JP2004230739A - Preventing method against abrasion of form roller and printing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce a circular abrasion of a form roller caused in the direction of rotation by a press plate edge, to stabilize the amount of ink transfer to press plates different in size and to prevent faulty printing on the surface of printing paper. <P>SOLUTION: In a printing method comprising a process (I) wherein a plurality of press plates 3 are juxtaposed perpendicularly to the axial direction on a plate cylinder 2 of a rotary press and inked from the form roller 1 composed of a core 5 and a rubber layer 6 covering the surface of the core 5 and printing is conducted in many times and a process (II) wherein the press plates 3 are replaced by press plates 3' different from the plates 3 in size subsequently to the process (I) and the plates 3' are inked from the form roller 1 to conduct printing, the form roller 1 is reciprocated axially in the width of reciprocation of 2-10 mm and in the number of times of reciprocation of 0.01-0.25 per one revolution of the plate cylinder 2, at least in the process (I). <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for preventing abrasion of an inking roller by edges of a plurality of printing plates arranged in parallel on a plate cylinder of a rotary printing press, and a printing method using the same. ADVANTAGE OF THE INVENTION According to this invention, while abrasion of a roller is suppressed and a life is extended, when it replaces with a printing plate of a different size and prints, color missing or color unevenness may occur at a position corresponding to the plate edge portion before replacement. Such printing defects do not occur.
[0002]
[Prior art]
Conventionally, for the purpose of evenly supplying ink to a printing plate in a rotary press, in order to properly distribute ink in the axial direction of an ink mixing roller, an ink mixing roller, an ink forming roller, It is known to provide a reciprocating roller capable of reciprocating in the axial direction, in addition to the roller. However, in this method, the shading of the ink remains on the inking roller after the ink has been transferred to the printing plate, and even on the reciprocating roller, and the uniformity of the ink on each roller is not always sufficient. Absent.
[0003]
In order to improve this, for example, Japanese Patent Application Laid-Open No. 6-122187 discloses an inking roller disposed in contact with a plate so as to supply ink to the plate mounted on the plate cylinder, and an inking roller. An ink cylinder or ink roller disposed in contact with the inking roller on the upstream side of the roller, and inking at a position after contact with the plate during rotation of the inking roller and before contact with the ink cylinder or inking roller; A roller arrangement including an ink mixing roller disposed in contact with the peripheral surface of the roller, and an ink mixing roller and an ink forming roller, or any one of them is provided so as to be able to reciprocate in the axial direction. An inking device having a reciprocating means for reciprocating in the axial direction so that the contact portions rub against each other is disclosed (see Patent Document 1).
[0004]
As described above, conventionally, reciprocating motion of a specific roller has been studied for the purpose of uniformity of ink supply to the printing plate due to shading of the remaining ink on the roller. As such a technique, for example, a technique of rotating an ink cylinder in a circumferential direction and simultaneously vibrating about 35 to 48 mm in a horizontal direction in the left and right directions is disclosed (see Non-Patent Document 1).
When printing a pattern whose density changes suddenly in the width direction, a metal ink reciprocating roller in contact with the inking roller is rotated with a stroke of 30 to 40 mm for two rotations of the plate cylinder in order to prevent ghost from occurring. One reciprocation is performed to reciprocate left and right, so as to adjust the unevenness in the width direction (see Non-Patent Document 2).
However, the above technique does not relate to the reciprocating motion of the inking roller itself.
[0005]
In order to solve the problems associated with high speed and wide amplitude, for example, Japanese Patent Laid-Open No. 7-40529 discloses that two inking rollers having different diameters have the same mass and are reciprocated in opposite directions to prevent vibration and the like. (See Patent Document 2).
Also, for example, Japanese Patent Application Laid-Open No. 7-323521 discloses that the ink reciprocating roller is disposed between the kneading roller and the ink reciprocating roller in order to prevent the rotation fluctuation of the ink reciprocating roller and, consequently, the rotation fluctuation of the plate cylinder and to prevent a printing trouble. If the rotational speed of the ink reciprocating roller is equal to or higher than the rotational speed of the motor, the one-way clutch does not transmit the rotation of the motor to the ink reciprocating roller. The roller is rotated at a high speed by the kneading roller, and when the invoking roller, which has come into contact with the ink source roller and having a low speed, comes in contact with the high-speed ink reciprocating roller via the transfer roller or directly, and the invoking roller is accelerated, The ink reciprocating roller has a braking effect due to the inertia of the retrieving roller, and the rotation speed of the ink reciprocating roller slightly decreases, and the ink reciprocating roller Rotational speed of 5 slower technique is disclosed than the rotational speed of the motor (see Patent Document 3).
However, these prior arts are techniques for controlling a calling roller, a transfer roller, an ink reciprocating roller, and the like to suppress a problem at the time of printing, and do not relate to a reciprocating motion of the ink forming roller itself.
[0006]
On the other hand, as shown in FIGS. 1 and 3, when printing a newspaper or the like using a rotary printing press, first, for example, four plates of A1 plate are first placed on the plate cylinder in a direction perpendicular to the axial direction. After printing in juxtaposition, if two of the printing plates of the A1 plate are replaced with one printing plate of the A0 plate and printing is performed, the edge of the original A1 plate comes into contact with the edge of the original A1 plate at high speed for a long time. At the position corresponding to the edge between the printing plates on the inking roller, abrasion occurs in the direction of rotation in the direction of rotation, and due to the worn portion, during printing of the A0 plate, color loss or the like occurs at the position corresponding to the original A1 printing plate. Color unevenness occurs.
Such a problem has not been solved by the above-described conventional technology.
[0007]
[Patent Document 1]
JP-A-6-122187 (Claims 1 and 2, FIGS. 1 and 2)
[Patent Document 2]
Japanese Patent Application Laid-Open No. 7-40529 (Claims 1 and 2, FIG. 5)
[Patent Document 3]
JP-A-7-323521 (Claim 1, FIGS. 1 and 2)
[Non-patent document 1]
"Newspaper Printing, Revised Edition", Published by The Japan Newspaper Association, published on October 31, 1980, page 33, line 20-25 [Non-Patent Document 2]
Keiji Yori et al., "Offset Printing Press Revised Edition", Published by Nippon Printing Newspaper, September 10, 1992, pp. 99-100, (5) Ink reciprocating roller
[Problems to be solved by the invention]
In the rotary printing press, it suppresses the occurrence of abrasion that occurs in the form of a ring in the rotating direction due to the plate edge of the ink forming roller, stabilizes the amount of ink transferred to printing plates of different sizes, and causes color loss and color unevenness on the printing paper surface. And other printing problems.
[0009]
[Means for Solving the Problems]
The present inventors have conducted intensive studies and as a result, by making the ink forming roller in the rotary printing press reciprocate at a specific low speed and a specific width in the axial direction, the wear of the ink forming roller can be suppressed, and the above problem is solved. They have found that they can be solved, and have completed the present invention.
[0010]
That is, a first aspect of the present invention is that a printing plate (3) is installed on a plate cylinder (2) of a rotary press in a direction perpendicular to an axial direction, and a core material (5) and a core material (5) are formed. A method of printing by applying ink to the printing plate (3) from an inking roller (1) comprising a rubber layer (6) covering the surface,
A printing plate for an inking roller, wherein the inking roller (1) is reciprocated in the axial direction with a reciprocating width of 2 to 10 mm and a reciprocating frequency of 0.01 to 0.25 per rotation of the plate cylinder (2). A method for preventing abrasion by edges is provided.
A second aspect of the present invention is that a plurality of printing plates (3) are juxtaposed perpendicularly to the axial direction on a plate cylinder (2) of a rotary press, and a core material (5) and a core material (5) are formed. A step (I) of performing inking on the printing plate (3) by inking the printing plate (3) from an inking roller (1) comprising a rubber layer (6) covering the surface, and printing the printing plate many times, and a printing plate following the step (I) Step (II) of replacing (3) with a printing plate (3 ') having a size different from that of the printing plate (3) and applying ink from the inking roller (1) to the printing plate (3'). At least in step (I), the ink forming roller (1) is reciprocated in the axial direction with a reciprocating width of 2 to 10 mm and a reciprocating frequency of 0.01 to 0.25 per rotation of the plate cylinder (2). A method for preventing abrasion of an inking roller by a plate edge, which is characterized in that it is moved.
A third aspect of the present invention provides a method for preventing abrasion by an edge of a plate of an inking roller according to the first or second aspect of the present invention used for printing newspaper.
According to a fourth aspect of the present invention, there is provided a printing method for preventing inconvenience of printing on a printing paper surface, using the method for preventing abrasion by a plate edge of an inking roller according to any one of the first to third aspects of the present invention. I do.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a diagram showing a relationship between a printing plate and an ink forming roller in a conventional rotary printing press. A plurality of printing plates 3 (for example, four printing plates of the same size (3-1 to 3-4) in FIG. 1) are juxtaposed on the rotary plate cylinder 2 perpendicularly to the axial direction. . An inking roller 1 is provided for supplying ink to the printing plate 3 on the plate cylinder. Although not shown, the supply of ink to the ink forming roller 1 is performed from an ink supply vat via an ink cylinder or an ink metering roller.
The printing plate 3 is usually made of metal or hard resin. As shown in FIG. 2, the printing surface of the printing plate 3 is raised, for example, by about 0.5 mm from the surface of the plate cylinder 2, and the edge has an edge shape.
The inking roller 1 includes a core material 5 and a rubber layer 6 covering the surface of the core material 5. The material of the rubber layer 6 is not particularly limited as long as it has ink resistance. For example, a nitrile rubber having a JIS A hardness of 20 to 50 degrees is preferably used.
[0012]
Therefore, when the printed matter such as newspaper is used for printing for 90 to 180 days in the above-described configuration, the edge-shaped portion of the printing plate on the inking roller 1 has a width of about 0.5 to 1 mm and a depth of about 0.5 to 1 mm. Abrasion portions 4 of about 0.05 to 0.4 mm are generated. Further, between adjacent printing plates, not only the worn portion on one side but also the worn portion on both sides makes the printing plate more easily dented.
Next, as shown in FIG. 3, the printing plates 3-1 and 3-2 are replaced with a printing plate 3 'having, for example, a double width, and the inking roller 1 having the abraded portion 4 is used. When printing is continued, color missing or color unevenness occurs at positions corresponding to the edge portions of the previous printing plates 3-1 and 3-2.
[0013]
The relationship between the printing plate and the ink forming roller according to the present invention will be described with reference to FIG. According to the present invention, the ink forming roller 1 has a reciprocating width of 2 to 10 mm, preferably 3 to 8 mm, and a reciprocating frequency of 0.01 to 0.25, preferably 0.02 per rotation of the plate cylinder 2. Reciprocates at ~ 0.2 times.
When the reciprocating width is smaller than the above range, the effect of preventing abrasion by the plate edge of the ink forming roller is reduced, and color missing or color unevenness is observed. It will be great.
Further, if the number of reciprocations is too small than the above range, the effect of preventing the abrasion by the plate edge of the ink forming roller is reduced, and color missing or color unevenness is observed. Dirt grows big.
Therefore, when a printed matter such as a newspaper is printed with the configuration of the present invention, the printed matter can be used for a total of 360 to 540 days.
[0014]
The corners 13 (not shown) of the printing plate 3 may be rounded and / or chamfered. The roundness r is 0.1 to 5 times, preferably 0.3 to 1 times the height of the printing surface of the printing plate 3 raised above the surface of the plate cylinder 2.
By rounding the corners 13 in this way, the abrasion of the inking roller 1 by the plate edge can be considerably suppressed without reciprocating the inking roller 1 in the axial direction. By combining with a method of reciprocating in the axial direction, it is possible to significantly reduce wear.
[0015]
In the present invention, as required, an ink bat, an ink source roller, a feeding roller, a transfer roller, an ink reciprocating roller, an ink kneading roller, a watering roller, a water reciprocating roller, a water source roller, etc. are provided as inking devices. You may be.
[0016]
The object to be printed using the present invention is not particularly limited, and includes newspapers, magazines, books, leaflets, and the like. These may be black-and-white printing or multicolor printing.
The size of the plate is not particularly limited, and examples thereof include A plate, B plate, and tabloid plate. There is no particular limitation on the type of printing paper or ink.
Examples of the type of printing machine include an offset printing machine.
[0017]
In the present invention, the printing plates 3 ′ having different sizes are exemplified by the A0 plate with respect to the original A1 plate as described above, but are not limited thereto. An-k version, Bm version, Bm + i version, Bm-i version (where i, k, m and n are 0 or positive integers) may be used, or a tabloid version may be used. .
[0018]
According to the present invention, even when the printing plate is replaced with a different plate and printing is performed, the period during which the ink applying roller can be used without causing printing defects such as color omission or color unevenness in the printed matter is 300 days or more, preferably It extends for more than 500 days, more preferably for more than 600 days.
[0019]
【Example】
Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited thereto.
[0020]
[Example 1]
As shown in FIG. 4, printing plates 3-1 to 3-4 are juxtaposed to the plate cylinder perpendicular to the axial direction, and printing of newspapers is performed for 500 days while reciprocating the ink forming roller in the axial direction. Was.
The printing conditions at this time are shown below.
Plate cylinder rotation speed: 550 rpm
Ink roller rotation speed: 1300 rpm
Number of reciprocating motions per rotation of the plate cylinder: 0.1 times Reciprocating motion amplitude: 5.0 mm
After printing for a total of 500 days, the printing plates 3-1 and 3-2 were replaced with the printing plate 3 'shown in FIG. 3, and spread pages of a newspaper were printed under the same printing conditions as described above. No color missing or color unevenness occurred at the edge of the printing plate between the printing plates 3-1 and 3-2, and clear printing was possible.
[0021]
[Comparative Example 1]
As shown in FIG. 1, after the ink printing roller was not reciprocated in the axial direction, the same plate cylinder rotation speed and ink coating roller rotation speed as those in Example 1 were used, and after performing printing for 120 days in total for newspaper printing, In the spread page printing of a newspaper, color missing or color unevenness occurred at the edge of the printing plate between the original printing plates 3-1 and 3-2.
[0022]
[Comparative Example 2]
Except that the number of reciprocating motions of the inking roller per rotation of the plate cylinder was 0.005, the same printing cylinder rotation speed and inking roller rotation speed as in Example 1 were used for a total of 150 days of newspaper printing. After that, in the spread page printing of the newspaper, color missing or color unevenness occurred at the edge portion of the printing plate between the original printing plates 3-1 and 3-2.
[0023]
[Comparative Example 3]
The number of reciprocating movements of the ink forming roller per one rotation of the plate cylinder was set to two times, and the number of rotations was increased in order to achieve the same plate cylinder rotation number and ink forming roller rotation number as in Example 1. Since the printing of newspapers tended to become dirty, the operation was stopped before reaching the same rotation speed as in Example 1.
[0024]
[Comparative Example 4]
When newspaper was printed at the same plate cylinder rotation speed and inking roller rotation speed as in Example 1 except that the reciprocation amplitude was set to 20 mm, dirt was generated on the printing paper surface.
[0025]
[Comparative Example 5]
Except that the amplitude of the reciprocating motion was set to 1.0 mm, the same plate cylinder rotation speed and inking roller rotation speed as in Example 1 were performed for a total of 160 days of newspaper printing. Of the printing plate between the printing plates 3-1 and 3-2.
[0026]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, generation | occurrence | production of the abrasion which generate | occur | produces in the rotating direction by the printing plate edge of an inking roller in a rotary printing press is suppressed, and life is extended at least 2 times or more, and the ink transfer amount to a printing plate is reduced. It is possible to stabilize and prevent printing defects such as color omission and color unevenness on the printing paper surface.
[Brief description of the drawings]
FIG. 1 is a view showing a relationship between a plate cylinder on which printing plates are juxtaposed and an ink forming roller according to the related art.
FIG. 2 is a view showing a relationship between abrasion of an inking roller by a printing plate according to the related art.
FIG. 3 is a diagram showing a relationship between a plate cylinder and an ink forming roller according to the related art, which are replaced with printing plates having different sizes.
FIG. 4 is a diagram illustrating an example of a relationship between an ink forming roller and a plate cylinder that perform a specific axial reciprocating motion according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Ink roller 2 Plate cylinder 3 Printing plate 3 'printing plate 4 Abrasion part 5 Core material (not shown)
6. Rubber layer (not shown)
13 Side corners

Claims (4)

A printing plate (3) is installed on a plate cylinder (2) of a rotary printing press perpendicularly to the axial direction, and a core material (5) and a rubber layer (6) covering the surface of the core material (5) are provided. )), The ink is applied to the printing plate (3) from the inking roller (1) to perform printing.
A printing plate for an inking roller, wherein the inking roller (1) is reciprocated in the axial direction with a reciprocating width of 2 to 10 mm and a reciprocating frequency of 0.01 to 0.25 per rotation of the plate cylinder (2). How to prevent wear by edges. A plurality of printing plates (3) are juxtaposed perpendicularly to the axial direction on a plate cylinder (2) of a rotary printing press to form a core material (5) and a rubber layer covering the surface of the core material (5). 6) a step (I) of inking the printing plate (3) by inking from the inking roller (1) comprising the printing plate (3), and printing the plate (3) many times; 3) A printing method comprising a step (II) of replacing a printing plate (3 ′) having a different size from that of the printing plate (3 ′) and performing printing by applying ink from the inking roller (1) to the printing plate (3 ′).
At least in the step (I), the ink forming roller (1) is reciprocated in the axial direction at a reciprocating width of 2 to 10 mm and a reciprocating frequency of 0.01 to 0.25 per rotation of the plate cylinder (2). To prevent abrasion by the printing plate edge of the ink forming roller. 3. The method for preventing abrasion by an edge of a printing plate of an inking roller according to claim 1 or 2, which is used for newspaper printing. A printing method for preventing inconvenience of printing on a printing paper surface using the method for preventing abrasion by a printing plate edge of an inking roller according to any one of claims 1 to 3.

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