JP2001219532A - Plate cylinder for gravure printing, method for gravure printing using its plate cylinder as well as method for manufacturing its plate cylinder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To print a part needing a density by an etching type printing plate and to print a color part or the like such as a photograph or the like needing reproducibility by a mechanical engraving type plate, by providing a plate formed of an etching type and a plate formed of a mechanical engraving type in a single plate cylinder for gravure printing. SOLUTION: In the plate cylinder having a plate used for gravure printing on a circumferential surface, the plate has a plate part formed by etching and a plate part formed by mechanical engraving.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a gravure printing plate cylinder used for gravure printing capable of multicolor printing, a gravure printing method using the plate cylinder, and a method of manufacturing the plate cylinder.

[0002]

2. Description of the Related Art Conventionally, a gravure printing method can be used for printing a long plastic film, etc., because a gravure printing method is capable of printing a strong one having a richer gradation and a higher printing speed than other printing methods. Printing method.

As a printing machine used for gravure printing,
The ink stored in the ink tank is adhered to a rotating cylindrical plate cylinder. Then, the ink on the surface of the plate cylinder is removed with a doctor, and the ink remaining in the recesses (cells) formed on the surface of the plate cylinder is transferred to the conveyed film by pressing the ink with the impression cylinder to perform printing. It was done.

Here, the method of making a plate cylinder can be roughly classified into a forming method by etching (etching method) and a forming method by mechanical engraving (mechanical engraving method). Examples of the etching method include a conventional method, a net gravure method represented by a direct method, a laser plate making performed without a film, and the like. In particular, the direct method is most often used because the cylinder (plate cylinder main body) is directly corroded by a corrosive liquid, and process control and the like are easy.

[0005] The plate cylinder formed by the etching method,
As shown in FIG. 3, the cell 50 has a prismatic or cylindrical shape in plan view and cross-sectional shape, and the volume of the cell can be sufficiently increased. Therefore, a sufficient amount of ink can be left in the cell 50, and it is most suitable for printing that requires density and resolution, such as solid printing.

On the other hand, in the mechanical engraving method, a continuous tone negative using a white opaque base is used as an original plate using a device (trade name, Heliocrissograph) manufactured by Hell Co., Ltd. In this method, a diamond needle is finely vibrated in the engraved portion instead of an electric signal, and the surface is engraved while rotating the cylinder to make a plate.

The plate cylinder formed by the mechanical engraving system has a stable tone reproducibility because the diamond needle is electrically controlled (the reprint plate to be manufactured again when the plate cylinder is damaged). Stability), and there is an advantage that the number of work steps for plate making is small and the plate can be manufactured in a short time. In particular, printing parts that require tone reproducibility, such as color printing and pictures such as photographs, are mainly reproduced with sumi, eye, red, and key, and plates formed by mechanical engraving are used. is the current situation.

[0008]

In a conventional plate cylinder, a plate cylinder formed by an etching method and a plate cylinder formed by a mechanical engraving method are separate bodies. In general, a case where only a plurality of plate cylinders are used in combination and a case where only a machine engraving type plate cylinder is used in combination are generally used.

Therefore, the plate cylinder of the mechanical engraving system is inferior in resolution of fine lines as compared with that of the etching system, and therefore, for example, Japanese characters (usually printed with a Sumi plate) used for text and the like are used. As described above, there is a problem that a portion that requires the resolution of a thin line cannot be reproduced well and a density cannot be obtained.

[0010] On the other hand, the plate cylinder of the etching system has a problem in that, in reproducing a pattern, the whole pattern is generally tightened, that is, the pattern lacks sharpness and the resolution is insufficient.

Specifically, the cross-sectional shape of the plate cylinder cell 50a formed by the etching method is substantially rectangular, whereas the shape of the plate cylinder cell 50a formed by mechanical engraving is shown in FIG. As shown in FIG. 4, it has a substantially pyramid shape.

The fact that the cross-sectional shape of the cell 50a in the mechanical engraving method is a pyramid shape means that the cell volume at the shadow portion (bottom portion of the cell) is smaller than the cell volume obtained by etching. In other words, the plate cylinder of the mechanical engraving method has a smaller amount of ink in the shadow portion than the plate cylinder of the etching method. Therefore, when such a plate cylinder of the mechanical engraving method is used, the ink amount in the shadow portion tends to be insufficient, and the ink amount tends to be insufficient particularly in the case of two to four colors of Sumi, Eye, Red, and Yellow. In a portion to be overlapped, as a result of the accumulation of the shortage of the ink amount, the shortage of the ink amount is conspicuously manifested, resulting in a printed matter lacking in thickness.

According to the present invention, a single printing cylinder for gravure printing is provided with a plate portion formed by an etching method and a plate portion formed by a mechanical engraving method, so that a portion requiring concentration can be printed by an etching method. It is an object of the present invention to print on a plate portion and to print a color portion of a photograph or the like that requires reproducibility on a plate portion of a mechanical engraving system.

[0014]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention has been made as a plate cylinder for gravure printing, a gravure printing method using the plate cylinder, and a method of manufacturing the plate cylinder. The feature as a plate cylinder for gravure printing is a plate cylinder having a plate used for gravure printing on a peripheral surface, and the plate is formed by etching a plate portion and mechanical engraving. And a plate section.

The plate cylinder has both functions of printing on a plate portion by etching with excellent fine line resolution and printing on a mechanically engraved plate portion with excellent tone stability and reproducibility. As a result, a well-balanced printed material can be obtained.

A feature of the gravure printing method using the plate cylinder is a gravure printing method for performing multicolor printing using a plurality of plate cylinders according to claim 1, wherein the plate cylinder is a machine-engraved plate. A part is formed on each of the separated images obtained by color separation of the same image, and printing is performed by printing the separated images of the respective plate cylinders together.

And a plate portion formed by etching;
In order to perform printing by combining a plurality of plate cylinders having both plate portions with a machine engraved plate portion, the entire plate is compared with a printing method using a plurality of plate cylinders having only one of the plate portions. The number of cylinders can be reduced, and the manufacturing cost can be reduced. Even if one of the plate cylinders is damaged, printing requiring reproducibility, such as color printing, can be performed on the machine-engraved plate portion. Can be easily and reliably performed, and its reproducibility is excellent.

A feature of the method for manufacturing a plate cylinder is a method for manufacturing a plate cylinder for gravure printing, which forms a plate used for gravure printing on the peripheral surface of the plate cylinder main body. A marker is provided at a position, a plate portion is first formed by etching with reference to the marker, and further, a plate portion is formed by mechanical engraving with reference to the marker in a portion of the plate cylinder body other than the plate portion by etching. Is to do.

In order to form a plate portion by etching and a plate portion by mechanical engraving on the basis of the marker,
Without displacing each plate part to a predetermined position,
It can be formed reliably. Moreover, by forming the plate portion by etching first, the plate portion by mechanical engraving can be processed with excellent reproducibility without being affected by chemicals by etching.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 2 schematically shows a gravure printing machine. The gravure printing machine includes a plurality of ink tanks 5 each storing a predetermined color ink 3, and a cylindrical plate cylinder 7 that rotates so as to apply the ink in each ink tank 5.
And a doctor 8 for scraping excess ink on the surface of the plate cylinder 7
And an impression cylinder 10 for pressing the ink remaining in the recesses (cells) formed on the peripheral surface of the plate cylinder against the conveyed sheet 9 to transfer the ink to a sheet (film or the like) and print the same. ing.

For example, in the case of back printing on a transparent film, the plate cylinder is used for the printing plate cylinder 7 from the upstream side in the sheet conveying direction.
a, eye plate cylinder 7b, red plate cylinder 7c, and key plate cylinder 7d
Is arranged. When printing on a sheet of paper or the like, the order of the plate cylinders for each color is reversed.

A plate portion (etching plate portion) 12 formed by an etching method is provided on the surface of each plate cylinder 7.
Plate part formed by mechanical engraving method (machine engraving plate part) 1
3 is provided. A plate is constituted by the etching plate portion 12 and the mechanical engraving plate portion 13. Each plate cylinder 7a, 7
The mechanical engraving plates 13 of b, 7c, and 7d are formed on the separated images obtained by color separation of the same image (photograph or the like). Therefore, by printing the separated images of the respective plate cylinders together to perform printing, desired color printing requiring stability and reproducibility can be performed.

The etching plate portion 12 can apply characters, barcodes, solid printing, or the like, which require density, and can impart sharpness to characters or lines.

In manufacturing the plate cylinder, as shown in FIG. 1, first, a marker 1 serving as a reference is attached to one end of a cylinder 7a.
Add 5. First, plate making is performed at a predetermined position of the plate cylinder 7 using a conventionally known etching method.

Next, a portion of the cylinder 7a where a plate is not made is made by mechanical engraving. That is, the diamond needle is finely vibrated in the engraved portion by applying an electric signal with the marker 15 as a reference, and the surface is engraved while rotating the cylinder 7a to make a plate.

The present invention is not limited to the above-described embodiment, and the plate formed on each cylinder is not limited to a single plate, and a plurality of plates can be provided in the axial direction and circumferential direction of the cylinder.

[0027]

As described above, according to the present invention, it is possible to perform gravure printing having the advantages of both the etching system and the mechanical engraving system. That is, for example, the character portions of the Sumi plate and the Aka plate are formed by an etching method, and the remaining portion of the Sumi plate and the Aka plate, the key plate and the eye plate (for example, color printing of a photograph or the like) are formed by a mechanical engraving method. By sequentially printing each color using the plate cylinder formed in this way, it is possible to obtain the stability of the pattern (photograph etc.) by the plate formed by the mechanical engraving method, and the resolution by the etching type plate portion. Character can be reproduced, and a well-balanced printed matter can be printed as a whole.

Even if the plate cylinder is damaged, printing requiring reproducibility, such as color printing, can be performed on the machine-engraved plate portion. Can be easily and reliably performed, and its reproducibility is excellent.

[Brief description of the drawings]

FIG. 1 shows an embodiment of a plate cylinder according to the present invention, wherein (a) is a perspective view showing a state where a plate portion is formed on a cylinder by an etching method, and (b) is a plate portion further formed by a mechanical engraving method. The perspective view of a state.

FIG. 2 is a schematic view showing the printing process.

3A and 3B show a conventional example, and FIG. 3A is a plan view of a plate cylinder cell formed by an etching method, and FIG.

FIG. 4A is a plan view of a plate cylinder cell formed by a mechanical engraving method, and FIG.

[Explanation of symbols]

7: plate cylinder, 7a: plate cylinder main body, 12: plate portion formed by etching, 13: plate portion formed by mechanical engraving, 15: marker

Claims (3)

[Claims] 1. A plate cylinder having a plate used for gravure printing on a peripheral surface thereof, wherein the plate includes a plate portion formed by etching and a plate portion formed by mechanical engraving. Plate cylinder for gravure printing. 2. A gravure printing method for performing multicolor printing using a plurality of plate cylinders according to claim 1, wherein each of the plate portions on which the same image is color-separated is machine-engraved. A gravure printing method, wherein a gravure printing method is performed in which a separation image is formed on a separation image, and the separation image of each plate cylinder is printed. 3. A method for producing a plate cylinder for gravure printing, wherein a plate used for gravure printing is formed on a peripheral surface of a plate cylinder main body, wherein a marker is provided at a predetermined position on the plate cylinder main body, and the marker is provided. First, form a plate part by etching,
Further, a method for producing a plate cylinder for gravure printing, characterized in that a plate portion is formed by mechanical engraving on a portion other than the plate portion of the plate cylinder body by the etching with reference to the marker.