EP0799934A1 - Process and apparatus for applying a CB coat on a paper web - Google Patents

Process and apparatus for applying a CB coat on a paper web Download PDF

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Publication number
EP0799934A1
EP0799934A1 EP96105296A EP96105296A EP0799934A1 EP 0799934 A1 EP0799934 A1 EP 0799934A1 EP 96105296 A EP96105296 A EP 96105296A EP 96105296 A EP96105296 A EP 96105296A EP 0799934 A1 EP0799934 A1 EP 0799934A1
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EP
European Patent Office
Prior art keywords
coating
roll
roller
nip
web
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.)
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Application number
EP96105296A
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German (de)
French (fr)
Inventor
Rüdiger KURTZ
Martin Kustermann
Michael Trefz
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Voith Patent GmbH
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Voith Sulzer Papiermaschinen GmbH
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Publication date
Application filed by Voith Sulzer Papiermaschinen GmbH filed Critical Voith Sulzer Papiermaschinen GmbH
Priority to EP96105296A priority Critical patent/EP0799934A1/en
Publication of EP0799934A1 publication Critical patent/EP0799934A1/en
Withdrawn legal-status Critical Current

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    • 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
    • B05C1/0834—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 the coating roller co-operating with other rollers, e.g. dosing, transfer 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
    • 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
    • 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
    • D21H23/58—Details thereof, e.g. surface characteristics, peripheral speed
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
    • B41M5/00—Duplicating or marking methods; Sheet materials for use therein
    • B41M5/124—Duplicating or marking methods; Sheet materials for use therein using pressure to make a masked colour visible, e.g. to make a coloured support visible, to create an opaque or transparent pattern, or to form colour by uniting colour-forming components
    • B41M5/1246—Application of the layer, e.g. by printing

Definitions

  • the invention relates to a method for producing a paper web which has a so-called CB layer, in particular with the features specified in the preamble of claim 1.
  • the invention also relates to an apparatus for performing this method.
  • a CB layer applied to paper contains a color former enclosed in microcapsules, which cooperates with a so-called CF layer (containing a color-reactive pigment) on another paper (e.g. in a set of forms) in such a way that visible signs (e.g. when copying) are visible arise.
  • the nip through which the paper web passes is set to a distance "which is not less than the thickness of the uncoated paper".
  • this known method it can be expected that it is very difficult or even impossible to transfer the coating slip onto the paper web surface with the necessary uniformity.
  • the distance between the two roller shells can be different due to different temperatures and the resulting local changes in diameter.
  • the invention is therefore based on the object of further developing the method specified in the preamble of claim 1 in such a way that the finished paper web, which has a pressure-sensitive CB layer, meets higher quality requirements than hitherto.
  • the device specified in the preamble of claim 4 is to be further developed.
  • the stated object is achieved by the characterizing method feature of claim 1 or by the characterizing device feature of claim 4.
  • the inventors have recognized that the microcapsules contained in the CB coating slip - as long as they are suspended in the liquid coating slip - can withstand a certain pressure.
  • the CB coating slip can be safely transferred to the paper web in a nip, but structural measures must be taken to ensure that there is not an excessively high mean surface pressure in the nip. This results in a much more even stroke application than before.
  • the banding to be expected in the prior art is avoided, in particular because the previously existing risk of slippage between the paper web and the roller surfaces has been eliminated. In other words, a certain frictional connection is made between the paper web and the two driven rollers. This means that achieved that paper web breaks are much less likely than previously to be expected.
  • the method according to the invention can thus be operated with a higher running efficiency than the known method.
  • the above-mentioned constructive measures include that a minimum length of the nip is ensured according to claim 3 or 5; ie the paper web comes in the nip in contact with both roller jackets simultaneously over a certain running distance. This helps to keep the mean surface pressure at relatively low values.
  • the length of the nip to be expected in the web running direction can be determined by means of known calculation methods (Hertz formula), namely taking into account the roller diameter, the line force as well as the materials and the modulus of elasticity of the roller shells.
  • Particularly favorable values can be achieved if one of the two rollers is designed as a shoe press roller; because in this case, the contact pressure is known to be distributed over a particularly large area. Similar to known shoe press rolls (from paper making machines), a particularly sensitive and gradual increase in the contact pressure can be ensured when the paper web and the CB layer to be applied enter the roll nip. At the same time, it is possible to ensure a relatively rapid, steep drop in pressure when leaving the nip. This further increases the uniformity (in other words, the smoothness) of the surface of the CB layer. The streak formation observed up to now is thereby almost completely avoided.
  • FIGS. 1 to 4 shows a device according to the invention for producing a CB layer, in each case in a schematic side view.
  • a coating roller 2 and a counter roller 1 together form a nip (a) through which a paper web 3 to be coated runs.
  • a supply and metering device for CB coating color generally designated CB
  • This device comprises a known scoop roller 6, which conveys the ink from a reservoir 12 to the coating roller 2. This forms a fine metering gap with a metering roller 14. In this way, a thin coating film is produced on the roll shell of the coating roll (2) from the supplied CB coating slip, which film is then transferred to the paper web (3) in the roll gap (a).
  • one of the two rollers rests in immovable bearings.
  • the bearings of the other roller are movable; i.e. they rest, for example, in swivel levers 4, which can be actuated by means of a loading device (e.g. hydraulic cylinder 13).
  • the hydraulic cylinder presses the two rollers 1 and 2 against each other. It is counteracted by an energy accumulator, e.g. a compression spring 14.
  • an energy accumulator e.g. a compression spring 14.
  • the other side of the paper web 3 (the top side according to FIG. 1) can remain unchanged when the CB layer is applied to the bottom side.
  • any medium e.g. Water, or starch or any coating color (for example a CF coating color) are applied to the counter roller 1, which then transfers this medium to the other side of the paper web 3.
  • FIG. 1 it is indicated that the peripheral speed v 1 of the metering roller 14 is lower than the working speed v of the entire device. As a result, a particularly fine dosage of the CB layer to be applied is achieved.
  • FIG. 2 differs from FIG. 1 essentially only in that a shoe press roll 1 'is provided instead of a normal counter roll.
  • This has a circumferential flexible press jacket 1a through which a stationary support body 7 extends.
  • a radially movable press shoe 5 has a concave (and adapted to the coating roller 2) sliding surface for the press jacket 1a. It is guided in the support body 7 and can press the press cover 1a sensitively onto the coating roller 2.
  • a stationary slide shoe 8 with a convex slide surface is provided on the support body 7.
  • an additional feed and metering device 16 can be provided on the outside of the press casing 1a.
  • FIGS. 1 and 2 the paper web essentially runs through the nip from top to bottom.
  • Feed and metering devices CF or 16 or 16 ' are used here. These are designed so that they are on the downward-facing side of the relevant Roll shell can be arranged.
  • the feed and metering device 16 'provided on the counter roll 1 of FIG. 3 forms, together with the roll shell, a liquid sump, while the other feed and metering devices CF or 16 avoid such a sump and are therefore suitable for higher working speeds.
  • the CB coating color (and / or possibly the medium to be applied to the opposite side) can be fed to the relevant roller 2 or 1 by means of a free jet nozzle known per se. Then, if necessary, excess CB coating color (or excess medium) can be scraped off the roller.

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  • Paper (AREA)
  • Color Printing (AREA)

Abstract

In a process for the mfr. of paper having a CB coating on one side, the raw paper is passed through the gap between a coating roll (2) and an opposing roll (1). The CB coating material, which contains an encapsulated colour-forming substance, is continuously applied to the coating roll - at a thickness determined by a metering roll (14) and is applied by the coating roll to the paper. The coating and opposing rolls (2, 1) are pressed against one another in such a way that an average pressure of up to 2 N/mm<2> and a linear force of a max. of 80 N/m is exerted between them. Also claimed is a coating machine for the process in which the coating and opposing rolls are provided with a means of generating a linear force between them in the region of up to 80 kN/m. Pref. a max. press. of 1 N/mm<2> is exerted in the nip, and the linear force in the nip, which takes into account the hardness, the elasticity, the diameter, and the nature of the material of the roll covering, is selected to ensure a nip length in the direction of web travel of at least 5 mm, and more pref. 10-20 mm. The roll diameter and the properties of the covering meet the above requirements. One side of the press may be formed by a shoe press and belt. The pres is generated between the rolls by a variable force generator working against a counter-mechanism such as a spring or pressure cylinder.

Description

Die Erfindung betrifft ein Verfahren zur Herstellung einer Papierbahn, die eine sogenannte CB-Schicht aufweist, im einzelnen mit den im Oberbegriff des Anspruches 1 angegebenen Merkmalen. Die Erfindung betrifft außerdem eine Vorrichtung zur Durchführung dieses Verfahrens. Bekanntlich enthält eine auf Papier aufgetragene CB-Schicht einen in Mikrokapseln eingeschlossenen Farbbildner, der mit einer sogenannten (ein farbreaktives Pigment enthaltenden) CF-Schicht eines anderen Papiers (z.B. in einem Formularsatz) derart zusammenwirkt, daß unter Druckeinwirkung (z.B. beim Durchschreiben) sichtbare Zeichen entstehen.The invention relates to a method for producing a paper web which has a so-called CB layer, in particular with the features specified in the preamble of claim 1. The invention also relates to an apparatus for performing this method. As is known, a CB layer applied to paper contains a color former enclosed in microcapsules, which cooperates with a so-called CF layer (containing a color-reactive pigment) on another paper (e.g. in a set of forms) in such a way that visible signs (e.g. when copying) are visible arise.

Zum Stand der Technik wird hingewiesen auf die DE 4224718 A1 und auf die dort angegebene Literatur.With regard to the prior art, reference is made to DE 4224718 A1 and to the literature given there.

Bei dem bekannten Verfahren wird der Walzenspalt, durch den die Papierbahn hindurchläuft, auf einen Abstand eingestellt, der "nicht kleiner als die Dicke des ungestrichenen Papiers ist". Bei dieser bekannten Methode ist zu erwarten, daß es sehr schwierig oder gar unmöglich ist, die Streichmasse mit der notwendigen Gleichmäßigkeit auf die Papierbahn-Oberfläche zu übertragen. Es ist nämlich sehr schwierig, den Walzenspalt über die gesamte Bahnbreite hinweg (die viele Meter betragen kann, max. ca. 10 m) exakt gleich einzustellen. So kann beispielsweise durch unterschiedliche Temperaturen und hierdurch verursachte örtliche Durchmesser-Veränderungen der Abstand zwischen den zwei Walzenmänteln unterschiedlich sein.In the known method, the nip through which the paper web passes is set to a distance "which is not less than the thickness of the uncoated paper". With this known method it can be expected that it is very difficult or even impossible to transfer the coating slip onto the paper web surface with the necessary uniformity. It is very difficult to set the roller gap exactly the same across the entire web width (which can be many meters, max. Approx. 10 m). For example, the distance between the two roller shells can be different due to different temperatures and the resulting local changes in diameter.

Der Erfindung liegt deshalb die Aufgabe zugrunde, das im Oberbegriff des Anspruches 1 angegebene Verfahren dahingehend weiterzuentwickeln, daß die fertige, eine druckempfindliche CB-Schicht aufweisende Papierbahn höheren Qualitätsansprüchen genügt als bisher. In gleicher Weise soll die im Oberbegriff des Anspruches 4 angegebene Vorrichtung weiterentwickelt werden.The invention is therefore based on the object of further developing the method specified in the preamble of claim 1 in such a way that the finished paper web, which has a pressure-sensitive CB layer, meets higher quality requirements than hitherto. In the same way, the device specified in the preamble of claim 4 is to be further developed.

Die gestellte Aufgabe wird durch das kennzeichnende Verfahrensmerkmal des Anspruches 1 bzw. durch das kennzeichnende Vorrichtungsmerkmal des Anspruches 4 gelöst.The stated object is achieved by the characterizing method feature of claim 1 or by the characterizing device feature of claim 4.

Die Erfinder haben erkannt, daß die in der CB-Streichfarbe enthaltenen Mikrokapseln - solange sie in der flüssigen Streichfarbe suspendiert sind - durchaus einem gewissen Druck standhalten können. Man kann also gemäß der Erfindung die CB-Streichfarbe gefahrlos in einem Walzenspalt auf die Papierbahn übertragen, wobei allerdings durch konstruktive Maßnahmen dafür gesorgt werden muß, daß im Walzenspalt eine nicht übermäßig hohe mittlere Flächenpressung vorhanden ist. Man erhält hierdurch einen wesentlich gleichmäßigeren Strichauftrag als bisher. Die beim Stand der Technik zu erwartende Streifenbildung wird vermieden, insbesondere weil die bisher vorhandene Gefahr von Schlupf zwischen der Papierbahn und den Walzenoberflächen beseitigt ist. Mit anderen Worten: Es wird ein gewisser Kraftschluß hergestellt zwischen der Papierbahn und den zwei angetriebenen Walzen. Hierdurch wird u.a. erreicht, daß Papierbahn-Abrisse viel seltener als bisher zu erwarten sind. Das erfindungsgemäße Verfahren kann also mit einem höheren Laufwirkungsgrad betrieben werden als das bekannte Verfahren.The inventors have recognized that the microcapsules contained in the CB coating slip - as long as they are suspended in the liquid coating slip - can withstand a certain pressure. Thus, according to the invention, the CB coating slip can be safely transferred to the paper web in a nip, but structural measures must be taken to ensure that there is not an excessively high mean surface pressure in the nip. This results in a much more even stroke application than before. The banding to be expected in the prior art is avoided, in particular because the previously existing risk of slippage between the paper web and the roller surfaces has been eliminated. In other words, a certain frictional connection is made between the paper web and the two driven rollers. This means that achieved that paper web breaks are much less likely than previously to be expected. The method according to the invention can thus be operated with a higher running efficiency than the known method.

Zu den oben erwähnten konstruktiven Maßnahmen gehört u.a., daß gemäß Anspruch 3 bzw. 5 für eine Mindestlänge des Walzenspaltes gesorgt wird; d.h. die Papierbahn kommt im Walzenspalt über eine gewisse Laufstrecke gleichzeitig mit beiden Walzenmänteln in Kontakt. Dies trägt dazu bei, daß die mittlere Flächenpressung auf relativ niedrigen Werten gehalten wird. Man kann im übrigen mittels bekannter Berechnungsmethoden (Formel von Hertz) die in Bahnlaufrichtung zu erwartende Länge des Walzenspaltes ermitteln, nämlich unter Berücksichtigung der Walzendurchmesser, der Linienkraft sowie der Werkstoffe und des Elastizitäsmoduls der Walzenmäntel.The above-mentioned constructive measures include that a minimum length of the nip is ensured according to claim 3 or 5; ie the paper web comes in the nip in contact with both roller jackets simultaneously over a certain running distance. This helps to keep the mean surface pressure at relatively low values. In addition, the length of the nip to be expected in the web running direction can be determined by means of known calculation methods (Hertz formula), namely taking into account the roller diameter, the line force as well as the materials and the modulus of elasticity of the roller shells.

Besonders günstige Werte können erzielt werden, wenn eine der beiden Walzen als Schuhpreßwalze ausgebildet ist; denn in diesem Fall wird bekanntlich die Anpreßkraft auf eine besonders große Fläche aufgeteilt. Ähnlich wie bei (von Papierherstellungsmaschinen) bekannten Schuhpreßwalzen, kann beim Einlauf der Papierbahn und der aufzutragenden CB-Schicht in den Walzenspalt für ein besonders feinfühliges und allmähliches Ansteigen des Anpreßdruckes gesorgt werden. Zugleich ist es möglich, beim Auslauf aus dem Walzenspalt für einen relativ raschen, steilen Druckabfall zu sorgen. Dadurch wird die Gleichmäßigkeit (mit anderen Worten: die Glätte) der Oberfläche der CB-Schicht noch weiter erhöht. Die bisher beobachtete Streifenbildung wird hierdurch so gut wie vollkommen vermieden.Particularly favorable values can be achieved if one of the two rollers is designed as a shoe press roller; because in this case, the contact pressure is known to be distributed over a particularly large area. Similar to known shoe press rolls (from paper making machines), a particularly sensitive and gradual increase in the contact pressure can be ensured when the paper web and the CB layer to be applied enter the roll nip. At the same time, it is possible to ensure a relatively rapid, steep drop in pressure when leaving the nip. This further increases the uniformity (in other words, the smoothness) of the surface of the CB layer. The streak formation observed up to now is thereby almost completely avoided.

Unter Umständen ist es vorteilhaft, im Walzenspalt eine besonders kleine Linienkraft (etwa zwischen Null und 10 kN/m) einzustellen. Dies ist mit den herkömmlichen Anpreßeinrichtungen nur schwer oder gar nicht erreichbar. Möglich ist dies jedoch mit einer speziellen Weiterbildung gemäß Anspruch 7.Under certain circumstances, it is advantageous to set a particularly small line force (approximately between zero and 10 kN / m) in the nip. This is difficult or impossible to achieve with conventional pressure devices. However, this is possible with a special training according to claim 7.

Jede der Figuren 1 bis 4 zeigt eine erfindungsgemäße, zum Herstellen einer CB-Schicht dienende Vorrichtung, jeweils in einer schematischen Seitenansicht.Each of FIGS. 1 to 4 shows a device according to the invention for producing a CB layer, in each case in a schematic side view.

In Fig. 1 ist folgendes vorgesehen: Eine Beschichtungswalze 2 und eine Gegenwalze 1 bilden miteinander einen Walzenspalt (a), durch den eine zu beschichtende Papierbahn 3 hindurchläuft. Im freiem Bereich der Mantelfläche der Beschichtungswalze 2 ist eine insgesamt mit CB bezeichnete Zuführ- und Dosiereinrichtung für CB-Streichfarbe angeordnet. Diese Einrichtung umfaßt eine bekannte Schöpfwalze 6, welche die Farbe aus einem Vorratsbehälter 12 zur Beschichtungswalze 2 fördert. Diese bildet mit einer Dosierwalze 14 einen Feindosierspalt. Hierdurch erzeugt man auf dem Walzenmantel der Beschichtungswalze (2) aus der zugeführten CB-Streichfarbe einen dünnen Streichfarbe-Film, der sodann im Walzenspalt (a) auf die Papierbahn (3) übertragen wird.The following is provided in FIG. 1: A coating roller 2 and a counter roller 1 together form a nip (a) through which a paper web 3 to be coated runs. In the free area of the outer surface of the coating roller 2, a supply and metering device for CB coating color, generally designated CB, is arranged. This device comprises a known scoop roller 6, which conveys the ink from a reservoir 12 to the coating roller 2. This forms a fine metering gap with a metering roller 14. In this way, a thin coating film is produced on the roll shell of the coating roll (2) from the supplied CB coating slip, which film is then transferred to the paper web (3) in the roll gap (a).

Schematisch ist angedeutet, daß die eine der beiden Walzen, z.B. die Beschichtungswalze 2, in unbeweglichen Lagern ruht. Dagegen sind die Lager der anderen Walze (der Gegenwalze 1) beweglich; d.h. sie ruhen beispielsweise in Schwenkhebeln 4, die mittels je einer Belastungseinrichtung (z.B. Hydraulikzylinder 13) betätigbar sind. Der Hydraulikzylinder bewirkt ein gegenseitiges Anpressen der beiden Walzen 1 und 2. Ihm wirkt entgegen ein Kraftspeicher, z.B. eine Druckfeder 14. Dadurch kann die im Walzenspalt wirkende Anpreßkraft bei Bedarf sehr feinfühlig, z.B. auch auf extrem niedrige Werte eingestellt werden.It is indicated schematically that one of the two rollers, e.g. the coating roller 2, rests in immovable bearings. In contrast, the bearings of the other roller (the counter roller 1) are movable; i.e. they rest, for example, in swivel levers 4, which can be actuated by means of a loading device (e.g. hydraulic cylinder 13). The hydraulic cylinder presses the two rollers 1 and 2 against each other. It is counteracted by an energy accumulator, e.g. a compression spring 14. As a result, the contact pressure acting in the nip can be very sensitive, e.g. can also be set to extremely low values.

Man wählt die Durchmesser der beiden Walzen 1 und 2 und die Werkstoffe, E-Modul und Härte der Walzenmäntel bzw. der Walzenbezüge sowie die Höhe der im Walzenspalt wirkenden Linienkraft derart, daß - in Laufrichtung gemessen - die Länge a des Walzenspaltes mindestens 5 mm beträgt, vorzugsweise zwischen 10 und 20 mm.One chooses the diameter of the two rolls 1 and 2 and the materials, modulus of elasticity and hardness of the roll shells or the roll covers as well as the height of the line force acting in the roll gap such that - measured in the running direction - the length a of the roll gap is at least 5 mm , preferably between 10 and 20 mm.

Die andere Seite der Papierbahn 3 (gemäß Fig. 1 die Oberseite) kann beim Auftragen der CB-Schicht auf die Unterseite unverändert bleiben. Alternativ hierzu kann - ähnlich Fig. 2, 3 oder 4 - mittels einer zusätzlichen Zuführ- und Dosiereinrichtung irgend ein Medium, z.B. Wasser, oder Stärke oder eine beliebige Streichfarbe, (beispielsweise eine CF-Streichfarbe) auf die Gegenwalze 1 aufgetragen werden, welche dieses Medium sodann auf die andere Seite der Papierbahn 3 überträgt.The other side of the paper web 3 (the top side according to FIG. 1) can remain unchanged when the CB layer is applied to the bottom side. As an alternative to this - similar to Fig. 2, 3 or 4 - any medium, e.g. Water, or starch or any coating color (for example a CF coating color) are applied to the counter roller 1, which then transfers this medium to the other side of the paper web 3.

In der Figur 1 ist angedeutet, daß die Umfangsgeschwindigkeit v1 der Dosierwalze 14 kleiner ist als die Arbeitsgeschwindigkeit v der gesamten Vorrichtung. Hierdurch wird eine besonders feine Dosierung der aufzutragenden CB-Schicht erreicht.In FIG. 1 it is indicated that the peripheral speed v 1 of the metering roller 14 is lower than the working speed v of the entire device. As a result, a particularly fine dosage of the CB layer to be applied is achieved.

Das Ausführungsbeispiel gemäß Figur 2 unterscheidet sich von Figur 1 im wesentlichen nur dadurch, daß anstelle einer normalen Gegenwalze eine Schuhpreßswalze 1' vorgesehen ist. Diese hat einen umlaufenden flexiblen Preßmantel 1a, durch den sich ein stationärer Tragkörper 7 erstreckt. Ein radial beweglicher Preßschuh 5 hat für den Preßmantel 1a eine konkave (und an die Beschichtungswalze 2 angepaßte) Gleitfläche. Er ist in dem Tragkörper 7 geführt und kann den Preßmantel 1a feinfühlig an die Beschichtungswalze 2 anpressen. Gegenüber dem beweglichen Preßschuh 5 ist am Tragkörper 7 ein stationärer Gleitschuh 8 mit einer konvexen Gleitfläche vorgesehen. Hier kann an der Außenseite des Preßmantels 1a eine zusätzliche Zuführ- und Dosiereinrichtung 16 vorgesehen werden.The exemplary embodiment according to FIG. 2 differs from FIG. 1 essentially only in that a shoe press roll 1 'is provided instead of a normal counter roll. This has a circumferential flexible press jacket 1a through which a stationary support body 7 extends. A radially movable press shoe 5 has a concave (and adapted to the coating roller 2) sliding surface for the press jacket 1a. It is guided in the support body 7 and can press the press cover 1a sensitively onto the coating roller 2. Compared to the movable press shoe 5, a stationary slide shoe 8 with a convex slide surface is provided on the support body 7. Here, an additional feed and metering device 16 can be provided on the outside of the press casing 1a.

Gemäß den Figuren 1 und 2 läuft die Papierbahn im wesentlichen von oben nach unten durch den Walzenspalt hindurch. Das umgekehrte ist jedoch ebenfalls möglich, wie die Figuren 3 und 4 zeigen. Man verwendet hierbei Zuführ- und Dosiereinrichtungen CF bzw. 16 oder 16'. Diese sind derart konstruktiv gestaltet, daß sie an der nach unten laufenden Seite des betreffenden Walzenmantels angeordnet werden können. Die an der Gegenwalze 1 der Figur 3 vorgesehene Zuführ- und Dosiereinrichtung 16' bildet zusammen mit dem Walzenmantel einen Flüssigkeitssumpf, während die anderen Zuführ- und Dosiereinrichtungen CF bzw. 16 einen solchen Sumpf vermeiden und deshalb für höhere Arbeitsgeschwindigkeiten geeignet sind.According to FIGS. 1 and 2, the paper web essentially runs through the nip from top to bottom. The reverse is also possible, however, as FIGS. 3 and 4 show. Feed and metering devices CF or 16 or 16 'are used here. These are designed so that they are on the downward-facing side of the relevant Roll shell can be arranged. The feed and metering device 16 'provided on the counter roll 1 of FIG. 3 forms, together with the roll shell, a liquid sump, while the other feed and metering devices CF or 16 avoid such a sump and are therefore suitable for higher working speeds.

Abweichend von den Figuren 1-4 könnte folgendes vorgesehen werden: Die CB-Streichfarbe (und/oder ggf. das auf die Gegenseite aufzutragende Medium) kann mittels einer an sich bekannten Freistrahldüse der betreffenden Walze 2 bzw. 1 zugeführt werden. Danach kann, falls erforderlich, überschüssige CB-Streichfarbe (bzw. überschüssiges Medium) von der Walze abgerakelt werden.Deviating from FIGS. 1-4, the following could be provided: The CB coating color (and / or possibly the medium to be applied to the opposite side) can be fed to the relevant roller 2 or 1 by means of a free jet nozzle known per se. Then, if necessary, excess CB coating color (or excess medium) can be scraped off the roller.

Claims (7)

Verfahren zum Herstellen einer Papierbahn, die auf einer Bahnseite eine sogenannte CB-Schicht aufweist, mit den folgenden Verfahrensschritten: a) Die auf einer Papiermaschine hergestellte rohe Papierbahn führt man durch einen von einer Beschichtungswalze (2) und einer Gegenwalze (1) gebildeten Walzenspalt (a); b) CB-Streichfarbe, die einen in Mikrokapseln eingeschlossenen Farbbildner enthält, wird kontinuierlich auf den umlaufenden Walzenmantel der Beschichtungswalze (2) aufgetragen und dort mittels einer Dosiereinrichtung (z.B. Dosierwalze 14, Rollrakel 11, Streichklinge oder dgl.) dosiert; c) die derart dosierte CB-Streichfarbe wird mittels der rotierenden Beschichtungswalze (2) in dem genannten Walzenspalt auf die Papierbahn (3) übertragen; d) dadurch gekennzeichnet, daß die zwei Walzen (1, 2) derart gegeneinander gedrückt werden, daß im Walzenspalt eine mittlere Flächenpressung von höchstens 2 N/mm2 vorhanden ist. Method for producing a paper web which has a so-called CB layer on one side of the web, with the following method steps: a) The raw paper web produced on a paper machine is passed through a nip (a) formed by a coating roller (2) and a counter roller (1); b) CB coating color, which contains a color former enclosed in microcapsules, is continuously applied to the circumferential roller jacket of the coating roller (2) and metered there by means of a metering device (for example metering roller 14, roller doctor blade 11, doctor blade or the like); c) the CB coating color metered in this way is transferred to the paper web (3) by means of the rotating coating roller (2) in the said nip; d) characterized in that the two rollers (1, 2) are pressed against one another such that an average surface pressure of at most 2 N / mm 2 is present in the roller gap. Verfahren nach Anspruch 1, dadurch gekennzeichnet, daß die mittlere Flächenpressung höchstens 1 N/mm2 beträgt.Method according to claim 1, characterized in that the mean surface pressure is at most 1 N / mm 2 . Verfahren nach Anspruch 1 oder 2, dadurch gekennzeichnet, daß man die im Walzenspalt auftretende Linienkraft - unter Berücksichtigung des Werkstoffes, der Härte und des Elastizitäts-Moduls der Walzenbezüge sowie der Walzendurchmesser - derart wählt, daß, in Bahnlaufrichtung gemessen, eine Spaltlänge (a) von mindestens 5 mm, vorzugsweise 10 bis 20 mm, vorhanden ist.Method according to claim 1 or 2, characterized in that the line force occurring in the nip - taking into account the material, the hardness and the modulus of elasticity of the roll covers and the roll diameter - is selected such that, measured in the direction of web travel, a nip length (a) of at least 5 mm, preferably 10 to 20 mm, is present. Vorrichtung zur Durchführung des Verfahrens nach einem der vorangehenden Ansprüche, mit einer Beschichtungswalze (2), die mit einer Gegenwalze (1) einen Walzenspalt bildet sowie mit einer der freien Mantelfläche der Beschichtungswalze (CB) zugeordneten Zuführ- und Dosiereinrichtung für CB-Streichfarbe,
dadurch gekennzeichnet, daß den zwei Walzen (1, 2) eine Anpreßeinrichtung zugeordnet ist, die zum Einstellen beliebiger Linienkräfte im Bereich bis 80 kN/m geeignet ist.Device for carrying out the method according to one of the preceding claims, with a coating roller (2) which forms a nip with a counter roller (1) and with a feed and metering device for CB coating color assigned to the free outer surface of the coating roller (CB),
characterized in that the two rollers (1, 2) are assigned a pressing device which is suitable for setting any line forces in the range up to 80 kN / m. Vorrichtung nach Anspruch 4, dadurch gekennzeichnet, daß Werkstoff, Härte und E-Modul der Walzenbezüge sowie die Walzen-Durchmesser derart gewählt sind, daß unter Anwendung der genannten Linienkraft eine Walzenspalt-Länge (a) von mindestens 5 mm vorzugsweise 10 bis 20 mm vorhanden ist, gemessen in Bahnlaufrichtung.Apparatus according to claim 4, characterized in that the material, hardness and modulus of elasticity of the roll covers and the roll diameters are selected such that a roll gap length (a) of at least 5 mm, preferably 10 to 20 mm, is present using the said line force is measured in the direction of web travel. Vorrichtung nach Anspruch 4, dadurch gekennzeichnet, daß eine der beiden Walzen einen elastisch verformbaren Preßmantel (1a) aufweist, der über einen Preßschuh (5) gleitet, so daß ein in Bahnlaufrichtung verlängerter Walzenspalt vorhanden ist.Apparatus according to claim 4, characterized in that one of the two rolls has an elastically deformable press jacket (1a) which slides over a press shoe (5), so that a roll gap which is elongated in the web running direction is present. Vorrichtung nach einem der Ansprüche 4 bis 6, dadurch gekennzeichnet, daß die Anpreßeinrichtung einen variablen Krafterzeuger (13) umfaßt, dem ein Kraftspeicher (z.B. Feder 14, Gegendruck-Zylinder oder dgl.) entgegenwirkt.Device according to one of claims 4 to 6, characterized in that the pressing device comprises a variable force generator (13) which is counteracted by a force accumulator (e.g. spring 14, counter-pressure cylinder or the like).
EP96105296A 1996-04-03 1996-04-03 Process and apparatus for applying a CB coat on a paper web Withdrawn EP0799934A1 (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102007029578A1 (en) * 2007-06-26 2009-01-08 Holger Volz Powder coating machine for applying powder layer on laminar designed workpieces, has transmission role and counter-pressure device, between which workpiece is passed through
CN103433173A (en) * 2013-08-20 2013-12-11 张银国 Paper adhesive-dispensing machine with full automatic cover-turning effect

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1433165A (en) * 1973-09-13 1976-04-22 Wiggins Teape Ltd Coated
US4347269A (en) * 1980-04-08 1982-08-31 The Wiggins Teape Group Limited Method of and apparatus for applying a coating to a web of sheet material
EP0385640A2 (en) * 1989-02-23 1990-09-05 The Wiggins Teape Group Limited Process for applying microcapsule-containing compositions to paper
WO1991015306A1 (en) * 1990-04-03 1991-10-17 Btg Källe Inventing Ab Process for two-faced coating of a travelling web
DE4224718A1 (en) * 1992-07-27 1994-02-03 Feldmuehle Ag Stora Paper web coating back application - uses gap between two rollers to apply layer to one side of glue impregnated paper web

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1433165A (en) * 1973-09-13 1976-04-22 Wiggins Teape Ltd Coated
US4347269A (en) * 1980-04-08 1982-08-31 The Wiggins Teape Group Limited Method of and apparatus for applying a coating to a web of sheet material
EP0385640A2 (en) * 1989-02-23 1990-09-05 The Wiggins Teape Group Limited Process for applying microcapsule-containing compositions to paper
WO1991015306A1 (en) * 1990-04-03 1991-10-17 Btg Källe Inventing Ab Process for two-faced coating of a travelling web
DE4224718A1 (en) * 1992-07-27 1994-02-03 Feldmuehle Ag Stora Paper web coating back application - uses gap between two rollers to apply layer to one side of glue impregnated paper web

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102007029578A1 (en) * 2007-06-26 2009-01-08 Holger Volz Powder coating machine for applying powder layer on laminar designed workpieces, has transmission role and counter-pressure device, between which workpiece is passed through
DE102007029578B4 (en) * 2007-06-26 2010-05-12 Holger Volz powder coater
CN103433173A (en) * 2013-08-20 2013-12-11 张银国 Paper adhesive-dispensing machine with full automatic cover-turning effect
CN103433173B (en) * 2013-08-20 2015-08-05 张银国 Automatically renovate scraps of paper glue spreader

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