JP4843860B2 - Dampening water supply method and dampening water supply device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a dampening water supply method and apparatus for offset printing, and more particularly to a dampening water supply method and apparatus for automating dampening water management during offset printing.
[0002]
[Prior art]
Conventionally, the fountain solution during printing on the offset printing press is supplied as a single fountain solution from the fountain (20) of the fountain solution (60) as shown in the side sectional view of FIG. While the original roller (21) is rotated and supplied to the plate surface (29) of the plate wound around the plate cylinder (40) through several landing rollers (19), ink is also applied to the ink application roller (23). Water was distributed for emulsification.
[0003]
Then, the adjustment of the dampening water supply amount can be made only by changing the number of revolutions of the dampening water supply source roller (21) or adjusting the nip pressure between the plurality of landing rollers (19) supplying the plate surface (29). In general, this was not performed, and there was no adjustment of the dampening water supply amount in the printing width direction.
[0004]
However, there are not a few cases where a good and bad portion of ink and fountain solution is generated depending on the arrangement of the printed pattern in the print width direction. In general, when the balance between the ink and the dampening water exceeds a certain range, the ink transfer rate from the printing plate (29) to the blanket (42) and the halftone dot shape of the printing tend to collapse due to the adverse effect on the emulsification of the ink. There was a problem. Therefore, the fountain solution supply in the conventional printing is performed under a single control, and it is difficult to adjust the quantitative balance of the ink and the fountain solution in the print width direction. There was a need to adjust the amount of water supplied.
[0005]
In addition, as described above, the ink back-flow phenomenon due to ink over-emulsification during printing causes the emulsified ink to adhere to the surface of the dampening water supply source roller (21), so that the dampening water supply amount is greatly reduced. There was a problem, and in the past, this was manually adjusted at the discretion of the operator.
[0006]
[Problems to be solved by the invention]
The present invention solves the problems and demands of the prior art, and the problem is that the entire moisture in consideration of the reverse flow phenomenon of ink due to ink over-emulsification also in the printing width direction. Another object of the present invention is to provide a dampening water supply method and apparatus capable of automatically adjusting the amount of water supply.
[0007]
[Means for Solving the Problems]
In order to achieve the above object in the present invention, first, in the invention of claim 1, dampening water is applied to the plate surface through a plurality of dampening water supply rollers including a dampening water supply source roller in offset printing. In the dampening water supply method for supplying a plurality of dampening water, the dampening water can be rotated while being in contact with the dampening water supply source roller and partially immersed in dampening water in the water boat. The dampening water supply method is characterized in that a soft roller that is not in contact with a roller other than the dampening water supply source roller among the rollers for use is rotatable.
[0008]
According to the first aspect of the present invention, the urethane having a thickness of 2 mm, the felt having a thickness of 2.5 mm, the silicon rubber having a thickness of 4 mm, and the porous having a thickness of 5 mm can be independently driven in contact with the dampening water supply roller. The soft roller made of high-quality urethane can remove the emulsified ink adhering to the surface of the dampening water supply roller during printing due to the reverse flow phenomenon of ink due to ink over-emulsification during printing, and therefore at the discretion of the operator It can be set as the dampening water supply method which makes adjustment of the amount of landing unnecessary.
[0009]
In the first aspect of the present invention, a sensor for detecting the amount of dampening water is provided on one of the plurality of dampening water supply rollers other than the dampening water supply source roller. The rotation of the soft roller is controlled by a signal, and the soft roller is divided into a plurality of parts along the axial direction, and each divided part of the soft roller is in contact with the dampening water supply source roller. The dampening water supply method according to claim 1, wherein the dampening water is rotated at different rotational speeds in a state.
[0010]
According to the invention described in claim 1, provided with a sensor for detecting the dampening water onto a single dampening water supply roller, allowed controlled rotation of said soft rollers by a signal from the sensor, and the existing ink key In accordance with the amount of ink supplied from the printer, each part divided into a plurality of parts in the width direction of the printing press, that is, a different amount of dampening water is supplied in the width direction of the printing machine. The dampening water supply method can automatically adjust the supply amount.
[0011]
According to a second aspect of the present invention, in the dampening water supply apparatus for supplying dampening water to the printing plate through a plurality of dampening water supply rollers including a dampening water supply source roller by offset printing, It can be rotated in a state where it is in contact with the fountain water source and partly immersed in the fountain solution in the water fountain, and a roller other than the fountain solution source roller among the fountain solution feed rollers Has a soft roller made of non-contacting rotatable urethane 2 mm thick, 2.5 mm thick felt, 4 mm thick silicon rubber, 5 mm thick porous urethane. This is a water supply device.
[0012]
According to the second aspect of the present invention, it is a single drive in contact with the dampening water supply roller , which is rotatable 2 mm thick urethane, 2.5 mm thick felt, 4 mm thick silicon rubber, By providing a soft roller made of 5 mm porous urethane, it is possible to remove the emulsified ink adhering to the surface of the dampening water supply roller during printing due to the reverse flow phenomenon of ink due to ink over-emulsification during printing. Therefore, it is possible to provide a dampening water supply device that eliminates the need to adjust the landing amount based on the judgment of the operator.
[0013]
Furthermore, in the invention of claim 2 , a sensor for detecting the amount of dampening water is provided on one of the plurality of dampening water supply rollers other than one dampening water supply source roller. The soft roller is divided into a plurality of parts along the axial direction, and each of the divided parts of the soft roller is in contact with the dampening water supply source roller. In this state, the dampening water supply device is characterized in that it can be rotated at different rotational speeds.
[0014]
According to the second aspect of the present invention, a sensor for detecting the amount of dampening water is provided on one dampening water supply roller, the rotation of the soft roller is controlled by a signal from the sensor, and an existing ink key is provided. In accordance with the amount of ink supplied from the printer, each part divided into a plurality of parts in the width direction of the printing press, that is, a different amount of dampening water is supplied in the width direction of the printing machine. It can be set as the dampening water supply apparatus which can adjust supply amount automatically.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
The dampening water supply method of the present invention is in contact with, for example, the dampening roller (22) and the inking roller (21) as the dampening water supply amount during printing, as shown in the overall feedback system configuration diagram of FIG. In order to use the measurement data on the swing roller (13), the amount of ink and the amount of dampening water on the swing roller (13) are measured by a sensor (7) using infrared rays. The sensor (7) may move in the width direction of the swing roller (13), or may be installed at a position corresponding to the number of divisions of the soft roller (10) described below.
[0016]
The analog signal output by the measurement by the sensor (7) is once taken into the analog-digital processing unit (6), and the analog signal is replaced with a digital signal and inputted to the control personal computer (5) incorporating monitoring and control logic. .
[0017]
The control personal computer (5) which has received the digital value of the dampening water amount measurement in the above takes the stable ink film thickness value and the stable dampening water amount value for printing stability at the start of printing. The digital values taken in regularly are sequentially compared with the value of the stable ink film thickness and the value of the amount of dampening water to determine whether the digital value is increasing or decreasing.
[0018]
Based on the above determination, an instruction based on a signal is sent to the motor driver (4) in order to give the soft roller (10) the amount of change considered necessary from the control personal computer (5) according to the logic. Directly, the rotational speed of the soft roller (10) is controlled by the motor (3). The number of motors (3) is a number corresponding to the number of divisions of the soft roller (10). Further, since the dampening water supply roller (21) normally rotates continuously during printing, if the soft roller (10) is stopped, the dampening water will be hampered. Therefore, while the soft roller (10) is normally in contact with the dampening water supply roller (21), the soft roller (10) is rotated in the opposite direction to reduce friction at the same rotational speed as the dampening water supply roller (21). Is desirable. Furthermore, the above mechanism can cope with printing troubles (roller flaking, set-off, choking, blistering phenomenon, etc.) due to ink over-emulsification during printing (over-emulsification is prevented).
[0019]
As for the ink reverse flow phenomenon due to ink over-emulsification, the emulsified ink should normally adhere to the surface of the dampening water supply roller (21) and be supplied to the plate surface (29) by the dampening water supply roller (21). In many cases, the amount of dampening water is greatly reduced, and improvement of the above situation has been dependent on workers. Due to the function of the mechanism of the present invention, the fountain solution supply roller (21) to which the emulsified ink is attached is greatly changed in the rotation of the soft roller (10) from the rotation speed of the fountain solution supply roller (21). It can be easily generated and cleaned.
[0020]
Furthermore, in normal printing, the level of dampening water from the dampening water supply roller (21) to the landing roller (19), the swim roller (22), etc. may be as uniform as possible in the printing width direction. desirable. As an existing dampening solution rising adjustment method, the operator manually adjusts the nip pressure adjustment between the rollers (21, 19, 22) with an adjustment mechanism attached to the printing press. This adjustment has a high degree of difficulty, and is an operation that always occurs when each of the rollers (21, 19, 22) is worn or after replacement.
[0021]
Therefore, if the mechanism of the dampening water supply device (100) of the present invention is adopted, it is an application of the control, and the wear of the dampening water supply source roller (21), the landing roller (19), and the swim roller (22). Even when and after replacement, the level of dampening water is improved in the printing width direction without fine adjustment of the nip pressure or the like.
[0022]
【Example】
Next, an Example demonstrates this invention concretely.
<Example 1>
As shown in FIG. 1, the roller for measuring the ink amount and the dampening water supply amount was set to a swing roller (13) in contact with the swim roller (22) and the ink roller (21). Further, the sensor (7) moving in the width direction of the swing roller (13) is connected to the analog-digital processing unit (6) to the control personal computer (5), and the control personal computer (5) is commercially available. The motor driver (4) and motor (3) connected to the control personal computer (5) were AC servo motors (made by Oriental Motor).
[0023]
For power transmission, a commercially available timing belt (2) and a pulley wound around the timing belt (2) are used. The pulley (16) was used, and the gear ratio of the pulleys was set to a ratio of 2: 1 between the roller-side pulley (15) and the motor-side pulley (16).
[0024]
Moreover, as shown in the perspective view of FIG. 2, the soft roller (10) in direct contact with the dampening water supply roller (21) has a diameter that is ½ of the diameter of the dampening water supply roller (21). Made in the size of. This soft roller (10) has a main shaft of SUS303 passed through the core material, a soft rubber is pasted on a cylindrical hollow brass, and is 1/5 the length of the dampening water supply roller (21). The fountain solution supply roller (21) is divided into four parts while considering the width of the roller pulley (15).
[0025]
Supply of dampening water with the rubber material and thickness of this soft roller (10) as 2 mm thick urethane, 2.5 mm thick felt, 4 mm thick silicon rubber, 5 mm thick porous urethane An offset printing test was performed using the apparatus (100).
[0026]
As a result, the effectiveness of the silicon rubber having a thickness of 4 mm and the porous urethane having a thickness of 5 mm having no particularly large friction and the responsiveness of the amount of dampening water with respect to rotation is recognized. Adjustment of the dampening water supply amount in the width direction was confirmed.
[0027]
【The invention's effect】
Since this invention is the above structure, there exist the following effects.
That is, according to the dampening water supply apparatus of the present invention and the dampening water supply method using the dampening water supply apparatus, the conventional dampening water supply source roller is in contact with the soft roller that can be driven independently. A dampening water supply method and apparatus that can remove emulsified ink adhering to the surface of the dampening water supply source roller due to ink overemulsification during printing, and thus eliminates the need to adjust the amount of landing by the operator's judgment. be able to.
[0028]
In addition, since the soft roller of at least two divisions in the print width direction, which can be driven independently, is in contact with each other. By applying feedback control so as to maintain a constant moisture content, a stable printing state can always be maintained. In addition, automatic return from the ink over-emulsification state during printing and fine adjustment of the nip pressure between the rollers are unnecessary, so that a dampening water supply method and apparatus that contribute to labor saving can be provided.
[0029]
Accordingly, the present invention provides a dampening water supply method and apparatus therefor in offset printing, and in particular as a dampening water supply method and apparatus for the purpose of automating dampening water management during offset printing. Demonstrate.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a feedback system in which a dampening water supply apparatus according to an embodiment of the present invention is represented by a cross-sectional side view.
FIG. 2 is a perspective view for explaining an embodiment of a dampening water supply apparatus of the present invention.
FIG. 3 is an explanatory view showing an example of a conventional dampening water supply device in a cross-sectional side view.
[Explanation of symbols]
2. Timing belt 3 ... Motor 4 ... Motor driver 5 ... Control PC 6 ... Analog-digital processing unit 7 ... Sensor 10 ... Soft roller 13 ... Swing roller 15 ... Roller side pulley 16 ... Motor side pulley 19 ... Landing roller 20 ... Water boat 21 ... Dampening water supply roller 22 ... Watering roller 23 ... Inking roller 29 ... Plate surface 40 ... Plate cylinder 42 ... Blanket 60 ... Dampening water 100 Dampening water supply device

Claims (2)

In a dampening water supply method for supplying dampening water to a printing plate through a plurality of dampening water supply rollers including a dampening water supply source roller by offset printing, the dampening water supply method supplies water to the dampening water supply roller. Thickness of 4 mm that can be rotated while being partially immersed in the dampening water in the boat and does not contact any of the plurality of dampening water supply rollers other than the dampening water supply roller. A soft roller made of either silicon rubber or 5 mm thick porous urethane can be rotated, and on one of the plurality of dampening water supply rollers other than the dampening water supply source roller. A sensor for detecting the amount of dampening water is provided, and the rotation of the soft roller is controlled by a signal from the sensor. The soft roller is divided into a plurality along the axial direction. Each part In a state where respectively in contact with the dampening water supply source roller, dampening water supplying method, characterized in that for rotating at different rotational speeds. In a dampening water supply device that supplies dampening water to a printing plate through a plurality of dampening water supply rollers including a dampening water supply source roller by offset printing, the dampening water supply device is in contact with the dampening water supply source and a water boat 4 mm, which can be rotated while being partially immersed in the fountain solution therein, and which is not in contact with rollers other than the fountain solution supply roller among the fountain solution supply rollers. A soft roller made of either silicon rubber or 5 mm thick porous urethane and on one of the plurality of dampening water supply rollers other than the dampening water supply roller. A sensor for detecting the amount of dampening water is provided, and the rotation of the soft roller is controlled by a signal from the sensor. The soft roller is divided into a plurality along the axial direction, and the soft roller is divided. Each part is Kishime was in a state of being in contact with the water supply source roller, dampening water supply apparatus, wherein the rotatable at different rotational speeds.

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