DE20002557U1 - Press fluid supply cabinet - Google Patents

Description

Baldwin Grafotec GmbH

G 1642 EN 31.01.2000

Printing machine fluid supply cabinet

The invention relates to a printing press fluid supply cabinet according to the preamble of claim 1.

Fountain water preparation devices for fountain water offset printing are known from EP 0 602 312 A1 and EP 0 711 661 B1. They are usually designed as an equipment cabinet.

Furthermore, there are printing machine cleaning devices for the automatic wet cleaning of surfaces of rotating cylinders of a wet water offset printing machine and/or a printing web running through such a printing machine, containing a water supply device for the automatic supply of cleaning water for the wet cleaning of the surface to be cleaned.

A printing machine cleaning device of this type is known from US 43 44 361. The known cleaning device contains a washing cloth transport device, by means of which a washing cloth can be transported from a clean cloth spindle via a pressing device for pressing a cloth section against the surface to be cleaned onto a dirty cloth spindle. A water supply device consists of a

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G 1642 EN -2- 31.01.2000

A large number of nozzles that can be connected to a tap water network and spray tap water via nozzles onto a section of the washcloth between the cleaning cloth spindle and the pressing device on the side of the washcloth on which the pressing device is also located. This is the side of the cloth facing away from the surface to be cleaned. The washcloth is in a dry state on the cleaning cloth roll.

It is also known from practice that instead of spraying tap water onto the washcloth, a wet washcloth soaked in wet detergent can be stored wound up on the cleaning cloth spindle. This is used in particular to clean the rubber blanket cylinders of offset printing machines. The washcloth is moistened by the washcloth supplier, who delivers the wet washcloth on a roll. For delivery and storage, before and after delivery, the washcloth roll must be packed airtight so that the wet detergent does not evaporate.

In practice, it has been shown that the damp washing cloth soaked in detergent is very good at removing grease and ink from printing press cylinders, in particular from a blanket cylinder of an offset printing press, but is not suitable for removing paper dust from a blanket cylinder or from other cylinders of a printing press or directly from the printing web. The printing web is normally a paper web, but can also consist of other materials or material mixtures, for example recycled paper and recycled plastic or only contain recycled plastic and other additives, or consist of a plastic film or the like.

Wetting a washcloth roll with water or a water solution in addition to detergent would make the washcloth roll very heavy.

G 1642 EN -3- 31.01.2000

Furthermore, water stored in the washcloth evaporates much faster than moist detergent contained in the washcloth, especially if the washcloth is installed in the cleaning device and is therefore exposed, but is not used for several hours, days or weeks and dries out during this time.

Paper dust is not only found on paper webs, but is also transferred from these to the cylinders of the printing press, where it can form paper dust crusts, sometimes mixed with printing inks and printing ink oil.

The invention is intended to solve the problem of creating a structurally simpler and more cost-effective way of supplying an offset printing machine with dampening water for dampening water offset printing and cleaning water.

This object is achieved according to the invention by the characterizing features of claim 1.

Accordingly, the cleaning water supply device is combined with a dampening water treatment device of the printing press in order to obtain cleaning water therefrom.

The invention has several advantages: The printing press cleaning device does not need its own tap water supply from a house pipe system, but receives the cleaning water via a short route from the dampening water preparation device located near the cleaning device on the printing press. The cleaning water can be taken from the fresh water supply line of the dampening water preparation device

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G 1642 EN -4- 31.01.2000

either before or after a decalcifier that may be included in the fresh water supply line to descale the water. Another possibility is to take the cleaning water from a storage container that can be inside or outside the cabinet.

However, according to other embodiments, the cleaning water can be the fountain water of the fountain water preparation device. This has the additional advantage that it is a "reuse" of the fountain water. The fountain water is usually conveyed from the fountain water tank of the fountain water preparation device to a fountain water tray of a printing unit, where part is transferred to the cylinders or rollers of the printing unit and another part is recirculated back into the fountain water tank of the fountain water preparation device and filtered. Nevertheless, a small proportion of paper dust and other dirt particles, for example ink particles, also get into the fountain water tank from the printing unit. Because of this, and also because of the natural aging of the fountain water, the fountain water must be cleaned or replaced from time to time. Due to the "reuse" according to the invention, such a replacement of fountain water is required less frequently.

Furthermore, the use of fountain solution as cleaning water has the advantage that it is compatible with the printing inks of the printing press.

The fountain solution consists mainly of water and so-called "additives": Such additives are added to the fresh water in the fountain solution tank of the fountain solution preparation device. The additives are used to set a pH value that is favorable for printing operations.

G 1642 EN -5- 31.01.2000

of the fountain solution, to prevent the formation of bacteria in the fountain solution, as corrosion inhibitors to prevent corrosion in the printing press, and/or to set a suitable electrical conductivity of the fountain solution, and/or for other purposes. Alcohol is also often added to the fountain solution.

The invention is not limited to the use of a washcloth, but instead other automatically operating cleaning devices can also be used, for example rotating brushes. According to the preferred embodiment, a washcloth is used which can be transported from a clean cloth spindle via a pressing element which presses a washcloth section against the surface to be cleaned, to a motor-driven dirty cloth spindle.

The term "washcloth" here means any type of flexible cleaning element, such as fabric, knitwear, plush, pile and the like.

Supplying the cleaning device with cleaning water from the fountain water preparation device has further advantages: Both are housed together in a single cabinet; only a single fresh water supply line from a house pipe network is required; their electrical control devices can be replaced by a common control device and/or connected to the higher-level control device of the printing press via a common data interface.

The invention is described below with reference to the drawings using preferred embodiments as examples. In the drawings show

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Fig. 1 schematically shows a printing press cleaning device with a
Liquid supply cabinet according to the invention,

Fig. 2 schematically shows another embodiment of the printing press fluid supply cabinet
after the invention,

Fig. 3 schematically shows yet another embodiment of a liquid supply cabinet according to the invention.

Fig. 1 shows a rubber blanket cylinder 2 of a dampening water offset printing machine as a representative of all possible applications of a cleaning device 1. The cylinder 2 rotates, for example, clockwise 4. A washing cloth 6 is automatically transported in cycles from a clean cloth spindle 8 via a pressing device 10 to a dirty cloth spindle 12 in the direction of an arrow 14 by a drive 16, e.g. a pneumatically or electrically operated ram, when the cloth section 18 that can be pressed onto the cylinder 2 by the pressing device 10 is lifted off the cylinder 2. Between the cyclic transport phases of the washing cloth 6 there is a cleaning phase during which the pressing device 10 presses a cloth section 18 onto the cylinder 2. In the pressed state, a relative movement takes place between the rotating cylinder 2 and the stationary cloth section 18, thereby stripping dirt from the outer surface of the cylinder 2.

The washing cloth 6 extends over the entire width of the cylinder 2. A large number of nozzles 20 are arranged over this width, for example a pipe extending parallel to the cylinder 2 with a large number of nozzle openings, to which cleaning water 24 is supplied via a cleaning water line 22, which is sprayed via the nozzles 20 onto the

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is sprayed onto the cloth section 26 located between the cleaning cloth spindle 8 and the pressing device 10.

The washing cloth 6 can be in a dry state on the cleaning cloth spindle 8 or it can contain moist detergent, for example chemical detergent. According to other embodiments, the detergent can be distributed in the washing cloth in a dry state on the cleaning cloth spindle 8. The detergent is used to loosen greasy or other firmly adhering dirt particles, in particular to remove printing ink residues. The cleaning water 24 is used to loosen paper dust from the surface to be cleaned, in this case the outer surface of the cylinder 2.

The cleaning water can be fresh water from a

Fresh water supply line 30 or dampening water 32 from a dampening water tank 34 of a dampening water preparation device 36. For fresh water, the cleaning water line 22 of the cleaning device 1 in or outside a cabinet 38 of the dampening water preparation device 36 can be fluidly connected via a controllable valve 40 to the fresh water line 30 of this dampening water preparation device 36, e.g. upstream of a further valve 42 for supplying fresh water from the fresh water supply line 30 into the dampening water tank 34.

The inlet side of the valve 40 for the cleaning water line 22 can be connected to the fresh water supply line 30 downstream or upstream of a water softener 44.

Fig. 1 also shows the further possibility of connecting the cleaning water line 22 to the dampening water 32 of the dampening water tank 34, for example via a sieve 46, a pump 48 and a check valve 50.

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The two connection options for the cleaning water line 22 can be present simultaneously or alternatively.

The dampening water preparation device 36 contains, as is known for example from EP 0711661 B1 and 0602312 A1, a cooling generator 52,
which generates cold by compressing and expanding refrigerant,
which cools the dampening water 32 via a heat exchanger 54, which
for this purpose in a tempering circuit 56 by means of a pump 58 through the
Heat exchanger 54 is conveyed.

The refrigeration generator 52 has, in a known manner, a refrigerant circuit which includes a compressor 60, a refrigerant condenser 62, a fan 64 cooling the latter, a refrigerant expansion valve 66 and a refrigerant collector 68.

In the dampening water tank 34, additives are added to the fresh water via a dosing device 70, for example to adjust the pH value, to achieve antibacterial effects, or as corrosion inhibitors, etc. Furthermore, alcohol or alcohol substitute can be added to the dampening water 32 consisting of the fresh water and the additives via a further dosing device 72.

The dampening water 32 is fed via a dampening water circuit 74 by means of a pump 76 to a dampening water tank 78, from which dampening unit rollers 80 transfer dampening water to further printing unit rollers 82. Excess dampening water flows from the dampening water tank 78 back into the dampening water container 34.

G 1642 EN -9- 31.01.2000

In order that the cleaning water 24 sprayed onto the washing cloth 26 has an optimal temperature for the printing process and for the cleaning process, a heat exchanger 84 can be provided in which the temperature of the dampening water 32 of the dampening water container 34 in the cleaning water line 22 is transferred to the cleaning water 24 taken from the fresh water supply line 30. For this purpose, a tempering circuit 86 with a pump 88 is provided, by which tempering liquid is conveyed through the heat exchanger 84 of the cleaning water line 22 and a heat exchanger 90 arranged in the dampening water 32 of the dampening water container 34.

Instead of arranging such a heat exchanger 90 in the dampening water 32 of the dampening water tank 34, dampening water could also be pumped from the temperature control circuit 86 through the heat exchanger 84 of the cleaning water line 22.

Fig. 2 shows only those parts of the printing press cleaning device which differ from Fig. 1. Identical parts which have the same function are provided with the same reference numbers. Fig. 2 is only described insofar as it differs from Fig. 1.

A pressure-maintaining valve 94 is connected in parallel to the pump 48 for conveying dampening water 32 from the dampening water tank 34 into the cleaning water line 22 for recirculating the dampening water from a predetermined overpressure of the cleaning water between this pump 48 and the nozzles 20.

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Furthermore, an expansion vessel 96 can be connected to the pressure side of this pump 48. This pressure expansion vessel 96 can reduce the switching cycles of the pressure holding valve 94.

Instead of a plurality of nozzles 20, a nozzle slot can be used which extends parallel to the spindles 8 and 12 over the washing cloth 6. The nozzles 20 or another water transfer device for transferring the cleaning water to the washing cloth can be arranged on the side of the washing cloth 6 like the pressing device 10 or preferably according to Figures 1 and 2 on the side facing away from it.

The cleaning water supply device 40, 46, 48, 50, 88, 90 for supplying the cleaning device 1 with cleaning water 24 and the dampening water preparation device 52, 34, 58, 64, 70, 72, 76 for preparing dampening water 32 can be housed together in the cabinet 38. Their control devices 98 and 99 are accordingly preferably also located in the cabinet 38. They can be replaced by a single control device 98/99 and/or connected to a higher-level control device of the printing press via a common data interface.

The electrical control device 98 of the cleaning water supply device controls the delivery of cleaning water 24 through the nozzles 20 by appropriately controlling the valve 40 of the fresh water line or the pump 48, which supplies dampening water as cleaning water instead of fresh water. This valve 40 and the pump 48 are only examples of any means for controlling the delivery of cleaning water 24 to the cleaning device 1.

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The cleaning water supply device may contain further valves and/or pumps and/or compressed air sources, as is known and therefore not described in detail.

According to a particular embodiment, the cabinet contains a common data interface 100, through which the dampening water preparation device 36 (40, 46, 48, 50, 86, 88, 90) and the cleaning water supply device (40, 46, 48, 50, 88, 90) can be connected to a higher-level control device of the printing press.

Fig. 3 is a copy of Fig. 1, which is supplemented by the detergent supply device 102, 104 and 106.

According to the further particular embodiment of the invention, which is shown in Fig. 3, the cabinet 38 also contains means or a supply device for supplying liquid detergent to the printing press or to a cleaning device 1 of the printing press. This means or detergent supply device in the cabinet 38 can, for example, contain a pump 102 and on its pressure side a controllable valve 104, the downstream side of which is connected or can be connected to the cleaning water line 22 or is connected or can be connected to the cleaning device 1 or a printing press via a separate line. The suction side of this detergent pump 102 is fluidly connected or can be connected to a detergent source 106, which is preferably a container arranged in or next to the cabinet 38.

G1642 EN -12- 31.01.2000

According to an embodiment not shown, the cleaning water and/or the washing agent can be applied directly to the cylinder 2 to be cleaned or to a paper web or to a cleaning element of the cleaning device 1. If the cleaning water or the washing agent is applied directly to a cylinder 2, its cylinder surface to be cleaned can be cleaned by a cleaning element such as a brush or a washing cloth 26 and/or scraped by a doctor blade.

"Cylinders" can be blanket cylinders, impression cylinders, plate cylinders, inking rollers and other rotating cylinder bodies of a printing press.

Claims (6)

1. Printing machine fluid supply cabinet for dampening water offset printing machines, which contains a dampening water preparation device ( 34 , 36 , 52 , 54 , 56 , 58 , 62 , 64 , 70 , 72 , 76 ) for preparing and supplying dampening water to a dampening water offset printing machine, characterized in that it additionally contains a cleaning water supply device ( 40 , 46 , 48 , 50 , 86 , 88 , 90 ) for supplying a cleaning device ( 1 ) of the offset printing machine with cleaning water ( 24 ) for the wet cleaning of rotating cylinders ( 2 ) of the offset printing machine and/or for the wet cleaning of a printing web running through the offset printing machine. 2. Printing machine fluid supply cabinet according to claim 1, characterized in that an electrical control device ( 98 , 99 ) of the cleaning water supply device and/or the dampening water preparation device is also accommodated in the cabinet ( 38 ). 3. Printing machine fluid supply cabinet according to claim 1, characterized in that a common electrical control device ( 98 , 99 ) is provided for the dampening water preparation device ( 34 , 36 , 52 , 54 , 56 , 58 , 62 , 64 , 70 , 72 , 76 ) and for the cleaning supply device ( 40 , 46 , 48 , 50 , 86 , 88 , 90 ). 4. Printing machine fluid supply cabinet according to one of the preceding claims, characterized in that a data interface ( 100 ) is provided for connecting the dampening water preparation device ( 34 , 36 , 52 , 54 , 56 , 58 , 62 , 64 , 70 , 72 , 76 ) and the cleaning water supply device ( 40 , 46 , 48 , 50 , 86 , 88 , 90 ) to a higher-level control device of the printing machine. 5. Printing machine fluid supply cabinet according to one of the preceding claims, characterized in that a heat exchanger circuit ( 86 ) is provided for heat exchange between the dampening water ( 32 ) and the cleaning water ( 24 ). 6. Printing machine liquid supply cabinet according to one of the preceding claims, characterized in that it contains a detergent supply device ( 102 , 104 , 106 ) for supplying liquid detergent to the printing machine or to a cleaning device ( 1 ) of the printing machine.