JP2007098615A - Printing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce deterioration of printing quality in waterless plate printing using water-based ink. <P>SOLUTION: This printing machine 1 is used for the waterless plate printing using the water-based ink. The printing machine 1 is equipped with an ink scraping roller 15 which removes residual ink remaining in a non-image area of a plate 5 mounted on a plate cylinder 13. The ink scraping roller 15 contacts with the plate 5 mounted on the plate cylinder 13. The surface energy of the ink scraping roller 15 is larger than the surface energy of the non-image area of the plate 5 and smaller than that of a printing image area of the plate 5. According to this constitution, the roller 15 removes the residual ink remaining in the non-image area of the plate 5. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to waterless printing using water-based ink.

  In current offset printing, oil-based ink is used. In recent years, offset printing using water-based ink instead of oil-based ink has been proposed. Patent Document 1 discloses a printing method in which a printing plate that does not require dampening water is used and printing is performed using an offset printing machine with water-based ink.

JP 58-16883 A

  By the way, the printing plate which does not require the dampening solution disclosed in Patent Document 1 uses, for example, a silicone resin or a fluororesin for the non-image area, but when such a plate is used, the non-image area It is difficult to completely remove the ink (water-based ink) remaining on the paper, and polka dot background stains remain on the paper, which may reduce the print quality.

  Therefore, the present invention has been made in view of the above, and in waterless printing using water-based ink, it is possible to reduce the ink remaining on the non-image area of the plate and suppress the deterioration of the printing quality. An object is to provide a printing machine.

  In order to solve the above-described problems and achieve the object, the printing machine according to the present invention is used for printing using a waterless plate that does not require application of water-based ink and fountain solution, and a line is formed. A plate provided with an image line portion for forming an ink image line image of the image line by transferring ink, and a non-image line portion where the image line is not formed, and in the plate, the non-image line And a residual ink removing means for removing the ink remaining in the part.

  In this printing machine, the ink remaining in the non-image area of the plate is removed by the residual ink removing means. As a result, the ink remaining in the non-image area of the plate can be reduced, and deterioration in print quality can be suppressed.

  In the printing machine according to the next invention, in the printing machine, the residual ink removing unit remains in the non-image area before the ink image image is transferred to a blanket or a printing medium. It is characterized by removing ink.

  Since this printing machine has the same configuration as the printing machine, the same operation and effect as the printing machine are achieved. Further, in this printing machine, before the ink image line image is transferred to the blanket or the printing medium, the ink remaining in the non-image area is removed. As a result, it is possible to more reliably suppress a decrease in print quality. Further, the amount of ink transferred from the plate to the blanket or the like can be made appropriate by the leveling effect of the ink adhering to the image area. As a result, the print quality is improved.

  In the printing machine according to the next aspect of the present invention, in the printing machine, the residual ink removing unit is configured such that the non-image portion is determined by a difference between a surface energy of the residual ink removing unit and a surface energy of the non-image portion. The ink remaining in the ink is removed.

  Since this printing machine has the same configuration as the printing machine, the same operation and effect as the printing machine are achieved. Further, in this printing machine, the ink remaining in the non-image area is removed by the difference between the surface energy of the residual ink removing means and the surface energy of the non-image area. As a result, the ink remaining in the non-image area can be removed with a simple configuration.

  In the printing machine according to the next aspect of the invention, in the printing machine, the surface energy of the residual ink removing unit is larger than the surface energy of the non-image area and smaller than the surface energy of the image area. Features.

  Since this printing machine has the same configuration as the printing machine, the same operation and effect as the printing machine are achieved. Further, in this printing machine, the surface energy of the residual ink removing means is made larger than the surface energy of the non-image area and smaller than the surface energy of the image area. As a result, it is possible to reliably remove the ink remaining in the non-image area while minimizing the influence on the ink adhering to the image area (for example, the disturbance of the ink image).

  The following printing machine according to the present invention is characterized in that, in the printing machine, at least the surface of the residual ink removing means is lower in hardness than the surface of the plate.

  Since this printing machine has the same configuration as the printing machine, the same operation and effect as the printing machine are achieved. Further, in this printing machine, at least the surface of the residual ink removing means has a lower hardness than the surface of the plate. As a result, damage to the surface of the plate can be suppressed, so that a decrease in durability of the plate can be suppressed.

  The following printing machine according to the present invention is characterized in that the printing machine further includes ink circulation means for returning the ink removed by the residual ink removing means to the plate.

  Since this printing machine has the same configuration as the printing machine, the same operation and effect as the printing machine are achieved. Further, in this printing machine, the ink removed by the residual ink removing means is returned to the plate again. As a result, the ink can be used effectively. Returning ink to the plate includes returning ink from the ink circulation means directly to the plate, and returning ink from the ink circulation means to the plate via an ink roller, an inking roller, or the like.

  The printing machine according to the present invention is characterized in that the surface energy of the ink circulation means is larger than the surface energy of the residual ink removing means in the printing machine.

  Since this printing machine has the same configuration as the printing machine, the same operation and effect as the printing machine are achieved. Further, in this printing machine, the surface energy of the ink circulating means is made larger than the surface energy of the residual ink removing means. As a result, the ink can be reliably removed from the residual ink removing means.

  The printing machine according to the present invention is characterized in that, in the printing machine, the hardness of at least the surface of the ink circulation means is higher than the hardness of the surface of the residual ink removing means.

  Since this printing machine has the same configuration as the printing machine, the same operation and effect as the printing machine are achieved. Further, in this printing machine, the hardness of at least the surface of the ink circulation means is made higher than the hardness of the surface of the residual ink removing means. Thereby, the ink can be reliably moved from the residual ink removing means to the ink circulation means.

  In the printing machine according to the present invention, after the ink is removed from the residual ink removing means by the ink circulation means in the printing machine, the residual ink removing means remains in the non-image area. Ink removal means for removing ink remaining in the residual ink removal means is further provided until the remaining ink is removed.

  Since this printing machine has the same configuration as the printing machine, the same operation and effect as the printing machine are achieved. Further, the printing machine further includes an ink removing unit after the ink is removed by the ink circulation unit and before the residual ink removing unit removes the ink remaining in the non-image area. As a result, it is possible to reduce the possibility that the residual ink that has not moved to the ink circulation means will be reattached to the plate, so that it is possible to suppress a decrease in print quality.

  The printing machine which concerns on this invention can reduce the ink which remains in the non-image part of a plate in the waterless printing using water-based ink, and can suppress the fall of printing quality.

  Hereinafter, the present invention will be described in detail with reference to the drawings. The present invention is not limited by the best mode for carrying out the invention (hereinafter referred to as an embodiment). In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art or those that are substantially the same.

(Embodiment 1)
The printing machine according to Embodiment 1 is a plate attached to a plate cylinder from an inking cylinder by adjusting at least the temperature of the ink in the ink supply path, more preferably the amount of water in waterless printing using water-based ink. It is characterized in that it suppresses deterioration in transferability of ink transferred to the plate or ink transferred from the plate to the blanket cylinder.

  FIG. 1 is an explanatory diagram illustrating a configuration of a printing machine according to the first embodiment. FIG. 2-1 is an explanatory diagram illustrating a state in which a plate is attached to the plate cylinder. FIG. 2B is a conceptual diagram illustrating an image forming unit and a non-image forming unit of a plate used in the printing machine according to the first embodiment. FIG. 3 is an explanatory diagram illustrating an overall configuration of a printing system including the printing machine according to the first embodiment. FIG. 4 is an explanatory diagram illustrating another example of the ink supply unit included in the printing machine according to the first embodiment.

  The printing machine 1 according to this embodiment is configured to transfer an image line image (ink image line image) formed by ink adhering to an image line portion formed on a plate to a printing medium via a blanket. It is a printing machine. The printing machine 1 uses a so-called waterless plate that does not require adhesion of moisture to the plate before transferring the ink, and uses water-based ink.

  The printing system 2 shown in FIG. 3 includes the printing machine 1 shown in FIG. 1 for each color to be printed. In printing, since normally four colors of C (Cyan), M (Magenta), Y (Yellow), and K (Black) are used, the printing system 2 has a total for C, Y, M, and K. Four printing machines 1 are provided. Next, the configuration of the printing machine 1 according to this embodiment will be described in detail.

  As described above, the printing machine 1 according to this embodiment performs printing by waterless printing using water-based ink. The printing machine 1 includes printing units 4 on both sides of a paper 3 that is a printing medium. As a result, the printing machine 1 can simultaneously print on both sides of the paper 3. Note that the printing unit 4 may be provided only on one side of the paper 3.

  In the printing machine 1 according to this embodiment, the printing unit 4 includes an ink supply head 10, an ink base roller 11, an inking roller 12 made of rubber (for example, nitrile rubber: NBR), and an ink scraping roller that is a residual ink removing unit. 15, a plate cylinder 13 and a blanket cylinder 14 to which a rubber blanket 7 is attached. Ink 6 is supplied from the ink supply head 10 to the ink base roller 11. Here, in the printing machine shown in FIG. 1, ink is supplied from the ink supply head 10 to the ink source roller 11. However, as in the ink supply unit shown in FIG. 4, ink supply such as an anilox roller or a roller having pores is provided. Ink may be supplied to the ink source roller 11 using the roller 17. Or you may use the spray supply system which sprays the spray of the ink to the ink base roller 11 using a spray etc.

  The ink base roller 11 and the inking roller 12 are in contact with each other, and water-based ink (hereinafter referred to as ink) 6 applied to the surface of the ink base roller 11 is transferred to the inking roller 12. The inking roller 12 and the plate cylinder 13 are in contact with each other, and the ink 6 applied to the surface of the inking roller 12 is transferred to the plate cylinder 13.

  As shown in FIG. 2A, the plate 5 is attached to the plate cylinder 13. The plate provided in the printing machine 1 according to this embodiment is a so-called lithographic plate, and the surface of the plate 5 is divided into an image line portion 5A and a non-image line portion 5B as shown in FIG. In waterless printing using oil-based ink, a silicone resin is used for the plate, and the non-image area is made a low-energy surface on which ink is difficult to adhere. Then, the olefin / paraffinic solvent contained in the oil-based ink causes the silicone resin to swell, thereby forming a thin oil film in the non-image area. By these actions, in waterless printing using oil-based ink, the oil-based ink is prevented from adhering to the non-image area of the plate.

  However, in waterless printing using a water-based ink, an olefin / paraffin solvent is not contained in the water-based ink, and therefore an oil film cannot be formed by swelling of the silicone resin. Therefore, when water-based ink is used, the non-image area 5B is made of a water-repellent material such as silicone resin or fluororesin, and the image area 5A is made of a hydrophilic material. As a result, the ink (hereinafter referred to as “line ink”) 6A forming the image line is adhered to the image line portion 5A of the plate 5, and the ink remaining (hereinafter referred to as “residual ink”) on the non-image area 5B of the plate 5 Ink) 6B adhesion amount is minimized. Then, the residual ink 6B in the non-image area 5B is removed by the ink scraping roller 15. With such a configuration, waterless printing using water-based ink can be realized.

The surface energy Ec of the ink scraping roller 15 is larger than the surface energy En (21 dyne / cm ^{2 to} 23 dyne / cm ² ) of the non-image area 5B (Ec> En), and the surface energy Ep (30 dyne) of the image area 5A. / Cm ^{2 to} 40 dyne / cm ² ) (Ec <Ep) is preferable. In this way, it is possible to reliably remove the residual ink 6B from the non-image area 5B, and it is possible to minimize the image ink 6A that moves from the image area 5A to the ink scraping roller 15. As a result, print quality can be improved. Further, when removing the residual ink 6B from the non-image area 5B, the ink scraping roller 15 and the plate 5 provided on the plate cylinder 13 come into contact with each other. It also has the effect of leveling the ink 6A. Thereby, since the transfer property of the ink with respect to the blanket 7 or paper can be ensured, it contributes to the improvement of printing quality.

  The ink scraping roller 15 is preferably made of a material having a lower hardness than the plate 5 attached to the plate cylinder 13. Thereby, it is possible to suppress a decrease in durability of the plate 5. As a material for forming at least the surface of the ink scraping roller 15, for example, polyethylene, polypropylene, silicone rubber, rubber (for example, nitrile rubber: NBR) or the like can be used. In the case where the non-image portion 5B of the plate 5 is formed of silicone rubber, the composition of the silicone rubber used for the ink scraping roller 15 is adjusted when silicone rubber is used on at least the surface of the ink scraping roller 15. As a result, the surface energy and hardness of the ink scraping roller 15 are adjusted.

  In this embodiment, the residual ink 6B remaining on the non-image portion 5B of the plate 5 is removed by the ink scraping roller 15, but a large amount of ink is transferred to the plate 5 and the residual ink remaining on the non-image portion 5B. 6B may be removed by the ink scraping roller 15. In this way, even if the amount of ink transferred from the inking roller 12 to the plate 5 increases, the residual ink in the non-image area 5B can be removed by the ink scraping roller 15, so that deterioration in printing quality can be suppressed. . As a result, there is an advantage that necessary and sufficient print quality can be maintained even if the amount of ink transferred from the inking roller 12 to the plate 5 is not strictly controlled.

  In waterless printing using water-based ink, the ink supplied from the ink supply head 10 is sequentially transferred to the ink source roller 11, the inking roller 12, the plate 5 of the plate cylinder 13, and the blanket 7 of the blanket cylinder 14. In the process, the temperature of the ink changes and the amount of water in the ink changes. When the temperature of the ink changes, depending on the change, the ink may be dried by the ink base roller 11 or the inking roller 12 and affect the transfer of the ink to the plate 5. Further, when the ink is dried by the plate 5 or the blanket, the transfer of the ink to the blanket 7 or the paper 3 may be affected. Even when the amount of water in the ink changes, the transfer of the ink to the plate 5, the blanket 7 or the paper 3 may be affected as in the case where the temperature of the ink changes. Further, if the amount of water in the ink is too large, the printing quality may be affected, and the drying of the ink transferred to the paper 3 may be affected. As a result, the prescribed print quality cannot be achieved, or the print quality varies.

  In order to solve the above problem, the printing machine 1 according to this embodiment includes at least ink temperature adjusting means such as an air conditioner, and more preferably ink moisture amount adjusting means such as a humidifier. Then, for example, by controlling the atmosphere of the ink supply path by the ink temperature adjusting means or the like, at least the temperature of the ink transferred to the plate 5 or the blanket 7 is preferably controlled to an appropriate value. As a result, the influence on the transfer of the ink to the paper 3 and the drying of the ink transferred to the paper 3 can be reduced, so that the print quality can be improved and the variation in the print quality can also be suppressed. Here, the ink supply path refers to a path through which ink passes from the ink supply head 10 serving as an ink supply unit to the time when the ink is transferred to the paper 3 serving as a printing medium.

  When controlling the atmosphere of the ink supply path, the ink supply path is provided with temperature adjustment means (ink temperature adjustment means) and humidity adjustment means (ink water content adjustment means) to control the humidity and temperature of the ink supply path atmosphere. To do. In this embodiment, as shown in FIG. 1A, the first temperature / humidity adjusting means 20A is provided in the vicinity of the plate cylinder 13, and the second temperature / humidity adjusting means 20B is provided in the vicinity of the blanket cylinder 14. . Then, the water amount and temperature of the ink transferred to the plate provided in the plate cylinder 13 are adjusted by the first temperature / humidity adjusting means 20A, and the ink transferred from the plate 5 to the blanket 7 by the second temperature / humidity adjusting means 20B. Adjust the moisture content and temperature of 6. Here, the first and second temperature / humidity adjusting means 20A and 20B have both the function of the ink temperature adjusting means for adjusting the temperature of the ink and the function of the ink moisture amount adjusting means for adjusting the moisture content of the ink. It is.

  The first and second temperature / humidity adjusting means 20A and 20B are controlled by a control device 30 (see FIG. 5) described later. In this embodiment, the control device 30 acquires the humidity and temperature in the vicinity of the plate cylinder 13 and the humidity and temperature in the vicinity of the blanket cylinder 14, and based on this, the first and second temperature and humidity adjusting means 20 </ b> A and 20 </ b> B. Feedback control. Here, regarding the ink temperature, the temperature of the ink on the plate 5 or the blanket 7 may be directly measured using a non-contact type thermometer. As for the water content of the ink, the water content of the ink on the plate 5 or the blanket 7 may be directly measured using a non-contact type water meter utilizing the absorption wavelength of water. The humidity and temperature in the vicinity of the plate cylinder 13 are provided in the vicinity of the blanket cylinder 14 by the first temperature / humidity sensor 40A provided in the vicinity of the plate cylinder 13. It is measured by the second temperature / humidity sensor 40B.

  As a method for adjusting the moisture content of the ink, for example, there is a method for adjusting the humidity around the plate cylinder 13 and the blanket cylinder 14. More specifically, for example, there are those that use a humidifier to switch the humidifier ON and OFF, and those that change the ratio between the ON period and the OFF period of the humidifier. As a method for adjusting the temperature of the ink, for example, there is a method of adjusting the temperature of the ink by adjusting the temperature around the plate cylinder 13 or the blanket cylinder 14. More specifically, for example, there is one that circulates air whose temperature has been adjusted around the plate cylinder 13 or the blanket cylinder 14. As a method for adjusting the temperature of the ink, for example, there is a method in which a fluid passage is provided in the plate cylinder 13 or the like, and a fluid whose temperature is adjusted (for example, water or air) is supplied to the fluid passage. The first and second temperature and humidity adjusting means 20A and 20B can be configured by combining the above-described method for adjusting the water content of the ink and the above-described method for adjusting the temperature of the ink. In addition, the ink water content adjusting means can be configured using, for example, the above-described method for adjusting the water content of the ink, and the ink temperature adjusting device can be configured using, for example, the above-described method for adjusting the ink temperature. Can be configured.

  A means for adjusting the water content or temperature of the ink transferred to the plate or blanket (for example, the first temperature / humidity adjusting means 20A) is provided at least in the vicinity of the plate 5 provided in the plate cylinder 13 and is transferred to the plate 5 Adjust the water content and temperature of the ink. Since the image is formed only after the ink is transferred to the plate, the final printing is the transfer of ink from the plate to the blanket in offset printing, and the transfer of ink from the plate to paper in so-called flexographic printing. It has the most impact on quality. For this reason, at least the water content and temperature of the ink after being transferred to the plate are adjusted. As a result, high print quality can be maintained, and variations in print quality can be suppressed.

  In the offset printing, it is preferable to further provide means for adjusting the water content or temperature of the ink transferred to the blanket 7 (second temperature / humidity adjusting means 20B in this embodiment). This makes it possible to control the state of the ink immediately before being transferred to the paper 3, thereby making it easier to improve the print quality. Further, as the printing speed increases, the adjustment of the water content and temperature of the ink after being transferred to the plate 5 may be insufficient for the desired print quality. In such a case, the ink is transferred to the blanket 7. By adjusting the water content and temperature of the ink that has been removed, it is possible to suppress a decrease in print quality.

  The ink moisture amount and temperature adjusting means may be provided in the ink supply head 10, the ink base roller 11, the inking roller 12, or the like. In this way, the water content and temperature of the ink can be controlled more precisely. As a result, even when the printing conditions such as the printing speed and the printing environment change, the printing quality can be maintained and the variation in the printing quality can be suppressed.

  The ink 6 transferred from the plate 5 included in the plate cylinder 13 to the blanket 7 included in the blanket cylinder 14 is transferred from the blanket 7 to the paper 3. The paper 3 to which the ink 6 has been transferred is dried by an ink drying means 21 provided on the paper exit side of the blanket cylinder 14. For example, an infrared lamp or a hot air drying device can be used as the ink drying means 21. In this embodiment, the moisture content of the ink 6 after passing through the ink drying means 21 is measured by the moisture meter 41, and the heating amount of the ink drying means 21 is controlled based on this. As the moisture meter 41, for example, a non-contact moisture meter using an absorption wavelength of water can be used. Next, the control device 30 according to this embodiment will be described.

  FIG. 5 is an explanatory diagram illustrating a configuration of the control device according to the first embodiment. As shown in FIG. 5, the control device 30 includes a processing unit 31, a storage unit 32, input and output interfaces 33 and 54, and input and output ports 35 and 36. The processing unit 31 included in the control device 30 is a part that executes control of the water content and temperature of the ink according to this embodiment. The processing unit 31 and the storage unit 32 are connected via an input port 35 and an output port 36. As a result, the processing unit 31 and the storage unit 32 can exchange data necessary for control with each other, and can issue commands to one of them.

  An input interface 33 is connected to the input port 35. The input interface 33 is connected to the first and second temperature / humidity sensors 40A and 40B and the moisture meter 41. Signals output from these sensors are converted into signals that can be used by the processing unit 31 by an A / D converter or a digital buffer provided in the input interface 33 and sent to the input port 35. Thereby, the process part 31 can acquire the information required for control of the moisture content and temperature of the ink which concerns on this embodiment.

  An output interface 34 is connected to the output port 36. Control objects such as the first temperature / humidity adjusting unit 20A, the second temperature / humidity adjusting unit 20B, and the ink drying unit 21 are connected to the output interface 34. The output interface 34 includes a control circuit, and operates the control target based on a control signal calculated by the processing unit 31. With such a configuration, based on the output signals from the sensors, the processing unit 31 included in the control device 30 controls the water content and temperature of the ink according to this embodiment.

  The storage unit 32 includes a computer program and a control map including a processing procedure for controlling the water content and temperature of the ink according to this embodiment according to this embodiment, or the water content of the ink according to this embodiment according to this embodiment. In addition, a control data map and the like used for temperature control are stored. Here, the storage unit 32 can be configured by a volatile memory such as a RAM (Random Access Memory), a nonvolatile memory such as a flash memory, or a combination thereof.

  The computer program may be capable of realizing the driving force distribution control processing procedure according to this embodiment in combination with a computer program already recorded in the processing unit 31. The control device 30 may realize the function of the processing unit 31 using dedicated hardware instead of the computer program. Next, control of the water content and temperature of the ink according to this embodiment will be described.

  FIG. 6 is a flowchart showing a procedure for controlling the water content and temperature of the ink according to the first embodiment. FIG. 7 is an explanatory diagram showing an example of a moisture content determination map used for determining the moisture content of ink. In the following explanation, an example of adjusting the temperature of ink and the amount of water of ink based on the temperature and humidity of the atmosphere in the ink supply path will be described. However, the temperature of the ink is set at least according to the temperature of the atmosphere in the ink supply path. Adjust it.

  In executing the control of the water content and temperature of the ink according to this embodiment (hereinafter referred to as the water content and temperature control), the processing unit 31 of the control device 30 includes the first and second temperature / humidity sensors 40A and 40B. The ambient temperature and ambient humidity in the vicinity of the plate cylinder 13 and the blanket cylinder 14 are acquired (step S101).

  In this embodiment, the ambient temperature in the vicinity of the plate cylinder 13 is regarded as the temperature T of the ink transferred to the plate 5 provided in the plate cylinder 13, and the ambient temperature in the vicinity of the blanket cylinder 14 is the temperature of the ink transferred to the blanket cylinder 14. Considered temperature T. The moisture content of the ink transferred to the plate 5 of the plate cylinder 13 is determined from the atmospheric humidity H in the vicinity of the plate cylinder 13 and the temperature T of the ink transferred to the plate 5 (that is, the ambient temperature in the vicinity of the plate cylinder 13). . The moisture content of the ink transferred to the blanket cylinder 14 is determined from the atmospheric humidity H in the vicinity of the blanket cylinder 14 and the temperature T of the ink transferred to the blanket cylinder 14 (that is, the ambient temperature in the vicinity of the plate cylinder 13). .

  Specifically, the water content of the ink is obtained in advance from the relationship between the ink temperature and the ambient humidity around the ink, and a water content determination map 50 shown in FIG. 7 is created and stored in the storage unit 32 of the control device 30. Keep it. The moisture content determination map 50 is created in advance by experiments, analysis, or the like. In determining the water content of the ink, the processing unit 31 obtains the ambient temperature (that is, the ink temperature T) acquired from the first and second temperature / humidity sensors 40A and 40B, and the ambient humidity H around the ink. Is given to the moisture content determination map 50. The water content determination map 50 returns the water content W of the ink corresponding to T and H at that time to the storage unit 32. By such a procedure, the temperature T and water content W of the ink transferred to the plate 5 of the plate cylinder 13 and the temperature T and water content W of the ink transferred to the blanket cylinder 14 are determined (step S102).

  Next, the processing unit 31 determines that the temperature T and water content W of the ink transferred to the plate 5 of the plate cylinder 13 determined in step S102 and the temperature T and water content W of the ink transferred to the blanket cylinder 14 are as follows. It is determined whether or not the predetermined set temperature Ts and the set water amount Ws are within the allowable ranges set in advance (step S103). In this embodiment, if the ink temperature T is in the range of Ts-a or more and Ts-b or less, the ink temperature T is determined to be within the allowable range of the set temperature Ts. Further, if the ink water content W is in the range of Ws-c or more and Ws-d or less, the ink water content W is determined to be within the allowable range of the set water content Ws. Here, a, b, c, and d are constants and are determined in advance by experiments, analysis, or the like.

  In this embodiment, the set temperature Ts and the set water amount Ws are common to the ink transferred to the plate 5 and the ink transferred to the blanket 7. In this way, there is an advantage that the setting of the set temperature Ts and the set water amount Ws can be reduced. The set temperature Ts and the set water amount Ws may be different between the ink transferred to the plate 5 and the ink transferred to the blanket 7. In this way, since the temperature and humidity of the ink can be set more finely with the plate 5 and the blanket 7, the printing quality such as color development and sharpness can be controlled more precisely.

  When the temperature T and water content W of the ink transferred to the plate 5 and the temperature T and water content W of the ink transferred to the blanket 7 are all within the allowable ranges of the set temperature Ts and the set water content Ws (step S103: Yes), the processing unit 31 maintains the setting of the operating conditions of the first and second temperature / humidity adjusting means 20A, 20B in the state up to that point (step S104).

  When at least one of the temperature T or the water content W of the ink transferred to the plate 5 or the temperature T or the water content W of the ink transferred to the blanket 7 is out of the allowable range of the set temperature Ts or the set water content Ws. (Step S103: No), the processing unit 31 adjusts the temperature or water content of the ink that deviates from the set temperature Ts or the set water content Ws (Step S105). Then, the temperature or water content of the ink falls within the allowable range of the set temperature Ts or the set water content Ws.

  For example, when the temperature T of the ink transferred to the plate 5 is outside the allowable range of the set temperature Ts, the processing unit 31 adjusts the temperature adjustment function of the first temperature / humidity adjustment unit 20A to adjust the temperature of the plate cylinder 13. Change the temperature in the vicinity. As a result, the temperature of the ink transferred to the plate 5 is set within the allowable range of the set temperature Ts. Further, when the moisture amount W of the ink transferred to the plate 5 is outside the allowable range of the set moisture amount Ws, the processing unit 31 adjusts the humidity adjustment function of the first temperature / humidity adjusting unit 20A to thereby adjust the plate cylinder. The humidity in the vicinity of 13 is changed. As a result, the water content of the ink transferred to the plate 5 falls within the allowable range of the set water content Ws.

  By the above procedure, the processing unit 31 is configured so that the temperature T and the water content W of the ink transferred to the plate 5 and the temperature T and the water content W of the ink transferred to the blanket 7 are all set temperature Ts and set water content Ws. Control within the allowable range. Thereby, in waterless printing using water-based ink, since the influence on the transfer of water-based ink to paper 3 and the drying of water-based ink transferred to paper 3 can be reduced, the printing quality can be improved, Also, variations in print quality can be suppressed.

  In the moisture amount and temperature control, the ink temperature and the ink moisture amount were adjusted based on the temperature and humidity of the atmosphere in the ink supply path. As parameters for controlling the ink temperature and the ink moisture amount, for example, Further, the line rate of the line to be printed may be used. Since the drying property of the ink varies depending on the image area ratio, by using the image area ratio as a control parameter, it is possible to further control the ink transfer performance and achieve higher printing quality.

  FIG. 8 is an explanatory diagram illustrating a procedure of ink drying control according to the first embodiment. This ink drying control can be realized by the control device 30 (see FIG. 5). In executing this drying control, the processing unit 31 of the control device 30 acquires the moisture amount Wp of the ink (hereinafter, dried ink) after being dried by the ink drying means 21 from the moisture meter 41 (step S201).

  Next, the processing unit 31 determines whether or not the moisture content Wp of the dry ink is within an allowable range of a predetermined preset dry ink moisture content Wps (step S202). In this embodiment, if the water content Wp of the dry ink is in the range of Wps-e or more and Wps-f or less, the water content Wp of the dry ink is determined to be within the allowable range of the set dry ink water content Wps. . Here, e and f are constants, and are determined in advance by experiment, analysis, or the like.

  When the water content Wp of the dry ink is within the allowable range of the set dry ink water content Wps (step S202: Yes), the processing unit 31 maintains the operation condition setting of the ink drying means 21 in the state up to that time. (Step S203). When the water content Wp of the dry ink is outside the allowable range of the set dry ink water content Wps (step S202: No), the processing unit 31 controls the ink drying means 21 to adjust the heating amount (step S204). The water amount Wp of the dry ink is set within the allowable range of the set temperature Ts or the set water amount Ws. As a result, the moisture content Wp of the dry ink can be maintained within a certain range, so that ink drying defects can be more reliably suppressed.

(Modification)
The printing machine 1a according to the modification of the first embodiment is used for so-called flexographic printing using water-based ink and a relief plate without water. Other configurations are the same as those in the first embodiment, and the moisture amount, temperature control, and drying control can be applied to this modification as they are. FIG. 9 is an explanatory diagram illustrating a configuration of a printing machine according to a modification of the first embodiment. FIG. 10 is an explanatory diagram illustrating an overall configuration of a printing system including a printing machine according to a modification of the first embodiment.

  In the printing machine 1a according to this embodiment, the printing unit 4a includes an ink supply head 10, an ink base roller 11, a rubber inking roller 12, an ink scraping roller 15 as a residual ink removing means, and a plate cylinder 13. Consists of. A plate 5 is attached to the plate cylinder 13, and ink is transferred from the inking roller 12. The plate attached to the plate cylinder 13 is a relief plate, and ink is transferred to the projections of the plate. The plate to which the ink has been transferred directly contacts the paper 3 and the ink transferred to the convex portion is transferred to the surface of the paper 3. As shown in FIG. 10, the printing system 2 a is configured to be able to print on both sides of the paper 3. For this reason, a total of four printing machines 1a for C, Y, M, and K are used as single-side printing units, and a total of two printing units are provided.

  As with the printing machine 1 according to the first embodiment (see FIG. 1), the printing machine 1a according to this modification is provided with humidity adjusting means and temperature adjusting means in the ink supply path, and the humidity of the atmosphere in the ink supply path is Control the temperature. In this modification, as shown in FIG. 9, temperature / humidity adjusting means 20 </ b> A is provided in the vicinity of the plate cylinder 13 to adjust the water content and temperature of the ink transferred to the plate provided in the plate cylinder 13. As a result, even in waterless relief printing using water-based ink, it is possible to reduce the influence on the transfer of water-based ink to the paper 3 and the drying of the water-based ink transferred to the paper 3, so that the printing quality can be improved. Also, variations in print quality can be suppressed.

  As mentioned above, in this embodiment and its modification, in waterless printing using water-based ink, at least the temperature of the ink in the ink supply path, more preferably the water content is adjusted. This suppresses deterioration in transferability of ink transferred from the inking cylinder to the plate attached to the plate cylinder or ink transferred from the plate to the blanket cylinder. Thereby, it is possible to suppress a decrease in print quality. Moreover, since the temperature and moisture content of the ink are adjusted, the drying property of the ink after being transferred to paper is also improved.

  In this embodiment and its modification, a residual ink removing means for removing ink remaining in the non-image area of the plate is provided. As a result, the ink remaining in the non-image area of the plate can be reduced, and deterioration in print quality can be suppressed. In addition, what is equipped with the structure disclosed by this embodiment and its modification has the effect | action and effect similar to this embodiment and its modification. In addition, the configurations disclosed in this embodiment and its modifications can be applied as appropriate in the following embodiments.

(Embodiment 2)
The printing machine according to the second embodiment is characterized in that residual ink adhering to a non-image portion of a plate provided in the plate cylinder is collected by an ink collecting unit and transferred to the plate again. Other configurations are the same as those of the first embodiment. Next, a detailed configuration of the printing machine according to the second embodiment will be described. In the following description, please refer to FIGS. 2-1 and 2-2 as appropriate. As in the first embodiment, the printing machine according to the second embodiment can be applied not only to offset printing but also to flexographic printing.

  FIG. 11 is an explanatory diagram illustrating a configuration of a printing machine according to the second embodiment. FIG. 12 is an explanatory diagram illustrating an example in which the printing machine according to the second embodiment is applied to so-called flexographic printing. A printing machine 1c shown in FIG. 11 is provided in the offset printing system 2 (see FIG. 3) according to the first embodiment. A printing machine 1d shown in FIG. 12 is provided in a flexographic printing system 2a (see FIG. 10) according to a modification of the first embodiment.

  As shown in FIG. 11, the printing machine 1 c includes a printing unit 4 c that includes an ink supply roller 17, an ink source roller 11, an inking roller 12, an ink scraping roller 15 that is a residual ink removing unit, and an ink that is an ink circulation unit. A circulation roller 16, a plate cylinder 13, and a blanket cylinder 14 are included. As shown in FIG. 12, the printing machine 1d includes a printing unit 4c that includes an ink supply roller 17, an ink source roller 11, an inking roller 12, an ink scraping roller 15 as a residual ink removing unit, and an ink circulation unit. An ink circulation roller 16 and a plate cylinder 13 are included.

  The ink circulation roller 16 is in contact with the ink scraping roller 15 and the inking roller 12. Here, at least one ink circulation roller 16 is required, and two or more ink circulation rollers 16 may be provided. As described in the above embodiment, in the printing machines 1c and 1d according to this embodiment, the residual ink 6B remaining on the non-image portion 5B of the plate 5 attached to the plate cylinder 13 is removed by the ink scraping roller 15. To do. Furthermore, in the printing machines 1c and 1d according to this embodiment, the residual ink 6B attached to the surface of the ink scraping roller 15 is attached to the ink circulation roller 16 which is the ink circulation means, and the plate is passed through the inking roller 12. Return to the plate 5 provided in the cylinder 13 (that is, transfer). This is economical because the residual ink 6B that is normally discarded can be reused.

  Here, the surface energy Er of the ink circulation roller 16 is preferably larger than the surface energy Ec of the ink scraping roller 15 (Er> Ec) and smaller than the surface energy Es of the inking roller 12 (Er <Es). . In this way, the residual ink 6B can be reliably moved from the ink scraping roller 15 to the ink circulation roller 16, and the residual ink 6B can be reliably moved from the ink circulation roller 16 to the inking roller 12. Can do. Further, in order to reliably transfer the ink 6 from the inking roller 12 to the image line portion of the plate, it is more preferable that the surface energy Es of the inking roller 12 is smaller than the surface energy Ep of the image line portion (Es < Ep).

  Further, it is preferable that at least the surface of the ink circulation roller 16 has a hardness higher than that of the surfaces of the ink scraping roller 15 and the inking roller 12. This is due to the following reason. In order to move the residual ink 6B from the ink scraping roller 15 and to move the residual ink 6B to the inking roller, a certain amount of pressure is generated between the ink circulation roller 16 and the ink scraping roller 15 or the like. Preferably it is. For this purpose, at least the surface of the ink circulation roller 16 is preferably made of a material having a higher hardness than the surface of the ink scraping roller 15 made of a rubber material such as silicone rubber or nitrile rubber (NBR). It is.

  Further, in order to easily adjust the surface energy of the ink circulation roller 16, for example, there is a method of blasting the surface of the ink circulation roller 16. For this purpose, at least the surface of the ink circulation roller 16 is preferably made of a material having a certain degree of hardness. As a material constituting the surface of the ink circulation roller 16, for example, a metal material such as copper or stainless steel can be used. Moreover, it is also good to plate copper, nickel, etc. on the surface of the resin material. Further, the surface of the ink circulation roller 16 may be made of a resin material having a higher hardness than the surface of the ink scraping roller 15 or the like (for example, fluorine resin or nylon resin). In this way, when the residual ink in the non-image area of the plate is transferred again to the plate via the ink circulation roller 16, the ink can be efficiently circulated.

  As described above, in the printing machines 1 c and 1 d according to this embodiment, the ink removed from the ink scraping roller 15 by the ink circulation roller 16 is moved to the inking roller 12. For this reason, the temperature and water content of the ink transferred from the inking roller 12 to the plates 5 and 5a deviate from the allowable range of the set value. As a result, the temperature and the ink after being transferred to the plates 5 and 5a There is a risk that the amount of moisture deviates from the allowable range of the set value.

  The printing machine 1c according to this embodiment includes a first temperature / humidity adjusting unit 20A in the vicinity of the plate cylinder 13 and a second temperature / humidity adjusting unit 20B in the vicinity of the blanket cylinder 14 as an ink temperature adjusting unit and an ink moisture amount adjusting unit. Is provided. The printing machine 1d according to this embodiment includes a temperature / humidity adjusting unit 20 in the vicinity of the plate cylinder 13 as an ink temperature adjusting unit and an ink moisture amount adjusting unit. In the printing machines 1c and 1d according to this embodiment, even if the temperature and water content of the ink after being transferred to the plate 5 deviate from the set values, the water content using the ink temperature adjusting device and the ink water content adjusting device is used. And by temperature control, the temperature and water content of the ink after being transferred to the plates 5 and 5a can be kept within the allowable range of the set value. As a result, it is possible to minimize problems caused by changes in ink temperature and water content due to reuse of residual ink and maintain high print quality.

(Modification)
FIG. 13 is an explanatory diagram illustrating a printing unit of a printing machine according to a modification of the second embodiment. The printing machine 1e according to this modified example has the same configuration as the printing machines 1c and 1d according to the second embodiment, but the ink scraping roller 15 that is a residual ink removing unit is an ink circulating roller 16 that is an ink circulating unit, and After contact, the ink removing blade 18 is provided as an ink removing means. Other configurations are the same as those of the printing machines 1c and 1d according to the second embodiment.

  As shown in FIG. 13, the printing machine 1 e includes an ink removing blade 18 after the ink scraping roller 15 comes into contact with the ink circulation roller 16. That is, after the residual ink 6B is removed from the ink scraping roller 15 as the residual ink removing means by the ink circulating roller 16 as the ink circulating means, the ink scraping roller 15 is moved to the non-image portion 5B of the plate 5. An ink removing blade 18 serving as an ink removing means is provided until the remaining residual ink 6B is removed.

  The ink removing blade 18 contacts the ink scraping roller 15 in the width direction of the ink scraping roller 15 at least during rotation of the ink scraping roller 15. Then, the residual ink 6B that has not moved to the ink circulation roller 16 is removed from the surface of the ink scraping roller 15. This can reduce the risk that the residual ink 6B that has not moved to the ink circulation roller 16 will re-adhere to the plate 5 of the plate cylinder 13, so that it is possible to suppress a decrease in print quality.

  As described above, the second embodiment and the modification thereof include the residual ink removing unit that removes the ink remaining in the non-image area of the plate, and the residual ink removed by the residual ink removing unit is returned to the plate again. Ink circulation means is provided. As a result, the ink remaining in the non-image area of the plate can be reduced, and the deterioration of printing quality can be suppressed, and the residual ink is reused. In addition, what is equipped with the structure disclosed by this embodiment and its modification has the effect | action and effect similar to this embodiment and its modification.

  As described above, the printing machine according to the present invention is useful for waterless printing using water-based ink, and is particularly suitable for suppressing the deterioration of printing quality.

1 is an explanatory diagram illustrating a configuration of a printing machine according to Embodiment 1. FIG. It is explanatory drawing which shows the state which attached the plate to the plate cylinder. FIG. 3 is a conceptual diagram illustrating an image forming unit and a non-image forming unit of a plate used in the printing machine according to the first embodiment. 1 is an explanatory diagram illustrating an overall configuration of a printing system including a printing machine according to Embodiment 1. FIG. It is explanatory drawing which shows the other example of the ink supply part with which the printing machine which concerns on Embodiment 1 is provided. FIG. 2 is an explanatory diagram illustrating a configuration of a control device according to the first embodiment. 3 is a flowchart showing a procedure for controlling the water content and temperature of ink according to the first embodiment. It is explanatory drawing which shows an example of the moisture content determination map used in order to determine the moisture content of ink. FIG. 5 is an explanatory diagram illustrating a procedure of ink drying control according to the first embodiment. It is explanatory drawing which shows the structure of the printing machine which concerns on the modification of Embodiment 1. It is explanatory drawing which shows the whole structure of the printing system provided with the printing machine which concerns on the modification of Embodiment 1. FIG. FIG. 6 is an explanatory diagram illustrating a configuration of a printing machine according to a second embodiment. It is explanatory drawing which shows the example which applied the printing machine which concerns on Embodiment 2 to what is called flexographic printing. FIG. 10 is an explanatory diagram illustrating a printing unit of a printing machine according to a modification of the second embodiment.

Explanation of symbols

11, 1a, 1c, 1d, 1e Printing machine 2, 2a Printing system 3 Paper 4, 4a, 4c Printing unit 5 Plate 5A Image area 5B Non-image area 6 Ink 6A Image ink 6B Residual ink 7 Blanket 10 Ink supply Head 11 Ink roller 12 Inking roller 13 Plate cylinder 14 Blanket cylinder 15 Ink scraping roller 16 Ink circulation roller 17 Ink supply roller 18 Ink removal blade 20 Temperature / humidity adjusting means 20A First temperature / humidity adjusting means 20B Second temperature Humidity adjusting means 21 Ink drying means 30 Controller 40A First temperature / humidity sensor 40B Second temperature / humidity sensor 41 Moisture meter

Claims (9)

It is used for printing using waterless ink and waterless printing that does not require application of dampening water,
A plate provided with an image line portion for forming an ink image image of the image line by forming an image line and transferring ink, and a non-image line portion where the image line is not formed,
In the plate, residual ink removing means for removing ink remaining in the non-image area,
A printing machine comprising: The residual ink removing means is
The printing machine according to claim 1, wherein the ink remaining in the non-image area is removed before the ink image image is transferred to a blanket or a printing medium. The residual ink removing means is
3. The printing according to claim 1, wherein the ink remaining in the non-image area is removed by a difference between a surface energy of the residual ink removing unit and a surface energy of the non-image area. machine.   The printing machine according to claim 3, wherein a surface energy of the residual ink removing unit is larger than a surface energy of the non-image area and smaller than a surface energy of the image area.   5. The printing machine according to claim 1, wherein at least a surface of the residual ink removing unit has a hardness lower than that of the surface of the plate.   The printing machine according to claim 1, further comprising an ink circulation unit that returns the ink removed by the residual ink removing unit to the plate.   The printing machine according to claim 6, wherein the surface energy of the ink circulation means is larger than the surface energy of the residual ink removing means.   The printing machine according to claim 6 or 7, wherein the hardness of at least the surface of the ink circulation means is higher than the hardness of the surface of the residual ink removing means.   After the ink is removed from the residual ink removing means by the ink circulation means, the residual ink removing is further performed after the residual ink removing means removes the ink remaining in the non-image area. The printing machine according to claim 6, further comprising an ink removing unit that removes ink remaining in the unit.

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