CN107053868B

CN107053868B - Printing sheet transport cylinder

Info

Publication number: CN107053868B
Application number: CN201710022476.9A
Authority: CN
Inventors: D·康策尔曼; J·福歇
Original assignee: Heidelberger Druckmaschinen AG
Current assignee: Heidelberger Druckmaschinen AG
Priority date: 2016-01-19
Filing date: 2017-01-12
Publication date: 2020-07-03
Anticipated expiration: 2037-01-12
Also published as: DE102016225090A1; CN107053868A

Abstract

The invention relates to a cylinder for conveying printed sheets, comprising a base body (13) and at least one cylinder cover (16) which is arranged in a manner that can be released from the base body (13) and/or adjusted relative to the base body (13), wherein an electric temperature control device is integrated into the cylinder cover (16), and the electric temperature control device heats and/or cools the printed sheets on the cylinder cover (16).

Description

Printing sheet transport cylinder

Technical Field

The invention relates to a cylinder for conveying printed sheets.

Background

DE 10305594B4 describes a drying cylinder with a cylinder jacket and a temperature control device fastened to the cylinder jacket. The temperature adjusting means is a heating wire and has a spiral shape. The drying cylinder also has a function of a pressing cylinder working together with the blanket cylinder or the plate cylinder.

The ink jet printer is not provided with the following counter-pressure cylinders: an inkjet print head operates with the pair of impression cylinders. Alternatively, the inkjet printer operates according to the NIP-Printing (NIP-Impact Printing) method. Problems in ink jet printers are: the print quality may fluctuate.

Disclosure of Invention

The object of the invention is to provide a printing sheet transport cylinder which is suitable for reducing printing quality fluctuations in inkjet printers.

The object is achieved by a cylinder for transporting a printed sheet, comprising a base body and at least one cylinder jacket, which is arranged in a releasable and/or adjustable manner relative to the base body, wherein an electrically operated temperature control device is integrated into the cylinder jacket, which heats and/or cools the printed sheet located on the cylinder jacket.

The advantage of this cylinder is that it can be conditioned (kondationier) before the printed sheet is printed by the inkjet method. This conditioning is particularly advantageous in the case of printed sheets made of paper or cardboard, the moisture of which must be adjusted to the values or value ranges required in printing technology. An additional advantage is that the electrically operated temperature control device can be composed of components of low mass and can be arranged uniformly distributed. In this way, the moment of inertia of the drum can be kept small and an unbalanced situation can be avoided. Furthermore, since the temperature control device is operated electrically, the temperature control device has a high reaction speed, as a result of which short control times can be achieved.

The drum according to the invention has different improvements.

In a further development, the cylinder can comprise a tensioning device with a retaining device for the front edge of the cylinder jacket and a retaining device for the rear edge of the cylinder jacket, the development being advantageous with regard to the simple subsequent assembly of the machine.

In one refinement, the drum casing is arranged on a circumferential section of the drum. The drum shell can be glued to the circumferential section or fastened or braced thereto by means of adhesive tape. If the roller cover is bonded to the peripheral section by means of a double-sided adhesive tape, the roller cover can be easily released from the peripheral section and the releasability of the roller cover from the base body is achieved. If the drum shell is bonded to the peripheral section by means of a non-releasable adhesive, the releasability of the drum shell from the base body is obtained by the releasability of the peripheral section from the base body, wherein the peripheral section together with the drum shell is removed from the drum and, if required, can be inserted into the drum again or replaced by a peripheral section additionally having another type of drum shell. In the last case, the peripheral section is configured as a replacement section (Wechselsegment). Such a replacement section is advantageous because it can be easily removed. For example, the replacement section can be removed from the drum for maintenance or repair work, and a structurally identical replacement section can be inserted into the drum, so that machine downtime due to maintenance or repair is avoided. The repair or maintenance of the replacement section can be carried out outside the machine, while the machine continues to operate with the replacement section.

In one refinement, the circumferential section is configured as a fold section (Klappsegment). The folding section is connected with the base body through a rotary joint. The drum is selectively operable in a first mode of operation in which the folder is unfolded (ausgeklappt) and a second mode of operation in which the folder is folded (eingeklappt). In a first operating mode, the drum can have a circular outer contour, which is determined by the folding section and a further such folding section. In the second operating mode, the drum can have an oval or diamond-shaped outer contour, which is defined by two folding sections that are folded together.

In one refinement, the temperature control device is divided into separately controllable zones. For example, the zones may be partially deactivated, so that in one operating mode a large number of zones are active and temperature-controlled, and in another operating mode a small number of zones are active and temperature-controlled. Likewise, the zones can be operated at different powers from one another, so that certain zones heat or cool the printed sheets more strongly than other zones.

In one refinement, the zones are controlled as a function of the format of the printed sheet. For example, the regions outside the page format can be deactivated, so that a small number of regions are activated if the page format is small and a large number of regions are activated if the page format is large. In this way unnecessary energy consumption is avoided.

In one refinement, the electric temperature control device comprises a Peltier element (Peltier-element). The advantage of this development is that the temperature control device is both a heating device for heating one printed sheet and a cooling device for cooling another printed sheet. Depending on the ambient temperature or depending on the initial temperature of the printed sheets of the respective print job, the temperature control device can be operated as a heating device in one print job and as a cooling device in another print job. Depending on the polarity of the applied dc voltage, the peltier element acts either as a heating element or as a cooling element. The temperature control device can thus be switched from its operating mode as a heating device to its operating mode as a cooling device by reversing the direction of the current.

In one refinement, the drum casing has a plurality of layers in a multilayer structure (Sandwich-Bauweise). One of these layers may be an Anti-grease layer (Anti-abskmier-Schicht) which is located completely radially outside with reference to the drum. The grease-resistant layer is structured in such a way that it repels the printing ink with regard to its material type and/or surface structure. Thus, printing ink which may be printed on the back side of the printed sheet and which has not yet dried completely does not slip onto the cylinder jacket from the back side lying on the grease-resistant layer. Another of these layers may be a radially more inner insulating layer. A temperature control layer, which may comprise the peltier element described above, for example, may be arranged radially between the heat insulation layer and the grease-resistant layer. The insulating layer need not necessarily be the radially innermost layer of the multilayer assembly. The radially innermost layer can also be formed by a carrier layer on which the thermal barrier layer is arranged.

The invention also relates to an inkjet printer (for example an inkjet digital printer) comprising at least one inkjet print head and a cylinder arranged in front of the inkjet print head in the transport direction of the printed sheet, which cylinder is designed in a manner corresponding to the cylinder according to the invention or in a manner corresponding to one of the developments of the cylinder according to the invention.

Drawings

Advantageous refinements also emerge from the following description of several exemplary embodiments and the drawings. The figures show:

FIG. 1: an ink-jet printer for printing ink on a substrate,

FIG. 2: the cylinder of an ink-jet printer is,

FIG. 3: the drum of the drum is lined with a cylinder,

FIG. 4: an alternative configuration of the drum is that of the drum,

FIG. 5: according to the detailed view of the drum of figure 4,

FIG. 6: cross-section of the folded section of the drum, and

FIG. 7: top view of different zones of the drum shell of the drum according to fig. 2 or 4.

In fig. 1 to 7, mutually corresponding components are denoted by the same reference numerals.

Detailed Description

Fig. 1 shows an inkjet printer 1 with a sheet feeder 2, a sheet receiver 3 and a printing unit 4. The printing mechanism 4 comprises a cylinder 5 and an inkjet print head 6 directed towards the cylinder 5 for multicolor printing, such as CMYK four-color printing. A cylinder 7 is arranged between the sheet feeder 3 and the cylinder 5, said cylinder 7 transporting a printed sheet 8 in a transport direction 9. The printing sheet 8 is moved by the drum 5 past the inkjet printing heads 6 and is printed by these inkjet printing heads 6. The printed sheets 8 comprise paper or cardboard and, in order to enable these printed sheets 8 to be printed in the printing unit 4 in a state which is optimal with respect to both temperature and humidity, these printed sheets 8 have been conditioned previously by the cylinders 7.

Fig. 2 shows the drum 7 in a separate view. The drum 7 comprises two

peripheral sections

10,11 of identical construction. Each

peripheral section

10,11 is carried by a rib or spoke 12 of the base body 13 and comprises a tensioning device 14, which tensioning device 14 has a clamping device 15 for holding the roller shell 16 at the front edge and a clamping device 17 for holding the roller shell 16 at the rear edge. The drum casing 16 is configured as a cylinder liner and comprises a grease-resistant layer 18 as a cover layer and a temperature control layer 19 thereunder, which temperature control layer 19 has a temperature control device 20 integrated into the temperature control layer 19. The temperature control layer 19 is a thick plastic film and is bonded to the grease-resistant layer 18. The grease-resistant layer 18 is a thin metal film having on its outer side a chrome-plated portion provided with a rough surface structure. The temperature-regulating device 20 is a peltier element assembly. The temperature control layer 19 is used to cool and heat the printed sheet 8 as required by the environmental conditions. The spokes 12 can be configured as air blades in order to conduct away the heat of the

peripheral edge sections

10,11 more quickly when cooling the printed sheet 8. Each printed sheet 8 lies over the entire surface area on the grease-resistant layer 18 when it passes over the cylinder 7 during its transport and is tempered by the temperature-control layer 19 through the grease-resistant layer 18.

Fig. 3 shows the

circumferential segments

10,11 in an enlarged manner in cross section, by way of example of the circumferential segment 10. A drum outer cover 16 (here in the form of a flexible cylindrical envelope) is located on the peripheral face of the peripheral edge section 10 and is constructed from a two-layer, multi-layer assembly. A tempering layer 19 with a tempering device 20 is located below, said tempering device 20 being integrated into the tempering layer 19. The temperature control device 20 comprises peltier elements and the temperature control device 20 can alternatively be designed as a heating wire assembly in the case of certain applications, when the temperature control device 20 is to be used only for heating and not for cooling. The grease-resistant layer 18 is located above and a printed sheet is located on the grease-resistant layer 18, which is not shown together in this figure. The grease resistant layer 18 has the property of repelling printing ink: the printing ink is printed on the underside of the printed sheet 8 and may not have completely dried.

Fig. 4 shows a configuration of the drum 7, in which the

circumferential segments

10,11 are configured as folding segments 21 and at the same time as replacement segments 22. This versatility is preferred, however of course the following configurations are possible: in these configurations, the

peripheral sections

10,11 are only the folded sections 21 (and not the replacement sections) or only the replacement sections 22 (and not the folded sections). If the

circumferential segments

10,11 have a replacement function, they can be released from the drum 7 by an operator (for example, when used for maintenance or repair work) and removed from the machine. This loosening and removal is schematically illustrated in fig. 4 in terms of the movement sequence of the peripheral segments 10, which peripheral segments 10 are shown in the different positions 10.1 to 10.5 that are successively occupied in the process.

Fig. 5 shows the drum 7 of fig. 4 in an enlarged view, wherein it can be seen that the

circumferential segments

10,11 are each supported by a clamping plate 23. One end of the clamping plate 23 is hinged to the base body 13 or to a component mounted on the base body 13 (here a gripper bridge), and the other end of the clamping plate 23 is connected in an articulated manner to an adjusting ring 25 via a coupling 24. The adjusting ring 25 is mounted coaxially with the geometric axis of rotation of the base body 13 and the drum 7 and is rotatable relative to the base body 13. By rotating the adjusting ring 25, the clamping plate 23 together with the

peripheral segments

10,11 and the drum casing 16 arranged thereon is adjusted into the extended operating position or into the collapsed operating position depending on the direction of rotation of the adjusting ring 25. The unfolded operating position is shown in the upper half of the image, for example with a peripheral segment 10, and the folded operating position is shown in the lower half of the image, for example with another peripheral segment 11. Of course, during operation, the two

peripheral sections

10,11 are in the same operating position, either in the folded operating position or in the unfolded operating position; that is, folding and unfolding are always achieved in pairs. The

circumferential segments

10,11 are designed as a flexurally rigid housing and can be connected to the clamping plate 23 by means of coupling devices. In addition, the coupling device comprises a retaining pin 26 on the

peripheral sections

10,11 and a receiving claw 27 on the clamping plate 23, respectively.

Fig. 6 shows an enlarged cross-sectional view of the circumferential segment 10 of fig. 5 and the drum casing 16 arranged on the circumferential segment 10. The roller cover 16 is either releasably (for example by means of a double-sided adhesive tape) or non-releasably (for example by means of a liquid adhesive) bonded to the peripheral section 10. The drum casing 16 is a four-layer multilayer assembly comprising, from top to bottom: a grease resistant layer 18, a temperature regulating layer 19, a thermal insulating layer 28, and a carrier layer 29. The grease-resistant layer 18 and the temperature control layer 19 are configured as in the case of the drum casing 16 of fig. 2 and 3. The insulating layer 28 prevents heat from accidentally flowing out of the temperature control layer 19 into the peripheral portion 10 when heating a printed sheet, not shown here. The carrier layer 29 serves to reinforce or stabilize the remaining

layers

18,19,28 and may consist of sheet metal or plastic film. Such a heat insulating layer 28 and/or carrier layer 29 may also be provided in the drum casing 16 below the tempering layer 19 of fig. 2 and 3.

Fig. 7 shows a sectional view of the drum shell 16 from fig. 2 and 3 or from fig. 5 and 6 in a flat state (folded-open) removed from the circumferential section 10, the drum shell 16 being shown in section. The section runs through the temperature control layer 19, so that it can be seen that: the tempering device 19 is divided into: a first zone 31 for small sheet sizes, a second zone 32 for medium sheet sizes, and a third zone 33 for large sheet sizes. The second zone 32 surrounds the first zone 31 from three sides as shown or alternatively in an annular manner (not shown in the drawing), and the second zone 32 is connected together with the first zone 31 when the printed sheet 8 is processed in medium format. The third zone 33 surrounds the second zone 32 from three sides as shown or alternatively in an annular manner (not shown in the figures), and the third zone 33 is activated together with the two

inner zones

31,32 when the printed sheet 8 is processed in large format. These

zones

31,32,33 are respectively connected to an electronic control device 30 when the drum casing 16 is inserted into the drum 7, said electronic control device 30 being schematically shown and may be located either outside or inside the drum 7.

In the exemplary embodiment shown in fig. 2, an electronic coupling (Elektro-kupplong) can be provided between the drum casing 16 and the circumferential segment 10, which electronic coupling automatically closes when the drum casing 16 is spread onto the circumferential segment 10. A coupling half in the form of an electrical contact is located on the drum casing 16 and another coupling half, also in the form of an electrical contact, is located on the peripheral section 10. Such an electronic coupling can be arranged in the embodiment shown in fig. 5 between the clamping plate 23 and the circumferential section 10 and is automatically closed in the event of the insertion of the circumferential section 10 into the drum 7. In both embodiments, the tempering device 20 can be supplied with electric current via an electronic coupling.

List of reference numerals

1 ink jet printer

2 sheet feeder

3-sheet material collector

4 printing mechanism

5 cylinders

6 ink jet print head

7 roller

8 printing sheet

9 direction of conveyance

10 peripheral edge segment

10.1-10.5 peripheral segment positions

10,11 peripheral edge segments

12 spoke

13 base body

14 tensioning device

15 clamping device

16 roller outer cover

17 clamping device

18 grease resistant layer

19 temperature adjusting layer

20 temperature control device

21 folding segment

22 replacement section

23 Splint

24 coupler

25 adjusting ring

26 holding pin

27 receiving claw

28 insulating layer

29 carrier layer

30 control device

31 first zone

32 second region

33 third zone

Claims

1. A cylinder (7) for transporting a printed sheet (8), comprising a base body (13) and at least one cylinder jacket (16) which is arranged in a manner that can be released from the base body (13) and/or can be adjusted relative to the base body (13), wherein an electric temperature control device (20) is integrated into the cylinder jacket, which heats and/or cools the printed sheet (8) which is located on the cylinder jacket (16), wherein the cylinder jacket (16) is a spread-open cylinder jacket.

2. The drum as claimed in claim 1, wherein the drum shell (16) is arranged on a circumferential section (10) of the drum (7).

3. The drum as claimed in claim 2, wherein the peripheral section (10) is a folded section (21).

4. The drum as claimed in claim 2, wherein the peripheral section (10) is a replacement section (22).

5. The drum as claimed in any one of claims 1 to 4, wherein the electrically operated tempering device (20) is divided into separately controllable zones (31,32, 33).

6. The cylinder according to claim 5, wherein the zones (31,32,33) are controlled according to the specifications of the printed sheets (8).

7. The drum as claimed in any one of claims 1 to 4, wherein the electrically operated temperature regulating device (20) is a Peltier element assembly.

8. The drum as claimed in any one of claims 1 to 4, wherein the drum shell (16) has a plurality of layers in a multilayer structure.

9. The drum as claimed in claim 8, wherein one of the layers is a grease-resistant layer (18) which is radially outermost.

10. The drum as claimed in claim 8, wherein one of the layers is an insulation layer (28) located radially more inward.

11. An inkjet printer comprising an inkjet print head (6) and a drum (7) configured according to one of claims 1 to 10, which is arranged in front of the inkjet print head (6) in a transport direction (9) of the printed sheet (8).