EP1607141B1 - Coating device - Google Patents

Abstract

The strip of paste material may be an adhesive. The paper or cardboard may be in contact with a large roller and the paste material is supplied through a slit immediately before a small diameter spreading roller (8) held in a bearing piece (7). (7) Has a thin extension flange (6) engaging mountings and holding a strip width limiting fitting (10) and a sealing body (15) with a sealing plate (11).

Description

The invention relates to a device for applying a liquid or pasty medium to a running substrate, wherein the substrate for direct application, the surface of a paper, cardboard or other fibrous web and indirect application is the surface of a transfer element, which the application medium to the fibrous web emits. The apparatus comprises an application chamber which, based on the running direction of the running substrate, is delimited at least on the outlet side by an element, for example a squeegee element and inlet side, by a further element, for example a batten bar or a further squeegee element, and the application chamber has a boundary element for adjustment at its side edge the application width, wherein the limiting element is equipped with a flexible sealing plate, which substantially seals the space between the running underground and the drain and inlet side elements.

Such an applicator is referred to as SDTA, i. Short Dwell Time Applicator, ie application device with a short exposure time of the application medium, referred to in the jargon.

As a coating medium, coating color, glue, starch, an impregnating agent or the like is used, which is applied in an application chamber and immediately afterwards brought to the desired coating weight.

The known from the prior art delimiting elements, which are also referred to as Randbegrenzer or as a format delimiter, and as the name suggests, a bar-free edge and a specific format or order width on the moving fibrous web during production and / or finishing set , have several disadvantages. In contact with the running surface of this is partially damaged due to the high friction.

In addition, from the raw material of the fibrous web and from the application medium dissolving particles can be deposited on the sealing plate. This abrasive particles thus damage the running ground, so the fibrous web itself and the supporting roller or if the current surface is an applicator roll, and their roll cover. Damage to the metering and / or equalization of the applied application medium serving doctor element is also recorded. In particular, when the doctor element is a circular-cylindrical doctor bar rotating in a doctor bed, this leads to a local dry running, with the negative consequences of the damage to the outer surface of the doctor bar and the associated quality of the coating layer.

The present invention is therefore based on the object to develop a generic application device in such a way that the disadvantages of the prior art can be avoided.

The object of the invention is achieved by a device according to the features of the characterizing part of claim 1.

The already known from the prior art, see document DE 202 13 757, sealing plate according to the invention is designed so that it has a current to the subsurface and the drainage and inlet side doctor elements or the dust bar directed, mounted wear body. DE 202 13 757 also serves as basis for the preamble of claim 1.

The surfaces of the running substrate and also those of the doctor elements, in particular the doctor element arranged on the outlet side, which realizes a metering and / or equalization of the layer deposited by an applicator chamber on the running substrate, are thus protected and thereby considerably increase the service life of these components.

It should be mentioned at this point again that the current substrate is a paper, cardboard or other fibrous web, which partially a so-called support or counter-roller wraps around. In the case of indirect application, the running substrate is a transfer element, which then delivers the application medium applied thereto to the fibrous web. As a transfer element is usually a roller, ie an applicator roll whose roll cover is particularly spared by the wear body according to the invention to the bar edge boundary elements.

The invention can therefore be used particularly expediently for so-called "Speedsizer" or "Speedcoater" marketed by the associated company of the Applicant. These coating machines coat a fibrous web, as just described, indirectly, in that two such applicator rolls form a gap with each other through which the fibrous web passes. The fibrous web should have on both sides a line-free edge. This non-marking edge is desired with regard to the avoidable spraying of application medium in the environment and can be achieved with eingezten limiting elements that can be moved accordingly to the moving web, achieve. The boundary elements remain in the once set position during operation. In addition, the format or the desired application width over the width of the web is determined with the limiting elements, which is why the limiting elements in their position are also changeable. This ensures an adaptation to the respective width of the web.

The inventive wear on a limiting element, more precisely on the sealing plate of a limiting element wear body has a low level of friction. The deposition or deposition of abrasive particles is prevented, whereby a uniform and high-quality coating layer is achieved.

An expedient embodiment of the wear body according to the invention may consist in that it is wear, shape and heat resistant with respect to the rest of the flexible material of the sealing plate, whereby the entire Limiting element has a longer life than previously achieved.

In the context of the invention it is proposed to bond the wear body with the remaining material of the sealing plate by gluing, welding, screwing, riveting, press-fitting or pouring. The wear body is then interchangeable in some of these types of connection and thereby further increases the service life of the limiting element.

As the material for the sealing plate rubber, foam rubber, polyurethane or the like is provided, whereas as a material for the wear body in the invention thermoplastics, such as polyethylene, polyester, or polymers, such as polyurethane, ceramic or material mixtures, such as rubber with graphite or so-called bearing metals , like bronze, are usable. The materials for the wear body are characterized by dimensional stability, heat resistance and, above all, a low coefficient of friction.

The wear body according to the invention may have a differently shaped surface. Accordingly, the surface of the wear body pointing toward the running substrate or to the applicator roll may be flat or spherical. But it may also have an oblique roof shape or the surface may be provided with groove-shaped incisions.

In addition or as an alternative, the surface of the wear body can be provided with a bevelled or rounded edge directed towards the outlet side and / or inlet side, such as the dust bar or a further doctor element. These design options are not limited to the aforementioned, but there are other possibilities conceivable that allow a drainage possibility of stripped by Dosierrakelelement application medium and avoid sharp edges to the running underground.

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

Figur 1:

eine grob schematische Seitenansicht einer Auftragsvorrichtung mit Seitenbegrenzungselement und Abdichtplatte gemäß dem Stand der Technik

Figur 2:

eine perspektivische Darstellung der erfindungsgemäßen Vorrichtung mit einem Begrenzungselement, einer Abdichtplatte und einem Verschleißkörper

Figuren 3 bis 6:

verschiedene Ausführungsformen des Verschleißkörpers

They show:

FIG. 1:

a rough schematic side view of an applicator device with side boundary element and sealing plate according to the prior art

FIG. 2:

a perspective view of the device according to the invention with a limiting element, a sealing plate and a wear body

FIGS. 3 to 6:

various embodiments of the wear body

FIG. 1 shows a known application device 1 from the prior art.

This device 1 is assigned to a running in the direction L substrate 2. In the case of direct application, the substrate 2 is the fibrous web itself and, for indirect application, for example, an applicator roll which, on a section of the roller not shown here, transfers the application medium M delivered by the applicator 1 to a likewise not visible up to 10m and more wide fibrous web of paper or cardboard transfers.

The device 1 is a so-called application device with a short residence time, because the application medium M applied to the running substrate in an application chamber 3 is immediately scraped off, i. brought to the desired coating weight or only equalized immediately, i. e. is equalized.

The device 1 consists of a matched to the width of the fibrous web support beam 4 and a terminal strip 5, which clamp between them a blade-like skirt 6, which in turn carries a doctor bed 7 for receiving a rotatable, circular cylindrical metering rod as doctor element. This should be referred to as element 8. The element 8 is at the outlet end of the application chamber. 3 arranged. This is the end where the running substrate 2 runs away from the application chamber. Analogously, the opposite end of the application chamber is the inlet-side or inlet-side end of the application chamber 3, ie where the substrate 2 of the application chamber 3 tapers. To limit this chamber 3, a further element 9 is accordingly arranged at the inlet end. In the figure 1 for a Stauleiste is provided. Instead of the drawn Stauleiste could be used as element 9 but also such a doctor element, such as the designated under number 8 with doctor bed 7 and 6 skirting, use.

The application chamber 3 is limited in its length (this corresponds to a width section of the device 1 or the current substrate 2) of lateral boundary elements 10, which are also referred to as a format delimiter because they determine the application width B of the applied with the application medium M line or allow a corresponding remaining edge free edge ..
An adaptation to the existing width of the fibrous web is possible.

The limiting elements 10, one of which is arranged on the side edge of the substrate are permanently installed, but can also be slidably installed to the center and to the outside.

For sealing the application chamber 3 serve additional sealing plates 11, wherein each limiting element 10 is provided with a flexible sealing plate 11. The flexible sealing plate consists of a one-piece molded sealing material, such as rubber, foam rubber or polyurethane.

During operation of the device 1 and today's high machine speeds of about 2000m / min touches the Abdichtplatte with the closely adjacent components, such as the running surface 2 and the squeegee parts 7, 8 and existing on the inlet side of the batten 9 (which also omitted can be and there may be a further doctor element for limiting the application chamber 3) can not avoid, whereby these components exposed due to the high friction damage are. In particular, the underground 2 is affected. In indirect application, where the substrate is designed as an applicator roll, especially the roll surface (the reference of the applicator roll) is at risk.

Therefore, in the context of the invention wear body has been developed, which are placed on the flexible Abdichtleisten or Abdichtplatten and thus significantly extend the life of the said vulnerable components.

Such a device 1a according to the invention is shown in perspective in FIG. 2 , in which the sealing plate 11 has been upgraded with said wear body 15. It otherwise has the same components as the known from Figure 1 device of the prior art, which is why a repetition of the structure is omitted here.

From the figures 3 to 6 special embodiments of the current underground (not shown here) facing surface 17 of the wear body 15 can be seen.

FIGS. 2 and 3 each show a flat surface 17 with a rounded edge 18 facing the substrate. The edge 18 can thereby contact the outer surface of the rotating metering rod 8 safely.

A formed below the surface 17 tab 20 of the wear body is used for attachment to the sealing plate 11 and / or on the limiting element 10. The compound can be completed with an insertable into the tab 20 bolts 21st

FIG. 3 shows a single tab 20.

In Figure 4 , two spaced tabs 20 are shown. In addition, the wear body here has a spherical surface 17.

FIGS. 5 and 6 approximately correspond to the embodiment of FIG. 4 but show different surface shapes. FIG. 5 shows a surface 17 with an oblique roof shape, and FIG. 6 shows a surface provided with groove-like incisions 22.

These surface shapes are suitable, on the one hand, to form the smallest possible contact surfaces with the running substrate 2 and, on the other hand, to guarantee the best possible lateral sealing conditions for the application medium M in the application chamber 3.

The wear body 15 can be glued to the other material of the sealing plate 11, welded, bolted, riveted, pressed or cast. The wear body 15 is then interchangeable in some of these types of connection and thereby further increases the service life of the limiting element as a whole.

As a material for the limiting element 10 and the sealing plate 11 rubber, foam rubber, polyurethane or the like is provided, whereas as a material for the wear body 15 more wear-resistant materials, such as thermoplastics of polyethylene, polyester, or ceramic or material mixtures, such as rubber with graphite or so-called bearing metals, such as bronze can be used.

The materials for the wear body 15 are characterized by dimensional stability, heat resistance and, above all, a low coefficient of friction than the materials which were hitherto used only for the sealing plates 11 or the delimiting elements 10.

It should be mentioned that the wear body is not only applicable to the illustrated device 1a, an SDTA device, but also on the known flexible format slide, which limit the length of the dosing of free jet applicator nozzles, can be placed.

LIST OF REFERENCE NUMBERS

1

applicator

2

underground

3

application chamber

4

stringers

5

terminal block

6

baseboard

7

doctor bed

8th

doctor element

9

damming strip

10

limiting element

11

sealing

15

wear body

17

Surface of the wear body

18

edge

20

flap

21

bolt

L

direction

M

application medium

Claims (7)

1. Device for applying a liquid or pasty medium to a moving substrate, the substrate (2) in the case of direct application being the surface of a paper, board or other fibrous web and, in the case of indirect application, being the surface of a transfer element which discharges the application medium (M) onto the fibrous web,
   comprising:

   an application chamber (3) which, in relation to the running direction (L) of the moving substrate (2), at least on the outlet side, is delimited by an element (8), for example a doctor element (8), and on the inlet side is delimited by a further element (9), for example a damming strip or further doctor element, and at its lateral end, the application chamber (3) in each case has a delimiting element (10) for adjusting the application width, the delimiting element (10) being equipped with a flexible sealing plate (11) which substantially seals off the space between the moving substrate (2) and the elements (8, 9) arranged on the outlet and inlet side,

   characterized in that
   the sealing plate (11) has an attached wearing element (15) which is oriented towards the moving substrate (2) and the elements (8, 9) on the outlet and inlet side.
2. Device according to Claim 1, characterized in that, in relation to the remaining flexible material of the sealing plate (11), the wearing element (15) is more wear-resistant, more dimensionally stable and more heat resistant and has a low coefficient of friction.
3. Device according to Claim 1 or 2, characterized in that the wearing element (15) is connected to the remaining material of the sealing plate (11) by means of adhesive bonding, welding, screwing, riveting, pressing in or casting in.
4. Device according to Claims 1 to 3, characterized in that the material that can be used for the sealing plate (11) is rubber, sponge rubber, polyurethane or the like, and the material that can be used for the wearing element (15) is thermoplastics such as polyethylene, polyester, or polymers such as polyurethane, ceramic or material mixtures such as rubber with graphite, or else what are known as bearing metals such as bronze.
5. Device according to Claims 1 to 4, characterized in that the wearing element (15) is replaceable.
6. Device according to Claim 4, characterized in that the surface (17) of the wearing element (15) that points towards the moving substrate is flat or convex or has a roof shape or is provided with groove-like incisions (22) and/or is provided with a chamfered or rounded edge (19) oriented towards the elements (8, 9) on the inlet and/or outlet side.
7. Device according to one or more of Claims 1 to 6, characterized in that the element (8) arranged on the outlet side is formed as a circularly cylindrical metering rod, and the element arranged on the inlet side is likewise formed as a metering rod or as a flat damming strip.

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