A printing method and printing equipment

Abstract

This invention relates to the field of printing technology and discloses a printing method and printing equipment. The printing method includes a printing process control method, which includes: monitoring the thickness of the dry ink layer after the printed material passes through a drying and curing device to obtain a dry ink layer thickness monitoring value; and adjusting the linear speed of the anilox roller and / or the flat rubber roller based on the dry ink layer thickness monitoring value and the target dry ink layer thickness value. In this invention, the ink layer printed on the surface of the printed material is a planar ink layer. By monitoring the thickness of the planar dry ink layer after drying and curing, it is possible to directly determine whether the dry ink layer thickness of the printed material meets the requirements. If the dry ink layer thickness of the printed material does not meet the requirements, the dry ink layer thickness of subsequent printed materials can be quickly and timely adjusted, thereby effectively reducing the time required for adjusting the dry ink layer thickness, improving production efficiency and the pass rate of printed materials, and reducing ink consumption while improving drying efficiency.

Description

Technical Field

[0001] This invention relates to the field of printing technology, and in particular to a printing method and printing equipment. Background Technology

[0002] Flexographic printing is an important component of flexible packaging. Flexographic printing presses mainly consist of a printing plate, an anilox roller, and a bottom roller. Current flexographic solid printing involves laser-engraving (or other methods) dots of varying line counts onto the printing plate. After passing through an inking and doctor blade, the anilox roller transfers the ink from the cells on its surface to the printing plate. The ink dots on the printing plate are then transferred to the substrate surface, creating a solid print. This type of printing using an anilox roller results in ink on the substrate surface composed of countless dots, each dot resembling a small hill, with gaps between adjacent dots. Flexographic printing presses are widely used because they use pure water-based inks with no VOC emissions. However, this method also results in higher power consumption during drying. Essentially, flexographic printing is dot-matrix printing. In solid prints (both surface and reverse), gaps exist between the dots on the printed surface. One indicator of a successful solid print is its light-blocking power. To reduce these gaps and improve light-blocking power, the screen count of the printing roller is increased. However, while increasing the screen count reduces the gaps, it also thins the dots, thus decreasing light-blocking power. Conversely, a lower screen count leads to larger gaps, sometimes requiring a second solid print to improve light-blocking power. Furthermore, in full-page solid printing, the resulting solid areas are formed by small hills of ink dots, reducing drying efficiency and impacting overall machine productivity. This can even result in a surface that is dry while the interior remains wet, affecting product quality.

[0003] Therefore, there is an urgent need for a printing method and printing equipment to solve the above problems. Summary of the Invention

[0004] The purpose of this invention is to provide a printing method and printing equipment that can quickly and timely adjust the dry ink layer thickness of subsequent printed materials when the dry ink layer thickness of the printed material does not meet the requirements, thereby effectively reducing the time required for adjusting the dry ink layer thickness of the printed material, improving production efficiency and the pass rate of printed materials.

[0005] To achieve this objective, the present invention adopts the following technical solution: A printing method includes a printing process control method; the printing process control method includes: The thickness of the dry ink layer after the printed matter has passed through the drying and curing device is monitored to obtain the dry ink layer thickness monitoring value; The linear speed of the anilox roller and / or flat roller is adjusted based on the monitored dry ink layer thickness and the target dry ink layer thickness.

[0006] As an improvement to the above technical solution, the step of adjusting the linear speed of the anilox roller and / or the flat roller based on the monitored dry ink layer thickness and the target dry ink layer thickness includes: If the measured dry ink layer thickness is greater than the target dry ink layer thickness, the linear speed of the anilox roller is reduced; if the measured dry ink layer thickness is less than the target dry ink layer thickness, the linear speed of the anilox roller is increased. The linear speed of the anilox roller shall not exceed the linear speed of the flat rubber roller.

[0007] As an improvement to the above technical solution, a method for determining printing parameters is also included; the method for determining printing parameters includes: Determine the target dry ink layer thickness based on the functional specifications of the target printed material; The target wet ink layer thickness value is determined based on the target dry ink layer thickness and printing ink parameters; Based on the printing ink parameters, the target wet ink layer thickness, the ink transfer coefficient between the anilox roller and the flat rubber roller, and the ink transfer coefficient between the flat rubber roller and the printed matter, the ink load of the anilox roller, the expected linear speed of the anilox roller, and the expected linear speed of the flat rubber roller are determined. The expected linear speed of the anilox roller is less than the expected linear speed of the flat rubber roller.

[0008] As an improvement to the above technical solution, the printing parameter determination method further includes: determining the first expected rotation speed of the anilox roller based on the expected linear velocity of the anilox roller, and determining the second expected rotation speed of the flat rubber roller based on the expected linear velocity of the flat rubber roller.

[0009] As an improvement to the above technical solution, the printing process control method further includes: using a first expected rotational speed as the initial rotational speed of the anilox roller and a second expected rotational speed as the initial rotational speed of the flat rubber roller.

[0010] As an improvement to the above technical solution, the printing ink parameters include solid content, volume ratio, and viscosity.

[0011] A printing apparatus that uses the printing method described in any of the preceding claims.

[0012] As an improvement to the above technical solution, the printing equipment includes an anilox roller, a flat rubber roller, a bottom roller, a drying and curing device, and an ink layer detection sensor; The anilox roller and the flat rubber roller are arranged opposite to each other. The anilox roller is used to supply ink to the flat rubber roller. The flat rubber roller and the bottom roller are arranged opposite to each other. The flat rubber roller and the bottom roller cooperate to print on the printed matter. The drying and curing device is used to dry and cure the printed matter after it has been printed by the flat rubber roller. The ink layer detection sensor is used to detect the thickness of the dry ink layer on the surface of the printed matter after it has been dried and cured by the drying and curing device.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: The printing method and equipment of this invention employ a flat rubber roller without halftone dots to perform solid printing on the printed matter. By controlling the linear speed difference between the anilox roller and the flat rubber roller, the ink layer thickness transferred from the anilox roller to the flat rubber roller is controlled, thereby controlling the ink layer thickness transferred from the flat rubber roller to the printed matter. This results in a uniformly thick flat ink layer printed on the surface of the printed matter, ensuring sufficient light-blocking power while reducing ink consumption and improving drying efficiency. Furthermore, by real-time monitoring of the dry ink layer (i.e., the flat dry ink layer) thickness after the printed matter passes through the drying and curing device, a dry ink layer thickness monitoring value can be obtained. Based on the comparison between the dry ink layer thickness monitoring value and the target dry ink layer thickness value, the linear speed of the anilox roller and / or the flat rubber roller is adjusted to adjust the linear speed difference between the anilox roller and the flat rubber roller, thereby adjusting the ink transfer coefficient between the anilox roller and the flat rubber roller, and further adjusting the dry ink layer thickness on the surface of the subsequently printed matter, ensuring that the dry ink layer thickness on the surface of the printed matter meets the requirements. The printing method and printing equipment of the present invention produce a planar ink layer on the surface of the printed matter. By monitoring the thickness of the planar dry ink layer after the surface of the printed matter has dried and cured, it is possible to directly determine whether the thickness of the dry ink layer of the printed matter meets the requirements. When the thickness of the dry ink layer of the printed matter does not meet the requirements, the thickness of the dry ink layer of subsequent printed matter can be adjusted quickly and timely, thereby effectively reducing the time required for adjusting the thickness of the dry ink layer of the printed matter, improving production efficiency and the pass rate of printed matter. Attached Figure Description

[0014] Figure 1 This is a flowchart of the printing process control method provided in the embodiments of the present invention; Figure 2 This is a flowchart of the printing parameter determination method provided in the embodiments of the present invention; Figure 3 This is a schematic diagram of a portion of the structure of the printing equipment provided in an embodiment of the present invention.

[0015] In the picture: 1. Anilox roller; 2. Flat rubber roller; 3. Bottom roller; 4. Drying and curing device; 5. Ink layer detection sensor; 6. Doctor blade; 7. Ink receiving tray; 100. Printed materials. Detailed Implementation

[0016] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0017] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0018] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0019] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0020] like Figure 1 As shown, this embodiment provides a printing method, for example, for solid-color printing. The printing method includes a printing process control method; the printing process control method includes: monitoring the thickness of the dry ink layer after the printed matter 100 passes through the drying and curing device 4, and obtaining a dry ink layer thickness monitoring value; adjusting the linear speed of the anilox roller 1 and / or the flat rubber roller 2 according to the dry ink layer thickness monitoring value and the target dry ink layer thickness value, thereby adjusting the linear speed difference between the anilox roller 1 and the flat rubber roller 2.

[0021] In this embodiment, the flat rubber roller 2 refers to a rubber roller without dots.

[0022] The printing method provided in this embodiment uses a flat rubber roller 2 without halftone dots to perform solid printing on the printed matter 100. By controlling the difference in linear speed between the anilox roller 1 and the flat rubber roller 2, the ink layer thickness transferred from the anilox roller 1 to the flat rubber roller 2 is controlled, thereby controlling the ink layer thickness transferred from the flat rubber roller 2 to the printed matter 100. This results in a flat ink layer of uniform thickness being printed on the surface of the printed matter 100, ensuring that the light-blocking force meets the requirements while reducing the amount of ink used and improving the drying efficiency. Furthermore, by real-time monitoring of the dry ink layer (i.e., the planar dry ink layer) thickness of the printed matter 100 after passing through the drying and curing device 4, the dry ink layer thickness monitoring value can be obtained. Based on the comparison result between the dry ink layer thickness monitoring value and the target dry ink layer thickness value, the linear speed of the anilox roller 1 and / or the planar rubber roller 2 is adjusted to adjust the linear speed difference between the anilox roller 1 and the planar rubber roller 2, thereby adjusting the ink transfer coefficient between the anilox roller 1 and the planar rubber roller 2, and further adjusting the dry ink layer thickness on the surface of the subsequently printed matter 100 until the dry ink layer thickness on the surface of the printed matter 100 meets the requirements. The printing method provided in this embodiment prints a planar ink layer on the surface of the printed matter 100. By monitoring the thickness of the planar dry ink layer after the printed matter 100 has dried and cured, it is possible to directly determine whether the thickness of the dry ink layer of the printed matter 100 meets the requirements. If the thickness of the dry ink layer of the printed matter 100 does not meet the requirements, it can be detected in time, and the thickness of the dry ink layer of the subsequent printed matter 100 can be adjusted quickly and timely. This effectively reduces the time required for adjusting the thickness of the dry ink layer of the printed matter 100, improves production efficiency, and increases the pass rate of the printed matter 100.

[0023] The ink transfer coefficient between the anilox roller 1 and the flat rubber roller 2 is usually between 0.4 and 0.7, and adjusting the difference in linear speed between the anilox roller 1 and the flat rubber roller 2 can change the transfer coefficient.

[0024] Furthermore, based on the monitored dry ink layer thickness and the target dry ink layer thickness, the difference in linear speed between the anilox roller 1 and the flat rubber roller 2 is adjusted. This includes: if the monitored dry ink layer thickness is greater than the target dry ink layer thickness, the linear speed of the anilox roller 1 is decreased; if the monitored dry ink layer thickness is less than the target dry ink layer thickness, the linear speed of the anilox roller 1 is increased; and if the monitored dry ink layer thickness is equal to the target dry ink layer thickness, the linear speed of the anilox roller 1 remains unchanged. The linear speed of the anilox roller 1 is not greater than the linear speed of the flat rubber roller 2, meaning that the adjusted linear speed of the anilox roller 1 cannot exceed the linear speed of the flat rubber roller 2.

[0025] Specifically, when the linear speed of the anilox roller 1 is less than the linear speed of the flat rubber roller 2, keeping the linear speed of the flat rubber roller 2 constant while decreasing the linear speed of the anilox roller 1 can correspondingly increase the linear speed difference between the anilox roller 1 and the flat rubber roller 2, thereby reducing the ink transfer coefficient between the anilox roller 1 and the flat rubber roller 2, and thus reducing the amount of ink transferred from the flat rubber roller 2 to the surface of the printed matter 100, and reducing the dry ink layer thickness of the printed matter 100. Conversely, keeping the linear speed of the flat rubber roller 2 constant while increasing the linear speed of the anilox roller 1 can correspondingly decrease the linear speed difference between the anilox roller 1 and the flat rubber roller 2, thereby increasing the ink transfer coefficient between the anilox roller 1 and the flat rubber roller 2, and thus increasing the amount of ink transferred from the flat rubber roller 2 to the surface of the printed matter 100, and increasing the dry ink layer thickness of the printed matter 100. Those skilled in the art will understand that the linear speed adjustment of the anilox roller 1 requires a short period of time, and after the printed matter 100 is printed by the flat rubber roller 2, it takes a certain amount of time to reach the dry ink layer thickness monitoring position. Therefore, after each adjustment of the linear speed of the anilox roller 1, it is necessary to wait for a first preset time before adjusting the linear speed difference between the anilox roller 1 and the flat rubber roller 2 according to the target dry ink layer thickness value and the new dry ink layer thickness monitoring value. The specific duration of the first preset time can be set as needed.

[0026] Furthermore, such as Figure 2 As shown, the printing method provided in this embodiment also includes a printing parameter determination method; the printing parameter determination method includes: determining the target dry ink layer thickness value based on the surface functional indicators of the target printed matter; determining the target wet ink layer thickness value based on the target dry ink layer thickness value and printing ink parameters; determining the ink loading of the anilox roller 1, the expected linear velocity of the anilox roller 1, and the expected linear velocity of the flat rubber roller 2 based on the printing ink parameters, the target wet ink layer thickness value, the ink transfer coefficient between the anilox roller 1 and the flat rubber roller 2, and the ink transfer coefficient between the flat rubber roller 2 and the printed matter 100, wherein the expected linear velocity of the anilox roller 1 is less than the expected linear velocity of the flat rubber roller 2. Specifically, in this embodiment, the printing ink parameters include solid content, volume ratio, and viscosity, etc. Those skilled in the art will understand that the target dry ink layer thickness value can be determined based on the functional indicators (such as light-blocking power) of the target printed matter through experiments or theoretical calculations. In this embodiment, the target dry ink layer thickness value corresponding to the functional indicators of the target printed matter is determined experimentally. After determining the ink load of the anilox roller 1, the selection of the anilox roller 1 or the structural design of the anilox roller 1 can be carried out according to the ink load of the anilox roller 1.

[0027] Furthermore, the method for determining printing parameters also includes: determining a first expected rotational speed of the anilox roller 1 based on its expected linear velocity, and determining a second expected rotational speed of the flat roller 2 based on its expected linear velocity. Those skilled in the art will understand that the linear velocity of the anilox roller 1 is equal to the product of its rotational speed and its circumference. Given the expected linear velocity of the anilox roller 1, the first expected rotational speed of the anilox roller 1 corresponding to its expected linear velocity can be determined based on the dimensions of the anilox roller 1. Similarly, the linear velocity of the flat roller 2 is equal to the product of its rotational speed and its circumference. Given the expected linear velocity of the flat roller 2, the second expected rotational speed of the flat roller 2 corresponding to its expected linear velocity can be determined based on the dimensions of the flat roller 2.

[0028] Furthermore, the printing process control method also includes: using a first expected rotation speed as the initial rotation speed of the anilox roller 1 and a second expected rotation speed as the initial rotation speed of the flat rubber roller 2, so that when the printing equipment starts printing, the thickness of the dry ink layer after the printed matter 100 is dried and cured by the drying and curing device 4 is as close as possible to or even equal to the target dry ink layer thickness value.

[0029] In other words, when the printing equipment starts printing, the first expected speed is taken as the initial speed of the anilox roller 1 and the second expected speed is taken as the initial speed of the flat rubber roller 2. After the printed matter 100 passes through the drying and curing device 4, the dry ink layer thickness monitoring value of the printed matter 100 obtained by the anilox roller 1 at the first expected speed and the flat rubber roller 2 at the second expected speed is detected. Then, the difference in linear speed between the anilox roller 1 and the flat rubber roller 2 is adjusted according to the dry ink layer thickness monitoring value and the target dry ink layer thickness value.

[0030] The printing method provided in this embodiment can be used not only with water-based inks, but also with other inks and adhesives, including but not limited to solvent-based inks, UV inks, solvent-free adhesives, dry laminating adhesives, and wet laminating adhesives. Furthermore, the printing method provided in this embodiment can be used for flexographic printing as well as gravure printing, etc. like Figure 3 As shown, this embodiment also provides a printing apparatus using the above-described printing method. The printing apparatus of this embodiment includes an anilox roller 1, a flat rubber roller 2, a bottom roller 3, a drying and curing device 4, and an ink layer detection sensor 5. The anilox roller 1 and the flat rubber roller 2 are arranged opposite to each other, and the anilox roller 1 supplies ink to the flat rubber roller 2. The flat rubber roller 2 and the bottom roller 3 are arranged opposite to each other, and the flat rubber roller 2 and the bottom roller 3 cooperate to print on the printed matter 100. The drying and curing device 4 is used to dry and cure the printed matter 100 after printing by the flat rubber roller 2. The ink layer detection sensor 5 is used to detect the dry ink layer thickness on the surface of the dried and cured printed matter 100 to obtain a dry ink layer thickness monitoring value.

[0031] Optionally, the printing equipment provided in this embodiment also includes a control system. The driving device of the anilox roller 1, the driving device of the flat rubber roller 2, the driving device of the bottom roller 3, the drying and curing device 4, and the ink layer detection sensor 5 are all connected to the control system. The control system can adjust the linear speed difference between the anilox roller 1 and the flat rubber roller 2 according to the dry ink layer thickness monitoring value and the target dry ink layer thickness value.

[0032] The printing equipment in this embodiment also includes a doctor blade 6 and an ink receiving tray 7. The doctor blade 6 is used to scrape off excess ink outside the cells of the anilox roller 1, retaining only the ink inside the cells to ensure the accuracy and consistency of ink transfer. The ink receiving tray 7 is located below the anilox roller 1 and the doctor blade 6, and is used to collect excess ink scraped off by the doctor blade 6 or thrown out by the anilox roller 1.

[0033] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present invention, and these improvements and substitutions should also be considered within the scope of protection of the present invention.

Claims

1. A printing method, characterized in that, Including printing process control methods; The printing process control method includes: The thickness of the dry ink layer of the printed matter (100) after passing through the drying and curing device (4) is monitored to obtain the dry ink layer thickness monitoring value; The linear speeds of the anilox roller (1) and / or the flat roller (2) are adjusted based on the dry ink layer thickness monitoring value and the target dry ink layer thickness value.

2. The printing method according to claim 1, characterized in that, The adjustment of the linear speed of the anilox roller (1) and / or the flat roller (2) based on the monitored dry ink layer thickness and the target dry ink layer thickness includes: If the measured dry ink layer thickness is greater than the target dry ink layer thickness, the linear speed of the anilox roller (1) is reduced. If the measured dry ink layer thickness is less than the target dry ink layer thickness, the linear speed of the anilox roller (1) is increased. The linear speed of the anilox roller (1) is not greater than the linear speed of the flat rubber roller (2).

3. The printing method according to claim 1, characterized in that, It also includes a method for determining printing parameters; the method for determining printing parameters includes: Determine the target dry ink layer thickness value based on the functional indicators of the target printed material; The target wet ink layer thickness value is determined based on the target dry ink layer thickness value and the printing ink parameters. Based on the printing ink parameters, the target wet ink layer thickness, the ink transfer coefficient between the anilox roller (1) and the flat rubber roller (2), and the ink transfer coefficient between the flat rubber roller (2) and the printed matter (100), the ink load of the anilox roller (1), the expected linear speed of the anilox roller (1), and the expected linear speed of the flat rubber roller (2) are determined. The expected linear speed of the anilox roller (1) is less than the expected linear speed of the flat rubber roller (2).

4. The printing method according to claim 3, characterized in that, The method for determining printing parameters further includes: determining the first expected rotation speed of the anilox roller (1) based on the expected linear velocity of the anilox roller (1), and determining the second expected rotation speed of the flat rubber roller (2) based on the expected linear velocity of the flat rubber roller (2).

5. The printing method according to claim 4, characterized in that, The printing process control method further includes: using a first expected rotation speed as the initial rotation speed of the anilox roller (1) and a second expected rotation speed as the initial rotation speed of the flat roller (2).

6. The printing method according to claim 3, characterized in that, The printing ink parameters include solid content, volume ratio, and viscosity.

7. A printing apparatus, characterized in that, Use the printing method according to any one of claims 1-6.

8. The printing equipment according to claim 7, characterized in that, It includes an anilox roller (1), a flat rubber roller (2), a bottom roller (3), a drying and curing device (4), and an ink layer detection sensor (5); The anilox roller (1) is arranged opposite to the flat rubber roller (2). The anilox roller (1) is used to supply ink to the flat rubber roller (2). The flat rubber roller (2) is arranged opposite to the bottom roller (3). The flat rubber roller (2) and the bottom roller (3) cooperate to print on the printed matter (100). The drying and curing device (4) is used to dry and cure the printed matter (100) after it has been printed by the flat rubber roller (2). The ink layer detection sensor (5) is used to detect the thickness of the dry ink layer on the surface of the printed matter (100) after it has been dried and cured by the drying and curing device (4).

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