EP1737660A1

EP1737660A1 - Device for embossed film printing

Info

Publication number: EP1737660A1
Application number: EP05730733A
Authority: EP
Inventors: Franz-Peter Richter; Jürgen Schölzig
Original assignee: MAN Roland Druckmaschinen AG
Current assignee: Manroland Sheetfed GmbH
Priority date: 2004-04-13
Filing date: 2005-04-06
Publication date: 2007-01-03
Anticipated expiration: 2025-04-06
Also published as: WO2005102700A1; EP1737660B1; JP2007532348A

Abstract

To transfer an image-type coating from a backing film to a printed sheet, an image-type adhesive layer is applied to the printed sheet. In a coating unit (2), the backing film comprising the image-type coating is rolled over the printed sheet using contact pressure, in such a way that the coating adheres to the adhesive sections, thus forming an image. To improve the flexibility of this application in a printing press, either the coating unit or the adhesive application unit (1) and the coating unit (2) are located in one or more coating modules of a printing press, thus producing a compact film transfer module (F) in a simple manner.

Description

Device for embossing foil printing

The invention relates to an apparatus for embossing foil printing in a coating module, which includes an apparatus for transferring imaging layers from a carrier foil to printed sheets.

It is known to produce metallic layers on printed sheets by means of a foil transfer process. For example, EP 0 569 520 B1 describes a printing material and a printing device that uses this material. A sheet-processing machine is shown, which has a feeder and a delivery, printing units and a coating unit being arranged between the two units. An adhesive sample is applied in at least one of the printing units by means of the planographic printing process. This adhesive pattern is applied in a cold printing process and has a specific imaging subject. A film guide is provided in the coating unit following the printing unit with an impression cylinder and a transfer cylinder. This is designed in such a way that a film strip or a transfer film is guided from a film roll through the pressure gap of the coating unit between the impression cylinder and the transfer cylinder. The film strip is rewound on the outlet side after leaving the coating plant. The transfer film has a carrier layer on which imaging layers such as metallic layers, for example made of aluminum, can be applied. A separating layer is provided between the metallic layer and the carrier film, which ensures that the metallic layer can be removed from the carrier layer.

When transporting printed sheets through the printing unit, each printed sheet is provided with an adhesive pattern. The printed sheet is then passed through the coating unit, the printed sheet resting on the impression cylinder being connected to the film material by means of the transfer cylinder. The downward-lying metallic layer forms a close connection with the areas on the printed sheet provided with adhesive. After the printing sheet has been transported further, the metallic layer adheres only in the area of the pattern provided with adhesive. The metallic layer in the area of the adhesive pattern is therefore removed from the carrier film. The transfer film used in this way is rewound. The printed sheet is laid out in the coated state.

It is known to use such coating units, for example in printing units of printing presses. However, this blocks the corresponding printing units from being used for printing images. In addition, the conversion of the affected printing units is complex.

OBJECT OF THE INVENTION

The object of the invention is therefore to provide a device by means of which flexible use of a printing machine is made possible when using the stamping foil printing.

The solution to this problem results from the features of patent claim 1.

In a particularly advantageous manner, the transfer film is brought into contact with the printing material in at least one coating module, which is preferably arranged downstream of one or more printing units of a printing press, on a impression cylinder by means of a transfer cylinder.

Within the sheet processing machine receiving the coating unit, the coating unit can advantageously be placed at any point on the machine. In the case of a printing press with a plurality of printing units, this enables imaging coatings or metallization layers to be applied both before and after and between the application of printing ink layers.

For this purpose, the coating unit is advantageously designed as a coating module in the manner of a transportable unit. Advantageously, according to the device according to the invention, it is also possible in a particularly simple manner to provide a plurality of coating units in succession within a sheet-processing machine. Different imaging coatings or metallization layers can thus be applied in succession within one subject. It is possible to provide a first adhesive pattern in a first coating unit with a first imaging coating and subsequently overlay another, including the first adhesive pattern and to provide another imaging coating.

The invention is illustrated in more detail below with reference to figures.

It shows:

1 is a first schematic representation of a device for film transfer on an impression cylinder,

2 shows a second schematic representation of a device for the film transfer on a push cylinder, FIG. 3 shows a first machine with a film transfer device, and FIG. 4 shows a second machine with a film transfer device, FIG. 5 shows an approximately tangential one 3, FIG. 6 an approximately tangential film guide according to FIG. 4.

FIG. 1 shows an integrated film transfer module F for the film transfer for use in a sheet-processing machine, for example a printing machine.

The foil transfer module F is equipped as follows:

- A sheet-guiding impression cylinder 4 is provided for the transport of printed sheets. The impression cylinder 4 can be used to transport printed sheets have one or more gripper fields with associated pressure surfaces and a corresponding one to multiple circumference.

- The impression cylinder 4 is assigned a coating unit 1 in quadrant A. The application unit 1 has a forme cylinder 11, an application roller 12 and a metering system 13. By means of the applicator unit 1, imagewise coatings can be applied to printing sheets held on the impression cylinder 4 via a printing form clamped on the forme cylinder 11.

- The impression cylinder 4 is assigned a coating unit 2 in quadrant B. The coating unit 2 is used for film transfer printing and has a transfer cylinder 21 which forms a transfer nip 6 with the impression cylinder 4. Furthermore, a film supply roll 22, a film collecting roll 23 and, if appropriate, web guides are provided for a film web 24 made of transfer film and guided around the transfer cylinder 21. The cylinders can correspond to the forme cylinder and the impression cylinder of a coating module of an offset printing machine.

- The impression cylinder 4 can also be assigned a calendering unit 3 arranged downstream of the coating unit 2. The calendering unit 3 essentially forms a calendering nip 32 together with the impression cylinder 4 by means of a calender roll 31.

In this way, an integrated film transfer module F is formed, which has two workstations that are used for the following work steps:

- A printed sheet to be coated is first provided in the first work station (applicator 1) in a printing gap 5 between a forme cylinder 21 and the impression cylinder 4 by means of a printing form with an imaging adhesive pattern.

- After that, the printing sheet is passed through in the following work station (coating unit 2) together with a film web 24 made of transfer film Transfer nip 6 between a cylinder equipped as a transfer cylinder 21 and the same impression cylinder 4, wherein the transfer film in the transfer nip 6 is pressed against the printing sheet. As a result of the pressing, an imaging layer is transferred from the transfer film to the printed sheet in the area of the adhesive pattern. The film web 24 is in this case unrolled from the film supply roll 22 in the direction of the rotary movement of the impression cylinder 4, passed around the transfer cylinder 21 and rolled onto the film collecting roll 23.

- Furthermore, the imaging layer transferred from the transfer film to the printed sheet can be rolled into the calendering gap 32 of the downstream calendering unit 3 to increase the adhesive strength and smoothness.

Such a device can be used in a coating module L of a sheet-fed printing press. In its basic design, such a lacquer module L has an arch-guiding impression cylinder 4, a forme cylinder 11, an application roller 12, e.g. an anilox roller, and a metering system 13, e.g. a chambered doctor blade system, on. For the application mentioned, the chambered doctor blade system can be used instead of the supply of lacquer for metering adhesive via the anilox roller or application roller and the forme cylinder, e.g. can be used on the substrate using a recessed blanket or a flexo print.

The basic concept of the lacquer module corresponds to a printing unit D of a printing press and instead of the forme and blanket cylinder only has one forme cylinder 11. In addition, there is no inking unit with a plurality of rollers and no dampening unit in a coating module L. The consequence of this is that a lacquer module L has free installation space above the coating devices. The lacquer module L therefore allows the integration of the elements necessary for the film guidance in a very simple, compact, user-friendly and inexpensive manner.

In a film transfer module F designed in this way, the printing material is also very advantageously through all the necessary nip points in one performed single gripper closure while it rests on a single impression cylinder 4.

FIG. 2 shows a second embodiment of an integrated film transfer module F for film transfer for use in a sheet-processing machine, for example a printing machine.

The foil transfer module F is equipped as follows:

- A sheet-guiding impression cylinder 4 is provided for the transport of printed sheets. The impression cylinder 4 can have one or more gripper fields with associated printing surfaces and a corresponding one to multiple circumference for transporting printed sheets.

- The impression cylinder 4 is assigned a coating unit 2 in quadrant A. The coating unit 2 is used for film transfer printing and has a transfer cylinder 21 which forms a transfer nip 6 with the impression cylinder 4. Furthermore, a film supply roll 22, a film collecting roll 23 and, if appropriate, web guides are provided for a film web 24 made of transfer film and guided around the transfer cylinder 21. The transfer cylinder 21 can the forme cylinder and the impression cylinder 4 the impression cylinder of a coating module e.g. of a coating module of an offset printing machine.

- The counter-pressure cylinder 4 in quadrant B is assigned a coating unit 3 arranged downstream of the coating unit 2. The calender 3 essentially forms a press nip 32 together with the impression cylinder 4 by means of a calender roll 31.

In this way, a film transfer module is formed which has two work stations for the following work steps: - A printed sheet to be coated is first provided with an imaging adhesive pattern in a separate work station upstream of the film transfer module by means of a printing form. The adhesive pattern can be generated in a coating module, for example using the high-pressure or flexographic printing process, or it can be done in an offset printing unit using the planographic printing process.

- The printed sheet is then guided in the film transfer module in the first work station (coating unit 2) together with a film web 24 of transfer film placed around the transfer cylinder 21 through the transfer nip 6 between the transfer cylinder 21 and the impression cylinder 4. Due to the pressing, the imaging layer is transferred from the transfer film to the adhesive pattern of the printed sheet. The film web 24 is unrolled from the film supply roll 22 and rolled onto the film collecting roll 23.

Then, in the further work station in the press nip 32 of the downstream calendering unit 3, the imaging layer transferred from the transfer film to the printed sheet can be rolled in to increase the adhesive strength and smoothness.

The embodiment described can be used in sheet-fed printing presses, for example, with configurations according to FIG. 3 or FIG. 4 as follows:

A printing unit D (see FIG. 3) or a coating module L (see FIG. 4) are arranged directly upstream of the film transfer module F, which here always serves as coating unit 2 for film transfer. For this, e.g. a machine configuration in the form of a so-called double-coating machine can be used (see FIG. 4).

Sheet printing machine according to Figure 3: In the embodiment of a sheet-processing machine according to FIG. 3, a printing unit D, for example an offset printing unit, can be arranged directly in front of the film transfer module F.

The printing unit D has a planographic printing plate on a plate cylinder, a blanket cylinder and an impression cylinder 4 and functions as an applicator unit 1. The adhesive is applied conventionally in the offset printing process by means of the planographic printing plate illustrated in accordance with the desired coating. The adhesive is applied in a printing nip 5 of the printing unit D. Alternatively, the plate cylinder can be separated from the printing blanket cylinder for the application of the high-pressure process when applying adhesive in the printing unit D. The blanket cylinder carries a recessed blanket or a flexographic printing plate. The blanket cylinder is assigned an applicator roller with a metering system (e.g. at the installation location of a rubber blanket washing device), preferably a screen roller with a chambered doctor blade system, for applying and removing adhesive.

Sheet printing machine according to Figure 4:

In a modified design, according to FIG. 4, the film transfer module F is preceded by a coating module L. A printing unit D can in turn be directly upstream of this.

A recessed blanket or a flexographic printing plate is fixed on the forme cylinder 11 of the lacquer module L arranged upstream of the film transfer module F. In this embodiment, the lacquer module acts as an application unit 1 for adhesive. A chambered doctor blade system as the metering system 13 thus serves for metering the adhesive via a screen or applicator roller 13 and the forme cylinder 11 on the printing material. The substrate with adhesive application is fed to the downstream coating module in the form of the film transfer module F.

If a coating module L is converted to a film transfer module F, then the anilox roller and the chamber doctor system are removed. The form cylinder serves as a transfer cylinder 21 for transfer film. The form cylinder at least assigned the film supply roll 22 for fresh transfer film and the film collecting roll 23 for used transfer film. The transfer cylinder 21 transfers the imaging layer in the transfer gap 6 from the transfer film to the printing material fixed in the gripper closure on the impression cylinder 4.

If necessary, the transfer cylinder 21 on the impression cylinder 4 is followed by a calender roller 31 in the conveying direction (here calender 3).

For special applications, e.g. if the printing material is very absorbent and the adhesive quickly blows away in the printing material, a first layer with adhesive can be applied as a basic coating in a printing unit D upstream of the coating module L.

In the embodiments according to FIGS. 3 and 4, one or more UV dryers 7 can be used in each case to use adhesive which dries under the action of UV radiation. The UV dryers 7 can each be assigned to an impression cylinder 4 after a printing nip 5 or after the transfer nip 6.

Drying can also take place in the area of the sheet delivery.

In this embodiment of the film transfer module F, the printing material is advantageously guided in all nip locations in a single gripper closure on a single impression cylinder 4.

Details of the transfer film are disclosed below: The transfer film mentioned above has a multilayer structure. As the carrier layer, it has a film which is preferably thin and tear-resistant. An imaging layer is applied to the carrier film by means of a separating layer. The separating layer serves to facilitate the lifting of the imaging layer from the carrier film. The imaging layer can be, for example, a metallized layer or a gloss layer or a texture layer or a colored layer or a layer containing an image pattern. The transfer film is used for so-called stamping film printing. In the case of stamping foil printing, an imaging adhesive pattern is applied to a printing sheet. This can easily be done using the offset printing process. Then the transfer film with the coated side is placed under pressure on the printing sheet, so that the imaging layers of the transfer film adhere to the printing sheet as a corresponding image pattern and are thereby lifted off the transfer film.

In the described devices for performing the stamping foil printing, the foil supply roll 22 is assigned to the respective coating unit 2 on the side of the sheet feeder. The film supply roll 22 has a rotary drive. The rotary drive is required for the continuously regulated supply of the unused film web 24 of the transfer film to the coating unit 2 and can therefore be controlled. On the discharge side of the coating unit 2, the used film web 24 is wound up on a film collecting roll 23. A drive that can be controlled must also be provided here for optimized production. Furthermore, tensioning rollers 25 can be provided in the area of the film guide. The tensioning rollers 25 are arranged adjacent to the transfer cylinder 21 with respect to the feeding and removal of the film web 24 to and from the transfer nip 6.

By means of such clamping rollers 25, the sheet 24 is always in the same chip ^"voltage held against the transfer cylinder 21st

In the embodiments according to FIGS. 5 and 6, the film guide is designed in a special way in which the tensioning rollers 25 are also arranged adjacent to the transfer cylinder 21.

However, according to FIGS. 5 and 6, the tensioning rollers 25 are preferably arranged in the vicinity of the transfer nip 6 in such a way that the film web 24 is guided into the transfer nip 6 approximately tangentially to the surface of the transfer cylinder 21. The tangential guidance of the film web 24 in this way reduces the frictional relationships between the film web 24 and the transfer cylinder 21 by largely minimizing the contact area between the film web 24 and the surface. Before the transfer cylinder 21. This is advantageous if the film web 24 can preferably be transported in the conveying direction in cyclical operation, for example taking into account the passage of the channel (transfer cylinder 21) or taking into account the subject. When the film web 24 is conveyed in a timed manner, it is preferably stopped whenever no coating is to be carried out or when the cylinders working together in the transfer nip 6 pass through a channel, interrupting the transfer action between their surfaces. A relative movement between the film web 24 and the surface of the transfer cylinder 21 is imperative.

In a further embodiment, a plurality of film webs 24 can be arranged in the axial direction in connection with corresponding film supply rolls 22 and associated film collecting rolls 23 parallel to one another over the format width. These film supply rolls 22 and film collecting rolls 23 can optionally be operated together or in pairs for each of the several film webs 24 individually in cyclical operation.

The cyclic operation of the film web 24 is preferably carried out via the drivable film supply rolls 22 and film collecting rolls 23, which are coupled, for example, to a machine control. A film storage known per se in the form of a film loop is provided for intermittent operation. The film loop can be formed, for example, by wrapping a dancer roller.

The surface of the transfer cylinder 21 is covered with a plastic cover, comparable to a rubber blanket or printing blanket. The plastic cover has a defined elasticity. In addition, the surface of the plastic coating is very smooth and has little adhesion to the transfer film. The plastic surface enables a clean transfer of the imaging layer to the printed sheet. Furthermore, the elastic construction of the plastic cover creates a comparatively wide pressure gap. Furthermore, a further enlargement of the transfer gap 6 is produced by a diameter of the impression cylinder 4 that is twice as large as that of the transfer cylinder 21. On the one hand, all of these measures make a broad one Pressure area in the transfer nip 6 and on the other hand allows a secure mobility between the surface of the transfer cylinder 21 pressing the transfer film and the impression cylinder 4. With these means, the transfer of even very fine patterns from the imaging layer to the printed sheet is ensured.

In addition to the device features described, a further processing unit, e.g. for embossing, cutting or punching, or a coating unit for surface finishing of the printing materials or an impression unit.

After transfer of the transfer film to the printing material and, if necessary, subsequent pressing and smoothing, the film on the printing material is imprinted or printed with conventional offset printing ink, alternatively with so-called UV ink, and / or a coating of the imaging coating from the transfer film, for example a UV coating in combination with an excimer drying.

For this purpose, at least one further printing unit and / or at least one coating module is arranged downstream of the film transfer module. For example, an additional coating of the imaging coating on the transfer film can achieve a ^" further increase in gloss.

The invention can be configured within the scope of the illustrated embodiments and should not be restricted to the specific features of the exemplary embodiments. LIST OF REFERENCE NUMBERS

1 - Commissioned work

2 - coating unit

3 - calendering unit

4 - impression cylinder

5 - pressure gap

6 - Transfer nip

7 - UV dryer

11 - forme cylinder

12 - applicator roller

13 - dosing system

21 - transfer cylinder

22 - Foil supply roll

23 - Foil collection roll

24 - film web

25 - tension pulley

31 - calender roll

32 - Calendering nip

A - Quadrant

B - quadrant

F - foil transfer module

D - printing unit

L _ lacquer module

Claims

claims

1. Device for embossing foil printing on printing sheets, with at least one applicator for the imagewise coating of a printing sheet with an adhesive and with a coating unit for transferring imaging layers from a transfer film to the printing sheet, the coating unit containing an impression cylinder and a transfer cylinder and the transfer film around the Transfer cylinder can be guided in such a way that the imaging layer adheres to the printed sheet in the area of the imagewise areas provided with adhesive and is lifted off the transfer film, characterized in that a printing unit (D) or coating module (L) of the sheet-processing machine has a film transfer module (F ) that the film transfer module (F) is a coating module or coating module (L) of the sheet-processing machine and that the transfer cylinder (21) in the film transfer module (F) is a forme cylinder of the coating module or coating module (L) or that the oil Sfer cylinder (21) is arranged downstream of the forme cylinder on the impression cylinder (4) of the coating module or lacquer module (L).

2. A device for embossed foil printing on printed sheets, with at least one ^~ applicator unit for imagewise coating of a printed sheet with an adhesive and with a coating unit for transferring imaging layers from a transfer foil on the sheet, wherein the coating unit contains an impression cylinder and a transfer cylinder, the form a common transfer nip, and the transfer film can be guided around the transfer cylinder in such a way that it is passed under pressure through the transfer nip together with the printing sheet guided on the impression cylinder, and the imaging layers after the printing sheet emerges from the transfer nip in the region of the Adhesive provided image-related areas adhered to the printing sheet and is lifted off the transfer film, characterized in that that a printing unit (D) or coating module (L) of the sheet processing machine is directly followed by a film transfer module (F), that the film transfer module (F) has at least one transfer cylinder (21) and an impression cylinder (4) and that the transfer cylinder (21) is a forme cylinder of a coating module or lacquer module (L) or that the transfer cylinder (21) is arranged downstream of the forme cylinder on the impression cylinder (4) of the coating module or lacquer module (L).

3. Device according to claim 1 or 2, characterized in that the transfer cylinder (21) within the film transfer module (F) are assigned a film supply roll (22) for fresh transfer film and a film collecting roll (23) for used transfer film, such that the transfer film as The film web (24) can be guided from the film supply roll (22) at least partially around the transfer cylinder (21) through the transfer nip (6) to the film collecting roll (23).

4. The device according to claim 1 to 3, characterized in that in the film transfer module (F) an applicator roller and a metering system are arranged detachably from the forme cylinder and that the forme cylinder can be converted to the transfer cylinder (21) by means of a smooth compressible press cover.

5. The device according to claim 4, characterized in that the press cover as a part of the cylindrical surface area of the transfer cylinder (21) of the coating unit (2) covering surface element on the transfer cylinder (21) or a covering carried by the transfer cylinder (21) can be positioned is.

6. The device according to claim 4, characterized in that on the surface of the transfer cylinder (21) a cut blanket or a correspondingly machined according to the area to be coated pressing surface plastic printing plate or a contoured according to the area to be coated, adhesive or otherwise, preferably detachable , attachable pressure segment is provided.

7. The device according to claim 1 to 6, characterized in that within the sheet processing machine receiving the coating unit, the coating unit can be placed anywhere on the machine.

8. The device according to claim 1 to 6, characterized in that the sheet processing machine is a printing press with a plurality of printing units and that the coating unit is arranged before or after or between the printing units.

9. The device according to claim 1 to 8, characterized in that the coating unit (2) is designed as a film transfer module (F) in the manner of a transportable unit.

10. The device according to claim 1 to 9, characterized in that that several coating units (2) are arranged one behind the other within a sheet-processing machine.

11.Device according to claims 1 to 10, characterized in that a coating unit (2) has an application unit (1) in the form of a printing unit (D) directly upstream.

12. The device according to claim 1 to 10, characterized in that a coating unit (2) is an application unit (1) in the form of a lacquer module (L) directly upstream.

13. The device according to claim 1 to 10, characterized in that a coating unit (2), an application unit (1) in the form of a coating module (L) and an application unit (1) in the form of a printing unit (D) are directly upstream.

14. The apparatus according to claim 3, characterized in that the transfer cylinder (21) guide devices for guiding the film web (24) to the transfer gap (6) are assigned.

15. The apparatus according to claim 14, characterized in that the guide devices for an approximately tangential to the surface of the transfer cylinder (21) directed guidance of the film web (24) for transfer gap (6) are arranged.

16. The apparatus of claim 14 or 15, characterized in that the transfer cylinder (21) tension rollers (25) are assigned for an approximately tangential guidance of the film web (24) in the transfer nip (6).

17. The apparatus according to claim 14 to 16, characterized in that the film web (24) can be transported in the conveying direction in cycle operation.