EP2995456A1 - Method for cleaning a rotating print-related surface in cylindrical form - Google Patents

Abstract

A method of cleaning a rotating surface (20) of a printing press cylinder or rotating surface (20) of a printing press roll or rotating surface (20) of a printing plate or transfer form disposed on a printing press cylinder within a printing couple, comprising the steps of: applying a liquid water based detergent (20); 19), which comprises at least 60% water and in the rest at least surfactants, on the surface to be cleaned (20) within the printing unit; Removing contaminants from the surface (20) to be cleaned within the printing unit with the aid of the detergent (19) and the cleaning device (1, 10); Removing the detached contaminants from the surface to be cleaned (20) within the printing unit at least by means of the cleaning device (1, 10).

Description

The invention relates to a method for cleaning a printing surface.

Printing units of an offset printing press have a forme cylinder, a transfer cylinder, an inking unit and preferably a dampening unit. On the form cylinder of such a printing unit at least one printing form is positioned, which may be formed as a printing plate, which is why forme cylinders are also referred to as a plate cylinder. On the transfer cylinder of such a printing unit at least one transfer mold is positioned, which may be formed as a blanket, which is why transfer cylinders are also referred to as rubber cylinders. The inking unit of such a printing unit is used for the application of printing ink and the optionally existing dampening unit of such a printing unit the application of dampening solution to the or each positioned on the form cylinder printing form. Starting from the or each printing form positioned on the forme cylinder, the printing ink is transferred via the or each transfer mold positioned on the transfer cylinder to a printing material to be printed, whereby the printing material to be printed is moved through a printing gap positioned between the transfer cylinder and an impression cylinder. The counter-pressure cylinder may be a satellite cylinder or else a transfer cylinder of another printing unit. During printing, a so-called blanket structure may form on the or each transfer form, which may consist of color residues and constituents of the printing material to be printed. Such a blanket structure affects the achievable print quality and can lead to web breaks when printing a web-shaped substrate. Therefore, it is known in the art to clean the or each transfer mold positioned on a transfer cylinder prior to the start of a new print production.

When printing high-quality printed products, such as when printing magazines or catalogs, a blanket wash can also be done during production. Here, a cleaning device is employed at full or reduced production speed to a rotating transfer cylinder and it is a detergent on the transfer cylinder, namely applied to the or each arranged on the transfer cylinder transfer form.

From the prior art, a variety of different cleaning devices for printing presses are known, which serve to clean a rotating cylindrical surface of a printing press cylinder or a printing press roll or a surface of a cylinder surface arranged on a printing plate or transfer mold, so which in particular a blanket washing can be performed. Such cleaning devices have a housing, wherein in the housing of such a cleaning device preferably more cleaning devices, namely a washing device and a separate drying device, are added. The washing device is used to wash the respective surface to be cleaned with the aid of a liquid detergent. The drying device serves to dry the cleaned surface.

From the US 3,309,993 A as well as from the US 4,015,307 A In each case such cleaning devices with a washing device and a drying device are known, which are received by a housing. Furthermore, it is known from this prior art that either the washing device or the drying device is set to the surface to be cleaned in order to solve in a first cleaning step on the washing device contaminants from the surface to be cleaned and transported away, and in a subsequent second Cleaning step to dry the cleaned surface.

To clean a rotating, printing-technical surface within a printing unit of a printing press, solvent-based, liquid detergents are used in practice. On the one hand, such highly solvent-containing detergents can attack the surface to be cleaned; furthermore, the handling of such highly solvent-containing detergents requires great care due to their potentially harmful potential.

On this basis, the present invention has the object to provide a novel method for cleaning a printing surface. This object is achieved by a method for cleaning a printing surface according to claim 1. The method according to the invention comprises at least the following steps: application of a liquid, water-based detergent which comprises at least 60% water and at least surfactants in the remainder, preferably to the surface to be cleaned within the printing unit with the aid of a cleaning device in contact with the surface to be cleaned; Removing impurities from the surface to be cleaned within the printing unit with the aid of the detergent and preferably also the application of the detergent to the cleaning surface to be cleaned; Removing the detached contaminants from the surface to be cleaned within the printing unit at least with the help of preferably also the application of the detergent serving cleaning device.

With the present invention, it is proposed for the first time to use a liquid, water-based detergent which has at least 60% water and at least surfactants in the rest for cleaning a printing-technical, rotating surface within a printing unit. On the one hand, such a detergent does not attack the surface to be cleaned; furthermore, such a water-based detergent does not represent a health hazard and environmental compatibility.

According to an advantageous development, a detergent is applied to the surface to be cleaned, which has at least 80% water and in the rest at least surfactants, wherein the same contains as surfactants exclusively non-ionic surfactants and / or anionic surfactants. The use of a detergent containing at least 80% of water is particularly preferred in order to avoid endangering the surfaces to be cleaned and endangering the health of press personnel.

According to an advantageous development, the water-based detergent before applying the detergent to the surface to be cleaned to a temperature between 30 ° C and 90 ° C, preferably to a temperature between 40 ° C and 80 ° C, more preferably to a temperature between 50 ° C and 70 ° C, heated. Then, when the water-based detergent is heated in this manner before application to the surface to be cleaned, particularly effective cleaning of the surface to be cleaned using a water-based detergent can be ensured.

According to an advantageous development, the water-based detergent is preferably sprayed onto the detergent serving for applying the detergent and applied over the preferably designed as a cleaning brush cleaning device on the surface to be cleaned, wherein the cleaning device at least when removing the impurities with a defined Linienanpresskraft against the surface to be cleaned is pressed, namely such that when cleaning a transfer mold the same deformed elastically in the range of their surface to be cleaned between 0.01 mm and 0.20 mm. This is a particularly advantageous cleaning of the surface to be cleaned using a water-based detergent possible. Then, when a transfer mold is cleaned by the method of the present invention, if the surface thereof is elastically deformed in the specified range, it can be cleaned particularly effectively using a water-based detergent.

Fig. 1:

einen Ausschnitt aus einer Reinigungsvorrichtung für eine Druckmaschine im Bereich einer als Reinigungsbürste ausgebildeten Reinigungseinrichtung der Reinigungsvorrichtung.

Preferred embodiments of the invention will become apparent from the dependent claims and the description below. Embodiments of the invention will be described, without being limited thereto, with reference to the drawings. Showing:

Fig. 1:

a section of a cleaning device for a printing machine in the area of a cleaning device designed as a cleaning brush cleaning device.

The invention relates to a method for cleaning a printing surface within a printing unit of a printing press. The method is used to clean a rotating cylindrical surface of a printing press cylinder or a printing press roll or to clean a surface of a printing plate or transfer mold arranged on a cylinder surface in the area of a printing unit or within a printing unit between two print jobs or even during production the same print job. Particularly preferably, the invention for cleaning a positioned on a transfer cylinder transfer mold, which may be formed, for example, as a blanket, blanket plate or blanket sleeve, use.

Fig. 1 shows a section of a cleaning device 1. The cleaning device 1 has a housing 30 in which a preferably designed as a cleaning brush 10 first cleaning device 10 or washing device and preferably further, a separate, not shown, second cleaning device or drying device is added. Such a separate drying device is preferred, but optional.

Alternatively, the cleaning device 10 can also be designed as a so-called not shown cloth system. In a so-called cloth system, instead of a cleaning brush, a cloth or fleece is used, which is unwound from a cloth roll designed as a neurole, pressed against the surface 20 to be cleaned via a pressure bar or pressing bar and thus brought into contact therewith. The soiled by the cleaning and / or drying process cloth section is here, for example, wound up again on a so-called dirt roll.

Alternatively, the cleaning cloth may also be used as a cover for a cleaning roller. It is unimportant whether the serving as a reference cleaning cloth has a closed shape and a body, which is preferably designed as a roller or whether the cleaning cloth has an open shape and is clamped on the Anpressleiste or Anpressbalken so that it is in contact with the To be cleaned surface 20 of a rotating body can withstand the friction forces occurring.

Then, when the cleaning device 1 comprises the washing device preferably designed as a cleaning brush 10 and further comprising a separate drying device, the same are preferably drivable starting from a common drive.

Then, when the cleaning device 1 comprises the washing device 10 formed as a cleaning device and further comprises a separate drying device, preferably only one of these devices is employed on the surface to be cleaned, in which case to ensure the alternate stopping or stopping of washing device and drying device to the cleaning surface, the housing 30, which receives these two devices, is pivotable about a pivot axis, not shown.

The cleaning device 1 is used to clean a rotating, printing-technical surface 20 in the region of a printing unit or within the printing unit of a printing press, preferably between two print jobs or during the production of a print job. To clean each surface 20 to be cleaned, a liquid, water-based detergent 19, which is kept ready in a storage container 18, can be applied to the surface 20 to be cleaned. The liquid, water-based detergent 19 is preferably applied to the surface 20 to be cleaned with the aid of the cleaning device 10 of the cleaning device 1, which is preferably designed as a cleaning brush 10. The liquid, water-based detergent 19 is removed in an advantageous embodiment for this purpose from the reservoir 18 and sprayed by means of a spray device 11 on the cleaning brush 10, which then when rolling on the surface to be cleaned 20, the water-based detergent 19 to be cleaned, rotating surface 20 applies.

Alternatively or additionally, the liquid, water-based detergent 19 can also be applied directly to the surface 20 to be cleaned, for example by direct spraying by means of the spraying device 11.

With the aid of the water-based detergent 19 applied to the surface 20, and preferably with the aid of the cleaning roller 10 rolling on the surface, it is possible to remove impurities from the surface 20 to be cleaned, the removed impurities from the surface 20 to be cleaned being at least applied by means of the application detergent cleaning brush 10 are removed from the surface 20 to be cleaned.

The water-based detergent thereby dissolves the contaminants by adhesion and cohesion effects of the surface 20 to be cleaned.

Then, when the cleaning device 1 comprises the cleaning brush 10 and further comprising a separate drying device, the cleaning brush 10 is preferably used the application of the liquid, water-based detergent 19, the removal of the impurities from the surface to be cleaned 20 and the partial or complete removal of the detached contaminants from the surface to be cleaned 20. The drying device is then optionally still the removal of the remaining impurities of the to be cleaned Surface 20 and at least the drying of the same.

Then, if the cleaning device 1 in addition to the cleaning brush 10 has no separate drying device, the cleaning brush 10 is the complete removal of the detached impurities and subsequent drying of the surface to be cleaned 20. When drying the surface to be cleaned 20 is no further detergent 19 on the cleaning brush 10 applied to the surface 20 to be cleaned.

As stated above, it is within the meaning of the present invention to apply a liquid, water-based detergent 19 to the printing-technical, rotating surface 20 to be cleaned within the printing unit, wherein the water-based detergent 19 at least 60% water, preferably at least 80% water, and at least surfactants in the remainder. As surfactants, the detergent 19 comprises exclusively nonionic surfactants and / or anionic surfactants.

It is particularly preferable to use a water-based detergent 19 which has at least 80% water, 10% to 19% surfactants and 1% to 10% solvent.

As the solvent, for example, glycol ether or a polar ester oil can be used.

The pH of the detergent used is preferably between 7 and 13, preferably between 8 and 12, particularly preferably between 10 and 11.

Preferably, a water-based detergent is used, which is sold by the company Schwegmann under the product name "SCHWEGO aqua clean", especially the detergent "SCHWEGO aqua clean CC 23".

According to an advantageous development of the present invention, the liquid detergent 19 is heated prior to application to the surface to be cleaned, namely before the spraying of the same via the spraying device 11 on the cleaning brush 10 and / or before direct spraying onto the surface to be cleaned, namely with the help of in Fig. 1 The heating means 19 is heated to a temperature between 30 ° C and 90 ° C, preferably to a temperature between 40 ° C and 80 ° C, more preferably at a temperature between 50 ° C and 70 ° C.

The spraying of the heated, liquid detergent 19 on the cleaning brush 10 by means of the spray device 11 is preferably carried out at a pressure between 1 bar and 5 bar.

When cleaning the surface to be cleaned 20, namely when applying the detergent 19 to the surface to be cleaned 20, when removing the impurities and the removal of impurities not only the surface to be cleaned 20 in the direction of arrow 21 is rotationally driven, but also beyond the washing brush 10 in the direction of the arrow 16. The speed of the washing brush 10 is preferably between 100 U / min and 500 U / min. In addition to this rotational movement, the washing brush 10 leads in the direction of Seen longitudinal axis 15, preferably, but not necessarily, a traversing movement.

The cleaning brush 10 is a brush which has a base body 13 and a bristle trim 14 carried by the base body 13, wherein the bristles of the bristle trim 14 are preferably made of plastic and have a thickness between 0.10 mm and 0.20 mm , However, other bristles may be used.

When cleaning the surface to be cleaned 20, namely at least when removing the impurities from the surface 10 to be cleaned and preferably also when applying the liquid, water-based detergent and removing the detached impurities, the cleaning brush 10 with a defined line pressing force 12 against the to be cleaned Surface 20 is pressed, namely such that when cleaning a transfer mold the same elastically deformed in the range of their surface to be cleaned between 0.01 mm and 0.20 mm. For this purpose, the cleaning brush 10 is preferably pressed with a Linienanpresskraft 12 between 0.5 N / mm and 10 N / mm against the surface to be cleaned 20 of the transfer mold. The degree of elastic deformation of the transfer mold also depends on such a line contact force whether the transfer mold is a conventional blanket, a metal back blanket or a transfer sleeve.

By using a water-based detergent 19, surfaces to be cleaned 20, in particular a surface of a transfer mold to be cleaned, within a printing press, namely within a printing unit, can be cleaned effectively and gently. Preferably, the water-based detergent 19 is heated before being applied to the surface 20 to be cleaned, wherein the cleaning brush 10, the application of the detergent 19 to the surface 20 to be cleaned and the detachment and at least partially Removing impurities serves, is pressed with a defined line pressing force 12 against the surface 20 to be cleaned.

LIST OF REFERENCE NUMBERS

1

cleaning device

10

cleaning device

11

spraying

12

contact force

13

body

14

brush border

15

longitudinal axis

16

rotary motion

17

heater

18

reservoir

19

laundry detergent

20

surface

21

rotary motion

30

casing

Claims (11)

A method of cleaning a rotating surface of a printing press cylinder or a rotating surface of a printing press roll or a rotating surface of a printing form or transfer form disposed on a printing press cylinder within a printing couple, comprising the steps of: Applying a liquid, water-based detergent (19) which comprises at least 60% water and in the rest at least surfactants, on the surface to be cleaned (20) within the printing unit; Removing contaminants from the surface (20) to be cleaned within the printing unit with the aid of the detergent (19) and a cleaning device (10); Removing the detached contaminants from the surface to be cleaned (20) within the printing unit at least with the aid of the cleaning device (10). A method according to claim 1, characterized in that a detergent (19) which has at least 80% water and in the rest at least surfactants, is applied to the surface to be cleaned (20) within the printing unit. A method according to claim 2, characterized in that a detergent (19) comprising at least 80% water, 10% -19% surfactants and 1% to 10% solvent, is applied to the surface to be cleaned (20) within the printing unit. Method according to one of claims 1 to 3, characterized in that within the printing unit, a detergent (19) to be cleaned Surface (20) is applied, which has as surfactants exclusively non-ionic surfactants and / or anionic surfactants. Method according to one of claims 1 to 4, characterized in that the liquid, water-based detergent (19) by means of the cleaning device (10) is applied, which is in contact with the surface to be cleaned, in particular rolls on the surface to be cleaned. A method according to claim 5, characterized in that the detergent (19) is sprayed onto the cleaning device (10) serving to apply the detergent (19) and applied to the surface (20) to be cleaned by the cleaning device (10) designed as a cleaning brush. Method according to one of claims 1 to 6, characterized in that the cleaning device (10) is pressed against the surface to be cleaned (20), at least during the removal of the contaminants with a defined line contact force, namely such that when cleaning a transfer mold the same in Area of their surface to be cleaned elastically deformed between 0.01 mm and 0.2 mm. A method according to claim 7, characterized in that for this purpose the cleaning device (10) with a line contact force (12) between 0.5 N / mm and 10 N / mm presses against the surface to be cleaned (20) of the transfer mold. Method according to one of claims 1 to 8, characterized in that the detergent (19) is heated to a temperature between 30 ° C and 90 ° C before applying the detergent to the surface to be cleaned (20). A method according to claim 9, characterized in that the detergent (19) is heated to a temperature between 40 ° C and 80 ° C. A method according to claim 10, characterized in that the detergent (19) is heated to a temperature between 50 ° C and 70 ° C.

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