EP1285755B1 - Coating machine for finishing printed sheets - Google Patents

Abstract

Coating machine comprises a drying device (9) arranged in a conveying direction (18) of a first coating unit (I). The drying device has endless conveying devices (10) with two deviating elements (11), a horizontal trunk, and sheet-holding systems (13). A drying system (12) is arranged above the sheet-conveying plane parallel to the lower trunk of the conveying devices. A sheet-guiding device (14) is arranged in the region of the drying system below the sheet-conveying plane. The drying device is connected to a second coating unit (II) which in turn is connected to a third coating unit (III).

Description

The invention relates to a coating machine for finishing printed sheets by means of a flowable material according to claim 1.

[State of the art]

A coating machine of this kind is out DE 298 18 148 U1 known and is designed with trained in row construction coating units. This document discloses a coating machine for refining printing sheets with a feeder unit, at least one downstream coating unit for the front of the printing sheets, a downstream sheet turning unit of at least one downstream coating unit for the back of the printing sheets, each coating unit comprising a sheet-guiding impression cylinder, a forme cylinder and a applicator roll containing Dosing system for a flowable material and each having a dryer device with a dryer system, and a downstream jib unit,
wherein in the conveying direction of the first coating unit for the sheet front side immediately the associated dryer device is arranged downstream, and wherein said dryer device immediately downstream of a second coating unit for the sheet front side and this second coating unit
for the sheet front side follow the sheet turning unit and at least the first coating unit for the sheet back.

From the point of view of process-stable drying, these dryer modules are disadvantageous for certain finishing orders.

Out DE-U-200 06 513 is a sheet-fed rotary printing machine with several printing units and a coating unit known. The coating unit downstream of the sheet in the conveying direction of a multifunction module. The multifunction module is prepared for individual or group-wise cultivation of a number of different options of various kinds and basically has on the input side a sheet conveying device and the output side a sheet guiding cylinder. In a first embodiment, the sheet conveying device is a sheet conveying drum, which takes over the sheet from the sheet guiding cylinder of the coating unit and to the sheet guiding cylinder of Multifunction module transfers. In a second embodiment, the sheet conveying device of the multifunctional module, instead of the sheet conveying drum, has a chain conveyor system revolving over deflecting elements, which consists of roller chains with articulated gripper systems. In this module further dryer devices are arranged.

OBJECT OF THE INVENTION

The invention has for its object to provide a coating machine of the type described above, which increases the coating quality of the printed sheet with double-sided coating.

According to the invention the object is achieved by the training features of claim 1. Further developments emerge from the dependent claims.

A first advantage of the coating machine is due to the fact that in-line operation a one-sided (front) or a two-sided (front and back) coating of sheets in high coating quality in conjunction with a process-stable drying, can be realized. The one-sided and double-sided coating can also be performed as a multiple coating. Before they enter the subsequent coating unit or subsequent sheet turning unit, the printed sheets are better, in particular more uniform, dried, which is due, in particular, to the formation of the drying devices. The process-stable drying noticeably reduces the risk of marks, scratches or smearing effects on the printed sheet, and an increase in the production output and higher layer orders can be achieved.
Similarly, in single-sided or double-sided operation, a multiple coating can be applied to the printed sheet. These are examples that are intended to facilitate the understanding of the invention. In addition, a further processing, for example, perforating, punching, embossing or marking, the printed sheet feasible.

It is also advantageous that previously in a processing machine, e.g. an offset printing machine and / or a gravure printing machine, produced printed sheets are then finished in the created coating machine or unprinted printed sheets, e.g. Recycling material, can be processed directly in the coating machine.

A further advantage is that, according to the invention, in the case of printed sheets printed on both sides, the coatings can be applied individually to the front or back side of the printed sheets-in the case of process-stable drying-in order to increase the coating quality. For example, a single-layer coating can be applied to a printed front side, and a two-layered one is particularly suitable for the back side Coating can be applied (and vice versa).

• der unterschiedlichen Saugfähigkeit des Materials der Druckbogen, und/oder
• von in oder auf den Druckbogen angeordneten Sujets und/oder Sicherheitsmerkmalen, und/oder
• von Glanzeffekten, und/oder
• des Oberflächenschutzes (Scheuerfestigkeit).

Such finishes are relevant as coatings for printed sheets whose front / back sides have been previously preferably printed in different printing processes. For example, such coatings (one or both sides) take place under the aspect:

• the different absorbency of the material of the sheet, and / or
• of sujets and / or security features arranged in or on the print sheet, and / or
• of gloss effects, and / or
• of surface protection (abrasion resistance).

According to the invention, furthermore, at least the first coating unit for the front side (in the conveying direction of the printed sheet) is followed by a drying device, which is preferably variable length executable. Such a drying device serves to improve the coating quality of the printed sheets by a process-stable drying. Depending on the flowable material used, sufficient time remains for the coated printed sheet to be blown off, oxidatively dried or crosslinked. As a flowable material preferably aqueous dispersion coatings, UV coatings, Flexoduckfarbe, opaque white or pigmented paints are used. The printed sheets are thus noticeably better dried before they are transferred in the conveying direction, for example to the next coating device, alternatively a smoothing device or another processing device for the sheet front side.

According to the invention, this next coating / smoothing device follows in the conveying direction a sheet turning unit and this at least one coating unit for the sheet back side, and the latter coating unit is followed by a drying device with drying systems, which is preferably variable length executable, preferably a downstream additional coating device or processing device, or directly a jib unit with dryer systems.

It is also advantageous that preferably all coating units have the same structure. Only the printing plates (printing / coating plate) and the dosing systems associated with the forming cylinders with applicator rollers can be used optionally according to the orders. In this case, the forme cylinders can be used universally in that optionally the forme cylinder of a coating unit carries a printing / coating plate (for example, planographic printing plate, flexible high-pressure mold), a punching device, preferably a punching plate, a perforating plate or a perforating knife, an embossing plate, a smoothing plate or a grooving plate.

Another advantage is given by the fact that the sheet turning unit of the coating machine is switchable in their mode of operation. Thus, the coating machine with its coating units for the non-inventive one-sided (Perfecting) as well as double-sided coating (perfecting operation) of the sheet can be used.

In an advantageous embodiment, each coating unit has a forme cylinder with plate clamping means and a plate changing device. Coating units with a setup that enables a set-up time reduction can thus be implemented on the coating machine.

[Examples]

Fig. 1

eine nicht erfindungsgemäße Beschichtungsmaschine mit je einer Beschichtungseinheit für die Vorder- und Rückseite von Druckbogen und einer Trocknervorrichtung,

Fig. 2

eine erfindungsgemäße Weiterbildung der Beschichtungsmaschine gemäß Fig. 1 mit zwei Trocknervorrichtungen,

Fig.3

eine Weiterbildung der Beschichtungsmaschine gemäß Fig. 2 mit einer zusätzlichen Beschichtungseinheit.

The invention will be explained in more detail using an exemplary embodiment. Here are shown schematically:

Fig. 1

a non-inventive coating machine, each with a coating unit for the front and back of sheet and a dryer device,

Fig. 2

an inventive development of the coating machine according to Fig. 1 with two dryer devices,

Figure 3

a development of the coating machine according to Fig. 2 with an additional coating unit.

A coating machine according to Fig. 1 has in the conveying direction 18 of the sheet on a investor unit, which is formed by a feeder 1 and a feed table 2, preferably a suction belt table. The feed table 2 is followed by a first coating unit I for the sheet front side, which has inter alia an oscillating device 3, a contact drum 4, a forme cylinder 6 and a pressure cylinder 5 as a sheet guiding cylinder. The form cylinder 6 is assigned as a metering system for a flowable material, such as a dispersion or UV coating, a screened applicator roller 7 with chamber doctor blade 8.

The first coating unit I for the sheet front follows in the conveying direction 18, a first dryer device 9. This dryer device 9 has an endlessly circulating conveyor 10 with two deflecting elements 11 and horizontally arranged strands and spaced thereon sheet holding systems 13. Parallel to the lower run of the conveying means 10, at least one drying system 12, for example IR dryers, thermo-air dryers or UV dryers, is arranged above the sheet conveying plane. According to the invention, a sheet guiding device 14, for example pneumatically actuated, is arranged at least in the area of the drying systems 12 below the sheet conveying plane. Through this education the dryer device 9, any number of drying systems 12 in the conveying direction 18 can be arranged successively in a horizontal plane.

In a preferred embodiment as a pneumatically actuated sheet guiding device 14 whose guide surface is in particular functionally connected to a coolant system. Such a coolant system is preferably formed by arranged on one of the guide surface for the sheet guide opposite surface coolant channels. The coolant channels can be flowed through by a coolant which is preferably processed in a cooling circuit.
Such a training is for example DE 298 16 734 U1 known.

The drying device 9 follows in the conveying direction 18 a second coating unit II for the sheet front side, which analogous to the first coating unit I has a forme cylinder 6, a screened applicator roller 7 with chamber doctor blade 8 and a pressure cylinder 5. This second coating unit II for the sheet front follows in the conveying direction 18, a sheet turning unit 15. In a development downstream of the forme cylinder 6 of the second coating unit II for the sheet front side a dryer system 12 at a distance from the sheet-guiding printing cylinder 5. Such a drying system 12 is, for example, a UV dryer.

As in Fig. 1-3 alternatively shown, the second coating unit II only with a sheet-guiding printing cylinder 5 and acting as a smoothing cylinder form cylinder 6 operable. As an alternative to the forme cylinder 6, at least one smoothing roll can also be installed. The Yankee cylinder serves to improve the mechanical structural property of the surface of the printed sheets and to increase the gloss. At the same time, the Yankee cylinder assists bowing a non-active second coating unit II. For this purpose, the forme cylinder 6 carries a smoothing plate or is itself designed as a Yankee cylinder or exchangeable by a Yankee cylinder.

The smoothing plate or the smoothing cylinder preferably has an adherent coating consisting of metals such as chromium, iron, nickel, cobalt or tungsten, their mixtures or alloys. Another preferred coating is molybdenum. These coatings additionally have a sealing layer, which is preferably formed from the group of polyorganosiloxanes.

The metering systems, for example, chamber doctor blade 8 and applicator roller 7, are turned off by the forme cylinder 6 or smoothing cylinder. Alternatively, the metering systems are also removable from the coating unit II. The coating unit II is preferably suitable for use with a smoothing device, but its use can also be implemented in downstream coating units (III-V).

The first deflecting element 11 in the conveying direction 18 is preferably mounted in the side walls of a frame 19 of the drying device 9, and the second deflecting element 11 downstream in the conveying direction 18 is mounted in the frame of the second coating unit II for the sheet front side. The length of the side walls of the frame 19 (including conveying means 10, sheet holding systems 13) is individually adaptable to the required dryer section (multiple arrangement of the dryer systems 12). The side walls of the frame 19 are integrally strung together in one piece or modular.

The deflecting elements 11 preferably have the same outer diameter. Furthermore, the axle centers of the deflecting elements 11 are preferably arranged in a plane. Likewise, the deflecting elements 11 are based on a single-sized Form cylinder 6 - and the sheet-guiding cylinder, pressure cylinder 5 and possibly transfer cylinder 17 and turning drum of the sheet turning unit 15, formed with the same diameters double size.

According to Fig. 1 the sheet turning unit 15 is arranged downstream of a first coating unit III for the sheet back and this coating unit III is a boom unit 16 downstream. The jib unit 16 has drying systems 12, for example IR dryers, thermo-air dryers, UV dryers, as well as circulating conveying means 10 with sheet holding systems 13 for depositing the printed sheets on a delivery pile.

According to Fig. 2 is in continuing education of Fig.1 - With the same machine configuration up to the sheet turning unit 15 - again subordinate the first coating unit III for the sheet back. This is followed by a second drier device 9, which is identical in construction to the already described drier device 9 (FIG. 1) downstream of the first coating unit I for the sheet front side (FIG. Fig. 1 ). The length of the side walls of the frame 19 (including conveying means 10, sheet holding systems 13) is also individually adaptable to the required dryer section (multiple arrangement of dryer systems 12).

The second dryer device 9 thus has endlessly circulating conveying means 10, two deflecting elements 11 and horizontally arranged strands and spaced sheet holding systems 13, furthermore at least one drying system 12 associated in parallel with the lower run of the conveying means 10 above the sheet conveying plane and at least one beneath in the area of the drying systems 12 the sheet conveying plane arranged in parallel sheet guiding device 14. The sheet guiding device 14 is pneumatically acted upon in a preferred embodiment and the guide surface is preferably with a Coolant system in functional connection.

The second drying device 9 is followed by a second coating unit IV for the sheet back side. This is followed by the jib unit 16 with dryer systems 12 and sheet guiding devices, which are preferably in functional connection with a coolant system.

FIG. 3 represents a further education of Fig. 2 according to which the second coating unit IV for the sheet backside is followed by a third coating unit V for the sheet back side with preferably a transfer cylinder 17 connected therebetween. The transfer cylinder is preferably associated with a sheet guiding device. Instead of the transfer cylinder 17, a drying device 9 can also be arranged.

The second coating unit IV for the sheet back or the third coating unit V for the sheet back optionally have a device for perforating or punching or cutting or numbering or embossing or marking, for example with security features or codes, the sheet on.

For example, the second coating unit IV can be used for the bow back for perforating and the third coating unit V for the sheet back is for coating, preferably painting, used. For this purpose, for example, the forme cylinder 6 of the second coating unit IV carries a perforating plate and the pressure cylinder 5 serves as an anvil cylinder. After perforating in the second coating unit IV for the back of the sheet, the printed sheets are coated again in the third coating unit V for the sheet back, preferably painted. This is followed by the jib unit 16 with dryer systems 12 and sheet guiding devices, preferably with a coolant system.

The metering systems of the coating units I-V are not limited to a chambered doctor blade 8 with application roller 7. Rather, two-roll mills can be used with liquid material which can be fed from above into a nip (nip roll principle) or two and three-roll mills according to the dip rolling / scooping roll principle.

In a further embodiment, at least one printing cylinder 5 of a coating device I - V and / or a drying device 9 is associated with a device for controlling the layer thickness or the gloss measurement. Preferably, after the contact gap of the forme cylinder 6 and the pressure cylinder 5 in the conveying direction 18, such a device is arranged at a distance from the sheet-guiding printing cylinder. In addition, at least one dryer system 12 can be arranged between this contact gap and this device.
Furthermore, in the drying device 9 in the conveying direction 18 after the drying systems 12 at a distance from the conveyed printing sheet, such a device for coating thickness measurement or gloss measurement can preferably be arranged.

The above-described embodiments of the coating machine are thus not exhausted. Rather, in the conveying direction 18, for example, a further coating unit with at least one sheet-guiding impression cylinder 5 and a forme cylinder 6 or a smoothing cylinder or at least one smoothing roll can be arranged in front of the first coating unit I. Such an arrangement is for example advantageous in already printed, dusted with powder sheet. With this upstream coating unit, the powder material is smoothed and in the subsequent coatings, the gloss effect and / or surface smoothness can be improved.

In a preferred embodiment, each coating unit I-V has on each forme cylinder 6 plate clamping means. The plate clamping means serve to accommodate the paint plate (rubber blanket with preferably metallic support layer, flexible high-pressure form), the smoothing plate, the perforating, embossing or stamping sheet and are preferably arranged circumferentially on the forme cylinder 6. Each form cylinder 6 is also associated with a plate changing device. Such a plate changing device is preferably assigned to each forme cylinder 6 on the side of the jib unit 16.
Regardless of the plate clamping means and plate changing means, each forme cylinder 6 is connected to a register setting device.

The mode of action is for example as follows. The printed sheets are fed in the conveying direction 18 by means of feeder 1, feed table 2, oscillating device 3, bearing drum 4 to the sheet-guiding printing cylinder 5 of the first coating unit I (for the sheet front side).
In the contact gap, formed by forme cylinder 6 (with rubber blanket, flexible high-pressure mold) and the sheet-guiding printing cylinder 5, a coating (full-surface painting, recessed lacquering) on the front side of the sheet. The flowable substance is an aqueous dispersion varnish in use.
The printed sheets are then transferred from the printing cylinder 5 to the sheet holding systems 13 of the drying device 9, guided by means of conveying means 10 in the sheet conveying plane past the drying systems 12 and transferred to the subsequent impression cylinder 5.
In the contact gap of the subsequent second coating unit II (for the sheet front side), for example, the forme cylinder 6 is active as a Yankee cylinder and to support the sheet guiding.
In the sheet turning unit 15, the sheets are turned on the principle of trailing edge application. The sheet turning unit 15 is reversible, so that the function of a transfer cylinder for the non-inventive one-sided coating feasible is. The sheet turning unit 15 is preferably formed as a Eintrommelwendung or a multi-drum application with at least one of the beater drum upstream storage drum.
The sheet turning unit 15 follows the first coating unit III (for the sheet backside). In the contact gap, formed by the form cylinder 6 (with flexible high-pressure mold) and the sheet-guiding printing cylinder 5, a spot coating (recessed lacquering) takes place on the back of the sheet. Thereafter, the printed sheets according to Fig. 1 transferred to the sheet holding systems of the jib unit 16 and dried.

According to Fig. 2 For example, the printed sheets are coated in the first coating unit III (for the sheet back side), for example with a UV varnish. For this purpose, a UV dryer system 12 is arranged downstream of the forme cylinder 6. The printed sheets are then transferred from the printing cylinder 5 to the sheet holding systems 13 of the drying device 9, guided by conveyor 10 in the sheet conveying plane to the dryer systems 12 and passed to the subsequent impression cylinder 5 of the second coating unit IV, coated and then transferred to the jib unit 16 and dried.

According to Fig. 3 After the turn, the printed sheets are coated in the first coating unit III (for the back of the sheet) with a varnish. The printed sheets are then transferred from the printing cylinder 5 to the sheet holding systems 13 of the drying device 9, guided by means of conveyor 10 in the sheet conveying plane to the dryer systems 12 and passed to the subsequent impression cylinder 5, which is preferably provided with a counter-punching sheet, the second coating unit IV. The forme cylinder 6 carries a perforating / stamping sheet and the printed sheets are perforated or punched. Subsequently, the printed sheets are transferred to the transfer cylinder 17 and from there to the printing cylinder 5 of the third coating unit V (for the back of the sheet) to hand over. In the last coating unit V, the printed sheets are coated again and subsequently transferred to the delivery unit 16 by means of drying systems 12 and deposited on the stack.

[REFERENCE LIST]

1

investor

2

feed

3

oscillating device

4

feed drum

5

pressure cylinder

6

form cylinder

7

applicator roll

8th

chambered doctor blade

9

dryer device

10

funding

11

deflecting

12

dryer system

13

Sheet holding system

14

sheet guiding device

15

Sheet turning unit

16

delivery unit

17

transfer cylinder

18

conveying direction

19

frame

I

first coating unit (for the sheet front side)

II

second coating unit (for the sheet front side)

III

first coating unit (for the back of the sheet)

IV

second coating unit (for the back of the sheet)

V

third coating unit (for the back of the sheet)

Claims (8)

1. A coating machine for the refining of print sheets with a feeder unit (1), at least one coating unit (I) arranged downstream for the front page of the print sheets, a sheet turner unit (15) arranged downstream, at least one coating unit (III) arranged downstream for the back page of the print sheets, wherein each coating unit (I, III) comprises a sheet-guiding impression cylinder (5), a form cylinder (6) and a dosing system (8) containing an application roller for a flow-capable substance and a dryer device (9) each with a dryer system (12), and a delivery unit (16) with dryer systems (12) arranged downstream, wherein in conveying direction (18) of the first coating unit (I) for the sheet front page the corresponding dryer device (9) is arranged immediately downstream, which comprises continuously circulating conveying means (10) with two reversing elements (11) and horizontally arranged strands and sheet holding systems (13) arranged at intervals, wherein at least one dryer system (12) is arranged above the sheet conveying plane parallel to the lower strand of the conveying means (10),
   wherein at least in the region of the dryer systems (12) below the sheet conveying plane a sheet guiding device (14) is arranged in parallel, and wherein a second coating unit (II) for the sheet front page is arranged immediately downstream of this corresponding dryer device (9) and the sheet turner unit (15) and at least the first coating unit (III) for the sheet back page follow this second coating unit (II) for the sheet front page.
2. The coating machine according to Claim 1, characterized in that in conveying direction (18) the first reversing element (11) is mounted in the frame (19) of each dryer device (9) and the second reversing element (11) is mounted in the frame of a coating (II, IV).
3. The coating machine according to at least Claim 1, characterized in that the reversing elements (11) have a same outer diameter.
4. The coating machine according to at least Claim 1, characterized in that the axis centre points of the reversing elements (11) are arranged in one plane.
5. The coating machine according to at least Claim 1, characterized in that the form cylinder (6) of the second coating device (II) for the sheet front page is a glazing cylinder.
6. The coating machine according to at least Claim 1, characterized in that in conveying direction (18) a dryer system (12) spaced from the print cylinder (5) is arranged downstream of the form cylinder (6) of the second coating unit (II) for the sheet front page.
7. The coating machine according to at least Claim 1, characterized in that the second coating unit (IV) for the sheet back page or the third coating unit (V) for the sheet back page comprises a device for perforating or punching or cutting or numbering or stamping or marking the print sheets.
8. The coating machine according to at least Claim 1, characterized in that each dryer device (9) comprises a pneumatically loadable sheet guiding device (14) whose guiding surface is functionally connected with a coolant system.

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