EP2862715A2 - Printing press - Google Patents

Abstract

Printing machine (10), with at least one gripperless printing unit (11) of a web-fed printing press, by means of which a substrate to be printed can be transported in the horizontal direction, with a transport device (16) via which the substrate to be printed is dimensionally stable and relatively rigid piece goods (17), which during transport and printing does not adapt to cylinder contours of the printing units (11) through which or each gripperless printing unit (11) can be transported, and with a feeder (22) which holds the piece goods (17) to be printed ready and over which to be printed piece goods (17) on the transport device (16) for subsequent printing in the printing units (11) is accurate to the circumference and pagespasser accurately placed.

Description

The invention relates to a printing press according to the preamble of claim 1. Furthermore, the invention relates to a method for operating a printing press.

In printing press construction, a distinction is made between sheet-fed presses and web-fed presses.

In a sheet-fed printing machine, individual printing sheets are printed in printing units of the sheet-fed printing machine as substrates to be printed, with the printing sheets to be printed being transported by means of a gripper system in the printing units through the sheet-fed printing press. Thus, cylinders of printing units of a sheet-fed printing press and positioned between the printing units transfer cylinders of the sheet printing machine associated gripper systems by means of which a printing sheet is detected at a front in the transport direction of the sheet edge so as to transport the printed sheet to be printed by the individual printing units of the sheet-fed press , At the beginning of the transport path of the printing sheet to be printed sheets to be printed by an investor of the sheet-fed press are kept, at the end of the transport path after printing the sheet, the printed sheets are designed via a boom. In a sheet-fed printing machine, such substrates can be printed as printed sheets, which are flexible and therefore unsteady, ie substrates which can adapt in their contour to the circumference of the cylinder of the printing press serving for the sheet transport. Thus, for example, as substrates in a sheet-fed printing press, sheets of paper, sheets of cardboard or sheets of flexible sheet metal can be printed.

Web presses have gripperless printing units and are used to print on a virtually endless substrate, such as printing on a continuous paper web to be unwound from a roll. Since in web presses a practically endless substrate belt is therefore printed, printing units of a web-fed printing press have no grippers, but merely devices for regulating the position of the substrate strip to be printed. Since no gripper must be controlled in web presses, higher printing speeds can be achieved with web presses, so that it is therefore possible to print in web presses a higher number of copies per unit time than in sheet-fed presses. In web presses so far only such substrates can be printed, which are flexible and non-rigid, such as paper, thin cardboard or films.

On this basis, the present invention has the object to provide a novel printing press and a method for operating the same. This object is achieved by a printing machine according to claim 1.

The printing machine according to the invention has a transport device over which the substrate to be printed is dimensionally stable and relatively stiff, which does not conform to cylinder contours of gripperless printing units of a web press during transport and printing, through which or each gripperless printing unit can be transported, and via a feeder, which holds the piece of goods to be printed ready and over which the piece goods to be printed on the transport device for subsequent printing in the gripperless printing units is accurate to the circumference and page exactly placed.

With the present invention, it is proposed for the first time to print form-stable and relatively stiff piece goods in gripperless printing units of a web-fed printing machine as a substrate to be printed on.

For this purpose, the transport device is used, with the help of which the dimensionally stable and relatively rigid cargo is transported for printing by the gripperless printing units of the web press. The feeder is used for accurate registration of the exact position of the page register and precise positioning of the dimensionally stable and relatively rigid piece goods on the transport device for registration-accurate printing of the piece goods in the gripper-free printing units of the web press.

When printing the piece goods in the printing press according to the invention significantly higher printing speeds can be realized as in sheet-fed presses. Furthermore, it is possible in a simple manner, dimensionally stable and relatively rigid piece goods with variable printing format paßgenau to print as long as the print size of the piece to be printed smaller than the circumference of a transfer cylinder used for printing the respective printing unit or maximum corresponds to this extent.

According to a first advantageous development, the transport device is designed as a conveyor belt system, which has at least one tensioned on deflection rollers conveyor belt, wherein the piece goods to be printed is fixed by the or each gripperless printing unit on the conveyor belt preferably by gluing or by magnetic effects or by electrostatic effects , According to a second, alternative advantageous development of the invention, the transport device is designed as a vacuum conveyor belt system or Saugförderbandsystem having at least one stretched at deflection rollers vacuum conveyor or suction conveyor, wherein the cargo to be printed fixed during transport through the or each gripperless printing unit on the vacuum conveyor belt or suction conveyor by vacuum is. Both advantageous developments of the invention allow the transport of the piece goods to be printed by the printing units of the web press with a high transport speed, which can be achieved at the printing speed which can be achieved with web presses is adjusted. This allows a particularly advantageous printing of the piece goods in the gripperless printing units of the web press.

The method according to the invention for operating a printing press is defined in claim 14.

With the transport device dimensionally stable and relatively rigid cargo is transported by the or each gripperless printing unit. With the feeder, for the subsequent printing, the piece goods are placed on the transport device with the exactness of the circumference and precise page-registration.

According to an advantageous development, the piece goods to be printed on the transport device is positioned such that each on the transport to be placed new piece goods with a defined distance to the respective upstream cargo is positioned on the transport device. The defined distance is preferably set depending on a circumference of the transfer cylinder and depending on a print format of the piece goods to be printed.

Fig. 1:

eine stark schematisierte Darstellung einer erfindungsgemäßen Druckmaschine;

Fig. 2:

ein Detail der Druckmaschine der Fig. 1;

Fig. 3:

ein alternatives Detail der Druckmaschine der Fig. 1;

Fig. 4:

ein Detail IV der Fig. 2 bzw. der Fig. 3; und

Fig. 5:

eine stark schematisierte Darstellung einer weiteren erfindungsgemäßen Druckmaschine.

Preferred embodiments of the invention will become apparent from the dependent claims and the description below. Embodiments of the invention will be described, without being limited thereto, with reference to the drawings. Showing:

Fig. 1:

a highly schematic representation of a printing machine according to the invention;

Fig. 2:

a detail of the printing press the Fig. 1 ;

3:

an alternative detail of the printing press Fig. 1 ;

4:

a detail IV of the Fig. 2 or the Fig. 3 ; and

Fig. 5:

a highly schematic representation of another printing machine according to the invention.

The invention relates to a printing press. Fig. 1 shows a highly schematic view of a printing machine 10 according to the invention, wherein in the illustrated embodiment, the printing machine 10 includes a plurality of gripperless printing units 11 of a web printing machine, through which a substrate to be printed in the horizontal direction 12 is transportable.

Of the printing units 11 are in Fig. 1 each a so-called forme cylinder 13, a so-called transfer cylinder 14 and a so-called printing cylinder 15 is shown, wherein the substrate to be printed between the transfer cylinder 14 and the printing cylinder 15 in the horizontal direction 12 is transported by the printing units 11.

In addition, the printing units 11 comprise an inking unit, not shown, and preferably a dampening unit, not shown.

For the invention, it is essential that the printing units 11 are printing units of a web-fed printing press, which accordingly have no grippers.

The printing machine 10 furthermore has a transport device 16, via which dimensionally stable and relatively stiff piece goods 17 can be transported through the gripperless printing units 11 of the web press as the substrate to be printed. Under dimensionally stable and relatively rigid cargo 17 is such general cargo to understand, which does not adapt to the cylinder contours of the printing units during transport and printing.

This dimensionally stable and relatively rigid piece goods are, for example, wood fiber boards such as MDF boards, thick cardboard boxes or glass panes.

In the illustrated embodiment of the Fig. 1 the transport device 16 is designed as a conveyor belt system which has at least one endless conveyor belt 19 tensioned on deflecting rollers 18. The printable, dimensionally stable and relatively rigid piece goods 17 are fixed for transport by the gripperless printing units 11 on the respective conveyor belt 19 preferably by gluing.

In the preferred embodiment of the invention, in which the dimensionally stable, relatively rigid piece goods 17 are fixed on the or each conveyor belt 19 by gluing, the respective conveyor belt 19 preferably has an at least two-layer structure of an outer layer 20 facing the goods to be transported 17 and an inner, facing away from the transporting cargo 17 layer 21, wherein it is preferably a layer 20 of polyurethane in the outer layer 20 of the respective conveyor belt 19, on which the cargo 17 is to be fixed by gluing. The piece goods 17 to be transported and to be printed on such a polyurethane layer can be fixed particularly advantageously by gluing and, after printing, can also be easily released from the respective conveyor belt 19.

As an alternative to gluing, the printable, dimensionally stable and relatively stiff piece goods 17 can be fixed on the respective conveyor belt 19 by electrostatic effects or magnetic effects or adhesive effects. The respective conveyor belt can be designed as a flat belt or chain belt or link belt. Then, when the conveyor belt is designed as a link belt, the same preferably comprises a plurality of chain-like connected chain elements whose dimensions are matched to the print format of the piece goods to be printed.

In contrast, it is also possible that the transport device 16 is designed as a vacuum conveyor belt system or Saugförderbandsystem, which Has at least one stretched on deflection rollers vacuum conveyor belt or suction conveyor.

In this case, the item to be printed 17 is then fixed or held by the or each gripperless printing unit 11 on the respective vacuum conveyor belt or suction conveyor belt by vacuum during transport.

Both in the transport direction one behind the other and in the transport direction next to each other, a plurality of conveyor belts, vacuum conveyor belts or suction conveyor belts for transporting the piece goods 17 to be printed can be used by the gripperless printing units 11 of the printing press 10.

So shows Fig. 5 an embodiment of a printing machine 10, which uses a plurality of conveyor belts 19 positioned behind one another in the transport direction. In each case, a conveyor belt 19, which is guided on deflecting rollers 18, is positioned between in each case two printing units 11 positioned one behind the other as well as in front of the foremost printing unit 11 and behind the rearmost printing unit 11.

In a further alternative of the invention can be provided that the transport device 16 comprises reversibly movable transport tables, however, such reversibly movable transport tables have the disadvantage of a limited production speed. Therefore, the use of a conveyor belt system for transporting the piece to be printed 17 by the printing units of the web press is preferred.

As Fig. 1 can still be removed, the printing press 10 of the invention further has a feeder 22, which holds the to be printed, dimensionally stable and relatively rigid piece goods 17 preferably in the form of a stack, and which the to be printed piece goods 17 on the transport device 16 for subsequent printing in the printing units 11 with the exactness of the circumference and the exact position of the page.

Downstream of the printing units 11 of the web-fed printing press, there is preferably a delivery, not shown, which receives the printed, dimensionally stable and relatively stiff piece goods after printing by the transport device 16.

With the present invention, therefore, it is proposed for the first time to print dimensionally stable and relatively rigid piece goods 17 in gripperless printing units 11 of a web-fed printing press, this piece goods 17 to be printed being transported by the transport device 16 through the gripperless printing units 11 of the web press, and wherein this is to be printed piece goods 17 by means of the feeder 22 for subsequent printing of the same in the gripperless printing units 11 with the exactness of the circumference and accurately positioned on the transport device 16.

The printable, dimensionally stable and relatively rigid piece goods 17 is positioned on the conveyor 16 with the help of the investor 22 accurate to the circumference and precise page, so that an accurate, register-accurate printing of the piece goods 17 can be done.

The transport device 16, in particular the or each conveyor belt 19 thereof, is guided stably in the printing machine in the lateral direction and in the circumferential direction. The register accuracy of the pressure is determined solely by placing the piece goods 17 on the transport device 16.

The feeder 22 is actuated by means of a signal, which is preferably dependent on the angular position of the cylinders of the printing units 11. This Signal can be embarrassed via a rotary position sensor, for example, the forme cylinder 13 or the transfer cylinder 14 of one of the printing units 11.

Alternatively, the actuation of the feeder 22 for the accurate positioning of the piece goods 17 with precise lateral register accuracy and on the transport device 16 can also take place as a function of the measurement of marks which are applied to a cylinder 13, 14 or 15 or to a printing forme. In contrast to this, it is also possible to control the feeder 22 without mark by scanning the printing form with a camera and a downstream image processing device for identifying previously defined image locations with exactness of the circumference.

The piece goods 17 to be printed are positioned by the feeder 22 on the transport device 16 in such a way that each piece goods 17 to be newly placed or repositioned on the transport device 16 is positioned on the transport device 16 at a defined distance Δl from the respective upstream piece goods 17 , This distance .DELTA.l is dependent on the extent of the transfer cylinder 14 of the printing units 11 involved in the printing as well as on the printing format of the piece goods to be printed 17. According Fig. 1 corresponds to the distance .DELTA.l between two directly successive, to be printed piece goods 17 the distance .DELTA.l between the trailing edges or alternatively the distance between the leading edges of the piece goods 17th

In an advantageous embodiment of the invention, the distance .DELTA.l between two successive, to be printed piece goods 17 corresponds to the circumference of the transfer cylinder 14 of the printing units 11. Per cylinder rotation is then a piece goods 17 printed.

The already mentioned exactness of the circumference and the position of the exact position of the piece goods 17 on the transport device 16 ensure that the position of the piece goods 17 to be printed on the transport device 16 with the position of a print image 23 on the transfer cylinder 14 (see Fig. 2 ) coincides. The remaining area of the transfer cylinder 14 carries according to Fig. 1 no image information.

Then, when the distance .DELTA.l between piece goods to be printed 17 corresponds to the circumference of the transfer cylinder 14 of the printing units 11 of the web press 10, a piece goods 17 are printed in each case for each machine revolution. In contrast, it is possible to increase the distance .DELTA.l between successive piece goods to twice the circumference of the transfer cylinder 14 of the printing units 11, in which case a piece goods 17 is printed only at every second machine revolution. Then, when the distance .DELTA.l corresponds to three times the circumference of the transfer cylinder 14 of the printing units 11, 11 pieces of goods 17 are printed at every third revolution of the web printing press in the printing units. Then, when the distance .DELTA.l corresponds to n times the circumference of the transfer cylinders 14 of the printing units 11, pieces of goods 17 are printed in the printing units 11 every n-th revolution of the web-fed printing press.

Typically, a printed image 23 to be applied by the respective transfer cylinder 14 to the respective article 17 occupies a relatively large section of the cylinder circumference of the respective transfer cylinder 14.

Then, when the image-guiding area of the transfer cylinder 14 occupied by the print image 23 to be printed is smaller than half the circumference of the cylinder, a plurality of print images may be successively printed on the circumference of the transfer cylinder 14 at each cylinder revolution. this shows Fig. 3 , where in Fig. 3 on the circumference of the transfer cylinder 14, two printed images 23 are positioned one behind the other.

In this case, per cylinder revolution of the web press several pieces of goods 17 can be printed consecutively, whereby the productivity of the web press, especially for small print sizes of the piece goods to be printed 17 can be increased.

In this case, the distance .DELTA.l between successive piece goods 17 is determined not only dependent on the size of the transfer cylinder 14 of the printing units 11, but rather additionally depending on the print size of the piece goods to be printed 17th

Then, if each revolution of the transfer cylinder 14 of the printing units 11 and thus per revolution of the web printing machine 10 two piece goods 17 to be printed, the distance .DELTA.l corresponds to half the circumference of the transfer cylinder 14. Then, if each piece of machinery 17 three piece goods are to be printed, corresponds to Distance .DELTA.l one-third of the circumference of the transfer cylinder 14. Then, if per machine revolution, a number m piece goods 17 are to be printed, the distance .DELTA.l corresponds to one m-th of the circumference of the transfer cylinder fourteenth

Preferably, the printed images 23 to be printed are evenly distributed over the circumference of the transfer cylinders 14 of the printing units 11. In this case, then the distance .DELTA.l between the cargo 17 is uniform. In contrast, it is also possible to make a non-uniform distribution of the printed images 23 on the circumference of the transfer cylinder 14 with a corresponding control of the web printing press 10.

Viewed in the axial direction of the cylinders of the printing units 11, several piece goods 17 can be printed simultaneously per cylinder revolution, in which case a plurality of piece goods 17 are positioned side by side on the feeder 22 of the transport device 16 over the width of the transport device 16.

With the present invention, it is thus possible for the first time, using the advantages of printing units 11 of a web press on such printing units dimensionally stable and relatively rigid piece goods 17 to print exactly the exact register and page registration.

It can be printed format variable, that is, piece goods 17 can be printed with different print formats. The printable printing format corresponds at most to the circumference of the transfer cylinder 14.

Preferably, the printing units 11 of the printing press 10 are all designed as offset printing units. Likewise, all printing units can be designed as gravure units or as screen printing units.

In contrast to this, it is also possible that first printing units 11 of the printing press are designed as offset printing units, whereas second printing units 11 of the printing press are designed as gravure printing units and / or as high-pressure units, in particular flexographic printing units, and / or as screen printing units. The second printing units 11 can be positioned upstream or downstream of the first printing units 11 as seen in the transport direction of the piece goods 17.

When printing the piece goods 17 in the printing machine 10 according to the invention significantly higher printing speeds can be realized than in sheet-fed presses. It is possible in a simple manner, dimensionally stable and relatively rigid piece goods 17 to print format variable and print accurate.

The print format of the piece goods 17 to be printed is smaller than the circumference of the transfer cylinder 14 used for printing of the respective printing units 11 or corresponds to this maximum extent. The transfer cylinders 14 used for printing transmit at least one printed image on their circumference or subject. The transfer cylinders 14 preferably transmit a plurality of printed images or subjects per revolution, so that a plurality of printed images or subjects are then transmitted one after the other at the circumference.

The exact alignment and exact page position placing the piece 17 to be printed on from the on the conveyor 16 via the feeder 22 for subsequent printing of the piece 17 is carried out accurate to the extent and true to the page to the or each print image or subject on the circumference of the transfer cylinder fourteenth

LIST OF REFERENCE NUMBERS

10

press

11

printing unit

12

transport direction

13

form cylinder

14

transfer cylinder

15

pressure cylinder

16

transport means

17

cargo

18

deflecting

19

conveyor belt

20

layer

21

layer

22

investor

23

print image

Claims (15)

Printing machine, with at least one gripperless printing unit (11) of a web-fed printing press, by means of which a substrate to be printed can be transported in a horizontal direction, characterized by a transport device (16) via which the substrate to be printed is dimensionally stable and relatively rigid piece goods (17), which does not conform to cylinder contours of the printing units (11) during transport and printing, can be transported by the or each pinless printing unit (11), a feeder (22), which holds the piece of goods (17) to be printed on and over which the item to be printed (17) on the transport device (16) for subsequent printing in the printing units (11) can be plotted with exact register accuracy and precise registration. Printing machine according to Claim 1, characterized in that the feeder (22) positions the piece goods (17) to be printed on the transport device (16) such that each piece goods (17) to be newly placed on the transport device (16) have a defined distance the respective upstream general cargo (17) on the transport device (16) is positioned. Printing machine according to claim 2, characterized in that the defined distance at which the feeder (22) positions the piece goods (17) to be printed on the transport device (16) depends on a circumference of the transfer cylinder (14) and on a printing format of the to be printed piece goods (17). Printing machine according to claim 3, characterized in that , if per revolution of the transfer cylinder (14) has a number m piece goods (17) is printed, the distance corresponds to a m-tel the circumference of the transfer cylinder (14). Printing machine according to claim 3, characterized in that when every n-th rotation of the transfer cylinder (14) a cargo (17) is printed, the distance corresponds to n times the circumference of the transfer cylinder (14). Printing machine according to one of claims 1 to 5, characterized in that the feeder (22) for accurately registering the piece goods (17) on the transport device (16) depending on the rotational angular position of a cylinder or depending on the measurement of a mark on a cylinder or are applied to a printing form, or is driven depending on a markerless scanning a printing form. Printing machine according to one of Claims 1 to 6, characterized in that the transport device (16) is designed as a conveyor belt system which has at least one conveyor belt (19) tensioned on deflecting rollers (18), the piece goods (17) to be printed being transported through the conveyor belt or each gripperless printing units (11) on the respective conveyor belt (16) is fixed. Printing machine according to claim 7, characterized in that the piece goods (17) to be printed are fixed on the respective conveyor belt (19) by electrostatic effects or magnetic effects or adhesive effects or by gluing. Printing machine according to claim 8, characterized in that the respective conveyor belt (19) has a multilayer construction, wherein the piece goods (17) to be printed on an outer polyurethane layer (20) of the respective conveyor belt (19) is fixed by gluing. Printing machine according to one of claims 1 to 6, characterized in that the transport device (16) is designed as a vacuum conveyor belt system or Saugförderbandsystem having at least one stretched at deflection rollers vacuum conveyor belt or suction conveyor, wherein the piece goods to be printed (17) during transport through the or each gripperless printing unit (11) on the vacuum conveyor belt or suction conveyor belt is fixed by vacuum. Printing machine according to one of claims 1 to 10, characterized by a boom, which receives the printed piece goods (17) after printing by the transport device (16). Printing machine according to one of claims 1 to 11, characterized in that the printing units (11) are all formed as gripperless offset printing units. Printing machine according to one of claims 1 to 12, characterized in that first printing units (11) are designed as gripperless offset printing units, whereas second gripperless printing units (11) are designed as gravure units and / or as high-pressure units and / or as screen printing units. Method for operating a printing press according to one or more of claims 1 to 13, characterized in that the transport device is transported dimensionally stable and relatively rigid piece goods through the or each gripperless printing unit, with the feeder for the subsequent printing the piece goods on the transport device with the exact circumference and is placed with exact page accuracy. A method according to claim 14, characterized in that the piece goods (17) to be printed on the transport device (16) is positioned such that each on the transport device (16) newly to be placed piece goods (17) with a defined distance to the respective upstream cargo (17) on the transport device (16) is positioned, wherein the defined distance depending on a circumference of the transfer cylinder (14) and of a print format of the piece to be printed (17) is set.

Images