JP2002019083A - Printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To print in high quality without unevenness in an ink. SOLUTION: An opposite contact position A of a smoothing roller 10 having ink repellency on a surface with a plate cylinder 1 is disposed at a downstream side of a rotating direction of the cylinder 1 from an opposite contact position B of the cylinder 1 with a rubber cylinder 11. Simultaneously, the position A is disposed at an upstream side of the rotation direction of the cylinder 1 from the position B of a form roller 5 with the cylinder 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing press provided with a smoothing roller for smoothing an ink film on a rotating body such as a plate by bringing the rotating body into contact with the body and pressing the rotating body.

[0002]

2. Description of the Related Art Conventionally, this type of printing machine has been disclosed in
There is one disclosed in Japanese Patent Application Publication No. 1-91078. What is disclosed herein includes a plate cylinder, an inking roller which is in contact with the plate cylinder and transfers ink to the plate cylinder, and a smoothing roller which is in contact with the plate cylinder. The contact position with the plate cylinder is positioned downstream of the contact position between the ink forming roller and the plate cylinder in the rotational direction of the plate cylinder. The publication also discloses a method in which a smoothing roller is brought into contact with an inking roller to smooth the ink on the inking roller, thereby indirectly making the ink film thickness uniform on the plate surface. I have.

[0003]

In actual printing, the ink layer transferred from the ink forming roller as the first rotating body transfers to the ink transfer target from the plate cylinder as the second rotating body. At this time, division, that is, cohesive failure occurs, and fine protrusions called filaments are formed on the surface of the ink remaining on the second rotating body after the ink transfer, and as a result, the ink surface on the second rotating body becomes uneven. Will occur. Even if the ink is transferred from the first rotating body to the ink surface where the unevenness has occurred, the adhesion to the image portion is poor, and the unevenness occurs in the transfer, so that a high quality printed matter cannot be obtained. Of the above-mentioned conventional printing presses, in the former case,
After the ink is completely supplied to the image area of the plate and the image shape is formed, pressure is applied by the smoothing roller. Adhesion to the part is poor, and uneven transfer occurs, and high-quality printing cannot be obtained even when pressure is applied by a smoothing roller in this state. Also, as in the latter case, even if the surface of the inking roller is pressed with a smoothing roller, unevenness due to cohesive failure occurs on the ink surface on the plate surface, resulting in poor adhesion to the image area and uneven transfer. And high quality printed matter cannot be obtained.

[0004] The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide a printing machine capable of performing high-quality printing without unevenness in ink.

[0005]

In order to achieve this object, an invention according to claim 1 includes a first rotating body and a first rotating body.
A second rotating body which is in contact with the first rotating body and which is in contact with the first rotating body, and an ink transfer in which ink is transferred from the second rotating body which is in contact with the second rotating body. In a printing press provided with an object and a smoothing roller which is in contact with the second rotating body, the smoothing roller has a surface having ink repulsion, and the smoothing roller and the second rotating member are provided. The contact position between the first rotating member and the first rotating member is set on the downstream side of the contact position between the second rotating member and the ink transfer target in the rotation direction of the second rotating member. The second rotating body is positioned on the upstream side in the rotation direction of the second rotating body with respect to the contact position with the second rotating body. Therefore, before the second rotator comes into contact with the first rotator, the ink film on the second rotator is smoothed, so that the ink adheres from the first rotator to the second rotator. It is transferred with good uniformity. Further, when the ink portion of the second rotating body passes through the smoothing roller and the ink separates from the surface of the smoothing roller, the interface separation between the ink surface and the roller surface occurs instead of the cohesive failure of the ink layer. Ink does not transfer to the smoothing roller.

According to a second aspect of the present invention, in the first aspect of the present invention, the first rotating body is an inking roller and the second rotating body is a plate cylinder. Therefore,
The ink film on the plate cylinder is leveled, and the ink is transferred from the inking roller to the plate cylinder with good adhesion and without unevenness.

According to a third aspect of the present invention, in the first aspect, the first rotating body is a plate cylinder and the second rotating body is a blanket cylinder. Accordingly, the ink film on the blanket cylinder is leveled, and the ink is transferred from the plate cylinder to the blanket cylinder with good adhesion and without unevenness.

According to a fourth aspect of the present invention, in the first aspect of the invention, the surface of the smoothing roller also has water repellency. Accordingly, the ink film and the water film on the second rotating body are smoothed, and the separation of the ink in the image area and the dampening solution in the non-image area is ensured. The ink is transferred to the non-image area uniformly with good adhesion and a uniform water film is formed on the non-image area.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side view showing an arrangement of cylinders in a printing press according to the present invention. Note that, for convenience, the smoothing roller 10 is hatched. In the figure, 1
Denotes a plate cylinder as a second rotating body having a plate (not shown) mounted on its peripheral surface, 2 to 5 denote inking rollers as a first rotating body in contact with the plate cylinder 1, 6, 7 Reference numeral denotes a swing roller which comes into contact with the ink forming rollers 2 and 3 and the ink forming rollers 4 and 5, respectively. Reference numeral 8 denotes a watering roller which is in contact with the plate cylinder 1, reference numeral 9 denotes a metering roller which is in contact with the watering roller 8 and supplies dampening water from a watercraft (not shown) to the watering roller 8.
Numeral 11 denotes a blanket cylinder which is in contact with the plate cylinder 1 and serves as an ink transfer target.

A first feature of the present invention is that the contact position A between the smoothing roller indicated by reference numeral 10 and the plate cylinder 1 is set at the highest position in the rotational direction of the plate cylinder 1 among the four inking rollers 2 to 5. The printing cylinder 1 is located at a position higher than the contact position B between the upstream inking roller 5 and the printing cylinder 1.
And the blanket cylinder 1 and the blanket cylinder 11
Is located downstream of the contact position C of the plate cylinder 1 in the rotation direction.

A second feature is that the smoothing roller 10 is formed by a surface having ink and water repellency. Further, the smoothing roller 10 is rotatably supported, and is rotationally driven by a frictional force from the plate surface of the plate cylinder 1,
Therefore, slight slippage occurs on the surface of the plate cylinder 1.

In such a configuration, when the plate cylinder 1 passes through the dampening roller 8, dampening water is supplied to the plate surface of the plate of the plate cylinder 1, and the dampening water is supplied to the non-image portion having hydrophilicity. Go to When the plate cylinder 1 passes through the four inking rollers 2 to 5, ink is supplied to the plate surface of the plate of the plate cylinder 1, and this ink moves onto the image portion having ink affinity. An image is formed on the cylinder 1, and the formed image is transferred to the blanket cylinder 11 when the plate cylinder 1 passes through the blanket cylinder 11.

After the transfer of the ink to the blanket cylinder 11 by the plate cylinder 1, the surface of the ink on the plate cylinder 1 is uneven due to the cohesive failure of the ink layer. Before the ink transfer by 5 is made,
Since the ink film is smoothed by the smoothing roller 10, the ink film is transferred to the image area with good adhesion and without unevenness. Further, as shown in FIG. 1, the contact position between the smoothing roller 10 and the plate cylinder 1 is set at a position downstream of the contact position between the wet roller 8 and the plate cylinder 1 in the rotation direction of the plate cylinder 1. In addition, by arranging the plate cylinder 1 and the ink setting rollers 2 to 5 so that the plate cylinder 1 is positioned on the upstream side in the rotation direction of the plate cylinder 1, the plate cylinder 1 is wetted after passing through the water setting roller 8. The dampening solution supplied from the roller 8 to the plate cylinder 1 is also present on the ink film in the form of water droplets, but the dampening solution moves to the non-image area due to the contact pressure of the smoothing roller 10. Therefore, thereafter, when the plate cylinder 1 passes through the four inking rollers 2 to 5, the supplied ink is supplied only to the image portion of the plate of the plate cylinder 1.

Further, the fountain solution contained in the ink in the image area is also discharged to the surface of the ink by the contact pressure of the smoothing roller 10 and moves to the non-image area. Therefore, the aggregation of the ink in the image portion and the dampening solution in the non-image portion are promoted, and the ink and the dampening solution on the plate surface are accurately separated. For this reason, the ink supplied from the ink setting rollers 2 to 5 is transferred to the image area without being hindered by the fountain solution and has good adhesion. Can be prevented. Separation of the ink and the fountain solution is further promoted by the fact that the image portion and the non-image portion have ink affinity and hydrophilicity, respectively.

Further, since the smoothing roller 10 is formed of a surface having ink repellency, even if the smoothing roller 10 is brought into direct contact with the surface of the plate cylinder 1 and pressurized, the smoothing roller 10 When the ink in the image area separates from the surface, no cohesive destruction of the ink layer occurs, and no interface destruction occurs between the ink surface and the surface of the smoothing roller. In this case, the ink on the plate surface is not transferred to the surface of the smoothing roller 10 because the interfacial separation occurs on the surface of the plate. For this reason, the ink on the plate surface is sufficiently smoothed, and the ink supplied from the inking roller is transferred to the image area with good adhesion and without unevenness.

Further, since the smoothing roller 10 is formed of a surface having ink and water repellency, even if the smoothing roller 10 is brought into direct contact with the surface of the plate cylinder 1 and pressurized, the surface of the plate Roller for smoothing ink and dampening water 1
No transfer to the zero surface. In addition, since a uniform water film is formed on the non-image portion, it is possible to prevent the transfer of the ink to the non-image portion. It is possible to prevent a printing trouble called a so-called "ground stain" generated by the adhesion. The smoothing of the ink and the fountain solution is further promoted by the smoothing roller 10 having a small surface roughness of 15 μm or less.

FIG. 2 is a side view showing the arrangement of the cylinders according to the second embodiment of the present invention. In the second embodiment, the contact position A1 between the smoothing roller 10 and the plate cylinder 1
Is positioned downstream of the contact position D between the dampening roller 8 and the plate cylinder 1 in the rotation direction of the plate cylinder 1. Even with such a configuration, after the plate cylinder 1 transfers the ink to the blanket cylinder 11, the ink surface on the plate cylinder 1 is uneven due to the cohesive failure of the ink layer. Before the transfer of the ink by the application rollers 2 to 5, the ink film is smoothed by the smoothing roller 10, so that the ink film is transferred to the image area with good adhesion and without unevenness. Further, the fountain solution existing in the ink in the image area is discharged to the surface of the ink by the contact pressure of the smoothing roller 10 and moves to the non-image area. Therefore, the aggregation of the ink in the image portion and the dampening solution in the non-image portion are promoted, and the ink and the dampening solution on the plate surface are accurately separated. Further, the ink and the dampening solution on the plate surface are accurately smoothed by the smoothing roller 10, and the ink supplied from the inking roller is transferred to the image area with good adhesion and without unevenness. In addition, since a uniform water film is formed on the non-image portion, it is possible to prevent a printing trouble called “ground stain”.

FIG. 3 is a side view showing the arrangement of the cylinders according to the third embodiment of the present invention. In the third embodiment, of the four inking rollers 2 to 5,
Ink roller 5 positioned at the most upstream in the rotation direction of plate cylinder 1
Instead, a smoothing roller 10 is provided. With such a configuration, the plate cylinder 1 can be
After the transfer of the ink to the plate cylinder 1, the surface of the ink on the plate cylinder 1 is uneven due to the cohesive destruction of the ink layer. Since the ink film is smoothed by No. 10, the ink film is transferred to the image area with good adhesion and without unevenness.

Further, in the same manner as in the first embodiment, the dampening water supplied from the dampening roller 8 to the plate cylinder 1 can be moved to the non-image portion, so that the ink on the plate surface can be moved. And the dampening solution are sufficiently separated. Therefore, as in the first embodiment, a uniform and highly separable ink film and a water film can be accurately formed on the plate surface, so that there is no ink unevenness and the quality is improved. Furthermore, since it is only necessary to replace the inking roller and the smoothing roller of the existing printing machine, without modifying the machine,
The smoothing roller can be easily installed in a short time.
In the third embodiment, the smoothing roller 10 is replaced with the inking rollers 4 and 5 located on the upstream side in the rotation direction of the plate cylinder 1 among the four inking rollers 2 to 5. It is desirable to provide.

FIG. 4 is a side view showing an arrangement of barrels according to a fourth embodiment of the present invention. In the figure, reference numeral 12 denotes an impression cylinder which is in contact with the blanket cylinder 11;
A claw 13 for holding the paper 14 is provided. The fourth embodiment is characterized in that the smoothing roller 10 is brought into contact with a blanket cylinder 11 as a second rotating body. Then, the contact position A4 is set at a position downstream of the contact position H between the blanket cylinder 11 and the paper 14 as the ink transfer target in the rotational direction of the blanket cylinder 11 and the plate cylinder 1 as the first rotating body. It is positioned on the upstream side in the rotation direction of the blanket cylinder 11 from the contact position C between the blanket cylinder 11 and the blanket cylinder 11. Further, the smoothing roller 10 is rotatably supported, and is rotationally driven by a frictional force from a blanket of the blanket cylinder 11, so that a slight slip occurs on the surface of the blanket cylinder 11.

With this configuration, before the blanket cylinder 11 comes into contact with the plate cylinder 1, the ink film and the water film on the blanket cylinder 11 are made uniform by the smoothing roller 10, and From which the dampening solution is discharged. In this state, since the blanket cylinder 11 contacts the plate cylinder 1 at the contact position C,
The ink supplied from the plate cylinder 1 transfers to the image portion of the blanket cylinder 11 with good adhesion and without unevenness. Accordingly, a high-quality image free from ink unevenness is printed on the paper 14 in contact with the blanket cylinder 11 at the contact position H downstream of the blanket cylinder 11 in the rotation direction of the blanket cylinder 11.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A smoothing roller 10 comprises a shaft and an elastic layer, the elastic layer comprising silicone rubber having ink repellency.
It is formed of polytetrafluoroethylene rubber or the like. Also, the elastic layer is formed of a material having no ink repulsion,
The outermost layer may be coated with silicon or the like, and as a result, the surface of the smoothing roller 10 only needs to have ink repellency.

In this embodiment, an example in which only one smoothing roller 10 is provided has been described. However, for example, the smoothing rollers 10 and the blanket cylinder 11 are respectively combined by combining the first and fourth embodiments. A plurality of rollers 10 may be provided so as to be in contact with each other. In the first to third embodiments, the rotational drive of the smoothing roller 10 is a frictional force from the plate surface of the plate cylinder 1, and in the fourth embodiment, the blanket cylinder 11 is used.
Friction force from the blanket, but not limited to this,
The frictional force of the peripheral surface of the other roller may be used, or a driving source such as a motor may be used instead of the frictional force. Any speed may be used as long as the slip occurs or is substantially the same as the surface speed of the plate cylinder. Further, in the present embodiment, an example in which the smoothing roller 10 is applied to a printing press equipped with a water supply device has been described. The same operation and effect can be obtained.

[0024]

As described above, according to the first aspect of the present invention, the ink on the surface of the second rotating body is supplied before the ink is supplied from the first rotating body to the second rotating body. Is sufficiently smoothed, so that the ink supplied from the first rotating body is transferred to the image area with good adhesion and without unevenness. In addition, when the ink separates from the surface of the smoothing roller, the ink layer does not undergo cohesive destruction but peels off at the interface between the ink surface and the roller, so that the ink does not transfer to the surface of the smoothing roller. In this way, a uniform ink film is formed on the surface of the second rotating body, so that there is no ink unevenness and the print quality is improved.

Further, according to the second aspect of the present invention, since a uniform ink film is formed on the surface of the plate cylinder, there is no ink unevenness and the print quality is improved.

According to the third aspect of the present invention, since a uniform ink film is formed on the surface of the blanket cylinder, ink unevenness is eliminated, and the quality of printing is improved.

According to the fourth aspect of the present invention, the first
Before the ink is supplied from the rotator to the second rotator,
Since the ink and the fountain solution on the surface of the second rotating body are sufficiently smoothed, the ink supplied from the first rotating body is
Transfer to the image area with good adhesion without unevenness. Also, when the ink separates from the surface of the smoothing roller, instead of cohesive destruction of the ink layer, interface separation between the ink surface and the roller occurs, so that ink or dampening water may transfer to the surface of the smoothing roller. Absent. Further, by forming a uniform water film on the non-image portion, it is possible to prevent the transfer of the ink to the non-image portion, and thus, the non-image portion locally becomes insufficient in hydrophilicity. It is possible to prevent a printing failure called a so-called “ground stain”, which is caused by adhesion of ink to a portion. Then, while the ink is supplied from the first rotating body to the second rotating body, the dampening solution is sufficiently separated from the image portion of the second rotating body, so that the ink is supplied from the first rotating body to the second rotating body. Second
The ink supplied to the rotator is uniformly transferred to the image area without being hindered by the fountain solution. As described above, since the uniform ink film and the water film are clearly separated from each other on the surface of the second rotating body to form an image, ink unevenness is eliminated and printing quality is improved.

[Brief description of the drawings]

FIG. 1 is a side view showing an arrangement of cylinders in a printing press according to the present invention.

FIG. 2 is a side view showing an arrangement of a trunk in a second embodiment of the present invention.

FIG. 3 is a side view showing an arrangement of a trunk in a third embodiment of the present invention.

FIG. 4 is a side view showing an arrangement of trunks according to a fourth embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Plate cylinder, 2-5 ... Inking roller, 8 ... Watering roller, 10 ... Smoothing roller, 11 ... Rubber cylinder, 12 ... Impression cylinder,
14 ... paper.

Claims (4)

[Claims] 1. A first rotating body, a second rotating body which is in contact with the first rotating body and to which ink is transferred from the first rotating body, and which is in contact with the second rotating body. In the printing press provided with an ink transfer target to which ink is transferred from the second rotating body and a smoothing roller in contact with the second rotating body, the smoothing roller has an ink repellency. The smoothing roller and the second rotating body have a contact position between the second rotating body and the ink transfer target, the rotation position of the second rotating body being greater than the contact position between the second rotating body and the ink transfer target. A printing machine characterized in that the printing machine is positioned downstream in the direction and upstream of the contact position between the first rotating body and the second rotating body in the rotation direction of the second rotating body. 2. The printing press according to claim 1, wherein:
A printing press, wherein the first rotating body is an inking roller, and the second rotating body is a plate cylinder. 3. The printing press according to claim 1, wherein:
A printing machine wherein the first rotating body is a plate cylinder and the second rotating body is a blanket cylinder. 4. The printing press according to claim 1, wherein:
A printing press, wherein the surface of the smoothing roller also has water repellency.