WO2000018514A1 - Device and method for applying a liquid or paste-like coating medium to a continuous undersurface - Google Patents

Abstract

The invention relates to a method for directly or indirectly applying a liquid or paste-like coating medium to a continuous surface. Said coating medium is applied in a number of individual application areas on the surface by means of a number of individual application nozzles (10) from which the coating medium is discharged. Said nozzles are in located at intervals from each other in the transversal and/or longitudinal direction of the surface, next to each other and/or behind each other, and are at a marked distance from the surface. Adjacent individual application areas run at least partially into their respective edge areas so that a layer of the coating medium is produced over essentially the entire width of the surface to be coated. An expulsion characteristic and/or a quantity of the expelled coating medium from one or more of the number of individual application nozzles (10) is varied in order to produce a desired transversal and/or longitudinal profile of the layer of coating medium and the coated surface is levelled. The expulsion characteristic and/or the quantity of coating medium that is expelled are varied differently, locally in relation to the transversal and/or longitudinal direction of the surface to be coated.

Description

 Device and method for applying a liquid or pasty application medium to a running surface

description

The present invention relates to a method for the direct or indirect application of a liquid or pasty application medium to a running surface according to the preamble of claim 1.

Such a method is usually used in the context of coating systems to coat a running surface, for example a material web, which is made of paper, cardboard or a textile material, on one or both sides with one or more layers of the application medium, for example color, starch, impregnation liquid or the like. In the so-called direct application, the liquid or pasty application medium is applied directly to the surface of the running material web by an application device, which is carried during the application on a circumferential support surface, for example an endless belt or a counter roller. With indirect application of the medium, on the other hand, the liquid or pasty application medium is first applied to a counter surface serving as a carrier surface, e.g. the surface of a counter roller equipped as an application roller, applied in order to be transferred from there in a roller gap through which the material web runs from the application roller to the material web.

A generic method according to the preamble of claim 1 is disclosed in the applicant's older DE 1 97 22 1 59 A1, which was published after the priority date of the present application. In this method for the direct or indirect application of a liquid or pasty application medium to a running surface, the application medium is spaced apart from one another by means of a plurality of widthwise and / or longitudinal directions of the surface and / or individual application nozzles arranged one behind the other and clearly distanced from the surface, from which the application medium emerges in each case, applied to the surface in a large number of individual application areas. In this case, adjacent individual application areas penetrate at least partially in their respective edge areas, so that an application medium layer is produced over essentially the entire width of the surface to be coated. In order to produce a desired transverse and / or longitudinal profile of the application medium layer, an ejection characteristic and / or a quantity of the ejected application medium can be varied by one or more of the plurality of individual application nozzles. The coating medium layer is then usually leveled to achieve a uniform coat weight.

Since in the aforementioned method the individual application areas generated by means of the individual application nozzles overlap in their respective edge regions, the resulting coat weight or basis weight is greater there than within the non-overlapping application area of an individual nozzle. With certain application parameters, but in particular when using special application medium types and / or particularly high running speeds, it has been found that the different coating weights are no longer possible in the subsequent leveling by means of a leveling device downstream of the individual application nozzles in the direction of travel of the surface to be coated in the overlapping and non-overlapping application areas of the coated surface and thus to achieve an overall uniform coating result.

The present invention is therefore based on the technical problem of developing the method known from DE 1 97 22 1 59 A1 in such a way that the critical job orders described in connection with the previously described inaccuracies in terms of line or basis weight occurring parameters are avoided as far as possible.

This technical problem is solved by an inventive method with the features of claim 1.

In this method for the direct or indirect application of a liquid or pasty application medium to a running surface, the application medium is arranged by means of a plurality of individual application nozzles spaced apart from one another in the width direction and / or longitudinal direction of the surface and / or one behind the other and clearly distanced from the surface. from which the application medium emerges, applied to the surface in a large number of individual application areas. In this case, adjacent individual application areas penetrate at least partially in their respective edge areas, so that an application medium layer is produced over essentially the entire width of the surface to be coated. Furthermore, an ejection characteristic and / or a quantity of the ejected application medium is varied by one or more of the plurality of individual application nozzles to produce a desired transverse and / or longitudinal profile of the application medium layer. The surface coated with the application medium is then leveled. The aforementioned variation of the ejection characteristic and / or the amount of the application medium ejected takes place locally differently with respect to the width direction and / or the longitudinal direction of the surface to be coated.

In other words, the ejection characteristic and / or the amount of the ejected application medium and thus also the application medium layer to be produced is deliberately influenced locally before the leveling. The areal or spatial extent of this type of local manipulation naturally depends strongly on the uninfluenced standard output characteristic and standard output quantity of the individual Application nozzles and their arrangement relative to each other and thus also the size, shape and orientation of the penetration or overlap area of the resulting individual application areas. It can be seen that, for example, single application nozzles with a narrow flat jet, which primarily extends in the width direction, generally require a smaller local change in the ejection characteristic and / or the ejection quantity in relation to the longitudinal direction of the surface to be coated than, for example, single application nozzles with a conventional one Spray cones that will require appropriate variation in both the width and length directions. The same applies analogously depending on the size, shape and orientation of the penetrating or overlapping marginal areas of adjacent individual order areas.

The method according to the invention advantageously allows the line weight or basis weight differences in the overlapping edge regions of the individual application regions generated by means of the individual application nozzles to be significantly reduced. In particular when using application-technically difficult types of application medium and / or high running speeds of the surface to be coated, it is therefore possible in the subsequent leveling to effectively compensate for the now only slight differences in the application medium layer produced and thus to achieve an overall uniform coating result. This contributes significantly to the production of a high quality end product. Of course, the invention can in principle also be used with regard to less critical types of application medium and order parameters and can also lead to a further improvement in the order result in these cases.

An advantageous embodiment feature of the method according to the invention provides that the locally different variation of the ejection characteristic takes place by deflecting the application medium emerging from the individual application nozzles. Such a process step is expediently described in Connected with a suitable deflection device. However, it is not absolutely necessary to generate a deflection at each individual application nozzle; For certain applications it may already be sufficient to carry out such manipulation only in connection with certain individual application nozzles. A distraction can basically take place at one or more points in the spatial spray distribution of the emerging application medium. These measures allow the individual order areas generated by means of the individual order nozzles and their at least partially overlapping edge areas to be influenced in a targeted manner and in this way to largely align the line or basis weights of the overlapping and non-overlapping order areas.

According to a further advantageous embodiment of the method according to the invention, the application medium is deflected by blowing on the application medium emerging from the individual application nozzles by means of a gaseous medium. Air is preferably used as the gaseous medium, but other suitable gases or gas mixtures can also be used. For ejecting the gaseous medium, one or more blowing nozzles can be used, for example, from which the gaseous medium flows directed towards the emerging application medium or partial areas thereof. Thus, the ejection characteristic of one or more individual application nozzles and thus also the distribution of the application medium and the resulting local coat or basis weight are influenced accordingly. The blowing nozzles can be designed to be adjustable and can be integrated into a control and / or regulating device.

Another variant of the method according to the invention in turn provides for the deflection of the application medium to be carried out by means of at least one deflection plate. The baffle plate is either stationary or preferably adjustable and / or movable in one or more axes formed and can have a flat, angled, curved in one or more planes curved or other suitable shape with respect to their longitudinal axis and the direction of ejection of a single application nozzle. Furthermore, the baffle may be curved curved or fitted in other suitable form angled with respect to its transverse axis and the local cross-sectional shape of the _^ application medium jet produced by means of the single-application nozzle rectilinear. It is also possible to make the geometry of the deflection plate itself variable. It is also expedient to integrate the adjustable baffle plate in a control and / or regulating device. In this way, with the aid of the aforementioned method steps, specific areas of the application medium jet or even the entire jet can be deflected in a targeted manner, and the ejection characteristics can thus be influenced locally.

According to a further aspect of the present invention, the locally different variation of the ejection characteristic can also take place by twisting and / or tilting predetermined individual application nozzles. Depending on the application, such an adjustment can in principle only be carried out only on certain selected individual application nozzles and also on all individual application nozzles. Furthermore, the respective individual application nozzles combined to form an application unit can be rotated and / or tilted individually differently or in groups or in their entirety in the same direction. These features of the method allow the coating or basis weight in the overlapping and non-overlapping zones of the individual application areas to be influenced particularly effectively. The rotatable and / or tiltable individual application nozzles are expediently incorporated into a suitable control and / or regulating device.

A still further advantageous embodiment of the method according to the invention provides that the locally different variation of the ejection characteristic and / or the amount of the ejected order mediums by at least partially shutting off and / or covering one or more individual application nozzles. This can be achieved, for example, with the aid of slide or cover elements corresponding to one or more individual application nozzles, which can have the same as well as different constructions and shapes. These slide or cover elements are also expediently part of a control and / or regulating device. A shut-off and / or cover can be carried out both on individual nozzles and / or the nozzle jet generated by them and on several or even all nozzles. The degree of shut-off and / or coverage can be the same for all or certain nozzles or differ from nozzle to nozzle. By at least partially or temporarily completely shutting off and / or covering, the spray form of the individual application nozzles and consequently also the local application quantity are effectively influenced and thus, in a particularly simple and effective manner, the most uniform possible distribution of the application medium on the achieved surface to be coated.

A further preferred embodiment of the method according to the invention finally provides that the locally different variation of the ejection characteristics and / or the amount of the application medium ejected by at least temporarily adding a diluent to the application medium to be ejected by means of the individual application nozzles and / or exiting from the individual application nozzles he follows. The admixture can thus take place before the application medium enters an individual application nozzle and / or within the individual application nozzle and / or within the actual nozzle jet or partial areas thereof. For this purpose, a suitable separate or integrated admixing device is to be provided, which, if it is adjustable, can expediently be connected to a suitable control and / or regulating device. If an admixture into the nozzle jet is intended, separate spraying devices can be provided, for example, or the single application nozzle can be equipped with separate spray openings for the application medium and the diluent. The spray devices can have the same or different spray properties. Water is preferably used as the diluent. Depending on the type of application medium, other suitable diluents are of course also conceivable. An admixture can take place both in connection with individual and several individual application nozzles, the admixture quantity being able to be the same or different in each case. These process features also make it possible to achieve a very uniform area or line weight in the case of processing-related types of application medium and application parameters.

Preferred exemplary embodiments of the invention with additional design details and further advantages are described and explained in more detail below.

According to a first exemplary embodiment, the method according to the invention is used in the context of a device which, in the present case, is designed as a device for the direct application of a liquid or pasty application medium to a running material web. The device comprises a counter or support roller over which the material web runs. Furthermore, the device has a support beam opposite the support roller, on which an application device is held. The application device is equipped with a distribution tube which feeds the application medium and to which a large number of individual application nozzles are provided which are spaced apart from one another with respect to the width direction of the material web and which here extend in a straight row evenly distributed across the entire width of the material web. The respective individual application nozzles are distanced from the surface of the material web to be coated. In the present example, each of the single application nozzles is via a control and / or regulating device individually controllable, so that the radiation characteristics of the individual application nozzles and / or the amount of the emitted application medium can be manipulated to preset a desired transverse and / or longitudinal profile of the application medium layer. In relation to the direction of rotation of the support roller, the application device is followed by a leveling device in the form of a doctor device.

The application medium emerges from the respective individual application nozzles in the form of a free jet which widens in the shape of a cone or wedge and runs through the ambient atmosphere, is sprayed onto the material web and forms an individual application area associated with the respective nozzle. When spraying, the adjacent free jets penetrate or overlap in part, and thus also the individual application areas generated, in their respective edge areas. Furthermore, during the spraying, if necessary, the ejection characteristic and / or the quantity of the application medium ejected from one or more of the plurality of individual application nozzles is varied to produce a desired transverse and / or longitudinal profile of the application medium layer. The application medium is applied in excess in the present case. The job generated is then equalized by means of the doctor device and the final longitudinal and / or transverse profile is thus set.

In the case of application medium types and application parameters that are not critical in terms of processing technology, an application medium layer of essentially the same layer thickness is produced over the entire width of the running material web during the general spraying process explained above. With such an application medium layer, the subsequent leveling makes it easy to achieve a uniform coat or surface weight. With certain types of application medium and application parameters, however, the small differences in layer thickness that occur in the overlap zones of the individual application areas generated by spraying and the associated coat weight or Differences in basis weight can no longer be compensated by the subsequent leveling alone.

For this reason, varying the expulsion characteristic and / or the amount is performed in the latter cases the ejected order _^ medium relative to the width direction and / or the longitudinal direction of the surface to be coated locally. The application medium layer to be produced is therefore influenced locally before the leveling in order to reduce the coating weight or basis weight differences between overlapping and non-overlapping zones of the individual application areas to such an extent that they can be easily compensated for by the leveling process and an overall uniform coating result can be achieved is.

The following exemplary embodiments likewise use the basic method steps set out in the preceding general first exemplary embodiment and the device used in this context. A repeated explanation of the essentially identical method steps and device elements is therefore omitted below and instead only reference is made to details that differ from these.

According to a second embodiment of the method according to the invention, in which individual application nozzles with a conical spray pattern are used, the locally different variation of the ejection characteristics of the individual application nozzles takes place in that the application medium emerging from the individual application nozzles is deflected by blowing with a gaseous medium and so the original ejection properties of the nozzle is changed locally. In the present example, the gaseous medium is air which flows out from air-blowing nozzles which act as deflection devices. The air blowing nozzles are from one or more sides onto the spray cone of a respective one Single application nozzle directed. The blowing nozzles are designed to be adjustable, so that, if necessary, both the blowing direction and the flow velocity and / or the flow distribution of the outflowing air can be influenced. The blowing nozzles are also integrated in a control and / or regulating device, which detects that from the sensors. Individual application nozzles generated transverse and / or longitudinal profile recorded before leveling and the blowing nozzles adjusted accordingly depending on the determined profile values.

According to a third embodiment of the method according to the invention, the locally different variation of the ejection characteristics of the individual application nozzles takes place by means of essentially flat baffle plates which can be moved in one or more axes with the aid of actuators. One or more baffle plates are provided for each individual application nozzle, which are arranged below the relevant nozzles in or on the emerging nozzle jet. Like the blowing nozzles mentioned in the second exemplary embodiment, the movable deflecting plates are also integrated in a control and / or regulating device in a corresponding manner. By means of the baffle plates, certain areas of the application medium jet are deflected in a targeted manner if necessary, and thus the ejection characteristics and thus also the local distribution of the application medium in the generated application medium layer are influenced locally before the leveling.

According to a fourth embodiment of the method according to the invention, the locally different variation of the discharge characteristic is carried out by rotating and / or tilting the individual application nozzles. The rotary and / or tilting movement is made possible by actuators corresponding to the individual application nozzles concerned. The rotatable and / or tiltable individual application nozzles and their actuators are integrated in a control and / or regulating device which, by means of sensors, also supports the transverse and / or longitudinal profile generated by the individual application nozzles recorded before leveling and regulates the rotation and / or tilting movement of the individual application nozzles as a function of the determined profile values.

According to a fifth embodiment of the method according to the invention, the locally different variation of the ejection characteristic __ and / or the amount of the ejected application medium takes place by at least partially shutting off and / or covering one or more individual application nozzles. For this purpose, a movable slide or cover element is provided in front of the nozzle outlet and / or in the area of the nozzle jet of a single application nozzle in question, which element can be actuated by means of an actuator. The slide or cover elements are integrated with their actuators in a control and / or regulating device analogous to the previously described exemplary embodiments, which detects the transverse and / or longitudinal profile generated by the individual application nozzles before the leveling and depending on the determined profile values actuated or readjusted the slide or cover elements accordingly. The degree of shut-off and / or coverage is either the same or different depending on the respective application parameters and the measured values of the sensors for all or only certain of the individual application nozzles equipped with the slide or cover elements. In this way, the shape of the application medium jet ejected from the nozzles as well as the spray pattern and consequently also the local application quantity and the associated weight per unit area or coat weight are influenced locally before the leveling.

According to a sixth embodiment of the method according to the invention, the locally different variation of the ejection characteristic and / or the amount of application medium ejected is achieved by at least temporarily adding a diluent, in the present example water, into the application medium to be ejected by means of the individual application nozzles. For this purpose, certain individual application nozzles in a row of nozzles are equipped with an adjustable admixing device which is in turn connected to a control and / or regulating device analogous to the previously described embodiment variants. Depending on the measured values recorded by the sensors of the control and / or regulating device of the transverse and / or longitudinal profile generated by means of the individual application nozzles, the degree of admixture of water is set or regulated accordingly in the nozzles concerned and thus the area or coating weight of the resulting application medium layer and its physical properties are influenced locally in a targeted manner. As in the previous examples, the overall leveling result is then achieved by the subsequent leveling process.

According to a seventh embodiment of the method according to the invention, the locally different variation of the ejection characteristic takes place by at least temporarily thermally influencing the application medium to be ejected by means of the individual application nozzles and / or emerging from the individual application nozzles and / or pre-metered onto the running surface. Such thermal influence can be achieved in particular by heating the individual application nozzles and thus also the application medium to be ejected. Furthermore, the thermal influence can also be carried out by means of hot air or steam, in particular water vapor; in such a case, one or more individual application nozzles can be designed, for example, as two-substance nozzles, ie for hot air / steam and for the application medium. With regard to the thermal influence of the pre-metered application layer, reference is made to the content of the applicant's older application, which is published after the priority date of the present application, DE 198 00 954 A1. With the help of the measures described above according to the seventh embodiment, the so-called film splitting can be avoided particularly effectively. The medium applied to the running surface dries more slowly and its viscoelasticity is reduced. As a result, the application medium flows better and application thickness differences and irregularities in the surface structure of the application layer become more easily balanced, so that under certain conditions it is even possible to dispense with subsequent leveling by means of a leveling or doctor device. The moisture introduced into the application layer by steam, in particular water vapor, can be removed again by means of a downstream drying device without. the composition of the application layer is impaired.

According to an eighth embodiment of the method according to the invention, which can also be combined with at least one of the variants described above, nozzle jets of adjacent individual application nozzles are emitted with an offset to one another. In this way, a distance between the jet streams is ensured and mutual jet jet contact and / or jet jet interference is avoided. In other words, there is no or no significant penetration of the nozzle jets during the actual spraying process and / or when the nozzle jets hit the surface to be coated. In such an arrangement, the at least partial overlap of the individual application areas, which can become extremely small with a suitable nozzle setting, results from the progressive movement of the running surface. This method variant has proven particularly useful when using flat jet nozzles which produce a relatively broad, narrow flat jet (free jet) with a sharply defined spray pattern.

The offset of the jet streams of adjacent individual application nozzles can be achieved, for example, by blasting the jet streams offset in the longitudinal direction of the surface to be coated. For this purpose, adjacent individual application nozzles (or also nozzle groups) can be arranged offset from one another by a predetermined distance in the longitudinal direction of the surface to be coated on a support bar and / or a distribution pipe for the application medium or the like. Or the nozzles can have different lengths relative to a reference plane formed and / or be individually adjustable in their distance from their attachment point and / or to the surface to be coated in order to achieve the desired offset. The offset of the individual application nozzles is preferably in a range from 5 to 25 mm. Depending on the radiation characteristics and the mutual distance between the nozzles, this value range can, however, deviate considerably.

The offset of the nozzle jets of adjacent individual application nozzles can moreover be achieved by an oblique jet of the nozzle jets in relation to the width direction of the surface to be coated. This variant is particularly suitable for applications in which flat jet nozzles used as individual application nozzles are arranged on a common axis which is essentially parallel to the width direction of the surface to be coated. In this arrangement, the nozzle jets would normally touch each other at an appropriate lateral distance. However, by arranging the individual application nozzles in the same direction, slightly twisted or rotatable or pivotable, a distance can be generated between the nozzle jets and mutual jet jet contact and / or nozzle jet interference can be avoided. The nozzle jets are thereby emitted obliquely with respect to the width direction of the surface to be coated with a predetermined rectified (but not necessarily the same for each nozzle) angle. This effect can of course also be achieved by adjusting the nozzle geometry and / or the radiation characteristic accordingly. Based on the width direction of the surface to be coated, the oblique radiation angle is preferably in a range from 5 to 15 degrees. Depending on the radiation characteristics and the mutual spacing of the nozzles, this range of values can, however, deviate considerably. The invention is not restricted to the above exemplary embodiment, which only serves to explain the basic concept of the invention in general. Rather, within the scope of protection, the method according to the invention can also take other forms than those described above. The method may in this case have particular characteristics _^ representing a combination of the respective individual features of the claims. As already indicated in the above exemplary embodiments, the device elements to be used in connection with the method steps according to the invention do not necessarily have to be provided for each individual application nozzle. For certain applications, it is sufficient to equip only a few selected individual application nozzles, individual application areas or their subsections with these elements. For example, it is conceivable to equip only every second individual application nozzle in a row of nozzles, or to provide a specific distribution pattern of these device elements in the case of a plurality of rows of nozzles arranged one behind the other.

According to a further aspect, the invention relates to a method for applying a liquid or pasty application medium to a running surface, the running surface being the surface of a running material web, in particular made of paper, cardboard or textile material, when applied directly, or the surface being applied indirectly of a transfer element, for example a transfer roller, which then transfers the application medium to the material web, and wherein the application medium is delivered to the substrate as a flat jet by means of at least one flat jet nozzle.

In the use of flat jet nozzles discussed above, it has arisen in practice as a further problem that the ejection characteristic of these flat jet nozzles does not have the desired shape shown in dotted lines in FIG. 3, which is characterized by a jet thickness d which is essentially constant over the entire jet width B. distinguished, but due to an effect referred to in technical jargon as "bone formation", which has the shape shown in dashed lines in FIG. 3 and which is characterized by thickening of the beam profile in the side end regions S and the central region M of the beam width.

It is therefore an object of the invention to show a possibility by means of which the desired uniformly thick ejection characteristic can be achieved or the ejection characteristic of flat jet nozzles can at least be approximated to the desired uniformly thick characteristic.

This object is achieved according to the invention by a method of the aforementioned type, in which the application medium in the area of the formation of the flat jet is influenced by means of at least one auxiliary medium. With the help of this auxiliary medium, the accumulation of application medium in the side end regions S or in the central region M of the flat jet can be counteracted or such accumulation can even be avoided completely, so that the desired ejection characteristic is obtained which is uniformly thick over the entire jet width.

The distribution of the application medium over the beam width can be influenced both by the supply of auxiliary substances and by the action of auxiliary radiation as auxiliary media.

Suitable auxiliaries are, for example, gases or liquids which are preferably supplied to the application medium under pressure. Because of the simple availability and the low costs associated with their use, air or / and steam, preferably water vapor, can advantageously be used as gases. For example, water and / or application medium can be considered as liquids.

As already mentioned above, the application medium can also be influenced by any type of radiation which is in the Is able to exert a force on the application medium. For example, the application medium can be influenced by ultrasound, preferably high-frequency ultrasound. The auxiliary medium can be supplied to the application medium with a characteristic which is suitable with regard to the desired uniformity of the ejection characteristics, for example round or flat or - particularly shaped. In the case of influencing the application medium by means of compressed air or ultrasound, it is proposed to select the jet characteristic of the auxiliary medium so that a pressure which prevents or counteracts the formation of the bulges of the bone profile is exerted on the application medium jet, particularly in its side end regions S and in its central region M. . In the case of the supply of liquid, in particular application medium, as the auxiliary medium, on the other hand, it is advantageous to supply this liquid mainly to the constricted areas E between the side end areas S and the central area M of the jet in order to "fill up" the jet profile in these areas.

According to the invention, the feed direction of the application medium and the feed direction of the auxiliary medium can enclose an angle of between approximately 20 ° and approximately 130 °.

The application medium can be influenced particularly effectively by means of the auxiliary medium if the application medium is supplied as a primary jet with an essentially circular cross section and is directed against a surface which is inclined relative to the feed direction of the primary jet to form the flat jet. If this flat jet formation surface is curved transversely to the feed direction of the application medium, the jet can hereby be fanned particularly broadly. The formation of an essentially uniform ejection characteristic over the jet width can be supported in that the feed direction of the primary jet includes an angle of between approximately 5 ° and approximately 25 ° with a straight line extending in the flat beam formation area. If the auxiliary medium acts on the application medium from the side facing away from the flat jet formation area, the application medium jet is guided or shaped between the flat jet formation area and the uniform compressed air jet, which enables a particularly effective influence on the ejection characteristics of the flat jet nozzle. With the above-described configuration of the flat jet nozzle with a flat jet formation surface, the achievement of a uniform ejection characteristic can therefore already be supported by using a compressed gas, for example compressed air, which is supplied to the application medium jet with a jet characteristic that is substantially uniform over its jet width.

The supply of the auxiliary medium has proven to be particularly effective at a position which is arranged in the feed direction of the application medium at most 10 mm after the start of the flat jet formation area. In addition, it is advantageous if this position is arranged in the immediate vicinity of the nozzle outlet, i.e. at a distance of at most 1 5 mm to the nozzle outlet.

A uniform application profile over the entire working width of the material web can be achieved when using flat jet nozzles according to the invention if the application device comprises a plurality of application nozzles distributed over the working width. With regard to the possibilities of arranging this plurality of flat jet nozzles offset in the running direction or transverse direction of the material web, reference is made to the above discussion of the application nozzles.

According to a further aspect, the invention further relates to a device for applying a liquid or pasty application medium to a running surface, the running surface being the surface of a running material web, in particular made of paper, cardboard or textile material, when it is applied directly, or, in the case of indirect application Surface of a transfer element, for example a transfer roller, which then transfers the application medium to the material web, and wherein the application device comprises at least one application nozzle which emits the application medium as a flat jet to the substrate. With regard to the further training possibilities of this device and the advantages achievable therewith, reference is made to the above discussion of the application method according to the invention.

The invention relating to the uniformity of the flat jet ejection characteristic will be explained in more detail below using an exemplary embodiment with reference to the accompanying drawing. It shows:

Figure 1 is a sectional side view of a flat fan nozzle according to the invention. FIG. 2 shows a further sectional view of the flat jet nozzle according to the invention along the line II-II in FIG. 1; and

Fig. 3 is a schematic representation of various discharge characteristics to explain the problem underlying this aspect of the invention.

In Fig. 1, a flat jet nozzle according to the invention is generally designated 10. It comprises a base part 12, in which a feed channel 14 for application medium 16 extends between an inlet end 14a and a beam shaping chamber 18. The feed channel 14 has an essentially circular cross section (see FIG. 2) and tapers on a section 14b toward the beam shaping chamber 18.

In the beam shaping chamber 1 8, the application medium 1 6 strikes a beam formation surface 20 which is inclined with respect to the application medium feed direction Z. In particular, a straight line G extending in the area 20 essentially in extension to the feed direction Z includes an angle y with this feed direction Z, the value of which preferably is between about 5 ° and about 25 °. As is shown in FIG. 2, the jet-forming surface 20 also extends in a trough-like manner in the transverse direction Q with respect to the applied application medium 16 in order to ensure a broad fanning out of the application medium jet. In order to give the application medium 1 6 sufficient time to form the desired flat jet profile (shown in dotted lines in FIG. 3), the jet formation surface 20 is also extended along an extension 1 2a of the base part 1 2, which extends over the exit-side end 1 8b of the jet shaping chamber 1 8 extends.

To support the formation of the desired flat jet characteristic, the flat jet nozzle 10 according to the invention has a further feed channel 22 for feeding an auxiliary substance 21 on the side of the jet shaping chamber 16 opposite the jet formation surface 20. The auxiliary 21 can be, for example, a compressed gas, such as compressed air or water vapor supplied under pressure, or a liquid, for example water or application medium. The auxiliary material feed channel 22 runs in an auxiliary material supply direction X, which includes an angle β with the application medium supply direction Z, the value of which is between approximately 20 ° and approximately 130 °, in the exemplary embodiment shown approximately 90 °.

In the embodiment shown in FIG. 1 of a flat jet nozzle 10 designed in particular for the use of compressed air as auxiliary material, the auxiliary material supply channel 22 narrows in its section 22b adjacent to the chamber 18 in the application medium supply direction Z, while the same section 22b according to FIG 2 widens in the transverse direction Q. The auxiliary substance 21 thus emerges from the auxiliary substance feed channel 22 as a flat jet, which presses the application medium 16 in the beam shaping chamber 18 evenly against the beam formation surface 20 over the entire beam width. In addition or as an alternative to the supply of an auxiliary substance 21, the formation of the beam character strategy in the region of the beam shaping chamber 18 or the beam formation surface 20 can also be influenced by means of a suitable type of radiation, for example by means of ultrasound. For this purpose, the flat jet nozzle 10 comprises an ultrasound source 24, the sound pressure of which acts on the application medium 16 in the region of the beam shaping chamber 18, again from the side opposite the beam formation surface 20.

It should also be added that the distance d1 between the central axis X of the auxiliary material supply channel 22 and the beginning of the beam shaping chamber 1 8 should be at most 1 0 mm, and that in an analogous manner the distance d2 between this axis X and the end 1 8b of the beam shaping chamber 1 8 should not exceed 1 5 mm.

Claims

Expectations 1 . Method for the direct or indirect application of a liquid or pasty application medium to a running surface, the application medium using a plurality of individual application nozzles which are spaced apart from one another in the width direction and / or longitudinal direction of the surface and / or one behind the other and clearly distanced from the surface which the order medium exits, in a variety of Single application areas is applied to the surface, adjacent individual application areas at least partially penetrate each other in their respective edge areas, so that an application medium layer is produced over essentially the entire width of the surface to be coated, an ejection characteristic and / or a quantity of the ejected application medium is varied by one or more of the plurality of individual application nozzles for producing a desired transverse and / or longitudinal profile of the application medium layer, and the surface coated with the application medium is leveled, characterized in that the variation in the ejection characteristic and / or the quantity of the ejected Application medium is locally different based on the width direction and / or the longitudinal direction of the surface to be coated. 2. The method according to claim 1, characterized in that the locally different variation of the ejection characteristic takes place by deflecting the application medium emerging from the individual application nozzles. 3. The method according to claim 2, characterized in that the deflection of the application medium is carried out by blowing the application medium emerging from the individual application nozzles by means of a gaseous medium. 4. The method according to claim 2 or 3, characterized in that the deflection of the application medium is carried out by means of at least one baffle. 5. The method according to one or more of the preceding claims, characterized in that the locally different variation of the discharge characteristic takes place by rotating and / or tilting predetermined individual application nozzles. 6. The method according to one or more of the preceding claims, characterized in that the locally different variation of the ejection characteristics and / or the amount of the ejected application medium is carried out by at least partially shutting off and / or covering one or more individual application nozzles. 7. The method according to one or more of the preceding claims, characterized in that the locally different variation of the ejection characteristic and / or the amount of the ejected application medium by at least temporarily adding a diluent into the to be ejected by means of the individual application nozzles and / or from the individual Application medium emerging from application nozzles takes place. 8. The method according to one or more of the preceding claims, characterized in that the locally different variation of Ejection characteristic by at least temporarily thermally influencing the one to be ejected by means of the individual application nozzles and / or application medium emerging from the individual application nozzles and / or pre-metered onto the running surface. 9. The method according to claim 8, characterized in that the thermal influence by_ The nozzles are heated. 10. The method according to claim 8 or 9, characterized in that the thermal influencing takes place by means of hot air or steam, in particular water vapor. 1 1. Method according to one or more of the preceding claims, characterized in that jet streams of adjacent individual application nozzles are emitted with an offset to one another, so that a distance between the jet streams is ensured and mutual jet jet contact and / or jet jet interference is avoided. 1 2. The method according to claim 1 1, characterized in that the offset of the jet streams of adjacent individual application nozzles is achieved by a blasting of the jet streams offset in the longitudinal direction of the surface to be coated. 1 3. The method according to claim 1 1, characterized in that the offset of the nozzle jets of adjacent individual application nozzles is achieved by an oblique radiation of the nozzle jets based on the width direction of the surface to be coated by a predetermined rectified angle. 4. A method for applying a liquid or pasty application medium (1 6) to a running surface, the running surface being the surface of a running material web, in particular made of paper, cardboard or textile material, in the case of direct application, or the surface being used for indirect application Surface of a transfer element, for example a transfer roller, which then transfers the application medium to the material web, and wherein the application medium (1 6) is delivered to the substrate as a flat jet by means of at least one application nozzle (10), characterized in that the application medium ( 1 6) in the area (1 8/20) of the formation of the flat jet by means of at least one auxiliary medium (21, 25). 5. The method according to claim 14, characterized in that the auxiliary medium is an auxiliary (21), for example a gas preferably fed under pressure or a liquid preferably fed under pressure. 6. The method according to claim 1 5, characterized in that the gas is air or / and steam, preferably water vapor. 7. The method according to claim 1 5, characterized in that the liquid is water or / and a Order medium is. 8. The method according to any one of claims 1 4 to 1 7, characterized in that the auxiliary medium is an auxiliary radiation (25) which is supplied, for example, as an ultrasound, preferably high-frequency ultrasound. 1 9. The method according to any one of claims 14 to 18, characterized in that the feed direction (Z) of the application medium (21) and the feed direction (X) of the auxiliary medium (21, 25) an angle (β) of between about 20 ° and enclose about 1 30 °. 20. The method according to any one of claims 14 to 1 9, characterized in that the application medium (1 6) supplied as a primary jet with a substantially circular cross-section and to form the flat jet against a surface oblique relative to the feed direction (Z) of the primary jet (20th ) is conducted. 21. A method according to claim 20, characterized in that the flat jet formation surface (20) is curved transversely (Q) to the feed direction (Z) of the application medium (1 6). 22. The method according to claim 20 or 21, characterized in that the feed direction (Z) of the primary beam with a straight line (G) extending in its extension in the flat beam formation surface (20) has an angle (y) of between approximately 5 ° and approximately 25 ° includes. 23. The method according to any one of claims 20 to 22, characterized in that the auxiliary medium (21, 25) on one Position acts on the application medium (1 6), which is arranged in the feed direction (Z) at most 10 mm after the start of the flat jet formation surface (20). 24. The method according to any one of claims 20 to 23, characterized in that the auxiliary medium (21, 25) acts on the application medium (1 6) at a position which is arranged at most 1 5 mm from the nozzle outlet (1 8b). 25. The method according to any one of claims 20 to 24, characterized in that the auxiliary medium (21, 25) acts on the application medium (1 6) from the side thereof facing away from the flat jet formation surface (20). 26. The method according to any one of claims 14 to 25, characterized in that it comprises a plurality of application nozzles (10) arranged distributed over the working width. 27. Device for applying a liquid or pasty application medium (1 6) to a running surface, the running surface being the surface of a running material web, in particular made of paper, cardboard or textile material, or the surface of a transfer element in the case of indirect application , for example one Transfer roller, which then transfers the application medium to the material web, and wherein the application device comprises at least one application nozzle (10) which emits the application medium (1 6) as a flat jet onto the substrate, characterized in that the application nozzle (10) in the area (1 8/20) of the formation of the flat jet comprises a device (22, 24) for influencing the application medium (26) by means of at least one auxiliary medium (21, 24). 28. The apparatus according to claim 27, characterized in that the auxiliary medium is an auxiliary (21) and that the device for influencing the application medium comprises at least one supply line (22) for supplying the auxiliary (21). 29. The device according to claim 28, characterized in that the auxiliary (21) is a preferably supplied under pressure gas or a preferably supplied under pressure liquid. 30. The device according to claim 29, characterized in that the gas is air and / or steam, preferably water vapor. 31 Apparatus according to claim 29, characterized in that the liquid is water or / and application medium. 32. Device according to one of claims 27 to 31, characterized in that the auxiliary (21) acts on the application medium (1 6) with a round or flat or specially shaped beam cross section. 33. Device according to one of claims 27 to 32, characterized in that the auxiliary medium is an auxiliary radiation (25) and that the device for influencing the application medium (1 6) comprises at least one transmitter (24) for emitting the auxiliary radiation. 34. Apparatus according to claim 33, characterized in that the auxiliary radiation (25) is ultrasound, preferably high-frequency ultrasound. 35. Apparatus according to claim 33 or 34, characterized in that the auxiliary radiation (25) acts on the application medium (1 6) with a round or flat or specially shaped beam characteristic. 36. Device according to one of claims 27 to 35, characterized in that the feed direction (Z) of the application medium (1 6) and the feed direction (X) of the auxiliary medium (21, 24) an angle (β) of between about 20 ° and enclose about 1 30 °. 37. Device according to one of claims 27 to 36, characterized in that the application nozzle (10) has an application medium supply channel (14) with a substantially circular cross-section and a feed channel (14) adjoining this and relative to the feed direction (Z) of the feed channel (1 4) sloping Surface (20) comprises. 38. Device according to claim 37, characterized in that the flat jet formation surface (20) is curved transversely (Q) to the feed direction (Z) of the application medium (1 6). 39. Apparatus according to claim 37 or 38, characterized in that the feed direction (Z) of the feed channel (1 4) with one in its extension in the flat jet formation surface (20) extending straight line (G) includes an angle (y) of between approximately 5 ° and approximately 25 °. 40. Device according to one of claims 37 to 39, characterized in that the auxiliary medium (21, 24) acts on the application medium (16) at a position which in the feed direction (Z) is at most 10 mm after the start of the flat jet formation surface ( 20) is arranged. 41. Device according to one of claims 37 to 40, characterized in that the auxiliary medium (21, 24) acts on the application medium (16) at a position which is arranged at most 15 mm from the nozzle outlet (18b). 42. Device according to one of claims 37 to 41, characterized in that the auxiliary medium (21, 24) acts on the application medium (16) from its side facing away from the flat jet formation surface (20). 43. Device according to one of claims 27 to 42, characterized in that it comprises a plurality of application nozzles (10) arranged distributed over the working width.