EP1806233B1 - Device for printing on bottles or similar receptacles - Google Patents

Description

The invention relates to a device according to the preamble of claim 1 and to a method according to the preamble of claim 20.

Are known cyclically operating devices or machines for direct printing of containers, especially in the form of glass or plastic bottles to apply there, for example, information and / or advertising permanently and captive. Printing is usually done either by screen printing or by pad printing.

Furthermore, methods and devices are known in which information about inkjet spraying by digital control (digital printing) information is applied directly to bottles. Such devices are known, for example, under the name "Videojet". In this method, pressure points are applied continuously, which are normally deflected, while only in the case of pressure individual drops of the ink can pass through the outlet nozzle in order to reach the surface of the bottle and produce a print job there. The print width corresponds to the font height, so that only a line- or line-shaped imprint with the width of the font height on the respective container (bottle) takes place.

Also known, in particular for office purposes, are so-called inkjet printers with inkjet printheads, which each produce a linear or line-shaped imprint during printing, which consists of individual printing dots and whose height corresponds to the height of one letter. When printing, a relative movement between the print head and the surface to be printed (paper sheet) in two mutually perpendicular axial directions is required, by movement of the print head in one axial direction, for example in the horizontal, and by further transport of the surface to be printed in the other axis direction.

Also known are a method or a print head with which a plurality of printing dots in a line close to each other or at a very small distance from each other, for example at least 150 printing dots per inch, can be generated on a surface to be printed, through a variety of individually controllable individual nozzles. The active print width of this printhead, which is also known under the name "Tonejet", is only dependent on the capacity of the computer power of the printhead driving computer. Thus, printheads from 1.7 to 6.8 inches print width (corresponding to a 256-bit control or a 1024-bit control) possible. With this print head, the printing of a sweeping impression with a sufficiently large area by relative movement between the surface to be printed and the print head is possible only in a single axial direction.

The generic teaching after the EP 1 243 425 A2 deals with an inkjet printing device that works with electrostatic printheads. Any problems with regard to caused by centrifugal pressure differences in the printhead are therefore not observed, because the known printheads are designed to be stationary.

The EP 1 225 053 A2 deals with a method of printing the sidewall of a three-dimensional object such as a plastic cup. For this purpose, the article in question is rotated around its main axis. In this case, several inkjet heads are passed, which are driven in dependence on the angular position of the object about the axis.
The object of the invention is to provide a device with a printing, especially a direct printing of bottles or similar container preferably on a rotationally symmetric surface with high print quality and high performance (printed container per unit time) is possible. To solve this problem, a device according to the patent claim 1 is formed. A method of operating a device according to claim 1 is defined in claim 20.

It is also an object of the invention to provide a device with which a printing of containers with non-rotationally symmetric surfaces, Thus, for example, the printing of containers with square, triangular, n-square or oval cross-sectional area is made possible.

The respective print image is achieved purely digitally in the apparatus according to the invention by corresponding control of the at least one print head or the individual nozzles of this print head with data stored in a memory, so that print masks, as hitherto in the large-area printing of containers, especially in Sieb- or Pad printing methods are required, not needed. This will u. a. greatly reduces the procedural effort and also created the ability to quickly and easily change the print or the print image, even during an ongoing work process.

In the apparatus according to the invention, the at least one print head is a Tonejet print head or a print head corresponding to such a Tonejet print head, i. H. it has at a printing area a plurality of individual nozzles, which are provided in succession in a print head longitudinal axis at a very close distance and each formed by a nozzle opening and at least one of each nozzle opening associated electrode. The existing ink in the print head exits at each Elnzeldüse or from the associated nozzle opening only when the activation of a single nozzle the associated electrode is subjected to an electrical voltage whose polarity and / or voltage potential of the polarity and / or the voltage potential of the Printhead or the ink in the printhead deviates so that a certain amount of ink is ejected or discharged from the nozzle opening of the activated individual nozzle by electrostatic forces. A printhead of this type will also be referred to hereinafter as an "electrostatic printhead".

Fig. 1 und 2

in schematischen Darstellungen einen elektrostatischen Druckkopf im Teilschnitt sowie in Seitenansicht, und zwar zusammen mit einem zu bedruckenden Behälter in Form einer Glas- oder Kunststoff-Flasche;

Fig. 3

In schematischer Darstellung eine Druckstation mit drei Druckköpfen zur Erzeugung eines Mehrfarben-Druckes auf einem Behälter;

Fig. 4

in schematischer Darstellung und in Draufsicht eine zum Bedrucken von Behältern dienende Maschine umlaufender Bauart;

Fig. 5

eine der Druckstationen der Maschine der Figur 4 während des Bedruckens eines Behälters;

Fig. 6-8

jeweils In vereinfachter Funktionsdarstellung eine der Druckstationen einer Maschine umlaufender Bauart, und zwar bei Ausführungsformen der Erfindung;

Fig. 9

in vereinfachter Funktionsdarstellung eine der Druckstationen einer Maschine umlaufender Bauart;

Fig. 10

eine weitere Ausführungsform in Form einer getakteten Maschine.

Containers within the meaning of the invention include bottles, cans or packages, wherein all containers may have cylindrical, non-cylindrical, rotationally symmetric or non-rotationally symmetrical shape and / or peripheral surface. Further developments of the invention are the subject of the dependent claims. The invention will be explained in more detail below with reference to the figures of exemplary embodiments. Show it:

Fig. 1 and 2

in schematic representations of an electrostatic printhead in partial section and in side view, together with a container to be printed in the form of a glass or plastic bottle;

Fig. 3

Schematically, a print station with three printheads for generating a multi-color print on a container;

Fig. 4

in a schematic representation and in plan view for printing on containers serving machine of rotating design;

Fig. 5

one of the printing stations of the machine FIG. 4 while printing on a container;

Fig. 6-8

In each case in a simplified functional representation of one of the printing stations of a machine rotating design, in embodiments of the invention;

Fig. 9

in a simplified functional representation of the printing stations of a machine rotating design;

Fig. 10

another embodiment in the form of a clocked machine.

In the figures, 1 containers are in the form of bottles, for example glass or plastic bottles (for example PET bottles), which are to be provided on their outer surfaces directly with an at least single-color imprint 2.

For printing the bottles 1, at least one electrostatic print head 3 is used to achieve the highest possible performance (number of bottles printed per unit time) and optimum print quality. This consists in Essentially from a housing 4, which forms, inter alia, a closed housing interior 5 for receiving a liquid or viscous ink. The housing 4 is formed so that its inner space 5 narrows funnel-shaped or wedge-shaped towards a lower housing section 4.1. At this housing section 4.1, which extends over the entire length of the housing 4 and is oriented parallel to a housing or printhead longitudinal axis DL, a plurality of individually controllable individual nozzles 6 for the controlled application of the ink is provided, in at least one row in the direction the printhead longitudinal axis DL successively and in a tight arrangement, so that, for example, 150 individual nozzles 6 per inch or more are formed on the housing section 4.1.

With the housing section 4.1 having the individual nozzles 6, the nozzle head 3 is arranged at a predetermined, small distance from the area of the respective bottle 1 to be printed, in such a way that the longitudinal axis of the print head DL or the longitudinal extension of the housing section 4.1 is parallel to the surface line of the bottle outer surface is oriented parallel to the bottle axis FA at the current pressure range and at a region to be printed on an example circular cylindrical outer surface of the bottle.

In particular, in the event that the bottle outer surface of the bottles to be printed is not circular cylindrical, it is provided to adjust the at least one nozzle head 3 and the rotating bottle axis FA to each other so that the individual nozzles 6 and each surface to be printed surface of the bottle outer surface to the optimum distance have each other.

Each individual nozzle consists of an opening 7 in the housing section 4.1 and a needle-shaped electrode 8 assigned to this opening, which is arranged coaxially with the axis of the respective opening 7 and ends at a slight distance from this opening within the housing interior 5. The print head 3 is arranged so that at least during the printing process, the ink received in the housing interior 5 is present with a certain hydrostatic pressure against the openings 7 of the individual nozzles 6, wherein However, the cross-section of the openings 7, taking into account the viscosity and / or the surface tension of the ink is chosen so that when not activated Elnzeldüse 6 despite the hydrostatic pressure ink at the respective opening 7 does not exit.

By means of the control device 9, the electrodes 8 can be controlled individually, in such a way that when the individual nozzle 6 is not activated, the corresponding electrode 8 is at the same electrical potential as the printing ink in the housing interior 5. When a single nozzle 6 is activated, the voltage potential of the associated electrode 8 becomes Electrode 8 changed by appropriate control short-term or pulse-like, so that over the opening 7 printing ink for generating a pressure point 10 is applied to the bottle 1.

The print head 3 is part of a printing station 11, which has at least one such print head. To adjust the print head 3 with respect to the respective bottle 1 or its upper or outer surface adjustment or spacer elements are provided on the print head 3, for example in the form of rollers 12 which are freely rotatably mounted about an axis parallel to the print head longitudinal axis DL and over which the print head 3 is supported on the bottle 1 outside the area to be printed.

At the for the FIGS. 1 and 2 The selected representation is the bottle to be printed 1 with its bottle axis FA in the horizontal direction oriented below the nozzle head 3, ie the nozzle head 3 is also oriented with its printhead longitudinal axis DL in the horizontal direction. During the printing process, the bottle 1 is rotated about its bottle axis FA by a controlled drive (arrow A). The print job 2 is thus carried out in rows or lines 2.1, each extending parallel to the bottle axis FA over the entire width of the area to be printed, namely progressively in the circumferential direction of the bottle 1. Since the activation of the individual nozzles 6 at high speed is possible and also for printing only a single relative movement between the respective bottle 1 and the print head 3, namely only the rotational movement of the bottle 2 is required to its bottle axis FA, is a high pressure performance achievable. The respective print image is generated purely digitally, without the need for a print mask, etc.

After applying the ink to the bottle 1, the drying or curing of the printing ink or the printing takes place, for example, by setting or drying in ambient air, by heat and / or UV treatment, etc.

For controlled rotation of the respective bottle 1 during the printing process, this is held with its mouth of the bottle 1.1 at a Einspannhaltung 13, of a in the FIGS. 1 and 2 not shown, driven by the control device 9 drive is driven circumferentially about a printing station axis DA coaxial with the bottle axis FA. With its bottom 1.2, the respective bottle 1 rests against a turntable-like supporting and centering element 14 during the printing process.

By the Einspannhalterung 13 and the support member 14, the respective bottle 1 is thus accurately positioned or centered in the printing station 11. By the rollers 12, the print head 13 is exactly positioned with respect to the outer surface of the bottle 1, so that even with tolerances in the bottle diameter of the required for optimal pressure narrow distance between the print head 3 and the outer surface of the bottle 1 is exactly maintained.

In order to improve the print 2 generated with the print head 3, in particular also with regard to contrast and / or sharpness, a corona element 15 is provided in the illustrated embodiment at the printing station 11, with which the outer surface of the bottle 1 at least on the to be printed Area is charged elektrostatlsch, with a the electrical potential of the ink in the housing interior 5 opposite polarity. At this corona element 15, which extends parallel to the bottle axis FA or printing station axis DA, the area to be printed is moved before the printing process by turning the bottle 1. Furthermore, it is also possible for the bottle 1 before the printing process via the bottle mouth 1.1 with a deionized or electrically charged gaseous medium, For example, to apply deionized or electrically charged air, so as to achieve a print quality improving electrostatic charge of the bottle 1.

It has been assumed above that the imprint 2 takes place with only one single ink and the printing station 11 therefore has only one single printhead 3. As a rule, however, a multi-color printing is required, namely using at least three different printing inks (eg red, blue and yellow) and, if necessary, an additional black printing ink. For this purpose, the printing station 11 is then formed with a plurality, ie with at least three print heads 3, as shown in the FIG. 3 is shown schematically. The individual print heads 3 are provided, for example, offset relative to one another by the bottle axis FA or about the print station axis DA, in such a way that the axes of the openings 7 and electrodes 8 of all print heads 3 are radial to the print station axis DA or bottle axis FA and thus oriented perpendicular to the respective currently printed surface area of the bottle 1. The printing operation is then carried out in such a way that applied in several temporally successive operations each turning the bottle 1 to the bottle axis FA and using a print head 3 of a color set of multicolor printing corresponding pressure and then after drying or setting using another printhead 3, the application of the further color set takes place.

Due to the staggered arrangement of the printheads 3 at the printing station 11a, it necessarily follows that only one of the printheads 3 has the optimum positioning with respect to the bottle 1 to be printed, ie a positioning in which the longitudinal axis of the printhead encloses the bottle axis FA vertical printing plane DE is located. In order to achieve optimum conditions for all print heads 3 of the printing station 11a, it may be expedient to design the printing station 11a such that each print head 3 is positioned in the printing plane DE before the printing operation with the axis of its individual nozzles 6, for example by virtue of the printheads 3 are provided on a common carrier, which surrounds the bottle axis FA or the printing station axis DA is pivotable, as with the double arrow B of the FIG. 3 is indicated. Other measures are conceivable.

For centering the print heads 3 with respect to the respective bottle 1 centering means are again provided at the printing station 11 a, for example in the form of rollers 12. Furthermore, the respective bottle 2 in the printing station 11 a also held by the Einspannhalterung 13 and the support member 14 and centered. To increase the quality of the multicolored imprint 2, the printing station 11 a, for example, also the corona element 15 and / or means in order to pressurize the respective bottle 1 inside with the electrically charged or deionized gaseous medium.

The motor drive for the Einspannhalterung 13 is further designed so that at the beginning of each printing process, especially at the beginning of printing each color set of multiple printing the Einspannhalterung 13 has a clearly defined position, for example, by a control operation with feedback of the current position of the Einspannhalterung 13 the control device 9 and by comparing the current position (actual value) with a predetermined desired value.

The FIG. 4 shows a schematic representation and in plan view of a machine 16 of rotating design for printing bottles 1. The bottles 1 are the machine 16 via a conveyor 17 standing upright supplied as a single-lane bottle flow (arrow C) and arrive at a bottle inlet 18, inter alia via an inlet star 18.1 in each case individually to a printing station 19 on a rotatably driven around a vertical machine axis MA in the direction of arrow D rotor 20. Die in the FIG. 4 only each indicated by their printing station axis DA printing stations 19 are formed, for example, according to the printing station 11a and provided at equal angular intervals on the circumference of the rotor 20. With the rotational movement of the rotor 20, the printed bottles 1 reach the bottle outlet 21 and are forwarded via a local outlet star 21.1 to the conveyor 17 and fed upright on this another use.

The FIG. 5 shows a printing stations 19 more in detail. Each printing station 19 is corresponding to the printing station 11 a with a plurality of print heads 3, of which in the FIG. 5 only one is shown, provided with the Einspannhalterung 13 and with the support element 14. The other elements described in connection with the printing station 11 or 11a are also present at each printing station 19, for example.

The Einspannhalterung 13 each printing station 19 is provided on a shaft 22 which is mounted in a pivotable bearing support 23, on which the motor drive 24 for the shaft 22 and Einspannhalterung 13 is provided. The bearing support 23 is pivotally provided at 25 on the rotor 20 about a horizontal axis tangential to the rotational movement D of the rotor 20, for example, controlled by a control cam, not shown such that the Einspannhalterung 13 received at the bottle inlet 18, the respective bottle 1 and then is brought by pivoting the bearing support 23 about the axis 25 in a horizontal position radially oriented to the machine axis MA. The relevant bottle 1 is then arranged clamped between the Einspannhalterung 13 and the support member 14 under the print heads 3, in such a way that the respective bottle 1 is oriented with its bottom 1.2 in the direction of the machine axis MA. The print heads 3, the support element 14 as well as the other functional elements of the individual printing stations 19 are fixed in this embodiment, i. not mitschwenkbar provided with the Einspannhalterung 13 on the rotor 20. Furthermore, in this embodiment, the print heads 3 are oriented at least during the printing process with their longitudinal axes L radially or approximately radially to the machine axis MA.

The FIG. 6 16 very schematically shows a machine 16a which differs from the machine 16 substantially in that the printing heads 3 are arranged not horizontally and radially to the machine axis MA at least during the printing process with their print head longitudinal axis DL, but with the machine axis MA or parallel to it Axis include an angle α, which opens to the top of the machine 16a out. Each print head 3 is thus radially after inclined outside and is at least during the printing process with its print head longitudinal axis DL in a common plane with the machine axis MA, in such a way that the individual nozzles having housing portion 4.1 relative to the machine axis MA radially outward and thus the distance of the individual nozzle 6 of the machine axis MA increases from the lower end of the respective nozzle head 3 to the upper end. Due to this inclination of the respective nozzle head 3 it is achieved that, at least during the printing operation, the pressure of the ink at the individual nozzles 6 or at the openings 7 of the nozzle head 3 resulting therefrom from gravity and centrifugal force is constant or approximately constant or approximately constant ., Differences in pressure, which result from the force acting on the ink gravitational force and centrifugal force, compensate each other, so that in each case the same pressure application or pressure point 10 is achieved in the same activation or control of the individual nozzles.

In accordance with the inclination of the printheads 3, the bottles 1 are also inclined at least during the printing process, i. the generatrix of the bottle outer surface on the currently printed line 2.1 in turn closes with the machine axis MA or the axis parallel to this the angle β. In a circular cylindrical area to be printed, the angles α and β are the same. Thus, each bottle 1 is oriented with its bottle axis FA during the printing process parallel to the printing longitudinal axis DL. In the illustrated embodiment, the individual printing stations 19a, which in turn have all the elements of the printing station 19 and 11 a, designed so that the bottles 1 are held during the printing process with its bottom of the bottle 1.2 above and with its mouth of the bottle 1.1 down.

The FIG. 7 shows as a further possible embodiment of a machine 16b, which differs from the machine 16a substantially only in that the bottles 1 point during the printing process with its held on the Einspannhalterung 13 bottle mouth 1.1 upwards and thus inclined radially inwardly below the rotor element 20.1 are arranged and not, as in project the machine 16a radially during printing over the rotor element 20.1.

The FIG. 8 again shows the machine 16b, but in their training for printing bottles 1 a on a conical peripheral region. The printheads 3 in turn have the inclination α with respect to the machine axis M. The inclination β of the bottle axes FA with respect to the machine axis MA differs significantly from the inclination α.

The machines 16a and 16b have in common that the respective print head 3 is at least during the printing process between the respective bottle 1 and the machine axis MA, i. the respective bottle 1 is offset radially outward with respect to the machine axis MA with respect to the print head 3.

In the case of the machines 16a and 16b, too, the printhead arrangement having the printheads 3 is designed, for example, such that the respectively used printhead 3 can be moved into the optimum printing position, for example by means of the printhead arrangement FIG. 3 pivoting indicated by the double arrow B, and that each print head 3 on the Drückkopfhalter 26 and / or each print head holder 26 on the rotor 20 and the rotor element 20.1 about an axis perpendicular to the print head longitudinal axis DL is pivotable and adjustable in particular in the print head longitudinal axis DL to the respective printing station 19a and 19b to adapt to the shape of the bottles to be printed 1 and 1 a and / or adjust the inclination angle α corresponding to the rotational speed of the rotor 20 and so as to achieve the most uniform pressure distribution along the individual nozzles 6 during the printing process ,

The FIG. 9 shows as another not belonging to the invention embodiment of a machine 16c, which differs from the machines 16 and 16b substantially in that the printheads 3, at least during the printing process with its printhead longitudinal axis DL tangential or approximately tangential to the rotational movement D of the rotor 20 and Rotor element 20.1 are oriented. In order to improve the pressure, it may be appropriate to the printheads 3 during Orient the printing process so that the axes of the individual nozzles 6 relative to the vertical or machine axis MA are slightly inclined, ie with the vertical γ include an acute angle that opens to the bottom of the machine 16c out. During the printing process, the bottles 1 are arranged under the respective nozzle head 3, in such a way that the surface line on which the current line 2.1 is printed, is oriented parallel to the print head longitudinal axis DL and thus also tangential or approximately tangential to the rotational movement D of the rotor 20th ,

It was assumed above that the printheads 3 with their printhead longitudinal axes DL inclined at least during the printing process radially to the machine axis MA or relative to the machine axis MA, but in a common vertical plane with this machine axis or are arranged tangentially to the rotational movement of the rotor. Other orientations of the printhead longitudinal axes DL are conceivable, for example in the form that the respective printhead longitudinal axis DL is inclined in or counter to the direction of rotation D of the rotor 20, and instead of or in addition to the inclination radially outward or radially inward.

The Fig. 10 shows a not covered by the claims machine 16d, which is not designed as a rotary machine, but as a linear machine, for example as a clock system. The bottles to be printed 1 are each supplied to the printing station 19d individually in this machine and centered in the printing station by local lower rollers 27. For the printing process, each bottle 1 horizontally oriented with its bottle axis FA is clamped on the bottle bottom 1.2 between a gripping holder 28 on the bottle mouth 1.1 and a supporting element 29 corresponding to the supporting element 14. Above the respective bottle is the at least one print head 3 having printhead assembly, which is supported by upper rollers 30 on the bottle circumference. By a drive motor 31, the upper rollers 30 are driven about a common axis parallel to the bottle axis FA, namely for the rotational movement of the bottle 1 during the printing operation. The gripping holder 28 is together with several Einspannhalterungen 28 at a rotatable about a machine axis MA rotatable rotor 32 is provided, which is further rotated after printing a bottle 1 by a respective rotation step or a division to remove the printed bottle 1 from the not moving with the rotor 32 printing station 19d and a new, to be printed bottle 1 in the printing station.

By way of example, the machines 16, 16b, 16c and 16d have in common that means are provided at each printing station 19-19d which make it possible to align the respective imprint 2 with design features which are present on the bottles 1 and 1a, respectively. For example, using an image recognition system, align each bottle 1 or 1a prior to printing by rotation about its bottle axis FA so as to have a predetermined orientation relative to the design feature at the beginning of the printing process.

Furthermore, there is the possibility, in particular in the case of the machines 16, 16a, 16b, 16c and / or 16d, in an angular range of the rotary movement of the rotor 20 or 32, the (angular range) after printing on the bottles 1 or 1a or on the printing station follows to provide means to achieve accelerated drying or curing of the ink, for example by exposure to heat and / or UV radiation. In the case of the machines 16, 16b, 16c, it is possible, for example, to swivel the bottles 1 or 1a held on the clamping holders 13 into a channel 33 extending on a partial angle of the rotary movement of the rotor 20 when the rotor 20 rotates, and to move it along this channel ,

The invention has been described above by means of exemplary embodiments. It is understood that numerous changes and modifications are possible without thereby departing from the inventive concept underlying the invention.

It is possible in an embodiment not covered by the claims, instead of acting as a spacer rollers 12, the distance between the bottle outer surface to be printed and the Adjusting the print head 3, that this distance is monitored by a provided on the print head 3 sensor, for example, an ultrasonic or light sensor and adjusted by a motor drive.

It is known in the art in the context of the equipment of containers to provide them in a first step first with a label or to print using the classic printing method, both the label, and the imprint for all containers are forcibly identical or constant. It is also known to provide the containers in a second step with variable information, this information from container to container (eg count number), from container group to container group (eg batch number) or even from day to day (eg ) may differ from each other.

The presented device is characterized u. a. in that the printed image or the container equipment to be applied to the containers is stored in digital form within the electronic control device 9, and is then applied to the container without the use of labels or printing masks.

Because the printed image to be applied is kept in digital form, it is possible for the first time to reshape this printed image for each container to be equipped, and thus to reassemble it, for example, for each container from constant and variable contents or information.

According to the invention, it is likewise provided that the variable information can also be image information. By doing this it is e.g. allows beverage packaging in any order and quantity distribution with visual representations of the players of popular team sports, such as football, equip.

It is also provided that the variable information is numerical or even alpha-numeric information, for example may be a date of manufacture or best before date or a numerical code.

Zich reference list

1, 1 a:

bottle

1.1

bottle mouth

1.2

bottle bottom

2:

imprint

2.1:

row

3:

printhead

4:

casing

4.1:

housing section

5

Housing interior

6:

Single nozzles on the housing section 4.1

7:

opening

8th :

electrode

9

electronic control device

10:

pressure point

11, 11a:

printing station

12:

role

13:

Einspannhalterung

14:

supporting

15

Corona element

16, 16a, 16b, 16c, 16d:

machine

17

carrier

18

bottle infeed

18.1:

feed star

19, 19a, 19b, 19c, 19d:

printing station

20:

rotor

20.1:

rotor member

21:

bottle outlet

21.1:

outlet star

22:

wave

23:

bearing bracket

24:

engine

25:

swivel axis

26:

Carrier for printhead or printhead assembly

27:

role

28:

Einspannhalterung

29:

supporting

30:

role

31:

Drive or motor

32:

rotor

33:

channel

A:

Container rotational movement

B:

Pivoting movement of the printhead assembly

C:

transport direction

D:

Direction of rotation of the rotor

FA:

bottle axis

THERE :

Printing station axis

DE:

pressure level

DL:

Printhead longitudinal axis

MA:

machine axis

α:

Inclination angle of the rotary head longitudinal axis with respect to the vertical

β:

Inclination angle of the bottle axis FA with respect to the vertical

Y:

Inclination angle of the axes of the individual nozzles 6 with respect to the vertical

Claims (23)

1. Device for printing with at least one print station (19a, 19b) having at least one print head (3), wherein the at least one print head (3) is an electrostatic print head (3) with a multiplicity of individually controllable individual nozzles (6) for the controlled dispensing of printing ink, and wherein the individual nozzles (6) are arranged consecutively in at least one row on a longitudinal print head axis (DL), characterised in that

   - the device for printing on bottles or similar containers is made on their container surfaces,

   - in the print station (19a, 19b), a controlled drive rotates the bottle or the container during the printing process about a print station axis (DA) on the same axis or substantially the same axis with the bottle or container axis (FA),

   - the device is made as a rotary machine with multiple print stations (19a, 19b) on a rotor (20) which can be driven in rotation around a vertical machine axis (MA), and that

   - the longitudinal print head axis (DL) of each print station (19a, 19b) encloses an angle (α) relative to the machine axis (MA) at least during the printing process, wherein said angle is open to an upper side of the machine (16a).
2. Device according to claim 1, characterised in that, by means to generate a controlled relative movement between the container to be printed on and the at least one print head (3), the at least one print head (3) is moved around the container axis (FA).
3. Device according to any one of the preceding claims, characterised in that the individual nozzles (6) define a printing area (4.1), and that the length of this printing area (4.1) is the same or larger than the width of a printed image (2) generated during printing, said width extending in the direction of the container axis (FA).
4. Device according to any one of the preceding claims, characterised by a preferably computer-aided control device (9) for activating the individual nozzles (6) of the at least one print head (3) and for activating the means to generate the relative movement between the particular container (1, 1a) and the at least one print head (3).
5. Device according to any one of the preceding claims, characterised in that the at least one print station (19a, 19b) has at least two, and preferably at least three print heads (3).
6. Device according to claim 5, characterised in that to generate a multi-colour print, multiple print heads (3) are allocated in each case to an area to be printed (2).
7. Device according to claim 5 or 6, characterised in that the print heads (3) are provided offset relative to each other around the container axis or around the print station axis (DA).
8. Device according to any one of the preceding claims, characterised in that, for printing, the print heads (3) can each be moved into a printing position or into a printing plane (DE) defining this printing position.
9. Device according to one of the preceding claims, characterised in that with circular cylindrical surfaces to be printed on, the longitudinal print head axis (DL) is oriented parallel or approximately parallel to the print station axis (DA).
10. Device according to one of claims 1-8, characterised in that, with surfaces to be printed on in a wedge shape, the longitudinal print head axis (DL) at least during the printing process encloses an angle with the container axis (FA) or with the print station axis (DA), wherein said angle is the same or approximately the same as the half taper angle of the wedge-shaped container surface.
11. Device according to any one of the preceding claims, characterised in that the at least one print station (19a, 19b) has means (13, 28) for gripping and / or securing the particular container (1, 1a) in the printing position.
12. Device according to claim 11, characterised in that the means for gripping and / or securing are formed by at least one clamping bracket (13, 28) and one supporting and / or centring element (14, 29), between which the particular container (1, 1 a) is held or clamped at least during the printing process.
13. Device according to claim 11 or 12, characterised in that, with the containers embodied as bottles (1, 1a), the means for gripping and / or securing to hold the bottles (1, 1a) are formed in the area of their bottle mouth (1.1) or their bottle neck.
14. Device according to any one of the preceding claims, characterised in that the at least one print head (3) of the at least one print station (11, 11a, 19, 19a, 19b, 19c, 19d) can be delivered for printing on the upper surface of the container.
15. Device according to any one of the preceding claims, characterised in that the at least one print head (3) of the at least one print station (11, 11a, 19, 19a, 19b, 19c, 19d) is spaced from the upper surface of the container by at least one spacer element (12).
16. Device according to any one of the preceding claims, characterised by a distance measuring system for adjusting and / or controlling the space between the at least one print head (3) and the upper surface of the container to be printed on during the printing process.
17. Device according to any one of the preceding claims, characterised by means (33) to dry or set the printing ink applied to the container surface, for example under the effect of heat and / or UV radiation.
18. Device according to any one of the preceding claims, characterised in that the at least one print head (3) of each print station (19a, 19b) is inclined relative to the vertical machine axis (MA) such that in the interior (5) of the at least one print head (3) along the printing area (4.1), the most even possible distribution of the pressure exerted by the printing ink arises, which results from the pressure of the liquid column of printing ink and from the centrifugal force while the rotor (20) is rotating.
19. Device according to any one of the preceding claims, characterised by its embodiment as a pulsed machine (16d) with at least one print station (19d) which supplies the containers (1, 1a) for printing in each case by means of a conveyor (32) and from which the containers (1, 1a) are moved away after printing by means of the conveyor (32) or another conveyor.
20. Method for operating a device according to claim 1, characterised in that the longitudinal print head axis (DL) is in an orientation or that it is moved into an orientation such that the pressure of the printing ink resulting from the gravitational force and from the centrifugal force arising due to the rotation of the rotor (20) which can be driven in rotation, along the individual nozzles (6) is constant or approximately constant, and that subsequently the surface line of the area to be printed on is oriented parallel to the longitudinal print head axis (DL), and moreover each print station (19a, 19b) has container gripping and / or holding means (13), in order to grip a bottle (1, 1a) available in each case on a container inlet (18), to move it into a printing position and to hold it there at least during the printing process.
21. Method according to claim 20, characterised in that the printed image to be transferred onto the container during a printing process is composed container-specifically of constant components and also of variable components.
22. Method according to claim 21, characterised in that the variable components are numeric or alpha-numeric components.
23. Method according to claim 22, characterised in that the variable components are numeric or alpha-numeric components.

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