DE102009026438A1 - Apparatus for cold foil stamping - Google Patents

Abstract

The film feed in a coating module for the transfer of imaging layers from a transfer film to a substrate should be extended in their applicability. For this purpose, a limited pressing surface is arranged in the coating module for transferring layers from the transfer film. For a targeted control of the film feed is possible. In this case, the transfer film is preferably guided past a press roll in a limited width and approximately tangentially. For film storage and film promotion special cyclically operable conveyors are assigned for this purpose.

Description

The The invention relates to a device for transferring imaging layers from a carrier film on printed sheet according to the preamble of claim 1.

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.

At the Transport of press sheets through the printing unit will print each sheet provided with an adhesive pattern. Thereafter, the sheet is through led the coating module, wherein by means of the press roll the resting on the impression cylinder sheet with the sheet material is associated. It goes down metallic layer a close connection with the adhesive provided Areas on the sheet.

To the further transport of the printed sheet adheres to the metallic Layer only in the area provided with the adhesive pattern at. The carrier film is thus the metallic layer in Removed range of adhesive patterns. The consumed in this way Transfer film is wound up again. The print sheet is coated Condition designed.

It is known such coating modules, for example in printing units of printing presses. A disadvantage of the known devices is that they are not flexible.

task The invention is therefore to provide a device by means of which the transfer of an imaging layer z. B. a metallization layer, on a sheet can be done safely, economically and accurately, the device being for an extended range of applications should be manageable. In particular, a partial film application be enabled.

The Solution of this problem results in a device according to the features of claim 1.

The Device provides a clock system for guiding the film web in front.

In Advantageously, the device is characterized in that a press roll has a pressing surface which is a pressing surface Partial area of the total area of a printed sheet occupies.

In Advantageously, such pressing surfaces are as tensionable Segments or as cut-out blankets or as custom-made, preferably photopolymer high-pressure plates or as soluble, for example under magnetic action, attachable pressing segments executed.

• – Ein so genanntes gestripptes Gummituch, bei dem die druckende Oberfläche bis auf die wirksame Fläche entfernt wurde
• – eine polymere Schneidplatte z. B. aus der Klischeeherstellung mittels eines Flachbettplotters, ggf. auch mit einem Trägermaterial aus Aluminium oder Polyester
• – eine Fotopolymerplatte z. B. aus einer Belichtung ggf. mit Aluminiumblech/folie als Trägermaterial.
• – Verwendbar ist auch ein Gummituch, das auf einem Metallträger aufgebracht ist; ein solches Gummituch kann ggf. eine dämpfende Zwischenschicht aufweisen und mit einer dünnen, aber harten und glatten Deckschicht versehen sein.

Different working materials can be used for this purpose. Can be used

• - A so-called stripped rubber blanket with the printing surface removed to the effective area
• - A polymeric cutting plate z. B. from the cliché production by means of a Flachbettplotters, possibly also with a support material made of aluminum or polyester
• - A photopolymer plate z. B. from an exposure, if necessary with aluminum sheet / foil as a carrier material.
• - Can also be used a blanket, which is applied to a metal support; Such a blanket may optionally have a cushioning intermediate layer and be provided with a thin but hard and smooth cover layer.

When Substructure of the corresponding partial press fabric is provided a pad with or without damping effect z. B. a To use vacuum blanket.

As clamping systems arise a clamping spindle as in a blanket cylinder known or so-called combination clamping rails for blankets or printing plates, as known from the blanket cylinders or the form of cylinders. The Depending on the design, the surface of the press cylinder lift is also suitable for profiled imprints.

Thereby results in an extended range of applications for the Method of cold foil stamping. The makeready shortening is achieved by prepared press cylinder lifts. In addition, register automation can be introduced become.

to Solution is to add that to the press cylinder with a register system z. B. executed via register pins is. The press cylinder should be adjustable z. B. in the manner of a Register system for automatic printing plate tensioning. The side and circumferential register can be like a forme cylinder be adjustable. In addition, the press cylinder lift be provided with register punches.

The Device is also advantageously used to a Improvement of the film utilization to achieve that the Transfer film in one or more Teilfolienbahnen lesser width is split. In combination with the aforementioned method can so different types of films are used side by side.

to Securing the efficiency of the coating process can be provided to control the film feed such that the Transfer film is then stopped, if no transfer of imaging or metallization layer takes place.

In Advantageously, a control of the transfer film such take place that when passing through a gripper of the sheet-guiding Impression cylinder receiving cylinder channels of the film feed is stopped, the press roll then under the transfer film passes through.

to Improvement of the gloss effect, the imaging layer by means so-called UV negative pressure paint can be applied. The UV negative pressure ink is by means of the printing unit for the adhesive in the corresponding Way applied over an offset printing plate.

advantageously, It is also possible to have several coating modules within to provide a sheet-processing machine in a row. In order to the application of different imaging coatings or Metallization layers within a subject take place successively. It is possible to use a single adhesive pattern with all picture element elements, the imaging layers next to each other transferred to. It is also possible a first Adhesive pattern in a first coating module with a first to provide imaging coating or metallization and superimposed in the following another, the first enclosing Apply adhesive pattern and with another imaging coating or to provide metallization.

in the Below, the invention is illustrated in more detail with reference to figures.

there shows:

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

2 to 5 the structure of a coating module according to the invention with a film transfer device and various variants for intermittent film guide

• – Ein Druckbogen wird zunächst mit einem flächigen oder bildgebenden Klebstoffmuster versehen (Druckwerk als Auftragwerk 1).
• – Im Folgedruckwerk wird der Druckbogen gemeinsam mit einer Transferfolie 5 unter Pressung durch einen Transferspalt 6 geführt, (Beschichtungswerk 2).

1 shows parts of a sheet-fed rotary printing press, which contains two printing units and is used for the following purposes:

• - A printed sheet is first provided with a two-dimensional or imaging adhesive pattern (printing unit as Auftragwerk 1 ).
• - In the following printing unit, the printed sheet is combined with a transfer film 5 under pressure through a transfer nip 6 guided, (coating plant 2 ).

The commissioned work 1 can be a known offset printing unit with an inking unit 11 , a plate cylinder 12 and a blanket cylinder 13 be. The blanket cylinder 13 acts with an impression cylinder 4 together.

The coating plant 2 can also be formed by an offset printing unit. The transfer gap 6 in the coating plant 2 is through a press roll 3 and an impression cylinder 4 educated. The press roll 3 may correspond to the blanket cylinder. The press roll 3 can also correspond to the form cylinder of a paint module. Within the coating plant used for the film transfer 2 is a track guide 14 shown for transfer foils. The transfer foil 5 is protected by protective devices 15 of the coating plant 2 on and executed again.

The foil supply roll 8th is the coating plant 2 assigned on the side of the sheet feeder. The foil supply roll 8th has a rotary drive 7 for continuous controlled feeding of the transfer film to the coating unit 2 on. In the film feeder can deflection or tension rollers for guiding the transfer film 5 in a substantially constant tension against the press roll 3 be provided. On the downstream side of the printing unit is a film collecting roll 9 provided for the used sheet material. A rotary drive 7 at the foil collecting roll 9 is always advantageous. It may even be provided that the transfer film 5 by means of the rotary drive 7 conveyed on the outlet side and held tight on the inlet side by means of a brake.

The press roll 3 (As blanket cylinder or forme cylinder or separate press roller) carries on its surface a compressible or damping, z. B. also provided with a compressible intermediate layer element. The press roll 3 can do this with a press cover 10 For example, be provided as a plastic coating, comparable to a blanket or blanket, which is held in a cylinder channel on jigs.

To ensure the efficiency of the coating process can be provided, the film feed of the transfer film 5 from the film supply roll 8th to the transfer gap 6 and to the foil collecting roll 9 is progressively controllable, with the transfer film 5 is then stopped if no transmission of imaging or covering layers is to take place.

The associated device preferably includes a corresponding feed control for the transfer film 5 , which ensures that at least that in the area of the press roll 3 and the impression cylinder 4 lying part of the film web is stationary as long as the cylinder channel passes.

This will be later in 2 to 5 Details explained.

A further improvement of the film utilization of the type described results when 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 partial film webs, the utilization of the transfer film 5 be improved even with zonally different lengths coating areas within a sheet.

Furthermore, in the film application module thus formed from the applicator 1 and the coating plant 2 dryer 16 be provided, by means of which the adhesive application or the entire film coating can be dried. Here come z. B. UV dryer in question.

Furthermore, the film application module can be a monitoring device 17 to scan the sheet surface included. The monitoring device 17 allows the evaluation of image contents of the coating and the detection of defects in the film coating. Such a monitoring device can also be provided in conjunction with the printing press, in which the film application module is integrated. Then it can be arranged for example in the sheet delivery of the printing press or a last printing unit.

The transport of the transfer film 5 can be on or between film guide rollers 14 by checking the web tension of the film web 5 be monitored. In a film web guide to one or more web tension measuring devices 19 intended.

Furthermore, to stabilize the film web 5 between a first deflection roller and a first inlet roller to the transfer station, a stabilizing device 30 be arranged to flutter the film web 5 to reduce. The stabilizer 30 has z. B. two rotatably mounted rollers, which is for variable adjustment of the wrap angle of the film web 5 is provided on the guide rollers, so that the guiding action and the damping effect on the film web 5 is adjustable depending on the operating state. The setting of the stabilizer 30 Can be used in conjunction with web tension control devices 19 and possibly a sensor device 20 be made for web break monitoring.

• 1. Ein Bahnzug oberhalb eines vorgebbaren Minimalwerts wird als Signal für Vorhandensein der Folienbahn 5 gewertet und der Maschinensteuerung zugeführt.
• 2. Ein Überschreiten des Maximalwerts des vorgebbaren Bahnzugs wird über Tänzerwalzen 18 oder Rollenantriebe 7 der Folienvorrats- 8 bzw. -sammelrolle 9 reduziert. Damit sind unzulässige Bahndehnung oder Bahnriss vermeidbar.
• 3. Bei Unterschreiten des minimal vorgebbaren Bahnzugs wird überprüft, ob die Bahnspannungsregelung noch aktiv ist. Ist eine Erhöhung der Bahnspannung über Tänzerwalzen 18 oder eine Bremse nicht möglich, wird Bahnriss erkannt.

Electrical signals of the web tension measuring devices are evaluated. Various operating states are possible for this:

• 1. A web train above a predetermined minimum value is used as a signal for the presence of the film web 5 evaluated and fed to the machine control.
• 2. Exceeding the maximum value of the predeterminable web train is over dancer rolls 18 or roller drives 7 the foil supply 8th or collecting roll 9 reduced. Thus, impermissible web elongation or web break can be avoided.
• 3. If the minimum specified tension is undershot, it is checked whether the web tension control is still active. Is an increase in web tension over dancer rolls 18 or a brake is not possible, web break is detected.

The additionally obtained information about the web tension as the actual value, in particular in the context of the aforementioned evaluations, can be used for the control of the printing or transfer process. For this purpose, the system can be coupled to a control station of the printing machine, via which the setpoint values for maximum and minimum web tension can be entered. This may depend on the type of transfer film used 5 and the pressure or transfer conditions in the coating module 2 be dependent on the properties of the printing material, the adhesive or the press fabric.

The necessary data can be transferred directly from data carriers to film supply rolls via interfaces read in and using parameter values from the setting of the transfer process on the coating module 2 to be changed.

The method relating to the film transfer is described in the described printing or application machine according to 1 as follows:
It is intended, at least in one the coating plant 2 following printing unit 50 apply a color print on the imagewise coated with a metallized layer sheet. Here, the sheet is from the coating plant 2 from the impression cylinder 4 via a sheet transfer drum or a sheet transfer unit to an impression cylinder 40 of the printing unit 50 transferred.

The printing unit 50 has as usual in offset printing the impression cylinder 40 , a rubber or blanket cylinder associated therewith 41 and a plate cylinder associated therewith 43 on. The plate cylinder 43 Here are shown schematically an inking unit and a dampening system assigned.

Between impression cylinder 40 and blanket cylinder 41 is another nip 60 educated. In this pressure gap 60 becomes printing ink from one on the plate cylinder 43 clamped pressure plate 44 out over one on the blanket cylinder 41 arranged cover 42 applied to the sheet.

The gap of the pressure gap 60 between the surfaces of the blanket cylinder 41 and the impression cylinder 40 is with the help of the blanket cylinder 41 associated adjusting devices 45 adjustable. This is usually spoken of in the area of offset printing from a Druckbeistellung, as said setting refers to the thickness of the processed material to be processed, in the printing gap 60 to be printed. For this purpose, a printing pressure is necessary to the ink from the blanket cylinder 41 on the on the impression cylinder 40 transferred substrate.

The settings in relation to the transfer gap 6 done by means of other control devices 46 that of the press roll 3 assigned.

The adjusting devices 45 . 46 are commonly used in offset printing on printing blanket or blanket cylinders of printing units or on cylinders of varnish modules.

Furthermore, as the surface of the press roll 3 a contoured or segmented pressing surface in the press fabric 10 be provided. For this purpose, instead of a full-surface pressing area on one or more areas to be coated limited segmented pressing areas on the press roller 3 used.

The segmented pressing surface can be used as an isolated surface element, as an annular, narrow, the pressure roller 3 wrapping surface element, as a surface line following, a limited peripheral portion covering, across the width of the press roll 3 reaching surface element or be pronounced in the form of several such surface elements and so the press fabric 10 form.

For this purpose, for example, a cut-out printing blanket, an imageable plastic high-pressure mold or a pressure pad to be fastened on a smooth base, possibly adhesively attachable or magnetically attachable, can be used to support the segmented pressing surface. A provided on its underside with a magnetic adhesive surface pressure element can, for. B. directly on the surface of the press roll 3 be put on. On the other hand, a magnetic film on the surface of the press roll 3 be clamped, then to the attachment or positioning of the segmented pressing surface 10 a Andrucksegment with magnetically adhering equipped back is placed. The surface and the inner structure of the Andrucksegmentes should correspond to the information described above in terms of elasticity and smoothness. Here, a compressible pad may be provided which carries a preferably smooth relatively firm functional position.

The function of this limited segmented pressing surface in the press fabric 10 is that - similar to the passage of a cylinder channel of the press roll 3 and the opposing impression cylinder 4 - The entrapment of the transfer film 5 is given only if the segmented pressing surface the transfer film 5 touching the transfer gap 6 passes. In other words, the pressing surface should only be applied to the transfer film in the areas 5 can act where actually imaging layers of the transfer film 5 are transferred to the sheet.

• I. Zunächst kann zur Ausführung einer Folientaktung die Transferfolie 5 neben dem Zeitraum des Kanaldurchlaufes 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 erreicht hat oder der Bereich der segmentierten Pressfläche schon vor dem Ende des zu beschichtenden Bogenbereiches endet. Die Transferfolie 5 muss also nur dann transportiert werden, wenn die segmentierte Pressfläche 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 nur beim Kanaldurchlauf angehalten. Beim Einsatz von Pressflächen in Form einzelner oder mehrerer, zylinderbreiter, über Teilumfänge reichender Segmente kann der Folienvorschub zusätzlich während freier Flächen am Umfang der Presswalze 3 angehalten werden.
• 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 von großem Vorteil. Bei einer segmentierten Pressfläche kann die Transferfolie 5 auf die Breite der Pressfläche 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 – 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.

There are two effects in a coating module 2 with in a press cover 10 provided segmented pressing surface achievable:

• I. First, to perform a film timing, the transfer film 5 In addition to the period of the channel passage in a very advantageous manner, even in the feed stopped when the area to be coated is located somewhere within the image area of the sheet and has not yet reached the area of the segmented pressing surface or the area of the segmented pressing surface before the end of Coating bow area ends. The trans ferfolie 5 So only has to be transported if the segmented pressing surface within the transfer nip 6 between press roll 3 and impression cylinder 4 is engaged. So can the utilization of the transfer film 5 almost completely between the sheets to be coated. The film transport is stopped here when using an annular pressing surface only at the channel pass. When using pressing surfaces in the form of single or multiple, cylinder-wide, sub-segments reaching segments of the film feed can additionally during free areas on the circumference of the press roll 3 be stopped.
• 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. In a segmented pressing surface, the transfer film 5 be used limited to the width of the pressing surface. The savings in film consumption is significant. The foil guide in the transfer gap 6 is characterized by a full-surface edition of a narrow web of the transfer film 5 on the segmented pressing surface - at least in the transfer nip 6 - clearly improved. Thus, with appropriate control by means of the device or devices for timing the film feed each of the partial film webs, the utilization of the transfer film 5 be improved even with 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.

In Combination with the aforementioned method can also be so different types of film are used side by side. In order to will allow surfaces to be different Foil color or different smoothness or texture be generated.

• – gestripptes Gummituch, bei dem die druckende Oberfläche aus Gummi bis auf die beim Prägen zur Wirkung zu bringende Fläche entfernt wurde
• – polymere Schneidplatte (Klischee für Flexodruck), die mittels Flachbettplotter herstellbar und ggf. mit Träger aus Aluminium oder Polyester ausgerüstet ist
• – eine Fotopolymerplatte (Flexodruck), deren Oberflächenkontur mit Belichtung und Auswaschen herstellbar ist (ggf. mit Träger aus Aluminium).
• – Verwendbar ist auch ein Gummituch mit einem Metallträger, das sich wie ein gestripptes Gummi- bzw. Drucktuch vorbereiten und einsetzen lässt.

For the construction of the partial press fabric, different working materials known per se can be used. Can be used

• - Stripped rubber blanket in which the rubber printing surface was removed except for the area to be embossed
• - Polymeric cutting plate (cliché for flexographic printing), which can be produced by means of a flatbed plotter and optionally equipped with a carrier made of aluminum or polyester
• - A photopolymer plate (flexographic printing), the surface contour can be produced with exposure and washing out (possibly with aluminum support).
• - Can also be used a rubber blanket with a metal carrier that can be prepared and used like a stripped rubber or blanket.

As a substructure of the corresponding press fabric 10 with segmented pressing surfaces is a pad with or without damping effect, such as a vacuum blanket (but only for press clothing without rigid support layer) used.

Clamping systems in the cylinder channel of the press roll 3 for fixing the press cover 10 For example, tensioning spindles may be as in a blanket cylinder or combination tensioning rails for blankets or printing plates as known from rubber or forming cylinders. The surface of the press cover 10 Depending on the structure, it is also suitable for profiled imprints. This results in an extended range of applications for the process of cold foil stamping. Using the above elements, a very simple and fast handling of the device of the film application module is possible.

• – eine Kanaltaktung beim Durchlauf von Zylinderkanälen der Presswalze 3 und des Gegendruckzylinders 4,
• – eine Formattaktung bei auf die Formatlänge des Folientransfers am Umfang der Presswalze 3 beschränkter Folienzuführung und
• – eine Prägebereichstaktung bei Beschränkung der Folienführung auf durch segmentierte Pressbereiche in der Pressbespannung 10 der Presswalze 3 definierter Folienzuführung

angeführt werden.According to the invention devices are provided which the cyclical promotion of the film web 5 allow. Here, as operating variants from the previously executed

• - A channel timing in the passage of cylinder channels of the press roll 3 and the impression cylinder 4 .
• - A formattaktung on the format length of the film transfer at the periphery of the press roll 3 limited slide feeder and
• - A Prägebereichstaktung when limiting the film guide on by segmented pressing areas in the press fabric 10 the press roll 3 defined film feed

be cited.

For the film feed (and the discharge) is usually the drive of the film rolls 8th . 9 continuously provided, as the mass of film rolls 8th . 9 too big for a quick change of the drive movement. This results in braking the film web to re-accelerate in the transfer area in the supply and discharge of the film web 5 opposite to the movement of the film rolls 8th . 9 excess or missing film lengths.

Therefore, solutions are proposed according to the invention, which in continuous Nachförderung or removal of the film web 5 attack can buffer the excess or missing pieces of track. These are basically already with the dancer rollers 18 described as a variant of foil stores. The dancer rollers 10 but are not accurate enough to the described in the described high-speed clocking in the film transfer process controllable, especially since they usually far away from the place of consumption and close to the film roll 8th . 9 are arranged to maintain the web tension there.

In the 2 to 5 Therefore, further possibilities for the rapid compensation of web displacements in the film timing in the cold foil process are given.

In 2 is a film transfer module accordingly 1 shown. Here are the dancer rollers 18 arranged to regulate the web tension. To compensate for major changes in the film promotion, such as stopping the film promotion in the transfer area (range of film transfer between press roll 3 and impression cylinder 4 ) without film consumption (channel timing, formattaktung, timing over embossed areas), are also in front of the inlet of the fresh film web 5 in the transfer gap 6 and after the exit of the used film web 5 from the transfer gap 6 as drive groups 22 designated roller pairs 23 . 24 arranged.

The drive groups 22 are described here for all the following embodiments and each show a pair of rollers, the film web 5 pinch and so defined with respect to a desired transport path can lead. The roller pairs of the drive groups 22 consist in 2 each from a foil guide roller 24 and a drive roller 23 , Both the foil guide roller 24 as well as the drive roller 23 is at least partially drivable. The drive of the drive roller 23 can not only in the transport direction of the film web 5 (from film roll 8th to 9 ) but can also generate return strokes. This is useful because the film web 5 at a deceleration does not stop immediately and thus runs over a desired breakpoint. This could be a piece of the film web 5 not used. A short defined return stroke after braking and stopping the film web 5 in the transfer area reduces or eliminates this unnecessary film consumption. This is the drive of the drive roller 23 quickly controllable. The drive roller 23 itself can be segmented in order to be able to execute the changing drive movements quickly. Furthermore, the film guide roller 24 opposite the drive roller 23 but can be swung on and off, but it can also permanently on the drive roller 23 stay employed.

So it can also be provided that the film guide roll 24 one more or less through the film web 5 perform controlled movement while the drive roller 23 performs a conveying movement and the return stroke movement. The foil guide roller 24 performs for a defined period in relation to the film transport direction a backward movement only by controlled hiring against the on the drive roller 23 overlying film web 5 out. The drive roller 23 then performs a continuous transport movement against the direction of the film web 5 by. This is possible because the film web 5 at this time due to lack of contact pressure by the press roll 3 against the impression cylinder 4 is freely movable in the transfer area.

Furthermore, the drive groups 22 also by deceleration at the time of foil dislocation, here at least on the feed side to the transfer gap 6 , the film web 5 Hold in the transfer area under the necessary tension, so that when the film transfer begins again with pressing by the press roller 3 against the impression cylinder 4 immediately good transfer quality is achieved again.

The system of the drive group 22 is also in segmented arranged film guide rollers 24 for format-width drive rollers 23 both for the guidance of a full-format wide film web 5 as well as for the guidance of, possibly also distributed, arranged Teilfolienbahnen 5 suitable. For this purpose, the segments of the film guide roll 24 correspondingly adjustable to the positions of the partial film webs 5 in the axial direction to the press roll 3 be arranged.

The drive group 22 can be simplified by the fact that the drive roller 23 with a rough or adhesive surface or as a suction roll is executed. With a correspondingly large loop through the film web 5 then sufficient adhesion for safe guidance of the film web 5 on the drive roller 23 be achieved. Then could on a foil guide roller 24 , even in segmented form, can be dispensed with. This is also true in terms of the format-width design of the drive roller 23 harmless. A designed as a suction roller drive roller 23 could then be designed so that, if necessary, provided in segments corresponding to the respective to be processed film web widths switchable suction devices.

According to 2 So is provided the film timing in the transfer area by means of the drive groups 22 opposite the foil storage by means of the dancers 18.1 . 18.2 perform. The dancer 18.1 in the area of the feed roll 8th takes this in the transfer area of stationary film web 5 under the action of the web tension sensor arranged there, the film piece on, by the clamping of the film web 5 by means of the drive group 22 becomes free. At the same time the dancer gives 18.2 a piece of film for the film winding free, because then no film web 5 is subsidized. With renewed onset of the film promotion after the end of the interruption of the film promotion in the transfer area of the process of film release and film storage runs on the dancers 18.2 . 18.1 reversed in each case.

In 3 is a simplified embodiment in a coating plant 2 shown. Here are also the dancers 18 shown, but only serve the web tension control.

Furthermore, in the area of the film feed to the transfer area with the transfer nip 6 again a drive group 22 intended. On the outlet side of the transfer area is a pendulum held Folienleitwalze 25 shown. This foil guide roller 25 may be a transverse to the course of the transport direction of the film web 5 perform directed compensation movement. The compensation movement is marked with a dashed representation. This is the path of the film web 5 lengthened and shortened. When the drive group 22 So the Fo lienbahn 5 holds back to the clock or feed back, the film guide roller 25 perform a compensating movement to shorten the web path and so release a piece of film web to compensate for this movement against the Abförderbewegung. If the promotion of the film web is to start again, the film guide roller leads 25 a movement to lengthen the path of the film web 5 down from. This is how the film web becomes 5 accelerated again or during acceleration by release on the drive group 22 vacant track piece can be compensated.

In 4 and 5 variants of the storage effects in the film timing are shown, which use a per se known principle of looping the film web by applying a vacuum. Here are film storage 26.1 . 26.2 . 27.1 . 27.2 . 28.1 and 28.2 one side of the coating unit 2 assigned. The foil stores 26.1 . 27.1 and 28.1 are each the feed side of the film web 5 to the transfer gap 6 and thus the feed roller 8th assigned. The foil stores 26.2 . 27.2 and 28.2 are each the discharge side of the film web 5 from the transfer gap 6 assigned away.

Each foil store 26.1 . 26.2 . 27.1 . 27.2 . 28.1 and 28.2 consists of a vacuum chamber into which a film loop 29 the film web 5 in and out again.

The effect of the film storage 26.1 . 26.2 . 27.1 . 27.2 . 28.1 and 28.2 is the following: By sucking air (for example by means of one or more fans) on the bottom side of the vacuum chambers, the film loop 29 each drawn into the vacuum chamber with a force corresponding to the negative pressure. This force does not outweigh the given by the web tension control tensile force of the film web 5 because the foil loops 29 otherwise would be sucked in the vacuum chambers. The system is self-regulating insofar as the film loops 29 can freely oscillate in the chamber against the force of the negative pressure and thus record or release each sheet of film track. As the system of film storage 26.1 . 26.2 . 27.1 . 27.2 . 28.1 and 28.2 freely oscillating executed here more drive groups must be provided as in the previously presented systems.

To regulate the film web promotion, the formation of the size of the film loops 29 ( 36 , please refer 6 ) be used. For this purpose, a sensor may be provided in each of the vacuum chambers, which is formed approximately on the basis of the distance measurement by means of ultrasound. This sensor detects how far the film loop 29 . 36 is formed or how far the film loop 29 . 36 is drawn into the vacuum chamber. On the basis of these constantly measured signals can then by means of the drives of the film rolls 7 . 8th and, if necessary, in conjunction with dancer rollers, the film web conveying be regulated.

• a) Zum Anhalten Folientransfers und damit auch des Folientransportes im Transferbereich (Transferspalt 6) wird durch das Stillsetzen der Antriebsgruppe 22 vor dem Transferspalt 6 bei laufender Folienrolle 7 eine auflaufende Folienbahnlänge frei und in den ersten Folienspeicher 26.1, 27.1, 28.1 oder 32.1 hineingezogen.
• b) Auf der Ablaufseite nach dem Transferbereich wird gleichzeitig die Folienbahn 5 aus dem zweiten Folienspeicher 26.2, 27.2, 28.2 oder 32.2 zur kontinuierlichen Aufwicklung freigegeben.
• c) Zum Fortsetzen des Folientransfers und damit dem erneuten Einsetzen des Folientransportes im Transferbereich wird die Antriebsgruppe wieder aktiviert und die eingezogene Folienschlaufe 29 aus dem ersten Folienspeicher 26.1, 27.1, 28.1 oder 32.1 wieder dem Transferbereich zugeführt.
• d) Gleichzeitig wird der zweite Folienspeicher 26.2, 27.2, 28.2 oder 32.2 wieder mit einer Folienschlaufe 29, 36 befüllt.

The two-sided arrangement of the film storage 26.1 . 26.2 . 27.1 . 27.2 . 28.1 and 28.2 (also 32.1 . 32.2 in 6 ) serves that the timing of the film web feed when stopping and continuing the film transport in the transfer area can be performed as follows:

• a) To stop film transfers and thus also the film transport in the transfer area (transfer gap 6 ) is stopped by stopping the drive group 22 in front of the transfer gap 6 while the film roll is running 7 an accumulating length of film web free and in the first film storage 26.1 . 27.1 . 28.1 or 32.1 drawn.
• b) On the drain side after the transfer area is simultaneously the film web 5 from the second foil store 26.2 . 27.2 . 28.2 or 32.2 released for continuous rewinding.
• c) To continue the film transfer and thus the reinsertion of the film transport in the transfer area, the drive group is reactivated and the retracted film loop 29 from the first foil store 26.1 . 27.1 . 28.1 or 32.1 returned to the transfer area.
• d) At the same time, the second film memory 26.2 . 27.2 . 28.2 or 32.2 again with a film loop 29 . 36 filled.

According to 4 are two variants for the arrangement of foil stores 26.1 . 26.2 . 27.1 and 27.2 shown.

At the bottom of the film transfer module of the coating plant 2 are small Folienspei cher 26.1 and 26.2 shown. These are with the drive groups 22 the transfer area at the transfer gap 6 combined. In addition, the foil stores 26.1 . 26.2 each foil guide rollers 14 for guiding the film web 5 assigned.

At the top of the film transfer module of the coating plant 2 are larger foil stores 27.1 and 27.2 shown. These are with their own drive groups and possibly with drive groups 22 the transfer area at the transfer gap 6 combined. In addition, the foil stores 27.1 . 27.2 each foil guide rollers 14 for guiding the film web 5 assigned. The foil stores 27.1 . 27.2 assigned drive groups 22 serve to hold the film web 5 if the negative pressure on the foil stores 27.1 . 27.2 collapses or other disturbances occur in the film promotion. In addition, created with these drive groups 22 Another rule option for rail transport.

The system of foil stores 26.1 . 26.2 is smaller in size, thus easier to integrate and responsive because of its small volume. With this system, so smaller fluctuations in the film web promotion can be compensated quickly and effectively and also serves the same timing.

The system of foil stores 27.1 . 27.2 is built larger, thus more receptive and can compensate for larger fluctuations in the film web promotion. This is suitable for a timing that has to bridge large spaces during film transfer, so if at the periphery of the press roll only short areas of film 5 to be transferred.

In 5 is a variant with foil stores 28.1 and 28.2 in a coating plant 2 shown, which allows even larger storage. The foil stores 28.1 . 28.2 are placed vertically and directly to the drive groups 22 the transfer area at the transfer gap 6 assigned. Due to the vertical arrangement, the supply of the film web 5 from the film loop 29 in the foil store 28.1 so directly and without Folienleiteinrichtung the first drive group 22 fed on the feed side to the transfer area. Likewise, the film web 5 on the discharge side of the transfer area without film guiding elements on the film storage 28.2 its film loop 29 be forwarded. In 5 are two foil guide rollers 14 for discharge from the housing of Beschich tungswerkes 2 shown. On the feed side of the film storage 28.1 and the discharge side of the film storage 28.2 are roller pairs 14 shown as a pinch rollers for better guidance of the film web 5 serve. The one film roll can turn as a drive roller 24 be executed in order to control the film web promotion here too.

In 6 is according to the previously described functionalities another variant with foil stores 32.1 and 32.2 in a coating plant 2 shown, which is compact and allows larger storage. The foil store 32.1 is approximately horizontally downstream under the film roll 7 arranged and the foil memory 32.2 is placed approximately perpendicular to the opposite side. The drive group 33 with two foil guide rollers 35 and a drive roller 34 on the inlet side of the transfer area is close to the transfer nip 6 assigned. The drive group 33 with a film guide roller 35 and a drive roller 34 on the discharge side of the transfer gap 6 is the foil store 32.2 assigned. Due to the horizontal arrangement, the supply of the film web 5 from the film loop 36 in the foil store 32.1 arranged compact and a smoothing and stabilizing device 30 the first drive group 33 on the feed side to the transfer area (transfer gap 6 ). For feeding and removing the film web 5 to and from the film storage 32.1 are foil guide rollers 31 provided to the film web 5 easy to hold.

Furthermore, the film web 5 on the discharge side of the transfer area after the transfer gap 6 over the film web 5 smooth-holding foil guiding elements 14 (in the manner of a smoothing and stabilizing device) are performed. These foil guiding elements 14 lead the film web 5 also from the field of printing mechanism protection 15 at the coating plant 2 out. On the discharge side after the transfer area to the film storage 32.2 can also drive a group 37 be arranged, which is a film guide roller 38 and a drive roller 39 having. To form a film loop 36 in the foil store 32.2 becomes the film web 5 supplied without additional guide. The removal of the film web 5 from the foil store 32.2 via a foil guide roller 31 ,

On the feed side and the discharge side of the film storage 32.1 and on the discharge side of the film storage 32.2 is ever a foil guide roller 31 shown, for better guidance of the film web 5 serve, so that the film web the film storage 32.1 exactly fed and from the film storage 32.2 kept smooth to wind up dissipated.

Alternatively, the drive group 37 for the discharge side of the film web 5 at the film guide roller 31 at the film storage 32.2 be arranged. This can because of the large wrap the foil guide 31 be driven by itself or it can also be assigned to this another drive roller.

The drive groups 22 , as well as the slides guide roll 25 out 3 , can also be combined with suction rollers. Then the clamping of the film web is not so critical. The control of the suction air to such suction rolls but is run at a very high clock frequency.

The vacuum chambers of the film storage 26.1 . 26.2 . 27.1 . 27.2 . 28.1 . 28.2 . 32.1 and 32.2 can be carried out according to leading to foil or Teilfolienbahnen. If the vacuum chambers have the width of a film web and are displaceable, it is possible to respond flexibly to desired coating conditions.

Furthermore, in the working area overlapping vacuum chambers separating means may be arranged, each of which the lateral position of the film web 5 or partial film webs. This allows the film storage 26.1 . 26.2 . 27.1 . 27.2 . 28.1 . 28.2 . 32.1 and 32.2 be divided advantageously into a plurality of parallel vacuum chambers. When separators can be used in the vacuum chambers and / or in the vacuum chambers transverse to the direction of the film or partial film webs 5 are displaceable, can thus be provided in the width adjustable and separate vacuum chambers. These are on individual film webs 5 different width or on partial film webs of the same or different widths tunable. Thus, the formation of film loops 29 . 36 improved and optimally adapted to the respective film or partial film webs.

When covering individual, not with a film web 5 occupied chambers, the air consumption of the vacuum device can be minimized and better regulated.

It has been shown that the suction at the vacuum chambers of the film storage 26.1 . 27.1 . 28.1 . 32.1 on the supply side to the transfer area and the cleaning of the film webs can serve. In particular, particles which adhere to the web edge (mica, dust, contamination) are sucked into the vacuum chambers and removed via the suction devices. Therefore, it is advantageous if at least one filter device is provided in the vacuum supply of the vacuum chambers, which serves to separate the contaminants. This can be done simultaneously with the storage of film loops 29 . 36 Also, a cleaning of the film web are made so that the transfer process proceeds undisturbed and the coating unit 2 kept clean.

The arrangement of the film storage 26.1 . 26.2 . 27.1 . 27.2 . 28.1 . 28.2 . 32.1 and 32.2 and the drive groups 22 . 33 can be designed so that they are interchangeable with dancers in existing film transfer devices. Thus, a more efficient film guide for existing systems can be retrofitted in a simple manner.

The film guide can be interrupted even if the press roller 3 has only partially occupied pressing surface, so that during the passage of not occupied with a pressing surface surface areas in the transfer nip 6 , the film web can be stopped.

The film feed and discharge can with controllable or self-regulating systems such as friction shafts and individual drives on the film rolls 8th . 9 be executed in the variants of a format-wide film roll or with multiple sub-film rolls.

1

commissioned

2

coating module

3

press roll

4

Impression cylinder

5

Transfer film / sheet

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

Printing blanket / blanket cylinder

14

Folienleiteinrichtung

15

Printing plant security

16

dryer

17

Inspection device / monitoring system

18

dancer roll

19

Bahnspannungsüberwachungl

20

Web break monitoring

21

Druckzylinderblasvorrichtung

22

cylinder gap

22

drive group

23

Folienleitwalze

24

drive roller

25

Folienleitwalze

26.1

film storage

26.2

film storage

27.1

film storage

27.2

film storage

28.1

film storage

28.2

film storage

29

Strap / foil loop

30

stabilizing device

31

Folienleitwalze

32.1

film storage

32.2

film storage

33

drive group

34

drive roller

35

Folienleitwalze

36

Strap / foil loop

37

drive group

38

Folienleitwalze

39

drive roller

40

Impression cylinder

41

Blanket cylinder

42

Blanket / blanket

43

plate cylinder

44

printing plate

45

setting device

46

setting device

50

printing unit

60

nip

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - EP 0569520 B1 [0002]

Claims (15)

Device for transfer of image-forming layers from a carrier foil to printed sheets at least with an applicator ( 1 ) for an imagewise coating of the printed sheets with an adhesive and with a coating module ( 2 ) for transferring the imaging layers from the carrier foil to the printed sheet in a transfer nip ( 6 ) between an impression cylinder ( 4 ) and a press roll ( 3 ), wherein the carrier film with the coated side in contact with the printed sheet together with this through the transfer nip ( 6 ) is feasible and thereby the image-forming layers are imagewise transferable to the printing sheet, and with a device for feeding the transfer film ( 5 ) to the coating plant ( 2 ) and for removal from the coating plant ( 2 ) with a drive for moving the transfer film in the working direction, wherein the film feed of the transfer film ( 5 ) is controllable by means of a film guide such that the transport of the transfer film ( 5 ) is stopped when in the transfer gap ( 6 ) of the coating plant ( 2 ) no transfer of an imaging layer to a printed sheet, characterized in that a control in conjunction with a film guide of the transfer film ( 5 ) is provided such that when passing through a gripper of the sheet leading impression cylinder ( 4 ) receiving cylinder channel ( 22 ) of the press roll ( 3 ) the film feed is stopped, wherein the press roll ( 3 ) with further contact of the transfer film ( 5 ) passes through and / or that as the surface of the pressing cylinder ( 3 ) a press cover ( 10 ) is provided with increased, contoured in the contoured pressing surface, wherein the pressing surface is limited to the maximum area to be coated and that when passing through a portion of the press roll ( 3 ) is stopped outside the limited to the area to be coated pressing surface of the film feed, wherein the pressure roller ( 3 ) with further contact of the transfer film ( 5 ) passes through. Device according to claim 1, characterized in that the transfer film ( 5 ) is subdivided into one or more sub-foil webs of lesser width and that the sub-foil webs are positioned or juxtaposed to the transfer nip ( 6 ), wherein the partial film webs are provided with the same or different imaging layers and layers of different color and / or different gloss and / or different surface structure can be generated. Apparatus according to claim 1 to 2, characterized in that the film web ( 5 ) are assigned to controllable conveyors for braking and accelerating in time with the processing of the film transfer. Apparatus according to claim 1 to 3, characterized in that the conveying devices ( 22 . 33 ) are formed as pairs of rollers, wherein the pairs of rollers the film web ( 5 ) lead by clamping and are drivable. Apparatus according to claim 3 to 4, characterized in that the conveying devices ( 22 . 33 ) a transfer area in front of the transfer nip ( 6 ) or before and after the transfer gap ( 6 ) and that the conveyors foil storage ( 26.1 . 26.2 . 27.1 . 27.2 . 28.1 . 28.2 . 32.1 . 32.2 ) assigned. Apparatus according to claim 1 to 6, characterized in that the film memory ( 26.1 . 26.2 . 27.1 . 27.2 . 28.1 . 28.2 . 32.1 . 32.2 ) as in each case at least one film loop ( 29 . 36 ) of the film web ( 5 ) receiving negative pressure chambers are formed. Apparatus according to claim 2 to 6, characterized in that the film memory ( 26.1 . 26.2 . 27.1 . 27.2 . 28.1 . 28.2 . 32.1 . 32.2 ) as one or more foil loops ( 29 . 36 ) a film web ( 5 ) or a plurality of partial film webs receiving negative pressure chambers are formed, wherein the negative pressure chambers have one or more separation means for limiting tion of negative pressure regions in the width of one or more film or partial film webs. Apparatus according to claim 6 to 8, characterized in that the vacuum chambers have suction devices for generating a negative pressure, wherein by means of one or more of the suction attachments of the or the film webs ( 5 ) are sucked and that the suction devices are assigned filter means for depositing the adhesions. Process for coating printed sheets in a sheet-processing machine, in particular a sheet-fed rotary printing press, using a transfer film consisting of image-forming layers and a carrier film ( 5 ) for the transfer of image-forming layers from the carrier film to the printed sheets in that - at least with an applicator ( 1 ) an imagewise coating of a printed sheet with an adhesive, and - that by means of a coating module ( 2 ), the image-forming layers are transferred from the carrier film to the printed sheet, wherein in the coating module ( 2 ) an impression cylinder ( 4 ) and a press roll ( 3 ) a common transfer gap ( 6 ) through which the transfer film ( 5 ) can be guided under pressure in such a way that, with the coated side on the impression cylinder ( 4 ) led printed sheet is applied, - wherein the imaging layer (s) after the exit of the sheet from the transfer nip ( 6 ) is adhered to the surface of the printing sheet in the region of the image-wise areas provided with adhesive and is lifted off the carrier film, the transfer film ( 5 ) in the transfer gap ( 6 ) is pressed against the printed sheet at least in the area of the imagewise coating / s and - that the transfer film ( 5 ) only through the transfer gap ( 6 ) is promoted when contact between the surface of the press roll ( 3 ) and the counter pressure cylinder ( 4 ) is made on resting printing material. Method according to claim 9, characterized in that on the press roll ( 3 ) one or more pressure segments are attached, which have a pressing surface whose surface is adapted to the surface extent of the image-wise coatings, and in that the transfer film ( 5 ), axially to the press roll ( 3 ), only in the area of provided with pressing surfaces Achsabschnitten the transfer nip ( 6 ) is supplied. A method according to claim 9 or 10, characterized in that on the press roller ( 3 ) one or more pressure segments are attached, the pressing surface of which is adapted to the areal extent of the imagewise coatings, and in that transfer film ( 5 ), in the circumferential direction to the press roll ( 3 ), only in the area of peripheral surfaces provided with pressing surfaces, the transfer nip ( 6 ) is supplied. A method according to claim 9 to 11, characterized in that the transfer film ( 5 ) the transfer gap ( 6 ) is supplied stepwise in the Achsabschnitten in which an occupancy with pressing surfaces ( 21 ) is present. A method according to claim 9 to 12, characterized in that the transfer film ( 5 ) before being fed to the transfer nip ( 6 ) in the stepwise feeding during a step in which no film promotion takes place, in a film memory can be stored and that the transfer film ( 5 ) after discharge from the transfer nip ( 6 ) in the stepwise feeding during a step in which no film promotion takes place, can be removed from a film storage. Method according to claim 13, characterized in that the transfer film / webs ( 5 ) before and after the transfer gap ( 6 ) is guided under the action of negative pressure in film storage with foil loops forming vacuum chambers. A method according to claim 14, characterized in that the transfer film ( 5 ) is cleaned in the film stores by means of suction devices of the vacuum chambers.