JPH056123Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an improvement of an inking device in a gravure printing press.

(Prior art) Gravure printing machines use solvent-based ink, so if the circumference of the plate cylinder exceeds 1000 mm, the ink may dry before it sticks to the paper or flow out of the cells. It is becoming difficult to perform stable printing.

Conventionally, when such unstable printing occurs, that portion is removed as so-called waste paper after printing. Alternatively, printing may be stopped midway and the plate cylinder inspected.

(Problem to be solved by the invention) However, the occurrence of such waste paper is undesirable because it increases costs. It is also inconvenient to stop the rotary press midway through the process, as this further increases the amount of paper waste.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the inking device in the gravure printing press according to the present invention is arranged near the position where the plate cylinder contacts the impression cylinder, An applicator that supplies ink is installed at a position away from the point of contact between the plate cylinder and the impression cylinder in the direction of rotation of the plate cylinder, and a doctor that removes excess ink is installed on the opposite side. The printer adopts a configuration in which a fancier roll is installed inside the ink pan.

(Function) An applicator for supplying ink to the plate cylinder at a position near the position where the plate cylinder contacts the impression cylinder and away from the point of contact between the plate cylinder and the impression cylinder in the direction of rotation of the plate cylinder. Since a doctor for removing excess ink is installed on the opposite side, the ink wetting angle with respect to the plate cylinder becomes large.

Therefore, the plate cylinder is always in contact with a large amount of ink over most of its circumference, except in the vicinity of the position where the plate cylinder contacts the impression cylinder, making it difficult for the plate cylinder to dry out.

Further, since the doctor is also located on the opposite side of the applicator near the position where the plate cylinder contacts the impression cylinder, a large amount of ink adheres to the plate cylinder until just before it reaches the impression cylinder. This also prevents the ink from flowing out of the cells before it is attached to the paper.

Inside the ink pan, a fancier roll rotates and supplies ink to the plate cylinder. This roll allows the ink to fill the cells without creating cavities. Therefore, the ink supply shortage is resolved.

(Example) An example of the present invention will be described based on FIGS. 1 and 2.

In these figures, reference numeral 1 denotes a plate cylinder in one unit of a gravure printing press, and reference numeral 2 denotes an impression cylinder in contact with the plate cylinder. The plate cylinder 1 has a circumferential length of 1000 mm or more.

The continuous paper 3 is sandwiched between the plate cylinder 1 and the impression cylinder 2 and is printed while traveling in one direction.

Reference numeral 4 denotes an ink pan installed under the plate cylinder 1, and ink 5 is partially filled in the ink pan. The ink 5 is constantly circulated between a predetermined tank (not shown).

Near the position where the plate cylinder 1 contacts the impression cylinder 2, an applicator 6 for supplying ink 5 to the plate cylinder 1 is located at a position away from the point of contact between the plate cylinder 1 and the impression cylinder in the direction of rotation of the plate cylinder. A doctor 7 for removing excess ink is also installed on the opposite side.

Therefore, the wetting angle θ of the ink with respect to the plate cylinder 1 is 300 degrees or more in this case.

The applicator 6 has a weir-like tip 8 with a ridge extending along the axial direction of the plate cylinder 1, and is adapted to be supplied with ink from a tank 10 by a pump 9.

The tank 10 is installed below the ink pan 4,
The ink 5 in the ink pan 4 is adapted to fall into the tank 10.

As a result, during printing, the ink 5 is constantly supplied by the pump 9 to the weir-like tip 8 of the applicator 6, and from the ridge it falls onto the surface of the plate cylinder 1 in its length direction and adheres thereto. Become.

Its structure is similar to that of the conventional one, except that the doctor 7 is installed near the contact area between the impression cylinder 2 and the plate cylinder 1, and on the opposite side of the applicator 6, which is installed on the rotating side of the plate cylinder 1. It is similar to that.

Inside the ink pan 4 is a fancier roll 11.
is installed. The fancier roll 11 is installed so as to form a gap A between it and the plate cylinder 1, and is rotated in the opposite direction to the plate cylinder 1 (in the same direction at the point of contact).
driven by.

Further, a guide wall 12 is installed in the ink pan 4 near the finer roll 11 and along its axial direction, and there are gaps B between both ends of the guide wall 12 and the inner surface of the ink pan 4. is formed.

As a result, the ink 5 in the ink pan 4 is
is splashed onto the surface of the plate cylinder 1 by the polisher roll 11. Then, the cells of the plate cylinder 1 are filled without forming any air bubbles. In addition, the guide wall 12
Since the height of the ink surface in the ink pan 4 in contact with the fannisher roll 11 is kept substantially constant, the amount of ink supplied to the plate cylinder 1 by the fannisher roll 11 is kept constant.

During the rotation of the plate cylinder 1, the ink 5 falls from the weir-like tip 8 of the applicator 6 onto the surface of the plate cylinder 1, and is further supplied at the fannisher roll 11, so that the ink enters the cells. is well filled.

Thereafter, the excess ink is scraped off by the doctor 7, and the ink is immediately transferred onto the paper 3.

(Effects of the invention) As described above, the present invention is capable of injecting ink near the position where the plate cylinder contacts the impression cylinder, and at a position away from the contact point of the plate cylinder and the impression cylinder in the rotational direction with respect to the plate cylinder. Since an applicator for supplying ink and a doctor for removing excess ink are installed on the opposite side, it is possible to increase the wetting angle of the ink on the plate cylinder. Therefore, the plate cylinder is always in contact with a large amount of ink over most of its circumference, except in the vicinity of the position where the plate cylinder contacts the impression cylinder, making it difficult for the plate cylinder to dry out.

Furthermore, since the doctor is also located near the position where the plate cylinder contacts the impression cylinder, a large amount of ink adheres to the plate cylinder until just before it reaches the impression cylinder. Therefore, the situation where the ink flows out from the cell before it adheres to the paper is also avoided.
In combination with the above-mentioned difficulty in drying out, it is possible to always perform proper printing even if the diameter of the plate cylinder is large.

Further, in the ink pan, the finesse roll rotates and supplies ink to the plate cylinder, so ink can be filled into the cells without creating bubbles, and insufficient ink supply can be more effectively prevented.

[Brief explanation of the drawing]

1 and 2 show an embodiment of an inking device for a gravure printing press according to the present invention, with FIG. 1 being a partially cutaway side view of one unit thereof, and FIG. 2 being a plan view. 1... Plate cylinder, 2... Impression cylinder, 3... Paper, 4... Ink pan, 5... Ink, 6... Applicator,
7...Doctor, 11...Furnisher roll, 1
2...Guidance wall.

Claims (1)

[Scope of utility model registration request] An applicator for supplying ink is placed near the point of contact between the plate cylinder and the impression cylinder, and an applicator is provided for supplying ink at a position remote from the contact point in the direction of rotation of the plate cylinder, and an extra applicator is placed at a position opposite to this point. An inking device for a gravure printing press, characterized in that a doctor for removing ink is installed, and a finer roll is installed in an ink pan below the applicator.