DE102008000451A1 - coating station - Google Patents

Abstract

A vacuum deaerator (12) has a pipeline (22) for supplying the deaerated coating agent (2a) to deaeration unit (34). A coating agent processing station (13) comprising a mixer (13.1) and storage container (13.2) are connected to upstream of vacuum deaerator. The vacuum deaerator is segmented into upper region (16) for performing deaeration of coating agent, and lower region (20) forming an additional work space (21) for storing the deaerated coating agent.

Description

The The invention relates to a coating station for coating a running Paper, cardboard or other fibrous web with at least one liquid to pasty application medium, comprising one above the fibrous web and spaced therefrom Application head of a curtain-commissioned work, the at least one Application medium in the form of a curtain to the fibrous web emits, wherein the contractor a vacuum deaerator for degassing or Venting the at least one application medium upstream is, with a discharge line for degassed application medium, a vacuum generating device and a discharge line for separated air or gas is present and the vacuum deaerator a conditioning station containing a mixer and / or reservoir upstream.

All Coating stations need such a treatment station. High gas or air contents in the order media, d. H. in the coating colors mostly associated with high coating machine speeds to the dreaded "skip coating", d. H. to holes and scratches in an angry line, which of course the Quality of the coating layer negatively affected. High gas contents result primarily from the coating color recipe, the coating color preparation and the circulation, the already mentioned machine speed and the used intended order system and other influencing factors.

at conventional coating methods, such as the blade or film coating coating color (generally the application medium) in multiple excess applied and then metered with a doctor element. The modern curtain coating eliminates the dosage, because there is no surplus. That means at Curtain painting is applied only to the quantities that are ultimately on should remain the substrate. Consequently, the amounts of paint that must be supplied to the curtain commissioned work very low. However, the curtain painting requires an almost complete ventilation of the coating color, because the curtain produced and delivered by the commission is very sensitive is. Also cause gas or air contents in advance the actual coating problems in the system.

The applicant's company has therefore submitted proposals such that the largest possible surface area of the medium to be degassed or vented is created, which can improve the venting effect. In addition, the venting is carried out under the influence of a vacuum. This is on the DE-A1-10 2005 060 848 referenced, in which the degassing or venting is described in a vacuum deaerator. To improve the venting effect, a vent in a cyclone breather is provided in front of the vacuum breather. The deaerated application medium is preferably provided for a curtain coating process.

In the DE-A1 103 52 807 is also described a solution for curtain coating, in which two successively arranged vacuum deaerator are provided.

From the DE-A1 10 2005 060 853 is a vacuum deaerator with built-in cascades and out of the DE-A1 10 2007 000 705 , ... 706 , ... 708 Built-in turntable with baffle arrangements are known.

At the It is also necessary that the system be painted kept clean. Especially with a change of order media is a meticulous, time-consuming cleaning required. at the specified known solutions is the cleaning and the device overhead and also medium losses Grade change very high.

It is therefore an object of the invention is a compact coating station for Specify venting or degassing, in which the disadvantages of the prior art does not occur.

The The object of the invention is achieved with the features of the device claims 1 and 4 solved.

According to the invention according to the first solution (device claim 1) provided that the intended per se known vacuum vent an additional work space (without internals) contains. The otherwise necessary additional close to the commissioned work arranged work containers - by a short To achieve line path - is thereby inventively complete omitted, which is why the required workload in here slightly enlarged vent tank is integrated.

A particularly expedient training of the vacuum principle working ventilator results by adding the total volume of the ventilator is divided into two areas.

Of the Upper area is used for ventilation. In this upper area So is the medium to be deaerated surrounded by the gas phase.

The lower area, so the additional working space is provided for storing the vented medium and is filled by a level control in operation to the desired level completely with the application medium. With this existing vented discharge medium that can subsequent commissioned work. This room contains nearly 100% application medium. as a memory. The required application medium is removed via a discharge pump as required. In this case, such a regulation takes place according to which the medium to be deaerated is introduced into the upper area and is vented there. This deaerated medium then refills the lower area. The advantage of this solution is that the storage made here takes place under venting pressure, whereby a consistently good quality of the application medium, ie coating color, can be achieved.

A very convenient training of the coating station arises by placing in the upper area of the breather tank For example, known cascade-like installations with z. B. turntables, return plates etc., which perform a multiple degassing or venting, are arranged. The application medium is only thinner Film or paint droplets exist. The volume of this upper Range is only about 5% liquid application medium plus solids and approx. 95% gas phase (air and / or water vapor) completed in this embodiment.

• – insgesamt weniger Platzbedarf
• – weniger Rohrleitungs- und Behälteraufwand
• – verkürzte Reinigungszeiten
• – geringe Farbverluste bzw. weniger streichfarbenhaltige Abwässer
• – geringe Kosten
• – bessere Entlüftungswirkung, da das Auftragsmedium auch im Standby-Betrieb unter Vakuum steht.

As advantages arise in the inventive solution with integrated in the vent working space:

• - Overall less space
• - Less piping and container effort
• - shorter cleaning times
• - Little loss of color or less coating-containing wastewater
• - low cost
• - Better venting effect, since the application medium is under vacuum even in standby mode.

According to the second solution (device claim 4) is provided according to the invention, that at least one supply line of the at least one Job media preparation station, as well as at least one Return line from the curtain applicator, each directly into the at least one vacuum ventilator.

If here by "direct" circulation is spoken, so means that, nevertheless, filters, measuring points, such as gas Valves, pumps, pulsation dampers, other pipe bends etc. can be involved in this cycle.

On In any case, however, is the existing in the prior art additional Work container (which is located close to the commissioned work is and so far the return from the breather received) completely omitted even in this solution.

When special advantage is the only short return (that is the medium content, which is kept away from the edge of the railway, as well as over a bypass line is returned and such Medium, which is given off during coating breaks further from the commissioned work, caught and returned) between commissioned work and the deaerator. This allows the recirculated Application medium degassed or vented very quickly, before it gets mixed again.

• – weniger Auftragsmedium (z. B. Streichfarbe) im System,
• – schnelle Auftragsmediums-Wechselzeiten bei Sortenwechsel möglich,
• – weniger Mediumsverluste treten auf,
• – schnellerer Start des Auftragsvorganges ist möglich,
• – geringer Reinigung- und Vorrichtungs-(Maschinen-)Aufwand.

Further advantages are:

• - less application medium (eg coating color) in the system,
• - fast application medium change times possible when changing grades,
• - less medium losses occur,
• - faster start of the order process is possible
• - Low cleaning and device (machine) effort.

Around to be able to avoid an air intake is in the return line, d. H. before the recycled medium again the Vacuum deaerator supplied, an idle protection or Aufstauragung provided. This includes a collecting element, z. B. a collection container of low volume, the one Control valve is connected downstream.

Furthermore can be applied to several application media or coating colors the coating station several mixers and possibly several associated storage containers include.

There every mixer and said storage tank are outside the coating station, even outside of the coating station harboring building, is no longer in accordance with the invention existing separate working container so shortened Circulation from the mixer or reservoir to the breather especially significant.

It can have at least one breather per medium to be applied to be available. As a result, it is possible to have multiple deaerators to use for only a single application medium. The latter possibility is useful for very wide machines.

Another very advantageous embodiment variant of the coating station according to the invention results from the fact that their individual units, such as vacuum deaerator, filters and measuring devices are mounted on a common frame. This makes it possible to create a very compact workstation. This can also be retrofitted and expanded in existing paper-making machines. Overall, the maintenance, cleaning and machinery costs are much lower than before. In addition, the accessibility to the individual units is ver improves and also created a local arrangement to commissioned work.

at Multiple job media may also have multiple frames in place be.

Regarding the residence time and the deaerating effect, it is advantageous if the working space (lower area) of the vacuum ventilator a working volume of about 100 to 2000 l, preferably 200 to 1500 l medium.

Advantageous it is also when vented into the exhaust duct for the Application medium and / or in the return line between the vacuum deaeration tank and the commissioned work a filter is installed.

Therefore offer, for example, commercially available, relatively inexpensive and effective cartridge filters or rotary filters.

meaningful is also the installation of flow and air content meters after the vacuum deaeration tank. expedient are those that work on a sonar basis. For example, such Devices under the name "Sonartrac" in the market available.

Mentioned should be that with the curtain-commissioned work both a single-layer, as well as a multilayer curtain application on a paper carton or other fibrous web is possible. As a result, can corresponding to the number of applied to the fibrous web Application media or coating layers a corresponding number on vacuum deaerators and mixers and / or storage containers be provided per to be deadened coating color. That means but also that a single vent tank, a single mixer and reservoir also several feed chambers of the commissioned work can serve.

Of the Advantage of the coating station according to the invention consists in that it is very compact and still less cleaning and fixture effort required and secondly, that at grade change coating color losses less than before are.

following the invention will be described in more detail on the basis of exemplary embodiments explained.

It show in a schematic representation:

1 a first variant of a compact coating station

2 a second variant of a compact coating station

1 shows a compact coating station 1 for coating a L, running in the direction of paper, cardboard or other fibrous web 2 with a liquid to pasty application medium 3 ,

The coating station 1 includes a curtain commissioned work 4 with one above the fibrous web 2 and spaced from her curtain applicator head 5 , The order header 5 containing the application medium (ie a coating color) 3 in the form of a curtain 6 to the fibrous web 2 is machine-wide.

The order header 5 indicates for each application medium to be applied 3 for a multi-shift order its own order chamber 7a to 7n on, each in a feed slot 8a - 8n with appropriate outlet nozzle 9a - 9n passes. The outlet nozzle (s) opens at the surface 10 of the example in the form of a nozzle block (slide, ie, Gleitschichtdüse trained application head 5 , where, in the case of multi-layer application, that of the outlet nozzles 9a - 9n delivered media on the surface 10 overlay each other and create a multi-layered curtain. The running curtain 6 then each generates an application medium layer 11 according to the desired number of application layers on the fibrous web 2 ,

The commissioned work 4 or the order header 5 is a vacuum deaerator 12 upstream, in turn, a coating medium processing station 13 upstream. This job media preparation station 13 includes at least one mixer 13.1 and at least one reservoir 13.2 , The mixer 13.1 contains a strong agitator and usually also has several feeds. The storage tank is used only for storage of the respective application medium and contains only a simple agitator for circulation. Mixer and reservoir can be far apart from the commissioned work spatially. Accordingly long then the connecting pipes are to be executed.

With this in the station 13 prepared medium 3 becomes the deaeration tank 12 via a feeder line 14 and a pump 15 filled directly.

The preparation of the coating medium can be done continuously, what you preferably without reservoir 13.2 gets along. The application medium is directly from the mixer 13.1 from the deaerator 12 fed.

The preparation of the application medium can also be carried out batchwise, which is referred to as "batchwise." But this works with the reservoir 13.2 , from which then the application medium directly to the deaerator 12 is supplied.

From the 1 is removable, that the vacuum deaerator 12 in its upper area 16 with cascading internals 17 for multiple degassing or venting of the application medium 3 is provided. These cascading installations 17 are as a turntable 17a be trained and be through a common engine 18 over a vertical shaft 19 driven. In this case, a speed of about 1500 min ^{-1 is} reached. As a result of the fast rotation, the application medium to be deaerated becomes 3 from each turntable 17a or each cascade out to the container wall 12a flung there, bounces there and then passes from there via oblique guides 17b down to the next turntable, reducing the application medium 3 in the same mode is further vented. This takes place until the partially degassed application medium has a lower area 20 of the deaeration tank 12 has reached.

This area 20 serves as an additional working space 21 , It has a working volume of on average approx. 1000 l of medium (per deaerator), which is directly available for the commissioned work. The vacuum deaerator 12 is therefore very close to the commissioned work 5 arranged and also takes up its return. These very short cycles from the mixer / reservoir to the breather and the commissioned work to the breather are very beneficial.

The almost completely deaerated application medium 3a is via a withdrawal line 22 the commissioned work 5 or the curtain application head so to speak bubble-free by means of a discharge pump 23 fed.

Between the vacuum deaerator 12 and the order header 5 is still a filter in the example shown 24 , ie a commercial cartridge filter, installed so that impurities in the commissioned work are almost impossible, creating a high-quality and uniformly closed trained coating layer 11 on the fibrous web 2 is reached.

It should be mentioned that in the example shown in the withdrawal line 22 immediately after the vacuum deaerator 12 and even before the filter 24 an air content measuring device 25 is installed.

In addition, at the head of the deaerator 12 a vacuum generating device 27 and a withdrawal line 28 for separated air or gas as well as an idling protection 29 in one of the commissioned work 4 outgoing and in the head of the vacuum deaerator 12 opening return line 26 available. The idle protection 29 includes an accumulation control with a collecting element 29.1 (eg small container) and a downstream control valve 29.2 or entry pump.

The vacuum deaerator 12 and other building units, such as filters 24 and measuring point 26 etc. are, moreover, on a common framework 30 mounted, so that there is a close together, easy vorzumontierende compact workstation. Of advantage here are the short circuits of the medium and also the associated piping costs.

At z. B. three media to be applied could also be three frames 30 to be available.

Add is that shown in the 1 an example with a single-layer order of the order medium 3 (see supply via line 22 to the middle order chamber 8th and bypass line 26 from this application chamber back into the deaerator 12 ) is shown. This order could also be multi-layered, for example, two-, three- or n-layered, which is why in these cases the number of application medium chambers with feed columns and outlet nozzles and also the number of deaerators 12 , Mixer 13.1 and reservoir 13.2 could be increased accordingly.

Only a single venting container is shown by way of example 12 for the order medium 3 ,

In 2 is another variant of the coating station 1 shown. It essentially corresponds to that of 1 , which is why the figures are also essentially those of 1 corresponds and a corresponding explanation is not repeated here. Only is in the return line 26 , starting from the commissioned work 4 to the ventilator 12 another filter 31 integrated, which also serves as a collection container. This filter 31 can any, known filter, such. B. be a rotary filter or a cartridge filter. But other designs are also possible.

In front of the breather 12 is in the said administration 26 a control valve 32 installed, which serves a controlled dosing of the application medium. It regulates the level in the filter 31 or the level in a pipeline.

The filter 24 however, acts only as a so-called police filter and is of smaller design.

In 2 is also a dashed line further supply line 33 drawn in from the feedstring 14 in the deaerator 12 (solid line) branches off and into the filter 31 leads. This feed is alternatively applicable to additionally fresh application medium or fresh coating color from the application medium processing station 13 in the filter 31 to lead. After filtering, the vacuum deaerator 12 with this filtered up medium via the said line 26 and the control valve 32 as I said, instead of the direct supply by means of a continuous supply line 14 , provided.

Not drawn, but optionally applicable is the integration of a heat exchanger module and temperature-controlled piping at least one point in the system.

tries were with the coating station according to the invention, wherein as a job medium z. B. a microcapsules contained Strechfarbe with a solids content of 32% and a viscosity of 240 mPas was vented. Before venting the gas content in the coating color was 2-25% and after venting less than 0.2%.

1

coating station

2

Fibrous web

3

application medium

4

Curtain applicator

5

Curtain applicator head

6

curtain

7a-7n

application chamber

8a-8n

feed gap

9a-9n

exhaust nozzle

10

surface

11

Application medium layer

12

Vacuum Deaerator

12a

Container inner wall

13

Application medium preparation station

13.1

mixer

13.2

reservoir

14

supply line

15

pump

16

upper Area

17

cascading fixtures

17a

turntable

17b

slope guides

18

engine

19

vertical wave

20

lower Area

21

additional working space

22

withdrawal line

23

discharge pump

24

filter

25

measuring device

26

bypass line

27

Vacuum generator

28

withdrawal line for separated air or gas

29

Idle Protection

29.1

collecting element

29.2

control valve

30

frame

31

filter

32

control valve

33

supply

L

direction

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• DE 102005060848 A1 [0004]
• - DE 10352807 A1 [0005]
• - DE 102005060853 A1 [0006]
• - DE 102007000705 A1 [0006]
• - DE 102007000706 A1 [0006]
• - DE 102007000708 A1 [0006]

Claims (14)

Coating station ( 1 ) for coating a running paper, board or other fibrous web ( 2 ) with at least one liquid to pasty application medium ( 3 ) comprising one above the fibrous web ( 2 ) and spaced from her arranged order head ( 5 ) of a curtain commissioned work ( 4 ) containing the at least one order medium ( 3 ) in the form of a curtain ( 6 ) to the fibrous web ( 2 ), whereby the commissioned work ( 4 ) a vacuum deaerator ( 12 ) for degassing or venting of the at least one application medium ( 3 ), wherein the vacuum deaerator ( 12 ) a withdrawal line ( 22 ) for degassed application medium ( 2a ), a vacuum generator ( 27 ) and a withdrawal line ( 28 ) for separated air or gas and the vacuum deaerator ( 12 ) a mixer ( 13.1 ) and / or reservoir ( 13.2 ), the application medium preparation station ( 13 ), characterized in that the vacuum deaerator ( 12 ) an additional work space ( 21 ) contains. Coating station ( 1 ) according to claim 1, characterized in that the vacuum deaerator ( 12 ) is divided into two parts of its total volume, the upper part ( 16 ) the venting of the application medium ( 3 ) and the lower area ( 20 ) the additional work space ( 21 ) forms or the storage of the deaerated application medium ( 3a ) serves. Coating station ( 1 ) according to claim 2, characterized in that the upper area ( 16 ) of the vacuum deaerator ( 12 ) with cascaded internals ( 17 ) is provided for multiple degassing or venting. Coating station ( 1 ) for coating a running paper, board or other fibrous web ( 2 ) with at least one liquid to pasty application medium ( 3 ) comprising one above the fibrous web ( 2 ) and spaced from her arranged order head ( 5 ) of a curtain commissioned work ( 4 ) containing the at least one order medium ( 3 ) in the form of a curtain ( 6 ) to the fibrous web ( 2 ), whereby the commissioned work ( 4 ) a vacuum deaerator ( 12 ) for degassing or venting of the at least one application medium ( 3 ) is connected upstream, wherein a discharge line ( 22 ) for degassed application medium ( 3a ), a vacuum generator ( 27 ) and a withdrawal line ( 28 ) is present for separated air or gas and the vacuum deaerator ( 12 ) a mixer ( 13.1 ) and / or reservoir ( 13.2 ), the application medium preparation station ( 13 ), characterized in that both at least one supply line ( 14 ) from the at least one workstation ( 13 ), as well as at least one return line ( 26 ) from the curtain commissioned work ( 4 ), in each case directly in the at least one vacuum venting ( 12 ) opens. Coating station ( 1 ) according to one of claims 1 to 4, characterized in that the at least one vacuum deaerator ( 12 ) an additional work space ( 21 ), whose working volume for the application medium is about 100 to 2000 l, preferably 200 to 1000 l. Coating station ( 1 ) according to at least one of claims 1 to 5, characterized in that in a discharge line ( 22 ) for the deaerated application medium ( 3a ) between the vacuum deaeration tank ( 12 ) and the order header ( 4 ) a filter ( 24 ) is installed. Coating station ( 1 ) according to at least one of the preceding claims, characterized in that in a discharge line ( 22 ) between the vacuum deaerator ( 12 ) and the commissioned work ( 4 ) a measuring device ( 26 ), in particular for air content measurement is arranged. Coating station ( 1 ) according to at least one of the preceding claims, characterized in that in a return line ( 26 ) starting from the commissioned work ( 4 ) and opening into the vacuum deaerator ( 12 ) a filter ( 31 ) is installed. Coating station ( 1 ) according to claim 6 or 8, characterized in that as a filter ( 24 . 31 ) A commercial cartridge filter or rotary filter is provided. Coating station ( 1 ) according to claim 8 or 9, characterized in that in the filter ( 31 ) a supply line ( 33 ) for fresh application medium from the mixer ( 13.1 ) and / or reservoir ( 13.2 ) ( 13 ) and the filtered application medium via a line ( 26 ) in the vacuum deaerator ( 12 ) can be introduced. Coating station ( 1 ) according to at least one of claims 1 to 7, characterized in that fresh application medium from the mixer ( 13.1 ) and / or reservoir ( 13.2 ) ( 13 ) only via one line ( 14 ) in the vacuum deaerator ( 12 ) can be introduced. Coating station ( 1 ) according to at least one of the preceding claims, characterized in that in a return (bypass) line ( 26 ) an idle protection ( 29 ) comprising a collecting element ( 29.1 ) and a control valve ( 29.2 ) is installed. Coating station ( 1 ) according to at least one of the preceding claims, characterized gekennzeich net, that at least one vacuum deaerator ( 12 ) per application medium to be deaerated ( 3 ) is provided Coating station ( 1 ) according to at least one of the preceding claims, characterized in that the vacuum deaerator (s) ( 12 ) as well as filters ( 24 ) and measuring equipment ( 25 ) on a common framework ( 30 ) are mounted.