Metal material printing equipment and printing method using the same

Abstract

The present invention relates to a printing apparatus for printing images such as characters and pictures on the surface of a metal material such as a steel plate, and a printing method using the same.

Description

Technical Field

[0001] The present invention relates to printing equipment for printing images such as characters and pictures on the surface of metal materials such as steel plates, and a printing method using the same.

Background Art

[0002] As methods for printing images such as characters and pictures on the surface of metal materials, there are a polymer transfer method, a roll transfer method, and an inkjet printing method.

[0003] The polymer transfer method outputs a sheet-like image film and transfers the image to the surface of the metal by methods such as thermal transfer and chemical transfer. Although it is easy to output to the film in the image transfer method for the metal surface using the film, it has the drawback that the manufacturing speed is slow because the film is transferred to the steel plate, and the image adhered to the metal surface in the film form may be deformed depending on the temperature and weather.

[0004] The roll transfer method is a method of forming a pattern of a certain pattern on the surface of a roll and transferring the image to the surface of the metal material using a roll-to-roll method. However, the transferred image is limited to a repeating image, and in order to use the roll transfer method, rolls with each image patterned must be prepared, so there is a difficulty that patterned rolls must be prepared every time for various images.

[0005] Inkjet printing is a method of printing images and typefaces onto the surface of metal materials using liquid ink containing pigments and polymer resins. However, this inkjet printing method has a problem in that, when using liquid ink, the surface of the metal material must be plasma-treated or its surface roughness controlled so that the liquid adheres well to the surface of the steel plate. In addition, because inkjet printing uses liquid ink, clogging can occur in the nozzles from which the ink is ejected, requiring not only nozzle management but also periodic cleaning and replacement of the nozzles. Furthermore, because liquid ink is used, stabilization work after ink ejection is essential, making it difficult to manufacture using a roll-to-roll method and limiting its use to batch type. In particular, since the printing material for inkjet printing is in the form of linked liquid polymers with pigments forming the image within them, there is a problem that the printed image may peel off when the material is bent or cut.

[0006] Recently, metal materials are being used in a variety of fields, and images such as text and pictures are frequently being applied to metal surfaces. However, conventional image printing methods are designed for printing on surfaces such as paper and polymer materials, and there are technical and production limitations when applying them to metal surfaces. Therefore, there is a need for a solution that can overcome the limitations of conventional printing methods. [Overview of the project] [Problems that the invention aims to solve]

[0007] One aspect of the present invention is a technology for printing images such as characters and pictures onto the surface of a metal material, and aims to provide a printing apparatus and a printing method using the same that can print images onto the surface of a metal material at high speed and stably.

[0008] Another aspect of the present invention is to avoid direct contact between the metal material and the photosensitive drum during the printing process of metal materials, thereby improving the lifespan of the photosensitive drum and the print yield.

[0009] The problems that the present invention will address are not limited to those described above. Further problems that the present invention will address are described in the overall content of the specification, and any person with ordinary skill in the art to which the present invention belongs will have no difficulty in understanding these further problems from the content of the specification. [Means for solving the problem]

[0010] One aspect of the present invention is a transfer belt 800 that is in close contact with a continuously moving metal material 100 and rotates in one direction to transfer and fix toner T attached to the surface of the metal material 100 to the surface of the metal material 100, A photosensitive drum 300 that is in close contact with the transfer belt 800 and rotates in the opposite direction to the transfer belt 800, and transmits the toner T attached to its surface to the surface of the transfer belt 800, A developing means 500 is provided on one side of the photosensitive drum 300 and provides the toner T to the surface of the photosensitive drum 300, A photosensitive drum charging means 410 that charges the surface of the photosensitive drum 300 before the toner T is supplied, Between the developing means 500 and the photosensitive drum charging means 410, there is an exposure means 200 that applies light energy to the surface of the photosensitive drum 300 according to the required image, A metal material charging means 101 charges the surface of the metal material 100 so that the toner T attached to the surface of the transfer belt 800 is transferred to the surface of the metal material 100, After the toner T has settled on the surface of the metal material 100, a removal means 600 is provided to remove the toner T remaining on the surface of the photosensitive drum 300. After removing the toner T mentioned above, a photosensitive drum discharge means 420 is used to remove the charge from the photosensitive drum 300. A fixing means 700 is located at the rear end of the transfer belt 800 and fixes the toner T that has been fixed to the surface of the metal material 100, We provide printing equipment, including printing facilities.

[0011] Yet another aspect of the present invention is a charging step of charging the surface of a photosensitive drum 300 that rotates in one direction, An exposure step is performed to apply light energy to the surface of the charged photosensitive drum 300 according to the required image. After the above exposure, a developing step is performed to provide toner T to the surface of the photosensitive drum 300. The steps include moving the toner adhering to the surface of the photosensitive drum 300 to the surface of the charged transfer belt 800, A transfer step in which toner attached to the surface of the above transfer belt 800 is continuously moved and fixed to the surface of the charged metal material 100, A fixing step in which the toner fixed to the surface of the above metal material 100 is fixed, After the above transfer, a removal step is performed to remove the toner remaining on the surface of the photosensitive drum 300 and the transfer belt 800. A discharge step in which the surface of the photosensitive drum 300 and the transfer belt 800 is discharged, This invention provides a method for printing on metal materials, including the method described above. [Effects of the Invention]

[0012] According to the present invention, a technology is provided that allows for the stable printing of images such as characters and pictures onto materials such as metals, and by manufacturing them continuously, the production efficiency of products can be improved. Furthermore, by easily forming a wide variety of images, it is possible to manufacture high value-added products.

[0013] Furthermore, according to the present invention, direct contact between the metal material and the photosensitive drum can be prevented, minimizing damage and wear to the photosensitive drum. This has the advantage of reducing the effort required to repair the photosensitive drum and improving its lifespan.

[0014] The diverse and beneficial advantages and effects of the present invention are not limited to those described above and can be more easily understood in the process of describing specific embodiments of the present invention. [Brief explanation of the drawing]

[0015] [Figure 1] This is a schematic diagram schematically showing an implementation example of the printing equipment of the present invention. [Figure 2] This is a schematic diagram specifically showing an implementation example of the laser exposure means in the printing equipment of the present invention. [Figure 3] This is a schematic diagram schematically showing another implementation example of the printing equipment of the present invention. [Figure 4] This is a schematic diagram schematically showing yet another implementation example of the printing equipment of the present invention. [Figure 5] This is a schematic diagram schematically showing yet another implementation example of the printing equipment of the present invention. [Figure 6] This is a schematic diagram schematically showing yet another implementation example of the printing equipment of the present invention. [Figure 7] This is a schematic diagram schematically showing the cross-section of the printed metal material of the present invention.

Embodiments for Carrying Out the Invention

[0016] The terms used in this specification are for explaining the present invention and are not intended to limit the present invention. Also, the singular forms used in this specification include plural forms as well, unless the relevant definition clearly indicates the opposite meaning.

[0017] The meaning of "including" used in this specification does not concretize the composition and does not exclude the existence or addition of other compositions.

[0018] Unless otherwise defined, all terms including technical terms and scientific terms used in this specification have the same meaning as commonly understood by those with ordinary knowledge in the technical field to which the present invention belongs. Terms defined in a dictionary are interpreted as having a meaning consistent with the relevant technical literature and the currently disclosed content.

[0019] While generally known laser or LED printing is used to print on flexible materials such as paper, this invention relates to a technology for printing images on metal materials. This invention uses a charging means, a photosensitive drum, a fuse roll, etc., to print on the surface of a metal material that moves continuously in a roll-to-roll manner or the like. This invention relates to a technology that uses a transfer belt to prevent damage to the surface of the photosensitive drum due to friction between the photosensitive drum and the metal material when the metal material has high hardness.

[0020] Preferred embodiments of the present invention will be described below with reference to the drawings. These embodiments can be modified in various forms and should not be construed as being limited to the drawings and the embodiments described below, but are provided for the purpose of providing a detailed explanation to those who are ordinary skill in the art to which the present invention pertains.

[0021] Figure 1 schematically shows one implementation example of the printer equipment of the present invention. According to Figure 1, the printer equipment of the present invention relates to a technology for printing an image onto the surface of a continuously moving metal material 100 using a roll-to-roll method. The above-mentioned image refers to characters, patterns, pictures, etc., and includes all kinds of hues and forms such as monochrome, achromatic, chromatic, and three-dimensional.

[0022] The printing equipment of the present invention includes a transfer belt 800, a photosensitive drum 300, a photosensitive drum charging and discharging means 400, an exposure means 200, a developing means 500, a removal means 600, a fixing means 700, and the like. Each component will be described in detail below.

[0023] The transfer belt 800 adheres closely to the metal material 100 and rotates in one direction, providing the function of transferring and fixing toner attached to the surface of the metal material 100. At the same time, it protects the surface of the photosensitive drum 300 and improves image quality. If the hardness of the metal material 100 is high, the surface of the photosensitive drum 300 may be damaged due to contact between the metal material 100 and the photosensitive drum 300. In this case, the repair and replacement costs of the photosensitive drum 300 will increase, the accuracy of the transferred image may decrease, and the print quality may deteriorate. Therefore, the present invention employs a method in which toner does not move from the photosensitive drum 300 to the metal material 100, but is transferred via the transfer belt 800.

[0024] On the other hand, a transfer belt drive roll 810 is provided for driving the transfer belt 800 in the traveling direction, and a transfer belt charging means 820 is provided to charge the surface of the transfer belt 800 before the toner T is supplied from the photosensitive drum 300 in order to receive the toner T, and a corona wire is usually used. On the other hand, after the toner T on the transfer belt 800 is transmitted to the metal material 100 and an image is transferred, a toner removal means 840 is provided to remove the toner T remaining on the transfer belt, and a transfer belt discharge means 830 may be provided to discharge the charge of the transfer belt after the toner T has been removed.

[0025] The photosensitive drum 300, while in contact with the transfer belt and rotating in the opposite direction, plays the role of transferring the toner T adhering to its surface to the transfer belt 800. The photosensitive drum 300 can be any type commonly used in the art to which the present invention belongs, and is not particularly limited. As a preferred example, an OPC (Organic Photo Conductor) drum can be used.

[0026] The developing means 500 is provided on one side of the photosensitive drum 300 and provides toner T for forming an image on its surface. The developing means 500 only needs to be able to provide toner to the photosensitive drum 300, and its form and pattern are not particularly limited. In Figure 1, as a preferred example, the developing means 500 includes a toner container 520 containing toner T and a developing roller 510 that transmits toner from the toner container 520 to the photosensitive drum 300. The developing roller 520 is not essential, and in some cases, toner may be provided directly from the toner container 520 to the photosensitive drum 300. On the other hand, the toner T forms an image on the surface of a metal material, and all toners known to a person of ordinary skill in the art to which the present invention belongs can be used, and its type is not particularly limited. For example, a substance having a polymer structure may be used. Furthermore, in the present invention, substances that can impart various functions to the toner (e.g., fluorescent substances, magnetic substances, electrically conductive substances, etc.) can be added, and not only can functional images be realized, but roughness can also be added or three-dimensional shapes can be realized by using a variety of toner particles.

[0027] The device includes a photosensitive drum charging means 410 for charging the surface of the photosensitive drum 300 before the toner T is dispensed. The photosensitive drum charging means 410 applies an electrostatic charge to the surface of the photosensitive drum. A corona wire is commonly used as the charging means.

[0028] Between the developing means 500 and the photosensitive drum charging means 410, there is an exposure means 200 that applies light energy to the surface of the charged photosensitive drum 300 according to the required image. The position of the exposure means 200 is not important, but the light energy is applied to the surface of the photosensitive drum 300 between the developing means 500 and the photosensitive drum charging means 410. Due to the light energy, some of the charge is removed from the surface of the photosensitive drum 300, and the developing means 500 adheres to the surface of the photosensitive drum 300 with toner. The light energy is preferably a laser or an LED (Light Emitting Diode). Figure 2 schematically shows the exposure means 200 when a laser is used, and includes a laser generator 210 and a scanning mirror 220 that adjusts the laser emitted from the laser generator 210 and scans the surface of the photosensitive drum 300 according to the required image to remove the charge.

[0029] The metal material charging means 101 is used to charge the surface of the metal material 100 so that the image forming toner T transmitted from the photosensitive drum 300 to the transfer belt 800 can move to and fix to the continuously moving metal material 100. The metal material charging means 101 not only serves to charge the metal material to a certain charge, but can also serve as a guide roll to help the metal material move at a constant speed. One or more metal material charging means 101 may be provided, and the metal material charging means 101 may be formed at the front end, rear end, or front and rear ends of the transfer belt 800 with respect to the direction of travel of the metal material 100, and may be located on the top, bottom, or both top and bottom of the metal material 100.

[0030] Even if there are two or more of the above-mentioned metal material charging means 101, they do not perform different roles from one another, and there is an advantage in that a stronger electrostatic attraction can be secured through two or more charging processes.

[0031] On the other hand, Figure 3 shows another implementation example of the present invention. As shown in Figure 3, a separate coating layer A, for example, a resin layer, is formed on the surface of the metal material 100, and when printing on the coating layer, a metal charging means 101' for charging the coating layer A can be positioned on top of the coating layer A.

[0032] The photosensitive drum 300 includes a removal means 600 for removing toner T remaining on its surface after it has supplied toner to the transfer belt 800. The removal means 600 may include a blade 610 for separating the residual toner from the surface of the photosensitive drum 300, and a collection cylinder 620 at the lower end of the blade 610 for collecting the separated toner to prevent the separated toner from falling onto the metal material 100 and degrading print quality.

[0033] On the other hand, such removal means can also be provided in the transfer belt 800. Specifically, it may include a blade 810 for removing toner T remaining on the surface of the transfer belt 800 after the toner T for forming the image has been fixed onto the metal material 100, and a collection cylinder 820 at the lower end of the blade 810 for collecting the separated toner to prevent the separated toner from falling onto the metal material 100 and degrading the print quality.

[0034] Figure 4 schematically shows yet another implementation example of the printer equipment of the present invention. The printing equipment shown in Figure 4 is a more concrete example of the removal means 600 for removing toner remaining on the surface of the photosensitive drum 300 after the toner T of the photosensitive drum 300 has moved to the surface of the transfer belt 800. In addition to the blade 610 and recovery cylinder 620 described above, it may further include an alcohol brush 630. Since the photosensitive drum 300 transfers the image while rotating at high speed, it may not be easy to remove the toner. In such cases, there is a problem that afterimages of the image may remain. For this reason, after primary removal with the blade 610, secondary removal can be performed by a chemical method using an alcohol brush or the like. On the other hand, the alcohol brush for chemical removal can also be similarly applied to the transfer belt 800.

[0035] After the toner T is fixed onto the metal material 100, fixing means 700 for fixing the toner T on the metal material 100 and stably forming an image may be provided at the rear end of the photosensitive drum 300 and transfer belt 800 with reference to the direction of travel of the metal material 100. The fixing means 700 may include a fused roll 710 that applies heat to the toner T and fixes the toner T fixed onto the metal material 100, and a pressure roll 720 that assists in fixing by applying pressure. In this case, the heating temperature of the fused roll 710 is preferably 25 to 400°C.

[0036] In the present invention, it is more preferable that the metal material charging means 101 and the pressure roll 720 have a structure that allows them to move up and down. The metal material 100 cannot always have a constant thickness; it may be a very thin film or a thick plate. Therefore, if the metal material charging means 101 and the pressure roll 720 have a variable structure that allows them to move up and down according to the thickness of the metal material 100, an image can be printed regardless of the thickness of the metal material 100.

[0037] On the other hand, one or more toners can be used to print various images, in which case two or more photosensitive drums, photosensitive drum charging means, photosensitive drum discharge means, exposure means, developing means, and removal means can be provided in pairs along the direction of travel of the transfer belt 800. Figure 5 schematically shows yet another implementation example of the printer equipment of the present invention. Figure 5 above realizes a printing equipment for transferring an image by providing four types of toner for printing a color image, and the four types of toner may be C (Cyan), Y (Yellow), M (Magenta), and K (Black). The above types of toner do not necessarily have to be four types, and W (White) may also be included. It is also possible to use some of them, and the order is not fixed. A person skilled in the art can arbitrarily select them considering the required image, work efficiency, etc. However, the white (W) toner can be positioned furthest forward in the direction of travel of the metal material.

[0038] Figure 5 shows the printing equipment when using four types of toner. In Figure 5, in order to fix the four types of toner to the metal material 100, four pairs of photosensitive drums 301, 302, 303, 304, photosensitive drum charging and discharging means 401, 402, 403, 404, exposure means 201, 202, 203, 204, developing means 501, 502, 503, 504, and removal means 601, 602, 603, 604 are positioned along the direction of travel of the transfer belt. As a result, as shown in Figure 5, the toner T conveyed by each pair is transmitted to a single transfer belt 800, which then fixes it back onto the metal material 100. At this time, the fixing means 700 for fixing the toner fixed on the metal material 100 is for fixing the final transferred image and does not necessarily need to be multiple.

[0039] On the other hand, as shown in Figure 5, when a large number of photosensitive drums are used, the length of the transfer belt 800 may increase, which may cause slack. Therefore, the system can be further equipped with transfer belt support rolls 811, 812, 813, and 814 that support the transfer belt 800 and ensure continuous movement.

[0040] Figure 6 shows yet another embodiment of the present invention. Figure 6 relates to equipment that can sequentially or simultaneously print on both sides of a metal material 100 in which the above-described printing equipment moves continuously, and schematically shows that the above-described printing equipment is positioned on the upper and lower parts of the metal material. That is, it shows a technology in which each component having the above-described function and role is provided on the upper and lower parts of the metal material, and both the front and back surfaces of the metal material can be printed.

[0041] The metal material printing method of the present invention will be described in detail below. The printing method of the present invention will be described with reference to the drawings mentioned above.

[0042] The present invention relates to a printing method for printing an image onto the surface of a continuously moving metal material 100, wherein first, the surface of a photosensitive drum 300 that rotates in one direction is charged. This forms a charge layer on the photosensitive drum 300 with one of two charges, and then prepares to apply an image using toner T. The surface of the photosensitive drum 300 may have either a positive (+) charge or a negative (-) charge.

[0043] Exposure is performed to apply light energy to the surface of the photosensitive drum 300, which has been charged by forming the above-mentioned charge layer. By removing the charge from the surface of the photosensitive drum 300, toner can be moved to the surface of the photosensitive drum 300 according to the required image. The above-mentioned light energy may take various forms, and it is preferable to use a laser or LED light source.

[0044] Toner adheres to the surface of the exposed photosensitive drum 300. This is called the developing stage. The toner is charged with a charge opposite to the charge of the photosensitive drum 300 and adheres to the surface of the photosensitive drum 300. In the developing stage, referring to the example in Figure 1, the developing roller 510 moves a certain amount of toner T from the toner container 520 to the photosensitive drum 300. However, the developing roller 510 is not necessarily required, and the toner may be moved directly from the toner container 520 to the photosensitive drum 300. In other words, the developing stage is the process by which toner adheres to a position on the surface of the photosensitive drum 300 where the charge has been removed.

[0045] Subsequently, the toner adhering to the surface of the photosensitive drum 300 moves to the charged transfer belt 800, transferring the toner to the surface of the transfer belt 800. At this time, the surface of the transfer belt 800 is charged with the opposite charge to that of the toner, attracting the toner and transferring it to the surface of the transfer belt 800. By using the transfer belt 800, it is possible to avoid direct contact between the photosensitive drum 300 and the metal material 100. In particular, when using a metal material with high hardness, the toner T on the surface of the photosensitive drum 300 is first transferred to the transfer belt 800 to prevent damage to the surface of the photosensitive drum.

[0046] As described above, a transfer step is performed in which toner adhering to the surface of the transfer belt 800 moves to the continuously moving charged metal material 100, fixing the toner to the surface of the metal material 100. The metal material 100 becomes charged with the same charge as the transfer belt 800 and with the opposite charge to the toner, so that the toner on the transfer belt moves to the metal material 100. The transfer step is a process in which an image is printed on the surface of the metal material 100, in which the metal material 100, being charged with the opposite charge to the toner, attracts the toner and fixes it to the surface of the metal material 100. The charging of the metal material 100 can be performed before, after, or both before and after the transfer step. On the other hand, as shown in Figure 3, if printing is performed on a separate coating layer A formed on the surface of the metal material 100, the metal material charging means 101' can be further provided to charge the coating layer A.

[0047] The toner fixed to the surface of the metal material 100 undergoes a fixing step, which can be performed by a thermocompression method. Specifically, it is preferable that heat is applied and pressure is applied simultaneously by a fuse roll 710 and a pressure roll 720. In this case, the heating temperature is preferably 25 to 400°C. In the case of the toner used in the present invention, as described above, it is used for printing on metal materials, and its main component is a polymer structure. In particular, because metal materials have a high heat transfer coefficient, melt adsorption of the toner is difficult, so it is necessary to heat it to an appropriate temperature for the toner to be adsorbed. For this purpose, since the reaction can occur at a temperature above room temperature and be fixed to the surface of the metal material, the heating temperature is preferably 25°C or higher. On the other hand, if it exceeds 400°C, there is a possibility that the polymer structure of the toner will decompose, so it is preferable that the heating does not exceed 400°C. More preferably, it is heated at 50 to 300°C.

[0048] A removal step is performed to remove toner remaining on the surface of the photosensitive drum 300 after the toner has moved to the transfer belt 800, and toner remaining on the surface of the transfer belt 800 after the toner has fixed to the metal material 100. This is to prevent a decrease in print quality, as toner remaining on the photosensitive drum 300 and the transfer belt 800 may leave afterimages in the subsequent printing process. In this case, as shown in Figures 1 and 4, the removal method involves physical removal via the blade 610 and the transfer belt blade 841, and the removed toner can be collected in the collection cylinder 620 and the transfer belt collection cylinder 842 to prevent it from falling onto the metal material. On the other hand, for more complete removal, chemical removal can be further performed using an alcohol brush 630 after the physical removal. Although not shown in the present invention, the alcohol brush may also be included in the transfer belt in some cases.

[0049] Subsequently, in order to eliminate any remaining charge on the photosensitive drum 300 and the transfer belt 800, a step is performed to discharge the surface of the photosensitive drum 300 and the transfer belt 800. Through this discharge, the photosensitive drum 300 is prepared to perform a new print.

[0050] The printing method of the present invention can print a color image using toner T of various hues, namely W (White), C (Cyan), Y (Yellow), M (Magenta), K (Black), etc. In this case, printing can be performed using two or more toners, and as described above, two or more pairs of photosensitive drums, photosensitive drum charging means, photosensitive drum discharge means, exposure means, developing means, and removal means are provided, arranged along the direction of travel of the transfer belt, and various hues can be realized by performing the charging step, exposure step, developing step, transfer step, and removal step two or more times in each pair. The order of the hues is not particularly limited in the present invention and can be determined considering the required image, work efficiency, etc.

[0051] An example of this is shown in Figure 5. In Figure 5, four pairs of photosensitive drums, photosensitive drum charging means, photosensitive drum discharge means, exposure means, developing means, and removal means are provided, and printing is performed by proceeding through each stage. On the other hand, when using white toner at the very front with respect to the direction of movement of the metal material, the white background image can be transferred first, which has the advantage of improving the overall image clarity.

[0052] On the other hand, as shown in Figure 6, in order to print on both the top and back surfaces of the metal material, the printing method of the present invention described above can be applied sequentially or simultaneously to the top and bottom surfaces to print an image on both sides of the metal material.

[0053] Next, the printed metal material obtained using the above-described printing equipment or printing method will be explained in detail. Figure 7 schematically shows the printed metal material of the present invention, and the present invention will be explained in detail with reference to Figure 7.

[0054] The printed metal material of the present invention includes a printed layer formed on a metal material, as shown in Figure 7(a). The metal material is not limited to any particular type, as described above, and can include steel plates, non-ferrous metals, metal alloys, etc.

[0055] The above-mentioned printed layer is preferably formed using the above-mentioned metal material printing equipment or metal material printing method. In other words, the above-mentioned printed layer is preferably formed using printing equipment and printing methods that use a laser, LED, or the like as the exposure means.

[0056] The above-described print layer can form a wider variety of images compared to images formed on existing metal materials. Compared to images formed by existing printing methods, the above-described print layer has the advantage of not only having clearer form and hue, but also higher resistance to peeling and superior processing characteristics. Existing printing methods have been roll coating and inkjet coating methods that use liquid pigments or dyes. These liquid-type methods use a mixture of transparent polymer resin (approximately 70-80 wt.%) and color particles (approximately 20-30 wt.%). In other words, since the majority of the pigment or dye is made up of transparent polymer resin, the form and hue do not appear clearly, and if the liquid particles are large, there is a high possibility of peeling due to the stress applied to the entire polymer, resulting in poor processing characteristics. In contrast, the print layer of the present invention uses solid powder toner, and since each powder particle corresponds to a unit particle containing hue, it can form excellent hues. Furthermore, because existing printing methods use liquid pigments or dyes, they are greatly affected by the surface condition of the material being printed on. For example, since the print quality is affected by the roughness and surface shape of the material surface, prior efforts for surface pretreatment, such as roughness control, are required. However, the printing method using lasers, LEDs, etc., according to the present invention is a method in which toner powder is printed by an electrostatic adsorption and compression process, and therefore can be formed more easily than existing methods.

[0057] On the other hand, the printed metal material of the present invention may further include a coating layer between the metal material and the printed layer, as shown in Figure 7(b). The coating layer may include a wet or dry plating layer such as an electro-galvanized (EG) layer or a hot-dip galvanized (GI) layer.

[0058] Furthermore, the coating layer may include a pre-treatment layer formed on the plating layer, an intermediate coating layer formed on the pre-treatment layer, and a top coating layer formed on the intermediate coating layer.

[0059] The above-mentioned pretreatment layer, intermediate coating layer, and top coating layer are not particularly limited in this invention and may include all those known in the art to which this invention belongs. A preferred example is described below.

[0060] The above pre-treatment layer is intended to improve the bonding strength between the base metal and the intermediate coating layer (primer layer), and is usually formed to a thickness of 1 μm or less. It can be a chromium-free (Cr-free) polymer coating or a chromium hexavalent (Cr) coating. 6+ ), chromium trivalent (Cr 3+ ) A coating can be applied.

[0061] The above-mentioned intermediate coating layer (primer layer) is for ensuring corrosion resistance and concealing the substrate layer, and is applied to a thickness of approximately 5 μm. It can be coated using polyester, urethane, epoxy, etc. However, the above-mentioned intermediate coating layer may be omitted depending on the purpose.

[0062] The above-mentioned topcoat layer exhibits surface properties and is directly related to the physical properties of the product, with the printed layer being formed on top of the topcoat layer. Therefore, the topcoat layer is intended for protection against physical impact to the surface, as well as for color and concealment, and can be made of materials such as polyester, urethane, or epoxy.

[0063] On the other hand, the printed metal material of the present invention may further include a transparent coating layer on the printed layer, as shown in Figures 7(c) and 7(d). The transparent coating layer serves to impart gloss or protect the printed layer. The transparent coating layer is not particularly limited in the present invention and may include all transparent coating layers known in the art to which the present invention belongs.

[0064] As an example, polymer-based materials are generally used for the transparent coating layer described above. Similar to the topcoat layer, high-molecular-weight resins such as polyester and urethane may be used, and fluororesins may be used for outdoor applications. The transparent coating layer can be formed to a thickness of approximately 1 to 5 μm depending on the application. [Explanation of Symbols]

[0065] 100: Metal materials 101, 101': Metal material charging means 200, 200', 201, 202, 203, 204: Exposure means 210: Laser generator 220: Scanning mirror 300, 300', 301, 302, 303, 304: Photosensitive drum 400, 400', 401, 402, 403, 404: Photosensitive drum charging and discharging means 410, 410', 411, 412, 413, 414: Photosensitive drum charging means 420, 420', 421, 422, 423, 424: Photosensitive drum discharge means 500, 500', 501, 502, 503, 504: Developing method 510, 510', 511, 512, 513, 514: Developing rollers 520, 520', 521, 522, 523, 524: Toner containers 600, 600', 601, 602, 603, 604: Removal means 610, 610', 611, 612, 613, 614: Blade 620, 620', 621, 622, 623, 624: Recovery tubes 630: Alcohol brush 700, 700': Fixing means 710, 710': Fuse Roll 720: Pressure Roll 800, 800': Transfer belt 810, 810': Transfer belt driven roll 811, 812, 813, 814: Transfer belt support rolls 820, 820': Transfer belt charging means 830, 830': Transfer belt discharge means 840, 840': Transfer belt toner removal means 841, 841': Transfer belt blade 842, 842': Transfer belt recovery tube

Claims

1. A transfer belt 800 that adheres closely to a continuously moving metal material 100 and rotates in one direction, thereby transferring and fixing toner T attached to the surface of the metal material 100 to the surface of the metal material 100, A photosensitive drum 300 that is in close contact with the transfer belt 800 and rotates in the opposite direction to the transfer belt 800, and transmits the toner T attached to its surface to the surface of the transfer belt 800, A developing means 500 is provided on one side of the photosensitive drum 300 and provides the toner T to the surface of the photosensitive drum 300, Before the toner T is supplied, a photosensitive drum charging means 410 charges the surface of the photosensitive drum 300, Between the developing means 500 and the photosensitive drum charging means 410, there is an exposure means 200 that applies light energy to the surface of the photosensitive drum 300 according to the required image, A metal material charging means 101 charges the surface of the metal material 100 so that the toner T adhering to the surface of the transfer belt 800 is transferred to the surface of the metal material 100, After the toner T has settled on the surface of the metal material 100, a removal means 600 is provided to remove the toner T remaining on the surface of the photosensitive drum 300. After removing the toner T, a photosensitive drum discharge means 420 is provided to remove the charge from the photosensitive drum 300. A fixing means 700 located at the rear end of the transfer belt 800 for fixing the toner T fixed to the surface of the metal material 100, Includes, The fixing means 700 includes a pressure roll 720, A metal material printing apparatus in which the pressure roll 720 and the metal material charging means 101 are each structured to be able to move up and down according to the thickness of the metal material 100.

2. The aforementioned printing equipment is A transfer belt drive roll 810 drives the transfer belt 800 in the travel direction, Before the transfer belt 800 receives toner T, a transfer belt charging means 820 is used to charge the transfer belt 800, After transferring the toner T to the metal material 100, a transfer belt toner removal means 840 removes the toner T remaining on the transfer belt. After the removal of the toner T, a transfer belt discharge means 830 is provided to discharge the transfer belt, A metal material printing apparatus according to claim 1, including the following:

3. The metal material printing apparatus according to claim 1, wherein the removal means 600 includes a blade 610 and a recovery cylinder 620 located at the lower end of the blade 610.

4. The metal material printing apparatus according to claim 2, wherein the transfer belt toner removal means 840 includes a blade 841 and a recovery cylinder 842 located at the lower end of the blade 841.

5. The metal material printing apparatus according to claim 3, wherein the removal means 600 further includes an alcohol brush 630 between the blade 610 and the recovery cylinder 620.

6. The metal material printing apparatus according to claim 1, wherein the aforementioned light energy utilizes a laser or an LED.

7. The metal material printing apparatus according to claim 4, wherein, when the light energy is a laser, the exposure means 200 includes a laser generator 210 and a scanning mirror 220.

8. The metal material charging means 101 includes one or more, and is provided at one of the front end, rear end, and front and rear ends of the transfer belt 800 with respect to the direction of travel of the metal material 100, as described in claim 1, for the metal material printing apparatus.

9. The metal material printing apparatus according to claim 1, wherein the developing means 500 includes a toner T container 520 and a developing roller 510 that provides the toner T of the toner T container 520 to a photosensitive drum 300.

10. The metal material printing apparatus according to claim 1, wherein the fixing means 700 includes a fused roll 710.

11. The photosensitive drum, photosensitive drum charging means, photosensitive drum discharge means, exposure means, developing means, and removal means are provided in pairs, two or more of them along the direction of travel of the transfer belt 800. The metal material printing apparatus according to claim 1, wherein each developing means provides toner of a different hue from the others.

12. The metal material printing equipment is located above and below the metal material, as described in any one of claims 1 to 11.

13. A charging step in which the surface of a photosensitive drum 300 that rotates in one direction is charged, An exposure step is performed in which light energy is applied to the surface of the charged photosensitive drum 300 according to the required image. After the exposure, a developing step is performed to provide toner T to the surface of the photosensitive drum 300, The steps include moving the toner adhering to the surface of the photosensitive drum 300 to the surface of the charged transfer belt 800, A transfer step in which toner attached to the surface of the transfer belt 800 is continuously moved and fixed to the surface of the charged metal material 100, A fixing step in which the toner fixed to the surface of the metal material 100 is fixed, After the transfer, a removal step is taken to remove the toner remaining on the surface of the photosensitive drum 300 and the transfer belt 800. A discharge step in which the surfaces of the photosensitive drum 300 and the transfer belt 800 are discharged, Includes, In the fixing stage, the pressure roll 720 moves up and down according to the thickness of the metal material 100. A metal material printing method comprising: during the transfer step, a metal material charging means 101 moves up and down according to the thickness of the metal material 100 to charge the metal material 100 so that the toner adhering to the surface of the transfer belt 800 can be fixed to the surface of the metal material 100.

14. The metal material printing method according to claim 13, wherein the fixing step is heating at 25 to 400°C.

15. The metal material printing method according to claim 13 or 14, wherein the fixing step is further further comprising applying pressure.

16. The aforementioned printing method requires two or more photosensitive drums when printing using two or more toners. The metal material printing method according to claim 13, wherein two or more of the charging, exposure, development, transfer, and removal steps are performed using each photosensitive drum.

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