JP2954895B2 - Printing press and ink recovery method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing press capable of efficiently collecting ink at the time of color change.

[0002]

2. Description of the Related Art A conventional flexographic printing machine for corrugated cardboard sheets is disclosed in Japanese Patent Application Laid-Open No. 63-77736. As shown in FIG. 4, the flexographic printing press discharges ink accumulated between the anilox roll 2 and the doctor roll 3 which are in contact with each other from both ends of the rolls 2 and 3 and receives the ink by an end pan 10 to discharge a pipe 11. And collected into the ink container 21 for reuse.

[0003] The flexographic printing press 20 uses a pump 2 to transfer the ink pulled up from an ink container 21 to a roll 2,
A water supply pipe 22 is connected via an electromagnetic valve 5 to the ink supply pipe 4 for supplying the ink between the rolls 3, 3. By injecting water, the rolls 2 and 3, the end pan 10, the discharge pipe 11, and the ink supply pipe 4 are washed.

At the time of this cleaning, the lower ends of the ink supply pipe 4 and the discharge pipe 11 have already been removed from the ink container 21 and are located above the bucket 23. The used ink is discharged to the bucket 23 and discarded.

The flexographic printing press 20 slides along the rolls 2 and 3 and collects between the rolls 2 and 3 in addition to the ink recovery mechanism and the cleaning mechanism for the rolls 2 and 3 described above. A scraper 14 is provided to scrape the ink that has been collected into the end pan 10, so that the speed of ink recovery and roller cleaning can be increased.

[0006]

The anilox roll 2 and the doctor roll 3 in the flexographic printing machine 20 each have a length of 2500 mm and a diameter of 240 mm, respectively, and are assumed to be flexographic inks of normal viscosity. The amount of ink remaining on the outer peripheral surfaces of these rolls 2 and 3 at the time of ink recovery by color change is about 25 to 30 cc and about 30 to 40 cc, respectively.

[0007] Even if the ink accumulated between the anilox roll 2 and the doctor roll 3 spontaneously flows into the end pan 10 during the color change time of 90 seconds, the remaining ink is: As shown in FIG. 5, when the height H from the contact point of the rolls 2 and 3 to the upper surface of the ink is H, H =
The remaining amount of the ink is about 470 c.
c.

Accordingly, when the amount of ink remaining on the outer peripheral surface of each of the rolls 2 and 3 is combined with 525 to 540 cc
About 525 to 540 g of ink will be discarded together with the washing water, resulting in ink loss. This ink loss increases as the viscosity of the ink increases.

When the ink is collected by scraping out the ink with the scraper 14, the ink can be recovered and removed completely, although it can be considerably improved, and an ink loss of about 150 cc (about 150 g) occurs.

[0010] As described above, in the conventional ink recovery in a printing machine, at least 150 cc for each color change.
As ink loss occurs, the trend of low-volume, high-mix production is increasing, and color change is frequently performed along with the replacement of printing plates. At present, considerable ink loss occurs per day, and printing costs increase. There was a problem.

Further, since a large amount of ink is discharged together with the washing water, there is a problem in that pollution is caused, and the cost for an apparatus for performing waste liquid treatment is increased.

It is therefore an object of the present invention to remarkably reduce ink loss, prevent pollution, and reduce wastewater treatment equipment and costs by recovering ink more efficiently.

[0013]

In order to solve the above-mentioned problems, the present invention provides a means for supplying a diluting liquid between locks prior to cleaning of a roll by a cleaning mechanism, and using the diluting liquid from the supplying means. The ink was removed from the roll surface and collected by a collection mechanism, and the amount of the diluent from the supply means was regulated by a measuring unit so that the collected ink had a reusable concentration.

In the printing press according to the present invention, the ink on the roll surface is removed and recovered by the diluent from the supply means, and the amount of the diluent from the supply means can be reused by the recovered ink. Since the ink density is regulated to be as low as possible, ink loss is significantly reduced as compared with the conventional ink recovery by spontaneous outflow or scraping out of a scraper.

Further, if a scraper is provided which slides along the rolls to scrape out the ink or diluent accumulated between the rolls, the ink can be collected more quickly.

Further, the supply means is provided with a measuring section for regulating the supply amount of the diluent and a plurality of supply ports.

On the other hand, as a method for collecting ink, ink collected between rolls that stop while being in contact with each other is collected, and then, while rotating the rolls with each other, ink is transferred between the rolls from the surface of each roll. The diluent to be removed is
The removed ink was supplied in such an amount that it could be reused when the ink was collected, and thereafter, the diluted ink that had been removed and accumulated between the rolls was collected.

In the ink recovery method according to the present invention, after the ink between the rolls is recovered by the scraper, the remaining ink on the roll surface may be recovered by removing the remaining ink with a diluent while rotating the rolls. Since the concentration of the diluting liquid is adjusted so that the collected ink can be reused, ink loss can be reduced as compared with the related art by the two-stage collection.

Incidentally, the diluting liquid mentioned here may be an aqueous liquid or an organic solvent. In short, any liquid that can dilute each ink according to various types of inks may be used.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a printing press and an ink collecting method according to the present invention will be described with reference to the accompanying drawings.

The flexographic printing press 1 shown in FIG. 1 has an anilox roll 2 and a doctor roll 3 which are in contact with each other,
An ink supply pipe 4 for supplying ink between the rolls 2 and 3 and a water supply pipe 6 connected to the ink supply pipe 4 via a solenoid valve 5 are provided.

Anilox roll 2 and doctor roll 3
Are driven by one end and rotated in contact with each other. For this reason, the flexographic printing press 1 has no drive mechanism on the other end side of the rolls 2 and 3, so that the operator can easily perform a predetermined operation such as replacement of the ink container.

In addition, below the anilox roll 2,
A printing cylinder 8 that supports the printing plate 7 in a roll shape so as to be in contact with the anilox roll 2 is provided.

As shown in FIGS. 1 and 2, the ink supply pipe 4 has a tip located above the rolls 2 and 3, and the ink sucked up by the pump 9 from the ink container is supplied to the rolls 2 and 3.
Supply between. A pair of end pans 10 are provided at both ends of the rolls 2 and 3 for receiving the ink supplied from the ink supply pipe 4 when the ink overflows. A discharge pipe 11 detachably connected to the ink container is connected to the end pan 10, and the ink in the end pan 10 is returned to the ink container through the discharge pipe 11.

The water supply pipe 6 is connected to a water source (not shown), and a measuring unit 12 for measuring and storing the water from the water source is provided at the tip. The measuring unit 12 is connected to a supply pipe 13 having supply ports opened at five locations above the rolls 2 and 3.

The measuring unit 12 accumulates a predetermined amount (200 cc) of water solution as a diluting liquid therein, and discharges the accumulated water solution to the supply pipe 13 in accordance with an instruction from a timing sequencer (not shown). . Then, a predetermined amount of the water liquid which has flowed out is sequentially dropped between the rolls 2 and 3 rotating at a low speed from the supply port of the supply pipe 13 to dilute the ink on the surfaces of the rolls 2 and 3.

As shown in FIGS. 1 and 2, between the anilox roll 2 and the doctor roll 3, a pointed urethane scraper 14 is located along the outer peripheral surfaces of the rolls 2 and 3. And this scraper 14
Is a flat belt 15 along the length direction of the rolls 2 and 3
Attached to. Both ends of the flat belt 15 are attached to the rotation shafts of a pair of drive motors 16, and the scraper 14 is slid along the rolls 2 and 3 by being wound by the drive motor 16. The drive motor 16 is fixed to a pair of vertically movable frames 17, respectively, and the frame 17 moves up and down, thereby causing the scraper 14 to
3 to be moved up and down to be detached.

In the flexographic printing press 1, ink is constantly supplied from the ink supply pipe 4 between the anilox roll 2 and the doctor roll 3 during a printing operation. The supplied ink is uniformly attached to the anilox roll 2 by the doctor roll 3 rotating in the opposite direction at a speed slightly lower than the rotation speed of the anilox roll 2,
Transfer from the surface of the anilox roll 2 to the printing plate 7 of the printing cylinder 8 rotating in the opposite direction at the same speed as the roll 2. Then, a predetermined printing is performed by the corrugated cardboard sheet contacting the printing plate 7 to which the ink has been transferred while traveling. During this printing operation, the scraper 14 is located above the drive-side ends of the rolls 2 and 3 in a state where the scrapers 14 are always separated from the rolls 2 and 3 by the raising of the frame 17. In addition, during the printing operation, the ink is applied to rolls 2, 3
When the ink overflows from both ends, the overflowed ink is returned from the end pan 10 through the discharge pipe 11 to the ink container, and is again used for printing.

On the other hand, when it is necessary to perform color change to the next ink after a certain printing operation is completed, the ink adhered to the rolls 2 and 3 is collected in the manner shown in the flowchart of FIG. A series of operations in the flexographic printing press 1 necessary for this collection are controlled centrally by a timing sequencer.

At the time of color change, the anilox roll 2 is in a state of free rotation, and the doctor roll 3 is in a state of being driven and rotated at a much lower speed than in the printing operation. Therefore, anilox roll 2 is replaced by doctor roll 3
The rotation at a low speed is caused by the contact with the object.

First, when the timing sequencer is instructed to collect ink by color change (S ₁ ), the timing sequencer stops the doctor roll 3 and the anilox roll 2 (S ₂ ). Then, the scraper 14 is lowered by moving the frame 17 downward (S ₃ ), and the scraper 14 is pressed against the outer peripheral surfaces of the drive-side ends of the rolls 2 and 3 without any gap.

Next, while the scraper 14 is pressed against the rolls 2 and 3, the rolls 2 and 3 are slid from the right driving side (DR) in FIG. 1 to the left operating side (OP) (S ₄ ). Stop at the end on the operation side of 2, 3 (S
₅ ) Apply ink collected between rolls 2 and 3 to end pan 1
Scrape to zero. The scraped ink is collected from the end pan 10 through the discharge pipe 11 into the ink container.
Then, the scraper 14 is raised by moving the frame 17 upward (S ₆ ) to separate the scraper 14 from the rolls 2 and 3.

Thereafter, while the doctor roll 3 and the anilox roll 2 are rotated at a low speed (S ₇ ), 200 c is passed from the measuring unit 12 through the plurality of supply ports of the supply pipe 13.
The liquid c is dropped between the rolls 2 and 3 (S ₈ ) to remove the ink from the surfaces of the rolls 2 and 3. The removed ink is diluted with the drip water solution and accumulated between the rolls 2 and 3. At the same time, the scraper 14 is moved from the operation side to the drive side while being separated from the rolls 2 and 3 (S ₉ ) and stopped above the drive side end of the rolls 2 and 3 (S ₁₀ ).

Since a predetermined amount of water is dropped from a plurality of supply ports of the supply pipe 13, the water is supplied uniformly and quickly over the entire width of the rolls 2 and 3, so that the ink is supplied to the rolls 2 and 3. It is efficiently removed from the outer peripheral surface in a short time.

Then, after stopping the doctor roll 3 (S ₁₁ ), the frame 17 is moved downward, and the scraper 14 is pressed again against the outer peripheral surface of the drive side end of the rolls 2 and 3 (S ₁₂ ). The scraper 14 is slid again from the drive side end of the rolls 2 and 3 to the operation side end (S ₁₃ ), and the ink diluted with the water liquid accumulated between the rolls 2 and 3 is scraped out to the end pan 10. Roll scraper 14 with rolls 2, 3
Stopped at the operation side end section (S _14). The diluted ink is collected from the end pan 10 through the discharge pipe 11 into the ink container during the supply of the liquid solution by drip and the scraping by the scraper 14. At this time, the end pan 10 and the discharge pipe 1
The ink adhering to the inner surface of the ink cartridge 1 is also removed and recovered by the water at the same time, so that the amount of recovered ink increases, and when the ink is replaced with the next color ink, the colors of the ink are not mixed, which is convenient.

Since the scraper 14 is slid from the driving side to the operating side to recover the diluted ink, in the embodiment of FIG. 1, most of the recovered diluted ink passes through the long discharge pipe 11. No collection time is required.

The amount of the water solution to be dropped depends on the type and viscosity of the ink, the size of the rolls 2 and 3, and the like.
When the ink on the surfaces of the rolls 2 and 3 and the discharge pipe 11 is removed and collected, the concentration of the collected ink is specified so that the ink can be reused in the ink container. There is no problem to return. In this way, after the remaining ink is almost exhausted, the scraper 14 is raised again by moving the frame 17 upward (S ₁₅ ), and the doctor roll 3 and the anilox roll 2 are rotated to shift to the cleaning step. (S _16).
At the same time, moves the scraper 14 is raised from the operating side to the drive side (S _17), is stopped at the driving end above the rolls 2,3 (S _18), ready for the next operation.

In the cleaning step, the electromagnetic valve 5 is opened while the rolls 2 and 3 are rotating, and a large amount of aqueous liquid is supplied from the water supply pipe 6 to the ink supply pipe 4 as a cleaning liquid. 2, 3, the end pan 10 and the discharge pipe 11 are washed. At this time, the lower ends of the ink supply pipe 4 and the discharge pipe 11 are detached from the ink container and located above the bucket. After the water liquid used for washing is discharged to the bucket, it is disposed. Will be done.

The ink may be collected by supplying a predetermined amount of water liquid twice in drops. In this case, while the water liquid is being supplied by drip in (S ₈ ), the scraper 14 is moved to (S ₉ ) while the scraper is raised in (S ₆ ).
Instead of moving the scraper 14 from the operation side (OP) to the drive side (DR), the ink is recovered for the first time by lowering and moving the scraper 14 once, and the water liquid is again supplied by instillation similarly. Thereafter, the second ink collection may be performed by using the movement of the scraper 14 from the drive side to the operation side.

At this time, the scraper 14 is raised while the doctor roll 3 and the anilox roll 2 are rotating,
It is lowered during ink collection by sliding.

When the effects of the flexographic printing press 1 according to the present invention were tested using the rolls 2 and 3 under the conditions described in the above section, the effects of the rolls 2 and 3 were determined. Almost all the ink adhering to the surface and the inner surface of the end pan 10 and the discharge pipe 11 could be recovered, and the ink loss could be reduced to almost zero.

Therefore, when the amount of cost reduction per month is calculated under the following conditions, the following is obtained. 1. Conditions (1) A three-color flexographic printing press equipped with three units shown in FIG. 1 and capable of simultaneously printing up to three colors is used. (2) The average number of printing colors required for a corrugated cardboard sheet per customer order is 1.7 colors. (3) The frequency of different printings per day, that is, the number of color changes is 30 times. (4) The operating day per month is 22 days. (5) Ink loss per day in a conventional flexographic printing machine (described in the column of [Problems to be Solved by the Invention]) When no scraper is used: about 540 g When a scraper is used: about 150 g Cost reduction (ink unit price is 710 yen / kg) (1) In comparison with a conventional flexographic printing press that does not use a scraper 1.7 (color / time) x 30 (times) x 0.54 ( kg) x 7
10 (yen / kg) × 22 (day / month) ≒ 43 (10,000 yen) (2) In comparison with a conventional flexographic printing press using a scraper 1.7 (color / times) × 30 (times) × 0 .15 (kg) x 7
10 (yen / kg) x 22 (day / month) ≒ 12 (10,000 yen).

Further, since the flexographic printing press 1 has almost no remaining amount of ink, it is possible to reduce the amount of the water used for cleaning in the cleaning step and the cleaning time. From this point, the cost can be reduced.

In this embodiment, the water liquid as the cleaning liquid and the water liquid as the diluting liquid are supplied from the same water supply pipe. However, separate liquid supply mechanisms are provided for each, and the cleaning liquid and the cleaning liquid are independently supplied to each other. A diluent may be supplied.

The ink collected between the rolls 2 and 3 or the diluted ink is collected not only by the scraper 14 but also by a blower tube having a blower section directed downward above the rolls 2 and 3. Arbitrary means can be used, such as a method of discharging ink by wind pressure from a blowing port, a method of providing a negative pressure mechanism in the discharge pipe 11 and discharging ink using the suction force.

[0046]

According to the present invention, there is provided a printing press and a method for recovering ink.
With the above-described configuration, the ink loss can be significantly reduced as compared with the related art, so that it is possible to greatly contribute to the reduction of the printing cost.

Further, it is possible to prevent pollution caused by the waste liquid and reduce the cost and the equipment for treating the waste liquid.

Further, when ink is collected by providing a scraper, the efficiency of ink collection is further improved.

When the supply means for the diluting liquid has a plurality of supply ports, the ink can be efficiently collected in a short time.

[Brief description of the drawings]

FIG. 1 is a perspective view of a main part showing an embodiment of a flexographic printing press according to the present invention.

FIG. 2 is a side view of the roller portion from its end surface.

FIG. 3 is a flowchart showing an ink recovery method of the present invention.

FIG. 4 is a perspective view of a conventional flexographic printing press.

FIG. 5 is a side view showing the remaining amount of ink.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Flexo printing machine 2 Anilox roll 3 Doctor roll 4 Ink supply pipe 5 Solenoid valve 6,22 Water supply pipe 7 Printing plate 8 Printing cylinder 9 Pump 10 End pan 11 Discharge pipe 12 Measuring unit 13 Supply pipe 14 Scraper 15 Flat belt 16 Drive motor 17 Frame 20 Conventional flexographic printing press 21, 21 'Ink container 23 Bucket

Continuation of the front page (72) Inventor Yukihiro Noto 2-15-28 Moundoshima, Nishiyodogawa-ku, Osaka-shi Inside Hamada Printing Machinery Co., Ltd. (72) Inventor Minori Ueno 2-15-28 Miganda, Nishiyodogawa-ku, Osaka-city Hamada Printing (56) References JP-A-7-214042 (JP, A) JP-A-6-286121 (JP, A) JP-A-7-89052 (JP, A) (58) Fields investigated (Int .Cl. ⁶ , DB name) B41F 31/02 B41F 31/20 B41F 35/04

Claims (5)

(57) [Claims] 1. A printing press provided with a collecting mechanism for collecting ink accumulated between a pair of rolls adjacent to each other and a washing mechanism for washing the rolls, wherein a diluting liquid is applied between the rolls prior to the washing of the rolls. Means for supplying to the
The ink is removed from the roll surface with the diluent from the supply means and is recovered by the recovery mechanism, and the amount of the diluent from the supply means is adjusted so that the recovered ink has a reusable concentration. A printing press characterized by the measuring unit . 2. The printing press according to claim 1, further comprising a scraper that slides along the roll to scrape ink or diluted ink accumulated between the rolls. 3. The printing press according to claim 1 , wherein the supply unit includes a plurality of supply ports . 4. A method for recovering ink collected between rolls which stop in contact with each other, and thereafter, while rotating each roll, a diluting liquid for removing ink from the surface of each roll is provided between the rolls. A method for recovering ink, in which the removed ink is supplied in such an amount as to have a reusable concentration when the ink is collected, and thereafter, the ink which has been removed and diluted to a reusable concentration accumulated between the rolls is collected. 5. The ink recovery method according to claim 4, wherein the ink accumulated between the rolls or the diluted ink is recovered by sliding a scraper along the rolls.