Metal material printing equipment and printing method with superior print quality, and the printed metal material obtained therefrom.

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, a printing method using the same, and a printed metal material obtained by 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, a printing method using the same, and a printed metal material obtained therefrom.

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. The image transfer method for the metal surface using the film is easy to output to the film, but has the disadvantage that the manufacturing speed is slow by transferring the film to the steel plate, and the image attached to the metal surface in the film form may be deformed by temperature and weather.

[0004] The roll transfer method forms a pattern of a certain pattern on the roll surface and transfers the image to the surface of the metal material using the roll-to-roll method. However, the transferred image is limited to a repeated image, and in order to use the roll transfer method, rolls patterned with each image 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 the 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 nozzle cleaning and replacement. Furthermore, because liquid ink is used, stabilization work after ink ejection is essential, making it difficult to manufacture using a roll-to-roll method, thus limiting its use to batch type. In particular, inkjet printing materials are in a form in which liquid polymers are linked together, and pigments form images within them, so there is a problem that the printed image may peel off when the material is bent or cut.

[0006] Recently, metal materials have been used in various fields, and images such as text and pictures are increasingly 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.

[0007] Furthermore, because metal materials have their own inherent hues, images may not appear sharp when printed on their surfaces. Therefore, there is a growing demand for high-quality printing methods for metal surfaces. [Overview of the project] [Problems that the invention aims to solve]

[0008] One aspect of the present invention is a technology for printing images such as characters and pictures onto the surface of a metal material. The invention aims to provide a printing apparatus capable of printing images onto the surface of a metal material at high speed and stably, a printing method using the same, and a printed metal material obtained therefrom.

[0009] Another aspect of the present invention relates to printing equipment capable of improving the quality of prints formed on a metal material, a printing method using the same, and a printed metal material obtained thereby.

[0010] 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 throughout the specification, and any person with ordinary skill in the art to which the present invention belongs will have no difficulty understanding these further problems from the contents of the specification. [Means for solving the problem]

[0011] One aspect of the present invention is a pre-printing device 1000, 1000' that prints a white image on the surface of a continuously moving metal material 100, The printing equipment 2000, 2000' prints the image onto the surface of the metal material 100 on which the above white image is printed. We provide printing equipment that offers excellent print quality, including [specific features / features].

[0012] Another aspect of the present invention is a pre-printing step of printing a white image on the surface of a continuously moving metal material 100, This is the main printing stage, where the image is printed onto the surface of the metal material 100 on which the above white image is printed. It provides a printing method that offers excellent print quality, including [specific features / features].

[0013] Another aspect of the present invention is a metal material, A white image layer formed on the above metal material, Print layer formed on the above white image layer We provide metal materials with printed quality that includes printing quality. [Effects of the Invention]

[0014] This invention provides a technology that enables the stable printing of images such as letters and pictures onto materials such as metals, thereby improving product production efficiency through continuous manufacturing. Furthermore, it offers the advantage of easily forming diverse and varied images, enabling the production of high-value-added products.

[0015] Furthermore, it has the advantage of ensuring excellent print quality, as the printed image is not interfered with by the inherent hue of the metal material, resulting in a sharp image.

[0016] The diverse yet significant 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]

[0017] [Figure 1] This is a schematic diagram illustrating one embodiment of the printer equipment of the present invention. [Figure 2] This is a schematic diagram specifically illustrating one embodiment of the pre-printing equipment among the printing equipment of the present invention. [Figure 3] This is a schematic diagram specifically illustrating another embodiment of the printing equipment among the printing equipment of the present invention. [Figure 4] This is a schematic diagram specifically illustrating one embodiment of the printing equipment of the present invention. [Figure 5] This is a schematic diagram specifically illustrating another embodiment of the printing equipment of the present invention. [Figure 6] This is a schematic diagram specifically illustrating one embodiment of the laser exposure means in the printing equipment of the present invention. [Figure 7] This is a schematic diagram specifically illustrating one embodiment of a removal means in the printing equipment of the present invention. [Figure 8] This is a schematic diagram specifically illustrating yet another embodiment of the printing equipment of the present invention. [Figure 9] This is a schematic diagram specifically showing another embodiment of the printing equipment of the present invention among the printing equipment of the present invention. [Figure 10] This is a schematic diagram schematically showing a cross-section of the printed metal material of the present invention. [Figure 11] An image is printed on the metal material. (a) shows an image printed on a white image layer, and (b) shows an image printed without a white image layer.

Embodiments for Carrying out the Invention

[0018] 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 definitions clearly indicate the contrary meaning.

[0019] The meaning of "including" used in the specification does not specify a configuration and does not exclude the existence or addition of other configurations.

[0020] Unless otherwise defined, all terms including technical terms and scientific terms used in this specification have the same meaning as generally understood by those with ordinary knowledge in the technical field to which the present invention belongs. Terms defined in advance are interpreted to have meanings consistent with the relevant technical literature and the currently disclosed content.

[0021] Generally known laser or LED printing is for printing on flexible objects such as paper, but the present invention relates to a technique for printing an image on a metal material. The present invention relates to a printing equipment in which each component such as a charging means, a photosensitive drum, and a fused roll is realized in one direction according to the traveling direction of a metal material in order to print on the surface of a metal material continuously moving in a method such as Roll-to-Roll, and a printing method using the same.

[0022] In particular, according to the present invention, compared to conventional printing methods on metal materials, it is possible to easily and economically realize not only diverse and complex images but also images with a wide range of hues.

[0023] On the other hand, metal materials often have their own inherent hue. Therefore, even if an image is printed on their surface, not all images will be clear. In other words, the print quality may be reduced. Therefore, the inventors of this invention have found that by first printing a white image on the surface of the metal material (pre-printing) and then printing the desired image on this background (main printing), better print quality can be ensured.

[0024] Preferred embodiments of the present invention will be described below with reference to the drawings. Embodiments of the present invention can be modified in various forms and should not be construed as being limited to the drawings and embodiments described below, but are provided for the purpose of explaining in detail to those who are ordinary skill in the art to which the present invention pertains.

[0025] Figure 1 schematically shows one embodiment of the printer equipment of the present invention. Referring to Figure 1, the printing equipment of the present invention is, as an example, a printing equipment that prints an image on the surface of a metal material 100 that moves continuously in a roll-to-roll manner, and includes pre-printing equipment 1000, 1000' that prints a white image on the surface of the continuously moving metal material, and main printing equipment 2000, 2000' that prints an image on the surface of the metal material 100 on which the white image has been printed.

[0026] The images above represent letters, patterns, pictures, etc., and can take various forms such as monochrome, achromatic, chromatic, and three-dimensional patterns. However, a white image refers to one realized in a single color of white.

[0027] The above-mentioned printing equipment 1000, 1000' forms a white image on the surface of the metal material 100, and by forming a white image on the surface of the metal material 100 before the image is printed by the main printing equipment 2000, 2000', the image printed in the main printing equipment has the advantage of ensuring excellent clarity.

[0028] First, I will explain the printing equipment 1000 and 1000' in detail.

[0029] Figure 2 shows an example of the above-mentioned pre-printing equipment 1000. Referring to Figure 2, the pre-printing equipment 1000 includes a pre-printing photosensitive drum 1300, a pre-printing photosensitive drum charging means 1410 and a pre-printing photosensitive drum discharge means 1420, a pre-printing exposure means 1200, a pre-printing developing means 1500, a pre-printing metal material charging means 1101, a pre-printing removal means 1600, a pre-printing fixing means 1700, and the like. The following describes each component in detail with reference to Figure 2.

[0030] The pre-printing photosensitive drum 1300 rotates in one direction while in close contact with the surface of the metal material 100, transferring and fixing the white toner W attached to the surface of the metal material 100 to transfer the image. Although the pre-printing photosensitive drum 1300 is shown rotating in one direction in Figure 2, it does not necessarily rotate only in one direction, and can rotate in both directions. The pre-printing photosensitive drum 1300 is sufficient if it is one that is commonly used in the art to which the present invention belongs, and its type is not particularly limited. As a preferred example, an OPC (Organic Photo Conductor) drum can be used.

[0031] The pre-printing and developing means 1500 is provided on one side of the pre-printing and photosensitive drum 1300 and provides white toner W for forming an image on the surface. The pre-printing and developing means 1500 only needs to be able to provide white toner W to the pre-printing and photosensitive drum 1300, and its form and shape are not particularly limited. In Figure 2, as a preferred example, the pre-printing and developing means 1500 includes a toner container 1520 containing white toner W and a developing roller 1510 that transmits the white toner from the toner container 1520 to the pre-printing and photosensitive drum 1300. The developing roller 1520 is not essential and may be provided directly from the toner container 1520 to the pre-printing and photosensitive drum 1300. On the other hand, the white toner W is for forming a white image on the surface of a metal material.

[0032] The system includes a pre-printing photosensitive drum charging means 1410 that charges the surface of the pre-printing photosensitive drum 1300 before the white toner W is supplied. The pre-printing photosensitive drum charging means 1410 applies an electrostatic charge to the surface of the pre-printing photosensitive drum. Corona wire is commonly used as the means for charging.

[0033] Between the pre-print developing means 1500 and the pre-print photosensitive drum charging means 1410, there is a pre-print exposure means 1200 that applies light energy to the charged surface of the pre-print photosensitive drum 1300 according to the required image. The position of the pre-print exposure means 1200 is not important, but the light energy is applied to the surface of the photosensitive drum 3100 between the pre-print developing means 1500 and the pre-print photosensitive drum charging means 1410. Due to the light energy, some of the charge is removed from the surface of the pre-print photosensitive drum 1300, and the pre-print developing means 1500 causes toner to adhere to the surface of the pre-print photosensitive drum 1300. The light energy is preferably a laser or an LED (Light Emitting Diode).

[0034] Figure 6 schematically shows the pre-print exposure means 1200 when using the above-mentioned laser, and includes a laser generator 1210 and a scanning mirror 1220 that adjusts the laser emitted from the laser generator 1210 to scan the surface of the pre-print photosensitive drum 1300 according to the required image and remove charge. The structure of Figure 6 can be applied not only to the pre-print equipment 1000, 1000' but also to the exposure means 1200, 1200', 2200, 2200', 2201, 2201', 2202, 2202', 2203, 2203', 2204, 2204' applied to the main printing equipment 2000, 2000' using the same principle.

[0035] The system includes a pre-printed metal material charging means 1101 that charges the surface of the metal material 100 so that the white toner W attached to the pre-printed photosensitive drum 1300 can move to and fix to the metal material 100. The pre-printed metal material charging means 1101 not only serves to charge the metal material 100 to a certain charge, but can also serve as a guide roll to allow the metal material to move at a constant speed. One or more pre-printed metal material charging means 1101 may be provided, and they may be formed at the front end, rear end, or front and rear ends of the pre-printed photosensitive drum 1300 with respect to the direction of travel of the metal material 100, and may be located on the top, bottom, or upper and lower parts of the metal material 100. Even if there are two or more pre-printed metal material charging means 1101, they do not perform different roles from one another, and there is an advantage in that a stronger electrostatic attraction can be ensured through two or more charging processes.

[0036] On the other hand, if a separate coating layer, such as a resin layer, is formed on the surface of the metal material 100, and printing is to be performed on the coating layer, the pre-printed metal material charging means 1101 for charging the coating layer can be positioned above the coating layer. The metal material charging means positioned above the coating layer can be applied in the same principle not only to the pre-printing equipment 1000 and 1000', but also to the main printing equipment 2000 and 2000' described later.

[0037] The system includes a pre-print removal means 1600 for removing the white toner W remaining on the surface of the pre-print photosensitive drum 1300 after the white toner W has settled on the surface of the metal material 100. The pre-print removal means 1600 may include a blade 1610 for separating the residual toner from the surface of the pre-print photosensitive drum 1300 and a collection container 1620 at the lower end of the blade 1610 for collecting the separated toner to prevent the separated toner from falling onto the metal material 100 and degrading print quality. Figure 7 shows a more concrete example of the removal means 1600 for removing the toner remaining on the surface of the pre-print photosensitive drum 1300, which may further include an alcohol brush 1630 in addition to the blade 1610 and collection container 1620 described above. The pre-print photosensitive drum 1300 rotates at high speed to transfer the image, and the removal of the toner may not be easy. In such cases, there is a problem that afterimages of the image may remain. For this purpose, after primary removal with the blade 1610, secondary removal can be performed using a chemical method with an alcohol brush 1630 or the like. The configuration of the blade, collection container, and alcohol brush can be applied not only to the pre-printing equipment 1000 and 1000' but also to the main printing equipment 2000 and 2000'.

[0038] After the white toner W is fixed onto the metal material, a pre-print fixing means 1700 can be provided at the rear end of the pre-print photosensitive drum 1300 with reference to the direction of travel of the metal material 100, to fix the white toner W on the metal material 100 and stably form an image. The pre-print fixing means 1700 may include a fused roll 1710 that applies heat to the white toner W to fix the white toner W fixed onto the metal material 100, and a pressure roll 1720 that applies pressure to assist in fixing. In this case, the heating temperature of the fused roll 1710 is preferably 25 to 400°C. The configuration of the fixing means, fused roll and pressure roll can be applied not only to the pre-printing equipment 1000 and 1000', but also to the main printing equipment 2000 and 2000' described later, with the same structure and principle.

[0039] In the present invention, it is more preferable that the metal material charging means 1101, 1101', 2101, 2101' and the pressure rolls 1720, 1720', 2720, 2720' have a structure that allows them to move up and down. The metal material 100 cannot always have a constant thickness; it can be a very thin film or a thick plate. Therefore, if the metal material charging means 1101, 1101', 2101, 2101' and the pressure rolls 1720, 1720', 2720, 2720' have a variable structure that allows them to move up and down according to the thickness of the metal material 100, then an image can be printed regardless of the thickness of the metal material 100.

[0040] On the other hand, Figure 3 shows another example of the pre-printing equipment 1000' in the present invention. Referring to Figure 3, the pre-printing equipment 1000' includes a pre-printing transfer belt 1800', a pre-printing photosensitive drum 1300', a pre-printing photosensitive drum charging and discharging means 1400', a pre-printing exposure means 1200', a pre-printing developing means 1500', a pre-printing removal means 1600', a pre-printing fixing means 1700', and so on. Each component will be described in detail below with reference to Figure 3.

[0041] The pre-printing transfer belt 1800' rotates in one direction while in close contact with the metal material 100, providing the function of transferring and fixing the white toner W attached to the surface of the metal material 100, and at the same time protecting the surface of the pre-printing photosensitive drum 1300' and improving image quality. If the hardness of the metal material 100 is high, the surface of the pre-printing photosensitive drum 1300' may be damaged due to contact between the metal material 100 and the pre-printing photosensitive drum 1300'. In this case, the repair and replacement costs of the pre-printing photosensitive drum 1300' will increase, and the accuracy of the transferred image may also decrease, potentially resulting in a decrease in print quality. This system employs a method in which the toner does not move from the pre-printing photosensitive drum 1300' to the metal material 100, but is transferred via the pre-printing transfer belt 1800'.

[0042] On the other hand, the device is equipped with a drive roll 1810' for driving the pre-printed transfer belt 1800' in the traveling direction, and a charging means 1820' for the pre-printed transfer belt is provided to charge the surface of the pre-printed transfer belt 1800' before receiving the white toner W from the pre-printed photosensitive drum 1300' in order to receive the white toner W, and corona wire is usually used. On the other hand, after the white toner W of the pre-printed transfer belt 1800' is transmitted to the metal material 100 and the image is transferred, a toner removal means 1840' is provided to remove the white toner W remaining on the transfer belt, and a discharge means 1830' for discharging the charge of the transfer belt after the toner W has been removed may be provided. The device for driving the pre-printed transfer belt 1800' is substantially the same as the equipment configuration for driving the main print transfer belt 2800' which will be described later.

[0043] The aforementioned pre-printing photosensitive drum 1300' is in contact with the transfer belt and rotates in the opposite direction, playing the role of transferring the white toner W adhering to its surface to the transfer belt 1800'. The pre-printing photosensitive drum 1300' can be any type commonly used in the art to which the present invention belongs, and its type is not particularly limited. A preferred example is the use of an OPC (Organic Photo Conductor) drum.

[0044] The pre-printing and developing means 1500' is provided on one side of the pre-printing photosensitive drum 1300' and provides white toner W for forming an image on its surface. The pre-printing and developing means 1500' is substantially the same as the pre-printing equipment shown in Figure 2 above, and its detailed description is replaced by the above description.

[0045] The device includes a pre-print photosensitive drum charging means 1410' that charges the surface of the photosensitive drum 1300' before the white toner W is supplied. The pre-print photosensitive drum charging means 1410' applies an electrostatic charge to the surface of the photosensitive drum. A corona wire is often used as the charging means.

[0046] Between the pre-print developing means 1500' and the pre-print photosensitive drum charging means 1410', a pre-print exposure means 1200' is provided to apply light energy to the surface of the charged pre-print photosensitive drum 1300' according to the required image. The position of the pre-print exposure means 1200' is not important, but the light energy is applied to the surface of the pre-print photosensitive drum 1300' between the pre-print developing means 1500' and the pre-print photosensitive drum charging means 1410'. The specific function and structure of this pre-print exposure means 1200' are the same as those of the pre-print exposure means 1200 described with reference to Figures 2 and 6 above, so the above description will be used instead.

[0047] The device includes a pre-printed metal material charging means 1101' that charges the surface of the metal material 100 so that the image-forming white toner W transmitted from the pre-printed photosensitive drum 1300' to the pre-printed transfer belt 1800' can move to and fix on the metal material 100. The pre-printed metal material charging means 1101' 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 pre-printed metal material charging means 1101' may be provided, and the pre-printed metal material charging means 1101' may be formed at the front end, rear end, or front and rear ends of the transfer belt 1800' with respect to the direction of travel of the metal material 100, and may be located on the top, bottom, or upper and lower parts of the metal material 100.

[0048] Even if there are two or more of the above-mentioned pre-printed metal material charging means 1101', they do not play different roles from one another, and there is an advantage in that a stronger electrostatic attraction can be ensured through two or more charging processes.

[0049] The above-mentioned pre-print photosensitive drum 1300' includes a pre-print removal means 1600' for removing toner remaining on its surface after providing the toner on its surface to the above-mentioned pre-print transfer belt 1800'. The specific function and structure of this pre-print removal means 1600' are the same as those of the pre-print removal means 1600 described with reference to Figures 2 and 7 above, and therefore the above description will be used instead.

[0050] On the other hand, a means for removing toner can also be provided in the pre-printing transfer belt 1800'. That is, after fixing the toner for image formation onto the metal material 100, a blade 1810' may be provided to remove the toner remaining on the surface of the pre-printing transfer belt 1800', and a collection container 1820' for collecting the separated toner may be included at the lower end of the blade 1810' to prevent the separated toner from falling onto the metal material 100 and degrading the print quality. The configuration for removing the toner remaining on the pre-printing transfer belt 1800' is the same in the main print transfer belt 2800' described later.

[0051] After the white toner W is fixed onto the metal material 100, a pre-print fixing means 1700' for fixing the white toner W onto the metal material 100 and stably forming an image can be provided at the rear ends of the pre-print photosensitive drum 1300' and the pre-print transfer belt 1800' with respect to the direction of travel of the metal material 100. The specific function and structure of this pre-print fixing means 1700' are the same as those of the pre-print fixing means 1700 described with reference to Figure 2 above, so the above description will be used instead.

[0052] Next, we will describe the printing equipment 2000 and 2000' in detail.

[0053] Figure 4 shows an example of the printing equipment 2000 described above. The printing equipment 2000 shown in Figure 4 includes a printing photosensitive drum 2300, a printing photosensitive drum filling means 2410, a printing photosensitive drum discharge means 2420, a printing exposure means 2200, a printing phenomenon means 2500, a printing metal material charging means 2101, a printing removal means 2600, a printing fixing means 2700, and the like.

[0054] The above-described printing photosensitive drum 2300 rotates in one direction while in close contact with the surface of the metal material 100 on which a white image has been pre-printed, transferring and fixing the toner T attached to the surface of the metal material 100 to transfer the image. In Figure 4, the above-described printing photosensitive drum 2300 is shown to rotate in one direction, but it does not necessarily rotate only in one direction; it can also rotate in both directions. The above-described printing photosensitive drum 2300 is sufficient if it is one that is commonly used in the art to which the present invention belongs, and its type is not particularly limited. As a preferred example, an OPC (Organic Photo Conductor) drum can be used.

[0055] The above-described print-developing means 2500 is provided on one side of the above-described print-photosensitive drum 2300 and provides toner T for forming an image on its surface. The above-described print-developing means 2500 only needs to be able to provide toner to the print-photosensitive drum 2300, and its form and shape are not particularly limited. In Figure 4 above, as a preferred example, the above-described print-developing means 2500 includes a toner container 2520 containing toner T and a developing roller 2510 that transmits toner from the toner container 2520 to the print-photosensitive drum 2300. The developing roller 2520 is not essential, and in some cases, toner can be supplied directly from the toner container 2520 to the photosensitive drum 2300. On the other hand, the above-described toner T forms an image on the surface of a metal material, and all materials known to a person of ordinary skill in the art to which the present invention belongs can be used, and the type is not particularly limited. As an example, a material having a polymer structure can be used. Furthermore, in this invention, various substances (for example, fluorescent substances, magnetic substances, electrically conductive substances, etc.) can be added to the toner to impart diverse functions, enabling not only the realization of functional images, but also the creation of roughness or three-dimensional shapes by using a variety of toner particles.

[0056] The printing photosensitive drum charging means 2410 charges the surface of the printing photosensitive drum 2300 before the toner T is supplied. The printing photosensitive drum charging means 2410 applies an electrostatic charge to the surface of the photosensitive drum. A corona wire is often used as the charging means.

[0057] Between the main print developing means 2500 and the main print photosensitive drum charging means 2410, there is a main print exposure means 2200 that applies light energy to the surface of the charged main print photosensitive drum 2300 according to the required image. The position of the main print exposure means 2200 is not important, but the light energy is applied to the surface of the main print photosensitive drum 2300 between the main print developing means 2500 and the main print photosensitive drum charging means 2410. Due to the light energy, some of the charge is removed from the surface of the main print photosensitive drum 2300, and the main print developing means 2500 causes toner to adhere to the surface of the main print photosensitive drum 2300. The light energy is preferably a laser or an LED (Light Emitting Diode). When using the above light energy, the specific structure and function of the main print exposure means 2200 are no different from those of the main print exposure means 1200 in Figure 6 described earlier.

[0058] The present invention includes a printing metal material charging means 2101 that charges the surface of the metal material 100 so that the toner T attached to the main printing photosensitive drum 2300 moves to and fixes on the metal material 100 on which the white image has been printed. The structure and function of the main printing metal material charging means 2101 are the same as those of the pre-printed metal material charging means 1101 and 1101' described earlier, so a detailed explanation is omitted.

[0059] On the other hand, the print removal means 2600 includes removing the toner T remaining on the surface of the print photosensitive drum 2300 after the toner T has settled on the surface of the metal material 100. The print removal means 2600 may include a blade 2610 for separating the residual toner from the surface of the print photosensitive drum 2300 and a collection container 2620 at the lower end of the blade 2610 for collecting the separated toner to prevent the separated toner from falling onto the metal material 100 and degrading print quality. It may further include an alcohol brush, which is no different from the print removal means 1600 described above and is shown in Figure 7, so a detailed description is omitted.

[0060] After the toner T is fixed onto the metal material 100, a printing fixing means 2700 for fixing the toner T on the metal material 100 and stably forming an image may be provided at the rear end of the printing photosensitive drum 2300 with reference to the direction of travel of the metal material 100. The printing fixing means 2700 may include a fused roll 2710 for applying heat to the toner T and fixing the toner T fixed onto the metal material 100, and a pressure roll 2720 for assisting in fixing by applying pressure. In this case, the heating temperature of the fused roll 2710 is preferably 25 to 400°C.

[0061] It is more preferable that the above-mentioned metal material charging means 2101 and pressure roll 2720 have a structure that allows for vertical movement. The metal material 100 cannot always have a constant thickness; it can be a very thin film or a thick plate. Therefore, if the above-mentioned metal material charging means 2101 and pressure roll 2720 have a variable structure that allows for vertical movement according to the thickness of the metal material 100, an image can be printed regardless of the thickness of the metal material 100.

[0062] On the other hand, one or more toners can be used to print various images. In this case, the main printing photosensitive drum, the main printing drum charging means, the main printing photosensitive drum discharge means, the main printing exposure means, the main printing development means, and the main printing removal means can be provided in pairs of two or more, depending on the direction of movement of the metal material. Figure 8 schematically shows yet another embodiment of such a printing apparatus. Figure 8 shows a printing apparatus for transferring an image by providing four types of toners to print a color image, and the hues of the four types of toner T may be C (Cyan), Y (Yellow), M (Magenta), and K (Black). The above types of toners do not necessarily have to be four types, and W (White) may also be included. Some or more of these may be used in overlapping order, and there is no prescribed order. A person skilled in the art can arbitrarily select them considering the required image, work efficiency, etc.

[0063] Figure 8 shows the printing equipment when using four types of toner. In Figure 8, four pairs of main printing photosensitive drums 2301, 2302, 2303, 2304, main printing photosensitive drum charging and discharge means 2401, 2402, 2403, 2404, main printing exposure means 2201, 2202, 2203, 2204, main printing phenomenon means 2501, 2502, 2503, 2504, and main printing removal means 2601, 2602, 2603, 2604 are provided to fix the toner fixed on the metal material 100. However, the main printing fixing means 2700 for fixing the toner fixed on the metal material 100 is for finally fixing the image and does not necessarily need to be in multiples.

[0064] On the other hand, as shown in Figure 8, when using a large number of photosensitive drums, there is a risk of sagging of the metal material 100 due to the characteristics of continuous methods such as roll-to-roll. Therefore, a large number of support rolls 2111, 2112, 2113, and 2114 can be provided to support the metal material while ensuring continuous movement. It is preferable that the support rolls 2111, 2112, 2113, and 2114 also have a variable structure that allows them to move up and down according to the thickness of the metal material 100.

[0065] Figure 5 shows another example of the printing equipment 2000' described above. The printing equipment 2000' shown in Figure 5 includes a printing transfer belt 2800', a printing photosensitive drum 2300', a printing photosensitive drum charging and discharging means 2400', a printing exposure means 2200', a printing developing means 2500', a printing removal means 2600', a printing fixing means 2700', and the like.

[0066] The print transfer belt 2800' rotates in one direction while in close contact with the metal material 100 on which the white image has been printed, providing the function of transferring and fixing the toner T attached to the surface of the metal material 100, while simultaneously protecting the surface of the print photosensitive drum 2300' and improving the image quality. If the hardness of the metal material 100 is high, the surface of the print photosensitive drum 2300' may be damaged by contact between the metal material 100 and the print photosensitive drum 2300'. In this case, the repair and replacement costs of the print photosensitive drum 2300' will increase, and the accuracy of the transferred image may also decrease, potentially resulting in a decrease in print quality. This system employs a method in which the toner does not move from the print photosensitive drum 2300' to the metal material 100, but is transferred via the print transfer belt 2800'.

[0067] On the other hand, the main printing transfer belt 2800' is provided with a drive roll 2810' for driving the main printing transfer belt 2800' in the traveling direction, and the main printing transfer belt charging means 1820' is provided to charge the surface of the main printing transfer belt 2800' before the toner T is supplied from the main printing photosensitive drum 2300' in order to transmit the toner T, and corona wire is usually used. On the other hand, after the toner T of the main printing transfer belt 2800' is transferred to the metal material 100 and an image is transferred, the main printing transfer belt is provided with a toner removal means 2840' for removing the toner T remaining on the transfer belt, and the main printing transfer belt discharge means 2830' for discharging the charge of the main printing transfer belt after the toner T has been removed.

[0068] The main printing photosensitive drum 2300' is in contact with the transfer belt and rotates in the opposite direction, playing the role of transferring the toner T attached to its surface to the transfer belt 2800'. The main printing photosensitive drum 2300' is no different from the previous printing photosensitive drum 1300' described earlier.

[0069] The print development means 2500' is provided on one side of the print photosensitive drum 2300' and provides toner T for forming an image on its surface. The print phenomenon means 2500' is substantially identical in technical content and configuration to the pre-print phenomenon means and the print phenomenon means shown in Figures 2, 3, and 4 above, and its detailed description will be replaced by the above description.

[0070] Before the toner T is provided, the photosensitive drum charging means 2410' for charging the surface of the print photosensitive drum 2300' and the photosensitive drum discharge means 2420' for discharging the charged print photosensitive drum are substantially identical in technical content and configuration to the photosensitive drum charging means and photosensitive drum charging means described in the previous printing equipment and the present printing equipment shown in Figures 2, 3, and 4 above. Therefore, a detailed explanation thereof will be replaced by the above description.

[0071] Between the main print developing means 2500' and the main print photosensitive drum charging means 2410', there is a main print exposure means 2200' that applies light energy to the surface of the charged main print photosensitive drum 2300' according to the required image. The position of the main print exposure means 2200' is not important, but the light energy is applied to the surface of the main print photosensitive drum 2300' between the main print developing means 2500' and the main print photosensitive drum charging means 2410'. The specific function and structure of the main print exposure means 2200' are the same as those of the main print exposure means 1200 described above with reference to Figures 2 and 6, so the above description will be used instead.

[0072] The printing metal material charging means 2101' includes a means for charging the surface of the metal material 100 so that the image-forming toner T transferred from the printing photosensitive drum 2300' to the printing transfer belt 2800' can move to and fix the metal material 100 on which a white image has been printed. The printing metal material charging means 2101' has no difference in configuration or technical content from the metal material charging means in Figures 2, 3, and 4 described above, and therefore the above description is used instead.

[0073] The above-mentioned main printing photosensitive drum 2300' includes a main printing removal means 2600' for removing toner remaining on the surface after the toner on the surface has been supplied to the above-mentioned main printing transfer belt 2800'. The specific function and structure of this main printing removal means 2600' are the same as those of the previous printing removal means 1600 described with reference to Figures 2 and 7, and therefore the above description is used instead.

[0074] On the other hand, a means for removing toner can also be provided in the print transfer belt 1800'. That is, after fixing the toner for image formation onto the metal material 100, a blade 2810' may be included to remove the toner remaining on the surface of the print transfer belt 2800', and a collection container 1820' for collecting the separated toner may be included at the lower end of the blade 2810' to prevent the separated toner from falling onto the metal material 100 and degrading the print quality. The configuration for removing the toner remaining on the print transfer belt 2800' is no different from that of the print transfer belt 1800' described above.

[0075] After the toner T is fixed onto the metal material 100, the main printing fixing means 2700' for fixing the toner W on the metal material 100 and stably forming an image can be provided at the rear ends of the main printing photosensitive drum 2300' and the main printing transfer belt 2800' with reference to the direction of travel of the metal material 100. The specific function and structure of this main printing fixing means 2700' are the same as those of the previously described printing fixing means 1700, 1700' and this printing fixing means 2700, which were explained with reference to Figures 2, 3, and 4, and will be replaced with the above description.

[0076] On the other hand, one or more toners can be used to print various images. In this case, two or more pairs of the main printing photosensitive drum, main printing photosensitive drum charging means, main printing photosensitive drum discharge means, main printing exposure means, main printing development means, and main printing removal means can be provided according to the direction of travel of the transfer belt 800. Figure 9 schematically shows yet another embodiment of the printing equipment of the present invention. Specifically, Figure 9 realizes a printing equipment for transferring an image by providing four types of toners to print a color image. The four types of toners T can be C (Cyan), Y (Yellow), M (Magenta), and K (Black). The above types of toners do not necessarily have to be four types, and W (White) can also be included. Some or more of these can be used in overlapping order, and there is no prescribed order. A person skilled in the art can arbitrarily select them considering the required image, work efficiency, etc.

[0077] Figure 9 shows the printing equipment when using four types of toner. In Figure 9, in order to fix the four types of toner to the metal material 100 on which a white image has been printed, four pairs of main printing photosensitive drums 2301', 2302', 2303', 2304', main printing photosensitive drum charging and discharge means 2401', 2402', 2403', 2404', main printing exposure means 2201', 2202', 2203', 2204', main printing development means 2501', 2502', 2503', 2504', and main printing removal means 2601', 2602', 2603', 2604' are positioned along the direction of travel of the transfer belt 2800'. As a result, as shown in Figure 9, the toner T transported by each pair is transmitted to a single main print transfer belt 2800', which then fixes it back onto the metal material 100. Note that the main print fixing means 2700' for fixing the toner fixed onto the metal material 100 is for fixing the final transferred image and does not necessarily need to be in multiple units.

[0078] On the other hand, as shown in Figure 9, when a large number of photosensitive drums are used, the length of the print transfer belt 2800' may increase, which may cause deflection. Therefore, support rolls 2811', 2812', 2813', and 2814' for the transfer belt may be provided to support the print transfer belt 2800' and ensure continuous movement.

[0079] On the other hand, when printing on both sides of a metal sheet 100, it is preferable to position one or more of the pre-printing equipment 1000, 1000' and one or more of the main printing equipment 2000, 2000' above and below the metal sheet 100.

[0080] Next, the printing method of the present invention will be described in detail. The printing method of the present invention includes a pre-printing step of printing a white image on the surface of a continuously moving metal material 100 and a main printing step of printing an image on the surface of the metal material 100 on which the white image has been printed.

[0081] An embodiment of the pre-printing method for printing the above white image will be explained with reference to Figure 2, and includes: a pre-printing charging step in which the surface of a pre-printing photosensitive drum 1300 that rotates in one direction is charged; a pre-printing exposure step in which light energy is applied to the charged surface of the pre-printing photosensitive drum 1300 according to the required white image; a pre-printing developing step in which white toner W is provided to the surface of the pre-printing photosensitive drum 1300 after exposure; a pre-printing transfer step in which the white toner W attached to the surface of the pre-printing photosensitive drum 1300 is moved and fixed to the surface of a charged metal material 100; a pre-printing fixing step in which the white toner W fixed to the surface of the metal material 100 is fixed; a pre-printing removal step in which the white toner W remaining on the surface of the pre-printing photosensitive drum 300 after transfer is removed; and a pre-printing discharge step in which the surface of the pre-printing photosensitive drum 300 is discharged.

[0082] To explain in more detail, first, the surface of the pre-printed photosensitive drum 1300, which rotates in one of the above directions, is charged (pre-printed charging). A charge layer is formed on the pre-printed photosensitive drum 1300, which is charged with one of the above charges, and then preparations are made to paint a white image using white toner W. The surface of the pre-printed photosensitive drum 1300 may have either a positive (+) charge or a negative (-) charge.

[0083] Exposure (pre-print exposure) is performed by applying light energy to the surface of the pre-print photosensitive drum 1300, which has been charged by forming the above-mentioned charge layer. This exposure removes the charge from the surface of the pre-print photosensitive drum 1300 using light energy, thereby allowing toner to be moved to the surface of the pre-print photosensitive drum 1300 according to the required white image. The light energy can take various forms, and it is preferable to use a laser or LED light source.

[0084] White toner W is applied to the surface of the exposed pre-print photosensitive drum 1300, and this is called the development process (pre-printing phenomenon). The white toner W is charged with the opposite charge to the charge of the pre-print photosensitive drum 1300 and adheres to the surface of the pre-print photosensitive drum 1300. In the development process, referring to an example in Figure 2, the developing roller 1510 transfers a certain amount of white toner W from the toner container 1520 to the pre-print photosensitive drum 1300. However, the developing roller 1510 is not always necessary, and the toner can be transferred directly from the toner container 1520 to the pre-print photosensitive drum 1300. In other words, the pre-print development stage is the process in which toner adheres to the surface of the pre-print photosensitive drum 300 according to the required image.

[0085] Subsequently, the toner adhering to the surface of the pre-printed photosensitive drum 1300 moves to the charged metal material 100, and a transfer (pre-print transfer stage) proceeds in which white toner is fixed to the surface of the metal material 100. The metal material 100 is charged with the same charge as the pre-printed photosensitive drum 1300 and with the opposite charge to the toner, so that the white toner W adhering to the pre-printed photosensitive drum 1300 moves to the metal material 100. The pre-print transfer stage is the process in which an image is printed on the surface of the metal material 100, in which the metal material 100 is charged with the opposite charge to the toner, attracts the toner, and is fixed 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 pre-print transfer stage. On the other hand, if a separate coating layer is formed on the surface of the metal material 100, the pre-print metal material charging means can be provided in contact with the coating layer so that the coating layer is charged in order to transfer the image onto the coating layer.

[0086] After the white toner fixed to the surface of the metal material 100 (pre-printing and fixing stage) is fixed, the fixing can be performed by a thermocompression method, specifically by applying heat and pressing with a fused roll 1710 and a pressure roll 1720. At this time, the heating temperature is preferably 25 to 400°C. In the case of the white toner W 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, since metal materials have a high heat transfer coefficient, it is difficult to melt and adsorb the toner, so the toner must be heated to an appropriate temperature so that it can be adsorbed. For this reason, since it can react and be fixed to the surface of the metal material at a temperature above room temperature, the heating temperature is preferably 25°C or higher. On the other hand, if the temperature 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 to 50 to 300°C.

[0087] In addition to the metal material 100 mentioned above, a removal step (pre-print removal step) is performed to remove toner remaining on the surface of the pre-print photosensitive drum 1300 after transfer. This is because residual toner may leave afterimages in the subsequent printing process, potentially degrading print quality. In this case, as shown in Figures 2 and 7, the removal is performed physically via a blade 1610, and the removed toner can be collected in a collection container 1620 to prevent it from falling onto the metal material. Alternatively, for more complete removal, chemical removal can be further performed using an alcohol brush 1630 after the physical removal.

[0088] Next, in order to eliminate any remaining charge on the pre-printed photosensitive drum 1300, a step is performed to discharge the surface of the pre-printed photosensitive drum 1300 (pre-printing discharge step). Through this discharge, the pre-printed photosensitive drum 1300 is prepared to proceed with a new print.

[0089] On the other hand, another embodiment of the pre-printing method for printing the above-mentioned white image will be explained with reference to Figure 3. This pre-printing charging step involves charging the surface of a pre-printing photosensitive drum 1300' that rotates in one direction; a pre-printing exposure step involves applying light energy to the charged surface of the pre-printing photosensitive drum 1300' according to the required white image; a pre-printing developing step involves providing white toner W to the surface of the exposed pre-printing photosensitive drum 1300'; and pre-printing transfer involves transferring the white toner W attached to the surface of the pre-printing photosensitive drum 1300' to the charged pre-printing drum. The process includes: moving the toner onto the surface of the belt 1800; moving the toner attached to the surface of the pre-print transfer belt 1800 onto the surface of the charged metal material 100 and fixing it; fixing the white toner W fixed to the surface of the metal material 100; removing the white toner W remaining on the surface of the pre-print photosensitive drum 1300' and the pre-print transfer belt 1800 after the transfer; and discharging the surface of the pre-print photosensitive drum 1300' and the pre-print transfer belt 1800.

[0090] To explain in detail, first, the surface of the pre-printing photosensitive drum 1300', which rotates in one of the above directions, is charged (pre-printing charged). The surface of the pre-printing photosensitive drum 1300', which rotates in one direction, is charged. This forms a charge layer on the pre-printing photosensitive drum 1300' with one of the above charges, and after this, preparations are made for painting a white image using white toner W. The surface of the pre-printing photosensitive drum 1300' can be either positive (+) or negative (-) charge.

[0091] Exposure (pre-print exposure) is performed to apply light energy to the surface of the pre-print photosensitive drum 1300' which has been charged by forming the above-mentioned charge layer. By removing the charge from the surface of the pre-print photosensitive drum 1300', toner can be moved to the surface of the pre-print photosensitive drum 1300' according to the required white image. The light energy can take various forms, and it is preferable to use a laser or LED light source.

[0092] White toner W is applied to the surface of the exposed pre-printed photosensitive drum 1300'. This is called the development process (pre-printing phenomenon stage). The white toner W is charged with a charge opposite to the charge of the pre-printed photosensitive drum 1300' and adheres to the surface of the pre-printed photosensitive drum 1300'. In the development process, referring to an example in Figure 3, the developing roller 1510' transfers a certain amount of white toner W from the toner container 1520' to the pre-printed photosensitive drum 1300'. However, the developing roller 1510' is not necessarily required, and the toner can be transferred directly from the toner container 1520' to the pre-printed photosensitive drum 1300'. In other words, the pre-printing development stage is the process in which toner adheres to a position on the surface of the pre-printed photosensitive drum 1300' where the charge has been removed.

[0093] Subsequently, the white toner W adhering to the surface of the pre-printed photosensitive drum 1300' moves to the charged pre-printed transfer belt 1800', transferring the white toner W to the surface of the pre-printed transfer belt 1800'. At this time, the surface of the pre-printed transfer belt 1800' is charged with the opposite charge to that of the white toner W, and it attracts the toner and transfers it to the surface of the pre-printed transfer belt 1800'. By using the pre-printed transfer belt 1800', it is possible to avoid direct contact between the pre-printed photosensitive drum 1300' and the metal material 100. In particular, when using a metal material with high hardness, the white toner W on the surface of the pre-printed photosensitive drum 1300' is first transferred to the pre-printed transfer belt 1800' to prevent damage to the surface of the photosensitive drum.

[0094] As described above, the white toner W attached to the surface of the pre-printed transfer belt 1800' moves to the charged metal material 100, and a transfer (pre-printed transfer stage) proceeds in which the white toner W is fixed to the surface of the metal material 100. The metal material 100 is charged with the same charge as the pre-printed transfer belt 1800' and with the opposite charge to the toner, so that the white toner from the pre-printed transfer belt moves to the metal material 100. The above transfer process is the process in which a white image is printed on the surface of the metal material 100, and the metal material 100 is charged with the opposite charge to the white toner, and is attracted to the white toner, fixing it to the surface of the metal material 100. The charging of the metal material 100 can be performed before or after the pre-printed transfer stage, or both before and after. On the other hand, if a separate coating layer is formed on the surface of the metal material 100, the pre-printed metal material charging means can be provided in contact with the coating layer so that the coating layer is charged in order to transfer the image onto the coating layer.

[0095] After the white toner fixed to the surface of the metal material 100 (pre-printing and fixing step) is fixed, the fixing can be performed by a thermocompression method, and more preferably, heat is applied and pressure is applied simultaneously by a fused roll 1710' and a pressure roll 1720'. At this time, the heating temperature is preferably 25 to 400°C. More preferably, it is heated to 50 to 300°C. Since this temperature range is the same as that described above, the above description is used instead.

[0096] After the toner is transferred to the pre-printing transfer belt 1800', and after the toner has settled on the surface of the pre-printing photosensitive drum 1300' and the metal material 100, a pre-printing removal step is performed to remove the toner remaining on the surface of the pre-printing transfer belt 1800'. This is to prevent a decrease in print quality, as residual toner on the pre-printing photosensitive drum 1300' and the pre-printing transfer belt 1800' may leave afterimages in the subsequent printing process. At this time, the removal method is to perform physical removal via blades 1610 and 1610', as shown in Figures 3 and 7, and the removed toner can be collected in collection containers 1620 and 1620' 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 1630 after the physical removal. Although not shown in the present invention, the transfer belt may also include the alcohol brush in some cases.

[0097] Next, a pre-printing discharge step is performed to discharge any remaining charge on the pre-printing photosensitive drum 1300' and the pre-printing transfer belt 1800' by discharging the surfaces of the pre-printing photosensitive drum 1300' and the pre-printing transfer belt 1800'. This discharge prepares the system so that new printing can proceed again.

[0098] The present invention has the advantage of making image correction easier, including the pre-printing step described above. While conventional inkjet printing requires discarding the print if an image error occurs, the present invention offers the advantage of correction and rework by reversing the transfer of the metal material to achieve a white image again. Furthermore, this is possible even if the metal material is transferred in the reverse direction or discontinuously, by re-transferring it.

[0099] Next, we will describe the main printing stage, in which an image (the main print image) is printed on the surface of the metal material 100 on which the above white image is printed. An example of the above main printing stage is shown below, with reference to Figure 4.

[0100] One embodiment of the above printing steps includes: a printing charging step that charges the surface of a printing photosensitive drum 2300 that rotates in one direction; a printing exposure step that applies light energy to the charged surface of the printing photosensitive drum 2300 according to the required image; a printing developing step that provides toner T to the surface of the printing photosensitive drum 2300 after exposure; a printing transfer step that moves and fixes the toner adhering to the surface of the printing photosensitive drum 2300 to the surface of a charged metal material 100; a printing fixing step that fixes the toner fixed to the surface of the metal material 100; a printing removal step that removes the toner remaining on the surface of the printing photosensitive drum 2300 after transfer; and a printing discharge step that discharges the surface of the printing photosensitive drum 2300.

[0101] The following stages in the main printing process—the main printing charging stage, main printing exposure stage, main printing development stage, main printing transfer stage, main printing fixing stage, main printing removal stage, and main printing discharge stage—are technically identical in function and content, except that the white toner W is replaced with toner T for the main printing image in the pre-printing stage, as explained earlier with reference to Figure 2. Therefore, the descriptions of each stage will be replaced with the descriptions of the pre-printing stage, as explained with reference to Figure 2.

[0102] On the other hand, in the main printing stage described above, a color image can be printed using toners of various hues, such as two or more hues, for example, W (White), C (Cyan), Y (Yellow), M (Magenta), and K (Black). In this case, printing can be done using two or more toners, and as described above, two or more pairs of the main printing photosensitive drum, main printing photosensitive drum charging means, main printing photosensitive drum discharge means, main printing exposure means, main printing development means, and main printing removal means are provided, and various hues can be realized by performing the main printing charging stage; main printing exposure stage, main printing development stage, main printing transfer stage, and main printing removal stage two or more times along the direction of travel of the metal material. An example of this is shown in Figure 8. In Figure 8, four pairs of main printing photosensitive drums, main printing photosensitive drum charging means, main printing photosensitive drum discharge means, main printing exposure means, main printing development means, and main printing removal means are provided, and the main printing is performed by proceeding through each stage. The order of the above hues is not particularly limited in this invention and can be determined considering the required image, work efficiency, etc.

[0103] Another embodiment of the main printing stage, in which the image (main print image) is printed on the surface of the metal material 100 on which the above white image is printed, is described below with reference to Figure 5.

[0104] Another embodiment of the above printing steps preferably includes: a printing charging step for charging the surface of the printing photosensitive drum 2300' which rotates in one direction; a printing exposure step for applying light energy to the charged surface of the printing photosensitive drum 2300' according to the required image; a printing developing step for providing toner T to the surface of the printing photosensitive drum 2300' after exposure; a step for moving the toner adhering to the surface of the printing photosensitive drum 2300' to the surface of the charged printing transfer belt 2800; a printing transfer step for moving and fixing the toner adhering to the surface of the printing transfer belt 2800' to the surface of the charged metal material 100; a printing fixing step for fixing the toner fixed to the surface of the metal material 100; a printing removal step for removing toner remaining on the surfaces of the printing photosensitive drum 2300' and the printing transfer belt 2800' after transfer; and a printing discharge step for discharging the surfaces of the printing photosensitive drum 2300' and the printing transfer belt 2800'.

[0105] The following stages in the main printing process using the transfer belt described above—the main printing charging stage, main printing exposure stage, main printing development stage, stage to move toner to the main printing transfer belt, main printing transfer stage, main printing fixing stage, main printing removal stage, and main printing discharge stage—are technically identical in function and content, except that the white toner W is replaced with toner T for the main printing image in the pre-printing stage using the transfer belt, as explained with reference to Figure 3. Therefore, the descriptions of each stage will be replaced with the descriptions of the pre-printing stage, as explained with reference to Figure 3.

[0106] On the other hand, in the main printing stage using the transfer belt 2800' described above, a color image can be printed using toners of various hues, such as two or more hues, for example, W (White), C (Cyan), Y (Yellow), M (Magenta), and K (Black). In this case, printing can be done using two or more toners, and as described above, two or more pairs of the main printing photosensitive drum, main printing photosensitive drum charging means, main printing photosensitive drum discharge means, main printing exposure means, main printing development means, and main printing removal means are provided, arranged along the direction of travel of the transfer belt, and the main printing charging stage; main printing exposure stage; main printing development stage; main printing transfer stage; and main printing removal stage are performed two or more times in each pair, making it possible to print various hues. An example of this is shown in Figure 9. In Figure 9, four pairs of main printing photosensitive drums, main printing photosensitive drum charging means, main printing photosensitive drum discharge means, main printing exposure means, main printing development means, and main printing removal means are provided, and printing is performed by proceeding through each stage. The order of the above hues is not particularly limited in this invention and can be determined considering the required image, work efficiency, etc.

[0107] On the other hand, in order to print an image on both sides of the metal material, the pre-printing step and the main printing step 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.

[0108] Next, the metal material manufactured using the printing equipment or printing method described above will be explained in detail. Figure 10 schematically shows the printed metal material of the present invention, and the present invention will be explained in detail below with reference to Figure 10.

[0109] The printed metal material of the present invention includes a white image layer formed on a metal material and a print layer formed on the white image layer, as shown in Figure 10(a). The metal material is not particularly limited in type, as described above, and can be steel plates, non-ferrous metals, metal alloys, etc.

[0110] The above-mentioned white image layer is preferably formed using the pre-printing equipment 1000, 1000' described above, or through the pre-printing step described above. The presence of the above-mentioned white image layer ensures that the subsequent print layer (the image print layer formed through this printing) can achieve superior print quality.

[0111] The above-mentioned printed layer is preferably formed using the printing equipment 2000, 2000' described above, or through the printing steps described above. The above-mentioned printed layer can form a wider variety of images compared to images formed on conventional metal materials.

[0112] The above-mentioned printed layer has the advantage of not only having clearer form and hue compared to images formed by conventional printing methods, but also having high resistance to peeling and excellent processing characteristics.

[0113] Conventional printing methods on metal materials have mainly involved roll coating and inkjet coating using 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 composed 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 delamination due to the stress applied to the entire polymer, resulting in poor processing characteristics.

[0114] In contrast, the printing method using lasers, LEDs, etc., of the present invention employs toner, which is a solid powder. As a result, each powder particle corresponds to a unit particle containing hue, enabling the formation of superior hue. Furthermore, conventional printing methods use liquid pigments or dyes, which are greatly affected by the surface condition of the material being printed on. For example, the print quality is affected by the roughness and shape of the material surface, requiring effort in pre-treatment of the surface, such as roughness control. However, the printing method according to the present invention prints using toner powder through an electrostatic adsorption and compression process, making it possible to easily form images on metal materials compared to conventional methods.

[0115] Furthermore, the printed metal material of the present invention has the advantage of higher adhesion of the printed layer compared to printing using conventional white ink. In other words, when using white liquid ink, the white ink particles containing polymers are large, which increases the likelihood of peeling of the image layer during curved surface processing or cutting. On the other hand, the white image layer of the present invention has the advantage of reducing the occurrence of peeling of the printed layer even under stress due to the dispersion of powder particles.

[0116] Figure 11 shows a printed metal material manufactured by laser printing an image onto copper foil. Figure 11(a) shows a case where a white image layer is printed first, as in the present invention, and the desired image is printed on the white image layer. Figure 11(b) shows a case where the desired image is printed on the inherent hue of copper. As can be seen from Figures 11(a) and (b), (a) has a clearer image than (b) when a white image layer is present, and superior print quality can be ensured.

[0117] On the other hand, the printed metal material of the present invention may further include a coating layer between the metal material and the white image layer, as shown in Figure 10(b). The coating layer may include wet or dry plating layers such as an electro-galvanized (EG) layer or a hot-dip galvanized (GI) layer.

[0118] 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.

[0119] The above-mentioned pretreatment layer, intermediate coating layer, and top coating layer are not particularly limited in this invention and may include all known in the art to which this invention belongs. A preferred example is described below.

[0120] 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, and is a chromium-free (Cr-free) polymer coating or chromium hexavalent (Cr) coating. 6+ ), chromium trivalent (Cr 3+ ) Coating can be applied.

[0121] The above-mentioned intermediate coating layer (primer layer) is for ensuring corrosion resistance and concealing the substrate layer. It should be approximately 5 μm thick and can be coated using polyester, urethane, epoxy, etc. However, the above-mentioned intermediate coating layer can be omitted depending on the purpose.

[0122] The above-mentioned topcoat layer (top coating layer) exhibits surface properties and is directly related to the physical properties of the product, with the above-mentioned white image layer formed on top of the topcoat layer. The purpose of this topcoat layer is to protect the surface from physical impact, and to conceal its color, etc. For this purpose, it can be made to a thickness of 15-20 μm, and materials such as polyester, urethane, and epoxy can be used.

[0123] 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 10(c) and (d). The transparent coating layer may serve to provide gloss or protect the printed layer. The transparent coating layer is not particularly limited in the present invention and may include all known in the art to which the present invention belongs.

[0124] For example, the transparent coating layer described above generally uses polymer-based materials, and similar to the topcoat layer, high-molecular-weight resins such as polyester and urethane may be used. For outdoor use, fluororesins can also be used. The transparent coating layer can be formed to a thickness of approximately 1 to 5 μm depending on the application. [Explanation of symbols]

[0125] 100 Metal Materials 1000, 1000' Pre-printing equipment 2000, 2000' Main printing equipment 1101, 1101' Pre-printed metal material charging means 2101, 2101' Charging means for printed metal materials 1200, 1200' Pre-print exposure means 2200, 2200', 2201, 2201', 2202, 2202', 2203, 2203', 2204, 2204' This printing exposure means 1210 Laser Generator 1220 Scanning Mirror 1300, 1300' Pre-print photosensitive drum 2300, 2300', 2301, 2301', 2302, 2302', 2303, 2303', 2304, 2304' Printing Photosensitive Drum 1400, 1400' Pre-printed photosensitive drum charging and discharge means 2400, 2400', 2401, 2401', 2402, 2402', 2403, 2403', 2404, 2404' Charging and discharging means for this printable photosensitive drum 1410, 1410' Pre-printed photosensitive drum charging means 2410, 2410', 2411, 2411', 2412, 2412', 2413, 2413', 2414, 2414' Charging means for the photosensitive drum used in printing 1420, 1420' Pre-printed photosensitive drum discharge means 2420, 2420', 2421, 2421', 2422, 2422', 2423, 2423', 2424, 2424' This printing photosensitive drum charging means 1500, 1500' prior printing phenomenon means 2500, 2500', 2501, 2501', 2502, 2502', 2503, 2503', 2504, 2504' Book printing phenomenon means 1510, 1510', 2510, 2510', 2511, 2511', 2512, 2512', 2513, 2513', 2514, 2514' Developing roller 1520, 1520', 2520, 2520', 2521, 2521', 2522, 2522', 2523, 2523', 2524, 2524' Toner Containers 1600, 1600' print removal means 2600, 2600', 2601, 2601', 2602, 2602', 2603, 2603', 2604, 2604' Book print removal means 1610, 1610', 2610, 2610', 2611, 2611', 2612, 2612', 2613, 2613', 2614, 2614' blade 1620, 1620', 2620, 2620', 2621, 2621', 2622, 2622', 2623, 2623', 2624, 2624' Collection container 1630 Alcohol Brush 1700, 1700' ahead printing fixing means 2700, 2700' book printing fixing means 1710, 1710', 2710, 2710' Fused Roll 1720, 1720', 2720, 2720' Pressure Roll 1800' Pre-printed transfer belt 2800' Printed Transfer Belt 1810', 2810' Transfer belt driven roll 1811', 1812', 1813', 1814', 2811', 2812', 2813', 2814' Transfer belt support roll 1820', 2820' Transfer belt charging means 1830', 2830' Transfer belt discharge means 1840', 2840' Transfer belt toner removal means 1841', 2841' Transfer Belt Blade 1842', 2842' Transfer Belt Collection Container

Claims

1. Pre-printing equipment 1000, 1000' for printing a white image on the surface of a continuously moving metal material 100; and Printing equipment 2000, 2000' prints an image onto the surface of a metal material 100 on which the aforementioned white image is printed; Includes, The aforementioned printing equipment 1000 is A pre-printed photosensitive drum 1300 rotates in one direction while in close contact with the metal material 100, transferring and fixing the white toner W attached to its surface to the surface of the metal material 100; A pre-print developing means 1500 is provided on one side of the pre-print photosensitive drum 1300 and provides the white toner W to the surface of the pre-print photosensitive drum 1300; A pre-print photosensitive drum charging means 1410 charges the surface of the pre-print photosensitive drum 1300 before the white toner W is supplied; Between the pre-print developing means 1500 and the pre-print photosensitive drum charging means 1410, a pre-print exposure means 1200 applies light energy to the surface of the pre-print photosensitive drum 300 according to the required image; Pre-printed metal material charging means 1101: Charges the surface of the metal material 100 so that the white toner W attached to the surface of the pre-printed photosensitive drum 1300 is transferred to the surface of the metal material 100; A pre-printing removal means 1600 for removing the white toner W remaining on the surface of the pre-printing photosensitive drum 1300 after the white toner W has been fixed to the surface of the metal material 100; and After removing the white toner W, the pre-printing photosensitive drum discharge means 1420 removes the charge from the pre-printing photosensitive drum 1300; The aforementioned printing equipment 2000 is, The print photosensitive drum 2300 rotates in one direction while in close contact with the previously printed metal material 100, transferring and fixing the toner T attached to the surface of the metal material 100; A print developing means 2500 provided on one side of the print photosensitive drum 2300, which provides the toner T to the surface of the print photosensitive drum 2300; A photosensitive drum charging means 2410 charges the surface of the photosensitive drum 2300 before the toner T is supplied; Between the print developing means 2500 and the print photosensitive drum charging means 2410, the print exposure means 2200 applies light energy to the surface of the print photosensitive drum 2300 according to the required image; A printing metal material charging means 2101 charges the surface of the metal material 100 so that the toner T adhering to the surface of the printing photosensitive drum 2300 is transferred to the surface of the metal material 100; The printing removal means 2600 removes the toner T remaining on the surface of the printing photosensitive drum 2300 after the toner T has been fixed to the surface of the metal material 100; and Printing equipment with superior print quality, comprising: a print photosensitive drum discharge means 2420 that removes the charge from the print photosensitive drum 2300 after removing the toner T;

2. The aforementioned printing equipment 1000 is A pre-print fixing means 1700 located at the rear end of the pre-print photosensitive drum 1300, which fixes the white toner W fixed to the surface of the metal material 100; The printing equipment with superior print quality according to claim 1, further comprising:

3. Pre-printing equipment 1000, 1000' for printing a white image on the surface of a continuously moving metal material 100; and Printing equipment 2000, 2000' prints an image onto the surface of a metal material 100 on which the aforementioned white image is printed; Includes, The aforementioned printing equipment 1000' is, A pre-printing transfer belt 1800' rotates in one direction while in close contact with the metal material 100, transferring and fixing the white toner W attached to the surface of the metal material 100; A pre-printing photosensitive drum 1300' that is in close contact with the pre-printing transfer belt 1800' and rotates in the opposite direction, transferring the white toner W attached to its surface to the surface of the pre-printing transfer belt 1800'; A pre-print developing means 1500' is provided on one side of the pre-print photosensitive drum 1300' and provides the white toner W to the surface of the pre-print photosensitive drum 1300'; A pre-print photosensitive drum charging means 1410' charges the surface of the pre-print photosensitive drum 1300' before the white toner W is supplied; Between the pre-print developing means 1500' and the pre-print photosensitive drum charging means 1410', a pre-print exposure means 1200' applies light energy to the surface of the pre-print photosensitive drum 1300' according to the required image; Pre-printed metal material charging means 1101' charges the surface of the metal material 100 so that the white toner W adhering to the surface of the pre-printed transfer belt 1800' is transmitted to the surface of the metal material 100; A pre-print removal means 1600' for removing the white toner W remaining on the surface of the pre-print photosensitive drum 1300' after the white toner W has been fixed to the surface of the metal material 100; and The system includes a pre-print photosensitive drum discharge means 1420' that removes the charge from the pre-print photosensitive drum 1300' after removing the white toner W; The aforementioned printing equipment 2000' is, The print transfer belt 2800' rotates in one direction while in close contact with the previously printed metal material 100, transferring and fixing the toner T attached to the surface of the metal material 100; A print photosensitive drum 2300' that is in close contact with the print transfer belt 2800' and rotates in the opposite direction to the print transfer belt 2800', while transferring toner T attached to its surface to the surface of the print transfer belt 2800'; A print developing means 2500' provided on one side of the print photosensitive drum 2300', which provides the toner T to the surface of the print photosensitive drum 2300'; A photosensitive drum charging means 2410' charges the surface of the photosensitive drum 2300' before the toner T is supplied; Between the print developing means 2500' and the print photosensitive drum charging means 2410', the print exposure means 2200' applies light energy to the surface of the print photosensitive drum 2300' according to the required image; Printing metal material charging means 2101' charges the surface of the metal material 100 so that the toner T adhering to the surface of the printing transfer belt 2800' is transmitted to the surface of the metal material 100; After the toner T has settled on the surface of the metal material 100, the print removal means 2600' removes the toner T remaining on the surface of the print photosensitive drum 2300'; and A print photosensitive drum discharge means 2420' to remove the charge from the print photosensitive drum 2300' after removing the toner T; Includes, The aforementioned printing metal material charging means 2101' has a structure that allows it to move up and down according to the thickness of the metal material 100, and is a printing device with excellent print quality.

4. A pre-print fixing means 1700' located at the rear end of the pre-print transfer belt 1800' for fixing the white toner W fixed to the surface of the metal material 100; The printing equipment with superior print quality according to claim 3, further comprising:

5. The aforementioned printing equipment 2000 is, A printing fixing means 2700 located at the rear end of the printing photosensitive drum 2300, which fixes the toner T fixed to the surface of the metal material 100; The printing equipment with superior print quality according to claim 1, further comprising:

6. The aforementioned printing equipment 2000' is, A printing fixing means 2700' located at the rear end of the printing transfer belt 2800' for fixing the toner T fixed to the surface of the metal material 100; The printing equipment with superior print quality according to claim 3, further comprising:

7. The aforementioned light energy is provided by a laser or an LED, as described in claim 1 or 3, for printing equipment with superior print quality.

8. When the light energy is a laser, the pre-print exposure means 1200, 1200' and the main print exposure means 2200, 2200' include a laser generator and a scanning mirror, according to claim 7, which is a printing apparatus with excellent print quality.

9. The aforementioned printing equipment is Transfer belt drive rolls 1810', 2810' that drive the aforementioned pre-printed transfer belt 1800' or the aforementioned main printable transfer belt 2800' in the traveling direction; Transfer belt charging means 1820', 2820' charge the pre-printing transfer belt 1800' or the main printing transfer belt 2800' before the white toner W or toner T is supplied to the pre-printing transfer belt 1800' or the main printing transfer belt 2800'; Transfer belt toner removal means 1840', 2840' for removing toner T remaining on the pre-print transfer belt 1800' or the main print transfer belt 2800' after the white toner W or toner T has been transferred to the metal material 100; and Transfer belt discharge means 1830', 2830' for discharging the transfer belt after the removal of the white toner W or toner T; Printing equipment with superior print quality as described in claim 3, including the features described above.

10. The printing equipment for superior print quality according to claim 1 or 3, wherein the aforementioned pre-print removal means 1600, 1600' or the main print removal means 2600, 2600' includes blades 1610, 1610', 2610, 2610', and collection containers 1842, 1842', 2842, 2842 located at the lower end of the blades.

11. The printing equipment for superior print quality according to claim 9, wherein the transfer belt toner removal means 1840', 2840' includes blades 1841', 2841' and collection containers 1842', 2842' located at the lower end of the blades.

12. The printing equipment with superior print quality according to claim 1 or 3, wherein the pre-printing and developing means 1500, 1500' or the main printing and developing means 2500, 2500' includes toner containers 1520, 1520', 2520, 2520' and developing rollers 1510, 1510', 2510, 2510' that provide toner from the toner containers to the photosensitive drums 1300, 1300', 2300, 2300'.

13. The printing equipment with superior print quality according to claim 2, 4, 5, or 6, wherein the aforementioned pre-printing fixing means 1700, 1700' or the main printing fixing means 2700, 2700' includes fused rolls 1710, 1710', 2710, 2710' and pressure rolls 1720, 1720', 2720, 2720'.

14. The aforementioned printing photosensitive drum, printing photosensitive drum charging means, printing photosensitive drum discharge means, printing exposure means, printing developing means, and printing removal means are provided in pairs of two or more along the direction of travel of the metal material 100. The printing equipment according to claim 5, wherein each print developing means provides toners of different hues.

15. The aforementioned printing photosensitive drum, printing photosensitive drum charging means, printing photosensitive drum discharge means, printing exposure means, printing developing means, and printing removal means are provided in pairs of two or more along the direction of travel of the printing transfer belt 2800'. The printing equipment according to claim 6, wherein each printing and developing means provides toners of different hues.

16. The aforementioned prior printing equipment and the present printing equipment are located above and below a metal material, and are printing equipment with excellent print quality as described in claim 1.

17. A pre-printing step in which a white image is printed on the surface of a continuously moving metal material 100; and This printing stage involves printing an image onto the surface of the metal material 100 on which the aforementioned white image is printed. Includes, The aforementioned printing stage is A pre-printing charging step in which the surface of a pre-printing photosensitive drum 1300 that rotates in one direction is charged; A pre-print exposure step in which light energy is applied to the surface of the charged pre-print photosensitive drum 1300 according to the required white image; A pre-printing development step in which white toner W is provided to the surface of the pre-printing photosensitive drum 1300; A pre-print transfer step in which the white toner W attached to the surface of the pre-print photosensitive drum 1300 is moved and fixed to the surface of the charged metal material 100; A preprint removal step to remove the white toner W remaining on the surface of the preprint photosensitive drum 1300; and The process includes a pre-printing discharge step in which the surface of the pre-printing photosensitive drum 1300 is discharged; The aforementioned printing stage is The main printing charging step involves charging the surface of the main printing photosensitive drum 2300, which rotates in one direction; This printing exposure step involves applying light energy to the surface of the charged printing photosensitive drum 2300 according to the required image; This is the print development step, where toner T is provided to the surface of the print exposure drum 2300; This print transfer step involves moving the toner adhering to the surface of the print photosensitive drum 2300 to the surface of the charged metal material 100 and fixing it there. This print removal step removes toner remaining on the surface of the print photosensitive drum 2300; and This includes a printing discharge step in which the surface of the printing photosensitive drum 2300 is discharged; A printing method with excellent print quality, wherein during the print transfer step, the printing metal material charging means 2101 charges the surface of the metal material 100 by moving up and down according to the thickness of the metal material 100 so that the toner attached to the surface of the printing photosensitive drum 2300 can be fixed to the surface of the metal material 100.

18. The aforementioned printing stage is A printing method with excellent print quality according to claim 17, further comprising a preprint fixing step of fixing the white toner W fixed to the surface of the metal material 100 between the preprint transfer step and the preprint removal step.

19. A pre-printing step in which a white image is printed on the surface of a continuously moving metal material 100; and This printing step includes printing an image onto the surface of the metal material 100 on which the aforementioned white image is printed. The aforementioned printing stage is A pre-printing charging step in which the surface of the pre-printing photosensitive drum 1300', which rotates in one direction, is charged; A pre-print exposure step in which light energy is applied to the surface of the charged pre-print photosensitive drum 1300' according to the required white image; A pre-print developing step that provides white toner W to the surface of the pre-print photosensitive drum 1300' following the pre-print exposure step; A step of moving the white toner W adhering to the surface of the aforementioned pre-printing photosensitive drum 1300' to the surface of the charged pre-printing transfer belt 1800'; A pre-printing transfer step in which toner adhering to the surface of the pre-printing transfer belt 1800' is moved and fixed to the surface of the charged metal material 100; A preprint removal step is to remove the white toner W remaining on the surface of the preprint photosensitive drum 1300' and the preprint transfer belt 1800' after the preprint transfer step; and A pre-printing discharge step in which the surfaces of the pre-printing photosensitive drum 1300' and the pre-printing transfer belt 1800' are discharged; Includes, The aforementioned printing stage is The main printing charging step involves charging the surface of the main printing photosensitive drum 2300', which rotates in one direction; This printing exposure step involves applying light energy to the surface of the charged printing photosensitive drum 2300' according to the required image; This print development stage provides toner T to the surface of the print photosensitive drum 2300'; A step of moving the toner adhering to the surface of the print photosensitive drum 2300' to the charged print transfer belt 2800'; This is the main printing transfer step, in which the toner adhering to the surface of the main printing transfer belt 2800' is moved and fixed to the surface of the charged metal material 100; This printing removal step removes toner remaining on the surface of the print photosensitive drum 2300' and the print transfer belt 2800'; and This includes a printing discharge step that discharges the surface of the printing photosensitive drum 2300' and the printing transfer belt 2800'; A printing method with excellent print quality, wherein during the print transfer step, the printing metal material charging means 2101' charges the surface of the metal material 100 by moving up and down according to the thickness of the metal material 100 so that the toner attached to the surface of the print transfer belt 2800' can be fixed to the surface of the metal material 100.

20. The aforementioned printing stage is A printing method with excellent print quality according to claim 19, further comprising a preprint fixing step of fixing the white toner W fixed to the surface of the metal material 100 between the preprint transfer step and the preprint removal step.

21. The aforementioned printing stage is Between the aforementioned print transfer step and the aforementioned print removal step, This printing and fixing step involves fixing the toner that has adhered to the surface of the metal material 100; A printing method with superior print quality according to claim 17, further comprising the above.

22. The aforementioned printing stage is Between the aforementioned print transfer step and the print removal step, a print fixing step is performed to fix the toner that has adhered to the surface of the metal material 100; A printing method with superior print quality according to claim 19, further comprising the above.

23. The aforementioned pre-printing and fixing step or the current printing and fixing step is heated to 25 to 400°C, a printing method with excellent print quality according to any one of claims 18, 20, 21, or 22.

24. A printing method for superior print quality according to any one of claims 18, 20, 21, or 22, wherein the aforementioned pre-printing and fixing step or the current printing and fixing step is further further comprising applying pressure.

25. The aforementioned printing stage requires two or more main printing photosensitive drums when printing using two or more toners. A printing method with excellent print quality according to claim 17 or 19, wherein two or more of the above-mentioned main print charging step, main print exposure step, main print development step, main print transfer step, and main print removal step are performed using each main print photosensitive drum.

Images