EP2070599A2 - Curtain application unit - Google Patents

Abstract

The tool has coating heads (1a, 1b) arranged above a fibrous sheet material (w) for dispensing downwardly directed coating medium to form medium curtains (c1, c2). A guiding plate (B) extends in a moving direction (L) of the sheet material, and the heads are adjustable in height and position in the moving direction. Edge guides (2) are provided in a region of both side edges of the guiding plate, and correspond to length of the guiding plate. The guides are adjustable in a breadth direction of the tool for adjusting and retention of breadth of all medium curtains and sliding layers (r1, r2).

Description

The present invention relates to a curtain applicator for coating a running paper, cardboard or other fibrous web, comprising at least two above the fibrous web arranged applicator heads, each directed downward application medium and each form medium curtains, having also in the running direction of the fibrous web below the applicator heads and forming an inclined plane guide plate, which receives the output from the applicator heads in order on its inclined plane, the guide plate down the medium curtains along the inclined plane in sliding layers and then from a trailing edge at the bottom of the guide plate flow as at least two-layer medium curtain on the surface of the fibrous web.

Coated paper such as printing paper, pressure-sensitive paper, thermal paper, catalogs, etc. is made by running a running web through a coater and then drying.

Machines that apply application media in this manner are called coaters.

Coating machines are conventionally in the form of blade coaters which work with a doctor blade element, such as a blade or doctor blade or an air knife, and which use the method of replenishment. That is, it is in this case applied to the web application medium in abundance and metered by means of doctor blade scraped off the excess application medium or blown away by means of the air knife. However, the metering has disadvantages, such that the fluid pressure during application of the application medium to the web, through the pressure of the squeegee o. Ä. A lot of application medium penetrates into the web and that by the wear of squeegee, rod o. Ä., The maintenance costs are high. In addition, the superfluous scrapped medium must be removed and regenerated, which is complicated and expensive.

In recent years, curtain coaters have frequently been used to coat the surface of a web of material, i. a paper-cardboard or other fibrous web used. With the help of a curtain applicator coating is done "contactless", i. There is no additional dosage.

The curtain coating is carried out in such a way that the relevant application medium is delivered to the moving web by an application head arranged above the web. For this purpose, the at least web-width application head has an application medium chamber and a likewise at least web-wide nozzle for dispensing the application medium in the form of a curtain layer. The delivered curtain layer then deposits on the surface of the web as a coating layer.

Curtain commissioned work as I said, unlike conventional coating machines. So it is only given as much to order medium, as will remain on the track. There is, as I said, no replenishment and there are no wearing parts, such as doctor elements available. This achieves advantages such that the maintenance is easy, the brushing amount can be easily regulated with high precision, the operability is good, and the effect of the surface enhancement by Contour Coat is high.

From the Japanese Patent Publication No. 2006-247611 is known such a curtain commissioned work. There it is disclosed that there are two or more application heads with which two or more layers can be applied to the material web.

In the FIG. 5 This prior art is shown in a partial sectional drawing of a curtain coater for two layers.

As in FIG. 5 2, the two-layer curtain applicator has two curtain heads 1a and 1b which discharge the application media ta and tb flowing through the inside of the slits da and db, respectively, downwardly. In addition, a guide plate B is provided in the form of an inclined plane Ba. On this guide plate B, the curtains ca and cb emitted by the two curtain heads 1a and 1b lay down in sequence as a two-layered medium layer ra and rb. From a downwardly directed curtain guide part Bb of the guide plate B at the lower edge part of this inclined plane Ba, this double layer reaches the surface of the fibrous web w as a two-layer medium curtain ca, cb.

In this way, the two coating layers sa (lower layer) and sb (upper layer) are formed on the surface of the moving web w. Furthermore, the arrow shows the direction of movement of the web w.

Incidentally, the curtain layers ca and cb fall down from the guns 1a and 1b by their own weight, but the surface tension of the coating medium causes the edge portions to be drawn toward the inside and the width of the curtain layers ca and cb to become narrower (constricted), so that a so-called "neck-in" occurs. To prevent such neck-in, an edge guide is provided.

Fig. 4 is a conceptual drawing of this edge guide. In the drawing, 1 is the applicator head, 2 is the edge guide, c is the medium curtain layer, and B is the guide plate. Since the edge guide 2 is made of metal and is hydrophilic, it has the effect of preventing neck-in.

• die Flussmenge gering ist,
• die Dicke des Mediumsvorhangs c dünn ist, und dass der Vorhang c, wie auf der Zeichnung ersichtlich, während des Herabfallens durch sein Eigengewicht in Breitenrichtung zerrissen wird und der Fluss eine geteilte Form annimmt.

But by the specific characteristics of the order medium happens if the distance s from the applicator head 1 to the guide plate B is inappropriate, that

• the flow rate is low,
• the thickness of the medium curtain c is thin, and that the curtain c, as seen in the drawing, is torn during its fall by its own weight in the width direction and the flow takes a split shape.

In order to ensure that such a phenomenon does not occur, the margin guide 2 could be replaced by a shorter one. It would certainly be possible to shorten the distance s from the application head 1 to the guide plate B up to the distance s1 before tearing in the width direction.

However, if this is realized, in the case of a large amount of flow, the layer r (r1, r2) on the guide plate B may become irregular.

Especially if at Fig. 5 the distance s from the second layer applying head 1b to the guide plate B is too short, it happens that the layer ra formed by the first layer coating head 1a on the guide plate B is scratched.

The invention is therefore based on the object to provide a curtain applicator available that does not have these disadvantages.

According to the invention the object is achieved in that the application heads are adjustable in height and in their position in the direction of movement of the fibrous web edge guides are provided in the region of both lateral edges of the guide plate, which correspond substantially to the length of extending in the web running direction guide plate and in Width direction of the commissioned work, are adjustable to adjust and maintain the width of all delivered medium curtains and sliding layers.

It is the case that the width of the application media dispensed from the application heads and the dimension between the inner surfaces of the one pair of edge guides can be regulated.

Effect and effect of the present invention are as follows.

In the vicinity of both edges in the widthwise direction of the surface of the guide plate which receives the medium curtains discharged from the plurality of guns sequentially on an inclined plane, flow down along the inclined plane and from the downwardly directed curtain guide at the bottom as a medium curtain on the surface of the web is allowed to flow, a pair of edge guides are provided on a sliding basis and along the surface of the edge guides on a sliding basis the applicator heads are movable. As a result, the height of the medium curtains from the dispensing from the guns to reach the guide plate is easily adjustable. Also, even if the flow amount is small and the thickness of the medium curtain is thin, it can not happen that, as the medium curtain falls down by its own weight, it tears in the width direction and becomes a split flow. Likewise, it does not happen that the medium layer on the guide plate becomes irregular, or that the medium layer on the guide plate is scratched by another application head, so that a stable medium layer of uniform thickness can be obtained on the guide plate. Furthermore, the provision of multiple edge guides with different lengths and the effort to replace them, saved.

Best embodiments of the invention:

Hereinafter, an embodiment of the present invention will be explained with reference to the drawings.

Fig. 1 :

eine Seitenansicht des den Vorhang bildenden Teils eines Vorhang-Auftragswerkes gemäß der vorliegenden Erfindung,

Fig. 2:

einen Schnitt am Pfeil A von Fig. 1,

Fig. 3:

einen Schnitt am Pfeil B von Fig. 1.

Fig. 4:

eine Vorderansicht eines Vorhang- Auftragswerkes mit Randführung gemäß dem Stand der Technik.

Fig. 5:

eine Seitenansicht des den Vorhang bildenden Teils eines Vorhang-Auftragswerkes gemäß dem Stand der Technik

Show it:

Fig. 1:

a side view of the curtain forming part of a curtain applicator according to the present invention,

Fig. 2:

a section on the arrow A of Fig. 1 .

3:

a section on the arrow B of Fig. 1 ,

4:

a front view of a curtain applicator with edge guide according to the prior art.

Fig. 5:

a side view of the curtain forming part of a curtain applicator according to the prior art

Further, in these figures, for the parts which correspond to those of in Fig. 4 and Fig. 5 explained prior art, the same reference numerals used.

In the figures, 1a designates the first application head which, when directed downwards, emits a first application medium and forms a medium curtain. With 1 b, the downstream, second application head is called, which also directed down directed application medium and forms another medium curtain.

In these applicator heads 1a and 1b, the height and the position in the direction of movement of the fibrous web w can be regulated.

Below the applicator heads 1a and 1b, an inclined guide plate B is arranged which receives the medium curtains discharged from the applicator heads sequentially on its inclined plane. Along this inclined plane leaves the guide plate B, the individual curtains superimposed flow down and flow from the downwardly directed curtain guide Bb at the bottom of a multi-layered (ie double-layered) medium curtain on the surface of the fibrous web w.

With c1, the medium curtain is designated by the application head 1a. Consequently, c2 is the medium curtain from the application head 1 b.

The medium layer formed on the guide plate B by means of the medium curtain c1 is indicated by r1, and by r2 the medium layer formed by means of the medium curtain c2 on the medium layer c1 is indicated.

In addition, a pair of edge guides 2 is provided, which is provided in the vicinity of both edges in the width direction of the guide plate B. In this case, the bottom of the edge guide 2 abuts on the top of the guide plate B. In this pair of edge guides 2 on Gleitbasis with respect to the center line C of the coater-containing vertical plane is a mutual symmetry and the measure between the inner surfaces is correct with the width of the delivered from the guns from Application medium (width of the medium curtain c1, c2) match. From the point a at the upper edge of the edge guides 2 to the point b at the lower edge side, there is the uniform height t1, from the point b downwards, the height gradually increases until it reaches the vertex c of the height t2. From the vertex c directed downstream, the height is gradually lower until it reaches the point d of the height t3. From point d, the height remains uniform downstream at t3.

In the slide-based edge guides 2, the position in the width direction can be regulated. Fig. 3 is an apparatus for regulating the position provided in the longitudinal direction of the slide-base edge guides 2 at two places. The position adjusting device 3 consists of an adjusting screw 4 which is rotatably mounted on the outside side surfaces of the edge guides on slide base 2 and the nut part 5 which is screwed with this adjusting screw 4 and at the same time fixed to the edge surface of the guide plate B.

The width of the application media dispensed from the applicator head is regulated to match the dimension between the inner surfaces of the edge guides 2, and there are many possible methods for doing so.

For example, in order to change the delivery width, at both edges of the slot of the applicator head 1, a spacer may be inserted from below, which is fixed from the outside and thus leakage of coating medium is prevented and at the same time the falling of the spacer is prevented. It is also possible if a lid is inserted into the slot from the side. This cover can be moved to regulate the delivery width of the slot.

The advantage of the embodiment described is that, even if the flow amount is small and the thickness of the medium curtain is thin, the medium curtain falling down by its own weight does not tear in the width direction and does not split (see Fig. 4 prior art).

In addition, it also does not happen that the medium layers r1 and r2 on the guide plate B become irregular or that the medium layer r1 on the guide plate is scratched by the other application head 1b. On the guide plate B, a stable medium layer of uniform thickness can be produced and obtained thereby causing the multi-layered curtain of uniform thickness to fall on the fibrous web w running underneath and form a uniform and very uniform application layer there.

In addition, the provision of previously several edge guides with different lengths and the effort to replace them, saved.

The present invention is not limited to the embodiment described above, and unless otherwise departing from the gist of the invention, many changes are possible. For example, could the height of the edge guides 2 on the inclined guide plate B are straight or constantly changing. The edge guide could also be in the form of a curved line, such as a sinusoid. However, it is not desirable to have steps in between.

In the figures, no edge guide is shown between the curtain guide Bb to the fibrous web w, but it would be desirable that such is arranged so as to be able to guide the multi-layered curtain well.

In the embodiment, a curtain coater for two layers has been shown and described, but a curtain coater for three or more layers may also be provided.

LIST OF REFERENCE NUMBERS

1

gun

1 a

gun

1 b

gun

2

edge guide

3

adjustment

4

screw

5

mother

a

Point

b

Point

d

Point

B

guide plate

bb

edge guide

t1, t2, t3

height

w

Fibrous web

c

vertex

C

center line

c1, c2

curtain

L

movement direction

r1, r2

medium layer

Claims (4)

Curtain coater for coating a running paper, board or other fibrous web, comprising at least two above the fibrous web (w) arranged applicator heads (1 a, 1 b), each directed down the application medium and each medium curtains (c1, c2) form, comprising also in the running direction (L) of the fibrous web below the applicator heads (1 a, 1 b) extending and forming an inclined plane guide plate (B), the (1 a, 1 b) of the applicator heads (1 a) emitted medium curtains (c1 , c2) in turn on its inclined plane, the guide plate (B) flowing down the medium curtains (c1, c2) along the inclined plane in sliding layers (r1, r2) and then from a trailing edge (Bb) at the lower end of the guide plate (B) as at least two-layered medium curtain flow onto the surface of the fibrous web, characterized in that the application heads (1 a, 1 b) in their height and in their Po Position in the direction of movement (L) of the fibrous web (w) are adjustable and edge guides (2) in the region of both lateral edges of the guide plate (B) are provided which correspond substantially to the length of the in the web running direction (L) extending guide plate (B) and seen in the width direction of the commissioned work, are adjustable to adjust and maintain the width of all delivered media curtains (c1, c2) and sliding layers (r1, r2). Curtain commissioned work according to claim 1, characterized in that
the edge guides (2) are plate-like and rest with their undersides on top of the guide plate (B) and their tops a backdrop-like management level for a Adjust the applicator heads (1a, 1b) in height and / or longitudinal direction. Curtain commissioned work according to claim 1 or 2, characterized in that
the edge guides are designed such that their height contour along the inclined plane of the guide plate (B) or seen in the running direction (L) of the fibrous web (w), is different. Curtain commissioned work according to claim 3, characterized in that
the height contour is formed so that from a point (a) at the upper end of the edge guides (2) to a downstream point (b) a uniform height (t1) is present, from the point (b) in the downstream direction, the height increases until it reaches a height t2 at a vertex (c) and gradually descends from the vertex (c) in the downstream direction until it reaches a point (d) of the height (t3) and from this point (d) from an equal height (t3) in the downstream direction.

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