JPH11207937A - Method and apparatus for cleaning press plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To alleviate an operator's operating load by improving a productivity and reducing a production cost and a printing material consumption amount. SOLUTION: A 'cleaning' function is selected in a menu screen of a trial printing system, and number of leaning sheets is set (step 104). In the system, when an ink removing operation is finished (step 107), or when a checked result of number of removing sheets in a step 105 is zero, an inking roller set to an attached state to a press plate so far is set to a released state, and printing of the set number of the cleaning sheets is started in the state that a calling operation of an ink transfer roller remains stopped (step 108). Thus, inks held in the plate, a blanket and a water supply roller group are transferred to a printing sheet, and all is removed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing plate cleaning method and a printing plate cleaning apparatus for removing ink on a printing plate.

[0002]

2. Description of the Related Art FIG. 6 shows a main part of an inker (ink supply device) in each printing unit in a rotary printing press. In the drawing, 1 is an ink fountain, 2 is ink stored in the ink fountain 1, 3 is an ink fountain roller, and 4 (4-1 to 4-
n) is an ink fountain key provided in plural in the axial direction of the ink fountain roller 3, 5 is an ink transfer roller, 6 is an ink roller group, 7 is a printing plate, 8 is dampening water, 9 is a water supply roller group, Reference numeral 10 denotes a plate cylinder, 17 denotes a blanket cylinder, and 18 denotes a blanket wound on the blanket cylinder 17.

[0003] This ink supply device includes an ink fountain key 4
The ink 2 in the ink fountain 1 is supplied to the ink fountain roller 3 by adjusting the opening degree of -1 to 4-n, and the ink supplied to the ink fountain roller 3 is transferred to the ink roller group 6 by the operation of calling the ink transfer roller 5. Is supplied to the printing plate 7. In this case, the ink application roller 6-1 in the ink roller group 6 is set on the printing plate 7, and the ink is applied to the printing plate 7 via the ink application roller 6-1 in the attached state. Supplied to Simultaneously with the ink supply, the dampening water 8 is supplied to the printing plate 7 via the water supply roller group 9.

When the printing plate 7 is replaced with a new printing plate 7 ', the opening of the ink fountain keys 4-1 to 4-n and the rotation of the ink fountain roller 3 are adjusted to values corresponding to the pattern of the new printing plate 7'. The amount etc. are preset. That is, the ink fountain key 4-
The ink 2 in the ink fountain 1 is transferred to the new printing plate 7 ′ via the ink roller group 6 by setting the degree of opening of the ink fountain roller 3, the rotation amount of the ink fountain roller 3, and the like as values according to the pattern of the new printing plate 7 ′. Supplied to In this case, test printing is performed before final printing to adjust the ink supply amount and obtain a satisfactory color tone. Thus, a desired ink film thickness distribution (gradient of ink film thickness) is created in the ink roller group 6.

However, in the conventional ink supply device, when the printing plate 7 is replaced with a new printing plate 7 ', the old printing plate 7
Is left in the ink roller group 6. That is, in this case, it is necessary to gradually change the ink film thickness distribution for the old printing plate 7 to the ink film thickness distribution for the new printing plate 7 ', and to adjust the ink supply amount until a satisfactory color tone is obtained. Excessive trial printing is required, and problems such as “increase in preparation time before printing”, “increase in labor load”, “waste of printing materials”, “decrease in production efficiency”, and “cost increase” occur.

The applicant of the present invention has disclosed, for the purpose of adjusting the ink supply amount until a satisfactory color tone is obtained and reducing the number of trial printings, as Japanese Patent Application No. 8-167144, entitled "Control of Ink Film Thickness." Method "was proposed. In the method of controlling the ink film thickness, when the old printing plate 7 is replaced with the new printing plate 7 ', first, ink removing is performed. That is, after the end of the final printing operation, on the display (not shown), a printing unit is selected, ink removal is selected, the operation of calling the ink transfer roller 5 is turned off, and the old printing plate 7 is removed. The machine is operated with the apparatus mounted, and a predetermined number of prints are performed, whereby the minimum ink film thickness distribution Ma required during printing in which the ink roller group 6 becomes thinner from upstream to downstream during printing. (See FIG. 7A), that is, the ink film thickness distribution Ma corresponding to the portion of the printing plate 7 where there is no picture is left.

Next, pre-inking 2 is performed on the display.
And performs the pre-inking 2 operation. In the pre-inking 2, the opening degree of the ink fountain keys 4-1 to 4-n, the rotation amount of the ink fountain roller 3, and the like are preset to values corresponding to the pattern of the new printing plate 7 '. The transfer roller 5 is called up a predetermined number of times, and the ink film thickness distribution according to the pattern of the new printing plate 7 'is reduced to the minimum ink film thickness distribution Ma required during printing remaining in the ink roller group 6. Mb (see FIG. 7B) is superimposed.

Then, Mb is added to the ink film thickness distribution Ma.
After the superimposition, the blanket 18 wound around the blanket cylinder 17 is washed, a predetermined number of test prints are performed with the printing plate 7 replaced with a new printing plate 7 ′, and the density check is performed on the test printed material. Do. In this density check, if the color tone is satisfactory, the control of the ink film thickness by “ink removing + pre-inking 2” is completed, and the operation shifts to final printing. If the color tone is not satisfactory, fine adjustment of the ink film thickness distribution is performed by pre-inking (+) or pre-inking (-), and test printing is performed again.

[0009]

However, in this method, when the printing plate is replaced, ink remains in the picture of the printing plate (old printing plate) before replacement.
The ink left on the printing plate causes problems such as "increase of preparation time before printing", "increase of labor load", "wasting of printing material", "decrease of production efficiency", and "cost increase".

That is, since the ink remains on the printing plate, the blanket and each part constituting the plate feeding / discharging device are soiled regardless of the presence or absence of the cylinder. For this reason, the treatment and handling of the printing plate after printing, including the plate discharging operation, become troublesome, and the work load on the operator increases. When the printing plate is supplied and discharged by the cylinder insertion method, the ink remaining on the printing plate is transferred to a blanket, so that the test printing is strongly affected by the pattern before the plate replacement. To eliminate this effect, a considerable number of trial prints are required,
A lot of broke occurs.

If the set value of the paper thickness is small, the ink on the printing plate may be transferred from the blanket to the impression cylinder by changing the printing plate. In this case, it leads to "increase in cleaning work" and "deterioration of test printing quality", etc., which causes an increase in work load and waste paper. In order to prevent ink from adhering to the impression cylinder, a method of setting a large gap between the blanket cylinder and the impression cylinder is conceivable.However, at the time of trial printing, the set value must be changed to a regular gap again.
Even though ink adhesion to the impression cylinder can be prevented, an increase in preparation time before printing is inevitable. Depending on the amount of ink remaining on the water supply roller group, the quality of test printing may be reduced. In order to eliminate this effect, it is necessary to increase the number of prints in the trial printing, which is a factor of increasing waste paper.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to improve the above-mentioned problems, improve productivity, reduce production costs and consumption of printing materials, It is an object of the present invention to provide a printing plate cleaning method and a printing plate cleaning device capable of reducing the work load of the printing plate.

[0013]

According to the present invention, there is provided an ink fountain roller including a plurality of ink fountain keys, wherein the ink in the ink fountain is supplied to an ink fountain roller by adjusting the opening of the ink fountain key. In the inker that supplies the ink supplied to the ink fountain roller to the printing plate via the ink-applying roller that has been applied, the ink-applying roller is removed, and a predetermined fixed number of By performing printing, the ink on the printing plate is removed. According to the present invention, it is possible to replace the printing plate with a new printing plate after removing the ink remaining on the old printing plate by printing a predetermined number of sheets with the ink applying roller removed.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on embodiments. FIG. 2 is a diagram showing a four-color sheet-fed rotary printing press to which the present invention is applied. In the figure, 11-1
11 to 11-4 are printing units for each color, and the printing units 11-1 to 11-4 are provided with the respective ink supply devices shown in FIG. The printing unit 11-
Printing plate automatic changers 12-1 to 12-1 corresponding to 1-111-4
12-4 are provided. The printing unit 11-
In 1-111-4, 17-1 to 17-4 are blanket cylinders,
Reference numerals 18-1 to 18-4 denote blankets wound on the surfaces of blanket cylinders 17-1 to 17-4, and reference numerals 19-1 to 19-4 denote impression cylinders.

The rotary printing press is provided with an operation desk 13 as shown in FIG. The operation desk 13 has an operation panel 13-1 on an upper surface of the desk, and a display unit 13-2 and an operation unit 13-3 are provided on the operation panel 13-1. A trial printing system (a personal computer in this example) 14 is placed on the upper surface of the operation desk 13. In this embodiment, although not shown, a control device is installed in the operation desk 13, and a trial printing system 14 is configured together with the control device. Further, from the operation unit 13-3, the blanket cylinder 17 is provided.
The gap between the pressure drum and the impression cylinder 19, that is, the paper thickness can be set.

The trial printing system 14 is loaded with standardized trial printing data. In this case, the trial printing data includes “inking count (ink transfer count)”, “test printing count”, and the like in pre-inking 1, ink removing, pre-inking 2, pre-inking (+) and pre-inking (−). Setting conditions such as “the number of removed inks”.

The operation panel 13-1 has a magnetic card 1
5 (see FIG. 4A) and the floppy disk 16 (see FIG.
(See (b)) is provided with an insertion slot (not shown) into which a recording medium is inserted and set. In this embodiment,
The actual printing data (print data) created based on the picture area information of the printing plate is recorded on a recording medium. That is, for each required printing plate, the printing unit in which the printing plate is used, the opening of the ink fountain key in the printing unit,
Set value data such as the rotation amount of the ink fountain roller is recorded as final printing data.

The test printing system 14 has a blanket cleaning function, a plate cleaning function, and a test printing function, in addition to a function for forming an optimum ink film thickness on each roller of the ink roller group 6. ing. These functions (control programs) are displayed on the menu screen M (see FIG. 5).
Will be displayed. That is, “pre-inking 1”, “pre-inking 2”, “blanket cleaning”, “cleaning (plate cleaning)”, “ink removing”, and “test printing” are displayed on the menu screen M. These functions can be selected by touching the selection keys K1 to K6.

On the menu screen M, a display section (setting display section) P1 of the number of ink calls by the "pre-inking 1" and "pre-inking 2" functions, and "cleaning"
Display section (setting display section) P2 of the number of prints in the function, display section (setting display section) P3 of the number of prints in the "ink removing" function, display section (setting display) of the number of prints in the "test printing" function Part) P4 is provided.

In the menu screen M, "blanket cleaning" is a function for selecting whether to perform blanket cleaning after the completion of the plate cleaning operation or to perform the blanket cleaning independently of the plate cleaning operation. Yes,
Each time the selection key K3 is touched, the display status of the display units P5 and P6 is switched to notify the current setting status.

In this rotary printing press, the printing unit 11
The plate exchange in (11-1 to 11-4) is performed as follows.

After the end of the final printing operation (step 101 shown in FIG. 1), for example, the printing unit 11-1 is replaced with the old printing plate 7 with the new printing plate 7 '. In this case, the operator sets the recording medium on which the final printing data of the new printing plate 7 'to be set in the printing unit 11-1 is recorded in the insertion slot of the operation desk 13, and inputs the print data. (Step 102). Then, the operator selects the number “1” corresponding to the printing unit 11-1 in “unit selection” of the menu screen M of the trial printing system 14, and sets the number of prints (the number of ink removals) on the display P3. Then, the "ink removing" function is selected by the selection key K5 (step 10).
3). Further, the operator sets the number of prints (the number of cleanings) on the display P2, and selects the "cleaning" function with the selection key K4 (step 104).

At this time, the ink roller group 6 in the printing unit 11-1 has an ink film thickness distribution Mb corresponding to the pattern of the printing plate 7 with respect to the minimum ink film thickness distribution Ma required during printing. Are superimposed.

In the case where the picture is hardly changed between the printed matter after the final printing operation and the printed matter to be newly performed, that is, when the patterns of the old printing plate 7 and the new printing plate 7 ′ hardly change, the ink removing operation is performed. Since there is no need, the number of prints set on the display unit P3 is set to zero.

When the function selection and setting in steps 103 and 104 are completed, the trial printing system 14 checks whether or not the setting of the number of ink removing sheets is zero (step 1).
05) If the number of ink removed is zero, the process immediately proceeds to step 108, and if the number of ink removed is not zero, the process proceeds to step 106.

In step 106, the trial printing system 14 starts ink removing. In this ink removing, the calling operation of the ink transfer roller 5 is turned off, and the machine is operated while the old printing plate 7 is mounted, and the number of ink removed set in step 103 is printed. , Thereby the ink roller group 6
The minimum ink film thickness distribution Ma required during printing, which becomes thinner from upstream to downstream, is left.

During the ink removal, the printing is performed while the call-out operation of the ink transfer roller 5 is stopped, so that the ink 2 in the ink fountain 1 is not supplied to the ink roller group 6 at all. Therefore, as for the ink held by the ink roller group 6, only the picture portion of the printing plate 7 is consumed by printing. As a result, the history of the ink is eliminated, and the minimum ink film thickness distribution Ma required during printing remains.

When the ink removing operation is completed (step 107) or when the result of checking the number of removed inks in step 105 is zero, the test printing system 14 is in a state where the ink is removed from the printing plate 7 until then. The ink application roller 6-1 was removed, and the operation of calling the ink transfer roller 5 was stopped.
Printing of the cleaning number set in step 104 is started (step 108).

During the cleaning, printing is performed with the ink setting roller 6-1 in the detached state and the ink transfer roller 5 in a state in which the calling operation is stopped, so that the printing plate 7 and the blanket 18 are printed. In addition, the ink held by the water supply roller group 9 is transferred to the printing paper and all the ink is removed.

After completing the cleaning (step 109), the trial printing system 14 presets the final printing data from the recording medium (step 11).
0). In parallel with this, the trial printing system 14
If "automatic cleaning" is selected by the selection key K3, the blanket 18 is automatically cleaned (step 11).
1). In other words, even if the cleaning in steps 108 and 109 is performed, paper dust or the like may adhere to the blanket 18, which affects the quality of test printing. Therefore, the blanket 18 is cleaned. When "single washing" is selected by the selection key K3, the trial printing system 1
No. 4 does not wash the blanket 18.

From the start of ink removal to the presetting of print data or blanket cleaning, all controls including cleaning are automatically performed. When all of these controls are completed, the test printing system 14 sets the ink forming roller 6-1 in a state in which the ink forming roller 6-1 is linked to the attachment / detachment of the cylinder, and also cancels the stop of the calling operation of the ink transfer roller 5, and
The state is switched to a state where normal printing work is possible (step 112).

After switching to a state in which normal printing work can be performed by the test printing system 14 (after completion of automatic operation), the operator sets a paper size preset device (not shown).
Is operated to preset the size of the printing paper for the new printing plate 7 '(step 113), and the printing plate 7 is replaced by the new printing plate 7' by operating the automatic plate replacement device 12 (step 114).

At the time of plate replacement, since the ink on the plate 7 has already been removed by the cleaning operation in steps 108 and 109, the blanket 18 and the automatic plate replacement device 12 are operated even when the plate is replaced. The constituent parts are not stained, and the cleaning work of each part is not required.
Also, even if the printing plate is replaced while the cylinder is in the loaded state, that is, even if the printing plate is replaced while the blanket cylinder 17 is in contact with the impression cylinder 19, there is no ink on the printing plate 7. Impression cylinder 1
9 does not adhere to the blanket cylinder 9 and the blanket cylinder 17,
9 and the blanket cylinder 17 need not be cleaned.

Further, conventionally, as described above,
A temporary setting operation before the plate replacement may be considered in which a gap between the blanket cylinder 17 and the impression cylinder 19 is widened to prevent ink from adhering to the impression cylinder 19. However, in this embodiment, such a work is not required, and the work process can be simplified and the preparation time before printing can be reduced. Further, in this embodiment, since the ink is also removed from the water supply roller group 9, the test printing after the pre-inking 2 is performed (step 115). Can be.

In this embodiment, the ink is also removed from the blanket 18 together with the removal of the ink from the printing plate 7 and the water supply roller group 9. Therefore, when there is little dirt on the blanket 18 due to small lot work or printing, the blanket cleaning function is set to “single cleaning”.
By doing so, the blanket cleaning operation in step 111 can be omitted.

[0036]

As apparent from the above description, according to the present invention, the ink on the printing plate is removed by removing the inking roller and printing a predetermined number of sheets. After removing the ink remaining on the old printing plate, it is possible to replace the new printing plate, eliminating the adverse effects of the ink remaining on the old printing plate, improving productivity, It is possible to reduce the production cost and the consumption amount of the printing material, and to reduce the work load of the operator.

[Brief description of the drawings]

FIG. 1 is a flowchart for explaining a characteristic operation of the present invention.

FIG. 2 is a diagram showing a four-color sheet-fed rotary printing press to which the present invention is applied.

FIG. 3 is a view showing an operation desk attached to the rotary printing press.

FIG. 4 is a diagram illustrating a recording medium on which print data is recorded.

FIG. 5 is a diagram showing a menu screen appearing on a display of the trial printing system.

FIG. 6 is a diagram illustrating a main part of an ink supply device in each printing unit in the rotary printing press.

FIG. 7 is a diagram showing ink film thickness distributions Ma and Mb formed on an ink roller group of the ink supply device.

[Explanation of symbols]

1: Ink fountain, 2: ink, 3: ink fountain roller,
4 (4-1 to 4-n): ink fountain key, 5: ink transfer roller, 6: ink roller group, 6-1: ink setting roller, 7 (7 '): printing plate, 8: dampening water, 9 ... Water supply roller group, 10 ... plate cylinder, 11 (11-1 to 11-4) ... printing unit, 12 (12-1 to 12-4) ... printing plate automatic exchange device, 13 ... operation desk, 14 ... trial printing system , 17
(17-1 to 17-4) ... blanket cylinder, 18 (18-1 to 1)
8-4) Blanket, 19 (19-1 to 19-4)
... impression cylinder, M ... menu screen, K1-K6 ... selection keys, P
1 to P6 ... Display unit.

Claims (2)

[Claims] 1. An ink fountain key is provided, a plurality of ink fountain keys are provided, ink in the ink fountain is supplied to an ink fountain roller by adjusting the opening of the ink fountain key, and the ink supplied to the ink fountain roller is brought into an applied state by a call-out operation of an ink transfer roller. In the inker that supplies ink to the printing plate via the ink forming roller, the ink forming roller is removed from the printing plate, and a predetermined fixed number of prints are performed to remove the ink on the printing plate. A printing plate cleaning method, characterized in that: 2. An ink fountain key is provided, a plurality of ink fountain keys are provided, ink in the ink fountain is supplied to the ink fountain roller by adjusting the opening degree of the ink fountain key, and the ink supplied to the ink fountain roller is brought into an applied state by a call operation of the ink transfer roller. A plate cleaning device in an inker for supplying a printing plate to a printing plate via an ink forming roller, wherein the ink forming roller is attached to and detached from the printing plate, and the ink forming roller is detached. A printing plate cleaning device, comprising: an ink removing unit that removes ink on the printing plate by performing printing of a predetermined number of sheets determined in advance.