and the flexible pressing component, so that the heat transfer roller heats the metal plate and the heat transfer paper.

[0014] S22. The bonding component moves along the pressing channel to achieve conveying around the heat transfer roller, and during the conveying process, the bonding component undergoes a heat transfer process under the bonding pressure of the heat transfer roller and the flexible pressing assembly.

[0015] Furthermore, the flexible pressing assembly includes: a flexible fabric layer and multiple support rollers;

[0016] The plurality of support rollers are distributed around the circumference of the heat transfer roller;

[0017] The flexible fabric layer is wound around the multiple support rollers;

[0018] The flexible fabric layer and the heat transfer roller form a C-shaped pressing channel.

[0019] Furthermore, the flexible fabric layer is a thermal insulation fabric layer.

[0020] Furthermore, the heat transfer roller has a hollow roller structure, and hot oil circulates inside the heat transfer roller.

[0021] Furthermore, the heat transfer roller is rotatable;

[0022] In step S2, the heat transfer roller drives the metal plate and the heat transfer paper to be transported by rotating.

[0023] Furthermore, prior to S1, the following is also included:

[0024] S00, Obtain the thickness of the metal sheet;

[0025] S01. Adjust the heat transfer roller to a preset speed according to the thickness of the board material and a first preset rule, wherein the thickness of the board material is inversely proportional to the preset speed.

[0026] Further, S1 includes:

[0027] S11. After coating one side of the metal sheet with powder, it is introduced into the preheating furnace and heated to the initial bonding temperature.

[0028] S12. The metal sheet discharged from the preheating furnace is cooled by a cold air blower;

[0029] S13. After the other side of the metal sheet after the initial curing treatment is coated with powder, it is introduced into the heating furnace and heated to the preset temperature.

[0030] S14. The outlet of the heating furnace is led out to the outside of the heating furnace.

[0031] Further, S3 includes:

[0032] S31. The heat transfer paper after the heat transfer process is conveyed to the heat transfer paper take-up roller for winding, and the metal plate after the heat transfer process is conveyed to the laminating machine, so that the laminating machine coats the non-transfer surface of the metal plate.

[0033] S32. The coated metal sheet is conveyed to the sheet winding roller for winding.

[0034] Furthermore, prior to S1, the following is also included:

[0035] S000, Obtain the thickness of the metal sheet;

[0036] S001. Adjust the preset temperature according to the thickness of the plate according to a second preset rule, wherein the thickness of the plate is proportional to the preset temperature;

[0037] S002. Adjust the heating temperature of the heat transfer roller according to the thickness of the plate material and a third preset rule, wherein the thickness of the plate material is inversely proportional to the heating temperature of the heat transfer roller.

[0038] A second aspect of this application provides a continuous heat transfer system for metal sheets, comprising:

[0039] A powder coating device is used to coat metal sheets with powder, so that a powder layer is formed on the surface of the metal sheets;

[0040] A heating furnace, located downstream of the powder coating device, is used to heat the powder-coated metal sheet to a preset temperature;

[0041] Transfer paper unwinding roller, used to unwind heat transfer paper;

[0042] A heat transfer roller is located downstream of the heating furnace and is used to simultaneously wind the heat transfer paper and the heated metal sheet, and to heat the metal sheet and the heat transfer paper to promote the heat transfer process of the heat transfer paper and the metal sheet that are in contact with each other.

[0043] A transfer paper take-up roller is located downstream of the heat transfer roller and is used to take up the heat transfer paper after the heat transfer process.

[0044] A sheet metal take-up roller, located downstream of the heat transfer roller, is used to take up the metal sheet after the heat transfer process.

[0045] As can be seen from the above technical solutions, this application provides a continuous heat transfer process and system for metal sheets; wherein, the continuous heat transfer process for metal sheets includes: S1, introducing the powder-coated metal sheet into a heating furnace and heating it to a preset temperature, and then exporting it from the outlet of the heating furnace to the outside of the heating furnace; S2, conveying both the heat transfer paper and the metal sheet to a conveyor that wraps around the heat transfer roller, so that the heat transfer roller heats the metal sheet and the heat transfer paper, and so that the metal sheet and the heat transfer paper, which are conveyed around the heat transfer roller and are in contact with each other, undergo a heat transfer process; S3, conveying the heat transfer paper after the heat transfer process to a transfer paper take-up roller for winding, and conveying the metal sheet after the heat transfer process to a sheet take-up roller for winding.

[0046] In this solution, the heating furnace can heat the powder-coated metal sheet to a preset temperature to achieve continuous heating and conveying of the metal sheet. At the same time, the heat transfer paper is independently heated by the heat transfer roller, so that the temperature control of the heat transfer paper and the metal sheet does not interfere with each other. This avoids the impact of adjusting the heating furnace temperature due to the adjustment of the sheet thickness on the transfer effect, thereby reducing the requirements for temperature control. Attached Figure Description

[0047] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0048] Figure 1A flowchart of a continuous heat transfer process for metal sheets is provided as an embodiment of this application;

[0049] Figure 2 This is a partial schematic diagram of a continuous heat transfer system for metal sheets provided in an embodiment of this application;

[0050] Figure 3 This is an overall schematic diagram of a continuous heat transfer system for metal sheets provided in an embodiment of this application;

[0051] In the picture:

[0052] 10. Metal sheet; 20. Heat transfer paper;

[0053] 100. Heating furnace; 110. Outlet;

[0054] 200. Heat transfer roller; 210. Flexible pressing assembly; 211. Pressing channel; 212. Support roller; 213. Flexible fabric layer;

[0055] 300. Sheet metal take-up roller;

[0056] 400. Transfer paper take-up roller;

[0057] 500. Laminating machine; 510. Bottom film unwinding roll; 520. Bottom film looper;

[0058] 600. Coating device; 610. Secondary coating equipment; 620. Primary coating equipment;

[0059] 700. Transfer paper unwinding roller; 710. Sheet unwinding machine; 720. Sewing machine; 730. Inlet looper; 740. Outlet looper; 750. Tensioner; 760. Washing line; 761. Hot alkaline water machine; 762. Hot water washing machine; 770. Drying oven; 771. Passivation machine; 780. Centering machine;

[0060] 810. Cutting machine; 820. Preheating furnace; 830. Air cooler; 840. Bottom film edge trimming machine; 850. Facial mask applicator. Detailed Implementation

[0061] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments in this application specification, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection claimed in this application.

[0062] In the description of the embodiments of the present application, it should be noted that the orientation or positional relationship indicated by terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the embodiments of the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation on the embodiments of the present application. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0063] In the description of the embodiments of the present application, it should be noted that unless otherwise clearly specified and limited, the terms "installed", "connected", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a replaceable connection, or an integral connection. It can be a mechanical connection or an electrical connection. It can be directly connected or indirectly connected through an intermediate medium. It can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific situations.

[0064] Please refer to Figure 1 and Figure 2 In the first aspect of the embodiments of the present application, a continuous heat transfer printing process for metal sheets is provided. This solution is applicable to the continuous heat transfer printing processing of metal sheets such as steel sheets and aluminum sheets, and can independently heat the metal sheet 10 and the heat transfer paper 20 respectively, so as to facilitate temperature control and ensure the heat transfer printing effect. The production system supporting this solution may include a metal sheet unwinder, a heat transfer paper unwinder, a guide roller group, a heating furnace 100, a heat transfer roller 200, a sheet winding roller 300, and a transfer paper winding roller 400. The metal sheet unwinder, the heat transfer paper unwinder, the guide roller group, the sheet winding roller 300 and the transfer paper winding roller 400 cooperate with each other to achieve the stable transportation of the metal sheet 10 and the heat transfer paper 20. The heating furnace 100 can heat the continuously transported metal sheet 10. The heat transfer roller 200 is located outside the heating furnace 100, and can receive and transport the metal sheet 10 and the heat transfer paper 20, and independently heat the metal sheet 10 and the heat transfer paper 20.

[0065] This solution includes the following steps:

[0066] S1. After introducing the metal sheet 10 with powder coating into the heating furnace 100 and heating it to a preset temperature, it is exported from the outlet 110 of the heating furnace 100 to the outside of the heating furnace 100;

[0067] S2. Both the heat transfer paper 20 and the metal sheet 10 are conveyed to the heat transfer roller 200 for conveying, so that the heat transfer roller 200 heats the metal sheet 10 and the heat transfer paper 20, and the metal sheet 10 and the heat transfer paper 20 that are conveyed around the heat transfer roller 200 and are pressed together are heat transferred.

[0068] S3. The heat transfer paper 20 after the heat transfer process is conveyed to the transfer paper take-up roller 400 for winding, and the metal sheet 10 after the heat transfer process is conveyed to the sheet take-up roller 300 for winding.

[0069] In step S1, the powder-coated metal sheet 10 refers to the metal sheet 10 after pretreatment, where powder coating is uniformly applied using a powder coating device, followed by heat curing of the powder layer. The powder coating device can achieve powder coating through electrostatic powder spraying, coating technology, or other methods; and the heat curing process can be carried out by a heating furnace 100. After powder coating, a uniform powder layer is formed on the metal sheet 10, allowing the ink pattern of the subsequent heat transfer paper 20 to bond tightly with the powder layer under heat and pressure, avoiding the problems of poor adhesion and easy peeling caused by the pattern directly adhering to the metal surface. The pretreatment of the metal sheet 10 may include processes such as cleaning, degreasing, and drying.

[0070] In this design, the heating furnace 100 can be a continuous heating device with precise temperature control. It has an inlet for the metal sheet 10 to pass through, and an internal heater heats the metal sheet 10 to a preset temperature (generally 230 to 280°C). Then, an internal traction mechanism guides the metal sheet 10 out through the outlet 110. In this embodiment, the preset temperature is set according to the sheet thickness. In this embodiment, the metal sheet 10 is heated inside the heating furnace 100, allowing for independent temperature control to ensure the curing effect of the powder layer. After the metal sheet 10 is removed from the heating furnace 100, its temperature gradually decreases. For thicker metal sheets 10, due to their higher heating temperature, additional cooling devices such as blowers can be installed downstream of the outlet 110.

[0071] In step S2, the heat transfer paper 20 can be a transfer paper with a preset pattern and the pattern layer coated with heat transfer ink or other special transfer media, which can be transferred to the surface of the cured powder layer of the metal plate 10 at an activation temperature of 200-230°C.

[0072] In this design, the heat transfer roller 200 refers to a cylindrical roller with heating function and controllable temperature. It can maintain a constant temperature on its outer periphery and allows the metal sheet 10 and the heat transfer paper 20 to be wound around it, so that the metal sheet 10 and the heat transfer paper 20 are bonded together, and the heat transfer paper 20 is heated to ensure that the heat transfer paper 20 reaches the activation temperature. In this embodiment, the angle at which the metal sheet 10 and the heat transfer paper 20 are wound around the heat transfer roller 200 can be 180° to 270°, so that the heat transfer roller 200 can provide bonding pressure to the metal sheet 10 and the heat transfer paper 20. During the process of the metal sheet 10 and the heat transfer paper 20 being wound around the heat transfer roller 200, the ink on the heat transfer paper 20 dissolves and transfers to the powder layer, and forms a decorative layer consistent with the pattern of the heat transfer paper after the metal sheet 10 cools down.

[0073] In step S3, after the metal sheet 10 and the heat transfer paper 20 are led out from the heat transfer roller 200, they separate from each other and are wound up separately.

[0074] In the continuous thermal transfer process for metal sheets provided in this embodiment, the heating furnace 100 is dedicated to heating the metal sheet 10 and its surface powder, while the thermal transfer roller 200 heats the thermal transfer paper 20, allowing the temperatures of the thermal transfer paper 20 and the metal sheet 10 to be adjusted independently. In existing methods where both the thermal transfer paper 20 and the metal sheet 10 are heated in a furnace using air as the heat transfer medium, changes in the thickness of the metal sheet 10 and the powder thickness necessitate temperature adjustments to ensure effective heating. These adjustments are slow, and to prevent ineffective transfer due to excessively low temperatures or damage to the thermal transfer paper due to excessively high temperatures, the furnace's temperature control precision is crucial. In this solution, however, the temperature and tension adjustments for the thermal transfer paper 20 and the metal sheet 10 can be performed independently with high heat transfer efficiency. This ensures the thermal transfer paper 20 is at its activation temperature, reducing the requirements for temperature control while maintaining the effectiveness of the thermal pressing process.

[0075] Meanwhile, the inventors discovered that, since heating furnaces generally use air as the heating medium, maintaining a constant temperature for both the metal sheet and the heat transfer paper in existing heating furnace methods is difficult, resulting in significant temperature fluctuations. In this embodiment, by wrapping the metal sheet 10 and the heat transfer paper 20 around the heat transfer roller 200, the heat transfer roller 200 can heat and maintain the temperature of both materials. This direct contact reduces temperature fluctuations in both materials, bringing their temperatures closer to a constant level, thereby improving the heat transfer effect and ensuring its stability.

[0076] In a more specific embodiment, a flexible pressing component 210 is provided on the outer periphery of the heat transfer roller 200, and a pressing channel 211 is formed between the flexible pressing component 210 and the heat transfer roller 200, which is arranged around the outer periphery of the heat transfer roller 200.

[0077] S2 includes:

[0078] S21. The heat transfer paper 20 and the metal plate 10 are both transferred to the pressing channel 211, so that the metal plate 10 and the heat transfer paper 20 form a bonding component, and the inner and outer sides of the bonding component abut against the heat transfer roller 200 and the flexible pressing component 210 respectively, so that the heat transfer roller 200 heats the metal plate 10 and the heat transfer paper 20.

[0079] S22, the bonding component moves along the pressing channel 211 to achieve conveying around the heat transfer roller 200, and during the conveying process, the bonding component undergoes a heat transfer process under the bonding pressure of the heat transfer roller 200 and the flexible pressing assembly 210.

[0080] In this embodiment, the bonding component can be configured with an inner layer of metal sheet 10 and an outer layer of heat transfer paper 20, that is, the inner side of the metal sheet 10 abuts against the heat transfer roller 200 and the outer side abuts against the heat transfer paper 20; the inner side of the heat transfer paper 20 abuts against the metal sheet 10 and the outer side abuts against the flexible pressing component 210.

[0081] In this embodiment, the flexible pressing component 210 is disposed on the outer periphery of the heat transfer roller 200 and can serve as an auxiliary mechanism to provide flexible pressing force to the heat transfer roller 200. Furthermore, a pressing channel 211 is formed between the component and the heat transfer roller 200, which can ensure that the inner and outer sides of the bonding component are subjected to pressure while the heat transfer paper 20 and the metal plate 10 are being introduced, thereby improving the heat transfer effect.

[0082] In practical applications, the inventors have discovered that the heat transfer roller 200 can provide bonding pressure to the bonding component from the inside out. In this embodiment, the flexible pressing component 210 can provide bonding pressure to the bonding component from the outside in, thereby forming a bidirectional clamping pressing channel 211 with the heat transfer roller 200, which improves the uniformity of pressure on the bonding component and enhances the adhesion and density of the transferred pattern.

[0083] In one embodiment, the flexible pressing assembly 210 includes: a flexible fabric layer 213 and a plurality of support rollers 212; the plurality of support rollers 212 are distributed around the heat transfer roller 200; the flexible fabric layer 213 is wound around the plurality of support rollers 212; a C-shaped pressing channel 211 is formed between the flexible fabric layer 213 and the heat transfer roller 200.

[0084] In this embodiment, there are six support rollers 212, which are arranged parallel to the heat transfer roller 200. The six support rollers 212 are arranged from the first to the sixth in a clockwise direction. In this embodiment, the flexible fabric layer 213 is sequentially laid from the first support roller 212 to the sixth support roller 212, then returns around the sixth support roller 212, and then sequentially returns from the sixth, fifth, ... back to the first support roller 212, so that the flexible fabric layer 213 is connected end to end, forming a C-shaped pressing channel 211.

[0085] In practical applications, the support rollers 212 are all mounted on the support member (not shown in the figure). Furthermore, the position of the support rollers 212 on the support member is adjustable. For example, a drive member (in the prior art) can be configured on the support member to push the support rollers 212 radially, or the position can be adjusted by adjusting the mounting position of the support rollers 212. By adjusting the position of the support rollers 212, the tension of the flexible fabric layer 213 can be adjusted.

[0086] In this embodiment, the flexible fabric layer 213 can be made of a fabric that is heat-resistant, wear-resistant, and highly flexible. As one implementation, the flexible fabric layer 213 is an insulation fabric layer, such as high-temperature resistant felt or aramid needle-punched felt.

[0087] In one embodiment, the heat transfer roller 200 has a hollow roller structure, and hot oil circulates inside the heat transfer roller 200. That is, in this embodiment, the heating function of the heat transfer roller 200 is achieved through the hot oil inside the roller. The hot oil has a high specific heat capacity and a more stable temperature regulation. Combined with an external oil temperature control system, the oil temperature can be precisely regulated.

[0088] In practical applications, this solution is used in large factories and on large equipment, where the metal sheet 10 can weigh several tons or tens of tons. Correspondingly, the heat transfer roller 200 has a large size. By using hot oil heating, the temperature fluctuation of the heat transfer roller 200 can be effectively reduced, the overall temperature consistency of the heat transfer roller 200 can be improved, and the transfer quality consistency of continuous production can be guaranteed.

[0089] In this embodiment, the heat transfer roller 200 consists of a metal plate 10, a heat transfer paper 20, and a flexible fabric layer 213, arranged from the inside out. As the metal plate 10 and heat transfer paper 20 enter the pressing channel 211, the inner side of the heat transfer paper 20 abuts against the metal plate 10, and the outer side abuts against the flexible fabric layer 213. Specifically, the heating temperature of the metal plate 10 by the heating furnace 100 is higher than the activation temperature of the heat transfer paper 20. Although the temperature of the metal plate 10 exiting the heating furnace 100 gradually decreases, it still maintains a relatively high temperature, ensuring that the metal plate 10 can provide heat to the heat transfer paper 20 after entering the pressing channel 211. In this embodiment, the heat transfer roller 200 can conduct heat to the metal plate 10, and then the metal plate 10 can transfer heat to the heat transfer paper 20, thus achieving full utilization of the heat from the metal plate 10. It should be noted that for some thicker metal sheets 10, a blower can be added between the heating furnace 100 and the heat transfer roller 200 to cool down the metal sheet 10, so as to avoid the metal sheet 10 being damaged by excessively high temperature or the heat transfer paper 20 being damaged by high temperature evaporation of ink, resulting in the transfer color becoming lighter.

[0090] In one embodiment, the heat transfer roller 200 is rotatable; in S2, the heat transfer roller 200 drives the metal plate 10 and the heat transfer paper 20 to be conveyed by rotating.

[0091] Compared to methods that rely on external traction rollers for driving, in this solution, the heat transfer roller 200 can be synchronously conveyed with the bonding parts, thereby improving the pattern alignment accuracy between the metal sheet 10 and the heat transfer paper 20, reducing the pattern misalignment rate, and achieving improved transfer quality and increased production efficiency.

[0092] In one embodiment, prior to S1, the following is also included:

[0093] S00, Obtain the thickness of the metal sheet 10;

[0094] S01. Adjust the heat transfer roller speed to the preset speed according to the first preset rule based on the thickness of the board material. The thickness of the board material is inversely proportional to the preset speed.

[0095] In practical applications, the inventors have discovered that the thickness of the substrate directly affects the powder coating effect of the powder coating device. Specifically, when the substrate is thicker, the heating time of the powder layer needs to be increased to ensure a good curing effect. When the substrate is thinner, the heating time of the powder layer needs to be reduced to avoid excessive aging of the powder layer. Furthermore, the rotation speed of the heat transfer roller 200 affects the heat transfer effect. Specifically, at a higher rotation speed, the contact time between the metal substrate 10 and the heat transfer paper 20 is shorter, increasing the risk of insufficient transfer. At a lower rotation speed, the contact time between the metal substrate 10 and the heat transfer paper 20 is longer, and prolonged contact at the current temperature can actually lead to a shallower transfer.

[0096] In this embodiment, when the sheet thickness is high, the conveying speed of the metal sheet 10 is reduced to prolong the heating time of the powder layer. Simultaneously, the preset speed value is reduced to match the rotational speed of the heat transfer roller 200 with the conveying speed of the metal sheet 10. The temperature of the heat transfer roller 200 is also appropriately reduced (the degree of reduction can refer to the third preset rule described below) to prolong the pressing time between the metal sheet 10 and the heat transfer paper 20, ensuring a good pressing effect. When the sheet thickness is low, the conveying speed of the metal sheet 10 is increased to reduce the heating time of the powder layer. Simultaneously, the preset speed value is increased to match the rotational speed of the heat transfer roller 200 with the conveying speed of the metal sheet 10. The temperature of the heat transfer roller 200 is also appropriately increased (the degree of increase can refer to the third preset rule described below) to reduce the pressing time between the metal sheet 10 and the heat transfer paper 20, thereby improving production efficiency while meeting the pressing effect requirements.

[0097] It should be noted that the rotation speed of the heat transfer roller 200 is generally synchronized with the production speed. Therefore, when adjusting the rotation speed of the heat transfer roller 200, other equipment (such as the sheet unwinding machine 710 and the transfer paper unwinding roller 700 described below) needs to be adjusted synchronously. Thus, steps S00 and S01 described above can be applied to the initial stage of sheet unwinding, that is, after the roll of metal sheet 10 is placed in the sheet unwinding machine 710, the production speed and the rotation speed of the heat transfer roller 200 are adjusted according to the thickness of the metal sheet 10. The degree of adjustment can be obtained from recorded and stored historical production data.

[0098] In practical applications, the first preset rule can be obtained based on actual recorded data of different sheet thicknesses, different conveying speeds, different preset speeds, and heat transfer effects. Workers can manually or through image recognition equipment judge the heat transfer effect on the metal sheet (suitable, too dark, too light, etc.) and record the temperature, sheet thickness, and conveying speed of each piece of equipment during production.

[0099] In one embodiment, S3 includes:

[0100] S31. The heat transfer paper 20 after the heat transfer process is conveyed to the heat transfer paper take-up roller 400 for winding, and the metal sheet 10 after the heat transfer process is conveyed to the laminating machine 500, so that the laminating machine 500 laminates the non-transfer surface of the metal sheet 10.

[0101] S32. The coated metal sheet 10 is conveyed to the sheet winding roller 300 for winding.

[0102] In this embodiment, a base film can be applied to the non-transfer surface of the metal sheet 10 using a laminating machine 500. The lamination utilizes the residual heat after the metal sheet 10 transfers the printing process, providing physical protection and decoration to the uncoated surface of the metal sheet 10. The base film can be, for example, a PE anti-rust film or a VCI vapor phase anti-rust film, which adheres tightly to the substrate surface to form a physical barrier layer.

[0103] In one embodiment, step S1 may include:

[0104] S11. After coating one side of the metal sheet 10 with powder, it is introduced into the preheating furnace 820 and heated to the initial bonding temperature.

[0105] S12. The metal sheet 10 discharged from the preheating furnace 820 is cooled by the air cooler 830.

[0106] S13. After applying powder coating to the other side of the metal sheet 10 after the initial curing treatment, it is introduced into the heating furnace 100 and heated to the preset temperature.

[0107] S14. The outlet 110 of the heating furnace 100 leads to the outside of the heating furnace 100.

[0108] In this embodiment, the initial binding temperature can be configured to be equivalent to a preset temperature.

[0109] In this embodiment, the powder coating process on one side of the metal sheet 10 can be performed by a primary powder coating device 620. For example, the primary powder coating device 620 can form a uniform powder layer on one side of the metal sheet 10 through spraying, roller coating, or other methods. The powder coating process on one side of the metal sheet 10 can be performed by a secondary powder coating device 620. The cooler 830 can cool the metal sheet 10 after powder coating on one side to stabilize the heat transfer effect.

[0110] In this embodiment, steps S11 to S13 enable the formation of a uniform powder layer on both sides of the metal sheet 10, thereby providing effective protection and decoration for both sides of the metal sheet 10. Both the preheating box 83 and the heating furnace 100 can employ infrared heating modules.

[0111] In one embodiment, prior to S1, the following is also included:

[0112] S000, Obtain the thickness of the metal sheet 10;

[0113] S001. Adjust the preset temperature according to the second preset rule based on the thickness of the board material. The thickness of the board material is directly proportional to the preset temperature.

[0114] S002. Adjust the heating temperature of the heat transfer roller 200 according to the thickness of the board material and the third preset rule. The thickness of the board material is inversely proportional to the heating temperature of the heat transfer roller 200.

[0115] It should be noted that the above steps S000, S001 and S002 can occur before or after step S01.

[0116] In this embodiment, the preset temperature for heating the metal sheet 10 by the heating furnace 100 is directly proportional to the sheet thickness; that is, the thicker the sheet, the higher the preset temperature. Conversely, the heating temperature of the heat transfer roller 200 is inversely proportional to the sheet thickness; that is, the thicker the sheet, the lower the heating temperature of the heat transfer roller 200. The heating temperature of the heat transfer roller 200 refers to the temperature at which it applies heat transfer paper. In the embodiment using circulating hot oil, the heating temperature of the heat transfer roller 200 can be the temperature of the circulating hot oil.

[0117] The inventors have discovered that the higher the thickness of the sheet metal, the slower the production line speed, and the greater the thermal impact on the heat transfer paper 20 after the metal sheet 10 and the heat transfer paper 20 are bonded together. Therefore, in this embodiment, the heating temperature of the heat transfer roller 200 is correspondingly reduced, which can prevent the heat transfer paper 20 from exceeding the activation temperature and time range due to the temperature of the sheet metal.

[0118] In practical applications, the second and third preset rules can be obtained based on actual records of different sheet thicknesses, preset temperatures, heating temperatures, and heat transfer effects.

[0119] Please see Figure 2 and Figure 3 The second aspect of this application provides a continuous heat transfer system for metal sheets, comprising: a powder coating device 600, a heating furnace 100, a transfer paper unwinding roller 700, a heat transfer roller 200, a transfer paper take-up roller 400, and a sheet take-up roller 300.

[0120] The powder coating device 600 is used to coat the metal sheet 10 with powder, so that a powder layer is formed on the surface of the metal sheet 10. The heating furnace 100 is located downstream of the powder coating device 600 and is used to heat the powder-coated metal sheet 10 to a preset temperature and to solidify the powder layer. The transfer paper unwinding roller 700 is used to unwind the heat transfer paper 20, and it can be located upstream of the heat transfer roller 200 and downstream of the heating furnace 100. The heat transfer roller 200 is located downstream of the heating furnace 100 and is used for heat transfer. Paper 20 and heated metal sheet 10 are wound synchronously, and the metal sheet 10 and heat transfer paper 20 are heated and kept warm to promote the heat transfer process of the heat transfer paper 20 and metal sheet 10 that are in contact with each other; the transfer paper take-up roller 400 is located downstream of the heat transfer roller 200 and is used to take up the heat transfer paper 20 after the heat transfer process; the sheet take-up roller 300 is located downstream of the heat transfer roller 200 and is used to take up the metal sheet 10 after the heat transfer process.

[0121] In a further improved embodiment, the outer periphery of the heat transfer roller 200 may be provided with the aforementioned flexible pressing component 210.

[0122] In this embodiment, upstream of the powder coating device 600, in the order from upstream to downstream, can be provided the following: a sheet unwinding machine 710, a sewing machine 720, an inlet looper 730, an outlet looper 740, a tensioning machine 750, a washing line 760, a drying oven 770, and a centering machine 780. These devices can all be existing, mature, mass-produced equipment.

[0123] The sheet metal unwinder 710 is used to unwind the metal sheet 10. Two unwinders can be installed, one as the unwinding device and the other as a backup, ensuring production continuity. The sewing machine 720 connects two rolls of metal sheet 10, ensuring that after one roll of metal sheet 10 is unwound, its tail can be fixedly connected to the head of another roll of metal sheet 10 by sewing, thus ensuring production continuity. The inlet looper 730 can store a certain length of metal sheet 10, acting as a buffer for unwinding. The outlet looper 740 stores a certain length of metal sheet 10 and can adjust the release speed of the sheet according to the subsequent production speed, thereby buffering the speed difference of subsequent cleaning lines 760, tensioners 750, etc., ensuring the coordination of subsequent processes. The tensioner 750 can adjust the conveying tension of the metal sheet 10 to ensure flat conveying of the sheet; in practical applications, multiple tensioners 750 can be installed and placed between different devices. The cleaning line 760 is used to remove oil, dust, and other impurities from the surface of the metal sheet 10, providing a clean base for powder coating. The drying oven 770 is used to remove surface moisture from the cleaned sheet metal to prevent moisture from affecting the powder coating effect. In practical applications, multiple drying ovens 770 can be set up to ensure the drying effect. The centering machine 780 is used to correct the conveying position of the metal sheet 10 to ensure that the sheet metal is conveyed in the center. In practical applications, multiple centering machines 780 can be set up and set up between different devices to ensure the centering conveying effect.

[0124] In this embodiment, the cleaning line 760 may include a hot alkaline water machine 761 and a hot water cleaning machine 762. The hot alkaline water machine 761 may be located upstream of the hot water cleaning machine 762, so that the metal sheet 10 is sequentially conveyed through the hot alkaline water machine 761 and the hot water cleaning machine 762. The hot alkaline water machine 761 can specifically remove surface oil and contaminants from the metal sheet 10, and then the hot water cleaning machine 762 rinses the metal sheet 10.

[0125] In one implementation, two drying ovens 770 can be installed downstream of the cleaning line 760. A passivation machine 771 is installed between the two drying ovens 770. The passivation machine 771 can form a passivation film, also known as a chemical conversion film, on the surface of the metal sheet 10, preventing the metal from easily oxidizing after cleaning and drying, and providing an adhesion surface for subsequent powder coating, increasing the adhesion of subsequent layers. In practical applications, the passivation film can be formed by spraying or roller coating with passivation liquid (such as chromium-free passivating agent or chromate passivating agent).

[0126] In one embodiment, the continuous heat transfer system for metal sheets provided in this embodiment further includes a preheating furnace 820 and a cooling fan 830; the powder coating device 600 includes: a primary powder coating device 620 and a secondary powder coating device 610; the primary powder coating device 620 is used to spray powder onto one side of the metal sheet 10; the secondary powder coating device 610 is used to spray powder onto the other side of the metal sheet 10; the preheating furnace 820 and the cooling fan 830 are disposed between the primary powder coating device 620 and the secondary powder coating device 610; the preheating furnace 820 is used to heat the metal sheet 10 passing through the primary powder coating device 620; the cooling fan 830 is used to cool the metal sheet 100 after it has been heated by the preheating furnace 820.

[0127] As one implementation, a cooling fan 830 can also be installed downstream of the heat transfer roller 200. The heat-transferred metal sheet 10 can be cured by the downstream cooling fan 830 to stabilize the heat transfer effect. The cooling fan 830 can be installed downstream of the laminating machine 500.

[0128] In one embodiment, the continuous heat transfer system provided in this embodiment further includes a shearing machine 810. Two shearing machines 810 may be included: an upstream shearing machine 810 positioned upstream of the sewing machine 720, and a downstream shearing machine 810 adjacent to the upstream of the sheet metal take-up roller 300. In practical applications, the metal sheet 10 is often conveyed in a coil structure, and during production, edge burrs easily appear at the head and tail of the coil. The upstream shearing machine 810 of the sewing machine 720 can cut the head and tail of the coil during coil changing to remove end edge burrs, improving the flatness and alignment of the tail of one coil with the head of another. The shearing machine 810 adjacent to the sheet metal take-up roller 300 can cut the coil, allowing the transferred metal sheet to be wound up to a preset length, ensuring that the wound product meets dimensional accuracy and usage requirements.

[0129] In one embodiment, a laminating machine 850 may be installed downstream of the heat transfer roller 200 laminating machine 500, specifically downstream of the air cooler 830 and between the downstream shear 810. The laminating machine 850 can cover the transfer surface of the cured metal sheet with a protective film to protect the pattern on the transfer surface.

[0130] In the application, a bottom film edge trimming machine 840 may be installed adjacent to the top of the face film applicator 850. The bottom film edge trimming machine 840 is capable of trimming the bottom film edge of the metal sheet 10 by removing the burrs from the bottom film edge.

[0131] The above are merely preferred embodiments of this application and are not intended to limit the present invention. Although this application has been described in detail with reference to examples, those skilled in the art can still modify the technical solutions described in the foregoing examples or make equivalent substitutions for some of the technical features. However, any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A continuous heat transfer process for metal sheets, characterized in that, include: S1. After the powder-coated metal sheet (10) is introduced into the heating furnace (100) and heated to the preset temperature, it is discharged from the outlet (110) of the heating furnace (100) to the outside of the heating furnace (100); S2. The heat transfer paper (20) and the metal plate (10) are both conveyed to the heat transfer roller (200) so that the heat transfer roller (200) heats the metal plate (10) and the heat transfer paper (20) and the metal plate (10) and the heat transfer paper (20) which are conveyed around the heat transfer roller (200) and are in contact with each other, and the heat transfer process is carried out. S3. The heat transfer paper (20) after the heat transfer process is conveyed to the transfer paper take-up roller (400) for winding, and the metal sheet (10) after the heat transfer process is conveyed to the sheet take-up roller (300) for winding.

2. The continuous heat transfer printing process for metal sheets according to claim 1, characterized in that, A flexible pressing component (210) is provided on the outer periphery of the heat transfer roller (200), and a pressing channel (211) is formed between the flexible pressing component (210) and the heat transfer roller (200) and the heat transfer roller (200). S2 includes: S21. The heat transfer paper (20) and the metal plate (10) are both transferred into the pressing channel (211) so that the metal plate (10) and the heat transfer paper (20) form a bonding component, and the inner and outer sides of the bonding component respectively abut against the heat transfer roller (200) and the flexible pressing assembly (210), so that the heat transfer roller (200) heats the metal plate (10) and the heat transfer paper (20); S22, the bonding element moves along the pressing channel (211) to achieve conveying around the heat transfer roller (200), and during the conveying process, the bonding element undergoes a heat transfer process under the bonding pressure of the heat transfer roller (200) and the flexible pressing assembly (210).

3. The continuous heat transfer process for metal sheets according to claim 2, characterized in that, The flexible pressing assembly (210) includes: a flexible fabric layer (213) and a plurality of support rollers (212). The plurality of support rollers (212) are circumferentially distributed around the heat transfer roller (200); The flexible fabric layer (213) is wound around the plurality of support rollers (212); A C-shaped pressing channel (211) is formed between the flexible fabric layer (213) and the heat transfer roller (200).

4. The continuous heat transfer process for metal sheets according to claim 1, characterized in that, The heat transfer roller (200) has a hollow roller structure, and hot oil flows inside the heat transfer roller (200).

5. The continuous heat transfer process for metal sheets according to claim 1, characterized in that, The heat transfer roller (200) is rotatable; In S2, the heat transfer roller (200) drives the metal plate (10) and the heat transfer paper (20) to be transported by rotating.

6. The continuous heat transfer process for metal sheets according to claim 5, characterized in that, Before S1, it also includes: S00, Obtain the thickness of the metal sheet (10); S01. Adjust the heat transfer roller (200) to a preset speed according to the thickness of the plate according to the first preset rule. The thickness of the plate is inversely proportional to the preset speed.

7. The continuous heat transfer process for metal sheets according to claim 1, characterized in that, S3 includes: S31. The heat transfer paper (20) after the heat transfer process is conveyed to the transfer paper take-up roller (400) for winding, and the metal plate (10) after the heat transfer process is conveyed to the laminating machine (500) so that the laminating machine (500) coats the non-transfer surface of the metal plate (10). S32. The coated metal sheet (10) is conveyed to the sheet winding roller (300) for winding.

8. The continuous heat transfer process for metal sheets according to claim 1, characterized in that, S1 includes: S11. After applying powder coating to one side of the metal sheet (10), it is introduced into the preheating furnace (820) and heated to the initial bonding temperature. S12. The metal sheet (10) discharged from the preheating furnace (820) is cooled by a cold air blower (830); S13. After the other side of the metal plate (10) after the initial curing treatment is coated with powder, it is introduced into the heating furnace (10) and heated to the preset temperature. S14. The outlet (110) of the heating furnace (100) is led out to the outside of the heating furnace (100).

9. The continuous heat transfer process for metal sheets according to any one of claims 1 to 8, characterized in that, Before S1, it also includes: S000, Obtain the thickness of the metal sheet (10); S001. Adjust the preset temperature according to the thickness of the plate according to a second preset rule, wherein the thickness of the plate is proportional to the preset temperature; S002. Adjust the heating temperature of the heat transfer roller (200) according to the thickness of the plate according to the third preset law. The thickness of the plate is inversely proportional to the heating temperature of the heat transfer roller (200).

10. A continuous heat transfer system for metal sheets, characterized in that, include: A powder coating device (600) is used to coat a metal sheet (10) with powder so that a powder layer is formed on the surface of the metal sheet (10). A heating furnace (100) is located downstream of the powder coating device (600) and is used to heat the powder-coated metal sheet (10) to a preset temperature. Transfer paper unwinding roller (700) is used to unwind heat transfer paper (20). A heat transfer roller (200) is located downstream of the heating furnace (100) and is used to simultaneously wind the heat transfer paper (20) and the heated metal plate (10), and to heat the metal plate (10) and the heat transfer paper (20) to promote the heat transfer process of the heat transfer paper (20) and the metal plate (10) that are in contact with each other; A transfer paper take-up roller (400) is disposed downstream of the heat transfer roller (200) and is used to take up the heat transfer paper (20) after the heat transfer process. A sheet metal take-up roller (300) is located downstream of the heat transfer roller (200) and is used to take up the metal sheet (10) after the heat transfer process.

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