A printing system and method for multi-view magnetic anti-counterfeiting images

Abstract

This invention relates to a printing system and method for anti-counterfeiting images, and particularly to a printing system and method for multi-view magnetic anti-counterfeiting images, solving the problems of ghosting, slow printing speed, and low color registration accuracy in existing magnetic anti-counterfeiting image printing technologies. The system includes a multi-color printing press, multiple magnetic rollers, and multiple magnetic orientation and shaping devices. In each printing color group of the multi-color printing press, one or more magnetic rollers are respectively located on the front and / or back of the printing surface of the substrate between the printing roller and the printing output roller. The number of magnetic orientation and shaping devices is equal to the number of printing color groups, and they are respectively located in each printing color group between the magnetic roller and the printing output roller closest to the printing output roller. Each magnetic orientation and shaping device includes an independent magnetic orientation device and a magnetic shaping device, which are located on opposite sides of the front and back of the printing surface at the same location on the substrate.

Description

Technical Field

[0001] This invention relates to a printing system and method for anti-counterfeiting images, and particularly to a printing system and method for multi-view magnetic anti-counterfeiting images. Background Technology

[0002] Magnetic anti-counterfeiting images are three-dimensional images obtained by using magnetic field interference to magnetically orient and shape ink coatings containing magnetic pigments. Since the magnetic field exists in three dimensions, the three-dimensional base points of the image can be used as effective parameter points for anti-counterfeiting. Therefore, they are widely used in anti-counterfeiting products.

[0003] In existing technologies, magnetic anti-counterfeiting image technology has been used in coating processes such as spraying and coating, as well as screen printing processes, for coating film materials and printing labels. Patent CN103962292A discloses an invention patent for a coating equipment and process for magnetic pigments, which discloses a magnetic orientation device, a magnetic shaping device, and an embodiment of using them with a screen printing machine. However, it only discloses continuous magnetic orientation and shaping after the screen of the screen printing machine is flattened with ink containing magnetic pigments; it does not address the color registration problem of multi-color magnetic anti-counterfeiting images. Furthermore, using the magnetic orientation device and magnetic shaping device with a screen printing machine presents the following two problems:

[0004] First, there is the issue of ghosting. When using magnetic orientation devices and magnetic shaping devices with screen printing machines, there is always a 1-times rule, which means that the thickness of the ink layer must be 1 times or more the size of the pigment particles in order to achieve a three-dimensional effect. Therefore, the thickness of the ink layer in screen printing needs to reach more than 10 micrometers. If the ink layer is too thick, the deflection will not be complete during magnetic orientation, resulting in black ghosting on the cross-section of many magnetic color pieces.

[0005] Secondly, there is the problem of extremely slow printing speed. To prevent ink leakage during screen printing, the ink viscosity is relatively high, typically above 1200 Pascals per second (Pa·s), which affects the magnetic alignment. To ensure all magnetic pigments in the ink achieve complete magnetic orientation, the screen printing machine usually needs to stop and wait approximately 2 to 3 seconds after each color is printed, resulting in very slow printing speed and low registration accuracy.

[0006] Therefore, there is an urgent need to develop a printing system and method for magnetic anti-counterfeiting images that can achieve high-precision color matching, better magnetic orientation effect, clearer visual disappearance of images and text, and faster printing speed. Summary of the Invention

[0007] The purpose of this invention is to solve the technical problems of ghosting, very slow printing speed and low color registration accuracy when using magnetic orientation device, magnetic shaping device and screen printing machine together in the prior art to print magnetic anti-counterfeiting images. The invention provides a printing system and method for multi-view magnetic anti-counterfeiting images.

[0008] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0009] A printing system for multi-view magnetic anti-counterfeiting images, characterized by:

[0010] It includes a multi-color printing press, multiple magnetic rollers, and multiple magnetic orientation and shaping devices;

[0011] The multicolor printing press includes an unwinding device, an infeeding device, a printing device, an exporting device, and a rewinding device connected in sequence.

[0012] The unwinding device is used to place the substrate to be printed; the infeeding device is used to infeed the substrate to be printed from the unwinding device to the input end of the printing device; the printing device includes multiple printing color groups for multi-color printing on the substrate to be printed; the exporting device is used to export the printed substrate from the output end of the printing device to the rewinding device; the rewinding device is used to rewind the exported printed substrate in real time.

[0013] Both the import and export devices are equipped with a correction mechanism for real-time correction of the substrate.

[0014] In each of the printing color groups, one or more magnetic rollers are respectively provided between the printing roller and the printing output roller on the front and / or back of the printing surface of the substrate, for activating the magnetic pigments in the printed ink coating containing magnetic pigments.

[0015] The number of magnetic orientation and shaping devices is equal to the number of printing color groups; each magnetic orientation and shaping device is respectively arranged in a corresponding manner between the magnetic roller and the printing output roller in each printing color group, which are closest to the printing output roller; each magnetic orientation and shaping device includes an independent magnetic orientation device and a magnetic shaping device, and the independent magnetic orientation device and the magnetic shaping device are respectively located on opposite sides of the front and back sides of the printing surface at the same position on the substrate, and there is a gap between both of them and the substrate;

[0016] The magnetic orientation device and magnetic shaping device are used to magnetically orient and magnetically shape the magnetic pigments in the ink coating containing magnetic pigments, so as to print multi-view magnetic anti-counterfeiting images on the substrate.

[0017] Furthermore, to meet different printing needs, the multicolor printing press is selected from multicolor letterpress printing presses, multicolor flexographic printing presses, or multicolor gravure printing presses. Specifically, multicolor letterpress printing presses are suitable for printing small batches of products containing multi-view magnetic anti-counterfeiting images where high registration accuracy is not required but frequent plate changes are necessary; multicolor flexographic printing presses are suitable for printing products containing multi-view magnetic anti-counterfeiting images where high registration accuracy is required and a significantly higher printing speed than letterpress printing is needed; and multicolor gravure printing presses are suitable for printing products containing multi-view magnetic anti-counterfeiting images that require not only accurate color registration and high printing speed but also good anti-counterfeiting effects.

[0018] Furthermore, in order to better control the area that needs to be magnetically shaped, and thus improve the effect of the final printed multi-view magnetic anti-counterfeiting image, a mask matching the pattern of the multi-view magnetic anti-counterfeiting image to be printed is provided between the magnetic shaping device and the substrate, so as to achieve magnetic shaping only on the area that needs to be magnetically shaped.

[0019] Furthermore, the magnetic roller includes a roller body and a plurality of first magnets irregularly spaced and embedded on the outer cylindrical surface of the roller body;

[0020] The axis of rotation of the roller body is perpendicular to the transport path of the printed material at its installation position; the roller body is made of non-magnetic material;

[0021] The plurality of first magnets are used to form an irregular magnetic field, which activates the magnetic pigments in the printed ink or coating containing magnetic pigments. The irregular magnetic field helps to accelerate the activation of the magnetic pigments in the printed ink or coating containing magnetic pigments, which is beneficial for subsequent magnetic orientation.

[0022] Furthermore, in order to achieve higher precision in magnetic orientation and thus more accurate printing of multi-view magnetic anti-counterfeiting images, the magnetic orientation device is an orientation magnetic roller;

[0023] The directional magnetic roller includes a magnetic roller body and a second magnet group embedded on the outer cylindrical surface of the magnetic roller body, which matches the multi-view magnetic anti-counterfeiting image pattern to be printed.

[0024] The axis of rotation of the magnetic roller body is perpendicular to the transport path of the printed material at its installation position; the magnetic roller body is made of non-magnetic material;

[0025] The second magnet group is used to magnetically orient the magnetic pigments in the ink coating containing magnetic pigments printed on each area of ​​the substrate according to the magnetic field direction required by the corresponding area on the multi-view magnetic anti-counterfeiting image to be printed, so as to obtain the visual effect required by the design.

[0026] Furthermore, both the first magnet and the second magnet group form a magnetic field through rare earth magnets, ferrites, rubber magnets, electromagnets, or electromagnet groups.

[0027] The magnetic shaping device achieves magnetic shaping through one or more of the following methods: hot air, thermal curing, UV curing, and EB curing.

[0028] Meanwhile, the present invention also provides a printing method for multi-view magnetic anti-counterfeiting images, which is characterized by including the following steps:

[0029] Step 1: Construct the printing system for the above multi-view magnetic anti-counterfeiting images;

[0030] Step 2: Select the substrate according to the requirements of the product containing the multi-view magnetic anti-counterfeiting image to be printed, and prepare the printing system of the multi-view magnetic anti-counterfeiting image built in Step 1 for pre-press preparation; during the pre-press preparation process, the viscosity of the selected ink coating containing magnetic pigments should be between 200 Pascal-second and 1200 Pascal-second, and the following conditions should be met when making the printing plate and setting the parameters of the multi-color printing machine: control the thickness of the printing ink layer between 3 micrometers and 8 micrometers;

[0031] Step 3: Printing, specifically including:

[0032] Step 3.1: Place the substrate selected in Step 2 onto the unwinding rack of the unwinding device of the multi-color printing press in the multi-view magnetic anti-counterfeiting image printing system that has completed pre-press preparation in Step 2.

[0033] Step 3.2: Start the multi-color printing press, each magnetic roller and each magnetic orientation and shaping device in the multi-view magnetic anti-counterfeiting image printing system that has completed the pre-printing preparation in Step 2. The import device imports the substrate placed on the unwinding frame in Step 3.1 from the unwinding device into the input end of the printing device. During the import process, the correction mechanism in the import device corrects the substrate in real time.

[0034] Step 3.3: The multiple printing color groups in the printing device are printed one by one on the substrate introduced in step 3.2. After each color is printed, it passes through the magnetic roller and magnetic orientation and shaping device set between the printing roller and the printing output roller in the printing color group in sequence to activate, magnetically orient and magnetically shape the magnetic pigment in the ink coating of that color until the magnetic orientation and magnetic shaping of the last color are completed, so that a multi-view magnetic anti-counterfeiting image is printed on the substrate.

[0035] Step 3.4: The export device exports the substrate with the multi-view magnetic anti-counterfeiting image printed in step 3.3 from the output end of the printing device to the winding device. During the export process, the correction mechanism in the export device corrects the substrate in real time.

[0036] Step 3.5: The winding device winds up the substrate printed with the multi-view magnetic anti-counterfeiting image exported in Step 3.4 in real time to obtain a product containing the multi-view magnetic anti-counterfeiting image, thus completing the printing process.

[0037] Furthermore, in order to meet different printing needs, in the multi-view magnetic anti-counterfeiting image printing system built in step 1, the multi-color printing machine is selected from multi-color letterpress printing machines, multi-color flexographic printing machines, or multi-color gravure printing machines.

[0038] Furthermore, in the multi-view magnetic anti-counterfeiting image printing system built in step 1, the multi-color printing machine is a multi-color gravure printing machine, and the magnetic shaping device achieves magnetic shaping through one or more combinations of hot air, thermal curing, UV curing, and EB curing.

[0039] In step 2, the selected substrate is PET polyester film, PC film, PVC heat shrink film, PP film, or PE film; the selected ink coating containing magnetic pigment is UV-type ink coating containing magnetic pigment, solvent-based ink coating containing magnetic pigment, or water-based ink coating containing magnetic pigment; when making the printing plate, the mesh size of the engraving plate is 25 mesh / cm² to 350 mesh / cm², and the depth of the engraving plate is 10 micrometers to 100 micrometers.

[0040] Furthermore, in order to achieve a simple mechanical structure, small footprint, moderate viscosity effect, excellent angular orientation of magnetized pigment particles, and extremely low volatile organic compound (VOC) content in the ink, making it more environmentally friendly, the multi-view magnetic anti-counterfeiting image printing system constructed in step 1 uses a multi-color gravure printing machine as the multi-color printing machine, and the magnetic shaping device achieves magnetic shaping through UV thermal curing, with the UV thermal curing using a strobe light source.

[0041] In step 2, the selected substrate is PET polyester film; the selected ink coating containing magnetic pigment is UV-type ink coating containing magnetic pigment, and its viscosity is 500 Pascals per second; when making the printing plate and setting the parameters of the multicolor printing machine, the screen mesh of the engraving plate is 250 meshes / square centimeter, the depth of the engraving plate is 30 micrometers to 50 micrometers, and the thickness of the printed ink layer is controlled between 6 micrometers and 8 micrometers.

[0042] UV thermosetting uses a strobe light source, which makes it easier to perform magnetic shaping on areas that need it and not on areas that do not need it, thus improving the effect of the final printed multi-view magnetic anti-counterfeiting image.

[0043] The beneficial effects of this invention are:

[0044] (1) In the multi-view magnetic anti-counterfeiting image printing system of the present invention, one or more magnetic rollers and magnetic orientation and shaping devices are sequentially set between the printing rollers and the printing output rollers in each printing color group of the multi-color printing machine, which solves the color registration problem of the multi-color magnetic anti-counterfeiting image; and according to the actual printing needs such as the characteristics of the product containing the multi-view magnetic anti-counterfeiting image to be printed, the printing quantity and process, different types of multi-color printing machines such as multi-color letterpress printing machines, multi-color flexographic printing machines or multi-color gravure printing machines can be selected.

[0045] Secondly, when using a multi-color letterpress printing machine, the thickness of the printed ink layer can be controlled between 3 and 8 micrometers through plate-making technology; when using a multi-color flexographic printing machine, the thickness of the printed ink layer can be controlled between 1 and 5 micrometers through plate-making technology; and when using a multi-color gravure printing machine, the thickness of the printed ink layer can be controlled between 1 and 150 micrometers through plate-making technology. Compared with screen printing machines, all of these can achieve a thinner ink layer thickness, avoiding the "1x rule" problem of screen printing machines, which requires the ink layer thickness to reach more than 10 micrometers. Therefore, the printing system of the multi-view magnetic anti-counterfeiting image of this invention can achieve a thinner ink layer thickness, making the visual disappearance of the image and text clearer, making the deflection during magnetic orientation more thorough, and greatly reducing the probability of ghosting.

[0046] Furthermore, the printing system using the multi-view magnetic anti-counterfeiting image of this invention can use a multi-color letterpress printing machine, a multi-color flexographic printing machine, or a multi-color gravure printing machine. Therefore, there is no need to worry about ink leakage during screen printing. Thus, ink coatings containing magnetic pigments with lower viscosity can be selected. The lower the viscosity of the ink coating containing magnetic pigments within a certain range, the more favorable it is for magnetic orientation, and the easier it is to print images and text with magnetic orientation effects. In addition, magnetic orientation and magnetic shaping can be quickly achieved through the magnetic orientation and shaping device without stopping the machine. Therefore, the printing speed can be greatly improved. Moreover, the registration accuracy is also greatly improved compared to using the magnetic orientation device and magnetic shaping device with a screen printing machine, and the magnetic orientation effect of the images and text is also better.

[0047] In summary, the present invention solves the technical problems of ghosting, very slow printing speed, and low color registration accuracy when using magnetic orientation devices, magnetic shaping devices, and screen printing machines together in the prior art for printing magnetic anti-counterfeiting images.

[0048] (2) In the printing system of the multi-view magnetic anti-counterfeiting image of the present invention, one or more magnetic rollers and magnetic orientation and shaping devices are sequentially arranged between the printing roller and the printing output roller in each printing color group; after each color is printed, the magnetic pigment in the printed ink coating containing magnetic pigment is activated by the magnetic roller, and then the magnetic orientation and shaping device is used to magnetically orient and shape the magnetic pigment in the printed ink coating containing magnetic pigment; compared with directly using the magnetic orientation and shaping device after each color is printed, the setting method of the present invention can greatly improve the deflection efficiency of the magnetic pigment and make the brightness of the printed multi-view magnetic anti-counterfeiting image more dazzling.

[0049] (3) In the printing system of the multi-view magnetic anti-counterfeiting image of the present invention, when multiple first magnets are embedded on the outer cylindrical surface of the magnetic roller body, an irregularly spaced embedding method is adopted. This can form an irregular magnetic field, which helps to accelerate the activation of magnetic pigments in the ink coating containing magnetic pigments and is beneficial to subsequent magnetic orientation.

[0050] (4) In the printing system of the multi-view magnetic anti-counterfeiting image of the present invention, the magnetic orientation device is preferably an orientation magnetic roller. The orientation magnetic roller includes a magnetic roller body and a second magnet group that matches the pattern of the multi-view magnetic anti-counterfeiting image to be printed and is embedded on the outer cylindrical surface of the magnetic roller body. Using an orientation magnetic roller as a magnetic orientation device can make the magnetic orientation more accurate, thereby making the printed multi-view magnetic anti-counterfeiting image more precise.

[0051] (5) In the printing system of the multi-view magnetic anti-counterfeiting image of the present invention, a mask matching the pattern of the multi-view magnetic anti-counterfeiting image to be printed is preferably provided between the magnetic shaping device and the substrate. This can better control the area that needs to be magnetically shaped, thereby making the final printed multi-view magnetic anti-counterfeiting image more effective.

[0052] (6) The printing system and printing method of the multi-view magnetic anti-counterfeiting image of the present invention can achieve magnetic shaping at the same time as printing, without the need to stop the machine and wait, which greatly improves the printing speed. Furthermore, when a multi-color gravure printing machine is selected for multi-color printing, it can achieve precise registration with extremely high registration accuracy.

[0053] (7) When printing products containing multi-view magnetic anti-counterfeiting images, if the ink layer is too thick, it is prone to ghosting; if the ink layer is too thin, the three-dimensional effect is not obvious, and the magnetic pigments cannot be effectively deflected, resulting in poor anti-counterfeiting effect. If the viscosity of the ink coating containing magnetic pigments is too high, the time for all magnetic pigments in the ink to achieve full magnetic orientation will be prolonged, which will lead to a decrease in printing speed. However, if the viscosity of the ink coating containing magnetic pigments is too low, the magnetic pigments will be affected by their own gravity and will not be able to achieve effective deflection. In this invention, through experimental verification, when a multi-color gravure printing machine is selected for multi-color printing, the ink layer thickness is controlled at 6 micrometers to 8 micrometers, and a viscosity of 500 Pascals is selected. When using inks containing magnetic pigments with a viscosity of 1200 Pascal-second, the magnetic deflection rate can reach 99%, and the magnetic rotation speed can reach 0.1 s, resulting in the best multi-view magnetic anti-counterfeiting image effect. Compared to screen printing, where the ink layer thickness is taken as the minimum achievable value of 10 micrometers and the viscosity of the ink containing magnetic pigments is also taken as the minimum achievable value of 1200 Pascal-second, the corresponding magnetic deflection rate is only 50% and the magnetic rotation speed is only 0.5 s. Obviously, the printing system and method of the multi-view magnetic anti-counterfeiting image of this invention significantly improves both the magnetic deflection rate and the magnetic rotation speed, resulting in a better anti-counterfeiting effect for the printed products containing multi-view magnetic anti-counterfeiting images.

[0054] (8) In the printing system and printing method of the multi-view magnetic anti-counterfeiting image of the present invention, the magnetic shaping device achieves magnetic shaping by UV heat curing. When the UV heat curing is preferably carried out by a strobe light source, it can more conveniently achieve magnetic shaping of the area that needs magnetic shaping and not magnetic shaping of the area that does not need magnetic shaping, thereby making the effect of the final printed multi-view magnetic anti-counterfeiting image better. Attached Figure Description

[0055] Figure 1 This is a schematic diagram of the structure of an embodiment of the multi-view magnetic anti-counterfeiting image printing system of the present invention;

[0056] Figure 2 This is a schematic diagram of the structure of the magnetic roller in an embodiment of the multi-view magnetic anti-counterfeiting image printing system of the present invention;

[0057] Figure 3 This is a schematic diagram showing the relative positional relationship between the magnetic roller and the substrate in an embodiment of the multi-view magnetic anti-counterfeiting image printing system of the present invention;

[0058] Figure 4 This is a schematic diagram of the structure of the directional magnetic roller in an embodiment of the multi-view magnetic anti-counterfeiting image printing system of the present invention;

[0059] Figure 5 This is a schematic diagram showing the relative positional relationship between the directional magnetic roller and the substrate in an embodiment of the multi-view magnetic anti-counterfeiting image printing system of the present invention.

[0060] The labels in the diagram are explained as follows:

[0061] 1-Unwinding device, 2-Inlet device, 3-Printing device, 31-Printing roller, 4-Outlet device, 5-Rewinding device, 6-Magnetic orientation and shaping device, 61-Magnetic orientation device, 611-Magnetic roller body, 612-Second magnet group, 62-Magnetic shaping device, 7-Magnetic roller, 71-Roller body, 72-First magnet, 01-Substrate. Detailed Implementation

[0062] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0063] See Figure 1 A printing system for multi-view magnetic anti-counterfeiting images includes a multi-color printing press, multiple magnetic rollers 7, and multiple magnetic orientation and shaping devices 6.

[0064] See Figure 1The aforementioned multicolor printing press includes an unwinding device 1, an infeeding device 2, a printing device 3, an exporting device 4, and a rewinding device 5 connected in sequence. The unwinding device 1 is used to place the substrate 01 to be printed. The infeeding device 2 is used to infeed the substrate 01 to the input end of the printing device 3 from the unwinding device 1. The printing device 3 includes multiple printing color groups for multicolor printing on the substrate 01. The exporting device 4 is used to export the printed substrate 01 from the output end of the printing device 3 to the rewinding device 5. The rewinding device 5 is used to rewind the exported printed substrate 01 in real time. Both the infeeding device 2 and the exporting device 4 are equipped with correction mechanisms for real-time correction of the substrate 01. Depending on the characteristics of the product containing multi-view magnetic anti-counterfeiting images to be printed, the printing quantity, and the actual printing requirements such as the process, the aforementioned multicolor printing press can be selected from different types of printing presses, such as multicolor letterpress printing presses, multicolor flexographic printing presses, or multicolor gravure printing presses. Among them, multi-color letterpress printing machines are suitable for printing small batches of products containing multi-view magnetic anti-counterfeiting images that do not require high registration accuracy but need frequent plate changes; multi-color flexographic printing machines are suitable for printing products containing multi-view magnetic anti-counterfeiting images that require high registration accuracy and a significantly higher printing speed than letterpress printing; multi-color gravure printing machines are suitable for printing products containing multi-view magnetic anti-counterfeiting images that require not only accurate color registration and high printing speed but also good anti-counterfeiting effects. In this embodiment, a multi-color gravure printing machine is selected. The printing plate roller of the multi-color gravure printing machine can be a laser direct-engraving roller, an electro-engraving roller, or a laser roller. In this embodiment, in order to accurately control the dimensional parameters such as cell shape, engraving depth, and width, and to make the pattern details clearly presented, the printing plate roller of the multi-color gravure printing machine in this embodiment preferably uses a laser direct-engraving roller. When using a laser direct-engraving roller, no chemical corrosives are used, making it more environmentally friendly.

[0065] See Figure 1 In each printing color group, one or more of the aforementioned magnetic rollers 7 are respectively arranged between the printing roller 31 and the printing output roller on the front and / or back of the printing surface of the substrate 01, for activating the magnetic pigments in the printed ink coating containing magnetic pigments. In this embodiment, one magnetic roller 7 is provided in each printing color group. In addition to providing one as in this embodiment, multiple rollers can also be provided. Multiple rollers can be arranged on the front of the printing surface of the substrate 01, on the back of the printing surface of the substrate 01, or on both the front and back of the printing surface of the substrate 01. The number and arrangement position are specifically determined by the multi-view magnetic anti-counterfeiting image to be printed. See also Figure 2 and Figure 3In this embodiment, the magnetic roller 7 preferably includes a roller body 71 and a plurality of first magnets 72 irregularly spaced and embedded on the outer cylindrical surface of the roller body 71; the axis of rotation of the roller body 71 is perpendicular to the transmission path of the substrate 01 at its installation position; the roller body 71 is made of a non-magnetic material; the plurality of first magnets 72 are used to form an irregular magnetic field, which helps to accelerate the activation of magnetic pigments in the printed ink containing magnetic pigments, which is beneficial to subsequent magnetic orientation. The first magnets 72 can form a magnetic field by means of rare earth magnets, ferrites, rubber magnets, electromagnets or electromagnet groups, etc.; in this embodiment, the first magnets 72 preferably form a magnetic field by means of neodymium iron boron rare earth magnets.

[0066] See Figure 1 The number of the aforementioned magnetic orientation and shaping devices 6 is equal to the number of the aforementioned printing color groups; each of the aforementioned magnetic orientation and shaping devices 6 is respectively arranged in a corresponding manner between the aforementioned magnetic roller 7 and the printing output roller in each printing color group, which is closest to the printing output roller; each magnetic orientation and shaping device 6 includes an independent magnetic orientation device 61 and a magnetic shaping device 62, and the independent magnetic orientation device 61 and magnetic shaping device 62 are respectively located on opposite sides of the front and back sides of the printing surface at the same position on the substrate 01, and there is a gap between both of them and the substrate 01. The size of the gap is determined by the magnetic angle and shaping shape of the multi-view magnetic anti-counterfeiting image to be printed, and is an empirical value; the aforementioned magnetic orientation device 61 and magnetic shaping device 62 are respectively used to magnetically orient and magnetically shape the magnetic pigment in the ink coating containing magnetic pigments to print a multi-view magnetic anti-counterfeiting image on the substrate 01. The specific structures of the aforementioned magnetic orientation device 61 and magnetic shaping device 62 can adopt the structures of the magnetic orientation device and magnetic shaping device disclosed in the invention patent CN103962292A, which describes a coating equipment and coating process for magnetic pigments. In addition to adopting the structures of the magnetic orientation device and magnetic shaping device disclosed in that patent, other structures of magnetic orientation devices and magnetic shaping devices capable of achieving magnetic orientation and magnetic shaping can also be adopted.

[0067] See Figure 4 and Figure 5In this embodiment, to achieve higher precision in magnetic orientation and thus more accurate printing of the multi-view magnetic anti-counterfeiting image, the magnetic orientation device 61 is preferably an orientation magnetic roller. The orientation magnetic roller includes a magnetic roller body 611 and a second magnet assembly 612 embedded on the outer cylindrical surface of the magnetic roller body 611, matching the pattern of the multi-view magnetic anti-counterfeiting image to be printed. The axis of rotation of the magnetic roller body 611 is perpendicular to the transmission path of the substrate 01 at its installation position. The magnetic roller body 611 is made of a non-magnetic material. The second magnet assembly 612 is used to magnetically orient the magnetic pigments in the ink coating containing magnetic pigments printed on each area of ​​the substrate 01 according to the magnetic field direction required by the corresponding area design on the multi-view magnetic anti-counterfeiting image to be printed, thereby obtaining the required visual effect. The second magnet assembly 612 can form a magnetic field using rare-earth magnets, ferrites, rubber magnets, electromagnets, or electromagnet assemblies. In this embodiment, the second magnet assembly 612 preferably forms a magnetic field using neodymium iron boron rare-earth magnets. The aforementioned magnetic shaping device 62 can achieve magnetic shaping through one or more combinations of hot air, thermal curing, UV curing, and EB curing. In this embodiment, the magnetic shaping device 62 preferably achieves magnetic shaping through UV thermal curing, and the UV thermal curing preferably uses a strobe light source. This makes it easier to perform magnetic shaping on areas that need it and not on areas that do not need it, thereby improving the effect of the final printed multi-view magnetic anti-counterfeiting image. To better control the areas that need magnetic shaping and further improve the effect of the final printed multi-view magnetic anti-counterfeiting image, a mask matching the pattern of the multi-view magnetic anti-counterfeiting image to be printed can also be provided between the magnetic shaping device 62 and the substrate 01, so that magnetic shaping is performed only on the areas that need it.

[0068] In addition, the present invention also provides a printing method for multi-view magnetic anti-counterfeiting images, comprising the following steps:

[0069] Step 1: Construct the printing system for the multi-view magnetic anti-counterfeiting image described above. The multi-color printing press in the constructed multi-view magnetic anti-counterfeiting image printing system can be a multi-color letterpress printing press, a multi-color flexographic printing press, or a multi-color gravure printing press. The magnetic shaping device 62 in the magnetic orientation and shaping device 6 of the constructed multi-view magnetic anti-counterfeiting image printing system can achieve magnetic shaping through one or more combinations of hot air, thermal curing, UV curing, and EB curing. In this embodiment, a multi-color gravure printing press is selected, and the magnetic shaping device 62 in the magnetic orientation and shaping device 6 achieves magnetic shaping through UV thermal curing. Furthermore, the UV thermal curing uses a strobe light source, which makes it easier to perform magnetic shaping on areas requiring magnetic shaping and not on areas not requiring magnetic shaping, thereby improving the final effect of the printed multi-view magnetic anti-counterfeiting image.

[0070] Step 2: Based on the requirements of the product containing multi-view magnetic anti-counterfeiting images to be printed, select substrate 01 and prepare the printing system for the multi-view magnetic anti-counterfeiting images built in Step 1 for pre-press preparation. During the pre-press preparation, the viscosity of the selected ink coating containing magnetic pigments should be between 200 Pascal-second and 1200 Pascal-second. Furthermore, when making the printing plate and setting the parameters of the multi-color printing press, the following conditions should be met: the ink layer thickness should be controlled between 3 micrometers and 8 micrometers. Taking a multi-color gravure printing press as an example, the selected substrate 01 can be PET polyester film, PC film, PVC heat shrink film, PP film, or PE film, etc. The selected ink coating containing magnetic pigments... The material can be a UV-type ink or coating containing magnetic pigments, a solvent-based ink or coating containing magnetic pigments, or a water-based ink or coating containing magnetic pigments, etc.; when making the printing plate, the mesh size of the engraved plate is 25 mesh / cm² to 350 mesh / cm², and the depth of the engraved plate is 10 micrometers to 100 micrometers; in this embodiment, the substrate 01 is preferably selected as a PET polyester film, and the selected ink or coating containing magnetic pigments is a UV-type ink or coating containing magnetic pigments, and its viscosity is 500 Pascals per second. When making the printing plate and setting the parameters of the multicolor printing machine, the mesh size of the engraved plate is 250 mesh / cm², the depth of the engraved plate is 30 micrometers to 50 micrometers, and the thickness of the printed ink layer is controlled between 6 micrometers and 8 micrometers;

[0071] Step 3: Printing, specifically including:

[0072] Step 3.1: Place the substrate 01 selected in Step 2 on the unwinding rack of the unwinding device 1 of the multi-color printing press in the multi-view magnetic anti-counterfeiting image printing system that has been prepared in Step 2.

[0073] Step 3.2: Start the multi-color printing press, each magnetic roller 7 and each magnetic orientation and shaping device 6 in the printing system of the multi-view magnetic anti-counterfeiting image that has been prepared in step 2. The import device 2 imports the substrate 01 placed on the unwinding rack in step 3.1 from the unwinding device 1 into the input end of the printing device 3. During the import process, the correction mechanism in the import device 2 corrects the substrate 01 in real time.

[0074] Step 3.3: The multiple printing color groups in the printing device 3 are printed one by one on the substrate 01 introduced in step 3.2. After each color is printed, it passes through the magnetic roller 7 and the magnetic orientation and shaping device 6 set between the printing roller 31 and the printing output roller in the printing color group to activate, magnetically orient and magnetically shape the magnetic pigment in the ink coating of that color until the magnetic orientation and magnetic shaping of the last color are completed, so that a multi-view magnetic anti-counterfeiting image is printed on the substrate 01.

[0075] Step 3.4: The export device 4 exports the substrate 01 with the multi-view magnetic anti-counterfeiting image printed in step 3.3 from the output end of the printing device 3 to the winding device 5. During the export process, the correction mechanism in the export device 4 corrects the substrate 01 in real time.

[0076] Step 3.5: The winding device 5 winds up the substrate 01 printed with the multi-view magnetic anti-counterfeiting image exported in step 3.4 in real time, and obtains a product containing the multi-view magnetic anti-counterfeiting image, thus completing the printing.

[0077] Table 1 below compares the relevant parameters when the magnetic orientation device and magnetic shaping device are used together with a screen printing machine, a coating machine, and a multi-color letterpress / flexographic / gravure printing machine for printing magnetic anti-counterfeiting images.

[0078] Table 1:

[0079]

[0080]

[0081] As shown in Table 1 above, when using the magnetic orientation device and magnetic shaping device with a multi-color letterpress / flexographic / gravure printing press for magnetic anti-counterfeiting image printing, compared to using them with a screen printing press and a coating machine, the ink layer is thinnest and the viscosity of the ink containing magnetic pigments is lowest (except for multi-color letterpress printing presses). This results in the highest achievable magnetic turning rate, the fastest magnetic rotation speed, and ink consumption only in the printing section. Therefore, using the multi-view magnetic anti-counterfeiting image printing system and method of this invention not only produces better anti-counterfeiting images but also saves ink and is more economical. Experiments have verified that when a multi-color gravure printing press is used, controlling the engraving depth to 30-50 micrometers, controlling the ink layer thickness to 6-8 micrometers, and selecting an ink containing magnetic pigments with a viscosity of 500 Pascal-second yields the best multi-view magnetic anti-counterfeiting image effect.

[0082] In summary, the printing system and method using the multi-view magnetic anti-counterfeiting image of this invention achieve magnetic shaping during printing without the need for machine downtime, significantly improving printing speed. Furthermore, when using a multi-color gravure printing machine, there is no ghosting problem, enabling precise registration with extremely high registration accuracy.

Claims

1. A printing system for multi-view magnetic anti-counterfeiting images, characterized in that: It includes a multicolor printing press, multiple magnetic rollers (7) and multiple magnetic orientation and shaping devices (6); The multicolor printing press includes an unwinding device (1), an inlet device (2), a printing device (3), an outlet device (4), and a rewinding device (5) connected in sequence. The unwinding device (1) is used to place the substrate (01) to be printed; the inlet device (2) is used to inlet the substrate (01) to be printed from the unwinding device (1) into the input end of the printing device (3); the printing device (3) includes multiple printing color groups for multi-color printing on the substrate (01); the outlet device (4) is used to outlet the printed substrate (01) from the output end of the printing device (3) to the rewinding device (5); the rewinding device (5) is used to rewind the outlet printed substrate (01) in real time. Both the import device (2) and the export device (4) are equipped with a correction mechanism for real-time correction of the substrate (01); In each of the printing color groups, one or more magnetic rollers (7) are respectively provided on the front and / or back of the printing surface of the substrate (01) between the printing roller (31) and the printing output roller, for activating the magnetic pigments in the printed ink coating containing magnetic pigments. The number of magnetic orientation and shaping devices (6) is equal to the number of printing color groups; each magnetic orientation and shaping device (6) is respectively arranged in a corresponding manner between the magnetic roller (7) and the printing output roller in each printing color group; each magnetic orientation and shaping device (6) includes an independent magnetic orientation device (61) and a magnetic shaping device (62), and the independent magnetic orientation device (61) and magnetic shaping device (62) are respectively located on opposite sides of the front and back sides of the printing surface at the same position on the substrate (01), and there is a gap between the two and the substrate (01); The magnetic orientation device (61) and magnetic shaping device (62) are used to magnetically orient and magnetically shape the magnetic pigments in the ink coating containing magnetic pigments, so as to print multi-view magnetic anti-counterfeiting images on the substrate (01).

2. The printing system for multi-view magnetic anti-counterfeiting images according to claim 1, characterized in that: The multicolor printing press can be a multicolor letterpress printing press, a multicolor flexographic printing press, or a multicolor gravure printing press.

3. The printing system for multi-view magnetic anti-counterfeiting images according to claim 2, characterized in that: A mask matching the multi-view magnetic anti-counterfeiting image pattern to be printed is provided between the magnetic shaping device (62) and the substrate (01) so as to achieve magnetic shaping only on the area that needs magnetic shaping.

4. The printing system for multi-view magnetic anti-counterfeiting images according to claim 2, characterized in that: The magnetic roller (7) includes a roller body (71) and a plurality of first magnets (72) irregularly spaced and embedded on the outer cylindrical surface of the roller body (71); The axis of rotation of the roller body (71) is perpendicular to the transmission path of the printing substrate (01) at its installation position; the roller body (71) is made of non-magnetic material; The plurality of first magnets (72) are used to form an irregular magnetic field to activate the magnetic pigments in the printed ink coating containing magnetic pigments.

5. The printing system for multi-view magnetic anti-counterfeiting images according to claim 4, characterized in that: The magnetic orientation device (61) is an orientation magnetic roller; The directional magnetic roller includes a magnetic roller body (611) and a second magnet group (612) embedded on the outer cylindrical surface of the magnetic roller body (611) and matching the multi-view magnetic anti-counterfeiting image pattern to be printed. The axis of rotation of the magnetic roller body (611) is perpendicular to the transmission path of the substrate (01) at its installation position; the magnetic roller body (611) is made of non-magnetic material; The second magnet group (612) is used to magnetically orient the magnetic pigments in the ink coating containing magnetic pigments printed on each area of ​​the substrate (01) according to the magnetic field direction required by the corresponding area on the multi-view magnetic anti-counterfeiting image to be printed, so as to obtain the visual effect required by the design.

6. The printing system for multi-view magnetic anti-counterfeiting images according to claim 5, characterized in that: The first magnet (72) and the second magnet group (612) both form a magnetic field through rare earth magnets, ferrites, rubber magnets, electromagnets or electromagnet groups; The magnetic shaping device (62) achieves magnetic shaping through one or more of the following methods: hot air, thermal curing, UV curing, and EB curing.

7. A method for printing multi-view magnetic anti-counterfeiting images, characterized in that, Includes the following steps: Step 1: Construct the printing system for the multi-view magnetic anti-counterfeiting image as described in claim 1; Step 2: According to the requirements of the product containing multi-view magnetic anti-counterfeiting images to be printed, select the substrate (01) and prepare the printing system of the multi-view magnetic anti-counterfeiting images built in Step 1 for pre-press preparation; during the pre-press preparation process, the viscosity of the selected ink coating containing magnetic pigments should be between 200 Pascals per second and 1200 Pascals per second, and when making the printing plate and setting the parameters of the multi-color printing machine, the following conditions should be met: control the thickness of the printing ink layer between 3 micrometers and 8 micrometers; Step 3: Printing, specifically including: Step 3.1: Place the substrate (01) selected in Step 2 on the unwinding rack of the unwinding device (1) of the multi-color printing machine in the multi-view magnetic anti-counterfeiting image printing system that has completed pre-press preparation in Step 2. Step 3.2: Start the multi-color printing press, each magnetic roller (7) and each magnetic orientation and shaping device (6) in the multi-view magnetic anti-counterfeiting image printing system that has completed the pre-printing preparation in Step 2. The import device (2) imports the substrate (01) placed on the unwinding rack in Step 3.1 from the unwinding device (1) into the input end of the printing device (3). During the import process, the correction mechanism in the import device (2) corrects the substrate (01) in real time. Step 3.3: The multiple printing color groups in the printing device (3) are printed one by one on the substrate (01) introduced in step 3.

2. After each color is printed, the magnetic roller (7) and magnetic orientation and shaping device (6) set between the printing roller (31) and the printing output roller in the printing color group are used to activate, magnetically orient and magnetically shape the magnetic pigment in the ink coating of that color until the magnetic orientation and magnetic shaping of the last color are completed, so that a multi-view magnetic anti-counterfeiting image is printed on the substrate (01). Step 3.4: The export device (4) exports the substrate (01) printed with the multi-view magnetic anti-counterfeiting image in step 3.3 from the output end of the printing device (3) to the winding device (5). During the export process, the correction mechanism in the export device (4) corrects the substrate (01) in real time. Step 3.5: The winding device (5) winds up the substrate (01) printed with multi-view magnetic anti-counterfeiting images exported in step 3.4 in real time to obtain a product containing multi-view magnetic anti-counterfeiting images and complete the printing.

8. The printing method for multi-view magnetic anti-counterfeiting images according to claim 7, characterized in that: In the multi-view magnetic anti-counterfeiting image printing system built in step 1, the multi-color printing machine is selected from multi-color letterpress printing machines, multi-color flexographic printing machines, or multi-color gravure printing machines.

9. The printing method for multi-view magnetic anti-counterfeiting images according to claim 7, characterized in that: In the multi-view magnetic anti-counterfeiting image printing system built in step 1, the multi-color printing machine is a multi-color gravure printing machine, and the magnetic shaping device (62) achieves magnetic shaping by combining one or more of hot air, heat curing, UV curing, and EB curing. In step 2, the selected substrate (01) is PET polyester film, PC film, PVC heat shrink film, PP film or PE film; the selected ink coating containing magnetic pigment is UV type ink coating containing magnetic pigment, solvent type ink coating containing magnetic pigment or water-based ink coating containing magnetic pigment; when making the printing plate, the mesh size of the engraving plate is 25 mesh / cm² to 350 mesh / cm², and the depth of the engraving plate is 10 micrometers to 100 micrometers.

10. The printing method of the multi-view magnetic anti-counterfeiting image according to claim 7, characterized in that: In the multi-view magnetic anti-counterfeiting image printing system built in step 1, the multi-color printing machine is a multi-color gravure printing machine, and the magnetic shaping device (62) achieves magnetic shaping by UV thermal curing, and the UV thermal curing uses a strobe light source. In step 2, the selected substrate (01) is a PET polyester film; the selected ink coating containing magnetic pigment is a UV-type ink coating containing magnetic pigment, and its viscosity is 500 Pascals per second; when making the printing plate and setting the parameters of the multicolor printing machine, the screen mesh of the engraving plate is 250 meshes / square centimeter, the depth of the engraving plate is 30 micrometers to 50 micrometers, and the thickness of the printed ink layer is controlled between 6 micrometers and 8 micrometers.

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