JPS58160150A - Full automatic control method and device for quantity of dampening water in metallic lithographic printing - Google Patents

Abstract

PURPOSE:To form optimum dampening-water film thickness onto a printing plate surface, and to execute clear metallic lithographic printing by optimally following and driving Dahlgren damping system or an Epick dampener device in conformity with the quantity of fluctuation of a fluctuation factor during the normal operation of a lithographic press. CONSTITUTION:Fluctuation factors of every kind of the quantity of dampening water adhering on the printing plate surface 21a of a plate cylinder 21 in lithographic printing are measured in succession during the operation of the lithographic press B, or reference value is set previously and optimum control command value is calculated at a real time through centralized input to a microcomputer 14, and the Dahlgren motor 19a or Epick dampener motor 19b are controlled in succession. Optimum dampening-water film thickness can be formed onto the printing plate surface 21a and controlled at all times, and clear metallic lithographic printing having excellent quality can be executed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for fully automatic control of the amount of dampening water supplied to the printing plate surface of a grate cylinder provided in a lithographic printing press, and an apparatus directly used for carrying out the method.

This lithographic printing method uses a printing plate in which the image area and the non-image area are almost on the same plane, but this is because the image area and the non-image area have different chemical properties. The former is liposensitive and the latter is hydrophilic. When moisture is applied to the entire surface of the printing plate, the moisture is repels from the printed areas. When ink is applied to the surface of a printing plate that does not dry out, it will adhere to the oil-sensitive printed areas, but not to other areas. In other words, this is a printing method that takes advantage of the repellency of water and oil.

Using this method, the material to be printed is placed on the printing plate surface and pressurized to produce a printed matter. Normally, originals used for printing have gradations created by continuous changes in density, but in the case of printing,
This gradation is generally expressed by the size of halftone dots, and therefore the shading of a planographic print is also expressed by the size of halftone dots.

Currently, most planographic printing uses offset printing.

That is, the principle is the same, but it is a method in which ink is first transferred from the printing plate surface to a rubber plunket, and then transferred to the printing surface for printing. In this invention, the term lithographic printing is used to include offset printing as well. There is.

As a result, during lithographic printing, the amount of dampening water adhered to the printing plate surface directly affects the adhesion of zero-peta ink and halftone ink in the printing area, and has an extremely large effect on the quality of finished printed matter.

In other words, if too much dampening water is used, the ink becomes emulsified and its transferability deteriorates, and a so-called water flow phenomenon occurs in which the ink floats in the dampening water and is washed away, resulting in smudging of the image, and vice versa. If there is too little water, ink will also adhere to non-image areas, resulting in smeared prints.

By the way, regarding the conventional control of the amount of dampening water applied to the printing plate surface in lithographic printing, Japanese Utility Model Application No. 50-73505 and Japanese Utility Model Application No. 1983
-78302 and Japanese Unexamined Patent Publication No. 53-40307, but both are for paper as the printing substrate and not for metal, which is the printing substrate of the present invention, so they remain unchanged. It is impossible to apply.

What happens is that the constituent materials of the object are separated from the rest.Hereinafter, lithographic printing of metal (metal base and metal plate coated with a resin coating on the metal surface, such as furiki, TFS, aluminum, etc.) Regarding the peculiarities of printing, in particular, the differences from paper lithographic printing are as follows: ■Printing substrate; In the case of paper, its surface is fibrous, so printing materials such as ink and dampening water are absorbed into its fibrous structure. In particular, ink adhesion, transferability, and other printability are superior to metals (metal plates with resin coatings applied to metal substrates and metal surfaces, hereinafter referred to as metals).

Metals require a structure that can easily absorb ink, etc.

■Ink: Lithographic ink for metals requires high adhesive strength (high tack) to improve its printability, and its properties are vastly different from those for paper.

Naturally, the materials of the constituent elements of the ink, such as pigments, vehicle (resin), and auxiliary agents, are also different.

■Printing work environment: In the case of metal, large drying equipment (mainly gas) is required due to the nature of the printing material and ink.

electricity, etc.), and are usually prone to high temperature and low humidity conditions.

In some cases (particularly depending on the season), temperature and humidity changes are drastic during the -day period.

In the case of paper, it is necessary to control humidity due to the nature of the material (paper expands and contracts when it absorbs moisture), and environmental conditions are controlled, making it easy to control dampening water.

On the other hand, in the case of metal, it is difficult to control the environment as described above, and it is also difficult to control the dampening water.

■Management of dampening water: For paper, it is relatively easy to control the amount of dampening water depending on the material (paper, ink, etc.) and environmental conditions, and the required dampening water film thickness is approximately 1-2 μm. The appropriate amount of water can be controlled only by controlling the water source roller of the dampening water supply device (generally).

Metals require precision water control because of their lack of hygroscopicity, high ink stickiness, and difficulty in S boundary control.

The optimal value for the film thickness of water is on the order of 0.2 to 0.54, which is much lower than that of paper, and is in a minute range, so it depends on the environmental conditions.

Highly influenced by ambient sources and humidity. Therefore, if we catch minute fluctuations in these conditions and take them into account as control factors for the water roller, the order of 0.2 to 0.5μ is low.
The dampening water film thickness of m cannot be fully controlled.

As mentioned above, metal lithographic printing requires a higher degree of accuracy in dampening water management than that of paper.

Strengthen.

The room temperature meter 2 and the hygrometer 3 measure the temperature and humidity in the room where the lithographic printing machine B is installed, and output a room temperature measurement value signal S.
2 and a humidity measurement value signal SS, respectively.

The water temperature gauge ≠ outputs a water temperature measurement value signal s4 of the dampening water stored in the dampening water tank here.

The ink holder j is connected to a round ink tank 23 used for printing.
A temperature measurement value signal Ss of the ink stored in the ink is output.

The plate thermometer 6 is a device that is placed directly above the supplied metal printing plate P and photoelectrically measures the surface temperature of the metal printing plate P by infrared projection, and outputs a plate temperature measurement value signal S6. do.

The pH meter 7 receives a measured value signal S? of the additive pH of the dampening water stored in the dampening water tank here. Output.

The cylinder thermometer group includes a plate cylinder J/, a bracket cylinder 244, and an impression cylinder λ! provided in the lithographic printing press B. The surface temperature of each specimen is photoelectrically measured using infrared absorption. The device outputs a cylinder temperature measurement value signal S8.

The printing press speed meter 2 detects and outputs a printing press speed ill fixed value signal 8g generated by the illustrated powerful motor that drives the lithographic printing press B.

The printing press operation signal generator 11 outputs a digital printing press operation signal Slo related to the start, stop, or emergency stop operation of the lithographic printing press B, and outputs the digital printing press operation signal Slo to the microcomputer lμ for operation of the lithographic printing press B. Commands and controls the start and stop of operation.

As shown in FIG. 3 or 4, the Dahlgren dampening device C or the Evitsukudambuna device is attached to the printing plate surface 2/a of the plate cylinder 21 of the lithographic printing press B. The chrome roller 26 is soaked in dampening water containing metal alcohol, and the chrome roller 26 and the metal ring roller 27 are in circumscribed contact with each other, and the attached roller 2t is the chrome roller 2B and the plate surface of the plate cylinder 21, 2/a. It straddles and becomes a mediate circumscription.

The attached roller 2j is driven by a vibrator (not shown) of the lithographic printing machine B, and the surface speed is equal to the plate cylinder λ/
, the chrome roller 26 is directly connected to the Dahlgren motor lA or the Evitsukudanbuna motor/b,
Both rollers 21, . Separation of the water film is carried out by a speed difference of 2r, and the speed is usually adjusted so that ChromeRow 2.26 is slower. In other words, the chrome roller 226 and the chrome roller 226 vary the moisture content on the printing plate surface 21a by the difference in the peripheral speed of the roller 21, and increasing the peripheral speed of the chrome roller roller increases the moisture content, and decreasing the peripheral speed decreases the moisture content. Become. Use this to adjust the moisture content.

The method of the present invention will now be explained with reference to FIGS. 1 to 3 or 4.

The fully automatic method for controlling the amount of dampening water in metal lithographic printing of the present invention involves first preparing in advance a standard value for the amount of dampening water to be supplied to the printing plate surface of the plate cylinder 21, 2/a, and setting it in advance in the lithographic printing machine B. Manually operate the keyboard 13 to enter the ink build-up amount reference value, the non-biline area value, the dampening water PA (isopropyl alcohol) concentration reference value stored in the dampening water tank 2.2, and the ink product value. All the standard setting value signals are input and stored in the micro combiator 1H, and then the lithographic printing press B is started and the printing press operation operation signal generator II outputs the microcomputer 11I in accordance with the operation of the lithographic printing press B.
-Digital printing press operating signal 8 that commands the start of operation.
When so is input into the microcomputer/4', the dampening water thickness measuring device 1, room temperature meter 2, hygrometer 3, water temperature meter ≠, ink position needle 5, plate thermometer 6, pm meter 7, and cylinder temperature are input. dampening water film thickness measurement value signal Sm, room temperature measurement value signal S2. Humidity measurement value signal Bm, water temperature measurement value signal s4.
Ink temperature measurement value signal BS, plate temperature measurement value signal Be,
pH measurement signal 8? .

Cylinder temperature measurement value signal S11. The printing press speed measurement value signal S9 is inputted to the microcomputer through the analog input device IO, and combined with the various reference setting value signals aS1 stored in advance, the optimal dampening water supply amount already stored is determined. The microcomputer 1lI- calculates the optimum control command value signal S1! in real time according to the calculation formula or calculation procedure that guides the control. At the same time, the various input value signals SSS and the optimum control command value signal S+ are outputted.
t on the display device /j' and store it in the printer It (7, the signal S+t on the mini-floppy disk 17)
, Sta, and continue to imicrocomputer 1tI.
The optimum control command value signal Bxt outputted from - is manually input to the motor control device 20 through the analog output device it, and the outputted motor speed command signal 814 is used to control the Dahlgren motor LRIA or the Evitsuku-Danbuna motor LRIB. The rotational speed is controlled at variable speed to drive the Dahlgren dampening device C or the Ebitzku Dambuna device.

That is, the printing plate surface 2/a of the plate cylinder 21
In order to optimally control the driving speed of the Dahlgren dampening water device C or the Epic dampening device DQ, which can freely control the supply amount of dampening water attached to the machine, it is necessary to use a group of measurement information related to print quality and operational information of the lithographic printing press B. A group of standard setting information manually set in advance is sequentially input to the microcomputer 144, and the microcomputer IQ is inputted in accordance with the arithmetic procedure for optimal control of the dampening water supply amount, which is stored in the microcomputer 1lfi in advance. - Display and record the optimum control command value and press the plate cylinder 21 on the printing plate surface 2.
/a is formed by constantly forming an optimal dampening water film thickness.

Thus, in the present invention, various fluctuation factors in the amount of dampening water adhering to the plate surface 2/a of the plate cylinder 21 in lithographic printing can be measured sequentially during the operation of the lithographic printing machine B, or reference values can be set in advance and the microcomputer/44 The optimum control command value is calculated in real time by central input into the Dahlgren motor/I? Since it sequentially controls the Dahlgren dampening water device C or the Ebitzku dampening device B during normal operation of the lithographic printing press B, it is possible to optimally track the Dahlgren dampening water device C or the Ebitzku dampening device C according to the fluctuation amount of the above-mentioned fluctuation factors. Since it can be driven in a subordinate manner, it is possible to constantly control the formation of an optimum dampening water film thickness on the printing plate surface 2/a, resulting in excellent effects such as being able to perform high-quality and clear metal lithography printing.

[Brief explanation of drawings]

Figure 1 is a block diagram showing the configuration of the device of the present invention, Figure 2 is a conceptual diagram of a lithographic printing machine showing the arrangement relationship with various measuring instruments, and Figure 3 is a Dahlgren dampening solution attached to the plate cylinder. A schematic perspective view of the apparatus. FIG. 4 is a schematic perspective view of the Evitsukudambuna apparatus attached to the plate cylinder. A... Fully automatic dampening water amount control device B... Lithographic printing machine 0-Dahl gray dampening water device D
...Ebitsukudanbuna device L...Mountain water P...
・Metal printing plate l...Mountain water film thickness measuring device...
・Indoor needle 3...Hygrometer ≠...Water temperature gauge...
・Ink holder 6...Plate thermometer 7...pI (meter?...SiIJ yda thermometer Ta...Printing press speedometer 13...Keyboard /Da...Microcomputer/J・...Display device /l...Printer 17
...Mini floppy disk/l...Analog output device/9a...Dahlgren motor/rib...Evitsukudan Buna motor 20...Motor control device 21...Plate cylinder J/a.・Printing surface 2
2... Dampening water tank 23... Ink tank 2hiro...
・Bracket cylinder 2j-・Impression cylinder 21kawa 1aum o-927・Metaling roller 2t・
...with roller Kota...water tank 30...ink row 2 Sl...dampening water film thickness measurement value signal S2...room temperature measurement value signal SS...humidity measurement value signal B4...water temperature measurement Value signal aS...Ink temperature measurement value signal S6...Plate temperature measurement value signal 8? ...pII measurement value signal Ba...Cylinder temperature measurement value signal S...Printing press speed measurement value signal 810...Digital printing press operation signal Ei11...
・Reference set value signal 8u...Optimum control command value signal s ts"...Input value signal 814...Motor speed command signal

Claims (1)

[Claims] 1. In optimally controlling the driving speed of a Dahlgren dampening water device or an Evitsuku Dambuna device that is attached to a plate cylinder and can freely control the amount of dampening water supplied, a group of measurement information related to printing quality and a planographic plate are used. Operational information of the printing press and a group of standard setting information set manually in advance are sequentially input into a microcomputer, and the calculation formula is stored in the microcomputer in advance to lead to appropriate control of the amount of dampening water supplied. The drive speed of the Dahlgren dampening water device or the Ebitsukudambuna device is controlled at variable speed based on the optimum control command value calculated from the microcomputer in accordance with the above, and the optimum control command value is displayed and recorded, and the plate cylinder printing surface is Fully automatic control method for dampening water amount in metal lithographic printing by constantly forming an optimal dampening water film thickness on the plate 2 Measurement information and information group include the measured value of the dampening water film thickness on the plate cylinder printing plate surface, the measured value of the dampening water film on the plate surface, and the measured value of the room temperature. Claim 1 describes the humidity measurement value, the dampening water temperature measurement value, the printing ink temperature measurement value, the printing plate temperature measurement value, the dampening water pH measurement value, the cylinder temperature measurement value, and the printing press speed measurement value. Fully automatic control method for dampening water amount in metal lithographic printing 3, the standard setting information group is the dampening water amount value, ink volume value, non-image area value, dampening water PA concentration value, and ink volume value. Fully automatic dampening water amount control method 4 in metal lithographic printing as set forth in claim 1 or 2, wherein various measuring instruments for obtaining measurement information of various objects related to printing quality are connected via an analog input device midway, In addition, a printing press operation signal generator that informs printing press operation information is connected to the input side of the microcomputer via a digital input device, and a keyboard for manually setting various standard setting information is connected to the input side of the microcomputer. A group of display/recording devices are connected to the output side of the system, and a motor control device directly connected to the Dahlgren motor or the Ebtsuku Danbuna motor provided in the Dahlgren dampening water device or the Ebtsuku Danbuna device via an intermediate analog output device, respectively.
The dampening water amount fully automatic control device 5 in metal lithographic printing, which is capable of controlling the drive speed of the Dahlgren dampening water device or the Evitsukudambuna device at an optimum variable speed, and various measuring instruments are placed facing the plate cylinder and installed on the printing surface of the plate cylinder. A dampening water film thickness measuring device for measuring the dampening water film thickness value of a lithographic printing machine, a room temperature needle for measuring the room temperature in which a lithographic printing machine is installed, and a hygrometer for measuring the humidity in the room in which a lithographic printing machine is installed. , a water temperature needle that measures the temperature of dampening water, and an ink thermometer that measures the temperature of ink used in lithographic printing machines.
A plate thermometer that measures the temperature of the metal plate to be printed and the pH of the dampening water.
In the metal lithographic printing according to claim 4, which comprises a pH meter for measuring values, a cylinder thermometer for measuring the surface temperature of various cylinders, and a printing press speed needle for measuring the driving speed of the lithographic printing press. Fully automatic dampening water flow control device