Method and matched equipment for printing multi-color hidden and color-changing anti-counterfeiting information

Abstract

The invention relates to a method and matched equipment for printing multi-color hidden and color-changing anti-fake information. The printing method comprises the steps that preparation work is conducted; printing multi-color hidden anti-counterfeiting information printing ink; performing infrared constant-temperature semi-curing; printing color-changing anti-counterfeiting information printing ink; and the UV curing lamp group completes curing. The matched equipment comprises a silk-screen printing platform, and a first silk-screen printing unit, an infrared constant-temperature box, a second silk-screen printing unit and a UV curing lamp box which are sequentially arranged on the platform in the paper conveying direction; the first silk-screen printing unit is used for printing a multi-color hidden anti-fake information ink layer, and the second silk-screen printing unit is used for printing a color-changing anti-fake information ink layer on the first ink layer. By simplifying the continuous silk-screen printing and curing process, continuous superposition printing of multi-color hidden anti-fake information and color-changing anti-fake information is successfully achieved, the anti-fake efficiency of printed matter is remarkably improved, and meanwhile the visual effect of the printed matter is enhanced.

Description

Technical Field

[0001] This invention belongs to the field of printing technology, specifically relating to a method and supporting equipment for printing multi-color hidden and color-changing anti-counterfeiting information. Background Technology

[0002] In today's anti-counterfeiting field, anti-counterfeiting materials face a dilemma: on the one hand, anti-counterfeiting features easily identifiable by consumers are often easily counterfeited by criminals; on the other hand, while materials with higher anti-counterfeiting levels offer high security, the detection process is complex and difficult for ordinary consumers to operate. However, multi-color hidden and color-changing anti-counterfeiting information printing technology cleverly balances these two aspects. It possesses both the characteristics of being easily identifiable by consumers and high anti-counterfeiting properties, making it difficult to counterfeit. Consumers only need to use simple tools, such as ultraviolet or infrared lamps, or change the viewing angle under natural light, to intuitively identify the anti-counterfeiting information.

[0003] However, achieving this multi-color hidden and color-changing anti-counterfeiting information printing is not easy; it requires a combination of inks with multiple effects, including "multi-band hiding and color changing." To fully present this anti-counterfeiting information graphic effect, sufficient ink layer buildup is necessary, generally requiring a thickness of at least 20μm. Otherwise, the effect is not obvious and hinders detection and observation of anti-counterfeiting measures. Existing conventional printing methods all have different limitations in meeting this requirement. For example, offset printing typically has an ink layer thickness of only 5μm, which is too thin to meet the requirements for presenting multi-color hidden and color-changing anti-counterfeiting effects, and therefore is not suitable for this anti-counterfeiting technology. Flexographic printing has an ink layer thickness of approximately 8-10μm, and gravure printing has an ink layer thickness of approximately 12-15μm. Although these ink layers are relatively thick, they are still insufficient to present multi-color hidden and color-changing anti-counterfeiting effects alone, requiring two overprinting passes. This occupies at least four printing presses, increasing the occupancy rate of printing processes and equipment. Furthermore, gravure printing has high start-up costs and expensive plate-making fees, with a single plate costing over 50,000 yuan. It also requires a large amount of ink, at least 10 kg, making proofing costs extremely high. While screen printing can achieve ink layer thicknesses of over 25μm, making it suitable for printing multi-color hidden and color-changing anti-counterfeiting information, it can only print one type of ink at a time, requiring multiple printings to achieve the combined effect. Moreover, different inks require different screen printing plates, which not only increases the difficulty and number of steps in registration but also leads to higher scrap rates and longer printing cycles. Summary of the Invention

[0004] In view of the problems existing in the prior art, the present invention aims to provide a method and supporting equipment for printing multi-color hidden and color-changing anti-counterfeiting information. By improving screen printing equipment and combining it with the "multi-band hidden and color-changing" anti-counterfeiting information graphic color printing process, the present invention successfully expands the original screen printing process technology route. Through a single printing, the comprehensive application of multi-band hidden and color-changing anti-counterfeiting information graphics can be achieved, that is, multiple functions or effects can be completed in one printing.

[0005] To achieve the above objectives, the present invention provides a method for printing multi-color hidden and color-changing anti-counterfeiting information, comprising the following steps: (1) Preparation: Select appropriate multi-color hidden anti-counterfeiting information ink (colorless transparent ink that will show specific color changes when irradiated with ultraviolet or infrared lamps under specific conditions, such as colorless to colored, or silver to red, blue, etc.), color-changing anti-counterfeiting information ink (which will show color changes under specific conditions, such as purple to green, blue to purple, etc.) and corresponding screen printing plates, and adjust the parameters of the printing equipment (such as the pressure, angle and speed of the doctor blade, the temperature, power and curing time of the infrared constant temperature box and UV curing lamp box, etc.). (2) Printing multi-color hidden anti-counterfeiting information ink: Start the first screen printing unit, transport the paper to the printing position, and the doctor blade evenly scrapes the multi-color hidden anti-counterfeiting information ink onto the paper; at this time, the ink on the paper has not yet solidified and appears transparent or semi-transparent. (3) Infrared constant temperature semi-curing: Paper printed with multi-color hidden anti-counterfeiting information ink is put into an infrared constant temperature box. The infrared constant temperature box heats the ink through infrared radiation to make it reach a semi-cured state. At this time, the semi-cured ink has a certain adhesion, but it has not been completely cured, which is convenient for subsequent printing operations. (4) Printing color-changing anti-counterfeiting information ink: Start the second screen printing unit, and transport the paper that has been treated with infrared constant temperature curing to the printing position. The doctor blade will evenly scrape the color-changing anti-counterfeiting information ink onto the semi-cured multi-color hidden anti-counterfeiting information ink. At this time, the ink on the paper is not yet fully cured. (5) UV curing lamp assembly completes curing: Paper printed with color-changing anti-counterfeiting ink enters the UV curing lamp box. The UV curing lamp irradiates the ink with ultraviolet light, causing it to cure quickly, resulting in printed materials with multi-color hidden and color-changing anti-counterfeiting information. The ink of this printed material has good adhesion and abrasion resistance, while maintaining the integrity and functionality of the anti-counterfeiting information.

[0006] Furthermore, in step (1), the mesh size of the screen printing plate is selected according to the particle size of the ink; a 160-200 mesh screen printing plate is used for multi-color hidden anti-counterfeiting information printing to ensure that enough microcapsules leak down to form a thicker ink layer; a 250-350 mesh screen printing plate is used for color-changing anti-counterfeiting information printing to ensure the neatness of the printing edges.

[0007] Furthermore, in step (3), the temperature of the infrared constant temperature chamber is 60-80℃ and the semi-curing time is 1-3 seconds.

[0008] Furthermore, in step (5), the power of the UV curing lamp box is 80-120W / cm and the curing time is 1-3 seconds.

[0009] To achieve the above objectives, the present invention also provides supporting equipment for the above-mentioned method of printing multi-color hidden and color-changing anti-counterfeiting information, including a screen printing platform, and a first screen printing unit, an infrared constant temperature chamber, a second screen printing unit, and a UV curing light box arranged sequentially along the paper conveying direction on the platform; the first screen printing unit is used to print the multi-color hidden anti-counterfeiting information ink layer, the second screen printing unit is used to print the color-changing anti-counterfeiting information ink layer on the first ink layer; the infrared constant temperature chamber is used for the semi-curing of the multi-color hidden anti-counterfeiting information ink; and the UV curing light box is used for the final curing of the two ink layers.

[0010] Furthermore, the screen printing plates of the first screen printing unit and the second screen printing unit are selected as 160-200 mesh and 250-350 mesh, respectively.

[0011] Furthermore, both the first and second screen printing units are equipped with screen printing plates, squeegees, suction platforms, registration inspection photoelectric sensors, and registration positioning blocks.

[0012] Furthermore, the registration inspection photoelectric sensor is installed on the frame on the paper feeding side of the screen printing unit, and the registration positioning block is retractably installed on the screen printing platform at the paper output end of the screen printing unit. The registration inspection photoelectric sensor and the registration positioning block are connected by a data connection cable to achieve linkage control. The two work together to ensure the precise alignment of the paper between different printing stations.

[0013] Furthermore, the alignment and positioning block consists of two L-shaped blocks arranged opposite each other.

[0014] The beneficial effects of this invention are: (1) The printing method of the present invention simplifies the continuous screen printing and curing process, and successfully achieves continuous superposition printing of multi-color hidden anti-counterfeiting information and color-changing anti-counterfeiting information, significantly improving the anti-counterfeiting effectiveness of printed products. At the same time, the product has a visual effect, showing unique color changes under different viewing angles, thereby improving market competitiveness. In addition, the method has high production efficiency and strong flexibility and scalability, which can adapt to diverse printing needs, further expanding the application scope and bringing significant economic benefits to enterprises.

[0015] (2) The supporting equipment of this invention, through the cooperation of two screen printing units with an infrared constant temperature chamber and a UV curing lamp box, realizes the continuous superposition printing of multi-color hidden anti-counterfeiting information and color-changing anti-counterfeiting information, making the printed products have higher anti-counterfeiting performance and difficult to counterfeit. At the same time, through the coordinated work of the registration inspection photoelectric eye and the registration positioning block, the precise alignment of the paper between different printing stations is ensured, which greatly improves the printing accuracy, reduces the scrap rate in the printing process, reduces the consumption of raw materials and energy, and thus reduces production costs. The automated conveying and curing system reduces manual intervention, enhances the degree of production automation, and improves efficiency. The high adaptability of the equipment enables it to meet diverse printing needs, such as anti-counterfeiting and decorative printing, expanding the scope of application. Attached Figure Description

[0016] Figure 1 This is a flowchart of a method for printing multi-color hidden and color-changing anti-counterfeiting information according to the present invention; Figure 2 This is a front view of a supporting equipment for printing multi-color hidden and color-changing anti-counterfeiting information according to the present invention; Figure 3 yes Figure 2 Top view of the positioning block; In the diagram: 1-Screen printing platform, 2-First screen printing unit, 3-Second screen printing unit, 4-Infrared constant temperature chamber, 5-UV curing light box, 201 / 301-Screen printing plate, 202-Multi-color hidden anti-counterfeiting information ink, 302-Color-changing anti-counterfeiting information ink, 203 / 303-Squeegee, 204 / 304-Alignment inspection photoelectric sensor, 205 / 305-Suction platform, 206 / 306-Data connection cable, 207 / 307-Alignment positioning block. Detailed Implementation

[0017] To make the technical problems and solutions solved by the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention. Example 1

[0018] like Figure 1As shown, this embodiment provides a method for printing multi-color hidden and color-changing anti-counterfeiting information, including the following steps: (1) Preparation: Select appropriate multi-color hidden anti-counterfeiting ink (colorless transparent ink that will show specific color changes when irradiated with ultraviolet or infrared lamps under specific conditions, such as colorless to colored, or silver to red, blue, etc.), color-changing anti-counterfeiting ink (which will show color changes under specific conditions (such as light change, temperature change, or changing the viewing angle), such as purple to green, blue to purple, etc.) and corresponding screen printing plates (for multi-color hidden anti-counterfeiting ink printing, use 160-200 mesh screen printing plates to ensure sufficient microcapsules leak down and form a thicker ink layer; for color-changing anti-counterfeiting ink printing, use 250-350 mesh screen printing plates to ensure neat printing edges), and install them on the corresponding screen printing unit. Further adjust the parameters of the printing equipment (such as the pressure, angle and speed of the doctor blade, the temperature, power and curing time of the infrared constant temperature box and UV curing lamp box, etc.). (2) Printing multi-color hidden anti-counterfeiting information ink: Start the first screen printing unit, transport the paper to the printing position, and the doctor blade evenly scrapes the multi-color hidden anti-counterfeiting information ink onto the paper; at this time, the ink on the paper has not yet solidified and appears transparent or semi-transparent. (3) Infrared constant temperature semi-curing: Paper printed with multi-color hidden anti-counterfeiting information ink enters the infrared constant temperature box. The infrared constant temperature box heats the ink through infrared radiation to make it reach a semi-cured state. At this time, the semi-cured ink has a certain adhesion, but it has not been completely cured, which is convenient for subsequent printing operations. During this process, the temperature of the infrared constant temperature box is 60-80℃ and the semi-curing time is 1-3 seconds.

[0019] (4) Printing color-changing anti-counterfeiting information ink: Start the second screen printing unit, and transport the paper that has been treated with infrared constant temperature curing to the printing position. The doctor blade will evenly scrape the color-changing anti-counterfeiting information ink onto the semi-cured multi-color hidden anti-counterfeiting information ink. At this time, the ink on the paper is not yet fully cured. (5) UV curing lamp assembly completes curing: Paper printed with color-changing anti-counterfeiting ink enters the UV curing lamp box. The UV curing lamp irradiates the ink with ultraviolet light, causing it to cure rapidly, resulting in printed materials with multi-color hidden and color-changing anti-counterfeiting information. The ink in this printed material has good adhesion and abrasion resistance, while maintaining the integrity and functionality of the anti-counterfeiting information. During this process, the power of the UV curing lamp box is 80-120W / cm, and the curing time is 1-3 seconds.

[0020] This invention successfully achieves continuous overlay printing of multi-color hidden anti-counterfeiting information and color-changing anti-counterfeiting information by combining screen printing and curing processes at two stations. This innovative method not only improves production efficiency but also reduces the complexity and potential errors in the printing process. The resulting printed products not only have excellent anti-counterfeiting properties but also greatly enrich the visual effect of the packaging, adding a unique competitive edge to the printed products.

[0021] The printing method described in this invention is not limited to printing multi-color hidden and color-changing anti-counterfeiting information. Its flexibility and scalability also allow for diverse printing effects by replacing or adjusting the lamp groups of the infrared constant temperature chamber and UV curing lamp box. For example, replacing the infrared constant temperature chamber lamp group with a UV mercury lamp group, or replacing the UV curing lamp box lamp group with a hammer pattern lamp group, can achieve combined and expanded applications of decorative effects + decorative effects (snowflake ink + hammer pattern ink), decorative effects + anti-counterfeiting effects (refractive effect + thermochromic ink), anti-counterfeiting effects + decorative effects (magnetic ink + ice flower effect), and anti-counterfeiting effects + anti-counterfeiting effects (fragrant ink + photochromic ink), producing printed materials with decorative effects and / or anti-counterfeiting functions. This design allows the same equipment to adapt to different printing needs, thereby greatly improving the efficiency and economic benefits of the equipment. Example 2

[0022] like Figure 2 As shown, this example provides supporting equipment for the above-mentioned method of printing multi-color hidden and color-changing anti-counterfeiting information, including a screen printing platform 1, and a first screen printing unit 2, an infrared constant temperature chamber 4, a second screen printing unit 3, and a UV curing light box 5 arranged sequentially along the paper conveying direction on the platform. The first screen printing unit 2 is used to print the multi-color hidden anti-counterfeiting information ink layer 202, and the second screen printing unit 3 is used to print the color-changing anti-counterfeiting information ink layer 302 on the first ink layer; the infrared constant temperature chamber 4 is used for the semi-curing of the multi-color hidden anti-counterfeiting information ink 202; and the UV curing light box 5 is used for the final curing of the two ink layers.

[0023] The screen printing plates 201 of the first screen printing unit 2 and the second screen printing unit 3 are selected with a mesh size of 160-200 and 250-350, respectively. The first screen printing unit 2, the infrared constant temperature chamber 4, the second screen printing unit 3, and the UV curing lamp box 5 are connected by a conveyor belt (which can be multi-segmented) to realize the transfer of paper. The specific settings of the conveyor belt can be flexibly adjusted according to the actual situation. This is a conventional technical means in this field and will not be described in detail here.

[0024] Both the first screen printing unit 2 and the second screen printing unit 3 are equipped with a screen printing plate 201, a doctor blade 203, a suction platform 205, a registration inspection photoelectric sensor 204, and a registration positioning block 207. The structure and placement of the screen printing plate 201, doctor blade 203, and suction platform 205 are existing technologies and will not be described in detail here. The registration inspection photoelectric sensor 204 and the registration positioning block 207 are new components. The registration inspection photoelectric sensor 204 is mounted on the frame on the paper feed side of the screen printing unit and is used to detect the registration marks or paper edge contours pre-printed on the paper; for example... Figure 3 As shown, the registration positioning blocks 207 are two L-shaped blocks arranged opposite each other, which are telescopically and symmetrically installed on the screen printing platform 1 on both sides of the paper output end of the screen printing unit. The registration inspection photoelectric sensor 204 and the registration positioning blocks 207 are connected by a data connection cable 206 to achieve linkage control, and are further connected to the printing press control system. The two work together to limit the paper position and ensure the precise alignment of the paper between different printing stations.

[0025] It should be noted that the first screen printing unit 2, the infrared constant temperature chamber 4, the second screen printing unit 3, the UV curing lamp box 5, and the registration inspection photoelectric sensor 204 (such as a CCD vision sensor) mentioned above can all be existing products currently available on the market. This application only involves the application of these devices and does not involve any improvement to their internal structure. The automatic telescopic drive mechanism of the registration positioning block 207 can adopt conventional mechanical mechanisms such as miniature cylinders, hydraulic cylinders, and electric push rods, and is equipped with a solenoid valve for precise control. The circuit connections and control logic between the conveyor belt, the registration inspection photoelectric sensor 204, the registration positioning block 207, and the suction platform 205 are all conventional settings and will not be described in detail here.

[0026] Working Principle: Multi-color hidden anti-counterfeiting ink and color-changing anti-counterfeiting ink, along with their corresponding screen printing plates, are installed on the first screen printing unit 2 and the second screen printing unit 3. The operating parameters of both units are adjusted. The conveyor belt is started to transport the paper forward. When the paper reaches the first screen printing unit 2, the registration inspection photocell 204 detects markings or edges on the paper using a visual sensor and sends a signal to the printing press's control system. The control system then controls the registration positioning block 207 to extend and lock the paper in position. Simultaneously, the linkage suction platform 205 starts synchronously, using negative pressure to hold the paper in place and prevent it from moving during printing. The first screen printing unit 2 operates, and the doctor blade 203 evenly applies the multi-color hidden anti-counterfeiting ink onto the paper.

[0027] After the multi-color hidden anti-counterfeiting information ink layer 202 is printed, the registration and positioning block 207 retracts, and the suction platform 205 stops adsorption simultaneously to ensure stable release of the paper. The conveyor belt sends the paper into the infrared constant temperature chamber 4, where the ink is heated by infrared radiation to reach a semi-cured state.

[0028] The paper is then sent to the second screen printing unit 3. The registration check photoelectric sensor 304 re-detects any markings or edges on the paper and sends a signal to the printing press's control system. The control system then extends the registration positioning block 307 to lock the paper in place. Simultaneously, the linkage suction platform 205 starts working, using negative pressure to hold the paper in place, ensuring precise alignment of the registration position when the paper is switched to the second printing station. The second screen printing unit 3 then begins operation, with the doctor blade 303 evenly applying the color-changing anti-counterfeiting ink onto the semi-cured multi-color hidden anti-counterfeiting ink layer 202.

[0029] After the color-changing anti-counterfeiting information ink is printed, the registration and positioning block 307 retracts, and the suction platform 305 stops adsorbing simultaneously to ensure stable release of the paper. The conveyor belt sends the paper into the UV curing light box 5, where the ink is irradiated with ultraviolet light to cure it quickly, resulting in a printed product with multi-color hidden and color-changing anti-counterfeiting information.

[0030] The supporting equipment described in this invention, through the cooperation of two screen printing units with an infrared constant temperature chamber and a UV curing lamp box, achieves continuous superposition printing of multi-color hidden anti-counterfeiting information and color-changing anti-counterfeiting information, giving the printed products higher anti-counterfeiting performance and making them difficult to counterfeit. Simultaneously, the coordinated operation of the registration inspection photoelectric sensor and registration positioning block ensures precise alignment of the paper between different printing stations, significantly improving printing accuracy, reducing the scrap rate during the printing process, and lowering the consumption of raw materials and energy, thereby reducing production costs.

[0031] The present invention has been described in detail above through specific and preferred embodiments. However, those skilled in the art should understand that the present invention is not limited to the embodiments described above. Any modifications, equivalent substitutions, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for printing multi-color hidden and color-changing anti-counterfeiting information, characterized in that, Includes the following steps: (1) Preparation: Select appropriate multi-color hidden anti-counterfeiting information ink, color-changing anti-counterfeiting information ink and corresponding screen printing plate, and adjust the parameters of the printing equipment; (2) Printing multi-color hidden anti-counterfeiting information ink: Start the first screen printing unit, transport the paper to the printing position, and the doctor blade evenly scrapes the multi-color hidden anti-counterfeiting information ink onto the paper; at this time, the ink on the paper has not yet solidified and appears transparent or semi-transparent. (3) Infrared constant temperature semi-curing: Paper printed with multi-color hidden anti-counterfeiting information ink is put into an infrared constant temperature chamber for semi-curing treatment. At this time, the semi-cured ink has a certain adhesion, but it has not been completely cured. (4) Printing color-changing anti-counterfeiting information ink: Start the second screen printing unit, and transport the paper that has been treated with infrared constant temperature curing to the printing position. The doctor blade will evenly scrape the color-changing anti-counterfeiting information ink onto the semi-cured multi-color hidden anti-counterfeiting information ink. At this time, the ink on the paper is not completely cured. (5) UV curing lamp assembly completes curing: Paper printed with color-changing anti-counterfeiting information ink enters the UV curing lamp box for final curing, resulting in printed products with multi-color hiding and color-changing anti-counterfeiting information.

2. The method for printing multi-color hidden and color-changing anti-counterfeiting information according to claim 1, characterized in that, In step (1), a 160-200 mesh screen is used for printing multi-color hidden anti-counterfeiting information ink, and a 250-350 mesh screen is used for printing color-changing anti-counterfeiting information ink.

3. The method for printing multi-color hidden and color-changing anti-counterfeiting information according to claim 1, characterized in that, In step (3), the temperature of the infrared constant temperature chamber is 60-80℃ and the semi-curing time is 1-3 seconds.

4. The method for printing multi-color hidden and color-changing anti-counterfeiting information according to claim 1, characterized in that, In step (5), the power of the UV curing lamp box is 80-120W / cm and the curing time is 1-3 seconds.

5. A set of equipment for a method of printing multi-color hidden and color-changing anti-counterfeiting information, characterized in that, The system includes a screen printing platform (1), and a first screen printing unit (2), an infrared constant temperature chamber (4), a second screen printing unit (3), and a UV curing light box (5) arranged sequentially on the platform along the paper conveying direction. The first screen printing unit (2) is used to print a multi-color hidden anti-counterfeiting information ink layer (202), and the second screen printing unit (3) is used to print a color-changing anti-counterfeiting information ink layer (302) on the first ink layer. The infrared constant temperature chamber (4) is used for the semi-curing of the multi-color hidden anti-counterfeiting information ink (202). The UV curing light box (5) is used for the final curing of the two ink layers.

6. The supporting equipment for a method of printing multi-color hidden and color-changing anti-counterfeiting information according to claim 5, characterized in that, The screen printing plates (201) of the first screen printing unit (2) and the second screen printing unit (3) are respectively selected as 160-200 mesh and 250-350 mesh.

7. The supporting equipment for a method of printing multi-color hidden and color-changing anti-counterfeiting information according to claim 5, characterized in that, The first screen printing unit (2) and the second screen printing unit (3) are each equipped with a screen printing plate (201), a doctor blade (203), a suction platform (205), a registration inspection photocell (204), and a registration positioning block (207).

8. The supporting equipment for a method of printing multi-color hidden and color-changing anti-counterfeiting information according to claim 7, characterized in that, The registration inspection photoelectric sensor (204) is installed on the frame on the paper feeding side of the screen printing unit. The registration positioning block (207) is telescopically installed on the screen printing platform (1) at the paper output end of the screen printing unit. The registration inspection photoelectric sensor (204) and the registration positioning block (207) are connected by a data connection line (206) to achieve linkage control. The two work together to ensure the precise alignment of the paper between different printing stations.

9. The supporting equipment for a method of printing multi-color hidden and color-changing anti-counterfeiting information according to claim 8, characterized in that, The alignment and positioning blocks (207) are two L-shaped blocks arranged opposite each other.

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