CA2141473C - Method and device for coating a material web - Google Patents
Method and device for coating a material web Download PDFInfo
- Publication number
- CA2141473C CA2141473C CA002141473A CA2141473A CA2141473C CA 2141473 C CA2141473 C CA 2141473C CA 002141473 A CA002141473 A CA 002141473A CA 2141473 A CA2141473 A CA 2141473A CA 2141473 C CA2141473 C CA 2141473C
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- Canada
- Prior art keywords
- applicator
- application medium
- roll
- gap
- application
- 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 - Fee Related
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Classifications
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- 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
- D21H23/52—Addition to the formed paper by contacting paper with a device carrying the material
- D21H23/56—Rolls
-
- 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
- B05C1/0813—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 characterised by means for supplying liquid or other fluent material to 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
-
- 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
- B05C1/14—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 travelling band
-
- 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
- B05C9/00—Apparatus or plant for applying liquid or other fluent material to surfaces by means not covered by any preceding group, or in which the means of applying the liquid or other fluent material is not important
- B05C9/04—Apparatus or plant for applying liquid or other fluent material to surfaces by means not covered by any preceding group, or in which the means of applying the liquid or other fluent material is not important for applying liquid or other fluent material to opposite sides of the work
Abstract
A method for at least one-sided coating of a material web with an application medium is performed by a two-element applicator device having at least one applicator roll and a counter element defining a gap through which the material web is conveyed. The method includes the steps of premetering the application medium onto the applicator roll and transferring the application medium onto the material web in the gap. Premetering of the application medium to the applicator device is performed by at least one free jet.
Description
214~.4'~ 3 METHOD AND DEVICE FOR COATING A MATERIAL WEB
BACKGROUND OF THE INVENTION
Field of the Invention The invention relates to methods and devices for coating running webs of material, and particularly to methods and devices for coating at least one side of a material web by premetering an application medium onto an applicator roll and transferring the medium onto the web in a gap formed by the applicator roll and a counter element.
Describtion of Related Technolocrv In the art of paper finishing, various methods and devices are known for coating a paper web with an application medium. The coating of the web may be performed by applying the medium directly onto the fiber web which loops around a portion of a periphery of a body with rotational symmetry. Another coating method includes premetering an application medium onto a surface of a body with rotational symmetry. In both cases, the application process includes two successive steps: 1) the coating is applied in excess utilizing an application nozzle; and 2) excess coating composition is removed utilizing an equalizing system, typically in the form of a doctor element; or successive doctor and blade devices. The composition transfer or metering may be performed, for example, in a film press. In conventional film presses, the application medium is applied onto the surface of the applicator roll, in which case the metering is usually 21414' 3 achieved by successive doctor devices. The premetering devices are disposed on the framework of the applicator roll and can be pressed onto the surface of the applicator roll with the aid of cylinders or similar devices. The premetering device may include a nozzle applicator system in which a sizing or coating composition flows through a special distributor (flow spreader) system into a pressure chamber of the applicator nozzle. Such a device may also include a doctor bar device. The application medium arrives into the application chamber through a slotted nozzle of the pressure chamber. The amount of sizing or coating composition is controlled with the aid of a doctor bar or a blade to which pressure can be applied.
Such devices may be complicated in structure, particularly with respect to the application and metering system and may be problematic since they utilize a metering element that can get worn down. Therefore, keeping the amount of film constant with respect to a function of time can present problems and cannot be directly influenced. A
transverse profile of an applied medium on an applicator roll can be kept constant only by tedious profile adjustment work. Otherwise coating composition application along a width of the machine does not necessarily occur uniformly. Furthermore, at high solid contents or in the case of extremely absorbent papers, there is a danger of the formation of profile ridges, which may cause a limitation of the minimum amount of coating composition that may be applied. The use of a metering element that is 21414' 3 readily worn leads to short life spans of such a metering element and thus to undesirable shutdown time of the machine necessitated for replacing the metering element.
Furthermore, control of the amount of coating composition applied to a roll is not possible without replacement of the metering element or without tedious adjustment work.
SUMMARY OF THE INVENTION
It is an object of the invention to overcome one or more of the problems described above. It is also an object of the invention to keep constant the amount of film to be transferred onto a fiber web as a function of time and with respect to the width of the machine, that is, transversely to the direction of movement of the fiber web.
Moreover, it is an object of the invention that the amount of coating composition film to be applied should be controllable for certain web widths. Furthermore, an object of the invention is to minimize the wear of a metering element and thus to achieve a longer time period between required changes of the metering element. An object of the invention is also to provide for low operating costs and suitability for use for both coating and starch application.
According to the invention, the metering element is preferably strongly built, easy to handle, show little tendency to be damaged, suitable for use at high application velocities, easy to operate and should have only a very small number of wearing parts.
BACKGROUND OF THE INVENTION
Field of the Invention The invention relates to methods and devices for coating running webs of material, and particularly to methods and devices for coating at least one side of a material web by premetering an application medium onto an applicator roll and transferring the medium onto the web in a gap formed by the applicator roll and a counter element.
Describtion of Related Technolocrv In the art of paper finishing, various methods and devices are known for coating a paper web with an application medium. The coating of the web may be performed by applying the medium directly onto the fiber web which loops around a portion of a periphery of a body with rotational symmetry. Another coating method includes premetering an application medium onto a surface of a body with rotational symmetry. In both cases, the application process includes two successive steps: 1) the coating is applied in excess utilizing an application nozzle; and 2) excess coating composition is removed utilizing an equalizing system, typically in the form of a doctor element; or successive doctor and blade devices. The composition transfer or metering may be performed, for example, in a film press. In conventional film presses, the application medium is applied onto the surface of the applicator roll, in which case the metering is usually 21414' 3 achieved by successive doctor devices. The premetering devices are disposed on the framework of the applicator roll and can be pressed onto the surface of the applicator roll with the aid of cylinders or similar devices. The premetering device may include a nozzle applicator system in which a sizing or coating composition flows through a special distributor (flow spreader) system into a pressure chamber of the applicator nozzle. Such a device may also include a doctor bar device. The application medium arrives into the application chamber through a slotted nozzle of the pressure chamber. The amount of sizing or coating composition is controlled with the aid of a doctor bar or a blade to which pressure can be applied.
Such devices may be complicated in structure, particularly with respect to the application and metering system and may be problematic since they utilize a metering element that can get worn down. Therefore, keeping the amount of film constant with respect to a function of time can present problems and cannot be directly influenced. A
transverse profile of an applied medium on an applicator roll can be kept constant only by tedious profile adjustment work. Otherwise coating composition application along a width of the machine does not necessarily occur uniformly. Furthermore, at high solid contents or in the case of extremely absorbent papers, there is a danger of the formation of profile ridges, which may cause a limitation of the minimum amount of coating composition that may be applied. The use of a metering element that is 21414' 3 readily worn leads to short life spans of such a metering element and thus to undesirable shutdown time of the machine necessitated for replacing the metering element.
Furthermore, control of the amount of coating composition applied to a roll is not possible without replacement of the metering element or without tedious adjustment work.
SUMMARY OF THE INVENTION
It is an object of the invention to overcome one or more of the problems described above. It is also an object of the invention to keep constant the amount of film to be transferred onto a fiber web as a function of time and with respect to the width of the machine, that is, transversely to the direction of movement of the fiber web.
Moreover, it is an object of the invention that the amount of coating composition film to be applied should be controllable for certain web widths. Furthermore, an object of the invention is to minimize the wear of a metering element and thus to achieve a longer time period between required changes of the metering element. An object of the invention is also to provide for low operating costs and suitability for use for both coating and starch application.
According to the invention, the metering element is preferably strongly built, easy to handle, show little tendency to be damaged, suitable for use at high application velocities, easy to operate and should have only a very small number of wearing parts.
The invention concerns a method for at least one-sided coating of s material web with as application medium in a two-clement applicator devioa having at least one applicator roll and a counter elcmeat defining a gap thr~oup~t which the material meb is conveyed. The inventive method includes the steps ofpremetaring the application 3 madium onto the applicator roll and traasfetring tbo application medium onto the material wcb in the gap. hremetering of the application medium to the applicator device is pettormed by at Icast one free jot.
In an aepoct of tha prasrnt invention, tire is provided a method of coating at least one sido of a fibrous web with an application medium in a two-element application device comprising two applicator elementr which aro driven in opposite direttioas and togs form a gap through which tho ~bmua web is led, in which math4d the application medium is pro-tnetcred onto at lean ono of said applicator elamaats and is tranaii!xrCd to the fibrous web in the gap, charactazwzed in that the pro-metering is carried 1 S vut by means of at least one ~ jet of application medium, aimed directly at a surface of said at lean one applicator elemeont.
rn another aspect ef the prat invention, t6ecn is prawidod ~ for coating at laast one side of a fibrous web with an spplicatjoa a:edium co~mpriaing:
two applicator oIdments, together forming a gap for the fibrous web to be Ied tluough, wherein said applicator elemanta are driven in opposite directions;
wherein at least one of said applicator elements is assigned an applicator unit;
such that the applicator wait includes at least one device for producing a free jet which 2S premeters the application medium onto s surface of ire ::signed applicator element.
1n yet another aped of the prasent invention, tfi~ere is provided apparatus for coating at Iaest one side of a fibrous web with as application medium comprising:
two applicator elements, together forming a gap for the $bmus web to be led thtnugh, whareia said agpl~~ator ~xemex~ts arc driven in opposite directions;
4(a) whe~reix~ at least one e~f said applicator elements is assigned an applicator unit;
suoh that the alrplicatar unit is implcrnented as an open haadbox which supplies the application mewdium onto the surface of its assigned applicator element;
the opeon hoadbox iacluding a means for pre-metering the quantf ty of application medium applied to said surface.
In yet ~othor aspect of the invcntlon, there is provided a marhod of costing at least one aide of a fibrous web with an application medium in a two-element application dovioo compria,ing two applicator elements which are driven in opposite directions aad t0 together form a gap through which the fibrous web is led, in which method the spplication matdium is pro-metered onto at least one of said applicator claments and is trensfa~x~od to W a $braus web in the gap, charncterizad in that the pre-metering is carried out by an open ;headbox including means for rnetcriag a quantity of application medium applied egad at least one applfcator element.
Other object ~tcui advantages aftho invention will ba apparent to tboso sldllod is the att from the: following detailed description taken in conjunction with the drawings and the appendai cl;alma.
I~RII:?F DESCRIPTIO1~T O~ T DRAWINGiS
1!'~g. 1 is a soheunatic sectional view of a device according to the invention.
hig. I is a schematic sectional view of a second embodiment of a device according to the invention.
z5 Hig. 3 is a schematic sectional view of a third embodimeutt of a device according to the invention.
F'ig. 4 is a schernatie sectional view ofa fourth embodiment of a device according to the inv~on.
F'~(g. 5 is a sohematie sectional view of a fifth embodiment of a device 3a ~oording to the invention.
DETAILED DESCRIPTION OF THE INVENTION
According to the invention, premetering of a coating or other application medium is performed utilizing a two-element applicator device that introduces the medium 5 onto the surface of an applicator roll, at least indirectly, that is, both directly as well as indirectly, by application of the application medium with the aid of at least one free jet. The use of a free jet provides the advantage of direct control of the applied amount and thus the thickness of the applied film on the surface. Also, the applied amount and film thickness may be altered by changing certain parameters of the jet, for example, discharge cross-section, discharge velocity and application angle of the free jet, in relation to the rate of rotation of the applicator roll.
The free jet can be directed either directly onto the surface of an applicator roll or onto the surface of a transfer roll, which, again, transfers the application medium at least indirectly, that is, directly or through another transfer roll, onto the surface of the applicator roll. The latter variation (indirect application) also provides the advantage of further metering action, especially the extension of the applied film based on the velocity difference of the surfaces of the applicator roll and the transfer roll obtained by suitable adjustment of the ratio of the diameters of the applicator roll and transfer roll.
21414' 3 According to the invention, a device for performing at least one-sided coating of a material web with an application medium includes first and second applicator elements driven in opposite directions and defining a gap for the passage of a material web therebetween. Also, an applicator unit cooperates with at least one of the applicator elements. The applicator unit includes an apparatus for producing a free jet. The free jet thus indirectly premeters an application medium onto the surface of the applicator element cooperating with the free jet. The apparatus for producing a free jet can be assigned directly to the applicator element (the free jet is directed directly onto the surface of the applicator element) or can be assigned to this indirectly by connecting at least one transfer element before it.
Preferably, the two-element applicator device is designed in the form of a two-roll applicator arrangement, that is, two applicator rolls with parallel axes are driven in opposite directions and form a press gap through which the material web is conveyed. The application of the application medium onto the web is accomplished by passage of the web through the press gap during which the application amount that was premetered onto the surface of the applicator roll is transferred onto the web. Such a device is suitable for one-sided coating, as well as for two-sided coating of fiber webs with application composition. The same or different application media can be applied to opposite sides of the web. According to the invention, the following is possible:
1 ) The application of a medium is performed directly, i.e., directly onto the surface of an applicator roll; and 2) The application is done here indirectly, i.e., onto the suxfaea of x transfer roil assigned to the applicator roll.
Possibility (2) above provides the advantage of additional tnatcring action with suitablo design of the ratio of the diantetera of the applicator roll xnd the transfer znll, as a rule, in the form of stretching or extending the film by the transfer roll.
This is 8spc~cially advantageous when a particularly thin applied film is desired on the surfisce of the fiber web.
'There are two prePcrrcd variations fur the design of the device for produci»g a free jet:
1 ) A free-jot nozzle device; and 2) A clwcd headbox with a pressure-loaded central oontainear and a va~iably adjustable outlet opening.
The flee jec nozzle device is a pure applicator device with its own supporting body, which includes, for example, a flow spreader and a slotted nozzle extending over the width of the machine (i.e,, the length of an applicator roll}. This device may be designed ae disclosed is US Patent Nos. 3,418,970, 3,521,602 and 4,231,318.
The application of a medium is 21414' 3 performed without the nozzle coming in contact with the surface of the applicator element. The free-jet nozzle device can be displaced in a radial direction with respect to the surface of the applicator roll and can be rotated around a certain axis in such a way that the application angle can be varied and adjusted with respect to the surface of the applicator roll. Preferably, the nozzle device is disposed with respect to a surface of an applicator roll (as shown in U.S. Patent No. 3,418,970) in such a way that a converging gap is formed in the direction of application, that is, in the direction of the movement of the roll, between the surface of the applicator or transfer roll and the free-jet nozzle device.
Furthermore, a nozzle channel of the nozzle device, i.e., a connecting line or tube between the flow spreader and the nozzle exit can be curved. The curvature of such a channel runs essentially in a direction converging to the applicator roll or transfer roll. Then, in this method, a low-air layer lies against the roll and an air-rich layer is toward the outside thereof.
The metering action of the two systems during application is determined by various factors. These include:
1) The flow or discharge cross-section from the free-jet nozzle or headbox container;
2) The discharge velocity of the application medium;
214 ~ 9~'~ 3 3) The pressure in the flow spreader or container; and 4) The rate of rotation of the applicator roll.
A change in the discharge cross-section and in the rate of rotation of the applicator roll or transfer roll can be realized simply with constructional measures, while the change of the discharge velocity should be considered as a function of the discharge cross-section and of the design of the nozzle or of the container (especially the cross-sectional changes between the flow spreader or container and discharge cross-section).
According to another aspect of the invention, the two-element applicator device can include an applicator roll, which, together with a belt moving therearound, forms an extended press gap for the passage of a material web therethrough. Then, preferably, the application of the free jet is onto the surface of the applicator roll, but application onto the web can also be considered under certain circumstances. Such a device is also suitable for one-sided and two-sided coating of material webs.
Preferably, according to the invention, devices for producing the free jet are disposed in the vicinity of the surface of the applicator roll or transfer roll which lies in the direction of rotation of the rolls, in the region before the press gap inlet. Arrangement in areas that are removed from the inlet of the press gap are also conceivable. In this case, preferably, additional equalization devices, for example, in the form of air to _ 2149.4" ~
brushes, are used on the roll surface to make the applied film uniform.
Application of a medium according to the invention with the aid of a free jet onto the surface of an application element provides the advantage of direct controllability of the premetering of the application medium onto the surface of an applicator element and thus of premetering of the applied amount to be transferred in the press gap. Furthermore, the system according to the invention provides the advantage that the amount of film to be applied can be kept constant as a function of time and along the width of the roll. The application and metering system is characterized by a low number of wearing parts and thus by longer time periods between the required change of the metering elements. The adjustability of the size of the discharge openings as well as changes in position with respect to the applicator element can be realized easily from the constructional point of view. The method according to the invention is suitable for coating compositions as well as for starch.
For application of a medium according to the invention with the aid of an open headbox, additional precautions are taken in order to achieve the desired direct influence on metering. Additional damping or other perturbing elements can be included in the discharge area from the open container.
With reference to the drawings, Fig. 1 shows a two-roll applicator device with a free-jet nozzle device assigned to ono of the applicator rolls and a short dwell time applicator (SDTA) with a doctor assigned to the other applicator roll. An applicator roll 1 and an applicator roll 2, which ere arranged so that their axes arc parallel to each other and arc supported rotatably. The rolls l and 2 define a roll gap 3 for the passage of a material or fiber web, especially a paper web 4 therethroltgh. The two applicator rolls 1 and 2 ere driven in directions opposite to each other and indicated by arrows a and b.
Essentially, an applicator unit or apparatus 5, b for a flowable medium is disposed in the vicinity of the roll periphery of each roll 1, ~ that moots f3~om down upward. ?he fiber web 4 is guided thmugh tho roll gap 3 from down upward. In regions '1, 8, which are forrtled by the roll L O gap 3 with the fiber web 4, a film of a flowable modium is applied through the roll surfaces, onto both aides of the ljber web 4. By passing the fiber web 4 upward through tho roll gap 3, the application medium, for example, a coating composition, is applied at the desired thickness onto the fiber web 4 corresponding to the distances of the rolling circles of both the rolls 1 and 2.
The applicator apparatus 5 is designed as a free-jet nozzle device. The nozzle channel of the free jet nozzle devioo 5 is preferably curved. The froe jet indicated by an arrow 13 is shown Schematically. The applicator apparatus 6 is designed as an STDA
with doctor, for example, as disclosed in DE 42 34 276 published on March 17, I99a.
The coating composition i~ applied on each roll surface 11 21414' ~
and 12 of the rolls 1 and 2.
Fig. 2 shows an embodiment of a device according to the invention which is analogous to the device shown in Fig. 1. However, the device of Fig. 2 also includes additional equalizing devices. Therefore, the same reference numbers are used for the same elements in both Figs 1 and 2. However, in Fig. 2, the fiber web 4 is guided through the press gap 3 from the top toward the bottom. In the region of the lower area of the part of the roll periphery or of the roll surfaces 11, 12 of each roll 1, 2, which runs from down upward, an applicator unit 5a and 5b, respectively, is disposed for the application medium, for example, a coating composition. In this case, in regions 7, 8, formed by the roll gap with the fiber web, a film of a flowable medium is applied onto the fiber web 4 through roll surfaces 11 and 12, respectively. In addition, in the vicinity of the roll surfaces 11 and 12, respectively, which are disposed downstream of the applicator devices 5a and 5b with respect to the direction of rotation of the rolls as indicated by arrows a' and b', additional equalizing devices 14 and 15, respectively, are provided in the form of air brushes. The air jets produced by the air brushes 14 and 15 make the applied coating composition more uniform before it is transferred onto the fiber web 4 in the roll gap 3.
Fig. 3 illustrates a two-roll applicator device according to the invention having additional transfer rolls which rotate in a direction opposite to that of the 21414' 3 applicator rolls, and define a gap therewith. The basic structure of the device of Fig. 3 corresponds to the structure of the device shown in Fig. 2 and therefore the same elements have been assigned the same reference numbers. Transfer rolls 16 and 17, with respective applicator devices 5a and 5b, in the form of at least one free-jet nozzle, are assigned to the applicator rolls 1 and 2, respectively. The applicator rolls 1 and 2 and respective transfer rolls 16 and 17, define gaps 30 and 31, respectively. Each of the transfer rolls 16 and 17 preferably have a smaller diameter than the respective applicator rolls 1 and 2. As a result, there is always a velocity difference between the surfaces 11 and 18 as well as the surfaces 12 and 19, between applicator rolls 1 and 2 and transfer rolls 16 and 17, respectively. This velocity difference contributes to stretching or extending of the coating or other application film and thus to an additional metering effect.
Fig. 4 illustrates a two-roll applicator device with a closed headbox cooperating with one applicator roll and an open headbox cooperating with the other applicator roll. In particular, Fig. 4 shows the possibility of premetering a coating composition directly onto an applicator roll of a two-roll applicator device using a closed headbox 19. The basic structure of the two-roll applicator device corresponds to that shown in Figs. 1 to 3 and therefore the same elements have been assigned the same reference numbers. Introduction of a coating composi-2141~'~~
tion onto the roll 2 is performed directly onto the surface 12 of the applicator roll 2. The headbox 19 includes a pressurizable container 20 with a discharge line 21 extending essentially over the entire width of the machine.
The flow-through cross-section of the discharge line 21 has a variable cross-section, but is constant over the width of the application.
The application of a medium onto the applicator roll 1 is performed with the aid of an open headbox 25, which has, for example, a central open container 26 with a separating weir and a discharge element 27 through which coating composition flows onto the surface 11 of the applicator roll 1.
In order to adjust metering action, additional means are necessary at the headbox (not shown). They are, for example, a diaphragm assigned to the discharge element 27, which acts as a damper.
Fig. 5 shows a two-element applicator device consisting of a roll and belt cooperating with a free-jet nozzle device. Fig. 5 shows a two-element applicator device which includes an applicator roll 1, which forms an extended press gap 23 with a revolving belt or wire 22. A
free-jet nozzle device 5a is assigned to cooperate with the applicator roll 1 and is disposed in the vicinity thereof.
The rotating endless belt 22 is coated by passing the belt through a container 28 filled with a medium, for example, a sizing suspension, and the amount of sizing that is carried away by the belt 22 is equalized with a blade 24, 214 ~. 4'~ 3 which is disposed downstream of the container 28 with respect to a direction of movement of the belt 22.
The embodiment of the device according to the invention shown in Fig. 5 is preferably suitable for two s sided coating with different application media, while the embodiments shown in Figs. 1 to 4 are preferably suitable for two-sided coating with the same application medium.
However, here, too, one can consider different and/or only one-sided coating. The embodiments shown in Figs. 1 and 4 10 provide the possibility to assign the same applicator units to the two applicator elements.
The foregoing detailed description is given for clearness of understanding only, and no unnecessary limitations should be understood therefrom, as 15 modifications within the scope of the invention will be apparent to those skilled in the art.
In an aepoct of tha prasrnt invention, tire is provided a method of coating at least one sido of a fibrous web with an application medium in a two-element application device comprising two applicator elementr which aro driven in opposite direttioas and togs form a gap through which tho ~bmua web is led, in which math4d the application medium is pro-tnetcred onto at lean ono of said applicator elamaats and is tranaii!xrCd to the fibrous web in the gap, charactazwzed in that the pro-metering is carried 1 S vut by means of at least one ~ jet of application medium, aimed directly at a surface of said at lean one applicator elemeont.
rn another aspect ef the prat invention, t6ecn is prawidod ~ for coating at laast one side of a fibrous web with an spplicatjoa a:edium co~mpriaing:
two applicator oIdments, together forming a gap for the fibrous web to be Ied tluough, wherein said applicator elemanta are driven in opposite directions;
wherein at least one of said applicator elements is assigned an applicator unit;
such that the applicator wait includes at least one device for producing a free jet which 2S premeters the application medium onto s surface of ire ::signed applicator element.
1n yet another aped of the prasent invention, tfi~ere is provided apparatus for coating at Iaest one side of a fibrous web with as application medium comprising:
two applicator elements, together forming a gap for the $bmus web to be led thtnugh, whareia said agpl~~ator ~xemex~ts arc driven in opposite directions;
4(a) whe~reix~ at least one e~f said applicator elements is assigned an applicator unit;
suoh that the alrplicatar unit is implcrnented as an open haadbox which supplies the application mewdium onto the surface of its assigned applicator element;
the opeon hoadbox iacluding a means for pre-metering the quantf ty of application medium applied to said surface.
In yet ~othor aspect of the invcntlon, there is provided a marhod of costing at least one aide of a fibrous web with an application medium in a two-element application dovioo compria,ing two applicator elements which are driven in opposite directions aad t0 together form a gap through which the fibrous web is led, in which method the spplication matdium is pro-metered onto at least one of said applicator claments and is trensfa~x~od to W a $braus web in the gap, charncterizad in that the pre-metering is carried out by an open ;headbox including means for rnetcriag a quantity of application medium applied egad at least one applfcator element.
Other object ~tcui advantages aftho invention will ba apparent to tboso sldllod is the att from the: following detailed description taken in conjunction with the drawings and the appendai cl;alma.
I~RII:?F DESCRIPTIO1~T O~ T DRAWINGiS
1!'~g. 1 is a soheunatic sectional view of a device according to the invention.
hig. I is a schematic sectional view of a second embodiment of a device according to the invention.
z5 Hig. 3 is a schematic sectional view of a third embodimeutt of a device according to the invention.
F'ig. 4 is a schernatie sectional view ofa fourth embodiment of a device according to the inv~on.
F'~(g. 5 is a sohematie sectional view of a fifth embodiment of a device 3a ~oording to the invention.
DETAILED DESCRIPTION OF THE INVENTION
According to the invention, premetering of a coating or other application medium is performed utilizing a two-element applicator device that introduces the medium 5 onto the surface of an applicator roll, at least indirectly, that is, both directly as well as indirectly, by application of the application medium with the aid of at least one free jet. The use of a free jet provides the advantage of direct control of the applied amount and thus the thickness of the applied film on the surface. Also, the applied amount and film thickness may be altered by changing certain parameters of the jet, for example, discharge cross-section, discharge velocity and application angle of the free jet, in relation to the rate of rotation of the applicator roll.
The free jet can be directed either directly onto the surface of an applicator roll or onto the surface of a transfer roll, which, again, transfers the application medium at least indirectly, that is, directly or through another transfer roll, onto the surface of the applicator roll. The latter variation (indirect application) also provides the advantage of further metering action, especially the extension of the applied film based on the velocity difference of the surfaces of the applicator roll and the transfer roll obtained by suitable adjustment of the ratio of the diameters of the applicator roll and transfer roll.
21414' 3 According to the invention, a device for performing at least one-sided coating of a material web with an application medium includes first and second applicator elements driven in opposite directions and defining a gap for the passage of a material web therebetween. Also, an applicator unit cooperates with at least one of the applicator elements. The applicator unit includes an apparatus for producing a free jet. The free jet thus indirectly premeters an application medium onto the surface of the applicator element cooperating with the free jet. The apparatus for producing a free jet can be assigned directly to the applicator element (the free jet is directed directly onto the surface of the applicator element) or can be assigned to this indirectly by connecting at least one transfer element before it.
Preferably, the two-element applicator device is designed in the form of a two-roll applicator arrangement, that is, two applicator rolls with parallel axes are driven in opposite directions and form a press gap through which the material web is conveyed. The application of the application medium onto the web is accomplished by passage of the web through the press gap during which the application amount that was premetered onto the surface of the applicator roll is transferred onto the web. Such a device is suitable for one-sided coating, as well as for two-sided coating of fiber webs with application composition. The same or different application media can be applied to opposite sides of the web. According to the invention, the following is possible:
1 ) The application of a medium is performed directly, i.e., directly onto the surface of an applicator roll; and 2) The application is done here indirectly, i.e., onto the suxfaea of x transfer roil assigned to the applicator roll.
Possibility (2) above provides the advantage of additional tnatcring action with suitablo design of the ratio of the diantetera of the applicator roll xnd the transfer znll, as a rule, in the form of stretching or extending the film by the transfer roll.
This is 8spc~cially advantageous when a particularly thin applied film is desired on the surfisce of the fiber web.
'There are two prePcrrcd variations fur the design of the device for produci»g a free jet:
1 ) A free-jot nozzle device; and 2) A clwcd headbox with a pressure-loaded central oontainear and a va~iably adjustable outlet opening.
The flee jec nozzle device is a pure applicator device with its own supporting body, which includes, for example, a flow spreader and a slotted nozzle extending over the width of the machine (i.e,, the length of an applicator roll}. This device may be designed ae disclosed is US Patent Nos. 3,418,970, 3,521,602 and 4,231,318.
The application of a medium is 21414' 3 performed without the nozzle coming in contact with the surface of the applicator element. The free-jet nozzle device can be displaced in a radial direction with respect to the surface of the applicator roll and can be rotated around a certain axis in such a way that the application angle can be varied and adjusted with respect to the surface of the applicator roll. Preferably, the nozzle device is disposed with respect to a surface of an applicator roll (as shown in U.S. Patent No. 3,418,970) in such a way that a converging gap is formed in the direction of application, that is, in the direction of the movement of the roll, between the surface of the applicator or transfer roll and the free-jet nozzle device.
Furthermore, a nozzle channel of the nozzle device, i.e., a connecting line or tube between the flow spreader and the nozzle exit can be curved. The curvature of such a channel runs essentially in a direction converging to the applicator roll or transfer roll. Then, in this method, a low-air layer lies against the roll and an air-rich layer is toward the outside thereof.
The metering action of the two systems during application is determined by various factors. These include:
1) The flow or discharge cross-section from the free-jet nozzle or headbox container;
2) The discharge velocity of the application medium;
214 ~ 9~'~ 3 3) The pressure in the flow spreader or container; and 4) The rate of rotation of the applicator roll.
A change in the discharge cross-section and in the rate of rotation of the applicator roll or transfer roll can be realized simply with constructional measures, while the change of the discharge velocity should be considered as a function of the discharge cross-section and of the design of the nozzle or of the container (especially the cross-sectional changes between the flow spreader or container and discharge cross-section).
According to another aspect of the invention, the two-element applicator device can include an applicator roll, which, together with a belt moving therearound, forms an extended press gap for the passage of a material web therethrough. Then, preferably, the application of the free jet is onto the surface of the applicator roll, but application onto the web can also be considered under certain circumstances. Such a device is also suitable for one-sided and two-sided coating of material webs.
Preferably, according to the invention, devices for producing the free jet are disposed in the vicinity of the surface of the applicator roll or transfer roll which lies in the direction of rotation of the rolls, in the region before the press gap inlet. Arrangement in areas that are removed from the inlet of the press gap are also conceivable. In this case, preferably, additional equalization devices, for example, in the form of air to _ 2149.4" ~
brushes, are used on the roll surface to make the applied film uniform.
Application of a medium according to the invention with the aid of a free jet onto the surface of an application element provides the advantage of direct controllability of the premetering of the application medium onto the surface of an applicator element and thus of premetering of the applied amount to be transferred in the press gap. Furthermore, the system according to the invention provides the advantage that the amount of film to be applied can be kept constant as a function of time and along the width of the roll. The application and metering system is characterized by a low number of wearing parts and thus by longer time periods between the required change of the metering elements. The adjustability of the size of the discharge openings as well as changes in position with respect to the applicator element can be realized easily from the constructional point of view. The method according to the invention is suitable for coating compositions as well as for starch.
For application of a medium according to the invention with the aid of an open headbox, additional precautions are taken in order to achieve the desired direct influence on metering. Additional damping or other perturbing elements can be included in the discharge area from the open container.
With reference to the drawings, Fig. 1 shows a two-roll applicator device with a free-jet nozzle device assigned to ono of the applicator rolls and a short dwell time applicator (SDTA) with a doctor assigned to the other applicator roll. An applicator roll 1 and an applicator roll 2, which ere arranged so that their axes arc parallel to each other and arc supported rotatably. The rolls l and 2 define a roll gap 3 for the passage of a material or fiber web, especially a paper web 4 therethroltgh. The two applicator rolls 1 and 2 ere driven in directions opposite to each other and indicated by arrows a and b.
Essentially, an applicator unit or apparatus 5, b for a flowable medium is disposed in the vicinity of the roll periphery of each roll 1, ~ that moots f3~om down upward. ?he fiber web 4 is guided thmugh tho roll gap 3 from down upward. In regions '1, 8, which are forrtled by the roll L O gap 3 with the fiber web 4, a film of a flowable modium is applied through the roll surfaces, onto both aides of the ljber web 4. By passing the fiber web 4 upward through tho roll gap 3, the application medium, for example, a coating composition, is applied at the desired thickness onto the fiber web 4 corresponding to the distances of the rolling circles of both the rolls 1 and 2.
The applicator apparatus 5 is designed as a free-jet nozzle device. The nozzle channel of the free jet nozzle devioo 5 is preferably curved. The froe jet indicated by an arrow 13 is shown Schematically. The applicator apparatus 6 is designed as an STDA
with doctor, for example, as disclosed in DE 42 34 276 published on March 17, I99a.
The coating composition i~ applied on each roll surface 11 21414' ~
and 12 of the rolls 1 and 2.
Fig. 2 shows an embodiment of a device according to the invention which is analogous to the device shown in Fig. 1. However, the device of Fig. 2 also includes additional equalizing devices. Therefore, the same reference numbers are used for the same elements in both Figs 1 and 2. However, in Fig. 2, the fiber web 4 is guided through the press gap 3 from the top toward the bottom. In the region of the lower area of the part of the roll periphery or of the roll surfaces 11, 12 of each roll 1, 2, which runs from down upward, an applicator unit 5a and 5b, respectively, is disposed for the application medium, for example, a coating composition. In this case, in regions 7, 8, formed by the roll gap with the fiber web, a film of a flowable medium is applied onto the fiber web 4 through roll surfaces 11 and 12, respectively. In addition, in the vicinity of the roll surfaces 11 and 12, respectively, which are disposed downstream of the applicator devices 5a and 5b with respect to the direction of rotation of the rolls as indicated by arrows a' and b', additional equalizing devices 14 and 15, respectively, are provided in the form of air brushes. The air jets produced by the air brushes 14 and 15 make the applied coating composition more uniform before it is transferred onto the fiber web 4 in the roll gap 3.
Fig. 3 illustrates a two-roll applicator device according to the invention having additional transfer rolls which rotate in a direction opposite to that of the 21414' 3 applicator rolls, and define a gap therewith. The basic structure of the device of Fig. 3 corresponds to the structure of the device shown in Fig. 2 and therefore the same elements have been assigned the same reference numbers. Transfer rolls 16 and 17, with respective applicator devices 5a and 5b, in the form of at least one free-jet nozzle, are assigned to the applicator rolls 1 and 2, respectively. The applicator rolls 1 and 2 and respective transfer rolls 16 and 17, define gaps 30 and 31, respectively. Each of the transfer rolls 16 and 17 preferably have a smaller diameter than the respective applicator rolls 1 and 2. As a result, there is always a velocity difference between the surfaces 11 and 18 as well as the surfaces 12 and 19, between applicator rolls 1 and 2 and transfer rolls 16 and 17, respectively. This velocity difference contributes to stretching or extending of the coating or other application film and thus to an additional metering effect.
Fig. 4 illustrates a two-roll applicator device with a closed headbox cooperating with one applicator roll and an open headbox cooperating with the other applicator roll. In particular, Fig. 4 shows the possibility of premetering a coating composition directly onto an applicator roll of a two-roll applicator device using a closed headbox 19. The basic structure of the two-roll applicator device corresponds to that shown in Figs. 1 to 3 and therefore the same elements have been assigned the same reference numbers. Introduction of a coating composi-2141~'~~
tion onto the roll 2 is performed directly onto the surface 12 of the applicator roll 2. The headbox 19 includes a pressurizable container 20 with a discharge line 21 extending essentially over the entire width of the machine.
The flow-through cross-section of the discharge line 21 has a variable cross-section, but is constant over the width of the application.
The application of a medium onto the applicator roll 1 is performed with the aid of an open headbox 25, which has, for example, a central open container 26 with a separating weir and a discharge element 27 through which coating composition flows onto the surface 11 of the applicator roll 1.
In order to adjust metering action, additional means are necessary at the headbox (not shown). They are, for example, a diaphragm assigned to the discharge element 27, which acts as a damper.
Fig. 5 shows a two-element applicator device consisting of a roll and belt cooperating with a free-jet nozzle device. Fig. 5 shows a two-element applicator device which includes an applicator roll 1, which forms an extended press gap 23 with a revolving belt or wire 22. A
free-jet nozzle device 5a is assigned to cooperate with the applicator roll 1 and is disposed in the vicinity thereof.
The rotating endless belt 22 is coated by passing the belt through a container 28 filled with a medium, for example, a sizing suspension, and the amount of sizing that is carried away by the belt 22 is equalized with a blade 24, 214 ~. 4'~ 3 which is disposed downstream of the container 28 with respect to a direction of movement of the belt 22.
The embodiment of the device according to the invention shown in Fig. 5 is preferably suitable for two s sided coating with different application media, while the embodiments shown in Figs. 1 to 4 are preferably suitable for two-sided coating with the same application medium.
However, here, too, one can consider different and/or only one-sided coating. The embodiments shown in Figs. 1 and 4 10 provide the possibility to assign the same applicator units to the two applicator elements.
The foregoing detailed description is given for clearness of understanding only, and no unnecessary limitations should be understood therefrom, as 15 modifications within the scope of the invention will be apparent to those skilled in the art.
Claims (34)
1. A method of coating at least one side of a fibrous web with an application medium in a two-element application device comprising two applicator elements which are driven in opposite directions and together form a gap through which the fibrous web is led, in which method the application medium is pre-metered onto at least one of said applicator elements and is transferred to the fibrous web in the gap, characterized in that the pre-metering is carried out by means of at least one free jet of application medium, aimed directly at a surface of said at least one applicator element.
2. The method according to claim 1, characterized in that an application angle of said at least one free jet is variable.
3. Apparatus for coating at least one side of a fibrous web with an application medium comprising:
two applicator elements, together forming a gap for the fibrous web to be led through, wherein said applicator elements are driven in opposite directions;
wherein at least one of said applicator elements is assigned an applicator unit; such that the applicator unit includes at least one device for producing a free jet which premeters the application medium onto a surface of its assigned applicator element.
two applicator elements, together forming a gap for the fibrous web to be led through, wherein said applicator elements are driven in opposite directions;
wherein at least one of said applicator elements is assigned an applicator unit; such that the applicator unit includes at least one device for producing a free jet which premeters the application medium onto a surface of its assigned applicator element.
4. Apparatus according to claim 3, characterized in that the device for producing said free jet is assigned directly to the applicator element.
5. Apparatus according to claim 3 wherein the applicator element is an applicator roll;
the applicator unit further includes a transfer roll, which is assigned to the applicator roll in such a way that the two together form a press nip; such that the device for producing the free jet is assigned to the transfer roll.
the applicator unit further includes a transfer roll, which is assigned to the applicator roll in such a way that the two together form a press nip; such that the device for producing the free jet is assigned to the transfer roll.
6. Apparatus according to one of claims 3 to 5, characterized in that the device for producing the free jet is a nozzle-like element.
7. Apparatus according to Claim 6 wherein said nozzle-like element is a free jet nozzle device.
8. Apparatus according to claim 7, characterized in that said free jet nozzle device includes outlet openings and wherein the position of said openings can be variably positioned with respect to the circumferential surface of the applicator roll or transfer roll.
9. Apparatus according to claim 6, characterized in that said nozzle-like element is arranged opposite the circumferential surface of the applicator roll or transfer roll such that said nozzle-like element and said surface form a converging gap in the direction of rotation of the applicator roll or transfer roll.
10. Apparatus according to claim 7, characterized in that said free jet nozzle device is arranged opposite the circumferential surface of the applicator roll or transfer roll such that the nozzle device and the surface form a converging gap in the direction of rotation of the applicator roll or transfer roll.
11. Apparatus according to claim 8, characterized in that said free jet nozzle device is arranged opposite the circumferential surface of the applicator roll or transfer roll such that the nozzle device and the surface form a converging gap in the direction of rotation of the applicator roll or transfer roll.
12. Apparatus according to one of claims 3 to 5, characterized in that the device for producing the free jet is a closed headbox with pressurized containers.
13. Apparatus according to one of claims 3 to 7, characterized in that the free jet includes outlet openings cross sections.
14. Apparatus according to claim 8, characterized in that said free jet outlet openings have variable cross sections.
15. Apparatus according to one of claims 3 to 14 further comprising equalizing devices connected downstream of the device for producing the free jet.
16. Apparatus according to claim 15 wherein said equalizing devices are designed in the form of air brushes.
17. Apparatus for coating at least one side of a fibrous web with an application medium comprising:
two applicator elements, together forming a gap for the fibrous web to be led through, wherein said applicator elements are driven in opposite directions;
wherein at least one of said applicator elements is assigned an applicator unit; such that the applicator unit is implemented as an open headbox which supplies the application medium onto the surface of its assigned applicator element;
the open headbox comprising means for metering the quantity of application medium applied to said surface.
two applicator elements, together forming a gap for the fibrous web to be led through, wherein said applicator elements are driven in opposite directions;
wherein at least one of said applicator elements is assigned an applicator unit; such that the applicator unit is implemented as an open headbox which supplies the application medium onto the surface of its assigned applicator element;
the open headbox comprising means for metering the quantity of application medium applied to said surface.
18. A method of coating at least one side of a fibrous web with an application medium in a two-element application device comprising two applicator elements which are driven in opposite directions and together form a gap through which the fibrous web is led, in which method the application medium is pre-metered onto at least one of said applicator elements and is transferred to the fibrous web in the gap, characterized in that the pre-metering is carried out by an open headbox including means for metering a quantity of application medium applied to said at least one applicator element.
19. In a method of at least one-sided coating of a material web with an application medium in an applicator device having at least one applicator roll and a counter element driven in opposite directions and defining a gap through which the material web is conveyed, said method comprising the steps of pre-metering the application medium onto the applicator roll and transferring the application medium onto the material web in the gap, the improvement comprising the steps of:
providing an apparatus having a nozzle for the emission of the application medium onto an application surface without the nozzle coming in contact with said application surface; and pre-metering the application medium to the applicator device by emitting the application medium from the nozzle for a distance of at least 4 mm and impinging the application medium directly onto the application surface, said surface being one of a surface of the applicator roll and a surface of the transfer roll.
providing an apparatus having a nozzle for the emission of the application medium onto an application surface without the nozzle coming in contact with said application surface; and pre-metering the application medium to the applicator device by emitting the application medium from the nozzle for a distance of at least 4 mm and impinging the application medium directly onto the application surface, said surface being one of a surface of the applicator roll and a surface of the transfer roll.
20. The improvement of claim 19 wherein the apparatus is at least one of displaceable in a radial direction with respect to the surface upon which the application medium is directed and rotatable about an axis thereof providing for variable adjustment of an angle between a direction of emission of the application medium and the surface upon which the application medium is directed.
21. A device for performing at least one-sided coating of a material web with an application medium, said device comprising:
first and second applicator elements driven in opposite directions and defining a gap for the passage of a material web therebetween, at least one of said applicator elements being a roll;
and an applicator unit assigned to at least one of said first applicator element, and said second applicator element, said applicator unit having an apparatus with a nozzle for the emission of an application medium directly onto a surface of one of the first applicator element, and the second applicator element without the nozzle coming in contact with said surface, said apparatus being variably displaceable in a radial direction in relation to said surface and rotatable about an axis thereof providing for variable adjustment of an application angle defined by a direction of emission of the application medium and said surface, wherein an outlet opening of the nozzle is disposed at least 4 mm from the surface upon which the application medium is applied.
first and second applicator elements driven in opposite directions and defining a gap for the passage of a material web therebetween, at least one of said applicator elements being a roll;
and an applicator unit assigned to at least one of said first applicator element, and said second applicator element, said applicator unit having an apparatus with a nozzle for the emission of an application medium directly onto a surface of one of the first applicator element, and the second applicator element without the nozzle coming in contact with said surface, said apparatus being variably displaceable in a radial direction in relation to said surface and rotatable about an axis thereof providing for variable adjustment of an application angle defined by a direction of emission of the application medium and said surface, wherein an outlet opening of the nozzle is disposed at least 4 mm from the surface upon which the application medium is applied.
22. The device according to claim 21 further comprising a transfer roll forming a press gap with one of the applicator elements.
23. The device according to claim 22 wherein the applicator unit is assigned to the transfer roll.
24. The device according to claim 21 wherein the apparatus applies the application medium directly onto one of the applicator elements.
25. The device of claim 23 wherein said apparatus applies the application medium directly onto the transfer roll.
26. The device according to claim 21 wherein the apparatus is disposed at a location directly upstream of an inlet of the gap formed by said applicator elements, the upstream location being defined with respect to a direction of rotation of one of said applicator elements
27. The device according to any one of claims 23 or 25 wherein the apparatus is disposed at a location directly upstream of an inlet of a gap formed by one of said applicator elements and said transfer roll, the upstream location being defined with respect to a direction of rotation of one of said applicator elements.
28. The device according to any one of claims 21 to 27 wherein the apparatus is a closed headbox having a container under pressure.
29. The device according to any one of claims 21 to 28 wherein the apparatus has outlet openings having cross-sections that are variably adjustable.
30. The device according to claim 21 further comprising equalizing devices for providing a uniform film of the application medium on the surface of at least one of the applicator elements, said equalizing devices disposed downstream of the apparatus with respect to a direction of rotation of at least one of said applicator elements.
31. The device according to any one of claims 23, 25, or 27 further comprising equalizing devices for providing a uniform film of the application medium on the surface of the transfer roll said equalizing devices disposed downstream of the apparatus with respect to a direction of rotation of at least one of said applicator elements.
32. The device according to any one of claims 30 or 31 wherein the equalizing devices are air brushes.
33. A device for performing at least one-sided coating of a material web with an application medium, said device comprising:
first and second applicator elements driven in opposite directions and defining a gap for the passage of a material web therebetween, at least one of said applicator elements being a roll;
an applicator unit assigned to a least one of said first and second applicator elements, said applicator unit designed as an open headbox for applying an application medium onto a surface of the assigned applicator element; and means for pre-metering a pressurized flow of application medium disposed at the headbox and directing the medium directly on the surface of the assigned applicator element, an outlet opening of the pre-metering means being disposed at least 4 mm from the surface of the assigned applicator element.
first and second applicator elements driven in opposite directions and defining a gap for the passage of a material web therebetween, at least one of said applicator elements being a roll;
an applicator unit assigned to a least one of said first and second applicator elements, said applicator unit designed as an open headbox for applying an application medium onto a surface of the assigned applicator element; and means for pre-metering a pressurized flow of application medium disposed at the headbox and directing the medium directly on the surface of the assigned applicator element, an outlet opening of the pre-metering means being disposed at least 4 mm from the surface of the assigned applicator element.
34. The method of claim 19 further comprising the step of:
providing a transfer roll forming a press gap with the applicator roll.
providing a transfer roll forming a press gap with the applicator roll.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP4402627.7 | 1994-01-31 | ||
| DE4402627A DE4402627A1 (en) | 1994-01-31 | 1994-01-31 | Web coating |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2141473A1 CA2141473A1 (en) | 1995-08-01 |
| CA2141473C true CA2141473C (en) | 2006-10-31 |
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ID=6508957
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002141473A Expired - Fee Related CA2141473C (en) | 1994-01-31 | 1995-01-31 | Method and device for coating a material web |
Country Status (6)
| Country | Link |
|---|---|
| EP (1) | EP0666370B1 (en) |
| JP (1) | JP3435242B2 (en) |
| AT (1) | ATE200326T1 (en) |
| CA (1) | CA2141473C (en) |
| DE (2) | DE4402627A1 (en) |
| FI (1) | FI108848B (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE29520678U1 (en) * | 1995-12-29 | 1996-05-30 | Voith Sulzer Papiermasch Gmbh | Applicator for direct or indirect application of a liquid or pasty medium to a running material web |
| DE29702629U1 (en) * | 1997-02-15 | 1997-04-10 | Voith Sulzer Papiermasch Gmbh | Device for the indirect application of liquid medium on one or both sides to a running web |
| DE19816337A1 (en) * | 1998-04-11 | 1999-10-14 | Voith Sulzer Papiertech Patent | Device for direct or indirect, one- or two-sided application of a liquid or pasty medium to a running surface |
| FI108993B (en) | 1999-06-30 | 2002-05-15 | Metso Paper Inc | Method and arrangement for applying a treating agent to a moving surface |
| JP2002263540A (en) * | 2001-03-14 | 2002-09-17 | Ishikawajima Harima Heavy Ind Co Ltd | Roll coater |
| DE10146463A1 (en) * | 2001-09-20 | 2003-04-17 | F Ee Gmbh Automation | Glue application station for a corrugated cardboard web has an application roller, where glue is sprayed at the roller surface for transfer to the corrugation peaks, and surplus glue is scraped clear for cleaning and recycling |
| DE102015113161A1 (en) * | 2015-08-10 | 2017-02-16 | KROENERT GmbH & Co KG | Method and device for applying a medium to a substrate |
| CN107737688A (en) * | 2017-09-06 | 2018-02-27 | 江门市泽天达科技有限公司 | A kind of steel plate coating machine |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2320883A (en) * | 1939-11-16 | 1943-06-01 | Parkinson Leonard | Paper-coating apparatus |
| US3257226A (en) * | 1962-11-08 | 1966-06-21 | Exxon Research Engineering Co | Wax coating method and apparatus |
| GB1042627A (en) * | 1964-07-17 | 1966-09-14 | British Cellophane Ltd | Improvements in and relating to coating travelling webs |
| US3418970A (en) * | 1964-11-02 | 1968-12-31 | Black Clawson Co | Paper coating apparatus |
| US3521602A (en) * | 1967-12-18 | 1970-07-28 | Black Clawson Co | Fountain coater |
| SE378769B (en) * | 1972-03-13 | 1975-09-15 | Inventing Ab | |
| BE802413A (en) * | 1973-07-16 | 1973-11-16 | Inventing Ab | PROCESS FOR APPLYING COATINGS OF DIFFERENT COMPOSITIONS ON A SHEET OF PAPER OR OTHERWISE. |
| US4231318A (en) * | 1978-07-03 | 1980-11-04 | The Black Clawson Company | Dual blade coater |
| DE3417487A1 (en) * | 1984-05-11 | 1985-11-21 | J.M. Voith Gmbh, 7920 Heidenheim | DEVICE FOR APPLYING A LIQUID ON A RUNNING TRAIN |
| DE3526257A1 (en) * | 1985-07-23 | 1987-01-29 | Sucker & Franz Mueller Gmbh | Apparatus for applying a defined amount of product to a roller casing |
| DE3716520A1 (en) * | 1987-05-16 | 1988-12-01 | Kleinewefers Gmbh | Device and process for applying adhesive |
| US5224995A (en) * | 1989-10-24 | 1993-07-06 | Pioneer Electronic Corporation | Apparatus for applying a coating to a surface of a substrate |
-
1994
- 1994-01-31 DE DE4402627A patent/DE4402627A1/en not_active Withdrawn
-
1995
- 1995-01-24 EP EP95100887A patent/EP0666370B1/en not_active Expired - Lifetime
- 1995-01-24 DE DE59509140T patent/DE59509140D1/en not_active Expired - Lifetime
- 1995-01-24 AT AT95100887T patent/ATE200326T1/en active
- 1995-01-30 FI FI950408A patent/FI108848B/en not_active IP Right Cessation
- 1995-01-31 JP JP01477395A patent/JP3435242B2/en not_active Expired - Fee Related
- 1995-01-31 CA CA002141473A patent/CA2141473C/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| DE4402627A1 (en) | 1994-07-14 |
| FI108848B (en) | 2002-04-15 |
| EP0666370B1 (en) | 2001-04-04 |
| JPH07313914A (en) | 1995-12-05 |
| FI950408A (en) | 1995-08-01 |
| FI950408A0 (en) | 1995-01-30 |
| JP3435242B2 (en) | 2003-08-11 |
| ATE200326T1 (en) | 2001-04-15 |
| CA2141473A1 (en) | 1995-08-01 |
| DE59509140D1 (en) | 2001-05-10 |
| EP0666370A1 (en) | 1995-08-09 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| MKLA | Lapsed |