阅读说明：本技术 用于喷墨印刷的印刷机 (Printing machine for ink-jet printing ) 是由 C·鲁帕纳 C·哈斯 M·莱瓦 U·昂斯特 U·费伦贝格 于 2019-07-17 设计创作，主要内容包括：本发明涉及一种用于喷墨印刷的印刷机,包括翻转装置和用于页张的输送路径。这样地布置用于润湿所述页张(2)的条件处理装置(3),使得它在所述页张(2)由所述翻转装置(1)翻转之前在其反面印刷侧(4)上润湿所述页张(2)。(The invention relates to printing press for inkjet printing, comprising a turning device and a transport path for sheets.A conditioning device (3) for moistening the sheet (2) is arranged in such a way that it moistens the sheet (2) on its reverse printing side (4) before the sheet (2) is turned over by the turning device (1).)

printing machine for inkjet printing, comprising a turning device (1) and a transport path (6) for a sheet (2),

it is characterized in that the preparation method is characterized in that,

a conditioning device (3) for moistening the sheet (2) is arranged in such a way that the conditioning device moistens the sheet (2) on its reverse printing side (4) before the sheet (2) is turned by the turning device (1).

2. The printing press as set forth in claim 1,

it is characterized in that the preparation method is characterized in that,

the conditioning device (3) is arranged, as viewed along the transport path (6) of the sheet (2), between a spray drum (7) towards which at least inkjet printing heads (8) are directed and a reversing drum (9) of the reversing device (1) which grips the sheet (2) at the rear edge (10) during the reversing.

3. A printing press according to claim 1 or 2,

it is characterized in that the preparation method is characterized in that,

the conditioning device (3) wets the sheet (2) indirectly by applying a conditioning fluid (12) to a cylinder (20) which transports the sheet (2) and in the process transfers the conditioning fluid to the sheet.

4. A printing press according to claim 1 or 2,

it is characterized in that the preparation method is characterized in that,

the conditioning device (3) wets the sheets (2) directly by applying a conditioning fluid (12) to the sheets (2) during transport of the sheets through the drum (13).

5. A printing press according to any one of claims 1 to 4 to ,

it is characterized in that the preparation method is characterized in that,

the conditioning device (3) is a spraying device (14).

6. A printing press according to claim 5, wherein,

it is characterized in that the preparation method is characterized in that,

the spraying device (14) has an arrangement of centrifugal discs (15).

7. A printing press according to any one of claims 1 to 6 to ,

it is characterized in that the preparation method is characterized in that,

the conditioning device (3) is arranged downstream of the thermal dryer (16), as viewed along the transport path (6) of the sheet (2).

8. The printing press as set forth in claim 7,

it is characterized in that the preparation method is characterized in that,

the conditioning device (3) rewrites the sheet (2) in order to at least partially compensate for the loss of moisture by the thermal dryer (16).

9. A printing press according to claim 7 or 8,

it is characterized in that the preparation method is characterized in that,

the thermal dryer (16) is a hot air dryer and/or an infrared dryer.

10. A printer according to any of claims 1 to 9,

it is characterized in that the preparation method is characterized in that,

the conditioning device (3) wets the sheet (2) with a water-containing conditioning fluid (12).

Technical Field

The invention relates to printing press for inkjet printing, comprising a turning device and a transport path for sheets.

Background

DE 102017212758 a1 shows a printing press in which a plurality of inkjet printing devices are arranged one behind the other along the partial circumference of the printing cylinder, a dryer is provided which is designed as an IR dryer and possibly in combination with a hot air dryer, the turning device operates according to the trailing edge turning principle (Prinzip der hinterkantenwendung).

A disadvantage is that moisture can be removed from the printed sheet by means of infrared or hot air dryers and this can lead to sheet deformation.

Disclosure of Invention

The object of the present invention is to provide sheet-fed printing presses in which the deformation of the sheets caused by the dryer is avoided.

This object is achieved by an sheet-fed printing press comprising a reversing device and a transport path for the sheet, characterized in that a conditioning device (konditieireinrichtung) for moistening the sheet is arranged in such a way that it moistens the reverse printing side of the sheet before the sheet is reversed by the reversing device.

The advantage of the printing press according to the invention is that the rewetting of the printed sheet by the dampening unit (R ü ckbefeucht ung) can be carried out on the unprinted sheet side of the printed sheet, which can absorb the rewetting liquid well.

There are many possible improvements:

the conditioning device can be arranged, as viewed along the sheet transport path, between a spray drum, to which at least inkjet printing heads are directed, and a reversing drum of the reversing device, which grips the rear edge of the sheet when the sheet is reversed (ergolift).

The conditioning apparatus can indirectly wet the sheets by applying a conditioning fluid (konditioinierfluid) to a roller that transports the sheets and transfers the conditioning fluid to the sheets there.

The conditioning apparatus can directly wet the sheets by applying a conditioning fluid to the sheets during transport of the individual sheets by the drum.

The conditioning apparatus may be a spray apparatus.

The spraying device may have a centrifugal disc arrangement.

The conditioning apparatus may be disposed after the thermal dryer, as viewed along the sheet conveying path.

The conditioning apparatus is capable of rewetting the sheet for at least partially compensating for moisture loss caused by the thermal dryer.

The thermal dryer may be a hot air dryer, or an infrared dryer, or a combination of the two.

The conditioning apparatus may be aqueous/water-containing

The conditioning fluid wets the sheet.

Drawings

Further developments emerge from the following description of embodiments and the accompanying drawings, in which:

FIG. 1: a full view of a sheet printing press having a sheet turning device and a condition processing device; and

FIG. 2: detailed views of a sheet turning device and a condition processing device.

Detailed Description

The printing press comprises a feeder 25 for sheets 2, an -th printing station 17 for printing a front printing side 5 of the sheets 2, and a second printing station 18 for printing a rear printing side 4 of the sheets 2, the sheets 2 forming a stack 26 in the feeder 25, wherein each sheet 2 of the sheets 2 has a front edge 11 and a rear edge 10, each printing station 17,18 comprising a spray cylinder 7 and at least inkjet printing heads 8 directed toward the spray cylinder 7.

The printing press is an Inkjet recto-verso printing press (Inkjet-perfector) and comprises a reversing device 1, which reversing device 1 is arranged, as viewed along the transport path 6 of the sheet 2, between the -th printing station 17 and the second printing station 18, the reversing device 1 operates according to the trailing edge reversing principle and comprises a storage drum 19 and a reversing drum 9 arranged downstream of the storage drum 19, the reversing drum 9 gripping the trailing edge 10 of the sheet 2 when the trailing edge 10 of the sheet 2 is transported on the storage drum 19 in the event of a reversal of the sheet 2.

The sheets 2 are transferred from the drum 20 to the drum 13 and from the latter (drum 13) to the storage drum 19. The drum 13 has a narrow, long contour deviating from a circular shape, and a guide 24 for the sheets 2 is arranged below the drum 13. The guide 24 is bowl-shaped and may be a pneumatic guide plate with blowing nozzles that create a cushion of air over which the sheet 2 is suspended.

After the sheets 2 are printed in the printing station 17, the sheets 2 are dried on their front printing side 5 by a thermal dryer 16. the thermal dryer 16 can be a hot air dryer or an infrared dryer or a combination of the two, by irradiating the sheets 2 with hot air and/or infrared radiation, the sheets 2 are excessively dried, which, if no countermeasures are taken, would lead to sheet deformation which is detrimental to the print quality.

The conditioning fluid 12 is applied to the reverse printing side 4 of the sheet 2, the conditioning fluid 12 being different from ink, base coat (primer), varnish or offset dampening solution, the conditioning fluid 12 being water (possibly with additives), since the reverse printing side 5 is already more or less protected (versiegelt) after it has been printed with ink in the printing station 17, and the absorption of the conditioning fluid 12 by this reverse printing side 5 is therefore poor at this point in time, it is therefore advantageous to apply the conditioning fluid 12 to the reverse printing side 4 which has not yet been printed and is thus absorbent, by means of the conditioning device 3, the conditioning fluid 12 can penetrate rapidly from the reverse printing side 4 into the sheet 2 of paper or cardboard.

The solid lines show the variant in which the conditioned fluid 12 is applied directly, the dashed lines show the second variant in which the conditioned fluid 12 is applied indirectly via the drum 20.

In both variants, the conditioning device 3 comprises a spraying device 14 with a housing 21, in which housing 21 an arrangement of centrifugal discs 15 is arranged. The drawing shows only the centrifugal disc 15 which is the foremost one of the centrifugal discs 15, which covers the other centrifugal discs. These centrifugal discs 15 produce a spray jet 23 of conditioned fluid 12, which conditioned fluid 12 is pumped into the housing 21 by means of the pump 22. In both variants, the application of the conditioning fluid 12 to the sheet 2 is carried out from below and before the sheet 2 is turned over by the drums 9, 19.

In the variant, the spray jet 23 impinges on the reverse printing side 4 of the sheet 2 in the region between the cylinder 20 and the guide 24 when the sheet 2 is gripped at its leading edge 11 by the gripper system 27 of the drum 13 and its trailing edge 10 is still on the cylinder 20.

In a second variant, when the sheet 2 is transported on the circumferential surface 28 of the cylinder 20, the spray jet 23 impinges on the circumferential surface 28 of the cylinder 20 and is transferred from the cylinder 20 to the reverse printing side 4, the spray jet 23 impinges on the cylinder 20 in the circumferential corner region of the cylinder 20, while no sheet transport takes place on the cylinder 20, for example, the transport of the sheet 2 takes place only in the th, second and third quadrants of the cylinder 20, while the spray jet 23 impinges on the circumferential surface 28 of the sheet 2 in the fourth quadrant.

List of reference numerals

1 turnover device

2 pages

3 Condition processing device

4 reverse side printing

5 front printing side

6 conveying path

7 spray cylinder

8 ink jet print head

9 turnover rotary drum

10 rear edge

11 front edge

12 Conditioning fluid

13 rotating cylinder (Trommel)

14 spraying device

15 centrifugal disc

16 thermal dryer

17 th printing station

18 second printing station

19 storage drum

20 roller

21 casing

22 pump

23 spray jet

24 guide device

25 feeder

26 pile of

27 gripping device system

28 circumferential surface