JP2008155644A - Device for controlling feeding of ink in inking arrangement - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To control feeding of ink in an inking arrangement by a simple means as required. <P>SOLUTION: In the inking arrangement 6 for an offset printer in particular, temperatures of an ink groove roller 8 and temperature adjustable inking arrangement rollers 11 can be respectively adjusted to affect the ink flow corresponding to application purposes. A temperature adjustment system T sets a negative temperature difference between the temperature of the ink groove roller 8 and the temperature of the inking arrangement rollers. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The invention relates to a method as described in the writing of claim 1 and to an apparatus as described in the writing of claim 10.

  In offset printers, inks with high viscosity are often used. Such rheological properties of the ink are referred to as thixotropy, and the viscosity of the ink is reduced by movement in particular. Therefore, in order to make the ink film thickness required for high-quality printing uniform with a thickness of a few micrometers, a relatively high-cost inking device having a large number of inking rollers is usually used. Ink is passed between the machine rollers by an ink separation process. The ink is usually removed from the ink groove by the ink groove roller under the influence of the dispensing means and supplied to the next inking roller in the first ink film. This inking roller usually receives the ink film synchronously from the ink groove roller as an ink transfer roller, or continuously receives the ink film from the ink groove roller as a film roller, and this is received by the inking roller. The ink is transferred to an ink roller group in which one or a plurality of ink form rollers for placing ink on the printing plate are arranged at the end portion. In sheet offset printing, four ink form rollers are often used, and in rotary offset printing, only two ink form rollers are often used. For this reason, the inking roller is divided into a plurality of inking roller trains.

  The basic role of the inking unit is to apply different inks to the printing plate for each zone, and then contact the relief ink that inevitably occurs on the ink forming roller, and then contact the ink forming roller with the printing plate. Before, it is possible to flatten as completely as possible by placing the ink again on the inking roller.

  Ink devices for offset printing devices are particularly suitable for high-quality printing in multi-roller inking machines, as the appropriate ink feed varies from picture to picture, and one printing device needs to be suitable for processing different pictures simultaneously. It is desirable to be able to influence the ink distribution in the inking device.

  It is known that ink separation at the exit of the inking roller gap depends on the temperature of the inking roller involved. When one cooled inking device roller is arranged in the ink roller group, the thickness of the ink is increased as compared with a state where the ink roller is not cooled.

  Such an apparatus is known from Patent Document 1, Patent Document 2, and Patent Document 3, for example. By using a so-called temperature control device, the viscosity of the fed ink is affected. At this time, it is known to arrange temperature control devices in almost all places of the printing device and the ink device.

The temperature adjustment can be performed from the inside by a heat medium flowing through the inking device roller. A temperature sensor is often used to measure the temperature of the surface of the inking device roller or cylinder in order to adjust the temperature of the temperature adjusting medium, respectively. The installation place in the inking device roller also extends over the ink groove roller, the ink kneading roller, and the ink form roller. A temperature control device for cooling and ink feeding stability is specifically described. In Patent Document 1, as a further effect, a reduction in stains in the printing apparatus and the attached inking apparatus is described. However, it is not known how the described apparatus can affect the ink feeding in the inking apparatus.
German patent invention No. 4335097 German Patent Invention No. 9316932 German Patent Invention No. 4202544

  SUMMARY OF THE INVENTION An object of the present invention is to provide an operating method and an inking device attached thereto that can avoid the disadvantages of the prior art and can control ink feeding in the inking device as required.

  This problem can be solved by a method having the features of claim 1 and by an apparatus having the features of claim 10.

In the method of the present invention, the temperature of the ink groove roller is set to a value lower than the temperature of the temperature adjustable roller in the ink roller group in the temperature adjusting device of the offset printing apparatus.
This behavior is preferably set for a printed pattern with a relatively low ink feed.

If the temperature of the ink groove roller is lower than the temperature of the subsequent ink device roller and the temperature difference between the ink groove roller and the ink device widens, the speed, the opening degree of the ink metering element, the synchronization cycle of the ink transfer roller, etc. If the operating parameters are the same, the color density when ink is applied to the substrate is increased.
Such behavior is a great advantage in the case of poster or display printing where there is a high demand for ink transfer or color density to the image represented by printing. In that case, a constant inking is reached in a very short time in the printing process.
The necessary temperature adjustment can be made by controlling the individual zones of the ink kneading roller. In that case, a system is constituted by one recovery pipe and a plurality of control valves.

By adjusting the temperature of the inking device, it is also possible to incorporate color density control, albeit at a certain limit.
At this time, in a related experiment, when the temperature of the ink groove roller was adjusted to 27 ° C. according to the present invention and the temperature of the ink kneading roller was set 13 ° C. higher than the temperature adjustment of the ink groove roller, the value of color density was It was shown that it can be increased to a maximum 0.30 concentration value, ie approximately 30%.

  Hereinafter, the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows a printing apparatus for sheet-fed offset printing in detail. The printing apparatus includes a plate cylinder 1, a transfer cylinder 2, and an impression cylinder 4 that is used for conveying a printing material in a sheet running direction 3. A dampening device 5 and an inking device 6 are assigned to the transfer cylinder 2 by a known method. Creation of a printed image on a sheet is performed in a printing gap between the transfer cylinder 2 and the impression cylinder 4. The dampening device 5 includes a dampening roller in addition to the dampening water container and the dampening water roller.

  The ink device 6 includes an ink groove 7, a doctor roller or ink groove roller 8, and an ink transfer roller 9. In addition, a metering system assigned to the ink groove roller 8 and not shown in detail in this figure is provided in the ink groove 7. For this purpose, a so-called ink slider or an ink discharge adjusting plate is usually used for the ink groove roller 8 to create a metering gap that can be changed according to the required amount of ink. The metering gap can be controlled for each zone, and can be automatically adjusted using a so-called ink adjusting device based on the color density value of the sheet.

  The ink transfer roller 9 is provided with a viscoelastic cover, and is in contact with the ink groove roller 8 and the first transfer roller 10 alternately while swinging by a driving device not described in detail here. The first transfer roller 10 is usually implemented as a so-called ink kneading roller in practical use. The ink device 6 further includes a plurality of ink kneading rollers 11. These ink kneading rollers 11 are driven while rotating and swinging in a settable axial direction. Further, four ink form rollers 12 are provided. Using these ink form rollers, a necessary amount of ink is attached to the plate cylinder 1 and applied to the printing plate wetted by the dampening device 5.

  In order to perform stable ink feeding, the inking device 6 needs to be filled. For stable ink delivery, all rollers wear a certain ink film on their active surface according to their placement within the ink roller group and surface characteristics including surface temperature. Need to be. It can be said that the ink feeding is stable when the local unevenness of the ink film thickness exceeds the film thickness difference caused by the process start.

Two roller trains emerge from the upper ink kneading roller 11, and these roller trains form an ink flow to four ink forming rollers 12 via two additional ink kneading rollers 11 and transfer rollers, respectively. ing. Dividing into multiple roller trains allows special ink flow distribution. Such inking devices are often configurable to be able to operate in standard or front heavy or symmetrical configurations for ink flow distribution during printing.
Ink is applied to the printing plate by the ink application roller 12, and the printed image is applied from the printing plate to the printing material placed on the impression cylinder 4 through the transfer cylinder 2.

  Here, the temperature adjustment of the ink kneading roller 11 of the roller group is performed individually independently of each other or together as the entire roller train.

  The temperature adjustment of the inking device 6 is performed by flowing a temperature adjusting liquid such as a heated medium, such as water, through each roller by a known method only illustrated in this document.

  For this purpose, a temperature adjusting connector TF for the ink groove roller and a temperature adjusting agent circulation T1 to T4 for the ink kneading roller 11 are provided. The temperature regulator circulation is provided with a cooling or heating device for the temperature regulator. The temperature adjusting agent is supplied to the respective rollers in the axial direction by the feed pump via the pipes and the temperature adjusting connectors TF or T1 to T4 respectively arranged, and is collected again.

The actual temperature control for the ink film on the inking device roller can be done directly through ink property measurements or indirectly through temperature regulator property measurements.
For this purpose, the temperature of the inking roller or ink is measured using a sensor directed at the surface of the temperature-controlled inking roller, and then controlled or controlled.
On the other hand, temperature regulation control or control uses a control valve to measure the temperature of the temperature regulator, correct this temperature by heating or cooling, and provide appropriate remixing or flow control during circulation. Can also be done.

  It is also possible to indirectly influence the temperature control by measuring the density on the sheet and in some cases density control on the basis of the measured values obtained.

  2 and 3 show connection diagrams for system operation.

FIG. 2 shows the configuration of the part of the inking device 6 already described. Numbers indicating the ink groove roller 8 and the ink kneading roller 11 are attached to the four printing devices D1 to D4. The ink groove roller 8 is connected by a temperature adjusting agent circulation TF. The ink kneading roller 11 is also connected to the temperature adjustment system by individual connectors T3 / T4 or one composite connector T1 to T4.
In this way, the temperature of the ink groove roller 8 can be set completely independently of the temperature of the ink kneading roller 11.
As the control variable, the return temperature of the temperature adjusting agent can be used.

  FIG. 3 shows a portion of one printing device of the inking device 6 already described. Here too, numbers indicating the ink groove roller 8 and the ink kneading roller 11 are given. The ink groove roller 8 is connected to the temperature adjustment system T via a control valve RF by a temperature adjustment agent connector TF. The upper first ink kneading roller 11 is also connected to the temperature adjustment system T via the temperature control agent connector T1 via a further control valve R1. Two further ink kneading rollers 11 are connected to the temperature adjustment system T via a further control valve R3 by means of a temperature regulator connector T3 / T4.

  Even in this arrangement, the temperature of the ink groove roller 8 can be set completely independently of the temperature of the ink kneading roller 11. As the control variable, the return temperature of the temperature adjusting agent can be used. The temperature of the ink groove roller 8 can be set by the control valve RF after the flow rate control.

The operation of the inking device 6 is performed as follows.
The ink flow is conveyed from the ink groove roller 8 to the first ink kneading roller 11 through the ink transfer roller 9. The temperature of the ink groove roller 8 and the ink kneading roller 11 is adjusted. In these, temperature adjusting agents flow independently of each other, and these temperature adjusting agents are supplied and circulated to the corresponding devices. The flow of the temperature adjusting agent in the ink groove roller 8 and the ink kneading roller 11 or the temperature of the temperature adjusting agent can be controlled independently of each other with respect to the amount and temperature of the temperature adjusting medium. Therefore, the ink groove roller 8 can be set at a temperature level different from that of the one or plural ink kneading rollers 11.

  The ink flow in the inking device 6 is as follows according to the temperature level of the ink groove roller 8 or one or a plurality of ink kneading rollers 11.

  When the temperature of the ink groove roller 8 is adjusted to a temperature level lower than the temperature level of one or more ink kneading rollers 11, the density of the ink flow from the ink groove roller 8 to the ink kneading roller 11 via the ink transfer roller 9. Increase. Thus, even if the ink metering setting is the same, the ink supply is controlled by controlling the temperature adjustment in the roller group with a small supply amount, for example, in the case of an image that requires a small amount of ink for a specific ink. The amount can be relatively large. As a result, a sufficient amount of ink is always prepared for the inking roller 12, so that sufficient ink is applied to the printing area of the printing plate.

  In order to improve the controllability, a sensor for measuring the ink film thickness can be provided. At this time, for example, the ink film thickness on the first ink kneading roller 11 is measured. Depending on the amount of ink required for the printing plate, the ink film thickness on the printing plate can be changed relative to each other by the described control mechanism by adjusting the temperature of the ink groove roller 8 and one or more ink kneading rollers 11. . Changes according to the process can be readjusted later without any problems.

  By narrowing or widening the temperature difference between the ink groove roller 8 and the roller of the inking device 6 according to the present invention, the ink flow is improved, and if the other operating parameters are the same, then the substrate The color density when the ink is applied is increased. Therefore, significant quality improvement can be achieved particularly in the case of a large area and color intensive image that requires a high degree of ink transfer or color density in the printed image on the substrate. Furthermore, permanent inking can be obtained in a very short time in the printing process.

  Necessary temperature adjustment can be performed by controlling the individual zones of the inking device roller 11 which can be adjusted in temperature.

  It is also possible to incorporate a new method of color density control, although to a limited extent, by adjusting the temperature of the inking device of the present invention. For this purpose, the color density printed on the sheet is measured for each ink in-line during the printing process and in the printing machine, or in an apparatus separate from the printing machine apart from the printing process. Based on the measured value, it can be determined whether too much ink is applied to the sheet, whether it is sufficient, or too little.

  If too little ink is applied, it can affect the controller of the temperature adjustment system to lower the temperature level at the ink groove roller 8 by a predetermined amount. As a result, the amount of ink fed to the inking device 6 increases, and the ink is sufficiently supplied to the sheet. If too much ink is applied, it can affect the temperature control system controller to raise the temperature level at the ink groove roller 8 by a predetermined amount. As a result, the amount of ink fed to the inking device 6 decreases and decreases until the amount of ink supplied to the sheet becomes the required amount.

  The necessary temperature difference between the ink groove roller 8 and the temperature-adjustable inking device roller 11 can be stored as a characteristic curve in the preliminary stage, inking device control or printing press control. Parameters include the area of the image to be printed and the ink consumption determined thereby, the type of ink, the general temperature level in the inking device 6, the density level of each printed image, and the temperature level of the ink in the ink groove 7. Temperature limits for the operation of the ink fountain 7 and the metering system, the speed of the printing press and possibly other printing technology related parameters.

  The characteristic curve can be recalled to the respective inking device 6 via its console during pre-setting or production control of the printing press. Similarly, characteristic curves can be stored in the temperature regulation system and recalled by the printing press controller in relation to the respective inking settings in each inking unit 6.

In order to adapt the method and apparatus to the current state of the machine, the following work cycle can be selected.
1. A temperature adjustment characteristic curve corresponding to the current preliminary stage data is preselected.
2. Controls temperature adjustment during one print command.
3. In some cases, the inking behavior in the sheet is observed by density measurement or ink film thickness measurement of the inking device roller.
4). Adapt or optimize temperature adjustment settings in fine steps.
5. Keep the temperature of the ink groove roller as constant as possible.
6). Save the characteristic curve newly obtained by changing the setting.
7). The print command parameters and characteristic curves of the print commands that have been completed are stored.
8). In order to execute the print command again or to execute a print command with similar or the same parameters, the stored characteristic curve is called up.

  In this connection, in order to execute a printing command, it is important and reasonable to measure the starting temperature of the ink in the ink fountain at the start of printing. This can be done using an infrared sensor via a sensor, possibly in a non-contact manner. In order to make the best settings, the ink can be preheated before the start of printing. In that case, it should be noted that the ink metering system cooperating with the ink groove roller 8 in the ink groove 7 is influenced by the hydrodynamic influence of the ink. Therefore, the ink must not be too high and not too hard so as not to change the ink metering or cause a mechanical movement leading to ink leakage from the ink groove. Don't be. This is an important basic parameter for the starting temperature and the control limit value of the temperature of the ink fountain roller 8.

  After the start of the printing command, an attempt is made to keep the temperature of the ink groove 7 as constant as possible by adjusting the temperature of the ink groove roller 8 within the scope of the method of the present invention. As a result, uniform inking can be performed over the printing surface, and at the same time, the ink supply is maintained at such a level that the printed image on the sheet is sufficiently saturated. Therefore, in order to avoid an obstacle to inking uniformity across the surface of the sheet, the temperature adjustment characteristic curve needs to be changed in fine steps.

In the present application, the temperature adjustment method according to the present invention has been described using examples in the description range. It is therefore possible to make adjustments within the principle of the ink groove roller being cooler than the further inking device roller within the scope of the method and the associated device of the present invention.

The top view of an offset printing apparatus is shown. 1 shows a diagram of an apparatus of a first embodiment of the invention. Fig. 2 shows a diagram of an apparatus according to a second embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Plate cylinder 2 Transfer cylinder 3 Conveyance direction 4 Pressure cylinder 5 Dampening device 6 Ink device 7 Ink groove 8 Ink groove roller 9 Ink transfer roller 10 Ink roller 11 Ink roller 12 Inking roller TF Temperature adjustment of ink groove roller T1 Temperature adjustment of ink kneading roller T2 Temperature adjustment of ink kneading roller T3 Temperature adjustment of ink kneading roller T4 Temperature adjustment of ink kneading roller T Temperature adjustment system RF control valve R1 control valve R2 control valve R3 control valve

Claims (19)

In a printing machine, preferably an offset printing machine, an ink groove roller (8), an ink transfer roller (9) or a film roller, in this application an additional inking device roller (11), which also assumes an ink kneading roller, an ink form roller (12) In an ink feeding control method in an inking device (6) in which at least the ink groove roller (8) and a plurality or all of the inking device rollers (11) are connected to a temperature control system (T),
The temperature of the ink groove roller (8) in at least one inking device (6) can be adjusted by the temperature adjustment system (T) so that the temperature located next to the ink groove roller (8) in the roller group of the inking device (6) can be adjusted. One or more inking rollers, and a temperature adjustable one or more inking rollers located next to the ink groove roller (8). (11) The temperature of (11) is adjusted to a temperature that can be set in advance independently of each other.   2. Method according to claim 1, characterized in that the temperature adjustment of the temperature-adjustable inking device roller (11) is carried out so that it is set to a uniform temperature level in all inking device rollers (11). .   In the various inking devices (6) of the multicolor printing machine, the temperature difference between the ink groove roller (8) and the attached temperature adjustable inking device roller (11) is adjusted independently of each other. The method according to claim 1 or 2, characterized in that:   The temperature difference for adjusting the temperature of the ink groove roller (8) and the attached temperature-adjustable inking device roller (11) can be selected in advance according to the ink consumption of the set printing plate. The method according to any one of claims 1 to 3.   The temperature difference between the ink groove roller (8) and the attached temperature-adjustable inking device roller (11) is adjusted according to the ink film thickness of the temperature-adjustable ink device roller (11) A method according to any one of claims 1 to 4, characterized in that:   6. The ink film thickness of one or more ink groove rollers (8) is measured technically at the inking device roller (11) located next in the group of rollers, according to claim 5. the method of.   The ink control measures one or more color density values of the ink printed on the sheet, and the ink groove roller (6) in the ink inking device (6) where a deviation from the specified value is found. 7. The method according to any one of claims 1 to 6, characterized in that it is carried out by changing the temperature difference between 8) and the temperature-adjustable ink device roller (11). Method.   When it is measured technically that the color density value of a certain ink printed on a sheet is too low, in the ink device (6) corresponding thereto, the ink groove roller (8) and the temperature adjustable one Widen the temperature difference with one or more or all inking rollers (11) or make the temperature level of the inking rollers (11) the same and lower the temperature level of the inking roller (8) The method according to claim 7.   When it is measured technically that the color density value of a certain ink printed on a sheet is too high, in the ink device (6) corresponding to the ink groove roller (8), a temperature adjustable one Reducing the temperature difference with one or more or all inking rollers (11) or increasing the temperature level of the ink fountain rollers (8) with the same temperature level of the inking rollers (11). 8. A method according to claim 7, characterized in that   The temperature difference between the temperature of the ink groove roller (8) and the temperature of the temperature-adjustable inking device roller (11) is determined by at least the area of the ink to be transferred and / or the type of ink and / or the density level of the image to be printed and 10. A method according to claim 1, characterized in that it can be recorded as a characteristic curve depending on / or further printing technical parameters.   11. Method according to claim 10, characterized in that the temperature difference characteristic curve can be called up automatically or manually during pre-adjustment of the printing press or during printing process control of the printing press.   The characteristic curve of the temperature difference can be adjusted during the printing process control of the printing press, and the characteristic curve values changed with respect to the printing technical parameters or the print command data can be stored, and the new print command 12. Method according to claim 10 or claim 11, characterized in that it can be called for An ink groove roller (8), an ink transfer roller (9) or a film roller, in particular an additional ink device roller (11) which is an ink kneading roller and a transfer roller, an ink form roller (12), and at least the ink groove roller (8 And an inking device (6) for carrying out the method according to claim 1, wherein part or all of the inking device roller (11) is connected to a temperature regulating system (T).
The ink groove roller (8) is assigned a temperature adjusting device (TF) that can be controlled independently from the temperature adjusting devices (T1 to T4) of the further inking device roller (11) capable of adjusting the temperature. Ink device to do.   In a multi-color printing machine, each ink groove roller (8) of each ink device (6) has a single temperature adjustment device that can be controlled independently from the temperature adjustment device (TF) of the other ink groove roller (8). 14. Inking device according to claim 13, characterized in that TF) is assigned.   The temperature adjusting device (TF) of the ink groove roller (8) of the inking device (6) is connected to the central temperature adjusting system (T) by an independently controllable control valve (RF). The inking device according to claim 12.   The temperature of the inking unit (6) of the multi-color printing machine, the temperature adjusting unit (TF) of the ink groove roller (8) can be adjusted by the joint temperature adjusting agent circulation (T). 13. Inking device according to claim 12, characterized in that it is connected to the temperature regulating system (T) independently of the regulating device (T1 to T4).   17. Inking device according to any one of the preceding claims, characterized in that one or all inking device rollers (11) adjustable in temperature are configured as ink kneading rollers.   18. The temperature regulator circulation (T) is connected in a control technical manner to a device for measuring the ink film thickness on the inking device rollers (11, 12). The inking apparatus as described in any one.   19. The temperature regulator circulation (T) is connected in control technology to an apparatus for performing color density value measurement on a sheet of paper, according to any one of the preceding claims. Ink machine.

Images