DE10136028C5 - Method and device for dosing a liquid medium in a processing machine - Google Patents

Abstract

To give a dosed feed of a fluid especially to a rotary printing press or varnishing machine, a liquid lubricant is fed at intervals on to the mantle surface of the application roller (15), before the chamber scraper system (16) in the direction of roller rotation, and at its sealing system (25). Each chamber scraper has an adjacent lubricator (17), with a feed pipe (18) and a switch valve (19) coupled to a control unit (20) or pulse generator.

Description

The invention relates to a method and a device for dosing a liquid medium in a processing machine, in particular in a rotary printing press or a varnishing machine, according to the preambles of the independent claims.

[State of the art]

A metering device of this kind is made EP 0 071 180 A1 known. The metering device consists of a chambered doctor blade, essentially formed by a housing with side walls and doctor blades arranged on the housing, a first doctor blade being arranged as a work doctor blade and a second doctor blade as a closing doctor blade. The metering device further includes an applicator roller on which the doctor system is supported, so that with the housing a chamber is enclosed. In the chamber, a liquid medium to be metered is fed by means of feed and excess medium removed by means of return line.

Out EP 0 401 250 B1 a metering system is known as a doctor blade system that in the region of the end faces laterally arranged and the housing chamber closing sealing elements (side seals) has. The sealing elements are adapted to the curvature of the associated application roller and consist of elastic or elastomeric material.

Furthermore, it is off US 5,150,651 A a dosing system known as doctor blade system with chamber doctor blade and associated anilox roll. In this case, the chamber doctor blade has inside the chamber formed for receiving liquid media arranged side seals. These side seals have recesses associated with the adjacent roller and acting as lubrication pockets. Each lubricant bag is equipped with a lubricating fluid with a supply line and a return line.

Out DE 197 29 977 A1 is an offset printing unit for painting substrates known. In this case, the metering device is formed by a chamber doctor blade system and an application roller, wherein the chamber doctor blade system has side seals. The applicator roller is in contact with a plate cylinder carrying a printing / lacquer form, and the plate cylinder is associated with a blanket cylinder adjacent thereto.

The disadvantage of such designs that arise in particular at the contact surfaces of side seals and associated applicator roller, depending on the contact pressure of the side seals, friction moments. In addition, friction moments occur at the contact surfaces of doctor blade and associated applicator roll. When friction moments occur, an energy conversion of irreversible character always occurs, i. H. it is primarily heat and abrasion.

When reducing the contact pressure at the contact surfaces there is a risk that leaks occur and the medium to be processed uncontrollably exits into the processing machine. If lubricant pockets are supplied with a lubricant, there is a risk of the lubricant mixing with the media to be processed. If the lubricant and the medium to be processed are identical, there is a risk that the medium to be processed, in particular at the side seals and squeegee blades, partly dries or crystallizes on the housing of the chamber doctor blade. In this case occur at the side seals leakages with the disadvantages already mentioned above, the side seals age early and on the doctor blades and the seals occurs premature wear.

Out EP 0 293 586 A2 a split ink fountain for a flexographic printing machine is known, which has a strip-shaped separating element, a so-called "color box divider" for separating the ink fountain in axial zones. This separating element is arranged within a chamber doctor blade housing and abuts against an anilox roller. The separating element has a Teflon separating strip and felt pads. To support the low-friction surface of the separating element, an aqueous liquid is supplied to the felt pads.

OBJECT OF THE INVENTION

The invention has for its object to provide a method and an apparatus of the type mentioned above, which avoid the disadvantages mentioned, in particular in the range of seals and doctor blades of a applicator roller containing a metering allow a low-wear dosing and reduce the friction moments noticeable.

The object is achieved by the training features of the independent claims. Further developments emerge from the dependent claims.

A first advantage of the invention is based on the fact that the friction moments on the seals (sealing systems) and the doctor blades, in particular in the area of the doctor blades adjacent to the sealing systems, are reduced by the use of a liquid lubricant.

A further advantage is that the drying or crystallization of the liquid medium to be processed on the doctor blades and sealing systems is noticeably avoidable. This also improves the dosing quality of the liquid medium to be processed.

Another advantage is that the heat development in the contact areas of the doctor blade system with the associated applicator roller is low. This is particularly at higher ambient temperatures, due to, for example, the doctor blade system adjacent drying equipment and / or at high processing conditions, advantageous.

Furthermore, it is advantageous that the metering achieved as a result of reducible wear on the sealing systems and doctor blades longer life. In addition, the machine service life, for example due to cleaning and service activities, reduced.

[Examples]

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

1 a rotary printing machine with printing and coating plants,

2 a coating unit with dosing device (side view),

3 the coating unit according to 2 (Top view).

According to 1 consists of a series-produced sheet-fed rotary printing presses from several printing units 1 , formed from plate cylinder 8th and blanket cylinder 9 and at least one inking unit. In conveying direction 14 The sheet material is followed by a first coating unit 2 For example, two drying devices 4 and at least a second coating unit 3 , The second coating plant 3 follows a boom 5 which at least one endless circulating conveyor system 7 and a delivery pile 6 having.

The paint works 2 . 3 each have a form cylinder 12 and a metering device 13 on. The sheet transport is by means of sheet guiding cylinder, especially transfer drums 10 and impression cylinder 11 , realized.

Each dosing device 13 has an applicator roll 15 , In particular, an anilox roll, which with a chamber doctor blade system 16 is coupled. The chambered doctor blade system 16 has an axis parallel to the applicator roll 15 extending housing for receiving a liquid medium to be processed, for example, paint on, and further consists of a first doctor blade 24 (Squeegee) and a second squeegee blade 23 (Working doctor) and each of the housing chamber formed in this way laterally limiting. sealing systems 25 ,

The squeegee blades 23 . 24 rely on the roll shell of the applicator roll 15 off and the chambered doctor blade system 16 is coupled to at least one feed and one return line (circulating line system) for the liquid medium to be processed, for example dispersion varnish.

The chambered doctor blade system 16 has sealing systems 25 on, which limit the chamber housing and with the applicator roll 15 are in contact. These contact points represent lubrication points, which each have a lubricator 17 , Preferably with the outlet opening on the applicator roll 15 directed, adjacent is assigned.

Preferred is in the direction of rotation of the applicator roll 15 in front of the first squeegee blade 24 (Closing squeegee) of the chamber doctor blade system 16 at least one lubricator 17 arranged, which always a sealing system 25 (Lubrication point) of the chamber doctor blade system 16 is assigned adjacent. Ie. Every lubrication point is a lubricator 17 assigned. The chambered doctor blade system is preferred 16 at both ends with two sealing systems 25 designed so that ever a lubricator 17 a sealing system 25 are assigned adjacent.

There are still chamber doctor blade systems 16 with seals arranged inside the housing chamber (eg. US 4,796,528 ). In such embodiments of the chamber doctor blade system 16 are each end sealing system 25 and the seals arranged inside the housing chamber (sealing system 25 ) each a lubricator 17 allocated adjacent. The lubricants are preferred 17 with a frame-fixed, paraxial to the applicator roll 15 arranged traverse 27 geared as a sliding joint. The lubricators 17 are doing in the axial direction of movement 26 along the traverse 27 displaceable. In a further embodiment, the lubricators 17 in addition to the traverse 27 pivotable, allowing the inclination angle of each lubricator 17 to the applicator roll 15 or to the chambered doctor blade system 16 is adjustable. Alternative to the traverse 27 are the lubricators 17 also on a machine protection (inside) displaceable and pivotable can be arranged.

At the outlet openings of the lubricators 17 is the liquid lubricant, in particular a fluid, for example water, continuously in very small amounts or preferably at intervals on the roll shell of the applicator roll 15 in the area of the contact points of the sealing systems 25 dispensable.

Every lubricator 17 is with a pipe system 18 coupled, each having a switching valve 19 having. Each switching valve 19 is with a controller 20 connected. Preferably, the switching valve 19 a pulse solenoid valve which is operable with a few milliseconds (≤ 50 ms) of electrical impulse. As a controller 20 is preferably a machine control, alternatively, as well as a pulse generator can be used. For the lubricant supply of every lubricator 17 is every switching valve 19 a Zuführstrang 21 upstream and the feed strands 21 have a central connection 22 for the liquid lubricant.

In a further embodiment, each lubricator 17 by means of pipe system 18 with at least one time-controllable pump (instead of the switching valve 19 ) connected. Such a pump controls all lubricators 17 or alternatively, each lubricator 17 by means of pipe system 18 executable with one time controllable pump. The pump is or are with a control 20 connected. The control 20 is preferably a machine control or a pulse generator. The pump or pumps is at least one Zuführstrang 21 with a connection 22 upstream.

The connection 22 is preferably connectable to a piping system for a liquid lubricant. At this connection 22 is the liquid lubricant, such as water, fed. In a further education is the connection 22 coupled with a fine filter and / or a pressure regulator and / or a lubricant circulation shut-off.

The liquid lubricant should be selected according to the liquid medium to be processed. Preferably, a fluid compatible with the lubricant can be used. If, for example, the medium to be processed is an aqueous dispersion varnish, it is preferable to use water or a fluid compatible with the medium to be processed as the liquid lubricant.

The usable liquid lubricant serves to reduce the friction moments at the contact points of doctor blades 23 . 24 and the sealing systems 25 with the applicator roll 15 while being compatible with the liquid medium to be processed.

The method and the device is not on the example described in a coating unit 2 . 3 limited. Rather, the method and apparatus are also in an offset printing unit 1 used. This is analogous to DE 197 29 977 A1 the metering device 13 , made from order roller 15 and chambered doctor blade system 16 , the plate cylinder 8th assigned. The inking unit of the offset printing unit 1 is inactive and the preferably screened applicator roll 15 is with the plate cylinder 8th in contact. Depending on the space conditions are the lubricators 17 in the direction of rotation of the applicator roll 15 before or after the chambered doctor blade system 16 , the sealing systems 25 assigned, arranged. The liquid medium to be processed is then removed from the applicator roll 15 to the plate cylinder 8th and from this to the blanket cylinder 9 transfer.

The mode of action is as follows: In the printing / coating operation, the lubricators are 17 the respective sealing systems 25 allocated adjacent. About the connection 22 becomes a liquid lubricant over the feed strands 21 to the switching valves 19 or pumps are fed, with the switching valves 19 or the pumps by means of control 20 about the piping systems 18 the liquid lubricant at intervals (intermittently) to the lubricators 17 respectively.

At the lubricators 17 the liquid lubricant is expelled in the form of drops or as a spray jet and impinges on the rotating applicator roll 15 , Preferably in the direction of rotation of the applicator roll before the first doctor blade 24 , on.

By supplying the liquid lubricant, preferably water, that of the preferably screened applicator roll 15 guided liquid medium, in particular paint, in the field of sealing systems 25 slightly diluted. However, this does not affect the liquid medium or the dosing or coating quality. Rather, the liquid lubricant reduces the build-up and hardening of the liquid medium in the area of the sealing systems 25 and the squeegee blades 23 . 24 ,

Furthermore, the functionality of the contact points on the sealing systems 25 and the squeegee blades 23 . 24 in conjunction with the applicator roll 15 ensured and reduced wear. Likewise, a cooling of the above-mentioned contact points can be achieved, which is especially true for adjacent, activated drying devices 4 is advantageous.

The method for dosing a liquid medium in a processing machine comprising an applicator roll and a chamber doctor blade system associated with the applicator roll assumes that at the lubrication points formed by a respective sealing system 25 and the roll shell of an applicator roll 15 , the lubrication points are preferably supplied with relatively small, adjustable lubricant quantities of a liquid lubricant.

Preferably, the supply of liquid lubricant in the direction of rotation of the applicator roll 15 on the lateral surface in front of the chamber doctor blade system 16 in the field of sealing systems 25 , In a preferred embodiment, the lubricant is applied to the lateral surface of the applicator roll 15 supplied at intervals (intermittently). Alternatively, the liquid lubricant is in the direction of rotation of the applicator roll 15 on the lateral surface also after the chamber doctor blade system 16 in the field of sealing systems 25 fed.

Alternatively, a continuous supply of lubricant can also be realized, wherein - due to the relatively small amount of lubricant required - the intermittent supply of lubricant is preferred. In both working methods (intermittent or continuous feeding), the principle of continuous lubrication exists, ie. H. there is no lubricant return.

LIST OF REFERENCE NUMBERS

1

printing unit

2

first coating plant

3

second coating unit

4

drying device

5

boom

6

delivery pile

7

conveyor system

8th

plate cylinder

9

Blanket cylinder

10

transfer cylinder

11

pressure cylinder

12

form cylinder

13

metering

14

conveying direction

15

applicator roll

16

Chambered doctor blade system

17

Lubricant dispenser

18

line system

19

switching valve

20

control

21

feed leg

22

connection

23

Second squeegee blade

24

First doctor blade

25

sealing system

26

movement direction

27

traverse

Claims (9)

Method for dosing a liquid medium in a rotary printing press or a varnishing machine, comprising an applicator roller and a applicator roller associated chambered doctor blade system, the chambered doctor blade system having a first and a second doctor blade and at least one end fitting on the lateral surface of the applicator roller sealing system for limiting the chambered doctor blade housing, and the applicator roller in the region of the sealing systems of the chambered doctor blade system a liquid lubricant from outside of the chambered scraper housing arranged lubricators is fed directly to the end side surfaces of the applicator roll in the direction of rotation of the applicator roll fed before the chamber doctor blade system, characterized in that the liquid lubricant at a central terminal ( 22 ) and that each lubricator ( 17 ) by means of a respective piping system ( 18 ) that with a switching valve ( 19 ) or a time-controllable pump and a respective upstream Zuführstrang ( 21 ), each switching valve ( 19 ) and each controllable pump with a controller ( 20 ), from the central terminal ( 22 ) is supplied with lubricant. A method according to claim 1, characterized in that the liquid lubricant is supplied continuously. A method according to claim 1, characterized in that the liquid lubricant is supplied at intervals. Device for dosing a liquid medium in a rotary printing press or a varnishing machine, comprising an applicator roller and an applicator roller associated Chamber doctor blade system, wherein the chamber doctor blade system has a first and a second blade and at least one end adjacent to the outer surface of the applicator roll sealing system for limiting the chambered blade housing, each sealing system in the direction of rotation of the applicator roll in front of the chambered doctor blade system adjacent to a arranged outside the chamber doctor blade housing adjacent lubricator is assigned and the outlet opening of the lubricator is directed to the end regions of the applicator roll, characterized in that each lubricator ( 17 ) with a line system ( 18 ) and an upstream switching valve ( 19 ), which with a control ( 20 ) is connected, that each switching valve ( 19 ) a feed train ( 21 ), which has a connection ( 22 ) for the lubricators ( 17 ), whereby at the terminal ( 22 ) a liquid lubricant can be fed in and from the lubricators ( 17 ) is deliverable at intervals. Apparatus for dosing a liquid medium in a rotary printing press or a varnishing machine, comprising an applicator roll and a chambered doctor blade system assigned to the applicator roll, the chambered doctor blade system having a first and a second doctor blade and at least one sealing system for limiting the chamber doctor housing at the end side of the applicator roll; each sealing system in the direction of rotation of the applicator roller in front of the chambered doctor blade system is assigned adjacent to a arranged outside the chamber doctor blade lubricator and the outlet opening of the lubricator is directed directly to the end regions of the applicator roll, characterized in that each lubricant dispenser ( 17 ) with a line system ( 18 ) and at least one upstream, temporally controllable pump, which with a control ( 20 ) is connected, that each pump at least one feed strand ( 21 ), which has a connection ( 22 ) for the lubricators ( 17 ), whereby at the terminal ( 22 ) a liquid lubricant can be fed in and from the lubricators ( 17 ) is deliverable at intervals. Apparatus according to claim 4 or 5, characterized in that the lubricators ( 17 ) fixed frame side and paraxial to the applicator roll ( 15 ) in the direction of movement ( 26 ) are movable. Apparatus according to claim 6, characterized in that the lubricators ( 17 ) on a frame-fixed traverse ( 27 ) are arranged. Apparatus according to claim 4 or 5, characterized in that the switching valve ( 19 ) is a pulse solenoid valve. Device according to claim 4 or 5, characterized in that the controller ( 20 ) is a machine control or a pulse generator.

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