JP5292745B2 - Gravure printing cylinder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plate cylinder for gravure printing, which can prevent a warpage developed on a web from being printed as a wrinkle. <P>SOLUTION: In the plate cylinder for gravure printing, which enables printing to be executed by transferring ink on the web, a minute cell region formed peripherally is installed at a position in contact with both the axial ends of a printing image region on a plate. The minute cell region is formed peripherally in a length contacting along the total length between both the ends of the printing image region or a length exceeding the total length and is so constituted as to locate both the ends of an effective impression cylinder region respectively within the minute cell region. In addition, a plurality of minute cells each having a size causing no transferring of ink on the web are formed in the minute cell region. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a gravure printing cylinder that performs printing by transferring ink to a web.

Gravure printing is used for various applications, and is also used as a printing method for building materials in addition to ordinary printed matter. In gravure printing, an image area for printing a pattern is formed on the surface of a plate cylinder. In this image area, a minute recess called a cell is formed, and printing is performed on the web by transferring the ink filled in the cell to the web. Recently, various proposals have been made to improve the quality of printing. For example, in Patent Document 1, it is possible to form minute cells in a non-image area that does not contribute to the printing of a pattern and prevent blurring. It is disclosed.
JP 2005-153001 A

  By the way, in conventional gravure printing, if distortion occurs for some reason before the web enters between the plate cylinder and the impression cylinder, the distortion is printed as wrinkles if it enters without improvement. was there. In particular, this wrinkle often occurs near both ends of the web, and the reason is considered as follows. That is, as described above, the plate surface of the plate cylinder has an image area where cells are formed and a non-image area where cells are not formed. The slipping property of the web in contact with the region and the non-image region is different. For this reason, the distortion generated on the web does not slip on the non-image area when pressed between the plate cylinder and the impression cylinder, so that the distortion is not released, resulting in wrinkles. It has been. As shown in FIG. 6, such wrinkles are linearly formed on the upstream side of the web, but are formed so as to expand in the axial direction as they go downstream. It was.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a gravure printing cylinder capable of preventing distortion generated on a web from being printed as wrinkles.

The present invention, the web disposed between the impression cylinder, a gravure printing plate cylinder for printing by transferring ink, which has been made to solve the above problems, on the plate surface and streaked areas and non-printing region formed at a position in contact with both axial ends of the streaked area on the plate surface, provided with a small cell area formed along the circumferential direction, the micro-cell The region is formed to have a length in contact with the entire length of both ends of the image line region along the circumferential direction, or a length exceeding the length, and both ends of the effective impression cylinder region in the minute cell region. In the image area, cells are formed. In the non-image area, no cells are formed. In the micro cell area, ink is transferred to the web. A plurality of minute cells of a size that does not work is formed.

  According to this configuration, a plurality of minute cells are formed in a region that is in contact with both ends of the image area and in which both ends of the effective impression cylinder region are located. When such a minute cell is formed, slipperiness similar to that of the image area can be imparted when the ink is filled. Therefore, even if distortion occurs near both ends of the web, the web slips in the same area as the image area in the both ends, so that the generated distortion is released and can be prevented from wrinkling. . As a result, it is possible to reliably prevent the quality from being wrinkled on the web. The effective impression cylinder area is an area where the pressing force of the impression cylinder acts on the plate cylinder via the web, and usually refers to the axial length of the impression cylinder.

  In such a micro cell, the filled ink needs not to be transferred to the web. For example, the opening width is preferably 40 μm or less, and more preferably 30 μm or less. This opening width indicates the length of the largest portion of the cell openings. For example, if the minute cell is an ellipse, it indicates the long diameter, and if it is a rectangle, it indicates the long side. On the other hand, from the viewpoint of imparting the same slipperiness as that of the image area, the opening width is preferably more than 10 μm, and more preferably 20 μm or more. At this time, the length between adjacent micro cells is preferably 20 μm or more. That is, it is preferable that the distance between the cells in the closest position is 20 μm or more. On the other hand, if it is too far away, the slipping property is lowered, so this interval is preferably 250 μm or less, and more preferably 200 μm or less.

  According to the gravure printing cylinder according to the present invention, it is possible to prevent the distortion generated on the web from being printed as wrinkles.

  Hereinafter, an embodiment of a gravure printing method using a gravure printing cylinder according to the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing a schematic configuration diagram of a gravure printing method according to the present embodiment, and FIG. 2 is a plan view of a plate cylinder, an impression cylinder, and a web.

  As shown in FIG. 1, in gravure printing, a web 3 to be printed is entered between a cylindrical plate cylinder 1 and an impression cylinder 2, and ink on the plate surface of the plate cylinder 1 is transferred to the web. In this method, printing is performed. The plate cylinder 1 and the impression cylinder 2 are arranged so that the rotation shafts 11 and 21 are parallel to each other. The impression cylinder 2 is configured to press the plate cylinder 1 with a predetermined pressure, and the ink is transferred to the web by this pressure.

  As shown in FIG. 2, in the present embodiment, the length in the axial direction increases in the order of the impression cylinder 2, the web 3, and the plate cylinder 1, and the diameter of the plate cylinder 1 is larger than that of the impression cylinder 2. . A rectangular image area 12 is formed on the surface of the plate cylinder 1, and its axial length is smaller than that of the impression cylinder 2. A plurality of recesses, that is, cells corresponding to the pattern to be printed are formed in the image line region 12, and ink filled in the cells is transferred to the web during printing. In addition, minute cell regions 13 in which a plurality of minute cells are arranged are formed at both ends of the image line region 12 in the axial direction. The minute cell region 13 extends axially outward from both ends of the image line region 12 and extends further outward than both ends of the impression cylinder 2. The length of the minute cell region 13 in the circumferential direction is the same as the drawing region. On the printing plate, the areas other than the image line area 12 and the minute cell area 13 are not formed with cells, and constitute a non-print area 14.

  Here, the minute cell 131 is a minute concave portion and has a size such that the filled ink does not transfer to the web 3. The opening shape is not particularly limited, and can be various shapes such as a circle, a rectangle, an ellipse, and a polygon. In addition, the largest opening width “a” is preferably 10 to 40 μm, and more preferably 20 to 30 μm. For example, as shown in FIG. 3, the opening width is the diameter of a circle and the length of one side of a square. Further, the arrangement of the plurality of minute cells 131 is not particularly limited, but as shown in FIG. 4, the interval S between the most adjacent minute cells 131 is preferably 20 to 250 μm, and preferably 20 to 200 μm. Further preferred. Such a minute cell 131 can be formed by various known methods such as engraving and etching in the same manner as the cell in the image area.

  Next, a gravure printing method using the above plate cylinder will be described. In gravure printing, color printing is performed by overlapping a plurality of colors on a web. Here, printing of one color will be described. First, the plate cylinder 1 is immersed in an ink reservoir (not shown), and ink is filled in the cells in the image area 12 and the minute cells 131 in the minute cell area 13. Next, the ink on the printing plate is scraped off by a doctor blade (not shown) so that the ink is filled only into the cells and the minute cells. Subsequently, the web 3 is inserted between the plate cylinder 1 and the impression cylinder 2, and the ink in the cells in the image area 12 is transferred onto the web 3 by pressing with the impression cylinder 2. Thereafter, the color gravure printing is completed by sequentially transferring other colors while drying the ink.

  As described above, according to the present embodiment, a plurality of minute cells 131 are formed in a region in contact with both ends of the image area 12 and both ends of the impression cylinder 2. When such a minute cell 131 is formed, the same slipperiness as that of the image area 12 can be imparted when the ink is filled. Therefore, even if distortion occurs near both ends of the web 3, the web 3 slips in the area at both ends in the same manner as the image area 12, so that the generated distortion is released and prevents wrinkles. be able to. As a result, it is possible to reliably prevent the quality from being wrinkled on the web 3.

  As mentioned above, although one Embodiment of this invention was described, this invention is not limited to the said embodiment, A various change is possible unless it deviates from the meaning. For example, as shown in FIG. 5A, the minute cell region may be formed in the circumferential direction so as to exceed the length of the image line region, or as shown in FIG. It may be formed over the entire area from the end of the line area to the end of the plate cylinder. That is, the area where ink is transferred to the web by the pressure from the impression cylinder, that is, the end of the effective impression cylinder area only needs to be in the minute cell area.

  Next, examples of the present invention will be described. However, it is not limited to the examples under the present invention.

  Below, the gravure printing mentioned above was performed using 16 types of plate cylinders. The sizes of the impression cylinder, the web, and the plate cylinder to be used are as follows. Here, 15 types of plate cylinders in which minute cell regions are formed and one type of plate cylinder in which minute cell regions are not formed were prepared. As the plate cylinder in which the minute cell region is formed, a plate cylinder in which minute cell regions having the same length as the radial direction length are formed at both ends of the image line region as shown in FIG. The size and shape of the minute cell region itself in each plate cylinder are the same, but the formed minute cells are different.

(1) Impression cylinder: 140mm diameter, 990mm length
(2) Web: width 1000mm
(3) Plate cylinder: diameter 320mm, length 1100mm
・ Image area: axial length 960mm, radial length 200mm
・ Small cell area: axial length 30mm, radial length 200mm
(4) Ink Solvent type black ink

上記のような版胴を用い、ウエブの搬送速度を、２００ｍ／ｓ、圧胴による圧力を、１．５ｋｇ／ｃｍ^２として、グラビア印刷を行った。その後、印刷が施されたウエブにおけるシワの有無、及び微少セル領域に対応する領域におけるインキの転移の有無を確認した。結果は、以下の通りである。

Using the plate cylinder as described above, gravure printing was performed at a web conveyance speed of 200 m / s and a pressure of the impression cylinder of 1.5 kg / cm ² . Thereafter, the presence or absence of wrinkles on the printed web and the presence or absence of ink transfer in the region corresponding to the minute cell region were confirmed. The results are as follows.

以上の結果より、微少セル領域を設けることで、シワの発生が防止できていることが分かる。また、各微少セルの開口幅が４０μｍ以下で、且つセル間隔を２０μｍ以上にすると、ウエブへのインキの転移がないことが分かった

From the above results, it can be seen that the generation of wrinkles can be prevented by providing the minute cell region. Further, it was found that when the opening width of each minute cell was 40 μm or less and the cell interval was 20 μm or more, there was no transfer of ink to the web.

1 is a perspective view showing a schematic configuration of an embodiment of gravure printing using a gravure printing cylinder according to the present invention. FIG. 2 is a plan view of a plate cylinder, an impression cylinder, and a web used in FIG. 1. It is a top view which shows the example of the micro cell of the plate cylinder of FIG. It is a top view which shows the example of the micro cell of the plate cylinder of FIG. It is a top view which shows the other example of the plate cylinder of FIG. It is a top view which shows the mode of the wrinkle which arises in the conventional web.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Plate cylinder 12 Image area 13 Minute cell area 131 Minute cell 2 Impression cylinder 3 Web

Claims (2)

A gravure printing cylinder that performs printing by transferring ink to a web arranged between the impression cylinder,
An image area and a non-image area formed on the printing plate;
To a position in contact with the axial end of the streaked area on the plate surface, provided with a small cell area formed along the circumferential direction,
The micro cell region is formed in a length that contacts the entire length of both ends of the image line region along the circumferential direction, or a length exceeding this,
In the minute cell region, it is configured so that both ends of the effective impression cylinder region are located,
A cell is formed in the image area,
No cells are formed in the non-image area,
A gravure printing cylinder in which a plurality of microcells having a size that does not transfer ink to a web are formed in the microcell region. 2. The gravure printing cylinder according to claim 1, wherein each of the microcells has an opening width of 40 μm or less and a length between adjacent microcells of 20 μm or more.

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