Patent Application
20180311973
The present invention relates to a press assembly having a plurality of processing stations for the processing of sheets. A plurality of processing stations are arranged in succession in a transport direction of the sheets for the inline processing of those sheets. At least one of these processing stations is embodied as a non-impact printing unit and at least one processing station, downstream of the non-impact printing unit, in the transport direction of the sheets, is embodied as a dryer. At least one additional processing station, located downstream of the non-impact printing unit, in a transport direction of the sheets, is embodied as a coating unit. The downstream coating unit is configured for applying a coating, in the form of a varnish, to each sheet. A plurality of individually controlled non-impact printing units are arranged along the transport path of the sheets. Each of the plurality of non-impact printing units is configured as an ink jet printer.
EP 1092533 A1 discloses a method for the sequential processing of sheet-type substrates, and a press assembly having a plurality of processing stations for the processing of sheets, wherein a plurality of processing stations are arranged in succession in the transport direction of the sheets for the inline processing of these sheets, wherein at least one of these processing stations is embodied as a non-impact printing unit and at least one processing station downstream of the non-impact printing unit in the transport direction of the sheets is embodied as a dryer.
DE 10 2012 218022 A1 discloses a cold foil application unit in connection with the processing of printed sheets.
WO 02/48012 A2 discloses devices for aligning sheets, wherein the sheets are fed to the device after being offset from one another in a shingled arrangement by a shingling device, and are transferred to a device that is located downstream after alignment of the front edge and one lateral edge of the sheet, wherein an alignment cylinder, onto the periphery of which at least part of a sheet can be brought, can be used for the stream-wise alignment of the leading edge of the sheet by means of front lay marks located on the periphery of the alignment cylinder.
WO 2009/120582 A2 discloses that, in a press assembly having a plurality of processing stations for the processing of sheets, spaced from one another, individually by means of a first processing station transported sheets have a first transport speed, and in that sheets that are transported from the first processing station to a second processing station have a second transport speed in this second processing station, wherein the second transport speed used in the second processing station is lower than the first transport speed used in the first processing station.
EP 2540513 A1 discloses a press assembly for the sequential processing of a plurality of sheet-type substrates, each having a front side and a back side, said press assembly including a first printing cylinder and a second printing cylinder, wherein on the periphery of the first printing cylinder in each case, at least one first non-impact printing unit for printing onto the front side of the substrate in question is provided, and downstream of the first non-impact printing unit in the direction of rotation of the first printing cylinder, a dryer for drying the front side of the substrate in question that has been imprinted by the first non-impact printing unit is provided, wherein on the periphery of the second printing cylinder in each case, at least one second non-impact printing unit for printing onto the back side of the substrate in question is provided, and downstream of the second non-impact printing unit in the direction of rotation of the second printing cylinder, a dryer for drying the back side of the substrate in question that has been imprinted by the second non-impact printing unit is provided, wherein the first printing cylinder and the second printing cylinder are arranged so as to form a common roller nip, wherein in this common roller nip, the first printing cylinder transfers the substrate in question, which has been imprinted and dried on its front side, directly to the second printing cylinder.
DE 10312870 A1 discloses a digital printing press for sheet printing, having a digital printing couple with free format in the peripheral direction, an intermediate cylinder that is connected downstream of the digital printing couple and is at least partially covered by an elastic material, and an impression cylinder that is connected downstream of the intermediate cylinder, wherein the impression cylinder has grippers for holding the sheets and the intermediate cylinder has recesses for receiving the grippers on its periphery.
DE 10 2014 010904 B3 discloses a device for the two-sided printing of sheet-type printing substrates, wherein the printing substrate is guided on an impression cylinder through more than 360°, wherein the side of the printing substrate opposite the printed side is moved back into the operating area of an ink application unit that has already imprinted the front side of the printing substrate on an impression cylinder upstream, wherein the ink application unit can preferably be pivoted between two impression cylinders disposed one after the other, and wherein the pivotable ink application unit is an inkjet print head, for example.
DE 10 2005 021185 A1 discloses a device for applying opaque white or an effect coating layer, wherein the effect coating layer is dried or cured after being applied, and is then overprinted, wherein one or more inkjet print heads are provided within a printing press, wherein the inkjet print head(s) for applying the opaque white layer or effect layer directly to the printing substrate or indirectly to the printing substrate via an intermediate carrier is located upstream of the infeed to or within the printing press in the transport path of the printing substrate.
DE 10 2009 000518 A1 discloses a sheet-fed printing press comprising a feed mechanism for introducing printing sheets that are to be printed into the sheet-fed printing press, at least one printing couple and/or coating unit for printing the printing sheets with a static printed image that is identical for all printed sheets, a delivery unit for discharging printed sheets from the sheet-fed printing press, and at least one printing unit that does not include a printing forme and is integrated into the sheet-fed printing press for printing the printing sheets with an especially dynamic, variable printed image, wherein the or each printing unit that does not include a printing forme is integrated into the sheet-fed printing press so as to be controllable on the basis of process parameters or operating parameters or application parameters or quality parameters.
EP 2657025 A1 discloses a sheet conveyor device that comprises the following components: a first conveyor unit which includes a first holder that holds an edge of a sheet, and conveys the sheet held by said first holder; a second conveyor unit which includes a second holder that holds the one edge of the sheet, and conveys the sheet held by said second holder; a third conveyor unit, wherein the third conveyor unit includes a third holder that holds the other edge of the sheet that is conveyed by the first conveyor unit, and conveys the sheet that is held by the third holder; an independent drive unit, which independently drives the first conveyor unit; a device drive unit, which drives the entire device including the second conveyor unit and the third conveyor unit; and a control unit, which controls the independent drive unit to adjust the speed at which the third conveyor unit conveys the sheet, on the basis of a dimension of the sheet, in a conveyance direction, wherein the first conveyor unit comprises a rotatably mounted transport cylinder, and the independent drive unit comprises an independent drive motor, which drives the transport cylinder independently of a device drive system, wherein the third conveyor unit is supported to be rockable between a receiving position, at which the third conveyor unit receives the sheet from the first conveyor unit, and a transfer position, at which the third conveyor unit transfers the sheet to the second conveyor unit, and by further comprising a fourth conveyor unit, which is located on a side of the transport cylinder that is upstream in the direction of sheet conveyance, comprises a fourth holder, which holds an edge of the sheet, and transfers the sheet that is held by the fourth holder to the first holder of the transport cylinder, wherein the control unit controls the independent drive motor, in order to adjust the rotational speed of the transport cylinder in accordance with the dimensions of the sheet in the direction of conveyance, so that the other edge of the sheet that is conveyed by the transport cylinder is opposite the third holder when the third conveyor unit is fixed at the sheet receiving position, and the fourth holder of the fourth conveyor unit is opposite the first holder of the first conveyor unit after the sheet has been transferred to the third holder.
DE 1033225 A discloses a sheet feeding mechanism for printing presses, in which endless belts slide over a vacuum chamber in such a way, wherein the chamber is closed, and the vacuum is active only in openings (suction openings) of the belt opposite the paper stack or individual paper sheets, and the sheet is thereby carried along by the belts, wherein the belts are made of wear-resistant steel, wherein blow openings (chambers, tubes, slots) are preferably located adjacent to and behind the suction opening points, and cause the sheet to be separated and to float by means of blown air.
DE 4413089 A1 discloses a method for feeding sheet-type printing substrates in a shingled arrangement to a printing press using a conveyor table, in which compressed air flows continuously beneath the shingle stream, opposite the direction of conveyance of the printing substrate being fed above the conveyor table.
DE 4012948 A1 discloses a conveyor table for guiding printed sheets to a printing press, having at least one suction chamber with an axial fan attached thereto, along with perforated suction belts revolving around said fan in the conveyance table over suction openings, wherein parallel to the suction belts, openings are provided in the conveyor table, which are connected to the surrounding environment separately from suction chamber.
DE 20 2004 006615 U1 discloses a device on a conveyor table, preferably on a suction belt table, for transporting sheet-type material in a stream of sheets in a shingled arrangement from a sheet feeding mechanism to a sheet processing machine, in particular a sheet-fed rotary printing press, having one or more transport belts, for example suction belts, which can be acted upon by suction air and which can be driven and are guided endlessly around the conveyor table, and having a blowing device, which blows air underneath the stream of sheets outside of the guide area of the transport belts in the area of guide regions of the conveyor table located laterally and parallel to the transport belts, wherein, at least in the guide areas on the outer sides of the transport belts, a plurality of individual ventilation openings distributed substantially over the entire surface of the guide regions are provided, and wherein a blown air infeed is provided, such that it is at least partially coupled for ventilation openings in such a way that the guide areas can be acted on with blown air, substantially in sub-regions or over their entire surface, wherein the ventilation openings are preferably embodied in the region of the outlet-side end of the conveyor table as nozzles that are each aligned from the center of the conveyor table toward the side edges.
DE 10157118 A1 discloses an apparatus for braking printed sheets in the delivery unit of a sheet-fed printing press, having a sheet brake that operates using suction air, wherein the sheet brake is connected to a negative pressure generator via a line system and at least one valve, so that a negative pressure can be applied in the suction area on the outer radius of the sheet brake, wherein at least one sensor for determining the position of the printed sheet and a control unit connected downstream are provided, and the valve can be actuated by the control unit based upon the signals from the at least one sensor.
DE 10 2009 048928 A1 discloses an inkjet printer for printing onto sheet-type substrates, wherein the printer includes the following components: a) a printing couple transport apparatus having at least one revolving printing couple transport belt, guided via rollers and having openings, and a suction chamber apparatus located below the printing couple transport belt, wherein the printing couple transport belt or printing couple transport belts include(s) an autonomous drive unit, which impress(es) a speed upon the transport belt or transport belts, b) an inkjet printing device located above the upper drum of the printing couple transport belt, which is guided approximately horizontally, c) a transport device, located upstream of the printing couple transport device in the transport direction of the printing sheets/substrates, having at least one revolving belt, wherein the transport belt or the transport belts include(s) an autonomous drive unit, which impress(es) a speed on the transport belt or the transport belts, wherein the ratio of the speed of the transport unit located upstream of the printing couple transport belt or printing couple transport belts of the printing couple transport device to the speed of the transport belt or the transport belts of the transport unit located upstream of the printing couple transport device is selected such that the printed sheets or substrates for all sheet formats provided for the inkjet printer come to rest end to end or spaced from one another by a slight distance of up to 10 mm on the printing couple transport belt or printing couple transport belts.
DE 10141589 B4 discloses a method for operating a sheet processing machine, in which the sheets are handled displaced in the direction of transport and in multiple processing stations, wherein the speed of displacement of each of the sheets can be adjusted independently, wherein the speed of each sheet is adapted to the processing step to be carried out in the respective processing station, and wherein the speed of the sheet is different in at least two of the processing stations. The processing output of the individual processing stations may be the same during a specified period of time, or the processing output of a first processing station during a specified period of time may be greater or less than the processing output of a second processing station located upstream or downstream.
DE 10 2004 014521 B3 discloses a device for transporting sheets in printing presses from the printing couples to the sheet delivery stack, consisting of at least one gripper carriage guided on both sides on chain tracks and having gripper systems for grasping and guiding the sheets, wherein the gripper carriage delineates a rectilinear guide path above the sheet delivery stack, and after the sheet has been delivered to the sheet stack, is guided along a radius of curvature within a deflection area, and further consisting of leading edge grippers for grasping the leading edges of the sheets and delivering the sheets to the sheet delivery stack, wherein a gripper carriage support mechanism is provided solely on the rectilinear guide path above the sheet delivery stack and in the deflection area.
U.S. Pat. No. 2,198,385 A discloses a gripper carriage, which, in the transfer area from the last sheet guiding cylinder to the gripper carriage, is supported centered via a cam roller on a cam disk, resulting in a true-to-register transfer of the sheet.
The object of the present invention is to provide a press assembly having a plurality of processing stations for the processing of sheets.
This object is achieved according to the invention by the provision of at least one processing station which is located upstream of the non-impact printing unit in the transport direction of the sheets and which is embodied as a coating unit. That upstream coating unit is configured for applying a coating, in the form of a primer or a cold foil, to each sheet. A dryer is located downstream of the at least one processing station that is situated upstream of the non-impact printing unit in the transport direction of the sheets and that is embodied as a coating unit for applying the primer or the cold foil. The dryer is also downstream of each of the at least one processing station that is situation downstream of the non-impact printing unit in the transport direction of the sheets and which non-impact printing unit is embodied as a coating unit for applying a varnish. The dryer, which is located downstream of the processing station that is configured as a coating unit for applying the primer or the cold foil, is configured for drying the sheets by irradiation with infared radiation and by hot air. At least one processing station, which is located either upstream or downstream of the non-impact printing unit, in the transport direction of the sheets, is embodied as a printing unit that imprints each of the sheets with at least one print image using one of an offset printing method or a flexographic printing method or a screen printing method. Each of the several processing stations is configured as an independently functional module.
The advantages to be achieved by the invention will be apparent from the following discussion.
Furthermore, the described solution can be used in a hybrid press assembly for processing sheet-type substrates, preferably in a hybrid printing press, which makes use of the high productivity of a conventional printing unit that prints, e.g. in an offset printing process or in a flexographic printing process or in a screen printing process, or a coating unit, in particular a varnishing unit, variably combined with at least one non-impact printing unit for flexibly printing variable print images, embodied, e.g. as an inkjet printer, with both the conventional printing unit or the coating unit and the non-impact printing unit being used for inline production at the optimum operating speed for each device. Such a hybrid press assembly is suitable in particular for producing packaging materials, e.g. sheets for the production of folding cartons, since the strengths of each of the printing devices are utilized, resulting in a flexible and efficient production of packaging materials. In this way, sheet-type substrates embodied, in particular, as rigid can be imprinted advantageously in a planar state and a horizontal position in a non-impact printing unit. The length of a linear transport unit can be reduced with less effort to a different number of printing couples or printing stations (color separations) and (intermediate) dryer configurations, e.g. for water-based or UV-curing printing inks or inks, than is possible with a rotary transport unit via cylinders. In addition, when sheet-type substrates of variable format lengths are used, a constant sheet gap can be achieved more easily between sheet-type substrates that are transported in immediate succession and spaced from one another, by means of a linear transport unit. At the same time, transporting sheet-type substrates by means of rotary bodies, in particular cylinders and gripper strips or gripper carriages, ensures the highest possible register accuracy with each transfer of a sheet-type substrate in a gripper closure to the next processing station downstream, as is known for sheet-fed offset printing presses.
Exemplary embodiments of the invention are illustrated in the set of drawings and will be detailed in the following.
The drawings show:
A characteristic common to all the production lines shown in
In the following, it is assumed by way of example that each press assembly having a plurality of processing stations 01; 02; 03; 04; 06; 07; 08; 09; 11; 12 processes a sequence of rigid sheets, in particular, e.g. composed of paper, single-ply or multi-ply paperboard, or cardboard, in particular to produce a packaging material. The substrates paper, paperboard, and cardboard differ from one another in terms of their respective grammage, i.e. the weight in grams of one square meter of said printing substrate. An aforementioned printing substrate having a grammage of between 7 g/m2 and 150 g/m2 is generally considered to be paper, printing substrate having a grammage of between 150 g/m2 and 600 g/m2 is generally considered to be paperboard, and printing substrate having a grammage of more than 600 g/m2 is generally considered to be cardboard. For manufacturing folding cartons, paperboards that offer good printability and are suitable for subsequent enhancement or processing, e.g. for varnishing and punching, are used, in particular. The fibers used in these paperboards include, e.g. wood-free fibers, fibers that contain a low percentage of wood, woody fibers, and recycled paper fibers. In terms of their structure, multi-ply paperboards include a cover layer, an inner layer, and a backing layer on the back. In terms of surface finish, paperboards may be uncoated, pigmented, coated or cast-coated, for example. Sheets may be formatted, e.g. in the range of 340 mm×480 mm to 740 mm×1060 mm; in the format specifications, the first number generally indicates the length in the transport direction T of the sheets and the second number generally indicates the width of the sheets orthogonally to the transport direction T.
In the block diagram of
If the next processing station 03 following feeder 01 is the cold foil application unit 03, the sheet is then typically transported from there to the processing station 04 embodied as offset printing unit 04. In cold foil application unit 03, a metallized coating layer detached from a carrier film is transferred to the printing substrate. By overprinting this coating layer, e.g. by means of an offset printing unit 04, various metal effects can be achieved. Cold foil application unit 03 is advantageously integrated, e.g. into offset printing unit 04, in that two additional printing couples 87; 88 are provided in offset printing unit 04. In the first printing couple 87 in the transport direction T of the printing substrate, a special adhesive is applied to the printing substrate, i.e. the sheet, by means of a standard printing forme. A second printing couple 88 in the transport direction T of the printing substrate is equipped with a foil transfer device, which contains the coating layer to be transferred. The foil that bears the coating layer is guided from an unwinding station into a printing nip between a transfer cylinder and a printing cylinder cooperating with said transfer cylinder, and is brought into contact with the printing substrate. The coating layer is colored by an aluminum layer and a protective coating layer, the coloring of which influences the color effect. An adherent layer adheres to the imprinted layer of adhesive, and the transfer layers remain adhered to the substrate. The carrier film is then wound up again. Following the cold foil transfer, overprinting inline with conventional printing inks as well as with UV and hybrid inks is possible, in particular in offset printing unit 04, to produce different metallic color shades.
A printing substrate that is especially absorbent, for example, and/or is prepared for printing via a non-impact printing unit 06 is fed by feeder 01 to the next processing station 02, e.g. embodied as a primer application unit 02, where at least one surface of said printing substrate is coated, e.g. with a water-based primer, in particular sealing it, before it is imprinted or varnished. Priming creates an undercoat or first coat on the printing substrate, in particular to improve or enable the adhesion of the printing ink or ink that will later be applied to the printing substrate. Primer application unit 02 is associated, e.g. with a printing couple 86 of a rotary printing press and includes, e.g. a printing couple cylinder 82 that cooperates with an impression cylinder 119 and has a forme roller 83, preferably in the form of an anilox roller 83, which is or at least can be thrown onto said printing couple cylinder 82, and at least one doctor blade 84 extending in the axial direction of forme roller 83, in particular a chamber blade system 84 (
The flexographic printing carried out by a processing station 04 embodied, e.g. as a flexographic printing device 04 is a direct letterpress process in which the raised areas of the printing forme are image-bearing; this process is often used for printing on packaging materials made of paper, paperboard, or cardboard, metallized foil, or plastic, such as PE, PET, PVC, PS, PP, or PC, for example. Flexographic printing uses low-viscosity printing inks and flexible printing plates made of photopolymer or rubber. In general, a flexographic printing unit 04 comprises a) an anilox roller, which inks up the printing forme, b) a printing cylinder, also called a forme cylinder, on which the printing forme is mounted, and c) an impression cylinder, which guides the printing substrate.
Processing station 04, which is embodied as a flexographic printing unit 04 or as an offset printing unit 04 that prints at least one static print image onto the sheets, preferably includes a plurality of printing couples 86, e.g. at least four, in each case, wherein each printing couple 86 preferably prints with a different printing ink, so that the printing substrate is imprinted with multiple colors, e.g. in a four-color printing process, as it passes through flexographic printing unit 04 or offset printing unit 04. The printing colors used are, in particular, the shades of yellow, magenta, cyan, and black. In an embodiment of printing device 04 that offers an alternative to the flexographic printing or offset printing method, processing station 04, which prints at least one static print image onto each of the sheets, is embodied as a printing unit 04 that prints by a screen printing method.
Once the printing substrate has been processed in the at least one non-impact printing unit 06, said printing substrate is fed, e.g. to a processing station 07 embodied as an intermediate dryer 07, wherein said intermediate dryer 07 is embodied for drying the printing substrate in question, e.g. by irradiating it with infrared or ultraviolet radiation, the type of radiation being dependent in particular on whether the printing ink or ink applied to the printing substrate is water-based or UV-curing. After intermediate drying, the printing substrate is fed to a processing station 08 embodied, e.g. as a varnishing unit 08. Varnishing unit 08 applies a dispersion varnish, for example, to the printing substrate, said dispersion varnishes consisting substantially of water and binders (resins), with surfactants as stabilizers. A varnishing unit 08 for applying a dispersion varnish to the printing substrate consists either of an anilox roller, a chamber blade, and a forme roller (similar to a flexographic printing unit), or of a dipping and forme roller. Varnishes, preferably based on photopolymerization, are applied by means of a printing forme, e.g. over the entire surface and/or a portion thereof. For full-surface varnishing, special varnishing plates made of rubber may also be used. In the transport path of the printing substrate, downstream of varnishing unit 08, a processing station 09 embodied, e.g. as a dryer 09 is provided, said dryer 09 being embodied for drying the printing substrate in question by irradiating it with infrared radiation or hot air.
If the press assembly in question includes a plurality of dryers 07; 09 along the transport path of the printing substrate, the dryer labeled with reference sign 09 is preferably the last of this plurality of dryers 07; 09 in the transport direction T of the printing substrate, wherein the intermediate dryer(s) 07 and the (final) dryer 09 may be structurally identical, or may be differently configured. If a printing substrate that dries by means of ultraviolet radiation is fed to dryer 09, i.e. a printing substrate to which a printing ink or ink that cures under UV radiation or a varnish that cures under UV radiation, e.g. a gloss varnish, has been applied, said dryer 09 is equipped with a radiation source that produces ultraviolet radiation. With dispersion varnishes, more intense gloss and matt effects can be achieved than with classic oil-based varnishes. Special optical effects can be achieved by adding effect pigments to the varnish. primer application unit 02, cold foil application unit 03, and varnishing unit 08 can be combined under the term coating unit 02; 03; 08.
After drying, the printing substrate is fed, e.g. to a processing station 11 that performs further mechanical processing of the printing substrate, e.g. by stamping, creasing, and/or separating parts, in particular punching copies out of their attachment in the preferably printed sheet. Each of the aforementioned further processing operations is carried out in or by means of a processing unit 46. The mechanical further processing is preferably carried out in conjunction with a cylinder that transports the respective sheet. Afterward, or directly from dryer 09, the printing substrate reaches a delivery unit 12, which is the last processing station 12 in each of the production lines shown in
The aforementioned sequence of processing stations 01; 02; 03; 04; 06; 07; 08; 09; 11; 12 arranged in the press assembly can be modified as shown in
In the production lines shown by way of example in
At least one of the processing stations 01; 02; 03; 04; 07; 08; 09; 11; 12 that cooperate with the at least one non-impact printing unit 06 is selected to participate in processing the sheets, dependent in each case upon whether the printing ink to be applied to the sheets in question, in particular by means of non-impact printing unit 06, is embodied as a water-based printing ink or ink, or as a printing ink or ink that cures under ultraviolet radiation. Each press assembly is thus configured for imprinting the sheets with a water-based printing ink or with a printing ink that cures under ultraviolet radiation.
Additional press assemblies that will be detailed in reference to
An advantageous press assembly mentioned here by way of example includes a plurality of processing stations for processing sheets, a plurality of processing stations 01; 02; 03; 04; 06; 07; 08; 09; 11; 12 being arranged one after the other in the transport direction T of the sheets for inline processing of these sheets, wherein at least one of these processing stations 06 is embodied as a non-impact printing unit 06, wherein a first processing station 01 situated upstream of non-impact printing unit 06 in the transport direction T of the sheets is embodied as a sheet feeder 01 or as a magazine feeder 01, wherein a processing station 08 located between first processing station 01 and non-impact printing unit 06 is embodied as a first coating unit 08 for applying a coating material to each of the sheets, wherein a first dryer 07 is located between first coating unit 08 and non-impact printing unit 06, wherein a first transport belt 17 is arranged so as to transport the sheets from first dryer 07 to non-impact printing unit 06, wherein a second dryer 07 is located downstream of non-impact printing unit 06 in the transport direction T of the sheets, wherein a device for transferring the sheets coming from non-impact printing unit 06 to a second coating unit 08 is provided, wherein a third dryer 09 is located downstream of second coating unit 08, and wherein a delivery unit 12 for the sheets is located downstream of third dryer 09 in the transport direction T the sheets.
A further mechanical processing device 11 may additionally be located between third dryer 09 and delivery unit 12. Additionally, a coating unit 03 for applying, e.g. a cold foil is located upstream of non-impact printing unit 06 in the transport direction T of the sheets. Non-impact printing unit 06 preferably has a plurality of individually controlled inkjet printers along the transport path of the sheets. In the operating area of non-impact printing unit 06, the sheets are preferably each guided horizontally and lying flat on a transport unit 22, the transport unit 22 having a linear transport path or a curved transport path for the sheets, at least in the operating area of non-impact printing unit 06, wherein the curved transport path is formed by a concave or convex arcuate line lying in a vertical plane and having a radius of between 1 m and 10 m. In the transport direction T of the sheets, upstream of non-impact printing unit 06, a transfer unit is located, for example, wherein the transfer unit aligns each of the sheets, at least in terms of its axial register and/or circumferential register relative to the printing position of non-impact printing unit 06, wherein the transfer unit includes, e.g. a suction drum 32 that holds each of the sheets by means of suction air. This press assembly is configured in particular for imprinting the sheets with a water-based printing ink or with a printing ink that cures under ultraviolet radiation. This press assembly is configured in particular for producing various packaging materials. The device for transferring the sheets coming from non-impact printing unit 06 to second coating unit 08 is embodied, e.g. as a rocking gripper 19 and a transfer drum 31 that cooperates with rocking gripper 19.
Sheets that are picked up from a stack in feeder 01, in particular in sheet feeder 01, are transported individually and spaced from one another through offset printing unit 04 at a first transport speed. The sheets transferred from offset printing unit 04 to non-impact printing unit 06 are transported in said non-impact printing unit 06 at a second transport speed, with the second transport speed used in non-impact printing unit 06 generally being lower than the first transport speed used in offset printing unit 04. To adjust the first transport speed used in offset printing unit 04 to the generally lower, second transport speed used in non-impact printing unit 06, the sheet gap existing, e.g. between directly successive sheets, i.e. the spacing that results, e.g. from the gripper channel width for the sheets being transported in the gripper closure by offset printing unit 04, is preferably decreased as these sheets are transferred from offset printing unit 04 to non-impact printing unit 06, such a spacing decrease amounting, e.g. to between 1% and 98% in relation to the original spacing. Directly successive sheets are thus also transported spaced from one another in non-impact printing unit 06, but with a generally smaller sheet gap or with narrower spacing than in offset printing unit 04, and therefore also at a lower, second transport speed. This second transport speed is preferably maintained when sheets that have been imprinted in non-impact printing unit 06 are transported first to an intermediate dryer 07 or dryer 09, and from there, e.g. by means of a feed table 18, to a mechanical further processing device 11 and on to delivery unit 12. However, the sheets can also be brought from their second transport speed to a third transport speed if required, e.g. by mechanical further processing device 11, wherein the third transport speed is generally higher than the second transport speed and, e.g. again corresponds to the first transport speed that is used, in particular, in offset printing unit 04. In mechanical further processing device 11, a second rocking gripper 19 is provided, for example, which picks the sheets coming from intermediate dryer 07 or dryer 09 up from feed table 18, and transfers them, e.g. to a second transfer drum 31 located in the zone of mechanical further processing device 11, after which the sheets are transported, e.g. by means of a gripper closure, through the zone of mechanical further processing device 11. Also in the zone of mechanical further processing device 11, which has a plurality of processing units 46, for example, arranged in a row, a rotary body, in particular a cylinder, preferably a transfer drum 44, is provided for each of said processing units for the purpose of transferring the sheets from one of the processing units 46 to the next, each such rotary body being located between two adjacent processing units 46. One of processing units 46 is embodied, e.g. as a punching unit, and another processing unit 46 is embodied, e.g. as a creasing unit. Each of these processing units 46 is configured to further process the sheets mechanically, preferably in cooperation with a cylinder for transporting the respective sheets. After the sheets and/or the copies that have been removed from them have been further processed mechanically, they are transported, e.g. by means of a second chain conveyor 21, to delivery unit 12, where they are collected, preferably stacked.
Each of the sheets is transported from the output of offset printing unit 04 at least up to the output of intermediate dryer 07 or dryer 09, preferably up to the beginning of mechanical further processing device 11, by means of a multi-part transport unit 22, i.e. consisting of a plurality of assemblies, in particular transport units, arranged in succession in the transport direction T of the sheets, wherein transport unit 22 transports each sheet in a lengthwise orientation, preferably lying flat horizontally, in the transport direction T along a linear transport path, at least in the operating area of the non-impact printing unit 06 located between offset printing unit 04 and intermediate dryer 07 or dryer 09. The linear transport path and the horizontally flat transport are preferably also continued during transport of the sheets through intermediate dryer 07 or dryer 09, which are located downstream of non-impact printing unit 06. If necessary, an intermediate dryer 07 or a dryer 09 can also be arranged between offset printing unit 04 and non-impact printing unit 06.
A second revolving transport belt 27 is preferably provided in the zone of action of non-impact printing unit 06, which is arranged between offset printing unit 04 and intermediate dryer 07 or dryer 09, on which belt the sheets are transported in succession, each preferably lying flat horizontally, along a linear transport path. The transfer unit is arranged, in particular, between the first transport belt 17 and the second transport belt 27. A third revolving transport belt 28 is preferably also provided in the operating area of intermediate dryer 07 or dryer 09, on which belt the sheets received from non-impact printing unit 06 are transported in succession, each preferably lying flat horizontally, along a linear transport path. The third transport belt 28 transfers the sheets that have been transported through intermediate dryer 07 or dryer 09 to feed table 18, from which the sheets are transported, in succession, preferably to mechanical further processing device 11. First transport belt 17, second transport belt 27, and third transport belt 28 preferably transport the sheets in the same, e.g. horizontal transport plane 29, in particular embodied as a planar surface. Transport unit 22 for transporting sheets in a press assembly having processing stations, each configured for processing sheets, thus comprises at least three transport units, specifically first gripper system 16 or first chain conveyor 16, first transport belt 17, and second transport belt 27. First chain conveyor 16 and first conveyor belt 17 are arranged therein so as to cooperate with one another for transferring a sequence of sheets from a first processing station to a second processing station that preferably immediately follows the first processing station in the transport direction T of the sheets. The sequence of sheets is transferred from first transport belt 17 to second transport belt 27, which belongs to the next processing station. Preferably, a third transport belt 28 is also provided, wherein the sequence of sheets is transferred from second transport belt 27 to third transport belt 28, which belongs to a third processing station that preferably immediately follows the second processing station in the transport direction T of the sheets. If the respective transport paths of first transport belt 17 and/or of second transport belt 27, and where appropriate, of third transport belt 28 are non-linear and/or not oriented horizontally, the transport belts 17; 27; 28 of transport unit 22 each transport the sheets along a curved transport path, in particular along a concave or convex arcuate line lying in a vertical plane and having a radius of at least 1 m, preferably having a radius of between 2 m and 10 m, in particular having a radius of between 3 m and 5 m. Each of transport belts 17; 27; 28 is preferably embodied as a suction belt conveyor, i.e. as a transport belt having at least one suction chamber 26 that applies suction to each sheet during its transport. In the case of transport belts 17; 27; 28 having a plurality of suction chambers 26 along the transport path provided for the sheets, these suction chambers 26 are preferably controllable individually and/or preferably independently of one another with respect to the effect of their suction air. A plurality of individually controlled non-impact printing units 06 are preferably arranged along the curved transport path, each of the plurality of non-impact printing units 06 being embodied, e.g. as an inkjet printer. Transport belts 17; 27; 28 of transport unit 22 each consist, e.g. of a plurality of parallel individual belts arranged side by side, orthogonally to the transport path provided for the sheets, and thus each extending longitudinally along the transport path provided for the sheets. In contrast to gripper system 16, each of transport belts 17; 27; 28 is understood as a gripper-less transport apparatus, with each transport belt 17; 27; 28 being embodied as revolving endlessly between at least two diverting devices.
In a press assembly having a plurality of processing stations for processing sheets, in which a plurality of processing stations 01; 02; 03; 04; 06; 07; 08; 09; 11; 12, at least one of said processing stations 06 being embodied as a non-impact printing unit 06, are arranged in succession in the transport direction T of the sheets for the inline processing of these sheets, e.g. a first alignment unit in the transport direction T of the sheets is located upstream of the first processing station 01; 02; 03; 04; 06; 07; 08; 09; 11; 12, this first alignment unit aligning each of the sheets, at least in terms of its axial register and/or its circumferential register, true to register relative to a processing position of the first processing station 01; 02; 03; 04; 06; 07; 08; 09; 11; 12. An additional alignment unit, for example, is also located between non-impact printing unit 06 and a processing station 01; 02; 03; 04; 07; 08; 09; 11; 12 situated downstream of non-impact printing unit 06 in the transport direction T of the sheets, wherein this additional alignment unit aligns each of the sheets, at least in terms of its axial register and/or its circumferential register, true to register relative to a processing position of the processing station 01; 02; 03; 04; 07; 08; 09; 11; 12 downstream of non-impact printing unit 06.
Suction drum 32, which is located in particular in the transfer unit, is also used, e.g. for adjusting the transport speed of each of the sheets to be transferred from offset printing unit 04 to non-impact printing unit 06. Since the second transport speed used in non-impact printing unit 06 is generally slower than the first transport speed used in offset printing unit 04, suction drum 32 slows each of the sheets that are fed to it in succession at the first transport speed by offset printing unit 04 by the leading edge of the sheet striking the at least one stop 34; if necessary, suction drum 32, which is holding the sheet in question, then aligns each of the suctioned sheets at least laterally by means of an axial movement of the suction drum, i.e. in response to a corresponding position signal from the first sensor 33 indicating a need for correction, and then accelerates or decelerates the gripped sheet by rotating said suction drum 32 at the second transport speed required in non-impact printing unit 06, wherein the sheet in question, e.g. upon reaching the second transport speed, is released from suction drum 32, after which suction drum 32 is moved to its rotational and/or axial operating position that is required for gripping the next sheet. Suction drum 32 therefore preferably rotates in a non-uniform manner, e.g. in each of its revolutions. Information regarding the position of the leading edge of the sheets, required for controlling the rotational position of suction drum 32, is provided, e.g. by an angular position sensor 47 located on a sprocket wheel 24, or alternatively by an angular position sensor of offset printing unit 04, in particular of the printing press.
As mentioned above, sheets of different formats, i.e. of different lengths and/or widths, can be processed using the above-described press assemblies, each of which includes a plurality of processing stations 01; 02; 03; 04; 06; 07; 08; 09; 11; 12 for processing sheets and at least one transport apparatus for transporting these sheets. The sheets, which are generally rectangular, therefore differ, e.g. in terms of their respective length, this length extending in each case in the transport direction T of these sheets. When a processing station 02; 03; 04; 06; 07; 08; 09; 11; 12 embodied, in particular, as a non-impact printing unit 06 to which the sheets are fed sequentially is used, to avoid decreasing the productivity of the respective press assembly with relatively shorter sheets, i.e. for sheets of smaller format as compared with the otherwise larger-format sheets that are processed in said press assembly, a method having the following method steps is proposed:
A method for operating a transport apparatus that feeds a plurality of sheets sequentially to a processing station 02; 03; 04; 06; 07; 08; 09; 11; 12, in which, for processing by means of the same processing station 02; 03; 04; 06; 07; 08; 09; 11; 12, sheets of different lengths are used, each extending in the direction of transport T of said sheets, wherein each of the sheets to be fed in succession to processing station 02; 03; 04; 06; 07; 08; 09; 11; 12 is transported with spacing by the transport apparatus, wherein the transport apparatus impresses a transport speed on each of the sheets to be transported, wherein the spacing between immediately successive sheets is held constant for sheets of different lengths, each extending in the transport direction T of these sheets, by varying the transport speed that is impressed by the transport apparatus onto the sheet in question, wherein the transport speed of the subsequent sheet in the transport direction T is varied in relation to the transport speed of the sheet immediately preceding it. The sheets to be fed in succession to the processing station 02; 03; 04; 06; 07; 08; 09; 11; 12 in question are transported in each case by the transport apparatus preferably with minimal spacing, although generally not with zero spacing, in order to achieve and/or maintain a high productivity of the processing station 02; 03; 04; 06; 07; 08; 09; 11; 12. The distance between successive sheets in transport direction T, i.e. between the trailing edge of a preceding sheet, extending transversely to transport direction T, and the leading edge of the sheet immediately following said sheet, extending transversely to transport direction T, ranges, e.g. from 0.5 mm to 50 mm, and is preferably less than 10 mm. If a shorter sheet will be processed after a longer sheet in a given processing station 02; 03; 04; 06; 07; 08; 09; 11; 12, the transport apparatus will accelerate the shorter sheet by increasing its transport speed. Conversely, the transport apparatus will slow a longer sheet down by reducing its transport speed if the longer sheet will be processed after a shorter sheet in the processing station 02; 03; 04; 06; 07; 08; 09; 11; 12 in question. As the processing station 02; 03; 04; 06; 07; 08; 09; 11; 12, a non-impact printing unit 06 is preferably used, the productivity of which is generally greatest when the sheets to be printed by it are fed to it successively at a constant minimum distance, regardless of their respective format. If a processing station 04 embodied e.g. as an offset printing unit 04 is located upstream of non-impact printing unit 06 in the press assembly in question, sheets that have been printed in offset printing unit 04 are fed to the transport apparatus at a transport speed that corresponds to the production speed of said offset printing unit 04, regardless of their respective format, wherein this transport speed of said sheets defined by offset printing unit 04 is adapted during its transport by the transport apparatus to the transport speed corresponding to a processing speed of non-impact printing unit 06. If these sheets will additionally be fed spaced a constant distance from one another, regardless of their respective format, to non-impact printing unit 06, longer sheets will be slowed down less than shorter sheets, although a reduction in their respective transport speed may be necessary in any case, since the processing speed of non-impact printing unit 06 is generally lower than the production speed of offset printing unit 04.
Each sheet is held in a force-fitting manner, e.g. by suction air, as it is transported by the transport apparatus. The transport speed of each sheet is preferably applied to it in each case by suction rings 76 of a suction drum 32 acting on it or by at least one endlessly revolving suction belt 52; 78. In the preferred embodiment, the transport speed to be applied to the sheet in question is adjusted by a preferably electronic control unit, wherein the control unit performs the adjustment of the transport speed, in particular for maintaining a constant distance between successive sheets, in a control loop, as described above, e.g. in conjunction with the rotary position control of suction drum 32 or, e.g. in conjunction with a control device that will be explained in detail in the following and, e.g. optical sensors 33; 36 that are connected to said control device and will also be described.
If, with the press assemblies described above, each of which includes a plurality of processing stations 01; 02; 03; 04; 06; 07; 08; 09; 11; 12 for processing sheets and at least two transport apparatuses for transporting these sheets, flexible sheets will be transported and processed, i.e. sheets of low rigidity, in particular thin sheets that are unable to transfer pushing forces, so that pushing forces acting on such a sheet will form waves in said sheet, then it is difficult to feed such sheets to the processing station 02; 03; 04; 06; 07; 08; 09; 11; 12 in question in a set position intended for said processing station 02; 03; 04; 06; 07; 08; 09; 11; 12.
A method for sequentially feeding a plurality of sheets to a processing station 02; 03; 04; 06; 07; 08; 09; 11; 12 for processing each of these sheets is therefore proposed, in which a first transport apparatus located upstream of the processing station 02; 03; 04; 06; 07; 08; 09; 11; 12 in transport direction T of the sheets feeds each of the sheets to the processing station 02; 03; 04; 06; 07; 08; 09; 11; 12 at a first transport speed in a pushing movement, wherein the first transport apparatus holds each of the sheets being fed to the processing station 02; 03; 04; 06; 07; 08; 09; 11; 12 during the pushing movement by means of at least one holding element, wherein the sheet in question being fed to the processing station 02; 03; 04; 06; 07; 08; 09; 11; 12 is gripped by a second transport apparatus assigned to said processing station 02; 03; 04; 06; 07; 08; 09; 11; 12 and is transported in the gripped state at a second transport speed, wherein the first transport speed of the first transport apparatus is lower than the second transport speed of the second transport apparatus, wherein the holding element in question of the first transport apparatus releases the sheet in question being fed to the processing station 02; 03; 04; 06; 07; 08; 09; 11; 12 only after the second transport apparatus has gripped said sheet that has been fed to processing station 02; 03; 04; 06; 07; 08; 09; 11; 12 and has begun to transport said sheet. A non-impact printing unit 06 is preferably used as processing station 02; 03; 04; 06; 07; 08; 09; 11; 12. Each of the sheets is transported in the first transport apparatus and/or in the second transport apparatus, in particular in the same transport plane 29. A first, in particular endlessly revolving transport belt 17, for example, is used as the first transport apparatus, and/or a second, in particular endlessly revolving transport belt 27 is used as the second transport apparatus, each of these transport belts 17; 27 being embodied, e.g. as a suction belt. In an alternative embodiment of the holding elements, each of said elements is embodied as a suction ring 76 of a suction drum 32. The holding element of the first transport apparatus in question exerts a holding force on the respective sheets being fed to the processing stations 02; 03; 04; 06; 07; 08; 09; 11; 12, wherein this holding force is greater, at least briefly, than a tensile force simultaneously acting on said sheet, exerted by the second transport apparatus. The first transport apparatus preferably holds each of the sheets being fed to the processing station 02; 03; 04; 06; 07; 08; 09; 11; 12 by means of the at least one holding element, in each case preferably by a force closure, e.g. by means of suction air. By means of the proposed method, the sheet to be fed to the processing station 02; 03; 04; 06; 07; 08; 09; 11; 12 is subjected to tensile stress and is thereby straightened in spite of the pushing movement carried out by the first transport apparatus. After the actual position of each sheet in transport plane 29 has been checked and, if the actual position deviates from a set position specified for the sheet in question in the processing station 02; 03; 04; 06; 07; 08; 09; 11; 12, after a position correction to the specified set position has been performed, each of the sheets is preferably transferred to the second transport apparatus.
At the unit for transferring the sheets, e.g. to mechanical further processing device 11, a method for arranging sheets in a shingled position is therefore carried out in a transfer unit located between a first processing station 01; 02; 03; 04; 06; 07; 08; 09; 11; 12 and a second processing station 01; 02; 03; 04; 06; 07; 08; 09; 11; 12 that follows the first processing station in the transport direction T of the sheets, in which the sheets to be shingled are transported in succession, each lying individually in a transport plane 29, from the first processing station 01; 02; 03; 04; 06; 07; 08; 09; 11; 12 to the transfer unit, in which a trailing edge in the transport direction T of each of the sheets coming from the first processing station 01; 02; 03; 04; 06; 07; 08; 09; 11; 12 is raised relative to transport plane 29 solely by means of blown air, and a subsequent sheet is pushed underneath the trailing edge of the sheet preceding it in each case. In said process, the blown air preferably acts with at least 50% of its intensity counter to the force of gravity, in a plane perpendicular to transport plane 29. Advantageously, it is provided that additional air is blown counter to the transport direction T of the sheets, substantially tangentially, at an acute angle formed with the transport plane 29, in the range of, e.g. 0° to 45°, from above, i.e. onto the surface of the sheets facing away from transport plane 29, onto the sheets being transported to the transfer unit. The additional blown air directed opposite the transport direction T of the sheets comes from a guide surface that forms an acute angle with the convergent transport plane 29 ranging, e.g. from 0° to 45°, wherein, in particular, nozzles for emitting the blown air are arranged in the guide surface. The blown air acting counter to gravity in the direction of transport plane 29 is preferably pulsed by the control unit. Each sheet to be transported from the first processing station 01; 02; 03; 04; 06; 07; 08; 09; 11; 12 to the subsequent second processing station 01; 02; 03; 04; 06; 07; 08; 09; 11; 12 is held in transport plane 29 by means of suction air, preferably acting on the leading half of the sheet in transport direction T. The suction air holding the sheet being transported in transport plane 29 from the first processing station 01; 02; 03; 04; 06; 07; 08; 09; 11; 12 to the second processing station 01; 02; 03; 04; 06; 07; 08; 09; 11; 12 downstream is preferably pulsed by the control unit. In the preferred embodiment, the control unit is used to adjust the operating width, directed orthogonally to transport direction T of the sheets, of the blown air acting counter to gravity in the direction of transport plane 29 and/or the operating width of the additional blown air directed opposite transport direction T of the sheets, and/or the operating width of the suction air holding the sheet to be transported in transport plane 29 from the first processing station 01; 02; 03; 04; 06; 07; 08; 09; 11; 12 to the second processing station 01; 02; 03; 04; 06; 07; 08; 09; 11; 12 downstream, in each case based upon the width of the sheet oriented orthogonally to transport direction T of the sheet. In that case, the adjustment of the operating width of the blown air acting in the direction of transport plane 29 counter to the force of gravity, and of the additional blown air directed opposite the transport T of the sheets, and of the suction air holding the sheet to be transported in transport plane 29 from the first processing station 01; 02; 03; 04; 06; 07; 08; 09; 11; 12 to the second processing station 01; 02; 03; 04; 06; 07; 08; 09; 11; 12 downstream, is carried out, coupled mechanically or electrically in each case, e.g. by a gearing mechanism, by means of a single displacement device. This displacement device is controlled by the control unit, e.g. automatically, in each case based on the format of the sheets to be transported from the first processing station 01; 02; 03; 04; 06; 07; 08; 09; 11; 12 to the second processing station 01; 02; 03; 04; 06; 07; 08; 09; 11; 12 downstream.
For shingling the sheet-type substrates, in particular the sheets 51, each preferably embodied as a printed sheet, a device for shingling sheets 51, also referred to in the following as shingling unit 132, is provided in the area, i.e. the operating area, of the transfer unit provided, in particular, in one of the above-described press assemblies (
Shingling unit 132 is shown by way of example in
In transport direction T of sheets 51, in an area between feed table 18; 134 and the side of blowing chamber 133 that faces said feed table 18; 134, upstream of the first blowing nozzle 136 or the first row of blowing nozzles, a baffle plate 141 is located, wherein the baffle plate 141 shields the leading edge of a sheet 51 directly following a sheet 51 that has been raised by the blown air from at least one of the blowing nozzles 136; 137, against the suction generated by the blowing nozzles 136; 137 located in the blowing chamber 133. The sheet 51 that is raised off of feed table 18; 134 by at least one of blowing nozzles 136; 137 or rows of blowing nozzles channels the blown air flowing from the at least one blowing nozzle 136; 137 and conducts this blown air over the surface of baffle plate 141 that faces blowing chamber 133. At its end located in the blowing direction, baffle plate 141 preferably has a concave curvature, and this curvature gives the blown air a flow direction away from feed table 18; 134, i.e. directed outward. As a result of baffle plate 141, the leading edge of sheet 51, which directly follows a sheet 51 that has been raised by the blown air from at least one of blowing nozzles 136; 137, remains unaffected until the trailing end of raised sheet 51 has passed over the blowing nozzle 136 or row of blowing nozzles first reached by said sheet 51 by way of its own forward advancement or feed directed in transport direction T. To prevent the leading edge of the sheet 51 that directly follows a sheet 51 that has been raised by the blown air from at least one of blowing nozzles 136; 137 from being raised prematurely by the action of the blowing nozzle 136; 137 or row of blowing nozzles that has been uncovered by the trailing end of the preceding sheet 51,the blown air of the blowing nozzle 136; 137 or row of blowing nozzles in question is switched off by means of the respectively associated valve 138; 139, on the basis of the forward advancement or feed of the sheet 51 that is currently raised off of feed table 18; 134, and that directly precedes a sheet 51 that is located between baffle plate 141 and feed table 18; 134. A sheet 51 that has been raised by the blowing nozzles 136; 137 or rows of blowing nozzles is raised by the suction (Venturi effect) generated by the blown air in question to a certain float height SH above feed table 18; 134, e.g. by a distance from the side of blowing chamber 133 that faces feed table 18; 134, the float height SH being dependent on the intensity of the blown air in each case and/or on the mass of the sheet 51 in question and/or on the transport speed of sheet 51 in question. To prevent sheets 51, e.g. of great mass and/or high transport speed, from vibrating and fluttering as they are transported over feed table 18; 134, a support plate 142 for supporting the raised sheet 51 is preferably provided in the area between feed table 18; 134 and the side of blowing chamber 133 that faces said feed table 18; 134, wherein the support plate 142 located, e.g. at an acute angle in relation to the side of blowing chamber 133 that faces feed table 18; 134 is embodied, e.g. in the form of an air-permeable grate. Sheet 51, which has been raised by the suction of the blown air and has been placed on support plate 142, is guided there in its transport direction T along this support plate 142 in a smooth movement, i.e. without fluttering. In feed table 18; 134, at least in an area opposite blowing chamber 133, a plurality of holes 143 or openings are preferably provided, through which air flows beneath the currently raised sheet 51 for the purpose of pressure equalization. These holes 143 are embodied, e.g. as circular, having a diameter d143 in the range of a few millimeters.
The transport apparatus described in reference to
As sheet 51 is being transported, a negative pressure prevailing in the first suction chamber 58 in transport direction T of sheet 51 to be transported is permanently present, and a negative pressure prevailing in the second suction chamber 59 in the transport direction T of sheet 51 in question is pulsed, i.e. this negative pressure is switched on and off alternatingly, each for an adjustable period of time. The second suction chamber 59 in transport direction T of sheet 51 therefore has a relatively small volume, to allow a negative pressure to be built up in it more quickly in light of the applicable transport speed for the sheets 51 of, in particular, several thousand, e.g. 10,000 to 18,000 sheets 51 per hour, and to allow a higher pulse rate to be achieved in the second suction chamber 59 in terms of the build-up and reduction of pressure. During its transport, this sheet 51 is then suctioned onto the at least one revolving suction belt 52 when the perforated surface 57 of the suction belt 52 in question is functionally connected to at least one of the suction chambers 58; 59 to which negative pressure is applied. In a highly advantageous embodiment of this transport apparatus, a pulsation of the negative pressure of the second suction chamber 59 in transport direction T of the sheet 51 is synchronized with a passage over the perforated surface 57 of suction belt 52 in question by sheet 51 to be transported.
A revolution speed v of suction belt 52 in question is adjusted by the preferably digital control unit 61 for processing a program with a drive 62 that sets this suction belt 52 into motion. This control unit 61 preferably also controls or adjusts the aforementioned synchronization of the negative pressure in the second suction chamber 59 in transport direction T of sheet 51 with the passage over perforated surface 57 of this suction belt 52 by the sheet 51, e.g. by means of a valve 67. The preferably controllable valve 67 is located, e.g. in a line that connects second suction chamber 59 to a pump (not shown), which is controlled, e.g. by control unit 61. Drive 62, which is preferably embodied as an electric motor, acts, e.g. on at least one of deflecting rollers 53.
Drive 62, which sets the revolution speed v of the suction belt 52 in question, is preferably controlled by control unit 61. Control unit 61 preferably sets a discontinuous revolution speed v of the suction belt 52 in question, i.e. the revolution speed v of the suction belt 52 in question is accelerated or decelerated in phase, deviating from an otherwise uniform speed, based on the control of drive 62.
At least one register mark 63 is located in at least one position on the suction belt 52 in question. A sensor 54 that detects the register mark 53 in question is provided in conjunction with the transport apparatus and is connected to control unit 61. The revolution speed v of the suction belt 52 in question is thereby preferably adjusted by control unit 61 on the basis of a difference, determined, e.g. by control unit 61, between a first signal s1, generated by sensor 64, that corresponds to an actual revolution speed, and a second signal s2 that corresponds to a set revolution speed. The second signal s2, which indicates the set revolution speed of the revolving suction belt 52 in question, is picked up, e.g. by a higher-level machine controller (not shown). Sensor 64, which detects the register mark 63 in question, is located, in particular, in the area of a slack span 66 of the suction belt 52 in question. Sensor 64, which detects the register mark 63 in question, is embodied as a sensor 64 that detects the register mark 63 in question, e.g. optically or inductively or capacitively or electromagnetically or by ultrasound. Register mark 63 is embodied, corresponding to the embodiment of sensor 64 in each case, e.g. as an optical signal surface applied to the relevant suction belt 52, or as a magnetic strip on the relevant suction belt 52, or as a recess or perforation in the relevant suction belt 52, or as a body that transmits a signal and is located in the relevant suction belt 52. The timing of the adjustment of the revolution speed v of the suction belt 52 in question, which is implemented by control unit 61, is preferably synchronized with the passage over the perforated surface 57 of the suction belt 52 in question by the sheet 51 to be transported.
In a further variant, for the sequential transport of individual sheet-type substrates or sheets 51, the transport apparatus includes at least one fixedly arranged suction chamber 58; 59 having a preferably table-shaped surface 69 in the area of tight span 54, wherein the preferably sole endlessly revolving suction belt 52, in particular perforated at least in sections, is arranged so as to move, in particular slide, over this surface 69 during transport of the sheet-type substrate in question, i.e. preferably a sheet 51, wherein the suction chamber 58; 59 in question is covered in the area of tight span 54 of suction belt 52 by the table-shaped surface 69. This table-shaped surface 69 is implemented, e.g. as a table panel. This suction belt 52 that holds sheet 51 in question during its transport is located in particular centered with respect to the width b51 of sheets 51, which is oriented orthogonally to transport direction T, and/or also centered with respect to the width b69 of table-shaped surface 69, which is oriented orthogonally to transport direction T. The width b52 of suction belt 52 oriented orthogonally to transport direction T is narrower than the width b51 of sheets 51 in question to be transported, which is oriented orthogonally to transport direction T, and is also narrower than the width b69 of the table-shaped surface 69 oriented orthogonally to transport direction T. The width b52 of suction belt 52 oriented orthogonally to transport direction T is, e.g. only 5% to 50% of the width b51, oriented orthogonally to transport direction T, of sheets 51 and/or the width b69, oriented orthogonally to transport direction T, of the table-shaped surface 69, so that during transport, the sheet 51 in question does not rest with its entire surface on suction belt 52, in particular not with its two side regions that extend orthogonally to transport direction T resting thereon.
To allow the sheet 51 in question to slide during its transport with as little friction as possible over the table-shaped surface 69 covering the at least one suction chamber 58; 59, at least one blow/suction nozzle 68 is located in at least two of the areas of table-shaped surface 69 that are not covered by suction belt 52. The air flow emerging from a respective blow/suction nozzle 68 preferably is or at least can be controlled, e.g. in terms of its intensity (i.e. its pressure and/or its flow velocity) and/or its duration, wherein the blow/suction nozzle 68 in question allows air to flow against the underside of sheet 51 in question during the transport thereof, whereby an air cushion is or at least can be formed between the underside of sheet 51 in question to be transported and table-shaped surface 69. In the preferred embodiment, each of blow/suction nozzles 68 is embodied as a Venturi nozzle, wherein the Venturi nozzle applies suction to a side region of the relevant sheet 51 to be transported by applying negative pressure in the direction of table-shaped surface 69. Blow/suction nozzles 68 are preferably each arranged in the table-shaped surface 69. One embodiment example of blow/suction nozzles 68 is shown in
The transport apparatus having central suction belt 52 and, in its peripheral area, blow/suction nozzles 68 for the sequential transport of individual sheet-type substrates is advantageously usable when the surfaces of sheets 51 to be transported are varnished and when these surface-varnished sheets 51 are received by the above-described transport apparatus, e.g. by a chain conveyor 16, while still in their moist state. The proposed solution not only enables additional suction belts 78 arranged parallel to the centrally located suction belt 52 to be dispensed with, but also avoids those problems that would have to be solved by synchronizing these additional suction belts 78 with the centrally arranged suction belt 52.
Moreover, once the leading edge of each of sheets 51 has been released by the gripper carriage 23 in question, it is moved by means of blow/suction nozzles 68 from the level of a gripper stop plane to a float level that is just above the table-shaped surface 69, i.e. a few millimeters above, and the leading edge of each of sheets 51 in question that has been released by the gripper is kept at the level of the table-shaped surface 69 by said blow/suction nozzles. Without blow/suction nozzles 68, when sheets 51 are transported at high speeds of, e.g. more than 10,000 sheets per hour, there is a risk of the released leading edge of each sheet, or in the case of sheets 51 that are transported in a shingled state, a risk of the leading edge of sheet 51 in question that has been pushed free, being raised upward and lifted off again by an air wedge. In addition, in the case of flexible sheets 51 or substrates, with which the transmission of inner transverse forces from the center belt to the outer edge regions of the substrate in question is limited, these outer edge regions are supported in terms of the conveying component of each by the air friction caused by the air flow LS.
In the case of a chain conveyor 16, the sheet-type substrates 51 are each transported individually by means of a gripper carriage 23 that is moved along a movement path (
In conjunction with the above-described press assemblies, the following method for operating a transport apparatus that feeds individual sheet-type substrates 51 sequentially to a processing station 02; 03; 04; 06; 07; 08; 09; 11; 12 can be advantageously embodied, in which the actual position of each substrate 51 in its transport plane 29 before it reaches the processing station 02; 03; 04; 06; 07; 08; 09; 11; 12 is determined mechanically by means of a control device that cooperates with the transport apparatus, and is automatically compared with a set position provided for the substrate 51 in question in said processing station 02; 03; 04; 06; 07; 08; 09; 11; 12. In the event of a deviation of the actual position from the set position, the substrate 51 in question is aligned by a transport element of the transport apparatus, the movement of which is controlled by the control device, in such a way that before the substrate 51 in question reaches processing station 02; 03; 04; 06; 07; 08; 09; 11; 12, it assumes its set position specified for said processing station 02; 03; 04; 06; 07; 08; 09; 11; 12. In a highly advantageous variant of this embodiment, the substrate 51 in question is aligned in transport plane 29 in each case solely by the transport element, both in transport direction T and transversely thereto, as well as around a pivot point located in transport plane 29. This means that in this variant of the operation of the transport apparatus, mechanical stops in particular are not involved in the alignment of the substrate 51 in question. The processing station 02; 03; 04; 06; 07; 08; 09; 11; 12 to which the substrate 51 in question is fed and the set position of which is aligned is preferably embodied as a non-impact printing unit. The substrate 51 in question is preferably held by the transport element in a force-locking manner, e.g. by suction air or by means of clamping, and in this operating state, which is held by the transport element, is aligned with respect to the set position specified for this substrate 51 in the processing station 02; 03; 04; 06; 07; 08; 09; 11; 12. In particular, a suction drum 32 or a suction belt 52; 78 is used as the transport element. The transport element transports each of the substrates 51 individually. The control device includes, e.g. the control unit and at least one of the, e.g. optical sensors 33; 36 connected thereto, the sensors 33; 36 being embodied with respect to the detection of the actual position of the substrate 51 in question, e.g. as a lateral edge sensor and/or as a leading edge sensor. The set position, with regard to which the substrate 51 in question is to be aligned, is or will be saved in the control unit and/or is or will be stored preferably such that it can be modified, e.g. by means of a program. The transport element is driven by a first drive that moves the substrate 51 in question in its transport direction T, and by a second drive that moves the substrate 51 in question transversely to its transport direction T, and by a third drive that rotates the substrate 51 in question about the pivot point located in transport plane 29, wherein these drives, each embodied, e.g. as a motor, in particular as a preferably electric servomotor, can be controlled by the control device, i.e. by the control unit thereof. In that case, the transport element is driven by its three drives, in particular simultaneously. The substrate 51 in question is fed by the transport apparatus to the processing station 02; 03; 04; 06; 07; 08; 09; 11; 12 at a transport speed greater than zero, and in the event of a deviation of the actual position from the set position, said substrate is aligned, preferably while maintaining this transport speed. If the transport element is embodied as a suction belt 52; 78, the transport speed at which the substrate 51 in question is fed to the processing station 02; 03; 04; 06; 07; 08; 09; 11; 12 in question corresponds, e.g. to the revolution speed v of said suction belt 52; 78.
An exemplary embodiment for carrying out the aforementioned method for operating a transport apparatus for feeding individual sheet-type substrates 51 sequentially to a processing station 02; 03; 04; 06; 07; 08; 09; 11; 12 is illustrated in
A further method for operating an apparatus for transporting sheet-type substrates 51 likewise uses a transport element for conveying the substrate 51 in question in its transport plane 29, wherein the transport element feeds the substrate 51 in question true to register to a processing station 02; 03; 04; 06; 07; 08; 09; 11; 12 located downstream of the transport element in transport direction T of the substrate 51 in question, wherein this processing station 02; 03; 04; 06; 07; 08; 09; 11; 12 is embodied, e.g. as a non-impact printing unit 06. A suction drum 32 having a plurality of suction rings 76, each embodied as a holding element, arranged axially side by side, or an arrangement of a plurality of suction belts 52; 78, each revolving along transport direction T of the substrate 51 in question, arranged side by side, transversely to the transport direction T of the substrate 51 in question, is preferably used as the transport element. The transport element for transporting the substrate 51 in question therefore always uses a plurality of holding elements arranged spaced from one another transversely to transport direction T thereof, wherein the substrate 51 in question is held in a force-locking manner by at least two of these holding elements, in each case up to an output position in relation to transport plane 29. The respective output positions of all the holding elements holding the substrate 51 in a force-locking manner are located on the same straight line 103. The transport element is used to adjust the diagonal register of the substrate 51 in question. The diagonal register of the substrate 51 in question is adjusted by adjusting the angle of rotation β of this straight line 103 about a pivot axis 94 perpendicular to transport plane 29, wherein the angle of rotation β of this straight line 103 is adjusted in accordance with the diagonal register of the substrate 51 in question to be adjusted, by actuating, triggered by a control unit, a single mechanical coupling element that acts simultaneously on all the holding elements holding the substrate 51 in question in a force-locking manner; the mechanical coupling element acting on the holding element in question thereby changes the output position of at least one of the holding elements holding the substrate in question in a force-locking manner. The holding elements holding the substrate 51 in question in a force-locking manner impress a transport speed that differs from holding element to holding element upon the substrate 51 in question, wherein the transport speed that is impressed upon the substrate 51 in question by the respective holding element is dependent in each case on the output position set for the respective holding element. As the mechanical coupling element, e.g. a linear transmission element including rocker arms and/or geared mechanical linkages is used, wherein either a rocker arm or a geared mechanical linkage is assigned to each holding element holding the substrate 51 in question in a force-locking manner.
The proposed method for operating an apparatus for transporting sheet-type substrates has the advantage that the transport element in question is not placed in an oblique position for adjusting the diagonal register in the transport apparatus,and as a result, if the lateral register and/or axial register of the substrate in question has already been adjusted, for example, this register cannot be adversely affected by the adjustment of the diagonal register. Instead, a differential speed, which is dependent on the respective position of the holding element in question, is set between the holding elements of the transport element involved in the adjustment of the diagonal register by actuating a single servo drive, thereby aligning the substrate in question in accordance with the desired diagonal register. The advantage of using only a single servo drive for adjusting the diagonal register is that it is unnecessary to coordinate different drives, each acting on one of the holding elements, or to synchronize these with one another, and as a result, a source of error is eliminated and a very precise adjustment of the diagonal register is made possible.
In a preferred embodiment of this method, by means of a control device connected to the control unit, the actual position in transport plane 29 of substrate 51 to be fed true to register to the processing station 02; 03; 04; 06; 07; 08; 09; 11; 12 is determined before the substrate reaches the transport element, and is compared with a set position specified for substrate 51 in question in the processing station 02; 03; 04; 06; 07; 08; 09; 11; 12, wherein in the event of a deviation of the actual position from the set position, the control unit controls a drive 93 for adjusting the mechanical coupling element such that when the substrate 51 in question reaches the respective output positions of all the holding elements that hold the substrate in question in a force-locking manner, the substrate assumes its set position in terms of diagonal register that is specified in processing station 02; 03; 04; 06; 07; 08; 09; 11; 12.
An exemplary embodiment for carrying out the latter method for operating an apparatus for transporting sheet-type substrates 51 will now be described with reference to
The embodiment variants according to
The third transport apparatus 128, which transports the substrate in question within the operating area of the first non-impact printing unit 06, and the second transport apparatus, which transports the substrate in question within the operating area of the second non-impact printing unit 127 and which includes at least one pulling element, preferably each include an independent drive 129; 131, wherein each of these independent drives 129; 131 is embodied, e.g. as a preferably electrically powered motor that is or at least can be controlled with regard to its respective rotational speed and/or angular position, wherein the printing of the substrate in question on its front side by the first non-impact printing unit 06 and on its back side by the second non-impact printing unit 127 is or at least can be synchronized by means of these independent drives 129; 131 that influence the movement pattern of each of the transport apparatuses in question.
In a preferred embodiment, the first dryer 121 for drying the primer applied to the front side of the substrate in question is located, e.g. in the area of impression cylinder 119 (
The first transport apparatus, which receives substrates from impression cylinder 119 and which includes at least one pulling element, and the second transport apparatus, which transports the substrates within the operating area of the second non-impact printing unit 127 and which includes at least one pulling element, each transport the substrates by means of gripper carriages 23, wherein these gripper carriages 23 are arranged successively with preferably fixed, in particular equidistant spacing, wherein each of these gripper carriages 23 is equipped with controlled or at least controllable holding means 79 (
In a particularly advantageous embodiment of the transport apparatus in question having gripper carriages 23, a plurality of belts are preferably located, at least lengthwise along transport direction T of the substrate in question, between immediately successive gripper carriages 23, wherein the substrate in question being held by the gripper carriage 23 in question rests with at least a portion of its surface on these belts, which are preferably arranged parallel to one another, for the purpose of stabilizing said substrate during its transport. Belts that are located between successive gripper carriages 23 are arranged, in particular spring-loaded, lengthwise along transport direction T of the substrate in question or are made of an elastic material.
In a further preferred embodiment, the gripper carriages 23 are guided, at least in the operating area of the first non-impact printing unit 06 and/or in the operating area of the second non-impact printing unit 127, by means of at least one guide element 71 situated along the movement path of the gripper carriage 23 in question, in each case for the purpose of stabilizing the movement path of said gripper carriages (
The press assembly shown in
In the press assembly according to
On the periphery of the impression cylinder 119 that has the first primer application unit 02, generally immediately downstream of the first primer application unit 02, e.g. a dryer 121 for drying the front side of the substrate in question, which has been primed by this first primer application unit 02, is provided, and/or on the periphery of the impression cylinder 119 that has the second primer application unit 126, generally immediately downstream of the second primer application unit 126, e.g. a dryer 122 for drying the back side of the substrate in question, which has been primed by this second primer application unit 126, is provided. The dryer 121 for drying the primer applied to the front side of the substrate in question, and/or the dryer 122 for drying the primer applied to the back side of the substrate in question, and/or the dryer 123 for drying the substrate in question that has been printed on its front side by the first non-impact printing unit 06, and/or the dryer 124 for drying the substrate in question that has been printed on its back side by the second non-impact printing unit 127 is or are each embodied as a dryer that dries the primed and/or printed substrate in question by means of hot air and/or by irradiating it with infrared or ultraviolet radiation. In a particularly preferred embodiment, the dryer 121; 122; 123; 124 for drying the primed and/or printed substrate in question by irradiating it with infrared or ultraviolet radiation is embodied as an LED dryer, i.e. as a dryer that generates the infrared or ultraviolet radiation by means of semiconductor diodes.
Moreover, in the press assembly according to
Finally, the substrate in question that has been printed on both sides, after being transported through the second printing cylinder, is preferably transported by means of a transport apparatus, e.g. to a delivery unit 12, where it is placed on a stack in the delivery unit 12. The transport apparatus that follows the second printing cylinder is embodied, e.g. as a chain conveyor, wherein the substrate in question is dried once again, preferably on both sides, during its transport through this transport apparatus, by means of at least one dryer 09, before being placed in delivery unit 12. In some production lines, it may be desirable to print on the substrate in question, which has been printed on its front side by the first non-impact printing unit 06 and/or has been printed on its back side by the second non-impact printing unit 127, on one side or both sides with additional printing inks, in particular special inks, and/or, e.g. to finish the surface of said substrate by an application of varnish. In this latter case, following the second printing cylinder, upstream of the transport apparatus for transporting the substrate in question to the delivery unit 12, at least one additional printing cylinder, e.g. a third, or preferably at least one additional cylinder pair composed of a third printing cylinder and a fourth printing cylinder is provided, on which at least one additional, e.g. third and/or fourth printing cylinder, in the same way as on the first printing cylinder and/or on the second printing cylinder, an additional printing unit, in particular an additional non-impact printing unit, or at least one varnishing unit 08, each optionally with an additional dryer, are again arranged. All of these printing cylinders arranged in a row then form in the press assembly in question a continuous transport path for the substrate in question, wherein this substrate is then transferred in each case from one printing cylinder to the next. The substrate in question can be processed, in particular printed, on both sides, without the need for a turning device for this substrate in this press assembly. The proposed press assembly is therefore highly compact and inexpensive.
The press assembly shown in
While preferred embodiments of a method and printing press arrangements for sequential processing of sheet-like substrates, in accordance with the present invention, have been set forth fully and completely hereinabove, it will be apparent to one of skill in the art that various changes could be made thereto, without departing from the true spirit and scope of the present invention which is accordingly to be limited only by the appended claims. CLAIMS
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2015 208 041.2 | Apr 2015 | DE | national |
| 10 2015 213 431.8 | Jul 2015 | DE | national |
| 10 2015 215 003.8 | Aug 2015 | DE | national |
| 10 2015 216 874.3 | Sep 2015 | DE | national |
| 10 2015 217 229.5 | Sep 2015 | DE | national |
This application is a continuation of prior U.S. patent application Ser. No. 15/569,154, filed Oct. 25, 2017. That application is the U.S. national phase, under 35 U.S.C. § 371, of PCT/EP2016/059647, filed Apr. 29, 2016; published as WO2016/174225A2 and A3 on Nov. 3, 2016 and claiming priority to DE 10 2015 208 041.2, filed Apr. 30, 2015; to DE 10 2015 213 431.8, filed Jul. 17, 2015; to DE 10 2015 215 003.8, filed Aug. 6, 2015; to DE 10 2015 216 874.3, filed Sep. 3, 2015 and to DE 10 2015 217 229.5, filed Sep. 9, 2015, the disclosures of which are expressly incorporated herein by reference in their entireties.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 15569154 | Oct 2017 | US |
| Child | 16031075 | US |
