EP1737664B1 - Embossing device - Google Patents

Abstract

The device has a coating module transferring imaging layers of a bearing foil on a printing paper. The module contains an impression cylinder (4) and a pressing roller (3), which together form a combined transfer crack (6). A transfer foil (5), provided in the area of a foil routing device for guiding the transfer foil to a transfer crack, is attached with a device for application of the layers and/or information containing imprints. An independent claim is also included for method for coating of printed sheets in a sheet of paper processing machine.

Description

The invention relates to a device and a method for transferring imaging layers from a carrier foil to printed sheets according to the preamble of claims 1 and 5.

It is known to produce metallic layers on printed sheets by means of a film transfer process. So is in the EP 0 569 520 B1 a printing material and a printing apparatus using this material are described. In this case, a sheet-processing machine is shown, which has a feeder and a boom, wherein printing units and a coating module are arranged between the two units. In at least one of the printing units, an adhesive pattern is applied by means of the planographic printing process. This adhesive pattern is applied in a cold printing process and has a specific imaging subject. In the printing unit following the coating module with a counter-pressure cylinder and a press roller, a film guide is provided. This is designed in such a way that a film strip or a transfer film is guided through the transfer nip of the coating module between the impression cylinder and the press roll from a film supply roll. The film strip is rewound on the outlet side after leaving the coating module. The transfer film has a carrier layer on which imaging layers such as metallic layers, for example of aluminum, can be applied. Between the metallic layer and the carrier film, a separating layer is provided, which ensures that the metallic layer can be removed from the carrier layer.

From the EP 0 441 596 A1 For example, a method and apparatus for applying images is known. There, for the application of security elements such as holograms, the foil strips carrying the security elements are guided past a press roll over the printing material sheets. The press roll is provided on its surface with cutouts, so that only short There are areas for pressing the webs against the printing material sheets. The film strips are not pressed in the area of the cutouts and thereby stopped in transport or transported backwards.

When printing sheets are transported through the printing unit, each sheet is given an adhesive pattern. Thereafter, the sheet is passed through the coating module, being brought by means of the press roller on the impression cylinder resting sheet with the film material in combination. In this case, the downwardly lying metallic layer enters into a close connection with the areas provided with adhesive on the printed sheet. After further transporting the printing sheet, the metallic layer adheres only in the area provided with the adhesive pattern. The carrier film is thus removed from the metallic layer in the region of the adhesive pattern. The used in this way transfer film is wound up again. The print sheet is laid out in the coated state.
It is known to use such coating modules, for example in printing units of printing presses. A disadvantage of the known devices is that they can not be used flexibly.

The object of the invention is therefore to provide a device by means of which the transfer of an imaging layer, e.g. a metallization layer can be done on a sheet safely, economically and accurately, the device should be manageable for an extended range of applications.

The solution to this problem results in a device according to the features of claim 1 and in a method according to the features of claim 5.

Advantageously, the device is designed so that a press roll has a pressing surface which occupies a partial area of the total area of a printed sheet.

Advantageously, such press surfaces are designed as tensionable segments or as cut-out rubber blankets or as passably produced, preferably photopolymer high-pressure plates or as detachable, for example under magnetic action, attachable pressing segments.

The device can also be advantageously used in order to improve the use of the film by dividing the transfer film into one or more partial film webs of lesser width. In combination with the above-mentioned method, it is thus also possible to use different types of film side by side.

To ensure the economy of the coating process is provided to control the film feed so that the transfer film is then stopped when no transmission of the imaging or metallization takes place.

The control of the transfer film is such that when passing through a gripper of the sheet-guiding impression cylinder receiving cylinder channel of the film feed is stopped, wherein the press roller then passes under the transfer film sliding.

To improve the gloss effect, the image-forming layer can be applied by means of so-called UV negative-pressure ink. The UV negative pressure ink is applied by means of the printing unit for the adhesive in a corresponding manner via an offset printing plate.

Advantageously, it is also possible to provide a plurality of coating modules behind one another within a sheet-processing machine. Thus, the application of different imaging coatings or metallization layers within a subject can take place one after the other. In this case, it is possible to transmit the imaging layers next to one another using a single adhesive pattern with all image-pattern elements. It is also possible to provide a first adhesive pattern in a first coating module with a first image-forming coating or metallization layer and, in the following, to apply another, the first enclosing adhesive pattern and to provide it with another image-forming coating or metallization layer.

In the following the invention is illustrated in more detail with reference to figures.

Figur 1

eine grundsätzliche Darstellung einer Druckmaschine mit einer Folientransfereinrichtung und

Figur 2

den Aufbau eines Beschichtungsmodules mit einer Folientrans- fereinrichtung und

Figur 3

eine Presswalze eines Beschichtungsmodules und

Figur 4

ein Detail der Presswalze.

Showing:

FIG. 1

a basic illustration of a printing machine with a film transfer device and

FIG. 2

the construction of a coating module with a film transfer and

FIG. 3

a press roll of a coating module and

FIG. 4

a detail of the press roll.

• Ein zu beschichtender Druckbogen wird in einem ersten Arbeitschritt mit einem bildgebenden Klebstoffmuster versehen. Der Auftrag des Klebers erfolgt im einer als Auftragwerk 1 konfigurierten Vorrichtung, z.B. einem konventionellen Druckwerk einer Offsetdruckmaschine über dort vorhandene Farb- und Feuchtwerke 11, eine Druckplatte auf einem Plattenzylinder 12, einen Drucktuch- oder Gummizylinder 13 und einen Gegendruckzylinder 4. Gleichfalls sind hier Auftragwerke in Form von Flexodruckeinheiten oder Lakkierwerken einsetzbar.
• Danach wird in einem zweiten Schritt gemeinsam mit einem Druckbogen eine Transferfolie 5 durch einen Transferspalt 6 geführt, wobei die Transferfolie 5 im Transferspalt 6 gegen den Druckbogen gepresst wird. Hierzu wird ein Beschichtungsmodul 2 verwendet, das einem Druckwerk oder einem Lackmodul oder einer Basiseinheit oder einer andersartigen Verarbeitungsstation einer Bogenoffsetdruckmaschine entsprechen kann.
• Der Transferspalt 6 im Beschichtungsmodul 2 wird durch eine Presswalze 3 und einen Gegendruckzylinder 4 gebildet.
  Hierbei kann die Presswalze 3 einem Drucktuchzylinder und der Gegendruckzylinder 4 einem Gegendruckzylinder eines an sich bekannten Offsetdruckwerkes entsprechen.
  Weiterhin kann die Presswalze 3 einem Formzylinder und der Gegendruckzylinder 4 einem Gegendruckzylinder eines Lackmodules einer Bogendruckmaschine entsprechen.
• Weiterhin kann dem Beschichtungsmodul 2 nachgeschaltet ein so genanntes Kalandrierwerk vorgesehen werden, wenn der beschichtete Druckbogen zur Steigerung der Haftung der Beschichtung bzw. zur Steigerung von Glätte und Glanz des Druckbogens unter erhöhtem Druck überwalzt werden soll.
  Innerhalb des für den Folientransfer genutzten Beschichtungsmodules 2 ist eine Bahnführung für Transferfolien 5 dargestellt.
  Für die Verarbeitung in Frage kommende Transferfolien 5 sind mehrschichtig aufgebaut. Sie weisen eine Trägerschicht auf, auf der mittels einer Trennschicht eine bildgebende Schicht aufgebracht ist. Die Trennschicht dient dem erleichterten Abheben der bildgebenden Schicht von der Trägerschicht. Die bildgebende Schicht kann z.B. eine metallisierte Schicht oder eine Glanzschicht oder eine Texturschicht oder eine eingefärbte Schicht oder eine ein oder mehrere Bildmuster enthaltende Schicht sein.

In FIG. 1 is a sheet-processing machine, here a printing press, shown, which consists of at least two printing units. The two printing units are used for the following purposes:

• A sheet to be coated is provided in a first step with an adhesive imaging pattern. The application of the adhesive takes place in a device configured as an applicator 1, for example, a conventional printing unit of an offset printing machine there existing inking and dampening 11, a printing plate on a plate cylinder 12, a blanket or blanket cylinder 13 and a counter-pressure cylinder 4. Likewise are here commissioned works in the form of flexographic printing units or Lakkierwerken used.
• Thereafter, in a second step, together with a printing sheet, a transfer film 5 is guided through a transfer nip 6, wherein the transfer film 5 is pressed in the transfer nip 6 against the printing sheet. For this purpose, a coating module 2 is used which can correspond to a printing unit or a lacquer module or a base unit or another type of processing station of a sheet-fed offset printing press.
• The transfer nip 6 in the coating module 2 is formed by a press roll 3 and an impression cylinder 4.
  Here, the press roller 3 a blanket cylinder and the impression cylinder 4 a counter-pressure cylinder of a known offset printing unit correspond.
  Furthermore, the press roller 3 a form cylinder and the impression cylinder 4 correspond to a counter-pressure cylinder of a paint module of a sheet-fed press.
• Furthermore, the coating module 2 downstream of a so-called calendering be provided when the coated sheet to increase the adhesion of the coating or to increase the smoothness and gloss of the sheet is to be rolled under increased pressure.
  Within the coating module 2 used for the film transfer, a web guide for transfer films 5 is shown.
  For processing in question transfer sheets 5 are constructed in multiple layers. They have a carrier layer on which an imaging layer is applied by means of a release layer. The separating layer serves to facilitate lifting of the imaging layer from the carrier layer. The image-forming layer may be, for example, a metallized layer or a glossy layer or a texture layer or a colored layer or a layer containing one or more image patterns.

The film supply roll 8 is assigned to the coating module 2 on the sheet feed side. The film supply roll 8 has a rotary drive 7. The rotary drive 7 is required for the continuous controlled feeding of the transfer film 5 to the coating module 2 and is therefore controllable.
Furthermore, in the field of film feed and removal guide devices 14, such as deflection or tensioning rollers, pneumatically actuated conducting means, baffles o. Ä. Provided. Thus, the film web of the transfer film 5 can always be performed flat without distortion and held in the same voltage against the press roller 3. The guide devices 14 may also contain aids for introducing the transfer film 5. In this case, automatic retraction aids for the film web of the transfer film 5 can be used.

In this way, the film feed in the area of the coating unit 2 surrounding Verschutzungen 15 is simplified. The protective function of the Verschutzungen 15 is maintained at the same time completely.

In this case, the transfer film 5 can be guided around the press roll 3, wherein the transfer film 5 can advantageously be fed and discharged from the press nip 6 only from one side of the coating module 2 (see dashed representation). The film web may differ from the illustration to Fig. 1 and depending on the space conditions on the one side of the coating module 2 advantageously in the feeding strand and the laxative strand are guided closely parallel to each other.
In a further embodiment, the transfer film 5 can also be fed in and out substantially tangentially on the press roll 3 or wrap it around the press nip 6 only in a small circumferential angle. For this purpose, the transfer film 5 is supplied from one side of the coating module 2 and discharged to the opposite side of the coating module 2.

On the outlet side of the printing unit, a film collection roller 9 is shown. On the film collecting roll 9, the used film material is wound up again. Again, a rotary drive 7 is provided for the optimized production, which is controllable. In essence, the transfer film 5 could also be moved by the rotary drive 7 on the outlet side and kept taut on the inlet side by means of a brake. A film control is possible in this context with dancer roller 18 mentioned later.

For the transfer process of the imaging eg wear layer of the transfer sheet 5 on the sheet in the transfer nip 6 between the press roll 3 and the impression cylinder 4 is essential that the surface of the press roll 3 so the blanket cylinder or forme cylinder is equipped by means of a compressible, damping element.
The press roll 3 is therefore provided with a press fabric 10 or as a roll with a corresponding coating. The press fabric 10 or press coating, for example, as a plastic coating, comparable to a Blanket or blanket, be executed. The surface of the press fabric 10 or press coating is preferably very smooth. It can also be formed from antiadhesive substances or structures. Here, for example, a relatively hard structure in the form of very fine spherical caps comes into question. A press fabric 10 is held on the press roll 3 in a cylinder channel on jigs.
The press fabric 10 may be equipped to improve the transmission properties in the transfer nip 6 with a targeted elasticity. This may optionally act in a compressible intermediate layer. This compressibility is preferably similar or less than in conventional blankets or blankets, which can also be used at this point.

The mentioned compressibility can be produced by means of a conventional compressible printing blanket. Furthermore, combined fabrics made of a hard blanket and a soft pad can be used.
Furthermore, a limited pressing surface can be provided directly on the press roll 3 or on the press fabric 10. This can be worked out of the surface of the press fabric 10 or it can be additionally attached as a partial surface of the material of the press fabric 10 on the press roller 3.

• Hierzu erfolgt die Steuerung der Transferfolie 5 derart, dass beim Durchlaufen eines Greifers des bogenführenden Gegendruckzylinders 4 aufnehmenden Zylinderkanales der Folienvorschub angehalten wird. Die Greifer halten den Druckbogen auf dem Gegendruckzylinder 4. Die Presswalze 3 weist einen dazu korrespondierenden Zylinderkanal 19 (siehe Fig. 3) auf, in dem eine Pressbespannung 10 gehaltert ist. Im Bereich der korrespondierenden Zylinderkanäle erfolgt keine Pressung der Transferfolie 5 zwischen der Presswalze 3 (Drucktuchzylinder) und dem Gegendruckzylinder 4. Die Presswalze 3 läuft dann an der Transferfolie 5 gleitend weiter, während die Transferfolie 5 zwischen Presswalze 3 und Gegendruckzylinder 4 frei liegend gespannt ist. Dieser Zustand dauert an bis am so genannten Druckanfang der Zylinderkanal 19 endet und die Transferfolie 5 erneut zwischen der Presswalze 3 und dem Gegendruckzylinder 4 unter Einschluss eines Druckbogens eingeklemmt wird. Dann wird die Transferfolie 5 weiter transportiert. Die Taktung des Folienvorschubes kann entsprechend einer notwendigen Beschleunigung bzw. Bremsung der Folienvorratsrolle 8 bzw. Foliensammelrolle 9 etwas früher beginnen bzw. aussetzen als dies die Kanalkanten des Zylinderkanals vorgeben. Bei reaktionsschnellen Taktungssystemen über so genannte Tänzerwalzen 18, wie sie beispielhaft in Figur 1 eingezeichnet sind, ist die Steuerung der Drehantriebe 7 der Folienvorratsrollen 8 bzw. Foliensammelrolle 9 ggf. nicht erforderlich. Mittels der Tänzerwalzen 18 wird ebenfalls die notwendige Folienspannung aufrecht erhalten.

To improve the efficiency of the coating process, it is provided that the film advance of the transfer film 5 from the film supply roll 8 to the transfer nip 6 and the film collection roll 9 is controllable so that as far as possible the transfer film 5 is stopped when no transfer of the imaging layer should take place :

• For this purpose, the control of the transfer film 5 is such that when passing through a gripper of the sheet-guiding impression cylinder 4 receiving cylinder channel of the film feed is stopped. The grippers hold the sheet on the impression cylinder 4. The press roll 3 has a corresponding cylinder channel 19 (see Fig. 3 ), in which a press fabric 10 is held. In the region of the corresponding cylinder channels, there is no pressing of the transfer film 5 between the press roll 3 (blanket cylinder) and the impression cylinder 4. The press roll 3 then continues to slide on the transfer film 5 while the transfer film 5 is between the press roll 3 and impression cylinder 4 is stretched freely lying. This state continues until at the so-called pressure start of the cylinder channel 19 ends and the transfer sheet 5 is again clamped between the press roller 3 and the impression cylinder 4, including a sheet. Then, the transfer sheet 5 is further transported. The timing of the film feed can begin or suspend slightly earlier than pretend the channel edges of the cylinder channel according to a necessary acceleration or braking of the film supply roll 8 or film collecting 9. In reaction-fast timing systems via so-called dancer rollers 18, as exemplified in FIG. 1 are shown, the control of the rotary actuators 7 of the film supply rolls 8 and film collection roller 9 may not be necessary. By means of the dancer rollers 18, the necessary film tension is also maintained.

A further improvement of the film utilization of the type described results from the fact that the transfer film 5 is divided into one or more Teilfolienbahnen lesser width. Thus, with appropriate control by means of the device or devices for timing the film feed each of the sub-film webs, the utilization of the transfer film 5 can be improved even in zonally different lengths coating areas within a sheet. For this purpose, each partial film web is conveyed only exactly in the area where the imaging surface layer is to be applied. In the areas not to be coated, each partial film web can be stopped independently of the other partial film webs, whereby no unnecessary film consumption arises.

Furthermore, to improve the coating process provided in the area of the adhesive application and in the area of the film order dryer 16 provided. Thus, in particular by means of UV drying, the imagewise applied adhesive layer can be predried by means of a first dryer 16 (intermediate dryer I), so that the wear layer of the transfer film 5 adheres better. Furthermore, the adhesive effect of the applied wear layer on the printed sheet can be improved by the action of a second dryer 16 (intermediate dryer II) by additionally accelerating the drying of the adhesive. Finally, the quality of the coating can be controlled by means of an inspection or monitoring device 17 after the foil application. For this purpose, the inspection device 17 is directed to a sheet-guiding surface of the coating module 2 after the transfer nip 6 and optionally sealed off from the dryer 16 or on a sheet-guiding surface of the coating module 2 downstream further sheet leading module. The coated sheet passing there can thus be checked for completeness and quality of the coating. As poorly recognized printed sheets can be marked or rejected in a sorter as waste.

According to Fig. 2 For example, the coating module may be provided with means for conditioning the transfer film in order to improve the layer transfer and the coating result. In this case, the film web 5 can be influenced by means of the film guiding device 14.

In a particular embodiment of the invention, a contoured segmented pressing surface 21 should be provided as the surface of the press roll 3. For this purpose, instead of a whole-area pressing surface 20, a segmented pressing surface 21 limited to one or more regions to be coated is used on the pressing roller 3.
The segmented pressing surface 21 may be formed as an isolated surface element, as an annular, narrow surface element encircling the press roll 3, as a surface line following a limited peripheral portion covering over the width of the press roll 3 reaching surface element or in the form of several such surface elements.

For this purpose, for example, a cut-out printing blanket, an imageable plastic high-pressure mold or a pressure-releasing segment 22, which can preferably be adhesively fastened or magnetically attached to a smooth base, the segmented pressing surface 21 can be used to support it. A provided on its underside with a magnetic adhesive surface Andrucksegment 22 may for example be placed directly on the surface of the press roll 3. On the other hand, a magnetic film can be clamped onto the surface of the press roll 3, on the then for attaching or positioning the segmented pressing surface 21, a pressure pad 22 with magnetically adhering equipped back is placed. The surface and the inner structure of the Andrucksegmentes 22 should correspond to the information described above with respect to elasticity and smoothness. Here, a compressible pad 23 may be provided which carries a preferably smooth relatively firm functional layer 24.

The function of this limited segmented pressing surface 21 is that - as in the passage of the cylinder channel 19 - the entrapment of the transfer film 5 is given only when the segmented pressing surface 21, the transfer film 5 touching the transfer nip 6 passes. In other words, the pressing surface 21 should only act on the transfer film 5, where actually imaging layers are to be transferred from the transfer film 5 to the printing sheet.

1. I. Zunächst kann zur Ausführung einer Folientaktung die Transferfolie 5 in sehr vorteilhafter Weise auch dann im Vorschub angehalten werden, wenn der zu beschichtende Bereich irgendwo innerhalb des Bildbereiches des Druckbogens liegt und noch nicht den Bereich der segmentierten Pressfläche 21 erreicht hat oder der Bereich der segmentierten Pressfläche 21 schon vor dem Ende des zu beschichtenden Bogenbereiches endet. Die Transferfolie 5 muss also nur dann transportiert werden, wenn die segmentierte Pressfläche 21 innerhalb des Transferspaltes 6 zwischen Presswalze 3 und Gegendruckzylinder 4 im Eingriff ist. So kann die Ausnutzung der Transferfolie 5 zwischen den zu beschichtenden Druckbogen fast vollständig erfolgen.
   Der Folientransport wird hierbei beim Einsatz einer ringförmigen Pressfläche 21 nur beim Kanaldurchlauf angehalten. Beim Einsatz von Pressflächen 21 in Form einzelner oder mehrerer, zylinderbreiter, über Teilumfänge reichender Segmente kann der Folienvorschub zusätzlich während freier Flächen am Umfang der Presswalze 3 angehalten werden.
2. II. Eine weitere Verbesserung der Folienausnutzung der beschriebenen Art ergibt sich dadurch, dass die Transferfolie 5 in eine oder mehrere Teilfolienbahnen geringerer Breite aufgeteilt wird. Die ist insbesondere in Verbindung mit der segmentierten Pressfläche 21 von großem Vorteil. Bei einer segmentierten Pressfläche 21 kann die Transferfolie 5 auf die Breite der Pressfläche 21 beschränkt eingesetzt werden. Die Einsparung beim Folienverbrauch ist bedeutend. Die Folienführung im Transferspalt 6 wird durch eine vollflächige Auflage einer schmalen Bahn der Transferfolie 5 auf der segmentierten Pressfläche 21 - zumindest im Transferspalt 6 - deutlich verbessert.
   Damit kann bei entsprechender Steuerung mit Hilfe der Einrichtung bzw. Einrichtungen zur Taktung des Folienvorschubes jeder der Teilfolienbahnen, die Ausnutzung der Transferfolie 5 auch bei zonal unterschiedlich langen Beschichtungsbereichen innerhalb eines Bogens verbessert werden. Dazu wird jede Teilfolienbahn nur genau in dem Bereich weitergefördert, wo die bildgebende Oberflächenschicht aufzutragen ist. In den nicht zu beschichtenden Bereichen kann jede Teilfolienbahn unabhängig von den anderen Teilfolienbahnen stillgesetzt werden, wobei damit kein unnötiger Folienverbrauch entsteht.

Thus, two effects can be achieved in the coating module:

1. I. First, to carry out a film timing, the transfer film 5 can be stopped in advance in a very advantageous manner, even if the area to be coated lies somewhere within the image area of the signature and has not yet reached the area of the segmented pressing area 21 or the area of the segmented area Pressing surface 21 ends before the end of the arch area to be coated. The transfer film 5 therefore only has to be transported if the segmented pressing surface 21 is in engagement within the transfer nip 6 between the press roll 3 and the impression cylinder 4. Thus, the utilization of the transfer film 5 between the sheets to be coated can be almost complete.
   The film transport is in this case stopped when using an annular pressing surface 21 only in the channel passage. When using pressing surfaces 21 in the form of single or multiple, cylinder-wide, over sub-segments reaching segments of the film feed can be additionally stopped during free areas on the circumference of the press roll 3 become.
2. II. A further improvement of the film utilization of the type described results from the fact that the transfer film 5 is divided into one or more Teilfolienbahnen lesser width. This is particularly advantageous in connection with the segmented pressing surface 21. In a segmented pressing surface 21, the transfer film 5 can be used limited to the width of the pressing surface 21. The savings in film consumption is significant. The film guide in the transfer nip 6 is significantly improved by a full-surface support of a narrow web of transfer film 5 on the segmented pressing surface 21 - at least in the transfer nip 6.
   Thus, with appropriate control by means of the device or devices for timing the film feed each of the sub-film webs, the utilization of the transfer film 5 can be improved even in zonally different lengths coating areas within an arc. For this purpose, each partial film web is conveyed only exactly in the area where the imaging surface layer is to be applied. In the areas not to be coated, each partial film web can be stopped independently of the other partial film webs, whereby no unnecessary film consumption arises.

In combination with the above-mentioned method, it is thus also possible to use different types of film side by side. This allows surfaces of different film color or different smoothness or texture to be created.

LIST OF REFERENCE NUMBERS

1

commissioned

2

coating module

3

press roll

4

Impression cylinder

5

Transfer foil / foil web

6

transfer nip

7

roller drive

8th

Film supply roll

9

Foil composite role

10

Press covering

11

Inking / dampening unit

12

plate cylinder

13

Blanket / blanket cylinder

14

Folienleiteinrichtung

15

Printing plant security

16

dryer

17

Inspection device / monitoring system

18

dancer roll

19

cylinder gap

20

Press area

21

segmented pressing surface

22

Andrucksegment

23

document

24

functional position

Claims (8)

1. A device for the transfer of imaging layer from a substrate foil onto print sheets at least with one application unit (1) for an image-based coating of the print sheets with an adhesive and with a coating module (2) for transferring the imaging layers from the substrate foil onto the print sheet in a transfer gap (6) between an impression cylinder (4) and a press roller (3), wherein the substrate foil with the coated side contacting the print sheet is jointly with the latter guidable through the transfer gap (6) and in the process the imaging layers can be transferred image-based onto the print sheet, and with a device for feeding the transfer foil (5) to the coating unit (2) and for discharging from the coating unit (2) with a drive for moving the transfer foil in working direction, wherein the foil feed of the transfer foil (5) is controllable by means of a device for the foil guidance in such a manner that the transport of the transfer foil (5) is stopped where in the transfer gap (6) of the coating unit (2) no transfer of an imaging layer onto a print sheet takes place, characterized in that the coating module (2) is a printing couple or coating module of a sheet-fed offset printing press, in that the press roller (3) is a printing blanket cylinder of the printing couple or a form cylinder of the coating module, and in that a control in conjunction with a foil guide of the transfer foil (5) is provided in such a manner that at least when passing a gripper of the cylinder slot (19) receiving the sheet-guiding impression cylinder (4) of the press roller (3) or at least in the region of free surfaces on the circumference of the press roller (3) which as surface comprises an elevated in outline contoured press surface (21) the foil feed is stopped, wherein the press roller (3) subject to continued touching of the transfer foil (5) passes through in a sliding manner.
2. The device according to Claim 1, characterized in that on the surface of the press roller (3) a cutout printing blanket or a plastic high-pressure form processed in accordance with the contoured press surface (13) of the region to be coated is arranged register-appropriately to the surface of the print sheet to be coated.
3. The device according to Claim 1 or 2, characterized in that on the surface of the press roller (3) or on a clothing (10) of the press roller (3) a pressure segment (22) contoured in accordance with the region to be coated that can be glued on or preferably releasably fastened otherwise such as for example magnetically held is provided for forming a segmented press surface (21).
4. The device according to Claim 1 to 3, characterized in that the transfer foil (5) is divided into one or a plurality of part foil webs of smaller width and in that the part foil webs are fed to the transfer gap (6) positioned and next to one another.
5. A device for the coating of print sheets in a sheet-processing machine utilising a transfer foil (5) formed of imaging layers and a substrate foil for the transfer of imaging layers from the substrate foil onto the print sheets with the steps,

   - that at least with one application unit (1) an image-based coating of a print sheet with an adhesive takes place, and

   - in that in a coating module (2) a transfer foil (5) is employed in whose imaging layers on the substrate foil image elements (21) are arranged in such a manner that their image side are adhesively arranged on the carrier foil,

   - that by means of a coating module (2) a transfer of the imaging layers or image elements (21) from the substrate foil onto the print sheet takes place, wherein in the coating module (2) an impression cylinder (4) and a press roller (3) form a common transfer gap (6),

   - wherein the transfer foil (5) is guidable through the transfer gap (6) in such a manner that it is placed with the coated side onto the print sheet guided on the impression cylinder (4) and under pressure is jointly with the print sheet guided through the transfer gap (6),

   - wherein the imaging layer/layers or image elements (21) following the exit of the print sheet from the transfer gap (6) in the region of the imaging regions provided with adhesive adheres in conformity on the print sheet and is lifted off the substrate foil, and

   - in that the transfer foil (5) in the transfer gap (6) is only pressed against the print sheet in the region of the imaging coating/coatings, characterized
   in that the transfer foil (5) is fed to the print sheet in a printing couple or coating module of a sheet-fed offset printing press via a printing blanket cylinder of the printing couple as press roller (3) or a form cylinder of the coating module as press roller (3), and

   - in that on the press roller (3) one or a plurality of pressure segments (22) are attached which have a press surface (21) whose surface is matched to the area extent of the imaging coatings and

   - in that the transfer foil (5) seen axially to the press roller (3) is fed to the transfer gaps (6) merely in the region of axial portions provided with press surfaces (21).
6. The method according to Claim 5, characterized in that the transfer foil (5) is fed to the transfer gap (6) in the form of part foil webs in the axial portions, which are occupied by press surfaces (21).
7. The method according to Claim 5, characterized in that on the press roller (3) one or a plurality of pressure segments (22) are attached which have a press surface (21) whose surface extent is matched to the surface extent of the imaging coatings and in that the transfer foil (5) seen in circumferential direction to the press roller (3), is fed to the transfer gap (6) merely in the region of circumferential portions provided with press surfaces (21),
   wherein the transfer foil (5) is fed to the transfer gap (6) in steps in the axial portions which are occupied by press surfaces (21.
8. The method according to Claim 5 to 7, characterized in that the print sheet in one or a plurality of printing couples following the coating by means of the transfer foil (5) is
   provided with a single or multi-coloured print image.

Images