Intaglio printing method

Abstract

To provide an efficient printing method using two pattern rollers even in a region where a pattern to be intaglio-printed is small.SOLUTION: The intaglio printing method includes a first ink transfer step of transferring ink from the first ductor roller to the pattern region on the intaglio plate surface by the first pattern roller. In the intaglio printing method, after the step, one of i) a second ink transfer step of transferring the ink from the second duct roller to the pattern region on the intaglio plate by the second pattern roller so that the ink film amount becomes smaller than the ink film amount transferred to the non-pattern region, or ii) a second ink transfer step of transferring the ink from the second duct roller to the pattern region and the non-pattern region on the intaglio plate by the second pattern roller is performed, and the ink film amount of the pattern region is larger than the ink film amount of the non-pattern region.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an intaglio printing method for producing an intaglio printed matter. [Background technology]

[0002] Valuable printed materials such as banknotes, passports, and securities must be difficult to counterfeit or copy, and so they are known to be produced using intaglio printing. The reason for this is that when intaglio printed materials are copied, the raised ink patterns do not reproduce.

[0003] In addition, in intaglio printing, the Zammel printing method is known, in which different inks are filled into the recesses of the intaglio plate surface from multiple pattern rollers, and after the excess ink is wiped off with a wiping roller or the like, the ink is transferred to the paper by strong pressure. Conventionally, Zammel printing distinguishes the functionality of a single design by filling the recesses of the intaglio plate surface with inks of different colors or functions and printing.

[0004] For example, a method has been disclosed in which a dam is provided within the intaglio printing line at the boundary of the Zimmer printing to prevent the inks from flowing into each other (see, for example, Patent Document 1).

[0005] Furthermore, when performing sammel printing, a method has been disclosed in which magnetic inks having almost the same saturation magnetization but different residual magnetization are used in combination (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 6600876 [Patent Document 2] Japanese Patent Application Publication No. 2019-107818 Summary of the Invention [Problem to be solved by the invention]

[0007] The intaglio printing method described in Patent Document 1 is a printing method in which ink does not flow when performing zanmer printing on a single design. Next, the intaglio printing method described in Patent Document 2 is a method in which magnetic properties are varied by zanmer printing on a single design, and both methods aim to print a single design in parts.

[0008] On the other hand, the present invention aims to use two pattern rollers for the design and non-design of the intaglio printed matter. In particular, when the design area to be printed by intaglio printing is small, the conventional printing method has the following two problems.

[0009] First, the first issue will be explained with reference to Figure 6. Figure 6 shows Conventional Example 1, with the upper part showing a cross-sectional view of the pattern roller P, the middle part a front view of the intaglio plate surface H, and the lower part a cross-sectional view of the wiping roller W, showing their relative positions. As shown in Figure 6, pattern A on the intaglio plate surface H ("JAPAN" in Figure 6) is characterized by its small pattern area compared to the area of ​​the plate surface.

[0010] The printing method involves first transferring ink T to the pattern area Ra, which is aligned with the pattern A, using the raised portion Pa of the upper pattern roller P. Therefore, the area of ​​the raised portion Pa and the pattern area Ra are the same. After that, excess ink is wiped off from the ink T transferred to the pattern area Ra on the intaglio plate surface H by the lower wiping roller W, and the intaglio printing is completed.

[0011] At this time, the wiping roller W comes into contact with the surface of the intaglio plate H and wipes away excess ink, but this is divided into area X, where ink T is wiped away, and area Y, where ink T is not wiped away. Area X comes into contact with the intaglio printing lines (recesses) and ink pigment of the intaglio plate H, causing significant wear of the wiping roller W, but area Y does not wear out because it does not come into contact with the intaglio printing lines (recesses) and ink pigment of the intaglio plate H. As a result, unevenness develops on the surface of the wiping roller W over long periods of printing, which poses the problem of poor intaglio printing.

[0012] Next, the second problem is solved by the printing method shown in Figure 7, which solves the first problem. Figure 7 shows Conventional Example 2, and the positional relationship of each material is the same as in Figure 6. In this printing method, ink T is transferred to one area of ​​the intaglio plate surface H without providing a convex shape to the upper pattern roller P. After the ink T has been transferred to the entire area R of the intaglio plate surface H, the excess ink is then wiped off by the lower wiping roller W. At this time, the entire surface of the wiping roller W comes into contact with the ink pigment, so the surface deformation of the wiping roller W is small, but ink T is required for the entire surface. Generally, to achieve ink prominence in a printed product, a line depth of approximately 30 μm for the pattern A is required, and the ink supply amount to the intaglio plate surface H requires an ink film thickness of at least 40 μm. This requires excess ink, resulting in excessive ink consumption.

[0013] In this specification, the term "design" refers to the pattern printed on paper by intaglio printing, "one side" refers to the final form of the intaglio printed matter, and "design area" refers to the area on one side where the design is formed. Furthermore, "ink" refers to intaglio ink, and "ink film amount" refers to the amount (amount) of ink T transferred from the pattern roller P to the intaglio plate surface H. [Means for solving the problem]

[0014] The present invention aims to solve these problems and provides an efficient printing method using two pattern rollers even in areas where there are few patterns to be intaglio printed.

[0015] An intaglio printing method for producing an intaglio printed matter, the method comprising at least a paper feeding step of feeding paper, an intaglio printing step of printing a design on the fed paper by intaglio printing, and a discharging step of discharging the paper with the printed design, wherein the intaglio printing step comprises: i) a first ink transfer step of transferring ink from a first duct roller to a design area on the intaglio plate surface by a first pattern roller; and ii) a second ink transfer step of transferring ink from a second duct roller to a non-design area on the intaglio plate surface by a second pattern roller. or ii) a first ink transfer step of transferring ink from a first duct roller to a first pattern roller onto a pattern area on the intaglio plate surface, and a second ink transfer step of transferring ink from a second duct roller to a second pattern roller onto a pattern area and a non-pattern area on the intaglio plate surface, wherein the ink film amount in the pattern area is greater than the ink film amount in the non-pattern area. [Effects of the Invention]

[0016] The intaglio printing method of the present invention uses two pattern rollers to vary the ink film thickness between the patterned and non-patterned areas, thereby reducing ink consumption and suppressing deformation of the wiping roller. This printing method is particularly effective for areas with small patterns on the intaglio print. [Brief explanation of the drawings]

[0017] [Figure 1] This is an intaglio printed matter S of the present invention. [Figure 2] FIG. 1 shows an intaglio printing section M of the invention. [Figure 3] 3A to 3C are diagrams showing a first method of transferring ink to an intaglio plate surface H in the first and second embodiments of the present invention. [Figure 4] 3A to 3C are diagrams showing a second method of transferring ink to an intaglio plate surface H in the first embodiment of the present invention. [Figure 5] 10A and 10B are diagrams showing a second method of transferring ink to an intaglio plate surface H in a second embodiment of the present invention. [Figure 6] FIG. 1 is a diagram showing a method of transferring ink to an intaglio plate surface H in Conventional Example 1 of the present invention. [Figure 7] FIG. 10 is a diagram showing a method of transferring ink to an intaglio plate surface H in Conventional Example 2 of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0018] DETAILED DESCRIPTION OF THE INVENTION The present invention will now be described in detail. An embodiment of the present invention relates to intaglio printing.

[0019] It should be understood that the present invention is not limited to the following embodiments, but includes various other embodiments within the scope of the technical ideas described in the claims.

[0020] Figure 1 shows an intaglio print S of the present invention, in which a design A ("JAPAN" in Figure 1) has been printed on paper K using an intaglio printing press. As shown in Figure 1, design A is characterized by its small design area relative to the area required for one page. From the standpoint of efficiency, typically, the number of pages required for a large sheet of paper (e.g., 50 pages) are laid out on the intaglio plate, and after printing, the pages are cut into small pieces to produce a single page of print. Therefore, the intaglio print S is the final form of one page.

[0021] Next, an intaglio printing press is composed of at least a paper feed section, an intaglio printing section M, and a paper discharge section. First, paper is transported one sheet at a time from the paper feed section (not shown) to the intaglio printing section M. As shown in Figure 2, the intaglio printing section M is composed of an impression cylinder L, an intaglio cylinder Q to which the intaglio plate surface is attached, a wiping roller W, a first pattern roller P1, an associated first duct roller U1, a second pattern roller P2, and an associated second duct roller U2.

[0022] As shown in Figure 2, ink T is supplied to the intaglio cylinder Q via two systems and transferred to the intaglio plate surface by a first duct roller U1, a first pattern roller P1, a second duct roller U2, and a second pattern roller P2. Next, excess ink is wiped off by a wiping roller W, and the paper passes between the intaglio cylinder Q and the impression cylinder L along the paper path N while being subjected to strong pressure, so that the ink T is transferred to the paper, which is then ejected one sheet at a time onto a paper ejection section (not shown) and stacked.

[0023] (First embodiment) First, the first embodiment will be described with reference to Figures 3 and 4. Figure 3 is a diagram illustrating a first method of transferring ink to an intaglio plate surface H, and is a detailed diagram of the pattern roller P1 in Figure 2 and the intaglio plate surface attached to the intaglio cylinder Q. The upper part shows a cross-sectional view of the pattern roller P1, and the lower part shows the positional relationship of the intaglio plate surface H in a front view. The raised portions Pa of the upper pattern roller P1 transfer ink T to a pattern area Ra that matches the pattern A. Therefore, the raised portions Pa and the pattern area Ra have the same area.

[0024] Figure 4 shows a second method of transferring ink to the intaglio plate surface H, and is a detailed view of the pattern roller P2, the intaglio plate surface attached to the intaglio cylinder Q, and the wiping roller W in Figure 2. The upper part is a cross-sectional view of the pattern roller P2, the center is a front view of the intaglio plate surface H, and the lower part is a cross-sectional view of the wiping roller W, showing their relative positions. The raised portions Pb of the upper pattern roller P2 transfer ink T to the non-pattern areas Rb of the entire intaglio plate surface H, excluding the pattern areas Ra. Therefore, the areas of the raised portions Pb and the non-pattern areas Rb are the same. The amount of ink wiped by the lower wiping roller W varies depending on the area, but deformation is suppressed because the ink comes into contact with the entire surface of the wiping roller W.

[0025] Next, we will explain the amount of ink film transferred to the intaglio printing plate surface H. For example, if the image depth of pattern A is 30 μm, the image area Ra formed by the first pattern roller P1 has an ink film amount of 40 μm to ensure sufficient prominence in the printed matter. On the other hand, the non-image area Rb formed by the second pattern roller P2 has an ink film amount of 20 μm to account for wear caused by the ink pigment, since there are no intaglio image lines.

[0026] As a result, the amount of ink used in the non-image area Rb can be reduced by approximately 50% compared to the conventional method in which ink T is transferred to the entire intaglio plate surface H as shown in Figure 7. Therefore, the first embodiment of the present invention is a printing method that can reduce the amount of ink used while suppressing deformation of the wiping roller surface.

[0027] (Second embodiment) The second embodiment will be described with reference to Figures 3 and 5. The method of transferring the first ink to the intaglio plate surface H is the same as in the first embodiment, as shown in Figure 3, and therefore will not be described here.

[0028] Next, as a second method of transferring ink to the intaglio plate surface H, as shown in Figure 5, the upper pattern roller P2 does not have any protrusions, and ink T is transferred to the entire area R of one surface. Therefore, ink is transferred to the pattern area Ra twice. The amount of ink wiped off by the lower wiping roller W varies depending on the area, but deformation can be suppressed because the ink comes into contact with the entire surface of the wiping roller W. Note that the positional relationship of each material in Figure 5 is the same as in Figure 4.

[0029] Next, we will explain the amount of ink film transferred to the intaglio printing plate surface H. For example, if the image depth of the pattern A is 30 μm, the ink film thickness is set to 20 μm in the pattern area Ra formed by the first pattern roller P1. On the other hand, the ink film thickness is set to 20 μm in the entire area R formed by the second pattern roller P2, since there are almost no intaglio printing lines. Therefore, the ink film thickness in the pattern area Ra is set to 40 μm by the first pattern roller P1 and the second pattern roller P2, which allows for a sufficient prominence in the printed matter.

[0030] Therefore, the ink usage amount in the non-pattern area Rb is reduced in the same manner as in the first embodiment compared to the conventional method. Note that the inks used in the first ink transfer method and the second ink transfer method may be the same or may be different. [Example]

[0031] First, we will explain the first example. To produce the intaglio print S shown in Figure 1, the intaglio printing unit M shown in Figure 2 was used. In the first ink transfer method, a pattern roller P1 shown in Figure 3 was provided with raised areas Pa, and ink T was transferred to the pattern area Ra of the intaglio plate surface H. In the second ink transfer method, a pattern roller P2 shown in Figure 4 was provided with raised areas Pb, and ink T was transferred to the non-pattern area Rb of the intaglio plate surface H. Excess ink was then wiped off with a wiping roller W, and strong pressure was applied to obtain the intaglio print S. The ink film thickness on the intaglio plate surface H was 40 μm for the first ink transfer method and 20 μm for the second ink transfer method. As a result, the amount of ink used was reduced, and the printing durability of the wiping roller was improved.

[0032] Next, a second embodiment will be described. As in the first embodiment, the intaglio printing unit M shown in FIG. 2 was used to produce the intaglio print S shown in FIG. 1. The first ink transfer method is similar to that of the first embodiment, and therefore will not be described here. The second ink transfer method involves transferring ink T to the entire area R of the intaglio plate surface H without providing protrusions on the pattern roller P2 shown in FIG. 5, wiping off excess ink with a wiping roller W, and applying strong pressure to obtain the intaglio print S. The ink film thickness on the intaglio plate surface H was 20 μm for the first ink transfer method and 20 μm for the second ink transfer method. As a result, the amount of ink used was reduced and the printing durability of the wiping roller was improved. [Explanation of symbols]

[0033] S: Intaglio plate K: Paper A: Design M: Intaglio printing department L: impression cylinder Q: Intaglio cylinder W: Wiping roller P1: First pattern roller U1: First duct roller P2: Second pattern roller U2: Second Duct Roller T: Ink N: Paper path H: Intaglio plate R: Entire area Pa: The convex portion of the pattern roller used in the first ink transfer method in the first embodiment and the second embodiment, and Conventional Example 1 Ra: Pattern area Pb: Convex portion of the pattern roller used in the second ink transfer method in the first embodiment Rb: Non-pattern area X: Ink wiping area Y: Area where ink is not wiped off

Claims

[Claim 1] a paper feeding step for feeding paper; an intaglio printing step of printing a design on the supplied paper by intaglio printing; a discharging step of discharging the paper on which the design is printed; 1. An intaglio printing method comprising at least The intaglio printing process i) a first ink transfer step of transferring ink onto a design area on the intaglio plate surface by a first duct roller and a first pattern roller; a second ink transfer step of transferring ink from a second duct roller to a non-pattern area of ​​the intaglio plate surface by a second pattern roller so that the ink film amount is smaller than the ink film amount transferred to the pattern area; or ii) a first ink transfer step of transferring ink from a first duct roller to the design area on the intaglio plate surface by a first pattern roller; a second ink transfer step of transferring ink from the second duct roller to the pattern area and the non-pattern area on the intaglio plate surface by the second pattern roller, 10. An intaglio printing method, wherein the ink film thickness in the design area is greater than the ink film thickness in the non-design area.

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