JPH10151722A - Gravure printing method and apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gravure printing apparatus capable of using a common gravure cyclinder and unnecessary for performing the production or plate making of the gravure cylinder which takes time at every printing. SOLUTION: A gravure printing apparatus consists of a gravure cylinder 1 having a large number of cells uniformly formed to the surface thereof, an ink filling means 2 filling the gravure cylinder 1 with ink K, an ink removing means 3 removing ink K from the cells of a part of the gravure cylinder 1 filled with ink K corresponding to an image to be printed, a matter-to-be-printed pressing means 4 pressing matter S to be printed to the gravure cylinder 1 after a part of the ink K is removed by the ink removing means 3 to perform printing and an ink recovery means 5 recovering the ink K from the ink removing means 3 to send the same to the ink filling means. Since the ink removing means 3 removes the ink K corresponding to an image to be printed, only a necessary ink image can be left on the gravure cylinder 1 and desired printing can be performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gravure printing apparatus and method for printing using a gravure cylinder having cells (small depressions) for filling ink on the surface.

[0002]

2. Description of the Related Art In conventional gravure printing, a large number of cells are formed on the surface of a metal gravure cylinder having a copper plating on the surface in accordance with an image to be printed, and used as a printing plate. Was. As a method of forming the cell, that is, a plate making method, there are a method by chemical etching and a method by mechanical engraving. When cells are formed on a gravure cylinder according to an image by any of the above methods, printing is performed using this cylinder. In this printing, the cells on the gravure cylinder are filled with ink and pressed against the substrate. Thereby, the ink filled in the cells is transferred to the printing substrate, and printing is performed. This is so-called gravure printing (intaglio printing).

[0003]

In conventional gravure printing, a gravure cylinder must be made each time an image is printed. However, any of the above etching methods and engraving methods can be used to make a gravure cylinder. It was time-consuming and troublesome. There is also a problem that the gravure cylinder is heavy and difficult to handle.

Further, in gravure printing, the cylinder diameter varies depending on the length of an image to be printed. Therefore, when printing images of different lengths, the gravure cylinder itself must also be manufactured before plate making, but the manufacture of gravure cylinders requires a number of plating and polishing steps, and time and It was costly. Also, since chemicals are used in the etching and plating processes,
Careful consideration was needed for the working environment.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and has as its object to provide a gravure printing apparatus and method which do not require the production and plate making of a gravure cylinder for each printing.

[0006]

According to the first aspect of the present invention, there is provided a gravure printing apparatus for performing printing on a printing medium by bringing a printing medium into contact with a gravure cylinder filled with ink in cells formed on the surface. A gravure cylinder having a large number of cells formed uniformly on the surface thereof, and an ink filling means for filling the gravure cylinder cells with ink.
Ink removing means for removing ink from some cells of the gravure cylinder filled with ink by the ink filling means according to an image to be printed, and gravure from which ink has been removed from some cells by the ink removing means And a printing material pressing means for sequentially pressing the printing material against the cylinder to perform printing.

In the gravure printing apparatus according to the first aspect, a gravure cylinder in which cells are uniformly formed on the surface is used in common for any image printing.
Then, the ink is removed from some cells of the gravure cylinder according to the image to be printed. That is, the ink other than the ink left as an image is removed. As a result, only the necessary ink corresponding to the predetermined image remains in the gravure cylinder. A predetermined image can be printed by pressing the printing material against the gravure cylinder. According to this device,
Different gravure printing can be performed using the same gravure cylinder.

According to a second aspect of the present invention, there is provided the gravure printing apparatus according to the first aspect, wherein the ink removing means further comprises a printing plate having an uneven portion formed on a surface according to an image to be printed. Contacting / separating means for contacting and separating the printing plate from / to the gravure cylinder, wherein the ink in the cells adheres to the projections of the printing plate and is removed.

According to a third aspect of the present invention, there is provided the gravure printing apparatus according to the first aspect, wherein the ink removing means has a lipophilic portion or a hydrophilic portion on a surface according to an image to be printed. The formed printing plate, and a contacting / separating means for contacting and separating the printing plate from / to the gravure cylinder, wherein the ink in the cells adheres to the lipophilic portion of the printing plate and is removed. It is characterized by.

According to a fourth aspect of the present invention, there is provided the gravure printing apparatus according to the first aspect, wherein the ink removing means further comprises a printing plate having a perforated surface formed in accordance with an image to be printed. Contacting and separating means for bringing the printing plate into contact with and separating from the gravure cylinder, wherein the ink in the cells adheres to portions other than the perforations of the printing plate and is removed.

In the gravure printing apparatus according to the second to fourth aspects, a printing plate is prepared by letterpress, planographic printing or stencil printing according to the image. Unnecessary ink is removed from the gravure cylinder by the created printing plate. This printing plate can be prepared by the usual method of making a relief plate, planographic plate, or stencil plate, which is much easier than gravure cylinder plate making, and the plate itself is lightweight and easy to handle.

[0012] The invention according to claim 5 is the invention according to claims 2 to 4.
Wherein the printing plate has an endless band shape, and the printing plate is extended and supported by a pair of rollers capable of variably setting a distance interval.

In the gravure printing apparatus according to the fifth aspect, the endless belt-shaped printing plate is stretched and supported between a pair of rollers capable of changing the distance. Therefore, even if the size of the image to be printed is changed, it can be easily coped with only by changing the size of the printing plate.

[0014] The invention according to claim 6 is the invention according to claims 1 to 5.
3. The gravure printing apparatus according to claim 1, further comprising an ink collecting unit that collects the ink removed by the ink removing unit and sends the ink to the ink filling unit.

In the gravure printing apparatus according to the sixth aspect, the ink removed from the gravure cylinder is collected and reused, so that the removed ink is not wasted.

According to a seventh aspect of the present invention, there is provided a gravure printing method in which a gravure cylinder in which cells formed on the surface are filled with ink is brought into contact with a substrate to perform printing on the substrate. An ink filling step of filling a large number of cells uniformly formed with ink, an ink removing step of removing ink from some cells of the gravure cylinder according to an image to be printed, and after the ink removing step, An ink transfer step of pressing the printing material against the gravure cylinder and transferring the ink remaining in the cells of the gravure cylinder to the printing material.

In the gravure printing method according to the present invention, a gravure cylinder having cells uniformly formed on the surface is commonly used for printing any image.
Then, the ink is removed from some cells of the gravure cylinder according to the image to be printed. That is, the ink other than the ink left as an image is removed. As a result, only the necessary ink corresponding to the predetermined image remains in the gravure cylinder. Then, a predetermined image can be printed by pressing the printing material against the gravure cylinder. According to this method, different gravure printing can be performed using the same gravure cylinder.

[0018] The invention according to claim 8 is the gravure printing method according to claim 7, wherein the ink removing step further comprises the step of: removing a printing plate having an uneven portion on a surface according to an image to be printed. By contacting and separating the gravure cylinder, the ink in the cells adheres to the projections of the printing plate and is removed.

According to a ninth aspect of the present invention, there is provided the gravure printing method according to the seventh aspect, wherein the ink removing step further comprises a step of forming a lipophilic portion or a hydrophilic portion on the surface according to an image to be printed. By causing the formed printing plate to contact and separate from the gravure cylinder, the ink in the cells adheres to the lipophilic portion of the printing plate and is removed.

[0020] The invention described in claim 10 is the invention according to claim 7.
The gravure printing method according to the above, further, the ink removing step, by contacting and separating the printing plate having a perforated surface on the gravure cylinder according to the image to be printed, the cell, The ink inside is attached to and removed from portions other than the perforations of the printing plate.

In the gravure printing method according to the eighth to tenth aspects, a printing plate is prepared by letterpress, planographic printing or stencil printing according to the image. Then, unnecessary ink is removed from the gravure cylinder by the created printing plate.
This printing plate can be prepared by a normal letterpress, planographic, or stencil making method, and is much easier than gravure cylinder plate making, and the plate itself is light in weight and easy to handle.

[0022]

FIG. 1 is a schematic view showing a gravure printing apparatus according to one embodiment of the present invention, and FIG. 2 is an explanatory view showing a gravure cylinder used in the present embodiment.
In FIG. 1, the gravure printing apparatus includes a gravure cylinder 1 having a plurality of cells C formed on a surface thereof, an ink filling means 2 for filling the gravure cylinder 1 with an ink K, and an ink K according to an image to be printed. Ink removing means 3 for removing the ink K from a part of the cells C of the gravure cylinder 1 filled with the ink, and the printing medium S is pressed against the gravure cylinder 1 after the ink removing means 3 has removed a part of the ink K. Substrate pressing means 4 for performing printing
And an ink collecting means 5 for collecting the ink K from the ink removing means 3 and sending it to the ink filling means 2.

As shown in FIG. 2, the gravure cylinder 1 is a plate having a cylindrical shape made of copper-plated metal or ceramic.
As shown in a partially enlarged manner in FIG.
Are formed uniformly. The cell C is a fine concave portion having an opening in which the distance between sides facing each other is approximately 10 μm in plan view. The shape of the cell C is not limited to a hexagon, but may be a circle or a square.

The size of a conventional general gravure printing cell is such that the distance between opposing sides is approximately 150 μm at the maximum and the depth is approximately 50 μm when viewed in plan. In the method of the present invention, the density is determined by the number of cells C in which the ink K remains, so that the conventional gravure cell can be changed to, for example, 256 gradations (16 × 16 gradations) by the method of the present invention.
When the size of the cell C of the present invention is expressed as follows, the distance between the sides facing each other is approximately 150 μm / 16,
That is, it is about 10 μm. Also, the depth of cell C is
It is preferable to make it about 10 μ in accordance with this size.

In order to produce the gravure cylinder 1, any of the well-known etching method and engraving method may be adopted as in the case of ordinary gravure plate making. The diameter of the gravure cylinder 1 can take any size regardless of the size of the printed matter, as described later. On the other hand, the axial length of the gravure cylinder 1 needs to be larger than the picture to be printed as a matter of course.

In the gravure printing apparatus, the gravure cylinder 1 is rotatably supported about a cylindrical axis by supporting means (not shown), and is driven to rotate by rotating means (not shown).

The ink filling means 2 stores the ink K,
The gravure cylinder 1 has an ink pan 20 capable of immersing a part of the gravure cylinder 1 in the ink K. That is, the gravure cylinder 1 is rotatably supported at a position where a part thereof is immersed in the ink K stored in the ink pan 20. When the gravure cylinder 1 is rotated in the direction of arrow A in FIG. 1 in this state, the ink K is filled in the cells C on the surface of the gravure cylinder 1. The doctor 21 is provided downstream of the ink filling position in the gravure cylinder 1 so as to be in contact with the gravure cylinder 1 in the axial direction. Is scraped off, and only the cells C are filled with the ink K.

The ink removing means 3 includes an endless belt-shaped relief printing plate 30 on the surface of which an image is formed by projections and depressions, and a pair of rollers 31, 3 for extending and supporting the relief printing plate 30.
Consists of two.

The relief printing plate 30 is a plate made of rubber, ultraviolet curing resin, or the like, and has a concavo-convex negative image obtained by inverting an image to be printed on the printing material S. As the letterpress printing plate 30, the same plate as a normal flexographic printing plate can be used. Therefore, the same method as that used for ordinary flexographic printing plate making may be used for plate making.

In the present embodiment, the relief printing plate 30 that has been made is processed into an endless band and used. However, the plate may be formed on a printing plate substrate that has been formed into an endless band in advance.

The perimeter of the relief printing plate 30 is determined by the size of the image to be printed, and is not directly related to the cylinder diameter of the gravure cylinder 1. That is,
Printing a continuous image on the printing material S by setting the circumference of the letterpress printing plate printing 30 to be the same length as the length of the image to be printed or an integer multiple of the length of the image to be printed. Becomes possible. At this time, since the density is expressed using the cells C uniformly formed on the surface of the gravure cylinder 1, the diameter of the gravure cylinder 1 can be constant regardless of the length of the image to be printed. Therefore, even if the length of the image to be printed is different,
Printing can be performed only by changing the circumference of the relief printing plate 30 without replacing the gravure cylinder 1.

The roller pairs 31 and 32 are provided on the relief printing plate 3.
A roller that extends and supports 0. One roller 31
Is rotated by a rotating means (not shown), and the relief printing plate 30 is configured to rotate in contact with the gravure cylinder 1 at the same peripheral speed as the roller 31 rotates. Accordingly, the rotation of the roller pairs 31 and 32 causes the relief printing plate 30 to sequentially contact and separate from the surface of the gravure cylinder 1.

The other roller 32 is provided with the roller 3
1 is a roller that rotates in accordance with the rotation of the roller 31, and can be moved and arranged in a direction (an arrow B direction in FIG. 1) that comes into contact with or separates from the roller 31. Thus, the relief printing plates 30 having various peripheral lengths can be supported by being stretched with an appropriate tension.

The printing material pressing means 4 comprises an impression cylinder roller 40 which sequentially presses and conveys a printing material S made of a roll-shaped printing paper or a soft sheet material to the gravure cylinder 1 filled with the ink K. The impression cylinder roller 40 is provided so as to be able to contact and separate from the gravure cylinder 1 in accordance with the thickness of the printing material S, and is driven to rotate at the same speed as the gravure cylinder 1.

The ink collecting means 5 has a suction port 50 for sucking the ink K attached on the relief printing plate 30.
The suction port 50 is connected to a vacuum suction means (not shown).

The suction port 50 is provided in the width direction of the relief printing plate 30 so as to remove all the ink K on the relief printing plate 30. The ink K sucked from the suction port 50 is returned to the ink pan 20 via a pipe (not shown). Incidentally, the ink collecting means 5 may be constituted by a hygroscopic member.

Next, the operation of the gravure printing apparatus will be described with reference to FIG. FIG. 3 is an explanatory diagram showing the transition of printing.

Before the printing, the cells C are uniformly formed in the gravure cylinder 1 as shown in FIG. This cell C corresponds to the maximum density cell of a gravure cylinder used for conventional gravure printing.

Next, the gravure cylinder 1 is filled with the ink K by the ink K filling means 2 as shown in FIG.
Is filled. Then, the relief printing plate 30 comes into contact with the gravure cylinder 1 as shown in FIG. At this time, since the relief printing plate 30 has irregularities formed on the surface in accordance with the image, only the projection 30 a is provided on the gravure cylinder 1.
Will come into contact with

When the letterpress printing plate 30 is separated from the gravure cylinder 1 in this state, as shown in FIG.
Is removed. Therefore, if a negative image (an image portion to be printed is formed into the concave portion 30b and a non-image portion is formed into the convex portion 30a) is formed on the relief printing plate 30, only the desired ink image is left on the gravure cylinder 1. be able to.

Finally, as shown in FIG. 4 (e), the substrate S is pressed against the gravure cylinder 1 and then separated from the gravure cylinder 1.
As shown in (f), desired printing can be performed on the printing medium. By repeating this operation sequentially, desired printing can be continuously performed on the printing substrate S.

[Other Embodiments] In the above embodiment, the relief printing plate 30 was used as the ink removing means 3, but a part of the ink K was removed from the gravure cylinder 1 as appropriate according to the image to be printed. If possible, another means may be used.

For example, in place of the relief printing plate 30, a lithographic plate having an image formed by a hydrophilic portion and an oleophilic portion, a stencil having an image formed by perforation, or the like may be used separately.
That is, when these plates are used, the ink K is removed by the lipophilic portion on the lithographic plate and the non-perforated portion on the stencil, so that a portion of the ink K is removed from the gravure cylinder 1 according to the image. Can be.

In addition to the above, for example, it is conceivable to scan the gravure cylinder 1 with a predetermined laser beam to heat the excess ink K and remove it by sublimation. In this case, there is an advantage that it is not necessary to make the letterpress printing plate 30 or the like as described above, but it is necessary to use an ink K and a high-power laser light source that can be removed by sublimation with a laser beam. This is disadvantageous in that the printing speed is reduced because the ink K is sequentially removed by scanning with a laser beam.

[0045]

According to the first aspect of the present invention, a gravure cylinder having uniformly formed cells can be used in common for any image printing. Therefore, it is not necessary to manufacture or make a gravure cylinder which requires time for each printing.

According to the second to fourth aspects of the present invention, the letterpress,
Unnecessary ink can be removed from the gravure cylinder by using a printing plate made of a lithographic plate or a stencil. This printing plate can be prepared by a normal letterpress, planographic, or stencil printing method, which is much easier than plate making with a gravure cylinder, and has an effect that the plate itself is lightweight and easy to handle.

According to the fifth aspect of the present invention, even if the size of an image to be printed is changed, it can be easily dealt with only by replacing the printing plate with one having a different size.

In the invention of claim 6, the ink removed from the gravure cylinder is collected and reused.
The removed ink is not wasted.

According to the seventh aspect of the present invention, a gravure cylinder having cells formed uniformly can be used in common for any image printing. Therefore, it is not necessary to manufacture or make a gravure cylinder which requires time for each printing.

In the invention of claims 8 to 10, unnecessary ink can be removed from the gravure cylinder by using a printing plate made of a relief plate, planographic plate or stencil plate. This printing plate can be prepared by a normal letterpress, planographic, or stencil printing method, which is much easier than plate making with a gravure cylinder, and has an effect that the plate itself is lightweight and easy to handle.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a gravure printing apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic view of a gravure cylinder according to an embodiment of the present invention.

FIG. 3 is an explanatory diagram illustrating an operation of gravure printing using a gravure printing apparatus.

FIG. 4 is an explanatory diagram illustrating an operation of gravure printing using a gravure printing apparatus.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 Gravure cylinder 2 Ink filling means 3 Ink removing means 4 Pressing means for printing material 5 Ink collecting means 30 Printing plate (topographic printing plate) 31, 32 Roller pair C cell S Printing material K ink

Claims (10)

[Claims] 1. A gravure printing apparatus for printing on a printed material by bringing a gravure cylinder filled with ink into cells formed on the surface into contact with the printed material, the gravure having a large number of cells formed uniformly on the surface. A cylinder; an ink filling means for filling the cells of the gravure cylinder with ink; and an ink removing means for removing ink from some cells of the gravure cylinder filled with ink by the ink filling means according to an image to be printed. A gravure printing apparatus comprising: a printing material pressing unit that sequentially presses a printing material onto a gravure cylinder from which ink has been removed from some cells by the ink removing unit to perform printing. 2. The method according to claim 1, wherein the ink removing unit includes: a printing plate having an uneven portion formed on a surface according to an image to be printed; and a contacting / separating unit configured to contact and separate the printing plate with the gravure cylinder. 2. The gravure printing apparatus according to claim 1, wherein the ink in the cells adheres to the projections of the printing plate and is removed. 3. An ink removing unit, comprising: a printing plate having a lipophilic portion or a hydrophilic portion formed on a surface according to an image to be printed; and a printing plate in contact with and separated from the gravure cylinder. The gravure printing apparatus according to claim 1, further comprising contact / separation means, wherein the ink in the cell is removed by attaching to the lipophilic portion of the printing plate. 4. The ink removing means comprises: a printing plate having a perforation formed on a surface according to an image to be printed; and a contacting / separating means for bringing the printing plate into contact with and separating from the gravure cylinder. The gravure printing apparatus according to claim 1, wherein the ink in the cells is removed by attaching to portions other than the perforations of the printing plate. 5. The printing plate has an endless band shape,
The gravure printing apparatus according to any one of claims 2 to 4, wherein the printing plate is extended and supported by a pair of rollers capable of variably setting a distance interval. 6. The gravure printing apparatus according to claim 1, further comprising an ink collecting unit that collects the ink removed by the ink removing unit and sends the ink to the ink filling unit. 7. A gravure printing method in which a gravure cylinder in which cells formed on the surface are filled with ink is brought into contact with a printing material to perform printing on the printing material. An ink filling step of filling the cells with ink; an ink removing step of removing ink from some cells of the gravure cylinder according to an image to be printed; and A gravure printing method, comprising: pressing an ink to transfer the ink remaining in the cells of the gravure cylinder to a printing material. 8. The ink removing step includes: contacting and separating a printing plate having an uneven portion on its surface with respect to the gravure cylinder according to an image to be printed, so that the ink in the cells is The gravure printing method according to claim 7, wherein the gravure printing method is attached to and removed from the convex portions of the printing plate. 9. The method according to claim 9, wherein the ink removing step comprises: contacting and separating a printing plate having a lipophilic portion or a hydrophilic portion formed on a surface thereof in accordance with an image to be printed, from the gravure cylinder; The gravure printing method according to claim 7, wherein the ink inside the printing plate adheres to the lipophilic portion of the printing plate and is removed. 10. The ink removing step comprises: contacting and separating a printing plate having a perforated surface formed in accordance with an image to be printed from the gravure cylinder, so that the ink in the cells is printed. The gravure printing method according to claim 7, wherein the gravure printing method is attached to a portion other than the perforations of the plate and is removed.