Manufacturing method of projection printing material

Abstract

To provide a manufacturing method of a printing material that is prevented from warping, in manufacturing of the printing material by processing such as cutting.SOLUTION: A manufacturing method of a projection printing material includes a processing amount calculation step of calculating a first processing amount for processing and removing one surface of a printing material to form a projection pattern part and calculating a second processing amount for processing and removing the other surface of the printing material such that the second processing amount is the same as the first processing amount. The projection printing material is manufactured by processing one surface of the printing material on the basis of the first processing amount calculated in the processing amount calculation step to form the projection pattern part, and processing the other surface of the printing material on the basis of the second processing amount.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a method for producing a relief printing plate. [Background technology]

[0002] The corrosion method is one of the methods for producing a relief original plate, which is one of the printing plates. To carry out the corrosion method, a pattern is first created using a DTP (Desk Top Publishing) system, which uses a personal computer to integrate the tasks required for print production, such as typesetting, illustration creation, and layout. After that, the film original plate on which the pattern has been output using a laser setter is inverted and attached to a glass dry plate, and the glass dry plate with the pattern is attached to a brass plate to burn the pattern. Next, the non-printing areas are corroded and dissolved using the corrosion platemaking method to form the raised image lines, and the relief original plate is produced by this method. In addition, depending on the height (depth) of the raised image lines, the process from pattern burning to the corrosion process is repeated several times to form the image lines by gradually corroding them.

[0003] The produced convex original plate can be used as a printing plate surface, but it has also been reproduced to produce a printing plate surface. As a method for producing a printing plate surface by reproducing a convex original plate, for example, nickel electroforming is used, in which an intaglio original plate is reproduced from the convex original plate, and then the intaglio original plate is reproduced again to produce a convex printing plate surface with raised image lines.

[0004] However, currently, the photosensitive materials required for the etching plate making method are becoming difficult to obtain, as their production has been discontinued. Furthermore, since the method requires the use of hazardous chemicals, the work is dangerous and environmentally undesirable.

[0005] In addition, the etching plate-making process is complicated and analogue, making it difficult to stabilize the quality of the raised lines. Furthermore, when targeting products that will be manufactured over a long period of time, the pattern plates will need to be stored for a long time, and there is a risk of deterioration and damage over time, so it is necessary to pay close attention and require specialized skills.

[0006] In recent years, therefore, cutting methods have come to be used as a means of processing convex master plates. Cutting is a processing method in which a machine tool is used to cut a solid plate material (metal) to leave the patterned area and remove the unpatterned area other than the patterned area.

[0007] However, when cutting a printing plate, most of the area other than the pattern is removed as a plain area, which reduces the thickness of the printing plate. Although the printing plate is flat before processing, if the printing plate is made of metal, there is a problem that the metal composition can cause the printing plate to warp in one direction when the printing plate is thinned.

[0008] The reason for this is that, as shown in FIG. 1, metal plate material (20) that is generally sold is manufactured by rolling processing using a roughing mill (2) and a finishing mill (3), and stress is contained inside the metal during rolling. As shown in FIG. 2(a), at the shipping stage, the balance of this stress is maintained and the plate material is shipped in a flat state. The arrows in the figure show a state in which the tensile stress and compressive stress are balanced inside the plate material (20), that is, internal stress. In contrast to this state, as shown in FIG. 2(b), if the thickness changes due to secondary processing, the balance of the internal stress is thought to be lost and warping occurs. For example, if the upper part of the plate material (20) shown in FIG. 2(b) is removed, warping tends to occur on the lower side.

[0009] Therefore, the direction of warping depends on the rolling direction in the plate manufacturing stage, and secondary processors are currently unable to predict the direction of warping. If the warping is minor, it is not a problem, but depending on the extent of the warping, it may become impossible to use the plate in the later process.

[0010] The warping may be eliminated by simple methods such as reducing the cutting thickness or thickening the plate itself. However, if the cutting thickness is reduced, the cutting thickness can be said to be the image height, so there is a possibility that the image height required for the printing plate surface cannot be obtained. Furthermore, if the plate itself is made thicker, the plate becomes heavy, which may cause problems in the subsequent processes and make it unusable.

[0011] One method for preventing warping of printing plates is lamination processing, which is targeted at printing plates, and involves laminating a resin layer via an adhesive layer on the back surface of an electroformed plate duplicated from an original plate, and then laminating a metal plate on the resin layer via an adhesive layer to prevent warping (see, for example, Patent Document 1).

[0012] Another example of a method for preventing warping of a printing plate is heat treatment, which is a method for preventing warping of a photosensitive resin plate by heat treating the plate in hot water or under humid conditions (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0013] [Patent Document 1] Jpn. Jpn. Published No. 46-37204 [Patent Document 2] Japanese Patent Application Publication No. 51-59970 Summary of the Invention [Problem to be solved by the invention]

[0014] However, the lamination process in Patent Document 1 requires a step of laminating a resin layer and a metal plate on the back surface of the electroforming plate, which increases the number of steps, resulting in problems of increased delivery time and costs. In addition, laminating a resin layer and a metal plate increases the thickness of the plate material, which increases the load on the printing machine and may make it impossible to implement if there are regulations regarding plate thickness.

[0015] Furthermore, the heat treatment in Patent Document 2 is effective when used on a resin plate, but in the case of a metal plate, the pattern may vary due to expansion and contraction caused by heat. In particular, for a multi-faceted plate on which multiple patterns are arranged, it is important to be able to control the inter-face dimensions, and expansion and contraction is undesirable. In addition, since the treatment is performed underwater or in a humidified environment, there is an issue that when a plate material that rusts easily, such as brass, is used, the plate material is prone to rusting.

[0016] SUMMARY OF THE PRESENT DISCLOSURE In view of the above circumstances, an object of the present invention is to provide a method for producing a relief printing plate material which is prevented from warping. [Means for solving the problem]

[0017] The method for producing a convex printing plate of the present invention is a method for producing a convex printing plate having a convex pattern portion, and is characterized in that it includes a processing amount calculation step for calculating the amount of processing for processing and removing one side of the printing plate to form the convex pattern portion, and a processing amount calculation step for calculating the amount of processing for processing and removing the other side of the printing plate so that the amount of processing is the same as the amount of processing for forming the convex pattern portion, a step of processing and removing one side of the printing plate to form the convex pattern portion based on the processing amount for forming the convex pattern portion calculated in the processing amount calculation step, and a step of processing the other side of the printing plate based on the processing amount for processing and removing the other side of the printing plate calculated in the processing amount calculation step. Effect of the Invention

[0018] The method for producing a convex printing plate of the present invention calculates the amount of processing required to process the pattern portion of the convex printing plate, and then, based on that, calculates the amount of processing for the non-pattern portion, and processes each surface, thereby preventing warping of the produced convex printing plate. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is a diagram showing processing of a metal plate material. [Diagram 2] 1 is a schematic diagram showing the principle by which warping occurs when a metal plate is processed. [Diagram 3]FIG. 1 is a flow diagram of a method for producing a relief printing plate according to a first embodiment of the present invention. [Figure 4] FIG. 2 is a diagram showing an example of the configuration of a relief printing plate according to the present invention. [Diagram 5] FIG. 2 is a diagram showing a processing area on the non-pattern side of a relief printing plate according to the present invention. [Figure 6] FIG. 2 is a diagram showing a processing area on the pattern side of a relief printing plate according to the present invention. [Figure 7] FIG. 6 is a flow diagram of a method for producing a relief printing plate according to a second embodiment of the present invention. [Figure 8] FIG. 13 is a diagram showing a processing area when processing a part of the pattern side. [Figure 9] FIG. 11 is a diagram showing a processing area on the non-pattern side in the second embodiment. [Figure 10] FIG. 13 shows the remaining processing area on the pattern side. [Figure 11] 13 is a diagram showing another example of a part of a processing area on the pattern side and the remaining processing area. FIG. [Figure 12] FIG. 13 is a diagram showing another configuration of the relief printing plate. [Figure 13] FIG. 11 is a diagram showing another example of a processing area for producing a convex plate material. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Hereinafter, a method for producing a relief printing plate according to an embodiment of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiment described below, and various other embodiments are included within the scope of the technical idea described in the claims.

[0021] In the present invention, the convex printing plate refers to a convex original plate used for duplication to prepare a printing plate, and a convex printing plate surface processed from a metal plate material and used directly as a printing plate surface, and the printing plate material prepared by the convex printing plate preparation method of the present invention can be used in either form. When the convex printing plate material is used as a convex original plate, as described in the prior art, it is duplicated by electroforming to prepare a convex printing plate surface and used as a printing plate surface. In the following explanation, an example in which a processed metal plate material is used directly as a printing plate surface will be explained.

[0022] (First embodiment) First, a method for producing a relief printing plate according to the first embodiment of the present invention will be described below. Fig. 3 shows a flow diagram of the method for producing a relief printing plate according to the first embodiment of the present invention.

[0023] In FIG. 3, STEP 1 is a process of fixing the printing plate to the fixed table of the machine tool. In STEP 1, the printing plate is fixed by a fixing means with the non-pattern side of the printing plate facing up and the pattern side facing down. The pattern side is the surface of the printing plate on which the convex pattern portion (5) is processed, and when printing, the ink attached to the convex pattern portion (5) is transferred to the printing medium. The non-pattern side is the surface opposite the pattern side, and when printing, it is the surface that comes into contact with the plate cylinder and is fixed. In detail, the process of STEP 1 fixes the non-pattern side to a cutting tool attached to the machine tool so as to face each other, and fixes the printing plate to the fixed table so as to face each other. The fixing means is not particularly limited, and may be, for example, air suction or magnetic suction. Although the process of fixing the printing plate to the fixed table of the machine tool in STEP 1 is described as being performed at the very beginning of the flow, it may be performed after STEP 2 described later.

[0024] In Fig. 3, STEP 2 is a process for calculating appropriate processing amounts for the pattern side and non-pattern side. The processing amount for the pattern side (first processing amount) is the volume of the plate material before processing that is processed (removed) in order to form the convex pattern portion (5), and a specific calculation method is as shown in the following formula (Mathematical formula 1).

[0025] (Number 1) Volume processed to form the pattern = Pattern height t × (area of ​​plate material S - surface area of ​​pattern s)

[0026] As an example of calculation, in the case of a convex plate material (1) in which one cylindrical pattern portion (5) with a diameter of 10 mm and a pattern height (t) of 1 mm is placed in the center of a plate material measuring 100 mm square as shown in Figure 4, the volume to be processed to form the pattern portion (5) can be calculated using the following formula (Equation 2).

[0027] (Number 2) 1 x (100 x 100 - 5 x 5 x π) = approx. 9921 mm 3 ] (π=pi)

[0028] In the method for producing a relief printing plate of the present invention, the appropriate amount of processing of the non-pattern side (second processing amount) is an amount that maintains the internal stress of the printing plate when a pattern is formed on the pattern side, and specifically, is the same volume as the processing amount for forming a convex pattern portion (5) on the pattern side. In other words, the processing amount of the non-pattern side is 9921 mm, which is the same as the processing amount of the pattern side. 3 If the non-patterned side has a flat surface, the processing thickness (T) of the non-patterned side can be calculated by the following formula (3).

[0029] (Number 3) Plate area S × processing thickness of non-pattern side (T) = processing amount of non-pattern side 100 x 100 x thickness of non-patterned side (T) = 9921 [mm 3 ] Processing thickness of non-patterned side (T) = 9921 / 10000 =0.9921[mm]

[0030] In Fig. 3, STEP 3 is a process for forming the non-pattern side using a cutting tool. If the shape of the non-pattern side is required to be flat, the preferred processing method for the non-pattern side is to remove the entire surface uniformly by milling using a face mill as a cutting tool or grinding using a grinding wheel as a cutting tool.

[0031] FIG. 5 is a diagram showing an example of a process in which the entire surface of the non-pattern side is uniformly removed by milling in the process of machining the non-pattern side in STEP 3. The volume of the milling process is 9921 mm, the same as the volume of the convex pattern portion (5) on the pattern side. 3 By setting the processed thickness (T) of the non-pattern side to 0.9921 mm, the volume of the non-pattern side and the processed volume of the pattern side can be made the same. Note that depending on the application of the convex plate material in the post-processing, it may be required that the shape of the non-pattern side is not flat. In such cases, when processing into an appropriate shape accordingly, the volume at the time of processing is appropriately designed to be the same as above. The following explanation uses an example where the non-pattern side is flat.

[0032] As a result of this processing of the non-pattern side, the balance of stresses within the printing plate is lost, but since the fixing means forcibly prevents the printing plate from deforming, warping does not become evident.

[0033] In Figure 3, STEP 4 is the process of releasing the fixing means of the machine tool, flipping the plate over and fixing it. At this time, the warping described above becomes apparent, so the plate is fixed again with the fixing means while suppressing the warping using manual power or a jig such as a vice. This turns the non-pattern side down and the pattern side up, allowing the convex pattern portion (5) to be formed. This process only suppresses the warping of the plate when it is fixed by the machine tool, and does not permanently eliminate the warping of the plate.

[0034] In Figure 3, STEP 5 is a process in which an end mill or the like is used as a cutting tool to process the plate so that only the necessary convex pattern portion (5) remains, as shown in Figure 6. When the processing of the convex pattern portion (5) is completed, the volume of the pattern side and the non-pattern side become equal, so the balance of stress within the plate material is equalized.

[0035] Thereafter, the fixing means of the machine tool is released, and the completed projection printing material 1 is removed. Since the projection printing material 1 has a uniform stress balance as described above, no warping occurs even when the fixing means is released.

[0036] In the method for producing a convex printing plate according to the first embodiment described above, an example has been described in which the non-pattern side is processed (STEP 3) before the pattern side is processed (STEP 5), but in the method for producing a convex printing plate according to the present invention, the pattern side may be processed before the non-pattern side is processed. In that case, in the step of fixing the printing plate to the fixing table in STEP 1, the pattern side of the printing plate is turned to the front and the non-pattern side is turned to the back, and the printing plate is fixed by a fixing means.

[0037] In addition, in the method for producing a convex printing plate according to the first embodiment of the present invention, an example in which the convex pattern portion (5) is processed into a cylindrical shape has been described, but in the present invention, the shape of the convex pattern portion (5) is not limited to this, and may be letters, numbers, symbols, numbers, designs, designs, illustrations, seals, patterns, etc., or patterns of letters, numbers, patterns, etc. may be formed by lines. Even in this case, the non-pattern side may be processed based on the volume for processing the convex pattern portion (5). The same applies to the second embodiment described later.

[0038] Furthermore, in the method for producing a convex printing plate according to the first embodiment of the present invention, the step (STEP 2) of calculating the amount of processing of the pattern side and non-pattern side is not limited to the order shown in Figure 3, and may be performed before fixing the printing plate, so long as it is performed before processing the non-pattern side.

[0039] (Second embodiment) Next, a method for producing a convex printing plate according to a second embodiment of the present invention will be described. Figure 7 shows a flow of the method for producing a convex printing plate according to the second embodiment of the present invention. In the second embodiment, the convex pattern portion (5) to be processed is also described as being cylindrical as shown in Figure 4, as in the first embodiment.

[0040] In Fig. 7, STEP 1 is a process of fixing the printing plate to the fixed table of the machine tool, similar to the first embodiment. The printing plate is fixed by fixing means with the pattern side facing up and the non-pattern side facing down. The fixing means is not limited, but may be, for example, air suction or magnetic suction. As in the first embodiment, the process of fixing the printing plate to the fixed table of the machine tool in STEP 1 is described as being performed at the very beginning of the flow, but it may be performed after STEP 2, which will be described later.

[0041] In FIG. 7, STEP 2 is a process for calculating the appropriate amount of processing for the pattern side and the non-pattern side. As explained in paragraph (0031), the appropriate amount of processing is 9921 mm for both the pattern side and the non-pattern side. 3 It becomes.

[0042] In Fig. 7, STEP 3 is a process of machining a part of the pattern side using an end mill or the like as a cutting tool. Here, an example will be described in which the part to be removed by machining is the periphery of the pattern shown in Fig. 8 (hereinafter referred to as "peripheral machining area (G1)").

[0043] In Figure 7, STEP 4 is the process of releasing the fixing means of the machine tool and turning the plate over. At this time, most of the pattern side remains uncut, so the balance of stress inside the plate does not change significantly and almost no warping occurs.

[0044] In Fig. 7, STEP 5 is a process for machining the non-pattern side with a cutting tool. STEP 5 is the same as STEP 3 described in the first embodiment, and is machined by milling using a face mill as a tool and polishing using a grinding wheel as a cutting tool so that the machined thickness (T) of the non-pattern side is 0.9921 mm, as shown in Fig. 9.

[0045] In FIG. 7, STEP 6 is a process of releasing the fixing means of the machine tool and turning the plate material over. As in STEP 1, the pattern side is turned over to the front and the non-pattern side is turned over to the back, and the plate material is fixed by the fixing means.

[0046] In Figure 7, STEP 7 processes all of the remaining part of the pattern side shown in Figure 10 (hereafter referred to as the "finishing processing area (G2)"). At this time, a slight positional shift occurs with respect to the position where the pattern was originally processed, but this positional shift is absorbed within the surrounding processing area (G1). Note that in the process of STEP 7, processing occurs in a state where the stress balance between the pattern side and non-pattern side of the printing plate is disrupted, but since the warping has been suppressed and fixed in the process of STEP 6 and the processing only involves removing the remainder, the effects of stress within the printing plate are tolerable.

[0047] In the method for producing the convex printing plate of the second embodiment, the initially formed convex pattern portion (5) may be scratched by being turned over once, which may cause damage to the surface of the convex pattern portion (5). In such a case, the height of the convex pattern portion (5) may be previously processed to be higher than necessary, and a final finishing process may be added in which the surface of the convex pattern portion (5) is scraped off by milling or the like.

[0048] In the method for producing the convex printing plate of the second embodiment, an example has been described in which the peripheral processing area (G1) is processed in the step (STEP 3) of processing a portion of the pattern side, and the finish processing area (G2) is processed in the step (STEP 7) of processing the remaining portion of the pattern side, but after processing the finish processing area (G2) shown in Fig. 10 in STEP 3, the peripheral processing area (G1) shown in Fig. 10 may be processed as the remaining portion in STEP 7. Furthermore, the division between the peripheral processing area (G1) and the finish processing area (G2) is not limited to the example shown in Fig. 10, and may be adjusted as appropriate depending on the pattern to be processed and the warpage state of the printing plate.

[0049] In the second embodiment, in the step (STEP 3) of processing a portion of the pattern side area, an example of processing the area (G1) around the pattern has been described, but the number of times of processing may be divided in the thickness direction of the plate material for processing. Specifically, as shown in Fig. 11, in STEP 3, a 0.5 mm area (G3) in the thickness direction of the plate material is processed, and in STEP 7, the remaining 0.5 mm thick area (G4) shown in Fig. 11 is processed to process the convex plate material (1). Also, when the number of times of processing is divided in the thickness direction of the plate material, it may be adjusted appropriately depending on the pattern to be processed and the warpage state of the plate material.

[0050] In the second embodiment described above, the pattern side is processed in two steps, but the non-pattern side may also be processed in two steps. Specifically, the processing thickness (T) of the non-pattern side processed in STEP 5 may be divided into two steps, whereby a part of the non-pattern side is processed in STEP 5, and after processing the pattern side in STEP 7, the remaining non-pattern side is processed to produce the convex plate material (1).

[0051] In the second embodiment described above, the pattern side is processed in two separate steps, but the non-pattern side may be processed in two separate steps, with the pattern side processed once in between. Specifically, a part of the non-pattern side may be processed in STEP 3, the pattern side may be processed in STEP 5, and the rest of the non-pattern side may be processed in STEP 7.

[0052] Furthermore, when processing the patterned side and the non-patterned side is performed alternately, the patterned side and the non-patterned side may each be processed three or more times.

[0053] In the second embodiment, by dividing the processing of at least one of the pattern side and the non-pattern side into two or more steps, it is possible to prevent the stress balance from being disturbed and deformation occurring during processing of the convex plate surface. Therefore, if warping occurs during processing according to the first embodiment, the manufacturing method of the second embodiment can be carried out to manufacture the convex plate material (1).

[0054] In the method for producing a relief printing plate of the present invention, when the processed printing plate is used as a relief printing plate surface, the pattern side and non-pattern side may be processed to match the printing cylinder (10) to which it is attached, as shown in Figure 12. In this case, the pattern side and non-pattern side are processed to match the curved surface of the printing cylinder (10).

[0055] Fig. 13 is a diagram for explaining the plate material (11) before processing, the processing area (G5) on the pattern side, and the processing area (G6) on the non-pattern side when processing the convex plate material (1) shown in Fig. 12. Fig. 13(a) shows the position where the convex plate material (1) is formed on the plate material (11) before processing. Fig. 13(b) is a diagram showing the processing area (G5) on the pattern side and the processing area (G6) on the non-pattern side for forming the convex plate material (1) shown in Fig. 13(a).

[0056] By the manufacturing method described in the first and second embodiments, if the amount of processing of the processing area (G5) on the pattern side and the processing area (G6) on the non-pattern side of the unprocessed plate material (11) is the same, warping of the processed convex plate material (1) can be suppressed. In addition, in the case where the shape of the non-pattern side is a curved surface as shown in FIG. 13, in order to make the amount of processing of the processing area (G5) on the pattern side and the processing area (G6) on the non-pattern side the same, the unprocessed plate material (11) may be prepared by calculating backwards from the shape of the convex plate material (1) to be finally produced and processed. For example, if the amount of processing of the pattern side is less than the amount of processing of the non-pattern side when processing as shown in FIG. 13(b), a plate material thicker than the unprocessed plate material (11) shown in FIG. 13(b) may be prepared and the amount of processing of the pattern side may be increased accordingly. Also, a plate material thinner than the unprocessed plate material (11) shown in FIG. 13(b) may be prepared and the amount of processing of the non-pattern side may be reduced accordingly. In addition, by adjusting the position where the convex printing plate (1) is formed on the unprocessed printing plate (11), the amount of processing on the pattern side and non-pattern side can also be adjusted. [Explanation of symbols]

[0057] 1. Convex plate material 2. Coarse mill 3 Finishing Mill 5 Convex pattern 10 Printing cylinder 11 Plate material before processing 20 Board material

Claims

[Claim 1] A method for producing a relief printing plate having a relief pattern portion, comprising the steps of: a processing amount calculation step of calculating a first processing amount for forming the convex pattern portion by processing and removing one surface of the plate material before processing, and calculating a second processing amount for processing and removing the other surface of the plate material so that the second processing amount is equal to the first processing amount; a step of processing and removing one surface of the printing plate based on the first processing amount calculated in the processing amount calculation step to form the convex pattern portion; A method for producing a convex printing plate, comprising the step of processing the other surface of the printing plate based on the second processing amount calculated in the processing amount calculation step.

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