JP2593653B2 - Plate fogging prevention device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Object of the Invention) [Field of Industrial Application] The present invention relates to an apparatus for drying excess ink on a plate cylinder surface of a gravure printing machine to prevent plate fogging.

[Prior Art] When gravure printing is performed using ink that is likely to cause plate fogging, as shown in FIG. 5, first, the ink on the surface of the plate cylinder 51 is scraped off with a doctor blade 52, and then a blowing tube 53 is used. By blowing a small breeze over the entire plate surface, and drying the fogging ink slightly remaining on the plate surface except for the cell part (pattern part).
Was transferred to the printed matter and caused a plate fogging phenomenon.

In such an apparatus, a safety bar 55 is provided in front of a contact portion between the plate cylinder 51 and the impression cylinder 54 to ensure safety.

Further, when a heat-sensitive ink is used, when printing by heating the ink, the ink surface is cooled in the plate cell (pattern portion) and ink transfer failure is likely to occur, so that printing may not be performed. At present, the wax-like heated ink is printed by heating the ink and the cylinder, but it is in a state where cooling of the surface of the picture portion on the plate cannot be completely prevented.

[Problems to be Solved by the Invention] However, the safety bar in the middle of the air passage obstructs the air flow.
In addition, the ink was dried due to the air, and printing defects were likely to occur due to drying of the plate. In addition, the airflow cannot be increased in order to prevent further drying of the plate in the cell part, and it is not possible to prevent plate fogging more aggressively in order to completely dry the plate fogging portion. There was a problem that the safety bar hindered the ventilation.

Further, in the case of using the heat-sensitive molten ink, if the air is blown over the entire surface of the plate, it is cooled down to the picture portion on the plate, which may result in poor ink transfer and a situation where printing cannot be performed.

Therefore, the present invention eliminates the need for the installation of a safety bar by making the role of the safety bar obstructing the air blowing to the plate surface blowing unit, and when using a normal printing ink, only the plate fogging portion By reliably and efficiently drying, there is no plate fogging, and a good printed matter is obtained, and when a thermal ink is used, the pattern portion is exposed to hot air, contrary to the above, and the non-pattern portion is removed. In this method, the wind is stopped to prevent the transfer of the stained portion and prevent the plate from fogging.

(Constitution of the Invention) [Means for Solving the Problems] The present invention provides a plate cylinder in which a safety bar is removed between a doctor blade and an impression cylinder at a mounting position of a safety bar of a conventional gravure printing press. An air blower tube with an air blower nozzle attached to the end of the plate is provided at the end of the plate.A pattern detector is provided on the plate cylinder to detect the pattern on the plate cylinder surface, and air is blown by a signal from the detector. It is configured to control the air flow from the pipe.

[Operation] The plate surface blowing unit is located at the position of the safety bar, and reliably blows the plate surface while also serving as the safety bar. In addition, when using normal ink, it is detected that the pattern portion of the plate body surface having the pattern portion and the plate fogging portion has reached below the air blowing nozzle, and the blowing of the plate blowing portion is stopped, and the plate fogging portion is stopped. When is below the air blowing nozzle, activate the plate surface blowing unit to blow air to the plate fogging unit, dry the ink on the surface, and when using heat-sensitive melting ink, the reverse timing to the above, that is, the pattern Hot air is applied to the portion to improve the ink transfer property, and hot air is stopped and cooled to the non-pattern portion, thereby preventing the transfer of the ink stained portion.

Embodiment An embodiment of the present invention will be described with reference to FIGS. 1 to 4.

In the gravure printing press, the plate cylinder 1 and the impression cylinder 2 are pressed against each other, and a print (paper) 3 is passed between the two cylinders to perform printing.

In FIG. 2, the plate cylinder 1 is rotating clockwise, and around the rotational circumference of the plate cylinder 1, the ink pan 4, the doctor blade 6 and the conventional safety bar 55 (see FIG. 5). Are arranged.

The plate cylinder 1 for the thermal transfer material has a feature that only a part of the plate has a pattern, and as shown in FIG. 3, a cell portion (pattern portion) 8 composed of an intaglio plate and a plate cover portion (pattern portion). 9). The plate cylinder 1 rotates, passes through the ink 5 in the ink pan 4, and adheres ink to the plate surface. Next, the doctor blade 6 is brought into contact with the plate surface to scrape off excess ink on the plate surface.

Further, air is sent from the plate surface blowing unit 7 to the plate surface, the fine ink remaining in the plate cover unit 9 is dried, and the pattern of the pattern unit 8 is pressed onto the printed matter (paper) 3 pressed by the impression cylinder 2. Print.

On the chuck portion of the plate cylinder 1, a picture detection unit 10 is provided. The pattern detection unit 10 includes an A detection unit 11 and a B detection unit 12 on the circumference.
Are slidably provided, and the A detection unit 11 and the B detection unit 12 are slid crosswise in accordance with the length of the picture portion 8 on the plate cylinder 1 to make the length of the picture portion 8. Thus, the detection unit 10
It can be set regardless of the circumference of the plate cylinder 1. The pattern detection may be performed by using the pattern reflected light without attaching the pattern detection unit 10 to the plate cylinder, or another appropriate means may be used.

The plate surface blowing unit 7 is provided between the doctor blade 6 and the impression cylinder 2 and at a position where the conventional safety bar is installed, and opens to the air blowing tube 13 and its end to the entire width of the plate cylinder 1. It is formed by an air blowing nozzle 14. A solenoid valve 15 is attached to the air blow pipe 13, and the solenoid valve 15 opens and closes based on a signal from a sensor 16. The sensor 16 may be of any type, such as a photoelectric type, a proximity type, etc.
The opening / closing of the solenoid valve 15 is controlled by a signal from the controller. That is, when using normal ink, the solenoid valve 15 is closed by a signal (detected during the interval between both sides formed by the A detection unit 11 and the B detection unit 12) that detects the pattern position, and the air blowing is stopped. During the rest, the electromagnetic valve 15 is opened to blow air to the air blowing nozzle 14.

In the case where the heat-sensitive ink is used, hot air is blown at a timing opposite to the above.

Note that the picture detection unit may be attached to only one unit, and the other units may detect the rotation angle of the plate cylinder and perform the blowing control.

[Effects of the Invention] According to the first aspect of the present invention, the plate surface blowing unit also serves as a safety bar of a conventional printing press, secures secure safety with a small number of components, and improves work efficiency. I do.

According to the second aspect of the present invention, the following effects are obtained in addition to the above effects.

In other words, the plate fogging portion and the pattern portion on the plate body surface are distinguished from each other, and the air is intermittently blown to the plate surface. No printed matter is obtained, and there is no fear of drying of the plate in the picture area. Therefore, it is possible to intensify the air flow and completely dry the fogging ink in the plate fogging part. The fogging that has occurred once can be reliably prevented.

Further, in the case of using the heat-sensitive molten ink, a good result can be obtained by detecting the picture portion and blowing the hot air at the opposite timing to the above.

[Brief description of the drawings]

FIG. 1 is a perspective view of the plate fogging prevention device of the present invention mounted on a plate cylinder, FIG. 2 is an explanatory view of a gravure printing machine, FIG. 3 is a perspective view of the plate cylinder, and FIG. FIG. 5 is an explanatory view of a conventional gravure printing machine. 1 ... plate cylinder, 2 ... impression cylinder, 6 ... doctor blade, 7
… Plate blower section, 8… Picture section, 9… Plate cover section, 10
…… Pattern detector, 11, 12 …… Detector, 13… Blower tube, 14
…… Blower nozzle, 15 …… Solenoid valve, 16 …… Sensor.

Claims (2)

(57) [Claims] 1. A safety bar between a pressure cylinder and a doctor blade in a gravure printing press having a plate cylinder, an impression cylinder in contact with the plate cylinder and a doctor blade, and a safety bar between the impression cylinder and the doctor blade. A plate fogging prevention device characterized in that a plate surface blowing unit comprising an air blower tube having an air blowing nozzle at the tip thereof is provided in place of a safety bar at a position where the plate is to be mounted. 2. A pattern detection unit is provided on the plate cylinder, and the air blowing control for the plate surface blowing unit detects the pattern position of the plate cylinder by the pattern detection unit, and controls the opening and closing of the air blower tube based on the detection signal. 2. The plate fogging prevention device according to claim 1, wherein air is intermittently blown to the plate cylinder.