WO2009053316A2

WO2009053316A2 - Stamping coating for film printing substrates

Info

Publication number: WO2009053316A2
Application number: PCT/EP2008/064046
Authority: WO
Inventors: Jürgen Schölzig
Original assignee: Manroland Ag
Priority date: 2007-10-22
Filing date: 2008-10-17
Publication date: 2009-04-30
Also published as: EP2212114A2; WO2009053316A3; DE102008042937A1

Abstract

The invention relates to a coating system for transferring imaging or covering layers from a transfer film to a printing substrate, used flexibly for producing complex printing substrates made of film material. At least one film application module FA is used to this end in a sheet rotation printing press, such that a variable combination of printing lines and paint lines is created. The coated film sheet can particularly be dried from the back side thereof.

Description

Embossing coating for film substrates

The invention relates to a method and a device for transferring imaging or covering layers from a carrier foil to printed sheets according to the preamble of patent claim 1 and of patent claim 7, 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 previously known production methods are limited to the processing of substrates made of paper or cardboard. A coating of film substrates in the cold foil stamping process has not been previously known.

The object of the invention is therefore to improve a method according to the preamble of claim 1 and a device according to the preamble of claim 7 by means of a film coating of sheet of film substrate can be simple, safe, economical and accurate with good adhesion of the film coating, wherein method and apparatus should be easy to handle.

The solution to this problem arises in the features of claims 1 and 7.

Advantageously, a method is proposed, in its application for film application and substrates from films are processed. For this purpose, a drying of the adhesive for the film coating is provided in particular from the uncoated back of the Folienbedruckstoffes ago. The corresponding drying device is arranged downstream of the film coating.

Here, the film application on film substrates in conjunction with an offset printing machine with upstream or downstream paint modules done. The application is carried out in a printing unit or paint module. Before or after the application can be additionally printed and intermediately dried eg with the help of a UV dryer. Finally, the use of heat-reduced UV dryer systems can be used in conjunction with the film application in cold foil lamination.

In the following, the invention will be explained in more detail with reference to drawings. Showing:

FIG. 1 shows a printing machine with a film transfer device,

Figure 2 shows a first configuration of a sheet-fed printing machine, as well

FIG. 3 shows a second configuration for this with two coating units,

FIG. 4 schematically shows steps of the process for the film transfer and FIG. 5 shows schematic variants of the process of drying.

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 may also correspond to the forme cylinder of a paint module. Within the used for the film transfer coating 2 a web 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, as shown in the context of applicator 1, an integrated in the applicator 1 film transfer device may be provided, whereby an integrated film application module is created. In this case, a press roll 3 'is assigned downstream of a printing gap between a blanket or form cylinder 13 and the impression cylinder 4 at a counter-pressure cylinder 4. Thus, a film web 5 'of a transfer film after the coating of the printing material by means of the applicator 1 to a transfer gap formed as mentioned above 6' fed and also be discharged directly again. The cold foil embossing thus takes place in a single integrated film application module FA, as indicated in FIG.

As shown schematically in FIG. 1 in the applicator 1, an applicator can also be arranged in a compact design within the coating module in an integrated film application module FA. For this purpose, an adhesive application device 1 'is assigned to the impression cylinder 4 and arranged upstream of the transfer nip, which would be provided here between the blanket cylinder 13 and the impression cylinder 3. The transfer film would be guided here around the blanket cylinder 13 or approximately tangentially past it through the designated printing nip. Such an adhesive applicator device 1 'may consist of a compact forme cylinder for supporting a printing form for the adhesive and an applicator of a chamber doctor blade and an anilox roller for supplying the adhesive. In this case, on the same counter-pressure cylinder 4, in turn, the adhesive application is first carried out on the printing substrate and the film application is carried out immediately thereafter.

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 is a film collecting roll 9 is provided for the used sheet material. A rotary drive 7 on the film collecting roller 9 is always advantageous. It can even be provided that the transfer film 5 is conveyed on the outlet side by means of the rotary drive 7 and held taut on the inlet side by means of a brake.

The press roll 3 (blanket or form cylinder or separate press roll) carries on its surface a compressible, e.g. also provided with a compressible intermediate layer element. For this purpose, the press roll 3 can be provided with a press cover 10, for example as a plastic cover, comparable to a blanket or blanket, which is held in a cylinder channel on clamping devices.

To ensure the efficiency of the coating process can be provided, the film feed of the transfer film 5 from the film supply roll 8 to the transfer nip 6 and the film collection roller 9 is gradually controlled, the transfer film 5 is then stopped, if no transfer of imaging or covering layers should take place.

The associated device preferably includes a corresponding feed control for the transfer sheet 5, which ensures that at least the lying in the region of the press roller 3 and the impression cylinder 4 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.

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.

Furthermore, in a follow-on printing unit 20, which adjoins the coating unit 2, an intermediate dryer Z is provided. The intermediate dryer Z is internally arranged halfway or in conjunction with a sheet guiding device 19. The sheet guide device 19 may be formed as a so-called sheet guide path with pneumatic devices for non-contact guidance of the printing material. It connects the path of the foil sheets B from the coating unit 2 to the subsequent printing unit 20 and is arranged below a sheet guiding drum 21 (here designed as a skeleton drum). The intermediate dryer Z is arranged within the sheet guiding device 19 or embedded between elements of the sheet guiding device 19 such that a sheet of film B passed over the sheet guiding device 19 can be irradiated from its lower side.

Furthermore, the film application module may include a monitoring device 17 for scanning the sheet surface.

With the device described above, it is possible to coat substrates or partially or completely coated substrates or to laminate or laminate or even to provide a particularly resistant surface layer. For this purpose, the device for the film transfer in a printing units of a sheet-fed printing machine downstream printing or coating plant is arranged. In such an arrangement, the surface of the fresh print is finished or protected by means of the film coating.

In a first step, the method is characterized in that the film application is carried out as a finishing application or functional application on film printing material. In a second point, the pretreatment of the film printing material and the application film is carried out by a corona treatment. In a third point, the use of heat-reduced UV dryer systems in conjunction with the film application in cold foil coating is used. To do this, the film guide can be tangential through the transfer nip or loop around the blanket cylinder. According to the invention, the film application to film substrates in conjunction with an offset printing machine should be such that an applied transfer film TF or an adhesive layer K, on which the transfer film TF adheres, in a subsequent printing unit 20 downstream of the coating unit 2 or even in the coating unit 2 itself of the uncoated Is dried back side. For this purpose, an intermediate dryer Z is used, which is arranged in a sheet guiding device 19 or assigned to this, that it can irradiate the film sheet B from the bottom. If the film sheet B consists of transparent or partially transparent film substrate, the drying radiation reaches the adhesive layer K through the substrate more directly than from the top side on the way through the mostly metallic transfer film layer TF

The intermediate dryer Z may be a UV dryer. For printing on film substrates UV printing inks are often used, which can be cured very quickly and efficiently by means of UV dryer, so that a firmly adhering to the Fol ienbedruckstoff ink layer is formed. To dry UV inks, special dryers have been developed that operate at relatively low temperatures. Conventional UV emitters or UV cold emitters, e.g. as excimer radiator. But there are also so-called NIR dryers in question.

In the case of film substrates, a corona or plasma treatment is often carried out to improve the color adhesion by applying a corona discharge or a plasma to the films. As a result, their surface tension changes so that the printing inks to adhere securely.

An advantage of the proposed method is that the curing effect is greatly improved by the back dryer irradiation. This results in a greatly reduced thermal influence on the film printing material

For the method of film application on film substrates, such as PET films, the following steps are generally to be provided: 1. The feeding of film sheet to the printing machine via a sheet feeder AN or a sheet feeder AN or the printing press directly upstream so-called roll-sheet feeder RB, in which the film sheet B are generated directly from a film web. 2. A corona or plasma pretreatment (device E) of the surface of the film printing material can be carried out in the plant or a plant module or a roller-bow feeder RB upstream of the machine.

3. A pre-coating of the foil sheet B can be carried out in a varnish module or printing unit D (with integrated varnishing device) for priming with a primer or to form a base layer with opaque white or to form gloss effects with so-called iriodin varnishes.

4. By means of UV or excimer intermediate dryer 16 of the film sheet B is then prepared for further coating steps. One, several or each printing unit D can be equipped with appropriate intermediate dryers 16 for this purpose. In general, intermediate dryers can be used as conventional UV lamps or

UV cold spotlights be executed. However, so-called NIR dryers can also be used for this work step.

Because of the film distortion before and after the application, however, preference is given to using heat-reduced UV dryer systems. 5. In the printing press, a sheet turning device W may be provided in order to be able to process the film sheets B from both sides.

6. The adhesive application for film application via a printing or coating unit or integrated into a printing compact coating device. For this purpose, a UV adhesive comes into consideration, which like the UV inks adheres well to the film substrate and can be dried quickly by using the mentioned dryer 16.

7. A corona or plasma treatment (device E) of the film layer to be applied is optionally possible. This depends on the given adhesion conditions of the surfaces involved. 8. The film application in the transfer nip 6 is preferably carried out under tangential guidance or with little wrap around of the transfer film 5 on the press roll. ze 3, which may be formed using a blanket or form cylinder or a different type of pressure roller.

9. After the film application, an intermediate drying can be carried out again for hardening with the aid of the previously mentioned dryers 16. 10. According to the invention, however, an intermediate dryer Z should be provided for this purpose, which irradiates the film sheets from the uncoated rear side in the sheet guiding device 19 of a subsequent printing unit D.

11. The printing of the required colored subjects is done with one or more colors and, if necessary, a renewed intermediate drying. 12. Using varnish modules, the finishing of sheet B with protective, gloss or effect layers can be combined with additional steps and intermediate or final drying. Lacquer modules are upstream or downstream of printing units.

Possible configurations of a sheet-fed rotary printing press including film application modules FA are described below.

FIG. 2 shows a first variant of such a configuration. The illustrated printing press has a roll-bow feeder RB. In the RoIIe-Bogen feeder RB, film sheets are cut from a film roll to fit perfectly and fed into the press at the machine cycle. Subsequently, a printing unit D or a paint module is arranged. In the configuration shown, the printing unit D or the paint module is followed by an application unit 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 delivery AU.

Between or in printing units D or before or in the film application module FA intermediate dryer 16 are arranged, by means of which the applied in respective workstations coatings can be dried. Specifically, an intermediate dryer Z is provided after each coating unit 2, by means of which the film sheet B can be irradiated from the back. In the area of feeding the film sheets from the roll-bow feeder RB into the first workstation of the printing press, a discharge device E is provided. It serves, in a manner known per se, for example by means of a corona discharge, to improve the surface properties of the film sheets for the acceptance of coatings. The discharge device E can also be integrated into the roll-bow feeder RB, so that the surface treatment of the foil sheet is also effective for the sheet transport to the printing press. With such a printing press, therefore, a film sheet cut from a film roll can first be coated, then coated with an imagewise or flat film layer, and subsequently printed again in multiple colors.

FIG. 3 shows a second variant of such a configuration. The printing press shown has a sheet feeder AN, to which a discharge device E for film treatment is assigned. Subsequently, either a printing unit D or a paint module is provided. This is followed by one or two-part film application module FA. Subsequently, a printing unit is again arranged, which is followed by a so-called turning device W. This serves to evert a film sheet coated on one side, so that its previous underside can be subsequently printed or coated from above.

In the configuration shown, the applicator 1 and a coating module 2 adjoin the turning device W, 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 delivery AU. Before feeding the film sheets to the film application module FA, they can be exposed again, but now with their upper rear side exposed to the action of a discharge device E.

Between or in printing units D or before or in the film application module FA intermediate dryer 16 are arranged, by means of which the applied in each work stations coatings can be dried. Specifically, an intermediate dryer Z is provided after each coating unit 2, by means of which the film sheet B can be irradiated from the back. With such a printing machine, each sheet of film can therefore first be coated from its upper side, then provided with a film coating, then printed or coated, then turned, then provided with a further film coating and subsequently printed again in multiple colors. Furthermore, in such machines further production possibilities result by providing printed sheets with optical or tactile patterns which are underlaid and visible or palpable by the film coating, or else by applying optical or tactile surface patterns over the film itself. These coating operations can again be done on one side or both sides on unprinted or printed surfaces.

According to the invention, the following mode of production is provided:

I. In a preferred embodiment, the drying of the Klebersujets K before applying the Foliensujets TF also in the application of Folienbe printed materials. Here, the film sheet B can be dried from the top and the adhesive layer K is achieved directly from the dryer radiation, so that a predrying of the adhesive is achieved.

II. In a particularly preferred embodiment, the drying of the Klebersujets K when applied Foliensujet TF in the application in Folienbe- printed matter also from the bottom or from the back of the film sheet B forth. In this case, the adhesive layer K is achieved directly by the dryer radiation, since the material of the film sheet B allows the dryer radiation to pass better than the metallic coating of the film substrate TF. Therefore, the intermediate dryer Z is provided in the sheet guiding device 19 of the printing unit 20 following the coating unit 2.

In Figures 4 and 5, the process of drying with the inventive arrangement is shown again in more detail. FIG. 4 shows the steps for applying film layers on a substrate in the context of the method according to the invention.

A) First, a sheet (here film sheet B) by singling a

Stack or by cutting from a roll provided. B) The surface of the film sheet B is optionally treated with a plasma under the action of a discharge device E for better color adherence.

C) A commissioned work 1 applies a Klebersujet K on the film sheet B. The adhesive may be a colorless or colored UV color.

D) The adhesive K is optionally pre-dried by means of a dryer 16 on the film sheet B. The dryer 16 may be a UV dryer.

E) In the coating unit 2, a film substrate TF is transferred from a film web 5 to the adhesive substrate K applied to the film sheet B.

F) The film sheet B is irradiated from its uncoated backside by means of the intermediate dryer Z and thus the adhesive substrate K is finished drying under the film TF.

FIG. 5 shows the possibilities of drying a coating with a transfer film layer TF from a film web 5 on a film sheet. The adhesive layer K on the film sheet B can be dried with appropriate means (right-hand illustration in FIG. 5) during the transfer of the transfer film layer TF from the film web 5 by means of a dryer 16. The dryer radiation (double lines, dotted lines) must penetrate the carrier film of the film web 5 and the transferred transfer film layer TF in order to reach the adhesive layer K. Therefore, the radiation of the dryer there reaches the overlying layer K only partially or at least only attenuated.

The same applies if the dryer 16 is applied when the coating is ready transferred on the foil sheet B (left-hand illustration in FIG. 5, top).

In FIG. 5, bottom left, it is shown that the irradiation of the foil sheet B by means of intermediate dryer Z leads from the unprinted rear side to a largely unhindered passage of the radiation. Thus, the adhesive layer K is well achieved and can be dried quickly and efficiently. LIST OF REFERENCE NUMBERS

1 applicator (1)

2 coating unit

3 pressing roller (pressure roller 3 ')

4 impression cylinders

5 transfer foil / foil web (5 ')

6 Transfer nip (press nip 6 ')

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

18 dancer roller

19 sheet guiding device

20 subsequent printing unit

21 sheet guiding drum / transfer cylinder

r commissioned work

3 'press roller / pressure roller

5 'transfer film / film web

6 'transfer nip / press nip

B sheet, printed sheet, foil sheet

D printing unit To investors

RB roll bow feeder

AU outrigger

FA Foil Application Module

W turning device

E discharge device

K adhesive layer, adhesive

TF transfer film layer, foiljet

Z intermediate dryer, back dryer

Claims

claims

1. A method for transferring image-forming layers from a carrier film to printing sheet in a sheet-fed rotary printing machine, comprising at least one applicator (1) for imagewise or surface coating of a printed sheet with an adhesive and at least one coating unit (2) for transferring imaging or covering Layers of the carrier film on the printing sheet, wherein in a coating unit (2) a transfer nip (6) is formed and the carrier film on the surface of a press roller (3) along and with the coated side on a printed sheet and under

Pressure can be conveyed together with the latter through the transfer nip (6), so that the image-forming or covering layers are adhesively transferred in adhesive-provided areas from the carrier film to the printed sheet, the printed sheets being film sheets, characterized in that they are printed on at least one printed sheet or coated or unprinted or uncoated first side in a transfer nip (6) with an imagewise or full-surface film coating of the carrier film (5) are provided and that the film sheets are dried after the application of the film coating.

2. The method according to claim 1, characterized in that each foil sheet is irradiated after the application of the film coating from its uncoated side to dry the adhesive.

3. The method according to claim 1 or 2, characterized in that each foil sheet is treated by means of a device for influencing its surface tension before the application of coatings.

4. The method according to claim 1 to 3, characterized in that - film sheets are coated in a sheet-processing machine on at least one side by means of a liquid medium and - that on this coating a pictorial or surface applied Fo- lienbeschichtung of a carrier film (5) is performed and - that the film sheets are provided on the thus coated side with one or more printed images by means of ink.

5. The method according to claim 1 to 4, characterized in that the adhesive and / or the liquid coating media and / or the printing inks are curable by means of UV radiation.

6. Process according to claims 1 to 5, characterized in that coatings applied to foil sheets can be dried alone or in combination.

7. An apparatus for transfer of imaging and / or ab- or overlapping transfer layers of a transfer film (5) on sheet with at least applicator (1) for imagewise or surface coating of printed sheets with an adhesive and at least one coating unit

(2) for transferring the transfer layers to the printing sheets, wherein each coating unit (2) has a transfer nip (6) in which the transfer film (5) at least tangentially passes a press roll (3) placed under pressure on the coated sheet with the coated side is, so that the image-forming or covering or overlapping layer in the region of the adhesive areas on the printing sheet adhesively transferred from the transfer sheet (5) on the sheets, characterized in that in a sheet-fed rotary printing machine between a sheet feeder (AN ) or roll-bow feeder (RB) and a sheet delivery (AU) a plurality of as printing and / or paint and / or coating units (D,

20), the sheet-fed rotary printing press, before or after the coating units (D, 20), is assigned at least one film application module (FA) containing an applicator unit (1) and a coating unit (2), and the working units and / or foil application modules (FA) each a dryer (16) can be assigned.

8. The device according to claim 7, characterized in that the sheet-fed rotary printing machine in the field of supplying unprinted or uncoated sides of the film sheet to a work unit (D, FA, 1) a discharge device (E), by means of which the film lienbogen a Surface treatment is suspendable.

9. The device according to claim 7, characterized in that the sheet-fed rotary printing machine in the region of feeding a transfer film (5) to a transfer film processing unit (FA, 1) loading device (E), by means of which the transfer layer having the side of the transfer sheets a surface treatment is exposable.

10.Vorrichtung according to claim 7, characterized in that the sheet-fed rotary printing machine whose working units or sheet leading sheet transport modules are provided in the area after the application of a coating with a drying device.

11.Vorrichtung according to claim 7 to 10, characterized in that in the sheet-fed rotary printing machine whose working units or sheet leading sheet transport modules are provided in the area after the application of a coating with a drying device, which are associated with the non-coated back or bottom of a film sheet in that the coating is irradiated from the side opposite the coating of the film sheet by means of the dryer.

12. The device according to claim 11, characterized in that the drying device is a UV dryer.

13. The apparatus of claim 11 or 12, characterized in that the UV dryer is arranged in the region of a sheet guiding device which guides the unprinted side of the film sheet.