EP1142711B1 - Printing machine with a controlling device for a dryer - Google Patents

Abstract

The controller for the drying apparatus of the printer (1) operated such that the mode of operation of the drying apparatus (3,4,5) is controlled by control signals. At least one signal of a parameter characteristic of the printing process is supplied to the controller (7). In response, the controller generates signals (8,9,10) which change the manner of operation of the drying apparatus in a predetermined way. The signals fed to the controlled may be e.g. setting values of the amount of color in the various printing and coating devices of the printer and/or on the amount of color etc. to be dispensed.

Description

The invention relates to a printing press with a controller for a drying device according to the preamble of patent claim 1.

[State of the art]

Sheet-fed printing machines with a plurality of printing units and in particular sheetfed offset printing presses, in which one or more finishing devices in the form of painting equipment are connected downstream of the printing units, have drying devices. Depending on the type of applied pressure (paint / varnish), these driers are used up as IR (infrared), TL (thermo-air) and / or W (ultraviolet) driers. The IR and UV dryers are among the radiation dryers, which can influence the radiant power and the magnitudes associated with the irradiation of the substrate. For the TL dryers, the volume flow (volume per unit time), the temperature and the humidification of the hot air can be influenced. The type of dryer to be used (drying equipment) depends on the type of substrate, the printing process and the type of ink / varnish printed.

Sheetfed offset presses often have one or more turning devices between the printing units, resulting in a high variability in the possibility of executable print jobs. Since the sheet with the freshly printed side comes to lie on the surface of the impression cylinder of the next printing unit in a sheet application, drying devices are increasingly associated with the turning devices. The type of dryer device, as already mentioned above, depends on the type of ink to be printed and / or the printing substrate. With one or more painting or other printing technology Finishing devices advanced printing machines have either between the individual printing and painting equipment and / or between the last printing or painting device and the boom one or more, often constructed according to different operating principle drying equipment. These are usually arranged in an extended conveying path between the last printing and coating unit and the delivery of the sheet-fed press. The arrangement of several and in particular working according to different physical working principle driers allows an individual adjustment of the drying process to the respective printing process. In the printing and coating units so curable or dry colors can be printed either by UV radiation or IR radiation. TL-drying devices also have the advantage that the sheet guide, especially in the field of sheet turning or other critical points within the sheet guide, can be influenced.

Sufficient drying or hardening of the printed inks / varnishes is a prerequisite for high quality prints. Within the conveying path of the sheets through the machine, touches on the freshly printed sheet surface can cause damage, which causes waste. The sheets stacked in the delivery must also be sufficiently dried with regard to the printed colors / lacquers, since otherwise the sheets which slide on one another during the stacking up will smear or stick together. Especially the latter would make further processing of the stack difficult or completely impossible.

High demands are placed on the setting of the differently constructed drying devices during the printing process. Already when setting up the printing press The operator has to make adjustments to the drying equipment in order to produce the required quality after the shortest possible time and number of spoil sheets (pre-run waste). Too high a selected setting of the dryer performance requires not only high energy consumption of the printing press and also a high waste heat, which would increase the temperature of the pressure chamber or be regulated by the air conditioning of the printing room to the intended value, but also the printing process itself is negative affected. It is known that the tack and viscosity of paint / varnishes changes, so that a high degree of engine heating together with the heating of ink and metering device may make re-adjustments that may cause paper waste. Too low set sizes for the dryer effect or dryer performance are also to be avoided, otherwise there is the described danger of smearing freshly printed sheet during sheet transport or in the display.

From DE 38 29 342 A1 a printer control system is known, in which the data generated in the individual work areas of a printing machine on computers can be provided via a network of the control of the printing press. It is thus possible to use pre-press data directly for pre-setting the press without the need to enter data manually or to use data carriers.

EP 0 355 473 B1 discloses an apparatus for drying printed products in a printing press which has a radiation device which is arranged outside the printing press. To transmit the radiation power to the sheets to be dried optical fiber cables are provided. Through this device, it is possible within the To reduce the printing machine resulting waste heat and thus the heating of machine components. By the optical fiber cable, which act on the printed sheet in a line with radiation in total, a differentiated adjustment of the amount of radiation according to the zonal color or paint quantity is also possible. However, these settings must be made by qualified and experienced personnel according to the current print job.

Although this prior art device reduces the thermal power introduced into the machine, it is complex overall in its construction. In order to achieve a control of the dryer which is individually adapted to the printing subject, sensors must additionally be arranged according to this device, by means of which the occupancy of the individual parts of the printed sheet is detected. An influence / control of conventional drying equipment is not possible in this way.

From DE 37 08 925 A1 a printing machine with at least one printing unit is known. Herein, a printing machine with at least one printing unit is proposed, in which a plurality of sensors for monitoring the printing operation and a plurality of actuators are provided for setting parameters of the printing process. For this purpose, a designated as a total electronic control is provided, which is connected by means of data lines to the printing press or the sensors and actuators in the printing press. In the function of the entire electronics, for example, functions of drying devices should be included. The press itself does not contain any additional controls, but only displays or operating options required for monitoring.

From DE 198 32 453 A1 is a maintenance and inspection system for a printing press. The system has a control, which is connected to signal transmitters and via which the main drive and other drives can be controlled. For this purpose, a designated as a maintenance and inspection computer computer is provided, which is in signal communication with the controller and a central computer. Signals of the drives and signal generators are supplied to the computer so that consumption, load or wear quantities can be calculated by means of the data. From this, the computer determines the time and scope of maintenance measures. So can be concluded from the switch-on of the dryer on the thermal stress of machine components.

OBJECT OF THE INVENTION

Object of the present invention is in a printing press to expand a control device according to the preamble of claim 1 such that while avoiding the disadvantages mentioned above a differentiated adapted to the present printing process and this not negatively influencing possibility for automatic adjustment of the dryer device is obtained.

This object is achieved by means of the features of claim 1. Further developments of the invention will become apparent from the dependent claims.

[Examples]

According to the invention, it is provided that the controller according to the invention is supplied with at least one variable characterizing the printing process in the form of one or more signals and that the controller, which is preferably designed as a programmable computer, determines at least one signal influencing the mode of operation of the dryer device, which is the dryer device is supplied.

Influencing here are the following enumerated variables of the respective enumerated drying devices:

In the case of a UV dryer, the UV power can be adjusted by reducing the power taking into account the Wien shift. For IR dryers, the total IR power can be varied by controlling the individual radiator outputs and switching off individual lamps (taking into account) Wien's displacement and the installed specific radiator wavelengths. For TL dryers, the volume flow (volume per unit time), the temperature and the pressure can be influenced. If the sheet-fed offset printing machine has UV intermediate dryers after each printing unit, then these UV intermediate dryers can be individually controlled in terms of performance depending on the color coverage of the respective previous printing unit.

Depending on the signals influencing the respective dryer, it is also possible to influence further variables which are indirectly involved in the drying process. Thus, the fan performance and the operation of the fan (suction / blowing) can be influenced by the operating state of the machine in the sheet guide. Also, depending on the set dryer performance, the sheet-web cooling can be preset accordingly and controlled during the printing process. The fan power for the extraction of a previously introduced TL flow rate is directly adjustable according to a signal provided by the controller. In drying facilities, in which air (hot or cold air) strikes the arch at variable angles, the angle of air flow directing elements (baffles or the like.) Can be influenced by appropriate fernansteuerbare adjusting means. Indirectly affected and thus also controllable is the amount of powder, the powder air volume flow and the Puderabsaugleistung. This is due to the fact that the amount of powder can be reduced as far as possible when the dryer setting is very differentiated to the current print job. Ultimately, a control of dryer elements in, transverse or angular position to the sheet travel direction is possible. If the individual drying devices are distributed in blocks over the format width, then the individual blocks / modules can also be controlled according to the color assignment (of the subject). Parts of the sheet, in which only a small or no inking takes place with correspondingly low or no dryer performance (radiation or hot air) applied, whereas portions of the sheet with medium or high paint application amount of high dryer performance are exposed.

The formation of signals for influencing the above enumerated variables controlled by a preferably designed as a computer controller. These are supplied to one or more signals characterizing the printing process. These signals can either be generated during the printing process by sensors or other signal transmitters, which are in any case already present on the machine or are available at the control station of the printing machine and in particular provided by the prepress in electronic form. Such a size would be in particular the operation the printing press or the color assignment during the print job to be executed. Especially when using intermediate dryers between the individual printing units, certain dryers can only be operated with little or no power if the corresponding preceding printing units are not used.

The color assignment of the individual printing units, the type of color or varnish used in the printing units as well as the color assignment (zonal color distribution) caused by the individual printing units are also variables influencing the printing process, which are detected by the control according to the invention and used to generate differentiated control signals for a or more dryers are usable. The zonal color assignment in the individual printing units can be taken in particular by a printing plate scanning by means of a plate scanner or directly as a data set from the digital prepress. Especially in the latter case of digital prepress then information about the type of paint or the paint used are then available, so that on the one hand is decidable by the controller, which dryer device is to be activated and also, with what power the respective activated dryer device to operate. There is thus an automatic switch from, for example, UV to IR dryer operation.

By transferring data from the respective print job from the preliminary stage and in particular the digital prepress stage, in addition to the type and quantity of the ink (color assignment), further print parameters can also be recorded. This is particularly the type of printing material, which is important when using in particular with directional and with adjustable air operable dryers. Thus, the line thickness, the surface texture, the grammage, the Thickness and the suction behavior of the printing material can be considered.

By one or more temperature sensors on or within the machine also the current machine or air temperature of the controller according to the invention can also be supplied, so that the setting of the dryer device can also be selected according to this value. In particular, the temperature and the volume flow of TL dryers can be influenced.

The consideration of quality features or the nature of the printing material has, in particular, a significance of drying devices which have adjustable blowing and / or suction devices in the volume flow and / or direction.

A further factor which can be taken into account in the control of the drying device according to the invention is the type and composition of the dampening solution and the consideration of the circumstance whether printing takes place in the wet or dry offset process.

By temperature sensors and other transducers in the feeder, boom and in particular the stack in arrival and delivery and the stacking temperatures and possibly the stack moisture of the printing material are considered.

Ultimately, both the speed currently being driven by the press (number of sheets per time) and the planned print speed entered at the time of presetting are taken into account. Thus, it is possible in UV and IR dryer devices designed as radiators, taking into account the Wien shift, the radiation power and adjust the drying effect according to the current printing speed or nachzuführen the printing speed. Especially this type of speed-dependent drying is preferably carried out according to predetermined characteristics, which can be selectively changed by the user via the control room or other input means. The machine operator thus has the option of adapting the predefined characteristic curve (programmed), for example in its steepness, to the current conditions. Ultimately, he can also select other predefined printing characteristics on the basis of observations during the printing operation or after quality analysis of printed copies produced. In particular, the quality and gloss of lacquer or other finishing coatings can be influenced.

Furthermore, the setting effected by the signals of the control device according to the invention, in particular TL drying devices for controlling suction devices, is also taken into consideration. So it is possible to adjust the suction power to the current heating power or dryer performance and thus optimally exploit the Trocknunegswirkung of the printed product. Cooling devices for sheets, stacks and machine equipment can also be controlled in this way.

The variables described above and characterizing the printing process are fed individually and preferably also in combination in the form of a plurality of signals to the controller according to the invention. The provision of signals influencing the dryer device takes place, for example, in such a way that a stored characteristic curve is selected for a given chromaticity, color assignment and type of printing material and during printing operation the power of the respective dryer device is tracked in accordance with the printing speed in accordance with this characteristic. As As already mentioned, the operator additionally has the option of selectively influencing the characteristic preselected by the controller according to the invention and, in particular, of appropriately setting the operating point of the dryer controller.

The dryer control according to the invention makes it possible, in particular, to reduce waste at the start of production and after restarts of stoppers. The machine operator does not have to make manual presettings of the drying devices since the basic settings for the drying devices can be determined by the given data of the print job to be executed. Due to the printing speed-dependent tracking of the dryer performance and changes in the machine speed, for example, to avoid critical conditions of the bowing in the reverse mode, guaranteed.

The controller according to the invention is preferably in signal communication with the control station of the printing machine, via which the variables enumerated above and characterizing in the printing process can be entered. The control station of the printing press is also available for the measured values determined within or outside the machine by corresponding signal transmitters or sensors.

By the dryer control according to the invention, in addition to a waste reduction, a considerable energy saving is possible. Since the drying devices are driven only with the power that is required according to the current conditions, the power consumption of the facilities is reduced to the respective required value. Since the drying equipment also produce waste heat, there is also a reduced heating of machine elements or the entire machine. This will also increase the lifespan the machine or machine components increased. Ultimately, a reduced performance of the dryer also avoids an increase in the pressure chamber temperature. In an air-conditioned pressroom, this also saves energy as less waste heat is produced by the dryers.

The control signals generated by the control device according to the invention for the drying devices can be stored on suitable storage medium for repeat jobs. Furthermore, operating data of the drying devices can also be recorded and stored, which is particularly advantageous for determining the service life of irradiation sources in the drying devices and for carrying out maintenance work. Ultimately, the control of UV or IR drying equipment is also dependent on the current life, since it is known that the effect of such drying equipment changes over the life. Operating dryers, each with currently adapted performance, also results in an overall increase in the service life of the corresponding components.

By a signal connection of the control device according to the invention with the control station of a printing machine, a remote diagnosis of the connected drying devices can be carried out when a diagnostic system is connected to the machine control station.

• Eine Druckmaschine mit mehreren Druck- und Lackierwerken, an verschiedenen Orten angeordnete Trocknereinrichtungen, eine diesen Trocknereinrichtungen zugeordnete Steuerung sowie den Leitstand der Druckmaschine.

Furthermore, the explanation of an embodiment of the invention with reference to the drawing. This shows:

• A printing machine with several printing and coating units, arranged at different locations drying equipment, a These controllers associated control and the control center of the printing press.

The figure shows a printing machine 1 with an investor (right) a boom (left), a number of printing units and, downstream of the last printing unit and upstream of the boom, coating unit. In the printing machine 1, a number of drying devices 3, 4, 5, 6 are arranged at different locations. These drying devices 3, 4, 5, 6 are designed according to different principles of action dryer (UV dryer, IR dryer, TL dryer device or combinations of these devices).

The individual drying devices 3, 4, 5, 6 are connected via lines to an associated controller 7. Via the lines, the drying devices 3, 4, 5, 6 can be influenced by the controller 7 in their mode of operation, i. In particular, the performance of the individual drying devices 3, 4, 5, 6 is variable. On the part of the controller 7, other sizes of the drying devices 3, 4, 5, 6 can be selectively changed. Preferred influencing variables which have been used in the present invention have been mentioned above.

The printing machine 1 has a signal generator 8 for the printing speed and / or the angular position of the printing cylinder of the printing press 1. The signals of the signal generator 8 are fed to the control station 2 of the printing press. The signals of the signal generator 8 via the control station 2 and not shown in the figure, control of the printing press 1 used for the activation of further arranged in the printing press 1 functional units.

The control station 2 of the printing machine 1 is in signal communication with the controller 7 of the drying devices 3, 4, 5, 6, so that the signals of the signal generator 8 (printing speed / angular position) and the controller 7 can be fed. Thus, on the part of the controller 7, a pressure-speed-dependent control of the drying device 3, 4, 5, 6 take place. In particular, several characteristic curves for tracking the dryer output as a function of the printing speed can be stored in the controller 7. Furthermore, a manual selection from different characteristic curves can also be carried out by the operator via the control station 2.

In principle, the figure shows two further signal transmitters 9, 10, by which the temperature outside (signal generator 9) and within (signal generator 10) of the temperature of the printing press 1 can be detected. The signal transmitters can be arranged in particular in the area of the sheet transport, the feeder, the boom or at other relevant points. By the signal generator 9, 10 provided temperature information further influencing variables by the controller 7 for the dryer device 3, 4, 5, 6 are taken into account.

At the printing press 1 further signal generator (not shown) may be attached, by which further influencing variables (parameters characterizing the printing process) can be detected. In particular, all the presetting data of the printing machine 1 as well as the setting values manually and / or automatically set during the printing process are supplied via the control station 2 of the printing press 1 to the control system 7. Thus, an adjustment of the drying devices 3, 4, 5, 6 as a function of the individual Printing and varnishing done color metering (depending on the sujet).

[REFERENCE LIST]

1

press

2

Control room (control and operation of printing press 1)

3

drying device

4

drying device

5

drying device

6

drying device

7

Control (drying device 3, 4, 5, 6)

8th

Signal transmitter (printing speed / angular position)

9

Signal transmitter (temperature outside printing machine 1)

10

Signal transmitter (temperature within printing press 1)

Claims (17)

1. Printing press (1), particularly an offset sheet printing press, with a control fitted to this, with a dryer unit (3; 4; 5; 6) in which the mode of operation of the dryer unit can be changed and with signal emitters (8-10) arranged in the press (1) which are in signal connection with the control fitted to the press (1), characterised in that a control (7) is provided for the dryer unit (3; 4; 5; 6), that at least one signal of a parameter characterising the print process is fed to the control (7) and that, as a result of which signals are generated by the control (7) by which the mode of operation of the dryer unit (3; 4; 5; 6) is changed in preset fashion.
2. Printing press (1) according to Claim 1, characterised in that the control (7) is in signal connection directly with signal emitters (8, 9, 10) arranged in the press (1).
3. Printing press (1) according to Claim 1 or 2, characterised in that control (7) is in signal connection with a control desk (2) of the press (1) by means of which adjustment values for the press (1) are fed to the control (7).
4. Printing press (1) according to Claim 1, 2 or 3 characterised in that data are fed to the control (7) by means of the signal connection via the control desk (2) which are determined in a pre-print stage and which relate to a print order to be carried out.
5. Printing press (1) according to one of Claims 1 to 4, characterised in that, in the press (1), individual printing and varnishing units are provided and that fed to the control (7) are adjustment values of an ink metering in the individual print and varnishing units of the press (1).
6. Printing press (1) according to one of Claims 1 to 5, characterised in that data are fed to the control (7) concerning the inks and/or varnishes to be used in a print order to be carried out for switching of the dryer unit (3; 4; 5; 6).
7. Printing press (1) according to one of Claims 1 to 6, characterised in that data are fed to the control (7) relating to the switching of the dryer unit (3; 4; 5; 6) in the case of the material to be printed used in a print order to be carried out.
8. Printing press (1) according to one of Claims 1 to 7, characterised in that, by means of the control (7), signals are generated for influencing the dryer power of the dryer unit (3; 4; 5; 6).
9. Printing press (1) according to one of Claims 1 to 8, characterised in that the dryer unit (3; 4; 5; 6) is constructed as an HA or hot air dryer, wherein, in each dryer unit (3; 4; 5; 6), means are provided for guiding an air stream and that, by means of control (7), signals are generated for influencing an air stream connected with the drying process.
10. Printing press (1) according to one of Claims 1 to 9, characterised in that, by the control (7), a signal processed by the control of the press (1) and reproducing the print speed of the press (1) is processed for speed dependent matching to the dryer unit (3; 4; 5; 6).
11. Printing press (1) according to one of Claims 1 to 10, characterised in that the dryer unit (3; 4; 5; 6) is provided with a device for sucking away hot air and that, by means of the control (7), the suction power of the hot air exhaust is adjusted in dependence on the actual mode of operation of the dryer unit (3; 4; 5; 6).
12. Printing press (1) according to one of Claims 1 to 11, characterised in that, by means of the control (7), in combination with the pre-installation data characterising the print process to be carried out, adjustment values for a dryer unit (3; 4; 5; 6) are determined and brought into adjustment.
13. Printing press (1) according to one of Claims 1 to 12, characterised in that, by the control (7), adjustment values for the printing press (1) are determined from the signals fed and the maximum achievable effect (maximum power) of the dryer unit (3; 4; 5; 6).
14. Printing press (1) according to one of Claims 1 to 13, characterised in that adjustment values of the dryer unit (3; 4; 5; 6) of a print order which has been carried out are stored in the control (7) and can be brought into use again at a later point in time.
15. Printing press (1) according to one of Claims 1 to 14, characterised in that cooling units for sheet pile or press units are provided and that, by means of the control (7), one or more cooling units are controlled in dependence on the current mode of operation of the dryer unit (3; 4; 5; 6).
16. Printing press (1) according to one of Claims 1 to 15, characterised in that, by the control (7), the dryer unit (3; 4; 5; 6) is controlled in dependence on measured values taken from the printed material.
17. Printing press (1) according to Claim 16, characterised in that parameters reflecting the quality of the print, such as, in particular, varnish or ink layer thickness and/or gloss are determined.

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