JPS5818269A - Stopping of ink flow in rotary printer - Google Patents

Abstract

PURPOSE:To prevent the dropping of ink from a plate drum and both end portions in the axial direction of a throttle roller by blowing air stream with a small amount of water onto an ink trap formed on the upside of the contact portion between the plate drum and the throttle roller. CONSTITUTION:When ink is fed from a nozzle 20 to a grooved ink trap 13 formed on the upside of the contact portion between a plate drum 11 and a throttle roller 12 in contact with the drum 11, air stream from paired air jet nozzles 27 provided on both sides of an ink supply position 28 is jetted onto the bottom of the ink trap 13 slighly inwards from the right-angled direction to the roller 12 in order to form an air curtain. At the same time, small amounts of water is added to air from jet nozzles 31 provided in proximity to the nozzles 27 on both outer sides of the nozzles 27 and the mixed gas is jetted onto the bottom of the ink trap 13 in an almost rightangled manner.

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 with an ink reservoir number ζ above the contact area between the plate cylinder and the squeeze roller pressed against the plate cylinder. It is.

Flexographic printing machines have a heavier mechanism than other general rotary printing machines, and in addition, they use printing ink with extremely low viscosity, or in other words, high fluidity, so they are generally 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 plate cylinder.

As shown in FIG. 1, this ink circulation supply method supplies ink pumped up from an ink tank 2 by driving a pump 1 to a groove-shaped ink reservoir 5 above the contact area between the plate cylinder 3 and the squeezing roller 4. 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 new ink to a printing press, if some ink remains on the plate cylinder, the existing ink can mix with the new ink and produce the desired color. 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 washing, the ink supply 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 remaining in the ink reservoir 5 are discarded. need to,
Since these residual inks are in large quantities, there is a problem in economic efficiency. In addition, washing with water 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. Further, the width of the printing pattern provided on the plate cylinder 3 is usually narrower than the width of the printing paper. By the way, in the above-mentioned conventional ink circulation supply method, the ink always flows to the end of the plate cylinder 3 regardless of the width or width of the printing pattern, and as a result, the area in contact with the air increases and the solvent in the ink evaporates. There is a disadvantage that the viscosity of the ink changes.

SUMMARY OF THE INVENTION Therefore, the purpose of this invention is to solve the above-mentioned drawbacks, to simplify the washing work of the printing press and to change the ink color, and to minimize the amount of ink discarded during washing, and to wash with a small amount of water. It is an object of the present invention to provide a method for damming ink supply, which makes it possible to reduce the size of equipment for treating cleaning water to make it 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 plate cylinder and a squeeze roller, in which a pair of air jet nozzles are provided on both sides of the ink supply position. Printing/Xl' The air jet nozzles are provided at intervals wider than the width dimension of the turn, and air is jetted slightly inward from the air jet nozzles toward the bottom of the ink pool to form an air curtain. A mixture of air and a small amount of water is injected almost perpendicularly to the bottom of the ink reservoir from a mixture injection nozzle placed close to this on the outside, and the supplied ink is dammed up by the air curtain. It is.

Embodiments of the present invention will be described below with reference to the accompanying drawings.As shown in FIGS. 2 and 3, a squeeze roller 12 is pressed against the plate cylinder 11, and a squeeze roller 12 is formed above the contact area between the two. Printing ink is supplied to groove-shaped ink reservoirs 13.

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 a 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 ink tank 1S is pressurized from above to cause the ink in the tank 1S 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 from the upper part of the outer periphery of the squeezing roller 12 to a position closer to the ink reservoir 13.

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.

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 that communicates with each tank storage chamber 17. The conduit 1
Any tank 18 can be opened or closed by opening and closing the valve 23 at the 5th end.
It is possible to supply the ink inside the ink reservoir 13 to the ink reservoir 13.

Further, as shown in FIG. 5, a cylinder 4 is provided on the side of each nozzle 20 and is operated by opening and closing the manual buff 1.
When the cylinder 24 is actuated to move the piston 25 forward, the tip of the piston 25 and a certain rod-shaped body 2 are
If the nozzle 20 is held between the nozzles 6 and 6 and deformed into a flat shape, the supply of ink can be controlled regardless of whether the electromagnetic valve 22 is opened or closed. For this reason, just before the end of printing work, when it is visually determined that the ink corresponding to the number of sheets to be printed is stored in the ink reservoir 13, the cylinder 24 is actuated to move the piston 25 forward. The amount of ink stored in the ink reservoir 13 after printing is completed can be reduced to a very small amount, resulting in an effect of saving ink.

A pair of air injection nozzles 27 are provided on both sides of the ink supply position above the ink reservoir 5. The interval between the air injection nozzles 27 is larger than the width dimension of the printing pattern 28 provided on the plate cylinder 11. This air injection nozzle 27 is connected to a bracket 2 provided on the ink reservoir 13.
The bracket 29 may be attached to the ink sump 9 for a fixed arrangement, or as shown in FIG. It can also be installed in a similar manner.

The tips of each of the air injection nozzles 27 are bent inward, so that the air supplied to each nozzle 27 is injected from the tips of the nozzles slightly inward rather than perpendicular to the bottom of the ink reservoir 13. ing.

The air supply pressure when the nozzle inner diameter is 6 mm is 0.
A value of about 5 instant/d is preferable, and if it is higher than 0.5 instant/d, the ink accumulated in the ink reservoir 13 will scatter, and if it is too small, the ink damming effect will be poor, and the ink will flow through the ink reservoir 13 toward both ends. It flows out.

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 this nozzle 31.

The injection port of the air-fuel mixture injection nozzle 31 is needle-shaped, and as the air-fuel mixture flows out from this 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 at right angles or slightly outward from the right angles.

The mixing ratio of water to air is preferably about 50:1 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 poor. Therefore, there is a risk that the plate cylinder 11 may be seize due to the heat of contact with the squeezing roller 12.

When the inner diameter of the needle-shaped injection port of the mixture injection nozzle 31 is 5 mm, the supply pressure of the mixture is preferably about IKf/d. Ink cannot be stopped.

Now, when air is injected from the air injection nozzle 27, this injected 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, a mist-like jet stream is formed between the 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 atomized jet flow as described above, the ink flows along the ink reservoir 13, but does not reach the position of the air injection nozzle 27. When you reach
Flow is prevented by the air curtain.

By the way, since the tip of the air injection nozzle 27 is bent so as to spray air obliquely, the ink that accumulates in the ink reservoir 13 between the pair of air injection nozzles 27 is formed at both ends as shown in FIG. The ink is tilted and some of the ink flows out to the side, passing through the position of the jet of air. 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 air-fuel mixture injection nozzle 31, a mist-like jet is formed at that position. This prevents further flow toward the
Ink pool 13 between a pair of mixture injection nozzles 31
Printing ink is stored on top.

Since the air-fuel mixture injected from the air-fuel mixture injection nozzle 31 contains water, water accumulates on the ink reservoir 13, this water flows to the end along the ink reservoir 13, and the upper water flow causes the plate cylinder 11 to flow. Since it can be cooled, it is possible to prevent the plate cylinder 11 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 this invention, in a printing press that supplies ink to a groove-shaped ink reservoir formed above a contact position between a plate cylinder and a squeeze roller, air is provided at both sides of the ink supply position. An injection nozzle was provided, and air was injected from this injection nozzle toward the bottom of the ink reservoir from a right angle inward from the PP, so that the flow of printing ink supplied to the ink reservoir by this injection air was almost dammed. At the same time, since the dammed part is inclined, the flow of ink that flows out beyond the position of the jet 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 injection nozzle placed outside the nozzle, the injected air-fuel mixture can reliably dam the flow of printing ink and mix it. Ink can be stored between the air jet nozzles.

For this reason, compared to rotary printing machines that circulate ink, the ink return line can be omitted, making cleaning work easier, and the amount of ink wasted during this process is also small. This can be effective in reducing costs. 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, making it possible to downsize the equipment that detoxifies the washing water and controlling the amount of ink supplied just before the end of printing. Since it is easy to install equipment for this purpose, it is possible to omit the above-mentioned equipment in some cases.

In addition, since air containing a small amount of water was injected from the mixture injection 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, thereby cooling the plate cylinder. It is possible to prevent burn-in on the plate cylinder.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing a conventional rotary printing press, FIG. 2 is a longitudinal sectional front view showing an embodiment of an apparatus for implementing the method according to the present invention, FIG. 3 is a longitudinal sectional side view of the same, and FIG. The figure is a partially cutaway front view showing one embodiment of the ink supply device, and FIG.
FIG. 3 is a sectional view showing the ink supply nozzle portion shown in the figure. DESCRIPTION OF SYMBOLS 11... Plate cylinder, 12... Squeezing roller, 13... Ink reservoir, 27... Air injection nozzle, 31... Mixture injection nozzle patent applicant Yone Yamazaki Kurado Agent Kama 1) Sentence' 2 Figure 4 Figure 5

Claims (1)

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