EP2172592B1 - Curtain application device - Google Patents

Abstract

The curtain coater (1) comprises a curtain-coater head (3) arranged above a fibrous material web (2) and corresponding to the width of the fibrous material web for delivering liquid to pasty application medium in the form of a single- or multi-layered curtain (4), which falls onto the fibrous material web following the gravity, and edge elements for guiding the curtain over its falling path i.e. between a trailing edge (5) of the coater head and the surface of the fibrous material web on its both edges. The edge guiding element is admitted with an auxiliary fluid for guiding the curtain. The curtain coater (1) comprises a curtain-coater head (3) arranged above a fibrous material web (2) and corresponding to the width of the fibrous material web for delivering liquid to pasty application medium in the form of a single- or multi-layered curtain (4), which falls onto the fibrous material web following the gravity, and edge elements for guiding the curtain over its falling path i.e. between a trailing edge (5) of the coater head and the surface of the fibrous material web on its both edges. The edge guiding element is admitted with an auxiliary fluid for guiding the curtain, and consists of a retainer and a guiding strip accommodated in the retainer. A partial area of an outer surface of the guiding strip is turned to the curtain edge and is formed in an elevated manner. The edge guiding element is designed, so that two streams of the auxiliary fluid sliding down the guiding strip are present parallel to the curtain and guide the curtain and/or the edge of the curtain. The retainer has two opposing channels, which receive the auxiliary fluid and between which the guiding strip is concentrically inserted, so that fluid-outlet-gaps originating from the channels are present between the retainer and the guiding strip, where the guiding strip has a contact surface for the falling curtain. The guiding strip has two opposing channels, which receive the auxiliary fluid and between which a projection of the guiding strip is present, where the projection has the contact surface on its side turned to the curtain. The side of the guiding strip turned to the curtain and/or the projection is rounded off and is provided with radius of 2-2.5 mm. The total guiding strips have a circular-cylindrical shape with a radius of 2-2.5 mm. The contact surface of the guiding strip is polished and consists of non-rusted metal such as aluminum, brass or stainless steel, or plastic. The auxiliary fluid is demineralized water, and water/coating color mixture or a mixture of water with surfactants, thickeners and starch, where 1-10 l/h of the auxiliary fluid are required for guiding and stabilizing the falling curtain. The curtain coater includes a sucking system on the lower side of the edge guiding element, a first suction opening and a second suction opening. The first suction opening is lockable with a counter surface of the moving web during the coating process. A suction effect of the second suction opening, which acts parallel to a web plane and is directed to the curtain, is reinforced.

Description

The invention relates to a curtain applicator for coating a running paper, cardboard or other fibrous web, comprising a disposed above the fibrous web and at least the width of the fibrous web corresponding curtain applicator for dispensing at least one liquid to pasty application medium in the form of a on or multilayer curtain, which falls substantially to gravity following the fibrous web, wherein for guiding the curtain across its fall path away, ie is provided between a spoiler edge of the applicator head and the surface of the fibrous web at its two edges depending on an edge guide element, wherein the edge guide element is acted upon with an auxiliary liquid for guiding the curtain.

A generic device and a method is for example from the DE 197 35 588 known. In this document it is disclosed that for spreading the curtain at each edge a separate partial stream of coating color of the inner surface of an immediately adjacent to the outlet slit of the slot nozzle of the curtain guide element is supplied. Below the guide element, a separating element is still arranged, which separates the respective edge of the curtain and discharges to the outside.

A generic device is from the DE -A1 102 32 949 (HPU 11401). In this case, it has been proposed that the curtain delivered by the curtain application unit is guided by edge guiding elements and corresponding emitted free jets of an operating medium, as a lubricant for the curtain edges, so to speak. The leadership of the curtain is not optimal with this solution. Cause is seen in the free-falling, but laterally unhindered propagation and / or deflection of the working medium beams.

With the known curtain applicators both only one layer and several layers of an application medium are deliverable. The order media can thereby be of different kind. An embodiment of a curtain commissioned work is among others 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 contains at least two application medium chambers from which the medium in each case reaches a sliding surface of the sliding layer nozzle via a feed gap, which in turn merges in each case into a slot-shaped outlet nozzle. The application medium emerging from the discharge nozzles arranged in parallel one behind the other overlaps one another. 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.

But there are also other versions of applicator heads are known in which one or more slot nozzles point down towards the underlying fibrous web. This is on the DE-A1 10012344 for single-layer order and the DE-A1 10359117 directed for multi-layer order.

When painting - both single-layer and multi-layer application - with the Curtain Coater (curtain coater), the coating width can be equal to or less than the width of the fibrous web, which is referred to as "inboard" -Fahrweise.

In the case of the so-called "overboard" approach, on the other hand, the curtain width is greater than the width of the fibrous web.

In practice edge guiding elements made of porous material are currently being used. These edge guide elements bring the curtain, which is about 200m long, close to the fibrous web. The disadvantage here is that the porous material often clogged.

The serving as a lubricant auxiliary fluid or water is still its amount undefined. The liquid used must run constantly, otherwise there is a danger of blockage. The required amount of liquid is enormously high and is at least 2 to 15l / h. This amount is higher, the higher the flow rate of the curtain.

It is therefore an object of the invention to provide a device which no longer has the disadvantages of the prior art.

The object of the invention is achieved with a curtain applicator with the features of claim 1.

According to the invention, it is provided that each edge guide element consists of a holder and a guide strip received in the holder, wherein a portion of the outer surface of the guide bar facing the curtain edge and raised and wherein the edge guide element is designed such that two parallel to the curtain, the guide bar down sliding currents are present on auxiliary liquid, which lead the curtain or the edge of the curtain on both sides.

The inventors have recognized that with two parallel auxiliary liquid streams a considerably safer and more stable guidance of the liquid curtain is possible.

The bracket extending in the longitudinal direction of the track encompasses the circumference of the guide rail to approximately 30 to 70%. The length of the bracket and the guide bar are essentially the same.

In an expedient embodiment, the holder has two diametrically opposite, the auxiliary liquid receiving recesses or channels. In a first embodiment, the guide bar is located centrally between the two channels. In a further possible embodiment, the guide strip accommodated in the holder has the two channels.

In both variants, starting from each channel, there is a liquid passage gap between the holder and the guide strip. It is important that the guide bar is raised at least on the side facing the curtain or at its acted upon by the auxiliary liquid part of the outer periphery including a contact surface to the falling curtain, preferably rounded. The curtain edges can thereby create approximately concave on this contact surface and stretch in the direction of the vertices of the guide bar.

The curtain is thereby guided parallel to the falling direction of the curtain between the two auxiliary liquid flows or films which are parallel to one another and fall vertically along the outer surface of the guide strip. The two films thus represent a barrier that the curtain can not skip at its edge. In other words, the application medium curtain runs down along the guide bar, thereby forming a barrier between the two auxiliary liquid streams. The curtain is trapped, as it were, between the two auxiliary liquid flows and thus can not deviate or deflect. Obviously, the surface tension of the application medium, ie that of the curtain, supports this act of guiding. The order medium curtain is therefore very stable.
It has also been found in experiments that in certain cases, the auxiliary liquid with the curtain on the outer edge of the curtain slightly mixed. It was also found that no mixing took place.

Completely surprisingly, however, the curtain has automatically applied to the contact surface in all attempts, without the operating staff of the coating machine had to help by hand.

It is also advantageous if a thin film of auxiliary fluid forms between the medium curtain and the guide rail, ie when auxiliary liquid flows down the vertical guide rail. As a result, possible deposits on the contact surface can be avoided.

It is expedient that the stability of the curtain can be optimized by adjusting the flow rate. The optimum flow rate was determined in tests 1 to 10 l / h.

The auxiliary liquid is preferably water, most preferably demineralized water. But even a water / coating mixture or, for example, a water / surfactant, water / thickener, water / starch mixture, etc. is well suited.

The two parallel auxiliary liquids can be the same type, but also different.

As a guide bar is particularly suitable, as already said, a circular cylindrical rod with a diameter of 2-20mm, preferably 2.5-6mm, most preferably 4-5mm.
However, it can also be formed semicircular, elliptical-cylindrical, semi-elliptical or prismatic cylindrical with rounded corners.
At the least, however, the guide strip should be designed to be raised on the side facing the media curtain. Again, radii are provided in a circular cylindrical shape between 1-10mm, preferably 1.25-3, most preferably 2-2.5mm.

The flow behavior of the auxiliary liquid is positively influenced if at least the contact surface with the curtain consists of a stainless metal, which is also polished. The material can be aluminum, brass or stainless steel. However, the drainage surface may also consist of plastic, in particular Teflon.

The object of the invention is also achieved with a curtain applicator according to claim 10.
A solution for improving the curtain stability and avoiding undesirable edge thickening could be found.

According to the invention it is provided that at the bottom, the surface of the fibrous web associated end of the edge guide element is a suction system. This suction system has a first suction opening and a second suction opening. The first suction opening can cooperate with a counter surface. The mating surface here represents the continuous fibrous web. During the coating operation (with inboard driving), the web is pressed against this first suction opening and thereby closed. The suction, ie the suction and suction speed of the second acting in web plane suction opening is thereby larger. As a result, the edge of the curtain, including auxiliary fluid, can be optimally extracted at its lower end. At the same time, undesirable application medium accumulations are equalized by constriction on the web surface. The suction sucks the web a bit with and thereby at the same time the web is stabilized in the edge region. The distance between the web and the curtain holders, ie the edge guide elements, is automatically set to 0mm.
Without this suction effect (if the web does not run along the edge guide element or the edge guide element is lifted from the web) much less or no application medium is sucked in by the curtain, so that the application medium can not or only partially reach the suction system.

Due to the structural design of the extraction system, the function change - suction with or without mating surface - automatically. The advantage is that without additional design or process engineering, the suction works optimally in the brushing operation, but that it reduces the suction of application medium outside of the coating operation without counter surface.

• stabile Führung des flüssigen Vorhangs ohne Auslenkung und Schwankung
• der Vorhang löst sich nicht vom Führungselement
• der Vorhang legt sich selbsttätig an die Führungsleisten an
• die Führungsleisten sind selbstreinigend
• die Führung des Vorhangs ist sowohl bei niedrigen (2,5l/min/m) als auch bei hohen (>30l/min/m) Durchflussmengen stabil
• der vom Auftragswerk abgegebene Vorhang erzeugt keine Randwülste bzw. Strichgewichtserhöhungen auf der Oberfläche der Faserstoffbahn
• die vorgeschlagene Vorhangsführung eignet sich für Auftragswerke mit Schlitzdüsen, für Gleitschichtdüsen, für Tandem- und Twindüsen sowie für Einschicht- oder Mehrschichtauftrag
• die vorgeschlagene Vorhangsführung eignet sich gleichermaßen gut für inboard-Fahrweise (Bahnbreite ist größer als die Vorhangsbreite) und overboard-Fahrweise (Bahnbreite ist kleiner als die Vorhangbreite)
• die vorgeschlagene Vorhangsführung eignet sich gleichermaßen gut für einen Auftrag im gestützten Bereich der Faserstoffbahn, als auch für einen Auftrag im freien Zug,
• für die Vorhangführung ist nur eine geringe Hilfsflüssigkeitsmenge notwendig
• einfache Bauweise
• neuartiges Absaugsystem
• nachträglicher Einbau in bestehende Vorhang-Auftragswerke ist möglich

The curtain coating units according to the invention have the following advantages:

• stable guidance of the liquid curtain without deflection and fluctuation
• the curtain does not come off the guide element
• The curtain attaches automatically to the guide rails
• The guide rails are self-cleaning
• Curtain guidance is stable at both low (2.5l / min) and high (> 30l / min / m) flow rates
• the curtain delivered by the commissioned work does not produce edge beads or line weight increases on the surface of the fibrous web
• The proposed curtain guide is suitable for commissioned work with slot nozzles, for sliding layer nozzles, for tandem and Twindüsen and for single-layer or multi-layer application
• The proposed curtain guide is equally well suited for inboard driving (web width is greater than the curtain width) and overboard driving (web width is smaller than the curtain width)
• The proposed curtain guide is equally well suited for an order in the supported area of the fibrous web, as well as for a job in the open,
• for the curtain guide only a small amount of auxiliary liquid is necessary
• simple construction
• new extraction system
• Subsequent installation in existing curtain coating units is possible

Figur 1:

ein erfindungsgemäßes Vorhang-Auftragwerk mit Randführungs- elementen in schematischer perspektivischer Darstellung

Figur 2:

eine Schnittdarstellung des erfindungsgemäßen Randführungs- elementes aus Figur 1, entlang der Schnittlinie AA,

Figur 3a bis 3d:

eine Schnittdarstellung des erfindungsgemäßen Randführungs- elementes aus Figur 1, entlang der Schnittlinie AA,

Figur 4:

eine Seitenansicht auf den unteren Bereich des erfindungsgemäßen Randführungselementes aus Figur 1,

Figur 5a und 5b:

schematische Darstellungen des Auftragsergebnisses ohne und mit erfindungsgemäßem Auftragswerk

The invention will be explained in more detail with reference to an embodiment. In a schematic representation:

FIG. 1:

an inventive curtain applicator with edge guiding elements in a schematic perspective view

FIG. 2:

a sectional view of the edge guiding element according to the invention FIG. 1 , along the section line AA,

FIGS. 3a to 3d:

a sectional view of the edge guiding element according to the invention FIG. 1 , along the section line AA,

FIG. 4:

a side view on the lower area of the Inventive edge guide element FIG. 1 .

FIGS. 5a and 5b :

schematic representations of the order result without and with inventive commissioned work

In the FIG. 1 For example, a curtain applicator 1 for coating a paper, board or other fibrous web 2 that moves in the direction L is shown with a liquid to pasty application medium M. It comprises, in addition to some not shown here units, such as air boundary layer control devices, start-stop collecting devices, especially gutters or trays, measuring equipment, feed lines, etc. one above the fibrous web 2 and spaced therefrom arranged and only slightly hinted curtain application head. 3 This application head 3 may be formed as a so-called Gleitschichtdüse or slot nozzle and is machine width, so reaching across the width of the fibrous web 2, executed. The application head 3 can be configured both for a multi-layer application and for a single-layer application, that is to say for a single-layer or multi-layer curtain 4. The single-layer or multi-layer curtain 4 drops from the tear-off edge 5 of the application head 3 essentially following the force of gravity, down onto the fibrous web 2 running in the direction L, and deposits on its surface as a coating layer AS.

How out FIG. 1 can be seen, the curtain applicator 1 each on each curtain side, so on the driver side FS and drive side TS, (in the figures, only one side is shown) on a lateral, columnar trained edge guide element 6. This is to avoid cross contraction. This edge guide element 6 thus serves to guide and also limit the size of the approximately 200 mm long single- or multilayer curtain 4 between the tear-off edge 5 and the surface of the fibrous web 2 at its lateral edges. In the FIG. 1 As already mentioned, only the one edge 4a is shown.

This in FIG. 1 visible edge guide element 6 is adjustable in the width direction of the curtain 4, as the horizontal double arrow V indicates. In the example shown, the edge guide element 6 is within the width of the fibrous web 2, what is called "inboard" driving.

In FIG. 2 is a the edge guide element 6 from FIG. 1 shown more clearly. It shows this in section along the section line AA FIG. 1

The edge guide element 6 has in this embodiment, a holder 7, in which two diametrically opposite recesses or channels 8a and 8b are incorporated. These channels 8a and 8b are acted upon by an auxiliary liquid 9, in particular water for guiding or as a lubricant for the curtain 4. Between the auxiliary liquid 9 leading recesses or channels 8 in the middle of a partially the inner side 10 of the edge guide element 6 forming guide rail 11 is installed. How clearly in FIG. 2 can be seen, from the recesses or the channels 8a, 8b outgoing auxiliary fluid passage column 12 of about 0.5 to 5mm width between the holder 7 and guide bar 11 are present. The auxiliary liquid 9 is passed at the uppermost point of the vertical guide bar 11 in the channels 8a, 8b from top to bottom. Due to the effect of gravity, the auxiliary liquid flows in the same direction as the guided curtain 4. The guide strip 11 is at least in the region of the inner side 10 of the edge guide element 6 or on its acted upon by the auxiliary liquid 9 outer surface 13 including a contact surface 14 for the falling curtain. 4 rounded (also elliptic or polygonal with rounded edges) shaped. The curtain or its edge 4a wets this raised area on both sides of the curtain 4, thereby preventing the detachment from the guide bar. As the auxiliary liquid 9, water is preferably provided which is sufficiently present in the area of a paper machine or coater. Only about 1 to 10 l / h auxiliary liquid 9 are necessary for guiding and stabilizing the falling curtain 4 when using the edge guide element 6 consisting of the holder 7 and guide strip 11.

The guide bar 11 has, as already mentioned, a circular cross-section, on the outer surface 13, the curtain edge 4 a or not shown curtain edge 4 b particularly well applies and the curtain 4 is characterized over its entire Fall height does not constrict and remains stable.

The contact surface 14 of the guide rail 11 may be polished. In the example chosen, the guide bar is a circular bar with a diameter of 4 mm and is also made of aluminum.

The extending in the longitudinal direction of the web, described above holder 7 surrounds the circumference of the guide rail 11 to about 30 to 70% and is in the FIG. 2 indicated by a circular arrow U (for looping). The length of the holder and that of the guide bar are substantially the same and correspond substantially to the drop height of the curtain 4.

In FIG. 3a is another embodiment from that in FIG. 2 shown shown. This embodiment shows a semi-elliptical trained guide rail 11. The holder 7 is here in three parts, consisting of support plate 7a and side parts 7b and 7c formed. In the side part 7a is the channel 8a and in the side part 7b of the channel 8b. The curtain 4 is clamped here between the draining on the guide rail 11 auxiliary liquid streams 9, so that the curtain touches the contact surface 14.

In FIG. 3b It is shown that the guide rail 11 has a semicircular cross section and a holder 7 which is divided into parts 7a, 7b. Also as shown in the previous figures, the channels 8a and 8b are provided in the holder 7. The outgoing from the channels auxiliary liquid 9 has here formed a thin film between the guide rail 11 and the curtain 4 including the contact surface 14.

In Figure 3c is a one-piece bracket 7, as in FIG. 2 to see, available. Only the guide bar 11 is here instead of a circular or elliptical shape as a polygon shaped so that in the end results in a convex shape .. The curtain 4 is also here as in FIG. 2 and 3a trapped between the draining on the guide rail 11 auxiliary liquid streams 9, so the curtain 4 touches the contact surface 14.

The 3d figure shows a further embodiment of the holder 7 and the guide rail 11. The holder is designed here U-shaped. In contrast to the previous embodiments shown here, the guide strip 7 includes the two opposing channels 8a and 8b receiving the auxiliary liquid 9. The guide strip 7 is designed so that between the channels 8a and 8b an extension 15 is present. The extension 15 is located on its side facing the curtain 4 and also has the contact surface 14 for the falling curtain 4. Also in this embodiment, between the channels 8a, 8b, the liquid passage column 12 between the holder 7 and guide bar 11 (here at the extension 15) are present. The side facing the curtain 4 with the contact surface 14 is also raised or rounded. The radius is about 2mm.

FIG. 4 shows a new embodiment of an extraction of coating medium in the edge region of the fibrous web. At the bottom of the edge guide element 6, a suction system is arranged. It has a first suction opening 16 and a second suction opening 17. The first suction opening 16 can be closed with a mating surface, in particular with the moving fibrous web 2 during the coating process. This means that the suction works differently with the counter surface than without the counter surface. With the counter surface pressed against the suction opening 16, the suction effect of the second curtain 4 directed towards the suction plane 17 acting parallel to the web plane is thereby considerably greater. Without mating surface (without the fibrous web, for example, under the edge guide bar 6) is much less or no coating medium sucked. The function change is effected by the illustrated operating principle and switches over almost automatically. The advantage is that the extraction works optimally in the brushing operation, but that outside the coating operation, ie when the counter-surface or fibrous web 2 does not close the suction opening 16, the suction (see arrow E1) is reduced to a minimum. As a result, as little application medium as possible can reach the suction system or lines 18 (arrow E2). The extraction system is thereby less dirty and less prone to failure.

Incidentally, the fibrous web 2 is sucked slightly in the suction, which advantageously stabilizes the fibrous web 2 in the edge region.
The distance a of the web 2 from the edge guide element 7 is thereby automatically set to 0mm. The particular advantage here is that "heavy edges", ie edge thickening 19 in the application layer AS, caused by constrictions 20 of the curtain 4 are avoided. This undesirable effect with the edge thickening 19, constriction 20 and a distance a between the surface of the fibrous web and the underside of the edge guide element 6 is in FIG. 5a indicated.
FIG. 5b on the other hand shows a level application layer AS achieved with the applicator according to the invention without the edge thickenings or edge beads 19 without constriction 20 and also a distance a of 0 mm.

LIST OF REFERENCE NUMBERS

1

Curtain applicator

2

Fibrous web

3

Curtain applicator head

4

curtain

4a, 4b

lateral curtain edge

5

tear-off edge

6

Edge guide element

7

bracket

7a

Retaining plate

7b, 7c

side panel

8a, 8b

Channel or recess

9

auxiliary liquid

10

inside

11

guide rail

12

Passage gap

13

outer surface

14

contact area

15

Extension of the guide rail

16

first suction opening

17

second suction opening

18

suction

19

Edge thickening of the application layer

20

Constriction of the curtain

AS

application layer

L

direction

M

application medium

FS

tender side

TS

drive side

V

Double-arrow adjustment

E1, E2

Arrow exhaust direction

U

wrap

Claims (7)

1. Curtain applicator (1) for coating a running paper web, cardboard web or other fibrous web (2), having a curtain applicator head (3) which is arranged above the fibrous web (2) and corresponds at least to the width of the fibrous web (2) for dispensing at least one liquid to pasty application medium (M) in the form of a single-layer or multiple-layer curtain (4) which falls onto the fibrous web (2) in a manner which substantially follows gravity, in each case one edge guiding element (6) being provided to guide the curtain (4) over its falling path, that is to say between a breakaway edge (5) of the applicator head (3) and the surface of the fibrous web (2) at the two edges (4a, 4b) of the said curtain (4), the edge guiding element (6) being loaded with an auxiliary liquid (9) in order to guide the curtain (4), and having an extraction system for extracting the curtain edge (4a, 4b) including auxiliary liquid (9), characterized in that each edge guiding element (6) consists of a holder (7) and a guide bar (11) which is received in the holder (7), the holder (7) having two channels (8a, 8b) which lie opposite one another, receive the auxiliary liquid (9) and between which centrally the guide bar (11) is inserted in such a way that liquid passage gaps (12) which emanate from the channels (8a, 8b) remain between the holder (7) and guide bar (11), and the guide bar (11) having a contact face (14) for the falling curtain (4), which contact face (14) is configured as a part region of the outer face (13) of the guide bar (11) so as to be elevated and to face the curtain edge (4a, 4b), and the two streams of auxiliary liquid (9) which slide down the guide bar (11) parallel to the curtain (4) guiding the curtain (4) or the edge (4a, 4b) of the curtain (4) on both sides, and in that, moreover, the extraction system is situated on the underside of the edge guiding element (6), there being a first extraction opening (16) and a second extraction opening (17), and it being possible for the first extraction opening (16) to be closed by way of a corresponding face, in particular the running fibrous web (2) during the coating operation, and it being possible for the suction action of the second extraction opening (17) which is directed towards the curtain (4) and acts parallel to the web plane to be intensified as a result.
2. Curtain applicator (1) according to Claim 1, characterized in that the guide bar (11) has two channels (8a, 8b) which lie opposite one another, receive the auxiliary liquid (9) and between which there is a projection (15) of the guide bar (11), the projection (15) having the contact face (14) for the falling curtain (4) on its side which faces the curtain (4), and there being liquid passage gaps (12) between the holder (7) and guide bar (11) which emanate from the channels (8a, 8b).
3. Curtain applicator according to Claim 1 or 2, characterized in that at least that side of the guide bar (11) or of the projection (15) which faces the curtain (4) is rounded and is provided with a radius between 1 and 10 mm, preferably between 1.25 and 5 mm, most preferably between 2 and 2.5 mm.
4. Curtain applicator according to Claim 1, characterized in that the entire guide bar (11) has a circular-cylindrical shape with a radius between 1 and 10 mm, preferably between 1.25 and 3 mm, most preferably between 2 and 2.5 mm.
5. Curtain applicator according to at least one of the preceding claims, characterized in that at least the contact face (14) of the guide bar (11) is polished and is composed of non-corroding metal, such as aluminium, brass or stainless steel, or else of plastic.
6. Curtain applicator according to at least one of the preceding claims, characterized in that preferably water, most preferably de-ionized water, but also a water/coating colour mixture or a mixture of water with, for example, surfactants, thickeners, size can be used as auxiliary liquid (9).
7. Curtain applicator according to at least one of the preceding claims, characterized in that only approximately from 1 to 10 1/h of auxiliary liquid (9) is/are necessary to guide and stabilize the falling curtain (4).

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