CN100564037C - printing press - Google Patents

Abstract

A kind of printing machine, execute supply printing ink in the printing ink storage part (11) between the compression roller (2) on the ink roller (1) to being formed to execute ink roller (1) and be crimped on this, by executing the rotation of ink roller (1) and compression roller (2), make printing ink be transferred to the forme of peace commentaries on classics on version roller (9) from executing ink roller (1), compression roller (2) is covered by lid (6), in this lid (6), tilt to dispose mist injection nozzle (21) with fine mist ejection printing ink diluent liquid, in this printing machine, mist injection nozzle (21) is arranged on the below of compression roller (2), compression roller (2) rotates, and will be transported in the printing ink storage part (11) from the mist of mist injection nozzle (21).A pair of mist injection nozzle (21) relatively is provided with the central portion of compression roller (2), and their ejection side leading section is relative mutually in the inboard.

Description

printing press

technical field

The present invention relates to a method of printing laminated cardboard, more particularly, to a method of preventing the viscosity of ink used in a printing machine from increasing, and a printing machine using the method.

Background technique

The flexographic printing method using water-based ink in layered cardboard printing has the advantages of fast ink drying, and subsequent processes such as punching can be directly performed after printing.

Fig. 9 is a side view of a conventional flexographic printing machine, and Fig. 10 is a perspective view of its main parts (see Japanese Patent Laid-Open Publication No. Hei 5-200986). The ink application roller 1 and the squeeze roller 2 are in contact with each other, and a groove-shaped ink reservoir 11 is formed between the two rollers 1 , 2 . Below the inking roller 1 is provided a forme roller 9 which is in contact with the roller 1 and on which a printing plate 90 is installed, and a support roller 91 is arranged below the forme roller 9 . The ink application roller 1 can be arranged to be very close to the plate roller 9 at a very small interval. When the two rollers 1, 2 rotate toward each other toward the direction (internal rotation direction) of extruding the ink in the ink storage part 11, the ink on the surface of the ink application roller 1 is transferred to the printing plate (not shown in the figure) mounted on the plate roller 9. shown), the layered cardboard S fed between the plate roll 9 and the backup roll 91 is printed.

As shown in FIG. 10 , ink is supplied to the ink storage unit 11 from a container 96 installed on the floor through a pump 97 , a supply pipe 94 , and an ink supply suction nozzle 4 . Inks used in flexographic printing presses, because they dry easily, cannot be continuously circulated, otherwise they will solidify due to the increase in viscosity. Therefore, disc-shaped containers 98, 98 should be used to receive the ink flowing out from the ends of the two rollers 1, 2, and be recycled into the container 96 through the return pipe 95, so that the ink can be continuously circulated during printing. The length of return pipe 95 and supply pipe 94 is greater than 8m.

When the ink replacement is interrupted due to ink color replacement, etc., the ink that adheres to and remains in the return pipe 96 and the supply pipe 94 is washed away during cleaning, flows out, and is discarded. In addition, since the ink circulation path is long, a large amount of waste liquid is generated to clean the path, and large-scale equipment must be used for waste liquid treatment. Therefore, there is a problem that the initial cost and operating cost of waste liquid treatment become large.

And, as shown in FIG. 8 , a sealed box 3 containing a removable ink cartridge 31 and having an ink supply suction nozzle 4 is slidably provided along the ink storage unit 11 in the printing press (see US Pat. No. 5,697,299).

Contents of the invention

The purpose of the present invention is to provide a printing method, more specifically a method for preventing ink viscosity from rising, and a printing machine using the method. Although the method and printing machine use aniline ink, it does not require a long The circulation path of the ink can prevent the viscosity of the ink from rising, so the ink loss during ink replacement is small, so there is no need for large-scale equipment for cleaning waste liquid treatment.

The present invention provides a printing machine that supplies ink to an ink storage portion formed between an ink application roller and a squeeze roller pressed against the ink application roller, and makes the ink Transfer from the inking roller to the printing plate mounted on the plate roller, the squeeze roller is covered by a cover, and in the cover, there are obliquely arranged fine mist spray nozzles that spray the ink dilution liquid in the form of a fine mist, in this printing machine , the fine mist spray nozzle is arranged below the squeeze roller, and the squeeze roller rotates to deliver the mist from the fine mist spray nozzle to the ink storage part.

The present invention provides a printing method of a printing machine in which ink is supplied from an ink supply suction nozzle to an ink storage portion formed between an ink application roller and a squeeze roller pressed against the ink application roller, by applying The rotation of the ink roller transfers the ink on the ink application roller to the printing plate installed on the plate roller. The ink supply suction nozzle is connected to the closed box that stores the suction ink inside. The closed box and the ink supply The suction nozzle is arranged in a movable manner along the ink storage part, and the method comprises repeating the following steps:

Only one ink supply suction nozzle is provided,

A process of supplying ink to the ink storage part from the ink supply suction nozzle at the central part in the longitudinal direction on the ink storage part,

After moving the ink supply suction nozzle to one end side of the ink storage part from this position along the ink storage part, stop it, suck the ink from the ink storage part into the airtight box by a predetermined amount, and generate ink flow in the ink storage part. process,

Moving the ink supply suction nozzle from the stop position to the other end side of the ink storage part along the ink storage part, sucking a predetermined amount of ink into the sealed box, and generating ink flow across both ends of the ink storage part.

In the above process, the diluted liquid is supplied into the ink storage portion 11 .

After ink is supplied, the ink supply suction nozzle 4 initially moves toward one end of the ink storage portion 11 , and then, the ink supply suction nozzle 4 moves toward the other end of the ink storage portion 11 .

When the ink supply suction nozzle 4 sucks ink toward the ink cartridge 31 inside the airtight case 3 at one end of the ink storage portion 11, the ink level at the end drops and the ink moves toward the end. Since this operation is also performed at the other end portion of the ink storage portion 11 , the ink also moves to the other end along the ink storage portion 11 . Next, ink is supplied into the ink storage portion 11 at a position apart from both end portions. At this time, ink flow occurs.

During the printing operation, since the above-mentioned cycle is repeated, the ink storage unit 11 has the effect of uninterrupted flow and agitation of the ink to prevent the viscosity of the ink from increasing. In particular, since the ink moves between both end portions of the ink storage portion 11, the moving distance of the ink is longer, thereby increasing the stirring effect. The supplementary diluent mixes better with the ink due to the agitation effect produced by the ink flow.

Since the ink supply suction nozzle 4 slides together with the airtight case 3 removably accommodating the ink cartridge 31, the pipeline between the ink supply suction nozzle 4 and the airtight case 3 is shortened. Therefore, it is not necessary to use a very long circulation path as in the prior art, so that the viscosity of the ink can be prevented from rising, and thus, ink loss during ink replacement can be greatly reduced. Therefore, the cost of waste liquid treatment can be significantly saved compared with the prior art.

Description of drawings

1 is a perspective view showing an ink application roller and a squeeze roller, and an ink supply suction nozzle of a layered cardboard printing machine;

Fig. 2 is the right side view of Fig. 1;

3A to 3D are explanatory views of ink supply and suction nozzle actions during ink supply and ink circulation mode;

4A to 4C are explanatory views of the operation of the waste liquid recovery nozzle during cleaning waste liquid recovery;

5A and 5B are sectional views of the baffle member in FIG. 1 on a vertical plane including the line D-D;

Figure 6 is a cross-sectional view of other embodiments of parts that squeeze the ink applicator;

Figure 7A shows the rising position of the ink supply suction nozzle, Figure 7B is its middle position, and Figure 7C is its descending position;

Fig. 8 is a perspective view showing a conventional printing machine not using flexographic ink;

Fig. 9 is a side view of an existing flexographic printing machine;

Fig. 10 is a perspective view of the main part of the flexographic printing machine in Fig. 9 .

Detailed ways

(the whole frame)

FIG. 1 is a perspective view showing an ink application roller 1 and a squeeze roller 2 of a layered cardboard printing machine, and this example is characterized in that an increase in the viscosity of ink in an ink reservoir 11 can be prevented.

As in the prior art, the printing press is equipped with an ink application roller 1 and a squeeze roller 2 in contact with each other, and a groove-shaped ink storage part 11 is formed between the two rollers 1, 2.

Ink is supplied to the ink storage unit 11 from an ink supply suction nozzle 4 which will be described later, and the set height of the liquid surface is controlled by a liquid level sensor (not shown).

The two rollers 1, 2 rotate mutually toward the direction of extruding the ink in the ink storage part 11 (direction of inward rotation), and the ink on the surface of the ink application roller (1) is transferred to the printing plate on the plate roller 9, Thus printing onto laminated cardboard.

The ink application roller 1 is a hard roller such as a ceramic roller or a plated roller having fine unevenness on the surface, and the surface of the squeeze roller 2 is formed of rubber. The two rollers 1, 2 are different due to printing machines, and the length in the axial direction is 1.5-4.7m. At both ends of the two rollers 12, shutter members 8, 8 are arranged to close the ends of the ink storage portion 11, and ink can also be recovered from the shutter members 8, 8 as will be described later. The two rollers 12 and the baffle member 88 are covered by the cover 6 .

build

FIG. 2 is a right side view of FIG. 1 with the cover 6 cut away. As shown in Figures 1 and 2, the cover 6 forms a frame that accommodates two rollers 1, 2), and on the top plate 65 of the cover 6, an opening (61) is provided at the upper position relative to the ink storage part 11, Nozzles 4 , 5 , 34 , 70 described later that move along the aforementioned ink storage portion 11 engage with the opening 61 . On the underside of the cover 6, an opening 62 is opened to allow printing (not shown in the figure) on the plate roller 9 to come into contact with the ink applicator roller 1 .

The bottom plate 63 that covers the squeeze roller 2 side is bent obliquely upward on the ink application roller 1 side, and the front edge forms a blocking plate 63 a that approaches the ink application roller 1 with a gap 67 therebetween.

The opening edge 61 a of the upper surface opening 61 of the cover 6 on the squeeze roll 2 side approaches the squeeze roll 2 with a gap 66 above the squeeze roll 2 .

Accordingly, an atomization chamber 60 having narrow gaps 66 , 67 with respect to the squeeze roll 2 is formed in the cover 6 .

One or more fine mist spray nozzles 21 are arranged in the atomization chamber 60 . The fine mist spray nozzle 21 sprays the dilution liquid in the form of a fine mist to keep the atomization chamber 60 in a state of high humidity close to the saturated state, so that the tiny particles of the dilution liquid adhere to the surface of the squeeze roller 2 in the form of a film , thus actively moistening. In addition, the particle diameter of the fine mist is 50um or less, preferably 30um or less for easy spraying.

In the embodiment, a pair of fine mist spraying nozzles 21, 21 are arranged obliquely upward at a slight distance from the central portion of the squeeze roll 2 along the roll's longitudinal direction, with spraying-side front ends facing each other inside (see FIG. 3A ).

A humidity sensor 68 is provided in the atomization chamber 60, which controls the spraying and the stop of the spraying. The spray chamber 60 maintains a high temperature near saturation.

Airtight box and ink supply suction nozzle

Above the squeeze roller 2 sandwiching the top plate 65 of the cover 6, a closed case (3) is arranged parallel to the squeeze roller and slidably arranged.

As will be described later, the airtight box body 3 is a main component for supplying and recovering ink, and at the same time, it is also a component that supports the ink supply suction nozzle 4 and the cleaning waste liquid recovery nozzle 5. Section 11 slides.

As shown in FIG. 1 , an ink cartridge 31 is removably accommodated inside the airtight box body 3 , and a nozzle mounting plate 33 connected to a lifting drive device 32 such as an air cylinder device is provided on the outside in a liftable manner.

The nozzle mounting plate 33 is horizontally located above the ink storage part 11, and two ink supply and suction nozzles 4, 4 are arranged at both ends, and two cleaning waste liquid recovery nozzles 5, 5 are respectively arranged downward inside.

According to the size of the printing machine, the size of the airtight box body 3, etc., the distance between the two ink supply suction nozzles 4, 4 is suitable to be 20-60 cm.

The lower ends of the ink supply suction nozzle 4 and the waste liquid recovery nozzle 5 are chamfered corresponding to the bottom shape of the ink storage portion 11 to form a pointed shape. The height positions of the lower ends of the two nozzles 4 and 5 are aligned.

The aforementioned lifting drive device 32 can move the nozzle mounting plate 33 up and down between the raised position and the lowered position. The lower ends of the nozzles 4 and 5 in the raised position are positioned slightly higher than the set height of the ink liquid level of the ink storage unit 11 (see FIG. 7A ). At the intermediate position, the lower ends of the nozzles 4, 5 are immersed in the ink storage portion 11 (see FIG. 7B ), and the lower ends of the nozzles 4, 5 at the descending position are immersed in the ink storage portion to such an extent that they barely bite into between the rollers 1, 2. 11 (see Figure 7C). More specifically, the distance L between the contact point G of the two rollers 1, 2 and the lower ends of the nozzles 4, 5 in the lowered position is on the order of several millimeters.

A flexible hose 4 a detachably and airtightly penetrating the airtight case 3 is connected to the ink supply suction nozzle 4 , and the front end of the hose 4 a is immersed in the aforementioned ink cartridge 31 . The length from the tip of the ink supply suction nozzle 4 to the tip of the tube 4 a inside the ink cartridge 31 can be shortened to about 1.2 m.

The suction pipe 35 for decompression and the air supply pipe 36 for pressurization are connected to the airtight case body 3, and by sending pressurized air from the air supply pipe 36 for pressurization to the airtight case body 3, the ink in the ink cartridge 31 can be squeezed out. The ink is supplied from the ink supply suction nozzle 4 to the ink storage portion 11 .

By suctioning the air in the airtight case 3 with the decompression suction tube 35 to depressurize the airtight case 3, suction can be applied to the ink supply suction nozzle 4, and the ink in the ink storage unit 11 can be sucked into the ink cartridge. 31 in.

In FIG. 1, although the suction pipe 35 for decompression and the air supply pipe 36 for pressurization may be connected to the airtight case 3 separately, it is also possible to use a common pipe for suction and pressurization.

The waste liquid recovery nozzle 5 is connected to a suction pipe 51 which is a bendable hose and connected to a recovery tank 50 . A suction pipe 53 for decompression is connected to the recovery tank 50 , and the air in the recovery tank 50 can be sucked by the suction tube 53 to depressurize the inside of the recovery tank 50 . A suction pipe 52 connected to the aforementioned baffle member 8 is connected to the recovery tank 50 .

5A and 5B are cross-sectional views of the baffle member 8 in FIG. 1 taken along a vertical plane including line D-D. A discharge hole 81 that communicates with and opens to the side surface and upper surface of the ink storage unit 11 is opened in the shutter member 8 , and the discharge hole 81 is connected to the recovery tank 50 through the suction pipe 52 . When the inside of the recovery tank 50 is depressurized, the waste liquid cleaned in the ink storage unit 11 can be sucked through the suction pipe 51 and the waste liquid recovery nozzle 5 . In addition, waste liquid can be sucked from the discharge hole 81 of the baffle member 8 through the aforementioned suction pipe 52 .

In the airtight box 3, in addition to the aforementioned nozzles 4, 5, two cleaning liquid supply nozzles 34, 34 and a dilution liquid supply nozzle 70 are provided.

The cleaning liquid supply nozzles 34, 34 are located above the ink application roller 1, and when the rollers 1, 2 are cleaned, a predetermined amount of cleaning liquid is connected to a cleaning liquid supply device (not shown) which is sprayed or dropped.

In addition, diluent supply nozzles 7 , 7 are arranged on both end sides of the ink storage unit 11 at positions where they do not collide with the airtight case 3 .

The diluent supply nozzles 7, 7, 70 are connected to a diluent supply device (not shown in the figure), which makes the diluent drop into the ink storage part 11, according to the usage amount and the supply amount of the ink, to The diluent is supplied to such an extent that the ink in the ink storage unit 11 is not too dilute.

The cleaning liquid, the diluent, and the diluent sprayed from the fine mist spray nozzles 21 and 21 are tap water in this embodiment. It goes without saying that additives may also be added thereto, and a liquid corresponding to the characteristics of the ink may be used.

The aforementioned slide driving device 25 slides the airtight case 3 along the ink storage portion 11, and as an example of this structure, the structure shown in FIG. 8 can be considered. Wherein, a rail 26 is provided above the two rollers 1 and 2 along the ink storage part 11 , and the rollers 27 , 27 , 27 , 27 connected to the airtight box 3 are embedded in the rail 26 . The airtight box body 3 moves along the track 26 . In addition, as described above, the lift drive device 32 mounted on the airtight case 3 lifts the nozzle mounting plate 33 (see FIG. 1 ).

The slide drive unit 25 can switch between at least two modes, an ink recovery/washing liquid recovery mode and an ink circulation mode, which will be described later. In the ink recovery and cleaning liquid recovery mode during color replacement, the airtight box 3 is reciprocated across the entire length of the ink storage part 11 one or more times, so as to recover ink and cleaning liquid. Its action is shown in Figure 4A to Figure 4C. The ink circulation mode is a mode during printing operation, and its operation is shown in FIGS. 3A to 3D .

Next, each operation of the ink circulation mode and the ink recovery/washing liquid recovery mode of this printing machine will be described.

(ink supply in ink circulation mode)

3A to 3D are explanatory diagrams illustrating the operation of the ink supply suction nozzle 4 in the ink circulation mode, and the printing machine in FIG. 1 is viewed from the upstream side of paper feeding, that is, from the F direction. For convenience of illustration, the cap 6 and the waste liquid recovery nozzle 5 are omitted.

When supplying ink to the empty ink storage unit 11 , ink is supplied from the ink supply suction nozzle 4 mounted on the airtight case 3 while sliding the airtight case 3 along the ink storage unit 11 . At this time, the ink application roller 1 and the squeeze roller 2 are rotated to agitate the ink while preventing the ink liquid surface from adhering to the rollers 1 and 2 at the boundary line.

When the ink is supplied to the set liquid level, the supply of ink is stopped by the operation of the liquid level sensor, and the airtight box 3 returns to the center of the ink storage part 11 once ( FIG. 3A ). At this time, the ink supply suction nozzle 4 is immersed in the ink storage part 11, and the supplied ink is about 2 liters. Then, the printing operation is started while the two rollers 1 and 2 are being rotated.

In the above-mentioned ink supply and printing operation, the dilution liquid is sprayed from the fine mist spray nozzles 21, 21 and the surface of the squeeze roller 2 is covered with fine particles of the dilution liquid to actively moisten, and at the same time, the atomization chamber 60 is filled with water. fine mist.

The mist chamber 60 maintains high humidity near saturation with a fine mist. Thus, the minute particles of the diluent covering the roller surface are continuously conveyed to the ink storage portion 11 by the rotation of the squeeze roller 2 .

When the ink diluent such as water is directly dropped into the ink storage portion 11, since the diluent and the ink have different properties (specific gravity, viscosity, etc.), the diluent does not directly associate with the ink, making it difficult to mix. However, in this example, the peripheral surface of the squeeze roller 2 is wetted with fine particles of the diluent, and this wetting is carried into the ink storage portion 11 by the rotation of the roller 2 . Thereby, the moisture on the surface of the squeeze roller 2 is directly compatible with the ink in the ink storage portion 11 and mixed well, so that the viscosity of the ink does not become uneven.

By arranging the fine mist spray nozzles 21, 21 obliquely below the squeeze roll 2 toward the far end of the roll 2 as in the present embodiment, the surface of the squeeze roll 2 can be actively wetted. That is, since the spraying distance of the fine mist spray nozzles 21 and 21 is long, the wide range of the squeeze roll 2 can be wetted with the fine mist.

In addition, since the fine mist leaking from the narrow outlet 66 above the squeeze roller 2 of the atomizing chamber 60 forms a high-humidity temperature atomizing atmosphere near the oil mist storage part 11, the moisture in the ink storage part 11 is suppressed from evaporating and the ink is prevented from being sprayed. viscosity rises.

In addition, the purpose of filling the inside of the cover 6 including the squeeze roller 2 with fine mist is disclosed in Japanese Patent Laid-Open Publication No. Hei 6-947. However, in this embodiment, the fine mist spray nozzles 21 , 21 are arranged below the squeeze roller 2 , and fine particles of the diluent covering the roller surface are sent to the ink storage unit 11 by the rotation of the squeeze roller. Therefore, even if the squeeze roller 2 and the top plate 65 of the cover 6 are close, the ink can be effectively diluted.

(ink circulation)

When the user operates the operation panel (not shown) of the printing machine to set the ink circulation program, the ink supply suction nozzle 4 is at the position shown in FIG. Ink is supplied from the ink cartridge 31 of the airtight case 3 for about 6 seconds. In addition, the ink circulation program can also be set constantly during printing operation.

Thereafter, as shown in FIG. 3B , the airtight case 3 moves toward one end of the ink storage portion 11 . The ink supply suction nozzle 4 descends to an intermediate position at its moving position, and the ink supply suction nozzle 4 is immersed in the ink of the ink storage portion 11 (state shown by a solid line in FIG. 3B ). After recovering the ink into the airtight case 3 in about 2 seconds, the ink in the ink storage part 11 is sucked while moving from this position to the center side of the ink storage part 11 by a predetermined area, in the embodiment, about 50 cm. (The position shown by the single dotted line in Fig. 3B). This area becomes the first recovery area.

When the ink supply suction nozzle 4 sucks ink in the first recovery area of the ink storage unit 11 , the liquid level in the recovery area drops, and the ink moves from the center side of the ink storage unit 11 to the first recovery area, so that the ink flows.

Moving the ink supply suction nozzle 4 in the first recovery area has the effect of stirring the ink.

Then, the suction of the ink is stopped, the tip of the ink supply suction nozzle 4 is lifted from the ink, and the airtight case 3 is moved to the end portion on the opposite side of the ink storage unit 11 . The ink supply suction nozzle 4 is lowered and immersed in ink at its moved position (the position shown by the solid line in FIG. 3C ). As in the case of the first recovery area, after recovering the ink in the airtight box body 3 in about 2 seconds, the airtight box body 3 and the ink supply suction nozzle 4 are only moved to the same area as before. The central side of the ink storage portion 11 moves while sucking ink (the position indicated by the dashed-dotted line in FIG. 3C ). As described above, the liquid level in this recovery area (referred to as the second recovery area) drops to move the ink from the center side of the ink storage section 11 , and the flow of ink occurs in the ink storage section 11 .

Next, in the state of stopping the suction of ink, the front end of the ink supply suction nozzle 4) is lifted from the ink storage part 11), and the airtight box body 3 is located at a position away from the suction position, and returns to the ink storage part 11) in this embodiment. central part. In this position, the ink supply suction nozzle 4 is still in the raised position, supplying ink to the ink reservoir 11 . By controlling with the aforementioned liquid level sensor, the liquid level does not rise above the set height.

During the printing operation, the above-mentioned cycle is repeated, and the ink is circulated between the ink storage unit 11 and the ink cartridge 31 .

The airtight case 3) is in a standby state at the center of the ink storage unit 11) when the ink circulation mode ends.

In addition, during printing operation, an appropriate amount of diluent is supplied from the diluent supply nozzles 7, 7 on both ends of the ink storage unit 11 and the diluent supply nozzle (70) attached to the airtight case 3.

As described above, during the printing operation, by repeating the suction of ink at both ends of the ink storage unit 11 and the supply of ink at the center of the ink storage unit 11, a continuous flow of ink can be generated in the ink storage unit 11, and the ink can be supplied to the ink storage unit 11. Stir. In particular, since the ink flows between both end sides of the ink storage portion 11, the moving distance becomes large, increasing the agitation effect.

And, the ink supply suction nozzle 4 moves together with the airtight box body 3 storing the ink, therefore, the path that the ink flows is relatively short, and it is unnecessary to need a very long circulation path as in the past, thereby preventing the viscosity of the ink from rising.

As long as the lower end of the nozzle 4 is spaced from the lower end of the ink storage unit 11 , the ink supply suction nozzle 4 may be moved while being immersed in the ink storage unit 11 .

At the positions where the dilution liquid is supplied with the dilution liquid supply nozzles 7, 7, 70, the viscosity of the ink decreases. However, by the ink flow caused by ink suction in the above-mentioned two recovery areas of the ink supply suction nozzle 4, and the ink flow caused by supplementing the ink used and reduced in the printing press, it is possible to prevent the viscosity of the ink from rising and prevent the ink Uneven viscosity.

In particular, as in the embodiment, by using the ink supply suction nozzle 4, the ink at the portion where the viscosity of the ink is temporarily lowered due to the supply of the diluent liquid from the diluent liquid supply nozzles 7, 7 is recovered into the ink cartridge 31, thereby making it possible to An effect of adjusting the viscosity of the ink inside the ink cartridge 31 is obtained.

(Ink recovery and cleaning fluid recovery mode)

After a predetermined amount of printing is completed, it is necessary to change the color of the ink corresponding to the next printing. At this time, the ink adhering to the rollers 1 and 2 is washed off.

4A to 4C are explanatory diagrams illustrating the operation of the waste liquid recovery nozzle 5 in the ink recovery and cleaning liquid recovery mode.

When ink replacement is performed, the rotation of the rollers 1 and 2 is stopped, and the ink supply suction nozzle 4 and the waste liquid recovery nozzle 5 are lowered to the lowered position of the ink storage unit 11 by the elevating drive device 32 ( FIG. 4A ). The suction pipe 51 connected to the waste liquid recovery nozzle 5 is bendable so as not to hinder the descent of the waste liquid recovery nozzle 5 .

The airtight case 3 is slid, and the ink in the ink storage portion 11 is sucked by the ink supply suction nozzle 4 mounted on the case 3 . At this time, the waste liquid recovery nozzle 5 is not sucked.

As in the embodiment, if the ink supply suction nozzle 4 is made to reciprocate once or twice across the entire length of the ink storage part 11 by using the vacuum pressure to suck the ink, almost all the ink in the ink storage part 11 can be sucked. ink.

Next, the ink supply suction nozzle 4 and the waste liquid recovery nozzle 5 are raised, the rollers 1 and 2 are rotated, and in this state, the airtight case 3 is slid to spray about 100 cc of ink from the cleaning liquid supply nozzle 34 onto the ink application roller 1. A cleaning solution consisting of water (Figure 4B).

The ink adhering to the ink application roller 1 in the form of a film is almost washed away, and the washing waste liquid remains in the ink storage portion 11 . The amount of ink adhering to the ink application roller 1 in the form of a film is very small, and the ink is water-based, so the amount of cleaning liquid required for cleaning is very small.

The rotation of the rollers 1 and 2 is stopped, and the ink supply suction nozzle 4 and the waste liquid recovery nozzle 5 are lowered to the lowered position of the ink storage unit 11 . The suction of the ink supply suction nozzle 4 is stopped. In this state, the airtight case body 3 is slid and only the waste liquid recovery nozzle 5 is sucked so that the waste liquid is sucked into the recovery tank 50 .

If the suction of the recovery tank 50 is carried out, the suction force also acts on the discharge holes 81 of the connecting plate member 8 at both ends of the ink storage part 11, and the cleaning waste liquid is also recovered from the baffle member 8 into the recovery tank 50 (FIG. 4C) . As in the case of ink recovery, if the waste liquid recovery nozzle 5 is reciprocated once or twice across the entire length of the ink storage part 11, almost all the cleaning liquid in the ink storage part 11 can be sucked. After recovery, the sealed case 3 is in a standby state at the central portion in the longitudinal direction of the ink storage portion 11 .

As mentioned above, when the ink is replaced, the ink can be recovered almost without loss, and accordingly, the amount of cleaning liquid required for cleaning the roller is small, and the concentration of the cleaning waste liquid is also low. Therefore, the treatment of the cleaning waste liquid does not require large equipment, so that the operating cost of the waste liquid treatment can be reduced.

In order to change the color, the ink cartridge 31 in the airtight box body 3 will be removed and replaced.

Then, the two nozzles 4, 5 are raised, the rollers 1, 2 are rotated, and new ink is supplied from the ink supply suction nozzle 4).

In this case, the ink supply suction nozzle 4 is not moved laterally and remains in the standby position. Furthermore, suction of the recovery tank 50 is facilitated.

As shown in FIG. 5A , the ink I flowing out from the nozzle 4 flows toward the shutter member 8 at the bottom of the ink storage portion 11 . A small amount of cleaning liquid H not recovered by the waste liquid recovery nozzle 5 remains at the bottom of the ink storage portion 11 . However, due to the flow of the ink I to the shutter member 8 side, the remaining waste liquid H is pushed by the ink I to flow.

Since the flow tendency of the ink I is different from that of the waste liquid in terms of specific gravity and viscosity, the waste liquid H and the ink I hardly mix and are pushed to flow to the baffle member 8 .

As shown in FIG. 5B, the ink I and the waste liquid H approach the shutter member while the height of the liquid surface rises.

At the discharge hole 81 of the baffle member 8 , since the suction force of the recovery tank 50 acts, the waste liquid pushed out of the discharge hole 81 of the baffle member 8 is sucked into the recovery tank 50 .

As described above, by pushing the waste liquid to flow toward the shutter member 8, the liquid level of the waste liquid gradually rises, and the opening of the discharge hole 81 on the ink storage portion 11 side is blocked by the liquid level. Therefore, air can be prevented from leaking out from the discharge hole 81, so that the waste liquid can be sucked with a strong suction force.

The suction of the recovery tank 50 is stopped just before the recovery of the ink from the discharge hole 81 to the recovery tank 50 is completed. The time for the ink supplied to the central part of the ink storage part 11 to flow to the end of the ink storage part 11 is measured in advance and set by the timer, or the end of the ink storage part 11 is arranged to detect the difference between the waste liquid and the liquid quality of the ink. Liquid quality detector, so that the aforementioned operations can be realized. In practice, the waste recovery is maintained for about 40 seconds.

As described above, substantially all of the cleaning waste liquid can be recovered. The waste liquid remaining on the wall surface of the wet ink storage unit 11, or the waste liquid that has not been recovered, is in a small amount, and thus does not affect the color of the ink even if it is mixed with new ink.

In this example, two ink supply suction nozzles 4, 4 are provided, which are immersed in ink and moved in two recovery areas. Instead, it is conceivable to increase the number of ink supply suction nozzles 4 and arrange them along the longitudinal direction of ink storage portion 11 to suck ink without sliding ink supply suction nozzles 4 . However, in this case, the stirring effect on the ink is poor.

In addition, in the present embodiment, the ink is supplied to the central portion of the ink storage portion 11 and sucked at the end portion. Alternatively, the ink may be supplied at the end of the ink storage unit 11 and sucked at the center.

In addition, in the above-mentioned embodiment, although the squeezing roller 2 is used as the squeezing member that squeezes the ink on the ink application roller 1, it is not limited thereto. For example, as shown in FIG. 6 , the belt-shaped plate 22 may be pressed against the ink application roller 1 across the entire length of the roller 1 to form the ink reservoir 11 therebetween.

In the case of FIG. 6 , the belt-shaped plate 22 faces in the direction opposite to the rotation of the ink application roller 1, and the support block 23 supporting the belt-shaped plate 22 constitutes the wall surface of the ink storage part 11, and the belt-shaped plate 22 doubles as the ink storage part 11. bottom of.

In the above-mentioned embodiment, the supply and recovery of ink to the ink storage unit 11 is performed by pressurizing and depressurizing the airtight case 3, and the recovery of cleaning waste liquid is performed by depressurizing the recovery tank (50). However, it is also possible to use a tube type oil well pump for oil supply, recovery, and recovery of cleaning waste liquid.

In the above embodiment, as shown in FIGS. 5A and 5B , when the remaining waste liquid H is squeezed to the end of the ink storage section 11 by the ink I supplied to the ink storage section 11, the discharge from the shutter member 8 The hole 81 recovers the remaining waste liquid through the recovery pipe 52 . However, the present invention is not limited thereto, and the shutter member 8 may be separated from the end faces of the rollers 1 and 2 to collect the waste liquid flowing down from the end of the ink storage unit 11 .

The present invention is not limited to water-based inks, and can also be implemented for glycol-based inks with low viscosity and good drying speed.

Claims (2)

1. A printing machine that supplies ink to an ink storage portion (11) formed between an ink application roller (1) and a squeeze roller (2) pressed against the ink application roller (1), by applying The rotation of the ink roller (1) and the squeeze roller (2) transfers the ink from the ink roller (1) to the printing plate mounted on the plate roller (9), and the squeeze roller (2) is covered by the cover (6) Covering, in the cover (6), a fine mist spray nozzle (21) that sprays ink dilution liquid in a fine mist form is arranged obliquely. In this printing machine, The fine mist spray nozzle (21) is arranged under the squeeze roller (2), and the squeeze roller (2) rotates to deliver the mist from the fine mist spray nozzle (21) to the ink storage part (11). 2. The printing machine according to claim 1, characterized in that a pair of fine mist spray nozzles (21) are arranged opposite to the central portion of the squeeze roller (2), and their spray-side front ends face each other inside.

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