阅读说明：本技术 一种采用led光源的柔性版制版组合曝光方法 (Flexographic plate making combined exposure method adopting LED light source ) 是由 田全慧 陈浩粟 王槐明 于 2021-08-19 设计创作，主要内容包括：本发明公开了一种采用LED光源的柔性版制版组合曝光方法,包括如下步骤：准备数字印前电子文件,制作彩色分色版的加网解释后数字文件；将可雕刻的柔性印刷版装载到激光雕刻机；激光雕刻机雕刻柔性印刷版的黑膜,形成印刷图文；曝光设备根据设定的制版参数使用LED光源对雕刻有印刷图文的柔性印刷版进行主曝光；所述曝光采用LED光源进行主曝光与背曝光组合曝光,形成网点底部的支撑面积,增强柔性印刷版对网点的支撑；对进行曝光后的柔性印刷版进行水洗、去粘、烘干等后处理；检测柔性印刷版上的网点面积率,若误差在允许范围内,则制备的柔性印刷版合格；否则需分析原因,重新雕刻,再曝光与后处理,直到印版检测结果合格。(The invention discloses a flexographic plate making combined exposure method adopting an LED light source, which comprises the following steps: preparing a digital pre-press electronic file, and manufacturing a digital file after screening and interpretation of a color separation plate; loading the engravable flexographic printing plate to a laser engraving machine; carving the black film of the flexible printing plate by a laser carving machine to form printing pictures and texts; the exposure equipment uses the LED light source to carry out main exposure on the flexible printing plate engraved with the printing image-text according to the set plate making parameters; the exposure adopts an LED light source to carry out main exposure and back exposure combined exposure to form a supporting area of the bottom of the screen dot and enhance the support of the flexible printing plate on the screen dot; carrying out post-treatment such as washing, de-sticking, drying and the like on the exposed flexible printing plate; detecting the area rate of the dots on the flexographic printing plate, and if the error is within an allowable range, determining that the prepared flexographic printing plate is qualified; otherwise, the reason needs to be analyzed, re-engraved, exposed and post-processed until the printing plate detection result is qualified.)

1. A flexographic plate making combined exposure method adopting an LED light source is characterized by comprising the following steps:

step 1, preparing a digital pre-press electronic file, and manufacturing a digital file after screening and interpretation of a color separation plate;

step 2, loading the flexible printing plate capable of being engraved into a laser engraving machine;

step 3, engraving the black film of the flexible printing plate by the laser engraving machine according to the digital file to form printing pictures and texts, measuring and checking the sizes of the dots on the engraved black film, and ensuring that the imaging process is 1 to 1 in copy;

step 4, carrying out main exposure and back exposure on the flexible printing plate engraved with the printing graphics by using an LED light source by exposure equipment according to the set plate making parameters; the main exposure adopts an LED light source to carry out combined exposure, so that the supporting area of the bottom of a dot is enlarged, and the supporting of the flexible printing plate on the dot is enhanced;

step 5, washing, removing the adhesive and drying the exposed flexible printing plate;

step 6, detecting the area rate of the dots on the flexographic printing plate, and if the error is within an allowable range, determining that the prepared flexographic printing plate is qualified; otherwise, the reason needs to be analyzed, re-engraved, exposed and post-processed until the printing plate detection result is qualified.

2. The flexographic plate making combined exposure method using the LED light source according to claim 1, wherein the main exposure using the LED light source combined exposure comprises the steps of:

the method comprises the steps of firstly, carrying out one-time quick exposure on a flexible printing plate through an LED light source to solidify the head part of a mesh point, then carrying out a plurality of times of slow exposure on the flexible printing plate through the LED light source to form a mesh point foot support, forming the slope of the enlarged mesh point through the slow reaction of materials, and changing the size of the mesh point foot.

3. The method for making a flexographic printing plate by exposure with an LED light source according to claim 1, wherein the plate making parameters in step 4 are obtained by the following steps:

step 4-1, manufacturing a test file, wherein the test file comprises 0, 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 95 and 100 halftone dot gradations;

4-2, carrying out exposure test on the back surface of the test plate through an LED light source aiming at different types of plates to obtain proper subbase thickness, and recording back exposure time;

step 4-3, carrying out combined exposure of main surface patterns on the test plate through an LED light source, wherein the combined exposure comprises one-time quick exposure and a plurality of times of slow exposure, and respectively recording the quick exposure time and the slow exposure times;

step 4-4, washing, removing the adhesive and drying the exposed test plate;

step 4-5, measuring and analyzing the mesh points of the test plate, recording different mesh point supporting forms by using a light table and a measuring instrument, and measuring the foot diameters and the head diameters of the mesh points;

and 4-6, judging the optimal dot foot and dot head diameter values according to the flexographic printing standard, and recording the corresponding fast exposure time and slow exposure times in the step 4-3 when the standard is reached.

4. The method for making a flexographic printing plate by exposure using an LED light source according to claim 1, wherein an error allowance range of a dot area ratio on the flexographic printing plate is ± 1%.

Technical Field

The invention relates to the technical field of flexographic plate making exposure, in particular to a flexographic plate making combined exposure method adopting an LED light source.

Background

The flexographic printing plate making technology exposes the printing material of the flexographic printing plate through an ultraviolet exposure system to form exposure patterns of dots, character lines and the like with different sizes, and forms the dots and the character lines protruding on the surface of the printing plate through post-treatment processes of washing, drying and the like.

In the plate-making production process of the flexible printing plate, small dots of a highlight part on the printing plate are easily washed off by a printing plate post-processing washing brush under the same condition, cannot be fixed on the printing plate, and can form a printing opening in the printing process, namely, a jump mark appears in the printing of a gradually changed color.

In order to solve the problems, the traditional method for making the flexographic printing plate can solve the problem of point drop of small dots by increasing the thickness of the printing plate substrate, but the increase of the thickness of the printing plate substrate causes printing faults, such as easy screen blocking of dots, plate warping during printing and the like, and cannot meet the requirement of printing quality of customers. Or the main exposure time of the printing plate is prolonged, the fastness of the small dots on the printing plate can be improved, but the flat-head dots of the printing plate are recessed due to the prolonged exposure time, so that the defective products such as whitish printing edges are easy to appear, the printing resistance of the printing plate is reduced, the dot area rate of the small dots is increased, and the printing effect of the printed products with light colors cannot be achieved.

Therefore, there is a need to improve the existing flexographic printing plate making process to overcome the above-mentioned drawbacks.

Disclosure of Invention

The invention aims to provide a flexographic plate making combined exposure method adopting an LED light source, which aims to solve the problems in the prior art.

The technical purpose of the invention is realized by the following technical scheme:

a flexographic plate making combined exposure method adopting an LED light source comprises the following steps:

step 1, preparing a digital pre-press electronic file, and manufacturing a digital file after screening and interpretation of a color separation plate;

step 2, loading the flexible printing plate capable of being engraved into a laser engraving machine;

step 3, engraving the black film of the flexible printing plate by the laser engraving machine according to the digital file to form printing pictures and texts, measuring and checking the sizes of the dots on the engraved black film, and ensuring that the imaging process is 1 to 1 in copy;

step 4, carrying out main exposure and back exposure on the flexible printing plate engraved with the printing graphics by using an LED light source by exposure equipment according to the set plate making parameters; the main exposure adopts an LED light source to carry out combined exposure, so that the supporting area of the bottom of a dot is enlarged, and the supporting of the flexible printing plate on the dot is enhanced;

step 5, washing, removing the adhesive and drying the exposed flexible printing plate;

step 6, detecting the area rate of the dots on the flexographic printing plate, and if the error is within an allowable range, determining that the prepared flexographic printing plate is qualified; otherwise, the reason needs to be analyzed, re-engraved, exposed and post-processed until the printing plate detection result is qualified.

Further, the main exposure adopts the steps of LED light source combination exposure as follows:

the method comprises the steps of firstly, carrying out one-time quick exposure on a flexible printing plate through an LED light source to solidify the head part of a mesh point, then carrying out a plurality of times of slow exposure on the flexible printing plate through the LED light source to form a mesh point foot support, forming the slope of the enlarged mesh point through the slow reaction of materials, and changing the size of the mesh point foot.

Further, the plate making parameters in step 4 need to be obtained through the following steps:

step 4-1, manufacturing a test file, wherein the test file comprises 0, 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 95 and 100 halftone dot gradations;

4-2, carrying out exposure test on the back surface of the test plate through an LED light source aiming at different types of plates to obtain proper subbase thickness, and recording back exposure time;

step 4-3, carrying out combined exposure of main surface patterns on the test plate through an LED light source, wherein the combined exposure comprises one-time quick exposure and a plurality of times of slow exposure, and respectively recording the quick exposure time and the slow exposure times;

step 4-4, washing, removing the adhesive and drying the exposed test plate;

step 4-5, measuring and analyzing the mesh points of the test plate, recording different mesh point supporting forms by using a light table and a measuring instrument, and measuring the foot diameters and the head diameters of the mesh points;

and 4-6, judging the optimal dot foot and dot head diameter values according to the flexographic printing standard, and recording the corresponding fast exposure time and slow exposure times in the step 4-3 when the standard is reached.

Further, the error of the dot area ratio on the flexographic printing plate is allowed to be within ± 1%.

In conclusion, the invention has the following beneficial effects:

according to the invention, the LED light source is used for exposing the printing plate, the dots of the exposed printing plate are flat-top dots, the supporting area of the bottom of the dots is enlarged, the support of the printing plate on the small dots is enhanced, the treatment resistance of the small dots is improved, the service life of the printing plate is prolonged, the quality of a flexo printing product is improved, the production efficiency is improved, energy conservation and emission reduction are realized, and the greening and standardization of the technology of a flexible plate making enterprise are promoted.

The invention adopts the combined exposure, firstly carries out one-time fast exposure on the flexible printing plate through the LED light source to solidify the head part of the lattice point, then carries out a plurality of times of slow exposures on the flexible printing plate through the LED light source to form the lattice point foot support, increases the gradient of the lattice point through the slow reaction of the material, changes the size of the lattice point foot part, has firm lattice point support, realizes good small lattice point reducibility at highlight positions during the flexible printing, has soft printing effect and excessively natural color gradient, and improves the quality of printed products.

Drawings

FIG. 1 is a schematic flow chart of a flexographic plate making combined exposure method using an LED light source according to the present invention.

Fig. 2 is a schematic flow chart of determining the combined exposure parameter according to the present invention.

Detailed Description

In order to make the technical means, the original characteristics, the achieved purposes and the effects of the invention easy to understand, the invention is further described with reference to the figures and the specific embodiments.

As shown in fig. 1, the present invention provides a flexographic plate making combined exposure method using an LED light source, which includes the following steps:

step 1, preparing a digital pre-press electronic file, and manufacturing a digital file after screening and interpretation of a color separation plate;

step 2, loading the flexible printing plate capable of being engraved into a laser engraving machine;

step 3, engraving the black film of the flexible printing plate by the laser engraving machine according to the digital file to form printing pictures and texts, measuring and checking the sizes of the dots on the engraved black film, and ensuring that the imaging process is 1 to 1 in copy;

step 4, carrying out main exposure and back exposure on the flexible printing plate engraved with the printing graphics by using an LED light source by exposure equipment according to the set plate making parameters; the main exposure adopts an LED light source to carry out combined exposure, so that the supporting area of the bottom of a dot is enlarged, and the supporting of the flexible printing plate on the dot is enhanced;

step 5, washing, removing the adhesive and drying the exposed flexible printing plate;

step 6, detecting the area rate of the dots on the flexible printing plate, and if the error is within an allowable range, determining that the area rate of the dots is smaller than the allowable range

The prepared flexographic printing plate is qualified; otherwise, the reason needs to be analyzed, re-engraved, exposed and post-processed until the printing plate detection result is qualified.

The main exposure adopts the LED light source to carry out the combined exposure steps as follows:

the method comprises the steps of firstly, carrying out one-time rapid exposure on a flexible printing plate through an LED light source to solidify the head part of a mesh point, then carrying out a plurality of times of slow exposure on the flexible printing plate through the LED light source to form a mesh point foot support, forming the slope of the mesh point through the slow reaction of materials, and changing the size of the mesh point foot.

The plate making parameters in the step 4 need to be obtained through the following steps:

step 4-1, manufacturing a test file, wherein the test file comprises 0, 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 95 and 100 halftone dot gradations;

4-2, carrying out exposure test on the back surface of the test plate through an LED light source aiming at different types of plates to obtain proper subbase thickness, and recording back exposure time;

step 4-3, carrying out combined exposure of main surface patterns on the test plate through an LED light source, wherein the combined exposure comprises one-time quick exposure and a plurality of times of slow exposure, and respectively recording the quick exposure time and the slow exposure times;

step 4-4, washing, removing the adhesive and drying the exposed test plate;

step 4-5, measuring and analyzing the mesh points of the test plate, recording different mesh point supporting forms by using a light table and a measuring instrument, and measuring the foot diameters and the head diameters of the mesh points;

and 4-6, judging the optimal values of the dot foot and the dot head diameters according to the flexographic printing standard, and recording the corresponding fast exposure time and slow exposure times recorded in the step 4-3 when the standard is reached.

The error allowable range of the dot area ratio on the flexographic printing plate is +/-1%.

In this document, the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", "vertical", "horizontal", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for the purpose of clarity and convenience of description of the technical solutions, and thus, should not be construed as limiting the present invention.

As used herein, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, including not only those elements listed, but also other elements not expressly listed.

The foregoing shows and describes the general principles, essential features, and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are given by way of illustration of the principles of the present invention, and that various changes and modifications may be made without departing from the spirit and scope of the invention as defined by the appended claims. The scope of the invention is defined by the appended claims and equivalents thereof.