DE102005011696A1 - Rotary foil transfer printing process has applied heat to aid transfer onto sheet material - Google Patents

Abstract

The printing process use a transfer foil carrier [5] that is fed between reels [8,9] and passes between a power cylinder [3] and a counter cylinder [4]. The transfer image is transferred onto sheets of paper. The process is aided by the application of heat from multiple heat sources, eg intra red elements [21].

Description

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

It is known to produce metallic layers on printed sheets by means of a film transfer process. So is in the EP 0 569 520 B1 a printing material and a printing apparatus using this material are described. In this case, a sheet-processing machine is shown, which has a feeder and a boom, wherein printing units and a coating module are arranged between the two units. In at least one of the printing units, an adhesive pattern is applied by means of the planographic printing process. This adhesive pattern is applied in a cold printing process and has a specific imaging subject. In the printing unit following the coating module with a counter-pressure cylinder and a press roller, a film guide is provided. This is designed in such a way that a film strip or a transfer film is guided through the transfer nip of the coating module between the impression cylinder and the press roll from a film supply roll. The film strip is rewound on the outlet side after leaving the coating module. The transfer film has a carrier layer on which imaging layers such as metallic layers, for example of aluminum, can be applied. Between the metallic layer and the carrier film, a separating layer is provided, which ensures that the metallic layer can be removed from the carrier layer.

At the Transport of press sheets through the printing unit will print each sheet provided with an adhesive pattern. Thereafter, the sheet is through guided the coating module, wherein by means of the press roller resting on the impression cylinder Sheet is associated with the film material. there the down-facing metallic layer is in close contact with the areas provided with adhesive on the sheet.

To the further transport of the printed sheet adheres to the metallic Layer only in the area provided with the adhesive pattern at. The carrier foil So the metallic layer is in the range of adhesive pattern taken. The used in this way transfer film will be back wound. The print sheet is laid out in the coated state.

It is known such coating modules, for example in printing units of printing presses. A disadvantage of the known devices is that they are not flexible and that the supply of the Transfer foil consuming and difficult to handle. In particular, are very special Foils required, the precisely specified release properties of the imaging layer exhibit.

task The invention is therefore to provide a device by means of which the carryover an imaging layer e.g. a metallization, on a sheet can be done safely, economically and accurately, the device should be easy to handle.

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 3.

Favorable Way becomes a guide the transfer sheet feeder used in which the transfer film are heated during supply to the transfer nip can.

The warming can by means of radiation, air currents or contact with tempering done.

On this way is the replacement the imaging layer of the carrier film improved and the Coating process influenced in a particularly advantageous manner.

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 becomes.

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

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

advantageously, it is also possible several coating modules within a sheet processing Provide machine in a row. Thus, the application of various imaging coatings or metallization layers within of a subject in succession. Here it is possible over a single adhesive pattern with all image pattern elements the imaging Transfer layers side by side. It is also possible a first adhesive pattern in a first coating module with a to provide the first imaging coating or metallization and overlaying following another, to apply the first enclosing glue pattern and with another imaging coating or metallization layer to provide.

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

there shows:

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

2 the construction of a coating module with a film transfer device.

• – Ein zu beschichtender Druckbogen wird in einem ersten Arbeitschritt mit einem bildgebenden Klebstoffmuster versehen. Der Auftrag des Klebers erfolgt im einer als Auftragwerk 1 konfigurierten Vorrichtung, z.B. einem konventionellen Druckwerk einer Offsetdruckmaschine über dort vorhandene Farb- und Feuchtwerke 11, eine Druckplatte auf einem Plattenzylinder 12, einen Drucktuch- oder Gummizylinder 13 und einen Gegendruckzylinder 4. Alternativ kann zu dem gleichen Einsatzzweck in entsprechender Anordnung auch ein Lackmodul einer Bogendruckmaschine Verwendung finden.
• – Danach wird in einem zweiten Schritt gemeinsam mit einem Druckbogen eine Transferfolie 5 durch einen Transferspalt 6 geführt, wobei die Transferfolie 5 im Transferspalt 6 gegen den Druckbogen gepresst wird. Hierzu wird ein Beschichtungsmodul 2 verwendet, das einem Druckwerk oder einem Lackmodul oder einer Basiseinheit oder einer andersartigen Verarbeitungsstation einer Bogenoffsetdruckmaschine entsprechen kann.
• – Der Transferspalt 6 im Beschichtungsmodul 2 wird durch eine Presswalze 3 und einen Gegendruckzylinder 4 gebildet. Hierbei kann die Presswalze 3 einem Drucktuchzylinder und der Gegendruckzylinder 4 einem Gegendruckzylinder eines an sich bekannten Offsetdruckwerkes entsprechen. Weiterhin kann die Presswalze 3 einem Formzylinder und der Gegendruckzylinder 4 einem Gegendruckzylinder eines Lackmodules einer Bogendruckmaschine entsprechen.
• – Weiterhin kann dem Beschichtungsmodul 2 nachgeschaltet ein so genanntes Kalandrierwerk vorgesehen werden, wenn der beschichtete Druckbogen zur Steigerung der Haftung der Beschichtung bzw. zur Steigerung von Glätte und Glanz des Druckbogen unter erhöhtem Druck überwalzt werden soll. Dies ist aber nur bei geeigneten Materialien sinnvoll.

In 1 is a sheet-processing machine, here a printing press, shown, which consists of at least two printing units. The two printing units are used for the following purposes:

• - A sheet to be coated is provided in a first step with an adhesive imaging pattern. The application of the adhesive takes place in a as an order 1 configured device, such as a conventional printing unit of an offset printing press on there existing inking and dampening 11 , a printing plate on a plate cylinder 12 , a blanket or blanket cylinder 13 and an impression cylinder 4 , Alternatively, a paint module of a sheet-fed printing machine can be used for the same purpose in a corresponding arrangement.
• - Then, in a second step, together with a sheet a transfer sheet 5 through a transfer gap 6 guided, with the transfer film 5 in the transfer gap 6 pressed against the sheet. For this purpose, a coating module 2 used, which may correspond to a printing unit or a paint module or a base unit or a different processing station of a sheet-fed offset printing press.
• - The transfer gap 6 in the coating module 2 is through a press roll 3 and an impression cylinder 4 educated. Here, the press roller 3 a blanket cylinder and the impression cylinder 4 correspond to a counter-pressure cylinder of a known offset printing unit. Furthermore, the press roll 3 a form cylinder and the impression cylinder 4 correspond to a counter-pressure cylinder of a paint module of a sheet-fed press.
• - Furthermore, the coating module 2 downstream of a so-called calendering be provided when the coated sheet to increase the adhesion of the coating or to increase the smoothness and gloss of the sheet is to be rolled under increased pressure. However, this only makes sense with suitable materials.

Within the coating module used for the film transfer 2 is a web guide for transfer films 5 shown.

Suitable transfer foils for processing 5 are multi-layered. They have a carrier layer on which an imaging layer is applied by means of a release layer. The separating layer serves to facilitate lifting of the imaging layer from the carrier layer. The image-forming layer may be, for example, a metallized layer or a gloss layer or a texture layer or a colored layer or a layer containing one or more image patterns.

The foil supply roll 8th is the coating module 2 assigned on the side of the sheet feeder. The foil supply roll 8th has a rotary drive 7 on. The rotary drive 7 becomes the continuous controlled feeding of the transfer film 5 to the coating module 2 needed and is therefore controllable.

Furthermore, in the field of Folienzu- and -abführung Leiteinrichtungen 14 , As deflecting or tensioning rollers, pneumatically actuated guide means, baffles, flat guide channels o. Ä. Provided. Thus, the film web of the transfer film 5 always guided without distortion just and in the same voltage against the press roller 3 being held. The guiding devices 14 can also help to introduce the transfer film 5 contain. This can also automatic feeding aids for the film web of the transfer film 5 be used.

In this way, the sheet feeder is in Area of the coating unit 2 surrounding protection 15 simplified. The protective function of the protective devices 15 is maintained at the same time completely.

The transfer foil 5 This can be done around the press roll 3 be guided around, with the transfer film 5 advantageously from one side of the coating module 2 out to the press nip 6 is added and deductible. In a further embodiment, the transfer film 5 also substantially tangential to the press roll 3 over or only wrapping around in a small circumferential angle to the press nip 6 be added and removed. This is the transfer film 5 from one side of the coating module 2 fed and to the opposite side of the coating module 2 dissipated.

On the downstream side of the printing unit is a film collecting roll 9 shown. On the foil collecting roll 9 the used foil material is rewound. Here, too, is a rotary drive for the optimized production 7 provide that is controllable. In essence, the transfer film could 5 also by the rotary drive 7 moved on the drain side and held on the inlet side by means of a brake punishment.

For the transfer process of the imaging eg wear layer of the transfer film 5 on the sheet in the transfer nip 6 between the press roll 3 and the impression cylinder 4 is essential that the surface of the press roll 3 Thus, the blanket cylinder or forme cylinder is equipped by means of a compressible, damping element.

The press roll 3 is therefore with a press cover 10 or provided as a roller with a corresponding coating. The press fabric 10 or press coating can be carried out, for example, as a plastic coating, comparable to a blanket or blanket. The surface of the press cover 10 or press coating is preferably very smooth. It can also be formed from antiadhesive substances or structures. Here, for example, a relatively hard structure in the form of very fine spherical caps comes into question. A press fabric 10 is on the press roll 3 held in a cylinder channel on jigs.

The press fabric 10 can improve the transfer properties in the transfer nip 6 be equipped with a targeted elasticity. This may optionally act in a compressible intermediate layer. This compressibility is preferably similar or less than in conventional blankets or blankets, which can also be used at this point. The mentioned compressibility can be produced by means of a conventional compressible printing blanket. Furthermore, combined fabrics made of a hard blanket and a soft pad can be used.

Furthermore, can directly on the press roller 3 or on the press fabric 10 be provided a limited pressing surface. This may be from the surface of the press fabric 10 be worked out or it can be used as a partial surface of the material of the press fabric 10 additionally on the press roller 3 be attached.

To ensure the economy of the coating process is provided that the film feed the transfer film 5 from the film supply roll 8th to the transfer gap 6 and to the foil collecting roll 9 is controllable so that as far as possible the transfer film 5 is then stopped if no transmission of the imaging layer is to take place:
For this purpose, a control of the transfer film 5 such that when passing through a gripper of the sheet-guiding impression cylinder 4 receiving cylinder channels of the film feed is stopped. The grippers hold the signature on the impression cylinder 4 , The press roll 3 has a corresponding cylinder channel, in which the fabric is held. In the area of the corresponding cylinder channels, there is no pressing of the transfer film 5 between the press roll 3 (Blanket cylinder) and the impression cylinder 4 , The press roll 3 then runs under the transfer film 5 sliding through while the transfer film 5 between press roll 3 and impression cylinder 4 is free to stretch. This state continues until the so-called pressure beginning of the Zylin derkanal ends and the transfer film 5 again between the press roll 3 and the impression cylinder 4 is trapped under inclusion of a printed sheet. Then the transfer film 5 transported further. The timing of the film feed can according to a necessary acceleration or braking of the film supply roll 8th or film collecting roll 9 Start or suspend a little earlier than dictate the channel edges of the cylinder channel. For reaction-fast timing systems via so-called dancer rollers 18 as exemplified in 1 are the control of the rotary actuators 7 the film supply rolls 8th or film collecting roll 9 may not be necessary. By means of dancer rolls 18 the necessary film tension is also maintained.

A further improvement of the film utilization of the type described results from the fact that the transfer film 5 is divided into one or more Teilfolienbahnen lesser width. Thus, with appropriate control by means of the device or devices for timing the film feed each of the partial film webs, the Ausnut tion of the transfer film 5 be improved even with zonally different lengths coating areas within a sheet. For this purpose, each partial film web is conveyed only exactly in the area where the imaging surface layer is to be applied. In the areas not to be coated, each partial film web can be stopped independently of the other partial film webs, whereby no unnecessary film consumption arises.

Furthermore, it is intended to improve the coating process in the area of the adhesive application and in the region of the film application dryer 16 provided. Thus, in particular by means of UV drying, the imagewise applied adhesive layer by means of a first dryer 16 (Intermediate dryer I) are predried, so that the wear layer of the transfer film 5 better adhered. Furthermore, the adhesive effect of the impressed wear layer on the printed sheet by means of a second dryer 16 (Intermediate dryer II) can be improved by the drying of the adhesive is additionally accelerated.

Finally, the quality of the coating by means of an inspection or monitoring device 17 be checked after the foil application. For this purpose, the inspection device 17 on a sheet-guiding surface of the coating module 2 after the transfer gap 6 and possibly sealed off from the dryer 16 or on a sheet-guiding surface of the coating module 2 be directed downstream of another bow leading module. The pre-applied coated printing sheet can thus be checked for completeness and quality of the coating. As poorly recognized printed sheets can be marked or rejected in a sorter as waste.

With Help of the described device, it is also possible in a the coating process pretreated transfer films or Transfer layers from a transfer sheet to a sheet.

Will the roll of film 8th provided with a data storage, for example, in the paper tube of the film roll 8th integrated, all relevant data can be set for setting the coating module 2 and store the sheet-processing machine in this data store. The adjustment data or operating parameters or characteristics of the transfer film 5 can when mounting the film roll (s) 8th be read out automatically. This is an automated setting or activation of all suitably equipped operations of the coating module 2 and the sheet processing machine in connection with the coating process using the transfer sheet 5 possible.

By pre-input via the central control station eg on the machine, the control panel of the coating module 2 or the central work preparation station within the control system. With film roll mounting can be checked whether the film roll 8th placed in the right place for the print job.

The parameterization of the coating by means of transfer foil 5 with regard to their processability, the peelability of the imaging layers also depends on the carrier film. For this purpose, according to the invention, a Folienbahnerwärmung before the transfer nip 6 or in the transfer gap 6 between press roll 3 and impression cylinder 4 in the coating module 2 to arrange.

The foil web 5 can be heated in this way for better detachment, ie separating the imaging layer (jewelry foil) of the carrier film.

• – eines oder mehrerer Wärmestrahlern 21, z.B. IR-Strahlern, gegenüberliegend der Folienbahn 5,
• – einer beheizte Kontaktwalze 20 zum Wärmeeintrag in die Folienbahn 5 über eine vergrößerte Fläche,
• – einer Einrichtung zum Anblasen mit temperierter Blasluft (Thermoluft), z.B. mittels eines Luftschwertes oder von Düsen,
• – einer Einrichtung zum Einblasen von beheizter Luft in einen Führungskanal (siehe z.B. die Folienleiteinrichtung 14) für die Leitung der Folienbahn 5 zum Transferspalt oder
• – einer oder mehrerer beheizbarer Umlenkrollen 19 für die Führung und Lenkung der Folienbahn 5 zum Transferspalt 6 (insbesondere auch annähernd tangential zur Presswalze 3).

For this purpose, a variety of means can be used. Possible is the alternative use of

• - One or more heat radiators 21 , eg IR emitters, opposite the film web 5 .
• - A heated contact roller 20 for heat input into the film web 5 over an enlarged area,
• - a device for blowing with tempered blowing air (thermal air), for example by means of an air sword or nozzles,
• - A device for blowing heated air in a guide channel (see, for example, the Folienleiteinrichtung 14 ) for the management of the film web 5 to the transfer gap or
• - One or more heatable pulleys 19 for the guidance and guidance of the film web 5 to the transfer gap 6 (In particular also approximately tangential to the press roller 3 ).

But it is also possible, the press roll 3 and / or the impression cylinder 4 to heat or to use a heatable blanket or a heatable press fabric.

The direct foil heating before entering the transfer gap 6 is the cheapest solution in this context. The heating should be as close as possible to the transfer gap 6 done so that the conditioning in the transfer nip 6 still fully effective.

By means of one or all of the described devices, the transfer film 5 be influenced in the simplest way so that the transmission of the imaging layer at any time and for a variety of types of film with optimal coating quality is manageable. Thus, both the Be stratification or stamping process controllable and on the other hand allows the use of versatile, possibly also inexpensive types of film.

By metrological monitoring will be a readjustment of the film warming in the context of changing Process parameters and environmental conditions allows.

Furthermore, depending on a sheet inspection, the film heating can be controlled. Depending on the degree of film heating, the detachment behavior of the imaging layer of the transfer film 5 unfavorably change. This is by means of a suitable and known inspection device 17 possible. The inspection device 17 is the transfer gap 6 in the coating module 2 or downstream in a subordinate, leading sheet area, and detects defects in the coating in a simple manner.

• – Bei einer zu starken Folienerwärmung könnte sich zu viel bildgebende Schicht von der Transferfolie 5 ablösen.
• – Bei einer zu schwachen Folienerwärmung könnte sich zu wenig bzw. insbesondere an feinen Bildmusterstellen auch gar keine bildgebende Schicht von der Transferfolie 5 ablösen.
• – Die Folienerwärmung kann auch in Bezug auf das Drucksujet partiell zu stark oder zu schwach sein.
• – Die Folienerwärmung muß an die Festigkeitsparameter der Trägerfolie angepasst sein.

The following cases are conceivable:

• - Too much film warming could lead to too much imaging layer of the transfer film 5 peel off.
• - If the film warming is too weak, too little or, in particular, fine image pattern spots or even no image-forming layer of the transfer film could occur 5 peel off.
• - The film heating may also be partially too strong or too weak with respect to the printed subject.
• - The film heating must be adapted to the strength parameters of the carrier film.

This Measurement results can be automatically used to readjust the film heating temperature, when in control of the coating module in a control loop be involved.

1.

commissioned

Second

coating module

Third

press roll

4th

Impression cylinder

5th

Transfer film / sheet

6th

transfer nip

7th

roller drive

8th.

Film supply roll

9th

Foil composite role

10th

Press covering

11th

Inking / dampening unit

12th

plate cylinder

13th

Printing blanket / blanket cylinder

14th

Folienleiteinrichtung

15th

Printing plant security

16th

dryer

17th

Inspection device / monitoring system

18th

dancer roll

19th

guide rollers

20th

guide roll

Claims (16)

Device for transfer of image-forming layers from a carrier foil to printed sheets at least with an applicator ( 1 ) for an imagewise coating of a printed sheet with an adhesive and with a coating module ( 2 ) for transferring the imaging layers from the carrier film to the printing sheet, wherein the coating module ( 2 ) an impression cylinder ( 4 ) and a press roll ( 3 ), which has a common transfer gap ( 6 ), and further wherein the transfer film through the transfer nip ( 6 ) is feasible, such that it with the coated side on the on the impression cylinder ( 4 ) guided printed sheet and under pressure together with the sheet through the transfer nip ( 6 ) between press roll ( 3 ) and impression cylinder ( 4 ) and wherein the image-forming layers after the exit of the printing sheet from the transfer nip ( 6 ) is adhered to the printing sheet in the region of the adhesive image areas and is lifted off the carrier film, characterized in that a thermal device for heat-influencing the transfer film ( 5 ) while guiding to the transfer nip ( 6 ) or within the transfer gap ( 6 ) is provided. Device according to claim 1, characterized in that that the device for heat influence entire area is arranged acting or zonal acting. Apparatus according to claim 1 or 2, characterized in that the device for heat influencing from one or more heat radiators ( 21 ) is formed. Apparatus according to claim 1 or 2, characterized in that the device for heat influencing from one or more heatable rollers ( 19 . 20 ) is formed. Apparatus according to claim 4, characterized in that the rollers ( 19 . 20 ) are zonal heated. Device according to Claim 1 or 2, characterized that the device for heat influence a heat supporting pneumatic device is. Apparatus according to claim 1 to 6, characterized in that the device for heat influencing part of a film web guide or Folienleiteinrichtung ( 14 ). Apparatus according to claim 1 or 2, characterized in that the means for heat influencing a heat transfer pad or a heat-conducting coating of the transfer film ( 5 ) conductive elements (press roll ( 3 ), Impression cylinder ( 4 ), Film guiding device ( 14 ), Rolls ( 19 . 20 )). Apparatus according to claim 7 or 8, characterized in that a film guiding device ( 14 ) as a module in the manner of a slide-in cassette in the coating module ( 2 ) is detachably insertable and that the film guiding device ( 14 ) heated blowing air is zuleitbar. Apparatus according to claim 9, characterized in that the guide device has a guide channel for guiding the film web ( 5 ) and that blowing air can be conducted into the guide channel by means of a blowing device, so that the blowing air is able to convey the film web ( 5 ). Apparatus according to claim 10, characterized in that blowing air can be conducted into the guide channel by means of a blowing device, so that the blowing air is able to convey the film web ( 5 ) and coated against one on the surface of the impression cylinder ( 4 ) guided printing material can be directed. Apparatus according to claim 1 to 11, characterized in that the transfer film ( 5 ) is divided into one or more sub-foil webs of lesser width and that by means of the foil guiding device, the sub-foil webs next to each other the transfer gap ( 6 ). Process for the imagewise coating of a printing sheet with an imaging layer from a transfer film by feeding a film web ( 5 ) to a coating module ( 2 ) using a device according to one of the preceding claims, characterized in that a film web ( 5 ) from a supply roll ( 8th ) is removed, that the film web ( 5 ) is fed to a film guide device that the film web ( 5 ) is completely or partially heated by means of a thermal device, that the film web ( 5 ) in the heated state one of a press roll ( 3 ) and an impression cylinder ( 4 ) of a coating module ( 2 ) formed transfer gap ( 6 ) is supplied, that an imaging layer with detachment from the transfer film ( 5 ) in the transfer gap ( 6 ) is transferred in the region of an imagewise applied adhesive to a printing sheet, and that the film web ( 5 ) after leaving the transfer gap ( 6 ) by means of further guidance means from the coating module ( 2 ) and a take-up roll ( 9 ) is supplied. Process according to Claim 13, characterized in that the temperature of the transfer film ( 5 ) is controllable. A method according to claim 13 or 14, characterized in that the achievable by the heating temperature of the transfer film ( 5 ) zonal across the width of the film web ( 5 ) is controllable. A method according to claim 13 to 15, characterized in that - the quality of the coating on the printed sheet by means of an inspection device ( 17 ) is metrologically detectable and - that the attainable by the heating temperature of the transfer film ( 5 ) is controllable in dependence on the measurement result, - that on detection of defects in the imaging layer on the sheet, the temperature is increased and - that upon detection of the decrease to large elements in the imaging layer on the sheet, the temperature is lowered.