EP1839861B2 - Film transfer installation with a further integrated processing device - Google Patents

Abstract

The device has a foil module with a reserve mandrel for accommodating transfer foil reserve roller. The collection device has collecting shaft (11) for accommodating transfer foil collection roll and for uncoiling a transfer foil web (16,17).The reserve shaft and collecting shaft is formed as friction shaft (13), so that the transfer of the rotation motion of the friction shaft takes place over the transfer foil collection roll (20,21). An independent claim is also included for a method for transferring a transfer layer of a carrier foil.

Description

The present invention relates to a device for transferring a transfer layer from a carrier film, which together form a transfer film, onto a printing material, comprising at least one film module with a supply shaft, for receiving at least one transfer film supply roll for storing and unwinding at least one transfer film web.
The device is intended to have a transfer film guide device at least for guiding the transfer film web from the supply shaft to a transfer nip along a film transport path, the transfer nip being formed by an impression cylinder and a film transfer cylinder for transferring the transfer layer to the printing substrate. For this purpose, the printing material is passed along a printing material transport path through the transfer nip. Furthermore, the device comprises a collecting device for receiving the guided through the transfer gap at least one transfer film web.

The invention further relates to a method for transferring a transfer layer from a carrier film, which together form a transfer film, to a printing material in which the transfer film is provided as at least one transfer film web on at least one transfer film supply roll on a supply shaft which supplies at least one transfer film web along a film transport path guided a transfer gap, the transfer layer is transferred from the transfer film within the transfer gap on a substrate and the transfer film web is then fed to a collection device.

Preferably, the invention relates to a device which is suitable for the so-called cold foil stamping.

In cold foil stamping, a transfer layer is transferred from a substrate to a substrate.

The carrier material used is a carrier film. On this carrier film, a lacquer layer is applied, which is responsible in particular for the coloring of the transfer layer. Connected to the lacquer layer is an aluminum layer, which causes the metallic luster of the transfer layer. Furthermore, a further adhesive layer can be provided on the aluminum layer, which improves the adhesive properties of the transfer layer with the adhesive on the printing substrate. The layers which are transferred from the carrier material is referred to as a transfer layer.

In order to transfer the transfer layer to a printing substrate, the transfer film is passed through a transfer nip together with the printing substrate. The transfer nip is formed by a transfer cylinder and an impression cylinder, which abut each other. Transfer cylinder and impression cylinder are rotated together with a force to each other, that in the transfer nip, the transfer layer is transferred to the substrate.

In order for a transfer of the transfer layer to the substrate area by area, the substrate is provided with an adhesive layer before the film transfer which corresponds to the area in which the film is transferred.

The adhesive used may be a colorless adhesive, an adhesive with a certain intrinsic color, or a glue colored according to the film. Already from the Bronzierungstechnik it is already known to transfer metal particles to use a particularly sticky color whose color corresponds to the desired metallization. In this respect, of course, a sticky color can also be used as an alternative to a colored adhesive.

The transfer layer can essentially be a metal layer but also other layers. For example, may be provided an aluminum layer, which is applied as needed on a yellow / golden lacquer layer or a silver-colored lacquer layer.

Furthermore, as the transfer layer, a colorless layer e.g. be used from PE film, which is transferred to the substrate so that it forms a protective layer there.

The use of a conductive layer as a transfer layer is possible, thereby electrically and / or thermally conductive area can be transferred to the substrate. The transfer of prepared delimited layer regions as a transfer layer is also possible, which may be, for example, RFID chips or their antennas. It is also possible to transfer suitable ceramics. In this way, it is conceivable that superconducting structures can be transferred to a printing substrate.

An apparatus for transferring a transfer layer on a substrate with a collection device and a transfer supply roll is from the document EP 987 106 known.

A device for cold foil stamping is in the EP 0 578 706 B1 presented.

Here, the cold foil stamping takes place within a multi-color printing machine. The printing material is transported along a predetermined transport path in the printing press. The printing material may be, for example, paper sheets, paperboard or even rolls.

In a first printing unit of the printing press, an adhesive is transferred to the substrate instead of a paint. For application of the adhesive in regions a correspondingly imaged printing plate is clamped in this printing unit and the adhesive is transferred onto the printing substrate like a conventional offset printing ink. Such an adhesive-applying printing unit is referred to as a commissioned work.

The printing material is then transported further into a second printing unit. In this second printing unit, the impression cylinder and the blanket cylinder are designed as a transfer unit.

In the area of this second printing unit there is a film module with a transfer film supply shaft and a transfer film collecting shaft. Via intermediate rollers of a film guiding device, the film is guided as a transfer film web from the transfer film supply shaft to the transfer nip and on to the transfer film collecting shaft.

To transfer the transfer layer to the printing substrate, the transfer film web and the printing material with the area-wise adhesive layer are passed together through the transfer nip so that the transfer layer rests on the adhesive layer. The transfer layer is then transferred onto the substrate by printing in the transfer nip. The adhesive removes the transfer layer cleanly from the transfer film.

For a clean transfer of the transfer layer to the printing substrate, the film and the printing material in the region of the transfer nip are driven at the same speed during the transfer.

In a subsequent press shop, the transferred transfer layer is then essentially acted upon, so that a durability of the film support is achieved.

In the EP 0 578 706 B1 is further described that also several narrow Teilfolienbahnen can be used. These can then be supplied to different transfer areas of a printing material in a transfer nip.

If the individual partial film webs are each stored on different supply shafts as transfer film rolls, then a considerable effort is necessary to use a plurality of partial film webs within a device.

If the partial film webs are stored as a plurality of partial film rolls on a common supply shaft, it can lead to various problems. On the one hand, no different speeds of the partial film webs are possible; on the other hand, it is particularly problematical if partial film rolls of different diameters are used. Since the supply shaft rotates at a certain speed, due to the different radii of the rollers, the web speeds, i. E. the different peripheral speeds of the rollers. To compensate for this so that the speed of the film web and the printing material is the same again in the transfer nip, is very expensive. Also, a reduced or increased web tension of the transfer film webs can result depending on the current radius and rotational speed of the supply shaft.

The object of the present invention is therefore to at least reduce the stated problems of the prior art so that a plurality of partial film webs can be used in a simple manner in a device for the transfer of a transfer layer to a sheet.

The object is achieved by a device of the abovementioned type according to claim 1 and by a method according to claim 17.

It is provided that a collecting shaft is used as collecting device for receiving at least one transfer film collecting roll for winding up the at least one transfer film web.

According to the invention, the supply shaft and the collecting shaft are designed as friction shafts so that the rotational movement of the friction shaft is transmitted to the at least one transfer film supply roll and transfer film collecting roll via a frictional connection between the shaft and the roll, which can be overcome by tensile forces of the transfer film web.

In the following and also in the past, instead of the transfer film supply or transfer film collection roll, the term simply also generally refers to a film roll or transfer roll roll or simply a roll.

The friction connection between shaft and roller can be done in various ways. A roll consists of the transfer film web wound on a roll sleeve. This sleeve is pushed onto the shaft. In one possible embodiment, there is a frictional connection between the inside of the sleeve and the surface of the friction shaft. This, the connection underlying friction can be constant or controllable. Is applied to the sleeve, e.g. By virtue of a tension on the film web, a tensile force is exerted, there is a slip between the sleeve and the surface of the friction shaft, as a result of which the rotation of the sleeve relative to the shaft is reduced or accelerated.

A second possibility of friction connection between shaft and roller is that the sleeve is first firmly connected to an outer ring of the shaft. This outer ring is then itself connected via a frictional connection with an inner ring of the shaft and can thus produce a friction connection between the shaft and roller. Slippage between roller and shaft can then be achieved analogously to what has been described.

As a friction connections are both direct, as well as indirect friction connections between the roller and sleeve, so also understand connections via intermediate elements.

It is then procedurally provided that at least one transfer ribbon supply roll and one transfer ribbon collection roll are provided on a transfer sheet supply and transfer roll collection roll.

If the diameter of the transfer film roll changes, the circumferential speed of the transfer film web on this roll changes as the rotational speed of the shaft is maintained. As the diameter decreases, the peripheral speed decreases. By a train on the film web then the peripheral speed can be increased again by a slip between the shaft and roller comes. This can occur in particular in the area of the transfer ribbon supply shaft.

In the area of the collecting shaft, the diameter of the roller and thus the peripheral speed can also increase. Here, by a tensile force on the film web, the peripheral speed can be reduced if the frictional force between the roller and shaft is overcome by the tensile force.

The described device makes it possible for a plurality of transfer film rolls to be provided in a simple manner on a shaft, be it the supply shaft or the collecting shaft. These rollers can have different diameters. Due to the slip that occurs between the roller and the shaft when the frictional force is overcome, the same peripheral speeds can be achieved for the rollers on the shaft regardless of their respective diameters.

To exert the necessary tensile force on the transfer film web to overcome the frictional force and thus an acceleration, i. E. To achieve an increase or decrease of the peripheral speed of the respective transfer film web on the roll, advantageously at least one preferred device for drawing the at least one transfer film web in the direction of the transfer gap is provided. A roller on the collecting roller can thus be selectively braked, a roller on the supply shaft can be specifically accelerated. This preferred means may e.g. Apply a tensile force to the transfer film via tapes. In particular, for this purpose, a band may be provided on the carrier film side of the transfer film. This tape can create contact with the film by suction.

According to the invention, it is expediently provided that the preferred device is a preferred roller pair, which exerts a tensile force on the at least one transfer film web by friction, so that a train is exerted in the direction of the transfer nip on the at least one transfer film roll. Such a preferred pair of rollers is relatively simple and allows a secure control of the Vorzugskraft. In particular, a drive of the rollers is possible, which is possible with the drive of the roller pair, which forms the transfer nip. It may in particular be the same drive.

In alternative or complementary respectively advantageous embodiments, it is provided that the preferred device is either arranged behind the transfer nip and exerts a tensile force on the at least one transfer film supply roll on the supply shaft in the direction of the transfer nip, and / or that the preferred device before the transfer nip is arranged and exerts a tensile force on the at least one transfer film collecting roll on the collecting shaft in the direction of the transfer nip and / or alternatively or additionally, it may also be provided that the preferred means comprises the impression cylinder and the film transfer cylinder, which form the transfer nip.

There are thus each safe advantages of the film web in the direction of the transfer nip possible. In particular, for those cases where the roles forming the transfer nip are not preferred, e.g. for the time in which a cylinder gap of one of the two rollers in the region of the transfer nip is still a preference by a preference device possible.

In a particularly advantageous embodiment of the invention, it is provided that at least two transfer film rolls are provided on the supply shaft or both on the supply shaft, as well as on the collecting shaft, each store and unwind a transfer film web. By providing a plurality of transfer film webs on a plurality of transfer film rolls on the supply shaft and / or the collecting shaft, in connection with the provision according to the invention of a friction shaft as supply shaft and / or collecting shaft, a flexible multi-web of the device can be achieved.

In particular, it can further be provided that a plurality of transfer film rolls are provided solely on the supply shaft and this shaft has a friction shaft. The collecting shaft itself must be provided as a driven shaft to allow winding of the transfer film webs. In principle, the supply shaft can passively follow it without its own drive or can also be provided according to the invention as a drive shaft. In a passive embodiment of the supply shaft, this may preferably be braked. In a further embodiment, both the supply shaft and the collecting shaft can each accommodate a plurality of transfer film rolls.

The slip is possible on the supply roll and also on the collecting roll.

In a further advantageous embodiment of the device according to the invention at least one determining means for determining the roll diameter of the at least two transfer film rolls is provided. This allows precise control of the diameters or radii of the individual transfer film rolls on the respective shaft.

It is then possible and procedurally provided that the diameters D of the individual transfer _{film supply rolls} are determined on the _{supply roll} , the average feed rate V _{vm of} the transfer film is determined by the transfer _nip and
the supply shaft is driven at an angular velocity w so that the nominal peripheral speed V _UnV = W * D / 2 of the transfer _{film supply roll} having the largest diameter is less than the mean feed rate V _{vm of} the transfer film through the transfer _nip .

By ensuring a respectively lower speed of the driven Transfer film roll on the supply shaft as the passage through the transfer nip necessary speed, in particular in conjunction with the proposed preferred means always a web tension of the transfer film web reached.

In order to achieve a preferred web tension, it is conveniently provided that in a further development, the supply shaft is driven such that the nominal peripheral speed V _{Unv of} the transfer _{film supply roll is} less than 100% but equal to or more than 95% of the average feed speed V _vm .

In an alternative or additional embodiment, which is provided in particular when the collecting shaft is designed and driven as a friction shaft, it is provided that the diameters D of the individual transfer film collecting rollers on the collecting _shaft are determined, the mean feed rate V _{vm of} the transfer film through the transfer _nip is determined and the collecting shaft is driven at an angular velocity w so that the nominal peripheral speed V _UnS = w * D / 2 of the transfer _{film collecting role} with the largest diameter is greater than the average feed rate V _{vm of} the transfer film through the transfer _nip .

Particularly preferably, it is provided that the collecting shaft is driven such that the nominal peripheral speed V _{UnS of} the transfer _{ribbon collecting roll is} more than 100% but less than or equal to 105% of the average feed rate V _vm .

The advantages of this embodiment are analogous to those in the supply shaft. In addition, these two embodiments can complement each other.

As at least one determining means for determining the roll diameter is provided that each transfer film roll is associated with a non-contact sensor, which can detect the distance of the surface of the transfer film roll to the sensor or directly the radius of the transfer film roll.

As a result, an influence on the transfer film can be minimized.

In particular, it may be possible for the non-contact sensor to be an ultrasonic sensor or an optical sensor which detects light reflected from the surface.

Alternatively, a contacting sensor can also be assigned as determining means for each transfer ribbon roll. As a result, it is advantageously possible to make a determination of the roll diameters which is not particularly susceptible to interference. Alternatively, a direct determination of the peripheral speed of the transfer film web on the transfer film roll is possible.

In a further development, it is provided that the contacting sensor is an impeller which determines a diameter change of the transfer film supply roll from a measured discharge path.

Alternatively, it can also be provided that the contacting sensor is a resistance sensor, which determines the amount of transfer film present on the transfer film roll via a measured resistance. For this purpose, it may in particular also be provided that the film itself has at least one conductive region. This can either be a continuous conductor or each conductive areas, which lie one above the other when wound film and thus have a resistance in dependence on the layer thickness. Alternatively, it is also possible to use a capacitive sensor instead of the resistance sensor.

According to the method, it is further provided that the transfer film web is drawn from the supply shaft and / or collecting shaft in such a way that its actual feed rate V _v at least temporarily corresponds to the sheet speed V _B in the region of the transfer nip. For this purpose, a corresponding control device for controlling the preferred device in dependence on the sheet speed is provided. At least if a transfer of the transfer layer is provided in the transfer nip can then be provided an equal speed of substrate and transfer film. Only then is a precise and clean transfer of the transfer layer to the substrate possible.

In a particularly advantageous further development, it is procedurally provided that the transfer film web is clocked so that its actual feed rate V _v at times in which no film transfer to the substrate is different from the printing material speed and is accelerated before an intended film transfer so that the actual Feed rate again the printing material speed V _B corresponds. In this way, transfer film can be saved if no transfer of transfer layer is provided on the substrate. This is the case, for example, when no printing material is being guided through the transfer nip, or when no transfer layer is to be transferred to certain areas of the printing material.

To enable this timing device is provided according to a sheet timing in the region of the transfer nip.

In a preferred embodiment it is provided that the film timing comprises at least two coupled guide rollers for guiding the transfer film web, which are provided on opposite sides of the transfer nip, these coupled guide rollers are simultaneously movable in a first direction via a drive means, so that the speed of Transfer film is reduced by the transfer nip and are simultaneously movable in a second direction so that the speed of the transfer film in the transfer nip corresponds to the transport speed of the printing substrate. When we speak of a simultaneous movement, it is meant here a coupled motion such that the guide rollers are moved together. The first guide roller of the film timing is thereby looped around by the, to be transferred to the transfer gap transfer film, the second guide roller of the transfer film, the away from the transfer gap to Collecting device is transported. Depending on the direction of movement of the rollers, the path, ie the length of the film between the first guide roller and the transfer nip, is reduced and, at the same time, the path between the second guide roller and the transfer nip is increased or vice versa. In this way, an acceleration of the film in the transfer nip or a slowing down of the film can be achieved simply by simultaneously moving, in particular via a coupled movement.

By means of at least one transfer film buffer according to the invention in the region between the supply shaft and the transfer nip and / or between the transfer nip and the collecting device, an even better timing of the transfer film can be made possible. The unwinding of the transfer film web from the supply shaft, the winding onto the collecting shaft takes place at an average web speed. This web speed is dependent upon the speed of the substrate and the amount of transfer layer required for a total print job, i. more exactly dependent on the length of the required transfer layer. The transfer film is always unwound at the same speed and stored in the transfer film buffer. Depending on whether a transfer of the transfer layer is provided on the sheet, then film is removed at the speed of the printing material from the memory and passed through the transfer nip. This speed in the transfer nip is typically higher than the average web speed. The used web can then be fed directly to the collecting device and optionally destroyed or by another transfer film buffer, the web can be temporarily stored so that it is supplied to the collecting shaft with the average web speed.

If, as described, a device for receiving and / or destroying the transfer film is provided instead of the collecting shaft, it is provided in a further development that the collecting device comprises at least one container and feeding elements for feeding the transfer film web to the container. As an alternative or included in this container, it can also be provided that the collecting device comprises at least one shredder for shredding the transfer film web. In this way, the space required for the collecting device can be reduced and a possible additional step can be saved.

Embodiments from which further inventive features may result, but to which the invention is not limited in scope, are shown in the drawings.

Fig. 1

Eine Vorrichtung zum Kaltfolientransfer nach dem Stand der Technik,

Fig. 2

eine nicht erfindungsgemäße Transfervorrichtung mit einer Friktionswelle als Vorratswelle,

Fig. 3

eine Transfervorrichtung nach Fig. 2 schematisch von oben und

Fig. 4

eine erfindungsgemäße Transfervorrichtung mit zwei Friktionswellen und Folientaktung

Show it:

Fig. 1

A device for cold foil transfer according to the prior art,

Fig. 2

a non-inventive transfer device with a friction shaft as Vorratswelle,

Fig. 3

a transfer device according to Fig. 2 schematically from above and

Fig. 4

a transfer device according to the invention with two friction waves and film timing

The FIG. 1 shows a device for transferring a transfer layer of a carrier film, which together form a transfer sheet, on a printing material 10 according to the prior art.

A transfer film web 3 is rolled up on a transfer sheet supply roll 2. This transfer sheet supply roll 2 is provided on a supply shaft 1 which rotates in a direction shown by an arrow. For rotation of the supply shaft 1, a, not shown here drive can be provided.

The roller 2 is fixedly connected to the supply shaft 1, so that the rotation of the shaft 1 transmits directly to the roller 2. In this way, the transfer film web 3 is unrolled from the supply shaft 1 and transported via a deflection roller 4 to a transfer nip 7. It can also be provided a plurality of deflection rollers 4 to allow a corresponding course of the transport path of the transfer film web 3.

The transfer film web 3 is then passed in the direction 6 through the transfer nip 7. The transfer nip 7 is formed by an impression cylinder 8 and a transfer cylinder 9, which are set against each other. A printing material 10, e.g. may be a sheet of paper is also passed in the direction 6 through the transfer nip 7 together with the transfer film web 3. It is important to ensure that the transfer film web 3 and the printing material 10 at least in the transfer nip 7 have the same feed rate. A corresponding drive of the supply shaft 1 must take this into account.

On the substrate 10, a commissioned work, not shown, an adhesive layer has been applied imagewise. If the film transfer takes place within a printing press, the adhesive application can be carried out in a first printing unit upstream of the transfer nip. The adhesive is then transferred to the printing substrate 10 as conventional ink via a printing plate and a blanket cylinder. The imagewise loading of the printing material 10 with adhesive is directly dependent on the imaging of the printing plate, as is the case with conventional paint application. In the case of an inline film transfer within a printing press, the transfer nip 7 can also be formed by a blanket cylinder and an impression cylinder set against it. It is then a second, following the commissioned work of the printing press. In another variant, it is also possible that the blanket cylinder of the commissioned work and the transfer cylinder 9 are employed on the same impression cylinder 8 and the transfer nip 7 is downstream of the printing nip for adhesive application, in this way, the adhesive application and the film transfer in a common compact Plant of the printing machine done. For a better overview, these more complex embodiments are not shown here.

The printing material 10 applied with an adhesive layer is guided through the transfer nip 7 together with the transfer film web 3. By means of the adhesive and under pressure, the transfer layer of the transfer film web 3 is then removed from the transfer film web 3 in the areas imaged with adhesive and transferred to the printing substrate 10. The used transfer film web 3 is led away via further deflection rollers 5 from the transfer nip 7 and fed to a collecting shaft 11. Here, the transfer sheet 3 is rolled up on a transfer sheet collecting roll 12, which is rotated in a direction shown by an arrow.

In the case illustrated here, a plurality of transfer film webs 3 can only be stored on a common supply shaft 1 if, in each case, the same web speed of the transfer film web 3 in the transfer nip 7 results from the rotational speed of the supply shaft 1. However, this is the case only for transfer film supply rolls 2, which have the same diameter. Rollers 2 with different diameters must then be different that are driven on different supply shafts 1.

The FIG. 2 shows an inventive apparatus for transfer of a transfer layer on a substrate 10, which makes it possible to drive a plurality of transfer film supply rolls 20, 21, 22 with different diameters on a common supply shaft and use.

In the case illustrated here, the supply shaft is designed as a friction shaft 13. Other elements that are identical to elements of the previous drawing are referred to here with the same reference numerals.

The friction shaft 13 is shown symbolically in the case illustrated here in that e.g. by means of compressed air individual pins are pushed out of the shaft 13 so that they make a frictional contact with the inside of a sleeve of a transfer film supply roll 20, 21, 22. In alternative embodiments, a friction shaft can also be designed so that elements are pressed by the sleeves into the interior of the shaft and here form a frictional contact with an inner ring of the shaft. Also, the sleeves can be directly fixedly connected to an outer ring of the shaft and the frictional contact is made between the outer ring and an inner ring of the shaft, so that an indirect frictional contact between the rollers and the shaft is produced. Possible usable friction waves are for example produced and distributed by the company AIRMAT TECHNOLOGIE in Vendin-le-Vieil (Lens) in France, e.g. a winding shaft under the trademark "MODEL FRB".

On the friction shaft 13, transfer sheet supply rolls 20, 21, 22 are provided. The rollers 20, 21, 22 in this case comprise sleeves, not shown, with which they rest on the surface of the friction shaft 13. About these sleeves, a frictional contact between the friction shaft 13 and the rollers 20,21,22 produced. The size of the friction, can be adjusted by a controller, not shown. For this purpose, it is for example possible to exert a hydraulic pressure on the responsible for the friction pins so that they are stronger or weaker pressed against the sleeves and thus increase or decrease the friction. It does not have to act directly to pins, it can also be used planar elements that produce correspondingly in the same way a frictional contact.

The friction shaft 13 is driven via a drive 14 so that it rotates in the direction of the arrow shown. The drive 14 may also be responsible for varying the friction force. The different diameters of the transfer film supply rolls 20, 21, 22 are detected by sensors 18, which determine without contact the radius of the rollers 20, 21, 22. The determined diameter D of the rollers 20, 21, 22 are transferred to a controller 19. This controls the drive 14 as a function of the detected diameters and the average feed rate V _{vm of} the transfer _{film webs} 16, 17, 33, which are unwound from the rollers 20, 21, 22. In the case shown here, the partial webs 16,17,33 are constantly transported with the feed rate V _{B of} the printing material 10 through the transfer nip 7. The mean feed rate V _vm therefore corresponds to the feed rate V _{B of} the printing substrate 10. The controller 19 causes the drive 14 to drive the friction _shaft 13 such that the nominal peripheral speed V _UnV of the largest diameter roll 21 is less than the average feed rate V _vm transfer film part webs. If the partial webs 16, 17, 33 have different average feed _rates V _vm , then the lowest of these speeds is selected as the guide speed. To determine possible different speeds, non-illustrated speed sensors may also be provided in the region of the individual partial webs 16, 17, 33. The nominal peripheral speed V _UnV designates the peripheral speed which the largest roller 21 would have if a rigid connection between the friction shaft 13 and the transfer _{ribbon supply roll} 21 were present.

The deviation of the nominal peripheral speed V _UnV from the feed rate V _vm can be fixed in the controller 19 or passed from the outside via a user interface, not shown, to the controller 19. A preferred deviation is - 5%.

The feed rate of the printing substrate V _B can also be determined by a sensor, not shown, or passed directly via a transport control of the printing material 10, not shown, to the controller 19. _Assign all transfer _{film webs} 16, 17, 33 as average feed rate V _UmV the feed rate V _{B of} the printing material 10, then this speed is sufficient to control the drive 14 from.

About deflection rollers 4, the transfer film webs 16, 17, 33 are supplied to the transfer nip 7 and then deflection rollers 5 of the collecting shaft 11th

It can be provided that all partial webs 16, 17, 33 are wound on a common gathering roll 12. Likewise, however, different sub-roles may be present.

Between the collecting shaft 11 and the transfer nip 7, a pair of preferential rollers 15 are provided. The partial film webs 16, 17, 33 are wound around the preferred rollers 15 so that a transfer of force to the partial film webs 16, 17, 33 is possible via the preferred rollers 15. If all the partial film webs 16, 17, 33 move at the same speed, a pair of rollers 15 is sufficient. At different speeds are for all partial film webs 16, 17, 33, the different speeds may have their own pairs of rollers 15 provide.

The preferred rollers 15 on on the partial film webs 16, 17, 33 tensile forces F1, F2. The preferred rollers 15 are driven by not shown control and drives so that they pull the Teilfolienbahnen 16, 17, 33 each with the feed rate V _B through the transfer nip 7. In this way, a certain tension of the partial film webs 16, 17, 33 is always achieved, even if no contact of the webs 16,17, 33 with the impression cylinder 8 or transfer cylinder 9 is present, which is the case, for example, in the passage of cylinder channels. By the tensile forces F1, F2, respectively, at least temporarily, the frictional forces between the transfer film supply rolls 20, 21,22 and the friction shaft 13 are overcome, so that there is a slip. Depending on the diameter of the rollers 20, 21, 22 a different train is generated, so that finally all the rollers have the same actual peripheral speed. The corresponds in the described case of the feed rate V _{B of} the printing material. In this way, the transfer film supply rolls 20, 21, 22 can also be provided with different diameters D on the friction shaft 13 so that they all have the necessary peripheral speed for a clean film transfer within the transfer nip 7.

The FIG. 3 shows a top view of the arrangement for a film transfer FIG. 2 from above. Only the elements in the region of the friction shaft 13 are shown here. Each transfer film supply roll 20, 21, 22 is assigned a single sensor 18 ', 18 "and 18"' which determine the respective diameters of the rolls 20, 21, 22. Like reference numerals denote like elements. Otherwise, the film transfer is performed as for FIG. 2 described.

In the FIG. 4 an alternative embodiment for a film transfer of partial film webs 16, 17 of transfer film supply rolls 20, 21 with different diameters D is shown. Identical elements are also identified by the same reference numerals.

How to Fig. 2 is described by preferred rollers 15 tensile forces F1, F2 on the partial film webs 16, 17 exerted by the friction shaft 13 in the direction of the transfer nip 7.

In addition, here also the collecting shaft is designed as a friction shaft 23. On this friction shaft 23, there are provided transfer ribbon collecting rollers 24, 25 having different diameters D 'which receive transfer ribbon webs 16, 17. To effect tensile forces F3 and F4 on the transfer film webs 16, 17 from the friction shaft 23 in the direction of the transfer nip 7, a preferred pair of rollers 32 is provided on the opposite side of the transfer nip, analogous to the already described pair of rollers 15 for maintaining a certain web tension and the desired Feed rates of transfer partial film webs 16, 17 in the transfer gap 7 provide. If only the friction shaft 23 are driven, then, analogous to the structure in Fig. 2 alone, the preferred shaft pair 32 may be provided. Likewise, the friction shaft 23 is driven so that the nominal peripheral speed of the roller 24, 25 with the smallest diameter runs about + 5% faster than the average feed rate V _{vm of} the film through the transfer _nip 7.

In the embodiment shown here, a film timing 26 is also provided. It comprises two guide rollers 27, 28 around which the film webs 16, 17 are looped. The guide rollers 27, 28 are coupled to each other via a coupling 29. The coupling 29 may, for example, be a pair of rods which axially engage the end faces of the guide rollers 27, 28 and thus interconnect them. Via a drive 30, the guide rollers 27, 28 are driven and driven so that they are moved in the direction of the double arrow 31 either to the collecting shaft or to the supply shaft. As a result, a film _timing can be realized, wherein the average feed rate V _{vm of} the film webs 16, 17 is slightly reduced. In a middle position of the guide rollers 27, 28, the film webs 16, 17 at the same speed V _B as the substrate 10 on. If the guide rollers 27, 28 are moved in the direction of the collecting shaft, the speed of the transfer film webs 16, 17 is reduced in the transfer nip 7, this is useful if no transfer layer is transferred and the transfer cylinder 9 is not employed on the impression cylinder 8. This is the case, for example, when passing through a cylinder channel. Then comes again substrate 10 in the transfer nip 7, the guide rollers 27, 28 are deflected in the direction of the supply shaft and accelerate in this way the Teilfolienbahnen 16, 17 until they again in the transfer nip 7 have the speed V _{B of} the printing material.

In this way, in areas where no film transfer to the substrate 10 takes place transfer foil can be saved.

An even greater saving of transfer film is possible by the provision of film stores, these can be provided in the form of vacuum stores for receiving film on both sides of the transfer nip 7. Such a foil storage is in the European patent application EP 0 578 706 A1 which is hereby incorporated by reference with respect to the embodiment of a film storage in the form of a buffer for receiving transfer film.

LIST OF REFERENCE NUMBERS

1

supply shaft

2

Transfer film supply roll

3

Transfer sheet

4, 5

guide rollers

6

transport direction

7

transfer nip

8th

Impression cylinder

9

transfer cylinder

10

substrate

11

collecting shaft

12

Transfer film collecting roller

13

friction shaft

14

driving device

15

drawing rollers

F ₁

Pulling force F ₁

F ₂

Pull-force F ₂

16, 17,33

Transfer sheet

18

sensor

19

control

20, 21, 22

Transfer film roll

23

friction shaft

24, 25

Transfer film collecting roller

26

film clocking

27, 28

leadership

29

coupling

30

drive

31

double arrow

32

drawing rollers

F ₃

Pull-force F ₃

F ₄

Traction

Claims (23)

1. Device for transferring a transfer layer from a carrier foil, which together form a transfer foil, to a printing material (10), comprising
   at least one foil module with a supply shaft (1) for receiving at least one transfer foil supply reel (2) for supplying and unwinding at least one web of transfer foil (3),
   a transfer foil guiding device at least to guide the web of transfer foil from the supply shaft to a transfer nip (7) along a foil transport path, the transfer nip (7) being formed by a counterpressure cylinder and a foil transfer cylinder to transfer the transfer layer to the printing material, for which purpose the printing material (10) is guided through the transfer nip (7) along a printing material transport path, and
   a collecting device for receiving the at least one web of transfer foil guided through the transfer nip (7), the collecting device comprising a collecting shaft (11) for receiving at least one transfer foil collecting reel (24, 25) for winding up the at least one web of transfer foil (16, 17, 33),
   characterized in
   that the supply shaft (1) and the collecting shafts are embodied as friction shafts (13, 23),
   that a respective drive (14) is provided to drive the respective friction shaft (13, 23) so that the transfer of the rotary movement of the respective friction shaft (13, 23) to the at least one transfer foil supply reel (20, 21, 22) and the transfer foil colleting reel (24, 25), respectively, is achieved by a frictional connection between shaft (13, 23) and reel (20, 21, 22), which may be overcome by traction forces (F1, F2, F3, F4) of the web of transfer foil (16, 17, 33).
2. Device according to Claim 1,
   characterized in
   that at least one traction device is provided to pull the at least one web of transfer foil (16, 17, 23) in the direction of the transfer nip (7).
3. Device according to Claim 2,
   characterized in
   that the traction device is a pair of traction rollers (15, 32) that applies a traction force (F1, F2, F3, F4) to the at last one web of transfer foil (16, 17, 23) via friction so that the at least one transfer foil supply reel (20, 21, 22) and/or transfer foil collecting reel (24, 25) is subjected to traction in the direction of the transfer nip (7).
4. Device according to Claim 2 or 3,
   characterized in
   that the traction device is arranged behind the transfer nip (7) and applies a traction force (F1, F2) in the direction towards the transfer nip (7) to the at least one transfer foil supply reel (20, 21, 22) on the supply shaft (13).
5. Device according to Claim 2 or 3,
   characterized in
   that the traction device is arranged in front of the transfer nip (7) and applies a traction force (F3, F4) in the direction towards the transfer nip (7) to the at least one transfer foil collecting reel (24, 25) on the collecting shaft.
6. Device according to Claim 2,
   characterized in
   that the traction device comprises the counterpressure cylinder (8) and the foil transfer cylinder (9) that form the transfer nip (7).
7. Device according to at least one of Claims 1 to 6,
   characterized in
   that at least two transfer foil reels (24, 25), each of which can supply and unwind a web of transfer foil (16, 17, 33), are provided on the supply shaft (13) or on both the supply shaft (13) and the collecting shaft (11, 23).
8. Device according to Claim 7,
   characterized in
   that at least one detecting means is provided to detect the reel diameters of the at least two transfer foil reels (20, 21, 22).
9. Device according to Claim 8,
   characterized in
   that a contactless sensor (18) capable of detecting the distance between the surface of the reel of transfer foil (20, 21, 22) and the sensor (18) or directly the radius of the reel of transfer foil (20, 21, 22) is associated with each reel of transfer foil (20, 21, 22) as the detecting means.
10. Device according to Claim 9,
    characterized in
    that the contactless sensor (18) is an ultrasound sensor or an optical sensor that detects light reflected by the surface.
11. Device according to Claim 8,
    characterized in
    that a contacting sensor is associated with each reel of transfer foil (20, 21, 22) as the detecting means.
12. Device according to Claim 11,
    characterized in
    that the contacting sensor is an idler wheel that determines a diameter change of the transfer foil supply reel (20, 21, 22) from a measured travel path.
13. Device according to Claim 11,
    characterized in
    that the contacting sensor is a resistance sensor that determines the amount of transfer foil present on the reel of transfer foil (20, 21, 22) via a measured resistance.
14. Device according to at least one of the preceding claims,
    characterized in
    that a foil timing device (26) is provided in the region of the transfer nip (7).
15. Device according to Claim 14,
    characterized in
    that the foil timing device (26) comprises at least two guide rollers (27, 28) coupled to each other for guiding the web of transfer foil (16, 17, 33), the guide rollers being provided on opposite sides of the transfer nip (7) and being simultaneously movable into a first direction by a drive device (30) so that the speed of the transfer foil through the transfer nip (7) is reduced, and the guide rollers being simultaneously movable into a second direction in such a way that the speed of the transfer foil in the transfer nip (7) corresponds to the transport speed of the printing material (10).
16. Device according to at least one of the preceding claims,
    characterized in
    that at least one transfer foil buffer is provided in the region between the supply shaft (13) and the transfer nip (7) and/or between the transfer nip (7) and the collecting device.
17. Method for transferring a transfer layer from a carrier foil, which together form a transfer foil, to a printing material (10) in which
    the transfer foil is provided as at least one web of transfer foil (16, 17, 33) on at least one transfer foil supply shaft (20, 21, 22) on a supply shaft (13),
    the at least one web of transfer foil (16, 17, 33) is guided to a transfer nip (7) along a foil transport path,
    the transfer layer is transferred from the transfer foil to a printing material (10) in the transfer nip (7), and
    the web of transfer foil (16, 17, 33) is subsequently guided to a collecting device,
    characterized in
    that the at least one transfer foil supply reel (20, 21, 22) is provided on a supply shaft (13) embodied as a friction shaft (13), the friction shaft (13) being driven by a drive (14), and
    that a transfer foil collecting reel (24, 25) is provided on a collecting shaft (23) embodied as a friction shaft and driven by a further drive.
18. Method according to Claim 17,
    characterized in
    that the diameters D of the individual transfer foil supply reels (20, 21, 22) on the supply reel (13) are determined, the mean advancing speed V_vm of the transfer foil through the transfer nip (7) is determined, and
    that the supply shaft (13) is driven at an angular speed w in such a way that the nominal circumferential speed V_UnV=w*D/2 of the transfer foil supply reel (21) that has the largest diameter is lower than the mean advancing speed V_vm of the transfer foil through the transfer nip (7).
19. Method according to Claim 18 or 19,
    characterized in
    that the supply shaft (13) is driven in such a way that the nominal circumferential speed V_UnV of the transfer foil supply reel (21) is less than 100% but equal to or more than 95% of the mean advancing speed V_vm.
20. Method according to one of Claims 17 to 19,
    characterized in
    that the diameters D of the individual transfer foil collecting reels (24, 25) on the collecting shaft (23) are determined,
    the mean advancing speed V_vm of the transfer foil through the transfer nip (7) is determined, and
    that the collecting shaft (23) is driven at an angular speed w in such a way that the nominal circumferential speed V_UnS=w*D/2 of the transfer foil collecting reel (24) that has the smallest diameter is higher than the mean advancing speed V_vm of the transfer foil through the transfer nip (7).
21. Method according to Claim 20,
    characterized in
    that the collecting shaft (23) is driven in such a way that the nominal circumferential speed V_UnS of the transfer foil collecting reel (24) is more than 100% but less than or equal to 105% of the mean advancing speed V_vm.
22. Method according to one of Claims 17 to 21,
    characterized in
    that the web of transfer foil (16, 17, 33) is pulled off the supply shaft (13) and/or the collecting shaft (23) in a way that its actual advancing speed V_v in the region of the transfer nip (7) at least temporarily corresponds to the speed of the printing material V_B.
23. Method according Claim 22,
    characterized in
    that the web of transfer foil (16, 17, 33) is timed in such a way that its actual advancing speed V_v deviates from the speed of the printing material V_B in times in which no foil transfer to the printing material (10) occurs and is accelerated prior to an envisaged foil transfer in a way that the actual advancing speed again corresponds to the speed of the printing material V_B.

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