DE102006056896A1 - Transfer of images/text from a carrier film to printed sheets, in a sheet-fed rotary printing press, varies the film draw tension at the transfer gap in the coating cycle according to film quality - Google Patents

Abstract

To transfer an image or text from a carrier film to a printed sheet, especially in a rotary sheet-fed printing press, the printed sheet moves from the adhesive application station (1) to the coating station (2). At the coating station, where matter or a coating layer is transferred, the carrier film passes around the surface of a press roller (3) at the roller transfer gap (6), to be pressed against the printed sheet. The draw tension on the web of transfer film (5) is variable in the sheet coating cycle on entering and/or leaving the transfer gap.

Description

The The invention relates to a method and a device for transfer Imaging or covering layers of a carrier film on printed sheet according to the preamble of claim 1 and of Claim 18.

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 a sheet-fed machine with a feeder and a boom, printing units and a coating unit are arranged. In at least one printing unit, an adhesive pattern is applied as a printed matter in the planographic printing process. In the coating unit after the printing unit, a counter-pressure cylinder, a pressure roller and a film guide are provided. Therein, a foil strip is guided through the transfer nip of the coating unit between impression cylinder and press roll from a film supply roll and wound up again on the exit side after leaving the coating unit. The transfer film contains a carrier film on which functional layers of various types, such as metallic layers, for example of aluminum, or plastic layers can be applied. Between functional layer and carrier film, a separating layer is provided, by means of which the functional layer can be removed from the carrier layer.

After this a sheet with a flat Adhesive or adhesive pattern is provided, he is guided through the coating plant, wherein by means of the press roller resting on the impression cylinder Sheet is associated with the film material. It goes the down-facing functional layer has a close connection with the areas provided with adhesive on the sheet. After that The functional layer adheres only in the area of adhesive provided pattern or even full-surface Kleberbe rich, wherein the carrier film the functional layer is removed in the region of the adhesive pattern. The print sheet is laid out in the coated state.

adversely the procedures described is that they are not flexible can be used, a comprehensive know-how to the complex processes require and are difficult to handle. Above all, those are so far known production methods on the processing of substrates limited to paper or cardboard. A coating of film substrates in a cold foil stamping process has not been announced yet.

task The invention is therefore a method according to the preamble of Claim 1 and a device according to the preamble of the claim 18 provide by means of which a film coating of sheet from different quality films simple, safe, economical and can be done exactly, with method and device simple should be manageable. A film coating module on a sheet-fed rotary printing press is intended provide an improvement in application quality in a tangential film guide.

The solution This object is achieved in a method according to the features of claim 1 and in a device according to the features of claim 18.

Favorable Way becomes a guide the transfer sheet feeder used in which the transfer film during feeding to the transfer nip through led a modular control system becomes.

A associated Device for feeding the Transfer film advantageously has a guide in the manner of a cassette module, by means of which the supply to the transfer gap and the removal from the transfer gap to simple Way allows become.

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 Also 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 transmission of the imaging or metallization takes place.

In Advantageously, a control of the transfer film such done that when passing through the gripper of the bow leading Impression cylinder receiving cylinder channel of the film feed is stopped, the press roll then under the transfer film passes through.

in the Channel area between blanket cylinder or press roller and impression cylinder touches the gripper back at the beginning of printing the application film and influences the surface refinement negative.

Around To prevent this, the film is the gripper passage through a clocked guide deflection so changed (closer brought to the blanket cylinder or the press roll) that it to no Greiferberführung comes.

The Control of the diversion can over a mechanical cam mechanism or electro-pneumatic actuator done the angle over the real-time computer is controlled.

occurring Web tension variations are caused by the signals of e.g. in the rotary axis mounted sensor (e.g., potentiometer) to the Folienaufwickelmotor directed and regulated by speed adjustment.

These Timed film deflection can also be mounted on the film outlet side become.

• – geringe Bahnspannungsschwankungen
• – keine Greifermarkierungen.
• – Zum besseren Ablöseverhalten der zu applizierenden Folienbeschichtung kann der Abrisswinkel auf der Auslaufseite durch Änderung der Position „A" unabhängig vom Taktvorgang verändert werden
• – Beim steilen Abrisswinkel kann auch der Taktvorgang ausgeschaltet werden.
• – Die verursachte Bahnspannungsänderung wird über einen nachgeschalteten „Tänzer" oder Aufwickelmotor korrigiert.
• – Veränderung des Einlaufwinkels durch Positionsänderung der Einlaufumlenkung. Stufenlose Verstellung von einer Position. I => II.
• – Skizze A zeigt die Extrempositionen zur Abrisswinkelveränderung (III/IV) auf der Auslaufseite.
• – Um eine gleichmäßige Folienapplikation über die Zylinderbreite zu erreichen kann der Gummizylinder aus Stahl gefertigt sein

Advantages are:

• - low web tension fluctuations
• - no gripper marks.
• - For better separation behavior of the film coating to be applied, the demolition angle on the outlet side can be changed by changing the position "A" independently of the cycle
• - With the steep demolition angle, the clocking process can also be switched off.
• - The induced web tension change is corrected via a downstream "dancer" or take-up motor.
• - Changing the inlet angle by changing the position of the inlet guide. Stepless adjustment from one position. I => II.
• - Sketch A shows the extreme positions for demolition angle change (III / IV) on the outlet side.
• - To achieve a uniform film application over the cylinder width, the rubber cylinder can be made of steel

Farther may be in a foil application module with or nearer tangential Film guide through the printing nip in a sheet-fed rotary printing press with a parent roll (up to format width max.) or several single rolls side by side, the winding / unwinding roller (s) have drives and brakes; of the Plate, rubber and impression cylinder has a channel and the impression cylinder are grippers for the Bedruckstofftransport.

By the channel passage (rubber cylinder / impression cylinder) occurs at each Sheet pass (Zyl.-rotation) to a web influence of the film web (Rail shortening in the channel affects web tension of the film).

at the current solution is at the film handling per web a (magnetic field) brake and on the film rewind a drive (friction shaft). The web tension is set in a controlled manner on the operating panel of the module. The dancer is not used in single roles. The module will be or subject clocking evolved, the web tension of a relatively high value for maintaining the channel passage must be reduced. These requirements lead to, in particular when the machine is running, the film web vibrates relatively strongly.

On the film web should be as possible uniform web tension act (low web tension, no stretching of the film). For this becomes dancer roller operation also driven with several single roles. The dancer controls (controls) the common channel passage the single roller tracks quasi largely.

The solution can be pneumatic wherein a dancer roller clamped on both sides with an air cushion in middle position over Proportional valves can be controlled. It is also a hydraulic, mechanical solution by means of springs and weights conceivable etc ..

Of the Channel push on The film web should be cushioned, so the effect Channel / cylinder circumference optimized to the web tension and it can a relatively constant web tension (web tension) can be set.

alternative can all single tracks over drove a "own" dancer be => constant web tension produce. The Folienauf- and -abwicklung can with individual drives or drive-brake combination executed.

to film guide in the channel region of the blanket cylinder or the press roll is a additional guide recoverable. This limits the shortening path of the film in the channel passage.

Of the Rubber cylinder or the press roll may also be a sleeve carrier. If necessary retracted in the channel area.

Of the Gripper can have a flat gripper back or largely be retracted in the channel (pressure cylinder projection minimized).

• – Betriebssicherheit des Systems erhöhen
• – Applizierqualität stabilisieren, Bahnspannung reduzieren
• – Bahnspannung regeln => Bediensicherheit/Verfügbarkeit.

The web tension of the film web can be regulated (desired-actual). The plate cylinder can / is off the blanket cylinder (contactless). The plate cylinder / inking unit is stopped in the application module (direct drive) or the inking unit disengaged (stopped).

• - increase the operational safety of the system
• - Stabilize applicator quality, reduce web tension
• - regulate web tension => operating safety / availability.

in the The invention will be described below with reference to drawings shown in more detail.

there shows:

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

2 a device for feeding transfer film in a detailed representation.

• – 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 press roll 3 (As blanket cylinder or forme cylinder or separate press roller) carries on its surface a compressible or damping, for example, also provided with a compressible intermediate layer element.

Alternatively, one in the applicator 1 integrated film transfer device may be provided, whereby an integrated film application module is provided. This is done on an impression cylinder 4 a printing gap between a blanket or form cylinder 13 and the impression cylinder 4 subordinate assigned an additional press roller. Thus, a film web of a transfer film after the coating of the printing material by means of the applicator 1 fed to a transfer gap formed as mentioned above and also be discharged directly again. The cold foil stamping takes place in a single integrated foil application module. In this case, an applicator can be arranged in a compact design within the coating module. For this purpose, an adhesive application device is the impression cylinder 4 assigned and the transfer nip, here between the blanket cylinder 13 and the impression cylinder 3 was provided, arranged upstream. The transfer film would be here around the blanket cylinder 13 or guided approximately tangentially past this by the designated pressure gap.

Such an adhesive application device 1' may consist of a chamber doctor blade and an anilox roller for supplying the adhesive.

The foil supply roll 8th is the coating plant 2 assigned on the page of the sheet feeder and 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 drain side and held on the inlet side by means of a brake punishment.

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.

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 dryer 16 be provided, by means of which the adhesive application or the entire film coating can be dried. Here come, for example UV dryer in question.

Furthermore, the film application module can be a monitoring device 17 for scanning the sheet surface with evaluation of image contents of the coating and detection of defects in the film coating included.

According to the invention is after 2 a device for guiding the film on the press roll 3 provided, which is substantially tangential to the press roll 3 through the transfer gap 6 with the impression cylinder 4 of the coating plant 2 to be led. A film guiding device 20 and if necessary, a film feeding device guide the film web 5 in the transport direction T through the coating plant 3 ,

A film guide is provided 14 which is approximately tangential between the press roll 3 and the impression cylinder 4 is aligned and a wrap of the press roll 3 forms less than 90 degrees. This will be a defined investment and leadership of the film web 5 on the press roller 3 achieves and at the same time the necessary conditions for a possible foil timing or a foil failure in the transfer gap 6 during a channel passage in the transfer nip 6 , but also for the use of narrow film webs 5 , created.

The film guide 14 for a film web 5 or partial film webs 19 includes on the inlet side to the transfer nip 6 starting from an inlet opening 16 on a printing unit protection 15 some guide rollers 22 ,

The film guide 14 can according to 2 connected to a so-called pressure cylinder blowing device 36 be arranged. This has nozzles for the formation of blowing jets S to substrates on the impression cylinder 4 in front of the transfer gap 6 to lead, these are also the transfer film 5 can hold tight and smooth.

Another part of the film guide 14 includes on the drain side of the transfer nip 6 starting to an outlet opening 17 on a printing unit protection 15 further guide rollers 32 . 34 ,

The film guide 14 is here in connection with an inlet protection 33 arranged. This serves to secure the transfer gap 6 against unintentional interventions. The foil web 5 can be around the run-in protection 33 or be guided through openings in the contour. The guide rollers 32 . 34 can in conjunction with the print engine protection 15 be arranged so that they slide the film web 5 take.

Alternatively, the lead role 34 be arranged adjustable, so that the wrap angle Z of the film web 5 on the press roller 3 is adjustable.

In this context, it is also important that the transfer film 5 at a channel passage in the transfer gap 6 with grippers G on the impression cylinder 4 can come into contact. The grippers G hold a signature B at its leading edge on the impression cylinder 3 for secure transport through the transfer gap 6 firmly. They stand with their so-called gripper back in the region of the pinching of the edge of the printing sheet B to a small extent over the circumference of the impression cylinder 4 above. Coordination to one at the press roll 3 also existing channel is chosen so that its associated edge only after the contour of the gripper G with the impression cylinder 4 comes into contact. Because the film web 5 but freely over the channel of the press roll 3 is curious, the gripper G in the unsupported there film web 5 Push. For this purpose, it is advantageous to make the wrapping angle Z of the film web adjustable in order to ensure early separation of the grippers G from the film web 5 during the passage of the channel in the transfer nip 6 to reach.

Preferably, the gripper G with one in the smallest possible extent over the circumference of the impression cylinder 4 protruding contour formed. Here, systems of grippers G can be used, the total continuous or intermittently radially to the impression cylinder 4 are adjustable so that the height of the gripper G can be minimized over the cylinder contour.

The film guide can be further supported by the fact that the cylinder channel of the press roll 3 is provided with a cover for largely cylindrical complement of the surface of the press roll. This will make the film web 5 Although in the area of the gripper G closer to the impression cylinder 4 introduced, the film guide is overall but continuous and quiet.

In addition, the leadership of the transfer film 5 through another guide roller 38 (please refer 1 ) are influenced in the area after the film removal from the film supply roll 8th is arranged. By means of this guide roller 38 , in their axial position relative to the position of the axis of the film supply roll 8th is adjustable, unevenness or irregularities of the film flow from the film supply roll 8th before feeding the film web 5 for film guidance 14 be compensated.

The foil collecting roll 9 can be a pressure roller 31 (please refer 1 ) be assigned with adjustable pressure force and bias as a friction and leadership role. By means of the pressure roller 31 can have a defined tension (foil tension) on the foil collecting roll 9 be maintained so that the sheet 5 only very limited sideways and disturbances are avoided for this reason. In addition, a film guide at the edges of the film web 5 be provided on flanges or suitable baffles, so that no lateral film flow from the winding core can be done and so a film wound roll just wrapped 9 arises.

Essential for the inventive design is the relationship shown below.

In the range of cylinder channels (eg 4.1 on the impression cylinder 4 ) between rubber cylinder or press roll 3 and impression cylinder 4 can be so-called gripper backs of grippers G, the counter-pressure cylinder 4 to transport sheet B are required, at the beginning of the printing surface, the transfer film 5 Touch, as they survive something over the cylinder contour. This circumstance negatively influences the surface finishing. To prevent this, according to the invention, the transfer film is changed during the gripper passage by a clocked guide deflection so that they are closer to the blanket cylinder or the press roll 3 is introduced and it can come to no Greiferberührung more. For deflecting the transfer film is a guide roller 34 used, by means of which a deflection angle X between the tangent plane on the press roller 3 in the transfer gap 6 and the plane in deflection direction of the transfer film 5 can be changed.

The control of the change of the deflection angle X of the transfer film 5 by means of the guide roller 34 can be done via a mechanical cam gear, an electric drive or an electro-pneumatic actuator, which is designed to be precise angle controlled via a real-time computer. The leading role 34 For this purpose, it is mounted on a linearly displaceable or pivotable holder and essentially in the direction of the double arrow in FIG 2 displaced.

At the same time and in the first place occurring according to the invention web tension fluctuations in the passage of the cylinder channels 3.1 respectively. 4.1 from impression cylinder 4 and press roll 3 balanced. This is done by extending the path of the film web when the cylinder channels 3.1 and 4.1 in the transfer gap 6 opposite or by shortening the path of the film web after passing through the cylinder channels 3.1 and 4.1 ,

Furthermore, signals of eg in the axis of rotation of the rotary drive 7 mounted sensor (eg potentiometer) on the take-up roll 9 be guided and adjusted by speed adjustment.

A clocked film deflection of this type can also be provided on the film inlet side. Here is one of the guide rollers 23 or 24 according to the guiding role 34 arranged movable and controllable. As a result, a deflection angle Y of the film web between the tangent plane to the press roller 3 in the transfer gap 6 and the plane in deflection direction of the transfer film 5 when entering the transfer gap 6 changed. Possibly. can the deflection angle Y in connection with the passage of the cylinder channels 3.1 and 4.1 be designed cyclically changeable.

Through the passage of the cylinder channels 3.1 and 4.1 from press roll 3 and impression cylinder 4 it comes with every sheet pass or each cylinder revolution to a web tension influence of the film web, since the web shortening in the cylinder channel 3.1 . 4.1 on the web tension of the transfer film 5 effect. These specifications mean that, especially during machine operation, the film web can vibrate relatively strongly. On the film web but should act as uniform as possible web tension and there should be no stretching of the film. For this purpose, a dancer roll operation (see dancer rolls 18 in 1 ) also with several single roles. The dancer rollers 18 regulate or steu ern the common channel passage even when using single roller tracks largely from, as the cylinder channels 3.1 . 4.1 yes for all Teilfolienbahnen the single roles come simultaneously to the effect.

The adjustment of the dancer rolls 18 can be performed pneumatically, with a dancer roller clamped on both sides 18 with an air cushion in central position can be controlled via proportional valves. It is also a hydraulic, mechanical solution by means of springs and weights conceivable, etc.

A designated as a channel shock cyclic force on the film web, its leadership behavior and disturbs the entry into the transfer gap, can be cushioned: The impact of known changes the path of the film web in the interaction of cylinder channel and Cylinder circumference on the web tension can be balanced and one be set relatively constant web tension (web tension).

Alternatively, when using several individual roles, the partial webs each have their own dancer roller 18 be routed to produce a constant web tension. The Folienauf- and -abwicklung can be performed with individual drives or drive-brake combination.

to film guide in the channel region of the blanket cylinder or the press roll is in an advantageous Way an extra guide recoverable. This limits the shortening path of the film in the channel passage.

Furthermore, a channel cover in the blanket cylinder or the press roll 3 be provided, which is the surface of the blanket cylinder or the press roll 3 largely continuously supplemented.

Of the Rubber cylinder or the press roller can also be a sleeve carrier, possibly retracted in the channel area.

The grippers G of the impression cylinder 4 may have a flat gripper back or be largely retracted in the channel, so that the printing cylinder projection is minimized.

The Web tension of the film web can after a desired-actual-value comparison on one for the film web should be regulated to proper web tension.

The plate cylinder can from the blanket cylinder or the press roll 3 parked and be driven without contact. However, the plate cylinder and the inking unit are preferably shut down in the application module. For this purpose, a direct drive of the plate cylinder is advantageous with its own drive motor. The inking unit can be disengaged from the drive of the printing unit that forms the application module and thus shut down.

Furthermore, a better separation behavior of the film coating to be applied is achieved by this arrangement, by the demolition angle on the outlet side by changing the distance of the guide roller 34 can be changed independently of a clock process. The change in the inlet angle can be achieved by a change in position of the inlet deflection by means of the guide roller 24 respectively. Here, a continuous adjustment between maximum positions for Abrisswinkelveränderung be provided on the outlet and the inlet side of the film web.

1

commissioned

2

coating plant

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

Rubber / blanket cylinder

14

film guide

15

Printing plant security

16

blower

17

Entry / exit opening

18

dancer roll

19

Part sheet

20

Folienleiteinrichtung

21

plug-in unit

22

sheave

23

sheave

24

sheave

25

dryer

26

monitoring system

27

28

29

Support plate

30

31

capstan

32

sheave

33

Made

34

sheave

35

bracket

36

Druckzylinderblasvorrichtung

37

blower

38

guide roll

3.1

cylinder gap

4.1

cylinder gap

S

blowing jet

G

grab

B

substrate

T

transport direction

Claims (13)

Method for transferring imaging or covering or covering layers from a carrier foil to printing sheets in a sheet-processing machine, in particular a sheet-fed rotary printing press, with at least one applicator ( 1 ) for an imagewise or areal coating of a printed sheet with an adhesive and with at least one coating unit ( 2 ) for transferring image-forming or covering layers from the carrier film to the printing sheet, wherein in a coating unit ( 2 ) a transfer gap ( 6 ) is formed and the carrier film on the surface of a press roll ( 3 ) along and with the coated side placed on a sheet and under pressure together with this through the transfer nip ( 6 ), so that the image-forming or covering layers are adhesively transferred in adhesive-provided regions from the carrier film to the printed sheet, characterized in that the web tensile force when feeding a transfer film ( 5 ) to the transfer gap ( 6 ) and / or during the removal of the transfer film ( 5 ) from the transfer nip ( 6 ) is changeable to the beat of the sheet coating. Method according to claim 1, characterized in that the web of the transfer film ( 5 ) in the working cycle of the coating plant ( 2 ) at the outlet of the transfer nip ( 6 ) in her wrap-around (Z) on the press roll ( 3 ) is changed. Method according to claim 1 or 2, characterized in that the web tension of the transfer film ( 5 ) in the cycle of a channel passage of cylinder channels ( 3.1 . 4.1 ) between the impression cylinder ( 4 ) and the press roll ( 3 ) is regulated, such that the web tension is increased briefly during the passage of the channel. Device for transfer of imaging and / or covering or covering layers from a transfer film ( 5 ) on printed sheets with an at least 1 ) for the imagewise or surface coating of printed sheets with an adhesive and with at least one coating unit ( 2 ) for transferring imaging and / or covering layers of the transfer film ( 5 ) on the printing sheets, each coating unit ( 2 ) a transfer gap ( 6 ), in which the transfer film ( 5 ) a press roll ( 3 ) at least tangent, is placed under pressure with the coated side on the print sheet, so that the image-forming or covering or covering layer in the region of the areas provided with adhesive on the printing sheet adhering to the transfer film ( 5 ) is transferred to the printed sheets, characterized in that in a film application module a controllable in time with the sheet coating film guide device for the transfer film ( 5 ) is arranged. Apparatus according to claim 4, characterized in that on the film guiding device for regulating the web tension of the transfer film ( 5 ) means for measuring the tensile force of the film web of the transfer film ( 5 ) is provided. Apparatus according to claim 5, characterized in that on the film guide device for controlling the web tension of the transfer film ( 5 ) one or more means for changing the web tension of the film web are provided using measured values of the device for measuring the tensile force of the film web. Apparatus according to claim 6, characterized in that on the film guiding device for regulating the web tension of the transfer film ( 5 ) one or more dancer rolls ( 18 ) are provided for changing the transport path of the film web by displacing the film web transversely to its conveying direction using measured values of the device for measuring the tensile force of the film web. Apparatus according to claim 6, characterized in that on the film guiding device for regulating the web tension of the transfer film ( 5 ) one or more drives ( 7 ) or brakes to change the tensile force of the winding or unwinding ( 8th . 9 ) are provided on the film web in its conveying direction using measured values of the device for measuring the tensile force of the film web. Apparatus according to claim 4, characterized in that on the film guiding device for regulating the web tension of the transfer film ( 5 ) means for clocked change of the wrap angle (Z) of the film web on the press roll ( 3 ) is provided. Apparatus according to claim 9, characterized in that at the inlet side of the transfer nip ( 6 ) a transversely to the web running direction of the transfer film ( 5 ) clocked displaceable guide roller ( 24 ) for clocked change of the wrap angle (Z) of the film web on the press roll ( 3 ) is provided. Apparatus according to claim 9, characterized in that at the outlet side of the transfer nip ( 6 ) a transversely to the web running direction of the transfer film ( 5 ) clocked displaceable guide roller ( 34 ) for clocked change of the wrap angle (Z) of the film web on the press roll ( 3 ) is provided. Apparatus according to claim 4, characterized in that the press roll ( 3 ) with a cylinder channel ( 3.1 ), which receives elements for the tension of a press fabric, covering element is provided. Apparatus according to claim 4 to 9, characterized in that the impression cylinder ( 4 ) with flattened gripper elements of grippers (G) for holding sheets (B) on the impression cylinder ( 4 ), wherein the projection of the gripper elements over the peripheral surface is minimized or 0.