EP1442884B1 - Method for stably guiding a partial width web in a printing unit of a printing press - Google Patents

Description

The invention relates to a method for a stable machine operation on printing units of a rotary printing machine for the operation with partially wide printing material according to claim 1.

Out US 5,046,416 is known a printing unit, which is associated with a Farbreduzierwerk. This color reducer scans unwanted ink from a color-leading cylinder in the print engine. To facilitate the doctoring, a solvent can additionally be applied with a spray device.

From the WO 02058931 A2 is a device for improving the printing process, for example, in production with part-width paper webs known, applied to the non-printing areas of the rollers of the inking unit, in particular on the two ends of these rollers, the ink dissolving or decomposing solvent or applied dropwise to the At the ends of the rollers applied and accumulated ink to prevent loss of solvent and thus a resulting drying and sticking of the ink.

The disadvantage is that the solvent applied to the rollers or in the edge region of the rollers cums with time and with increasing speed and contaminates the printing press. In addition, drying problems can occur at the edge of the paper web, as a result, a greasing in the dryer or depositing and / or marking in the folding structure or folder can occur.

The invention has the object to eliminate the above-mentioned disadvantages and to provide a method for a stable machine operation on printing units of an offset rotary printing press for the operation with varying and partially wide substrate, by means of which drying out of the ink at the non-printing areas of the rollers and cylinders Pressure unit is prevented and thus the stickiness - the so-called tack - is kept at a low level to reduce the risk of web breaks, and to reduce the burden of the rollers and blankets (sleeves).

This object is solved by the features in the characterizing part of patent claim 1.

Advantageous embodiments of the invention are described in the dependent claims in conjunction with the description.

It is significant that by means of the method, a non-flowing medium, such as a commercial roller paste or a roller grease, is finely distributed to the non-printing areas of a cylinder or a roller in the inking or dampening unit by means of blown air.
The non-flowing medium adheres to the surface of the cylinder or roller and prevents the paint from drying out and accumulating.

Via a pump system with distributor unit, the non-flowing medium is finely distributed to the surface, ie to the non-printing areas, the cylinder or the roller in the inking or dampening unit by means of compressed air. The non-flowing medium can be applied for example by means of a metering on the rider roll, such as a ceramic rider roll, or at any other incoming nip. By splitting operations, the non-flowing medium is distributed at the non-printing areas in the entire inking unit or in the entire roller mill.
When operating with partially wide web color accumulates at the non-printing zones.

Therefore, in addition to the non-printing areas of the rider roll doctor units can be adjusted to remove the adhering in the course of the printing process and accumulating mixture of ink and non-flowing medium. Due to the axial movement of the rubbing cylinder in an inking unit, the ink has the characteristic during the printing process to migrate outward on the individual rollers and / or cylinders and build up on the rollers. Of the On the one hand, color build-up causes the machine to be sprayed and dirty, on the other hand, the color build-up causes higher wear of the rollers and blankets and reduces their service life.
With the doctor units, it is now possible to produce a color flow by the doctor unit decreases the color of the rider roll and feeds the paint collector. By moving the squeegees on their receiving unit axially, or arranges in a certain way, can also make color separations on the roller or adjustments to narrower substrates.
On the one hand, the squeegees determine the track edge of the colored strip. But since several doctor blades can be arranged close to each other, the entire remaining color-free range can be covered, so that will certainly prevent spreading of the color beyond the track edge even with prolonged printing duration. But you can also adjust the width of the individual squeegee the width of the color-free zone, the squeegees of different widths are arranged interchangeable.

The operation of the doctor blade units takes place from the control desk. For example, after a time cycle that can be set on the control console, the ink / protective medium mixture is removed by the doctor blade device, for example, from the rider roll or other rollers and / or cylinders, wherein both the setting and setting time can be freely selected depending on the production requirements. After each setting or Abrakelvorgang fresh non-flowing protective medium, such as roller paste, is applied with a short time delay and the cycle begins again.
The doctor blades are switched on and off by means of a pneumatic cylinder, wherein the contact pressure of the doctor blade on the rider roll is adjustable. The squeegee must be evenly but only slightly adjusted to avoid excessive wear.

By automated dosing of roller paste in the edge areas of the inking unit or the printing unit, especially for partial width productions Reduced load on the rubber cylinder sleeve, blanket and ink rollers.
Depending on the width of the printing material correspondingly many doctor blades are to be attached.
The ink / protective medium mixture removed by the doctor blade is collected in a paint trough which is arranged below the doctor blade. This must be emptied from time to time.

At least two lubrication points are provided on a printing unit in order to be able to apply the non-flowing medium to the non-printing areas.

Fig. 1

Offsetrotationsdruckmaschine mit Vorrichtung für einen stabilen Maschinenlauf zur Produktion mit teilbreitem Bedruckstoff,

Fig. 2

Seitenansicht einer Druckeinheit der Offsetrotationsdruckmaschine nach Fig. 1,

Fig. 3

eine Dosiereinheit,

Fig. 4

eine Dosiereinheit und

Fig. 5

eine Vorrichtung für einen stabilen Maschinenlauf nach Fig. 2.

The invention will be explained in more detail below using an exemplary embodiment and with reference to the figures. It shows very schematically:

Fig. 1

Offsetting rotary printing machine with a device for a stable machine run for the production with part wide printing material,

Fig. 2

Side view of a printing unit of the offset rotary printing machine according to Fig. 1 .

Fig. 3

a dosing unit,

Fig. 4

a dosing unit and

Fig. 5

a device for a stable machine after Fig. 2 ,

The Fig. 1 shows an offset rotary printing machine 1 consisting of four printing units 2 to 5, wherein the printing units 2 to 5 can print a substrate 6, for example, both sides. The in Fig. 1 shown printing material 6 does not draw on the total printing width 8 of individual rollers 9 and cylinder 10 of the printing units 2 to 5, so that at the respective edge zones of the rollers 9 and cylinder 10 non-printing areas 11 and 12 arise. The printing units 2 to 5 thus print a part-width printing material 6. At the non-printing areas 11 and 12 metering nozzles 13 are arranged, by means of which, with the aid of blowing air, a non-flowing protective medium 14 on the surface. the respective rollers 9 and / or cylinder 10 is applied finely distributed. The protective medium 14 is in the viscosity range of about 300 to 400 dPa * s.

Fig. 2 shows one of the printing units 2 to 5, wherein the printing material 6 is passed between two transfer cylinders 15, 16 and printed on both sides. The transfer cylinders 15, 16 are connected to the form cylinders 17, 18 in connection, wherein the forme cylinder 17, 18 are supplied by built-up of several rolls color 19, 20 and dampening units 21, 22 with printing ink and dampening solution. On at least one of the rollers of the ink 19, 20 and / or dampening 21, 22 and / or on one of the cylinders 15 to 18 is at its non-printing areas 11, 12, a doctor unit 23 on and off.
For example, as in Fig. 2 shown, the doctor unit 23 on a rider roller 24 of the inking and dampening roller train on and off. The metering nozzles 13 are arranged, for example, on the rider roll 24 and / or on an incoming gap 40 between a transfer roll 7 and the rider roll 24, or at any incoming nip. By cleavage operations, the non-flowing protective medium 14 is distributed to the non-printing areas 11,12 throughout the inking unit 19, 20 or in the entire roller mill according to the width of the non-printing area 11,12. The metering nozzles 13 can be positioned according to the width of the non-printing area 11,12 and / or activated accordingly, wherein a plurality of metering nozzles 13 can be arranged on the non-printing areas 11, 12 and by means of a computer and / or control unit, by means of the control station or can be controlled, activated and / or positioned by means of the machine control. The metering nozzles 13 are supplied, for example, by a pump system 25 with distributor unit 26 with the protective medium 14. In this case, the control or regulation of the dosing and application duration of protective medium 14, not shown in detail, by means of the control station or the machine control, taking into account the general operating conditions, in particular Substrate width, machine speed, length of the print job and temperatures in the roll mill and in the cylinder group, the application of the protective medium and / or the doctoring of the mixture of protective medium and ink is controlled.
An offset rotary printing machine 1, not shown in detail, can be equipped with a plurality of pump systems 25 for different printing units 2 to 5 and / or for different printing inks to be processed by means of the printing units 2 to 5.

The doctor unit 23 according to the invention (see Fig. 5 ), for example consisting of one or more doctor blades 27 and a rotating body, not shown, extends parallel to the rider roll 24 and is adjustable against this, wherein the doctor unit 23 is capable of, located on the rider roll 24 mixture of ink and not remove the flowing protective medium 14.
Against the lateral surface of the rotatable against the rider roll 24 or against the lateral surface of the rider roll 24 one or more doctor blades 27 are employed. These doctor blades 27 are fastened by means of a clamping unit 28 to a rod 29 whose axis is also parallel to the rider roll 24. The mixture of printing ink and non-flowing protective medium 14, which has been removed from the lateral surface with the squeegee 27, is transferred to a collecting container 30 arranged below the squeegee 27.
By axially displacing the doctor blades 27 on the rod 29, or arranging them in a specific manner, adjustments to the respective width of the printing materials 6 can also be made.
It is also possible to adapt the width of the individual squeegees 27 to the width of the non-printing regions 11, 12, with the squeegees 27 of different width being arranged to be exchangeable.
The doctor unit 23 is mounted in lever arms 31, which are connected to a pressure-medium-operated cylinder 32, by means of this cylinder 32, the doctor unit 23 on the rider roll 24 on and off.

Fig. 3 shows a metering unit 33, which consists of a pneumatically actuated valve 34, whereby in a defined time protective medium is metered into a blast air line 35. The protective medium 14 is conveyed by means of the pump system 25 via the distributor unit 26 and lines 38, 39 to the metering valve 34. While the Blasluftleitung 35 is acted upon, a small amount of protective medium 14 is passed into the Blasluftstrom 37. Due to the strong Ausblasströmung the protective medium 14 is divided and applied by the metering nozzles 13 finely distributed on the surface of the respective roller 9 and / or cylinder 10.

Fig. 4 shows a further metering unit 33 ', which consists of at least two pneumatically actuated valves 34', 41, wherein between the first valve 34 'and the second valve 41, a chamber 36 for metering the protective medium 14 is formed. The protective medium 14 is conveyed by means of the pump system 25 'via the distributor unit 26' and lines 38 ', 39' in the chamber 36, wherein the first valve 34 'is opened and the second valve 41 remains closed. After a corresponding period of time, the chamber 36 is completely or depending on the amount conveyed partially filled with protective medium 14, wherein the first valve 34 'is closed. To blow out the dosed in the chamber 36 protective medium 14, the second valve 41 is first opened and the first valve 34 'is supplied with blown air 37'. For example, the blown air 37 ', which penetrates into the chamber 36 in a pulsed or jerky manner, blows out the metered protective medium 14, whereby it is applied in a finely distributed manner on the surface of the respective roller 9 and / or cylinder 10 by the metering nozzles 13'.

The device is not intended to be limited to use only on offset rotary presses, especially sheetfed or web offset rotary presses. The device can also be used on rotary high-pressure machines, for example flexographic printing presses, or rotogravure presses.

Reference numerals:

1

Offset rotary printing press

2

printing unit

3

printing unit

4

printing unit

5

printing unit

6

substrate

7

Transfer roll

8th

Total printing width

9

roller

10

cylinder

11

Non-printing area

12

Non-printing area

13

dispensing nozzle

14

protective medium

15

transfer cylinder

16

transfer cylinder

17

form cylinder

18

form cylinder

19

inking

20

inking

21

dampening

22

dampening

23

squeegee unit

24

riding roller

25, 25 '

pump system

26, 26 '

distribution unit

27

doctor

28

clamping unit

29

pole

30

receptacle

31

lever arm

32

Fluid-operated cylinder

33, 33 '

dosing

34, 34 '

Valve

35

blast air

36

chamber

37, 37 '

Air flow / blown air

38, 38 '

management

39, 39 '

management

40

Incoming gap

41

Valve

Claims (9)

1. Method for a stable machine run on printing units (2 to 5) of a rotary printing machine (1), in particular an offset rotary printing machine, for operation with part-width printing material (6), wherein a medium is applied to non-printing regions, characterised in that a non-flowing protective medium (14) is applied to the non-printing regions (11, 12) of at least one roller (9) of an inking unit (19, 20) or dampening unit (21, 22) and/or to the non-printing regions (11, 12) of at least one transfer cylinder (15, 16) or forme cylinder (17, 18) by means of blast air (37) through a metering nozzle (13) in a finely distributed manner with formation of a thin-layer protective film.
2. Method according to claim 1, characterised in that in the case of a printing unit (2 to 5) having an inking unit (19, 20) and dampening unit (21, 22) with a rider roller (24) and transfer roller (7) with respect to the non-printing regions of the rider roller (24) there is arranged at least one doctor unit (23) that can be thrown on and off, whereby if necessary a mixture of protective medium (14) and printing ink can be removed from the non-printing regions (11, 12) of the rider roller (24).
3. Method according to claim 2, characterised in that the protective medium (14) is applied to the rider roller (24) and to the transfer roller (7).
4. Method according to claim 3, characterised in that the metering nozzle (13) is arranged in the inflow nip (40) of the transfer roller (7) and rider roller (24).
5. Method according to one of claims 1 to 4, characterised in that provided for the supply of the metering nozzle (13) there is a metering unit (33) which consists of a pneumatically actuated valve (34), as a result of which the protective medium (14) is metered into a blast-air line (35) in a defined time.
6. Method according to one of claims 1 to 4, characterised in that provided for the supply of the metering nozzle (13') there is a metering unit (33') consisting of at least two pneumatically actuatable valves (34', 41), wherein a chamber (36) for metering the protective medium (14) is formed between the first valve (34') and the second valve (41), and the protective medium (14) is conveyed into this chamber (36).
7. Method according to one of claims 1 to 6, characterised in that the protective medium (14) is a grease, an oil, an ink, a wetting paste or a roller paste and lies in a viscosity range between 300 to 400 dPa*s.
8. Method according to claim 2, characterised in that the time sequence and the sequence of motions of throwing the doctor units (23) on and off and the application of the protective medium (14) are controlled by a computing and/or control unit.
9. Method according to claim 8, characterised in that the application of the protective medium (14) and/or the doctoring of the mixture of protective medium (14) and printing ink are/is controlled by the computing and/or control unit in consideration of the general operating states, in particular printing-material width, running speed of the machine, length of the print-application and temperatures in the roller frame and in the cylinder group.

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