JP2001018363A - Method for attaching flexible printing plate and block copy sheet for printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for attaching a flexible printing plate by which it is possible to easily attach the flexible printing plate securely to a plate cylinder, and a block copy sheet for the printing plate. SOLUTION: This method for attaching a flexible printing plate is to attach a flexible printing plate 70 to the plate cylinder of a printing press with a block copy sheet 10 for the printing plate interposed between the plate cylinder and the printing plate 70. The tip of the printing plate 70 is fixed to the block copy sheet 10 by a printing plate fixing means 12 provided on the block copy sheet 10 and both printing plate 70 and block copy sheet 10 are mounted on the plate cylinder simultaneously. Further, the block copy sheet 10 is interposed between the plate cylinder of the printing press and the flexible printing plate 70. The printing plate fixing means 12 for fixing the tip of the printing plate 70 is provided on the tip of the printing plate 70.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for mounting a flexible printing plate on a plate cylinder of a printing press via a printing plate undersheet, and to a printing plate undersheet.

[0002]

2. Description of the Related Art Conventionally, various techniques for mounting a printing plate (hereinafter, also referred to as a "plate") on a plate cylinder of a printing press are known. 6 and 7 show a printing plate 70 and a plate cylinder 61 in a printing press to which the printing plate 70 is mounted. FIG.
6 is a schematic cross-sectional view taken along the line Y-Y in FIG. 7.

As shown in FIG. 6, a plate cylinder 61 of a printing press includes:
It has a shape in which a part of a cylinder is cut in the axial direction of the cylinder, and a groove 65 is provided in a substantially flat surface (hereinafter, referred to as a plane portion 61a) which is a cut end thereof. And the groove 6
The plate 5 includes a plate-end clamp mechanism 62 for holding the plate tip, which is the leading end of the printing plate 70, and a plate-end clamp mechanism 63 for holding the plate tail, which is the rear end of the printing plate 70. Each of the clamp mechanisms 62 and 63 is rotatably supported by the lower teeth 62b and 63b, the upper surface of which forms substantially the same plane as the flat surface portion 61a, and the lower teeth, and holds the plate tip between the lower teeth and the upper surface. And possible upper teeth 62a, 63a.

A top 61c is formed between the plane portion 61a and the curved surface portion 61b of the plate cylinder 61. Although not shown,
In some plate cylinders, the upper surface of the lower teeth of the clamp mechanism forms a top portion between the plate cylinder and the curved surface portion instead of the flat surface portion. Normally, a portion where the plane portion 61a and the curved surface portion 61b intersect is rounded to form a curved surface with a radius of 10 to 20 mm.
Such a portion is also referred to as a top in this specification.

As shown in FIG. 7, positioning pins 64 are projected from the upper surface of the lower teeth 62b of the plate tip clamping mechanism at two places spaced apart in the axial direction of the plate cylinder 61. The positioning pins 64 of the upper teeth 62a of the printing plate clamp mechanism.
A notch 66 is formed at a location corresponding to. A notch 71 is also formed at a position corresponding to the positioning pin 64 on the printing plate 70a of the printing plate 70 indicated by a two-dot chain line in the drawing.

On the other hand, in order to adjust the printing pressure at the time of printing, there is known a technique in which a printing plate under sheet is interposed between a printing plate cylinder and a printing plate, and the printing plate is mounted on the plate cylinder. Have been.

[0007]

By the way, with the recent trend toward smaller lots and diversification of printed matter, a support made of a material other than metal which is inexpensive and easy to handle (eg, plastic film, paper, etc.) has been developed. There is a growing need for flexible printing plates. However, such a printing plate has high flexibility, so that some problems occur when the printing plate is mounted on the plate cylinder.

For example, in the above-described plate cylinder 61 and printing plate 70, assuming that the printing plate 70 is a flexible printing plate, the operator holds the printing plate 70b of the flexible printing plate 70 shown in FIG. When the plate tip 70a of the printing plate is pushed between the upper teeth 62a and the lower teeth 62b of the plate tip clamping mechanism, and the notches 71 of the plate 70 contact the two positioning pins 64, the plate tip 7
0a may be deformed and the printing tip 70a may be fixed in the deformed state. That is, if the operator presses the printing plate 70 a little too much when the printing plate is mounted, the printing plate 70 is deformed so that the plate tip 70a protrudes in the pressing direction from between the two positioning pins 64.
However, if the press-in of the printing plate 70 is insufficient to avoid such deformation, the notch 71 is
In this case, the printing plate 70 cannot be accurately positioned.

As in the above-mentioned example, the mountability of the flexible printing plate to the plate cylinder is poor, and it has been difficult to mount the flexible printing plate on the plate cylinder in a constant state. This means that when this flexible printing plate is applied to multicolor printing (for example, four-color printing) or the like that requires a plurality of plate cylinders and requires precise registration between the plate cylinders, This was a cause of misregistration.
The present invention has been made based on the above background,
It is an object of the present invention to provide a method for mounting a flexible printing plate and a printing plate under sheet that enable a flexible printing plate to be mounted on a plate cylinder reliably and easily.

[0010]

The above object of the present invention is achieved by the following constitution. (1) In a method of mounting a flexible printing plate, wherein the printing plate is mounted on the plate cylinder with a printing plate underlay sheet interposed between a plate cylinder and a flexible printing plate of a printing press, The printing plate fixing means provided in the above, the plate end of the printing plate is fixed to the under sheet, and the printing plate and the under sheet are simultaneously mounted on the plate cylinder, a flexible printing plate How to attach. (2) The printing plate under sheet interposed between the plate cylinder and the flexible printing plate of the printing press, wherein the printing plate is provided with printing plate fixing means for fixing the printing plate. Underprint sheet for printing plate characterized by:

Here, the printing plate fixing means may be a pin protruding from the printing plate of the printing plate and inserted into a hole provided in the printing plate. And a double-sided tape to which a printing plate can be adhered on the other side. When providing pins, it is preferable to provide a plurality of pins so that the distance between the pins is narrower than the distance between the positioning pins projecting from the plate cylinder. The printing plate fixing means may be provided integrally with the underlay sheet, or may be provided separately.

As the sheet-like member used for the underprint sheet for a printing plate, a plastic member such as polyethylene terephthalate, polypropylene, or polyethylene, a metal member such as aluminum or SUS, or a member made of paper, synthetic paper, cloth, or the like can be used. Any material having good fit with the plate cylinder may be used. Also, as the under-print sheet, one having at least one surface formed on a rough surface or an adhesive surface may be used, and the under-sheet may be wound around the plate cylinder such that the rough surface or the adhesive surface is on the front side.

[0013] In the method of mounting a flexible printing plate according to the present invention, the printing plate fixing means provided on the underlay sheet fixes the plate tip of the flexible printing plate to the underlay sheet. The plate and the underlay sheet are simultaneously mounted on the plate cylinder. Therefore, since the printing plate tip of the flexible printing plate is reinforced by the underlay sheet, the printing plate tip does not abut on the positioning pins of the plate cylinder and is not deformed. accurately,
And it can be easily mounted.

[0014] Further, the underplate sheet for a printing plate according to the present invention comprises:
The printing plate is provided with printing plate fixing means for fixing the printing plate. That is, according to the present invention, since the underlay sheet and the printing plate tip are fixed integrally, winding is performed while positioning the underlay sheet on the plate cylinder, which was necessary when using the underlay sheet conventionally. The work and the work of winding while positioning the printing plate on the plate cylinder can be performed simultaneously. Therefore, the work of mounting the printing plate is significantly simplified.

[0015]

Embodiments of the present invention will be described below in detail with reference to the drawings. In addition, about the member already demonstrated, the description is simplified or abbreviate | omitted by attaching | subjecting the same code | symbol in a figure, or an equivalent code | symbol. FIG. 1 shows an underprint sheet 10 for a printing plate according to a first embodiment of the present invention, and a plate cylinder 61 in a lithographic printing press to which the underprint sheet 10 is mounted.

A substantially semi-elliptical notch 1 in a plan view is formed in the under-sheet 10 at a position corresponding to the positioning pin 64 of the plate cylinder 61.
1 is formed. The under-print sheet 10 is positioned at a predetermined distance (hereinafter, referred to as “width”) W1 in a direction perpendicular to the axial direction of the plate cylinder 61 from the side of the plate tip 10a.
Multiple (here 9) fixing pins (printing plate fixing means)
12 project from the plate cylinder 61 at appropriate intervals along the axial direction of the plate cylinder 61. The interval between the fixing pins 12 is smaller than the interval between the positioning pins 64 of the plate cylinder 61.

FIG. 2 is a sectional view taken along line Y1-Y1 in FIG. In FIG. 2, the flexible printing plate 70 fixed to the underlay sheet 10, that is, in a state in which the fixing pins 12 are inserted into holes provided in the printing plate itself, is shown by a two-dot chain line. Here, the fixing pins 12 are cylindrical, and the printing plate 70 is
When it is placed on top, the tip of the fixing pin 12 projects from the surface of the printing plate 70. However, the shape of the fixing pin is not limited, and may be, for example, a prismatic shape, or a shape whose tip does not protrude from the plate surface.

Also, as shown in FIG.
In a state where 0 is overlapped, the plate edge of the printing plate 70 protrudes from the plate edge of the underlay sheet 10 by a predetermined width W2. Here, the leading edge of the underlay sheet 10 and the printing plate 7
Although the zero plate ends are aligned, these plate ends may be slightly offset.

FIG. 3 is a schematic cross-sectional view of Y2-Y2 when the printing plate is fixed to the underlay sheet 10 in FIG. 1 and the underprint sheet 10 and the printing plate tip are clamped by the printing plate clamp mechanism 62. Show. As shown in FIG.
The width W1 from the position where the fixing pin 12 is provided to the leading edge of the plate tip is set to be shorter than the width W3 from the portion of the underlay sheet 10 covering the top 61c of the plate cylinder 81 to the leading edge of the plate tip. You. The tip of the fixing pin 12 does not protrude outward beyond the extension of the outer surface of the printing plate 70 wound on the curved surface portion 61b of the plate cylinder 61.

Hereinafter, an example of a method of mounting the printing plate 70 using the underlay sheet 10 will be described. First, as shown in FIG.
The fixing pins 12 of the underlay sheet 10 are inserted into holes provided in the printing plate 70, and the plate tip of the printing plate 70 is fixed to the underlay sheet 10. Next, the underside sheet 10 and the printing plate 70 are gripped by the bottom of the plate, and the plate is clamped by a plate clamp mechanism 62 shown in FIG.
Between the upper teeth 62a and the lower teeth 62b, and the notch 11 of the under-plate sheet 10 and the similar notch of the printing plate (not shown) are brought into contact with the positioning pins 64 of the plate cylinder 61. next,
The upper teeth 62a and the lower teeth 62b shown in FIG. 1 are closed to fix the under-plate sheet 10 and the plate tip of the printing plate. Then, as shown in FIG. It winds on 61b. When the bottom of the underlay sheet 10 ends just before the top 61c on the side of the bottom edge clamp mechanism 63 as shown in FIG. 6, the bottom of the printing plate 70 is wider than the bottom of the underlay sheet 10. It protrudes by W2. Finally, the protruding plate edge of the printing plate 70 is clamped and fixed by the plate edge clamp mechanism 63 shown in FIG.

According to the printing plate mounting method as described above, the plate tip of the flexible printing plate 70 is fixed to the printing plate 10 by the fixing pins 12 provided on the printing plate 10, and the printing plate 70
And the under sheet 10 are simultaneously mounted on the plate cylinder 61. Therefore, since the printing plate tip of the flexible printing plate 70 is reinforced by the underlay sheet 10 at the time of mounting, the printing plate 70 does not deform even if it comes into contact with the positioning pin 64 of the plate cylinder 61 somewhat. This allows the operator to easily and accurately mount the flexible printing plate 70 on the plate cylinder, reliably prevent misregistration, and significantly reduce the burden on the operator.

In addition, the underlay sheet 10 of this embodiment is provided with a fixing pin 12 for fixing the printing plate 70 of the printing plate 70 at the printing plate, and the printing pin of the printing plate 70 is moved by the fixing pin. The plate 70 is wound around the plate cylinder 61 together with the plate 70 in a state in which the plate 70 is fixed to the sheet, so that the plate 70 is
1 can be attached. Therefore, such an underlay sheet 1
A value of 0 greatly simplifies the work of mounting the plate 70.

The fixing pins 12 of the underlay sheet 10 are
The width W1 of the underlay sheet 10 from the position where the fixing pins 12 are provided to the leading edge of the plate tip is the width W1 of the underlay sheet 10
Is arranged so as to be shorter than the width W3 from the portion covering the top 61c of the printing plate to the leading end of the plate tip, and the leading end of the fixing pin 12 is provided on the outer surface of the printing plate 70 wound on the curved surface portion 61b of the plate cylinder 61. The shape does not protrude outward from the extension surface. Therefore, there is no fear that the fixing pin 12 will be in contact with an ink roller or blanket cylinder (not shown) to damage them.

FIG. 4 shows a second embodiment of the present invention. The undercut sheet 30 has no notch formed in the plate tip 30a. A double-sided tape 32 is adhered to the underplate sheet 10 along the side of the plate tip 30a. Although not shown, when a flexible printing plate is overlaid on the under sheet 30,
As in the first embodiment, the bottom edge of the printing plate is the undersheet 30.
Is projected from the edge of the plate.

FIG. 5 is a schematic cross-sectional view showing a state in which the plate ends of the under-print sheet 30 and the printing plate 70 are clamped by the plate-end clamping mechanism. The plate tip clamping mechanism 82 of the plate cylinder 82 has upper teeth 82a and lower teeth 82b, and a positioning stopper 84 protrudes from the lower teeth 82b. Upper teeth 82
A is provided with an insertion hole into which the positioning stopper 84 is inserted when the upper teeth 82a and the lower teeth 82b are closed. The form of the positioning stopper is not limited, and a pin-like or plate-like one can be employed.

Hereinafter, an example of a method of mounting the printing plate 70 using the underlay sheet 30 will be described. First, the printing plate 70 is overlaid on the underlay sheet 30 with the plate tips aligned, and the printing plate 70 is fixed to the underlay sheet 30 by the double-sided tape 32. Next, the upper edge 82a and the lower tooth 82 of the underplate sheet 10 and the printing plate 70 are gripped by the plate edge and the plate tip is clamped.
b, the plate tip of the underprint sheet 30 and the printing plate 70 are brought into contact with the positioning stopper 84 of the plate cylinder 81.
Next, the upper teeth 82a and the lower teeth 82b are closed to fix the plate tips of the underplate sheet 30 and the printing plate 70, and the underplate sheet 30 and the printing plate 70 are wound around the curved surface portion 81b of the plate cylinder. (See FIG. 5). Finally, the bottom of the printing plate 70 is fixed by a bottom fixing means (not shown). The form of the printing plate fixing means is not particularly limited.

The present invention can be applied to the undercut sheet 30 having no notch as in the underlay sheet 30 described above. 70 can be accurately mounted on the plate cylinder 81, and misregistration can be reliably prevented.

It should be noted that the present invention is not limited to the above-described embodiment, and appropriate modifications and improvements can be made.
For example, in the first embodiment, a notch similar to the notch 11 of the underlay sheet 10 is provided at the plate tip of the printing plate, but when the printing plate 70 is overlaid on the underlay sheet 10 The notch of the printing plate 70 may be larger than the notch of the underlay sheet 10 so that the periphery of the notch 11 of the underlay sheet 10 is exposed inside the periphery of the notch of the printing plate 70 when viewed from above. In this case, the printing plate 70 does not come into contact with the positioning pins 64 of the plate cylinder 61, so that the printing plate 70 is not deformed.

[0029]

As described above in detail, according to the method of mounting a flexible printing plate of the present invention, the printing plate fixing means provided on the underlay sheet allows the printing plate tip of the flexible printing plate to be set. The flexible printing plate and the underlay sheet are fixed to the underlay sheet, and are simultaneously mounted on the plate cylinder. Therefore, since the printing plate tip of the flexible printing plate is reinforced by the underlay sheet, the printing plate tip does not abut on the positioning pins of the plate cylinder and is not deformed. It can be mounted accurately and easily. Further, the printing plate underlay sheet according to the present invention is provided with a printing plate fixing means for fixing the printing plate tip on the plate tip, and the printing plate fixing means fixes the printing plate tip with the printing plate fixing means. The printing plate can be mounted on the plate cylinder by wrapping the underlay sheet together with the printing plate around the plate cylinder in a state of being fixed to the plate cylinder. Therefore, the work of mounting the printing plate and the underlay sheet is significantly simplified.

[Brief description of the drawings]

FIG. 1 is a plan view showing a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line Y1-Y1 in FIG.

FIG. 3 is a sectional view taken along line Y2-Y2 in FIG.

FIG. 4 is a plan view showing a second embodiment of the present invention.

FIG. 5 is a view showing the operation of the underlay sheet of FIG. 4;

FIG. 6 is a view showing a conventional flexible printing plate material.

FIG. 7 is a view showing a conventional flexible printing plate material.

[Explanation of symbols]

 10, 30 Underprint sheet (underprint sheet for printing plate) 10a, 30a Plate tip 11 Notch 12 Fixing pin (Printing plate fixing means) 32 Double-sided tape (Printing plate fixing means) 61, 81 Plate cylinder 62, 82 Plate tip clamp Mechanism 70 printing plate (flexible printing plate)

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Koji Oishi 4000F, Kawajiri, Yoshida-cho, Haibara-gun, Shizuoka F-term in Fujisha Shin Film Co., Ltd. (reference) 2C020 DA02 DA11

Claims (2)

[Claims] 1. A method of mounting a flexible printing plate, comprising mounting a printing plate on the plate cylinder with a printing plate under sheet interposed between the plate cylinder and the flexible printing plate of a printing press, The printing plate fixing means provided on the lower sheet fixes the plate tip of the printing plate to the lower sheet, and simultaneously mounts the printing plate and the lower sheet on the plate cylinder. How to attach the printing plate. 2. A printing plate undersheet interposed between a plate cylinder of a printing press and a flexible printing plate, wherein the printing plate is provided with printing plate fixing means for fixing the printing plate. An underprint sheet for a printing plate, characterized in that: