JP2004276489A - Sheet for flexography - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet for flexography capable of being fastened tight on a printing cylinder so that a cushioning board interposed between the printing cylinder and the sheet becomes easily and accurately a specific thickness. <P>SOLUTION: The sheet for flexography 10 winds round almost the whole periphery of the printing cylinder 20 via a cushioning board 7. The sheet 10 is fixed by making the cushioning board 7 into a state of being compressed in a thickness direction by attracting one end part 12 to the other end part 11. A mark 15 for recognizing that the cushioning board 7 is compressed to a specific thickness is marked near the one end 12 to feature the sheet for flexography. The mark 15 is marked at a position conforming to a mark 27 provided to the printing cylinder 20. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flexographic printing sheet used in flexographic printing, which is most suitable for printing on cardboard, small labels, and the like. More specifically, a flexographic printing sheet wound around a printing cylinder (plate cylinder) via a cushion disk. About.
[0002]
[Prior art]
Flexographic printing, which can be printed on corrugated cardboard with a rough surface, labels that display various information in small areas, and polyamide-based synthetic fiber films with high precision, has the reproducibility of halftone dots and color It is excellent in stability and the like, and has the feature that not only can characters and lines be printed sharply, but also water-based ink and completely solvent-free ink can be used.
[0003]
As shown in FIG. 3, a printing press for such flexographic printing includes a fountain roller 3 for sucking ink 2 stored in an ink pan 1, an anix roller 5 for transferring the sucked ink 2 to a printing plate 4, and a printing press. A transparent sheet 10 for flexographic printing to which the plate 4 is to be attached, a printing cylinder (plate cylinder) 20 around which the sheet 10 is wound, and a pressurizing cylinder (which presses the conveyed band-shaped printing material W against the printing plate 4 ( (Impression cylinder) 6 and the like. The printing plate 4 is formed of, for example, about half the length of the sheet 10 with a flexible rubber or a photosensitive resin, and the entire surface is adhered to the surface of the sheet 10 with a double-sided adhesive tape. The sheet 10 is made of a transparent polyester material and has a length substantially equal to the outer circumference of the printing cylinder 20, and bar-shaped hooks 13 and 14 are provided at both ends 11 and 12 over the entire width as shown in FIG. Fixed.
[0004]
A groove-shaped concave portion 21 is formed in the surface of the printing cylinder 20 in the longitudinal direction, and a fitting 22 for fixing the hooks 13 and 14 is fitted in the concave portion 21. The attachment 22 includes a fixing groove 23 into which one of the hooks 13 is fitted, a gutter-like portion 24 having a C-shaped cross section, and a shaft 25 rotatably inserted into the gutter-like portion 24. On the surface of the shaft 25, a rotation groove 26 into which the other hook 14 is fitted is formed in the longitudinal direction.
[0005]
Then, the sheet 10 to which the printing plate 4 is adhered is wound around the outer periphery of the printing cylinder 20 so that the printing plate 4 is exposed to the outside, and each of the hooks 13 and 14 fixed to both ends 11 and 12 is attached. The fitting 22 is fitted into the fixing groove 23 and the rotating groove 26. The locking member 13 fitted in the fixing groove 23 is fixed, and the locking member 14 fitted in the rotating groove 26 is wound around the bottom side of the gutter-like portion 24 by rotation of the shaft 25, and The other end 12 is drawn toward the one end 11. The sheet 10 is thus fastened, the back surface of the sheet 10 is in close contact with the front surface of the printing cylinder 20, and the printing cylinder 20 is fastened.
[0006]
By the way, the distance from the surface of the printing material W to the surface of the printing cylinder 20 is generally set to 7 mm. Therefore, a conventional printing plate 4 having a size of about 7 mm was used. However, a thin printing plate 4 having a thickness of about 3 mm has recently been used in order to make it possible to print neatly and to reduce costs.
[0007]
When a thin printing plate 4 is used, a cushion plate (not shown) of about 4 mm is arranged between the sheet 10 and the printing cylinder 20. The cushion board is located at a position overlapping with the back surface of the printing plate 4 via the sheet 10 and is attached to the back surface of the sheet 10 or is attached to the surface of the printing cylinder 20. In addition, the cushion disk is formed into a continuous foam using a material such as rubber or urethane foam.
[0008]
Patent Document 1 discloses a flexographic printing raising member provided with a 3 mm-thick printing plate and an approximately 4 mm-thick cushion plate, and a photosensitive printing plate winding method.
[0009]
[Patent Document 1]
JP 2002-347364 A
[Problems to be solved by the invention]
By setting the printing plate 4 to bite into the printing material W by, for example, only 0.1 mm, it is possible to print clearly on the printing material W. Since the distance from the surface of the printing substrate W to the surface of the printing cylinder 20 is set to be 7 mm, the thickness from the surface of the printing cylinder 20 to the surface of the printing plate 4 is preferably 7.1 mm.
[0011]
For example, assuming that the printing plate 4 is 3 mm thick, the sheet 10 is 0.19 mm thick, the double-sided tape is 0.1 mm thick, and the cushion board is 4 mm thick including the adhesive to be attached to the sheet 10, the printing cylinder is The thickness from the surface of the plate 20 to the surface of the printing plate 4 is 7.29 mm. Therefore, the operator has to rotate the shaft 25 of the fixture 22 and tighten the seat 10 to compress the cushion board by 0.19 mm in the thickness direction so that the thickness becomes 3.81 mm.
[0012]
However, it is difficult to judge that the thickness of the cushion board has become 3.81 mm by tightening the sheet 10, and it is not possible to prevent the printing plate 4 from penetrating the printing material W by 0.1 mm. is there. Therefore, in a printing press in which a cushion board is interposed between the printing plate 4 and the printing cylinder 20, characters and line drawings are blurred or crushed, which is a feature of flexographic printing. May not work. The same applies to the flexographic printing raising member disclosed in Patent Document 1.
[0013]
Therefore, an object of the present invention is to provide a sheet for flexographic printing that can be fastened to a printing cylinder so that a cushion disc interposed between the printing cylinder and the cushion board easily and accurately has a predetermined thickness. I do.
[0014]
[Means for Solving the Problems]
The sheet for flexographic printing according to the present invention is wound around almost the entire circumference of the printing cylinder via the cushion disk, and the other end is pulled toward one end, thereby fixing the cushion disk in a state compressed in the thickness direction. The flexographic printing sheet is characterized by being provided with a mark for recognizing that the cushion board has been compressed to a predetermined thickness.
[0015]
According to the sheet for flexographic printing, the worker pulled the other end to one end of the sheet because the mark for recognizing that the cushion disk was compressed to a predetermined thickness was added. At times, it can be determined that the cushion disk is compressed and has a predetermined thickness, using the mark as a guide. The predetermined thickness is a thickness of a cushion board for enabling clear printing, for example, a printing plate attached to the surface of a sheet is only 0.1 mm on a printing material. It is the thickness of the bite.
[0016]
Further, in the flexographic printing sheet, it is preferable that the mark is provided near the other end and in a position overlapping a mark of a printing cylinder. According to this flexographic printing sheet, the vicinity of the other end where the mark is attached is drawn toward the one end, and when the mark overlaps with the mark of the printing cylinder, the operator can move the cushion board to a predetermined thickness. It can be determined that the data has been compressed. In addition, the mark of the printing cylinder can be, for example, an edge of a concave portion formed in the printing cylinder or a symbol or code set on the printing cylinder.
[0017]
In the flexographic printing sheet, it is preferable that the mark is constituted by a scale. According to the flexographic printing sheet, since the mark is formed by the scale, the tightening adjustment of both ends of the sheet can be finely adjusted.
[0018]
Further, in the flexographic printing sheet, the mark is preferably attached to a label to be attached. According to the sheet for flexographic printing, the work is easier than directly attaching a mark to the sheet, and even if the sheet is already in circulation, the present invention is applied by attaching a label provided with the mark. Can be implemented.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
One embodiment of a sheet for flexographic printing according to the present invention will be described with reference to FIGS. The same parts as those in the related art are denoted by the same reference numerals, and description thereof is omitted.
[0020]
The sheet 10 for flexographic printing according to the present embodiment is characterized in that a mark 15 for recognizing that the cushion board 7 interposed between the sheet 10 and the printing cylinder 20 has a predetermined thickness is provided. . The mark 15 serves as a guide to tighten the sheet 10 wound around substantially the entire circumference of the printing cylinder 20 via the cushion disk 7.
[0021]
That is, the hook 13 fixed to the one end 11 of the sheet 10 is fitted into the fixing groove 23 (see FIG. 4) of the mounting tool 22 (see FIG. 4) fitted into the concave portion 21 of the printing cylinder 20, and the other. When the shaft 25 is rotated in a state where the end portion 12 is fitted in a rotation groove 26 formed in the shaft 25 of the mounting tool 22, the other end portion 12 is drawn to the one end portion 11, and thus the position of the mark 15 is set. Thus, the degree to which the other end 12 of the sheet 10 is pulled toward the one end 11 can be determined.
[0022]
Then, when the other end 12 of the sheet 10 is pulled to a predetermined position, a mark 27 on which the mark 15 overlaps is set on the printing cylinder 20. The mark 27 can utilize the edge of the concave portion 21 on the side where the shaft 25 is arranged. However, the mark 27 may be a symbol or code such as a straight line, a circle or a triangle, and may be formed by attaching a seal or the like to the surface of the printing cylinder 20, applying ink or the like, or engraving.
[0023]
The mark 15 attached to the sheet 10 has a shape corresponding to the mark 27 set on the printing cylinder 20. That is, when the mark 27 of the printing cylinder 20 is an edge or a straight line of the concave portion 21, the mark is a straight line. Further, when the mark 15 is constituted by a scale provided in the length direction of the sheet 10, fine adjustment can be performed in accordance with various printing materials W having different thicknesses, materials, and the like.
[0024]
Such a mark 15 is provided by attaching a label 16 to the sheet 10. A reference line (not shown) such as a line indicating a direction or a center line is drawn on the label 16, and the label 16 is attached so as to match the reference line (not shown) drawn on the sheet 10. Therefore, the label 16 is preferably made of a material capable of drawing the mark 15 and the reference line, and is preferably transparent. However, in the case of the label 16 made of a non-transparent material, the reference line can be constituted by a slit.
[0025]
It is preferable that such a label 16 is adhered to the back surface of the sheet 10 so that the label 16 is hard to be peeled off and dirty. The label 16 is attached to the sheet 10 so that the label 16 can be applied to the sheet 10 in circulation. Note that the mark 15 may be drawn directly on the sheet 10.
[0026]
Then, the sheet 10 with the mark 15 is attached with the printing plate 4 exposed to the outside, and the hook 13 fixed to the one end portion 11 with the cushion disc 7 joined to the printing cylinder 20 is attached. The hook 14 fixed to the other end 12 is fitted into the rotating groove 26 formed on the shaft 25, while being fitted into the fixing groove 23 of the fitting 22 fitted into the recess 21 of the printing cylinder 20. At this time, the mark 15 attached to the sheet 10 is located at a position away from the mark 27 of the printing cylinder 20.
[0027]
Then, by rotating the shaft 25, the hook 14 fixed to the other end 12 of the sheet 10 is rolled into the bottom side of the gutter-like portion 24. Then, the diameter of the seat 10 is reduced, and the cushion board 7 is compressed in the thickness direction. Further, since the other end 12 of the sheet 10 is pulled toward the one end 11, the mark 15 approaches the mark 27 of the printing cylinder 20. When the mark 15 on the sheet 10 overlaps the mark 27 of the printing cylinder 20, the operator stops the rotation of the shaft 25.
[0028]
When the rotation of the shaft 25 is stopped, for example, the cushion board 7 which was initially 4 mm thick is compressed to 3.81 mm thick, and the thickness from the surface of the printing cylinder 20 to the surface of the printing plate 4 is 7.1 mm. It becomes. When the distance from the surface of the printing cylinder 20 to the surface of the printing material W is 7 mm, the printing plate 4 is in a state of being cut into the printing material W by 0.1 mm, and the printing material W is printed clearly.
[0029]
In this manner, clear printing can be performed only by pulling the other end 12 of the sheet 10 toward the one end 11 so that the mark 15 attached to the sheet 10 overlaps the mark 27 of the printing cylinder 20.
[0030]
The present invention is not limited to the above-described embodiment, but can be variously modified within the scope of the technical matters described in the claims. For example, when the sheet 10 is fixed so that both ends 11 and 12 thereof overlap each other, marks 15 and 15 may be added to both ends 11 and 12 of the sheet 10. Further, even when the regulating members (not shown) for preventing the cushion board 7 from being compressed to a predetermined thickness or more are provided on both sides of the cushion board 7, the same operation can be performed. it can.
[0031]
【The invention's effect】
According to the present invention, the degree to which the other end is drawn to one end of the sheet is clear because the mark for recognizing that the cushion board has a predetermined thickness is attached to the sheet for flexographic printing. Therefore, the cushion board can be easily and accurately compressed to a predetermined thickness. Therefore, the printing material printed by the printing machine equipped with the sheet of the present invention can sufficiently exhibit the features of flexographic printing, such as high density and powerful printing.
[Brief description of the drawings]
FIG. 1 is a perspective view of a printing cylinder in the process of winding a sheet for flexographic printing according to an embodiment of the present invention. FIG. 2 is a perspective view of a printing cylinder in which a sheet for flexographic printing of the embodiment of the present invention is wound. FIG. 3 is a schematic view of a printing machine for flexographic printing. FIG. 4 is an enlarged front view of a main part of a printing cylinder constituting the printing machine for flexographic printing.
7 Cushion board 10 Sheet (for flexographic printing) 11 One end 12 End 15 Mark 16 Label 20 Printing cylinder 27 Mark

Claims (4)

A sheet for flexographic printing, which is wrapped around substantially the entire circumference of a printing cylinder via a cushion disc and attracts the other end to one end to fix the cushion disc in a compressed state in the thickness direction,
A mark for recognizing that the cushion disc has been compressed to a predetermined thickness, which is provided with a mark for flexographic printing. 2. The flexographic printing sheet according to claim 1, wherein the mark is provided near the other end and at a position overlapping a mark of a printing cylinder. 3. The flexographic printing sheet according to claim 1, wherein the mark is configured by a scale. The sheet for flexographic printing according to any one of claims 1 to 3, wherein the mark is attached to a label to be attached.

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