JP3635059B2 - Flexographic printing machine and flexographic ink supply / collection device - Google Patents

Description

[0001]
[Field of the Invention]
The present inventionFlexoThe present invention relates to a printing machine in which ink supply, recovery, and cleaning waste liquid recovery are performed with a common nozzle, and an ink tank is disposed outside the printing machine to facilitate replacement of the ink tank.
[0002]
[Prior art]
Corrugated cardboard sheets can be printed with a low viscosity and quick-drying water quality like flexographic printing.FlexoThere are methods that use ink, and methods that use ink with high viscosity and slow drying, such as pre-slot printing.
If the low viscosity ink is not allowed to flow, the viscosity will rise in a short time. Therefore, as shown in FIG. 7, between the inking roll (1) and the squeezing roll (2) in pressure contact with the inking roll. Ink is supplied to the ink storage part (11) formed on the ink storage part (11), and the ink is discharged from both ends of the ink storage part (11) to the trays (500) and (500). The ink is returned to the ink tank (502), the ink in the ink tank (502) is sucked up by the pump (503), and supplied to the ink reservoir (11) through the ink supply pipe (504). It is circulated to suppress the increase in ink viscosity.
[0003]
When changing the color of the ink, the cleaning liquid for cleaning the rolls (1) and (2) is supplied from the cleaning liquid supply pipe (507) connected to the ink supply pipe (504) through the ink supply pipe (504). The rolls are supplied to (11), and the rolls are cleaned by rotating the rolls (1) and (2). The cleaning waste liquid is recovered from the ink return pipe (501) to the waste liquid recovery tank (506) via the switching valve (505).
In the above case, the ink circulation pipe becomes longer due to the necessity of the ink supply pipe (504) and the ink return pipe (501), and the recovery of the ink is a drop of the ink by its own weight in the pipe. Therefore, it is necessary to thicken the pipe line to about 40 mm and to collect the ink smoothly.
If the conduit through which the ink flows is long and thick, the amount of ink remaining on the inner surface of the conduit without being collected during the color change of the ink naturally increases. In addition, the residual ink remaining on the saucer (500) (500)KiThe amount is too much and wastes ink. In addition, a large amount of cleaning liquid is required to wash away a large amount of ink adhering to the inside of the pipe line or the tray during roll cleaning, and there is a problem of waste liquid treatment.
[0004]
Therefore, the applicant previously said that the low viscosityNoIn a printing machine that uses ink, a printing machine has been proposed in which the inside of an ink tank is pressurized to supply ink, and the pressure is reduced to collect ink (Japanese Patent No. 3009354).
In the above printing machine, the ink tank is accommodated in a sealed box, one end of the conduit passes through the box in an airtight manner and reaches the ink tank, and the other end of the conduit is connected to an ink supply / recovery nozzle, and the sealed box By pressurizing the inside, the ink in the ink tank is supplied from the nozzle to the ink reservoir, and when changing the color of the ink, the ink tank is set to a negative pressure so that the residual ink in the ink reservoir is transferred to the ink tank. It is to be collected.
When changing the color of the ink, the cleaning waste liquid that has washed the inking roll and the squeeze roll is collected in an ink storage section formed between the two rolls. Is performed by a separate nozzle and pipe (see Japanese Patent No. 2951637).
[0005]
[Problems to be solved by the invention]
As described above, if the flow paths of the ink and the cleaning waste liquid are different, the number of pipes increases. In addition, in order to solve the problem of cleaning the piping from the ink supply / recovery nozzle to the ink tank when changing the color of the ink, the sealed box that houses the ink tank should be placed close to the ink reservoir. The conduit from the ink tank to the nozzle is shortened, and when the ink tank is replaced, the conduit including the nozzle is also replaced.
For corrugated board printers, the height of the ink reservoirMustThe sealed box is at a height of about 1.5 m from the installation floor of the printing press. For this reason, it is troublesome to lift the heavy ink tank to the sealed box for ink replacement.
In addition, the work of removing and positioning and fixing the piping from the ink tank to the nozzle is troublesome and the workability is poor.
Furthermore, in a printing apparatus in which a plurality of printing units are arranged for each ink color, each time an ink tank is replaced, an adjacent printing unit must be separated to ensure a work space for replacing the ink tank. The operating rate of the printing press is greatly reduced.
The present invention clarifies a printing machine that can solve the above problems.
[0006]
[Means for solving the problems]
Of the present inventionFlexoPrinterAnd ink supply / collection equipmentIs formed between the inking roll (1) and the squeezing member (20) in pressure contact with the inking roll.Both ends are weir members (12) (12) Occluded byIn a printing machine in which ink is stored in the ink storage section (11) and the ink from the inking roll (1) is transferred to the printing plate attached to the plate cylinder (9) by rotation of the inking roll (1).Ink reservoir (11) In the ink storage section, without collecting the collected ink or cleaning waste liquid piping (11) Without collecting the collected ink or cleaning waste liquid piping, Make the dual-purpose nozzle (4), which is used for both the supply and recovery of ink and the recovery of waste liquid from the roll cleaning, face the ink reservoir (11),The combined nozzle ( 4 ) Against common distribution pipe (44) Connect one end of the distribution pipe (44) The other end ofInk tank (31) and waste liquid recovery tank (5) installed outside the printing pressCut intoVia the valve (45)ReamConnected,Sealed box ( 3 ) By repeating the pressurization and decompression in the inside, the increase in the viscosity of the flexo ink is prevented by a cycle of supplying and collecting a predetermined amount of ink,Ink tank (31)IsHoused in a sealed box (3), a suction pipe (35) for pressure reduction and an air supply pipe (35a) for pressurization are connected to the sealed box, and the waste liquid recovery tank (5) can be shut off from the outside air and is suctioned for decompression. Connected to tube (51)It is made.
[0007]
[Action and effect]
By pressurizing the inside of the sealed box (3), the ink in the ink tank (31) can be supplied from the dual-purpose nozzle (4) to the ink reservoir (11).
Inside the sealed box (3)By pressurizing the ink tank (31) The flexo ink inside is the ink reservoir (11) Supply to the sealed box ( 3 ) InsideBy depressurizing,Ink reservoir (11)Had accumulated inInk can be collected by suction into the ink tank (31).This ink supply and ink recovery cycle is repeated to stir the ink and prevent an increase in the viscosity of the flexographic ink.
Since the suction collection is performed, the ink can be collected smoothly and in a short time even if the flow pipe (44) from the ink reservoir (11) to the sealed box (3) is thin. In addition, since the ink is collected by suction, the amount of ink remaining in the form of a thin film on the inner surface of the flow pipe (44) is extremely small. Therefore, a small amount of cleaning liquid is required for cleaning the inner surface of the flow pipe (44) including the rolls (1) and (2) and the dual-purpose nozzle (4), and the cleaning waste liquid can be easily treated. This point is that a large amount of ink remaining in the ink circulation path must be washed away with a large amount of cleaning liquid, as in the case of ink recovery by dropping the ink by its own weight in a thick pipe in the conventional water-based ink circulation system. It is very different from the thing.
[0008]
Cleaning waste liquid collected in the ink reservoir (11) by roll cleaningSwitching valve (45) SwitchBy depressurizing the waste liquid recovery tank (5), it can be recovered in the waste liquid recovery tank (5).
During the roll cleaning, cleaning waste liquid flows into the flow pipe (44) up to the switching valve (45) including the dual-purpose nozzle (4), and the ink that is thinly adhered to the inner surface of the flow pipe (44) Washed away. Further, when the cleaning waste liquid is recovered, the dual-purpose nozzle (4) is immersed in the cleaning waste liquid, and even the outer peripheral surface of the nozzle tip is washed away by the waste liquid. For this reason, it is not necessary to wash the dual-purpose nozzle (4) and the distribution pipe (44) separately from the roll, and it is not necessary to replace the dual-purpose nozzle (4) and the distribution pipe (44) every time the color of ink is changed.
Accordingly, the distribution pipe (44) is pulled out of the printing press to be a fixed pipe, the sealed box (3) is arranged outside the printing press, and the ink tank (31) in the sealed box (3) and the distribution pipe ( 44)Is possible.
[0009]
Since the ink tank (31) can be replaced outside the printing press,RThere is no need to separate the matching printing units. Therefore, even during printing, the ink tank can be replaced andKiCan be replenished and the operating rate of the printing press can be increased. When changing the ink color,RThere is no need to separate the matching printing units.
Since the distribution pipe (44) including the dual-purpose nozzle (4) does not have to be replaced when changing the color of the ink, the ink change can be set up quickly in this respect as well.
Replacing the ink tank without lifting the ink tank (31) by placing the sealed box (3) near the floor where the printer is installedButit can.
Piping can be simplified because the common nozzle is used to supply and collect ink and to collect cleaning waste liquid.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Outline of printing press and printing unit
Figure 1 shows low viscosityFlexoCorrugated cardboard using inkFlexoA printing machine comprising: a sheet feeding device (200) for feeding stacked cardboard sheets one by one to a printing unit; a plurality of printing units U corresponding to the number of printing colors; A punching ruled line device (300) is provided for punching corresponding to the line and applying a ruled line corresponding to the folding line.
As shown in FIG. 2, each printing unit U is arranged so as to be movable on rails (102) and (102), and can be opened and closed between adjacent printing units, and the units are closed during printing. The unit can be opened when exchanging and maintaining the stamp.
[0011]
The inking roll (1) and the squeeze roll (2) are relatively in contact with the upper part of the frame (100) of the printing unit U.NearA groove-like ink storage portion (11) is formed so as to be separable, and the bottom portion gradually narrows between the two in contact.
A plate cylinder (9) is provided below the inking roll (1) in contact with the roll, and a receiving roll (91) is provided below the plate cylinder (9).
The ink storage unit (11) is supplied with ink from a dual-purpose nozzle (4) for supplying and recovering ink, supplying cleaning liquid, and recovering cleaning waste liquid, which will be described later, and the liquid level is detected by a liquid level sensor (not shown). Is controlled to the set height.
As is well known, the inking roll (1) and the squeezing roll (2) rotate in the direction to squeeze the ink in the ink reservoir (11), and the ink on the surface of the inking roll (1) is transferred onto the plate cylinder (9). It transfers to a printing plate (not shown), and it prints on the corrugated cardboard sheet S supplied between the plate cylinder (9) and the receiving roll (91).
[0012]
The inking roll (1) is inserted on the surface of a hard roll such as a ceramic roll or a plating roll.KiFine irregularities to be accumulated are formed.
The squeezing roll (2) has a surface made of rubber.
The total length of both rolls (1) and (2) is 1.5 to 4.7 m, although it varies depending on the size of the printing press.
Weir members (12) and (12) that block the end portions of the ink storage portion (11) are pressed against both ends of both rolls (1) and (2).Weir member (12) (12) Does not have a tray for collecting ink or an ink return line unlike a conventional flexographic printing machine.
[0013]
Mist room (60)
As shown in FIG. 3, both the rolls (1), (2) and the weir member (12) are covered with a cover (6), and a mist chamber (60) is formed between the squeezing roll (2) and the cover (6). Has been.
The cover (6) is formed in a housing that accommodates both rolls (1) and (2), and the ceiling plate (65) is used for running the combined nozzle (4) corresponding to the ink reservoir (11). An opening (61) is opened at a position corresponding to the ink reservoir (11), and the lower surface is in contact with the inking roll (1) by the printing plate attached to the plate cylinder (9).To get outAn opening (62) is opened.
The bottom plate (63) on the squeeze roll (2) side of the cover is the ink reservoir (11)BelowAnd has a closing plate (63a) that bends diagonally upward to the inking roll (1) side, and whose leading edge approaches the inking roll (1) over its entire length.The closing plate (63a) Tip edge and inking roll ( 1 ) Between (67) Is forming.
[0014]
Cover (6)Ceiling wall (65)Is close to the inking roll (1) and the squeeze roll (2), and between the squeeze roll (2) and the cover (6), SuRit-like narrow gap (66) ButAn open mist chamber (60) is formed.
One or a plurality of fine spray nozzles (21) are arranged in the mist chamber (60).
The fine mist injection nozzle (21) sprays the diluting liquid, tap water in the embodiment in the form of a fine mist to maintain the mist chamber (60) at a high humidity close to saturation, so that the surface of the squeeze roll (2) Wet the liquid fine particles in a thin film and moisten it actively (wet) .
The fine mist has a particle size of 50 μm or less, preferably 30 μm or less.
A humidity sensor (68) is provided in the mist chamber (60), and spraying and spray stop are controlled by the sensor, and the mist chamber (60) is saturated or saturated.In harmonyMaintained near high humidity.
[0015]
Through the top opening (61) of the cover (6),Thinning liquid supply nozzle (70) Deploy  Dilute solution on the end side of the ink reservoir (11)SupplementCharge. FruitIn the example, the diluting liquid is tap water, but the pipe to the diluting liquid supply nozzle (70) isIllustratedOmitted.
The diluting liquid supply nozzle (70) is used together with the following dual-purpose nozzle (4) to store the ink reservoir (11).ofIt can also be arranged to be movable in the longitudinal direction.
[0016]
Combined nozzle ( 4 )
As shown in FIG. 2, a slide base (41) is disposed above the cover (6) so as to be laterally movable along the ink storage part (11), and the slide base is controlled by a control unit (not shown).IsIt is linked to a slide drive device (not shown).
A combined nozzle (4) is mounted on the slide base (41) via a lifting / lowering drive device (42) such as an air cylinder, and the lower end of the nozzle faces the ink reservoir (11).
The combined nozzle (4) is used to supply ink to the ink reservoir (11), collect ink from the ink reservoir (11), and wash the two rolls (1) and (2) as described later. It also serves the four functions of supplying cleaning liquid and collecting cleaning waste liquid collected in the ink reservoir (11) after cleaning.
The raising / lowering drive device (42) can switch the dual-purpose nozzle (4) to three stages of an ascending position, an intermediate height position, and a descending position.
Ascent positionWhenThe lower end of the combined nozzle (4) is slightly above the set liquid level of the ink in the ink reservoir (11).
MiddleheightpositionInThe lower end of the combined nozzle (4) is at a position slightly lower than the set height of the ink liquid level.
Lower positionInThe lower end of the dual-purpose nozzle (4) penetrates into the deepest part of the ink reservoir (11) to such an extent that it is barely caught between the rolls (1) and (2).
The lower end of the dual-purpose nozzle (4) is sharply wedged with the surfaces on both rolls (1) and (2) being cut obliquely corresponding to the bottom shape of the ink reservoir (11).
[0017]
The combined nozzle (4) is connected to the flow pipe (44). The distribution pipe (44) is located outside the side wall of the unit frame (100) and the flexible tube (44b) in the section from the combined nozzle (4) to the side wall of the unit frame (100).FixedAnd a vertical pipe (44a) from the top to the bottom
.
The flexible tube (44b) has a sufficient length corresponding to the movement stroke of the dual-purpose nozzle (4).
The inner diameter of the vertical tube (44a) and the flexible tube (44b) is a thin tube of about 8 to 10 mm. This is a conventional aqueous quick-drying innKiThe diameter is 1/4 or less compared to the inner diameter of the circulating pipe 40 mm.
The lower end of the vertical pipe (44a) is selectively connected to the ink tank (31) and the waste liquid recovery tank (5) via the switching valve (45).
On the lower end of the side wall of the unit frame (100), a platform (101) is projected outward, and on the platform (101), a sealed box (3) for accommodating an ink tank (31) and a waste liquid recovery tank (5). ) Is deployed.
[0018]
Sealed box ( 3 ) And ink tank (31)
The sealed box (3) is the main component for ink supply and recovery,As shown in FIG.The ink tank (31) is accommodated in the inside so as to be removable.
The closed box (3) has an upper lid (30) that can be opened and closed, and a through hole (32) is formed in the center of the upper lid (30).
The ink tank (31) is obtained by removing a lid of a container for selling ink, and a guide tube (33) immersed at the lower end of the ink tank (31) is provided with a small through-hole (32) of the sealed box (3). ) Airtightly and detachably connected to the switching valve (45).
[0019]
The closed box (3) is connected with a suction pipe (35) for pressure reduction and an air supply pipe (35a) for pressurization, and pressure air is fed into the sealed box (3) from the pressurization air supply pipe (35a). The pressure in the sealed box (3) is increased to push out the ink in the ink tank (31), and the ink is stored from the dual-purpose nozzle (4) through the guide pipe (33), switching valve (45), and distribution pipe (44). Ink can be supplied to the section (11).
The suction pipe (35) for suction is used to suck the air in the sealed box (3), and the pressure in the sealed box (3) is reduced, so that a suction force is applied to the dual-purpose nozzle (4). Thus, the ink in the ink reservoir (11) can be sucked and collected in the ink tank (31).
In the embodiment, the suction pipe (35) for decompression and the air supply pipe (35a) for pressurization are common, and one compressor is provided by the following air circuit (40).(400)Thus, the inside of the sealed box (3) can be switched between pressurization and decompression.
[0020]
Air circuit for pressurization and decompression (40)
As shown in FIG. 4, the air circuit (40) is formed by branching the first and second flow paths (400a) and (400b) from the compressor (400).
The first flow path (400a) is connected to the sealed box (3) through a pressure reduction and pressurization common pipe (35), and the second flow path (400b) is connected to an ejector (vacuum generator) (406), a switching valve ( 408) to the common pipe (35).
The ejector (406) is a known one that generates a vacuum by sucking the first flow path (400a) side by sending compressed air from the second flow path (400b) to the ejector.
A third flow path (400c) extends from the ejector (406) on the extension of the second flow path (400b), and is opened to the atmosphere via a silencer (407).
In the first flow path (400a), a switching valve (401), a pressure reducing valve (402), and a switching valve are arranged in order from the upstream side between the branch (400d) to the hermetic box (3) and the compressor (400). A valve (403) is provided.
The second flow path (400b) includes a switching valve (404), a pressure reducing valve (405), and the above-described one from the upstream side between the branch (400d) to the hermetic box (3) and the compressor (400). An ejector (406) and a switching valve (408) are provided.
Switching valve (401) (403) (408) Is an electromagnetic valve that can be switched between open and closed.
[0021]
When pressurizing the sealed box (3),Second flow path (400b) Two switching valves (404) (408) Close the first flow path (400a) Two switching valves (401) (403) open.
compressor (400) As shown by the arrow A, the high pressure air flow from the pressure reducing valve (402) , Air supply pipe for pressurization (35a) Through sealed box ( 3 ) Flow into the sealed box ( 3 ) Pressurize the inside.
During decompression, the second flow path (400b) Two switching valves (408)(404) is opened, and the two switching valves (401) and (403) of the first flow path (400a) are closed.
compressor(400)High-speed air from the second flow path (400b) flows from the second flow path (400b) to the third flow path (400c) as indicated by arrow B, and as indicated by arrow C, the third flow path (400c) from the sealed box (3) side. Air flow to thebox ( 3 )Inside is negative pressure.
When a high-speed air flow is released from the third passage (400c) to the atmosphere, it passes through the silencer (407), so the air emission sound is lowered and no noise is generated.
The air circuit (40) is merely an example for switching the inside of the sealed box (3) between pressurization and decompression, and the air circuit is limited to the above embodiment.IsOf course, it is naturally desirable that the switching between pressurization and depressurization can be performed quickly.
[0022]
Waste liquid recovery tank ( 5 )
The waste liquid recovery tank (5) is connected to the switching valve (45) through an inflow pipe (51), and has a drain port (53) with a partition valve (54) at the bottom.
An air circuit (50) is connected to the waste liquid recovery tank (5) via an air supply / exhaust pipe (52).
The air circuit (50) is switched between depressurization and pressurization in the waste liquid recovery tank (5) in the same manner as the air circuit (40) on the closed box (3) side.Huhit can. However, the compressor of the air circuit (50) on the waste liquid recovery tank (5) sideー, The compressor of the air circuit (40) on the closed box (3) side(400)And switching of the switching valve (409)HuhAnd one compressor(400)Then, the two air circuits (40) and (50) are selectively operated.
As will be described later, the waste liquid collection tank (5) collects the cleaning waste liquid collected in the ink reservoir (11), opens the gate valve (54), and discharges the waste liquid collection tank (5). Cleaning waste liquid can be discharged without pressure. Accordingly, it is not essential that the air circuit (50) has a function of pressurizing the waste liquid recovery tank (5). When the cleaning waste liquid is discharged from the waste liquid recovery tank (5), if the inside of the tank is pressurized, there is an advantage that the discharge time is shortened.
[0023]
Cleaning liquid supply pipe ( 7 )
A cleaning liquid supply pipe (7) is connected to the flow pipe (44) from the switching valve (45) to the dual-purpose nozzle (4) in proximity to the switching valve (45).
In the embodiment, the cleaning liquid is tap water, and the water pipe is connected to the flow pipe (44) via the gate valve (71) to form the cleaning liquid supply pipe (7).
[0024]
Ink viscosity detection means ( 8 )
The flow pipe (44) is provided with an ink viscosity detecting means (8) on the side of the combined nozzle (4) with respect to the cleaning liquid supply pipe (7).
The ink viscosity detecting means (8) is provided with an ink reservoir small pot (81) in the vicinity of the flow pipe (44), and the ink supply pipe (82) and the pot (81) from the flow pipe (44) to the pot (81). ) To the circulation pipe (44) to connect the ink return pipe (83). The ink supply pipe (82) and the ink return pipe (83) are provided with gate valves (84) and (85), respectively.
In the pot (81), the Zahn cup (86) is arranged so as to be movable in the vertical direction relative to the pot (81).
By operating the gate valves (84) and (85), the ink is accumulated in the pot (81), the Zaan cup (86) immersed in the pot (81) is raised relative to the pot (81), and the Zaan cup ( The ink dripping into the pot (81) from the small hole on the bottom surface of 86) is detected by the detectors (86a) and (86b), and the viscosity of the ink is measured according to the time until dripping is completed.
Ink viscosity is measured periodically during printing operation or at a desired timing. When the ink viscosity is higher than the set value, a signal is sent to the control unit (not shown), depending on the amount of ink used and supplied. As long as the ink in the ink reservoir (11) does not become too thin, the ink tank penetrates the ink reservoir (11) from the thinning liquid supply nozzle (70) or airtightly through the sealed box (3). (31)DyingFrom the thinning liquid supply pipe (not shown) into the ink tank (31),Supply dilute solution.
[0025]
Ink recovery / washing waste recovery mode and ink circulation mode
The slide drive device (not shown) for the dual-purpose nozzle (4) can be switched to at least two modes of an ink recovery / washing waste liquid recovery mode and an ink circulation mode.
Ink recovery / cleaning liquid recovery modewhen, Combined nozzle (4)At intermediate height position1 over the entire length of the ink reservoir (11)TimesOr it makes it reciprocate several times.
Ink circulation modewhenIn the printing operation mode, as shown in FIG. 5A, the dual-purpose nozzle (4) waiting in the center of the ink reservoir (11) is replaced with the ink reservoir (11) as shown in FIG. 5B. And is slid from the moving position to the center of the ink reservoir (11) by a predetermined section, in the embodiment, about 50 cm. Next, as shown in FIG.Combined nozzle ( 4 ) TheIt is moved to the other end of the ink reservoir (11), and is slid for a predetermined section from the moving position to the center of the ink reservoir (11). Next, the sealed box (3) is moved to a position away from the slide section, in the embodiment, to the center of the ink storage section (11), and is temporarily stopped here. This cycle is repeated during the printing operation.
The combined nozzle (4) stands by at the center in the length direction of the ink reservoir (11) at the end of the two operation modes.
[0026]
Next, supply of ink to the empty ink reservoir (11), operation of the combined nozzle (4) during printing operation, cleaning of the rolls (1) and (2) accompanying the color change of the ink, and the ink tank (31) The exchange will be described.
[0027]
Ink supply
In order to supply ink to the empty ink reservoir (11), the inside of the sealed box (3) is pressurized by the action of the air circuit (40), and is moved upward by a slide driving device (not shown).It is inThe combined nozzle (4) is slid along the ink reservoir (11). The ink pushed out from the ink tank (31) is discharged from the dual-purpose nozzle (4) to the ink reservoir (11).
At this time, the inking roll (1) and the squeeze roll (2) are rotated to prevent the ink surface lines from adhering to the rolls (1) and (2), and the ink is stimulated to produce a stirring effect. Get.
When the ink is supplied up to the set liquid level, the ink supply is stopped by the action of the liquid level sensor, and the combined nozzle (4) once returns to the center of the ink reservoir (11) (FIG. 5A).
[0028]
Nozzle for printing operation ( 4 ) Behavior
When the printing roll is started by rotating the inking roll (1) and the squeeze roll (2), the following operation is performed by a program incorporated in a control unit (not shown).
Combined useThe nozzle (4) moves to the vicinity of one end of the ink reservoir (11) and has an intermediate height.UntilDescend and insert tipKiImmerse in the reservoir (11). The nozzle (4) moves about 50 cm from its moving position to the center side of the ink reservoir (11). During this 50 cm movement, the sealed box (3) is set to a negative pressure, and the ink in the ink reservoir (11) is sucked and collected in the ink tank (31) (FIG. 5B).
The combined nozzle (4) has a collection section at the end of the ink reservoir (11).( 50 cm Moving section )When the ink is collected by suction, the liquid level in the collection section is lowered, and the ink moves from the central side of the ink storage section (11) to the collection section, and ink flows.
[0029]
Next, the suction and recovery of the ink is stopped, the nozzle (4) is raised, and the ink reservoir (11) is placed on the opposite end.Combined nozzle ( 4 ) TheMove. From the moving position, the nozzle (4) is lowered to the intermediate height position in the same section as described above and moved laterally while sucking and collecting ink.
In the same manner as described above, the liquid level of the collection section is lowered from the center side of the ink reservoir (11).Toward the collection sectionInk moves and ink flow is generated in the ink reservoir (11).On the other hand, the ink is agitated by the flow, and the increase in viscosity is prevented.
[0030]
Next, with the ink suction and recovery stopped, the nozzle (4)TheIt is moved up and moved away from the suction collection position, and in the embodiment, it is moved to the center of the ink reservoir (11). At that position, the sealed box (3) is pressurized and the ink reservoir from the nozzle (4). Supply ink to (11). The liquid level does not exceed the set height due to the liquid level sensor.
During the printing operation, the above cycle is repeated, and ink is supplied between the ink reservoir (11) and the ink tank (31).Reciprocate and stir to prevent ink viscosity increase.
[0031]
Ink collection
In order to change the ink, the remaining ink in the ink reservoir (11) is collected.
The rotation of the rolls (1) and (2) is stopped, and the combined use nozzle (4) is lowered to the deepest position of the ink storage section (11) by the elevating drive device (42).
The reason why the rotation of the rolls (1) and (2) is stopped is to prevent the combined nozzles (4) and (5) from being caught between the rolls.
The ink in the reservoir (11) is sucked and collected while sliding the combined nozzle (4).
Since the ink is sucked and collected by vacuum pressure, if the dual-purpose nozzle (4) is reciprocated once or twice over the entire length of the ink reservoir (11), most of the amount in the ink reservoir (11) is obtained. Can be collected by suction. In addition, the amount of ink remaining in the form of an extremely thin film on the inner surface of the flow pipe (44) extending from the dual-purpose nozzle (4) to the switching valve (45) is extremely small.
[0032]
Roll cleaning
The switching valve (45) is switched to shut off the flow pipe (44) from the sealed box (3) and the waste liquid recovery tank (5).
With the combined nozzle (4) raised, the rolls (1) and (2) are rotated. The gate valve (71) of the cleaning liquid supply pipe (7) is opened, and the cleaning liquid is supplied from the combined nozzle (4) to the ink reservoir (11).
Since the cleaning liquid is discharged from the dual-purpose nozzle (4) through the flow pipe (44), the inside of the flow pipe (44) is cleaned.
By the rotation of the rolls (1) and (2), the ink adhering to the rolls (1) and (2) in the form of a thin film is almost washed away, and the reservoir (11) itself is also washed.
B(1)( 2 )Further, since the ink adhering to the thin film and the amount of ink remaining on the wall surface of the ink reservoir (11) are very small and the ink is water-based, the amount of cleaning liquid required for cleaning is small.
[0033]
Stop the rotation of rolls (1) and (2) and lower the combined nozzle (4) to the deepest position of the ink reservoir (11)LetIn this state, switch the switching valve (45).Switch the distribution pipeCommunication with waste liquid recovery tank (5)As well asThen, the waste liquid recovery tank (5) is depressurized by the air circuit (50).
A suction force acts on the dual-purpose nozzle (4), and the cleaning waste liquid in the ink reservoir (11) is collected from the dual-purpose nozzle (4) to the waste liquid recovery tank (5).
At this time, by opening both the gate valves (84) and (85) of the ink supply pipe (82) and the ink return pipe (83) of the ink viscosity detecting means (8), the cleaning waste liquid is discharged from the flow pipe (44). The ink viscosity detecting means (8) branches and flows, returns to the flow pipe (44), and is recovered in the waste liquid recovery tank (5), so that the ink viscosity detecting means (8) is also cleaned.
As mentioned above, ink can be recovered with almost no loss when changing ink, and the amount of cleaning liquid required for cleaning the roll is small, and the concentration of the cleaning waste liquid is low. This eliminates the need for expensive equipment and can reduce running costs for waste liquid treatment.
[0034]
Ink tank replacement
Switching valve (45) By Sealed box ( 3 ) ButThe ink tank (31) is replaced while being disconnected from the flow pipe (44). This is performed including not only the ink tank (31) but also the guide pipe (33) connected to the switching valve (45). The guide tube (33) is removed from the through hole (32) of the sealed box (3).
When the sealed box (3) is placed at a low position as in the embodiment, the ink tank (31) can be taken in and out by opening the sealed box (3) upward.
2 and 4, the switching valve (45) is used to open and close the lid (30) of the sealed box (3), to remove and remove the guide tube (33), and to put the ink tank (31) in and out of the sealed box (3). Is in the way,In carrying outIf the positional relationship does not interfere with each other and a part or the whole of the guide tube (33) is a flexible tube, there is no problem in replacement of the guide tube (33) and the ink tank (31).
If the ink tank (31) and the guide pipe (33) are replaced and the guide pipe (33) is connected to the switching valve (45), the switching valve (45) is switched to the ink tank (31) side again, and the same as above. Then, the sealed box (3) is pressurized by the action of the air circuit (40), and ink is supplied to the ink reservoir (11).
[0035]
Mist room (60) Working
During the above ink supply and printing operation, a thinning liquid is sprayed from the fine mist spray nozzles (21) and (21) to cover the surface of the squeeze roll (2),Cover with the fine particles of the dilute solution and moisten it (wet), and fill the mist chamber (60) with fine mist.
Since the mist chamber (60) is maintained at high humidity close to saturation with fine mist, the fine particles of the thinning liquid covering the roll surface are continuously connected to the ink reservoir (11) by the rotation of the squeeze roll (2). Brought in.
When the ink thinning liquid is directly dropped into the ink reservoir (11), the thinning liquid does not readily conform to the ink due to the difference in the specific gravity, viscosity, etc. of the thinning liquid and the ink. Wet the peripheral surface in a thin film with fine particles of the liquid.,By bringing this wetting into the ink reservoir (11) by rotating the roll, the wet moisture on the surface of the squeeze roll (2) immediately blends in with the ink in the ink reservoir (11) and mixes well, causing unevenness in the viscosity of the ink. It does not occur.
Fine spray nozzles (21) and (21) are placed under the squeeze roll (2)TheOn the roll sidea littleBy tilting and deploying, the surface of the squeeze roll (2) is more effectively wetted.
In addition, since the fine mist that escapes from the narrow outlet (66) above the squeezing roll (2) in the mist chamber (60) creates a high humidity atmosphere in the vicinity of the ink reservoir (11), the moisture in the ink reservoir (11) is evaporated. Suppresses and prevents an increase in ink viscosity.
[0036]
Effects of the embodiment
As described above, when replacing the ink, the ink tank (31) and the guide tube (33) are replaced as one set.KiHowever, it does not mix with the ink in the next ink tank.
In addition, since cleaning liquid and cleaning waste liquid flow through the flow pipe (44) up to the switching valve (45) including the dual-purpose nozzle (4) during roll cleaning, it is not necessary to clean the pipe line separately. It is not necessary to exchange the pipe every time the color of the ink is changed. Accordingly, it is possible to pull out the pipe line to the outside of the printing machine, place the sealed box (3) outside the printing machine, and replace the ink tank outside the printing machine. The closed box (3) is located near the floor where the printing machine is installed.KiCan be replaced without lifting the tank high. There is no need to separate adjacent printing units for ink tank replacement.
Ink supply / recovery, cleaning liquid supply, and cleaning waste liquid recovery are performed with a common nozzle, simplifying piping.
[0037]
In the embodiment, the cleaning liquid supply pipe (7) is connected to the flow pipe (44), which is a supply path of ink supply, recovery, and cleaning waste liquid, but the cleaning liquid is directly dropped onto the inking roll (1). In this case, the cleaning liquid is supplied separately. Even if the cleaning liquid does not pass through the flow pipe (44), the cleaning waste liquid passes through the flow pipe (44).JustSince the ink adhering to the inner surface of the flow pipe (44) is washed away, there is no problem.
[0038]
As in the embodiment, when the cleaning liquid is supplied from the dual-purpose nozzle (4), the cleaning liquid is supplied directly from the dual-purpose nozzle (4) to the empty ink reservoir (11), but the angle is adjusted to the dual-purpose nozzle (4). The surface of the inking roll is directly dropped from the dual-purpose nozzle (4) to the inking roll (1) by connecting the device or the moving device (not shown) to the inking roll (1) side. It is also possible to wash away the fine irregularities of the surface effectively.
[0039]
In the above embodiment, in the ink circulation cycle by the ink recovery and ink supply during the printing operation shown in FIG.slideAlthough the ink was recovered, the combined nozzle (4) may be suctioned and collected at the end of the inking roll (1) in a stopped state, and the combined nozzle (4 ) Does not need to run for a certain section.
[0040]
In the above embodiment, the squeezing roll (2) is used as the squeezing member (20) for squeezing the ink on the inking roll (1). However, the invention is not limited to this, and as shown in FIG. The belt-like plate (22) can be pressed and brought into contact with the application roll (1) over the entire length of the roll to form the ink reservoir (11) between them.
[0041]
The present invention can be applied not only to water-based inks but also to glycol-based inks having a low viscosity and a good drying speed, and is not limited to the configuration of the above-described examples. Various modifications can be made within the range described in (1).
[Brief description of the drawings]
FIG. 1 is a schematic front view of a printing machine.
FIG. 2 is a perspective view in which a part of the printing unit is broken.
FIG. 3 is a cross-sectional view of the vicinity of an ink storage portion of a printing unit.
FIG. 4 is an explanatory diagram of ink supply, recovery, cleaning liquid supply, cleaning waste liquid recovery conduits and pressurization / decompression air circuits for a sealed box and a waste liquid recovery tank.
FIG. 5 is an operation explanatory diagram of a combined nozzle.
FIG. 6 is a cross-sectional view of another embodiment of a squeeze member for an inking roll.
FIG. 7 is an explanatory diagram of a conventional quick-drying ink circulation path.
[Explanation of symbols]
(1) Inking roll
(11) Ink reservoir
(2) Drawing roll
(3) Sealed box
(31) Ink tank
(4) Nozzle
(5) Waste liquid collection tank

Claims (7)

Flexo ink is stored in the ink storage part (11) formed between the inking roll (1) and the squeezing member (20) brought into pressure contact with the inking roll, and by rotating the inking roll (1), In a flexographic printing machine in which ink from an inking roll (1) is transferred to a printing plate attached to a plate cylinder (9), both ends of the ink reservoir (11) are either ink stored in the ink reservoir (11) or Without providing a cleaning waste recovery pipe, it is closed by the weir members (12) and (12), and the dual nozzle (4) is used in the ink reservoir (11) for both the supply and recovery of flexographic ink and the recovery of the roll cleaning waste liquid. The combined nozzle (4) is connected to the ink tank (31) and the waste liquid recovery tank (5) arranged outside the printing press through a common distribution pipe (44) and a switching valve (45). The ink tank (31) is stored in the sealed box (3) and the pressure is reduced in the sealed box. The suction pipe (35) is connected to the pressurizing air supply pipe (35a), and the waste liquid recovery tank (5) can be shut off from outside air, and is connected to the vacuum suction pipe (51). By pressurizing, the ink in the ink tank (31) is supplied to the ink reservoir (11) through the flow pipe (44) and the combined nozzle (4), and the pressure in the sealed box (3) is made negative. The ink in the storage section (11) is collected from the dual-purpose nozzle (4) to the ink tank (31) through the distribution pipe (44), and the increase in the viscosity of the flexographic ink is prevented by repeating the ink supply and ink collection cycles. By making negative pressure in the waste liquid recovery tank (5), the cleaning waste liquid collected in the ink reservoir (11) by the roll cleaning is transferred from the combined nozzle (4) to the waste liquid recovery tank (5) through the distribution pipe (44). A flexographic printing machine characterized by collecting. The flexographic printing machine according to claim 1, wherein the cleaning liquid supply pipe (7) is connected to the flow pipe (44), and the dual-purpose nozzle (4) is also used to supply the cleaning liquid. The flexographic printing machine according to claim 1 or 2, wherein the dual-purpose nozzle (4) is arranged so as to be capable of moving laterally and ascending and descending along the ink reservoir (11). After supplying ink to the ink reservoir (11), the combined nozzle (4) is moved to one end side of the ink reservoir (11) to suck and collect a predetermined amount of ink, and in the ink reservoir (11) The ink flow is caused to flow to the ink collecting position, and then the dual-purpose nozzle (4) is moved to the other end of the ink reservoir (11) to suck and collect a predetermined amount of ink in the same manner as described above. The ink flow to the collection position is generated, and then the dual-purpose nozzle (4) is moved to a position away from the ink collection position, and then the ink is supplied to the ink storage section (11). The flexographic printing machine according to any one of claims 1 to 3, further comprising a program for repeating a cycle of ink collection near both ends of the ink storage section (11) and ink supply at a position away from the collection position. 5. The flexographic printing machine according to claim 4 , wherein the dual-purpose nozzle (4) collects ink while moving a predetermined distance from the end of the ink reservoir (11) to the center of the ink reservoir (11). The flexographic printing machine according to any one of claims 1 to 5 , wherein an ink viscosity detecting means (8) for measuring the viscosity of the ink is incorporated in the middle of the flow pipe (44). The ink or cleaning waste liquid formed between the inking roll (1) and the squeezing member (20) pressed against the inking roll, with both ends in the longitudinal direction of the roll stored in the ink reservoir (11) Ink storage part (11) closed by dam members (12) and (12) without providing a recovery pipe, and an ink tank (31) and a waste liquid recovery tank located away from the ink storage part (11) (5) In the ink supply / recovery device that supplies and recovers flexographic ink,
The ink nozzle (31) and waste liquid recovery tank (31) and the waste liquid recovery tank (to be installed outside the printing press) are placed on the ink storage section (11). 5), the common nozzle (4) is connected through a common flow pipe (44) and a switching valve (45), and the ink tank (31) is accommodated in the sealed box (3). The vacuum suction pipe (35) and the pressurization air supply pipe (35a) are connected, and the waste liquid recovery tank (5) can be shut off from the outside air, and is connected to the vacuum suction pipe (51), and the sealed box (3) By pressurizing the inside, the ink in the ink tank (31) is supplied to the ink reservoir (11) through the distribution pipe (44) and the combined nozzle (4), and the inside of the sealed box (3) is made negative pressure The ink in the ink reservoir (11) is collected from the dual-purpose nozzle (4) to the ink tank (31) through the distribution pipe (44), and a predetermined amount of ink is supplied. And the ink recovery cycle is repeated to prevent the increase in the viscosity of the flexographic ink, and the waste liquid recovery tank (5) has a negative pressure so that the cleaning waste liquid collected in the ink reservoir (11) by roll cleaning can be removed. A flexographic ink supply / recovery device for collecting from a dual-purpose nozzle (4) to a waste liquid recovery tank (5) through a distribution pipe (44).

Images