JPS6018542B2 - Method for damming ink supply in rotary printing presses - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for damming the supplied ink in a rotary printing press that supplies printing ink to an ink reservoir above the contact area between a plate cylinder and a squeeze roller pressed against the plate cylinder. be.

Flexo printing machines have a simpler mechanism than other general rotary printing machines, and they use printing ink with extremely low viscosity, or in other words, high fluidity, so they are widely used for printing on cardboard, etc. has been done.

Since such a flexo printing machine has a simple mechanism as described above, a circulating supply method is used to supply ink to the printing press.

As shown in FIG. 1, in this ink circulation supply method, the ink pumped up from the ink tank 2 by the drive of the pump 1 is supplied to the groove-shaped ink reservoir 5 above the bushy part of the bottle holder 3 and the squeezing roller 4. The excess ink flowing down from both ends of the ink reservoir 5 is received by a saucer 6 and returned to the tank 2.

Generally, when supplying regular ink to a flexographic printing machine, if old ink remains in the glue feed direction, the existing ink will mix with the new ink and the desired color will not be expressed. For this reason, after finishing printing work or when replacing printing ink, the remaining printing ink is washed away by washing with water or the like.

For this reason, in the conventional ink circulation supply method, during the washing operation, the ink remaining in the ink supply/input pipe from the tank 2 to the ink reservoir 5, the ink return pipe from the ink reservoir 5 to the tank 2, and the ink sink 5 is removed. Since these inks need to be discarded and the amount of remaining ink is large, there is a problem in terms of economic efficiency.

In addition, the washing process is time-consuming and requires a large amount of water, and discharging the washing water into rivers causes pollution problems, so it is necessary to install large-scale equipment to detoxify the water.
Furthermore, the width dimension of the printing pattern provided on the plate cylinder 3 is
It is usually narrower than the width of the printing paper. by the way,
In the conventional ink circulation supply method described above, the ink always flows to the edge of the printing plate 3 regardless of the width or narrowness of the printing pattern, and as a result, the area in contact with air increases and the solvent in the ink evaporates. There is a disadvantage that the ink viscosity changes.
SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above-mentioned drawbacks, to simplify the washing work of the printing press and the work of changing the ink color, to collect the amount of ink discarded during washing, and to wash the printing press with water using a small amount of water. It is an object of the present invention to provide a method for damming a supplied ink, which makes it possible to reduce the size of equipment for making the washing water harmless, or to make it unnecessary to install the equipment.

This invention provides a rotary printing press that supplies ink to a groove-shaped ink reservoir formed above a contact area between a printing press and a squeezing roller, in which a pair of air jet nozzles are provided on both sides of the ink supply position. The air is provided at intervals wider than the width of the printing pattern, and the air is jetted slightly inward from the air jet nozzles toward the bottom of the ink pool to form an air curtain, and the air is sprayed slightly inward from the air jet nozzles to the outside of each air jet nozzle. A mixture of air mixed with a small amount of water is injected almost perpendicularly to the bottom of the ink reservoir from a mixture blocking nozzle placed close to this, and the supplied ink is dammed up by the air curtain. be.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

As shown in FIGS. 2 and 3, a squeezing roller 12 is pressed against the plate 8 and 11, and printing ink is supplied to a groove-shaped ink reservoir 13 formed above the contact area between the two. ing.

The printing ink can be supplied in any manner, and in the illustrated embodiment,
As shown in FIG. 4, compressed air discharged from the compressor 14 is supplied into the closed tank 16 through the conduit 15, and the supply pressure of this compressed air is applied to the tank storage chamber of the closed tank 16.
The inside of the ink tank 18 placed in the tank 7 is pressurized from above to cause the ink in the tank 18 to flow into the supply pipe 19 inserted into the tank 18, and the flexible nozzle 20 connected to the end of the supply pipe 19 The ink is discharged to a position closer to the ink reservoir 13 than above the outer periphery of the squeezing roller 2.

A sensor 21 for detecting the amount of ink stored is provided on the ink reservoir 13, and when the sensor 21 is activated, the conduit 1
An electromagnetic valve 22 provided in the middle of the tank 5 closes to cut off the supply of compressed air to the tank storage chamber 17.

Note that a plurality of tank storage chambers 17 are formed inside the sealed tank 16, and a valve 23 is attached to the end of the conduit 15 conveyed to each tank storage chamber 17. By arranging the nozzles 20 at the tips of the ink supply pipes 19 inserted into each tank 18 in parallel in the longitudinal direction of the ink reservoir 13, the ink inside any tank 18 can be released by opening and closing the valve 23 at the end of the conduit 15. can be transferred to the ink reservoir 13.

Further, as shown in FIG. 5, a cylinder 24 is provided on the side of each nozzle 20 to be operated by opening and closing a manual valve, and when the cylinder 24 is operated to advance the piston 25, the tip of the piston 25 A rod-shaped body 26 fixed as appropriate
By supporting the nozzle 20 and deforming it into a flat shape, ink supply can be controlled regardless of whether the electromagnetic valve 22 is opened or closed.

Therefore, when it is visually determined that the ink corresponding to the number of sheets to be printed is stored in the ink reservoir 13 immediately before the end of the printing operation, the cylinder 24 is actuated to advance the piston 25, thereby allowing printing. The amount of ink stored in the ink reservoir 13 after the completion of printing can be used as the amount of ink, which can be effective in saving ink. A pair of air injection nozzles 27 are provided on both sides of the ink false supply position on the ink reservoir 5.

The spacing between the air jet nozzles 27 is larger than the width dimension of the printing pattern 28 provided on the plate cylinder 11. This air injection nozzle 27 may be installed in a fixed position by being attached to a placket 29 provided on the ink reservoir 13, or as shown in FIG.
The bracket 29 is moved along the ink reservoir 13 by the rotation of 0.
It is also possible to have an adjustable position by moving it. The tip of each air injection nozzle 27 is bent inward, and the air supplied to each nozzle 27 is injected from the tip of the nozzle slightly inward rather than perpendicular to the bottom of the ink reservoir 13. It has become so.

When the nozzle inner diameter is 6 ribs, the combined air pressure is 0.
．． Approximately 5k9/base is preferable; if it is higher than 0.5k9/base, the ink accumulated in the ink reservoir 13 will scatter, and if it is too small, the ink damming effect will deteriorate and the ink will flow through the ink reservoir 13 towards both ends. .

This nozzle 27 is located on the outside of the air injection nozzle 27.
A mixture injection nozzle 11 is provided adjacent to the nozzle 31, and a mixture of air and a small amount of water is supplied to the nozzle 31.

The injection port of the air-fuel mixture injection nozzle 31 has a needle shape, and as the air-fuel mixture flows out from the needle-shaped injection port, the injected air-fuel mixture becomes a mist. This injection mixture is blown toward the bottom of the ink reservoir 13. Note that when the injected mixture is injected slightly inward from a right angle to the bottom of the ink reservoir 13, water is mixed with the stored ink. It is preferable to inject it slightly outward.

The mixing ratio of water to air is preferably about 50 to 1 in terms of volume. If the ratio of water is higher than the above ratio, water will easily mix into the stored ink, and if the ratio of water is lower, the water cooling effect will be reduced. There is a danger that the plate cylinder 11 may become burnt due to contact heat with the squeezing roller 12.

When the inner diameter of the needle-shaped injection port of the air-fuel mixture jetting/zuru 31 is set to 5 Yanagi, the air-fuel mixture supply pressure is preferably about lk9/kg; if the pressure is higher than the above, the stored ink will scatter, and if it is lower, the , the accumulated ink cannot be dammed up.

Now, when air is injected from the air injection nozzle 27, the air is injected toward the bottom of the ink reservoir 13, and an air curtain is formed between the nozzle 27 and the bottom of the ink reservoir 13. Further, when a mixture of air and water is supplied to the mixture injection nozzle 31, this mixture is supplied to the nozzle 31.
is injected from the injection port toward the bottom of the ink reservoir 13,
As a result of the jetting, a tight jet stream is formed between the jet nozzle 31 and the bottom of the ink reservoir 13. When ink is supplied from the ink supply nozzle 20 to the ink reservoir 13 during the formation of the air curtain and the atomized jet flow as described above, the ink flows along the ink reservoir 13, but
When the air reaches the air injection nozzle 27, the flow is blocked by the air curtain.

By the way, since the tip of the air injection nozzle 27 is bent to spray air obliquely, the ends of the ink that accumulates in the ink reservoir 13 between the pair of air injection nozzles 27 are shown in FIG. As the mirror tilts, some of the ink passes through the spraying position of the spray air and flows out to the side.

This amount of ink that flows out to the side is small, and when this small amount of ink flows to the installation position of the mixture injection nozzle 31,
Because a mist-like jet stream is formed at that position,
The atomized jet stream prevents the printing ink from flowing further to the side, and the printing ink is stored on the ink reservoir 13 between the pair of air-fuel mixture injection nozzles 31. Mixture injection nozzle 3
Since the air-fuel mixture injected from 1 contains water, the water collects on the ink reservoir 13, and this water flows along the ink reservoir 13 to the end, and the flow of the water cools the plate chest 11. Therefore, it is possible to prevent the paste bait from burning.

Note that water falling from the end of the ink reservoir 13 is received by a saucer or the like and drained to an arbitrary position.

As described above, in the present invention, in a printing press that supplies ink to a groove-shaped ink reservoir formed above the contact position between the plate cylinder and the squeeze roller, there are air holes on both sides of the ink supply position. A spray nozzle was provided, and air was sprayed from this spray nozzle toward the bottom of the ink pool slightly inward rather than at right angles, so the flow of printing ink supplied to the ink pool could be almost dammed by the spray nozzle. At the same time, since the dammed part is oblique, the flow of ink that flows out beyond the spraying position of the jetting air is weak and in a small amount.

Therefore, by injecting the air-fuel mixture toward the bottom of the ink reservoir from the air-fuel mixture nozzle placed outside the nozzle, the flow of printing ink can be reliably dammed by this injected air-fuel mixture. , ink can be stored between the air-fuel mixture spray nozzles. For this reason, compared to rotary printing machines that circulate ink, the ink return line can be omitted, making cleaning easier, and the amount of ink discarded at that time is also small, reducing printing costs. This can be effective in reducing In addition, since the washing process is simple, the printing ink color can be quickly changed, which is effective in improving work efficiency. Furthermore, since only a small amount of ink is discarded, it can be washed with a small amount of water, and four facilities have been installed to detoxify the washing water.
- Not only can it be molded, but it is also easy to install a device that controls the ink supply just before the end of printing, so the above equipment can be omitted in some cases.

In addition, since air containing a small amount of water was injected from the mixture lighting nozzle, water accumulated in the part of the ink reservoir where ink was not stored, and this water flowed to both ends of the ink reservoir, so can be cooled and prevent burn-in of the plate cylinder.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing a conventional rotary printing press, Fig. 2 is a longitudinal sectional front view showing an embodiment of a diamond press that implements the method related to this invention, and Fig. 3 is a longitudinal sectional side view of the same. FIG. 4 is a partially cutaway front view showing one embodiment of the ink supply connecting device, and FIG. 5 is a sectional view showing the ink supply nozzle portion of FIG. 4. 1 1... Plate arm, 12... Squeezing roller, 13... Ink reservoir, 27... Air injection nozzle, 31...
・Nami Aiki Shosei nozzle. Figure 1 Figure 2 Figure 5 Figure 3 Figure 4

Claims (1)

[Claims] 1. In a rotary printing press that supplies printing ink to a groove-shaped ink reservoir formed above the contact area between the plate cylinder and the aperture roller, ink is injected from a pair of air jet nozzles placed on both sides of the ink supply position. Air is injected slightly inward from the bottom of the reservoir to form an air curtain, and a small amount of water is added to the air from a mixture injection nozzle placed close to this nozzle outside of the air injection nozzle. A method for damming ink supply in a printing press, characterized in that a mixture is injected almost perpendicularly to the bottom of an ink reservoir.