Plate making process of flexographic plate

Abstract

The invention discloses a plate-making process of a flexographic plate. The plate-making process comprises the following steps: S1, overlapping a base material to be exposed and a pattern plate, and placing the overlapped base material and pattern plate in an exposure machine; s2, the LED lamp panel is started at high power; s3, moving the LED lamp panel from the front end of the to-be-exposed substrate to the rear end of the to-be-exposed substrate in parallel; s4, the LED lamp panel waits in situ, and the power of the LED lamp panel is reduced; s5, when the color concentration of the color block is above the demarcation point, using amplitude modulation to change the size of the lattice points to express the depth of the image tone, and when the color concentration of the color block is below the demarcation point, using frequency modulation to change the distribution frequency of the lattice points in unit area to express the depth of the image tone; s6, the LED lamp panel is closed and reset, and the polymerization reaction of the to-be-exposed base material is finished; and S7, the printing plate conducts inspection type printing, the quality of a printed pattern is observed, mixed screening is achieved in a mode of combining amplitude modulation and frequency modulation, screen points are reinforced through a high-energy LED exposure machine, and therefore the high-line-number effect is achieved, and meanwhile the service life of the printing plate is guaranteed.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of flexographic printing, in particular to a flexographic printing plate making process. BACKGROUND

[0002] A flexographic printing plate is a type of printing plate used in flexographic printing, which belongs to the intaglio printing method. It is mainly made of photosensitive resin material and has good flexibility, which can be well attached to the curved printing cylinder to ensure the smooth progress of the printing process. For example, the flexographic printing plate can be elastically deformed under the pressure of the printing cylinder, thereby well adapting to various different printing surfaces.

[0003] The printing screen line (printing resolution) refers to a way to measure the resolution of a printed product, also known as screen line number or line number. It is represented by the number of screen lines arranged per unit length (usually per inch). These screen lines are actually composed of screen dots, which are the basic building blocks of printed images. In the printing process, a continuous tone image (such as a photograph) is broken down into many screen dots of different sizes through halftone technology. The size and distribution density of the screen dots determine the tone and clarity of the image. Higher screen line numbers mean more screen dots per unit length, which can represent finer image details and smoother tone transitions. This is because more screen dots can more accurately simulate different brightness and color levels in continuous tone images.

[0004] However, due to differences in the material of the flexographic printing plate, the performance of the printing machine, and the performance of the printing ink, too high a screen line number can cause the raised part of the printing plate to be too soft, making it impossible to perform normal printing work or having a very short service life. At a certain screen dot value, there is a clear dividing point on the printed product, i.e. above the dividing point, the printed product can be normally printed, while below the dividing point, the details of the image will be lost and the tone reproduction will be inaccurate. Therefore, the conventional screen line number of a flexographic printing plate is generally between 100-150 lines / inch, so it is difficult to apply it to high-quality printed products such as books, magazines, newspapers, etc. that can provide clear text and high-quality image printing. SUMMARY

[0005] In order to overcome the shortcomings of the prior art, the present application provides a flexographic printing plate making process.

[0006] The technical scheme adopted by the present application to solve its technical problems is: A flexographic printing plate making process, comprising the following steps: S1 installing the substrate: overlapping the substrate to be exposed and the pattern plate and placing them in the exposure machine; S2 starting the device: starting the exposure machine and starting the LED lamp plate at high power; S3 plane scanning exposure: the LED lamp plate is moved in parallel from the front end of the substrate to be exposed to the rear end of the substrate to be exposed; S4 oxygen barrier layer forming: the LED lamp plate waits in place and reduces its power; S5 plate making exposure: the color density of the color block is above the demarcation point, the size of the dot is changed using amplitude modulation to express the depth of the image tone, and the color density of the color block is below the demarcation point, the distribution frequency of the dot in the unit area is changed using frequency modulation to express the depth of the image tone; S6 exposure end: the LED lamp plate is turned off and reset, and waits for the polymerization reaction of the substrate to be exposed to end; S7 printing inspection: the printing plate is subjected to test printing and the printing pattern quality is observed.

[0007] In the process S4, the LED lamp plate waits in place for 30 seconds to 2 minutes, waiting for the surface of the substrate to be exposed to cure an oxygen barrier layer due to polymerization reaction.

[0008] The thickness of the oxygen barrier layer is 1-10 mm.

[0009] In the S5 plate making exposure, the screen line number is 150-200 lines, the color density of the color block is below 10%-13% of the dot, the distribution frequency of the dot in the unit area is changed using frequency modulation to express the depth of the image tone, the screen line number is 200-250 lines, the color density of the color block is below 14%-20% of the dot, and the distribution frequency of the dot in the unit area is changed using frequency modulation to express the depth of the image tone.

[0010] The beneficial effects of the present application are: the present application realizes hybrid screening by combining amplitude modulation and frequency modulation, and reinforces the dot by a high-energy LED exposure machine, thereby achieving high line number effect while ensuring the service life of the printing plate. BRIEF DESCRIPTION OF DRAWINGS

[0011] The present application will be further described below in conjunction with the drawings and examples.

[0012] Figure 1 is the process flow chart of the present application. DETAILED DESCRIPTION

[0013] To make the purpose, technical solutions and advantages of the present application clearer and more explicit, the present application will be further described in detail below in conjunction with specific embodiments and with reference to the drawings. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0014] It is understood that these descriptions are only exemplary and are not intended to limit the scope of the present application.

[0015] Some embodiments of the present application provide a method for manufacturing a flexographic printing plate.

[0016] Referring to Figure 1 A flexographic plate manufacturing process, comprising the following steps: S1 installing a substrate: placing the substrate to be exposed and the pattern plate in the exposure machine after superimposing them; S2 starting the device: starting the exposure machine, and starting the LED lamp plate at high power; S3 planar scanning exposure: moving the LED lamp plate from the front end of the substrate to be exposed to the rear end of the substrate to be exposed in parallel; S4 forming an oxygen barrier layer: the LED lamp plate waits in place and reduces its power; S5 plate manufacturing exposure: the color density of the color block is above the demarcation point, the size of the dot is changed using amplitude modulation to represent the depth of the image tone, and the color density of the color block is below the demarcation point, the distribution frequency of the dot in the unit area is changed using frequency modulation to represent the depth of the image tone; S6 exposure end: turning off the LED lamp plate and resetting it, and waiting for the polymerization reaction of the substrate to be exposed to end; S7 printing inspection: the printing plate is subjected to test printing, and the quality of the printed pattern is observed, and the inspection process is manually observed by the naked eye.

[0017] The present application realizes hybrid screening by combining amplitude modulation and frequency modulation, and reinforces the dot by using a high-energy LED exposure machine, so as to achieve a high-line-number effect while ensuring the service life of the printing plate In the present application, the substrate actually needs to be tested for the power of the LED lamp plate, the time and speed of planar scanning exposure according to different brands and different models, to ensure that the thickness of the oxygen barrier layer is accurate, so as to avoid that the printed template made during subsequent plate manufacturing exposure does not meet the requirements, similarly, the power of the LED lamp plate, the exposure time and the like required for the oxygen barrier layer of different thicknesses also need to be tested, that is, for a certain brand and a certain model of resin, if the printed template to be made is required to be flat, then a plurality of oxygen barrier layers of different thicknesses need to be made at the same time, and the power of the LED lamp plate, the time and speed of planar scanning exposure and the like are recorded, subsequently, the substrate to be exposed with different thicknesses of the oxygen barrier layer is subjected to different low-power plate manufacturing exposure, until it is tested that the power of the LED lamp plate is a certain power, the thickness of the oxygen barrier layer is a certain thickness, and the exposure time is a certain time, and the three conditions are met at the same time, the effect of the printed template is the best, then the power of the LED lamp plate corresponding to the oxygen barrier layer of the thickness, the time and speed of planar scanning exposure and the like are the planar scanning exposure parameters required by the printed template.

[0018] The LED lamp plate waits in place for 30 seconds to 2 minutes in the process S4, waiting for the surface of the to-be-exposed substrate to be cured by a layer of oxygen barrier layer due to polymerization reaction.

[0019] The thickness of the oxygen barrier layer is 1-10 millimeters.

[0020] In the plate-making exposure S5, the screen line number is 150-200 lines, the color block color density is 10%-13% or less of the screen dot, the frequency of the screen dot in the unit area is changed to express the depth of the image tone, the screen line number is 200-250 lines, the color block color density is 14%-20% or less of the screen dot, and the frequency of the screen dot in the unit area is changed to express the depth of the image tone.

[0021] The demarcation points of the color density of the color block are different for different printing materials (such as corrugated board, carton packaging, and plastic packaging), and therefore, the actual printing environment needs to be considered for adjustment.

[0022] In the present application, the term "a plurality of" refers to two or more, unless otherwise explicitly limited. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items. The terms "mounting", "connected", "connection", "fixed", and the like should be interpreted broadly, for example, "connection" can be fixed connection, detachable connection, or integrally connected; "connected" can be directly connected, or indirectly connected through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0023] It should be noted that when an element is referred to as "assembled to", "mounted to", "fixed to" or "provided to" another element, it can be directly on another element or there can be a middle element. When an element is considered to be "connected" to another element, it can be directly connected to another element or there can be a middle element. The terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation.

[0024] In the description of the present application, the terms "one embodiment", "some embodiments", "a specific embodiment" and the like are intended to mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present application, the illustrative description of the above terms does not necessarily mean the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0025] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A plate-making process for flexographic printing plates, characterized in that, The plate-making process includes the following steps: S1 Substrate Mounting: Place the substrate to be exposed and the pattern plate overlapping inside the exposure machine; S2 Start-up Equipment: Starts the exposure machine; LED light board starts at high power. S3 planar scanning exposure: The LED light board moves parallel to the front end of the substrate to be exposed to the rear end of the substrate; S4 oxygen barrier layer forming: The LED light board is left in place and its power is reduced; S5 plate making exposure: When the color density of the color block is above the dividing point, amplitude modulation is used to change the size of the halftone dots to represent the depth of the image tone. When the color density of the color block is below the dividing point, frequency modulation is used to change the distribution frequency of the halftone dots per unit area to represent the depth of the image tone. S6 Exposure complete: Turn off the LED light panel and reset it, and wait for the polymerization reaction of the substrate to be exposed to complete; S7 Printing Inspection: The printing plate is inspected during printing, and the quality of the printed pattern is observed.

2. The plate-making process for flexographic printing plates according to claim 1, characterized in that, In step S4, the LED light board waits in place for 30 seconds to 2 minutes, allowing the surface of the substrate to be exposed to solidify an oxygen barrier layer due to the polymerization reaction.

3. The plate-making process for flexographic printing plates according to claim 2, characterized in that... The thickness of the oxygen barrier layer is 1-10 mm.

4. The plate-making process for flexographic printing plates according to claim 1, characterized in that, In the S5 plate-making exposure, for halftone dots with a screen ruling of 150-200 lines and a color density of 10%-13% or less, frequency modulation is used to change the distribution frequency of halftone dots per unit area to represent the depth of the image tone. For halftone dots with a screen ruling of 200-250 lines and a color density of 14%-20% or less, frequency modulation is used to change the distribution frequency of halftone dots per unit area to represent the depth of the image tone.

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