JP3196337B2 - Offset printing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an offset printing apparatus, and more particularly to an offset printing apparatus which improves mass productivity and printing stability, and efficiently performs clear printing with high accuracy and excellent finish.

[0002]

2. Description of the Related Art Conventionally, as a method of printing on a printing material such as paper, film, cloth, metal, or the like, an ink applied to an image portion of a printing original plate on which a desired pattern image is formed is directly transferred to the printing material. With the direct printing method (direct printing), the ink adhered to the image portion of the printing original is temporarily transferred to an offset roll, and the offset roll is transferred to the offset roll as a second printing original. There is an offset method (offset printing) in which the transferred ink is transferred to a printing substrate.

The offset roll used in the offset method usually has a structure in which an elastic resin sheet such as a rubber blanket is wound around a metal cylinder. Therefore, in the offset method, since the ink applied to the image portion of the printing original is transferred to the printing material via the elastic resin surface, the direct printing method is applied to the printing original and the printing material. As compared with the case where the printing is performed, a smaller printing pressure is required, and a good printing durability is obtained. For this reason, the offset method is widely used in various types of printing methods such as lithographic printing, letterpress printing, and intaglio printing.

[0004] offset printing apparatus for printing by the offset method, for example, in the case of gravure (intaglio) offset printing device, normally, as shown in FIG. 9, the outer peripheral surface of the cylinder from the image section 9 and the non-image portion 7 An offset roll 21 in which a rubber blanket is wrapped around a cylinder is placed in contact with the original roll 20 on the original roll 20 that has become the printing original plate 2. The original roll 20 is designed to rotate at an arbitrary rotation speed, and the offset roll 21 is designed to rotate in contact with the original roll 20. Further, a pickup roll 4 for applying the ink 6 in the ink tank 5 to the original roll 20 is in contact with the original roll 20. Further, the gravure offset printing apparatus includes a doctor blade 8 for scraping off the ink 6 applied to the master roll 20.

[0005] The process of transferring a desired image to, for example, a cylindrical printing material 22 using this gravure offset printing apparatus will be briefly described. First, the pickup roll 4, the original roll 20, and the offset roll 21 are separated from each other. Figure 9
Rotate in the direction of the arrow shown. At this time, the pickup roll 4 rotates in a direction opposite to the original roll 21, and the ink 6 is adhered to the outer peripheral surface in the ink tank 5.

Next, the ink 6 adhered to the outer peripheral surface of the pickup roll 4 comes into contact with the original roll 20 and is applied to the printing original 2 of the original roll 20. Next, the ink 6 applied to the non-image portion 7 of the printing original plate 2 is scraped off by a doctor blade 8 and removed.
Remains only in the image portion 9 of the printing original plate 2. Next, the ink 6 remaining on the image portion 9 comes into contact with an offset roll 21 rotating in a direction opposite to the original roll 20 and is transferred onto the offset roll 21. Next, the ink 36 transferred to the offset roll 21 is transferred to the printing substrate 22 that rotates in contact with the offset roll 21. It is to be noted that a case where a desired image is transferred to a flat printing material is also performed in the same manner. In addition, this step is similarly performed, for example, on an original plate roll 20 in which the printing original plate 2 is a lithographic system, an original plate roll 20 in which the printing original plate 2 is a letterpress type.

[0007]

However, in the conventional gravure offset printing apparatus, the original roll 20 and the offset roll 21 are always in contact with each other, and the original roll 20 and the offset roll 21 are connected to one another. The motor is driven to rotate. Therefore, according to various situations in each step at the time of printing, a change in ink viscosity, and the like,
Rotational angular velocity of the original roll 20 and offset roll 2
There is a problem that the original roll 20 and the offset roll 21 cannot be controlled independently so that the rotation angular velocity of 1 becomes an optimum value. For this reason, there has been a problem that a printing failure is likely to occur, for example, a pattern of an image to be transferred to the print substrate 22 is missing, a pinhole is generated, and an adhesive strength of an ink film is reduced.

Further, since the original roll 20 and the offset roll 21 are always in contact with each other at a constant pressure, if the gravure offset printing apparatus is stopped for a relatively long time, There is a problem that the wound rubber blanket is easily deformed or deteriorated. Therefore, in order to prevent deformation and deterioration of the rubber blanket, when the gravure offset printing apparatus is stopped for a relatively long period of time, the offset roll 21 is removed from a predetermined position, and set again at the predetermined position during operation. But this method is
There is a problem that it takes time and effort to prepare for the work, and the workability is significantly reduced.

The ink 6 is always in contact with the atmosphere in the ink tank 5, on the surface of the pickup roll 4, on the surface of the original roll 20, on the surface of the offset roll 21, and the like. Therefore, the solvent contained in the ink 6 evaporates gradually during each step, and the viscosity of the ink 6 gradually increases. For this reason, the transfer condition of the ink 6 changes according to the viscosity of the ink 6, and there is a problem that a printing defect such as a decrease in print reproducibility on the printing substrate 22 occurs.

SUMMARY OF THE INVENTION An object of the present invention is to provide an offset printing apparatus capable of improving mass productivity and printing stability and efficiently performing clear printing with high accuracy and excellent finish. The purpose is to provide.

[0011]

In order to achieve the above object, the present invention provides a method for supplying ink to an image portion of an original roll,
In an offset printing apparatus in which the ink of the image portion is transferred to an offset roll that is rolled and contacted with the original roll, and the transferred ink is transferred to a printing substrate, the transfer of the original roll and the offset roll to each of the transfer rolls is performed. Opening of
Until the beginning, the viscosity of the ink at the time of each transfer is
It is an object of the present invention to provide an offset printing apparatus characterized by having a rotation drive control device that rotates at a rotation angular velocity according to each process so as to obtain a value appropriate for copying . At least one of the original roll and the offset roll is connected to a contact control device for controlling the contact / non-contact state of both rolls, and an ink supply device capable of maintaining a constant viscosity of the ink supplied on the original roll is installed. Good to do. Further, when the ink of the image portion of the original roll is transferred to the offset roll, | SP value of the original roll−SP value of the ink at the time of transfer of the image portion |> | SP value of the surface of the offset roll−
Rotation drive system that rotates the original roll and offset roll at a rotational angular velocity that results in the SP value of the ink during the transfer of the image area
It may have a control device. Further, when the ink transferred to the offset roll is transferred to a printing material, | SP value of the surface of the offset roll-SP value of the ink transferred to the offset roll |> | SP value of the surface of the printed material-Transfer to the offset roll SP of used ink
It is also possible to have a rotation drive control device that rotates the offset roll at a rotation angular velocity that results in |. Further, the S of the ink supplied to the image portion of
It is preferable that the relationship of P value <SP value of the surface of the offset roll <SP value of the surface of the material to be printed is satisfied. In addition, SP value of ink containing no solvent> S on surface of material of printing material
The relationship may be the P value. It is also possible to provide a rotation drive control device that adjusts the rotation angle of the offset roll so that the transfer position between the offset roll and the printing medium does not overlap the previous transfer position.

[0012]

The original roll and the offset roll of the offset printing apparatus according to the present invention rotate at desired rotational angular velocities, respectively, and are connected to a rotational drive control device for independently controlling the rotational angular velocities. Therefore, the original roll and the offset roll can be independently controlled so as to have an optimum rotational angular velocity according to various situations in each step of printing. Therefore, transfer with excellent stability can be performed efficiently with high accuracy.

That is, in the conventional offset printing, the ink adhered to the image portion of the printing original plate on the surface of the original printing roll is transferred to the printing material via the offset roll. For this reason, while the ink is being transferred to the printing substrate, the solvent contained in the ink permeates into the elastic resin constituting the surface of the offset roll. Therefore, the elastic resin swells due to the permeation of the solvent, changes the surface characteristics of the offset roll, and lowers the transfer accuracy.

Here, in order to prevent the transfer accuracy from lowering, it is necessary to evaporate the solvent by the next cycle, but it is difficult in terms of time to completely evaporate the solvent by the next cycle. . Thus, if the cycle time is lengthened and the solvent is completely evaporated, the productivity is reduced. In the present invention, since the rotational angular velocity of the original roll and the rotational angular velocity of the offset roll can be independently controlled, the ink transfer position to the offset roll can be sequentially shifted for each cycle. For this reason,
The time for the solvent to evaporate sufficiently can be obtained without lengthening the cycle time. Therefore, transfer with excellent stability can be efficiently performed with high accuracy.

Further, the original roll and the offset roll of the offset printing apparatus according to the present invention have a function capable of making contact and non-contact with each other, and at least one of the original roll and the offset roll has the contact / non-contact state. A contact control device to control is connected. Therefore,
When the transfer of the ink is not performed, the original roll and the offset roll can be brought into a non-contact state. For this reason, even if the offset printing apparatus is stopped for a relatively long period of time, the offset roll is not deformed or deteriorated, and transfer with excellent stability can always be performed with high accuracy.

Furthermore, the offset printing apparatus according to the present invention is provided with an ink supply apparatus having a function of maintaining the viscosity of the ink supplied onto the original roll constant, so that the ink is initially set. Conditions can always be maintained. Therefore, the transfer condition of the ink can be always kept constant, and the print reproducibility on the printing material can be improved.

Further, by adding a device for controlling the amount of ink supplied to the ink supply device or a device for supplying a desired amount of ink only to the image portion of the printing original plate, the transfer with higher stability can be achieved. Can be performed with high accuracy and efficiency.

[0018]

Next, as an embodiment of an offset printing apparatus according to the present invention, a gravure offset printing apparatus will be described.
This will be described with reference to the drawings. 1 is a configuration diagram of a gravure offset printing device according to one embodiment of the present invention, FIG. 2 is a configuration diagram of an ink supply device installed in the gravure offset printing device shown in FIG. 1, and FIGS. It is an enlarged block diagram of each roll part of the gravure offset printing apparatus shown in FIG.

As shown in FIGS. 1 to 8, a gravure offset printing apparatus 1 according to the present embodiment includes an original roll 20 mounted on an original roll support 12 fixed on a support 16, Two linear guides 15 that intersect perpendicularly with the roll 20 and are fixed on a support 16
An offset roll 21 placed on top of the linear guide 15 and movable on the linear guide 15 is disposed in parallel with the original roll 20 and faces the offset roll 21 with the original roll 20 interposed therebetween. And an ink supply device 40 for supplying the ink 6 onto the original roll 20.

The original roll 20 is formed of a metal cylinder and has a surface serving as a gravure printing original plate 2 having an image portion 9 and a non-image portion 7. In the present embodiment, since the printing material 22 described later has a smaller diameter than the original roll 20, a part of the outer peripheral surface of the original roll 20 (arcs A → B → C shown in FIG. 3). Only used for actual printing. A rotation drive source 18 for driving the original roll 20 at an arbitrary angular velocity is connected to the original roll 20. As the rotation drive source 18, for example, a pulse motor, a servo motor, or the like is used.

Furthermore, the original roll 20 is described later, in particular, as shown in FIGS. 3-8, the ink supply port 24 of the ink supply KyuSo location 40 for supplying ink 6 on the original roll 20 Are in close proximity. In the vicinity of the ink supply port 24, an ink leveling blade 17 for leveling the ink 6 supplied onto the original roll 20 is provided. Furthermore, a doctor blade 8 for scraping and removing the ink 6 applied to the non-image portion 7 is in contact with the original roll 20.

The rotary drive source 18 is connected to a rotary drive controller 50 for controlling the rotational angular velocity of the original roll 20 according to the situation. The rotation drive control device 50 also controls the rotational angular velocity of the offset roll 21 described later, and the control of the rotational angular velocity of the original roll 20 and the control of the rotational angular velocity of the offset roll 21 are performed independently. .

[0023] The offset roll 21 includes a metal cylinder, has as an elastic resin, rubber blanket is wound structure using a silicon rubber. The offset roll 21 is connected to a rotary drive source 19 that drives the offset roll 21 at an arbitrary rotational angular velocity. The rotation drive source 19 is connected to a rotation drive control device 50 that controls the rotation angular velocity of the offset roll 21 according to the situation.

An air cylinder 25 is provided on the offset support 11 that supports the offset roll 21, and the offset support 11 moves on the linear guide 15 by driving the air cylinder 25 (coarse). Motion). And, by this movement, the offset roll 2
1 is in a contact / non-contact state with the original roll 20.

That is, when transferring the ink 6 to the printing substrate 22, the original roll 20 and the offset roll 21 are used.
And when the transfer of the ink 6 is not performed,
The original roll 20 and the offset roll 21 can be separated (in a non-contact state). Here, in the air cylinder 25, for example, a ball screw and a pulse motor are arranged in series, or a ball screw and a thermo turbo are arranged in series to perform fine movement, and the driving state of the air cylinder 25 is changed to a state. It is designed so that the contact pressure between the original roll 20 and the offset roll 21 can be freely controlled by performing control in accordance therewith.

Further, the air cylinder 25 is connected to a contact control device 60 for controlling the driving state of the air cylinder 25 according to the situation. In the ink supply device 40, as shown in FIG. 2, an ink supply port 24 is provided via an ink supply pipe 30 in a closed ink tank 27 containing the ink 6. Further, a nitrogen gas cylinder 26 for pressure-feeding the ink in the ink tank 27 toward the ink supply port 24 via a gas supply pipe 31 is connected to the ink tank 27.

The ink supply port 24 is connected to the original roll 20.
The gas supply pipe 31 is provided with a flow controller 29 for controlling the flow rate of the gas supplied to the ink tank 27. A flow controller (not shown) is connected to the flow controller 29, and always controls the amount of ink supplied onto the original roll 20.

Further, the ink supply pipe 30 has an ON state.
/ OFF valve 28 is provided and the ON / OF
By turning on / off the F valve 28, the ink is ejected and stopped from the ink supply port 24. The ON / OFF valve 28 has an ON (not shown).
A / OFF control device is connected to control the ejection and stop of the ink onto the original roll 20. Here, the ink in the ink tank 27 is to be pumped by a nitrogen gas, without oxidation, also the ink tank 27, since has become a closed state, ejecting ink supply port 24 or al Ink can always maintain certain properties and viscosity.

Below the offset roll 21, a fixed support 34 is provided. On the upper surface of the fixed support table 34, there are provided two
The linear guide 14 is fixed, and a movable support 33 that moves on the linear guide 14 is mounted on the linear guide 14. The air cylinder 13 is mounted on the movable support 33, and the movable support 33 is moved on the linear guide 13 by the driving of the air cylinder 13.
To or away from. Further, a drive control device (not shown) is connected to the air cylinder 13 to control the position of the movable support 33.

Further, on the upper surface of the movable support table 33,
An air cylinder 23 is installed at a right angle, and a print support 32 that supports the print 22 is installed above the air cylinder 23. Further, a drive control device (not shown) is connected to the air cylinder 23, and controls the vertical movement of the substrate support 32.

The printing substrate 22 is a printing substrate support 32.
At an upper predetermined position, it is installed in parallel with the offset roll 21. The printing substrate 22 will be described later in detail,
It has a cylindrical shape that rotates in contact with the offset roll 21, and by rotating in contact with the offset roll 21, the ink 36 transferred to the offset roll 21 is transferred, and printing is performed on the surface thereof. Will be

The print support 32 is designed to move in the vertical direction by the driving of the air cylinder 23, and the movement of the movable support 33 on the linear guide 14 and the print support 32. The printing substrate 22 is brought into contact with the offset roll 21 in a non-contact state by the vertical movement of the printing medium 22. That is, when the ink is transferred to the printing substrate 22, the offset roll 21 and the printing substrate 22 are brought into contact with each other, and when the transfer is not performed, the offset roll 21 and the printing substrate 22 can be separated. Has become.

Next, a specific operation of the gravure offset printing apparatus 1 according to the present invention will be described with reference to the drawings. First, the starting point A of the printing area on the original roll 20 is
As shown in FIG. 3, the ink supply device 40 is operated while approaching directly below the ink supply port 24, and a desired amount of ink is supplied from the ink supply port 24 onto the gravure printing original 2 of the original form roll 20. 6 is started, and the rotation drive source 18 is driven by a command transmitted from the rotation drive control device 50 to rotate the original roll 20 at a desired rotation angular velocity in the direction of the arrow shown in FIG. Here, the rotation angular velocity of the original roll 20 will be described later in detail, and is appropriately determined in consideration of the evaporating state of the solvent in the ink 6 (SP value of the ink 6 described later) changing every moment. It is sequentially changed according to each step described later. The determination / change of the rotational angular velocity is automatically controlled by the rotational drive control device 50. Since the ink supply needs to be performed quickly for the reason described below, a high speed (for example, 90
(Degrees / second).

The ink 6 supplied onto the original roll 20 is applied to the gravure printing original plate 2 while being leveled by an ink leveling blade 17 to a constant amount. The end point C of the printing area (point A → point C) on the original roll 20 is
Upon reaching beneath the ink supply port 24, the supply of ink is stopped, it changes the rotational speed. The rotation speed is such that the viscosity of the ink in the image portion 9 changes every moment,
0, when the ink is transferred to the offset roll 21 in such a state that the transfer is performed well (for example, 9
(Degrees / second). This state is shown in FIG.
You. This will be described later.

Thereafter, the ink 6 applied to the non-image portion 7 of the gravure printing original plate 2 is scraped off by a doctor blade 8, and the ink 6 is removed from the gravure printing original plate 2.
Remains only in the image portion 9 (concave portion). When the starting point A approaches the position where the original roll 20 and the offset roll 21 come into contact with each other in a predetermined manner, the rotation speed is changed to a rotation speed suitable for transfer (for example, 30 degrees / second).
In parallel with the above operation, the rotary drive source 19 is driven by a command transmitted from the rotary drive control device 50, and the rotational speed of the offset roll 21 is set to the same peripheral speed as that of the original roll 20 (for example, 30). (Degrees / second), while rotating the master roll 20 in the opposite direction to the rotating direction,
The offset roll support 11 is moved toward the original roll 20 by the air cylinder 25 and the fine movement motor,
A predetermined position of the offset roll 21 is brought into contact with the original roll 20 (for example, a point A of the original roll 20,
D point of the offset roll 21). By this step, FIG.
As shown in FIG. 7, the ink 6 adhered to the image portion 9 of the arc A → B → C on the original roll 20 is sequentially transferred onto the arc D → E → F on the surface of the offset roll 21.

Until the ink 6 is transferred to the offset roll 21, the ink 6 remaining on the image portion 9
The solvent in the image portion 9 evaporates in proportion to the time of contact with the atmosphere, and the concentration of the ink 6 increases to increase the viscosity. Here, the nonvolatile component S contained in the ink 6
Since the P (Solubility Parameter ) value is larger than the SP value of the solvent contained in the ink 6, when the solvent in the ink 6 evaporates, the SP value of the ink 6 increases. That is,
The SP value of the ink 6 remaining in the image portion 9 increases with time. This SP value is called the solubility parameter or solubility factor, and SP = δ =
(CED) ^1/2 [(cal / cm ³ ) ^1/2 ] where CED indicates cohesive energy density. Represented by
Those with similar SP values have the property of being more likely to adhere. While the SP value of the ink in the atmosphere changes (increases) every moment, the original roll 20 and the offset roll 2
Since the SP value of the material No. 1 is constant, the original roll 20
The transfer of the ink 6 from the offset roll 21 to the offset roll 21 and the transfer of the ink 6 from the offset roll 21 to the print
This means that there is an optimal time for each. Hereinafter, in this example, the initial SP value of the ink ≦ the SP value of the rubber blanket wound around the surface of the offset roll The SP value of the rubber blanket <the SP value of the material of the printing material, and a sufficient time has elapsed since printing was completed. An explanation regarding the SP value will be given on the assumption that the relationship of SP value of the ink containing no solvent after the passage of time ≧ SP value of the material of the printing substrate is satisfied.

That is, if the time until the ink 6 remaining on the image portion 9 is transferred to the offset roll 21 is too short, the SP value of the ink 6 remaining on the image portion 9 becomes The SP value of the offset roll 21 becomes smaller than the SP value of the offset roll 21, and a difference occurs between the SP values of the two.
Is hardly transferred to the offset roll 21. On the other hand, if the time until the ink 6 remaining on the image portion 9 is transferred to the offset roll 21 is too long, the SP value of the ink 6 remaining on the image portion 9 becomes:
The SP value becomes larger than the SP value of the offset roll 21 and a difference occurs between the two SP values, so that the ink 6 becomes difficult to be transferred to the offset roll 21. According to this embodiment , the transfer can be performed at an optimal time by appropriately selecting the rotation angular velocity of the original roll 20 from the ink scraping step to the transfer from the original roll 20 to the offset roll 21. Good transfer can be performed.

Next, after transferring the ink 6 to the offset roll 21, the offset roll support 11 is moved backward to the original position by a command transmitted from the contact control device 60, and the offset roll 21 is moved to the original roll 2.
Separate from 0 to bring them into a non-contact state. At this time, the original roll 20 that has come into non-contact with the offset roll 21
Can stop the rotation. Thus, the ink 6 is transferred from the original roll 20 to the offset roll 21.
When the transfer is not performed, the original roll 20 and the offset roll 21 can be kept in a non-contact state, so that the surface of the offset roll 21 can be prevented from being deformed or deteriorated. Therefore, transfer with excellent stability can always be performed with high accuracy.

In parallel with this operation, the rotation drive source 19 is controlled by a command transmitted from the rotation drive control device 50.
And the rotation angular velocity of the offset roll 21 is changed so that the starting point D of the area to which the ink 36 is transferred is adjusted to an appropriate speed (for example, described later) until near the contact position between the offset roll 21 and the printing material 22. 90 degrees /
Seconds).

Next, the air cylinders 13 and 23 are driven, and as shown in FIG. 7, the printing medium 22 is brought into contact with the offset roll 21 rotating while being separated from the original roll 20. The offset roll 21
A suitable speed (eg, 36 degrees / second, as described below)
Rotate with. In this step, the ink 36 transferred to the offset roll is transferred to the printing substrate 22.

At this time, prior to this, the SP value of the ink 36 transferred onto the offset roll 21 is in contact with the atmosphere immediately after the transfer, so that the solvent contained in the ink 36 evaporates, The SP value of the ink 36 increases and gradually approaches the SP value of the printing substrate 22. Here, in order to improve the printing speed and perform printing with high productivity, it is desirable that the SP value of the ink 36 be brought close to the SP value of the printing medium 22 as quickly as possible. Therefore, by selecting a rubber blanket having a property that the solvent contained in the ink 36 easily penetrates as the rubber blanket wound around the offset roll 21, the amount of the solvent contained in the ink 36 is reduced, and the ink blank is reduced. 3
A method of promoting an increase in the SP value of No. 6 has been adopted. Further, as shown in FIG. 6, forced drying with warm air may be used together.

Further, when the ink 36 transferred to the offset roll 21 is transferred from the offset roll 21 to the print substrate 22, the time until the ink 36 is transferred to the print substrate 22 is too short. Thus, the SP value of the ink 36 does not approximate the SP value of the printing medium 22. Also, the SP value of the portion of the ink 36 that is in contact with the offset roll 21 does not increase so much, and does not leave the vicinity of the SP value of the offset roll 21. Therefore, the ink 36 is provided between the offset roll 21 and the printing medium 2.
Since the ink 36 is pulled from both sides, the transfer form of the ink 36 film causes cohesive failure and interfacial failure, and good transfer of the ink 36 is not performed.

On the other hand, if the time until the ink 36 transferred to the offset roll is transferred to the printing material 22 is lengthened, the SP value of the ink 36 becomes
Approaching the SP value. Further, the SP value of the portion of the ink 36 that is in contact with the offset roll 21 also increases, and becomes sufficiently higher than the SP value of the offset roll 21. Therefore, the transfer form of the ink 36 is the offset roll 2
The interface between the ink 1 and the ink 36 is broken, and good transfer is performed.

Further, if the time until the ink 36 transferred to the offset roll is transferred to the printing material 22 is lengthened, the SP value of the ink 36 becomes larger than the SP value of the printing material 22, and The adhesion of the ink 36 to the printed matter 22 is reduced, and the offset roll 21
The transfer of the ink 36 from above to the print substrate 22 is not performed.

From this phenomenon, the offset roll 21
After separating from the original roll 20, by selecting the rotation angular velocity of the offset roll 21 to transfer from the offset roll 21 to the printing substrate 22,
The transfer can be performed at an optimal time, and the ink 3
6 can be set in a favorable state, and optimal transfer can be performed. In this way, the print substrate 22
The desired pattern was accurately printed on the surface of.

When one printing operation is completed, the print medium 22 is printed.
Is first lowered by the air cylinder 23,
Further, the printing medium 22 is retracted in the horizontal direction by the air cylinder 13, and as shown in FIG. Further, when the next printing cycle is performed, the ink transfer position to the offset roll 21 is rotated so as not to overlap with the previous area, that is, the arc D → E → F, and the surface position of the offset roll 21 is changed. Then, the same process as described above is performed, and continuous printing is performed.

As described above, the offset roll 21
Can be independently rotated, so that when transferring to the next printing cycle, the ink transfer position to the offset roll 21 can be prevented from overlapping the previous position. For this reason, it is possible to sufficiently secure the time required for the solvent of the ink that has permeated the offset roll 21 to evaporate in the previous cycle. Therefore, transfer with excellent stability can be efficiently performed with high accuracy.

Further, the ink 6 is applied to the original form roll 20.
Can always be supplied at a constant viscosity and the ink 6
Supply timing and supply timing can be arbitrarily controlled. Therefore, a desired amount of ink can be supplied only to the image portion 9 of the gravure printing original plate 2. Here, the ink 6 remaining on the image portion 9 of the gravure printing original plate 2 after the transfer of the ink 6 to the offset roll 21 comes into contact with the atmosphere, and the solvent contained in the ink 6 evaporates, and the viscosity of the ink 6 increases. Increases, causing a viscosity difference between the ink 6 and the ink 6 supplied next time. Ink 6 with this viscosity difference
Is pulled by the transfer, cohesive failure occurs in the low viscosity portion of the ink 6, and the offset roll 21
The so-called "trapping phenomenon" occurs in which the amount of the ink 6 transferred to the ink decreases. In order to suppress the occurrence of the trapping phenomenon, immediately after the transfer from the original roll 20 to the offset roll 21 is completed, the original roll 20
To the next supply of ink. It is also conceivable to increase the amount of the ink 6 to be supplied next time and to allow the solvent contained in the ink 6 to penetrate into the ink 6 remaining last time to reduce the difference in viscosity between the two.

The ink supply device 40 of the gravure offset printing device 1 according to the present invention can always supply the ink 6 to the original roll 20 with a constant viscosity and arbitrarily control the supply amount and supply timing. Can be made, depending on the state (viscosity) of the ink 6 remaining last time,
The amount of the ink 6 to be supplied next time can be controlled. Therefore, the difference in viscosity between the two inks 6 can be easily reduced, and transfer with excellent stability can be performed efficiently with high accuracy.

In the present embodiment, the gravure offset printing apparatus has been described. However, the present invention is not limited to this. The present invention can also be applied to a printing apparatus that performs printing by a method. In this embodiment, the image portion 9 and the non-image portion 7 are formed on the surface of the original roll 20 and the surface of the original roll 20 is directly used as the gravure printing original plate 2. A printing original plate of a desired form may be wound around the surface and installed.

In this embodiment, a rubber blanket made of silicon rubber is wound around the offset roll 21 for use. However, the present invention is not limited to this.
The elastic resin to be wound around 1 may be arbitrarily determined depending on the permeability of the solvent contained in the ink 6 and the SP value. Further, in this embodiment, the offset roll support 11 placed on the linear guide 15 is moved by the air cylinder 25 (coarse movement) and the combination of the motor and the ball screw (fine movement) to move the offset roll 21. I went,
The invention is not limited thereto, and the offset roll 21 may be moved by another method.

Further, in the present embodiment, the offset roll 21 is moved to contact / non-contact the original roll 20 with the offset roll 21. However, the present invention is not limited to this.
The contact / non-contact may be performed by moving the original roll 20 or by moving both. Further, in the embodiment, when the original roll 20 and the offset roll 21 are in contact with each other, they are driven to rotate. However, the present invention is not limited to this. You may make it rotate with movement.

In this embodiment, the ink supply device 4
At 0, using a nitrogen gas cylinder 26, the ink 6
However, any other gas may be used as long as it is an inert gas that does not change the properties of the ink 6. The means for feeding the ink 6 under pressure is not limited to this. In this embodiment, the ink supply port 24
Then, the ink 6 is ejected and supplied onto the original roll 20. However, the ink 6 may be supplied using the pickup roll 4 as shown in FIG.

In the present embodiment, the printing medium 22
Although a roller having a cylindrical shape that rotates in contact with the offset roll 21 was used, the present invention is not limited to this, and the print target 22 may be a sheet of paper, a film, a cloth, a metal, or the like. If there is, the shape may be determined arbitrarily, and the supply form of the print substrate 22 may be determined arbitrarily such as a sheet-fed type or a rotary type.

Further, in this embodiment, the linear guide 14
The moving support 33 placed on the upper surface is moved by the air cylinder 13 and the substrate support 32 is moved to the air cylinder 2.
The movement of the printing medium 22 is performed by moving the printing medium 22 by using the method 3, but the invention is not limited thereto, and the printing medium 22 may be moved by another method.

[0056]

As explained above, according to the first aspect of the present invention, each of the original roll and the offset roll
Transfer from original roll to offset roll and off
The transfer from the set roll to the print substrate starts until the start of each transfer.
Then, the viscosity of the ink at the time of each transfer is
Can be rotated at a rotational angular velocity according to each process so that the value becomes appropriate . Therefore, exposed to the atmosphere
Considering the change in SP value due to the change in viscosity of
The rotation angular speeds of the plate roll and offset roll can be changed individually.
The original roll, offset roll and
Offset from the original roll in consideration of the SP value of
Transfer to offset rolls and printing materials from offset rolls
Transfer timings to transfer to a good SP value.
Has the effect of being able to control
You.

According to the second aspect of the present invention, the original row
Not transferring ink between the roll and offset roll
The two rolls in a non-contact state, and
The offset roll may be deformed or deteriorated
Prevent and always stable when using offset printing equipment
Transfer can be performed with high precision. Also, the original version
Rolls are supplied with ink of a certain viscosity.
Printing conditions can be kept constant at all times.
Has the effect of improving print reproducibility
You.

According to the third to sixth aspects of the present invention, the in
This has the effect of ensuring the transfer of the key. Further
According to the seventh aspect of the present invention,
Necessary for the solvent of the ink that has penetrated the
The required time can be secured, so this is also stable
Transfer efficiency and high efficiency.
There is fruit.

[Brief description of the drawings]

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

FIG. 2 is a configuration diagram of an ink supply device installed in the gravure offset printing device shown in FIG.

FIG. 3 is a partially enlarged configuration diagram of the gravure offset printing apparatus shown in FIG.

FIG. 4 is a partially enlarged configuration diagram of the gravure offset printing apparatus shown in FIG.

FIG. 5 is a partially enlarged configuration diagram of the gravure offset printing apparatus shown in FIG.

FIG. 6 is a partially enlarged configuration diagram of the gravure offset printing apparatus shown in FIG. 1;

FIG. 7 is a partially enlarged configuration diagram of the gravure offset printing apparatus shown in FIG.

FIG. 8 is a partially enlarged configuration diagram of the gravure offset printing apparatus shown in FIG.

FIG. 9 is a partially enlarged configuration diagram of a conventional gravure offset printing apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Gravure offset printing apparatus 2 Gravure printing original plate 6 Ink 7 Non-image part 8 Doctor blade 9 Image part 11 Offset roll support 12 Original roll support 13 Air cylinder 14 Linear guide 15 Linear guide 17 Ink leveling blade 18 Rotation drive source 19 Rotation drive source 20 Original roll 21 Offset roll 22 Printed material 23 Air cylinder 24 Ink supply port 25 Air cylinder 26 Nitrogen gas cylinder 27 Ink tank 36 Ink transferred to offset roll 40 Ink supply device 50 Rotation drive control device 60 Contact control device

──────────────────────────────────────────────────の Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B41F ⁷ /00-7/40 B41F 13/00-13/40 B41F 33/00-33/08

Claims (7)

(57) [Claims] An ink is supplied to an image portion of an original roll,
In an offset printing apparatus in which the ink of the image portion is transferred to an offset roll that is rolled and contacted with the original roll, and the transferred ink is transferred to a printing substrate, the transfer of the original roll and the offset roll to each of the transfer rolls is performed. Opening of
Until the beginning, the viscosity of the ink at the time of each transfer is
An offset printing apparatus comprising: a rotation drive control device that rotates at a rotation angular velocity according to each process so that a value appropriate for copying is obtained . 2. A contact control device for controlling a contact / non-contact state of both rolls is connected to at least one of the original roll and the offset roll, so that the viscosity of ink supplied onto the original roll can be kept constant. The offset printing apparatus according to claim 1, further comprising an ink supply device. 3. When the ink of the image portion of the original roll is transferred to an offset roll, | SP value of original roll−
SP value of ink during transfer of the image area |> | - | having a rotational drive control device for rotating an original roll and offset roll to become the rotational angular velocity SP value of the offset roll surface SP value of ink during transfer of the image portion The offset printing apparatus according to claim 1, wherein: 4. When the ink transferred to the offset roll is transferred to a printing material, | SP value on the surface of the offset roll−SP of the ink transferred to the offset roll
The rotation drive control device for rotating the offset roll at a rotational angular velocity that satisfies the following equation: | value | SP value on the surface of the printed matter-SP value of ink transferred to the offset roll | An offset printing apparatus as described in the above. 5. The printing medium according to claim 1, wherein a relationship of SP value of the ink supplied to the image portion of the original roll <SP value of the surface of the offset roll <SP value of the surface of the printing material is satisfied. An offset printing apparatus as described in the above. 6. The offset printing apparatus according to claim 5, wherein a relation of SP value of the ink containing no solvent> SP value of the material surface of the printing substrate is satisfied. 7. The offset according to claim 1, further comprising a rotation drive control device that adjusts a rotation angle of the offset roll so that a transfer position between the offset roll and the printing material does not overlap a previous transfer position. Printing device.