DE102010031576A1 - Curtain applicator - Google Patents

Abstract

The invention relates to a curtain applicator (1) for dispensing at least one liquid to pasty application medium in the form of a single-layer or multi-layer curtain (3) which essentially falls following the force of gravity onto a substrate (2) to be coated, whereby for guiding the curtain ( 3) at least one edge guide element (5) is provided at its edges over at least part of its fall path, the edge guide element (5) being provided with an auxiliary or lubricant (6) on its side that comes into contact with the falling curtain (3) can be acted upon. According to the invention, a container (7) for the auxiliary or lubricant (6) is provided at a distance (h) above the edge guide element (5), the fill level (F) of which is automatically refilled with auxiliary or lubricant (6), at least one falling supply line (13) leading to the auxiliary or lubricant (6) branches off the container (7), with which the at least one edge guide element (5) with the auxiliary or lubricant (6) can be acted upon.

Description

The invention relates to a curtain applicator for dispensing at least one liquid to pasty application medium in the form of a single or multilayer curtain, which falls substantially to gravity on a substrate to be coated, wherein for guiding the curtain over at least a portion of its fall path away at its edges at least one edge guide element is provided, wherein the edge guide element can be acted upon on its coming into contact with the falling curtain side with an auxiliary or lubricant.

A generic device and a method are for example from the DE A1-197 35 588 known. In this document it is disclosed that for spreading the curtain at each edge as an auxiliary liquid, a separate partial flow of coating color of the inner surface of an immediately adjacent to the outlet slit of the slot nozzle of the curtain edge guide element is supplied.

A device is out of the DE-A1 102 32 949 known. It has also been proposed that the curtain delivered by the curtain applicator be guided by edge guide elements. For this purpose, free rays of a working medium are used as a lubricant for the curtain edges.

The edge guide elements, which are often made of a porous material, bring the curtain close to the substrate to be coated, for example, a paper, cardboard or other fibrous web approach.

The supply of an auxiliary or lubricant or a fluid, for example, in the DE 10 2008 054 92 and the DE 10 2008 042 379 described.

In practice, the supply of the auxiliary or lubricant, z. As water, usually via a pressurized pipe network. This pipe network usually carries air with it. Air in the lubricant can be caused by pumps.

If this assistant or lubricant now contains air, this can lead to detachment of the curtain from the edge guide elements, which leads to an unsatisfactory order quality. But also contamination of the following machine parts is caused by the demolition of the curtain. In the worst case, this can even lead to the demolition of a paper or board web in their manufacturing or finishing process.

It is therefore an object of the invention to provide a curtain applicator, which does not have the disadvantages of the prior art. In particular, an auxiliary or lubricant without air inclusions should be fed to the curtain edge guide elements.

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

According to the invention a arranged at a distance above the edge guide element container for the auxiliary or lubricant is provided, the level of auxiliary or lubricant is automatically replenished, wherein the container branches off at least one auxiliary or lubricant leading supply line, with the at least one edge guide element with the auxiliary or lubricant can be acted upon.

The inventive arrangement is very simple and can be in any existing curtain applicator for single or multi-layer order both in known slot nozzles, as well as with sliding layer nozzles or tandem and Twindüsen for inboard (web width is greater than the curtain width) and overboard -References (web width is smaller than the curtain width) retrofit.

It is very useful if the supply line for the auxiliary or lubricant falls steadily, because it avoids so-called air bags in the line.

The supply line may consist of a rigid tube, such as a downpipe or a flexible hose or a combination of both mentioned embodiments.

It is required for each edge guide element branching off from the container such supply line.

In the event that more than one edge guide element is supplied from one and the same container, it is possible that the supply lines on the first leg to the container as a common line, d. H. are designed as a distribution channel.

It is essential that the container always has to have a filling level or level. The filling level does not necessarily have to remain constant, but must be within predefined minimum-maximum limits. This results in a constant medium pressure, with which the loading of the at least one edge guide element with the auxiliary or lubricant is effected. The height distance of the container for the generation of the medium pressure is also helpful.

The inventive "closed" line system - without further arrangement of a pump - now avoids air bubbles in the auxiliary or lubricant.

Since a constant fluid pressure on the edge guide element and thus a constant flow of the auxiliary or lubricant is achieved, the operation of the curtain applicator can run smoothly.

For narrow machines, a single filled container, to which the edge guide element located on each curtain is connected, is sufficient. This embodiment is particularly cost-effective, because relatively few components and only one control are required.

For wide machines, it is conceivable to use one container per side.

The height at which the container is arranged opposite the at least one edge guide element should be approximately 1 to 10 m. The height depends on the design of the edge guide element (also signable as a curtain holder). The more permeable (eg porous or with passage openings provided) this edge guide element is, the lower the height can be selected.

It is useful if the height is adjustable. This allows the pressure over the height to adapt to the requirements of different edge guide elements.

In an alternative embodiment, it can also be provided that the height can be varied by shifting the maximum-minimum limits of the filling level. As a result, the container can remain in place and the supply pressure is varied so to speak remotely controlled.

It can also be very advantageous if a floating switch known per se is provided for adjusting the filling level of the container. When the level drops, this float switch will open and allow more liquid to flow into the container or shut off the supply of liquid as soon as the level is at normal levels.

Preferably, a control is provided with a control unit.

It is advantageous with regard to a trouble-free curtain application if the filling quantity of auxiliaries or lubricants in the collecting container is about 2 to 100 liters, preferably 5 to 10 liters.

An advantageous embodiment also results when an adjustable throttle valve is installed in the supply line for the auxiliary or lubricant in each case before an edge guide element. Due to the resulting friction in the throttle valve, pressures and thus throughputs between the driver's side and the drive side of the machine in which the curtain application takes place can be adjusted individually. In this case, a simple mechanical arrangement is possible directly next to the curtain application head of the curtain applicator.

A further advantageous embodiment results if in the supply line and / or the distribution channel in each case before a marginal guide element, a so-called, per se known rotameter is installed. So you can set the amount of auxiliaries or lubricants very specific.

As auxiliaries or lubricants is incidentally liquid, preferably water, most preferably demineralized water but also a water / coating mixture or mixtures of surface-active substances, or a water-surfactant, water-thickener, or water-starch mixture in question.

• – stabile Führung des flüssigen Vorhangs ohne Auslenkung und Schwankung;
• – der Vorhang löst sich nicht vom Führungselement; die Führung des Vorhangs ist sowohl bei niedrigen als auch bei hohen Durchflussmengen stabil;
• – der vom Auftragswerk abgegebene Vorhang erzeugt keine Randwülste bzw. Strichgewichtserhöhungen auf der Oberfläche der Faserstoffbahn und weist außerdem eine gleichmäßige Strichschicht auf dem Substrat bzw. der laufenden Faserstoffbahn auf; das Hilfs- bzw. Gleitmittel kann weitestgehend ohne Luftblasen zur Vorhangrandführung zur Verfügung gestellt werden.

The curtain applicator according to the invention has the following advantages:

• - stable guidance of the liquid curtain without deflection and fluctuation;
• - The curtain does not detach from the guide element; curtain guidance is stable at both low and high flow rates;
• The curtain delivered by the applicator does not produce edge beads or line weight increments on the surface of the fibrous web and also has a uniform coating layer on the substrate or the running fibrous web; the auxiliaries or lubricants can be made available to the curtain edge guide as far as possible without air bubbles.

The invention will be explained in more detail with reference to an embodiment.

It shows in a schematic representation:

1 a curtain applicator only schematically indicated with edge guide elements, which can be acted upon by an auxiliary or lubricant, with a view to the machine longitudinal direction

2 : a second embodiment

3 a third embodiment variant

In the figures, the same components are provided with the same reference numerals.

In the 1 is a curtain applicator 1 for coating a substrate 2 shown. In the example, the substrate is a paper, board or other fibrous web moving through a manufacturing and / or finishing machine 2a , which should be coated with a liquid to pasty application medium. The curtain applicator 1 includes some units not shown here for clarity, such as applicator head, air boundary layer control devices, medium collecting devices such as gutters or trays, measuring devices, etc. The said applicator head is above the fibrous web 2a or spaced from her and may be formed as a so-called Gleitschichtdüse or slot nozzle. The application head is machine-wide, ie over the width of the fibrous web shown here 2a reaching, and can both for a multi-layer order, as well as for single-layer order, so for the delivery of a single or multi-layer curtain 3 be educated.

The single or multi-layered curtain 3 essentially follows the gravity of a spoiler edge 4 the curtain head, which is also only indicated, on the fibrous web 2a down and settles on its surface as a coating layer AS.

Like from the 1 can be seen, the curtain-commissioned work 1 lateral, columnar-shaped permeable edge guide elements 5 (also as a curtain holder markable) in each case on the driver side FS and drive side TS of the manufacturing or finishing machine or coating machine on. These edge guide elements 5 serve the guidance and also format limitation of the approx. 200 mm long single or multilayer curtain 3 at its lateral edges.

In the example shown are the edge guide elements 6 within the width of the fibrous web 2a , which is referred to as "inboard" driving.

The two edge guide elements 5 should with an auxiliary or lubricant 6 to guide the edges of the curtain 3 be charged.

This is one above the edge guide elements 5 arranged container 7 for the auxiliary or lubricant 6 available. The container 7 is by means of a pump 8th via a supply line 9 filled until a desired level F is reached. In the example, the capacity is about 10 liters. The level F is kept constant here, including a float switch 10 serves. The float switch 10 Floats, as the name implies, on the surface of the liquid and measures the level F. When it sinks, a signal goes to a control unit 11 is passed on. Then a command to open a valve 12 for the supply of further aids 6 , Upon reaching the level F, the valve closes 12 ,

From the container 7 branches a vertical downpipe 13 the length h between 1 m and 10 m. The downpipe 14 extends to a substantially horizontally extending distribution channel 14 , over each of the two edge guide elements 5 at its upper area with the auxiliary or lubricant 6 be applied, which then on the insides of the edge guide elements 5 , which come in contact with the curtain edges, flows down.

The level F results in a constant medium pressure at the edge guide elements 5 and thus a constant flow without air bubbles in the auxiliary or lubricant 6 , This is always for a trouble-free operation of the curtain applicator 1 taken care of.

Only indicated in this embodiment is that immediately before each edge guide element 5 a rotameter 15 in the distribution channel 14 is installed. This can be the amount of sliding or auxiliary 6 set specifically. The distribution channel 14 branches symmetrically to both edge guide elements 5 from the supply line designed as a downpipe.

As auxiliaries or lubricants 6 Water is preferably provided which is always sufficiently available in the area of a paper-making and / or finishing machine.

2 shows one opposite 1 modified version, which is that the supply line 13 Here is not a rigid downpipe, but two flexible hoses.

Also marked is in the container again 7 the filling level F, which does not necessarily have to be constant, but within the specified minimum (see min) - maximum (see specification "max") - limits should be. The setting is made again via the control unit 11 , which is not shown here. Due to the capacity results in a medium pressure, which is for the application of the on both edges of the curtain 3 existing edge guide elements 5 is needed. The height distance h of the container 7 to the edge guide elements 5 is also shown. Only indicated in this embodiment is that immediately before each edge guide element 5 a rotameter 15 into the supply line 13 is installed. Otherwise, the execution corresponds to that of 1 and should therefore not be described repeatedly.

3 also shows one opposite 1 but also opposite 2 modified version. This is that the supply line 13 here in the first part, which is from the container 7 branches off again, as at 1 , as a strand, but in the downstream direction after split in two strands continued. The two strands extend to the two edge guide elements 5 ,

Also marked is in the container again 7 the filling level F, which is within the specified minimum (see min) - maximum (see max) limits and with the control unit not shown 11 is adjustable and changeable. Immediately before each edge guide element 5 is shown in contrast to the two previous figures that each have a throttle valve 16 into the supply line 13 is installed.

Otherwise, the execution corresponds to that of 1 and 2 and should therefore not be described repeatedly.

LIST OF REFERENCE NUMBERS

1

Curtain applicator

2

substratum

2a

Fibrous web

3

curtain

4

tear-off edge

5

Edge guide element

6

Auxiliary or lubricant

7

container

8th

pump

9

feed

10

float switch

11

control unit

12

Valve

13

supply line

14

distribution channel

15

rotameter

16

throttle valve

AS

application layer

F

level

H

distance

FS

tender side

TS

drive side

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 19735588 A1 [0002]
• DE 10232949 A1 [0003]
• DE 10200805492 [0005]
• DE 102008042379 [0005]

Claims (12)

Curtain applicator ( 1 ) for dispensing at least one liquid to pasty application medium in the form of a monolayer or multilayer curtain (US Pat. 3 essentially following gravity on a substrate to be coated ( 2 ), whereby to guide the curtain ( 3 ) has at least one edge guiding element at its edges along at least part of its fall path ( 5 ) is provided, wherein the edge guide element ( 5 ) at his with the falling curtain ( 3 ) coming into contact with an auxiliary or lubricant ( 6 ) is acted upon, characterized in that a at a distance (h) above the edge guide element ( 5 ) arranged containers ( 7 ) for the auxiliary or lubricant ( 6 ) whose level (F) of auxiliaries or lubricants ( 6 ) is automatically refilled, with the container ( 7 ) at least one falling, the auxiliary or lubricant ( 6 ) leading supply line ( 13 ) branches, with which the at least one edge guide element ( 5 ) with the auxiliary or lubricant ( 6 ) can be acted upon. Curtain applicator according to claim 1, characterized in that the level (F) of the container ( 7 ) or a filling level within predetermined maximum-minimum limits is adjustable. Curtain applicator according to claim 1 or 2, characterized in that the filling level (F) of the container ( 7 ) with a float switch ( 10 ) is kept constant. Curtain applicator according to one of claims 1 to 3, characterized in that a control unit ( 10 ) is provided for controlling the level (F). Curtain applicator according to claim 1, characterized in that the distance (h) of the container ( 7 ) to the at least one edge guide element ( 5 ) is about 1 to 10 m. Curtain applicator according to claim 5, characterized in that the container ( 7 ) in its height (h) is variable or adjustable. Curtain applicator unit according to claim 5, characterized in that the height (h) can be varied in such a way that the minimum and maximum limits of the filling level in the container ( 7 ) shifts. Curtain applicator according to claim 1, characterized in that in the supply line ( 13 ) in each case in front of the edge guiding element ( 5 ) an adjustable throttle valve ( 16 ) is located. Curtain applicator according to claim 1, characterized in that the supply line ( 13 ) into a distribution channel ( 14 ) - and vice versa - flows. Curtain applicator according to at least one of the preceding claims, characterized in that in the supply line ( 13 ) and / or in the distribution channel ( 14 ) a known rotameter ( 15 ) for adjusting the amount of auxiliary or lubricant ( 6 ) for the edge guide element ( 5 ) is installed. Curtain applicator according to at least one of the preceding claims, characterized in that the filling amount of auxiliary or lubricant ( 6 ) in the container ( 7 ) is about 2 to 100 liters, preferably 5-10 liters. Curtain applicator according to at least one of the preceding claims, characterized in that as auxiliary or lubricant ( 6 ) a liquid, preferably water, most preferably demineralized water, but also a water / coating mixture or a water surfactant; Water thickener, water-starch mixture is usable.

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