JPH08295010A - Ink replacement device of flexographic printer - Google Patents

Abstract

PURPOSE: To shorten a cleaning liquid recovery time significantly, eliminate the dilution of ink by a residual cleaning liquid in an ink circulation feed path to prevent ink viscosity (concentration) from becoming low, eliminate the mixing of a residual ink of an old order in the ink circulation feed path to prevent ink of a new order from becoming turbid, and consequently, enhance productivity and print quality. CONSTITUTION: When cleaning an ink circulation feed mechanism, a cleaning liquid is fed to the ink circulation feed mechanism from a cleaning liquid pipe 16 as is the case with a prior art ink replacement device, by switching a direction selector valve 26 to ink containers 4a, 4b. Further, the ink circulation feed mechanism is cleaned to recover a waste liquid (cleaning liquid after cleaning). After that, an ink container 4 for storing ink of a new order is connected to the ink feed pipe 8 side of the mechanism, and at the same time, a direction selector valve 27 is switched to the waste liquid recovery part 25 so that the ink 3a, 3b is supplied only for a specified time, and a residual waste liquid (residual cleaning liquid) is forcibly discharged to the waste liquid recovery part 25 with the ink 3a, 3b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink exchanging device for a flexographic printing machine which automatically changes ink when changing colors due to order changes.

[0002]

2. Description of the Related Art An ink exchanging device for a conventional flexographic printing machine will be described with reference to FIGS. 4 (a) and 4 (b) and FIG. As shown in FIG. 4 (a), an ink exchange device for a general flexographic printing machine has an ink circulation supply mechanism for supplying ink to the printing section by circulating the ink between one of the ink containers and the printing section. And an ink container replacement mechanism for selectively connecting a connection part of the ink circulation supply mechanism to one of the ink containers, and a cleaning liquid is supplied to the ink circulation supply mechanism when cleaning the ink circulation supply mechanism. And a cleaning liquid supply mechanism.

FIG. 4A is a perspective view of an ink exchanging device,
FIG. 4 (b) is a side view of a printing unit including an ink roller (anilox roll and rubber roll), a printing cylinder and a receiving roll, and FIG. 5 is a flowchart showing the operation of the ink exchanging device. The printing section of the flexographic printing machine is shown in Fig. 4.
It has a structure shown in (a) and (b). That is, 28 is a printing cylinder having a printing plate 29 wound around the outer peripheral surface thereof, 30 is a receiving roll disposed to face the printing cylinder 28, 1 is an anilox roll (ink roll), 2 is a rubber roll (ink roll), The printing unit is configured by these.

[0004] 3 is a flexo ink, the flexo ink 3 from the ink container 4a (or ink container 4b) through the ink pump 7 → ink supply pipe 8 to the nip portion P between the anilox roll 1 and the rubber roll 1. Supplied. Then, the ink 3 supplied to the nip portion P is doctored by the rubber roll 2 and uniformly transferred to the outer peripheral surface of the anilox roll 1, and further the anilox roll 1
Plate 29 wound around the surface of the printing cylinder and the outer peripheral surface of the printing cylinder
By contact with the printing plate 29, it is transferred to the printing plate 29.

On the other hand, the corrugated board sheet 31 passes between the printing cylinder 28 and the receiving roll 30 and comes into contact with the printing plate 29, so that the corrugated board sheet 31 is subjected to predetermined printing. Ink 3a in ink container 4a during printing operation
Are supplied to the nip portion P. The remaining ink 3a overflows from both ends of the nip portion P, flows down to the end pans (ink reservoirs) 15a and 15b, and further returns to the ink container 4a through the return pipes (discharge pipes) 10a and 10b. .

As described above, the ink 3a is circulated in the ink circulation supply mechanism during the printing operation. When the predetermined printing is completed, order change (ink color change and printing plate exchange) is required. The ink circulation supply mechanism will be described more specifically. 11a and 11b are ink supply ports of the ink containers 4a and 4b, and 5 and 5 are lids of the ink containers 4a and 4b provided with the ink supply ports 11a and 11b.
12 is a joint provided at the lower end of the ink supply pipe 8,
The joint 12 is one of the ink supply ports 11a and 11b.
It is detachably attached to one.

Reference numeral 13 is a filter provided in the middle of the ink supply pipe 8, and 7 is an ink supply pipe 8 above the filter 13.
An ink pump 14 provided in the middle of the ink funnel device 14 is an ink funnel device provided at the tip of the ink supply pipe 8.
4 is disposed immediately above the nip portion between the anilox roll 1 and the rubber roll 1. End pans 15a and 15b are arranged directly below both ends of the anilox roll 1 and the rubber roll 1, and end pans 10a and 10b are the same end pan 15.
The return pipes (discharge pipes) 10 extending from a and 15b are return pipes (discharge pipes) connected to the return pipes 10a and 10b, and the lower end of the return pipe 10 is a return port 6 of the ink containers 4a and 4b.
It is connected to one of a and 6b.

The cleaning liquid supply mechanism will now be described in detail. A cleaning liquid pipe 16 is connected to the ink supply pipe 8 via a solenoid valve 18 and a T-shaped joint 17. Next, specifically explaining the exchange mechanism,
20 is a cylinder for raising and lowering a joint, 21 is a cylinder for driving a bucket, 22 is a cylinder for driving a holder, 2
3 is a holder, 25 is a waste liquid bucket, and 32 is a bracket that connects the joint 12 and the return pipe 10.

The operation of the ink exchange device at the time of order change is as follows. As shown in FIG. 4A, the joint 12 and the return pipe (exhaust pipe) 10 are provided with a bracket 32.
Are connected to each other by and are movable in the front-rear direction, the left-right direction, and the up-down direction. 5 (a) (b) (c) (d)
Is a flowchart for ink replacement, and is shown in FIG.
Is the state when the ink is circulated (the state when the ink is started), FIG. 5B is the state when the ink is collected, and FIG.
Shows the state when the ink is washed with the washing liquid.

First, the ink circulation in the ink circulation path is stopped by stopping the ink pump 7, and the ink is collected in the ink container 4a for a predetermined time by a timer setting as shown in FIG. 5 (b). Then, the bracket 32 connecting the joint 12 and the return pipe (discharge pipe) 10 is raised and retracted by a recovery end signal, and the joint 12 and the lower end portion of the return pipe 10 are inked as shown in FIG. 5C. It is moved to a position separated from the container 4a, that is, a predetermined position on the waste liquid bucket 25, and stopped.

In this state, the solenoid valve 18 is opened, and the cleaning liquid is passed through the cleaning liquid pipe 16 and the T-shaped joint 17, and the inside of the ink supply pipe 8 of the ink circulation supply path is connected to the ink funnel device 14.
To automatically clean the inside of the ink supply pipe 8 and the ink funnel device 14, and further, the ink in the nip portion between the anilox roll 1 and the rubber roll 1 and the ink in the end pans 15a and 15b. And the return pipes 10a, 1
Wash away the ink in 0b and 10.

During this time, the anilox roll 1 and the rubber roll 2 are spun at low speed to wash away the first color ink adhering to the outer peripheral surfaces of both rolls 1 and 2, both shaft ends and the end pans 15a and 15b. At the same time, the cleaning liquid is supplied to the cleaning liquid pipe 16
→ The ink supply pipe 8 is connected to the ink container 4 via the T-shaped joint 17.
The ink in the ink supply pipe 8, the ink pump 7, the filter 13 and the joint 12 is also washed away by automatically supplying in the direction of a.

By the above operation, all the cleaning liquid is discharged from the return pipes 10a, 10b, 10 → the ink supply pipe 8 → the opening joint 12 to the waste liquid bucket 25. The supply of cleaning liquid is controlled by a timer that can adjust the time,
The solenoid valve 18 is closed and stopped by a signal after a lapse of a predetermined time. Even after the supply of the cleaning liquid is stopped, each device is stopped as it is, and the cleaning liquid is collected for a certain period of time. Then, the recovery operation completion signal from the timer causes the process to proceed to the next returning step. That is, the bracket 32
To move the joint 12 to the supply port 11b of the ink container 4b in which the ink of the next new order has been put in advance.
And the tip of the return pipe 10 to the return port 6b of the ink container 4b to stop the movement of the bracket 32, and then lower the bracket 32, as shown in FIG.
As shown in, the joint 12 is brought close to the supply port 11b and automatically connected. Further, the tip of the return pipe 10 is connected to the return port 6b.

In this state, the ink pump 7 is started, and the ink of the next new order is circulated in the ink circulation supply path as described above to perform printing with the new order ink.

[0015]

In the conventional ink exchange device of the flexographic printing machine shown in FIGS. 4 and 5, when printing with the ink of the old order is completed, the ink pump 7 is stopped and the lower end of the ink circulation path. Section (the lower ends of the ink supply pipe 8 and the return pipe 10) and the ink container 4a are disconnected, and the circulating ink is collected in the current (old order) ink container, and then the waste liquid bucket is replaced by the replacement mechanism. 25, the cleaning liquid supply mechanism is operated, the ink circulation path is cleaned with the cleaning liquid, the contaminated cleaning liquid liquid after cleaning is discharged into the waste liquid bucket 25, and then the supply of the cleaning liquid is stopped, After collecting the polluted cleaning liquid for a predetermined time by natural discharge, the lower end of the ink circulation path is connected to the ink container 4b of the next new order, and printing with the new order ink is started. Unishi to have.

That is, after the supply of the cleaning liquid is stopped, the polluted cleaning liquid is recovered after waiting for spontaneous outflow.
Therefore, a considerable amount of time is required to collect the liquid in the roll nip portion and the circulation path. However, in reality, because it is necessary to give priority to productivity, the next printing (ink supply) is restarted without taking sufficient liquid recovery time. Therefore, when ink circulation is started, the roll nip portion and circulation path The residual cleaning liquid remaining on the way flows back into the ink container, the ink is diluted, the viscosity of the ink is reduced, and the old order residual ink is mixed, and the new order ink is discolored.
There is a problem that the print quality is degraded and the new order ink cannot be used.

The present invention is proposed in view of the above-mentioned problems, and an object thereof is to significantly reduce the time for collecting the cleaning liquid and to eliminate the dilution by the cleaning liquid remaining in the ink circulation supply path. Ink viscosity (concentration) can be prevented from lowering, old-order ink remaining in the ink circulation supply route can be eliminated, and new-order ink contamination can be prevented. As a result, productivity and print quality can be improved. The point is to provide an ink exchanging device for a flexographic printing machine.

[0018]

In order to achieve the above object, the present invention prints ink by circulating a plurality of ink containers and circulating ink between one of the ink containers and a printing unit. Ink circulation supply mechanism for supplying the ink to the ink supply section, an ink container replacement mechanism for selectively connecting a connection portion of the ink circulation supply mechanism to the ink container to one of the ink containers, and a cleaning liquid for cleaning the ink circulation supply mechanism. In the ink exchanging device of the flexographic printing machine, which has a cleaning liquid supply mechanism for supplying the same to the ink circulation supply mechanism and a waste liquid recovery unit for recovering the waste liquid after cleaning, the waste liquid is supplied to the ink circulation supply mechanism. A waste liquid discharge system for discharging the waste liquid to the waste liquid recovery unit is provided (Claim 1).

In the ink exchanging device of the flexographic printing machine according to the first aspect, a waste liquid discharge system is provided at the lower end of the return pipe to the ink container of the ink circulation supply mechanism so that the liquid path is in the direction of the waste liquid collecting part. It may be constituted by a direction switching for switching to the direction of the ink container and a waste liquid discharge pipe extending from the same direction switching valve to the waste liquid collecting section (claim 2). In the ink exchanging device for the flexographic printing machine according to claim 2, a three-way valve or a two-way valve may be used as the direction switching valve (claim 3).

[0020]

The ink exchange device of the flexographic printing machine of the present invention is constructed as described above, and at the time of cleaning, the direction switching valve is switched to the direction of the ink container so that the cleaning liquid is supplied with the ink like the conventional ink exchange device. Supply to the circulation supply mechanism, wash the ink circulation supply mechanism, and waste liquid (cleaning liquid after cleaning)
After collecting the ink to the waste liquid collection unit, connect the ink container that stores the new-order ink to the ink supply pipe side of the ink circulation supply mechanism, switch the direction switching valve to the direction of the waste liquid collection unit, and set the ink for a predetermined time. Is supplied to forcibly discharge the residual waste liquid (residual cleaning liquid) together with the ink to the waste liquid collecting section. In this state, after a lapse of a predetermined time, or when the color of the returning liquid reaches a predetermined concentration, the direction switching valve is switched to the direction of the ink container, and new order ink is circulated to the ink circulation supply mechanism to print the ink. Supply to the department.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An ink exchanging device for a flexographic printing machine according to the present invention will be described with reference to an embodiment shown in FIGS. FIG.
FIG. 2 is a perspective view of the ink exchanging device, and FIG. 2 is a flow chart showing the function (operating state) of the ink exchanging device.

1 and 2 in FIG. 1 are anilox rolls and 2
Is a rubber roll, 3 is a flexo ink, 4a and 4b are ink containers, 5 and 5 are lids of the same ink containers 4a and 4b, 6a,
6b is a return port provided on the lids 5 and 5, 7 is an ink pump,
8 is an ink supply pipe, 10 is a return pipe (discharge pipe), 11a,
11b is the above-mentioned lid, 6a, the supply port provided in 6b, 12 is a joint, 13 is a filter, 14 is an ink funnel device,
15a and 15b are end pans, 16 is a cleaning liquid pipe, 17 is a T-joint, 18 is a solenoid valve, 20 is a joint lifting cylinder, 21 is a bucket drive cylinder,
22 is a holder driving cylinder, 23 is a holder, 2
5 is a waste liquid bucket (waste liquid recovery unit), 26 is a three-way valve (direction switching valve), and 27 is a waste liquid discharge pipe.

The structure and function of the printing section of the flexographic printing machine are the same as those of the conventional one. Next, the operation of the ink exchange device of the flexographic printing machine will be specifically described.
When the printing of a certain order is completed and the ink is to be replaced by an order change, the ink pump 7 is stopped and the start push button switch of the control circuit (not shown) of the replacement mechanism is pressed to replace the ink. Start. That is,
From the state of FIG. 2 (a), first, the ink pump 7 is stopped and the ink in the ink circulation path is collected in the ink container 4a as shown in FIG. 2 (b). At this time, the three-way valve 26
Are switched in the direction of the ink container 4a.

When the predetermined time set by the timer has elapsed from this state and the ink recovery is completed, the recovery completion signal at this time attaches to the ink supply pipe 8 and its lower end as shown in FIG. 2 (c). The joint 12 that is being lifted by the joint lifting cylinder 20 and the holder 2
3 by retracting the holder driving cylinder 22,
Joint 12 of ink supply pipe 8 and return pipe (discharge pipe) 1
The lower end portion of 0 is moved above the waste liquid bucket (waste liquid recovery unit) 25.

In this state, the solenoid valve 18 is opened, and the cleaning liquid is automatically supplied in the direction of the anilox roll 1 and the rubber roll 2 through the cleaning liquid pipe 16 and the T-shaped joint 17, and the inside of the ink supply pipe 8 and the ink funnel. Rinse the inside of the device 14. Further, the ink in the roll nip portion, the ink in the end pans 15a and 15b, and the return pipe 10
A, 10b and the ink inside the return pipe 10 are washed away.

At this time, the anilox roll 1 and the rubber roll 2 are idling at a low speed, and the first color ink adhering to the outer peripheral surfaces of both rolls 1 and 2, both shaft ends, and the inside of the end pans 15a and 15b. Wash away. On the other hand, the cleaning liquid is automatically supplied in the direction of the cleaning liquid pipe 16 → the T-shaped joint 17 → the ink container 4a to wash away the ink inside the ink supply pipe 8 and the ink inside the ink pump 7, the filter 13 and the joint 12. .

By the above work, all the cleaning liquid is discharged from the lower end of the return pipe 10 and the joint 12 of the ink supply pipe 8. The supply of the cleaning liquid is controlled by a timer or the like capable of adjusting the time, and the solenoid valve 18 is closed by a signal obtained when a predetermined time has elapsed, the supply of the cleaning liquid is stopped, and the next step is started. That is, when the supply of the cleaning liquid is stopped, the cleaning liquid is collected for a certain period of time. Then, the holder driving cylinder 22 is operated to transfer the joint 12 of the ink supply pipe 8 and the lower end of the return pipe 10 which are supported by the holder 23 to be movable in the vertical direction to the right side in FIG. , A joint 12 to the supply port 11b of the ink container 4b in which new ink of the next order has been previously stored, and a return pipe 10 to the return port 6b of the ink container 4b.
The lower end of each of them is made to correspond and stopped.

When the collection of the cleaning liquid is completed, the holder 23 is moved to the bucket driving cylinder 2 as shown in FIG. 2 (d).
1, the joint lifting cylinder 20 lowers the supply pipe side joint 12 of the ink circulation supply path, and the supply port 1 of the ink container 4b of the next new order.
Close to 1b and connect automatically. Further, the three-way valve (electromagnetic valve) 26 is switched to the direction of the waste liquid bucket (waste liquid recovery unit) 25. At this time, the ink supplied by the ink pump 7 is forced to extrude and dilute the residual waste liquid (residual cleaning liquid) in the ink circulation path for a predetermined time,
The waste liquid is discharged from the waste liquid discharge pipe 27 to the waste liquid bucket (waste liquid recovery unit) 25 outside the ink container.

The forced discharge time is set by a timer based on experience, and the color of the returned waste liquid is detected by a sensor, and the detection signal is fed back to control.
The operator visually judges and decides. When the forced discharge time has elapsed, the three-way valve 26 is set to the ink container 4
By switching to the direction of b, the circulating ink 3b is collected in the ink container 4b, and then the in 3b in the ink container 4b is circulated to the ink circulation supply mechanism to supply the in 3b to the printing unit.

In this way, the residual waste liquid (residual cleaning liquid) is forcibly discharged by the ink of the new order, and the ink replacement time is greatly shortened. In addition, the diluted ink is not returned to the ink container to prevent the ink viscosity from decreasing. Although the three-way valve 26 is used in the above-described embodiment, the directional switching valve is not limited to the three-way valve, and the two-way valve shown in FIG.
The one-way valve 33 may be used.

That is, FIG. 3A corresponds to the state of FIG. 2D, and the two-way valve 33 is provided in the lower portion of the discharge pipe 10. Further, FIG. 3B shows a printing unit in which ink or water returning from the discharge pipe 10 is temporarily stored in the ink reservoir 35 and then sucked up by the discharge pump 34. A one-way valve 33 is provided. In this example, by stopping the discharge pump 34 and opening the two-way valve 33, it is possible to prevent the residual waste liquid (residual cleaning liquid) from mixing into the new-order ink can 4b. From these viewpoints, the two-way valve 33 may be used.

[0032]

As described above, the ink exchanging device of the flexographic printing machine of the present invention switches the direction switching valve to the direction of the ink container at the time of washing, so that the washing liquid is circulated and supplied in the same manner as the conventional ink exchanging device. The ink circulation supply mechanism, the ink circulation supply mechanism is washed, and the waste liquid (cleaning liquid after cleaning) is collected in the waste liquid collection unit, and then the ink container storing the new order ink and the ink supply pipe side of the ink circulation supply mechanism And the direction switching valve is switched to the direction of the waste liquid collecting unit, ink is supplied for a predetermined time, and the residual waste liquid (residual cleaning liquid) is forcibly discharged together with the ink to the waste liquid collecting unit. In this state, after a lapse of a predetermined time, or when the color of the returning liquid reaches a predetermined concentration, the direction switching valve is switched to the direction of the ink container, and new order ink is circulated to the ink circulation supply mechanism to print the ink. Since it is supplied to the parts, the recovery time of the cleaning liquid can be greatly shortened, the dilution due to the residual waste liquid (remaining cleaning liquid) remaining in the ink circulation supply path can be eliminated, and the decrease in ink viscosity (concentration) can be prevented, and the ink circulation supply It is possible to eliminate the contamination of old-order ink remaining in the path, prevent contamination of new-order ink, and consequently improve productivity and print quality.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of an ink exchanging device of a flexographic printing machine according to the present invention.

FIG. 2A is a flowchart showing a state of ink circulation supply, FIG. 2B is a state of ink collection, FIG. 2C is a state of ink cleaning with a cleaning liquid, and FIG. Is.

FIG. 3A is a side view showing a case where a two-way valve is provided in the return pipe, and FIG. 3B is a side view showing a case where a two-way valve is provided in the ink reservoir.

4A is a perspective view showing an ink exchanging device of a conventional flexographic printing machine, and FIG. 4B is a side view showing a printing unit.

FIG. 5 (a) is a flow chart showing the state of ink circulation supply, (b) is the state of ink recovery, (c) is the state of ink cleaning with a cleaning liquid, and (d) is a flow chart showing the state of ink supply start. Is.

[Explanation of symbols]

 1 Anilox roll (ink roller) 2 Rubber roll (ink roller) 3a, 3b Flexo ink 4a, 4b Ink container 5, 5 Lid 6a, 6b Return port 7 Ink pump 8 Ink supply pipe 10 Return pipe (drain pipe) 10a 〃 10b 〃 11 Supply Port 12 Joint 13 Filter 14 Ink Funnel Device 15 End Pan 16 Cleaning Liquid Pipe 17 T-Joint 18 Solenoid Valve 20 Joint Elevating Cylinder 21 Bucket Drive Cylinder 22 Holder Drive Cylinder 23 Holder 25 Waste Liquid Bucket (Waste Liquid Collection Section) 26 3-way valve (direction switching valve) 27 Waste liquid discharge pipe

Claims (3)

[Claims] 1. A plurality of ink containers, an ink circulation supply mechanism for supplying ink to the printing unit by circulating the ink between one of the ink containers and the printing unit, and the ink of the ink circulation supply mechanism. Connect the connection to the container to 1 of each ink container.
Replacement mechanism for selectively connecting two ink containers, a cleaning liquid supply mechanism for supplying a cleaning liquid to the ink circulation supply mechanism when cleaning the ink circulation supply mechanism, and an ink circulation supply mechanism using the cleaning liquid for collecting waste liquid after cleaning. An ink exchanging device for a flexographic printing machine, comprising a waste liquid collecting part, wherein the ink circulation supply mechanism is provided with a waste liquid discharging system for discharging the waste liquid to the waste liquid collecting part. 2. A direction switch for switching the direction of the liquid between the direction of the waste liquid recovery unit and the direction of the ink container by providing the waste liquid discharge system at the lower end of the return pipe to the ink container of the ink circulation supply mechanism. The ink exchange device for a flexographic printing machine according to claim 1, comprising a valve and a waste liquid discharge pipe extending from the same direction switching valve to the waste liquid recovery section. 3. The ink exchanging device for a flexographic printing machine according to claim 2, wherein a three-way valve or a two-way valve is used as the direction switching valve.