JP2882966B2 - Humidifier and method for offset printing press - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a humidifying apparatus and method for an offset printing press.

[0002]

2. Description of the Related Art A lithographic offset plate is composed of a chemically treated ink-philic portion and a hydrophilic portion. In order to achieve good printing, a coating of a dampening solution is held on the hydrophilic portion. There must be. Generally, after a dampening solution is applied to the plate surface, the ink is supplied as a thin film from the inking roller. At this time, the dampening solution on the plate surface is mixed with the ink on the inking roller (hereinafter referred to as emulsification). Printing is performed by discharging the dampening liquid onto the plate surface when the contact surface rotates again with the plate surface (hereinafter, referred to as emulsification destruction) to supplement the hydrophilic portion.

[0003] Normally, continuous humidifiers are widely used because of their relatively good print quality and good maintainability as compared with other types, for example, brush type, spray type or Molton type. This continuous humidification device is classified into a plate surface humidification type, an ink-applying roller humidification type, and a composite type combining these.

[0004] Among them, a plate surface humidification type continuous humidifier is
As shown in FIG. 4A, a dampening solution is directly supplied to the printing plate 9 by a series of rollers 2, 3, 4 independent of the inking device. In addition, as shown in FIG. 4 (b), the continuous humidifier of the ink-applying roller humidifying type sends the dampening liquid not to the plate surface 9 but to one of the rollers of the inking device (for example, the ink-applying roller 7). This is a type in which the hydrophilic portion of the plate surface 9 is wetted by the action mainly of the emulsification destruction.

FIG. 4C shows a composite type continuous humidifier.
The dampening roller 4 supplies dampening water directly to the plate surface 9 as shown in FIG.
Are connected by a bridge roller 10.

[0006]

In order to perform the desired printing, it is necessary to supply a dampening solution as a uniform film on the plate surface and to appropriately emulsify the ink device. This moderate emulsification refers to an emulsification level that can cause demulsification to such an extent that the boundary between the image area (the ink-affected area) and the non-image area (the hydrophilic area) is filled with a dampening solution. If it is not possible to obtain and maintain this proper emulsification, ghosts, rollers, or poor dot reproduction will occur in the printed matter.

[0007] The emulsified state of the inking unit differs depending on the type of humidification. It also varies depending on the image area ratio of the printed matter. For example, the emulsification of a plate surface humidification type continuous humidifier is a so-called indirect emulsification in which a dampening solution on the plate is sucked up by an ink application roller, and is relatively hard to emulsify. Therefore, in order to obtain a suitable emulsification, it is necessary to increase the amount of moisture supplied to the plate surface. In particular, in the case of a high image coverage, the moisture supply film becomes thick, and water marks and roller marks may occur.

[0008] The continuous humidifying device of the ink forming roller humidifying type is
Since the dampening liquid is supplied directly to the ink application roller, it is easily emulsified as compared with the plate surface humidification type. In addition, a ghost phenomenon occurs due to defective dot reproduction and defective ink transfer. The combined type continuous humidification device is an intermediate humidification system that humidifies the plate surface and also humidifies the ink application roller connected by the bridge roller. The aim is to make up for the disadvantages.

However, since the dampening roller has an ink film like the inking roller and is transferred by emulsified water transfer, the over-emulsification phenomenon on the inking roller is completely improved. There was a problem that was not. The present invention is proposed in view of the above problems,
The aim is to minimize roller eyes and ghosts over a wide range from low drawing to high drawing,
It is an object of the present invention to provide a humidifying device and a humidifying method for an offset printing press that can improve the reproducibility of halftone dots.

[0010]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides offset printing in which a dampening solution is continuously supplied to a printing plate via a dampening roller, a metering roller and a dampening roller. An ink receiving roller that rotates in contact with the dampening roller and that can contact and separate from at least one of the ink application roller and the metering roller. An ink transfer roller that rotates in contact with the moving roller and that can move toward and away from the ink receiving roller.

Further, the method for humidifying an offset printing machine according to the present invention is characterized in that when printing is performed while a dampening liquid is continuously supplied from a dampening source roller to a plate surface via a metering roller and a dampening roller.
A roller which rotates while being in contact with the dampening roller;
And at least one of the metering rollers
When the ink receiving roller is separated from the ink application roller,
Contact the swinging roller that swings and rotates in contact with the ink application roller.
Touching and rotating against the ink receiving roller.
Release the detachable ink transfer roller from the ink receiving roller.
Then, the dampening solution is supplied from the dampening roller to the plate surface. Further, the method of humidifying the offset printing press according to the present invention, when printing while continuously supplying dampening liquid from the dampening source roller to the plate surface through the metering roller and the dampening roller, when the dampening roller, Contact rotation and ink application
Roller and / or metering roller
An ink receiving roller is rotated in contact with the ink form roller such, swinging the swinging rotation in contact with the ink form roller
The ink roller that rotates while contacting the moving roller
The ink transfer roller which can be separated from the roller is separated from the ink receiving roller, and the dampening liquid is supplied from the dampening roller to the printing plate via the ink receiving roller and the ink applying roller.

Further, the method of humidifying an offset printing machine according to the present invention is characterized in that when printing is performed while continuously supplying a dampening liquid from a dampening source roller to a plate surface via a measuring roller and a dampening roller,
A roller which rotates while being in contact with the dampening roller;
And at least one of the metering rollers
Whether the ink receiving roller is an ink application roller or a metering roller
Release and swing in contact with the ink application roller.
Contacting with the swinging roller and receiving the ink
Ink transfer roller which can be separated from the roller
It is characterized in that the dampening solution is supplied to the plate surface by rotating the dampening solution in contact with the roller and passing through the ink receiving roller, the ink transfer roller, the oscillating roller and the ink applying roller.

The method of humidifying an offset printing machine according to the present invention is characterized in that when printing is performed while a dampening solution is continuously supplied from a dampening source roller to a plate surface via a metering roller and a dampening roller.
A roller which rotates while being in contact with the dampening roller;
And at least one of the metering rollers
When the ink receiving roller is rotated in contact with the ink application roller
Both swing rollers rotate in contact with the ink application roller and swing.
Roller and the ink receiving roller.
An ink transfer roller that can be separated
The dampening fluid is supplied to the plate surface through the ink receiving roller, the ink transfer roller, the oscillating roller, and the ink applying roller from the damping roller by rotating the contacting roller. And supplying it to the printing plate after passing through.

Here, the metering roller is separated from the dampening roller.
And contact rotation with the ink receiving roller.
Sign.

[0015]

According to the present invention, there is provided an ink delivery roller for printing while continuously supplying a dampening liquid from a dampening source roller to a plate surface via a metering roller and a dampening roller. The ink receiving roller is separated from the ink receiving roller and the ink receiving roller is separated from the ink applying roller, and the dampening solution is supplied from the dampening roller to the plate surface, or the ink receiving roller is separated from the ink transfer roller, and the ink receiving roller is connected to the ink receiving roller. The contact damper is supplied to the plate surface via the ink receiving roller and the ink applying roller from the dampening roller, or the ink receiving roller and the ink transfer roller are contacted and rotated, and the ink receiving roller is moved to the ink applying roller. From the dampening roller to the plate surface via the ink receiving roller, ink transfer roller, swing roller and ink application roller. Alternatively, the damping liquid is supplied to the printing plate from the dampening roller via the ink receiving roller, the ink transferring roller, the swing roller, and the ink forming roller by rotating the ink receiving roller in contact with the ink transfer roller and the ink forming roller. The ink is supplied from the dampening roller to the plate via the ink receiving roller and the ink applying roller,
By rotating the metering roller and the ink receiving roller in contact,
By supplying the dampening solution, an optimum emulsified state suitable for the printed matter is obtained.

[0016]

【Example】

(First Embodiment) Next, a humidifying device for an offset printing press according to the present invention will be described with reference to an embodiment shown in FIGS. 1 and 2. The humidifying device comprises a dampening source roller in a dampening solution pan 1. A dampening water supply system comprising a metering roller 3 for making the dampening solution transferred to the dampening source roller 2 into an appropriate dampening liquid film and a dampening roller 4 rotating in contact with the tuning roller 3 And a dampening liquid dispersion system including an ink receiving roller 5 rotating in contact with the dampening roller 4 and an ink transfer roller 6 rotating in contact with the oscillating roller 8.

The ink receiving roller 5 has a driving device (not shown) for rotating the ink receiving roller 7 in contact with the ink receiving roller 7.
And a driving device (not shown) for rotating the contact. Although an air cylinder and a link mechanism are used for these driving devices, other driving devices may be used. Next, the operation of the humidifier of the offset printing machine will be specifically described. FIGS. 2A to 2D show a state in which the ink receiving roller 5 and the ink transfer roller 6 are operated, the contact form is changed, and the dampening solution supply pattern is changed to four patterns (see broken lines). ing.

FIG. 2A shows the ink transfer roller 6 when printing is performed while the dampening liquid is continuously supplied from the dampening source roller 2 to the plate surface 9 via the metering roller 3 and the dampening roller 4. Is separated from the ink receiving roller 5, the ink receiving roller 5 is further separated from the ink applying roller 7, and the dampening solution is supplied from the dampening roller 4 to the plate surface 9. In this case, overemulsification of the inking unit is prevented as in the case of the plate surface humidification type continuous humidification unit. In addition, the ink receiving roller 5 smoothes the unevenness of the moisturizing film caused by having a thicker moisturizing film, which is a drawback of the plate surface moisturizing type continuous moisturizing device.

This smoothing can be applied to the ink transfer roller 6 which rotates in contact with the oscillating roller 8. The above-mentioned contact state is a humidification form mainly suitable for printed matter with a low image coverage, and this humidification form is referred to as a plate surface humidification type for convenience. FIG.
(B), when printing is performed while the dampening liquid is continuously supplied from the dampening source roller 2 to the plate surface 9 via the metering roller 3 and the dampening roller 4, the ink receiving roller 5 is connected to the ink applying roller 7; And the ink transfer roller 6 is separated from the ink receiving roller 5 to rotate the dampening solution.
From the ink supply roller 5 and the ink application roller 7 to the plate surface 9.

This form of humidification is a form of humidification suitable for printed matter having a relatively high image coverage. This humidification form is referred to as a composite type (1) for convenience. In this method, since the ink flows from the ink application roller 7 to the dampening roller 4 via the ink receiving roller 5, the dampening roller 4 performs both the supply of the dampening liquid and the supply of the ink. As a result, the number of rollers for transferring the ink onto the plate surface 9 increases, a smoothing effect is obtained, and the occurrence of rollers and ghosts is prevented.

The difference from the conventional composite type is that the ink transfer roller 6 is in contact with the swing roller 8.
In this case, the ink transfer roller 6 functions to evaporate the over-emulsified water on the swing roller 8. FIG.
(C) shows an ink receiving roller 5 and an ink transfer roller 6 when printing is performed while the dampening liquid is continuously supplied from the dampening source roller 2 to the plate surface 9 via the metering roller 3 and the dampening roller 4. Is rotated while the ink receiving roller 5 is separated from the ink applying roller 7, and the dampening solution is dampened. The ink receiving roller 5, the ink transfer roller 6, the swing roller 8, and the ink applying roller 7 are separated from the roller 4. This shows a state in which the paper is supplied to the printing plate 9 through the printing plate 9. The feature of this contact form is that the dampening liquid is sent to the oscillating roller 8 instead of the ink applying roller 7,
A proper emulsification of the inking unit is to be obtained quickly. In addition, over-emulsification of the ink application roller 7 is prevented.

This type of humidification is a type of humidification that develops the above-mentioned composite type (1) to prevent over-emulsification of the ink application roller 7, and is referred to as a composite type (2) for convenience. . FIG. 2D shows the ink receiving roller 5 when the printing is performed while the damping liquid is continuously supplied from the dampening source roller 2 to the plate surface 9 via the measuring roller 3 and the damping roller 4. By rotating the roller 6 and the ink application roller 7 in contact with each other,
The dampening solution is supplied from the dampening roller 4 to the plate surface 9 via the ink receiving roller 5, the ink transfer roller 6, the swing roller 8, and the ink forming roller 7, and the dampening roller 4 forms the ink receiving roller 5 with the ink receiving roller 5. The state in which the ink is supplied to the plate 9 via the roller 7 is shown.

This contact form is a humidification form particularly suitable for a printed matter having a high image quality, and this humidification form is referred to as a composite type (3) for convenience. In this humidification mode, when the ink flow rate is high such as a high image coverage, the inking unit is emulsified at an early stage, so that an appropriate dampening solution film is maintained on the hydrophilic portion on the plate surface. As described above, the humidification mode is freely controlled, and an appropriate emulsified state corresponding to the image streak rate or the image state of the printed matter is freely appeared, so that a very useful multi-type dampening solution supply. Means.

An important roller in constituting the multi-type dampening solution supply means is the ink transfer roller 6,
With the installation of the ink transfer roller 6, the form of humidification of the dampening solution can be freely changed. Further, the dampening solution supply means is linked with the image area ratio meter. For example, in a multi-color offset printing machine or the like, by changing the humidification form for each printing color, printing of each color can be performed in a state where it can be most desired. Systematizing the selection of the humidification form is relatively simple and the effect is further enhanced.

(Second Embodiment) FIG. 3 shows a second embodiment. Reference numerals 1, 4 to 9 denote the same parts as described above, 22 denotes a dampening source roller, 33 denotes a metering roller, and the metering roller 33 and the ink receiving roller 5 rotate in contact with each other. In this embodiment, as shown in FIG.
From the damping source roller 22 to the metering roller 33 and the damping roller 4
When the printing is performed while continuously supplying the dampening liquid to the plate surface 9 through the above steps , the metering roller 33 is separated from the dampening roller 4, and
The dampening solution is distributed on the plate surface 9 almost equally with the inking device by rotating the ink receiving roller 5 in contact with the ink receiving roller 5 . According to this method, the emulsification speed of the inking device can be increased, the printing density fluctuation occurring at the start of printing can be suppressed, and the consumption of the dampening solution can be reduced.

In this embodiment, the oscillating roller 8, the ink receiving roller 5, and the metering roller 33 make the ink and dampening liquid uniform in the width direction of the roller. The ink and dampening solution in the roller width direction may be made uniform.

[0027]

The present invention is configured as described above,
The following effects can be achieved. That is, in order to print a variety of printed matter in the best possible condition, the conventional one type of humidifier is insufficient and inevitably causes a printing failure. The humidifier and offset printing method of the machine can freely change the supply state of the dampening solution, and can obtain the optimal emulsification state according to the printed matter, from low printing to high printing. Roller ghosts, ghosts, and the like can be minimized over a wide range up to and the reproducibility of halftone dots can be improved.

[Brief description of the drawings]

FIG. 1 is a side view showing a first embodiment of a humidifier of an offset printing press according to the present invention.

FIGS. 2A to 2D are explanatory diagrams showing a contact state between an ink receiving roller and an ink transfer roller with respect to another roller.

FIG. 3 is a side view showing a second embodiment of the humidifier of the offset printing press.

FIGS. 4A to 4C are side views showing respective examples of a conventional humidifier of an offset printing press.

[Explanation of symbols]

 2,22 damping source roller 3,33 metering roller 4 dampening roller 5 ink receiving roller 6 ink transfer roller 7 ink application roller 8 swing roller 9 printing plate

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yagiya, 5007 Itozakicho, Mihara City, Hiroshima Prefecture Mitsubishi Heavy Industries, Ltd.Mihara Works (72) Inventor Fumihide Kimura 5007, Itozakicho, Mihara City, Hiroshima Prefecture Mitsubishi Heavy Industries, Ltd. Mihara Works (56) References JP-A-4-226352 (JP, A) JP-A-55-57464 (JP, A) JP-A-64-78840 (JP, A) (58) Fields studied (Int. Cl. ⁶ , DB name) B41F 7/24-7/40 B41F 31/14 B41F 31/30-31/38 B41F 33/10

Claims (6)

(57) [Claims] 1. A dampening device for an offset printing machine for continuously supplying dampening liquid to a printing plate via a dampening roller, a metering roller and a dampening roller. An ink receiving roller that can be brought into and away from at least one of a forming roller and a metering roller; and a rotating roller that swings and rotates in contact with the ink forming roller, and can be brought into and out of contact with the ink receiving roller. A humidifier for an offset printing press, characterized by having a simple ink transfer roller. 2. When printing while continuously supplying a dampening liquid from a dampening source roller to a plate surface via a metering roller and a dampening roller, printing is performed while contacting and rotating the dampening roller.
Contact at least one of the setting roller and the metering roller.
Separating the detachable ink receiving roller from the ink applying roller
Oscillating with the ink application roller and oscillating
The ink receiving roller which rotates while being in contact with the roller
An ink transfer roller that can be separated from and
A dampening solution is supplied from the dampening roller to the plate surface while being separated from the roller. 3. When printing while continuously supplying a dampening liquid from a dampening source roller to a plate surface via a metering roller and a dampening roller, printing is performed while rotating while contacting with the dampening roller.
Contact at least one of the setting roller and the metering roller.
The detachable ink receiving roller rotates in contact with the inking roller, and swings in contact with the inking roller.
Contact with the swinging roller that rotates
An offset printing machine characterized in that an ink transfer roller which can be brought into contact with and separated from a transfer roller is separated from an ink receiving roller, and dampening liquid is supplied from the dampening roller to the printing plate via the ink receiving roller and the ink applying roller. Humidification method. 4. When printing while continuously supplying a dampening liquid from a dampening source roller to a plate surface via a metering roller and a dampening roller, printing is performed while contacting and rotating the dampening roller.
Contact at least one of the setting roller and the metering roller.
The detachable ink receiving roller is
Away from the metering roller and
It rotates in contact with the oscillating roller,
Ink transfer roller that can contact and separate from the ink receiving roller
The offsetting printing press, wherein the fountain solution is supplied to the plate surface by rotating the dampening solution from the dampening roller through the ink receiving roller, the ink transfer roller, the oscillating roller, and the ink applying roller. Wet method. 5. When printing while continuously supplying a dampening solution from a dampening source roller to a plate surface via a metering roller and a dampening roller, printing is performed while contacting and rotating the dampening roller.
Contact at least one of the setting roller and the metering roller.
Turn the detachable ink receiving roller into contact with the ink application roller.
As well as swinging in contact with the ink application roller
Contact with the swinging roller that rotates
Ink transfer roller
The fountain solution is rotated by contact with the receiving roller, and the dampening solution is supplied from the dampening roller to the plate surface via the ink receiving roller, the ink transfer roller, the swing roller, and the ink forming roller. A method of humidifying an offset printing press, wherein the method supplies the humidified ink to a printing plate via a roller. 6. The metering roller is separated from the dampening roller, and
6. The method according to claim 5, wherein the rotation is performed in contact with an ink receiving roller .