EP1981655B1 - Cleaning device for an embossing device - Google Patents

Description

The invention relates to a method and a device for transferring imaging or covering layers from a carrier foil to printed sheets according to the preamble of patent claim 1 and of patent claim 18, respectively.

It is known to produce metallic layers on printed sheets by means of a film transfer process. So is in the EP 0 569 520 B1 a printing material and a printing apparatus using this material are described. In a sheet-fed machine with a feeder and a boom, printing units and a coating unit are arranged. In at least one printing unit, an adhesive pattern is applied as a printed matter in the planographic printing process. In the coating unit after the printing unit, a counter-pressure cylinder, a pressure roller and a film guide are provided. Therein, a foil strip is guided through the transfer nip of the coating unit between impression cylinder and press roll from a film supply roll and wound up again on the exit side after leaving the coating unit. The transfer film contains a carrier film on which functional layers of various types, such as metallic layers, for example of aluminum, or plastic layers can be applied. Between functional layer and carrier film, a separating layer is provided, by means of which the functional layer can be removed from the carrier layer.

After a printing sheet is provided with a two-dimensional adhesive application or an adhesive pattern, it is passed through the coating unit, wherein by means of the pressure roller, the pressure sheet resting on the impression cylinder is brought into contact with the film material. The down-facing functional layer engages tightly with the adhesive-provided areas on the signature. Thereafter, the functional layer adheres only in the area provided with adhesive pattern or even full-surface adhesive areas on, wherein the carrier film, the functional layer is removed in the region of the adhesive pattern. The print sheet is laid out in the coated state.

When applying the coating method, it is possible that detach from the film web or the cut edge before or after the film order small to very small particles that pollute the coating and reduce the success of the work. This can also be done by the coating process itself.

Known in the art are cleaning devices in printing machines such as impression cylinder washing machines or blanket washing devices. These can be designed as cloth washing devices or brush washing devices, also in combination with extraction systems. Likewise suitable for such purposes are Klischeereinigungsanlagen by spraying and suction comparable to a device according to the DE 195 26 574 A1 , Furthermore, spray-suction elements in a traversing arrangement are comparable to a device according to the DE 195 20 551 A1 suitable. Furthermore, cleaning devices as pure suction, eg as suction, usable.

The object of the invention is therefore to provide a method according to the preamble of claim 1 and a device according to the preamble of claim 18, by means of which a film coating of printed sheets can be simple, secure, economical and accurate, and method and apparatus should be easy to handle and in particular, contamination of the coating area due to film waste or impurities originating from the transfer film should be avoided.

The solution of this problem results in a method according to the features of claim 1 and in a device according to the features of claim 10th

According to the invention, an apparatus and a method for cleaning the press roller and / or the film web which is contaminated with film waste or linting of the film edges is proposed. For this purpose, the press roll and / or the guide of the film web are provided with a cleaning system. This can be a known so-called brush washer or a cloth washer or a suction, as they are widely used in printing machines.

Also suitable are Klischeereinigungsanlagen which act by means of the action of a spray and an associated suction device. But it can also be provided in a traversing arrangement, the arrangement of a spray-suction element. Finally, a stripping brush can be provided in a rotating arrangement with integrated suction.

To carry out the cleaning process, the cleaning system is operated inline, i. During the application process, impurities that are continuously accumulated in the press nip are disposed of from the transfer film or film waste. Likewise, the cleaning of the press roll can be done offline, i. the cleaning of the press roller takes place after the end of the application process.

The cleaning can be supplemented by a method and a device which refers to the removal of film residues by means of a suction device on the film web itself. In this case, devices can be used which are arranged similar to a vacuum cleaner on the film guide. Advantageously, a combination of film guide and suction device can be used for this purpose. However, the or a suction device can also be employed as an alternative or in addition to the press cylinder in order to suck off loose particles adhering thereon from the film web.

Depending on the cleaning device, the device can also be used for the printing process, which can be used on the printing unit when the film application is not switched on. Furthermore, an integrated in a control station of the printing press and automated process-generating software ensures that the required processes are coordinated with each other. The automated cleaning of the press roll takes place without additional removal of transfer film and therefore offers a great time savings.

In the following, the invention is illustrated in more detail with reference to drawings.

Figur 1

eine Druckmaschine mit einer Folientransfereinrichtung.

Showing:

FIG. 1

a printing machine with a film transfer device.

FIG. 1 shows parts of a sheet-fed rotary printing press with two printing units. In it, a printed sheet is first provided with a two-dimensional or imaging adhesive pattern (printing unit as commissioned work 1). In the following printing unit, the printed sheet is guided together with a transfer film 5 under pressure through a transfer nip 6 (coating unit 2).

The applicator 1 may be a per se known offset printing unit with an inking unit 11, a plate cylinder 12 and a blanket cylinder 13. The blanket cylinder 13 cooperates with a counter-pressure cylinder 4.

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

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

As in FIG. 1 schematically shown in the order unit 1, can be arranged in an integrated film application module FA and a contractor in a compact design within the coating module. For this purpose, an adhesive application device 1 'associated with the impression cylinder 4 and the transfer gap, which would be provided here between the blanket cylinder 13 and the impression cylinder 3, be arranged upstream. The transfer film would be guided here around the blanket cylinder 13 or approximately tangentially past it through the designated printing nip.

Such an adhesive applicator device 1 'may consist of a compact forme cylinder for supporting a printing form for the adhesive and an applicator of a chamber doctor blade and an anilox roller for supplying the adhesive. In this case, on the same counter-pressure cylinder 4, in turn, the adhesive application is first carried out on the printing substrate and the film application is carried out immediately thereafter.

The film supply roll 8 is assigned to the coating unit 2 on the sheet feed side. The film supply roll 8 has a rotary drive 7 for the continuous controlled feeding of the transfer film to the coating unit 2. In the film feed deflection or tension rollers for guiding the transfer film 5 may be provided in a substantially constant tension against the press roller 3. On the downstream side of the printing unit is a film collecting roll 9 is provided for the used sheet material. A rotary drive 7 on the film collecting roller 9 is always advantageous. It can even be provided that the transfer film 5 is conveyed on the outlet side by means of the rotary drive 7 and held taut on the inlet side by means of a brake.

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

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

The associated device preferably includes a corresponding feed control for the transfer sheet 5, which ensures that at least the lying in the region of the press roller 3 and the impression cylinder 4 part of the film web is stationary as long as the cylinder channel passes.

A further improvement of the film utilization of the type described results when the transfer film 5 is divided into one or more Teilfolienbahnen lesser width. 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 a sheet.

Furthermore, in the film application module thus formed from the applicator 1 and the coating unit 2 dryer 16 may be provided by means of 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.

According to the invention, in the described coating unit 2 or a film application module FA, an apparatus and a method for cleaning the press roller 3, which is contaminated with film waste or linting of the film edges, are used. The impurities occur as mica, mica dust, e.g. on the cutting edge of the film web 5. Mica preferably lays down in the area of the format edges of the film web 5 on the surface of the press roll 3, 3 'and accumulates there cumulatively. To counteract this problem, the press roller 3 is provided with a cleaning device R. This may be a known so-called brush washer or a cloth washing system, as they are widely used in printing machines. These systems can also be combined with suction devices

According to FIG. 1 For example, cleaning means R of the press roll 3 may alternatively be arranged in the sheet transport direction on the front or rear side of the circumference of the press roll 3. Furthermore, a cleaning device R 'can be arranged on the pressure roller 3'.

The cleaning devices R, R 'are arranged on the circumference of the press roll 3 and the pressure roller 3 and arranged abstellbar this. For this purpose, holders and motion drives of known type are arranged in the coating unit 2 or foil application module FA.

To carry out the cleaning process, a cleaning device R or R 'is preferably operated inline. This means that the cleaning devices R or R 'disposed of during the coating process by means of the coating unit 2 and the film application module FA continuously in the press nip 6 impurities or film waste from the transfer film. For this purpose, at least one cleaning device R or R 'is permanently attached to a region of the press roll 3 or the pressure roll 3' free of the transfer film 5.

Likewise, the cleaning of the press roll 3 can take place offline, i. the cleaning of the press roll 3 takes place after completion of the coating process.

Likewise suitable for the cleaning of the press roll 3 or pressure roll 3 'are Klischeereinigungsanlagen. Klischeereinigungsanlagen are known from the application in flexographic printing machines and act by means of the action of a directed onto the surface to be cleaned spray jet and the flushed impurities receiving suction device.

Alternatively, the arrangement of a similarly acting spray suction element can be provided in a traversing arrangement.

Both devices can also be used during the coating operation on the press roll 3, 3 '. In this way, the press roller 3, 3 'constantly be kept free of impurities.

It is also possible to use cleaning devices which have only one suction device, such as e.g. a suction bar.

Finally, a stripping brush can be provided in a rotating arrangement with an integrated device in the stripping brush for the extraction of the stripped contaminants.

Depending on the type of cleaning device R, this can also be used for the conventional printing process, if this is used in unused film coating on the printing unit. Then, the cleaning device R can be used to the blanket cylinder or the impression cylinder 4 for cleaning the surface of color contamination.

Furthermore, a coupled to the machine control of the printing press and automated software ensure that a corresponding mutual coordination of the required processes of coating and cleaning takes place on each other. The automated cleaning of the press roll takes place without additional removal of transfer film and therefore offers a great time savings.

The latter also applies in particular to the offline cleaning, which takes place in the case of the transfer film 5 released from the press roll 3 or pressure roll 3 'so that the transfer film 5 is guided at a distance from the surface of the press roll 3 or pressure roll 3' so that the press roll 3 or pressure roller 3 'can rotate without film transport. In this case, the film web 5 on the press roll 3 or pressure roller 3 'can be under blown by blowing air, so that the film web 5 on an air cushion on the surface of the press roll 3 and 3 Andruckwalze 3' floats.

In offline mode, i. In the case of a transfer film removed from the coating unit 2 or the foil application module FA, without film transfer, an indirect cleaning of the press roll 3 or pressure roll 3 'can take place via the impression cylinder 4 and a washing device R "assigned to it.

Furthermore, the controller can ensure that the cleaning of aggregates involved in the coating process is coordinated with one another.

So, at the same time in offline mode. an inking unit, an applicator, a press roll and involved printing cylinder are cleaned.

The use of cleaning equipment in connection with film transfer applications is not limited to the examples described. Rather, it can also be applied to other areas of the guidance of the film web. This is possible, for example, in the area of guide elements or film rolls or web drives or dancer roll.

In particular, cleaning devices in the form can also be arranged directly in connection with a guide device of the film web of the transfer film 5. In this case, cleaning devices can be arranged both on one side and on both sides of the film web. In particular, the cleaning devices can also be assigned to the edges of the film web, since there the dirt particles or mica particles from the film cut preferably occur.

Furthermore, cleaning devices may be arranged on the film web both in the region of the feed of the transfer film 5 to the transfer nip 6 and in the region of the discharge of the transfer film 5 from the transfer nip 6. This ensures that particles which are first in the transfer nip, e.g. released by the transfer process and dragged along by the film web, also be safely removed and so can not pollute the printing press.

The cleaning devices on the film web are preferably designed as suction devices. As a result, a combination of web guiding devices and cleaning elements can be advantageously used. If necessary, the suction devices can be designed in the manner of so-called vacuum cleaners, as known from the field of sheet guides on sheet-fed presses.

Finally, in the coating device according to Fig. 1 the cleaning devices R, R 'are also designed as combined devices for cleaning the press rolls 3, 3' and the film webs 5, 5 'guided accordingly. For this purpose, in particular a suction device is suitable, which is equipped with corresponding areas of action in the direction of the various elements involved in the transfer process.

The cleaning devices R, R 'can for the combined use of the press roll 3, 3' and the film web of the transfer film 5, 5 'also partially mechanically acting elements, such as brushes, and in addition pneumatically acting elements, such as suction slots have. The pneumatically acting cleaning elements can be carried out on the mechanically acting cleaning device R, R 'retrofitted.

In principle, other possible combinations of cleaning devices based on mechanical, fluidic, pneumatic, electrical or magnetic effects are conceivable within the scope of the invention. The above-described embodiment is not to be understood as limiting the possible embodiments of the invention in this regard. LIST OF REFERENCE NUMBERS 1 commissioned 2 coating plant 3 press roll 4 Impression cylinder 5 Transfer foil / foil web 6 transfer nip 7 roller drive 8th Film supply roll 9 Foil composite role 10 Press covering 11 inking 12 plate cylinder 13 Blanket cylinder 14 guide 15 Printing plant security 16 dryer 17 monitoring device 18 dancer roll 1' commissioned 3 ' pressure roller 5 ' sheet 6 ' press nip R - R " cleaning device FA Foil application module

Claims (19)

1. A method for the transfer of imaging or covering layers of a transfer foil (5, 5') from a substrate foil onto print sheets in a sheet-processing machine, in particular a sheet-fed rotary printing press, at least with a form unit (1) for an imaging or surface coating of a print sheet with an adhesive and with at least one coating unit (2) for the transferring of imaging or coating layers from the substrate foil onto the print sheet, wherein in a coating unit (2) a transfer gap (6) is formed and the substrate foil can be guided along the surface of a press roller (3, 3') placed onto a print sheet with the coated side and under pressure jointly with said print sheet through the transfer gap (6, 6'), so that the imaging or covering layers are adheringly transferred from the substrate foil onto the print sheet in regions provided with adhesive, characterized

   - in that at least one cleaning device (R, R') in the region of a position which is free of the transfer foil (5, 5') is engaged with the press roller (3, 3') in direction of rotation in front of or after the transfer gap (6, 6')

   - and in that the cleaning device (R, R') during the rotation of the press roller (3, 3') is operated in a mode cleaning the surface of the press roller (3, 3') and/or

   - in that at least one cleaning device (R, R') in the region of a guide of a foil web of the transfer foil (5, 5') is engaged with the transfer foil (5, 5') in a region in running direction in front of and/or after the transfer gap (6, 6'),

   - and in that the cleaning device (R, R') during the transport of the foil web of the transfer foil (5) is operated in a mode cleaning the surface or the surfaces and/or the edge regions of the foil web of the transfer foil (5, 5'),

   wherein the cleaning device (R, R') during a coating operating of print sheets is brought in connection with the foil web of the transfer foil (5, 5') by applying a foil coating from a substrate foil (5, 5') in transfer gap (6, 6') in a mode cleaning the surface with the press roller (3, 3') limiting the transfer gap (6, 6') and/or in a mode cleaning the surface or
   wherein the cleaning device (R, R') in the stationary state of a coating operation of print sheets for applying a foil coating from a substrate foil (5, 5') is engaged with the press roller (3, 3') limiting the transfer gap (6, 6') in a transfer gap (6, 6'), wherein the transfer gap (6, 6') is switched without pressure and wherein the transfer foil (5, 5') during the cleaning operation is lifted off the press roller (3, 3') such that the press roller (3, 3') can rotate without touching the transfer foil (5, 5').
2. The method according to Claim 1, characterized in that the cleaning is effected by means of a brush.
3. The method according to Claim 1, characterized in that the cleaning is effected by means of a washing cloth.
4. The method according to Claim 1, characterized in that the cleaning is effected by means of a device for spraying on and sucking off washing medium.
5. The method according to Claim 1 to 4, characterized in that the cleaning is effected subject to the adding of washing agent.
6. The method according to Claim 1 to 5, characterized in that the cleaning is effected subject to the sucking off of contaminations.
7. The method according to Claim 1 to 6, characterized in that the cleaning is effected cyclically when printing couples adjacent to the coating unit (2) or the foil form module (FA) are likewise cleaned.
8. The method according to Claim 1 to 7, characterized in that the cleaning is effected cyclically when consumption or time sequences that can be preset corresponding to the process of the foil coating have been satisfied.
9. The method according to Claim 8, characterized in that the cleaning of the press roller (3, 3') is effected in conjunction with a cleaning in the form unit (1), wherein in the form unit (1) devices for removing coating media from an inking couple and/or from a blanket cylinder and/or an impression cylinder (4) are used.
10. A device for the transfer of imaging and/or covering layers from a transfer foil (5, 5') onto print sheets with at least one form unit (1) for the imaging or surface coating of print sheets with an adhesive and with at least one coating unit (2) for the transferring of imaging and/or covering layers of the transfer foil (5, 5') onto the print sheets, wherein each coating unit (2) comprises a transfer gap (6, 6'), in which the transfer foil (5, 5') at least being at a tangent to a press roller (3) and placed on the print sheet with the coated side under pressure is guided so that the imaging or covering layer is adheringly transferred in the region of the regions provided with adhesive adhering to the print sheet from the transfer foil (5, 5') onto the print sheets, characterized
    in that in a printing press in the coating unit (2) at least one cleaning device (R, R') of a press roller (3, 3') in the region of a position that is free of the transfer foil (5, 5') in direction of rotation in front of or after the transfer gap (6, 6') is assigned to the press roller (3, 3') and/or to a guide of the foil web of the transfer foil (5, 5') in the region of a guide of the foil web of the transfer foil (5, 5') in running direction in front of and/or after the transfer gap (6, 6') and can be brought into functional connection with the press roller (3, 3') and/or the transfer foil (5, 5').
11. The device according to Claim 10, characterized in that the cleaning device (R, R') is a brush washing device, which can optionally be assigned an extraction device.
12. The device according to Claim 10, characterized in that the cleaning device (R, R') is a blanket washing device.
13. The device according to Claim 10, characterized in that the cleaning device (R, R') is a plate washing device, which acts on the surface to be cleaned by means of spraying on washing media and sucking off the contaminations.
14. The device according to Claim 13, characterized in that the cleaning device (R, R') is embodied as a washing unit traversing over the length of the press roller (3, 3').
15. The device according to Claim 10 to 14, characterized in that the cleaning device (R, R') itself is formed as device for extracting contaminations or in that the cleaning device (R, R') is assigned at least one device for extracting contaminations.
16. The device according to Claim 10 to 15, characterized in that a further cleaning device (R") is assigned to an impression cylinder (4) interacting with the press roller (3, 3').
17. The device according to Claim 10 to 16, characterized in that a control device is provided on the sheet-fed printing press by means of which the cleaning device (R, R', R") can be activated, wherein the operation of the cleaning device (R, R', R") can be initiated during the coating operation for the foil coating or outside the coating operation for the foil coating.
18. The device according to Claim 17, characterized in that the control is provided such that the cleaning is effected cyclically according to the consumption or time sequences that can be preset corresponding to the process of the foil coating.
19. The device according to Claim 17, characterized in that the control is provided such that the cleaning of the press roller (3, 3') can be activated in conjunction with a cleaning in the form unit (1), wherein in the form unit (1) devices for removing coating media from an inking couple and/or a blanket cylinder and/or an impression cylinder (4) known per se are provided.

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