EP2571694A1

EP2571694A1 - Format-related cold film embossing

Info

Publication number: EP2571694A1
Application number: EP11720074A
Authority: EP
Inventors: Jürgen Schölzig
Original assignee: Manroland Sheetfed GmbH
Current assignee: Manroland Sheetfed GmbH
Priority date: 2010-05-17
Filing date: 2011-05-06
Publication date: 2013-03-27
Anticipated expiration: 2031-05-06
Also published as: PL2571694T3; CN102985257A; DK2571694T3; WO2011144462A1; EP2571694B1; CN102985257B; DE102011007462A1

Abstract

The film feed in a coating module for transferring imaging layers from a transfer film onto a printing material is to have its applicability extended. To this end, a limited pressing surface is arranged in the coating module for transferring layers from the transfer film (5). Targeted control of the film advancing is therefore possible. Here, the transfer film is preferably guided in a limited width and approximately tangentially past a press roll (3). In order to limit pressing surfaces, format supports (30, 31, 32) for the press fabric (10) are provided.

Description

Format-related cold foil stamping

The invention relates to a device for transferring imaging layers from a carrier film to printing sheet according to the preamble of patent claim 1 and a method according to the preamble of claim 13. It is known to produce metallic layers on printed sheets by means of a film transfer process. Thus, EP 0 569 520 B1 describes a printing material and a printing device using this material. In this case, a sheet-processing machine is shown, which has a feeder and a boom, wherein printing units and a Beschichtungsmo- 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. When printing sheets are transported through the printing unit, each sheet is given an adhesive pattern. Thereafter, the sheet is passed through the coating module, wherein by means of the press roller on the impression cylinder resting sheet with the film material in combination is brought. In this case, the downwardly lying metallic layer enters into a close connection with the areas provided with adhesive on the printed sheet. After further transporting the printing sheet, the metallic layer adheres only in the area provided with the adhesive pattern. The carrier film is thus removed from the metallic layer in the region of the adhesive pattern. The used in this way transfer film is wound up again. The print sheet is laid out in the coated state.

From DE 102009026438 A1 a device for cold foil stamping is known. In this device, the film feed in a coating module for the transfer of imaging layers from a transfer film to a printing material is to be extended in its applicability. For this purpose, a limited pressing surface is arranged in the coating module for transferring layers from the transfer film. For a targeted control of the film feed is possible. In this case, the transfer film is preferably guided past a press roll in a limited width and approximately tangentially. For film storage and film promotion special cyclically operable conveyors are assigned for this purpose. The timing of the sheet feeding may be performed with respect to a circumferentially existing interruption of cylinder-knitting surfaces or with respect to circumferential or over the width of cylinder-knitting surface-variable transfer zones for the transfer film.

From DE 102 13 651 A1 a cylinder with a fastening device for a flexible, upper elevator in a processing machine is known. The cylinder has a flexible, upper-lift fixing device provided with a fixing device disposed within the cylinder periphery. This is for separately securing a lower elevator between the cylinder circumference and the upper elevator disposed on the cylinder. The lower elevator consists of a flexible carrier material on which a plurality of base forms are arranged at intervals. The fixing device is drivable. The lower elevator, which is accommodated in the fixing device in the end fixing area, can thus be moved on the cylinder circumference. Thus, in each case at least one pad shape can be positioned to the upper elevator. It is known to use such coating modules, for example in printing units of printing presses. A disadvantage of the known devices is that they can not be used flexibly.

The object of the invention is therefore to provide a device by means of which the transfer of an imaging layer, e.g. a metallization layer can be done on a sheet safely, economically and accurately, the device should be manageable for an extended range of applications. In particular, a partial film application is to be made possible.

The solution of this problem arises according to the invention in a device having the features of claim 1 and in a method according to the features of claim 13.

The device provides a timing system for guiding the film web, wherein the pressing surface is highlighted depending on the format to be coated on the press roller.

Advantageously, the device is characterized in that a press roller has a pressing surface which occupies a partial area of the total area of a printed sheet.

Advantageously, such pressing surfaces are designed as below a blanket stretchable segments for the blanket provided on the press roll over the entire surface.

For this purpose, different elevator materials can be used for a press cover. Can be used

- For the blanket / the press fabric of the press roll suitable so-called underlay sheets or even format sheets, which extend only to the effective area for the film transfer

- Underlay sheet / size sheet, which are clamped together with the blanket / with the press fabric on the press roll - Underlay sheet / format sheet, each of which can be tensioned on its own and locked under the blanket / press fabric to the press roll

- On the press roll stick-on pad segments, which are positioned in the active area on the surface of the press roll and spanned by the blanket

As a neutral substructure of the corresponding partial press fabric is provided for the entire area of the press roll surface, a pad with or without a damping effect such as. Again, to use a vacuum blanket, which serves the leveling of the entire surface, while the format sheets come only in the work area of the film transfer itself.

As clamping systems arise a clamping spindle as in a blanket cylinder known or so-called combination clamping rails for blankets or printing plates, as known from the blanket cylinders or the form of cylinders. Depending on the structure, the surface of the press cylinder elevator is also suitable for profiled embossing. This results in an extended range of applications for the process of cold foil stamping. The makeready shortening is achieved by prepared press cylinder lifts. In addition, register automation can be introduced.

As a solution, add the press cylinder to a register system, e.g. can be executed via register pins. The press cylinder may be further adjustable e.g. in the manner of a register system for automatic printing plate tension. In this case, a lateral and a Umfangsreg ister as in a forme cylinder be adjustable, the setting can be set up motor and / or automatically executable. In addition, the press cylinder elevator may be provided with register punches.

The device can also be used in an advantageous manner in order to achieve an improvement in the use of the film in that the transfer film into or several Teilfolienbahnen smaller width is divided. In combination with the above-mentioned method, it is thus also possible to use different types of film side by side. To ensure the efficiency of the coating process can be provided to control the film feed such that the transfer film is then stopped when no transmission of the imaging or metallization takes place. Advantageously, the control of the transfer film is such that when passing through a surface opposite to the surface of the sheet counter-pressure cylinder surface area of the press roller, the film feed is stopped, wherein the press roller can then slide through under the transfer film, since the transfer film is not between the active surfaces in Transfer nip is trapped.

In the following the invention is illustrated in more detail with reference to figures. Showing:

1 shows a basic illustration of a printing press with a film transfer device, FIG. 2 shows the structure of a coating module with a film transfer device,

FIGS. 3 and 4 show the arrangement of a press fabric according to the invention on a press roll, FIGS. 5a and 5b show alternative constructions of press fabric,

Figures 6 and 7 further inventive press clothing on a

Press roll and FIG. 8 shows another mountable and demountable press fabric according to the invention on a press roll.

FIG. 1 shows parts of a sheet-fed rotary printing press which contains two printing units and is used for the following purposes:

- A printed sheet is first provided with a two-dimensional or imaging adhesive fabric pattern (printing unit as commissioned work 1).

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

The applicator 1 can be a per se known offset printing unit with an inking unit 1 1, a plate cylinder 12 and a blanket cylinder 13. The blanket cylinder 13 cooperates with a counter-pressure cylinder 4.

The coating unit 2 can also be formed by an offset printing unit. The transfer nip 6 in the coating unit 2 is formed by a press roll 3 and an impression cylinder 4. The press roller 3 may correspond to the blanket cylinder. The press roll 3 may also correspond to the forme cylinder of a paint module. Within the used for the film transfer coating 2 a web guide 14 is shown for transfer films. The transfer film 5 is thereby switched on and executed by protective devices 15 of the coating unit 2.

The film supply roll 8 is assigned to the coating unit 2 on the side of the sheet feed. The film supply roll 8 has a rotary drive 7 for the continuous controlled feeding of the transfer film to the coating unit 2. In the film feed deflection or tension rollers for guiding the transfer film 5 may be provided in a substantially constant tension against the press roller 3. On the downstream side of the printing unit, a film collecting roller 9 is provided for the used sheet material. One Rotary drive 7 on the film collection roller 9 is always advantageous. It can even be provided that the transfer film 5 is conveyed on the outlet side by means of the rotary drive 7 and held taut on the inlet side by means of a brake. The press roll 3 (as blanket cylinder or forme cylinder or separate press roll) carries on its surface a compressible or damping, for example, also provided with a compressible intermediate layer element. For this purpose, the press roll 3 can be provided with a press cover 10, for example as a plastic cover, comparable to a blanket or blanket, which is held in a cylinder channel on clamping devices.

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

The associated device preferably includes a corresponding feed control for the transfer film 5, which ensures that at least the lying in the region of the press roller 3 and the impression cylinder 4 part of the film lienbahn stands still as long as the cylinder channel 26 of the impression cylinder 4 passes. For this purpose, details will be explained later in FIGS. 2 to 4.

A further improvement of the film utilization of the type described results when the transfer film 5 is divided into one or more Teilfolienbahnen lesser width. Thus, with appropriate control by means of the device or devices for timing the film feed each of the sub-film webs, the utilization of the transfer film 5 can be improved even in zonally different lengths coating areas within an arc. Furthermore, dryer 16 can be provided in the film application module thus formed from the applicator 1 and the coating unit 2, by means of which the adhesive application or the entire film coating can be dried. Here, for example, UV dryers come into question. Furthermore, the film application module may include a monitoring device 17 for scanning the sheet surface. The monitoring device 17 enables the evaluation of image contents of the coating and the detection of defects in the film coating. Such a monitoring device can also be provided in conjunction with the printing press, in which the film application module is integrated. Then it can be arranged for example in the sheet delivery of the printing press or a last printing unit.

The transport of the transfer film 5 can be monitored on or between film guide rollers 14 by checking the web tension of the film web 5. One or more web tension measuring devices 19 are provided for this purpose in a film web guide.

Furthermore, a stabilization device 30 can be arranged to stabilize the film web 5 between a first deflection roller and a first inlet roller to the transfer unit in order to reduce flapping movements of the film web 5. The stabilizing device 30 has z. B. two rotatably mounted rollers, which is provided for the variable setting of the wrap angle of the film web 5 on the guide rollers, so that the guiding action and the damping effect on the film web 5 is adjustable depending on the operating state. The adjustment of the stabilization device 30 can be carried out in conjunction with means for web tension control 19 and possibly a sensor device 20 for web break monitoring. Electrical signals of the web tension measuring devices are evaluated. Various operating states are possible for this:

1 . A web train above a predeterminable minimum value is evaluated as a signal for the presence of the film web 5 and fed to the machine control.

2. Exceeding the maximum value of the predeterminable web train is about dancer rollers 18 or roller drives 7 of Folienvorrats- 8 or -sammelrolle

9 reduced. Thus, impermissible web elongation or web break can be avoided. 3. If the minimum specified tension is undershot, it is checked whether the web tension control is still active. If it is not possible to increase the web tension by means of dancer rollers 18 or a brake, web break is 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 machine, via which the setpoint values for maximum and minimum web tension can be entered. This may depend on the type of transfer film 5 used and on the printing or transfer conditions in the coating module 2 in connection with the properties of the printing substrate, the adhesive or the press cover.

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

The method relating to the film transfer is described in the Druckbzw. It is provided, at least in a printing unit 50 following the coating unit 2, to apply a color print to the printing sheet which is coated imagewise with a metallized layer. In this case, the printed sheet from the coating unit 2 is transferred from the impression cylinder 4 via a sheet transfer drum or a sheet transfer unit to an impression cylinder 40 of the printing unit 50.

The printing unit 50 has, as usual in offset printing units, the counter-pressure cylinder 40, an associated rubber or blanket cylinder 41 and a plate cylinder 43 associated therewith. The plate cylinder 43 are here shown schematically an inking unit and a dampening unit assigned.

Between counter-pressure cylinder 40 and blanket cylinder 41, a further pressure gap 60 is formed. In this printing gap 60 ink is applied from a spanned on the plate cylinder 43 printing plate 44 via a arranged on the blanket cylinder 41 cover 42 on the sheet. The gap of the printing gap 60 between the surfaces of the blanket cylinder 41 and the impression cylinder 40 is adjustable by means of the printing blanket cylinder 41 associated adjusting devices 45. In this case, in the area of offset printing, it is customary to speak of a printing provision, since the setting referred to relates to the thickness of the printing material to be processed, which is to be printed in the printing nip 60. For this purpose, a printing pressure is necessary to transfer the ink from the blanket cylinder 41 to the held on the impression cylinder 40 substrate.

The adjustments with respect to the transfer nip 6 are made by means of further actuators 46 associated with the press roll 3.

The actuators 45, 46 are commonly used in offset printing on printing blanket or blanket cylinders of printing units or on cylinders of varnish modules.

Furthermore, should be provided as a surface of the press roll 3 a contoured or segmented pressing surface in the press fabric 10. For this purpose, according to the invention, instead of a full-surface pressing area, segmented pressing areas limited to one or more areas to be coated are used on the pressing roller 3.

The segmented pressing surface may be formed as an isolated surface element, as an annular, narrow surface element encircling the press roll 3, as a surface line following a limited peripheral portion covering over the width of the press roll 3 reaching surface element or in the form of several such surface elements pronounced and so the press fabric 10 form.

The function of this limited segmented pressing surface in the press fabric 10 is that - as in the passage of a cylinder channel of the press roll 3 and the opposing impression cylinder 4 - the entrapment of the transfer film 5 is given only if the segmented pressing surface, the transfer sheet 5 touching the Transfer nip 6 passes through. In other words, the pressing surface should only be able to act on the transfer foil 5 in the areas where In fact, imaging layers are to be transferred from the transfer sheet 5 to the signature.

Thus, two effects can be achieved in a coating module 2 with a segmented pressing surface provided in a compression stress 10:

I. First, to carry out a film timing, the transfer film 5 can be stopped in advance in a very advantageous manner in addition to the period of the channel passage, if the area to be coated is located somewhere within the image area of the sheet and has not yet reached the area of the segmented pressing surface, or the area of the segmented pressing surface ends before the end of the sheet area to be coated. The transfer film 5 therefore only has to be transported if the segmented pressing surface is in engagement within the transfer nip 6 between the press roll 3 and the impression cylinder 4. Thus, the utilization of the transfer film 5 between the sheets to be coated can be almost complete.

The film transport is stopped here when using an annular pressing surface only at the channel pass.

When using pressing surfaces in the form of single or multiple, cylinder-wide, over sub-segments reaching segments of the film feed can be additionally stopped during free areas on the circumference of the press roller 3.

II. 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. This is particularly advantageous in connection with the segmented pressing surface. In a segmented pressing surface, the transfer film 5 can be used limited to the width of the pressing surface. The savings in film consumption is significant. The film guide in the transfer nip 6 is significantly improved by a full-surface support of a narrow web of transfer film 5 on the segmented pressing surface - at least in the transfer nip 6.

This can be done with appropriate control by means of the device or directions for the timing of the film feed of each of the partial film webs, the utilization of the transfer film 5 are improved even with zonally different coating areas within an arc. For this purpose, each partial film web is conveyed only exactly in the area where the image-forming 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.

In combination with the above-mentioned method, it is thus also possible to use different types of film side by side. This allows surfaces of different film color or different smoothness or texture to be created.

For the construction of the partial press fabric, different working materials known per se can be used. Can be used

- Underlay sheet / size sheet, which are clamped together with the blanket / with the press fabric on the press roll

- Underlay sheet / format sheet, each of which can be tensioned on its own and locked under the blanket / press fabric to the press roll

As a substructure of the corresponding press fabric 10 with segmented press surfaces is a pad with or without damping effect, such as a vacuum cloth (but only in press clothing without rigid support layer) used.

Clamping systems in the cylinder channel of the press roll 3 for fastening the press fabric 10 can clamping spindles as in a blanket cylinder or Kombinati be onsspannschienen for blankets or printing plates, as known from the rubber or the Formzyl. The surface of the press fabric 10 is suitable depending on the structure for profiled imprints. This results in an extended range of applications for the process of cold foil stamping.

Using the above elements, a very simple and fast handling of the device of the film application module is possible.

According to the invention devices are provided which allow the cyclic promotion of the film web 5. In this case, operating variants can be derived from the previously explained facts

a channel timing in the passage of cylinder channels of the press roll 3 and the impression cylinder 4,

- a formattaktung or a sujettaktung, on the coating or

Application length is related, limited to the format length of the film transfer on the circumference of the press roll 3 film feed and

- A Prägebereichstaktung when limiting the film guide to defined by segmented pressing areas in the press fabric 10 of the press roll 3 film feed

be cited.

For the film feed (also the discharge) usually the drive of the film rolls 8, 9 is provided continuously, since the mass of the film rolls 8, 9 is too large for a quick change of the drive movement. As a result, when the film web is slowed down until it accelerates again in the transfer region in the supply and discharge regions of the film web 5, excess or missing film lengths are produced with respect to the movement of the film rolls 8, 9. Such transition areas between film start and format or application start are also different in relation to each used according to the invention used format documents, as will be explained later in connection with Figure 5.

Therefore, solutions are proposed according to the invention, which can buffer the resulting in continuous Nachförderung or removal of the film web 5 excess or missing pieces of web. These are basically already with the dancer rolls 18 as a variant of foil stores. However, the dancer rolls 10 are not sufficiently controllable on the described in the described high-speed clocking in the film transfer process, especially since they are usually far away from the place of consumption and close to the film roll 8, 9 to maintain the web tension there.

In FIGS. 2 to 5, further possibilities for rapid compensation of web displacements in film timing in the cold foil process are therefore specified.

FIG. 2 shows a film transfer module corresponding to FIG. Here, the dancer rollers 18 are arranged to regulate the web tension. To compensate for major changes in the film promotion, such as stopping the film transfer in the transfer area (range of film transfer between press roller 3 and impression cylinder 4) without film consumption (channel timing, format clocking, timing on embossed areas), see in addition to the enema of fri see Film web 5 in the transfer nip 6 and after the exit of the used film web 5 from the transfer nip 6 as drive groups 22 designated pairs of rollers 23, 24 are arranged.

The drive groups 22 are described here for all subsequent embodiments and each show a pair of rollers that can pinch the film web 5 and thus defined in terms of a desired transport path can lead. The pairs of rollers of the drive groups 22 consist in Figure 2 of a respective foil guide roller 24 and a drive roller 23. Both the film guide roller 24 and the drive roller 23 is at least partially driven. The drive of the drive roller 23 can be directed not only in the transport direction of the film web 5 (from film roll 8 to 9), but can also generate return strokes. This makes sense, since the film web 5 does not stop immediately when decelerating and thus runs over a desired breakpoint. As a result, a piece of the film web 5 could not be used. If a short defined return stroke is performed after the braking and stopping of the film web 5 in the transfer region, this step reduces or eliminates this unnecessary film consumption. For this purpose, the drive of the drive roller 23 can be controlled quickly. The drive roller 23 itself can be segmented to quickly handle the changing drive motions to be able to execute. Furthermore, the film guide roller 24 with respect to the drive roller 23 can be pivoted up and down, but it can also be permanently employed on the drive roller 23. Thus, it can also be provided that the film guide roller 24 perform a more or less controlled by the film web 5 movement, while the drive roller 23 performs a conveying movement and the return stroke movement. The film guide roller 24 carries out a reverse rotation movement for a defined period of time with respect to the film transport direction only by controlled adjustment against the film web 5 resting on the drive roller 23. The drive roller 23 then performs a continuous transport movement against the direction of the film web 5. This is possible because the film web 5 is free to move at this time due to lack of contact pressure by the press roller 3 against the impression cylinder 4 in the transfer area. ,

Furthermore, the drive groups 22 can also hold the film web 5 in the transfer area under the necessary tension by braking at the time of sheet breakage, in this case at least on the feed side to the transfer nip 6, thus immediately upon restart of the film transfer with pressing by the press roller 3 against the impression cylinder 4 good transfer quality is achieved again.

The system of the drive group 22 is also suitable for segmented film guide rollers 24 in format width drive rollers 23 both for the guidance of a full-width film web 5 as well as for the guidance of, possibly also distributed, arranged sub-film webs 5. For this purpose, the segments of the film guide roller 24 can be arranged correspondingly adjustable to the positions of the partial film webs 5 in the axial direction to the press roller 3.

The drive group 22 can be simplified by designing the drive roller 23 with a rough or adhesive surface or as a suction roller. With a correspondingly large looping through the film web 5, sufficient adhesion for the secure guidance of the film web 5 on the drive roller 23 can then be achieved. Then it would be possible to dispense with a foil guide roller 24, even in segmented form. This is also in terms of the format widths Execution of the drive roller 23 harmless. A drive roller 23 designed as a suction roller could then be designed in such a way that suction devices which can be switched as needed in segments corresponding to the respective film web widths to be processed are provided if required.

The dancer arrangement for compensating the conveying paths of the transfer film web 5 during the timing of the feed can also be designed in the form of loop guides for the transfer film web 5 operated by means of negative pressure. The film supply and removal can be performed with controllable or self-regulating systems such as friction shafts and individual drives on the film rolls 8, 9 in the variants of a format-wide film roll or with multiple sub-film rolls. Furthermore, it is provided that the transfer film web 5 is guided past the press roller 3 in the region of the transfer gap 6 in an approximately tangential path. For this purpose, a film section 5.1 in the region of the film inlet into the transfer nip 6 is guided by the film guide roller 14 at a corresponding angle with respect to a tangent through the transfer nip 6 into it.

Furthermore, a film section 5.2 in the region of the film outlet from the transfer nip 6 from a further film guide roller or the outlet side drive roller 23 at an appropriate angle with respect to a tangent through the transfer nip 6 out of this out.

By forming the angle between the film sections 5.1 and 5.2 or the respective angle between the film sections 5.1 and 5.2 and a tangent (see tangent line T in Figure 4) through the transfer gap 6 on the one hand ensures that the gripper on the impression cylinder 4 during the passage of the cylinder channel 26 can not push into the transfer film web 5 and damage them. This concerns, in particular, the outlet side of the transfer film web 5 at the transfer nip 6, since there the so-called gripper backs project slightly into the region of the cylinder channel 27 of the press roll 3 and can press against the freely stretched transfer film web 5. Furthermore, the angle between the film sections 5.1 and 5.2 but also chosen so that the transfer film web 5 touches the surface of the press roller 3 only in a very narrow range. Ideally, this should be only a contact strip of a few mm in length at the circumference of the press roll 3 over the entire width of the press roll 3. The formation of the narrow contact strip ensures that the timing of the movement of the transfer film web 5 at the moment of release or pressure reduction on the transfer film 5 in the transfer nip 6 can be done quickly by the transfer film 5 can be stopped as soon as possible. The same applies at the beginning of the conveying movement at the next beginning of a new transfer area (beginning of a press project or end of the cylinder channel).

The arrangement of the extent of the film sections 5.1 and 5.2 in relation to a tangent T is also shown schematically in FIG.

In Figure 3 and 4, the inventive arrangement of format documents for the press fabric 10 is shown.

In Figure 3, the press fabric 10 for the press roller 3 is shown in a planar view. It shows the work areas for a planned film transfer. The working direction with respect to the direction of rotation of the press roll 3 is shown at the top by a directional arrow. The workspaces are marked by three format pads 30, 31, 32, which are the left margin

(Beginning of printing) connect the press fabric 10 and end against the working direction at the form edges K1, K2, K3. The size documents 30, 31, 32 are provided with a width corresponding to the required working areas and with the respective desired length of the working format arranged in the work area format edges K1, K2, K3 and cover so different areas of a Presssujets on the circumference of the press roll 10 from.

In Figure 4, this arrangement is schematically transferred to a cylinder section through the transfer nip 6 forming press roller 3 and the associated impression cylinder 4 with the direction of rotation. Here, the formats terlagen 30, 31, 32 superimposed on each other in the view and therefore different thickness drawn. The format edges K1, K2, K3 are now located at different peripheral points of the surface of the press roll 3. The press fabric 10 is laid over the substrates 30, 31, 32 in a line and follows their surface contour. Thus, in the area of the format edges K1, K2, K3, fine steps are formed in the surface of the press fabric 10, after the end of which a corresponding reduction in pressure is achieved in the transfer nip 6, if a printed sheet is guided there together with the transfer film web 5 resting against the press roll 3. Due to the pressure reduction no film transfer can take place there, since the transfer film 5 is no longer clamped. This is shown here with respect to the base 30 and to the associated form edge K1.

Over the width of the press roller 3 results in the same state for the two documents 31 and 32 with respect to the format edges K2 and K3. Thus, the transfer sheet 5 is released in different circumferential positions with respect to the three working areas of the press. Preferably, in this case, the transfer film 5 is divided into three sub-film webs corresponding to the width of the work areas of the press substrate for the size documents 30, 31, 32. Now, if a device for timing according to the above description is provided for each of the sub-webs of the transfer sheet 5, each partial film web can be stopped at the time of release on passage of one of the format edges K1, K2, K3 through the transfer nip 6 in the transport, since they do not more in the transfer nip 6 is clamped. This allows considerable savings in film consumption. The same applies to the adjoining cylinder channel 27. FIG. 4 also shows the guide of the transfer film web 5 in film sections 5.1 and 5.2 before and after the transfer nip 6, as has already been explained in connection with FIG. Here, a tangent T on the pressure roller 3 is shown by the transfer nip 6 as a dotted line. It can be seen that the angle of the film section 5.2 on the outlet side of the transfer film web 5 with respect to the tangent line T can be greater than that of the film section 5.1 on the inlet side before the transfer nip 6. The angle of the film sections 5.1 and 5.2 with respect to the tangent line T determining film guiding elements are indicated by dashed lines as guide rollers. FIGS. 5a and 5b show diagrammatically the arrangement of a press fabric according to the invention on the unwound surface of a press roll 3. Here, the surface of the press roll 3 is designated in its extension in the direction of rotation with a format length 38. The surface is followed by a cylinder channel 27.

In FIG. 5 a, a backing sheet 39 extended over the entire surface is arranged on the surface of the press roll 3. Over the underlay sheet 39, a size pad 30 used for pressing in the cold foil transfer is arranged. About the pad sheet 39 and the size pad 30, the press fabric 10 is attached. The fixation on the press roll 3 takes place with known clamping means.

As an alternative, in Figure 5b is on the surface of the press roll 3 a over the entire surface extended format pad 31 is attached. The size pad 31 is formed as a high-pressure plate or paint plate known technique. From such a high-pressure plate produced by known plate-making process Presssujet is worked out, which is shortened compared to the reaching over the format length 38 base of the high-pressure plate. Accordingly, a paint plate of known type can be formed. The pressjet forms the effective pressing surface of the size pad 31 used for the press-format-related pressing during cold-foil transfer. About the size pad 31, the press fabric 10 is attached. The fixation of the press fabric 10 on the press roll 3 is also done here with known

Clamping devices. Furthermore, in the arrangement of Figure 5b, a pad sheet below the high-pressure plate or paint plate can be provided.

If in the arrangement of Figure 5b, the press fabric 10 is omitted, as well as an effective size pad 31 may be formed, which can then be used directly for the desired pressure on a selected print format during film transfer. As already indicated above, transition areas Ü at the transitions respectively illustrated from the area outside the respectively defined printing format or press set to the beginning of the printing format at the edge of the format documents 30 or 31 in the arrangements according to FIGS. 5a and 5b.

The printing format or press pattern used here is designated as the application length AL.

The transition areas Ü result from the transition of the support of the press fabric 10 from the press roll 3 or a support such as the Unterla- arc 39 or the base region of the high-pressure plate or the stripped paint plate except for the format documents 30 and 31st

For the transition region Ü, a start-stop ramp for the acceleration and the braking movement of the film web 5 is then set in the film timing. This is necessary for safety reasons to ensure complete film transfer. If an arrangement without press fabric 10 is performed in FIG. 5b, then this transition region Ü-as indicated by the dashed arrows-is reduced to almost zero. The start-stop ramp can then be very short. The start-stop ramp can be adjusted via a corresponding control software for driving the film web 5 and is the same or different adjustable for both format edges, ie at startup and in the process.

In connection with the application length AL, the control parameters for the film timing are entered automatically via a control station or manually by the operator. The control of the film timing then takes place, depending on the nature of the size pad 30, 31 or the structure of format pad 30, 31 and press cover 10 automatically in adapted start-stop ramps.

The above-described relationships with regard to the transition regions Ü and the application length AL also apply to the arrangements according to FIGS. 3, 4 and 6 to 8.

In the figures 6 and 7, the arrangement of a press fabric 10 is shown with respect to a printing format of the same length format documents 32, 33, 34, the may have a same length in the circumferential direction of the press roll 3, but are arranged in each case different assignment to over the format length 38 extending working surface of the press roll 3 with respect to the circumferential direction.

FIG. 6 shows three developments of the surface of the press roll 3. The effective working surface of the press roll 3 is designated by limiting arrows as the format length 38, which extends in the direction of the circumference of the press roll 3. The working surface of the press roll 3 is delimited by a cylinder channel 27, which is here shown in each case at the right end of the format length 38, ie at a printing end 29, and which extends analogously on the press roll 3 up to a print start 28.

In each of the subfigures, a size pad 32 or 33 or 34 is shown on the working surface of the press roll 3, each covering a shorter print format for the cold foil transfer, which is not extended over the entire format length 38. However, the press fabric 10 covers each case the press roller 3 over the entire format length 38 from.

In the first subfigure, the size pad 32 extends from the print start 28 to a position spaced from the print end 29. Thus, a print format for the cold foil transfer can be covered, which extends over the shorter print format corresponding to the size pad 32, starting at the beginning of the print 28 and ending before the print end 29, the format length 38.

In the second subfigure, the size pad 33 extends at a distance from the beginning of the print 28 to a position spaced apart from the print end 29. Thus, a print format for the cold foil transfer can be covered, which extends over the shorter print format corresponding to the size pad 33, starting after the print start 28 and ending before the print end 29, the format length 37.

In the third subfigure, the size pad 34 is extended to the printing end 29 at a distance after the print start 28. Thus, a print format for the cold foil transfer can be covered, which ends on the shorter print format according to the size pad 34, starting after the print start 28 and ending at the end of printing 29, the format length 38. FIG. 7 shows the arrangement of the size pads 32, 33, 34 in the plan view on the working surface of the press roll 3 shown unwound.

The size pad 32 is shown here in a corresponding to the first part of Figure 6 designated narrow working track A.

The size pad 33 is here shown in a corresponding to the first part of Figure 6 designated narrow working track B.

The size pad 34 is here shown in a corresponding to the first part of Figure 6 designated narrow working track C.

However, the format pads 32, 33, 34 can also extend in their respective position to the format length 38 across the entire width transversely to the movement or circumferential direction of the press roller 3.

With the arrangements shown can be achieved in the extent of the distances of the format documents 33, 33, 34 to the print start 28 and / or to the printing end 29 in over the width of the press roller 3 extending format pads 32, 33, 34 a film saving in area cold foil transfer, as in In the areas not covered by the size pad 30 and in which the cylinder channel 27 extends, the film transport during the rotation of the press roller 3 and the impression cylinder 4 with the signature can be stopped. In these areas, the transfer film 5 is not clamped in the region of the transfer gap 6.

In the case of format sheets 32, 33, 34 arranged in working tracks A, B, C, it is possible to achieve a film saving correspondingly to each of the partial film webs using partial film webs of lesser width matched to the working tracks A, B, C. In this case, the transport of the partial film webs is stopped in the previously described areas, if the respective sub-film web is not clamped between the press fabric 10 on the press roller 3 and arranged on an associated impression cylinder 4 printed sheet for performing the film transfer in the region of the transfer gap 6. Of course, this functionality also applies to the region of the cylinder channel 27 for each partial film web. Finally, FIG. 8 shows a distributed arrangement of size pads 34, 35, 36 and 37 on the working surface of the press roll 3. The work surface is again designated by the format length 38.

On the working surface of the press roller 3, the format documents 34 to 37 are distributed in each of a work tracks D, E and F.

In working track D, the format pad 34 is assigned to the print start 28 next. In the working track E, the format documents 35 and 36 are arranged one behind the other wherein the format pad 36 is assigned to the printing end 29 next. In working track F, the format pad 37 is placed in a middle region between the beginning of printing 28 and the end of printing 29.

The formation of the effective pressing surfaces with the press fabric 10 is shown schematically in the circumferential direction of the press roller 3 to the right of the representation of the entire work surface.

Such an arrangement can be achieved by pre-mounting the format pads 34 to 37 on a mounting pad 48. For this purpose, the format documents 34 to 37 may be formed as self-adhesive elements. They can also be attached by means of magnetically acting adhesive. Likewise, a high-pressure plate or a varnish plate known technique can be used here according to Figure 5b, where the format documents 34 to 37 are worked out accordingly. The mounting pad 48 or a corresponding high-pressure plate are preferably provided with register devices 47 for equable mounting on the press roller 3. These are formed, for example, as known register punches on the start of printing 28 and cooperate with corresponding stop devices, such as register pins, on the press roller 3. Thus, a prefabricated pressed article can be produced and easily mounted in the coating module 2 on the press roller 3.

Furthermore, in connection with the register devices 47 or independently thereof, an adjusting device (not shown here) can be used in conjunction with the mounting device. be provided 48 terlage. By means of such an adjusting device, the mounting pad 48 can be positioned independently below the press fabric 10, to adjust the position of the Presssujets the format documents 34 to 37 on the working surface of the press roller 3.

The embodiment according to FIG. 8 is particularly suitable for the use of partial film webs for reduced cold foil transfer. The film feed and the film removal of the coating module 2 are then provided with means for unwinding and winding of partial film webs.

The Teilfolienbahnen are chosen here only as wide as that of the format documents 34 to 37 is specified. The film transport can then be stopped separately for each partial film web in the region of the non-elevated surfaces on the press roller 3 and in the region of the cylinder channel 27. The measures for implementing the mode of operation according to the invention are simple and can be realized for common types of press rolls 3 in the form of blanket or blanket or blanket cylinders.

The format documents 30 to 37 can be applied to the press roll 3 over the whole area or even over part of the area (see FIGS. 3, 7 and 8) in virtually any conceivable arrangement. In this case, an assembly together with the press cover 10 or separately executable. The size documents 30 to 37 may be formed as a conventionally used underlay sheet for blankets or as aufklebbare on the surface of the press roll 3 documents from self-adhesive film. The format documents 30 to 37 are formed from so-called calibrated material whose thickness is precisely determined and whose flatness is of high quality in order to ensure a uniform Beistelldruck for the cold foil transfer in the transfer nip 6. As a principle advantageous and easy to use arrangement a stripped rubber blanket or a paint plate for the production of the size documents 30 to 37 is used. The blanket or the varnish plate then preferably has a talltragerplatte and a photopolymer surface. In this case, no additional covering press fabric 10 must then be used.

As a further advantageous and easy-to-use arrangement, the use of one or more matched to the Presssujet or the application length A-matched pad sheet is provided with a blanket as a press cover 10, so that the pad sheets then allow the cold foil transfer over the desired application length AL.

LIST OF REFERENCE NUMBERS

1 applicator

2 coating module

3 press roll

4 impression cylinders

5 transfer foil / foil web

6 transfer gap

7 roller drive

8 foil supply roll

9 foil collecting roll

10 press clothing

1 1 inking / dampening unit

12 plate cylinders

13 blanket / blanket cylinder

14 film guide

15 print protection

16 dryers

17 Inspection device / monitoring system

18 dancer roller

19 web tension monitoring

20 web tear monitoring

21 pressure cylinder blowing device

22 drive group

23 foil guide roller

24 drive roller

25 film guide roller

26 Cylinder channel of the impression cylinder

27 Cylinder channel of the press roll

28 start of printing

29 end of printing

30 format document

31 format document

32 format document

33 format document

34 format document

35 format document 36 format pad

37 format document

38 format length

39 underlay sheet

40 impression cylinder 41 blanket cylinder 42 blanket / blanket 43 plate cylinder

44 pressure plate

45 adjusting device

46 adjusting device

47 Register device 48 Mounting pad 50 Printing unit

60 pressure gap

K1 format edge

K2 format edge

K3 format edge

A working track

B work track

C work track

D work track

E work track

F working track

T tangent, tangent line Ü transitional range AL application length

Claims

claims

Device for transferring image-forming layers from a carrier film to printed sheets at least with an applicator (1) for image-wise coating the printed sheets with an adhesive and with a coating module (2) for transferring the image-forming layers from the carrier film to the printed sheet in a transfer nip (6) between a counter-pressure cylinder (4) and a press roller (3), wherein the carrier film is guided with the coated side in contact with the printing sheet together with this through the transfer nip (6) and the image-forming layers are imagewise transferred to the printing sheet , and with a device for feeding the transfer film (5) to the coating unit (2) and for discharging from the coating unit (2) with a drive for moving the transfer film in the working direction, wherein the film feed of the transfer film (5) by means of a film guide so controllable is that the transport of the transfer film (5) then is stopped, if in the transfer nip (6) of the coating unit (2) no transfer of an imaging layer takes place on a sheet, characterized

in that a control in connection with a film guide of the transfer film (5) is provided such that the film transport is stopped or started at fixed times when the transfer film (5) is conveyed through the transfer nip (6),

the surface of the press cylinder (3) having a press fabric (10) which is provided with one or more format supports (30 to 37) which contour the support surface of the press fabric (10) on the press roll (3) and extend to an outline of a press surface. is provided, wherein the pressing surface on the press roller (3) is limited to the maximum area to be coated, and

wherein, when passing through a portion of the press roll (3), the film feed is stopped outside the press surface defined by the size pads (30 to 37) on the area to be coated, the press roll (3) slidingly passing through the transfer film (5).

Device according to claim 1, characterized in that

that the transfer film (5) is divided into one or more sub-film webs of lesser width and that the sub-film webs are positioned or side by side supplied to the transfer nip (6), wherein the sub-film webs are provided with the same or different imaging layers and layers of different color and / or different gloss and / or different surface structure can be generated.

Apparatus according to claim 1 or 2, characterized in that the format documents (30, 31, 32) as calibrated underlay sheets (39) for blankets and as together with the press fabric (10) on the press roller (3) tensionable underlay sheet (39) for blankets or as a separately supported and below the press fabric (10) on the press roller (3) mountable and supported pad sheet (39) are formed for rubber blankets.

Device according to Claim 1 or 2, characterized

in that the size documents (30 to 32) are designed as calibrated backing sheets which have been formed on one side and adhered to the surface of the press roll (3) and that they are straddled by means of the press fabric (10).

Apparatus according to claim 3 or 4, characterized in that format documents (30 to 32) formed as a calibrated and one-sided adhesive backing sheet (39), adhesively attached to the surface of the press roll (3) and spanned by the press fabric (10).

Device according to Claim 1 or 2, characterized

in that the size documents (30 to 32) are in the form of vacuum blankets and in that the vacuum blankets are held together with the press fabric (10) on the press roll (3) or the vacuum blankets are held separately and underneath the press fabric (10) on the press roll (3) are mounted and held.

7. Apparatus according to claim 1 or 2, characterized in that

that the size pad (31) is formed as a high-pressure mold, wherein on the high-pressure form a one or more parts of the film transfer comprehensive machined, that the format pad on the surface of the press roll (3) is stretched or adhesively attached and held separately or together with the press fabric (10) on the press roller (3) is designed to be tensioned and that the format documents are spanned by means of the press fabric (10).

8. Apparatus according to claim 1 or 2, characterized in that

format sheets (33 to 37) are formed as individual elements, that the size pads (33 to 37) are adhesively formed on one side, and that the size pads (33 to 37) are releasably adhered to the surface of the press roll (3), with an adhesive or adhesive magnetic adhesion is provided, and that they are spanned by the press fabric (10).

9. Device according to claim 1 or 2, characterized

that format documents (33 to 37) are formed as individual elements, that the format documents (33 to 37) are formed on one side adhering and that the format documents (33 to 37) are releasably adhered to a mounting pad (48), wherein an adhesive or magnetic adhesion it is provided that the mounting pad (48) with the format pads (33 to 37) is held on the surface of the press roller (3) and that the mounting pad (48) with the format pads (33 to 37) by means of the press cover (10) be overstretched.

10. Apparatus according to claim 1 to 9, characterized

in that the format documents (30 to 37) or a mounting pad (48) with format pads (33 to 37) or a format pad (31) in the manner of a high-pressure plate can be positioned so as to be positionable on the press roller (3) by register means (47).

1 1. Device according to claims 1 to 10, characterized in that

in that the size documents (30 to 37) or a mounting pad (48) with format pads (33 to 37) or a format pad (31) in the manner of a high-pressure plate by means of an adjusting device and optionally additional register means (47) on the working surface of the press roller (3) and are positionably mounted opposite or in common with the press fabric (10).

12. Apparatus according to claim 1 to 1 1, characterized

in that the film web (5) is assigned controllable conveying devices for braking and accelerating in time with the processing of the film transfer, wherein the conveying devices (22, 33) designed as roller pairs clampingly guide the film web (5) and the roller pairs are at least partially drivable.

13. A method for coating printed sheets in a sheet-processing machine, in particular a sheet-fed rotary printing press using a transfer film (5) formed from imaging layers and a carrier film for transferring image-forming layers from the carrier film to the printed sheets, characterized

- That at least with an applicator (1) an imagewise coating of a sheet with an adhesive takes place, and

in that a coating module (2) transfers the imaging layers from the carrier film to the printed sheet, wherein in the coating module (2) an impression cylinder (4) and a press roll (3) have a common transfer gap (6) through which the transfer film ( 5) can be guided under pressure such that it is placed with the coated side on the printed sheet guided on the impression cylinder (4),

in which, after the exit of the printing sheet from the transfer nip (6), the image-forming layer adheres to the printed sheet in the area of the adhesive image-forming areas and is lifted off the carrier sheet, the transfer sheet (5) at least in the transfer nip (6) Area of the imagewise coating (s) against the printed sheet. is pressed and

- That a partial increase in the surface of a press fabric (10) on a press roller (3) by inserting format documents (30 to 37) below the press fabric (10) on the press roller (3) is performed in the region of a pressing surface designed as Presssujet, and

in that the transfer film (5) is conveyed through the transfer nip (6) only if there is contact between the press fabric (5) resting on the press fabric (30) resting on the size (30 to 37) on the surface of the press roll (3). 10) rests and the on the counter-pressure cylinder (4) is guided lying lying printing material.

14. The method according to claim 13,

characterized,

in that one or more format pads (30 to 37) are clamped on the press roller (3) separately or in connection with the press cover (10) or are held on the surface of the press roller (3) by means of a mounting pad (48), the mounting pad (48 ) is provided as a magnetic film, adhesive film or vacuum blanket, on which the format documents (30 to 37) are adhesively attached, such that they have a press surface as a press surface, the surface of which is adapted to the surface area of the imagewise coatings, and the transfer film (5), seen circumferentially and / or axially to the press roll (3), is supplied to the transfer nip (6) only in the region of peripheral and / or axial sections provided with pressing surfaces.