EP4209351B1 - Sheet processing machine, use of the sheet processing machine, method for conveying sheets and use of sheet guiding elements containing deionization devices - Google Patents

Description

The invention relates to a sheet processing machine, a use of the sheet processing machine, a method for conveying sheets in a sheet processing machine and the use of a sheet guide element containing a deionization device in a sheet processing machine, in particular a turning device of a sheet processing machine.

For example, in sheet-fed printing machines, increased electrostatic charging of the sheets can occur, especially at high speeds, especially in printing units. In the printing units, this means that a printed sheet is attracted to the following sheet guide plates due to the charge, even despite the presence of air cushions, and the fresh ink on the underside is smeared on the sheet guide plates.

Even in the turning area, increased electrostatic charging of the printed sheets can occur, especially at high speeds. This causes the sheets to enter the cylinder gussets between the turning drum/printing cylinder or the later printing zone in a wavy manner. During a smoothing process, the sheet can no longer be pushed on the printing cylinder surface and is folded.

From the EP 0 306 682 A2 a device for conveying sheets through the printing zone of the rubber cylinder and printing cylinder of a sheet-fed rotary printing machine is known, with deionization rods being arranged upstream of the two ionization rods generating unlike charges, which are directed at the sheet from below or from above, for neutralization of the sheets, with both z. B. with suitable AC voltage can be supplied. This neutralization of the charges creates clear initial conditions for the later positive charging of the arc. To eliminate the frictional connection between the sheet and a cover, a further deionization rod is arranged shortly before the transfer point of the printed sheet to the gripper systems of the sheet removal drum. The arrangement is quite complex and increases the adhesion of the sheets to the cylinder.

From the EP 1 155 834 A2 a device for removing electrical charges from flat material is known, the positive charge of a printing medium lying on a metal plate being compensated for by means of first ionizer tips. Due to the remaining negative charge on the underside of the print carrier, the discharged surface rests against another metal plate, with the negative charge being compensated for by the downstream ionization rod. This complex arrangement is not suitable for sheet guiding elements in sheet processing machines, especially in turning devices of sheet processing machines.

From the EP 1 679 187 B1 or the US 2006/150841 A1 a sheet guiding device with an electrically insulated, comb-shaped edge is known, with an unloading device for unloading the printing material sheets being arranged in the area of the edge. The arrangement in the edge close to the printing cylinder results in a reduced effect. The edge made of non-conductive material is subject to increased wear, especially in the critical area of the arch transfer zone, and causes stability weaknesses in the event of a crash. Furthermore, the arrangement of the discharge device in the concentric interconnect makes it difficult to maintain the optimal electrode spacing, which leads to reduced effectiveness.

From the DE 197 55 745 A1 a device for electrostatically influencing signatures is known, with a flat charging electrode being applied to the guide surface of a sheet guide plate. The device is intended to pull the sheets onto the sheet guide plate through an attractive effect and in one direction through the flow of blown air be kept in suspension. In reality, such a device cannot maintain a stable flying height of the bows. Furthermore, the flat support electrode disrupts the nozzle distribution, which must be designed according to the arch support requirements.

From the DE 100 38 774 A1 a fan unit in a printing press is known, which includes controllable ion fans. Even in a sheet turning device, a sheet of printing material can be guided and turned adhering to the turning drum by means of a generated negative pressure. For this purpose, fan units containing ion fans can be arranged within a cylinder or integrated into its surface. This is time-consuming and not sufficiently effective.

From the DE 10 2007 049 643 A1 a device for turning a sheet during conveyance through a printing press is known, with a brake arrangement for a sheet being arranged fixed to the frame. The braking arrangement consists of a generator for an alternating magnetic field and a pneumatic guide device for the sheet. As the sheet passes the generator, a current should be induced in the ferromagnetic material of the sheet or the printing ink on the sheet. A magnetic field emanating from the eddy current is intended to counteract the field of the generator so that the arc is braked. The effect of this principle is questionable. The arcs are also not discharged because no ions are emitted from the generator.

From the DE 10 2010 028 702 A1 a turning device of a sheet-fed printing press is known, an ionization device being assigned to the sheet transport path on or in conjunction with a storage drum, the sheets guided on the storage drum or the sheets fed to the storage drum being able to be charged with electrical charges.

The DE 100 56 018 A1 shows a device for supporting sheet guidance and sheet storage, with a sheet guide element that blows air enclosing a deionizing device inside.

The DE 10 2008 001 165 A1 shows a sheet-guiding cylinder of a processing machine, the cylinder containing a base body on which a cylinder jacket that is electrically insulated from this is arranged.

The invention is based on the object of creating an alternative sheet processing machine or an alternative method for conveying sheets in a sheet processing machine or of improving the sheet guidance in general in a sheet processing machine, in particular a turning device of a sheet processing machine. In particular, the secure sheet guidance should be improved, especially in the area of a turning device, especially with low grammage or foil sheets.

According to the invention the task is solved by the features of an independent claim. Advantageous refinements result from the subclaims, the description and the drawings. At this point, all embodiments of the invention disclosed in the claims of the documents originally submitted are explicitly included in the description.

The invention has the advantage that an alternative sheet processing machine or an alternative method for conveying sheets in a sheet processing machine is created. In particular, the sheet guidance is further improved, especially in the area of a turning device, which can advantageously lead to a significant increase in the performance of a sheet-processing machine, for example a sheet-fed printing machine, in particular a sheet-fed offset printing machine.

Particularly preferably, deionization of a sheet can be achieved after the sheet has been detached from a sheet guide cylinder, in particular a storage drum, in a turning device. The machine can be suitable or equipped for processing low-weight sheets and/or for processing foil sheets. The machine can process, in particular print, sheet material with a grammage of over 250 g/m ² , but preferably under 250 g/m ² , particularly preferably under 150 g/m ² and very particularly preferably under 80 g/m ² and/or painted.

One, two or more discharge electrodes can preferably be arranged in the area of the sheet guiding element, in particular a sheet guiding plate of a turning device. The arrangement can be done as a cassette. For example, one or more discharge electrodes can be placed on the sheet guide plate or one or more discharge electrodes can be embedded in the sheet guide plate. Electrodes that are embedded are preferably positioned between insulators, the surfaces of which end in particular tangentially on the sheet guide plate.

The sheet guiding element, in particular the sheet guiding plate, preferably delimits the long side of a turning space of a turning device downwards. The sheet guiding element, in particular sheet guiding plate, is preferably spaced from the cylinder tangent between a storage drum and a turning drum in such a way that the distance to the sheet corresponds to the optimal electrode distance. Furthermore, a device, in particular a tightening suction device on the storage drum, can be provided, which additionally stretches or tightens the sheet in the vicinity of the cylinder tangent between the storage drum and the turning drum, so that not only the optimal electrode distance is maintained over the entire sheet length, but also the influence there can be carried out on the sheet, where it remains free of ion-binding contact with grounded machine parts on the top and bottom, so that the ions have little hindrance in the activated deionizing process Ambient air can pass over, which ultimately leads to the maximum possible discharge of the arc.

An unloading cassette is preferably introduced into the sheet guide element, in particular the sheet guide plate, under the turn for unloading the sheets. A discharged sheet is thereby freed from electrostatic forces and can be smoothed so that it can pass a subsequent processing station or printing zone without waves or wrinkles.

In the case of machines containing turning devices, it makes sense, especially when processing printing materials with low grammage or made of film material, to provide deionization devices in addition to the deionization device in the perfecting process in further or preferably all printing units and possibly additional works and/or a delivery, since the printing material is always is recharged in a pressure zone. For this purpose, deionization devices containing sheet guiding elements designed as sheet guiding plates are preferably used, which particularly advantageously ensure optimal unloading and guidance of the printing materials at a suitable distance from the sheet conveying path.

Fig. 1:

Ausschnitt einer bogenverarbeitenden Maschine mit einem einem Bogenfördersystem eines Druckwerkes zugeordneten Bogenleitelement;

Fig. 2:

Vergrößerte Ansicht eines Kammfinger aufweisenden Bogenleitbleches mit Entionisationseinrichtung;

Fig. 3:

Perspektivische Ansicht des Bogenleitbleches mit Kammfingern und Entionisationseinrichtung;

Fig. 4:

Vergrößerte Ansicht eines eine Abdeckung aufweisenden Bogenleitbleches;

Fig. 5:

Abdeckung für Entionisationseinrichtung;

Fig. 6:

Perspektivische Ansicht eines eine Abdeckung aufweisenden Bogenleitbleches;

Fig. 7:

Ausschnitt einer bogenverarbeitenden Maschine mit einer Wendeeinrichtung mit einem eine Entionisationseinrichtung aufweisenden Bogenleitelement;

Fig. 8a:

Ausführungsform eines Bogenleitbleches der Wendeeinrichtung mit aufgesetzter Entladeelektrode;

Fig. 8b:

Ausführungsform eines Bogenleitbleches der Wendeeinrichtung mit integrierten Entladeelektroden;

Fig. 9:

Ausschnitt einer bogenverarbeitenden Maschine mit einem letzten Bogenführungszylinder und einer Auslage;

Fig. 10:

Bogenführungszylinder mit nachgeordneter Kettenradwelle und unterhalb der Kettenradwelle angeordnetem Bogenleitblech;

Fig. 11:

Bogenführungszylinder mit nachgeordneter Kettenradwelle und unterhalb der Kettenradwelle angeordnetem eine Abdeckung aufweisenden Bogenleitblech.

The invention will be explained below by way of example. The associated drawings show schematically:

Fig. 1:

Detail of a sheet processing machine with a sheet guiding element assigned to a sheet conveying system of a printing unit;

Fig. 2:

Enlarged view of a sheet guide plate with comb fingers and a deionization device;

Fig. 3:

Perspective view of the sheet guide plate with comb fingers and deionization device;

Fig. 4:

Enlarged view of a sheet guide plate with a cover;

Fig. 5:

Cover for deionization device;

Fig. 6:

Perspective view of a sheet guide plate having a cover;

Fig. 7:

Detail of a sheet processing machine with a turning device with a sheet guide element having a deionization device;

Fig. 8a:

Embodiment of a sheet guide plate of the turning device with attached discharge electrode;

Fig. 8b:

Embodiment of a sheet guide plate of the turning device with integrated discharge electrodes;

Fig. 9:

Detail of a sheet processing machine with a final sheet guide cylinder and a delivery;

Fig. 10:

Sheet guide cylinder with downstream sprocket shaft and sheet guide plate arranged below the sprocket shaft;

Fig. 11:

Sheet guide cylinder with a downstream sprocket shaft and a sheet guide plate arranged below the sprocket shaft and having a cover.

The Fig. 1 shows, for example, a section of a sheet-processing machine 1, in particular a sheet-fed printing machine, here specifically one
Sheet-fed offset rotary printing machine, preferably in aggregate and series design, especially for film sheet processing. In a preferred embodiment, the machine 1 is a film sheet processing machine, in particular with appropriate equipment. An offset printing machine 1 can be operated in the offset process, but other printing processes such as e.g. B. screen printing, inkjet, etc. can be used in the machine 1. The machine 1 contains any number of sheet processing works, which can be used, for example, as feed, primer, printing, varnish, drying, inspection and/or finishing plant, for example an inline processing plant, can be carried out. In the aggregate and series construction, the successively arranged works of the machine 1 are preferably designed to be largely identical in construction, for example identical substructure modules can be used. Furthermore, the machine 1 can contain a feeder for feeding sheets or an output device for outputting the processed sheets. Furthermore, the machine 1 could also have inline processing devices and/or one or more inline processing units, which can be designed, for example, as a foil finishing unit, cold foil unit, calendering unit, punching unit, numbering unit, screen printing unit, perforating unit, embossing unit, etc. In particular, a turning device 3 is arranged between two works of the machine 1, with which the sheets are turned in a perfecting and reverse printing mode. The machine 1 is preferably designed to be switchable between the straight printing and straight and reverse printing operating modes.

The machine 1 contains in particular at least two or a plurality of printing units 2 and/or one or more coating units for processing sheets. The printing units 2 of the machine 1 preferably each contain a transfer cylinder or blanket cylinder 6 and a forme cylinder or plate cylinder, not shown. A rubber cylinder 6 of a printing unit 2 interacts with a sheet guide cylinder, in particular a printing cylinder 5. A sheet conveying system, preferably a sheet conveying drum 7 or a transfer drum or a transfer cylinder, is provided between two sheet guiding cylinders, in particular printing cylinders 5. The printing cylinders 5 and the sheet conveyor drum 7 are double-sized and the blanket cylinders 6 and the plate cylinders are single-sized. Single-sized cylinders can hold approximately one and double-sized cylinders can hold approximately two sheets of maximum format at the same time on the circumference. In an alternative embodiment, the sheet guide cylinders, in particular printing cylinders 5, or transfer or transfer drums could also be designed to be single-sized, triple-sized or larger.

The double-sized printing cylinders 5 and the sheet conveyor drum 7 each preferably have two gripper systems for fixing sheets to be conveyed, in particular sheets of film. These gripper systems, which are arranged diametrically to one another, for example in gripper channels, hold the sheet to be processed for conveyance. The gripper systems preferably have fixed gripper surcharges, which interact with gripper fingers that can be moved via roller levers, for example by means of control cams and cam rollers, to clamp the sheets. The gripper impacts of the printing cylinder 5 and the sheet conveyor drum 7 describe a gripper impact path during their respective rotation, which largely corresponds to the sheet conveying path. During conveyance, the sheets can rest on the respective cylinder or the cylinder surface of a sheet guide cylinder, in particular printing cylinder 5. The sheets are transferred between the sheet guide cylinders, in particular printing cylinders 5, and the sheet conveying systems, in particular sheet conveying drums 7, of the printing units 2 of the machine 1, preferably in gripper closure. The last work of the machine 1 is preferably followed by a delivery 4 with a delivery chain circle, which takes the sheets from the last sheet guide cylinder, in particular a printing cylinder 5, by means of a gripper carriage and conveys them to a delivery stack. For example, a last work of the machine 1 before the delivery 4 can be designed as a printing, coating, drying, inspection or finishing work such as an inline processing work.

In the printing units 2 of the machine 1, the rubber cylinders 6 are in operative connection with the plate cylinders and known inking or inking and dampening units are arranged, which apply the corresponding printing ink to a printing plate stretched on the respective plate cylinder. A plate cylinder is inked by at least one, but preferably several, rollers of the associated inking or inking and dampening unit during its rotation. When the plate cylinder is unrolled on the rubber cylinder 6, the printing ink is applied to the motif using a rubber blanket covered rubber cylinder 6. A printing gap or a printing zone is formed between a rubber cylinder 6 and a printing cylinder 5, through which the sheet to be printed is conveyed by the printing cylinder 5 by means of the gripper systems. In the printing gap, the printing ink is transferred from the rubber cylinder 6 onto the sheet in accordance with the motif. The printing cylinder 5 in particular has a full-surface lateral surface for carrying the sheets to be conveyed, which forms the printing gap with the rubber blanket of the rubber cylinder 6.

A plate cylinder and a blanket cylinder 6 of a respective printing unit 2 of the machine 1 preferably each have a cylinder pin on both sides, via which the cylinders are rotatably mounted in the frame of the respective printing unit 2. Both plate cylinders and blanket cylinders 6 preferably each have bearing rings (not shown) arranged on both sides. The plate cylinder bearing rings are in contact with the rubber cylinder bearing rings during the printing process and roll against each other under pressure. The bearer rings are preferably dimensioned in such a way that no significant torque transfer takes place between the cylinders during printing operation, i.e. no predetermined torque is transmitted via the bearer rings.

The machine 1 preferably has a drive wheel train, which particularly preferably drives the sheet guide cylinders, in particular printing cylinders 5, of the printing units 2 as a continuous drive gear train. The sheet conveyor systems, in particular the sheet conveyor drums 7 or transfer drums or transfer cylinders, are also preferably driven by the drive wheel train. The printing cylinders 5 and the sheet conveyor drums 7 each have interlocking gears that form the drive wheel train. The drive wheel train is driven by at least one main drive motor, which drives in the middle or preferably in the area of the front works of the machine 1. For example, the input of the main drive motor in the first system in the sheet conveying direction BFR can be done directly following first printing unit 2, in particular on the gear assigned to the shaft of the first printing cylinder 5. The cylinders or drums are driven around their respective axis of rotation by the continuous drive wheel train. The rubber cylinders 6 of the printing units 2 are also preferably driven by the drive wheel train. Further rotating bodies or rollers of the machine 1 or the printing units 2 can also be driven at least temporarily by the drive wheel train, and these can also be designed to be coupled to the drive wheel train.

For example, an individual drive, in particular a plate cylinder direct drive, can be assigned to one or each plate cylinder of a printing unit 2. Direct drives are in particular individual drives whose rotors are aligned and preferably mounted concentrically directly to the assigned cylinders. During printing, the plate cylinder in question can then be electronically synchronized with the rubber cylinder 6, which is preferably driven by the main drive motor via the drive wheel train. For this purpose, a rotary encoder can be assigned to the plate cylinder and/or blanket cylinder 6, which can be connected to a quality control device, a control unit of the printing unit 2 and/or the machine control. Alternatively, the plate cylinder(s) can also be driven via the drive wheel train from the main drive motor, for example via clutches.

In a film sheet processing machine 1, sheet substrate containing film material or sheet substrate consisting of film material is processed, in particular printed and/or varnished. For processing foil sheets, the sheet processing machine 1 has, in particular, suitable equipment. The foil sheet processing machine is preferably designed as a foil sheet printing machine at least for printing foil sheets. In particular, the machine 1 can have a film sheet processing package that is specifically adapted to the film material. For example, the machine 1 can have at least one, for example Printing units 2 contain a primer unit upstream and/or contain a special double sheet control device and/or the gripper systems of the machine 1 can be adapted to the low thickness of the film sheet material and/or printing inks and/or varnishes or dryers used can be adapted to the film material. Film material can be, for example, film made of PVC, PP, PS, PET. A machine 1 could also process special papers, laminated papers or cardboard boxes.

Particularly when printing foil, the foil sheets are charged in each active printing unit 2 of the machine 1. The foil sheets become extremely statically charged again, especially during each printing process. In particular, deionization devices 8 are therefore provided at least in the printing units 2 and/or coating units of the machine 1, which are arranged downstream of the printing nip of the first printing unit 2 of the machine 1 with respect to the sheet conveying direction BFR. Deionization devices 8 are preferably provided in all works of the machine 1 downstream of the first printing unit 2. But a deionization device 8 can also be assigned to a system and/or the first printing unit 2 of the machine 1. The deionization devices 8 are provided in particular in each printing unit 2 and/or coating unit of the machine 1, with only one deionization device 8 being arranged in particular in each printing unit 2 and/or coating unit. More preferably, such a deionization device 8 is also provided in one or each additional plant, such as a paint, drying, inspection or finishing plant. Charging devices for the targeted charging of cylinders or sheets are particularly not provided.

The sheets, in particular foil sheets, are conveyed or transported along a sheet conveying path by the sheet guiding cylinders, in particular printing cylinders 5, and the sheet conveying systems, in particular sheet conveying drums 7, of the machine 1. This is particularly true below and along the sheet conveyor path One or all printing units 2 are provided with a sheet guiding element starting in the area of the sheet guiding cylinder, in particular printing cylinder 5. Such a sheet guiding element is preferably designed as a metal sheet guiding plate 9 in particular, which extends in particular over the width of the machine. In particular, such a sheet guide plate 9 has comb fingers 10 in the area facing the sheet guide cylinder, in particular printing cylinder 5. With regard to the sheet conveying direction BFR, the comb fingers 10 are each followed by a deionization device 8, wherein the comb fingers 10 of the sheet guide plate 9 consist in particular partially or completely of metallic material. Furthermore, the comb-shaped areas of the sheet guiding elements could be provided with blown air openings and in particular could be converted to blown air, so that a force acting pneumatically on the sheets can be generated in these areas. In particular, the sheets, in particular foil sheets, could therefore be peeled off from the lateral surface of the upstream sheet guide cylinder, in particular printing cylinder 5, by the pneumatically acting comb fingers 10. The sheet guiding surfaces of the comb fingers 10 are therefore assigned blown air openings that can be pressurized. In particular, the excess pressure above ambient pressure exerts a blowing air effect on the sheets conveyed along the sheet conveying path.

A sheet guiding element, in particular sheet guiding plate 9, below a sheet conveying system, in particular a sheet conveying drum 7, can consist of a one-piece sheet or can also be composed of several sections. For example, an upstream guide piece can form a first area and a downstream guide piece can form a second area for sheet guidance. For example, a first section or partial sheet can extend from the jacket of the sheet guide cylinder, in particular the printing cylinder 5, to vertically below the axis of rotation of the sheet conveyor drum 7. A second section or partial sheet can connect in the sheet conveying direction BFR and up to the lateral surface of the downstream sheet guide cylinder, in particular the printing cylinder 5, enough. A deionization device 8 is assigned in particular to the first section of the sheet guiding element. In particular, the deionization device 8 is assigned to the sheet guiding element or the sheet guiding surface of the sheet guiding element in the area of the upstream sheet guiding cylinder, in particular printing cylinder 5. Particularly preferably, the deionization device 8 forms the sheet guide surface in its arrangement area.

In particular, the section or a second region of the sheet guiding element, in particular sheet guiding plate 9, which is downstream with respect to the sheet conveying direction BFR, is designed concentrically to the axis of rotation of the sheet conveying system, in particular the sheet conveying drum 7. In particular, the sheet guide surface of the second section of the sheet guide element, in particular the sheet guide plate 9, is designed concentrically around the axis of rotation or the gripper impact path of the sheet conveyor drum 7. The first section of the sheet guiding element, in particular the sheet guiding plate 9, in or from the area of the sheet guiding cylinder, in particular printing cylinder 5, can have a sheet guiding surface that constantly approximates the rotation of the sheet conveying system, in particular the sheet conveying drum 7. The sheet guiding element is therefore designed in a spiral shape. The first section can also be designed concentrically around an axis spaced from the axis of rotation of the sheet conveyor drum 7.

In particular, a sheet guiding element, in particular a sheet guiding plate 9, can be assigned at least one fan 14, which can be controlled in particular to generate blowing and/or suction air. A fan 14 is preferably arranged on the sheet guiding element, in particular a sheet guiding plate 9, in such a way that it generates blowing and/or suction air in the area of the sheet guiding surface of the sheet guiding element, in particular the sheet guiding plate 9. The sheet guiding element, in particular sheet guiding plate 9, is assigned corresponding openings, for example Venturi nozzles, facing the sheet conveying path. Outside any openings provided The sheet guiding element, in particular sheet guiding plate 9, but preferably has a closed sheet guiding surface.

In particular, a sheet guiding element, in particular sheet guiding plate 9, can be designed such that a sheet guiding surface extends in the area of the lateral surface of the sheet guiding cylinder, in particular printing cylinder 5, starting up to the downstream sheet guiding cylinder, in particular printing cylinder 5, below the sheet conveying system, in particular the sheet conveying drum 7. A first region of the sheet guiding element, in particular sheet guiding plate 9, starting in the area of the upstream sheet guiding cylinder, in particular printing cylinder 5, can have the comb fingers 10 and be further away from the axis of rotation of the sheet conveying system, in particular the sheet conveying drum 7, than a subsequent second region of the sheet guiding element, in particular sheet guide plate 9. A largely closed sheet guide surface for the sheets is preferably formed by the comb fingers 10 and the first region of the sheet guide plate 9.

The first area of the sheet guide plate 9 can begin in a rotation angle range of the sheet conveyor drum 7, which is spaced between 15° and 25°, in particular approximately 20°, from the transfer centers formed by gripper closure between the upstream printing cylinder 5 and the sheet conveyor drum 7. The sheet guide plate 9 or the comb fingers 10 can be arranged at a distance of, for example, 2 mm to 50 mm, in particular between 25 mm and 30 mm, from the sheet conveying path formed by gripper impacts of the sheet conveying drum 7. The first area of the sheet guide plate 9 preferably steadily approaches the axis of rotation of the sheet conveyor drum 7 or the sheet conveyor path.

In a second region of the sheet guiding plate 9 adjoining the first region of the sheet guiding plate 9 in the sheet conveying direction BFR, the sheets are preferably guided concentrically to the axis of rotation of the sheet conveying drum 7 or a guide parallel to the gripper impact path of the sheet conveyor drum 7 or parallel to the sheet conveyor path. The second area of the sheet guide plate 9 can, for example, be designed at a distance of 5 mm to 10 mm from the sheet conveying path. The second area of the sheet guide plate 9 can, for example, begin in a rotation angle range of 60 ° to 90 ° at a distance from the transfer center between the printing cylinder 5 and the sheet conveyor drum 7. The sheet guiding element, in particular the sheet guiding plate 9, can thus be designed in such a way that its first region, which is upstream of the sheet conveying direction BFR, has a multiple, for example double or triple, distance from the gripper impact path or the sheet conveying path compared to the downstream second region.

A deionization device 8 is preferably arranged in the first region of the sheet guide plate 9, with this being arranged downstream of the comb fingers 10 in the sheet conveying direction BFR when comb fingers 10 are provided. Comb fingers 10 can, for example, extend over a rotation angle range of the sheet conveyor drum 7 of approximately 5°. A deionization device 8 can directly follow the comb fingers 10 or extend over a rotation angle range of the sheet conveyor drum 7 of at least approximately 10°. The sheet guide surface of the sheet guide plate 9 formed by the comb fingers 10 and/or deionization device 8 approaches, in particular, steadily, as seen in the sheet conveying direction BFR, the axis of rotation of the sheet conveyor drum 7 or its gripper impact path or the sheet conveyor path. For example, the first area of the sheet guide plate 9 can merge into the second area, which is largely concentric to the sheet conveying path, within a rotation angle range of the sheet conveying drum 7 of, for example, approximately 60 °. The machine 1 can have further works or printing units 2, with some or preferably all works or printing units 2 comprising or containing sheet guiding elements, in particular sheet guiding plates 9, for sheet guidance. The sheet guiding elements, in particular sheet guiding plates 9, of the machine 1 are in particular designed to be identical in construction.

The Fig. 2 shows an enlarged view of a sheet guide element designed as a sheet guide plate 9 with a deionization device 8. The deionization device 8 here has a cassette arranged in the sheet guide plate 9 with at least one discharge electrode 12. Preferably, the cassette can be embedded in the sheet guide plate 9 below a sheet conveyor system, in particular the sheet conveyor drum 7, and can also have a plurality of preferably similar discharge electrodes 12. The cassette here preferably has two discharge electrodes 12. The cassette is preferably arranged downstream of metallic comb fingers 10, in which case an upstream guide surface section 9.1 can also be formed between the comb fingers 10 and the cassette. In the sheet conveying direction BFR, the cassette of the deionization device 8 is preferably directly followed by a downstream guide surface section 9.2 of the sheet guide plate 9. In this arrangement, the upstream guide surface section 9.1 and the downstream guide surface section 9.2 are part of a common guide surface of the sheet guiding element 9. Particularly preferably, the upstream guide surface section 9.1 and/or the downstream guide surface section 9.2 is also made of metal.

The sheet guiding element, in particular the sheet guiding plate 9, preferably encloses the sheet conveying system, in particular the sheet conveying drum 7, for example a transfer drum without a lateral surface, in a spiral shape. This means that the front part of the sheet guiding element, in particular the sheet guiding plate 9, is kept further apart from a rotation axis of the sheet conveying system, in particular the sheet conveying drum 7, than the following part of the sheet guiding element, in particular the sheet guiding plate 9. The sheet guiding element, in particular the sheet guiding plate, then moves 9, preferably tangentially into a concentric radius to the sheet conveyor system, in particular the sheet conveyor drum 7, in order to achieve the optimal electrode spacing in the areas of the furthest distance from the guide plate spiral, with the exception of the comb finger 10. This means that the guide surface of the Sheet guiding element 9 approaches the radius of the sheet conveying drum 7 in the sheet conveying direction BFR and then leads around it concentrically to the radius of the sheet conveying drum 7.

The Fig. 3 shows a perspective view of the sheet guiding element, in particular sheet guiding plate 9, with comb fingers 10 and deionization device 8. The comb fingers 10 facing a sheet guiding cylinder, in particular the printing cylinder 5, contain spaced apart, in particular metallic, finger elements, between which the movable gripper fingers of the gripper systems of the sheet guiding cylinder, in particular of the printing cylinder 5, can be passed through. The comb fingers 10 can, for example, be arranged at a distance of a few millimeters, for example between 1 and 10 mm, preferably between 2 mm and 3 mm, to the lateral surface of the printing cylinder 5. With regard to the sheet conveying direction BFR, the deionization device 8 is arranged downstream of the comb fingers 10. The deionization device 8 preferably contains both insulators 11 and one or more discharge electrodes 12 provided with electrical connections. The discharge electrodes 12 are connected to a controllable generator, in particular a high-voltage generator.

The insulators 11 of the deionization device 8 are each arranged transversely to the sheet conveying direction BFR, preferably over the entire width of the sheet guiding plate 9 and have surfaces arranged perpendicular to the sheet conveying path or to the sheet guiding surface of the sheet guiding plate 9. Each discharge electrode 12 is arranged here in particular between two insulators 11. A front insulator 11 with respect to the sheet conveying direction BFR adjoins the particularly metallic comb fingers 10 with its vertical or tangential surface. After the deionization device 8, the sheet guide plate 9 preferably directly adjoins a vertical or tangential surface of a rear or last insulator 11 with respect to the sheet conveying direction BFR.

The Fig. 4 shows an enlarged view of a sheet guide element having a cover, in particular a sheet guide plate 9. The complete deionization device 8 or the complete unloading cassette can be arranged interchangeably in the sheet guide plate 9. Alternatively, the deionization device 8 can also be left in the sheet guiding element, for example rigidly or by means of displacement, whereby a cover, for example a cover part 13, can also close the opening. For example, a cover for the discharge-generating elements is provided by means of a cover made of non-conductive material, in particular plastic, which in particular has openings or cutouts. The cutouts are preferably arranged in such a way that the charge carriers of the discharge electrodes 12 are not influenced. An arrangement above the discharge cassette is preferably carried out in such a way that the ions emerge through preferably narrow slots and can thus reach the underside of the sheet.

The Fig. 5 shows, for example, a cover for a deionization device 8 of a sheet processing machine, as described above. The cover is arranged as a cover part 13 transversely to the sheet conveying direction BFR above the deionization device 8, not shown, in particular a discharge electrode 12, and in particular is made entirely of a non-conductive material, in particular plastic. The cover part 13 has a plurality of preferably uniformly arranged elongated holes oriented transversely to the sheet conveying direction BFR, which here, for example, have a dimension of 25 mm transversely to the sheet conveying direction BFR and 8 mm in the sheet conveying direction BFR. In particular, each elongated hole is assigned an electrode tip of the deionization device 8, in particular the discharge electrode 12, that emits positive ions and one that emits negative ions. The electrode tips indicated here act through the elongated holes, but in particular do not protrude into the sheet guide surface of the cover. The electrode tips are therefore preferably below the surface or at a distance from it Sheet guide surface of the cover part 13 is arranged. A discharge electrode 12 here has alternating, in particular equally spaced, positive and negative ion-emitting electrode tips, which can work with or without blown air support.

The Fig. 6 shows a perspective view of a sheet guide element having a cover part 13, in particular a sheet guide plate 9. The cover part 13 is inserted into the sheet guide plate 9 in such a way that a preferably continuous sheet guide surface that is as trouble-free as possible is formed. Blowing air openings in the sheet guiding element, in particular sheet guiding plate 9, can be provided and are not shown. However, Venturi nozzles are preferably provided in the sheet guiding surface of the sheet guiding element, in particular the sheet guiding plate 9, blowing to the side. These are particularly preferably arranged on the input and/or output side with a blowing direction component towards the edges of the sheet guiding surface. This enables a resulting balanced floating height of the sheets on an air cushion, which lies approximately in the gripper impact path, ie that the pressure forces of the flow on the sheet only represent a counterpart to its surface load, which, for example, is only 1 Pa for a 100 g/m ² sheet and at z. B. a 28 g/m ² sheet is almost 0 Pa. The forces acting on the sheet through the Venturi nozzles therefore depend on the flow gap between the sheet guide surface and the sheet. If there is a deviation from the balanced flying height, the force effect is always aligned back to this balanced flying height. The increase in pressure forces below the flying height when the sheet approaches the sheet guiding surface is comparatively higher than the increase in suction forces when moving away from the sheet guiding surface beyond the flying height.

The mechanism of action is that disruptions are caused by the extreme adhesion forces resulting from the printing press between the sheet, in particular the film sheet, and the sheet guide cylinder, in particular the printing cylinder 5 become. When transferring the sheets from the sheet guide cylinder, in particular printing cylinder 5, to the sheet conveying system, in particular the sheet conveying drum 7, the sheet is difficult to detach because the pull-off forces only act tangentially. As the movement progresses, the sheet cuts the sheet conveyor drum radius as a secant due to the pull-off forces in the sheet and the resulting "excess" of unwound sheet length allows the sheet adhering to the printing cylinder surface to continue to follow the printing cylinder 5. This increases the only really detaching radial components of the previously only tangentially acting pull-off force, but these are still small and the sheet continues to follow the printing cylinder surface until the release loop of the sheet is peeled off by the pneumatically acting forces of the comb plate, in particular without mechanical contact. The air cushion generated by the Venturi nozzles cannot take part in the withdrawal of the sheet from the printing cylinder 5, since the suction potential of the air cushion does not act on the regular sheet path or the balanced floating height.

Furthermore, the sheet is attracted to the sheet guide element, in particular sheet guide plate 9, by the electrostatic charge when it is pulled off in this way from the sheet guide cylinder, in particular printing cylinder 5, and would be placed on it. The existing air cushion of the sheet guide plate 9 could act as a surface load against the unevenly distributed field forces of the electrostatic charge and therefore not create a balance and therefore not a floating state. There would be areas of intensive contact with the sheet guide plate 9. However, any intensive contact with the sheet guide plate 9 leads to visible scratches in the surface of the sheets, especially of foil sheets, or to smearing, especially on sheets of paper. However, due to the special design of the sheet guiding element described above, in particular a sheet guiding plate 9, an effective distance-preserving measure for scratch-free or smear-free guidance of sheets, in particular foil sheets, on the sheet guiding surface under a sheet conveyor system, in particular the sheet conveyor drum 7, after the sheet has been detached sheet from the sheet guide cylinder, in particular printing cylinder 5, created. The solution created prevents the sheet, in particular the foil sheet, from coming into contact with the sheet guide element, in particular the sheet guide plate 9, especially with the comb and the following guide surface parts, and thus prevents scratches or smearing.

In the machine 1, a control or an automatic sensor-controlled regulation of one, several or all discharge electrodes 12 of one, several or all deionization devices 8 of the machine 1 can also be provided. For example, individual discharge electrodes 12 or several discharge electrodes 12 of a deionization device 8 or several or all deionization devices 8 of the machine can be connected to a generator, in particular a high-voltage generator. The discharging effect can be adjusted by controlling the generator. For example, the intensity of the deionization device 8 can be controlled or regulated by measuring technology in such a way that it is possible to control or regulate the discharge in a manner adapted to the existing statics on the sheet, in particular a sheet of film. Furthermore, particularly in the case of exchangeable unloading cassettes, these can be arranged elsewhere on the machine 1. In particular, such a cassette or deionization device 8 can be used in the turning space. The unloading cassettes can therefore be designed to be interchangeable with one another in the machine 1 or have a modular structure.

The Fig. 7 shows a section of a sheet processing machine 1 equipped, for example, for film sheet processing, in particular as described above, with a turning device 3 and with a sheet guiding element. The turning device 3 is designed here as a three-drum turning device and contains a transfer drum 15, a storage drum 16 and a turning drum 17. The turning device 3 is preferably arranged between printing units 2 of the machine 1, with the transfer drum 15 being a sheet guide cylinder, in particular printing cylinder 5, of a printing unit 2 directly Upstream or downstream of the turning drum 17 is a sheet guide cylinder, in particular printing cylinder 5, of the following printing unit 2. The printing cylinders 5 are in turn operatively connected to a rubber cylinder 6 and this further to a plate cylinder, not shown, in the printing units 2, as described above. The machine 1 can be switched between the straight printing and straight and reverse printing operating modes, whereby in the straight printing operating mode, sheets are conveyed without turning by transferring the leading edge of the sheet between the drums.

The transfer drum 15 and the turning drum 17 of the turning device 3 are, for example, single-sized and the storage drum 16 is, for example, double-sized. For sheet conveying, the transfer drum 15 has a gripper system (not shown) arranged in a gripper channel for clamping the sheets at the front edge. The sheets are transferred in the gripper connection to a gripper system of the storage drum 16, which is also not shown and is arranged in a gripper channel. The sheets are clamped at the front edge of the storage drum 16 and fed to the turning drum 17 during the rotation of the storage drum 16. The turning drum 17 contains a gripper system, also not shown, for sheet conveying, in particular grippers and/or suction cups, which are pivotably mounted in the turning drum 17. Alternatively, the turning drum 17 can also contain a pliers gripper system for taking over or conveying the sheets. Other cylinder arrangements or other cylinder sizes can also be used. For example, the transfer drum 15 can also be designed to be double-sized.

In the face printing operating mode, the sheets are taken over by the gripper system of the turning drum 17 in a transfer center at the front edge from a gripper system of the storage drum 16. When a sheet is turned in perfecting and reverse printing, this sheet is guided past the transfer center by the storage drum 16 and grasped at the rear edge by the gripper system of the turning drum 17. This captured sheet is then used during the Rotational progress of the turning drum 17 is turned according to the principle of rear edge turning, so that its old rear edge becomes the new front edge from its reversal of movement and the old front edge lying on the storage drum 16 becomes the new rear edge. The turning device 3 is assigned a sheet guiding element to support the sheet guidance, particularly in the perfecting and reverse printing mode. For example, a sheet guiding element, designed in particular as a sheet guiding plate 9, can be arranged below the storage drum 16 and the turning drum 17 to support the sheet guidance. The sheet guiding element, in particular sheet guiding plate 9, can also be designed, for example, as a sheet guiding element, in particular sheet guiding plate 9, which can be moved depending on the operating mode. A sheet guide element that can be moved in this way, in particular a sheet guide plate 9, can be delivered to the sheet conveying path for sheet guidance at least in the perfecting and reverse printing operating mode.

The storage drum 16, which is not shown in detail, can, for example, have format-adjustable jacket segments, which interlock like a comb when the format is adjusted and form the sheet-bearing jacket surface. The two gripper systems of the double-sized storage drum 16 for the leading edges of the sheets, which are arranged diametrically to one another, are arranged on preferably fixed front jacket segments. Fixing systems, in particular suction systems, for example rotary suction cups and/or tightening suction cups, can be provided on the rear casing segments, which are adjustable relative to the front casing segments, for taking over and guiding the trailing edges of the sheet. By means of rotary suction cups, the sheets can be tightened, in particular longitudinally and/or transversely, while lying on the storage drum 16 during the sheet conveyance from the transfer drum 15 to the turning drum 17. Even when the turned sheet is removed from the storage drum 16 by the turning drum 17, the sheet can preferably be tightened by the fixing systems, in particular suction systems such as the rotary suction cups or tightening suction cups in the tines of the rear adjustable jacket segments of the storage drum 16.

To support the sheet guidance in perfecting and reverse printing, the sheet guiding element arranged below the storage drum 16 and the turning drum 17 can be designed to be adjustable, so that its sheet guiding surface is aligned at least approximately parallel to the sheet conveying path. The sheet conveying path corresponds at least approximately to a surface which is applied tangentially to both the lateral surface of the storage drum 16 and the turning drum 17. The sheet guiding surface of the sheet guiding element, in particular the sheet guiding plate 9, can also be slightly closer to the turning drum 17. The sheet guide element, in particular the sheet guide plate 9, has at least partially a flat guide surface 9.3, which is particularly preferably located below the turning drum 17, in particular below the axis of rotation of the turning drum 17. A deionization device 8 is assigned to the sheet guide element, in particular the flat guide surface 9.3 of the sheet guide plate 9. The deionization device 8 has at least one discharge electrode 12 for discharging an arc. The deionization device 8, in particular the at least one discharge electrode 12, causes a discharged sheet to be freed from electrostatic force effects so that it can be smoothed in such a way that it can pass through the subsequent printing gap or the printing zone without waves and without wrinkles.

The Fig. 8a shows an embodiment of a sheet guide plate 9 of the turning device 3 with an attached discharge electrode 12. The discharge electrode 12 is arranged transversely to the sheet conveying direction BFR, preferably across the machine width, and is provided with corresponding electrical connections. The discharge electrode 12 is preferably assigned to the flat guide surface 9.3 of the sheet guide plate 9, with the flat guide surface 9.3 in the sheet conveying direction BFR being able to be followed by an area approximating the turning drum 17. Preferably, at least one fan 14 can be assigned to the sheet guiding element, in particular the sheet guiding plate 9, which can be controlled in particular to generate blowing and/or suction air. Dem Sheet guiding element, in particular sheet guiding plate 9, is associated with corresponding openings, for example Venturi nozzles, facing the sheet conveying path. In particular, the fan 14 can generate suction and/or blowing air at least in the area of the flat guide surface 9.3 of the sheet guide plate 9. The fan 14 can be provided in the area of the discharge electrode 12 on the opposite side of the sheet guide plate 9. The sheet guiding element, in particular the sheet guiding plate 9, can also be made in one piece or consist of several sections, with a fan 14 also being able to be assigned to an upstream section arranged largely below the storage drum 16.

The Fig. 8b shows an embodiment of a sheet guide plate 9 of the turning device 3 with an integrated deionization device 8. The deionization device 8 can have a cassette embedded in the sheet guide plate 9, which is designed to be exchangeable. The deionization device 8 preferably has a plurality of discharge electrodes 12, which are arranged at a distance from one another transversely to the sheet conveying direction BFR, preferably across the machine width. Insulators 11 are preferably positioned between the discharge electrodes 12, which are preferably embedded here, the surfaces of which end tangentially on the sheet guide plate 9, in particular as already described above. The sheet guiding element, in particular sheet guiding plate 9, can preferably be assigned at least one fan 14 for generating blowing and/or suction air, in particular at least in the area of the flat guiding surface 9.3, as described above. Furthermore, in the case of the at least one embedded discharge electrode 12, a cover can be provided to produce a largely closed sheet guiding surface in the area of the discharge electrode 12. In this case, a cover part (not shown) which has openings adapted to one or more discharge electrodes 12 can be assigned to the sheet guide plate 9, in particular directly above the discharge electrode 12 or discharge electrodes 12, in particular as described above. The cover part, not shown, can be designed or arranged as described above.

One of the sheet guiding elements described, in particular such a sheet guiding plate 9, is assigned to the transfer area between the storage drum 16 and the turning drum 17 in the machine 1. A sheet guide plate 9 in particular delimits the long side of the turning space downwards and is arranged at a distance from the cylinder tangent between the storage drum 16 and the turning drum 17 so that the distance to the sheet corresponds to the optimal electrode distance. Furthermore, a fixation of the sheet lying on the storage drum 16 can be provided by the fixing systems, in particular suction systems, for example rotary suction cups and/or tightening suction cups, of the storage drum 16, so that the sheet is additionally stretched or tightened in the vicinity of the cylinder tangent between the storage drum 16 and the turning drum 17 becomes. In particular, this can ensure that not only the optimal electrode spacing is maintained over the entire length of the arc, but that the influence can be carried out on the arc where it remains free of ion-binding contact with grounded machine parts on the top and bottom. This advantageously means that the ions can pass into the activated deionizing ambient air with little hindrance.

The Fig. 9 shows, for example, a section of a sheet processing machine 1, in particular a film sheet processing machine 1, for example as described above, with a delivery 4. The machine 1 is accordingly preferably equipped for film sheet processing and in particular is designed as a film sheet processing machine, as already described above. The delivery 4 contains a sheet conveying system, not shown in further detail, which takes over the sheets processed in the machine 1, for example printed and/or painted, from the last sheet guide cylinder and conveys or transports them to a delivery stack, not shown. This sheet conveyor system is preferably designed as a chain conveyor system with two delivery chains guided on the side of the frame of the delivery 4, between which the gripper carriage is equally spaced and are arranged parallel to each other. The gripper carriages have sheet fixing systems with which the sheets to be conveyed are gripped at the front edge. The gripper carriages can take over the leading edges of the sheets from the last sheet guide cylinder of machine 1 in the gripper close. The gripper carriages, which are driven and guided in an endless rotation, have gripper fingers which can be moved, in particular against fixed gripper impacts, for taking over the sheets, preferably at the front edge of the last sheet guide cylinder of the machine 1.

In the delivery 4, the gripper carriages are guided by the delivery chains on a gripper carriage track in the sheet conveying direction BFR up to the delivery stack, where the gripper carriages release the sheets for storage. To release the sheet, the clamped sheet leading edges are released by lifting the gripper fingers from the gripper cuffs that are firmly arranged on the gripper carriage. The movement of the gripper fingers can take place via control cams and control levers via a gripper shaft on which the gripper fingers are firmly arranged. With regard to the sheet conveying direction BFR, the delivery stack is preferably preceded by a sheet brake, which delays the sheets to be deposited from the machine speed to the delivery speed after they have been released. After deceleration by the sheet brake, the sheets are aligned, for example, at the front, back and/or side edge stops and neatly placed on the delivery stack. The delivery stack is lowered by a stack lifting drive during the sheet deposition process in such a way that the delivery stack surface forms an at least approximately constant storage level for the incoming sheets.

On the sheet conveying path to the delivery stack, at least one mechanical sheet guiding element is arranged in the delivery 4 below the sheet conveying path, which guides the sheets after the last sheet guiding cylinder on the way to the delivery stack. From the endlessly rotating gripper carriages of the chain conveyor system, the sheets printed on both sides in machine 1, for example, are the last Sheet guide cylinder conveyed to the delivery stack. The gripper cuffs rotating with the gripper carriages describe a gripper cuff path which largely corresponds to the sheet conveying path or limits it on one side and thus defines it. The last sheet guiding cylinder of the machine 1 is in particular a printing cylinder 5 of the last printing, varnishing, drying, inspection or finishing plant, which in particular has an at least approximately closed lateral surface. The printing cylinder 5 is preferably designed to be double-sized and contains two gripper systems arranged diametrically to one another in gripper channels, as already described above. In particular, these gripper systems also have movable gripper fingers corresponding to the gripper surcharges that limit or define the sheet conveying path. From these gripper systems, the leading edges of the sheets are taken over by the gripper carriages of the chain conveyor system in the gripper closure. To take over the leading edge of the sheet, the gripper fingers of the printing cylinder 5 are set at a gap with the gripper fingers of the gripper carriage. This transfer of the leading edge of the sheet takes place in a transfer center, in which the leading edge of the sheet is briefly fixed by both grippers.

The chain conveyor system in the delivery 4 has a chain wheel shaft arranged adjacent to the last sheet guide cylinder, in particular printing cylinder 5, with two chain wheels 18 arranged coaxially and at a distance from one another, which are firmly connected to the chain wheel shaft. The delivery chains run over the chain wheels 18 and can be driven in a rotating manner by them. The sprocket shaft can, for example, be driven via the continuous drive wheel train together with sheet conveying systems and sheet guiding cylinders in the works or printing units 2 of the machine 1. Below the sprocket shaft between the sprockets 18, the sheet guide element is arranged, which is preferably designed as a sheet guide plate 9 arranged between the side walls and extending over the width of the machine. This sheet guide plate 9 preferably has an at least approximately closed surface for sliding and/or floating guidance of the sheets.

The sheet guide plate 9 can be provided with a color-repellent coating. Furthermore, nozzle openings, in particular Venturi nozzles, can be assigned to the sheet guide plate 9 for pneumatic guidance of the sheets.

For example, one or more blow boxes or fans 14 can be arranged below the sheet guide plate 9, which can also be formed from assembled partial guide plates, via which blowing air nozzles of the sheet guide plate 9 can be supplied with blown air and / or suction air, so that between the sheet guide plate 9 and An air cushion can be formed on the sheets conveyed or transported by the gripper carriage, in particular for perfect and reverse printing. A preferably deactivatable smoothing device can be assigned to the sheet guiding element, in particular the sheet guiding plate 9. Such a smoothing device can be deactivated or is not used when sheets with fresh ink, for example in perfect printing or foil sheets, are transported or guided. The sheet guiding elements, in particular sheet guiding plates 9, of the machine 1 are in particular designed to be identical in construction. In order to avoid sticking of the sheets on the display stack, dryers and/or powder devices (not shown) can be provided in the display 4. It is also possible to integrate a coolant circuit in the sheet guiding element in order to be able to control or regulate heating of the sheet guiding element.

The sprocket shaft in the delivery 4 in particular has no lateral surface for carrying the sheets. In a further development, the sprocket shaft can contain two or more support disks or suction disks or individual suction cups, such as corner suction cups, in addition to the chain wheels 18 for the rotating delivery chains. For example, the support disks with or without corner suction cups or the suction disks can be designed to be axially displaceable and adjustable to the respective sheet side edges. Such disks can also be axially adjusted automatically and/or independently of one another. Such disks contain support surfaces, in particular on the circumference, which have a minimal axial Have extension. Due to this extension of the support disks in the axial direction, a respective sheet can be fixed on the lateral surface of the sheet guide cylinder, in particular the printing cylinder 5, when the sheet is taken over. A sheet fall is thus avoided as long as the sheet is between the disks and the last sheet guide cylinder, in particular printing cylinder 5. The sheets are preferably pressed against the lateral surface of the printing cylinder 5 in small press gaps by support elements arranged on brackets. The support elements can have elastic surfaces. Such disks are preferably also designed to be double-sized and can preferably have recesses for the rotating gripper carriages of the chain conveyor system.

The Fig. 10 shows a last sheet guide cylinder, in particular printing cylinder 5, of the machine 1 with a downstream chain wheel 18 of the chain wheel shaft and a sheet guiding element arranged below the chain wheel shaft, in particular a sheet guiding plate 9 described above. A connecting line is drawn between the axis of rotation of the chain wheel 18 and the axis of rotation of the printing cylinder 5 which the transfer center is located in the transfer area. The sheet guide plate 9 is arranged below the chain wheel shaft and has metallic comb fingers 10 in the area facing the printing cylinder 5, in particular as already described for the printing unit 2. In the area of the sheet guide cylinder, in particular the printing cylinder 5, the sheet guide plate 9 is preferably further away from the axis of rotation of the chain wheel shaft or the chain wheel 18 than the areas of the sheet guide plate 9 adjoining in the sheet conveying direction BFR. The comb fingers 10 can, for example, be at a distance of a few millimeters, For example, between 1 and 10 mm, preferably between 2 mm and 3 mm, to the lateral surface of the printing cylinder 5. In particular, the sheet guide plate 9 in the delivery 4 is designed to be at least approximately identical to the sheet guide plates 9 in the printing units 2 or units of the machine 1. This ensures that the same favorable sheet guiding conditions are preferred throughout the entire machine 1.

The Fig. 11 shows a sheet guide cylinder, in particular printing cylinder 5, for example as described above, with a downstream chain wheel shaft and a sheet guide element, in particular sheet guide plate 9, arranged below the chain wheel shaft and having a cover, as described above. The sheet guide plate 9 shown in side view has a cover, in particular a cover part 13 containing non-conductive or non-metallic material described above or made of non-conductive or non-metallic material. The deionization device 8 can, for example, be removed from the sheet guiding element, in particular the sheet guiding plate 9. The deionization device 8 can be removed, for example, from below or between sprockets 18 of the sprocket shaft. The deionization device 8 can, for example, be removed laterally and/or by displacing at least part of the sheet guide plate 9. The cover, in particular the cover part 13, closes the opening required by the deionization device 8. The cover is preferably dimensioned or attachable in such a way that a continuous or approximately full-surface sheet guiding surface of the sheet guiding plate 9 is created. The cover part 13 can be designed or arranged as already described above.

How it works: Through a sheet conveyor system in the turning device 3 and/or in a work or printing unit 2, in particular a turning drum 17 or sheet conveyor drum 7 or a gripper carriage in the delivery 4, the sheets are fed by a sheet guide cylinder, in particular a storage drum 16 or a Printing cylinder 5, taken over and guided past a deionization device 8 along the sheet guiding element, in particular the sheet guiding plate 9, on the sheet conveying path. In a further development, a device can be provided in the area of a transfer drum or a sprocket shaft, which additionally guides the sheet in the vicinity of the gripper impact path, held only at the edges, so that the optimal electrode distance is maintained over the entire length of the sheet and the sheet does not touch the sheet guide plate 9 prematurely and falls below the optimal electrode distance.

The sheets, in particular foil sheets, are detached from the lateral surface of the sheet guide cylinder, in particular printing cylinder 5, by the sheet guide element, in particular the sheet guide plate 9, preferably with a spiral shape. In particular, the comb fingers 10 of the release loop of the sheet move away from the lateral surface at a suitable distance when pulled off. Allowing a minimal pull-off loop advantageously increases the detaching radial component of the pull-off forces. By arranging the Venturi nozzles along the guide contour of the sheet guide element in connection with the associated balanced floating height of the sheets under the gripper impact path, the suction forces of the air cushion can act on the sheet located on the regular sheet path. In this way, the sheet is held on the outside of the radius of the gripper impact path and the release loop is kept small.

The at least one discharge electrode 12 embedded in particular at the beginning of the guide plate causes charge equalization on the sheet to reach sufficient charge neutrality, so that the sheet is not attracted as an electrical conductor by the sheet guide element, in particular sheet guide plate 9. The deionization device 8 in particular provides positive and negative ions in order to be able to compensate for the changing charge states on the sheet surface. The use of a deionization device 8 takes place in particular in each printing unit 2 or unit of the machine 1, because the sheet, in particular foil sheets, is extremely recharged during each printing process.

The sheets are optimally unloaded in particular by the deionization device 8 of the or each printing unit 2, preferably each unit, the turning device 3 and/or the delivery 4. By unloading, the sheet is constantly floating to the next conveyor system, for example a printing cylinder 5 or a gripper carriage. to be fed without the sheet being scratched by contact with the sheet guiding element, in particular a sheet guiding plate 9. The one or more discharge electrodes 12 of a respective deionization device 8 ensure in particular an active discharge with both positive and negative ions. The generators provided preferably work in a range of 3 to 6 kV, optimally with a high voltage of at least approximately 4.5 kV. The high voltage can also be adjusted depending on the electrostatic charge determined. A respective sheet is unloaded by the deionization devices 8, so that the deionized sheets, free from electrostatic forces, lie on the sheet guide plate 9 or the air cushion generated by the sheet guide plate 9. The sheets remain free of deformation and smearing across the entire machine 1.

List of reference numbers used

1

machine

2

Printing unit

3

Turning device

4

Display

5

Printing cylinder

6

Rubber cylinder

7

Sheet conveyor drum

8th

Deionization facility

9

sheet guide plate

9.1

upstream guide surface section

9.2

downstream guide surface section

9.3

flat guide surface

10

Comb fingers

11

Insulators

12

discharge electrodes

13

Cover part

14

Fan

15

transfer drum

16

storage drum

17

turning drum

18

Sprocket

BFR

Sheet conveying direction

Claims (34)

1. Sheet-processing machine (1) comprising sheet-processing units, wherein the machine (1) includes at least two printing units (2) for processing sheets, wherein each of the printing units (2) comprises a blanket cylinder (6) and a plate cylinder, and a blanket cylinder (6) of a printing unit (2) cooperates with a respective sheet guide cylinder (5), wherein a sheet conveyor system (7) is provided between two sheet guide cylinders (5), wherein the sheets are conveyed along a sheet conveyor path by the sheet guide cylinders (5) and the sheet conveyor systems (7) of the machine (1), wherein a sheet guide element (9), which starts in the region of the sheet guide cylinder (5), is provided beneath and along the sheet conveyor path in one or all printing units (2), wherein the first segment of the sheet guide element (9), starting in the region of the sheet guide cylinder (5), has a sheet guide surface that steadily approaches the axis of rotation of the sheet conveyor system (7), wherein such a sheet guide element (9) is configured as a sheet guide plate (9) and has comb fingers (10) in the region facing the sheet guide cylinder (5), wherein, with respect to the sheet-conveying direction (BFR), a respective deionization device (8) adjoins the comb fingers (10), and wherein the sheet guide surfaces of the comb fingers (10) are assigned blower air openings, to which an overpressure can be applied.
2. Sheet-processing machine according to claim 1, wherein the comb fingers (10) of the sheet guide plate (9) are made partially or completely of metallic material.
3. Sheet-processing machine according to claim 1 or 2, wherein a first region of the sheet guide element (9), which starts in the region of the upstream sheet guide cylinder (5), has the comb fingers (10) and is arranged at a greater distance from the axis of rotation of the sheet conveyor system (7) than a subsequent second region of the sheet guide element (9).
4. Sheet-processing machine according to claim 1, 2 or 3, wherein a substantially closed sheet guide surface for the sheets is formed by comb fingers (10) and the first region of the sheet guide plate (9).
5. Sheet-processing machine according to claim 1, 2, 3 or 4, wherein the sheet guide plate (9) or the comb fingers (10) are arranged at a distance of 2 mm to 50 mm, in particular between 25 mm and 30 mm, from the sheet conveyor path formed by gripper pads of a sheet conveyor drum (7).
6. Sheet-processing machine according to claim 1, 2, 3, 4 or 5, wherein the sheet guide surface of the sheet guide plate (9), which is formed by the comb fingers (10) and/or deionization device (8), steadily approaches the axis of rotation of the sheet conveyor drum (7), or the sheet conveyor path, as viewed in the sheet-conveying direction (BFR).
7. Sheet-processing machine according to claim 1, 2, 3, 4, 5 or 6, wherein the comb fingers (10) are arranged at a distance of between 1 and 10 mm, preferably between 2 mm and 3 mm, with respect to the lateral surface of an impression cylinder (5).
8. Sheet-processing machine according to claim 1, 2, 3, 4, 5, 6 or 7, wherein deionization devices (8) are provided at least in the printing units (2) of the machine (1) that are arranged downstream from the press nip of the first printing unit (2) of the machine (1) with respect to the sheet-conveying direction (BFR).
9. Sheet-processing machine according to claim 1, 2, 3, 4, 5, 6, 7 or 8, wherein the machine (1) includes a multiplicity of printing units (2) and one or more coating units for processing sheets, and deionization devices (8) are provided at least in the printing units (2) and coating units of the machine (1) that are arranged downstream from the press nip of the first printing unit (2) of the machine (1) with respect to the sheet-conveying direction (BFR).
10. Sheet-processing machine according to claim 1, 2, 3, 4, 5, 6, 7, 8 or 9, wherein such a deionization device (8) is also provided in each case in one or each additional unit, such as a drying, inspection or finishing unit.
11. Sheet-processing machine according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10, wherein a deionization device (8) is also assigned to an infeed unit and/or the first printing unit (2) of the machine (1).
12. Sheet-processing machine according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or 11, wherein one deionization device (8) is exclusively arranged in each printing unit (2) and/or coating unit.
13. Sheet-processing machine according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12, wherein the sheet guide elements (9), in particular sheet guide plates (9), of the machine (1) are configured to be identical.
14. Sheet-processing machine according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 or 13, wherein the sheet guide plate (9) in the delivery (4) is configured to be at least approximately identical to the sheet guide plates (9) in the printing units (2) or units of the machine (1).
15. Sheet-processing machine according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 or 14, wherein the entire deionization device (8), or the entire discharge cassette, is exchangeably arranged in the sheet guide plate (9).
16. Sheet-processing machine according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 or 15, wherein the discharge cassettes are configured to be exchangeable among one another in the machine (1) or have a modular configuration.
17. Sheet-processing machine according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 or 16, for processing foil sheets, comprising a delivery (4), wherein a delivery (4) comprising a delivery chain loop (18) is arranged downstream from the last unit of the machine (1), the loop taking the sheets from the last sheet guide cylinder (5) by means of gripper carriages and conveying them to a delivery pile, wherein, on the sheet conveyor path to the delivery pile, at least one mechanical sheet guide element (9) is arranged in the delivery (4) beneath the sheet conveyor path, which guides the sheets downstream from the last sheet guide cylinder (5) on the path to the delivery pile, and wherein a deionization device (8) is assigned to the first segment of the sheet guide element (9).
18. Sheet-processing machine according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 or 17, wherein the machine (1) comprises a foil sheet processing package, which is specifically matched to the foil material, in particular a foil made of PVC, PP, PS or PET.
19. Sheet-processing machine according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17 or 18, wherein the machine (1) comprises at least one primer unit and/or a special double-sheet detector unit, and/or the gripper systems of the machine (1) are matched to the thin nature of the foil sheet material, and/or printing inks and/or coating materials or dryers that are used are matched to the foil material.
20. Sheet-processing machine according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18 or 19, wherein the machine (1) comprises at least one primer unit arranged upstream from the printing units (2).
21. Sheet-processing machine according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20, wherein a deactivatable smoothing device is assigned to the sheet guide element (9) in the delivery (4).
22. Sheet-processing machine according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 or 21, wherein the discharge-generating elements are covered by means of a cover made of non-conducting material, in particular plastic material.
23. Sheet-processing machine according to claim 22, wherein the cover has openings or cut-outs, which are arranged in such a way that the charge carriers of the discharge electrodes (12) are not influenced.
24. Sheet-processing machine according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22 or 23, wherein the intensity of the deionization device (8) is controlled by closed-loop or open-loop control by way of measuring equipment in such a way that it is possible to control the discharge in a manner that is matched to the static electricity at the sheet, in particular the foil sheet.
25. Sheet-processing machine according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23 or 24, comprising a turning device (3), wherein in the turning device (3) sheets can be taken from a sheet guide cylinder (16) by a sheet conveyor system (17) and can be conveyed in a sheet-conveying direction (BFR) on a sheet conveyor path, wherein a sheet guide element (9) is provided beneath and/or along the sheet conveyor path, and wherein a deionization device (8) is assigned to the sheet guide element (9).
26. Use of the sheet-processing machine according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24 or 25 for processing foil sheets, wherein the foil material is a foil made of PVC, PP, PS or PET.
27. Method for conveying sheets in a sheet-processing machine (1), wherein sheets are taken from a sheet guide cylinder (5, 16) by a sheet conveyor system (7, 17, 18) and are conveyed in a sheet-conveying direction (BFR) on a sheet conveyor path along a sheet guide element (9), wherein the sheets are guided by the sheet guide element (9), wherein the sheets are guided past a deionization device (8) assigned to the sheet guide element (9), and wherein the deionization device (8) provides positive and negative ions in order to equalize the alternating charge states on the sheet surface, wherein in a unit (2) and/or a delivery (4) of the machine (1) the sheets are taken from a sheet guide cylinder (5) by a sheet conveyor system (7, 18) and are conveyed in the sheet-conveying direction (BFR) on a sheet conveyor path, wherein the sheets are guided by a sheet guide element (9), which starts beneath and along the sheet conveyor path in the region of the sheet guide cylinder (5), wherein the sheets are guided first by a sheet guide surface of the sheet guide element (9) that is arranged at a greater distance from the axis of rotation of the sheet conveyor system (7, 18) and then by a sheet guide surface of the sheet guide element (9) that is arranged closer to the axis of rotation of the sheet conveyor system (7, 18), and wherein the sheets are peeled off the lateral surface of the sheet guide cylinder (5) by pneumatically acting comb fingers (10) of the sheet guide element (9), which starts in the region of the sheet guide cylinder (5), and are guided to the deionization device (8).
28. Method according to claim 27, wherein the sheets are guided first by a sheet guide surface that steadily approaches the axis of rotation of the sheet conveyor system (7, 18) and then by a sheet guide surface of the sheet guide element (9) that is arranged concentrically with respect to the axis of rotation of the sheet conveyor system (7, 18).
29. Method according to claim 27 or 28, wherein in at least one unit (2) and/or a delivery (4) of the machine (1) the sheets are taken from a sheet guide cylinder (5) by a sheet conveyor system (7, 18) and are conveyed in the sheet-conveying direction (BFR) on a sheet conveyor path, wherein the sheets are guided by a sheet guide element (9) arranged beneath and along the sheet conveyor path, wherein the sheets are guided first on a sheet guide surface of the sheet guide element (9) that has a deionization device (8), which sheet guide surface is arranged at a greater distance from an axis of rotation of the assigned sheet conveyor system (7, 18) than a subsequent sheet guide surface of the sheet guide element (9) in the sheet-conveying direction (BFR).
30. Method according to claim 27, 28 or 29, wherein the sheets are peeled off the lateral surface of the sheet guide cylinder (5) by metallic comb fingers (10) of the sheet guide element (9), which starts in the region of the sheet guide cylinder (5), and are guided to the deionization device (8).
31. Method according to claim 27, 28, 29 or 30, wherein, downstream of a or the deionization device (8), the sheets are guided concentrically with respect to the axis of rotation of the sheet conveyor system (7, 18) to a downstream sheet guide cylinder (5).
32. Use of a sheet guide element (9) that contains a deionization device (8) in a sheet-processing machine (1) according to claim 1, and of a turning device (3) of a sheet-processing machine (1), wherein a guide surface (9.1, 9.2, 9.3) of the sheet guide element (9) that contains the deionization device (8) is arranged at a distance of more than 10 mm from the sheet conveyor path of a sheet guide cylinder (5, 16) and of a sheet conveyor system (7, 17, 18) arranged immediately downstream thereof.
33. Use according to claim 32, wherein a sheet guide plate (9) that contains the deionization device (8) is arranged at a distance of 20 mm to 50 mm, or 25 mm to 30 mm, from the sheet conveyor path formed by gripper pads of a sheet conveyor drum (7) or a delivery chain loop (18) or by a cylinder tangent at a storage drum (16) and a turning drum (17).
34. Use according to claim 32 or 33, wherein a guide surface (9.1, 9.2, 9.3) of the sheet guide element (9) that contains the deionization device (8) is arranged at a distance of more than 15 mm, 20 mm or 25 mm from the sheet conveyor path.

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