A multi-roller continuous high-speed transfer machine

Abstract

The present invention provides a multi-roller continuous high-speed transfer machine, characterized in that it includes: a box body as a heat preservation chamber; a plurality of parallel heat transfer rollers arranged in the box body; a steering mechanism arranged in the box body so that the heat transfer paper is always located between the metal strip and the heat transfer roller when it is wrapped around the plurality of heat transfer rollers; and a plurality of pressing roller groups that press the metal strip and the heat transfer paper on the heat transfer rollers, the metal strip and the heat transfer paper are sequentially wrapped around a part of the roller surface of each heat transfer roller. The steering mechanism is provided to enable the metal strip and the heat transfer paper to complete a 180-degree turn after leaving one heat transfer roller and before wrapping around the next transfer roller, thereby ensuring that the heat transfer paper is always located between the metal strip and the heat transfer roller when it is wrapped around the heat transfer roller, thereby further improving the transfer quality.

Description

Technical Field

[0001] The present invention relates to a multi-roller continuous high-speed thermal transfer device, by adopting the device, the ink pattern on the thermal transfer paper or thermal transfer film can be continuously and high-speed transferred to the metal plate strip, and in particular to a multi-roller continuous high-speed transfer machine with a steering mechanism. Background Art

[0002] Thermal transfer technology originated in Japan and South Korea, and then gradually emerged in industrially developed countries such as Europe and the United States. Figure 1 As shown, thermal transfer technology refers to a surface printing decoration technology that brings thermal transfer paper or thermal transfer film 11 printed with an ink pattern 12 into close contact with a substrate 13, heats both to a certain temperature, applies a certain pressure, and maintains for a certain time, so as to transfer the ink pattern 12 on the thermal transfer paper or thermal transfer film 11 to the substrate 13 to form a final printed product.

[0003] In 1993, Japan took the lead in applying thermal transfer technology to the surface printing and decoration of textiles and daily necessities, and led this emerging technology to quickly become popular in developed countries. In early 1996, my country purchased thermal transfer films and thermal transfer machines from Japan, and thermal transfer technology was introduced to China.

[0004] Thermal transfer technology was first used in textile printing production. With the rapid development of science and technology, the application field of thermal transfer technology is becoming wider and wider. Ceramics, metals, rubber, leather, wood, etc. can all use thermal transfer technology to print exquisite patterns. In the past 20 years, the application of thermal transfer technology on metals has made great progress, from the initial small metal components to security doors, fire doors, architectural aluminum profiles, steel and wood furniture and other metal plates and metal components with relatively large surface areas.

[0005] Through the thermal transfer process, various decorative patterns imitating natural wood texture or marble pattern are formed on the surface of metal plates and metal components, which can not only meet people's admiration for natural decorative effects, but also save a lot of forest resources and protect the environment. Moreover, compared with wood, metal plates have the advantages of safety and fireproof, high strength and light weight, so the metal plate thermal transfer technology is increasingly recognized and respected by people. The use of thermal transfer metal plates is very wide, and can be applied to various fields such as aluminum alloy doors and windows, anti-theft doors, fire doors, steel and wood furniture, filing cabinets, computer shells, household appliances, metal accessories, etc.

[0006] As one of the prior arts related to the present invention, most domestic metal plates adopt a single-piece thermal transfer process, and the method is: open the upper and lower frames of the vacuum transfer bed, place the metal plate to be transferred on the vacuum transfer bed, cover the surface of the metal plate with powder coating with thermal transfer paper, close the upper and lower frames, use a vacuum pump to evacuate the gas in the transfer bed, let the silicone skin of the transfer bed be tightly pressed against the outside of the thermal transfer paper, so that the thermal transfer paper is close to the surface of the metal plate, and then push the transfer bed into the oven, heat it at 180℃~200℃ for 3~5 minutes, and the pattern on the thermal transfer paper will be transferred to the surface of the metal plate.

[0007] In practical applications, this method has the following disadvantages: the single-piece thermal transfer process has a low degree of automation, each process requires manual operation, the process flow is cumbersome, and the efficiency is extremely low; the vacuum transfer bed is large in size, and the upper and lower frames are frequently opened and closed. The sealing device at the opening and closing of the upper and lower frames is complicated, the sealing effect is poor, and it is easy to leak air, which affects the transfer quality.

[0008] As the second prior art related to the present invention, in recent years, with the development of thermal transfer technology, on the basis of single-piece thermal transfer technology, a single-roller semi-continuous thermal transfer device for metal strips has begun to appear. Figure 2 It is a schematic diagram of a single-roller semi-continuous thermal transfer device disclosed in patent CN201776980U, and is also a continuous thermal transfer device for steel plates and strips. The device includes a hot box 25, a single thermal transfer roller 22 arranged in the hot box, and a paper placing device 24-1 and a paper receiving device 24-2 for thermal transfer paper 28 arranged on the upper part of the hot box. On both sides of the thermal transfer roller, there are respectively provided an introduction roller 23-1 and an outlet roller 23-2 for the metal strip 27. The axes of the introduction roller 23-1, the thermal transfer roller 22 and the outlet roller 23-2 are distributed in a "V" shape. Its working principle is: one end of the metal strip 27 is connected to the unwinder, and the other end is connected to the coiler. After degreasing, roughening, powder spraying and curing, the metal strip 27 enters the thermal transfer device. The metal strip 27 and the thermal transfer paper 28 are respectively wrapped around the circumference of the thermal transfer roller 22, and the thermal transfer paper 28 is located between the metal strip 27 and the thermal transfer roller 22, and thermal transfer begins. In actual production, the quality of thermal transfer can be controlled by adjusting parameters such as the temperature of the thermal transfer roller 22, the temperature of the metal strip 27, the ambient temperature of the hot box 25, the pressure between the thermal transfer roller 22-thermal transfer paper 28-metal strip 27, and the travel speed of the metal strip 27.

[0009] Compared with the single-piece thermal transfer technology, the metal sheet single-roller semi-continuous thermal transfer technology can realize the semi-continuous thermal transfer of metal sheets, improve the degree of automation and work efficiency, further ensure the transfer quality, and reduce the intensity of manual operation. However, the disadvantage of this technology is that due to the configuration of the process equipment of the whole line unit, as well as the capacity of the key equipment for powder spraying, curing, and thermal transfer, the technology is still in the semi-continuous production mode of single-roll continuous production and shutdown when changing rolls, and can only run at a low speed (running speed not higher than 10m / min), which restricts and affects the further promotion of thermal transfer technology in the production field. Summary of the invention

[0010] The present invention provides a multi-roller continuous high-speed thermal transfer device, through which continuous, high-speed, high-quality thermal transfer of metal plates and strips can be achieved, thereby greatly improving the automation level and work efficiency of thermal transfer technology, better ensuring the transfer quality, promoting the development of thermal transfer technology, and providing more powerful technical guarantees for the extensive promotion of this technology in the production field. The specific technical scheme is described as follows.

[0011] As a multi-roller continuous high-speed transfer machine of the present invention, it includes: a box body as an insulation room; a plurality of parallel thermal transfer rollers arranged in the box body; a steering mechanism arranged in the box body so that the thermal transfer paper is always located between the metal plate and the thermal transfer roller when it is wrapped around the thermal transfer roller; and a plurality of pressure roller groups that press the metal plate and the thermal transfer paper onto the thermal transfer roller, the metal plate and the thermal transfer paper being wrapped around a portion of the roller surface of each thermal transfer roller in sequence.

[0012] In the above-mentioned multi-roller continuous high-speed transfer machine, preferably, the steering mechanism includes a steering roller provided above two adjacent thermal transfer rollers.

[0013] In the multi-roller continuous high-speed transfer machine as described above, preferably, the number of the thermal transfer rollers is 3-7, and the thermal transfer rollers are metal rollers belonging to thermal oil thermal transfer rollers or metal rollers belonging to electromagnetic heating thermal transfer rollers.

[0014] In the multi-roller continuous high-speed transfer machine as described above, preferably: the wrapping angle of the metal strip and / or the thermal transfer paper on the thermal transfer roller is greater than 180 degrees, preferably 200-260 degrees, and more preferably 230 degrees.

[0015] In the multi-roller continuous high-speed transfer machine as described above, it is preferred that: one thermal transfer roller is correspondingly provided with one or more pressure roller groups; when one thermal transfer roller is correspondingly provided with multiple pressure roller groups, the multiple pressure roller groups are symmetrically distributed around the bisector of the wrapping angle of the metal sheet on the thermal transfer roller or are evenly distributed in the wrapping area of ​​the metal sheet on the thermal transfer roller; when one thermal transfer roller is correspondingly provided with one pressure roller group, the multiple rollers constituting the pressure roller group are symmetrically distributed around the bisector of the wrapping angle of the metal sheet on the thermal transfer roller.

[0016] In the multi-roller continuous high-speed transfer machine as described above, preferably: compared with the bisector of the wrapping angle of the metal sheet on the thermal transfer roller, the pressure roller group is closer to the starting wrapping point of the metal sheet on the thermal transfer roller.

[0017] In the multi-roller continuous high-speed transfer machine as described above, preferably: the pressure roller group includes multiple pressure rollers driven by the same cylinder, the multiple thermal transfer rollers are individually driven by variable frequency speed regulating motors, and the roller diameter of the thermal transfer roller is φ2000~φ3000mm, preferably φ2000mm.

[0018] In the multi-roller continuous high-speed transfer machine as described above, it is preferred that: it also includes an inlet roller and an outlet roller, and a metal sheet strip inlet and a metal sheet strip outlet are arranged on the box body. After the metal sheet strip enters the box body from the metal sheet strip inlet, it turns through the inlet roller and begins to wrap around the thermal transfer roller, and after leaving the last thermal transfer roller, it turns through the outlet roller and leaves the box body from the metal sheet strip outlet.

[0019] In the multi-roller continuous high-speed transfer machine as described above, it is preferred that: it also includes a thermal transfer paper unwinder and a thermal transfer paper winder, the thermal transfer paper is unwound by the thermal transfer paper unwinder and enters the box to be wound around the thermal transfer roller, and is wound through the thermal transfer paper winder after leaving the last thermal transfer roller.

[0020] In the multi-roller continuous high-speed transfer machine as described above, it is preferred that: it also includes: a metal sheet strip inlet and a metal sheet strip outlet arranged on the box body; an introduction roller that guides the metal sheet strip from the metal sheet strip inlet to the thermal transfer roller; and an outlet roller that guides the metal sheet strip from the thermal transfer roller to the metal sheet strip outlet, and the thermal transfer paper unwinder and the thermal transfer paper winder are arranged on different sides of the box body from the metal sheet strip inlet and the metal sheet strip outlet.

[0021] In the above-mentioned multi-roller continuous high-speed transfer machine, preferably, the diameter of the steering roller is smaller than the diameter of the thermal transfer roller.

[0022] In the multi-roller continuous high-speed transfer machine as described above, preferably: the axis of the steering roller is parallel to the axis of the thermal transfer roller, and the projection of the axis of the steering roller on the axis line connecting the two adjacent thermal transfer rollers is located in the middle of the axis line.

[0023] In the multi-roller continuous high-speed transfer machine as described above, preferably: the steering mechanism arranged above two adjacent thermal transfer rollers includes two steering rollers, the two steering rollers are parallel to each other and the axis line between them is parallel to the axis line between the two adjacent thermal transfer rollers.

[0024] In the above-mentioned multi-roller continuous high-speed transfer machine, preferably, the axes of the two adjacent thermal transfer rollers and the axes of the two steering rollers form an isosceles trapezoid.

[0025] In the above-mentioned multi-roller continuous high-speed transfer machine, it is preferred that the axis of one of the heat transfer rollers and the axes of the two upper adjacent steering rollers form an inverted isosceles triangle.

[0026] The present invention provides a steering mechanism to enable the metal strip and the thermal transfer paper to complete the steering after leaving one thermal transfer roller and before being wrapped around the next transfer roller, ensuring that the thermal transfer paper is always located between the metal strip and the thermal transfer roller when being wrapped around the thermal transfer roller, thereby further improving the transfer quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their description are merely used to explain the present invention and do not constitute an improper limitation on the present invention.

[0028] Figure 1 Schematic diagram of thermal transfer technology, where (a) represents before thermal transfer, (b) represents during thermal transfer, and (c) represents after thermal transfer.

[0029] Figure 2 It is a schematic diagram of a single-roller continuous thermal transfer device.

[0030] Figure 3 It is a schematic diagram of a multi-roller continuous high-speed thermal transfer device.

[0031] Figure 4 This is a schematic diagram of a thermal transfer paper unwinding machine.

[0032] Figure 5 This is a schematic diagram of a thermal transfer paper winder. DETAILED DESCRIPTION

[0033] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other without conflict.

[0034] In the description of the present invention, the terms "longitudinal", "lateral", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and do not require that the present invention must be constructed and operated in a specific orientation. Therefore, they should not be understood as limitations on the present invention. The terms "connected" and "connected" used in the present invention should be understood in a broad sense. For example, they can be fixed connections or detachable connections; they can be directly connected or indirectly connected through intermediate components. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0035] The present invention provides a multi-roller thermal transfer device, which together with other process equipment before and after the unit constitutes a metal strip continuous high-speed thermal transfer unit. The process flow of the metal strip continuous high-speed thermal transfer unit is: unwinding - sewing (welding) - inlet looper - cleaning - passivation - drying - powder spraying - curing - thermal transfer - cooling - outlet looper - coating - winding. The thermal transfer equipment, as the main process equipment of the whole unit, plays a vital role in the production speed and product quality of the unit.

[0036] The use of this metal strip continuous high-speed thermal transfer unit can achieve continuous and high-speed thermal transfer of metal strips, thereby greatly improving the automation level and work efficiency of thermal transfer technology, better ensuring the transfer quality, promoting the development of thermal transfer technology, and providing more powerful technical guarantees for the widespread promotion of this technology in the production field.

[0037] The following is combined with Figures 3 to 5 The structure and working principle of the multi-roller continuous high-speed thermal transfer device are described in detail.

[0038] Figure 3The schematic diagram of the multi-roller continuous high-speed thermal transfer device is shown in FIG. The metal strip 34 comes out of the curing furnace and enters the heat preservation chamber 33, turns through the introduction roller 35, and is sequentially wrapped around the roller surfaces of multiple thermal transfer rollers 37 and multiple steering rollers 39. The thermal transfer paper 32 is unwound from the transfer paper unwinder 31 and is also sequentially wrapped around the roller surfaces of multiple thermal transfer rollers 37 and multiple steering rollers 39. The metal strip 34 and the thermal transfer paper 32 are tightly attached to the roller surfaces of the thermal transfer rollers 37 and the steering rollers 39 under the tension of the strip and the tension of the transfer paper with a certain pressure. The pressing roller group 36 arranged around each thermal transfer roller 37 presses the metal strip 34 and the thermal transfer paper 32 wrapped around the roller surface of the thermal transfer roller 37 under the drive of the cylinder to ensure uniform contact and tight attachment of the metal strip 34, the thermal transfer paper 32 and the roller surface of the thermal transfer roller 37. After passing through multiple heat transfer rollers 37, the metal strip 34 that has completed the transfer is turned by the lead-out roller 30 and comes out of the heat preservation chamber to enter the subsequent process, and the heat transfer paper 32 that has completed the transfer enters the transfer paper take-up machine 38 for collection. The heat transfer paper unwinder 31 and the heat transfer paper take-up machine 38 are installed on the top of the heat preservation chamber 33, and the heat transfer paper 32 is contained within the metal strip 34, so that the heat transfer paper 32 always enters the transfer device from between the metal strip 34 and the heat transfer roller 37, and leaves the transfer device from between the metal strip 34 and the heat transfer roller 37.

[0039] By adopting the method of arranging a steering roller above the thermal transfer roller, a disadvantage of dividing multiple thermal transfer rollers into upper and lower rows for multi-roller transfer is overcome: the thermal transfer paper on the upper row of thermal transfer rollers is not between the metal plate and the thermal transfer rollers, and the thermal transfer quality of the upper row of thermal transfer rollers will be affected to a certain extent, which in turn affects the thermal transfer effect.

[0040] exist Figure 3 In the embodiment, three heat transfer rollers are arranged in a row at the bottom, and four steering rollers 39 are arranged in a row at the top. In fact, as the number of heat transfer rollers increases, the number of steering rollers can be increased accordingly.

[0041] Generally, the axis of the steering roller 39 is parallel to the axis of the thermal transfer roller 37 to function with maximum efficiency. The steering roller 39 can be a free roller, which is driven to rotate under the friction of the plate strip, or it can be given a driving force to rotate as necessary.

[0042] from Figure 3 It can be seen that two steering rollers 39 are arranged between two adjacent thermal transfer rollers 37 and above the two thermal transfer rollers. That is to say, after the metal sheet 34 or the thermal transfer paper 32 passes around the first thermal transfer roller 37 on the left, it successively passes through two steering rollers 39 to achieve steering, ensuring that the thermal transfer paper 32 is always located between the metal sheet and the thermal transfer roller during transfer.

[0043] from Figure 3It can be seen that the two steering rollers are parallel to each other and the axis line between them is parallel to the axis line of the two adjacent thermal transfer rollers below, and the axis of each of the two adjacent thermal transfer rollers and the axis of each of the two steering rollers, the quadrilateral formed by the lines between these four is an isosceles trapezoid.

[0044] In addition, from Figure 3 It can also be seen that there are two spaced-apart steering rollers above the middle thermal transfer roller 37, and the axis of the thermal transfer roller and the axes of the two adjacent steering rollers above it form an inverted isosceles triangle relationship to ensure the wrap angle on the transfer roller. Of course, the distance between the two steering rollers can be adjusted depending on the size of the wrap angle of the thermal transfer paper on the transfer roller.

[0045] although Figure 3 As shown in the figure, two steering rollers are arranged above two adjacent thermal transfer rollers 37 to ensure the wrapping angle of the metal strip and the thermal transfer paper on the thermal transfer rollers. However, according to the requirements for the wrapping angle, one steering roller or three steering rollers can be arranged above two adjacent thermal transfer rollers 37 to complete the steering task. When one steering roller is preferably arranged, the projection of the axis of the steering roller on the axis line connecting the two adjacent thermal transfer rollers 37 is located in the middle of the axis line.

[0046] The multiple heat transfer rollers involved in heat transfer can be arranged according to actual needs. Figure 3 The axes of the three heat transfer rollers shown in the figure are located at the same horizontal height and are designed to be in a row. However, the axes of the multiple heat transfer rollers may no longer be located at the same horizontal height according to actual needs, and may be staggered from each other. For example, the axis of the middle heat transfer roller may be at a higher horizontal height than the axes of the heat transfer rollers on both sides. Of course, the steering roller should also be adjusted upward accordingly to ensure an appropriate wrap angle.

[0047] As the thermal transfer roller, a heat-conducting oil type thermal transfer roller or an electromagnetic heating type thermal transfer roller can be used as required. The thermal transfer roller can be a metal roller that does not need to be coated with a rubber layer on the surface, or a metal roller coated with a rubber layer on the surface can be used as required. There are multiple thermal transfer rollers, but from an overall perspective, the preferred number of thermal transfer rollers is 3 to 7, such as 3, 4, 5 or 7. The specific number is related to the design speed of the unit. On the premise of meeting the speed requirements of the unit, the fewer the better.

[0048] As a turning mechanism that allows the thermal transfer paper 32 to always wrap around the thermal transfer roller from between the metal plate belt 34 and the thermal transfer roller 37, this specification uses Figure 3The invention is described by taking two steering rollers located above any thermal transfer roller as an example, but the invention is not limited to this. It can be any steering structure under the prior art that can complete the steering task of the thermal transfer paper and the metal strip and ensure that the thermal transfer paper completes the transfer work by being located between the metal strip and the thermal transfer roller, such as any mechanical structure that enables the metal strip to flip 180 degrees before the application date of this application. This will not be discussed in detail.

[0049] The present invention provides a steering mechanism to enable the metal strip and the thermal transfer paper to complete a 180-degree turn after leaving one thermal transfer roller and before being wrapped around the next transfer roller, thereby ensuring that the thermal transfer paper is always located between the metal strip and the thermal transfer roller when being wrapped around the thermal transfer roller, thereby further improving the transfer quality.

[0050] The insulation chamber 33 may be made of insulation materials commonly used in heating furnaces and have a certain insulation effect. A heating device may not be provided inside the chamber. Of course, a heating device may be provided as needed.

[0051] In order to cooperate with the continuous and high-speed thermal transfer of metal plates and strips, the thermal transfer paper unwinding machine adopts a turret-type double-station form and is equipped with an automatic edge correction device to ensure that the thermal transfer paper always follows the horizontal movement of the strip edge. Figure 4 This is a schematic diagram of a thermal transfer paper unwinding machine, in which a turntable 47 is mounted on a bracket 45 via a spindle 46, and two air shafts 44 and 48 arranged 180 degrees opposite to each other are mounted on the turntable for mounting thermal transfer paper rolls 42 and 49, and a steering guide roller 43 is arranged on the turntable 47 and the bracket 45 for guiding the direction of the thermal transfer paper when unwinding. The thermal transfer paper roll 49 on the air shaft 48 is at the paper placing station, and the thermal transfer paper roll 42 on the air shaft 44 is at the waiting station. When the thermal transfer paper roll 42 is about to be put away, the thermal transfer paper 41 is pressed down onto the thermal transfer paper roll 42 for rapid bonding and shearing. The turntable 47 drives the air shafts 44 and 48, the thermal transfer paper rolls 42 and 49, and the steering guide roller 43 installed thereon to rotate 180°. In this way, the thermal transfer paper roll 42 on the air shaft 44 enters the paper placing station, and the remaining thermal transfer paper rolls 42 on the air shaft 48 enter the waiting station. The worker manually removes the remaining thermal transfer paper rolls 42, installs new thermal transfer paper rolls, and waits for the next station rotation.

[0052] The heat transfer paper winding machine 37 adopts a fixed double-station form, such as Figure 5 As shown, the air shafts 52 and 54 are installed on the bracket 53. When the air shaft 54 ​​is being rolled up, the paper roll 51 that has been rolled up on the air shaft 52 is manually unloaded and put in a waiting state; after the air shaft 54 ​​has completed rolling up, the paper head is manually rolled toward the air shaft 52 for rolling up, and the paper roll 55 that has been rolled up on the air shaft 54 ​​is unloaded and put in a waiting state, and this rotation is repeated to ensure that the thermal transfer paper is continuously rolled up and collected.

[0053] In short, conventional equipment sold on the market can be used as the thermal transfer paper unwinding machine and the thermal transfer paper winding machine.

[0054] The quality of thermal transfer of metal strips mainly depends on three factors: thermal transfer temperature, thermal transfer time and thermal transfer pressure. The multi-roller continuous high-speed thermal transfer device is studying how to ensure the continuity, high speed and high quality of thermal transfer on the basis of ensuring the thermal transfer temperature, thermal transfer time and thermal transfer pressure. The following will explain this in turn.

[0055] (1) Thermal transfer temperature

[0056] The best thermal transfer temperature for metal strips should be controlled at 200-220℃, such as 221℃, 223℃, 225℃, 227℃, 228℃, 229℃, etc. Temperatures below 200℃ will reduce the transfer rate of thermal transfer paper ink and affect the color and durability of the transfer pattern; temperatures above 220℃ will cause the transfer pattern to become coked, dull, and sticky, thus affecting the transfer quality.

[0057] In order to strictly control the thermal transfer temperature, this patent adopts a thermal oil type thermal transfer roller 37 with high heat conduction efficiency, good thermal conductivity uniformity and high control accuracy, wherein the thermal oil is evenly distributed in the roller body interlayer. Since the thermal oil has good fluidity, it prevents the local temperature difference of the roller body from being too large. All thermal transfer rollers use a separate thermal oil supply system and temperature control system, which provides conditions for accurately and conveniently adjusting the transfer temperature. Of course, electromagnetic heating thermal transfer rollers based on electromagnetic induction current can also be used as needed.

[0058] All thermal transfer rollers are surrounded in the insulation chamber 33. When performing thermal transfer operations, except for windows at the entrance and exit of the steel strip and transfer paper (i.e., there are a steel strip entrance and exit and a thermal transfer paper entrance and exit), the rest of the insulation chamber 33 adopts a closed structure, and the outer wall is paved with insulation material to ensure the temperature in the insulation chamber, reduce heat loss, and improve energy efficiency.

[0059] In addition, the metal strip itself has a certain temperature when it comes out of the curing furnace and enters the insulation chamber 33. A metal strip temperature detection device is set at the entrance of the insulation chamber 33 to strictly control the temperature of the strip itself within the optimal transfer temperature range. In order to control the temperature of the strip within the range of 200 to 220°C, various known technologies can be adopted, such as setting a metal strip temperature detection device at the entrance of the insulation chamber 33 to strictly control the temperature of the strip itself within the optimal transfer temperature range. Under normal circumstances, the temperature of the metal strip is slightly higher than the thermal transfer temperature when it comes out of the curing furnace. At this time, it is necessary to start the cooling device after the curing furnace to cool it down. Here, the metal strip temperature detection device and the cooling device form an electrical closed-loop control to ensure that the metal strip enters the temperature range of the thermal transfer device.

[0060] (2) Thermal transfer time

[0061] The best thermal transfer time for metal strips should be controlled within 16 to 20 seconds, such as 16.5 seconds, 17 seconds, 17.5 seconds, 18 seconds, 18.5 seconds, 19 seconds, etc. If the transfer time is too short, such as less than 16 seconds, the transfer rate of the thermal transfer paper ink will be reduced, affecting the color and durability of the transferred pattern; if the transfer time is too long, such as more than 20 seconds, the ink will spread, the pattern will be blurred, and scars will appear, thus affecting the transfer quality.

[0062] (3) Thermal transfer pressure

[0063] There are two factors that influence and determine the thermal transfer pressure. One is the tension of the metal strip 34 itself, and the other is the pressing force of the pressure roller group 36 on the metal strip 34, the thermal transfer paper 32 and the thermal transfer roller 37.

[0064] As for the tension of the metal strip 34 itself, its size can be adjusted by adjusting the tension devices (not shown) before and after the thermal transfer device, and sufficient tension is provided without causing plastic deformation of the metal strip 34 to ensure that the metal strip 34 presses the thermal transfer paper 32 against the roller surface of the thermal transfer roller 37. In order to avoid the metal strip 34 generating additional tension when wrapping around multiple thermal transfer rollers 37, causing the extension of the metal strip 34 and thus affecting the transfer quality, all thermal transfer rollers 37 are driven and adjusted separately by variable frequency speed regulating motors to control their output torque to keep balance with the friction resistance torque of the thermal transfer roller 37. At the same time, tension detection devices are respectively set at the inlet and outlet of the transfer device, and the tension detection value forms a closed-loop control with the front and rear tension devices to ensure that the inlet tension and outlet tension are always balanced and stable.

[0065] The pressing force of the pressure roller group 36 on the metal strip 34, the thermal transfer paper 32 and the thermal transfer roller 37 can be adjusted by adjusting the cylinder pressure of the pressure roller group 36. A driving method in which one cylinder is configured for each pressure roller group can be adopted.

[0066] In addition to the above three main factors, in order to further improve the transfer effect, it is also necessary to consider the spatial layout of the thermal transfer roller, the roller diameter, the number of rollers and the thermal transfer speed.

[0067] When the metal strip passes through the thermal transfer device at a certain running speed, the temperature of the strip and the thermal transfer roller are strictly controllable. In order to make the strip, transfer paper and thermal transfer roller fit tightly and ensure sufficient transfer time, it is necessary to make a reasonable spatial layout of the thermal transfer roller.

[0068] like Figure 3As shown, each heat transfer roller is provided with two sets of pressure roller groups 36 along the roller surface, and the two sets of pressure roller groups 36 are respectively located at or near the inlet and outlet of the metal strip 34 on the heat transfer roller. Of course, the pressure roller group can also be placed closer to the intersection of the center bisector of the wrap angle B of the metal strip 34 on the heat transfer roller and the roller surface according to the situation. The general arrangement principle of the pressure roller group should be to arrange the pressure rollers as evenly as possible on the arc surface of the heat transfer roller wrapping around the metal strip, in order to make the pressing and fitting between the metal strip, the heat transfer paper and the heat transfer roller more uniform. Figure 3 It can be seen that each set of pressing roller group 36 includes 3 pressing rollers. Of course, more pressing rollers can be used according to actual needs. The roller surface of the pressing roller is covered with a high-temperature resistant rubber layer to ensure that the roller surface and the surface of the metal plate and strip are evenly and tightly fitted, further ensuring the integrity and uniformity of the transfer pattern.

[0069] In principle, when the running speed of the metal strip is constant, the larger the diameter of the thermal transfer roller and the fewer the rollers, the more conducive it is to shorten the length of the transfer device, simplify the thermal transfer device equipment, and improve the reliability of the thermal transfer device. However, considering the difficulty of processing, transportation, installation, and maintenance of the thermal transfer roller, the roller diameter cannot be too large. In the present invention, the preferred roller diameter of the thermal transfer roller is φ2000~φ3000mm, such as 2200mm, 2300mm, 2500mm, 2800mm, etc. Under the condition of meeting the production requirements, a smaller roller diameter is more preferred. For example, in Figure 5 The preferred roller diameter is 2000 mm.

[0070] Based on the above analysis of the spatial layout, roller diameter and number of thermal transfer rollers, the thermal transfer speed of the metal strip can reach up to about 70m / min, which fundamentally changes the current maximum thermal transfer speed of 10m / min of the existing production line.

[0071] In addition, the wrap angle B of the metal strip or the thermal transfer paper on the thermal transfer roller is in the range of 260° to 200°.

[0072] The thermal transfer paper unwinder 31 and the thermal transfer paper winder 38 are installed on the top of the heat preservation chamber 33. The installation position must ensure that the thermal transfer paper 32 is always contained within the metal strip 34, that is, the thermal transfer paper 32 always enters the transfer device from between the metal strip 34 and the thermal transfer roller 37, and leaves the transfer device from between the metal strip 34 and the thermal transfer roller 37. In principle, after the thermal transfer roller is arranged, the metal strip and thermal transfer paper at the entrance and exit should be as close to the thermal transfer roller as possible to increase its wrap angle.

[0073] Those skilled in the art know that thermal transfer technology is based on ink sublimation and immersion. The premise of ink sublimation is heating. At a certain temperature, it takes a certain amount of time for the ink to sublimate and immerse into the substrate. This time is the thermal transfer time, which is the biggest factor limiting the speed increase of the unit. In order to increase the speed of the unit while ensuring sufficient thermal transfer time, the inventors thought of using a multi-roller form to extend the fitting length of the metal strip and the thermal transfer roller as much as possible in a limited space. That is, the multi-roller continuous high-speed thermal transfer device of the present invention realizes the continuity, high speed and high quality of the strip thermal transfer process on the basis of ensuring the transfer temperature, transfer time and transfer pressure, greatly improves the automation degree and work efficiency of the strip thermal transfer technology, better guarantees the transfer quality, promotes the development of thermal transfer technology, and provides a more powerful technical guarantee for the wide promotion of this technology in the production field.

[0074] In addition, although the present invention Figure 3 The diameters of the multiple heat transfer rollers are the same, but they can also be designed differently according to actual needs.

[0075] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A multi-roller continuous high-speed transfer machine, characterized in that: include: As a box for the insulation room; A plurality of parallel heat transfer rollers arranged in the box; A steering mechanism disposed in the box so that the thermal transfer paper is always located between the metal strip and the thermal transfer roller when the thermal transfer paper is wrapped around the thermal transfer roller, and a plurality of pressing roller groups pressing the metal strip and the thermal transfer paper onto the thermal transfer roller; The metal strip and the thermal transfer paper are sequentially wrapped around a portion of the roller surface of each thermal transfer roller; One heat transfer roller is provided with one or more pressing roller groups. When one heat transfer roller is provided with multiple pressing roller groups, the multiple pressing roller groups are symmetrically distributed around the bisector of the wrapping angle of the metal strip on the heat transfer roller or are evenly distributed in the wrapping area of ​​the metal strip on the heat transfer roller. When one heat transfer roller is provided with one pressing roller group, the multiple rollers constituting the pressing roller group are symmetrically distributed around the bisector of the wrapping angle of the metal strip on the heat transfer roller; The steering mechanism disposed above two adjacent thermal transfer rollers includes two steering rollers; The two steering rollers are parallel to each other and the axis connecting the two steering rollers is parallel to the axis connecting the two adjacent thermal transfer rollers; The distance between the two steering rollers can be adjusted depending on the wrapping angle of the thermal transfer paper on the transfer roller.

2. The multi-roller continuous high-speed transfer machine according to claim 1, characterized in that: The steering mechanism includes a steering roller disposed above two adjacent thermal transfer rollers.

3. The multi-roller continuous high-speed transfer machine according to claim 1, characterized in that: The number of the thermal transfer rollers is 3-7. The heat transfer roller is a metal roller belonging to a thermal oil type heat transfer roller or a metal roller belonging to an electromagnetic heating type heat transfer roller.

4. The multi-roller continuous high-speed transfer machine according to claim 1, characterized in that: The wrapping angle of the metal strip and / or the thermal transfer paper on the thermal transfer roller is greater than 180 degrees.

5. The multi-roller continuous high-speed transfer machine according to claim 1, characterized in that: The wrapping angle of the metal strip and / or the thermal transfer paper on the thermal transfer roller is 200-260 degrees.

6. The multi-roller continuous high-speed transfer machine according to claim 1, characterized in that: The wrapping angle of the metal strip and / or the thermal transfer paper on the thermal transfer roller is 230 degrees.

7. The multi-roller continuous high-speed transfer machine according to claim 1, characterized in that: Compared to the bisector of the wrapping angle of the metal sheet strip on the thermal transfer roller, the pressure roller group is closer to the starting wrapping point of the metal sheet strip on the thermal transfer roller.

8. The multi-roller continuous high-speed transfer machine according to claim 1, characterized in that: The pressing roller group includes a plurality of pressing rollers driven by the same cylinder. The plurality of thermal transfer rollers are driven individually by variable frequency speed regulating motors; The roller diameter of the thermal transfer roller is φ2000-φ3000 mm.

9. The multi-roller continuous high-speed transfer machine according to claim 8, characterized in that: The roller diameter of the thermal transfer roller is φ2000 mm.

10. The multi-roller continuous high-speed transfer machine according to claim 1, characterized in that: It also includes an inlet roller and an outlet roller, a metal strip inlet and a metal strip outlet arranged on the box body, After the metal strip enters the box from the metal strip inlet, it turns through the introduction roller and starts to wrap around the thermal transfer roller. After leaving the last thermal transfer roller, it turns through the exit roller and leaves the box from the metal strip outlet.

11. The multi-roller continuous high-speed transfer machine according to claim 1, characterized in that: It also includes a thermal transfer paper unwinding machine and a thermal transfer paper winding machine. The thermal transfer paper is unwound by the thermal transfer paper unwinding machine and enters the box to be wound on the thermal transfer roller. After leaving the last thermal transfer roller, it is wound by the thermal transfer paper winding machine.

12. The multi-roller continuous high-speed transfer machine according to claim 11, characterized in that: It also includes: a metal strip inlet and a metal strip outlet arranged on the box body; An inlet roller for guiding the metal sheet strip from the metal sheet strip inlet to the thermal transfer roller; and The metal strip is guided from the thermal transfer roller to the outlet roller of the metal strip. The thermal transfer paper unwinding machine and the thermal transfer paper winding machine are arranged on different sides of the box body as well as the metal sheet strip inlet and the metal sheet strip outlet.

13. The multi-roller continuous high-speed transfer machine according to claim 2, characterized in that: The diameter of the steering roller is smaller than the diameter of the thermal transfer roller.

14. The multi-roller continuous high-speed transfer machine according to claim 1, characterized in that: The axes of the two adjacent thermal transfer rollers and the axes of the two steering rollers form an isosceles trapezoid.

15. The multi-roller continuous high-speed transfer machine according to claim 1, characterized in that: An inverted isosceles triangle is formed between the axis of one of the heat transfer rollers and the axis of the two steering rollers adjacent thereto.

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