DE102008040404A1 - Curtain-coating unit for coating a moving paper, cardboard or other fiber web with fluid to pasty coating medium in the form of one or more layered curtain, comprises a function unit of curtain coating head and drip pan - Google Patents

Abstract

The curtain-coating unit comprises a function unit of curtain coating head, drip pan (7, 9) and/or an air barrier removal device (8) that present itself directly over the surface of fiber material web (2) to be coated and in running direction of the web seen directly before the curtain to be delivered. The multi-layered curtain (3) reduces the gravity following on the surface of the fiber material web and produces a coating layer (13). The function units are adapted to the width of the fiber material web. The air barrier removal device with the drip pan forms a component group. The curtain-coating unit comprises a function unit of curtain coating head, drip pan (7, 9) and/or an air barrier removal device (8) that present itself directly over the surface of fiber material web (2) to be coated and in running direction of the web seen directly before the curtain to be delivered. The multi-layered curtain (3) reduces the gravity following on the surface of the fiber material web and produces a coating layer (13). The function units are adapted to the width of the fiber material web. The air barrier removal device with the drip pan forms a component group. The component group and the curtain coating head are movable relative to each other. The curtain coating head is connected over support arm flexibly with the component group and an adjustment of the curtain-coating head is guidable by an operating position in a stand-by position. The curtain coating pan is integrated for forming the component group in the air barrier removing unit. The component group comprises two cutting edges arranged to each other in horizontal direction during starting and stopping the coating process lying in web running direction. The air barrier removing unit and/or the component group comprise a suction opening and/or a blow opening, which are turned respectively to the fiber material web surface and are tightly arranged. The curtain coating head is movable without tipping movement in or against the running direction of the fiber material web. The displacement movements of the air barrier removing unit and/or the component group and/or coating head are guidable on hydraulic, electric or pneumatic way. The air barrier removing unit comprises a plain lower side that is turned to the direction of the fiber material web.

Description

The The invention relates to a curtain applicator for coating a running paper, cardboard or other fibrous web with at least a liquid to pasty application medium in Form of a single or multi-layer curtain, which is essentially following gravity on the surface of the fibrous web falls down and there achieves a coating layer comprising the functional units curtain application head, drip tray and a Air boundary layer removal device, the directly over the fibrous web surface to be coated and in Running direction of the fibrous web seen immediately before the delivered Curtain is located and the functional units substantially to the Width of the fibrous web are adjusted.

A generic device is for example from the WO 03/049871 known. This document discloses an applicator head with which a plurality of application media or a plurality of layers of an application medium can be delivered. This embodiment of a curtain commissioned work is among other things from the EP-A1-1 255 615 known and is referred to in professional circles as "Slide Die", ie Gleitschichtdüse. This so-called sliding layer nozzle, which is also referred to as a cascade nozzle, contains at least two application medium chambers, from which the medium in each case passes through a feed gap, which in each case merges into a slot-shaped outlet nozzle, onto a sliding surface of the sliding layer nozzle. The application medium emerging from the outlet nozzles arranged parallel to each other in succession overlaps one another on this sliding surface. At a trailing edge or as a detachment line to be designated edge of the nozzle, this multilayer separates and falls down as a multilayer curtain either initially on an intermediate guide plate or directly on the substrate to be coated or the surface of the moving fibrous web.

A further embodiment of a curtain coater is a slit nozzle extending over the width of the fibrous web, from which the curtain is discharged downwardly essentially following gravity. Such a commission is from the WO 06/0973676 A1 known.

Another curtain commissioned work is from the WO 2006/008336 A1 known. Thus, in a ready position, the curtain can be collected in a starting channel, cumbersome adjustments of the commissioned work are necessary.

A device for removing, but at least minimizing the registered with the high-speed fibrous web air boundary layers is from the DE-A1 103 58 508 removable.

This removal device is designed plate-like and arranged at a very small distance of only a few millimeters above the fibrous web. In certain embodiments and in solid webs, the air boundary layer removal device may even touch the fibrous web, so to speak "immerse" in it. See in this regard the DE A1-10 2006 036 448 ,

For the start-stop process or in the case of coating interruptions it also necessary a curtain sump for the still or already falling curtain. This will cause pollution the fibrous web, the coating machine and the environment prevented. This embodiment, ie the provision of the air boundary layer removal device and the drip tray (especially since there is still another tub below the Fibrous web gives to catch the over the edge of the web Be submitted curtain parts) requires a relatively large Construction costs.

From the DE.A1-103 59 676 it is known that the drip pan has a nose, that is, a cutting edge for penetrating the curtain.

These Cutting edge is relatively high above the surface of the Fibrous web arranged, which is why the curtain when entering is severed in this far above and thereby to a high "dump height" of separated curtain part and therefore leads to not insignificant, unwanted Abspritzungen.

It is therefore an object of the invention to provide an improved, simpler and specify more compact curtain applicator, which has the disadvantages of the prior art does not have.

The The object of the invention is with a curtain-commissioned work with the Characteristics of claim 1 solved. According to the invention provided that the air boundary layer removal device with the drip tray forms an assembly, said assembly formed and the curtain applicator head are movable relative to each other.

These Arrangement has the advantage that the entire curtain commissioned work, which yes at least the width of the fibrous web to be coated corresponds, is simpler and more compact and less Requires space. It reduces the number of required Individual components and assemblies, drives and required movements. Also, the start and stop process of the curtain coating process be optimized.

It can be provided that the formed assembly air boundary layer removal device with Drip tray carries the curtain applicator head and more stable as the curtain head is formed.

But also the opposite case is possible. In this case is the curtain head is made more stable and the assembly to the curtain head suspended.

A Another possibility is that the necessary Stability only by the connection of both units (ie Assembly and gun) is achieved.

According to the invention provided that the curtain applicator head on support arms articulated with the air boundary layer removal device or the connected assembly according to the invention is and thus a slight adjustment of the curtain application head from an operational to a standby position and vice versa is possible.

The Position change of the order header (here is both to a slot nozzle as well as to a cascade or Gleitschichtdüse thought) is due to the articulated connection, without the order header to tilt with his dispensing nozzle. At a The tilting movement becomes areas of the curtain nozzle wetted with application medium in the normal coating operation do not come in contact with the medium. At the so wetted Areas can accumulate and build up media parts, whereby then there is the risk of disturbances of the curtain in the coating operation. This is so with the articulated invention Connection of the application head avoided.

The Supporting arms are as a so-called coupling rocker or parallel gear formed and each parallel to each other on the plate-like air boundary layer removal device or the common module mounted.

Advantageous is that with the curtain application head also existing edge guide elements or edge guide rails for double-sided leadership the delivered single or multi-layer curtain with movable are.

Around to be able to form the common assembly, it is expedient if the curtain sump directly into the air boundary layer removal device integrated or embedded. The total space requirement is thereby considerably lower. In addition, these can now be Moving components together as an assembly, which in terms of bearings and drives and with regard to necessary supply lines, etc. a lot is easier.

The said assembly thus performs two functions, namely first, the air boundary layer of the high-speed fibrous web to strip or divert and secondly when starting and stopping the coating process the already or still falling curtain catch.

Around the catching when stopping or interrupting the coating process to be able to accomplish is a driving in, so penetrating necessary for the curtain.

Therefore is provided that the front (this is the side in the web running direction seen in front of the curtain) of the assembly formed at least one, preferably two vertically above the other arranged cutting edges whose width in turn to the Width of the integrated drip tray is adjusted. It could but also more than two superimposed cutting be present, staggered one above the other like a Christmas tree are.

Furthermore can be provided that the upper cutting edge opposite a lower cutting edge in the web running direction by a certain Amount offset is arranged, with about 0 to 70 mm, preferably 5 to 10 mm are proposed. By this configuration can the lower cutting edge pulls the curtain into it cut first and cause a pre-cutting. With the upper one Cutting edge is achieved trimming.

The Plumpshöhe is significantly lower than in versions with only one cutting edge, resulting in far fewer Abspritzungen occur. Also the amount of application medium from the lower part of the separated Curtain that is still or already on the surface of the fibrous web falls is low. In addition, advantageously, that The lower cutting edge is very close above the fibrous web surface located. Therefore, on the surface of the fibrous web no unwanted, excessive weight arise when starting the coating process.

The Air boundary layer removal device, d. H. the lower part of common assembly can be designed in various ways.

In a first variant, it may be plate-like and be formed touching the fibrous web surface. However, it is more expedient with regard to the effect of the air boundary layer removal device if at least one intake opening and / or at least one blow opening is present on its underside. The said openings face the fibrous web surface. The said suction does not necessarily have to be integrated in the module but could be located as an extra unit on the upstream side of the assembly.

Also could the blow opening as a slot die be formed over the entire width of the Air boundary layer removal device or the assembly formed extends. This achieves a flat, radial Flow with high kinetic energy. This radiation is at an angle of 5 to 45 ° the direction of movement of Fiber web counter-directed and acts as elastic Barrier and particularly effective against that of the fibrous web entrained air boundary layer.

The openings, ie suction opening and blow opening are arranged so that the radial flow out of the blow opening through the intake together with braked air the air boundary layer is sucked. Here you can by setting an overpressure and setting a negative pressure one optimal ratio of the currents and thus an optimal effect of the air boundary layer removal device to reach.

in the The invention also provides that the air boundary layer removal device and integrated collection tray existing assembly for adjustment the desired position, d. H. Operating or standby position, is movable in or against the direction of the fibrous web, whereas the curtain applicator maintains a fixed position.

A Alternatively, it is to firmly arrange the assembly and the curtain applicator head in or against the direction of the fibrous web movable.

The Speed with moving curtain application head is about 1 to 5 cm / second. Will the out of the air boundary layer removal device and drip tray moves existing assembly is a higher Speed possible. It is up to approx. 1 m / sec. The lighter and flatter this assembly is built, the more it can be moved faster.

The Adjustments are, for example, hydraulic, electrical or pneumatically feasible.

To It should also be mentioned that the lower part of the assembly formed, So the actual air boundary layer removal device, a level has directed towards the fibrous web toward bottom. These Bottom is made of a metal or a wear-resistant Made of plastic or a combination of materials.

One wear-resistant material is especially advantageous when the fibrous web is contacted at one point.

Advantageous with regard to the effect of air boundary layer removal it may also be if the assembly in the direction of movement of the Fibrous web is arranged inclined, the inclination angle can be about 5-30 °.

following The invention is based on an embodiment closer explained. In a schematic representation:

1 : A first variant of the curtain applicator invention in operating position (coating operation) and in a schematic side view

2 : the curtain applicator according to the invention gem. 1 in standby position and schematic side view

3 : A second variant of the curtain applicator invention in operating position (coating operation) and in a schematic side view

4 : the commissioned work according to the invention 3 in standby position and schematic side view

In the individual figures are the same components or designations with provided the same reference number. The individual embodiments should only be provided with reference numerals and explained so far will be like differences to the previous figures.

In the 1 is a curtain commissioned work 1 for coating a running paper, cardboard or other fibrous web 2 with liquid to pasty application media in the form of a single or multi-layered curtain 3 in operating position (coating operation) I shown. The fibrous web 2 runs in the example via two spaced-apart support rollers 4 and 5 that the fibrous web 2 during their run through the coating or fibrous web manufacturing machine lead. But would also be possible only a single support roller below the commissioned work. The movement or running direction of the fibrous web 2 is indicated in the example shown by the arrow L.

The curtain commissioned work 1 also includes above the fibrous web 2 arranged functional units, such as a curtain order header 6 , a curtain sump 7 , an air boundary layer removal device 8th (Also called "Aircut"), and one below the fibrous web 2 existing additional drip tray 9 for catching scraps of paper in a web break and also for collecting the application medium, which is released "overboard", ie falls over the edge of the web. The commissioned work 1 But also does not include shown with various measuring equipment, supply lines, etc.

The order header 6 is here as a so-called sliding layer nozzle (slide the) is formed, which is designed like the other functional units machine width.

The order header 6 has for a multi-layer order, so for each application medium M its own application medium chamber with feed gap on or all on the surface of the curtain application head 3 each in a slot-shaped outlet nozzle according to the desired number of layers. The sliding layer nozzle, ie the application head 6 has on its surface also a downwardly inclined and curved located sliding surface 6a on. The sliding surface 6a goes into a separation or tear-off edge 6b over, in the direction of the fibrous web to be coated 2 shows. From this in the width direction of the commissioned work sheet spoiler 6b , which also machine-wide, as well as the entire order header 6 is, dissolves previously on the sliding surface 6a formed coating layer (or superposed application medium layers in multi-layer application) and forms or form the single or multi-layer curtain 3 out.

The order header 6 However, could also be designed as a slot nozzle - application head with downwardly directed discharge slot.

Incidentally, in the example shown here, the curtain hits 3 on an unsupported area of the railway 2 on that between the backup rollers 4 and 5 lies.

Into the air boundary layer removal device 8th is very space saving the curtain sump 7 integrated, creating a jointly movable assembly 10 originated. When starting and stopping the coating process, the module penetrates 10 with her right side 10a the already or still falling curtain 3 , The right side 10a has two superimposed transverse cutting edges 11 and 12 on.

It can be seen that the lower cutting edge 12 closer than the upper cutting edge 11 to the curtain 3 is arranged. The distance a is about 15 to 60 mm, preferably 25 mm. This distance may need to be readjusted if the so-called teapot effect (with deflection of the curtain 3 ) entry.

The upper cutting edge 11 is opposite the lower cutting edge 12 in the web running direction L by an amount s - away from the curtain - offset. The amount s is about 0 to 70 mm, preferably 5 to 10 mm in size. This achieves that the lower cutting edge 12 first the curtain 3 cuts through when entering. The lower cutting edge 12 thus leaves the curtain 3 or when moving out of the module 10 later than the upper cutting edge 11 ,

The lower cutting edge 12 causes a Vorschneiden the curtain 3 , The regrooving is done with the upper cutting edge 11 accomplished. As a result, the falling truncated coating mass is divided and thus can not lead to an excessive coating weight of the application layer 13 to lead. In addition, occur significantly less sprayings than before when driving in or when retracting, so less cleaning is necessary.

The air boundary layer removal device 8th or the module 10 also has a first channel 14 on that into a suction opening 15 or slot die opens and has a second channel 16 up in a blow hole 17 opens up. Both openings 15 and 17 are each at the bottom of the air boundary layer removal device 8th present and the fibrous web surface 2a facing.

The said first existing channel 14 is placed under vacuum, which is represented by a minus sign. This will be via the suction port 15 sucked the disturbing air boundary layer LG and discharged to the outside.

The second integrated channel 15 is pressurized with air or steam (see the plus sign). From the blow opening 16 , which also like channel 14 and opening 15 across the entire width of the air boundary layer removal device 8th extends, thereby penetrating a flat, radial flow with high kinetic energy to the outside. This radiation is at an angle of approximately 5 to 45 ° of the direction of movement L of the fibrous web 2 opposite direction. As a result, this flow acts as an elastic barrier against the air boundary layer LG entrained by the fibrous web.

Both openings, so intake opening 14 and blowing opening 16 are arranged to each other so that the radial flow from the blow opening 16 through the intake opening 14 is sucked together with braked air of the air boundary layer LG, whereby these disturbing air layers very successful from the sensitive curtain 3 be kept away. In addition, a non-contact web guide is possible. That is, the assembly 10 acts contactless.

The assembly 10 is linearly reciprocable for starting or interrupting the coating process, as the double arrow V shows.

During the operating position shown I is the assembly 10 only partially over the drip tray 9 and below said applicator head and in the direction L of the fibrous web, immediately in front of the curtain 3 and thus at the inlet side Z to the curtain 3 , With her left end 10b is the assembly 10 also exactly above the first support roller 4 ,

The curtain order header 6 is arranged in the example shown in a fixed position.

2 shows a representation of the curtain applicator 1 in standby position II , As you can see is the assembly 10 this has been moved to the right, so that the integrated drip tray 7 the still or already falling curtain 3 can catch, from where the collected medium can also be discharged and, if necessary, after appropriate treatment of the gun is also fed again. The curtain head 6 has opposite the in 1 shown painting position I his position has not changed. This is very advantageous because at the next painting process no costly repositioning of the line of impact of the curtain 3 must take place.

3 shows a second variant of the curtain applicator invention, which with 100 is designated and again as at 1 the operating position I (Prank) shows.

Unlike in 1 shown variant here is the module 10 fixed, but the curtain application head 6 movable.

The air boundary layer removal device 8th or the module 10 is capable of the curtain application head 6 to carry, which is why support arms 18 or a coupling rocker are present. The order header 6 is about joints 19 hinged to the assembly 10 stored and thereby to the module 10 relatively movable or in the desired positions, such as the operating position I according to this 3 and also a standby position II of the curtain-commissioned work, what the following 4 shows, movable. This movement is with curved double arrows in 3 and 4 specified. The order header 6 is in the standby position II where the already or still falling curtain 3 from the drip pan 7 is recorded steeper than in the 3 shown operating position I hired.

When adjusting the position I in II or vice versa, the order header 6 a coupling movement.

With the curtain application head 3 are incidentally also existing curtain edge guide elements 20 with movable.

Not shown here, but in principle is also possible, the back-up roller 4 and 5 relative to the common assembly 10 to move down.

The movements of the assembly 10 or the order header 6 can be preferably carried out hydraulically, electrically or pneumatically.

It should be added that the in 3 and 4 Examples shown preferably for a so-called overboard driving style, ie where the curtain is wider than the fibrous web.

In the examples of 1 and 2 are not marginal guiding elements (or curtain holder) 20 shown, but may also be present. It is an overboard, as well as an inboard driving possible.

With the inboard mode of operation, the module can generally be used 10 for stopping the curtain application between the edge guide elements 20 drive.

1, 100

Curtain applicator

2

Fibrous web

2a

top the fibrous web

3

curtain

4

supporting roll

5

supporting roll

6

Curtain applicator head

6a

sliding surface

6b

tear-off edge

7

drip tray

8th

Air boundary layer remover

9

drip tray

10

module

11

upper cutting edge

12

lower cutting edge

13

application layer

14

first channel

15

suction

16

second channel

17

blowing opening

18

Beam

19

joint

20

Edge guiding element

A

distance

L

motion or direction

LG

Air boundary layer

M

application medium

s

amount for offset

Z

supply side

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

• WO 03/049871 [0002]
• EP 1255615 A1 [0002]
• WO 06/0973676 A1 [0003]
• WO 2006/008336 A1 [0004]
• - DE 10358508 A1 [0005]
• - DE 102006036448 A1 [0006]
• - DE 10359676 [0008]

Claims (9)

Curtain commissioned work ( 1 . 1a . 1b . 1c ) for coating a running paper, board or other fibrous web ( 2 ) with at least one liquid to pasty application medium in the form of a single or multilayer curtain ( 3 ) substantially following gravity on the surface of the fibrous web ( 2 ) and there is a coating layer ( 13 ), comprising the functional units curtain application head ( 6 ), Drip tray ( 7 . 9 ) as well as an air boundary layer removal device ( 8th ) directly above the fibrous web surface to be coated ( 2a ) and in the direction of the fibrous web ( 2 ) seen immediately before the curtain ( 3 ), wherein the functional units substantially to the width of the fibrous web ( 2 ), characterized in that the air boundary layer removal device ( 8th ) with the drip tray ( 7 ) an assembly ( 10 ) and this assembly ( 10 ) and the curtain application head ( 6 ) are movable relative to each other. Curtain coater according to claim 1, characterized in that the curtain application head ( 6 ) via support arms ( 18 ) hinged to the assembly ( 10 ) and thus an adjustment of the curtain application header ( 6 ) from an operating position ( I ) to a standby position ( II ) and vice versa executable. Curtain coater according to claim 1 or 2, characterized in that the curtain sump tray ( 7 ) to form the assembly ( 10 ) into the air boundary layer removal device ( 8th ) is integrated. Curtain coater according to one of claims 1 to 3, characterized in that the assembly ( 10 ) when starting and stopping the coating process with its in the web running direction (L) seen downstream side ( 10b ) the already or still falling curtain ( 3 ), which is why this page ( 10b ) at least one, preferably two superimposed transversely extending cutting edges ( 11 ) and (12) Curtain coater according to one or more of the preceding claims, characterized in that the air boundary layer removal device ( 8th ) or the assembly ( 10 ) an intake opening ( 15 ) and / or a blow opening ( 17 ), both openings ( 15 . 17 ) each of the fibrous web surface ( 2a ) are facing. Curtain coater according to at least one of the preceding claims, characterized in that the air boundary layer removal device ( 8th ) or the assembly ( 10 ) in or against the running direction (L) of the fibrous web ( 2 ), whereas the curtain applicator head ( 6 ) maintains a fixed position. Curtain coater according to at least one of claims 1 to 5, characterized in that the air boundary layer removal device ( 8th ) or the assembly ( 10 ), whereas the curtain applicator head (FIG. 6 ) without a tilting movement in or against the running direction (L) of the fibrous web ( 2 ) is movable. Curtain coater according to one of claims 6 or 7, characterized in that the adjustment movements of the air boundary layer removal device ( 8th ) or the assembly ( 10 ) and / or the order header ( 6 ) are preferably carried out by hydraulic, electrical or pneumatic means. Curtain coater according to at least one of the preceding claims, characterized in that the air boundary layer removal device ( 8th ) has a flat bottom that the fibrous web surface ( 2a ), wherein this underside is made of a metal and / or a wear-resistant plastic.