DE20020703U1 - Painting device for a rotary printing machine - Google Patents

Description

[Utility model application]

MAN Roland Printing Machines AG Mühlheimer Strasse 341
63075 Offenbach
5

[Name of the invention] Coating device for a rotary printing machine

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[Description]

The invention relates to a varnishing device for a rotary printing press, in particular a sheet-fed printing press, according to the preamble of claims 1 and 2. 5

[State of the art]

A varnishing device of this type is known from DE 197 29 977 A1 as an offset printing unit for varnishing printing materials in a rotary printing machine. In this varnishing device, the plate cylinder carries either a planographic printing form with an elastic surface or a flexible letterpress form. A dosing system is assigned to the plate cylinder, which has a screened form roller arranged in the area of the bearings of the dampening form roller that can be exchanged (for the dampening form roller), with a chamber doctor blade assigned to the form roller. During varnishing, the inking unit with its ink form rollers is separated from the plate cylinder. It is advantageous if the printing form that can be fixed on the plate cylinder is fed and removed by means of an automated plate clamping and changing device.

Another coating device for a rotary printing machine is known from EP 0 620 115 A1. At least two coating units are provided for in-line coating of printing materials. The first coating unit, which is arranged upstream in the direction of conveyance of the printing material, is designed as a flexographic printing unit with a forme cylinder carrying a flexible letterpress forme, which is in contact with a printing cylinder guiding the printing material, a screened application roller, which in turn is in contact with the forme cylinder, and an adjustable chamber doctor blade. The second coating unit arranged downstream is designed as a conventional coating unit and can be used specifically for full-surface coating.

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In the printing industry, flexible rubber blankets are stretched over the forme cylinder for full-surface varnishing. Such rubber blankets have an improved damping function and are less expensive than varnish plates and correspond to the rubber blankets used on blanket cylinders of offset printing units.

From DE 196 13 119 Al a bearing is known for a coating tower of a sheet-fed rotary printing machine with a sheet guide cylinder.

.10 coating cylinder with an application unit is known, whereby the coating cylinder is designed as a printing form cylinder with a plate tension arranged in the printing units of sheet-fed offset printing machines. In addition, a plate changing device for the coating plates is assigned to the coating cylinder.

The disadvantage of using rubber blankets in rotary printing machines is that tensioning a rubber blanket is very complex and therefore requires long set-up times. Another disadvantage of using varnish plates is that they do not have enough dampening properties and the varnish plates are more expensive than rubber blankets.

[Task of the invention]

The invention is based on the object of creating a painting device of the type described above, which in particular has a structure which enables a reduction in set-up time and is universally applicable.

The problem is solved by the training features of claims 1 and 2. Further developments arise from the dependent claims.

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A first advantage of the coating device is that this device is suitable for processing different types of varnish, such as printing varnish, aqueous dispersion varnish, UV varnish, blister varnish, or even special inks such as metallic printing inks or flexographic printing inks.

It is also advantageous that the varnishing device can be used in an offset printing unit and/or in a varnishing unit. This device can be operated in an offset printing unit in indirect printing and in a varnishing unit in direct printing.

In indirect printing, the offset printing unit consists, in a manner known per se, of at least one printing cylinder that guides the printing material, a blanket cylinder and a plate cylinder, with at least one inking unit being assigned to the plate cylinder. This design is suitable for waterless or dampening solution-free offset printing (dry offset). For wet offset printing, a dampening unit is arranged upstream of the inking unit in the direction of rotation of the plate cylinder.

In direct printing, the coating unit consists of at least one printing cylinder that guides the printing material, a forme cylinder and a dosing system with at least one application roller.

In an offset printing unit, a layered body is fixed to the plate cylinder in indirect printing (with a downstream blanket cylinder) and in a varnishing unit, the layered body is fixed to the forme cylinder in direct printing.

It is also advantageous that the plate cylinders in offset printing units and/or the forme cylinders in coating units are each assigned a plate changing device, so that a change

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the laminated body can be realized automatically in every printing/coating unit.

A further advantage is that the laminated body consists of a flexible carrier layer, a compressible layer arranged on the carrier layer, preferably a rubber layer, and a rubber blanket covering layer arranged on the layer. The laminated body has flat, interconnected layers which, when stretched out, are curved to fit the cylinder.

A laminated body has (compared to lacquered plates) improved damping properties, for example in the case of a channel impact, and can be used universally for full-surface or recessed lacquering (spot lacquering). With recessed lacquering, it is advantageous that at least the rubber blanket covering layer of the laminated body can be stripped (partial removal of the rubber blanket covering layer for recessed lacquering).

It is also advantageous that the plate clamping devices for both plate cylinders and forme cylinders are of uniform design and can preferably be adjusted to a uniform thickness of the printing forms to be clamped, i.e. the thickness of the carrier layer of the laminated body corresponds to the thickness of an offset printing plate.

[Examples]

The invention will be explained in more detail using an embodiment. The following schematically show:

Fig. 1 a printing press with offset printing units

and paint works,

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Fig. 2 a varnishing device for an offset printing unit,
5

Fig. 3 a painting device for a painting plant,

Fig. 4 a laminated body in construction.

A rotary printing machine, for example a sheet-fed printing machine, with several offset printing units 1 is designed in a series construction, with a first varnishing unit 2 and a second varnishing unit 3 being arranged downstream of the offset printing units 1 in the conveying direction of the sheet-shaped printing material. A dryer system 4 is arranged between the varnishing units 2, 3 for drying the printing materials to be processed. A delivery unit 5 is arranged downstream of the second varnishing unit 3, which is formed, among other things, by the circulating conveyor systems 7, which transport the sheet-shaped printing material onto a delivery stack 6 and deposit it.

An offset printing unit 1 essentially consists of a plate cylinder 8, a blanket cylinder 9 and a printing cylinder 11 as a sheet guide cylinder. An inking unit 15 with a roller train and ink application rollers 16 is assigned to the plate cylinder 8; if necessary, a dampening unit is also adjacent to the plate cylinder 8, which will not be discussed further here. Between the printing units 1, the varnishing units 2, 3 and the drying system 4, a transfer cylinder 10 is arranged for transporting the printing materials.

The coating unit 2 consists of a printing cylinder 11, a printing gap (coating gap) forming with the printing cylinder 11

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Form cylinder 12, which carries a layer body 17, and a first dosing system 13. In the present example, the first dosing system 13 is formed by a screened application roller that can be brought into contact with the form cylinder 12 and a chamber doctor blade that is functionally connected to this application roller. Alternatively, dosing systems can also be used as two-roller systems with a paint supply fed into the common roller gap from above (squeeze roller principle) or roller systems with a scoop roller that dips into a storage container (scoop/dip roller principle).

The second varnishing unit 3 consists of the printing cylinder 11, a forme cylinder 12 which forms the printing gap (varnishing gap) with it, which has a layer body 17 and a second metering system 14. The second metering system 14 is designed as a two-roller unit (squeeze roller principle) by means of an applicator roller and a metering roller, for example. Alternatively, chamber doctor systems with a screened applicator roller or roller units based on the scoop/dip roller principle can also be used here.

The dosing systems 13, 14 can each be coupled to a separately controllable circuit for the circulation of coating liquids.

The varnishing device for an offset printing unit of a rotary printing machine has plate clamping devices 24 on the circumference of the plate cylinder 1 for fixing the layer body 17. The layer body 17 is flexible and consists of a carrier layer 18 that can be fixed in the plate clamping devices 24 of the plate cylinder 8. A compressible layer 19, preferably a rubber layer, is fixedly arranged on the carrier layer 18. A fixed rubber blanket cover layer is fixed on this compressible layer 19.

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20. The rubber blanket cover layer 20 is functionally connected to the adjacent rubber blanket cylinder 9 of the offset printing unit 1.

The coating device for a coating unit 2 and/or 3 of a rotary printing press has plate clamping devices 24 on the circumference of the forme cylinder 12 for fixing the layer body 17. This layer body 17 is flexible and is constructed analogously to the layer body 17 in the offset printing unit 1 with a carrier layer 18, a compressible layer 19, preferably a rubber layer, and a rubber blanket cover layer 20. The carrier layer 18 is fastened in the plate clamping devices 24 of the forme cylinder 12 and the rubber blanket cover layer 20 is in functional connection with the adjacent printing cylinder 11 which guides the printing material.

Preferably, the carrier layer 18 is a metallic material or at least the carrier layer 18 contains a metallic material. Such metallic materials are in particular steel or aluminum. Alternatively, plastic materials can be used as the carrier layer 18. The layer body 17 is flexible and the carrier layer 18 in particular is dimensionally stable.

The compressible layer 19 preferably has air inclusions and/or closed air channels to increase the damping function.

Preferably, the layered body 17 can be stripped at least at the rubber blanket covering layer 20. The layered body 17 can therefore also be used for recessed varnishing (spot varnishing). In the stripped area of the rubber blanket covering layer 20, the compressible layer 19 underneath is arranged recessed to the level of the rubber blanket covering layer 20 and is therefore not a varnish carrier.

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Claims (9)

1. Varnishing device for a rotary printing machine with a printing cylinder, a rubber blanket cylinder and a plate cylinder with at least one associated inking unit, wherein the inking rollers of the inking unit can be turned on and off relative to the plate cylinder, characterized in that plate clamping devices ( 24 ) are arranged on the circumference of the plate cylinder ( 1 ) for fixing a laminated body ( 17 ) and that this laminated body ( 17 ) is bendable and has a carrier layer ( 18 ) that can be fixed in the plate clamping devices ( 24 ) and at least one fixed compressible layer ( 19 ) arranged on the carrier layer ( 18 ) and a fixed rubber blanket cover layer ( 20 ) arranged on this layer ( 19 ), wherein the rubber blanket cover layer ( 20 ) is functionally connected to the adjacent rubber blanket cylinder ( 9 ). 2. Coating device for a rotary printing machine with a printing cylinder, a forme cylinder and a dosing system with at least one applicator roller assigned to the forme cylinder, characterized in that plate clamping devices ( 24 ) are arranged on the circumference of the forme cylinder ( 12 ) for fixing a layered body ( 17 ) and that this layered body ( 17 ) is bendable and a carrier layer ( 18 ) fixable in the plate clamping devices ( 24 ) and at least one fixed compressible layer ( 19) arranged on the carrier layer (18 ) and a fixed blanket cover layer ( 20 ) arranged on this layer ( 19 ) are in functional connection with the adjacent printing cylinder ( 13 ) guiding a printing material. 3. Painting device according to claim 1 or 2, characterized in that the carrier layer ( 18 ) is a metallic material or at least contains a metallic material. 4. Painting device according to claim 3, characterized in that the metallic material of the carrier layer ( 18 ) is an aluminum material. 5. Painting device according to at least claim 1 or 2, characterized in that the compressible layer ( 19 ) is a rubber layer and has air inclusions or air channels. 6. Painting device according to at least claim 1 or 2, characterized in that at least the rubber blanket cover layer ( 20 ) is strippable. 7. Painting device according to at least claims 1 and 2, characterized in that the compressible rubber layer ( 19 ) is vulcanized onto the carrier layer ( 18 ). 8. Coating device according to claim 1, characterized in that a plate changing device ( 23 ) is assigned adjacent to the plate cylinder ( 8 ). 9. Painting device according to claim 2, characterized in that a plate changing device ( 23 ) is assigned adjacent to the forme cylinder ( 12 ).