JPH11291439A - Removing device of ink sticking to non-image area of waterless lithography - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the possibility of slippage of the rotation of an adhesive roller and to simplify a device. SOLUTION: An ink removing device 1 is equipped with an adhesive surface on the peripheral roller surface of an adhesive roller 2 and also with friction rollers 3 on the lateral sides of the adhesive roller 2. The peripheral roller surface of the adhesive roller 2 is in contact with a plate surface on a plate cylinder during the transfer of ink onto a blanket cylinder. Besides, the friction rollers 3 are in contact with bearers of the plate cylinder. In waterless lithographic printing, the friction rollers 3 rotate in company with the bearers and a driving force is transmitted to the adhesive roller 2. Although part of the ink sticks also to a non-image area and becomes an ink stain, this is removed immediately by the ink removing device 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention removes ink adhering to a non-image area of a printing plate by incorporating it into a printing press using a waterless lithographic plate, and supplies a clear and reproducible printed material at low cost. The present invention relates to a device for removing ink adhered to a non-image area of a waterless planographic plate.

[0002]

2. Description of the Related Art Among lithographic printing methods widely used as a printing method, a waterless lithographic printing method that does not use dampening water has become widespread because of its simple operation.

The lithographic printing method without water is schematically described below with reference to a conceptual diagram of a lithographic offset printing press shown in FIG. That is, the lithographic ink without water in the ink fountain 50 is sent to the ink mixing roller group 52 via the ink transfer roller 51. Here, the ink is usually spread while being transferred between 14 or more roller groups to form a thin film of about several μm.
Is transferred to a lithographic plate without water on the peripheral surface of the plate cylinder 54. Thereafter, the ink is transferred from the plate cylinder 54 to the blanket cylinder 55, and is printed on the paper 57 sandwiched between the blanket cylinder 55 and the impression cylinder 56.

When ink stains occur in the non-image areas of the waterless planographic plate over time, the operation of the printing press is interrupted each time to clean the ink stains in the non-image areas.

[0005]

By the way, in the case of lithographic printing without water, the non-image area of the lithographic printing plate is made of an ink-repelling silicone rubber layer. Weak and dirty compared to lithographic plates that use. For this reason, in waterless lithographic printing, a high-viscosity ink must be used. Therefore, it is necessary to transfer between a large number of ink kneading rollers as a kneading process for forming a uniform thin film, which complicates a printing machine,
This has contributed to increased manufacturing and operating costs.

[0006] Further, during printing, heat generated by ink splitting generated between the rollers during transfer between a plurality of ink forming rollers and mechanical heat generated by rotation of the plate cylinder and the like cause the temperature of the ink forming rollers to increase. In addition, the plate surface temperature increases, and the ink viscosity of the lithographic ink without water becomes lower than the initially set value. When such a decrease in viscosity occurs, the ink adheres and remains in the non-image area in the form of particles and appears as a print stain on a printed matter, thus deteriorating the quality.

Further, in waterless lithographic printing, since the rise in the plate surface temperature cannot be suppressed by dampening water, in order to solve the above-mentioned problems, cooling water is passed through the rollers, or cold air is passed through the plate cylinder. A cooling device, such as spraying, is provided. For this reason, the installation of these cooling devices has been a major factor in increasing manufacturing and operating costs.

In view of the above problems, the applicant of the present application has proposed a device for removing ink adhering to a non-image area of a waterless planographic plate in Japanese Patent Application No. 8-349683.
Such an ink removing device is provided with a rotatable roller, and the peripheral surface of the roller contacts the peripheral surface of the roller with the ink adhered to the non-image area of the waterless lithographic plate, whereby the ink is removed from the roller. It is an adhesive surface that can be transferred to and held on the peripheral surface.

However, in the above-described ink removing device, the adhesive roller is rotated with the rotation of the plate cylinder by the adhesive force of the ink. Therefore, the plate cylinder and the adhesive roller can be completely and smoothly rotated at a constant speed. There is a possibility that the rotation of the adhesive roller may be deviated, and there is room for further improvement.

The present invention solves the above-mentioned problems, and can provide a clearer and more reproducible printed material at a low cost by incorporating the adhesive roller into a waterless lithographic printing machine without causing the rotation of the adhesive roller to be shifted. Another object of the present invention is to provide an apparatus for removing ink adhered to a non-image area of a waterless planographic plate, which can simplify the apparatus.

[0011]

The present invention employs the following means as means for achieving the above object.

That is, the apparatus for removing ink adhered to the non-image area of a waterless planographic plate according to the first aspect of the present invention is provided side by side with a plate cylinder 25, for example, as shown in the following embodiment. 25, the ink 30 adhered to the non-image area 36 of the waterless lithographic plate 35 and the roller peripheral surface 2c are brought into contact with each other to transfer the ink 30 to the roller peripheral surface 2c and to form an adhesive surface that can be held on the roller peripheral surface 2c. And a friction roller 3 provided on the side of the adhesive roller 2 and transmitting a driving force to the adhesive roller 2 from the printing drum 25 side.

When the lithographic printing machine is used, the driving force is transmitted from the plate cylinder 25 side to the adhesive roller 2 via the friction roller 3 during operation of the lithographic printing machine, and the adhesive roller 2 is rotated. I do. When the ink 30 adhered to the non-image area 36 of the waterless planographic plate 35 is brought into contact with the roller peripheral surface 2c, the ink 30 of the non-image area 36 is brought into contact with the roller peripheral surface 2c.
, And is held as it is.

The apparatus for removing ink adhered to the non-image area of the waterless planographic plate according to the second aspect of the present invention is, for example, as shown in the following illustrated embodiment. In the apparatus for removing ink adhered to the portion, the friction roller 3 is pressed against the bearer 25a of the plate cylinder 25.

When the plate cylinder 25 rotates during the operation of the lithographic printing press, the friction roller 3 rotates with the rotation of the bearer 25a, and a driving force is transmitted to the adhesive roller 2, so that the adhesive roller 2 rotates.

The apparatus for removing ink adhering to the non-image area of the waterless planographic plate according to the third aspect of the present invention is, for example, as shown in the following illustrated embodiment. In a device for removing ink adhered to the portion, a plate member 41 is provided on the peripheral surface of the plate cylinder 25 outside the lithographic plate 35 without water,
It is characterized in that the friction roller 3 is pressed against the plate member 41.

When the plate cylinder 25 rotates during the operation of the lithographic printing press, the friction roller 3 rotates with the rotation of the plate member 41, and a driving force is transmitted to the adhesive roller 2, so that the adhesive roller 2 rotates. .

An apparatus for removing ink adhered to a non-image area of a waterless planographic plate according to claim 4 is, for example, as shown in the following embodiment shown in the drawings. In a device for removing ink adhered to a non-image area of a lithographic printing plate, a friction roller 3 has a bearer 3
a, and a hard rubber material 3b is wound around the outer periphery of the bearer 3a.

A device for removing ink adhered to a non-image portion of a waterless planographic plate according to claim 5 is, for example, a non-image line of a waterless planographic plate according to claim 1 as shown in the following embodiment. In the apparatus for removing the ink adhered to the portion, the adhesive roller 2 includes an inner layer 2a having an air supply port 2e on the side and a large number of fine discharge holes 2d formed in the peripheral surface thereof;
a outer rubber layer 2b covering the outer peripheral surface of a and sealing the discharge hole 2d
It is characterized by comprising.

When air is pressed into the inner layer 2a from the outside through the air supply port 2e, the rubber outer layer 2b expands, and the outer diameter of the adhesive roller increases.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a device for removing ink adhering to a non-image area of a waterless lithographic plate of the present invention (hereinafter abbreviated as "adhered ink removing device"), a lithographic printing press equipped with the same, An example of a lithographic printing method using a lithographic printing machine is shown in FIGS.
A description will be given based on FIG.

As shown in FIG. 3, the adhering ink removing device 1 includes an adhesive roller 2 and friction rollers 3 on both sides thereof, and is supported by a rotating shaft 4 so that both end surfaces are rotatable in a forward direction. ing.

As shown in FIG. 4, the adhesive roller 2 has a two-layer structure including an inner layer 2a and an outer layer 2b. The constituent material of the inner layer 2a is a metal. The constituent material of the outer layer 2b is the same synthetic rubber as nitrile rubber, chloroprene rubber, urethane rubber or the like used as a roller material of a normal lithographic printing press, and has a hardness (penetration; JISK2207) of 30 or less. preferable. Roller peripheral surface 2 of this adhesive roller 2
By contacting the ink adhering to the non-image area of the waterless lithographic plate with the ink c, the ink is transferred to the roller peripheral surface 2c and is made to be an adhesive surface that can be held as it is.

Roller peripheral surface 2c having such an adhesive surface
As an example of the adhesive roller 2 provided with
In addition, there may be mentioned those obtained by depositing an ink having a higher viscosity than the ink attached to the non-image area of the waterless planographic plate to be removed. The viscosity of the high-viscosity ink used in this case is determined in relation to the ink used for lithographic printing without water, but in the present invention, the tack value (incometer value at 30 ° C., 400 rpm) is 1 unit.
It is preferably higher than 2. The high-viscosity ink may be colored or colorless, but is preferably a non-drying type in order to maintain stable adhesive strength.

Such an adhesive roller 2 is, for example, shown in FIG.
As shown in the figure, a high-viscosity ink for removal is added to the nip between the swing roller 12 and the kneading roller 13, and the ink is spread and thinned to about 5 μm to 10 μm. 2c.

As another example of the pressure-sensitive adhesive roller 2 having the roller peripheral surface 2c having a pressure-sensitive adhesive surface, a synthetic rubber such as nitrile rubber, chloroprene rubber, urethane rubber or the like constituting the outer layer 2b contains a lipophilic component. Can be mentioned. Examples of the lipophilic component include linseed oil, linseed oil, soybean oil, vegetable oil such as castor oil, processing oil obtained from vegetable oil, machine oil, spindle oil, mineral oil such as light oil, rosin, etc. Can be mentioned. The content of these lipophilic components is preferably about 50 to 80% by weight based on the weight of the synthetic rubber. The pressure-sensitive adhesive roller 2 containing this lipophilic component preferably has a hardness (penetration; JISK2207) of 30 or less, particularly preferably 20 or less.

Such an adhesive roller 2 can be obtained by mixing a synthetic rubber raw material with a lipophilic component and molding the mixture by a conventional method.

On the other hand, the friction roller 3
As shown in FIG. 6, a cylindrical bearer 3a and a bearer 3
a of a hard rubber material 3b wound around the outer periphery of a. The constituent material of the rubber material 3b is a blanket made of fiber which is stable against pressure and heat, or hardness (penetration; J
(ISK2207) A rubber of 80 or more is preferred.

The adhesion ink removing device 1 of the present invention can be applied not only to lithographic printing without water but also to lithographic printing using a conventional dampening solution.

As shown in FIG. 1, the lithographic printing press 20 incorporates a device 1 for removing adhering ink.
The apparatus 1 for removing the adhered ink may be configured such that the roller peripheral surface 2c of the adhesive roller 2 is transferred from the transfer of the ink to the plate surface on the plate cylinder 25 until the plate cylinder 25 and the blanket cylinder 26 come into contact with each other. It is incorporated in such a way that it contacts the upper plate. At this time, as shown in FIG. 2, the adhering ink removing device 1 attaches the friction roller 3 to the bearer 25a on the side of the plate cylinder 25.
Are pressed against each other. When the plate cylinder 25, the blanket cylinder 26, and the impression cylinder 27 shown in FIG. 1 are rotated by respective gears (not shown) on the sides, the friction roller 3 rotates with the rotation of the bearer 25a, and the driving force is applied to the adhesive roller 2. To be communicated to. With such a configuration, the friction roller 3
Can be rotated at a constant speed with respect to the plate cylinder 25 without deviation.

The size of the adhering ink removing device 1 incorporated in the lithographic printing press 20 is appropriately determined in relation to the size of the entire printing press and other components. When the size of the diameter is set to 1.0, the size of the diameter of the attached ink removing device 1 is set to be about 0.1 to 0.4.

Next, a planographic printing method using such a planographic printing machine 20 will be described. This lithographic printing method can be applied to either lithographic printing without water or lithographic printing using dampening solution. Hereinafter, lithographic printing without water will be described as an example.

The lithographic ink 30 without water in the ink fountain 21
Is transferred to an ink mixing roller group 23 via an ink transfer roller 22. At this time, as the lithographic ink 30 without water, one having a lower viscosity than that of conventional lithographic printing, for example, one having a tack value of 4.0 to 6.0 can be used.

The lithographic ink without water is spread and spread while transferring between the ink kneading roller groups 23 to become a thin film. However, since a low-viscosity ink is used in advance, this thin film can be easily formed. Therefore, as shown in FIG. 1, the number of rollers in the ink mixing roller group 23 can be reduced as compared with the related art. Although FIG. 1 is a conceptual diagram, the number of each ink mixing roller does not necessarily represent a real number. However, in the lithographic printing press of the present invention, the number of ink mixing rollers is reduced to half or less of the conventional lithographic printing press. can do.

The ink 30 spread in a uniform thin film is continuously transferred to the plate surface (waterless planographic plate) on the peripheral surface of the plate cylinder 25 rotating in the direction of the arrow in FIG. At this time, since the ink 30 has a low viscosity, the plate surface 35 is in a state where the particulate ink (ink stain) 30 adheres to the non-image area 36 as shown in FIG. Thereafter, when the plate cylinder 25 further rotates, the plate cylinder 25 and the blanket cylinder 2 are rotated.
Until the contact portion 6 comes in contact with the adhered ink removing device 1, it comes into contact with the roller peripheral surface 2 c of the adhesive roller 2. At this time, the particulate ink 30 in the non-image area 36 moves to the roller peripheral surface 2c side and is held as it is. Therefore, as shown in FIG. 8, the printing surface 35 on the printing drum 25 that has passed through the contact portion has ink attached only to the image portion 37 and ink attached to the non-image portion 36 is removed. ing. Here, the image portion 37 is ink-receptive, and the ink adhering to the portion is located in the concave portion more than the non-image portion 36, whereas the ink adhering to the non-image portion 36 as dirt is an image. It is located on the convex portion from the line portion 37 and is in a floating state. Therefore, when the roller peripheral surface 2c of the adhesive roller 2 is brought into contact with the plate surface 35, even if the image portion 37 and the non-image portion 36 are uniformly contacted without distinction, only the ink stain on the non-image portion 36 is obtained. Is removed.

The ink 30 on the plate surface 35 thus removed is transferred to the blanket cylinder 26 and printed on the paper 40 sandwiched between the blanket cylinder 26 and the impression cylinder 27. At this time, the non-image area 3
Since the ink stains on No. 6 have been removed, the printed matter obtained is clear and has good reproducibility.

As described above, some lithographic printing presses operate while the plate cylinder 25 and the blanket cylinder 26 are in contact with the bearer, and do not have the bearer or do not contact the bearer even if the bearer is present. Some rotate at a certain interval. In the illustrated embodiment described above, the lithographic printing press that operates while contacting the bearer was described, and the example in which the friction roller 3 was pressed against the bearer 25a was described. However, the present invention is not limited to this, and the configuration shown in FIG. 9 can be applied to a lithographic printing press having no bearer in the same manner as described above. That is, in FIG. 9, 5 mm is set at both ends on the plate cylinder 25 outside the plate surface 35.
The width plate member 41 is attached with an adhesive to serve as a drive source. When the apparatus 1 for removing attached ink is incorporated into a lithographic printing press, the friction roller 3 is pressed against the plate member 40.

Further, the nip pressure due to the volume expansion of the rubber may change due to the temperature rise during the operation of the lithographic printing press. In the adhesion ink removing apparatus according to the present invention, for example, the nip width between the roller and the plate cylinder is 1 mm. The contact of 0.5 to 2.0 mm may not be uniform. Therefore, in the present invention,
The configuration shown in FIG. 10 is more preferable. That is, the adhesive roller 2 has a large number of fine discharge holes 2d formed in the peripheral surface of the inner layer 2a and an air supply port 2e provided on one side of the inner layer 2a. Then, if necessary, a weak pressure air is supplied from a compressor (not shown) through the air supply port 2e.
As shown in FIG. 11, the outer layer 2b can be expanded radially outward by a predetermined dimension a from the friction roller 3 by air pressure. With such a configuration, when a change in the nip pressure occurs during operation, it is possible to immediately deal with the change without stopping the machine as in the current situation.

[0039]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto.

Example 1 An adhesive roller (diameter 6 cm, length 50 cm) having a rubber material having a hardness of 30 as an outer layer was prepared, and a TA medium (trade name: TA Medium, manufactured by Taniguchi Ink Co., Ltd.) having a tack value of 12 was provided on the peripheral surface of the roller. I arrived
A rubber material having a hardness of 85 was used for the friction roller to obtain an attached ink removing device. Next, this apparatus is assembled by pressing a friction roller against a bearer of a plate cylinder into a portion as shown in FIG. 1 inside a waterless lithographic printing machine (trade name: 3200CD type printing machine; manufactured by Ryobi), and performs lithographic printing. I got the machine. Next, a waterless plate (trade name: waterless planographic plate; manufactured by Toray Industries) and a waterless paper plate (trade name: PR-1 type; manufactured by Printechno) were attached to the lithographic printing machine, and a tack value of 5 was obtained. Waterless lithographic ink (trade name: TA-Red; manufactured by Taniguchi Ink Co., Ltd.) at 30 ° C.
Printing was performed. As a result, in the waterless version, 3000
Even after printing one sheet, no background stain and no image disorder occur, and in the waterless paper plate, no background stain or image disorder occurs even after printing 1,000 sheets.
In each case, clear and reproducible printed matter could be obtained.

Example 2 Using the lithographic printing press obtained in Example 1, 3,000 sheets of lithographic printing ink (trade name: Technocolor-Red; manufactured by Taniguchi Ink Co.) using a dampening solution having a tack value of 5 in the same manner. Printing was done. As a result, as in Example 1, no background stain and no image disturbance occurred, and a clear and reproducible printed matter could be obtained.

Example 3 Mineral oil was previously applied to an adhesive roller of the same size as that of Example 1 for 6 minutes.
A material containing about 0% by weight was manufactured, and a rubber material having a hardness of 85 was used as a friction roller to obtain an attached ink removing device. The apparatus for removing adhered ink was installed in the same printer as in Example 1, and 3000 sheets were printed in the same manner as in Example 1. As a result, as in the case of Example 1, no background stain was generated at all, and a clear and reproducible printed matter could be obtained.

Comparative Example 1 A commercially available waterless lithographic ink (trade name: Technocolor Waterless Red; manufactured by Taniguchi Ink Co., Ltd.) was used by adjusting its tack value to 5, and the structure as shown in FIG. 12 was used. Waterless plate (trade name: waterless lithographic plate: manufactured by Toray Industries) and waterless paper plate (trade name: -1 type; Print Techno) Company)
Printing was performed in the same manner as in Example 1. As a result, background smearing occurred during printing.

[0044]

As described above, according to the adhesion ink removing apparatus of the present invention, since the driving force is transmitted to the adhesive roller via the friction roller, the adhesive roller and the plate cylinder are used in waterless lithographic printing. Rotation can be performed completely smoothly at a constant speed, and rotation of the adhesive roller can be eliminated to improve the efficiency of removing ink adhering to the non-image area of the plate surface.

Further, since the friction roller is pressed against the bearer of the plate cylinder, there is no need to separately provide a drive source, the structure is simple, and the apparatus can be simplified.

Further, since the outer layer of the adhesive roller can be expanded outside the friction roller by a predetermined size by injecting air from the outside into the adhesive roller, a change in nip pressure between the plate surface and the adhesive roller during operation can be reduced. If this occurs, it is possible to adjust the nip pressure while operating without stopping and stopping the machine as in the current situation, thereby improving the working efficiency.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of a waterless lithographic printing press incorporating a device for removing adhered ink according to the present invention.

FIG. 2 is a schematic plan view of the attached ink removing device and the plate cylinder of the present invention.

FIG. 3 is a schematic side view of the attached ink removing device of the present invention viewed from a direction orthogonal to an axial direction.

FIG. 4 is a vertical sectional view taken along line AA in FIG. 3;

FIG. 5 is a view for explaining one step of a method of manufacturing the attached ink removing device according to the present invention.

FIG. 6 is a vertical sectional view taken along line BB in FIG. 3;

FIG. 7 is a conceptual diagram for explaining the lithographic printing method of the present invention.

FIG. 8 is a conceptual diagram for explaining a lithographic printing method.

FIG. 9 is a schematic side view of a part of another embodiment of the attached ink removing device of the present invention viewed from a direction perpendicular to an axial direction.

FIG. 10 is a longitudinal sectional view of an adhesive roller portion in still another embodiment of the attached ink removing device of the present invention.

FIG. 11 is a view for explaining nip pressure adjustment in the embodiment of FIG. 10;

FIG. 12 is a conceptual diagram of a conventional waterless lithographic printing press.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Adhered ink removing device 2 Roller 2a Inner layer 2b Outer layer 2c Roller peripheral surface 2d Discharge hole 2e Air supply port 3 Friction roller 3a Bearer 3b Rubber member 20 Waterless lithographic printing machine 21 Ink fountain 22 Ink transfer roller 23 Ink kneading roller group 24 Ink Wear roller 25 plate cylinder 26 blanket cylinder 27 impression cylinder 30 ink 35 printing plate (waterless planographic printing plate) 36 non-image area

Claims (5)

[Claims] 1. A method in which the ink is transferred to and held on the roller peripheral surface by contacting the ink adhering to the non-image area of the waterless planographic plate of the plate cylinder in parallel with the plate cylinder and the roller peripheral surface. A non-waterless lithographic plate comprising: a rotatable adhesive roller having an adhesive surface on a roller peripheral surface; and a friction roller provided on a side of the adhesive roller and transmitting a driving force from the plate cylinder to the adhesive roller. A device for removing ink adhering to the image area. 2. The apparatus according to claim 1, wherein a friction roller is pressed against the bearer of the plate cylinder. 3. The non-image area of a waterless planographic plate according to claim 1, wherein a plate member is provided on the outer peripheral surface of the plate cylinder outside the waterless planographic plate, and a friction roller is pressed against the plate member. For removing ink adhering to the surface. 4. The friction roller according to claim 1, wherein a bearer is provided on a side of the adhesive roller, and a hard rubber material is wound around an outer periphery of the bearer. A device for removing ink adhering to non-image areas of waterless planographic plates. 5. The adhesive roller includes an inner layer provided with an air supply port on a side thereof and a plurality of fine discharge holes formed in a peripheral surface thereof, and a rubber outer layer covering an outer peripheral surface of the inner layer and sealing the discharge holes. The apparatus for removing ink adhered to a non-image area of a waterless planographic plate according to claim 1, characterized in that the apparatus is provided with.