JPH06171061A - Wetting water cooling circulation device - Google Patents

Abstract

PURPOSE:To improve and maintain print quality by providing a means for storing wetting water from a water drum for each color, a means for sending water to a main tank, a means for separating wetting water from paper powder, oil, powder and ink, a means for checking water shortage and replenishing water, a means for cooling wetting water, a means for sending water to a storage tank temporarily and a means for distributing water to water drums. CONSTITUTION:Wetting water stored in a main tank 1 is sent to a header 8 on the side of a printer by a circulation pump 6, and then is distributed to water drums 30 to 33 for each color unit. The water drums 30 to 33 are filled with a specified quantity of wetting water. Surplus wetting water is collected to the header 9 on the printer side from a return pipe, and bubble is separated from the wetting water in a bubble removal tank 10. Further, the wetting water is returned to a ladder tank 2 by a return water pump 1. In the tank 2, ink oil are removed from the wetting water and further, paper powder and powder are removed by a filter leaving the wetting water only without a floating material. In addition, the water quantity of the tank 1 is maintained to a constant level using a water feeder device 7, then a liquid temperature is measured by a liquid thermometer 20, and the liquid temperature is maintained at a constant level with the concurrent action to turn a cooler 4 ON/OFF.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for controlling the concentration and liquid temperature of dampening water circulated and used in an offset printing machine, and more particularly to impurities and etches composed of ink, fine particles of paper and the like. The present invention relates to a dampening water management device containing a liquid.

[0002]

2. Description of the Related Art Conventionally, in the offset printing method or the like, so-called dampening water is adhered to a non-image area where ink should not be placed so that the ink can be repelled. The presence or absence of adherence is controlled. Therefore, how to maintain the function of dampening water with high performance
It is a very serious problem for the quality of the printed matter by the offset printing method. And usually, in the dampening water, water and an etchant (a liquid used by adding to the dampening water)
And alcohol such as isopropyl alcohol or ethyl alcohol.

Although the content of alcohol is very small, it lowers the surface tension of the dampening water to improve the wettability of the plate, and the dampening water acts so as to spread evenly over the plate. That is, a proper amount of alcohol contributes strongly to the performance of the principle part of the offset printing method.

The etchant also contains gum arabic (a colloidal substance composed of a water-soluble polymer). Gum arabic has a so-called desensitizing action, but this action is greatly influenced by the pH value and is considered to exert its function most in a certain acidic range. For this reason, the fountain solution is usually in the acidic region (pH value of 4.0 to 6.
Often used in 5). By the way, when the dampening water is circulated (generally practiced for saving dampening water), the ink and the fine pieces of paper are usually contained in the dampening water that is returned without being consumed by the printing machine. Impurities such as oil, oil and powder are mixed. Generally, paper contains calcium carbonate as a component and exhibits acidity, while the etchant exhibits weak alkalinity. For this reason, a neutralizing action occurs in the dampening water during use, and even if the etchant is mixed in a relatively large amount, fluctuations in the pH value are suppressed. As a result, the pH value of the dampening water is kept stable in the acidic range, that is, a so-called buffering action occurs.

On the other hand, in the case of the dampening water cooling circulation device, the device is installed at a place distant from the printing machine, or the size is unbalanced with the printing machine. However, there was no sense of unity as it interfered with the operation of the printing machine. In terms of piping, the water boat of the printing machine and the cooling circulation device are simply connected directly to each unit, so the piping space is taken up more than necessary and the cooling circulation device itself becomes large. There was a tendency to end up.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a compact size dampening water cooling / circulating apparatus which is integrated with a printing machine. The purpose of the present invention is to provide a device for controlling the concentration of dampening water and the temperature of liquid which can maintain the concentration of the etchant in the dampening water at an appropriate constant concentration to improve and maintain the print quality.

[0007]

Means provided by the present invention in order to solve the above problems will be described below. In other words, in the dampening water cooling circulation device that manages the state of dampening water used in the offset printing method, (a) From the water boat (tank for supplying dampening water to the plate) for each color in the printing machine ,
A means for temporarily storing the dampening water in one batch, (b) A means for sending the temporarily stored dampening water to the main tank,
(C) A means for separating the dampening water from the paper powder, oil, powder, ink, etc. mixed in the dampening water collected in the main tank, and (d) the amount of the dampening water collected in the main tank. (E) Dampening water cooling means that manages the dampening water collected in the main tank to a preset water temperature, (f) (c) to (c) The means for sending the dampening water treated in step 1 to the temporary storage tank located near the printing machine. Means, and a dampening water cooling circulation device comprising at least the above means (a) to (g).

Further, the dampening water is temporarily stored in a batch from a water boat (a tank for supplying the dampening water to the plate surface) for each color in the printing machine, and foam is generated from the stored dampening water. The dampening water cooling circulation device is provided with means for removing the above.

Alternatively, in the above apparatus, (a) means for measuring the concentration of alcohol contained in dampening water, and means for supplying alcohol, (b) means for measuring concentration of etchant contained in dampening water, And a dampening water cooling circulator equipped with an etchant supply means.

[0010]

According to the dampening water cooling circulation control device according to the present invention, the dampening water that has recirculated from the water boat (tank for supplying dampening water to the plate surface) for each color to the printing machine is temporarily returned. A part of the function of the dampening water cooling circulator is installed in the printing machine main body so that it can be distributed and supplied through the means for collectively storing it in the water tank and the means for temporarily storing it in the water boat for each color of the printing machine from the main tank. By installing it, it is possible to reduce the piping space and the size of the cooling and circulating device.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A fountain solution cooling circulation system according to the present invention will be described below with reference to the drawings.

In FIG. 1, the dampening water stored in the main tank 1 is sent by the circulation pump 6 through the water feed pipe to the head water 8 for heading water installed on the printing machine side. Depending on each color unit, the water boat 30-33
Dispense dampening water to (for 4-color machine in the figure). Water is guided from the roller, which is in contact with the water surface of the water boat, to the printing plate surface for printing. The water boats 30 to 33 are designed to maintain a predetermined amount of dampening water. The dampening water that has not been consumed by the printing machine and the remaining dampening water are collected from the return water pipe to the return water header 9 installed on the printing machine side, and then the foam is removed in the foam removal tank 10. The dampening water is separated and only the dampening water is returned to the ladder tank 2 by the return water pump 12.

In the ladder tank 2, ink, paper powder, powder, etc. are returned during printing and dampening water is carried along with them, so that ink, oil, etc. are removed from the dampening water. In the next filter-5, paper dust that could not be removed by the ladder tank 2,
Remove powder etc. and make sure that only the dampening water from which floating matter has been removed will return to the main tank. Further, a water replenishing device 7 for supplementing water consumed by printing is provided to keep the amount of water in the main tank 1 constant.

In addition, in order to maintain the liquid temperature at a preset temperature, the liquid temperature is measured by the liquid thermometer 20, and the liquid temperature is kept constant while turning on / off the cooler 4 according to the measured value. In order to keep the concentration of the etchant in the dampening water constant, the etchant concentration in the dampening water is measured by the etchant concentration meter 21, and when the concentration is lower than the set value, the etchant supply pump from the etchant tank 24 is used. At 25, the undiluted etchant is poured into the main tank 1 to keep the etchant concentration constant. Similarly, in order to keep the alcohol concentration in the dampening water constant, the dampening water sent by the circulation pump 6 to the water header 8 is branched to the sub tank 3 and sent by the alcohol concentration meter 23. The alcohol concentration in the sewage water is measured. When the alcohol concentration is lower than the set value, the alcohol is pumped from the alcohol tank 26 to the main tank 1 by the alcohol supply pump 27. Further, the level sensors 11 and 22 monitor the level of the liquid surface to prevent troubles.

As described above, while the dampening water is circulated between the main tank and the water boat in the printing machine, the state of the dampening water is constantly controlled, and the insufficient water is replenished while the proper printing condition is maintained. To do.

[0016]

According to the dampening water cooling circulation control device of the present invention, the dampening water that has recirculated from the water boat (tank for supplying dampening water to the printing plate) for each color in the printing machine is supplied. A part of the functions of the dampening water cooling circulation device is supplied so as to be distributed and supplied through a means for temporarily storing collectively and a means for temporarily storing the water from the main tank to the water boat for each color of the printing machine. By installing it in the main body, it is possible to reduce the piping space and the size of the cooling circulation device. In addition, by integrating the printing machine and the dampening water cooling / circulating device, the dampening water cooling / circulating device that contributes to improving the operability of the printing press and greatly improving and maintaining the printing quality is provided. Can be provided.

[0017]

[Brief description of drawings]

FIG. 1 shows an embodiment of a dampening water management apparatus according to the present invention,
It is a schematic block diagram.

FIG. 2 shows an embodiment of a dampening water management apparatus according to the present invention,
It is a schematic flowchart.

[Explanation of symbols]

1 ... Main tank 2 ... Ladder tank 3 ... Sub tank 4 ... Cooler 5 ... Filter-6 ... Circulation pump 7 ...
Water replenishing device 8 ... going water header-9 ... returning water header-10 ... foam removing tank11 ... level sensor
12 ... Return water pump 20 ... Liquid thermometer 21 ... Etching solution concentration meter 22 ... Level sensor-23 ... Alcohol concentration meter 24 ... Etching solution tank 25 ... Etching solution supply pump
26 ... Alcohol tank 27 ... Alcohol supply pump 30, 31, 32, 33 ... Water boat 40 ... Flow control valve

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masao Mogi 1-5-1 Taito, Taito-ku, Tokyo Toppan Printing Co., Ltd.

Claims (3)

[Claims] 1. A dampening water cooling circulation device for controlling the state of dampening water used in an offset printing method, comprising: (a) a water boat (for supplying dampening water to a printing plate for each color to a printing machine; (B) means for temporarily storing the dampening water from the tank), (b) means for sending the temporarily stored dampening water to the main tank, (c) dampening water collected in the main tank Means for separating dampening water from paper powder, oil, powder, ink, etc. that are mixed in, (d) means for detecting the amount of dampening water collected in the main tank and replenishing the lacking water, (E) Damping water cooling means for controlling the dampening water collected in the main tank to a preset water temperature, (f) dampening water treated in (c) to (e), near the printing machine From the means to send to the temporary storage tank in the place located in
A dampening water cooling / circulating device comprising at least the above-mentioned means (a) to (g) for supplying dampening water to water tanks for respective colors of a printing machine. 2. A fountain solution is temporarily stored in a batch from a water boat (a tank for supplying the fountain solution to the printing plate) for each color in the printing machine, and bubbles are generated from the batch-stored dampening water. The dampening water cooling circulation device according to claim 1, further comprising means for removing the above. 3. (a) means for measuring the concentration of alcohol contained in dampening water, and means for supplying alcohol, (b) means for measuring concentration of etchant contained in dampening water, and means for supplying etchant. The above (1) and (2) are provided.
Alternatively, the dampening water cooling circulation device described in 2.