CA1264428A - Process and an apparatus for the continuous application of an even coating to a strip of material, in particular paper or cardboard, that passes over a counter roller - Google Patents
Process and an apparatus for the continuous application of an even coating to a strip of material, in particular paper or cardboard, that passes over a counter rollerInfo
- Publication number
- CA1264428A CA1264428A CA000514930A CA514930A CA1264428A CA 1264428 A CA1264428 A CA 1264428A CA 000514930 A CA000514930 A CA 000514930A CA 514930 A CA514930 A CA 514930A CA 1264428 A CA1264428 A CA 1264428A
- Authority
- CA
- Canada
- Prior art keywords
- strip
- applicator
- roller
- coating
- coating material
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 239000000463 material Substances 0.000 title claims abstract description 114
- 239000011248 coating agent Substances 0.000 title claims abstract description 78
- 238000000576 coating method Methods 0.000 title claims abstract description 78
- 238000000034 method Methods 0.000 title claims abstract description 20
- 239000011111 cardboard Substances 0.000 title abstract description 5
- 239000011087 paperboard Substances 0.000 title abstract description 4
- 230000000903 blocking effect Effects 0.000 claims abstract description 13
- 239000007788 liquid Substances 0.000 claims description 13
- 230000000694 effects Effects 0.000 claims description 3
- 230000002093 peripheral effect Effects 0.000 claims description 2
- 238000000926 separation method Methods 0.000 claims description 2
- 230000004888 barrier function Effects 0.000 abstract 1
- 239000000123 paper Substances 0.000 description 8
- 239000007787 solid Substances 0.000 description 7
- 230000035515 penetration Effects 0.000 description 4
- 208000036366 Sensation of pressure Diseases 0.000 description 2
- 239000011230 binding agent Substances 0.000 description 2
- 238000004140 cleaning Methods 0.000 description 2
- 239000012530 fluid Substances 0.000 description 2
- 238000007726 management method Methods 0.000 description 2
- 238000007789 sealing Methods 0.000 description 2
- 238000001035 drying Methods 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000000049 pigment Substances 0.000 description 1
- 230000008092 positive effect Effects 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 238000009827 uniform distribution Methods 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
- 238000009736 wetting Methods 0.000 description 1
Classifications
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H23/00—Processes or apparatus for adding material to the pulp or to the paper
- D21H23/02—Processes or apparatus for adding material to the pulp or to the paper characterised by the manner in which substances are added
- D21H23/22—Addition to the formed paper
- D21H23/32—Addition to the formed paper by contacting paper with an excess of material, e.g. from a reservoir or in a manner necessitating removal of applied excess material from the paper
- D21H23/40—Addition to the formed paper by contacting paper with an excess of material, e.g. from a reservoir or in a manner necessitating removal of applied excess material from the paper only one side of the paper being in contact with the material
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05C—APPARATUS FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05C1/00—Apparatus in which liquid or other fluent material is applied to the surface of the work by contact with a member carrying the liquid or other fluent material, e.g. a porous member loaded with a liquid to be applied as a coating
- B05C1/04—Apparatus in which liquid or other fluent material is applied to the surface of the work by contact with a member carrying the liquid or other fluent material, e.g. a porous member loaded with a liquid to be applied as a coating for applying liquid or other fluent material to work of indefinite length
- B05C1/08—Apparatus in which liquid or other fluent material is applied to the surface of the work by contact with a member carrying the liquid or other fluent material, e.g. a porous member loaded with a liquid to be applied as a coating for applying liquid or other fluent material to work of indefinite length using a roller or other rotating member which contacts the work along a generating line
- B05C1/0804—Apparatus in which liquid or other fluent material is applied to the surface of the work by contact with a member carrying the liquid or other fluent material, e.g. a porous member loaded with a liquid to be applied as a coating for applying liquid or other fluent material to work of indefinite length using a roller or other rotating member which contacts the work along a generating line the material being applied without contact with the roller
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05C—APPARATUS FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05C1/00—Apparatus in which liquid or other fluent material is applied to the surface of the work by contact with a member carrying the liquid or other fluent material, e.g. a porous member loaded with a liquid to be applied as a coating
- B05C1/04—Apparatus in which liquid or other fluent material is applied to the surface of the work by contact with a member carrying the liquid or other fluent material, e.g. a porous member loaded with a liquid to be applied as a coating for applying liquid or other fluent material to work of indefinite length
- B05C1/08—Apparatus in which liquid or other fluent material is applied to the surface of the work by contact with a member carrying the liquid or other fluent material, e.g. a porous member loaded with a liquid to be applied as a coating for applying liquid or other fluent material to work of indefinite length using a roller or other rotating member which contacts the work along a generating line
- B05C1/0826—Apparatus in which liquid or other fluent material is applied to the surface of the work by contact with a member carrying the liquid or other fluent material, e.g. a porous member loaded with a liquid to be applied as a coating for applying liquid or other fluent material to work of indefinite length using a roller or other rotating member which contacts the work along a generating line the work being a web or sheets
- B05C1/083—Apparatus in which liquid or other fluent material is applied to the surface of the work by contact with a member carrying the liquid or other fluent material, e.g. a porous member loaded with a liquid to be applied as a coating for applying liquid or other fluent material to work of indefinite length using a roller or other rotating member which contacts the work along a generating line the work being a web or sheets being passed between the coating roller and one or more backing rollers
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05C—APPARATUS FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05C11/00—Component parts, details or accessories not specifically provided for in groups B05C1/00 - B05C9/00
- B05C11/02—Apparatus for spreading or distributing liquids or other fluent materials already applied to a surface ; Controlling means therefor; Control of the thickness of a coating by spreading or distributing liquids or other fluent materials already applied to the coated surface
- B05C11/04—Apparatus for spreading or distributing liquids or other fluent materials already applied to a surface ; Controlling means therefor; Control of the thickness of a coating by spreading or distributing liquids or other fluent materials already applied to the coated surface with blades
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H25/00—After-treatment of paper not provided for in groups D21H17/00 - D21H23/00
- D21H25/08—Rearranging applied substances, e.g. metering, smoothing; Removing excess material
- D21H25/10—Rearranging applied substances, e.g. metering, smoothing; Removing excess material with blades
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H5/00—Special paper or cardboard not otherwise provided for
- D21H5/0005—Processes or apparatus specially adapted for applying liquids or other fluent materials to finished paper or board, e.g. impregnating, coating
- D21H5/0012—Processes or apparatus specially adapted for applying liquids or other fluent materials to finished paper or board, e.g. impregnating, coating by bringing paper into contact with an excess of fluids, the paper carrying away only a part of the fluid material, e.g. by passing through liquids, gases or vapours
- D21H5/0015—Processes or apparatus specially adapted for applying liquids or other fluent materials to finished paper or board, e.g. impregnating, coating by bringing paper into contact with an excess of fluids, the paper carrying away only a part of the fluid material, e.g. by passing through liquids, gases or vapours only one side of the paper being in contact with the treating medium, e.g. paper carried by support
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H5/00—Special paper or cardboard not otherwise provided for
- D21H5/0005—Processes or apparatus specially adapted for applying liquids or other fluent materials to finished paper or board, e.g. impregnating, coating
- D21H5/006—Controlling or regulating
- D21H5/0062—Regulating the amount or the distribution, e.g. smoothing, of essentially fluent material already applied to the paper; Recirculating excess coating material applied to paper
- D21H5/0065—Regulating the amount or the distribution, e.g. smoothing, of essentially fluent material already applied to the paper; Recirculating excess coating material applied to paper with blades
Landscapes
- Coating Apparatus (AREA)
- Application Of Or Painting With Fluid Materials (AREA)
- Paper (AREA)
Abstract
ABSTRACT
In the continuous application of an even coating on a strip of material (5) that passes over a counter roller (6), in particular paper or cardboard, the coating material is delivered at very low pressure with the help of an applicator roller (2) and under the control of a guide plate (8) and into the applicator gap (7) that is formed by the counter roller and the applicator roller. The coating material is dosed by means of a dosing element (15), partially de-watered in the vicinity of a layer that is close to the strip of material so as to form a blocking barrier, and then finally dosed in a final dosing assembly by means of a final dosing element (24) at very low application pressure. A three-stage process of this kind, or the apparatus which is suitable for carrying out this process, makes it possible to achieve consistently good coating quality at comparatively high throughput speeds of the material and at extremely low application weights.
In the continuous application of an even coating on a strip of material (5) that passes over a counter roller (6), in particular paper or cardboard, the coating material is delivered at very low pressure with the help of an applicator roller (2) and under the control of a guide plate (8) and into the applicator gap (7) that is formed by the counter roller and the applicator roller. The coating material is dosed by means of a dosing element (15), partially de-watered in the vicinity of a layer that is close to the strip of material so as to form a blocking barrier, and then finally dosed in a final dosing assembly by means of a final dosing element (24) at very low application pressure. A three-stage process of this kind, or the apparatus which is suitable for carrying out this process, makes it possible to achieve consistently good coating quality at comparatively high throughput speeds of the material and at extremely low application weights.
Description
~ 21712-197 A PROCESS AN~ AN APPARATUS FOR THE CONTINUOUS APPLICATION OF AN
EVEN COATING TO A STRIP OF MATERIAL, IN PARTICVLAR PAPER OR
CARDBOARD, THAT PASSES OVER A COUNTER ROLLER
~ he present invention relates to a process and an apparatus for the continuous application of an even coating to a strip of material, in particular paper or cardboard, that passes over a counter roller, on which the coating material is first applied in excessive quantities by means of an applicator roller and then stripped off.
When coating moving strip material, in particular of paper or cardboard, there is an increasing desire for ever higher speeds of movement of said material, for processing to be effected at higher concentrations of solids in the coating material, so as to economize in the energy used for drying, and, possibly simul-taneouslyr for the achievement of the lowest application weights.
Today, the speeds a~ which such material move are generally in the order of 1,200 to 1,400 metres per minute. At such speeds, it i5 principally mass printing papers such as so-called LWC (dry appli-cation weight 4-8 g/m2) that are coated.
The application and dosing procedures that are usual today mean the above speeds cannot, in essence, be exceeded unless the solids content of the coating material is considerably reduced so as to main~ain the application weight that is desired.
Known application and dosing procedures include the single roller application machine ~flooded-nip coater), and the so-called short-dwell coater.
, ' , A single roller applicator machine is described, for example, in DE-OS 29 31 800. In this process the coating material is applied to the strip of paper in excessive quantities by means of an application roller and is then equalized and dosed by a dosing element, usually configured as a rigid blade in the case of low application weights. When this is done, t:he excess quantity can be controlled by the width of the applicator gap located between the applicator roller and the counter roller and by the speed of rotation of the applicator roller. The liquid pressure that is generated in the applicator gap leads to de-watering of a layer of coating material that is proximate to the strip o paper, this then forming a blocking or filter layer that prevents the component elements of the coating material being forced too strongly into the paper strip during dosing. At relatively low strip speeds the pressure of the liquid in the applicator gap can be controlled by the width of the gap and the rotational speed.
At high strip speeds the applicator gap must be adjusted so as to be extremely narrow, otherwise the vortices that are formed in the applicator gap will cause uncoated areas on the strip of material.
However, if the gap is adjusted to be narrow, hydrodynamic pres-sure will rise out of all proportion and the positive effect of partial de-watering that was initially achieved will be reversed with the result that the coating material will be forced into and even through the strip of material. In addition, the film-split-ting effect that occurs in the diverging portions of the appli~
cator gap will be increased, and this will result in an extremely uneven film of excess material.
, ,, :
The short-dwell process for coating strips of material is described in European patent application 51 698. Here, the coating material is passed under pressure to a chamber that is defined on the run-off side of the strip of material by the dosing element and on the supply side of the strip oi~ material by an overflow plate that is arranged at a limited distance rom the material strip and on the front side by a sealing element. In operation three to five times the application quantity will run over on the overflow plate. Since the applicator roller is eliminated, this is a very compact applicator machine with which machine speeds of up to approximately 600 to 700 m/min can be achieved by suitable matching of the paper strip and the coating material. With the same limiting conditions, under certain cir-cumstances somewhat smaller coating weights can be applied than with the single roller applicator machine, since at lower speeds the hydrodynamic pressure at the dosing element is also relatively low and for this reason there does not always have to be a blocking layer ahead of the dosing element. At the above-cited speeds the overflow of coating material is relatively smooth and even, so that as a rule complete wetting of the strip of material will be ensured.
At high strip speeds, however, the liquid pressure on the dosing element increases out of all proportion; because of the fact that there is no blocking layer the coating material is forced into or through the strip of material. In addition, the impulse of the liquid boundary layer increases so strongly on the strip of material that the dosing element, formed in most .. .. . .
~- :
.~ ~,, "' ~' ` .
21712-~97 instances as a rigid blade, cannot withstand this pressure, in particular if there is a high proportion of solids in th~ ~o~ting material. Thus, for the same limiting conditions, the application weiyht applied by a flooded-nip coater is, as a rule, smaller than that of a short-dwell coater at speeds in excess of 700 m/min. In addition, the overflow plate entails the disadvantage that when a short-dw~ll coater operates rapidly the coating material sprays uncontrolled out of the overflow gap since the air boundary layer that enters the application zon~ with the strip of material can penetrate as far as the dosing element and this, too, leads to uncoated areas in the application of the coating.
It is the aim of the present invention to provlde a process by which comparatively hlgh material ~trip spleeds can be achieved with constant yood quality, preferably at extremely low application weights of tbe coating. Furthermore, it is also the ob~ective of the present invention to create an apparatus with which the good coa~ing quality can be achieved in a surprisingly simple ~anner even at high machine speeds, by purposefully selected and inter-reactin~ systems.
The invention provides a process ~or the continuous application o~ an e~en coating on a strip of material that passes across a coun~er roller, on which ~he coating material is at ~lrst applied in an excess quantity by means of an applicator roller, a~d then metered to a desired coating thickness, characteri in that the coating material is supplied in a controlled pre-dosed quantity along a specific zone w~h the help of the applicator roller, this being done as far as ~he applicator gap between the .....
;." :`` ' ' ', ~' :. :
~2~ 8 21712-lg7 ap~licator roller and the counter rollert and i5 applled to the strip of ma~erial at very low pressurs such that the coating material is partially de-watered in a thin blocking layer contiguous to the strip of ma~erial.
The invention al~o pro~ides apparatus for the continuous appllcation of a uniform coatlng onto a strip of ma~erial tha~
passes over a coun~r roller, comprislng: an applicator roller supplied from a li~uid chamber and used for coating the ma~erial, and a metering device with a metering element, characterlzed in ~hat the applicator roller has a supply side provided ~i~h a guid~
plate that extends into the applicator gap between the applicator roller and the counter rollex.
The process entails considerable advantages. By the pre-dosed managemen~ of the coating material into the applicator gap between the applicator roller and the counter roller, the hydrodynamic pressure that builds up at this point can be varied within a very wide range by adjusting the roller gap, preferably in such a manner that it ls minimized as the roller ~ap becomes greaker. The coating material is dellvered more evenly, i.e., without the inclusion of air and in greater quantities to the applicator gap, ~o that the ~ap can be ad~usted so as to be larger than is the case wi~h the conventional flooded-nip coaters, and so that less turbulenca result at lower hydrodynamlc pressure with the result that the risk of there being uncovered area~ is smaller.
A low applicatlon pressure in the pre-dosing assembly is to be taken as being a value of 0 to 20~ of the application 80rce s :~ ~
~,. ;....
, :
~ 21712-197 (linear pressure) in the area of the final dosing, 0% indicating -that a dosing element used for dosing is adjusted to a -fixed gap of 0.01 to 0.1 mm, this being done as a function of speed, coating material, etc. The dosing o-f the coating material ensures that exactly as much excess is moved forward for final metering as is required for sufficient rinsing or washing at this point, in which connection it is importan-t that during the process there is a partial de-watering of a thin boundary layer of the coating material contiguous to the material strip, in which the solid components tpigments and binders) of the coating material are as far as possible immobilized. The layex that is formed in this manner then acts as a blocking layer during the final metering process and prevents the penetration of solid components of the coating material into the strip of paper.
The apparatus that is proposed for sending only a pre-dosed quantity of the coating material to the applicator gap and for carrying out the process ensures that even at high machine speeds a precisely defined blocking layer in a metered coating material is formed on the material strip, thus preventing the pressure of the liquid on a final metering element driving the coating material too powerfully into the strip of ma~terial. In addition, the guide plate distributes the coating material abso-lutely evenly, both in the direction of movement of the strip of material and transverse to thisj and delivers it free of air bubbles lnto the applicator gap. In addition, in a preferred embodiment of the invention it is~foreseen that the guide plate can be curved so as to correspond to the circumference of the applicator roller, at least in the area that i9 proximate to the-_ ~, ' ~' ` . .
' ' :
: ~
~ 4 ~ 21712-197 applicator gap between the applicator roller and the counter roller. This results in exact management of the coating material, in particular is so configured that the distance from the guide plate to the periphery of the applicator roller is adjustable. In this way the hydrodynamic pressure that builds up in the appli-cator gap can be very precisely adjusted and reproduced. In particular, no air bubbles are introduced into the gap, which means that it is possible to achieve a particularly even coating that is free of faults.
In order to compensate for pressure variations that may, for example, be attributable to the coating-material supply, there is most expediently between the guide plate and the liquid chamber a slot-like opening through which the excess coating material that has not been delivered by the applicator roller to the applicator gap, can drain off.
For the further management of coating material there is a guide blade between the applicator gap and the metering element, this guide blade being provided with overflow openings and which on its~upper and lower side is matched essentially to the peripheral area of the applicator roller and the counter roller both at a distance from these and in contact with them.
In order to achieve a partial de-watering effect or a blocking layer in the coating material a particular geometrical configuration of the metering device is exploited. Most e~pediently, the metering device is configured as a raker bar which on its end face that is proxlmate to the strip of ma-terial is of a converging, preferably convexly converging, shape, . . .
.
' ~2~ 8 21712-197 converging relative to the strip of material towards the final metering element.
The Einal metering element is preferably configured as a rigid blade. In order tha-t the apparatus is easily accessible in all three oE the different systems, the final metering element and its retaining element and a catch basin that is arranged benea-th these, as well. as the pre-metering element and its retaining elements with an associated collector chamber, are arranged on a frame that can be pivoted about an essentially hori7.ontal shaft.
By swinging down the apparatus as a whole it is possible to ensure easy access to all the individual components for cleaning, repair, and replacement. Furthermore, the guide plate can be swung away independently, in order to provide access to the applicator roller.
Two preferred embodiments of the invention are described in greater detail below on the basis of the drawings appended hereto, wherein:
Figure I is a side view in section showing an applicator and metering apparatus with an applicator assembly, a metering assembly, and a final dosing assembly;
Figure 2 shows schematically the process of coating a strip of material, as shown in Figure 1, Figure 3 shows a further configuration of the pre-meter-ng assembly of Figure 1;
Figure 4 is a front view of the pre metering assembly of Figure 3.
~' .
::
:, ' ~'' .
~ 2~ 21712-197 The applicator and pre-metering apparatus -that is shown in Figure 1 has an applicator 1 with a rotating applicator roller
EVEN COATING TO A STRIP OF MATERIAL, IN PARTICVLAR PAPER OR
CARDBOARD, THAT PASSES OVER A COUNTER ROLLER
~ he present invention relates to a process and an apparatus for the continuous application of an even coating to a strip of material, in particular paper or cardboard, that passes over a counter roller, on which the coating material is first applied in excessive quantities by means of an applicator roller and then stripped off.
When coating moving strip material, in particular of paper or cardboard, there is an increasing desire for ever higher speeds of movement of said material, for processing to be effected at higher concentrations of solids in the coating material, so as to economize in the energy used for drying, and, possibly simul-taneouslyr for the achievement of the lowest application weights.
Today, the speeds a~ which such material move are generally in the order of 1,200 to 1,400 metres per minute. At such speeds, it i5 principally mass printing papers such as so-called LWC (dry appli-cation weight 4-8 g/m2) that are coated.
The application and dosing procedures that are usual today mean the above speeds cannot, in essence, be exceeded unless the solids content of the coating material is considerably reduced so as to main~ain the application weight that is desired.
Known application and dosing procedures include the single roller application machine ~flooded-nip coater), and the so-called short-dwell coater.
, ' , A single roller applicator machine is described, for example, in DE-OS 29 31 800. In this process the coating material is applied to the strip of paper in excessive quantities by means of an application roller and is then equalized and dosed by a dosing element, usually configured as a rigid blade in the case of low application weights. When this is done, t:he excess quantity can be controlled by the width of the applicator gap located between the applicator roller and the counter roller and by the speed of rotation of the applicator roller. The liquid pressure that is generated in the applicator gap leads to de-watering of a layer of coating material that is proximate to the strip o paper, this then forming a blocking or filter layer that prevents the component elements of the coating material being forced too strongly into the paper strip during dosing. At relatively low strip speeds the pressure of the liquid in the applicator gap can be controlled by the width of the gap and the rotational speed.
At high strip speeds the applicator gap must be adjusted so as to be extremely narrow, otherwise the vortices that are formed in the applicator gap will cause uncoated areas on the strip of material.
However, if the gap is adjusted to be narrow, hydrodynamic pres-sure will rise out of all proportion and the positive effect of partial de-watering that was initially achieved will be reversed with the result that the coating material will be forced into and even through the strip of material. In addition, the film-split-ting effect that occurs in the diverging portions of the appli~
cator gap will be increased, and this will result in an extremely uneven film of excess material.
, ,, :
The short-dwell process for coating strips of material is described in European patent application 51 698. Here, the coating material is passed under pressure to a chamber that is defined on the run-off side of the strip of material by the dosing element and on the supply side of the strip oi~ material by an overflow plate that is arranged at a limited distance rom the material strip and on the front side by a sealing element. In operation three to five times the application quantity will run over on the overflow plate. Since the applicator roller is eliminated, this is a very compact applicator machine with which machine speeds of up to approximately 600 to 700 m/min can be achieved by suitable matching of the paper strip and the coating material. With the same limiting conditions, under certain cir-cumstances somewhat smaller coating weights can be applied than with the single roller applicator machine, since at lower speeds the hydrodynamic pressure at the dosing element is also relatively low and for this reason there does not always have to be a blocking layer ahead of the dosing element. At the above-cited speeds the overflow of coating material is relatively smooth and even, so that as a rule complete wetting of the strip of material will be ensured.
At high strip speeds, however, the liquid pressure on the dosing element increases out of all proportion; because of the fact that there is no blocking layer the coating material is forced into or through the strip of material. In addition, the impulse of the liquid boundary layer increases so strongly on the strip of material that the dosing element, formed in most .. .. . .
~- :
.~ ~,, "' ~' ` .
21712-~97 instances as a rigid blade, cannot withstand this pressure, in particular if there is a high proportion of solids in th~ ~o~ting material. Thus, for the same limiting conditions, the application weiyht applied by a flooded-nip coater is, as a rule, smaller than that of a short-dwell coater at speeds in excess of 700 m/min. In addition, the overflow plate entails the disadvantage that when a short-dw~ll coater operates rapidly the coating material sprays uncontrolled out of the overflow gap since the air boundary layer that enters the application zon~ with the strip of material can penetrate as far as the dosing element and this, too, leads to uncoated areas in the application of the coating.
It is the aim of the present invention to provlde a process by which comparatively hlgh material ~trip spleeds can be achieved with constant yood quality, preferably at extremely low application weights of tbe coating. Furthermore, it is also the ob~ective of the present invention to create an apparatus with which the good coa~ing quality can be achieved in a surprisingly simple ~anner even at high machine speeds, by purposefully selected and inter-reactin~ systems.
The invention provides a process ~or the continuous application o~ an e~en coating on a strip of material that passes across a coun~er roller, on which ~he coating material is at ~lrst applied in an excess quantity by means of an applicator roller, a~d then metered to a desired coating thickness, characteri in that the coating material is supplied in a controlled pre-dosed quantity along a specific zone w~h the help of the applicator roller, this being done as far as ~he applicator gap between the .....
;." :`` ' ' ', ~' :. :
~2~ 8 21712-lg7 ap~licator roller and the counter rollert and i5 applled to the strip of ma~erial at very low pressurs such that the coating material is partially de-watered in a thin blocking layer contiguous to the strip of ma~erial.
The invention al~o pro~ides apparatus for the continuous appllcation of a uniform coatlng onto a strip of ma~erial tha~
passes over a coun~r roller, comprislng: an applicator roller supplied from a li~uid chamber and used for coating the ma~erial, and a metering device with a metering element, characterlzed in ~hat the applicator roller has a supply side provided ~i~h a guid~
plate that extends into the applicator gap between the applicator roller and the counter rollex.
The process entails considerable advantages. By the pre-dosed managemen~ of the coating material into the applicator gap between the applicator roller and the counter roller, the hydrodynamic pressure that builds up at this point can be varied within a very wide range by adjusting the roller gap, preferably in such a manner that it ls minimized as the roller ~ap becomes greaker. The coating material is dellvered more evenly, i.e., without the inclusion of air and in greater quantities to the applicator gap, ~o that the ~ap can be ad~usted so as to be larger than is the case wi~h the conventional flooded-nip coaters, and so that less turbulenca result at lower hydrodynamlc pressure with the result that the risk of there being uncovered area~ is smaller.
A low applicatlon pressure in the pre-dosing assembly is to be taken as being a value of 0 to 20~ of the application 80rce s :~ ~
~,. ;....
, :
~ 21712-197 (linear pressure) in the area of the final dosing, 0% indicating -that a dosing element used for dosing is adjusted to a -fixed gap of 0.01 to 0.1 mm, this being done as a function of speed, coating material, etc. The dosing o-f the coating material ensures that exactly as much excess is moved forward for final metering as is required for sufficient rinsing or washing at this point, in which connection it is importan-t that during the process there is a partial de-watering of a thin boundary layer of the coating material contiguous to the material strip, in which the solid components tpigments and binders) of the coating material are as far as possible immobilized. The layex that is formed in this manner then acts as a blocking layer during the final metering process and prevents the penetration of solid components of the coating material into the strip of paper.
The apparatus that is proposed for sending only a pre-dosed quantity of the coating material to the applicator gap and for carrying out the process ensures that even at high machine speeds a precisely defined blocking layer in a metered coating material is formed on the material strip, thus preventing the pressure of the liquid on a final metering element driving the coating material too powerfully into the strip of ma~terial. In addition, the guide plate distributes the coating material abso-lutely evenly, both in the direction of movement of the strip of material and transverse to thisj and delivers it free of air bubbles lnto the applicator gap. In addition, in a preferred embodiment of the invention it is~foreseen that the guide plate can be curved so as to correspond to the circumference of the applicator roller, at least in the area that i9 proximate to the-_ ~, ' ~' ` . .
' ' :
: ~
~ 4 ~ 21712-197 applicator gap between the applicator roller and the counter roller. This results in exact management of the coating material, in particular is so configured that the distance from the guide plate to the periphery of the applicator roller is adjustable. In this way the hydrodynamic pressure that builds up in the appli-cator gap can be very precisely adjusted and reproduced. In particular, no air bubbles are introduced into the gap, which means that it is possible to achieve a particularly even coating that is free of faults.
In order to compensate for pressure variations that may, for example, be attributable to the coating-material supply, there is most expediently between the guide plate and the liquid chamber a slot-like opening through which the excess coating material that has not been delivered by the applicator roller to the applicator gap, can drain off.
For the further management of coating material there is a guide blade between the applicator gap and the metering element, this guide blade being provided with overflow openings and which on its~upper and lower side is matched essentially to the peripheral area of the applicator roller and the counter roller both at a distance from these and in contact with them.
In order to achieve a partial de-watering effect or a blocking layer in the coating material a particular geometrical configuration of the metering device is exploited. Most e~pediently, the metering device is configured as a raker bar which on its end face that is proxlmate to the strip of ma-terial is of a converging, preferably convexly converging, shape, . . .
.
' ~2~ 8 21712-197 converging relative to the strip of material towards the final metering element.
The Einal metering element is preferably configured as a rigid blade. In order tha-t the apparatus is easily accessible in all three oE the different systems, the final metering element and its retaining element and a catch basin that is arranged benea-th these, as well. as the pre-metering element and its retaining elements with an associated collector chamber, are arranged on a frame that can be pivoted about an essentially hori7.ontal shaft.
By swinging down the apparatus as a whole it is possible to ensure easy access to all the individual components for cleaning, repair, and replacement. Furthermore, the guide plate can be swung away independently, in order to provide access to the applicator roller.
Two preferred embodiments of the invention are described in greater detail below on the basis of the drawings appended hereto, wherein:
Figure I is a side view in section showing an applicator and metering apparatus with an applicator assembly, a metering assembly, and a final dosing assembly;
Figure 2 shows schematically the process of coating a strip of material, as shown in Figure 1, Figure 3 shows a further configuration of the pre-meter-ng assembly of Figure 1;
Figure 4 is a front view of the pre metering assembly of Figure 3.
~' .
::
:, ' ~'' .
~ 2~ 21712-197 The applicator and pre-metering apparatus -that is shown in Figure 1 has an applicator 1 with a rotating applicator roller
2 that delivers coating material -from a fluid chamber 3 connected to a supply line 4, the coating material being delivered to an applicator gap 7 located between the applicator roller 2 and a counter roller 6 that is used to support a web or strip 5 of material.
The coating material passes so as to be pre~dosed between the circumferential surface of the applicator roller 2 and a guide plate 8 and into the area of the applicator gap 7. The guide plate 8 can be adjusted by ~eans of an adjuster 9 so as -to vary the spacing 44 of the guide plate from the circumferential surface of the applicator ro].ler 2, so that the hydrodynamic pres-sure of the coating material that builds up in the applicator gap 7 can be adjustable and reproducible. On its upper side remote from the applicator roller 2 the guide plate 8 has a run-off 11, over which excess coating material can flow from the applicator gap 7 into a return line 12, as indicated by the direction of the arrow 10, and pass from there to a collector line 13. From there, the coating material flows back into a collector tank (not shown~
: from which it is once again delivered to the supply line 4.
In the above case the applicator roller 2 and the counter roller 6 rotate in opposite directions. Viewed in the direction of movement of the web or strip 5 of material there is a metering assembly 14 installed downstream or following the applicator gap 7. This metering assembly 14 has a pre-metering element 15 in the form of a raker bar supported in a carrier block 1~ that serves as a retaining element and is supported by means oE
_ g _ .
' : ' '; -' ~
~ 21712-197 a pressure hose ].7. The suitable application of pressure in the pressure hose 17 means that the metering element 15 can be adjusted relative to the strip or web 5 of material.
Between the metering assembly 14 and the applicator gap 7 there is a wedge-shaped and tapered guide blade 18 that, also serves to guide the coating material; -this guide blade 18 i5 also provided with overflow holes 19, through which coa~ing material removed by the metering element 15 runs back into a collector chamber 21 and from there through a return line 22 to the collec-tor line 13. The spacings from the upper and lower sides of theguide blade 18 are matched to the perimeter of the applicator roller 2 and of the counter roller 6 so as to provide for the desired guidance and control of the coating material or else held in contact against the applicator roller 2.
Viewed in the direction in which the strip o material moves~ there is a final metering assembly 23 arranged ~ollowing the dosing assembly 14. The final metering assembly has a rigid blade 24, the holding elements of which are in the for~ of a bar support 25, a clamp bar 26, and a lock bar 27. The final metering assembly 23 is arranged in a catch basin 28 connected through an opening 29 to the collector chamber 21. Chamber 21 is sealed off by means of a sealing lip 31 from the fluid chamber 3. The final metering a~sembly 23 and the associated catch basin 28 are arranged on a~frame 32, in the same manner as the pre-metering assembly~l4 with its associated collector chamber 21, this frame being supported so as to be able to pivot about an essentially hori~ontal shaft 33, so that the pre-mekering assembly 14 and the final pre-metering assembly 23 can be swung do~n and thus make the .'. ' A~3 2l7l2-l97 be swung down and thus maXe -the applicator assembly 1 accessible Eor purposes of repair, cleaning, or the like.
The method of operation of the applicator and metering assembly is described in greater detail on the basis of Figure 2, which applies to cases of very high speeds of movement, The coating material is delivered to the applicator gap 7 by the applicator roller 2 and with the help of the guide plate 8, so that the strip of material 5 consisting of paper or card-boaxd is wetted with coating material on the side that is proxi-mate to the applicator roller 2. This application is made withvery low liquid pressure, so that the penetration of the aqueous components of the coating material is small, as is indicated by the reference number 34. Since an excess of coating material has been applied, the excessive coating material runs, as is indicated by the arrow 10, across the upper side of the guide plate 8 and back into ~he collector tank.
The metering element 15 has a convex face surface that converges towards the strip of material 5. The adjustable metering element 15 works at very low force relative to the specific area force in the contact zone, so that it is possible to achieve uniform distribution of the coating material both in the direction of movement of the strip 5 as well as transverse1y thereof, this being done with very little penetration. A partial de-watering of a thin blocking layer 3S is achieved on the strip ~ o material 5 as a result of the geometrical configuration of the : metering element 15, and the solid components, such as pigments and binding agents, , .
`
-:
'' '.
that go to make up the coating material are to the greatest extent possible immobili~ed in this thin blocking layer 35.
f et~,r~ r/9 ~; Within the area of the final ~e~ element 24, this blocking layer 35 ensures that the coating material is not forced too powerfully into the strip of material 5. The excess that passes to the final dosing element 24 in the case of minimum pene-tration 34, has been reduced to the minimum quantity and equalized, which means that the application pressure required for ~lef~ 9 final ~4~ can be reduced to a minimum~ This in turn leads to reduced wear in the final dosing element 24 and/or a lower appli-cation weight at higher strip speeds, or to a higher possible content of solids in the coating material.
Figures 3 and 4 show a further embodiment of the guide plate 8 from Fiyure 1 and here numbered 8l. For the remainder, the reference numbers are the same as those in Figure 1 and refer to the same parts in the associated description. Furthermore, the guide plate 8 7 iS separate from the liquid chamber 3, the line of separation 37 forming a horizontal plane with the axis 38 of the applica~ion roller 2.
Between the guide plate 8' and the liquid bath 3 there is a slot 39 that serves as an overflow for excess coating material and helps to achieve a greater degree of accuracy in the e~ g pre-~4~}~ process.
In order to provide a mounting for it, the guide plate 8' has lugs 40 at i~s two ends and within the return line 12, these lugs being connected to a~bearing shaft 41. This shaft 41 is supported in the walls of the return line 12 so as to be able to pivot, and continues through this to the outside and bears at each end a rotatable arm 42 that is connected rigidly to it. At the free ends the arms 42 connect to operating cylinders 43, which means that the guide plate 8' can be pivoted about the axis of the bearing shaft 410 Outside the return line 12, on both sides there is an adjustable stop 45 so as to provide adjustment of the delivery gap 44 and the arms 42 rest against these adjustable stops when the guide plate 8' is in the operating position.
To enable the tip 50 of the guide plate 8' that pro-trudes into the applicator gap to be adjusted even more precisely, a spring plate 46 is secured in the area of the tip 50 of the guide plate 8' by means of bolts 47 and an elastic base 48, in the manner of a single-ended lever. By rotating the bolts 47, the free end 49 of the spring plate 46 that protrudes into the appli-cator gap 7 can be moved up and down on the tip 50 of the guide plate 8' that serves as a centre of rotation, by which means the spacing 49 in the applicator gap 7 can be additionally varied.
This additional spring plate 46 can also be provided for the guide plate 8 shown in Figure 1.
The arrange~ent described above operates as follows:
An excess quantity of coating material is pumped into the liquid chamber 3, whereupon a constant and equal level is achieved automatically by the slot 39, in that the coatiny material that is not picked up by the applicator roller 2 drains off through the slot 39 into the return line 12. In this connec-tion, the slot 39 must be sufficiently large that the coating material delivered by the applicator roller 2 can be passed at almost no pressure through the delivery gap 44, so that a controlled hydrodynamic pressure can be allowed to build up first in the applicator gap 7.
It is, of course, to be understood that the present invention is not restricted to the exemplary versions that are shown herein, but that it permits modifications within the frame-p,~e ~l e ~
work of the claims. Thus, the^~ element 15 does not necessarily have to be formed as a doctor blade but can also be configured as a bent blade and, optionally, as a roller-type rake.
,77 ~,f~ln~
In the same way, the final ~ element 24 can, under certain circumstances, and depending on operating conditions, be formed as a raker bar and optionally as a bent blade or a roller-type rake.
, ` :"i ,~
The coating material passes so as to be pre~dosed between the circumferential surface of the applicator roller 2 and a guide plate 8 and into the area of the applicator gap 7. The guide plate 8 can be adjusted by ~eans of an adjuster 9 so as -to vary the spacing 44 of the guide plate from the circumferential surface of the applicator ro].ler 2, so that the hydrodynamic pres-sure of the coating material that builds up in the applicator gap 7 can be adjustable and reproducible. On its upper side remote from the applicator roller 2 the guide plate 8 has a run-off 11, over which excess coating material can flow from the applicator gap 7 into a return line 12, as indicated by the direction of the arrow 10, and pass from there to a collector line 13. From there, the coating material flows back into a collector tank (not shown~
: from which it is once again delivered to the supply line 4.
In the above case the applicator roller 2 and the counter roller 6 rotate in opposite directions. Viewed in the direction of movement of the web or strip 5 of material there is a metering assembly 14 installed downstream or following the applicator gap 7. This metering assembly 14 has a pre-metering element 15 in the form of a raker bar supported in a carrier block 1~ that serves as a retaining element and is supported by means oE
_ g _ .
' : ' '; -' ~
~ 21712-197 a pressure hose ].7. The suitable application of pressure in the pressure hose 17 means that the metering element 15 can be adjusted relative to the strip or web 5 of material.
Between the metering assembly 14 and the applicator gap 7 there is a wedge-shaped and tapered guide blade 18 that, also serves to guide the coating material; -this guide blade 18 i5 also provided with overflow holes 19, through which coa~ing material removed by the metering element 15 runs back into a collector chamber 21 and from there through a return line 22 to the collec-tor line 13. The spacings from the upper and lower sides of theguide blade 18 are matched to the perimeter of the applicator roller 2 and of the counter roller 6 so as to provide for the desired guidance and control of the coating material or else held in contact against the applicator roller 2.
Viewed in the direction in which the strip o material moves~ there is a final metering assembly 23 arranged ~ollowing the dosing assembly 14. The final metering assembly has a rigid blade 24, the holding elements of which are in the for~ of a bar support 25, a clamp bar 26, and a lock bar 27. The final metering assembly 23 is arranged in a catch basin 28 connected through an opening 29 to the collector chamber 21. Chamber 21 is sealed off by means of a sealing lip 31 from the fluid chamber 3. The final metering a~sembly 23 and the associated catch basin 28 are arranged on a~frame 32, in the same manner as the pre-metering assembly~l4 with its associated collector chamber 21, this frame being supported so as to be able to pivot about an essentially hori~ontal shaft 33, so that the pre-mekering assembly 14 and the final pre-metering assembly 23 can be swung do~n and thus make the .'. ' A~3 2l7l2-l97 be swung down and thus maXe -the applicator assembly 1 accessible Eor purposes of repair, cleaning, or the like.
The method of operation of the applicator and metering assembly is described in greater detail on the basis of Figure 2, which applies to cases of very high speeds of movement, The coating material is delivered to the applicator gap 7 by the applicator roller 2 and with the help of the guide plate 8, so that the strip of material 5 consisting of paper or card-boaxd is wetted with coating material on the side that is proxi-mate to the applicator roller 2. This application is made withvery low liquid pressure, so that the penetration of the aqueous components of the coating material is small, as is indicated by the reference number 34. Since an excess of coating material has been applied, the excessive coating material runs, as is indicated by the arrow 10, across the upper side of the guide plate 8 and back into ~he collector tank.
The metering element 15 has a convex face surface that converges towards the strip of material 5. The adjustable metering element 15 works at very low force relative to the specific area force in the contact zone, so that it is possible to achieve uniform distribution of the coating material both in the direction of movement of the strip 5 as well as transverse1y thereof, this being done with very little penetration. A partial de-watering of a thin blocking layer 3S is achieved on the strip ~ o material 5 as a result of the geometrical configuration of the : metering element 15, and the solid components, such as pigments and binding agents, , .
`
-:
'' '.
that go to make up the coating material are to the greatest extent possible immobili~ed in this thin blocking layer 35.
f et~,r~ r/9 ~; Within the area of the final ~e~ element 24, this blocking layer 35 ensures that the coating material is not forced too powerfully into the strip of material 5. The excess that passes to the final dosing element 24 in the case of minimum pene-tration 34, has been reduced to the minimum quantity and equalized, which means that the application pressure required for ~lef~ 9 final ~4~ can be reduced to a minimum~ This in turn leads to reduced wear in the final dosing element 24 and/or a lower appli-cation weight at higher strip speeds, or to a higher possible content of solids in the coating material.
Figures 3 and 4 show a further embodiment of the guide plate 8 from Fiyure 1 and here numbered 8l. For the remainder, the reference numbers are the same as those in Figure 1 and refer to the same parts in the associated description. Furthermore, the guide plate 8 7 iS separate from the liquid chamber 3, the line of separation 37 forming a horizontal plane with the axis 38 of the applica~ion roller 2.
Between the guide plate 8' and the liquid bath 3 there is a slot 39 that serves as an overflow for excess coating material and helps to achieve a greater degree of accuracy in the e~ g pre-~4~}~ process.
In order to provide a mounting for it, the guide plate 8' has lugs 40 at i~s two ends and within the return line 12, these lugs being connected to a~bearing shaft 41. This shaft 41 is supported in the walls of the return line 12 so as to be able to pivot, and continues through this to the outside and bears at each end a rotatable arm 42 that is connected rigidly to it. At the free ends the arms 42 connect to operating cylinders 43, which means that the guide plate 8' can be pivoted about the axis of the bearing shaft 410 Outside the return line 12, on both sides there is an adjustable stop 45 so as to provide adjustment of the delivery gap 44 and the arms 42 rest against these adjustable stops when the guide plate 8' is in the operating position.
To enable the tip 50 of the guide plate 8' that pro-trudes into the applicator gap to be adjusted even more precisely, a spring plate 46 is secured in the area of the tip 50 of the guide plate 8' by means of bolts 47 and an elastic base 48, in the manner of a single-ended lever. By rotating the bolts 47, the free end 49 of the spring plate 46 that protrudes into the appli-cator gap 7 can be moved up and down on the tip 50 of the guide plate 8' that serves as a centre of rotation, by which means the spacing 49 in the applicator gap 7 can be additionally varied.
This additional spring plate 46 can also be provided for the guide plate 8 shown in Figure 1.
The arrange~ent described above operates as follows:
An excess quantity of coating material is pumped into the liquid chamber 3, whereupon a constant and equal level is achieved automatically by the slot 39, in that the coatiny material that is not picked up by the applicator roller 2 drains off through the slot 39 into the return line 12. In this connec-tion, the slot 39 must be sufficiently large that the coating material delivered by the applicator roller 2 can be passed at almost no pressure through the delivery gap 44, so that a controlled hydrodynamic pressure can be allowed to build up first in the applicator gap 7.
It is, of course, to be understood that the present invention is not restricted to the exemplary versions that are shown herein, but that it permits modifications within the frame-p,~e ~l e ~
work of the claims. Thus, the^~ element 15 does not necessarily have to be formed as a doctor blade but can also be configured as a bent blade and, optionally, as a roller-type rake.
,77 ~,f~ln~
In the same way, the final ~ element 24 can, under certain circumstances, and depending on operating conditions, be formed as a raker bar and optionally as a bent blade or a roller-type rake.
, ` :"i ,~
Claims (12)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A process for the continuous application of an even coating on a strip of material that passes across a counter roller, on which the coating material is at first applied in an excess quantity by means of an applicator roller, and then metered to a desired coating thickness, characterized in that the coating material is supplied in a controlled pre-dosed quantity along a specific zone with the help of the applicator roller, this being done as far as the applicator gap between the applicator roller and the counter roller, and is applied to the strip of material at very low pressure such that the coating material is partially de-watered in a thin blocking layer contiguous to the strip of material.
2. A process according to claim 1, characterized in that the low pressure is brought about by a contactless arrangement of the applicator roller relative to the material strip, and furthermore by a subsequent pressureless initial metering of the coating material and a subsequent final metering thereof.
3. Apparatus for the continuous application of a uniform coating onto a strip of material that passes over a counter roller, comprising: an applicator roller supplied from a liquid chamber and used for coating the material, and a metering device with a metering element, characterized in that the applicator roller has a supply side provided with a guide plate that extends into the applicator gap between the applicator roller and the counter roller.
4. A device according to claim 3, characterized in that the guide plate is curved so as to match the periphery of the applicator roller at least in the area that is proximate to the applicator gap between the applicator roller and the counter roller.
5. An apparatus according to claim 3 or 4, characterized in that the guide plate is configured so as to be adjustable either totally and/or partially in regard to its distance from the periphery of the applicator roller.
6. A device according to claim 3, characterized in that the guide plate is formed as a continuation of the upper edge of the liquid chamber for the coating material such that between the liquid chamber and the lower portion of the guide plate there is a passage for excess coating material.
7. An apparatus according to claim 6, characterized in that the line of separation between the guide plate and the edge of the chamber forms an essentially horizontal plane with the axis of the applicator roller.
8. An apparatus according to claim 3, characterized in that on the supply side a guide blade is positioned after the applicator gap, said guide blade housing a metering element and being provided with overflow openings, and having lower and upper sides at a distance from or in contact with the peripheral area of the applicator roller and the counter roller and conforming to the curvature thereof.
9. An apparatus according to claim 8, characterized in that the metering element operates at a very low level of forces relative to the specific surface force in the contact zone with the strip of material, the geometry of this metering element being such as to effect partial de-watering in a thin blocking layer of the coaling material that is contiguous to the strip of material.
10. An apparatus according to claim 8 or 9, characterized in that the metering element is configured as a doctor blade, having on its face end that is proximate to the strip of material a convex shape that converges towards the strip of material.
11. An apparatus according to claim 3, wherein the metering device has a pre-metering element and a final metering element, wherein the pre-metering element operates at, a low level of force relative to the specific surface force in the contact zone with the web of material and is provided on the end facing the web of material with a geometry effecting a partial de-watering in a thin boundary layer of the coating material near the web of material.
12. An apparatus according to claim 11, wherein the pre-metering element is designed as a doctor blade and at its end facing the web of material converges in the direction to the final metering element and relative to the web of material.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP3527379.8 | 1985-07-31 | ||
| DE3527379 | 1985-07-31 | ||
| DEP3623402.8 | 1986-07-11 | ||
| DE19863623402 DE3623402A1 (en) | 1985-07-31 | 1986-07-11 | METHOD AND DEVICE FOR CONTINUOUSLY APPLYING A Uniform Coating To A Material Web Running Across A Counter-Roller, Especially Paper Or Cardboard Web |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1264428A true CA1264428A (en) | 1990-01-16 |
Family
ID=25834559
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000514930A Expired - Lifetime CA1264428A (en) | 1985-07-31 | 1986-07-30 | Process and an apparatus for the continuous application of an even coating to a strip of material, in particular paper or cardboard, that passes over a counter roller |
Country Status (10)
| Country | Link |
|---|---|
| JP (1) | JPH0616876B2 (en) |
| AT (1) | AT393702B (en) |
| CA (1) | CA1264428A (en) |
| CH (1) | CH668567A5 (en) |
| DE (1) | DE3623402A1 (en) |
| FI (1) | FI84326C (en) |
| FR (1) | FR2585591B1 (en) |
| GB (1) | GB2178677B (en) |
| IT (1) | IT1213461B (en) |
| SE (1) | SE465112B (en) |
Families Citing this family (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0420541Y2 (en) * | 1987-01-26 | 1992-05-11 | ||
| JPH07213Y2 (en) * | 1987-10-26 | 1995-01-11 | 三菱重工業株式会社 | Coating equipment |
| JPH01239197A (en) * | 1988-03-14 | 1989-09-25 | Oji Paper Co Ltd | Coated paper manufacturing method and its manufacturing equipment |
| DE3916620A1 (en) * | 1989-05-22 | 1990-12-06 | Jagenberg Ag | DEVICE FOR COATING A MATERIAL RAIL THROUGH A COUNTER ROLLER |
| DE4205312A1 (en) * | 1992-02-21 | 1993-08-26 | Voith Gmbh J M | ROLLER APPLICATION DEVICE FOR APPLYING COATING INK ON A PAPER RAIL |
| ATE144567T1 (en) * | 1992-02-21 | 1996-11-15 | Voith Gmbh J M | APPLICATION DEVICE FOR APPLYING COATING PAINT TO A PAPER METHOD |
| DE4224726A1 (en) * | 1992-07-27 | 1994-02-03 | Voith Gmbh J M | Coating device with application gap formed between an application roller and a counter roller |
| DE4309937A1 (en) * | 1993-03-26 | 1994-09-29 | Jagenberg Ag | Device for coating a paper or cardboard web |
| DE9314280U1 (en) * | 1993-09-22 | 1994-01-20 | Jagenberg AG, 40476 Düsseldorf | Device for coating a paper or cardboard web |
| DE4413232A1 (en) * | 1994-04-15 | 1995-10-19 | Voith Gmbh J M | Device for applying at least one liquid medium to a running web of material |
| DE19527902B4 (en) * | 1995-07-29 | 2004-02-26 | Voith Paper Patent Gmbh | Application system for a device for coating a paper or cardboard web |
| ATE210223T1 (en) * | 1995-07-29 | 2001-12-15 | Jagenberg Papiertech Gmbh | APPLICATION SYSTEM FOR A DEVICE FOR COATING A PAPER OR CARDBOARD WEB |
| DE19541574A1 (en) * | 1995-11-08 | 1997-05-15 | Jagenberg Papiertech Gmbh | Device for coating of material webs, especially paper or cardboard |
| DE19603861C1 (en) | 1996-02-03 | 1997-07-31 | Jagenberg Papiertech Gmbh | Device for coating a material web, in particular a paper or cardboard web |
| DE102004063043B3 (en) * | 2004-12-22 | 2006-07-20 | Vits Systems Gmbh | Apparatus for applying a coating composition to a paper web |
| CN109550648B (en) * | 2017-09-27 | 2020-10-09 | 一川企业有限公司 | Closed circular scraper glue supply device |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| BE786407A (en) * | 1971-08-02 | 1973-01-18 | Ilford Ltd | COATING PROCESS AND APPARATUS, IN PARTICULAR TABLECLOTH |
| DE2931800C2 (en) * | 1979-08-04 | 1982-09-02 | J.M. Voith Gmbh, 7920 Heidenheim | Coating device |
| JPS5653777A (en) * | 1979-10-05 | 1981-05-13 | Fujikura Ltd | Method and apparatus for painting filament |
| US4396648A (en) * | 1982-02-08 | 1983-08-02 | Consolidated Papers, Inc. | Paper coating apparatus and method |
| JPS58223459A (en) * | 1982-05-19 | 1983-12-26 | Fuji Photo Film Co Ltd | Method and device for coating |
| CH662167A5 (en) * | 1982-12-31 | 1987-09-15 | Wescho Ladenbau Gmbh | ELECTRIC LIGHT FOR REPRAESENTATION OF GOODS. |
| JPS6067167U (en) * | 1983-10-12 | 1985-05-13 | 三菱重工業株式会社 | Coater transfer device |
| DE3338095A1 (en) * | 1983-10-20 | 1985-05-09 | J.M. Voith Gmbh, 7920 Heidenheim | PAINTING DEVICE |
| DE3345413A1 (en) * | 1983-12-15 | 1985-06-27 | Basf Farben + Fasern Ag, 2000 Hamburg | Inclusion pigments and process for their preparation |
-
1986
- 1986-07-11 DE DE19863623402 patent/DE3623402A1/en active Granted
- 1986-07-23 CH CH2963/86A patent/CH668567A5/en not_active IP Right Cessation
- 1986-07-24 IT IT8621250A patent/IT1213461B/en active
- 1986-07-25 SE SE8603229A patent/SE465112B/en not_active IP Right Cessation
- 1986-07-30 FR FR8611070A patent/FR2585591B1/en not_active Expired - Fee Related
- 1986-07-30 CA CA000514930A patent/CA1264428A/en not_active Expired - Lifetime
- 1986-07-30 FI FI863117A patent/FI84326C/en not_active IP Right Cessation
- 1986-07-31 AT AT0207186A patent/AT393702B/en not_active IP Right Cessation
- 1986-07-31 GB GB8618741A patent/GB2178677B/en not_active Expired - Fee Related
- 1986-07-31 JP JP61179012A patent/JPH0616876B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| FI863117A0 (en) | 1986-07-30 |
| DE3623402A1 (en) | 1987-05-21 |
| JPH0616876B2 (en) | 1994-03-09 |
| FI84326B (en) | 1991-08-15 |
| DE3623402C2 (en) | 1988-02-04 |
| FI84326C (en) | 1991-11-25 |
| SE8603229D0 (en) | 1986-07-25 |
| FR2585591A1 (en) | 1987-02-06 |
| SE465112B (en) | 1991-07-29 |
| GB2178677B (en) | 1990-01-04 |
| SE8603229L (en) | 1987-02-01 |
| IT8621250A0 (en) | 1986-07-24 |
| FR2585591B1 (en) | 1991-05-17 |
| FI863117A7 (en) | 1987-02-01 |
| JPS6287273A (en) | 1987-04-21 |
| CH668567A5 (en) | 1989-01-13 |
| GB8618741D0 (en) | 1986-09-10 |
| IT1213461B (en) | 1989-12-20 |
| ATA207186A (en) | 1991-05-15 |
| AT393702B (en) | 1991-12-10 |
| GB2178677A (en) | 1987-02-18 |
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