JPH06218908A - Printing machine for corrugated cardboard - Google Patents

Abstract

PURPOSE:To execute a plurality of colours printing at the same time by a pair of printing cylinders by a migration supply of ink only to a part on a letterpress form plate for printing where a necessity arises through a contact of a plurality pieces of transfer cylinders on which a form plate for an ink transfer is wound with the letter press form plate for printing. CONSTITUTION:On a periphery of a printing cylinder 2 on which a letterpress form plate 1 for printing is wound, there are provided with plural pairs of transfer cylinders 4 on which an ink transfer form plate 3 is mounted, the ink transfer form plate 3 having a projected portion of a symmetrically opposed shape and with the same size as, or a little larger than the letterpress form plate 1 for printing. The transfer cylinder 4 is so composed that it can execute a contact or a separation against a surface of the letterpress form plate 1 for printing through a driving means. For example, in an engagement of three pairs of the transfer cylinders 4a to 4c with one pair of the printing cylinder 2, different colors of inks are respectively fed to three pairs of ink migration supply portions and three colors of multicolor printing can be executed. Ink 8 which is fed to the ink transfer form plate 3 that executes winding engagements from anilox rollers 5 to the transfer cylinders 4, is transferred to the letterpress form plate 1 for printing, and then is transferred to a sheet of a corrugated board 11 which is running in synchronism state between receiving rollers.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a corrugated board printing machine equipped with a corrugated board box making machine or the like for printing on corrugated board using water-based ink.

[0002]

2. Description of the Related Art A conventional flexographic printing machine for printing using a water-based ink is an ink formed by combining a pair of ink rolls, an anilox roll 5 and a rubber roll 6, as shown in FIG. The flexo ink 8 is supplied to the reservoir, and the ink is transferred onto the printing relief printing plate 1 for engagement with the anilox roll 5 to perform predetermined printing.

The flexo ink 8 is supplied from the ink container 9 through the ink supply pipe 10 to the nip portion of the ink roll formed by the anilox roll 5 and the rubber roll 6, and is then appropriately doctored by the rubber roll to form the anilox roll 5. It is evenly spread to the peripheral surface, and is further transferred from the anilox roll 5 to the relief printing plate 1 for printing wound around the printing cylinder (plate cylinder) 2. Then the printing plate 1
The ink 8 supplied to the paper is transferred onto the corrugated cardboard sheet 11 that runs in synchronization with the receiving roll 7 located below so that predetermined printing can be performed.

In the figure, reference numerals 12 and 13 denote transport rolls which sandwich the corrugated cardboard sheet 11 and transfer it downstream at a predetermined timing. By the way, the conventional flexographic printing machine is provided with one set of ink supply unit for one set of printing cylinders 2, and when performing multicolor printing, for example, when printing two colors as shown in FIG. 2 (b). It was necessary to install two sets of the flexographic printing machine having different ink colors along the traveling direction of the corrugated board sheet 11. In a conventional flexographic printing machine, when performing such multi-color printing, due to the structure in which a plurality of sets of printing machines are sequentially passed, the accuracy of printing misalignment often deteriorates due to variations in the sheet conveyance timing. It was also difficult to print cosmetically by combining colors by overprinting to produce the desired color. In addition, the structural machine with multiple sets of printing machines installed side by side has become larger,
There was also a drawback that the laying area was wide.

Further, in an offset printing machine for performing multicolor printing, for example, as shown in FIG. 3, ink 14 is applied from an ink supply section to a plate (printing plate) 17 once wound around a plate cylinder 16 through a group of kneading rollers 15. The sheet is supplied, further transferred to the transfer cylinder 18, and then transferred onto the sheet 20 that travels in synchronization with the impression cylinder 19 located below, so that predetermined printing is performed. That is, the ink 14 is supplied to the ink reservoir formed by the doctor blade 21 and the duct roller 22, and then the duct roller 22 is rotated and the calling roller 23 that alternately comes in contact with and separates from the roller 22 and the kneading roller 15 is fed to the kneading roller 15 side. Is appropriately kneaded, and is supplied to the original plate 17 wound around the peripheral surface of the plate cylinder 16 via the inking roller 24. The ink image formed on the original plate 17 is once transferred to the transfer cylinder 18, and printing is performed on the printing paper 20 sent between the transfer cylinder 18 and the impression cylinder 19, and the sheet 20 after printing is discharged. It will be loaded and stacked on the paper table 25.

This type of printing machine can meet cosmetic needs such as cosmetic printing and high printing precision, and can meet the market needs to increase the product value.
The target is 0, and since it is close to solid printing, the composite paper having a corrugated surface such as the corrugated cardboard sheet 11 has a limited pressurization amount in order to prevent the deterioration of the corrugated board strength, and uneven printing occurs and good printing cannot be performed. There are drawbacks. Further, when pressure is applied to the transfer cylinder 18 so as to follow the uneven surface, the corrugated cardboard sheet 11 is crushed and the corrugated cardboard sheet 11 is crushed.
The strength of the product when formed into a box is significantly reduced.
(For these reasons, the printing paper was limited to liner paper, cardboard, and other sheets with a smooth surface.) In addition, this type of offset printing machine uses an aluminum thin plate or the like as the original plate (printing plate) 17, Since the original plate manufacturing cost rises, it is unsuitable for a high-mix low-volume production such as the corrugated board sheet 11.

As described above, the conventional flexographic printing machine and offset printing machine have various problems when used as a corrugated board printing machine. In recent years, in order to increase the commercial value of corrugated cardboard sheet printing, there has been a strong demand for cosmetic printing and improvement of printing accuracy. In order to meet the demand, research on corrugated cardboard printing machines using a new format has become an issue. ing.

[0008]

As described in the section of the prior art, the conventional flexographic printing machine has only one set of ink supply device for the printing cylinder wound with the printing plate. However, in the case of multicolor printing, for example, printing with three colors, it is necessary to arrange three sets of flexographic printing machines having different ink colors in parallel.

Therefore, due to the structure in which the sheets of paper are successively passed through a printing machine having different ink colors, it is difficult to produce high-quality printing such as overprinting due to the occurrence of printing deviations due to variations in the sheet conveying timing. In addition, there is a drawback that the total length of the device and the laying space associated therewith become large. In addition, in the offset printing machine, the printing plate is close to a solid printing plate and it is impossible to uniformly contact the front surface with a corrugated sheet such as a corrugated sheet, so good printing cannot be performed. If the transfer cylinder is excessively contacted with the sheet, the corrugated cardboard sheet itself is crushed and the strength when formed into a box is significantly reduced.

In addition, since the original plate (printing plate) of this type of printing machine is usually made of aluminum and the like, and the manufacturing cost is high, the printing cost is high for a product such as a corrugated cardboard sheet that is produced in a small amount in various kinds. Not suitable. The present invention aims at proposing a new type of corrugated board printing machine to address these problems.

[0011]

The structure of the present invention for achieving the above object will be described with reference to FIG. 1 corresponding to an embodiment. The present invention is a relief printing plate for printing which is engaged with a corrugated cardboard sheet 11. An ink transfer printing plate 3 which is located around a set of printing cylinders 2 on which 1 is wound, has a size substantially the same as the size of the printing plate 1 for printing, and has a projecting part of the opposite hand shape. A plurality of sets 4a, 4b, ... Of the transfer cylinders 4 wound with are arranged so that they can be brought into contact with and separated from the relief printing plate 1 for printing.

[0012]

According to the present invention, a plurality of transfer cylinders, on which the ink transfer printing plate is wound by the above-mentioned means, are brought into contact with and separated from the printing relief printing plate, so that only a necessary portion on the printing relief printing plate is provided. It becomes possible to transfer and supply ink,
Multiple colors can be printed simultaneously with one set of printing cylinders.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. 1. Reference numeral 1 denotes a printing relief printing plate, and the printing relief printing plate 1
Located around the (plate cylinder) 2 on the printing cylinder with the
There are provided a plurality of sets of transfer cylinders 4 to which the ink transfer printing plate 3 having the same size as or slightly larger than the printing plate 1 and having a projection having an opposite hand shape is attached. (The figure shows three sets) The cylinder 4 is driven by a drive means (not shown),
It is constructed so that it can be brought into contact with and separated from the surface of the relief printing plate 1 for printing. Further, an ink supply section constituted by a pair of known anilox rolls 5 and rubber rolls 6 is engaged with the other side of the respective ink transfer printing plates 3.

Reference numeral 7 in the figure provided below the sheet path line is a receiving roll. Based on the above configuration, the function will be described next. The flexo ink (water-based ink) 8 is supplied from the ink container 9 through the ink supply pipe 10 to the nip portion of the ink roll formed by the anilox roll 5 and the rubber roll 6, and then is appropriately doctored by the rubber roll 6 to be anilox. It is evenly spread over the peripheral surface of the roll 5, and is further supplied from the anilox roll 5 to the ink transfer printing plate 3 wound around the cylinder 4. The ink 8 of the ink transfer printing plate 3 is rotatably transferred and then supplied to the printing relief printing plate 1. Subsequently, the ink 8 supplied to the printing relief printing plate 1 for printing is transferred to the corrugated cardboard sheet 11 that runs in synchronization with the receiving roll 7 located below so that predetermined printing can be performed.

In the figure, 12a and 12b are cardboard sheets 11.
It is a conveyance roll that nips and conveys to the downstream at a predetermined timing. In the example of FIG. 1, three sets of transfer cylinders 4 are engaged with one set of printing cylinders 2, but this combination may be two sets, and various other types are possible. In this example, inks of different colors (three primary colors yellow, red, and blue) are loaded in the three sets of ink transfer supply sections.
Multicolor printing is possible. Moreover, if the degree of mixing of the ink 8 is properly adjusted (the amount of ink transfer on the printing plate can be used) and overprinted, all desired colors other than achromatic color can be produced.
Cosmetic printing, which has been in high demand in recent years, is possible. Another feature is a set of printing cylinders 2 and a printing relief printing plate 1.
Since the multi-color printing is performed, the printing deviation due to the timing deviation at the time of transferring the corrugated cardboard sheet 11 is reduced, and the product value can be greatly improved. Furthermore, since it is possible to mix various colors depending on the mixing degree of the three colors, it is not necessary to change the color of each ink roll part, which is conventionally required, and productivity is improved by greatly shortening the set change time. According to this method, it is possible to eliminate the need to change the color of the loss (waste) ink, so that the resources of the ink can be saved and the cost can be significantly reduced. The present invention is not limited to the above embodiments, and various changes can be made without departing from the scope of the present invention.

[0016]

As described above, according to the present invention, it is located around a set of printing cylinders on which a printing relief printing plate that engages with a corrugated cardboard sheet is wound, and is substantially the same as the convex portion of the printing relief printing plate. A plurality of sets of transfer cylinders having the same dimensions and wound with an ink transfer printing plate having convex parts of opposite shapes,
Since it is arranged so that it can be brought into contact with and separated from the relief printing plate for printing, it has the following effects. (1) Even though it is a multi-color printing machine, the apparatus can be made extremely small, and the installation space can be reduced. (2) Since the same relief printing plate as that used in the conventional flexographic printing machine is used, even a composite sheet having a corrugated uneven surface such as a corrugated board sheet can be surely printed without crushing the steps. (3) If the three primary colors of color are separately filled in each of a plurality of sets of ink transfer supply parts, the mixing ratio is appropriately selected (ratio of the amount of ink transfer to the printing plate), and overprinting is performed, all desired You can print in the colors. (4) Productivity can be improved by eliminating the need for color change time. (5) Since one set of printing cylinders performs multicolor printing at the same time, the deviation caused by the sheet conveyance timing is eliminated, and the printing accuracy is greatly improved.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention, in which (a) is a schematic view and (b) is a partially enlarged view.

2A and 2B show a conventional example, in which FIG. 2A is a schematic diagram, and FIG.

FIG. 3 is a schematic view showing another conventional example.

[Explanation of symbols]

 1 Letterpress printing plate for printing 2 Printing cylinder 3 Printing plate for ink transfer 4 Transfer cylinder 11 Corrugated board sheet

Claims (1)

[Claims] 1. A printing cylinder which is engaged with a corrugated cardboard sheet and is positioned around a set of printing cylinders wound around, and has a size substantially the same as that of the convex portion of the printing plate for printing, and the opposite. A corrugated board printing machine, characterized in that a plurality of sets of transfer cylinders around which an ink transfer printing plate having a hand-shaped convex portion is wound are arranged so as to be able to come into contact with and separate from the printing plate printing plate.