JP2018089821A - Printing plate with abrasion replacement signature arranged - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printing plate capable of determining replacement timing of the printing plate at a glance by directly checking abrasion status of the printing plate without using specific measuring devices or the like.SOLUTION: There is provided a printing plate capable of checking abrasion status by arranging an abrasion replacement signature area by either arranging a recess which can discriminate abrasion of the printing plate on at least a part of a convex shape of the printing plate, or arranging a first layer as a layer in abrasion acceptable range layer and a second layer as a layer in abrasion unacceptable range layer on the printing plate.SELECTED DRAWING: Figure 2

Description

  The present invention is used for printing plates used for printed materials for mass production of a single product, particularly for security printed materials requiring precise printing accuracy such as banknotes, passports, securities, identification cards, and passports. This relates to the printing plate.

  Printing plate surfaces used for letterpress printing, dry offset printing, flexographic printing, etc. are mainly made of metal using nickel, lead, brass, etc., and molded by applying pressure to hard plastic such as vinyl chloride. There are resin-made products using ultraviolet curable resins, but recently, printing plates made of resin are often used because of the ease of processing and high-definition lines.

  Metal and resin printing plates are subject to wear due to contact with rollers and printing substrates during printing. When wear increases, printing defects such as distortion of the printed pattern, misalignment of printing dimensions, and missing image areas Had occurred. Further, due to the characteristics of the plate surface material, the resin printing plate surface is worn out more quickly than the metal printing plate surface.

  Therefore, at present, the worn printing plate is replaced before printing defects such as printing pattern distortion, printing dimension deviation, and image line missing. However, as for the wear state of the printing plate, the method of checking and replacing the printing quality is not the general method for directly observing the printing plate, so the influence on the printing quality is due to the printing plate. It is difficult to determine whether it is due to other printing base materials such as excessive ink supply, blanket distortion, etc. For this reason, the printing plate number that can be used is not used, and it may be replaced with a new printing plate. Economical and efficiency issues such as increased usage of the printing plate and machine stoppage due to plate replacement remain. It was a situation.

  In the case of security prints, strict management is particularly required for print quality. As part of this, machine processing such as reading information, numbers, symbols, codes, etc. printed on printed matter with a machine and collating them with genuine products, and processing such as true / false discrimination based on the results are increasing. . At that time, printing defects due to various factors affect the reading accuracy, and as a result, there is a problem that uniform quality control cannot be performed.

  FIG. 5 shows an example of printing failure due to wear of the printing plate surface. If there is information on the state where the letter “C” is rotated 90 degrees to the right as shown in the plan view of FIG. 5A and the cross-sectional view of FIG. As a result, the printing plate surface is worn away as shown in FIG. In such a case, as shown in FIG. 5D, the space portion of the character “C” disappears and the character “O” is printed. The space of characters is one of the important identification elements. When a printed matter such as that shown in FIG. 5D is provided, incorrect information is widely disseminated and, for example, machine authentication such as OCR is performed. In such a case, there is a problem in that reading failure occurs due to erroneous recognition.

  As an example of the printing plate surface management method, the deterioration of the support layer, which is a phenomenon specific to the printing plate surface, and the reversible change, for the purpose of determining deterioration over time uniformly and determining the expiration date of use without fail. An identification code for managing the expiration date for use due to deterioration over time, including at least one characteristic of deterioration and wear of the photocatalytic substance depending on the number of printed printing plate surfaces, is assigned, and a plurality of plate-making printing plates can be obtained by this identification code. A method of managing on a database and making the finished state of a printed matter uniform is disclosed (for example, see Patent Document 1).

JP 2001-322224 A

  Although the management method of Patent Document 1 described above is not a simple management based on time, the environment in which the printing plate is used is predicted based on the data stored in the database and the determination level of the replacement time is determined. Since this is not an observing method, a problem remains in uniform quality control of printed matter.

  An object of the present invention is to solve the above-mentioned problems. At least a part of the convex portion of the printing plate surface is provided with a concave portion that can identify the wear of the plate surface, or the printing plate surface is provided with a layer having an allowable wear range. Depending on whether the second layer is provided as a layer in which wear of the first layer is not wearable, a wear exchange sign region is provided to provide a printing plate surface on which the wear state can be confirmed.

  The printing plate surface in the present invention is a printing plate surface having a convex shape, and a wear exchange sign region is provided on at least a part of the convex shape on the printing plate surface, and the wear exchange sign region includes a processed portion and a non-processed portion. And a part of the upper part of the processed part has a concave shape.

  The printing plate surface in the present invention is a printing plate surface having a convex shape, and at least a part of the printing plate surface is composed of two layers of a first layer and a second layer, and the hues of the first layer and the second layer. A wear exchange sign region is formed by a boundary portion due to the difference between the two.

  The printing plate surface in the present invention is characterized in that the difference in hue is a complementary color relationship.

  Since the wear state of the printing plate surface can be directly confirmed without using a special measuring device or the like, the replacement time of the printing plate surface can be determined at a glance, and uniform quality control of the printed matter has become possible.

  Since it can be used up to the wear limit of the printing plate surface, waste such as replacement in the middle of wear does not occur, and economical and efficient improvement is possible.

An overall view of the printing plate is shown. The wear exchange sign area | region of Embodiment 1 in this invention is shown. The wear exchange sign area | region of Embodiment 2 in this invention is shown. The state at the time of abrasion of Embodiment 2 in this invention is shown. The state of printing failure when the printing plate surface is worn is shown.

  DESCRIPTION OF EMBODIMENTS Embodiments for carrying out the present invention will be described with reference to the drawings. However, the present invention is not limited to the embodiments described below, and includes various other embodiments within the scope of the technical idea described in the scope of claims.

(First embodiment)
FIG. 1 shows an overall view of a printing plate surface in the present invention. In addition to the printing surface (2) on which information such as characters, symbols, and patterns is printed, the printing plate surface (1) includes color patches (3), gradation scales (4), and alignment for color matching of printed materials. A register mark (5) is provided for this purpose.

  The printing plate surface (1) in the present invention refers to a printing plate surface in which a printing portion such as a relief printing plate surface, a dry offset printing plate surface, and a flexographic printing plate surface is formed in a convex shape, and printing is performed by placing ink on the convex shape portion. It is. In the case of the printing plate surface of FIG. 1, the printing surface (2), the color patch (3), the gradation scale (4), and the registration marks (5) are convex.

  Of these, the color patch (3), gradation scale (4), and registration mark (5) are used for inspecting the printed matter and guaranteeing the quality, and are cut and removed in a subsequent cutting step. .

  FIG. 2 shows a wear exchange sign region in the present invention. The wear exchange sign region (6) is provided on at least a part of the convex shape on the printing plate surface (1). There is no limitation as long as it is a convex part, but considering the influence on the printed matter, etc., convex parts other than the printing surface (2), that is, color patch (3), gradation scale (4), registration mark (5 Etc.) at least partially.

  In the first embodiment, the case where the wear replacement sign region (6) is provided in the color patch (3) will be described below.

  As shown in FIG. 2 (b) which is a plan view of FIG. 2 (a) and a cross-sectional view taken along the line AA ′ of FIG. 2 (a), the wear replacement sign region (6) has a non-machined portion. It has a part (8), and the processed part (7) is partially concave with respect to the non-processed part (8).

  The shape of the wear exchange sign region (6) may be any shape such as a line shape such as a straight line, a dotted line, a wavy line, a broken line, or a halftone dot shape such as a gradation scale. However, a complicated shape is not preferable because it may be difficult to determine the presence or absence of appearance. Therefore, a simple straight line or halftone dot that can clearly determine the presence or absence of appearance is preferable.

  For example, when the wear exchange sign region (6) is formed in the shape of a drawing line, a plurality of drawing lines having a predetermined width (W1) are arranged at a predetermined pitch (P1). A wear exchange sign region (6) is formed by applying a concave processed portion (7) having a predetermined depth to the portion.

  When printing is continued using the printing plate surface (1) provided with the wear exchange sign region (6), the printing plate surface gradually wears, and as shown in the cross-sectional view of FIG. The surface and the surface of the non-processed part (8) have the same height.

  The printed matter printed on the printing plate surface (1) in which the surface of the processed portion (7) and the surface of the non-processed portion (8) are at the same height is an exchange sign “×” as shown in FIG. The symbol appears. When this exchange sign appears, it is determined that the quality limit required for the printed material has been reached, and the printing plate (1) is exchanged.

  In the first embodiment, the symbol “x” is used as the exchange sign. However, the present invention is not limited to this, and any form such as a character, a symbol, a stroke, a pattern, or a pattern may be used. However, a complicated exchange sign is not preferable because it may be difficult to determine the presence or absence of an appearance. Therefore, a simple exchange sign that can clearly determine the presence or absence of appearance is preferable.

  The number of wear exchange sign regions (6) needs to be provided in at least one place in the printing plate surface. However, depending on the nature of the printing machine, pressure may not be uniformly applied to the entire surface of the paper or plastic sheet to be printed. In that case, it is preferable to arrange in the place where the pressure is most applied. Further, when the printing machine is a rotary press, the center of the cylinder on which the printing plate is mounted tends to expand due to the influence of heat or the like, so that the contact pressure is increased. Therefore, it is preferable to arrange a total of three locations, one at the center of the printing plate and one at each end.

  Moreover, about the concave shape in the process part (7) of a wear exchange sign area | region (6), the depth and width of a concave are the thickness of a printing plate surface (1), the image line part of a printing surface (2), and a non-image line. It can be arbitrarily determined according to the unevenness difference of the part and the quality limit required for the printed matter. Specifically, the depth and width are determined so that the concave portion of the processed portion (7) is worn away at the height of the image line portion that can maintain the print quality.

  Moreover, about the formation method of a process part (7), if it is a method which can form a recessed part, it will not specifically limit, The formation method by the photoengraving method, the corrosion method, and the engraving processing machine is mentioned as an example.

  However, the photoengraving method is a method of removing the uncured non-image portion after optically curing the image portion, or a method of removing the non-image portion after optically softening, There exists a subject that it is difficult to provide a recessed part accurately. Further, the corrosion method is a method in which the non-image area is exposed by masking the portion of the copper plate that becomes the image area, and the non-image area is corroded using a corrosive solution such as ferric chloride. Due to the influence of the above, there is a problem that it is difficult to accurately provide the concave portion.

  In consideration of these, it is preferable to use a processing machine that can engrave each of the X axis, Y axis, and Z axis with high accuracy, such as an NC engraving machine or a laser engraving machine.

(Second embodiment)
Next, another form of the wear exchange sign region in the present invention will be described. In the second embodiment, the printing plate surface has a two-layer structure including a first layer and a second layer.

  FIG. 3 shows a wear exchange sign region in the second embodiment of the present invention. As for the printing plate surface having a two-layer structure, any one having a two-layer structure as a whole or a part having a two-layer structure can be carried out. However, when a part is a two-layer structure, manufacture of a plate surface base material becomes complicated, and since the plate surface exchange sign is expressed only in a part having a two-layer structure, the entire surface is preferably a two-layer structure.

  As shown in FIG. 3B, which is a cross-sectional view taken along the line AA ′ of FIG. 3A, the first layer (10) is a layer that allows the plate surface to wear, and the second layer (9) is It is provided on the printing plate as a layer that should not be worn. That is, in the second embodiment, all the convex portions on the printing plate surface are formed as the wear exchange sign region.

  If printing is continued using the printing plate surface (1) provided with the wear exchange sign region in the second embodiment, the printing plate surface gradually wears out, and the first plate surface as shown in the sectional view of FIG. The layer (10) will wear and the second layer (9) will be exposed.

  When the printing plate surface (1) from which the second layer (9) is exposed is observed, the hue changes as shown in FIG. When this exchange sign appears, it is determined that the quality limit required for the printed material has been reached, and the printing plate (1) is exchanged.

  At this time, it is easy to understand that the hues of the first layer (10) and the second layer (9) are different, and they have complementary colors such as black and white, yellow and blue, and red and green. It is preferable. Furthermore, it is preferable that the first layer (10) shields the second layer (9) and only the first layer (10) can be observed. Specifically, hues with high color density (black, blue, red) are used for the first layer (10), and hues with low color density (white, yellow, green) are used for the second layer (9). By using it, the first layer having a high color density is worn and the second layer (9) is easily recognized.

  Thus, about 2nd embodiment, the abrasion condition of a printing plate surface is confirmed by the difference of the hue of a two-layer structure. Therefore, when the plate surface is worn at an arbitrary portion in the printing plate surface and the second layer (9) is exposed, the printing plate surface (1) is replaced. As shown in the plan view of FIG. 4A and the cross-sectional view of FIG. 4B, when there is information on the state where the character “C” is rotated 90 degrees to the right, the number of prints is increased as shown in FIG. When the first layer (10) is worn and the second layer (9) is exposed as shown in c), the space portion of the letter “C” is shown in FIG. Disappears and the character “O” is printed.

  The material of the first layer (10) and the second layer (9) is preferably a material that can be easily laser-processed or NC-processed, such as vinyl chloride, PET resin, ABS resin, polyethylene, or polypropylene, and that is easily colored. . There is no problem even if the materials of the first layer (10) and the second layer (9) are different. Furthermore, there is no problem in using the first embodiment and the second embodiment in combination.

  The thickness of the first layer (10) and the second layer (9) can be arbitrarily changed as long as it can be mounted on a printing press as a printing plate. In the case of a general printing machine, the thickness of the plate surface is in the range of 0.3 mm to 2.0 mm, and naturally the first layer (10) and the second layer (9) are formed within the range. There is a need. In addition, if the thickness of the second layer (9) is thin, the ink may adhere to the non-image area, and may adhere to the printing surface that should not be printed as dirt. In order to prevent these printing defects, the thickness of the second layer (9) is preferably 0.2 mm or more.

  The same effect can be obtained not only in the first layer (10) and the second layer (9) but also in a plurality of layers of two or more layers. In this case, there is no restriction | limiting in a several layer, It is preferable to implement in the physically possible range.

  Hereinafter, although the Example of the plate surface produced specifically according to the form for implementing the above-mentioned invention is described in detail, this invention is not limited to this Example.

  Wear exchange for a part of the image area on a vinyl chloride plate surface with a thickness of 0.38 mm and a height of 0.28 mm from the non-image area to the image area. A dent of the sign was given 0.08 mm (using an NC engraving machine) to obtain a printing plate of the present invention.

  The first layer is made of black vinyl chloride having a thickness of 0.1 mm, and the second layer is made of a white vinyl chloride plate substrate having a thickness of 0.48 mm. The plate surface of the present invention was obtained using an NC engraving machine after setting the unevenness of the line part to 0.28 mm.

DESCRIPTION OF SYMBOLS 1 Printing plate surface 2 Printing surface 3 Color patch 4 Gradation scale 5 Registration mark 6 Wear exchange sign area | region 7 Processed part 8 Non-processed part 9 2nd layer 10 1st layer

Claims (3)

A printing plate surface having a convex shape,
At least part of the convex shape on the printing plate surface is provided with a wear exchange sign region, the wear exchange sign region has a processed part and a non-processed part, and the upper part of the processed part is partially A printing plate having a concave shape. A printing plate surface having a convex shape,
At least a part of the printing plate surface is composed of two layers of a first layer and a second layer, and a wear exchange sign region is formed by a boundary portion due to a difference in hue between the first layer and the second layer. A printing plate characterized by comprising:   The printing plate surface according to claim 2, wherein the difference in hue is a complementary color relationship.

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