DE102008000743A1 - Film guide in a cold foil unit - Google Patents

Abstract

In an aggregate for the cold foil transfer to a printing machine, the improvement of the guidance of a film web (5) is provided. In this case, in the region of a feed of the film web (5) or the discharge of the coating module (2) a stabilizing device (30) is attached. This consists of rotating guide rollers (30, 31) and may be rotationally or obliquely adjustable. One of the guide rollers (30, 31) may be provided as a spreader roller.

Description

The The invention relates to film guide imaging during transfer Layers of a carrier film on printed sheet after Preamble of 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, between two units printing units and a coating unit are arranged. 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 unit 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 passed through the transfer nip of the coating unit between the impression cylinder and the press roll from a film supply roll. The foil strip is rewound on the outlet side after leaving the coating unit. 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 led the coating unit, wherein by means of the press roller the resting on the impression cylinder sheet with the sheet material is associated. It goes down metallic layer a close connection with the adhesive provided Areas on the sheet. After further transport of the printing sheet, the metallic layer adheres only in the area the pattern provided with adhesive. 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 units, for example in printing units of printing presses. A disadvantage of the known devices is that they are not flexible and that the feeder the transfer film is difficult to handle.

In Relation to the loads of the film webs, depending on from the web or machine speed, the Aufwickelgüte adjust the roll of film and changes in web tension, the film web tends to irregular movements when draining the film roll. Especially as a result of variables of the application nozzle and a so-called channel excitation tends the film web to more or less strong vibrations, so that the film web in the free area a beating Movement begins to perform transverse to the conveying direction.

Known Although systems with so-called dancer rollers have a dampening effect but on the web tension can in vibration resonance advised film web, d. H. their striking transverse movement, not always calm enough.

The Hitting or flapping the film web has the consequence that it in the application process to quality loss due to wrinkling in the Film web and beyond to errors in the film application can come.

task The invention is therefore to provide a device by means of derer the transmission of an imaging layer to a Sheet can be done economically and safely, the device should be easy to handle.

The Solution of this problem results in a device according to the features of claim 1.

In Advantageously, to guide the transfer film a feeder used in which the transfer film while feeding to the transfer nip and the discharge after the transfer gap is monitored by sensors.

A associated device for supply and discharge the transfer film advantageously has a guide in the manner of guide rolls, by means of which the supply to the transfer nip and the derivation after the transfer gap allows in a simple manner become.

To the Stabilizing the film web is between a first deflection roller or the unwinding roll and a first inlet roll or guide for the film web to the transfer nip a stabilizer arranged. This will be an effective reduction of the beating Movement of the film web reached. This happens in a very simple way and way, since the stabilizer on the outside of the printing unit functioning as a coating unit can be.

The Stabilization device has z. B. two rotatably mounted rollers (Guide rollers), which is an S-shaped deflection for form the film web and in its suspension eccentric are arranged adjustable.

At least one of the two guide rolls can be designed here as a spreader roll become. Thus, the film web is in its plane transverse to the direction stretched and kept smooth, which in turn reduces a contributes to the process damaging wrinkling.

to Influencing or regulating the position of the film web in the width direction or transversely to the direction of an inclination of the Guide rollers, for example, via a bearing on eccentric be provided adjustable bearing elements, so that a guide roller pair is formed.

After all can in conjunction with the storage of Leitwalzenpaares the arrangement a pivot bearing for changeable adjustment of the wrap angle the film web may be provided on the guide rollers. In this way are the guiding action and the damping effect of the guide rollers sensitively adjustable to the film web depending on the operating condition.

Also for web break monitoring for the film web can the guide rollers on sensory equipped recording elements be mounted so that the pivotal position or axle load of the Guide rollers is detectable.

A Surface coating of the guide rolls contributes to safe avoidance of film deposits on their surface and reduces the risk of retransmission of these deposits in unwanted areas of the same or another track. Furthermore, the surface coating avoids also damage to the transfer layer on the film web, which could make them useless.

All above adjusting elements on the described guide rollers or their suspensions can optionally over electrical, pneumatic, hydraulic actuators arranged controllable become.

The Stabilization device described is also in the same way can be used on the foil outlet side. This can be a reduction from acting out of the drain area in the application gap Folds in the coating module achieved and the coating quality increase.

A Web break detection of the film web can by means of an ultrasonic sensor by direct scanning of the film web in a freely guided Section to be executed.

The Web break detection can also be done with capacitive sensors by direct Scanning against elements made by the film web touching. These can be rotating Be guide rolls or stationary fins.

The Web break monitoring can still be independent from the guide rollers also indirectly via a web tension measuring device performed by measuring radially directed bearing forces a measuring roller, which is wrapped around the web or coating film is, the presence of the film web is detected bar. about a measuring amplifier, the electrical signals are evaluated. In the course of operation, the web tension forces deviate from given values by falling below a minimum value or exceeding a maximum value this evaluated as a crack or overload of the film and fed to the machine control. Possible installation locations for the measuring device are at the retractor or on the unwinding device of the film web, in the region of film guide rollers or at dancer rolls.

The Device can be used in an advantageous manner when a Improvement of the film utilization is to be achieved by that the transfer film in one or more Teilfolienbahnen lesser Width is divided. In combination with the aforementioned method So also different types of foil next to each other be used.

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

there demonstrate:

1 : An overview of a printing press with a film transfer device and

2 and 3 : The structure of inventive devices for film control.

In 1 a sheet-processing machine is shown, which consists of at least two printing units. The two printing units are used for the following purposes:
A printing sheet is provided in the first printing unit with an imaging adhesive pattern (Auftragwerk 1 ).

Thereafter, in the next printing unit, together with a printing sheet, a transfer film 5 through a transfer gap 6 guided, with the transfer film 5 in the transfer gap 6 pressed against the sheet is (coating plant 2 ).

The commissioned work 1 can be a well-known offset printing unit with an inking unit 11 a plate cylinder 12 , a blanket cylinder 13 and a sheet leading impression cylinder 4 be. Likewise, this may be a so-called paint module in which the blanket cylinder 13 is designed as a form cylinder. The form cylinder is filled with paint or glue from a z. B. trained as a chamber doctor blade device instead of the inking unit 11 provided.

The transfer gap 6 in the coating plant 2 is through a press roll 3 and an impression cylinder 4 educated. Here, the press roller 3 the blanket cylinder and the impression cylinder 4 correspond to the impression cylinder of an offset printing unit. Furthermore, the press roll 3 the form cylinder and the impression cylinder 4 correspond to the impression cylinder of a paint module of a sheet-fed press.

The transfer foils 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 the lifting of the imaging layer from the carrier layer. The imaging layer may, for. Example, a metallized layer or a glossy layer or a textured layer or a colored layer or a pattern containing one or more image patterns.

The foil supply roll 8th is the coating plant 2 assigned on the side of the sheet feeder. The foil supply roll 8th has a rotary drive 7 on. The rotary drive 7 is used for continuous controlled feeding of the transfer film to the coating unit 2 needed and is therefore controllable. Furthermore, a deflecting or tensioning roller is provided in the region of the film feed. Thus, the film web of the transfer film is always in the same voltage relative to the press roller 3 held. 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 kept taut on the inlet side by means of a brake.

The transfer process of the imaging z. B. metallized layer on the printing paper takes place in the transfer nip 6 between the press roll 3 and the impression cylinder 4 ,

Likewise, a press roll 3 ' , as in 1 indicated in the order work 1 the transfer nip between blanket cylinder 13 and impression cylinder 4 downstream and the impression cylinder 4 be assigned. By means of the press roll 3 ' can a transfer film 5 ' on one on the printing cylinder 4 held sheet so that the imaging or metallization layer can be done there directly downstream of the imaging adhesive application.

The press roll 3 is with a press cover 10 z. B. as a plastic coating, comparable to a blanket or blanket, be provided. The press fabric 10 is held in a cylinder channel on jigs.

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 done so that during the passage of a gripper of the sheet leading impression cylinder 4 receiving cylinder channel of the film feed is stopped.

An improved film utilization results from the fact that the transfer film 5 is divided into one or more Teilfolienbahnen lesser width.

Within the coating plant used for the film transfer 2 is a web guide for transfer films 5 represented, film guide rollers 14 by means of which the transfer film 5 the transfer gap 6 is fed and removed from this. In this case, according to the film guide arranged openings in at the coating plant 2 existing protections 15 provided. These openings are designed so that the film webs 5 easily accessible and dissipatable and at the same time the protective function is fully retained.

• a. Die Transferfolie 5 wird von der dem Auftragwerk 1 zugewandten Seite des Beschichtungswerkes 2 zum Transferspalt 6 geführt, etwa tangential zur Presswalze 3 durch den Transferspalt 6 und auf der gegenüber liegenden Seite abgeführt.
• b. Die Transferfolie 5 (strichliiert) wird von der dem Auftragwerk 1 abgewandten Seite des Beschichtungswerkes 2 zur Presswalze 3, um die Presswalze 3 herum durch den Transferspalt 6 und auf der gleichen Seite wieder abgeführt.
• c. Die Transferfolie 5' (strichliiert) wird im Auftragwerk 1 auf der der Bogenzufuhr abgewandten Seite des Druckwerkes einem Transferspalt 6' zwischen der Presswalze 3' und dem Druckzylinder 4 zugeführt und von dort wieder abgeführt, wobei der Transferspalt 6' einem dem Farb- bzw. Kleberdruck dienenden Druckspalt zwischen dem Drucktuchzylinder 13 und dem Druckzylinder 4 nachgeordnet ist.

In 1 three variants of the web guide are shown:

• a. The transfer foil 5 is from the the commission 1 facing side of the coating plant 2 to the transfer gap 6 guided, approximately tangential to the press roller 3 through the transfer gap 6 and dissipated on the opposite side.
• b. The transfer foil 5 (dashed) is from the the commission 1 opposite side of the coating plant 2 to the press roll 3 to the press roller 3 around through the transfer gap 6 and dissipated again on the same side.
• c. The transfer foil 5 ' (dashed) becomes in the order work 1 on the side facing away from the sheet supply of the printing unit a transfer nip 6 ' between the press roll 3 ' and the impression cylinder 4 supplied and discharged from there again, the transfer gap 6 ' a printing gap between the blanket cylinder serving for color or adhesive printing 13 and the impression cylinder 4 is subordinate.

In 1 is a main variant of an approximately tangential film guide between the press roll 3 and the impression cylinder 4 in relation to the press roll 3 or the wrap of the press roll 3 provided by less than 90 degrees. This should be a defined investment of the film web 5 on the press roller 3 achieves and at the same time the necessary conditions for a film timing or a film discontinuity in the transfer gap 6 during a channel pass, but also for the use of narrow film webs 5 be created.

In an embodiment according to the invention according to the 2 and 3 and therefore can transport the transfer film 5 on or between film guide rollers 14 by means of the metrological control of the web tension of the film web 5 be monitored.

In a film web guide to one or more web tension measuring device 23 . 25 provided, the force measuring devices has. The principle is based on the measurement of radially directed bearing forces of a guide roll substantially in the direction of the bisecting line to the take-off directions of the sheeting wrapped around the film web 5 , In this case, the film tear or web break detection can take place with a significant drop in the measured force below a defined threshold value.

A web tension measuring device 23 can according to 2 on a film deflecting roller 14 the web guide of the film web 5 be arranged. In this case, the reaction force of the film web 5 on the storage of Folienumlenkwalze 14 preferably at an angle of 45 degrees, ie substantially in the direction of the bisector on the inside to the right-angled deflection of the film web 5 determined.

A web tension measuring device 25 can according to 3 also on a separate measuring roller 24 in conjunction with the web guide of the film web 5 be arranged. In this case, the reaction force of the film web 5 on the storage of the measuring roller 24 preferably at an angle according to the bisector on the inside of the deflecting web guide of the film web 5 determined. This complicates the storage of Folienumlenk- or guide rollers 14 avoided.

To stabilize the film web 5 will, as in 1 shown, between a first pulley 20 and a first entry roller 14 a stabilizer 30 arranged. The stabilizer 30 is preferably approximately in the middle of the distance between the adjacent film guide elements (here deflection roller 20 and inlet roller 14 ) arranged. This is the area between the structure of the Folienrollollung on the coating plant 2 and the film feed to the transfer nip 6 in the coating plant 2 to be bridged.

With this arrangement, an efficient reduction of the beating movement or flutter movement of the film web 5 reached.

The stabilizer 30 has z. B. two rotatably mounted rollers 31 . 32 (Guide rollers), as a guide roller pair on a pivotable and possibly eccentrically adjustable with respect to their axis alignment storage device 33 are arranged.

At least one of the two guide rollers 31 . 32 can be executed here as a spreader roll. This is the film web 5 stretched in their plane transverse to the direction of rotation and kept smooth, which in turn contributes to reducing harmful to the process of wrinkling.

For regulating or adjusting the position of the film web 5 in the width direction, an inclination of the guide rollers 31 . 32 for example, about the said storage on eccentrically adjustable storage facilities 33 be provided.

Finally, the arrangement of a pivot bearing 34 for changeable adjustment of the wrap angle of the film web 5 at the guide rollers 31 . 32 be provided so that the guiding action and the damping effect of the guide rollers 31 . 32 on the film web 5 is adjustable depending on the operating state. The donation turns the wrap around the film web 5 at the guide rollers 31 . 32 and thus their areal edition increased or decreased.

The adjustment and operation of the stabilizer 30 can be used in conjunction with a web tension control and if necessary with a device for web break monitoring (for both see Sensor 25 ).

• 1. Ein Bahnzug (Bahnspannung) oberhalb eines vorgebbaren Minimalwerts wird als Signal für das Vorhandensein der Folienbahn 5 gewertet und dieses wird der Maschinensteuerung zugeführt.
• 2. Ein Überschreiten des Maximalwerts des vorgebbaren Bahnzugs (Bahnspannung) wird über Tänzerwalzen 18 oder die Rollenantriebe 7 der Folienvorratrolle 8 bzw. Foliensammelrolle 9 reduziert. Damit kann eine unzulässige Dehnung oder ein Riss der Folienbahn 5 vermieden werden.
• 3. Ein Unterschreiten des Minimalwerts des vorgebbaren Bahnzugs (Bahnspannung) wird überprüft, indem abgefragt wird, ob die Bahnspannungsregelung noch aktiv ist. Ebenso kann über Tänzerwalzen 18 oder eine Bremse die Bahnspannung wieder erhöht werden. Ist dies nicht möglich wird ein Bahnriss erkannt.

Electrical signals of the web tension measuring devices 23 . 25 are evaluated. Various operating states are possible for this:

• 1. A web tension (web tension) above a predeterminable minimum value is used as a signal for the presence of the film web 5 evaluated and this is fed to the machine control.
• 2. Exceeding the maximum value of the before Changeable web tension (web tension) is about dancer rolls 18 or the roller drives 7 the film supply roll 8th or film collecting roll 9 reduced. This can be an impermissible strain or a crack of the film web 5 be avoided.
• 3. A drop below the minimum value of the predeterminable web tension (web tension) is checked by asking whether the web tension control is still active. Likewise can over dancer rolls 18 or a brake, the web tension can be increased again. If this is not possible, a web break will be detected.

The additionally obtained information about the web tension as the actual value, in particular in the context of the aforementioned evaluations, can be used for the control of the printing or transfer process. For this purpose, the system can be coupled to a control station of the printing press. The setpoints for maximum and minimum web tension (web tension) can be entered via the control station. These values may vary depending on the type of transfer film used 5 and the pressure or transfer conditions in the coating module 2 be dependent on the properties of the printing material, the adhesive or the press cover.

The necessary data can be read via interfaces directly from data carriers to film supply rolls and by means of parameter values from the setting of the transfer process at the coating module 2 to be changed.

1

commissioned

2

coating plant

3

Press roller ( 3 ' )

4

Impression cylinder

5

Transfer foil / foil web ( 5 ' )

6

Transfer gap ( 6 ' )

7

roller drive

8th

Film supply roll

9

Foil composite role

10

Press covering

11

inking

12

plate cylinder

13

rubber cylinder

14

Folienumlenk - / - guide roll

15

Printing plant security

16

dryer

17

inspection device

18

dancer roll

19

scanning beam

20

capacitive sensor

21

ultrasonic sensor

22

scanning beam

23

Web tension measuring device

24

measuring roll

25

Web tension measuring device

30

stabilizing device

31

guide roll

32

guide roll

33

storage facility

34

pivot bearing

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - EP 0569520 B1 [0002]

Claims (15)

Device for transferring image-forming layers from a transfer film ( 5 . 5 ' ) coated with an image-wise coating with an adhesive sheet with a coating unit ( 2 ), which has a common transfer gap ( 6 . 6 ' ) forming impression cylinder ( 4 ) and a press roll ( 3 ), wherein the transfer film ( 5 ) from a film supply roll ( 8th ) around the press roll ( 3 . 3 ' ) or approximately tangentially to the press roller ( 3 . 3 ' ) is feasible, such that it with the coated side on the on the impression cylinder ( 4 ) guided print sheet lying on and under pressure for transferring the coating together with the sheet through the transfer nip ( 6 . 6 ' ), and wherein the thus-used transfer film ( 5 ) after exiting the transfer gap ( 6 ) is fed to a film collecting device, characterized in that guide devices ( 30 ; 31 . 32 ) for guiding the transfer film ( 5 . 5 ' ) from the film supply roll ( 8th ) to the transfer gap ( 6 . 6 ' ) of the web of the transfer film ( 5 . 5 ' ) are assigned to prevent lateral movements, and that the guide devices ( 30 . 31 . 32 ) and / or regulation of the web tension of the web of the transfer film ( 5 . 5 ' ) are assigned adjustable. Apparatus according to claim 1, characterized in that guide devices ( 30 ; 31 . 32 ) for guiding the transfer film ( 5 . 5 ' ) from the film supply roll ( 8th ) to the transfer gap ( 6 . 6 ' ) of the web of the transfer film ( 5 . 5 ' ) for regulating the web tension of the web of the transfer film ( 5 . 5 ' ) are assigned adjustable. Device according to Claim 1 or 2, characterized in that the guide devices ( 30 ; 31 . 32 ) under the action of force on the freely stretched film web ( 5 . 5 ' ) are arranged so that they are substantially on the area of the film web ( 5 . 5 ' ) act on which the largest transverse movements of the film web ( 5 . 5 ' ) occur. Apparatus according to claim 1 to 3, characterized in that as Folienleiteinrichtung a stabilization device ( 30 ) in conjunction with one or more rotating Folienumlenk- or guide rollers ( 31 . 32 ) for guiding the film web ( 5 . 5 ' ) under the action of force on the freely stretched film web ( 5 . 5 ' ) is provided. Apparatus according to claim 2 to 4, characterized in that the stabilization device ( 30 ) in conjunction with rotating Folienumlenk- or guide rollers ( 14 ) for guiding the film web ( 5 . 5 ' ) from the film supply roll ( 8th ) to the transfer gap ( 6 ) and / or from the transfer gap ( 6 ) to the film collecting roll ( 9 ) is provided. Apparatus according to claim 4 or 5, characterized in that the rotating Folienumlenk- or guide rollers ( 31 . 32 ) individually, in pairs or several times to guide the film web ( 5 . 5 ' ) are provided, so that the film web ( 5 . 5 ' ) is deflected by force transversely to its plane and conveying direction. Apparatus according to claim 6, characterized in that at least one of the rotating Folienumlenk- or guide rollers ( 31 . 32 ) as a spreader roll for smooth guidance of the film web ( 5 . 5 ' ) is provided. Apparatus according to claim 7, characterized in that the rotating Folienumlenk- or guide rollers ( 31 . 32 ) in pairs or more on each end common bearing elements ( 34 ) are arranged and that this in the leadership of the film web ( 5 . 5 ' ) for increasing or decreasing the looping at the Folienumlenk- or guide rollers ( 31 . 32 ) about an axis parallel to the axes of the Folienumlenk- or guide rollers ( 31 . 32 ) are pivotally provided. Apparatus according to claim 3 to 8, characterized in that the rotating Folienumlenk- or guide rollers ( 31 . 32 ) in pairs or several times on each one end common bearing element ( 33 ) are arranged and that they are used to control the web guiding direction in the guidance of the film web ( 5 . 5 ' ) are provided pivotable relative to an axis parallel to the roll axes tilted. Apparatus according to claim 1 to 9, characterized in that one or more guide devices in the region of a contacting guide of the film web ( 5 . 5 ' ) at least one sensor ( 23 . 25 ) for detecting the presence or absence of a film web ( 5 . 5 ' ) or a reaction force from the deflection of the film web ( 5 . 5 ' ) is assigned to the / the Folienleiteinrichtung / s. Apparatus according to claim 10, characterized in that one or more Folienumlenk- or guide rollers ( 14 . 24 . 31 . 32 ) a web tension measuring device ( 23 . 25 ) for detecting the reaction force from the deflection of the film web ( 5 . 5 ' ) around the film deflecting roller or guide roller ( 14 . 24 . 31 . 32 ) assigned. Device according to one or more of the preceding claims, characterized in that at least the surfaces of the transfer layer of the film web ( 5 . 5 ' ) touching Folienumlenk- or guide rollers ( 14 . 20 . 24 . 31 . 32 ) are provided with a coating, wherein the coating of an adhesion of foil material or a damage of the transfer layer of the films train ( 5 . 5 ' ) counteracts. Device according to one or more of the preceding claims, characterized in that the transfer film ( 5 . 5 ' ) is divided into a format film web or a plurality of sub-film webs of smaller width, wherein the sub-film webs the transfer gap ( 6 ) can be fed parallel to one another, and that the format film web or each part film web or a plurality of part film webs share sensors ( 20 . 21 . 23 . 25 ) for detecting the presence of a film web ( 5 . 5 ' ) be assigned. Device according to one or more of the preceding claims, characterized in that that of the sensors ( 20 . 21 . 23 . 25 ) for detecting the presence of a film web ( 5 . 5 ' ) generated signals of a machine control of the printing press and / or a control of the coating module ( 2 ) can be fed, wherein by means of the machine control on the basis of the detected signals, a shutdown of the machine or an influence on the web tension of the film web ( 5 . 5 ' ) he follows. Apparatus according to claim 14, characterized in that the of the sensors ( 20 . 21 . 23 . 25 ) for detecting the presence of a film web ( 5 . 5 ' ) signals generated as a format film web or partial film web of a device for adjusting the stabilization device ( 30 ) and / or for controlling the roller drives ( 7 ) and / or the setting of the dancer rollers ( 18 ) and / or braking devices in conjunction with a film supply roll ( 8th ) and / or a film collecting device of the film web ( 5 . 5 ' ) he follows.