EP1976700A1

EP1976700A1 - Overprintable embossing coating

Info

Publication number: EP1976700A1
Application number: EP06829280A
Authority: EP
Inventors: Guido Reschke; Herbert Spottke; Michael Zinke; Jürgen Schölzig
Original assignee: Manroland AG
Current assignee: Manroland AG
Priority date: 2005-12-27
Filing date: 2006-12-05
Publication date: 2008-10-08
Also published as: WO2007073833A1; US8057625B2; DE102006048523A1; US20090008028A1; CN101346232B; CN101346232A; WO2007073833A8; JP2009521348A

Abstract

The invention relates to a coating unit (2) for transferring imaging or covering layers from a transfer film (5) to a printed material. Said coating unit should be flexible thus enabling the integrated production of complex printed material. In particular, overprinting of film coatings should be able to be carried out in a problem-free manner. One or several discharge devices (E, EI), which are connected to the film application module (FA), are used for modifying the surface tension of the transfer film (5) or the printed sheet in the rotary sheet printing machine ensuring the printing and also the film-coated surfaces of the printed sheet are of high quality.

Description

Overprintable embossing coating

The invention relates to a method and a device for transferring imaging or covering layers from a carrier foil to printed sheets with subsequent overprinting according to the preamble of claims 1 and 9, respectively.

It is known to produce metallic layers on printed sheets by means of a film transfer process. Thus, EP 0 569 520 B1 describes a printing material and a printing device using this material. 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 loading-stratification 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 a printing sheet is provided with a two-dimensional adhesive application or an adhesive pattern, it is passed through the coating unit, wherein by means of the pressure roller, the pressure sheet lying on the impression cylinder is brought into contact with the film material. The down-facing functional layer engages tightly with the adhesive-provided areas on the signature. Thereafter, the functional layer adheres only in the area of the adhesive-provided pattern or else entire adhesive layer. 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.

A disadvantage of the described procedures is that they can not be used flexibly, require extensive know-how about the complex processes and are difficult to handle. Above all, the further processing is limited in previously known production methods.

The object of the invention is therefore to provide a method according to the preamble of claim 1 and a device according to the preamble of claim 17, by means of which a film coating of printed sheets with subsequent overprinting can be simple, secure, economical and accurate, said method and apparatus should be easy to handle.

The object is achieved in a method according to the features of claim 1 and in a device according to the features of claim 9.

In an advantageous manner, a method is proposed, in the use of which for film application, it is possible without any problems to apply ink to printing substrates of the most varied types, including the regions of the film application provided with metallic layers by pretreatment thereof. This allows a wide variety of substrates, as well as functional packaging, e.g. provided with jewelry effects, wherein a sheet-fed rotary printing machine used and the film coating is carried out in the cold foil stamping process.

The printability of the areas coated by the film application is thereby improved by increasing the surface tension. For this purpose, the coated printing sheet is exposed to a corona discharge or a discharge plasma. After that can be printed with high quality. The device for this purpose according to the invention can be used without much effort in a sheet-fed rotary printing press, by being used in the coating unit of the film application or one of these following sheet guiding device assigned to the printing material top.

Likewise, a pretreatment of the printing substrate and the application film can be carried out by a corona treatment.

An advantage of the method is that no heat input or only a reduced heat input compared to hot foil lamination takes place. This results in a greatly reduced Passerverzug, which is particularly important for metallic substrates.

In the following, the invention is illustrated by way of drawings. Showing:

FIG. 1 shows a configuration of a coating unit,

Figure 2 shows a sheet-fed press with a coating plant and

Figure 3 is a schematic of the coating process.

FIG. 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 fabric pattern (printing unit as commissioned work 1).

In the following printing unit, the printed sheet is fed together with a transfer film 5 under pressure through a transfer nip 6 (coating unit 2).

The applicator 1 may be a known per se offset printing unit with an inking unit 11, a plate cylinder 12 and a blanket cylinder 13. The blanket cylinder 13 cooperates with a counter-pressure cylinder 4. The coating unit 2 can also be formed by an offset printing unit. The transfer nip 6 in the coating unit 2 is formed by a press roll 3 and an impression cylinder 4. The press roller 3 may correspond to the blanket cylinder. The press roll 3 can also correspond to the forme cylinder of a lacquer module. It carries a press fabric 10 for generating an intensive pressing of the transfer film on the substrate in the transfer nip 6. Within the used for the film transfer coating 2 a film guide 14 is shown for transfer films. The transfer film 5 is thereby switched on and executed by protective devices 15 of the coating unit 2.

Alternatively, by incorporating a film guide in the applicator 1, an integrated film application module FA can be created. The transfer film is then used after the coating of the printing material with an adhesive in an additional transfer gap for cold foil stamping.

The film supply roll 8 is assigned to the coating unit 2 on the side of the sheet feed. The film supply roll 8 has a rotary drive 7 for the continuous controlled feeding of the transfer film to the coating unit 2. In the film feed deflection or tension rollers for guiding the transfer film 5 may be provided in a substantially constant tension against the press roller 3. On the downstream side of the printing unit, a film collecting roller 9 is provided for the used sheet material. A rotary drive 7 on the film collecting roller 9 is always advantageous.

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

According to the invention, a pretreatment of the raw printing material, the application film or the substrate coated by means of cold foil coating is carried out by corona treatment. It is known per se to carry out a so-called corona or plasma treatment when using metallic substrates or printing substrates made of plastic film to improve the color adhesion. In this case, the surface tension of the printing material is changed by applying a pressure to the surface of the film with a corona discharge or a plasma generated by a discharge so that the printing inks to be applied are securely adhered. In this way, an optimized appearance of the print is achieved.

FIG. 2 shows a correspondingly configured printing press. A roll-bow feeder RB or sheet feeder AN is planned. By means of a roll-sheet feeder RB be cut from a printing substrate accurately fitting sheet and fed in the machine cycle of the press. Subsequently, a printing unit D or a paint module is arranged. In the area of the sheet feeder from the sheet feeder RB or AN in the first workstation of the printing machine, a discharge device E may be provided to improve the surface properties of the print sheets for the adoption of coatings in a known manner by means of corona discharge. However, the discharge device E can also be integrated in the sheet feeder RB or AN.

The printing unit D or paint module is followed by an applicator 1 and a coating module 2, which can also be arranged as an integrated film application module FA within a printing unit. Thereafter, if necessary, several further printing units D are provided up to the sheet boom AU.

In the area of the sheet guiding devices from the coating module 2 to the following printing unit D, a second discharge device E1 is provided. The second discharge device E serves to improve the surface properties of the foil application-coated printing sheets for the adoption of further coatings, such as printing inks or varnishes. In each case between printing units D or in printing units D or before and / or in and / or after the film application module FA optionally intermediate dryer Z are arranged in connection with known sheet transfer devices. With each intermediate dryer Z, the coating previously applied in the respective workstation can be dried optimally in a process-related manner. The intermediate dryer Z can be switched process dependent. Between printing units D, a turning device W can be provided. This serves to turn over a printed sheet provided on one side with a film coating and possibly with impressions, so that its previous underside can subsequently be printed or coated.

FIG. 3 schematically shows the method of printing on substrates provided with a previous film application. Shown here are four workstations which are each coupled to one another by means of a sheet transfer device T, so that the printed sheets pass through all the stations continuously.

As the first workstation an applicator 1 is provided. There, as already described above, the adhesive nozzle required for the film transfer is applied to the printing sheet.

As a second workstation, a coating unit 2 is provided. There, in a transfer nip 6, the film application of a transfer sheet 5 on the provided with the adhesive print sheet. For this purpose, a film feed for the transfer film 5 is provided. According to the invention, a discharge device E2 for surface treatment can be arranged on one or the other or on both sides of the transfer film 5 to be supplied. Thus, the image-forming layer to be transferred on the transfer sheet 5 can be changed in its surface property from a certain or both sides. The influence of the printing material side facing the imaging layer can improve their adhesion to the substrate. In a third workstation, a surface treatment of the printing sheet is provided by means of a discharge device E1. There, the printed sheet held on a sheet-guiding drum or a transfer cylinder is treated by means of a corona discharge directly or via a plasma P or via an air stream carrying the plasma P. In particular, when using a Tragluftstroms for a discharge plasma, a good distribution of charge-bearing gas particles is possible. Thus, the surface tension in particular of the coated by means of film application parts of the printing material is increased particularly evenly. The preparation for further work processes is so optimal. The discharge device E can be combined with an intermediate dryer Z. The control of discharge and optionally intermediate drying can be done centrally in connection with process parameters in connection with the type of substrates used, films and types of adhesive. As a fourth workstation finally a printing unit D is provided. Here finally a printing by means of printing ink or a coating by means of lacquer takes place. The discharge station E1 can also be arranged on the corresponding impression cylinder of the printing unit D. The printing or coating can be carried out particularly efficiently and with high quality by the prior surface treatment of the foil areas of the printing sheet. In particular, printing inks or lacquers can be used here, which are otherwise not suitable for printing or coating of films, but are well suited for normal substrates.

For the method of film application with subsequent printing on printing materials of various types, the following steps can be provided:

1. optional corona / plasma pretreatment of the substrate in the system or an installation module or a RoIIe sheet feeder upstream of the machine. 2. Adhesive application (eg UV adhesive) for film application via a printing or coating unit or integrated compact coating device.

3. Optional corona / plasma treatment of the film layer to be applied (depending on adhesion ratios of the surfaces involved).

4. Film application in the transfer nip (preferably tangential guidance of the transfer film to printing blanket or form cylinder or pressure roller).

5. Optional corona / plasma treatment of the applied film layer on the substrate immediately after the film transfer.

6. optionally after the film application an intermediate drying.

7. optional corona / plasma treatment of the applied film layer on the substrate directly before further printing or additional coating of the printed sheet already coated by means of film application.

8. The required colored subjects are printed with one or more colors and, if necessary, another intermediate drying.

The necessary or even possible configurations of a sheet-fed rotary printing press, including one or more film application modules, which are necessary or even possible for these method steps, are manifold and arise analogously from the devices already described above by way of example. LIST OF REFERENCE NUMBERS

1 applicator

2 coating unit

3 press roll

4 impression cylinders

5 transfer foil / foil web

6 transfer gap

7 roller drive

8 foil supply roll

9 foil collecting roll

10 press clothing

11 inking unit

12 plate cylinders

13 blanket cylinder

14 guide

15 print protection

16 dryers

17 monitoring device

D printing unit

To investors

RB roll bow feeder

AU outrigger

FA Foil Application Module

W turning device

E discharge device

E1 discharge device

E2 discharge device

T sheet transfer device

P discharge plasma

Claims

claims

1. A method for transferring at least one imaging and / or covering or covering application layer of a transfer film (5) on sheet in a sheet-processing machine, in particular Bogenrotationsdruck- machine, the at least one applicator (1) for a pictorial or surface coating of Printing sheet with an adhesive and a transfer nip (6) containing coating unit (2), wherein the application layer of the transfer film (5) is transferred to the printing sheet in that the transfer film (5) in the transfer nip (6) on the surface of a press roll (3) guided along and is applied with the coated side under pressure on the press sheet, so that the application layer adheres upon detachment of the transfer film (5) from the printed sheets in adhesive areas, characterized

that the printed sheets provided in the sheet-fed rotary printing machine with at least one image-forming or covering or covering application layer are guided on a guide surface,

- That the printed sheets on the guide surface are subjected to contactless at least a surface tension of the application layer increasing surface treatment, and

- That the sheets are provided with the inclusion of coated with the application layer areas with an imagewise or full-surface coating of ink or paint.

2. The method according to claim 1, characterized in that each printed sheet is provided with a coating of a liquid medium for surface treatment or coloring prior to the application of the application layer.

3. The method according to claim 1 or 2, characterized in that the Transferfoiie (5) on its respective application layer bearing side by means of a device for influencing the surface tension before being fed to the transfer nip (6).

4. The method according to claim 1 or 2, characterized in that the transfer film (5) on its respective application layer bearing side and on the opposite side by means of a device for influencing the surface tension of the supply to the transfer nip (6) is treated.

5. The method according to claim 1 to 4, characterized in that each printed sheet is treated in conjunction with and after the application of an application layering means of influencing its surface tension.

6. The method according to claim 1 to 5, characterized in that the sheets are subjected to the influence of the surface tension by means of a drying device for curing or drying of the applied layers of radiation, such as UV radiation.

7. The method according to claim 1 to 6, characterized in that each printed sheet before or in connection with a color printing operation by means of a device for influencing its surface tension is treated.

8. The method according to claim 5, characterized in that each printing sheet after the step of influencing the surface tension by means of a drying device for curing or drying of the applied layers of radiation, such as UV radiation, is exposed.

9. The method according to claim 1 to 8, characterized in that the surface of the carrier foil or each printing sheet for influencing its surface tension by means of a device for generating a discharge plasma, an electric charges carrying carrier gas stream is supplied.

10.Vorrichtung for transfer of at least one imaging and / or covering or overlapping application layer of a transfer sheet (5) on sheet in a sheet-processing machine, in particular Bogenrotati- onsdruckmaschine, the at least one applicator (1) for a pictorial or planar Coating the sheet with an adhesive and a transfer nip (6) containing coating unit (2), wherein the

Transfer film (5) in the transfer nip (6) guided along the surface of a press roller (3) and is placed with the coated side under pressure on the sheet, so that the application layer adheres in detachment of the carrier film from the sheets in glued areas, characterized,

- That the sheet-fed rotary printing machine between a sheet feeder (AN) or roll-bow feeder (RB) and a sheet delivery (AU) has a plurality of as printing and / or paint and / or coating units (D) formed working units, - that at least a film application module (FA) with an applicator unit (1) and a coating unit (2) is provided, to which a guide surface is assigned for the printing sheet provided with an application layer, - That the guide surface or resting thereon arranged sheet is associated contactless a surface tension of the sheet and / or the application layer increasing means (E)

and in that the device is assigned a printing unit (D) or a coating unit for printing or coating the printed sheets, including the areas coated with the application layer, with printing ink or varnish.

11.Vorrichtung according to claim 10, characterized in that the working units and / or foil application modules (FA) each one

Dryer (16) can be assigned.

12. The device according to claim 10, characterized in that the working units and / or foil application modules (FA) each one

Coating module for generating a cover or protective layer on the raw sheet is arranged upstream.

13. The apparatus of claim 9 to 12, characterized in that the sheet-fed rotary printing press associated with a sheet guiding plane in the supply of unprinted or uncoated pages of the sheet to a work unit (D, FA, 1) a discharge device (E) by means of which the printed sheets of a surface tension changing their surface tension can be exposed.

H.Vorrichtung according to claim 9 to 12, characterized in that the sheet-fed rotary printing machine a web guide plane of a transfer (5) one or both sides assigned in the supply of the transfer film (5) to a processing unit (FA ₁ 1) at least one Discharge device (E, E1, E2), by means of which the transfer layer of Transfer film (5) can be exposed to a surface tension changing surface treatment.

15. The apparatus of claim 9 to 12, characterized in that the sheet-fed rotary printing press associated with a sheet guiding plane in the region of the discharge of a printing sheet from a application unit transmitting the application unit (FA, 1) a discharge device (E, E1, E2), by means of which the Application layer having printed sheet of a surface tension whose surface tension changing surface exposure can be suspended.

16. The apparatus of claim 9 to 12, characterized in that the sheet-fed rotary printing machine associated with a sheet delivery in the region of feeding a printing sheet to a transfer film processing unit (FA, 1) downstream printing or coating plant (D) a discharge device (E, E1, E2), by means of which the printing sheet having the application layer can be exposed to a surface treatment which alters its surface tension.

17. The apparatus of claim 9 to 16, characterized in that the discharge device (E, E1, E2) has a discharge plasma generating device and that in the discharge device (E) a

Device for generating a plasma directed transporting carrier gas stream is provided.