EP3377430A1

EP3377430A1 - Vacuum transport method and vacuum chamber for an inkjet printing machine, and inkjet printing machine

Info

Publication number: EP3377430A1
Application number: EP16791341.7A
Authority: EP
Inventors: Marc Nicole; Sylvain Rebet
Original assignee: Toutin Service
Current assignee: Toutin Service
Priority date: 2015-10-23
Filing date: 2016-10-21
Publication date: 2018-09-26
Also published as: CN108137252A; IL258678A; WO2017068167A1; FR3042734A1; JP2019502614A

Abstract

The present invention relates to a method for transporting cardboard sheet elements 12 in an inkjet printing machine 10 comprising a vacuum transport device 13 and at least one printing head 14, - during a pressing phase, a vacuum effect is applied through the vacuum transport device 13 to each cardboard sheet element 12 as it passes under a printing head 14; - during a shutoff phase, the vacuum effect is interrupted under any printing head 14 under which a gap separating two cardboard sheet elements 12, 12' passes. The invention also relates to a vacuum chamber 20 for implementing the method, comprising a shutoff device 21 for interrupting the vacuum effect, and to an inkjet printing machine 10 comprising such a vacuum chamber 20.

Description

Vacuum transport method and vacuum chamber for an ink jet printing machine, and ink jet printing machine.

1. Field of the invention

The invention relates to the field of vacuum transport and more particularly the vacuum transport of cardboard plate elements in inkjet printing machines.

2. Prior Art

Vacuum transport devices are known: these devices make it possible to accurately transport cardboard plate elements within machines by pressing them against strips or conveyor belts under which one or more vacuum boxes are located. The conveyor belts or conveyor belts are conventionally provided with holes for the vacuum effect to properly apply to the transported cartonboard elements.

These transport devices naturally generate turbulence and they are commonly used in plate processing or printing machines, where they are used to transport the cardboard plate elements between the different stations of the machine, from a station introduction where each plate element is extracted from a stack at the entrance of the machine, to a receiving station at the output of the machine.

These transport devices have been designed in particular for the transport of flat or corrugated boardboard elements, in printing or converting machines, particularly in the packaging manufacturing industry. These cardboard sheet elements are frequently of large size, they are fragile and can be damaged by roller transport devices, the latter being more particularly adapted to the sheets, for example sheets of paper or fabric, which support the pressure and are flexible.

Also known are digital inkjet printing machines, for example using a continuous liquid ink jet technology, or a drop-on-demand technology.

Until now, very few printing machines on boardboard elements combine digital inkjet printing technologies with vacuum transport technologies. Indeed, to ensure good quality inkjet printing it is necessary to ensure both a good flatness of the substrate on which we want to print and also the absence of any turbulence in the vicinity of the print heads. These machines are complex or they do not allow to obtain a good quality of printing.

3. Objectives of the invention

The invention particularly aims to overcome all or part of these disadvantages of the prior art.

More specifically, it is an object of the invention to provide a vacuum transport method and a vacuum chamber for an inkjet printing machine, as well as an ink jet printing machine for ensure both a good print quality on the entire surface of the substrate, especially in areas near the edges of the cardboard plate element, and high productivity.

4. Summary of the invention

All or some of these objectives, as well as others which will appear more clearly later are achieved by the invention using a method of transporting cardboard elements in a jet printing machine. ink composition comprising a vacuum transport device and at least one print head. According to the invention, during a plating phase a vacuum effect is applied through the vacuum transport device to each cardboard plate element when it passes under a print head and during a phase of shutter, the vacuum effect is interrupted under any print head below which passes an interval separating two plate elements.

The succession of the plating and sealing phases ensures a good positioning of the substrates under the printing heads, while avoiding the formation of turbulence when a gap between two plate elements passes under a print head. Thus the print quality is optimal over the entire surface of the substrate, including in areas near the front and rear edges of the plate member.

Optionally, during the plating phase the vacuum effect can also be interrupted under a print head by one or more additional shutter phases. Thus one or more shutter phases interrupt the vacuum effect fleetingly under the substrate without affecting the quality of printing, which simplifies the implementation of the process. The invention also relates to a vacuum chamber for transporting cardboard plate elements in an inkjet printing machine comprising a vacuum transport device and at least one printing head, said vacuum chamber comprising a shutter device for interrupting the vacuum effect.

A vacuum chamber according to the invention can be connected to a standard vacuum box or directly placed inside such a box, and allows to implement the transport method according to the invention, thanks to the shutter device allowing to interrupt the vacuum effect.

Advantageously, the shutter device makes it possible to interrupt the vacuum effect on a surface substantially corresponding to the printing zone of an inkjet printing head. Thus the vacuum effect is interrupted only in an area where it could generate turbulence harmful to the print quality in areas near the front and rear edges of the substrate.

In one embodiment, the shutter device is rotatable. Thus the control of the implementation of the transport method is simplified and achieves high printing rates. Alternatively, the shutter device can be oscillating.

In a particular mode of implementation, the vacuum chamber comprises a device for adjusting the length of application of the vacuum effect. Thus the vacuum effect can be applied over a length corresponding for example to the width of the substrate, to eliminate the risk of turbulence detrimental to the quality of printing in areas near the lateral edges of the substrate.

The invention also relates to an inkjet printing machine comprising a vacuum transport device for transporting cardboard sheet elements, a print head for inkjet printing on the plate elements and a vacuum chamber as defined above. Such a machine is capable of ink jet printing on cartonboard members at a high rate while providing good print quality even in areas near the front and back edges of the substrates.

Advantageously, an ink jet printing machine according to the invention comprises a device for detecting the edge of the cardboard plate elements and a control device capable of synchronizing the rotation of the shutter device with the detection of the edge of a plate element. Thus the machine will correctly implement the transport method according to the invention, and therefore ensure good print quality with a high rate, including interval variations between two successive plate elements. 5. List of figures

Other features and advantages of the invention will appear more clearly on reading the following description of a particular embodiment, given as a simple illustrative and nonlimiting example, and the appended drawings, among which:

Fig. 1 schematically shows an inkjet printing machine according to the invention;

Fig. 2 to FIG. 4 represent different steps of a vacuum transport method and a vacuum chamber according to the invention;

Fig. 5 represents another example of a vacuum chamber according to the invention.

6. embodiment

In connection with FIGS. 1 to Fig. 5, various embodiments according to the invention.

Shown schematically in FIG. 1 an inkjet printing machine

Implementing the vacuum transport method according to the invention. Conventionally, a stack of cardboard plate elements is arranged in an insertion station 11. In the insertion station 11, the cardboard plate elements 12 are deposited one after the other on a device Many types of introductory stations have been described which, for example, enable the cardboard plate element on the top of a substantially horizontal pile to be grasped, or the element at the base of such a battery, or even using inclined batteries, or even a manual introduction. All types of introduction station can be used for the implementation of the invention.

Fig. 1 represents a succession of four elements in cardboard plates 12, carried by the transport device 13. The transport device 13 shown is a carpet through which there are numerous openings for applying a vacuum effect to the cardboard plate elements 12. Conventionally under the belt 13 is a vacuum box (not shown in Fig. 1), in which a vacuum is created to produce the vacuum effect.

Any type of vacuum transport device 13 may naturally be used in the context of the invention in place of the carpet, such as for example a plurality of vacuum strips.

The cardboard plate elements 12 are held by the vacuum effect on the transport device 13 which moves them under one or more inkjet printing heads 14. The machine shown in FIG. 1 has four printhead bars 14, but the invention relates to inkjet printing machines having any number of printhead bars 14.

In the remainder of the disclosure, the term print head 14 will be used to designate a print head bar, each bar having one or more printheads aligned to produce a continuous print throughout the length of the print head. the print bar 14.

A vacuum transport method according to the invention is illustrated in FIG. 2 to FIG. 4.

According to the method according to the invention, during a plating phase shown in FIG. 2 the vacuum effect is applied to each carton element 12 as it passes under a print head 14; and during a shutter phase shown in FIG. 3, the vacuum effect is interrupted under any print head 14 below which passes an interval separating two successive cardboard board members 12 and 12 '.

The plating phase ensures an excellent position of the substrate 12 on which the ink is projected, and thus to obtain excellent print quality. The shutter phase avoids that the vacuum effect generates turbulence when a gap between two successive cardboard plate members 12 and 12 'passes under a print head 14.

As shown in FIG. 4, the closing phase ends when a new cardboard plate member 12 'is under the print head 14. Then begins a new plating phase of the cardboard plate member 12' on the device vacuum transport 13.

Thus, the print head 14 projects ink with good print quality, including the areas near the trailing edge and the leading edge respectively of the cardboard plate members 12 and 12 '.

The invention also relates to a vacuum chamber 20 for transporting cardboard plate elements 12 in an inkjet printing machine 10 comprising a vacuum transport device 13 and at least one printing head 14. According to the invention the chamber 20 comprises a shutter device 21 for interrupting the vacuum effect.

The printing machine 10 shown in FIG. 1 comprises four vacuum chambers 20 according to the invention, each placed under the transport device 13 facing a printing head 14.

The operation of a vacuum chamber 20 according to the invention is illustrated in FIG. 2 to

Fig. 4. The vacuum chamber 20 shown in FIG. 2 to FIG. 4 is placed under the transport 13, facing a print head 14, in a larger vacuum box not shown.

As shown in FIG. 2, the vacuum chamber allows the application of the vacuum effect to a substrate 12 passing under a print head 14 which can project ink to the surface of the substrate.

As shown in FIG. 3, the closure device 21 of the vacuum chamber 20 interrupts the vacuum effect when a gap between two successive plate elements 12 and 12 'passes under the print head 14.

Preferably, the shutter device 21 makes it possible to interrupt the vacuum effect on an interruption surface substantially equal to the printing surface of a print head 14. In the embodiment shown, the surface interruption is defined by the space between two cardboard plates 22, but many other examples of construction in accordance with the invention are conceivable by the person skilled in the art.

Advantageously, the shutter device 21 is of rotary type. Alternatively, the shutter device 21 may be oscillating, or even perform translational movements.

The parallelepipedal shape of the chamber 20 on the FIG. 1 to Fig. 4 serves only to materialize the location in the room within a machine, but is not limiting.

Thus, in a particular mode of implementation of the invention shown in FIG. 5, the vacuum chamber 20 takes the form of a cylinder containing a shutter device 21, said shutter device 21 rotating or oscillating about the cylinder axis.

The vacuum effect is generated within a box in which is placed or to which the vacuum chamber 20 is connected, an opening in the cylinder of the chamber 20 for propagating the vacuum effect inside the cylinder and then the to apply to a plate element 12 of cardboard.

Optionally, the vacuum chamber 20 may comprise an adjustment device 23 of the length L of application of the vacuum effect. The adjustment device 23 makes it possible to adjust the length L of the zone of application of the vacuum effect to the width of the element made of cardboard plate 12. Thus, the vacuum effect does not produce turbulence on the edges. side of the cardboard plate elements 12 which ensures good print quality on the substrate areas close to these edges.

In the nonlimiting example of implementation of the invention shown in FIG. 5, the adjusting device 23 takes the form of a cylinder which fits into the cylindrical shape of the chamber 20 so as to limit the propagation of the vacuum effect within the chamber 20. Other constructions of the adjustment device 23 are naturally conceivable for the person skilled in the art, such as for example a sliding shutter on the surface of the plates. carton 22.

The invention also relates to a printing machine 10 implementing the vacuum transport method, comprising a vacuum transport device 13 for transporting cardboard plate elements 12, a printing head 14 intended to print by jet d ink on the cardboard plate elements 12, and a vacuum chamber 20 having a shutter device 21 for interrupting the vacuum effect, said vacuum chamber being placed under the print head 14.

In the nonlimiting example of implementation of the invention shown in FIG. 1, the machine

10 comprises four print heads 14, and four vacuum chambers 20. These vacuum chambers can be placed each in a different vacuum box, or several in a single box, or all four in a single box. The shape and the number of vacuum boxes are therefore not decisive for the invention. Naturally, the invention relates to machines comprising at least one printing head 14 and a vacuum chamber 20.

Advantageously, the printing machine 10 according to the invention comprises a device 15 for detecting the edge of the cardboard plate elements 12, and a control device 16 for synchronizing the rotation of the shutter device 21 with the detection of the edge of a cardboard plate element 12.

The device for detecting the edges of the cardboard plate elements 12 may for example comprise an optical sensor, or a mechanical sensor. Many other constructions of the detection device 15 are conceivable by the person skilled in the art without departing from the scope of the invention.

The control device 16 is of the microprocessor or microcontroller type. On the basis of the signals emitted by the detection device 15, it synchronizes the closure device 21 of each of the vacuum chambers 20 with the detection of the edges of the cardboard plate elements 12.

Optionally, the control device 16 can also furtively interrupt the vacuum effect when a cardboard plate element 12 passes under a print head 14. In particular, in the event that the shutter devices 21 are of rotary type, when the rate of the printing machine 10 is high and when the intervals between two plate elements successive cardboard 12 and 12 'vary little, this control mode makes it possible to vary the rotation of the shutter devices 21 by limiting abrupt acceleration and deceleration.

This mode of operation then corresponds to the vacuum transport method according to the invention as defined above but where, during the plating phase, the vacuum effect is also interrupted under a print head 14 by one or more shutter phases additional.

Claims

A method of transporting cardboard board members (12) in an inkjet printing machine (10) comprising a vacuum transport device (13) and at least one print head (14), characterized in that what

during a plating phase, a vacuum effect is applied through the vacuum transport device (13) to each cardboard plate element (12) as it passes under a print head (14);

during a shutter phase, the vacuum effect is interrupted under any print head (14) below which passes an interval separating two cardboard plate elements (12, 12 ').

Method of transporting plate elements according to claim 1, characterized in that during the plating phase the vacuum effect is also interrupted under a print head (14) by one or more additional sealing phases.

Vacuum chamber (20) for transporting cardboard plate elements (12) in an inkjet printing machine (10) comprising a vacuum transport device (13) and at least one printhead (14), characterized in that said vacuum chamber (20) comprises a shutter device (21) for interrupting the vacuum effect.

Vacuum chamber (20) according to claim 3, characterized in that the shutter device (21) makes it possible to interrupt the vacuum effect on a surface substantially corresponding to the printing area of a print head (14) inkjet.

Vacuum chamber (20) according to claim 3 or 4, characterized in that the shutter device (21) is rotatable.

Vacuum chamber (20) according to claim 3 or 4, characterized in that the shutter device (21) is oscillating.

7. Vacuum chamber according to one of claims 3 to 6, characterized in that it comprises a device (23) for adjusting the length (L) of application of the vacuum effect.

8. Inkjet printing machine (10), comprising

A vacuum transport device (13) for transporting cardboard plate elements (12),

A print head (14) for inkjet printing on the cardboard plate members (12),

characterized in that it comprises a vacuum chamber (20) according to one of claims 3 to 7 placed under the print head (14).

9. Ink jet printing machine (10) according to claim 8, characterized in that it comprises

A device (15) for detecting the edge of the cardboard plate elements (12), A control device (16) adapted to synchronize the rotation of the shutter device (21) with the detection of the edge of a cardboard plate element (12).