EP3988304A1 - Printing machine with twin printing unit and method for operating such a printing machine - Google Patents

Abstract

The invention relates to a printing machine (100) for printing a printing material web (1) with a plurality of flexographic printing units (11) arranged in a row, the flexographic printing units (11) being arranged in a plane (E) accessible to the machine operator, and characterized in that that always two flexographic printing units (11, 11a, 11b) of the plurality of flexographic printing units (11, 11a, 11b) together form a double printing station (10), and that the two flexographic printing units (11, 11a, 11b) of a respective double Printing station (10) each have an impression cylinder (16a, 16b) and that a dryer (19a) is arranged on the path (la) of the printing material web (1) between the two impression cylinders (16a, 16b).

Description

description

The invention relates to a printing machine according to the preamble of claim 1 and a method for operating such a printing machine having the features of claim 22.

State of the art

Increasingly high demands are being placed on printing machines designed or used for packaging printing in terms of cost-effectiveness and ease of operation, while at the same time maximizing variability for product manufacture. For example, the printing press should cause as little waste as possible, for example when changing over between different print jobs. Common in-line web printing machines designed for packaging printing, especially flexographic printing, usually have a machine design in which a substrate is guided over a large number of cylinders and rollers between different process levels (e.g. for printing and for drying), so that a no insignificantly long web section is stored in the printing press and potentially corresponding waste can occur.

In order to produce folding box blanks, inline machines for printing and rotary die-cutting of box blanks are known, for example from EP 1 731 277 B1 . In this case, a web-shaped substrate is printed in a web printing machine with a plurality of printing units, possibly using different printing processes. The web of printing material is then further processed by punching, embossing, varnishing, etc.

From the DE 103 43 411 B4 is a rotary printing machine known with a plurality of printing units, wherein the printing units for a quick job change with so-called sleeves can be fitted. For this purpose, the axes of the sleeves can be moved into a changing position by motor, in which the axes are easily accessible. After the sleeves have been changed, they are moved back together with their axes from an exchange position to an operating position.

A disadvantage of the printing presses known from the prior art is that changing the sleeves requires a break in printing, with the downtime reducing the performance of the printing press. If a color change is required, longer downtimes are required. Furthermore, every time the machine stops, there is start-up waste, i.e. printed substrate web, which is scrap.

task

It is therefore the object of the present invention to create a printing press which enables a simple and rapid job change while producing as little waste as possible, and to describe a method for operating such a printing press.

Technical solution

This object is achieved by a printing machine having the features of claim 1 and by a method having the features of claim 22.

The invention relates to a printing machine for printing a printing material web with a plurality of flexographic printing units arranged in a row, the flexographic printing units being arranged in a plane accessible to the machine operator, and is characterized in that two flexographic printing units of the plurality of flexographic printing units together always form a double printing station form, and that the two flexographic printing units of a respective double printing station each have an impression cylinder and that a dryer is arranged on the path of the printing material web between the two impression cylinders.

The printing machine according to the invention serves to print a printing material web, in particular made of paper, cardboard, plastic or composite materials, and has a plurality of flexographic printing units arranged in a row. Due to the in-line design, the printing machine can be expanded as required. The flexographic printing units are arranged in a plane that is accessible to a machine operator, in particular a horizontal plane, at an ergonomically easily accessible height level.

Advantageously, two flexographic printing units together always form a double printing station. The two flexographic printing units of a printing station each have an impression cylinder. This structure of a printing station can be referred to as a twin printing unit or so-called double ink deck, DID, in contrast to the so-called single ink deck, SID.

The drier is preferably a radiation drier such as a UV drier or an electron beam drier. A UV dryer applies ultraviolet radiation to the printing ink, causing the printing ink to harden. The same applies to electron beam dryers. When UV or electrons are used, the term "curing" is used instead of "drying". A corresponding dryer can therefore also be referred to as a curing device.

The printing material can be printed on a first side (front side) and on the opposite second side (back side). The substrate can be guided over guide rollers. The change from the front to the back can take place. A turning device that is additional to the guide rollers does not need to be provided.

The wording "the flexographic printing units are arranged in a plane accessible to the machine operator" means that the flexographic printing units as such are arranged in a plane accessible to the machine operator. Components of the flexographic printing units, in particular cylinders and/or rollers, can lie outside of this plane. For example, the impression cylinder or impression cylinders of a double printing unit must be arranged slightly higher than the impression cylinders and anilox rollers of the same double printing unit.

1. i) Wenigstens eine Doppel-Druckstation mit zwei Druckwerken, mit zwei Gegendruckzylindern und mit einem bevorzugt horizontalen Bahnverlauf zwischen den Gegendruckzylindern, wobei ein Heißlufttrockner am Bahnverlauf zwischen den Gegendruckzylindern angeordnet ist. Zusätzlich mit einem weiteren Heißlufttrockner am Bahnverlauf nach dem zweiten Druckwerk. Der weitere Heißlufttrockner kann eine kurze Trockenstrecke (bei Farbauftrag) oder eine lange Trockenstrecke (bei Lackauftrag) aufweisen. Zu i) siehe auch die Figuren 2a und 2b.

The invention can preferably include the following different variants:

1. i) At least one double printing station with two printing units, with two impression cylinders and with a preferably horizontal web path between the impression cylinders, with a hot-air dryer being arranged on the web path between the impression cylinders. Additionally with another hot air dryer on the web after the second printing unit. The additional hot-air dryer can have a short drying section (when applying paint) or a long drying section (when applying paint). For i) see also the Figures 2a and 2b .

• ii) Wenigstens eine Doppel-Druckstation mit einem gemeinsamen Gegendruckzylinder, wobei ein Heißlufttrockner am Umfang des Gegendruckzylinders angeordnet ist. Zusätzlich mit einem weiteren Heißlufttrockner am Bahnverlauf nach dem zweiten Druckwerk. Der weitere Heißlufttrockner kann eine kurze Trockenstrecke (bei Farbauftrag) oder eine lange Trockenstrecke (bei Lackauftrag) aufweisen. Zu ii) siehe auch die Figuren 2c und 2d.
• iii) Wenigstens eine Doppel-Druckstation mit einem gemeinsamen Gegendruckzylinder, wobei ein UV-Trockner am Umfang des Gegendruckzylinders angeordnet ist. Zusätzlich mit einem weiteren UV-Trockner am Bahnverlauf nach dem zweiten Druckwerk. Der weitere UV-Trockner kann ein einfacher oder ein doppelter Trockner sein, d.h. eine oder zwei UV-Einheiten umfassen. Zu iii) siehe auch die Figuren 2e und 2f.

Optionally in addition to i):

• ii) At least one double printing station with a common impression cylinder, with a hot air dryer being arranged on the periphery of the impression cylinder. Additionally with another hot air dryer on the web after the second printing unit. The additional hot-air dryer can have a short drying section (when applying paint) or a long drying section (when applying paint). For ii) see also the Figures 2c and 2d .
• iii) At least one double printing station with a common impression cylinder, with a UV dryer being arranged on the circumference of the impression cylinder. Additionally with another UV dryer on the web after the second printing unit. The further UV dryer can be a single or a double dryer, ie it can comprise one or two UV units. For iii) see also the Figures 2e and 2f .

The provision of two counter-pressure cylinders with a web section or web path between the two cylinders advantageously allows a long drying section to be realized through the dimensioning of the web path and the dryer arranged there. Depending on the length of the drying section, only one Dryers or two or more consecutive dryers, preferably structurally identical dryers, can be provided. In printing units that process varnish, the drying section can be longer than in printing units that process printing ink, since varnish requires a longer drying time. If only a short drying section is required, it can be advantageous to provide a common counter-pressure cylinder.

The provision of two counter-pressure cylinders with a web section or a web path between the two cylinders advantageously allows the length of the drying section between the two counter-pressure cylinders to be matched to the production speed. In printing machines with a high production speed (e.g. based on a specified standard speed), the drying section can be constructed longer (e.g. based on a specified standard section). In printing presses with low production speeds, the drying section can be designed to be correspondingly shorter. The drying section can be variable, e.g. by changing the distance between the two cylinders using a motor. The number of dryers can be variable, e.g. where dryer modules are added or removed (manually or automatically).

A further advantage is that costs can be saved because only one printing unit frame is required and because the "small" dryer is associated with lower production costs and lower energy consumption.

Two colors can be printed with a double unit, so instead of an 8-color machine with eight units, only an 8-color machine with four units is required. The works with non-stop or double works can be combined.

It is preferred that the two flexographic printing units of a respective double printing station can be activated/deactivated alternatively. This enables continuous production, ie a flying order change. As an alternative to this, the two flexographic printing units of a respective double printing station can be activated/deactivated together. "Activatable"/"Deactivatable" means that the activated Printing units participate in the printing process (printing mode) and the deactivated printing units do not participate in the printing process (non-printing mode) or that the printing units are switched to the corresponding modes.

In an advantageous development of the printing press according to the invention, the two flexographic printing units of a respective double printing station are arranged mirror-symmetrically to the common impression cylinder. While printing is in one flexo printing unit, the other flexo printing unit can be set up or serviced.

In an advantageous development of the printing press according to the invention, the two flexographic printing units of a respective double printing station are arranged mirror-symmetrically to the two impression cylinders. While printing is in one flexo printing unit, the other flexo printing unit can be set up or serviced. Alternatively, both printing units of a double printing station can be operated simultaneously with intermediate drying, e.g. with hot air or IR drying.

In a particularly advantageous and therefore preferred embodiment, each double printing station is followed by a dryer. This has the advantage that after the application of ink, the applied amount of ink can be completely dried and the web of printing material can be deflected without any problems, without the printing ink being deposited from the printed side of the printing material onto a guide roller, for example. Alternatively, it is provided that each double printing station includes at least one dryer, preferably two, three or four dryers.

A particularly advantageous and therefore preferred embodiment is that each double printing station can be operated with different drying systems, eg UV, IR or hot air, depending on the process requirements. This has the advantage that it can be dried with UV, IR or hot air as required (so-called hybrid drying) and the ink application can advantageously completely dry the amount of ink applied and the printing material web can be deflected without any problems there is a shedding. Alternatively, it is provided that each double printing station comprises at least one dryer, preferably two, three or four dryers of different systems.

In a particularly advantageous and therefore preferred embodiment, each double printing station can be operated with different dryer systems, e.g. UV, IR or hot air, depending on the process requirements, which can be exchanged, e.g. by exchanging corresponding cassettes. This has the advantage that drying can be carried out either with UV or with hot air, as required, and the ink application can advantageously completely dry the applied amount of ink and the printing material web can be deflected without problems without it being set off. Alternatively, it is provided that each double printing station includes at least one dryer, preferably two, three or four dryers, of different systems.

In a particularly advantageous and therefore preferred embodiment, each double printing station can be operated with different dryer systems, e.g. UV, IR or hot air, depending on the process requirements, and that these can also be interchanged with a plurality of double printing units, e.g Cassettes between double printing units. As an example, the UV dryer from a double printing station of a first printing unit can be exchanged for an IR emitter from another double printing station. This has the advantage that it can be dried with either UV, IR or hot air, as required, and the ink application can advantageously be complete drying of the applied amount of ink and the printing material web can be deflected without any problems without it being set off .

It is also preferred that the dryer is a UV dryer or that the dryers are UV dryers. It is also preferred that the common impression cylinder of a respective double printing station is designed as a temperature control cylinder, in particular as a cooling cylinder.

Temperature control, in particular cooling, can advantageously keep the shape and/or the circumference of the temperature-controlled cylinder, in particular of the impression cylinder, constant.

It is also preferred that the dryer is a UV dryer or that the dryers are UV dryers. It is also preferred that at least one of the impression cylinders on the respective double printing station is designed as a temperature control cylinder, in particular as a cooling cylinder.

It is also preferred that both impression cylinders on the respective double printing station are designed as temperature control cylinders, in particular as a cooling cylinder.

In a particularly advantageous and therefore preferred embodiment, it is provided that in each double printing station on the circumference of the tempering cylinder in the direction of transport of the printing material, the following are arranged one after the other: a flexographic printing unit; one or two UV dryers or IR dryers; a flexographic printing unit; and one or two UV dryers or IR dryers.

It is also advantageous if a respective flexographic printing unit is equipped with an inking device and with a flexographic printing cylinder with a printing sleeve carrying the printing form.

In practice, it has proven to be advantageous if a respective impression cylinder has a radius of less than 1000 mm (in the case of hot-air drying).

In a particularly advantageous and therefore preferred embodiment, it is provided that, in addition to the plurality of flexographic printing units, there is at least one further flexographic printing unit as an individual printing station, preferably as a varnishing unit.

In a particularly advantageous and therefore preferred embodiment, it is provided that the individual printing station is arranged before the plurality of flexographic printing units or that the individual printing station is arranged after the plurality of flexographic printing units.

In a particularly advantageous and therefore preferred embodiment, it is provided that the single printing station is arranged downstream of the double printing station—or a last double printing station—in the printing material transport direction.

In a particularly advantageous and therefore preferred embodiment, it is provided that in the individual printing station the impression cylinder is designed as a temperature control cylinder, in particular as a cooling cylinder, and that the following are arranged one after the other on the circumference of the temperature control cylinder in the printing material transport direction: a flexographic printing unit; and one or two UV dryers or IR dryers.

In a particularly advantageous and therefore preferred embodiment, it is provided that dryer systems consisting of single printing stations, e.g. UV, IR or hot air, can be exchanged and operated with those from double printing stations, depending on the process requirements. As an example, the UV dryer from the single printing station (SiD - single ink deck) can be exchanged with the IR dryer of the double printing station (DiD - double ink deck). This has the advantage that it can be dried with either UV, IR or hot air, as required, and the ink application can advantageously be complete drying of the applied amount of ink and the printing material web can be deflected without any problems without it being set off .

In a particularly advantageous and therefore preferred embodiment it is provided that the printing material on a section - or on all sections - a) between two double printing stations and / or b) between the double printing station - or a last double printing station - and the Single printing station runs in a second level, which is substantially below the level.

In a particularly advantageous and therefore preferred embodiment, it is provided that the length of the web of printing material on the section—or on all sections—is less than the length of the web of printing material in a double printing station.

The length of the substrate web in a double printing station between two impression cylinders can, for example, be less than 1.5 meters or less than 1 meter.

In a particularly advantageous and therefore preferred embodiment, it is provided that the printing material web, starting from the second plane, forms a loop that is open at the top or bottom in each double printing unit.

In a particularly advantageous and therefore preferred embodiment, it is provided that the loop runs around the impression cylinder and around at least two or three guide rollers, which is or are arranged between the plane and the further plane.

In a particularly advantageous and therefore preferred embodiment, it is provided that the last double printing station is followed in succession by a single printing station and a hot-air dryer in the printing material transport direction.

In a particularly advantageous and therefore preferred embodiment it is provided that the printing machine comprises at least one double printing station with two impression cylinders and that the printing machine comprises at least one double printing station with a common impression cylinder.

In a particularly advantageous and therefore preferred embodiment, it is provided that the double printing station with a common impression cylinder includes a dryer on the circumference of the common impression cylinder.

The invention also relates to a method for operating a printing press, as described above, for printing a printing material web. According to the invention, a maximum of one flexographic printing unit of the two flexographic printing units of a respective double printing station is activated and prints onto the printing material web. The respective other flexographic printing unit, ie the inactive printing unit of a double printing station, can advantageously be subjected to a set-up process or a maintenance process or it is in an inactive waiting position. During a set-up process, for example, print sleeves can be exchanged or colors can be changed. Special colors can also be easily used and exchanged. The maintenance process can be, for example, a blade change on the squeegee. In a particularly advantageous and therefore preferred development of the method according to the invention, the flexographic printing units of a respective double printing station can be activated in register and the flexographic printing units of a respective double printing station can be deactivated in order to enable a flying change between the flexographic printing units when changing jobs. This means that when there is a job changeover, there should be a switchover from one flexo printing unit to the other flexo printing unit in a printing station, so the flexo printing units of the various printing stations are synchronized with one another in such a way that no waste is produced between the jobs and the printing material can continue to be printed on continuously.

In a particularly advantageous and therefore preferred development of the method according to the invention, a measuring device can be provided, e.g. with a camera and e.g. Printing station transmitted, so that the latter can carry out a flying change in register and/or with - for a high-quality print - optimized preset print infeed (distance between impression cylinder and impression cylinder or printing material and distance between impression cylinder and anilox roller).

Alternatively, a method according to the invention can also provide for both of the two flexographic printing units of a printing station to be activated and to print on the printing material web. A machine with, for example, four printing stations can print eight colors instead of only four according to this alternative.

In a particularly advantageous and therefore preferred embodiment, it can be provided that the printing material, in particular the web, is already pretreated and/or preprinted, for example by applying a cold foil and/or one or more inks. Such a pretreated and/or preprinted web can be printed with colors, eg four or eight. The imprinting can be done in register with an already existing imprint and/or order.

The invention described and the advantageous developments of the invention described also represent advantageous developments of the invention in combination with one another - insofar as this is technically sensible.

With regard to further advantages and configurations of the invention that are advantageous in terms of construction and function, reference is made to the subclaims and the description of exemplary embodiments with reference to the accompanying figures.

example

The invention will be explained in more detail using the attached figures. Corresponding elements and components are provided with the same reference symbols in the figures. For the sake of better clarity of the figures, a true-to-scale representation has been dispensed with.

Fig. 1

eine erfindungsgemäße Druckmaschine bzw. eine Konfiguration mit sechs DID-Station gefolgt von einer SID-Station;

Fig. 2a-f

eine Druckstation der Druckmaschine aus Fig. 1;

Fig. 3

eine Bahndruckmaschine gemäß dem Stand der Technik;

Fig. 4

den Unterschied zwischen einer DID- und einer SID-Station;

Fig. 5

eine DID-Station mit zwei gleichzeitig aktivierbaren Flexodruckwerken;

Fig. 6

eine DID-Station mit zwei abwechselnd aktivierbaren Flexodruckwerken;

Fig. 7

eine sogenannte Gable-Top-Anwendung;

Fig. 8

eine Konfiguration mit vier SID- gefolgt von zwei DID-Stationen;

Fig. 9

eine Konfiguration mit vier DID- gefolgt von vier SID-Stationen; und

Fig. 10

ein Doppeldruckwerk.

It show in schematic representation

1

a printing machine according to the invention or a configuration with six DID stations followed by one SID station;

Fig. 2a-f

a printing station of the printing machine 1 ;

3

a prior art web printing machine;

4

the difference between a DID and a SID station;

figure 5

a DID station with two flexographic printing units that can be activated simultaneously;

6

a DID station with two flexographic printing units that can be activated alternately;

7

a so-called gable top application;

8

a configuration with four SID followed by two DID stations;

9

a four DID followed by four SID station configuration; and

10

a double printer.

figure 3 shows a rotary printing machine 100 according to the prior art for printing a printing material web 1. The printing material web 1 is transported in the transport direction T through a plurality of processing units and processed in the process. The processing tools are flexographic printing units 11 (in the direction of web travel 11a at the inlet and 11b at the outlet of the double printing unit), an embossing unit 12 and a punching and creasing unit 13. Adjacent to the web run of the printing material web 1, inspection systems 4 are provided, which can be used as cameras, for example are designed to continuously monitor the register accuracy of the processing of the printing material web 1. In particular, the circumferential register and the lateral register are monitored.

The inspection systems 4 and the flexographic printing units 11, embossing unit 12 and punching and creasing unit 13 are connected to a control unit 22 for data transmission and can be controlled by it.

figure 1 shows a printing machine 100 in an overview. The printing press 100 according to the invention has a plurality of flexographic printing units 11 . A printing material web 1 moving in the web transport direction T is printed with the flexographic printing units 11 . The flexographic printing units 11 are numbered consecutively with DW1 to DW7. The flexographic printing units 11 are arranged in a row on a horizontal level E that is easily accessible for a machine operator. Two flexographic printing units 11 together form a printing station 10, at least in DW1 to DW6, which are also referred to as twin printing units (or double printing stations or DID). be able. The DW7 is designed as a conventional flexographic printing unit 11 (or single printing station or SID). In this, for example, a flat application of paint can take place. The color magenta is printed in the first printing station 10 DW1, the color cyan is printed in the second printing station 10 DW2, the color yellow is printed in the third printing station 10 DW3 and the color black is printed in the sixth printing station DW6. Special colors S1 and S2 are printed in the further printing stations 10 DW4 and DW5.

A dryer 19 is provided after each printing station 10, viewed in the direction of web travel T. In addition to the flexographic printing units 11 can - as well as in the printing press 100 from figure 3 - An embossing unit 12, a punching and creasing unit 13 and a control unit 22 may be provided.

The structure of a respective printing station 10 is closer in the Figure 2a -f shown.

the Figures 2c and 2d show a printing material web 1 transported in web transport direction T, which is guided with the aid of deflection rollers 20 and wraps around an impression cylinder 16. Two flexographic printing units 11, each with a flexographic printing cylinder with a printing sleeve 15, an impression cylinder 16 and an inking device 21, form a printing station 10. The flexographic printing units 11 with their components are arranged in a plane E. The two flexographic printing units 11 have a common impression cylinder 16. The arrangement of flexographic printing cylinders 15 and inking device 21 of the two flexographic printing units 11 is mirror-symmetrical to a vertical mirror axis through the impression cylinder 16. The printing station 10 is designed in such a way that one of the two flexographic printing units 11 prints and this flexographic printing unit 11 is in an activated position. The other, inactive flexographic printing unit 11 was turned off by the common impression cylinder 16. The activation or deactivation of a flexographic printing unit 11 is effected by an actuating movement s figure 1 and Figure 2c-d a first print job is processed in the right flexographic printing units 11 of a respective printing station 10. At the same time, a second job can be prepared in the left-hand flexographic printing unit 11 of the printing stations 10, or this flexographic printing unit 11 can be serviced, for example a blade change on the squeegee can be carried out. If at a certain point in time a first order has been processed, the right flexographic printing unit 11 automatically moves into an inactive waiting position and at the same time the left flexographic printing unit 11 moves into an active position in order to print the second order. The end of printing of a first print job and the start of printing of a second, subsequent print job are therefore almost at the same time. This process, which has been described for a first printing station 10, also takes place in the other printing stations 10, precisely for the route, ie in the second printing station 10 there is a switchover from the first to the second job and thus the switchover from the right flexographic printing unit 11 to left flexographic printing unit 11 exactly at the point of the printing material web 1 where the first printing station 10 has completed the change. Waste, ie waste, can thus be saved. In other words: the flexographic printing units 11 of the various printing stations 10 are synchronized with register accuracy when there is a job change, so that there is almost no waste.

The change from one print job to a subsequent print job is event-driven. The triggering event can be a specific printing time, a specific printed length on the substrate web, a specific number of printed copies, a change of material or a trigger by the machine operator. With such an event-driven control of the printing machine 100 by means of a control unit 22, the printing machine 100 is able to simultaneously prepare next print jobs while a current print job is being processed and to process them in sequence.

A dryer 19a, preferably a hot-air dryer 19a, is arranged on the circumference of the common impression cylinder 16. This preferably serves as an intermediate dryer. A dryer 19 is also arranged. This preferably serves as a final dryer.

the Figures 2a and 2b show (compared to the Figures 2c and 2d ) A variant in which instead of the common impression cylinder 16 comprises two impression cylinders 16a and 16b. The web 1 is guided on a web course/path 1a, preferably horizontally, between the two impression cylinders 16a and 16b. The dryer 19a is now arranged on the path of the web 1a instead of on the common impression cylinder. The dryer preferably serves as an intermediate dryer. A dryer 19 is also arranged. This preferably serves as a final dryer.

Alternatively, a dryer system with one or two permanently installed UV dryers or interchangeable drying systems, eg IR or hot air, can be arranged between the two impression cylinders 16, where the web 1 is preferably guided horizontally on a web course/path 1a. The dryer(s) is/are preferably used as intermediate dryer. A dryer 19 is also arranged. This preferably serves as a final dryer.

Figure 2b 12 shows a (pre)conditioning unit 50. This can advantageously be used to condition/precondition the web before it enters the first printing unit, in particular to temper it to the operating temperature and/or to shrink it. In this way register problems can be avoided because the web is then already tempered and/or shrunk before the first printing unit as it would otherwise only be after the (eg second) printing unit or its downstream dryer.

the Figures 2e and 2f show (compared to the Figures 2a and 2b ) a variant in which a common impression cylinder 16 is again present. This time, a UV dryer is arranged on the circumference of the common impression cylinder. This preferably serves as an intermediate dryer. In addition, a UV dryer 19 is arranged. This preferably serves as a final dryer.

figure 4 shows the difference between a DID station 31 (on the left in the figure) and a SID station 30 (on the right in the figure). Such stations can, in the configurations shown in this application (see e.g figure 7 ) be provided.

Both stations are designed as so-called "short web" stations: When printing UV inks, the drying section can be much shorter. In particular, UV dryers can be arranged to save space on the circumference of a (central) impression cylinder or between two impression cylinders. Compared to the thermal drying of water-based or solvent-based paints (see e.g figures 1 , 8th and 9 ) the dryer section is significantly shorter. The web guide between the stations can also take place on a level below level E, which is accessible to the machine operator. The web is thus guided "from below" to the stations. The short path between the stations ensures improved register behavior. The start-up process for the printing press is also significantly shorter. The (central) impression cylinder or the two impression cylinders is/are preferably designed as a temperature control cylinder, in particular as a cooling cylinder.

The DID station 31 comprises the following in the direction of the printing material transport: a deflection roller 20 for the web 1, a central impression cylinder 16, assigned to this a first flexographic printing unit 11 (with flexographic printing cylinder 15 and inking device 21, e.g. a screen cylinder), one or (like shown) two dryers 19, a second flexographic printing unit 11, one or (as shown) two further dryers 19 and two deflection rollers 20. The dryers are preferably UV dryers. Such a station can transmit two colors at the same time.

Alternatively, the DID station 31 can include the following in the direction of the printing material transport: a deflection roller 20 for the web 1, two counter-pressure cylinders 16, assigned to this, a first flexographic printing unit 11 (with a flexographic printing cylinder 15 and an inking device 21, e.g. a screen cylinder), one or ( as shown) two dryers 19, a second flexographic printing unit 11, one or (as shown) two further dryers 19 and two deflection rollers 20. The dryers are preferably UV dryers or IR dryers. Such a station can transmit two colors at the same time.

The SID station 30 comprises the following in the direction of the printing material transport: preferably two deflection rollers 20 for the web 1, an impression cylinder 16, assigned to this a flexographic printing unit 11 (with flexographic printing cylinder 15 and inking device 21, e.g. a screen cylinder), one or (as shown ) two dryers 19a, 19b and preferably a deflection roller 20. The dryers are preferably UV dryers. Such a station can transmit one color.

figure 5 shows a DID station with two flexographic printing units 11 that can be activated simultaneously. On the (central) impression cylinder 16, one or (as shown) two dryers 19 are arranged after each flexographic printing unit 11. The dryers are preferably UV dryers

Alternatively, a DID station can be provided with two flexographic printing units 11 that can be activated simultaneously, with two impression cylinders 16, with after each flexographic printing unit 11 one or two dryers 19 is/are arranged. The dryers are preferably UV dryers or IR dryers.

figure 6 shows a DID station with two flexographic printing units 11 that can be activated alternately. One or (as shown) two dryers 19 are arranged on the (central) impression cylinder 16 after the last flexographic printing unit 11 . The dryers are preferably UV dryers.

Alternatively, the DID station can be provided with two flexographic printing units 11 that can be activated alternately, with one or two dryers 19 being arranged after the last of the two flexographic printing units 11 . The dryers are preferably UV dryers or IR dryers.

figure 7 shows another application. This is a machine with 4 DID short web stations 31 and one SID station 30 as well as a final thermal dryer 19. Eight colors and a varnish or silicone can be applied. A web guide 40 is provided between the last station 31 and the station 30 . Such an application is used, for example, in the production of so-called "gable top" packaging. As an alternative to the embodiment shown, two impression cylinders can be provided in each of the printing units.

figure 8 shows a configuration with four SID stations 30 followed by two DID stations 31. A thermal dryer 19 is associated with each station. The web is guided "from above" to the stations. The printing sequences can be: CMYK process colors, spot color 1, spot color 3. The spot color units can be converted to other spot colors 2 and 4 during ongoing production.

figure 9 Figure 12 shows a configuration with four DID stations 31 followed by four SID stations 30. A thermal dryer 19 is associated with each station. The web is guided "from above" to the stations. The printing sequences can be: process colors CMYK, spot color 1, spot color 2. The last two stations 30 are inactive and are prepared or converted, for example, for an upcoming print job (spot colors 3 and 4).

Unlike in figure 1 shown, the printing machine 100 shown there can also have the following structure: at least one double printing station 10 (preferably corresponding to Figures 2a to 2f : with two impression cylinders) and at least one single printing station 11 (preferably according to the figures 4 to the right). Any combination and sequence is possible. A respective variant is eg off figure 8 (4 times SID and 2 times DID) or off figure 9 (4 times DID and 4 times SID) evident: the double printing units shown there with a common impression cylinder would have to be replaced by double printing units with two impression cylinders. In addition, one or more SID and/or one or more DID units without a dryer can also be provided on the impression cylinder.

figure 10 shows a double printing unit with two mutually spaced impression cylinders 16a and 16b. A pressure cylinder 15 and an anilox roller 21 are associated with the first impression cylinder 16a; a further impression cylinder 15 and a further anilox roller 21 are assigned to the second impression cylinder 16b. Two dryers 19a and 19b are arranged between the two impression cylinders on the path of the printing material webs. After the second impression cylinder 16b, two further dryers 19c and 19d are arranged on the path of the printing material web. Within the double printing unit, the path of the web follows a loop 1' which is open at the bottom.

Reference List

1

substrate web

1'

loop

1a

trajectory

10

printing station

11

flexographic printing unit

11a

Flexographic printing unit (infeed of a double printing station)

11b

Flexographic printing unit (end of a double printing station)

12

embossing plant

13

Stamping and creasing unit

14

inspection system

15

Flexo printing cylinder with printing sleeve

16

Common impression cylinder

16a

Impression cylinder

16b

Impression cylinder

17

embossing cylinder

18

punch cylinder

19

dryer

19a,b,c,d

dryer

20

pulley

21

paint application device

22

Control unit (machine control with interface)

30

SID Station (Single Ink Deck)

31

DID Station (Double Ink Deck)

40

web guidance

50

(Pre-)conditioning unit

100

printing press

s

actuating movement

E

level

f

second level

T

web transport direction

DW

printing unit number

M

magenta

C

cyan

Y

Yellow

K

Black

S1, S2

special colours

Claims (27)

Printing machine (100) for printing a printing material web (1) with a plurality of flexographic printing units (11) arranged in a row, the flexographic printing units (11) being arranged in a plane (E) accessible to the machine operator, characterized, that always two flexographic printing units (11, 11a, 11b) of the plurality of flexographic printing units (11, 11a, 11b) together form a double printing station (10), and that the two flexographic printing units (11, 11a, 11b) of a respective double printing station (10) each have an impression cylinder (16a, 16b) and that a dryer (19a) on the path (1a) of the printing material web (1) between the two impression cylinders (16a, 16b) is arranged. Printing machine according to claim 1,
characterized,
that the two flexographic printing units (11, 11a, 11b) of a respective double printing station (10) can be activated and deactivated together or alternatively can be activated and deactivated. Printing machine according to one of the preceding claims,
characterized,
that the two flexographic printing units (11, 11a, 11b) of a respective double printing station (10) are arranged mirror-symmetrically to the two impression cylinders (16a, 16b). Printing machine according to one of the preceding claims,
characterized,
that each double printing station (10) is followed by a dryer (19) or that each double printing station (10) comprises at least one dryer (19a, 19b, 19c, 19d), preferably two, three or four dryers. Printing machine according to claim 4,
characterized,
that the dryer (19, 19a, 19b, 19c, 19d) is a UV dryer or IR dryer or that the dryers (19, 19a, 19b, 19c, 19d) are UV dryers or IR dryers. Printing machine according to claim 4 or 5,
characterized,
that at least one impression cylinder of the two impression cylinders (16a, 16b) of a respective double printing station (10) is designed as a temperature control cylinder. Printing machine according to claim 6,
characterized,
that in each double printing station (10) a flexographic printing unit (11) is arranged on the circumference of the respective temperature control cylinder (16a). Printing machine according to one of the preceding claims,
characterized,
that a respective flexographic printing unit (11) is equipped with an inking device (21) and a flexographic printing cylinder (15) with a printing sleeve carrying the printing form. Printing machine according to one of the preceding claims,
characterized,
that a respective impression cylinder (16) has a radius of less than 1000 mm. Printing machine according to one of the preceding claims,
characterized,
that in addition to the plurality of flexographic printing units (11), there is at least one further flexographic printing unit (11a) as an individual printing station (10a), preferably as a varnishing unit (10a). Printing machine according to one of the preceding claims,
characterized, that the individual printing station (10a) is arranged in front of the plurality of flexographic printing units (11), or that the individual printing station (10a) is arranged after the plurality of flexographic printing units (11). Printing machine according to one of the preceding claims,
characterized,
that the single printing station (10a) of the double printing station (10) - or a last double printing station (10) - is downstream in the printing material transport direction (R). Printing machine according to claim 12,
characterized,
that in the individual printing station (10) the impression cylinder (16) is designed as a temperature control cylinder (16) and is arranged on the circumference of the temperature control cylinder (16) in the printing material transport direction (R) one after the other: - a flexographic printing unit (11); and - one or two UV or IR dryers (19, 19). Printing machine according to one of the preceding claims,
characterized, that the printing material web (1) on a section - or on all sections - a) between two double printing stations (10) and/or b) between the double printing station (10) - or a last double printing station (10) - and the single printing station (10a) in a second plane (F) which is substantially below the plane (E). Printing machine according to claim 14,
characterized,
that the length of the printing substrate (1) on the section - or on all Sections - is less than the length of the printing material web (1) in a double printing station (10). Printing machine according to claim 14 or 15,
characterized,
that the printing material web (1), starting from the second plane (F), forms a downwardly open loop (1') in each double printing unit (10). Printing machine according to claim 16,
characterized,
that the loop (1') leads around one or both counter-pressure cylinders (16) and around at least two or three guide rollers (23), which is or are arranged between the plane (E) and the further plane (F). Printing machine according to one of the preceding claims,
characterized,
that the last double printing station (10) is followed in succession by a single printing station (10a) and a hot air dryer (25) in the printing material transport direction (R). Printing machine according to one of the preceding claims,
characterized,
that the dryer (19a) on the path (1a) of the printing material web (1) between two impression cylinders (16a, 16b) of a double printing station (10) is a hot air dryer (19) or a UV dryer (19). Printing machine according to one of the preceding claims,
characterized,
that the printing machine (100) comprises at least one double printing station (10) with two impression cylinders (16) and that the printing machine (100) comprises at least one double printing station (10) with a common impression cylinder (16). Printing machine according to claim 20,
characterized,
that the double printing station (10) with a common impression cylinder (16) comprises a dryer (19a) on the circumference of the common impression cylinder (16). Method for operating a printing machine (100) according to one of the preceding claims, for printing a printing material web (1),
characterized,
that of the two flexographic printing units (11) of a respective double printing station (10) a maximum of one flexographic printing unit (11) is activated and prints. Method for operating a printing machine according to Claim 20,
characterized,
that the respective other flexographic printing unit (11) of a double printing station (10) is subjected to a set-up process or a maintenance process. Method for operating a printing machine according to one of the preceding claims,
characterized,
that the two flexographic printing units (11) of a respective double printing station (10) can be activated and deactivated in register. Method for operating a printing machine according to one of the preceding claims,
characterized,
that at least one flexographic printing unit (11) of a double printing station (10) can be activated and deactivated in register with another flexographic printing unit (11) of the printing press (100) or with a processing unit of the printing press (100). Method for operating a printing machine according to Claim 25,
characterized,
that the processing unit is an embossing unit or a stamping unit. Method for operating a printing machine according to one of the preceding claims,
characterized,
that a measuring device is provided which measures printing forms and transmits the data obtained in the process to a double printing station, so that the latter carries out a flying change with register accuracy and/or with an optimized preset print infeed.

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