Device for direct or indirect application of liquid or viscous coating medium onto a moving material web

Information

  • Patent Grant
  • 6309463
  • Patent Number
    6,309,463
  • Date Filed
    Tuesday, May 2, 2000
    24 years ago
  • Date Issued
    Tuesday, October 30, 2001
    22 years ago
Abstract
A device for direct or indirect application of a liquid or viscous coating medium onto a moving material web, specifically a paper or cardboard web, includes an applicator unit which, in the direct application method, applies the coating medium in the form of a coating layer directly onto the material web at a point of application. In the indirect application method, the coating medium is first applied onto an applicator element, for example an applicator roll, which then transfers, at the point of application, the coating medium to the material web in the form of a coating layer. In addition, a drying device for drying of the coating layer is provided downstream from the point of application, viewed in the direction of flow of the material web. In the applicator unit, a device for moistening and/or warming the material web, coating medium or the coating layer is additionally provided before the drying device, viewed in the flow direction of the material web.
Description




BACKGROUND OF THE INVENTION




1. Field of the Invention




The present invention relates to a device for direct or indirect application of a liquid or viscous coating medium onto a moving material web, specifically a paper or cardboard web.




2. Description of the Related Art




Devices for direct or indirect coating of a moving material web are generally known in the current state of the art. Reference can be made to the VOITH SULZER article “Advances in Coating Equipment” by Dr. M. Kustermann. This article may be acquired from the assignee under order number P3008.




The process of coating medium application by use of an applicator unit onto the moving material web is generally influenced by a series of disturbing influences. Even when the coating medium is supplied to the material web, irregular air flows across the operating width of the material web that is to be coated may negatively influence the coating result. Particularly at high operating speeds, these air currents originate from the boundary air layer that is carried along by the material web on its surface. It also has a negative effect on the coating result if the absorption capacity of the material web that is to be coated varies in its longitudinal or flow direction, or in its cross direction. This specifically addresses the absorption capacity of the material web, which is at least one factor responsible for how quickly the coating medium dewaters into the material web. It is also detrimental if, based on the given physical characteristics such as surface tension and viscose elasticity, undesirable structures occur in the applied medium. In indirect application methods, there are additional irregularities in the surface structure of the coated material web, resulting for example, from the so-called film splitting effect. In direct application methods—for example when utilizing an open jet nozzle coater with a downstream doctoring device, a “Spray Coating” coater, a “Curtain Coating” coater or similar problems may develop. These problems include effects such as doctoring streaks, grooving when utilizing profiled metering rods, ink splashes or film splitting when utilizing smooth metering rods, and metering rod flooding (this term is generally used for excessive build up of coating medium at the end of a metering rod), which may negatively influence the coating result.




SUMMARY OF THE INVENTION




The present invention further develops an applicator unit of the generic concept so that the negative influence of the previously explained effects upon the achieved coating result are at least reduced, if not entirely eliminated.




An applicator unit is provided which, in the direct application method, applies the coating medium in the form of a coating layer directly onto the material web at an application point. In the indirect application method, the coating medium is first applied onto an applicator element, for example an applicator roll, which then, at an application point, transfers the coating medium to the material web in the form of a coating layer. A drying device for drying of the coating layer is provided downstream from the point of application, viewed in the web flow direction.




A device for moistening and/or warming of the material web and/or the coating medium or the application layer is provided prior to the dryer, when viewed in the direction of material web flow. An advantage of the method according to the invention is to be found in that the coating medium dries slower, thereby reducing its viscose elasticity. The result is that the coating medium remains free-flowing, so that the differences in applied coating thickness and irregularities in the surface structure of the coating layer can be uniformly distributed. Collectively, an independent leveling of the coating layer results. Moistening and/or warming may be effected by use of vapor, preferably water vapor which is caused by evaporation of a liquid in the area of the applicator unit and/or outside the applicator unit and is then supplied to the applicator unit. Additionally, or alternatively, moistening may also occur through spraying of a liquid, preferably water. In addition to a certain level of dilution of the coating medium, the warming of the coating medium that is preferably achieved with vapor also results in a viscosity reduction, which ensures better flow of the coating medium.




The utilization of water, be it in the form of water vapor or in the form of a water spray mist, offers the advantage that the applied water can again be removed in the downstream dryer and, therefore, the structure of the coating layer is not impaired.




The moistening and/or warming device as provided under the invention may be located at one or more of the locations discussed below:




For example, the moistening and/or warming device may be located immediately prior to the point of application, when viewed in direction of web flow. If it releases the vapor or the spray mist in the direction toward the point of application, the material web and the coating medium could be moistened simultaneously. Moistening of the material web reduces variations in its absorption and provides for uniform dewatering of the coating medium into the material web. Moistening and/or warming of the coating medium reduces its surface tension and reduces its viscosity, homogenizing the wetting of the material web with the coating medium and increasing the uniformity of the layer that is to be applied, even prior to the transfer to the material web.




Additionally, the influence of boundary air layer which, particularly at high material web speeds is carried along by the web and impairs the coating result, is reduced.




The moistening and/or warming device which is located before the applicator unit may, for example, include a vapor supply line which, in the area of the applicator unit, is equipped with at least one vapor outlet opening on the side facing the application area. Particularly with a view toward reducing the influence of the boundary air layer that is transported along by the material web, the vapor outlet opening forming side sections of the vapor supply line or of the side sections following the vapor outlet opening, viewed in vapor flow direction, are preferably tapered in the direction of vapor flow. An excessive amount of vapor may be blown into the application nip through this vapor outlet nozzle, so that at least a portion of the introduced vapor will again leave the application area along the material web surface, although in opposite direction to the web flow direction. However, it is also possible to introduce only a sufficient amount of vapor which can be absorbed by the material web and/or the coating medium and which, therefore, can be carried along.




The moistening and/or warming device may also be located following the point of application, viewed in direction of material web flow. For example, in direct application methods, it may be located between the point of application and a device for leveling and/or metering the coating layer which would be installed downstream from the point of application, viewed in direction of web flow. However, it is also possible that the moistening and/or warming device is provided following a device for leveling and/or metering the coating layer, which would be installed downstream from the point of application, viewed in direction of web flow.




When the moistening and/or warming device is installed after the point of application when viewed in direction of material web flow, it is preferable that the moistening and/or warming device directs the vapor or the spray mist substantially orthogonally to the material web surface, since this permits effective moistening of the coating layer surface. In addition, the kinetic energy of the vapor can basically be used for averaging.




For example, the moistening and/or warming device may include a vapor supply line which is equipped with at least one vapor outlet opening in the side section facing the material web.




In order to ensure sufficient moistening of the coating layer, it is further suggested that a vapor outlet section of the vapor supply line extends in direction of material web flow, over a distance of between approximately 0.1 cm and approximately 200 cm, preferably between approximately 50 cm and 100 cm.




The moistening and/or warming device additionally offers the possibility of influencing the transverse or longitudinal profile of the coating layer. A multitude of vapor or spray mist outlet sections can be provided consecutively transversely to the material web, which are independently controllable with regard to the dispensed volume of vapor or spray mist within a given time period.




In order to avoid condensing of the vapor, or settling of spay mist droplets in other than the desired areas of the applicator unit, a suction device may be provided. Since the tendency will exist for the material web to carry along the vapor or the spray mist with its movement, the suction device is located following the moistening and/or warming device, viewed in direction of material web flow.




In the instance of the previously discussed moistening and/or warming device which is located before the point of application, the suction device may also be arranged before the moistening and/or warming device, viewed in direction of material web flow.




When utilizing a leveling and/or metering device, a collecting device for excess coating medium is generally allocated to this unit. Through simple design modifications, this collecting device may also be utilized as a suction device at the same time.




It is also possible that the moistening and/or warming device is located at a distance from the point of application, relative to the direction of web flow. Treatment by moistening or warming may be useful even a long distance before the point of application if the design characteristics of the applicator unit demand this, or if an indirect application method is selected whereby a smooth and uniform coating application onto the applicator element can considerably influence the coating result on the material web. Thus, in the indirect application method, the moistening and/or warming device is located in the area of the applicator element. In this arrangement, the moistening and/or warming device may be installed at a location where the coating medium is applied to the applicator element. Regular metering and/or leveling of the coating layer which is applied to the applicator element occurs with indirect application. The moistening and/or warming device may then be placed at a location where the coating medium that is applied to the coating element is metered and/or leveled.




Generally, metering rods are utilized as well as doctoring blades for metering and/or leveling. Good results have been achieved if initially only the metering rod is moistened or warmed and the coating medium is moistened and warmed indirectly by the moistened or warmed metering rod. The applicator device includes at least one metering rod for metering and/or leveling of the coating medium on the applicator element or the material web, and the moistening and/or warming device moistens and/or warms the metering rod in an area remote from the point of engagement with the applicator element or the material web.




Generally, the metering rod is mounted substantially along its entire length in a metering rod bed. A simple design solution for moistening or warming the metering rod is that it may be moistened and/or warmed via a channel system running through the metering rod bed and which is open toward a bearing surface for the metering rod. Simple sluices may be used for the channel system, which are often already present in conventional metering rod beds.




In addition, the current invention relates to a method for direct or indirect application of a liquid or viscous coating medium onto a moving material web, specifically a paper or cardboard web. Regarding the advantages that are achievable with the method according to the current invention, reference can be made to the previous discussion on the applicator unit in accordance with the current invention.











BRIEF DESCRIPTION OF THE DRAWINGS




The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein:





FIG. 1

is a rough, schematic, side view of one embodiment of an applicator device according to the current invention for single sided, direct coating of a material web;





FIG. 2

is a schematic illustration of one embodiment of a moistening and/or warming device, with which transverse successive segments of the material web may be moistened at different levels;





FIG. 3

is a rough, schematic, side view of another embodiment of an applicator device according to the current invention, for two-sided coating of a material web;





FIG. 4

is a rough, schematic, side view of another embodiment of a section of the applicator device according to the current invention for indirect coating of a material web, whereby moistening and/or warming occurs in the area of a transfer roll of the applicator unit; and





FIG. 5

is a rough, schematic, side view of another embodiment of an applicator device whereby a metering rod is moistened and/or warmed.











Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate one preferred embodiment of the invention, in one form, and such exemplifications are not to be construed as limiting the scope of the invention in any manner.




DETAILED DESCRIPTION OF THE INVENTION




Referring now to the drawings and particularly to

FIG. 1

, there is shown an applicator device according to the present invention, generally identified with


10


. The applicator device


10


serves to directly apply a liquid or viscous medium


20


onto material web


16


which is moving in the direction of the arrow L, whereby the web is guided around a backing roll


12


in the area of the applicator device


10


. The backing roll


12


rotates around its axis A in direction of arrow P.




The applicator device


10


includes an applicator unit


18


, for example an open jet nozzle coater which generally applies an excess of coating medium onto the material web


16


at an application point S. Since open jet nozzle coaters are basically well known, we can refer to the current state of the art with respect to their design and operation. Obviously, other types of applicator units, such as for example “Curtain Coating” or “Spray Coating” units may be utilized in place of the open jet nozzle coater


18


.




A leveling and/or metering device


22


(subsequently referred to as “doctoring device” for short) is provided following the point of application S, viewed in flow direction L, which includes a doctor blade


22




b


mounted on a blade beam


22




a


. The doctor blade


22




b


is adjusted against the material web


16


, or the coating layer


24


, whereby the contact pressure or contact force may be adjusted by use of an adjusting device. Such doctoring devices are known in the art and need not be explained here in further detail.




Following the doctoring device


22


as viewed in flow direction L of material web


16


, a dryer arrangement


26


is provided which at least partially removes moisture contained in material web


16


and coating layer


24


. Regarding design and operation of such essentially known drying devices, we again refer to the state of the art.




According to the current invention, an initial moistening and/or warming device


30


which is located prior to the application point S, viewed in flow direction L of material web


16


, is provided for the applicator device


10


. In addition, a second moistening and/or warming device


32


is provided between the application point S and the doctoring device


22


. Finally, a third moistening and/or warming device


34


is provided between the doctoring device


22


and the dryer device


26


. However, not all three moistening and/or warming devices


30


,


32


and


34


need be present in each instance. That is, only one or two of these three moistening and/or warming devices


30


,


32


,


34


may be provided in other embodiments.




The example illustrated in

FIG. 1

shows all three moistening and/or warming devices


30


,


32


,


34


in the form of vaporizing units which release vapor, preferably water vapor, onto the material web


16


, coating medium


20


, or the coating layer


24


. Preferably, a saturated or overheated water vapor is used.




The moistening and/or warming device


30


includes a vapor supply pipe


36


which is equipped with vapor discharge openings


36




a


on its side facing the point of application S. A nozzle body


36




b


, which tapers toward the direction of application point S, connects to these vapor discharge openings


36




a


and preferably extends to immediately before the application point S. In a preferred arrangement, the vapor is supplied by the moistening and/or warming device


30


to the area before the application point S in such volumes that at least a portion of this vapor exits this area in opposite direction to the direction of flow L of material web


16


, as indicated by arrows


36




c


in FIG.


1


. This prevents the boundary air layer that is carried along by the material web


16


from reaching the application point S and influencing the coating result. However, it is also possible for the moistening and/or warming device


30


to release the vapor only onto the coating medium


20


, while a separate moistening and/or warming device


31


releases vapor only onto the material web


16


.




The moistening and or warming device


32


located between the application point S and the doctoring device


22


includes a supply section


32




a


and a distribution section


32




b


. The side of distributor section


32




b


facing the material web


16


includes a multitude of vapor discharge openings


32




c


from which vapor is supplied substantially orthogonally to the material web


16


or the coating layer


24


, as indicated in

FIG. 1

by five small arrows. With a view toward a simple and cost effective design, the moistening and/or warming device


32


is preferably constructed of sheet metal.




The moistening and/or warming device


34


which is located between the doctoring device


22


and the dryer


26


is of similar construction as the moistening and/or warming device


32


. Vapor is supplied through a supply line


34




a


to a distributor section


34




b


from which the vapor is released, substantially orthogonally, onto the coating layer


24


. The moistening and/or warming device


34


is also preferably constructed of sheet metal.




The vapor supplied to the material web


16


or to the coating layer


24


is carried along by the material web in direction of flow L, if it is not absorbed by the web, thereby leaving the area of the moistening and/or warming device. As mentioned previously, flowing off of the vapor in opposite direction to flow direction L is even desirable in the moistening and/or warming device


30


. The escaping vapor may deposit itself in cool areas of the applicator device


10


or in other parts along the entire length and may lead to undesirable condensate formation there. In order to guard against this effect, or in order to prevent this effect, vapor suction devices may be allocated to the moistening and/or warming devices


30


,


32


,


34


. For example, the sheet metal construction of the moistening and/or warming device


34


is equipped with a suction section


34




d


, which is located immediately following the distributor section


34




b


, as viewed in flow direction L of material web


16


. The extracted vapor can be removed from the suction section


34




d


through a suction line


34




e


which, if desired, may be equipped with a blower.




With the moistening and/or warming device


32


located between the application point S and the doctoring device


22


, the suction device may be constructively formed particularly simply by the collecting device


22




d


and the doctoring device


22


. In this arrangement, the metered off coating medium may be thinner due to condensate. This may be tolerated especially because the metered off coating medium is thickened somewhat compared to the coating medium that is applied to the material web since the material web—due to its absorption properties—removes moisture from the coating medium applied to it. It is, however, also possible to provide a suction pipe


38


, reaching into the collecting device


22




d


, to which a blower


40


can be connected.




A suction device may also be allocated to the moistening and/or warming devices


30


and


31


, even though this has been left off the illustration in

FIG. 1

in order to provide better clarity. For reasons of space, this suction device is located before devices


30


or


31


, viewed in flow direction L of material web


16


.




In order to permit zoned vaporizing of the application layer


24


in transverse direction Q of the material web


16


, the moistening and/or warming devices may be equipped with a multitude of vapor outlet openings


34




b


,


34




b


′,


34




b


″,


34




b


′″ . . . , to which separate vapor supply lines


34




a


,


34




a


′,


34




a


″,


34




a


′″ . . . are allocated, as illustrated in

FIG. 2

of the moistening and/or warming device


34


. The volume flow of the vapor supplied by the vapor supply lines


34




a


,


34




a


′ . . . may be influenced by non-illustrated control units including only schematically depicted valve units


42


. The vaporizing cross profile in the moistening and/or warming devices


30


,


31


and


32


may of course, also be varied analogically.




The applicator device


110


illustrated in

FIG. 3

serves for double sided indirect application of liquid or viscous coating medium


120


,


120


′ onto a material web


116


which is moving in flow direction L. This applicator device


110


includes two coating units


118


,


118


′ which apply the liquid or viscous coating medium


120


,


120


′ onto the surface


112




a


or


112




a


′ of two applicator rolls


112


,


112


′. The two applicator rolls


112


,


112


′ together form or define an application nip through which the material web


116


runs. The applicator rolls


112


,


112


′ rotate around their respective axes A and A′ in direction of the arrows P and P′, so that they are in contact with material web


116


substantially skid and slip free. Through the rotation of the applicator rolls


112


,


112


′ the coating medium


120


,


120


′ is transported from the applicator units


118


and


118


′ to the material web


116


. In accordance with

FIG. 1

, a dryer


126


is provided after the applicator device


110


, following the application point S when viewed in flow direction L.




Similar to the arrangement in

FIG. 1

, moistening and/or warming devices


130


,


130


′ and


134


, or


134


′ are provided before the application point S, and the dryer


126


, respectively. The moistening and/or warming devices


134


and


134


′ correspond in their design and function to the moistening and/or warming devices according to

FIG. 1

, to the description of which we refer herewith.




Unlike the moistening and/or warming device


30


of the design according to

FIG. 1

, the moistening and/or warming devices


130


,


130


′ do not release vapor in the direction of the application point S, but instead deliver a spray mist of finely atomized liquid drops. Again, the state of the art is known for utilization of suitable atomizers as a moistening and/or warming devices


130


and


130


′ and will, therefore, not be discussed in further detail here.




Only one design form for single sided direct application and one design form for double sided indirect application has been illustrated and discussed herein. Furthermore, a vaporizing device is shown only in the last mentioned design form, and only in the flow direction prior to the point of application S. However, it is to be understood that the current invention also relates to design forms for double sided direct application, single sided indirect application, or even combined direct and indirect application. Further, each of the aforementioned devices


30


,


31


,


32


,


34


,


130


,


130


′,


134


,


134


′ may further be arranged as a device producing and/or supplying vapor, or as a device for atomizing liquid, or as a combination of these device types.




We will now discuss

FIG. 4 and 5

. For the identification of identical or identically functioning components as illustrated in

FIGS. 1 through 3

, the same reference numbers are used, but are increased by 100 or by integral multiples of 100. Regarding the description of such components, reference can be made to the preceding descriptions of

FIGS. 1 through 3

.





FIG. 4

illustrates a section of an applicator device


210


which serves to indirectly apply liquid or viscous medium


220


onto a material web which is not illustrated in detail. The coating medium


220


is initially applied by use of an applicator unit


218


onto an applicator and transfer roll


212


which rotates in direction of arrow P. The coating medium


220


that has been applied to the transfer roll


212


is moistened and/or warmed by use of a moistening and/or warming device


230


. The moistening and/or warming device


230


, which is schematically depicted as a nozzle, is directed toward a nip between the transfer roll


212


and a metering rod


244


. Metering rod


244


serves as the doctoring element for metering the layer thickness of the applied coating medium


220


. In relation to the direction of rotation of the transfer roll


212


, the moistening and/or warming device


230


is located after the metering rod


244


. Moistening and/or warming device


230


favors uniform distribution of the coating medium


220


on the transfer roll


212


so that there are substantially identical application conditions at the transfer point, which is not illustrated in detail, where the coating medium is transferred to the material web, across the entire width of the transfer roll


212


and the material web, as well as in longitudinal direction of the material web. In addition, the nozzle type moistening and/or warming device


230


, which is directed toward the nip between metering rod


244


and transfer roll


212


, prevents so-called film splitting whereby parts of the coating medium which is to be applied to the transfer roll


212


adhere to the metering rod


244


.





FIG. 5

illustrates a backing roll


312


, rotating in direction of an arrow P, which in part of its circumference is in contact with a material web


316


which is covered with a layer of a coating medium


320


. The coated material web


316


runs through a doctoring device


322


which removes excess coating medium


320


from the material web


316


by use of a metering rod


344


. The metering rod


344


rotates around its rod axis


346


and is mounted in a metering rod bed


348


, substantially along its entire length. For this purpose, the metering rod bed


348


is equipped with a partially cylindrical bearing surface


350


against which the metering rod


344


supports itself. Channels


352


are incorporated in the bearing surface


350


along the metering rod


344


which are open toward the metering rod


344


either along their entire length or have outlet openings distributed along the length of the metering rod


344


. The channels


352


are part of a moistening and/or warming device


330


which supplies vapor or a spray liquid through the channels


352


onto the outside surface of the metering rod


344


. The metering rod


344


, rotating in the metering rod bed


348


, carries the moisture and/or warmth into the area of its contact with the material web


316


, where the moisture and/or warmth are at least partially transferred to the coating medium


320


and the material web


316


. Obviously, a nozzle arrangement directed into the nip between metering rod


344


and roll


312


may additionally be provided through which moistening and/or warming of the coating medium


320


and the material web


316


can be achieved by vaporizing or spraying.




Since the channels


352


are already available on conventional metering rod beds and serve as flushing channels, a conventional metering rod bed may substantially be utilized without modifications in order to achieve the arrangement in FIG.


5


. Thus, manufacturing and design expenditures may be kept low.




While this invention has been described as having a preferred design, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.



Claims
  • 1. An apparatus for directly applying a coating medium onto a moving fiber material web having a direction of movement, said apparatus comprising:an applicator unit configured for directly applying a layer of the coating medium onto the fiber web at an application point; a drying device disposed after said application point relative to the direction of movement of the fiber web, said drying device being configured for drying the coating layer; at least one primary moistening/warming device disposed before said drying device relative to the direction of movement of the fiber web, said moistening/warming device being configured for at least one of moistening and warming at least one of the fiber web, the coating medium and the coating layer; and at least one secondary moistening/warming device, being configured solely to direct at least one of moisture and heat toward at least one of the fiber web, the coating medium and the coating layer, each said secondary moistening/warming device including a housing defining a chamber and a source of at least one of heat and moisture, said chamber being open and directed toward at least one of the fiber web, the coating medium and the coating layer.
  • 2. The apparatus of claim 1, wherein at least one of said at least one of primary moistening/warming device and said at least one secondary moistening/warming device comprises a vapor device configured for at least one of production and supply of water vapor.
  • 3. The apparatus of claim 1, wherein at least one of said at least one primary moistening/warming device and said at least one secondary moistening/warming device comprises a spray device configured for spraying water.
  • 4. The apparatus of claim 1, wherein at least one of said at least one primary moistening/warming device and said at least one secondary moistening/warming device is disposed immediately before said application point relative to the direction of movement of the fiber web.
  • 5. The apparatus of claim 4, wherein at least one of said at least one primary moistening/warming device and said at least one secondary moistening/warming device is configured for emitting one of a vapor and a spray mist toward said application point.
  • 6. The apparatus of claim 5, wherein at least one of said at least one primary moistening/warming device and said at least one secondary moistening/warming device includes a vapor supply line configured such that at least one vapor outlet is directed toward said application point.
  • 7. The apparatus of claim 6, wherein a nozzle body attaches to said vapor supply line, said nozzle body being directed toward said application point and being tapered in a direction of vapor flow.
  • 8. The apparatus of claim 1, wherein at least one said secondary moistening/warming device is disposed after said application point relative to the direction of movement of the fiber web.
  • 9. The apparatus of claim 8, further comprising a doctor device disposed after said application point relative to the direction of movement of the fiber web, said doctor device being configured for at least one of metering and leveling of the coating layer, at least one said secondary moistening/warming device being disposed between said application point and said doctor device.
  • 10. The apparatus of claim 8, further comprising a doctor device disposed between said application point and at least one said secondary moistening/warming device, said doctor device being configured for at least one of metering and leveling of the coating layer.
  • 11. The apparatus of claim 8, wherein at least one of said at least one primary moistening/warming device and said at least one secondary moistening/warming device is configured for emitting one of a vapor and a spray mist in a direction substantially orthogonal to the fiber web.
  • 12. The apparatus of claim 8, wherein at least one of said at least one primary moistening/warming device and said at least one secondary moistening/warming device includes a vapor supply line having a first side section facing the fiber web, said vapor supply line having at least one vapor outlet opening in said first side section.
  • 13. The apparatus of claim 8, wherein said vapor supply line includes a vapor outlet section having a width oriented substantially parallel to the direction of movement of the fiber web, said width being approximately between 0.1 cm and 200 cm.
  • 14. The apparatus of claim 13, wherein said width of said vapor outlet section is approximately between 60 cm and 100 cm.
  • 15. The apparatus of claim 1, wherein the fiber web has a width, said apparatus further comprising one of a plurality of vapor outlet sections and a plurality of spray mist outlet sections aligned in a direction substantially parallel to the width of the fiber web, a flow rate of said outlet sections being independently controllable.
  • 16. The apparatus of claim 1, further comprising a suction device.
  • 17. The apparatus of claim 16, wherein said suction device is disposed after at least one said secondary moistening/warming device relative to the direction of movement of the fiber web.
  • 18. The apparatus of claim 16, further comprising:a doctor device configured for at least one of leveling and metering the coating layer; and a coating medium collecting device associated with said doctor device, said collecting device being in fluid communication with said suction device.
  • 19. An apparatus for indirectly applying a coating medium onto a moving fiber material web having a direction of movement, said apparatus comprising:an applicator roll configured for applying a layer of the coating medium onto the fiber web at an application point; an applicator unit associated with said applicator roll, said applicator unit being configured for applying the coating medium onto said applicator roll; a drying device disposed after said application point relative to the direction of movement of the fiber web, said drying device being configured for drying the coating layer; at least one primary moistening/warming device disposed before said drying device relative to the direction of movement of the fiber web, said moistening/warming device being configured for at least one of moistening and warming at least one of the fiber web, the coating medium and the coating layer; and at least one secondary moistening/warming device, being configured solely to direct at least one of moisture and heat toward at least one of the fiber web, the coating medium and the coating layer, each said secondary moistening/warming device including a housing defining a chamber and a source of at least one of heat and moisture, said chamber being open and directed toward at least one of the fiber web, the coating medium and the coating layer.
  • 20. The apparatus of claim 19, wherein at least one said primary moistening/warming device is disposed before and at a distance away from said application point.
  • 21. The apparatus of claim 20, wherein at least one said primary moistening/warming device is disposed adjacent to said applicator roll.
  • 22. The apparatus of claim 21, wherein said applicator roll includes a receiving point configured for receiving the coating medium from said applicator unit, at least one said primary moistening/warming device being disposed adjacent to said receiving point of said applicator roll.
  • 23. The apparatus of claim 21, wherein said applicator unit includes a doctor device configured for at least one of metering and leveling the coating medium on the applicator roll, at least one said secondary moistening/warming device being disposed adjacent to said doctor device of said applicator unit.
  • 24. The apparatus of claim 23, wherein said doctor device comprises at least one metering rod having a length, a bearing surface and a point of engagement with said applicator roll, said at least one metering rod having an area remote from said point of engagement, at least one said secondary moistening/warming device being configured for at least one of moistening and warming said remote area of said at least one metering rod.
  • 25. The apparatus of claim 24, further comprising a metering rod bed having a channel system extending through said metering rod bed, said at least one metering rod being mounted in said metering rod bed substantially along said length of said at least one metering rod such that said channel system opens toward said bearing surface of said at least one metering rod, at least one said secondary moistening/warming device being configured for at least one of moistening and warming said least one metering rod through said channel system of said metering rod bed.
  • 26. The apparatus of claim 1, wherein at least one of said at least one primary moistening/warming device and said at least one secondary moistening/warming device is configured to deliver a spray mist of liquid droplets.
Priority Claims (1)
Number Date Country Kind
198 00 954 Jan 1998 DE
Parent Case Info

This is a divisional of application Ser. No. 09/229,227 filed Jan 12, 1999.

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