PatentDe  


Dokumentenidentifikation EP0776273 26.10.2000
EP-Veröffentlichungsnummer 0776273
Titel VERFAHREN UND VORRICHTUNG ZUM AUFBRINGEN EINER BESCHICHTUNG AUF BÖGEN
Anmelder Minnesota Mining and Mfg. Co., Saint Paul, Minn., US
Erfinder VOGEL, S., Mark, Saint Paul, US;
STIFTER, F., Gregory, Saint Paul, US;
PIERRE, R., Bernard, Saint Paul, US;
LE RICHE, P., Frederic, Saint Paul, US
Vertreter Patentanwälte von Kreisler, Selting, Werner et col., 50667 Köln
DE-Aktenzeichen 69518925
Vertragsstaaten DE, FR, GB, IT
Sprache des Dokument EN
EP-Anmeldetag 13.07.1995
EP-Aktenzeichen 959256413
WO-Anmeldetag 13.07.1995
PCT-Aktenzeichen US9508772
WO-Veröffentlichungsnummer 9605066
WO-Veröffentlichungsdatum 22.02.1996
EP-Offenlegungsdatum 04.06.1997
EP date of grant 20.09.2000
Veröffentlichungstag im Patentblatt 26.10.2000
IPC-Hauptklasse B42C 3/00
IPC-Nebenklasse B42C 9/00   

Beschreibung[en]
Technical Field

The present invention relates to an apparatus and method for applying coating material to both opposing major surfaces of a plurality of individual sheets, for example sheets of paper.

Background of the Invention

It is necessary in certain fields to apply coating material to paper and, in some cases, to apply different coating materials to the two opposing major surfaces of the paper. For example, in the production of so-called repositionable notes it is known to apply a primer material to one side of the paper from which the repositionable notes will be cut and to apply a low adhesion backsize, or release, material to the other side of the paper. The repositionable adhesive is applied to the paper on top of the primer material. Conventionally, for the production of repositionable notes, the various coatings are applied to a web of paper from a roll. The coating materials are dispersed in solvents and coated directly on the paper. The web is dried between coatings and then rewound and the coated roll is subsequently cut into sheets which are used to produce the notes. When the paper web is coated with materials dispersed in an organic solvent and is under tension when the coatings are applied, the tendency of the paper web to curl or wrinkle can be substantially eliminated, otherwise great care is required to balance the paper sheet's expansion during coating.

A process for the production of repositionable notes, in which a release material and a primer material are coated successively on opposite sides of a paper web is described in WO-A-87/05315. In some cases, it is desirable to apply coating material to cut sheets rather than to a web of paper. For example, in the production of repositionable notes it is desirable to have the option of using a stack of preprinted sheets as the supply source, instead of a plain paper web, to extend the flexibility of the production process. In addition, for environmental reasons, there is a desire to move away from the use of materials containing organic solvents in coating processes towards the use of water-based materials. Moreover, many inks are soluble in organic solvents, but insoluble in water. Problems can arise, however, in applying coating materials (and, particularly, water-based coating materials) to individual sheets because the risk that the sheets will curl or wrinkle is greatly increased. Any curling or wrinkling not only spoils the appearance of the sheets but can also make it difficult to apply further coating materials.

Co-pending U.S. Patent Application Serial No. 08/196,490 filed February 15, 1994 entitled "Method" and Apparatus for Applying a Coating Material to a Sheet", discloses apparatus and a method for forming pads of repositionable notes from a stack of uncoated individual paper sheets. The sheets are fed from the stack in an overlapped condition to a coating station in which a continuous layer of a water-based primer material is applied to one major surface of the web-like overlapped sheets and a continuous layer of a water-based low adhesion backsize (LAB) material is applied simultaneously to the other major surface. The overlapped sheets are then dried and fed to a second coating station in which stripes of repositionable adhesive are applied to the web-like overlapped sheets on the surface to which the primer was applied in the first coating station. Thereafter, the sheets are adhered together in a stack and trimmed to form pads of repositionable notes. In that process, curling or wrinkling of the sheets is avoided by applying the primer and LAB coatings simultaneously to both sides of the sheets and then drying both coatings simultaneously.

EP 684 974 is a document falling under Art. 54(3) EPC and comprised in the state of the art of the present application, as far as novelty is concerned.

This document discloses an apparatus for coating overlapped sheets by (i) simultaneously applying an aqueous primer to a first major surface of the overlapped sheets and an aqueous low adhesion backsize to a second major surface of the overlapped sheets, (ii) drying the coatings, and then (iii) applying a further coating onto the primed first major surface of the sheets by (A) disposing the further coating material onto a transfer surface, and (B) transferring the coating material from the transfer surface to the overlapped sheets by contacting the overlapped sheets with the transfer surface as the sheets are conveyed past the transfer surface.

However, it has been found that existing systems for applying a coating material to sheets, including the aforementioned U.S. Patent Application Serial No. 08/196,490, while having their own utility, are not as effective or efficient as desired in coating some materials onto certain sheet materials. Therefore, an object of the present invention is to provide an improved method and apparatus for applying a coating material onto sheets.

This object has been achieved by the present invention as defined in the methods according to claims 1 and 10 and in the apparatus according to claim 17.

The dependent claims define further advantageous embodiments of the invention.

Brief Description of the Drawings

Embodiments of the invention will be described, by way of example, with reference to the accompanying drawings, wherein like structure is referred to by like numerals in the several views, and in which:

  • Figure 1 is a schematic side view of apparatus which includes a coating station, in accordance with the invention;
  • Figure 2 is a schematic top view of the apparatus shown in Figure 1;
  • Figure 3 is a view of a coating station forming part of the apparatus shown in Figure 1;
  • Figure 4 is a view similar to Figure 3 showing part of the coating station in greater detail;
  • Figure 5 shows a coating material supply system for the coating station of Figs. 3 and 4;
  • Figure 6 is a diagrammatic side view of part of an adhesive coating station at the downstream end of the apparatus shown in Figure 1 with an alternative coating section;
  • Figure 7 is a diagrammatic side view of a modified version of the apparatus shown in Figure 1 with an alternative guiding section; and
  • Figure 8 is an enlarged partial view of part of Figure 4.

Detailed Description of the Invention

The apparatus shown schematically in Figure 1 and 2 is specifically for use in the production of repositionable notes from sheets of any suitable substrate material, example, paper, polymeric film or foils, such as metallic foils and, in particular, for the application to individual sheets of a primer material, a low adhesion backsize (LAB) material, and a repositionable adhesive so that the sheets can subsequently be used to form repositionable notes. In the following description, it will be assumed that the sheets (which may be pre-printed) are of paper. The paper may be any suitable paper, such as the paper utilized to construct the Post-it® brand repositionable notes available from Minnesota Mining and Manufacturing Company ("3M") of St. Paul, Minnesota. In the following description, it will be assumed, unless otherwise noted, that the sheets (which may be pre-printed) are of paper.

The apparatus has a paper path entry 1 which receives a succession of paper sheets (not shown) from any suitable source, for example a stack. From the paper path entry 1, the sheets travel in the direction indicated by the arrow 2 through a double coating station 3, a sheet overlapping station 4, a dryer 5, a sheet guiding section 6. Conveniently, the apparatus may be used in conjunction with an adhesive coating station 7. The coating station 7 may be any quitable coating station, but the present invention is most conveniently used in conjunction with the coating station disclosed in co-pending United States patent application filed of even date herewtih, entitled "Method and Apparatus for Applying a Coating Material to Sheets", and commonly assigned to the Assignee of the present invention, and the contents of that co-pending application are incorporated herein by reference. Alternatively, the output of the present invention may be stored, such as in stacked form and independently and subsequently coated with a separate coating station. The control and synchronization of the drives of the various stations may be performed by a central electronic control unit (not shown), for example a Siemens PLC 135.

Individual sheets arrive one after another at the paper path entry 1 of the apparatus and are fed by a nip roll pair 10 into the double coating station 3 (shown in greater detail in FIGs. 3 and 4). It is one of the advantages of the present invention, as compared to other arrangements, such as in the above identified co-pending U.S. Patent Application Serial No. 08,196,490 filed February 15, 1994 entitled "Method and Apparatus for Applying a Coating Material to a Sheet", that the sheets are fed into the coating station in a non-overlapped condition. This exposes all, or a substantial portion, of both major surfaces of the sheets to coating by the LAB and the primer. Further, handling of the sheets is more convenient, since the "pseudo-web" is of uniform thickness.

The sheets are preferably all of the same size, for example A2, and weight, for example 70 gsm. The paper may be of any convenient weight, including, but not limited to papers having a weight between 45 grams per square meter (gsm) and 90 gsm. The double coating station 3 comprises an upper coating station 11 and a lower coating station 12 located, respectively above and below the paper path. As the sheets pass through the double coating station the upper station 11 applies a coating of primer material to one side of each sheet and the lower station 12 simultaneously applies a coating of LAB material to the other side of each sheet. In one embodiment of the present invention, the primer material and the LAB material are coated over substantially both major surfaces of the sheets. Typically, mechanical means are used to grip and advance the sheets through the apparatus, preventing the primer and LAB to be coated over the entire major surfaces of the sheets.

Paper is commonly formed by accumulating paper fibers on a wire mesh or screen and compressing the accumulated fibers between the screen and a "felt" or cloth layer opposite the screen layer. This produces paper having a "wire" side and a "felt" side. It has also been found advantages to convey the sheets S through the apparatus of the present invention with the "wire" side presented for coating of the release material and the "felt" side presented for coating of the primer and ultimately for coating of the adhesive.

The primer material may, for example, be a water-based solution of an organic binding agent and a cleaved mineral pigment. More specifically, the primer material may be obtained by mixing approximately 3-7% by weight of the binding agent MOWIOL (Trade Mark) available from Hoechst AG, Frankfurt/Main, Germany and approximately 3-8% by weight of the pigment AEROSIL (Trade Mark) available from Degussa AG, Frankfurt/Main, Germany with approximately 90% by weight of water.

The LAB material may be any suitable material, including, but limited to, acrylate co-polymers, silicone materials, urethanes, and fluoro polymers. For example, the LAB may be a water-based solution of the material described in co-pending United States patent applicaiton Serial No. 08/040,876, filed March 31, 1994 and commonly assigned to the Assignee of the present invention, the contents of which are incorporated herein by reference. The solution comprising typically from about 5% to about 10% solid material. Other LAB materials that may be employed with the present invention include those disclosed in United States Patent Nos. 5,202,190 and 5,032,460.

The upper coating station 11 comprises a metering roller 13 and a coating roller 14, located above the path of the sheets of paper throught he double coating station. The coating roller 14 cooperates with a coating drum 16 of the lower coating station 12 which also comprises a metering roller 17 and a transfer roller 18, all located below the paper path through the double coating station. The coating drum 16 has a cut-out portion 9 of rectangular cross-section (shown in greater detail in Figure 8) which contains a conventional sheet gripper 9A (shown closed in Figure 8) for grasping sheets from the feed nip 10. In addition, the drum is covered, around less than half its circumference, with a blanket 20 (not shown in Fig. 8) whereby, as described below, the coating roller 14 and coating drum 16 form a coating nip only when the blanket is located directly adjacent the coating roller 14. As described below, the upper coating station 11 provides substantially full surface roll coating of primer material on the upper surface of the sheets, and the lower coating station 12 provides substantially full surface roll coating of LAB material on the lower surface of the sheets. In each case, the portions engaged with the grippers (as described herein) are not coated.

In the upper coating station, a trough 15 for the printer material is formed by the surfaces of the metering and coating rollers 13, 14 adjacent the nip between the rollers and on the upper side thereof together with two opposed end walls (not shown) which engage in grooves (not shown) adjacent the ends of the rollers. As the rollers 13, 14 rotate, the primer material forms a film on the coating roller 14 and is transferred to a sheet passing underneath the roller.

The thickness of the primer film on the coating roller 14, and hence the amount of primer coated onto a sheet, is dependent on the viscosity of the primer and on the pressure between the metering and coating rollers 13, 14 and, for a given primer, can be adjusted by moving the metering roller towards or away from the coating roller thereby adjusting the pressure between the rollers. The trough 15 is supplied with primer by nozzles 60 (see also Figure 5) which receive the primer from a tank 61 by means of a pump 62. The trough 15 also has overflow outlets 63 through which excess primer is returned to the tank.

In the lower coating station 12, a trough 19 for LAB material is similarly formed between the metering roller 17 and the transfer roller 18. As in the upper station, the coating material forms a film on the transfer roller, the thickness of which can be adjusted by moving the metering roller 17 towards or away from the transfer roller 18, thereby controlling the amount of LAB material that passes from the transfer roller to the blanket covering 20 on the coating drum 16 (but not on to the remainder of the drum, which the transfer roller 18 does not contact).

In a similar manner to the trough 15 in the upper coating station 11, the trough 19 is supplied with LAB material by respective nozzles 60A (see also Figure 5) which receive the LAB material from a respective tank 61 A by means of a pump 62A. The trough 19 has overflow outlets 63A through which excess LAB material is returned to the tank 61A. As the blanket covers part of the drum 16 moves around adjacent the coating roller 14 of the upper station, a sheet that is incoming from the feed nip 10 of the double coating station 3 will be picked-up by the gripper 9A in the drum and carried through the coating nip between the roller 14 and the blanket 20 on the drum 16 and, as the sheet passes through the nip, it will be coated on one side with the LAB material. Sheet strippers (not shown) are located on the downstream sides of the coating roller and the coating drum to ensure that sheets do not wrap around either the roller or the drum but are fed out to the overlapping station 4. The next sheet from the feed roll nip 10 will be picked up and carried between the coating roller and the coating drum when the blanket covering once again moves around adjacent the roller 14.

It will be appreciated that the coating in the double coating station 3 is discontinuous because it occurs only when the blanket covering 20 on the coating drum 16 is adjacent the coating roller 14 (i.e. when a sheet is passing through the coating nip). A typical coating weight for the LAB material on the sheets is from about 0.5 gsm to about 12.0 gsm and the coating weight of the primer material would be matched to that to ensure that the coated sheets remain flat. Because the primer and the LAB materials are applied to the paper sheets simultaneously in the coating station and are preferably selected to have appropriately selected characteristics, such as viscosity, % solids, coating weights, the risk that the sheets will curl or wrinkle is substantially eliminated.

The blanket covering 20 on the coating drum 16 can be of any suitable type, for example a DuPont "CYRELL" polyurethane blanket available from E.I. DuPont Demours of Wilmington, Delaware.

On the exit side of the coating nip 14, 16, in the sheet overlapping station 4 a gripper unit 27 is positioned to take sheets as they emerge from the coating nip and deposit them on a conveyor 30 (not shown in Figure 4). The gripper unit 27, which is conventional, comprises sheet grippers 28 carried on an endless chain 29 the movement of which is synchronized with the sheet feed so that a gripper 28 is positioned to receive each sheet that leaves the coating nip. A blower 31, located below the paper path on the exit side of the coating nip, provides a cushion of air to support the sheet as they are being carried by the sheet grippers 28. The blower 31 incorporates a heater (not shown) which serves to dry the LAB coating on the sheet to some extent, to prevent the sheets from sticking to the conveyor The conveyor 30 is run at a slower speed than the chain 29 of the gripper unit so that each sheet is deposited on the conveyor with the leading edge of the sheet lying on top of the trailing edge of the preceding sheet, forming a pseudo-web of sheets Typically, the extent of the overlap is from about 1 centimeter (cm) to about 2 cm The conveyor 30 is a vacuum conveyor connected to a source 32 of low pressure so that the sheets are positively held on the conveyor and the overlapped relationship between them is maintained.

At the output end of the conveyor 30, the sheets pass over an air knife 33 which is arranged to reverse the direction in which the sheets are overlapped. The air knife 33 is arranged to direct a current of air at the sheets so that the trailing edge of each sheet is moved out from underneath the leading edge of the succeeding sheet and deposited instead on top of that leading edge. Instead of using an air knife 33 to change the direction of overlap of the sheets, an equivalent mechanical arrangement could be employed, for example an arrangement similar to that described in GB-A-2 166 717.

The double coating station 3 together with the sheet overlapping station 4 may be based on the "GUILA SPEED GS GS 8000" coater available from Billhofer Maschinenfabrik GmbH of Nürnberg, Germany.

Returning to Figure 1, the pseudo-web of sheets now moves out of the sheet overlapping station 4 and into the dryer 5 in which moisture is removed from the primer and LAB coatings. The dryer 5 is preferably a radio-frequency dryer, for example a particularly adapted version of the Model No. SP 890 GF"C" -AG manufactured by Proctor Strayfield Ltd. of Berkshire, England. The dryer 5 is provided with a control unit (not shown) which adjusts the power of the dryer in accordance with the line speed of the apparatus. That control unit may, for example, be a Siemens PLC 55 95U interconnected with the central electronic control unit of the whole apparatus. The overlapped sheets move through the dryer 5 continuously on an endless belt 40 and are dried to attenuate the tendency of the sheets to curl but which ensures that they emerge substantially dry. The use of a radio-frequency dryer is not essential and the overlapped sheets could, instead, be dried using infra-red heating or hot air. Alternatively, the endless belt 40 could be heated to dry the sheets. However, radio-frequency drying is preferred for its simplicity and lower energy consumption.

Downstream of the dryer 5, the overlapped sheets move through the guiding section 6 in which they are side registered and aligned with each other in preparation for advancement to further processing stations, such the adhesive coating station 7, previously identified as the subject of a co-pending United States patent application filed of even date herewith, entitled "Method and Apparatus for Applying a Coating Material to Sheets", and commonly assigned to the Assignee of the present invention. As described in the above indicated co-pending application, the overlapped sheets pass through a transfer nip 50 (see also Fig. 6) where they contact an endless transfer belt 51 to which an adhesive coating has previously been applied in the form of a plurality of stripes extending longitudinally of the belt. The adhesive may be a pressure-sensitive adhesive, preferably a repositionable microsphere pressure-sensitive adhesive, for example as described in U.S. Patent No. 4,495,318 to Howard, or U.S. Patent No. 3,691,140 to Silver. Adhesives for use with the present invention also includes film-forming materials known in the art, including those containing organic solvents.

At the transfer nip 50, the adhesive is transferred in continuous stripes to the pseudo-web of overlapped sheets on the surface to which primer was applied in the double coating station 3. The adhesive-coated sheets are then pulled away from the transfer belt 51 at a vacuum roller 52 (shown in Figure 6) the interior of which is connected to a source of low pressure. The removal of the sheets from the transfer belt 51 is facilitated by the direction in which the sheets overlap (i.e. by the fact that the air knife 33 has caused the leading edge of each sheet to underlap the trailing edge of the preceding sheet). Following removal from the transfer belt 51, the sheets are held to a vacuum belt 53 which passes around the roller 52 and carries the sheets (still overlapped) out of the adhesive coating station 7 to the sheet exit 8 of the apparatus. The sheets may then be stacked and trimmed to form pads of repositionable notes, for example those available under the trademark "Post-it"® available from the Minnesota Mining and Manufacturing Company ("3M") of St. Paul, Minnesota.

Although the above description refers to the sheets as being paper, they could (as already mentioned) be formed of other materials, for example polymeric films or metallic foils, as previously described. When the sheets are paper, they are preferably fed through the apparatus with the "machine direction" of the paper sheets aligned with the machine process direction; in that way, the tendency of the sheets to curl or wrinkle can be further attenuated.

Papers of different weights and textures can be used if desired. For example, although the above description refers to a sheet size of A2, the described apparatus is readily adaptable to handle sheets of A4 size. Likewise, although the above description refers to sheets of weight 70 gsm, the apparatus could also handle sheets of a higher weight (e.g. 90 gsm) and sheets of a lower weight (e.g. 70 gsm and possibly even as low as 45 gsm).

If the sheets supplied to the double coating station 3 are pre-printed, the above-described method results in the LAB coating material being applied over the printed matter on the sheets. The LAB coating then serves to protect the printed matter, especially against removal by the adhesive on an adjacent sheet when the sheets are subsequently stacked and cut to form pads of repositionable notes. The protection offered by the LAB coating enables the use of stronger adhesives on printed notes to be considered. Of course, the sheets maybe printed on after the double coating station 3, whether or not pre-printed, using any conventional printing operation.

Although it is advantageous for the primer and LAB coating to be applied to the sheets simultaneously in the double coating station 3 as described above, that is not essential. However, the simultaneous application of the coatings is preferred, particularly when the coating materials are water-based, since it assists in maintaining the sheets in a flat condition.

Apparatus in which the primer and LAB coatings are not applied simultaneously is illustrated in Fig. 7. In that apparatus, the primer coating station 11 is located prior to the LAB coating station 12 and, consequently, the coating roller 14 of the upper station 11 and the coating drum of the lower station 12 both require a respective counter-pressure roller 14A, 16A. In each coating station, the arrangement for supplying coating material to the coating roller/drum also differs from that shown in Fig. 1 in that, in each case, the metering roller 13, 17 dips into a respective tank 13A, 17A of coating material and applies the coating material to a respective transfer roller which, in turn, applies the coating material to the coating roller/drum 14, 16. The remainder of the apparatus shown in Fig. 7 (comprising the overlapping station 4, the dryer 5, the guiding section 6 and the adhesive transfer station 7) is effectively as described above with reference to Fig. 1.

The present invention has now been described with respect to several embodiments thereof. It will be apparent to those skilled in the art that many changes may be made in the embodiments described without departing from the scope of the invention. Thus, the scope of the present invention should not be limited to the structures and processes described herein, but rather by the definitions of the claims.


Anspruch[de]
  1. Verfahren zum Aufbringen eines Beschichtungsmaterials auf Wasserbasis auf die beiden gegenüberliegenden Hauptflächen mehrerer Blattelemente, wobei das Verfahren folgende Schritte aufweist:
    • (a) sequentielles Transportieren der Blattelemente entlang eines Blattweges;
    • (b) gleichzeitiges Aufbringen eines Beschichtungsmaterials auf Wasserbasis (9,11,12) auf beide Hauptflächen jedes einzelnen Blattelements während des Transports der Blattelemente entlang des Blattweges;
    • (c) sequentielles Anordnen (4) der beschichteten Blattelemente mit sich überlappenden Enden und Weitertransport der Blattelemente entlang des Blattweges;
    • (d) Trocknen (5) der beschichteten Blattelemente; und
    • (e) kontinuierliches Aufbringen (7) weiteren Beschichtungsmaterials auf mindestens eine Hauptfläche der sich überlappenden Blattelemente während des Transports der Blattelemente entlang des Blattweges.
  2. Verfahren nach Anspruch 1, bei dem Schritt (c) umfasst:
    • (f) sukzessives Ablegen der Blattelemente auf der Transporteinrichtung (10), wodurch der Vorderkantenbereich jedes Blattelements auf dem Hinterkantenbereich des vorangehenden Blattelements abgelegt wird, und
    • (g) Ändern (4) der relativen Positionen der Blattelemente, wodurch vor dem Auftragen von weiterem Beschichtungsmaterial auf Wasserbasis der Hinterkantenbereich jedes Blattelements über dem Vorderkantenbereich des nachfolgenden Blattelements liegt.
  3. Verfahren nach Anspruch 2, bei dem Schritt (b) das Aufbringen (11) eines Grundiermaterials auf Wasserbasis auf einen Hauptbereich einer Hauptfläche des Blattelements und (12) eines rückseitenformatierten Materials auf Wasserbasis mit geringer Haftkraft auf einen Hauptbereich der anderen Hauptfläche des Blattmaterials umfasst.
  4. Verfahren nach Anspruch 2, bei dem Schritt (e) kontinuierliches Auftragen mindestens eines Streifens Haftmaterials auf Wasserbasis auf eine Hauptfläche der sich überlappenden Blattelemente umfasst.
  5. Verfahren nach Anspruch 1, bei dem Schritt (d) teilweises Trocknen einer Hauptfläche jedes Blattelements vor dem überlappenden Anordnen der Blattelemente und dann gleichzeitiges Trocknen beider Hauptflächen der sich überlappenden Blattelemente umfasst.
  6. Verfahren nach Anspruch 1, bei dem Schritt (d) gleichzeitiges Trocknen beider Hauptflächen der sich überlappenden Blattelemente umfasst.
  7. Verfahren nach Anspruch 3, bei dem jedes Blattelement eine aus Filz bestehende Hauptfläche und eine aus Draht bestehende Hauptfläche aufweist, und bei dem Schritt (a) den Schritt des Ausrichtens der Blattelemente umfasst, derart, dass das Grundiermaterial auf der Filzseite der Blattelemente und das rückseitenformatierte Material mit geringer Haftkraft auf der aus Draht bestehenden Hauptfläche des Blattelements aufgebracht wird.
  8. Verfahren nach Anspruch 1, bei dem das Beschichtungsmaterial auf Wasserbasis in ausgerichteten Zonen auf gegenüberliegenden Hauptflächen der Blattelemente aufgebracht wird.
  9. Verfahren nach Anspruch 1, bei dem die Blattelemente aus Papier bestehen und Schritt (a) folgenden Schritt umfasst:

    (h) Ausrichten der Bearbeitungsrichtung der Papierblattelemente mit dem Blattweg, damit verhindert wird, dass die Blattelemente sich aufrollen und zerknittern.
  10. Verfahren zum Auftragen von Beschichtungsmateriallen auf Wasserbasis auf beide Hauptflächen mehrerer Blattelemente, wobei das Verfahren folgende Schritte umfasst:
    • (a) sequentielles Transportieren der Blattelemente entlang eines Blattweges;
    • (b) gleichzeitiges Aufbringen (3) eines Grundiermaterials auf Wasserbasis auf eine Hauptfläche jedes Blattelements und eines rückseitenformatierten Materials auf Wasserbasis mit geringer Haftkraft auf die andere Hauptfläche des Blattmaterials während des Transports der Blattelemente entlang des Blattweges;
    • (c) sukzessives Ablegen der Blattelemente auf einer Transporteinrichtung im Blattweg, wodurch der Vorderkantenbereich jedes Blattelements zur Bildung einer Pseudobahn sich überlappender Blattelemente (4) auf dem Hinterkantenbereich des vorangehenden Blattelements abgelegt wird;
    • (d) Leiten eines Luftstroms (33) an den sich überlappenden Blattelementen zum sequentiellen Ändern der relativen Überlappungspositionen der Blattelemente, wodurch der Hinterkantenbereich jedes Blattelements über dem Vorderkantenbereich jedes vorangehenden Blattelements liegt; und
    • (e) Trocknen (5) der sich überlappenden Blattelemente während des Transports entlang des Blattweges.
  11. Verfahren nach Anspruch 10, ferner mit folgendem Schritt:

    (f) Auftragen (7) eines Haftmaterials auf Wasserbasis auf die sich überlappenden Blattelemente während des Transports entlang des Blattweges, wobei das Haftmaterial auf diejenige Hauptfläche der Blattelemente aufgebracht wird, auf die in Schritt (b) Grundiermaterial aufgebracht worden ist.
  12. Verfahren nach Anspruch 10, bei dem zumindest einige der Blattelemente zumindest auf derjenigen Hauptfläche vorbedruckt sind, auf die in Schritt (b) das rückseitenformatierte Material mit geringer Haftkraft aufgebracht worden ist.
  13. Verfahren nach Anspruch 10, bei dem Schritt (e) folgende Schritte umfasst:
    • (i) Transportieren der sich überlappenden Blattelemente entlang des Blattweges auf einem Band, das nicht auf Hochfrequenzstrahlung reagiert; und
    • (ii) Bestrahlen der Materialien auf Wasserbasis auf den Blattelementen mit Hochfrequenzstrahlung zwecks Reduzierung des Wassergehalts der Materialien auf Wasserbasis auf einen gewünschten Pegel.
  14. Verfahren nach Anspruch 10, ferner mit dem Schritt des teilweisen Trocknens der Blattelemente nach Durchführen von Schritt (b) auf derjenigen Hauptfläche, die dann auf der Transporteinrichtung abgelegt wird.
  15. Verfahren nach Anspruch 10, bei dem sich die Blattelemente um ungefähr 1 cm bis 2 cm überlappen.
  16. Verfahren nach Anspruch 11, mit dem Schritt des Ausrichtens der Blattelemente vor dem Auftragen des Haftmaterials in Schritt (f).
  17. Vorrichtung zum Aufbringen eines Beschichtungsmaterials auf Wasserbasis auf beide Seiten mehrerer Blattelemente, wobei die Vorrichtung aufweist:
    • (a) eine Transporteinrichtung zum sequentiellen Transportieren der Blattelemente entlang eines Blattweges;
    • (b) eine Doppelbeschichtungsstation (3) zum sequentiellen Empfangen der Blattelemente von der Transporteinrichtung, wobei die Doppelbeschichtungsstation eine erste (11) und eine zweite (12) Beschichtungsstation auf gegenüberliegenden Seiten des durch die Doppelbeschichtungsstation führenden Blattweges aufweist, wobei die erste und die zweite Beschichtungsstation jeweils eine Quelle des Beschichtungsmaterials auf Wasserbasis und jeweils ein Beschichtungselement zum Berühren der Blattelemente an einer Stelle auf dem Blattweg umfasst, damit Beschichtungsmaterial von der jeweiligen Quelle auf die jeweilige Seite jedes Blattelements aufgebracht wird, wobei die Beschichtungselemente in der ersten und der zweiten Beschichtungsstation der Doppelbeschichtungsstation einander gegenüberliegende Beschichtungsrollen (14) aufweisen, die auf gegenüberliegenden Seiten des Blattweges angeordnet sind und somit eine Berührungsstelle für die Beschichtung bilden, wodurch Beschichtungsmaterial gleichzeitig auf beide Seiten eines die Berührungsstelle durchlaufenden Blattelements aufgetragen wird;
    • (c) eine Überlappungs-Transporteinrichtung, die Blattelemente von der Doppelbeschichtungsstation empfängt und mit einer solchen Geschwindigkeit bewegt werden kann, dass der Vorderkantenbereich jedes die Doppelbeschichtungsstation verlassenden Blattelements auf dem Hinterkantenbereich des vorangehenden Blattelements auf der Transporteinrichtung abgelegt wird, wodurch eine Pseudobahn sich überlappender Blattelemente gebildet wird;
    • (d) ein Luftmesser (33), das derart angeordnet ist, dass es einen Luftstrom an den sich überlappenden Blättern so leitet, dass die relativen Positionen der Blätter in der Pseudobahn verändert werden, wodurch der Hinterkantenbereich jedes Blattelements über dem Vorderkantenbereich des nachfolgenden Blattelements liegt; und
    • (e) eine Trocknungseinrichtung (5) im Blattweg zum Entfernen von Wasser aus dem in der Doppelbeschichtungsstation auf die Blattelemente aufgebrachten Beschichtungsmaterial.
  18. Vorrichtung nach Anspruch 17, ferner mit:

    (f) einer weiteren Beschichtungsstation (7) mit einer Quelle des Beschichtungsmaterials auf Wasserbasis und einem Beschichtungselement zum Berühren der Pseudobahn aus sich überlappenden Blattelementen an einer Stelle des Blattweges zwecks Aufbringens von Beschichtungsmaterial von der jeweiligen Quelle auf eine Seite der Pseudobahn aus sich überlappenden Blattelementen.
  19. Vorrichtung nach Anspruch 17, mit einem Abdeckelement (20) über einem Teil des Umfangs einer der Beschichtungsrollen, wodurch die Berührungsstelle für die Beschichtung nur dann gebildet wird, wenn dieser Teil der Rolle an die andere Beschichtungsrolle angrenzt.
  20. Vorrichtung nach Anspruch 19, bei der die eine Beschichtungsrolle (14) eine Blattgreifeinrichtung (9) zum Ziehen jedes Blattelements durch die Berührungsstelle für die Beschichtung aufweist.
  21. Vorrichtung nach Anspruch 20, mit einer weiteren hinter der Doppelbeschichtungsstation angeordneten Blattgreifeinrichtung zum Entfernen jedes Blattelements aus der Doppelbeschichtungsstation und Ablegen des Blattelements auf der Überlappungs-Transporteinrichtung.
  22. Vorrichtung nach Anspruch 17, mit einem Gebläse (31) zum Erzeugen eines Luftkissens, welches die Blattelemente während des Entfernens aus der Doppelbeschichtungsstation hält.
  23. Vorrichtung nach Anspruch 22, bei der das Gebläse eine Heizeinrichtung zum teilweisen Trocknen der Blätter auf derjenigen Seite aufweist, die dann auf der Überlappungs-Transporteinrichtung abgelegt wird.
  24. Vorrichtung nach Anspruch 17, bei der der Trockner (5) eine Transporteinrichtung aufweist, die nicht auf Hochfrequenzstrahlung reagiert und derart angeordnet ist, dass sie das überlappende Blattelement entlang eines Teils des Blattweges transportiert, und eine Quelle der Hochfrequenzstrahlung aufweist, die auf das Beschichtungsmaterial auf Wasserbasis auf den Blattelementen gerichtet ist.
  25. Vorrichtung nach Anspruch 18, ferner mit einer im Blattweg angeordneten Ausrichtstation zum Ausrichten der sich überlappenden Blattelemente vor deren Eintritt in die weitere Beschichtungsstation.
  26. Vorrichtung nach Anspruch 18, bei der das Beschichtungselement in der weiteren Beschichtungsstation ein Transferband (51) mit einer Transferfläche aufweist, welche die sich überlappenden Blattelemente an einer Stelle am Blattweg berührt.
Anspruch[en]
  1. A method for applying water-based coating material to both opposing major surfaces of a plurality of sheet members by
    • (a) conveying the sheet members sequentially along a sheet path;
    • (b) applying water-based coating material (3,11,12) simultaneously to both major surfaces of each sheet member individually as the sheet members are being conveyed along the sheet path;
    • (c) arranging (4) the coated sheet members in sequential end-to-end overlapping relation and continuing to convey the sheet members along the sheet path; and
    • (d) drying (5) the coated sheet members,
    • (e) continuously applying (7) further coating material to at least one major surface of the overlapped sheets members as the sheet members are being conveyed along the sheet path.
  2. A method as claimed in claim 1, in which step (c) comprises:
    • (f) depositing the sheet members successively on conveying means (10) whereby the leading edge portion of each sheet member is deposited on the trailing edge portion of the preceding sheet member, and
    • (g) changing (4) the relative positions of the sheet members whereby the trailing edge portion of each sheet member overlies the leading edge portion of the succeeding sheet member before the application of the further water based coating material.
  3. A method as claimed in claim 2, in which step (b) comprises applying (11) water-based primer material over a major portion of one major surface of the sheet member and (12) water-based low adhesion backsize material over a major portion of the other major surface of the sheet member.
  4. A method as claimed in claim 2, in which step (e) comprises continuously applying at least one stripe of water-based adhesive material to one major surface of the overlapped sheet members.
  5. A method as claimed in claim 1, in which step (d) comprises partially drying one major surface of each sheet member before the sheet members are arranged in overlapping relation and then drying both major surfaces of the overlapped sheet members simultaneously.
  6. A method as claimed in claim 1, in which step (d) comprises drying both major surface of the overlapped sheet members simultaneously.
  7. A method as claimed in claim 3, wherein the sheet member each include a felt major surface and a wire major surface, and wherein step (a) includes the step of orienting the sheet members so that the primer material is coated on the felt side of the sheet members and the low adhesion backsize material is coated on the wire major surface of the sheet member.
  8. A method as claimed in claim 1, wherein the water-based coating material is applied in aligned zones on opposing major surfaces of the sheet members.
  9. A method as claimed in claim 1, in which the sheet members are paper and step (a) includes the step of:

       (h) aligning the machine direction of the paper sheet members with the sheet path to attenuate curling and wrinkling of the sheet members.
  10. A method for applying water-based coating materials to both major surfaces of a plurality of sheet members by
    • (a) conveying the sheet members sequentially along a sheet path
    • (b) applying simultaneously (3) a water-based primer material to one major surface of each sheet member and a water-based low adhesion backsize material to the other major surface of each sheet member as the sheet members are being conveyed along the sheet path;
    • (c) depositing the sheet members successively on conveying means in the sheet path, whereby the leading edge portion of each sheet member is deposited on the trailing edge portion of the preceding sheet member to form a pseudo-web of overlapped sheet members (4);
    • (d) directing a current of air (33) at the overlapped sheet members to sequentially change the relative overlapped positions thereof, whereby the trailing edge portion of each sheet member overlies the leading edge portion of each succeeding sheet member; and
    • (e) drying (5) the overlapped sheet members as they are being conveyed along the sheet path.
  11. The method of claim 10, further including the step of:

       (f) applying (7) a water-based adhesive material to the overlapped sheet members as they are being conveyed along the sheet path, the adhesive material being applied to the sheet members on the major surface to which primer material was applied in step (b).
  12. A method as claimed in claim 10, in which some at least of the sheet members are pre-printed at least on the major surface to which the low adhesion backsize material is applied in step (b).
  13. A method as claimed in claim 10, in which step (e) comprises the steps of:
    • (i) conveying the overlapped sheet members along the sheet path on a belt which is non-reactive to radio-frequency radiation; and
    • (ii) exposing the water based materials on the sheet members to radio-frequency radiation to reduce the water content of the water-based materials to a desired level.
  14. A method as claimed in claim 10, including the further step of partially drying the sheet members after step (b) on the major surface that is then deposited on the conveying means.
  15. A method as claimed in claim 10, in which the sheet members are overlapped by from about 1 cm to 2 cm.
  16. A method as claimed in claim 11, including the step of aligning the sheet members before the adhesive material is applied in step (f).
  17. Apparatus for applying water-based coating material to both sides of a plurality of sheet members, the apparatus comprising :
    • (a) a conveyor for conveying the sheet members sequentially along a sheet path
    • (b) a dual coating station (3) positioned to receive the sheet members sequentially from the conveyor, the dual coating station comprising first (11) and second (12) coating stations located on opposite sides of the sheet path through the dual coating station, each of which first and second coating stations comprises a respective source of water based coating material and a respective coating member positioned to contact the sheet members at a point along the sheet path to apply coating material from the respective source to the respective side of each sheet member said coating members in the first and second coating stations of the dual coating station comprise coating rollers (14) disposed in opposed relationship on opposite sides of the sheet path to form a coating nip whereby coating material is applied simultaneously to both sides of a sheet member passing through the coating nip ;
    • (c) an overlapping conveyor arranged to receive sheet members from the dual coating station and movable at such a speed that the leading edge portion of each sheet member leaving the dual coating station is deposited on the trailing edge portion of the preceding sheet member on the conveyor thereby forming a pseudo-web of overlapping sheet members;
    • (d) an air knife (33) positioned to direct a current of air at the overlapped sheets to change the relative positions thereof in the pseudo-web whereby the trailing edge portion of each sheet member overlies the leading edge portion of the succeeding sheet member; and
    • (e) a dryer (5) in the sheet path for removing water from the coating material applied to the sheet members in the dual coating station.
  18. The apparatus of claim 17, further including:

       (f) a further coating station (7) comprising a source of water-based coating material, and a coating member positioned to contact the pseudo-web of overlapping sheet members at a point along the sheet path to apply coating material from the respective source to one side of the pseudo-web of overlapping sheet members.
  19. Apparatus as claimed in claim 17, including a covering member (20) over part of the circumference of one of the coating rollers whereby the coating nip is formed only when that part of the roller is located adjacent the other coating roller.
  20. Apparatus as claimed in claim 19, in which the said one of the coating rollers (14) includes a sheet gripper (9) for pulling each sheet member through the coating nip.
  21. Apparatus as claimed in claim 20, including a further sheet gripper downstream of the dual coating station for removing each sheet member from the dual coating station and depositing the sheet member on the overlapping conveyor.
  22. Apparatus as claimed in claim 17, including a blower (31) positioned to provide a cushion of air to support the sheet members as they are being removed from the dual coating station.
  23. Apparatus as claimed in claim 22, in which the blower includes a heater for partially drying the sheets on the side that is then deposited on the overlapping conveyor.
  24. Apparatus as claimed in claim 17, in which the dryer (5) comprises a conveyor which is non-reactive to radio-frequency radiation and is arranged to convey the overlapped sheet member along part of the sheet path, and a source of radio-frequency radiation directed to the water-based coating material on the sheet members.
  25. Apparatus as claimed in claim 18, further including an aligning station located in the sheet path to aligning the overlapping sheet members before they enter the further coating station.
  26. Apparatus as claimed in claim 18, in which the coating member in the further coating station comprises a transfer belt (51) having a transfer surface positioned to contact the overlapping sheet members at a point along the sheet path.
Anspruch[fr]
  1. Procédé de dépôt de couche de matières aqueuses sur les deux surfaces principales opposées d'une multiplicité de feuilles individuelles par les opérations consistant
    • (a) à convoyer les feuilles individuelles séquentiellement le long d'un circuit de feuilles;
    • (b) à déposer une couche de matières aqueuses (3, 11, 12) simultanément sur les deux surfaces principales de chaque feuille individuellement pendant que les feuilles individuelles sont convoyées le long du circuit de feuilles;
    • (c) à disposer (4) les feuilles individuelles enduites en relation séquentielle de recouvrement d'une extrémité à l'autre et à continuer à convoyer les feuilles individuelles le long du circuit de feuilles;
    • (d) à sécher (5) les feuilles individuelles enduites,
    • (e) à déposer en continu (7) une autre couche de matière sur au moins une surface principale des feuilles individuelles en recouvrement pendant que les feuilles individuelles sont convoyées le long du circuit de feuilles.
  2. Procédé tel que revendiqué à la revendication 1, dans lequel l'étape (c) comprend les opérations consistant :
    • (f) à déposer les feuilles individuelles successivement sur un dispositif de convoyage (10) ce par quoi la portion du bord de tête de chaque feuille individuelle est déposé sur la portion du bord postérieur de la feuille individuelle précédente, et
    • (g) à changer (4) les positions relatives des feuilles individuelles ce par quoi la portion du bord postérieur de chaque feuille individuelle repose sur la portion du bord de tête de la feuille individuelle suivante avant le dépôt de l'autre couche de matière à base aqueuse.
  3. Procédé selon la revendication 2, dans lequel l'étape (b) comprend l'opération consistant à déposer (11) un matériau primaire à base aqueuse sur une portion majeure d'un surface principale de la feuille individuelle et (12) un matériau d'encollage dorsal à faible adhérence sur une portion majeure de l'autre surface principale de la feuille individuelle.
  4. Procédé selon la revendication 2, dans lequel l'étape (e) comprend l'opération consistant à déposer en continu au moins une bande de matériau adhésif à base aqueuse sur une surface principale des feuilles individuelles en recouvrement.
  5. Procédé selon la revendication 1, dans lequel l'étape (d) comprend l'opération consistant à sécher partiellement une surface principale de chaque feuille individuelle avant de disposer les feuilles individuelles en relation de recouvrement et à sécher ensuite simultanément les deux surfaces principales des feuilles individuelles en recouvrement.
  6. Procédé selon la revendication 1, dans lequel l'étape (d) comprend le séchage simultané des deux surfaces principales des feuilles individuelles en recouvrements.
  7. Procédé selon la revendication 3, dans lequel chaque feuille individuelle comprend une surface principale côté feutre et une surface principale côté toile, et dans lequel l'étape (a) comprend l'étape consistant à orienter les feuilles individuelles de sorte que le matériau primaire soit déposé sur le côté feutre des feuilles individuelles et de sorte que le matériau d'encollage dorsal de faible adhérence soit déposé sur la surface principale du côté toile de la feuille individuelle.
  8. Procédé selon la revendication 1, dans lequel la couche de matière à base aqueuse est déposée dans des zones alignées sur les surfaces principales opposées des feuilles individuelles.
  9. Procédé selon la revendication 1, dans lequel les feuilles individuelles sont en papier et l'étape (a) comprend l'opération consistant :

    (h) à aligner la direction de la machine des feuilles de papier individuelles avec le circuit des feuilles pour atténuer l'ondulation et le plissement des feuilles individuelles.
  10. Procédé de dépôt de couches de matières à base aqueuse sur les deux surfaces principales d'une multiplicité de feuilles individuelles par les opérations consistant
    • (a) à convoyer les feuilles individuelles séquentiellement le long d'un circuit de feuilles;
    • (b) à déposer simultanément (3) un matériau primaire à base aqueuse sur une surface principale de chaque feuille individuelle et un matériau d'encollage dorsal de faible adhérence à base aqueuse sur l'autre surface principale de chaque feuille individuelle pendant que les feuilles individuelles sont convoyées le long du circuit de feuilles;
    • (c) à déposer les feuilles individuelles successivement sur un dispositif de convoyage dans le circuit de feuilles, ce par quoi la portion de bord de tête de chaque feuille individuelle est déposée sur la portion de bord postérieur de la feuille individuelle précédente pour former une pseudo-bande de feuilles individuelles en recouvrement (4);
    • (d) à diriger un courant d'air (33) sur les feuilles individuelles en recouvrement pour changer séquentiellement les positions relatives de recouvrement de celles-ci, ce par quoi la portion de bord postérieur de chaque feuille individuelle repose sur la portion de bord de tête de chaque feuille individuelle suivante; et
    • (e) à sécher (5) les feuilles individuelles en recouvrement lorsqu'elles sont convoyées le long du circuit de feuilles.
  11. Procédé selon la revendication 10, comprenant en outre l'étape consistant :

    (f) à déposer (7) un matériau adhésif à base aqueuse sur les feuilles individuelles en recouvrement lorsqu'elles sont convoyées le long du circuit de feuilles, le matériau adhésif étant déposé sur les feuilles individuelles aux feuilles individuelles sur la surface principale sur laquelle le matériau primaire a été déposé à l'étape (b).
  12. Procédé selon la revendication 10, dans lequel au moins certaines des feuilles individuelles sont pré-imprimées au moins sur la surface principale sur laquelle est déposé le matériau d'encollage dorsal de faible adhérence à l'étape (b).
  13. Procédé selon la revendication 10, dans lequel l'étape (e) comprend les opérations consistant :
    • (i) à convoyer les feuilles individuelles en recouvrement le long du circuit de feuilles sur une bande qui est non réactive au rayonnement radiofréquence; et
    • (ii) à exposer les matériaux à base aqueuse sur les feuilles individuelles au rayonnement radiofréquence pour réduire la teneur en eau des matériaux à base aqueuse à un niveau souhaité.
  14. Procédé selon la revendication 10, comprenant l'étape supplémentaire consistant à sécher partiellement les feuilles individuelles après l'étape (b) sur la surface principale qui est ensuite déposée sur le dispositif de convoyage.
  15. Procédé selon la revendication 10, dans lequel les feuilles individuelles se recouvrent sur une longueur allant de 1 cm à 2 cm.
  16. Procédé selon la revendication 11, comprenant l'étape consistant à aligner les feuilles individuelles avant le dépôt du matériau adhésif à l'étape (f).
  17. Dispositif de dépôt de couche de matières aqueuses sur les deux faces d'une multiplicité de feuilles individuelles, le dispositif comprenant
    • (a) un convoyeur pour le convoyage des feuilles individuelles séquentiellement le long d'un circuit de feuilles; la pseudo-bande par laquelle la portion de bord postérieur de chaque feuille individuelle repose sur la portion de bord de tête de la feuille individuelle suivante; et
    • (e) un sécheur (5) dans le circuit des feuilles pour éliminer l'eau de la couche de matière déposée sur les feuilles individuelles dans la station de dépôt double.
  18. Dispositif selon la revendication 17, comprenant en outre :

    (f) une autre station de dépôt (7) comprenant une source de matériau d'enduction à base aqueuse, et un élément d'enduction positionné pour se mettre en contact avec la pseudo-bande de feuilles individuelles en recouvrement en un point le long du circuit de feuilles pour déposer une couche de matière de la source respective sur un côté de la pseudo-bande de feuilles individuelles en recouvrement.
  19. Dispositif tel que revendiqué à la revendication 17, comprenant un élément de couverture (20) sur une partie de la circonférence de l'un des cylindres d'enduction par lequel est formé l'espacement d'enduction seulement lorsque cette partie du cylindre est située en position adjacente par rapport à l'autre cylindre d'enduction.
  20. Dispositif tel que revendiqué à la revendication 19, dans lequel ledit un des cylindres d'enduction (14) comprend un preneur de feuilles (9) pour tirer chaque feuille individuelle à travers l'espacement d'enduction.
  21. Dispositif tel que revendiqué à la revendication 20, comprenant un autre preneur de feuilles en aval de la station de dépôt double pour retirer chaque feuille individuelle de la station de dépôt double et déposer la feuille individuelle sur le convoyeur de recouvrement.
  22. Dispositif tel que revendiqué à la revendication 17, comprenant une soufflerie (31) positionnée pour fournir un coussin d'air pour soutenir les feuilles individuelles lorsqu'elles sont retirées de la station de dépôt double.
  23. Dispositif tel que revendiqué à la revendication 22, dans lequel la soufflerie comprend un radiateur pour sécher partiellement les feuilles du côté qui est ensuite déposé sur le convoyeur de recouvrement.
  24. Dispositif tel que revendiqué à la revendication 17, dans lequel le sécheur (5) comprend un convoyeur qui est non réactif au rayonnement radiofréquence et est disposé pour convoyer la feuille individuelle en recouvrement le long d'une partie du circuit de feuilles, et une source de rayonnement radiofréquence dirigé vers le matériau d'enduction à base aqueuse sur les feuilles individuelles.
  25. Dispositif tel que revendiqué à la revendication 18, comprenant en outre une station d'alignement située sur le circuit des feuilles pour aligner les feuilles individuelles en recouvrement avant qu'elles n'entrent dans la station d'enduction suivante.
  26. Dispositif tel que revendiqué à la revendication 18, dans lequel l'élément d'enduction dans l'autre station d'enduction comprend une bande de transfert (51) ayant une surface de transfert positionnée de manière à entrer en contact avec les feuilles individuelles en recouvrement en un point le long du circuit de feuilles.






IPC
A Täglicher Lebensbedarf
B Arbeitsverfahren; Transportieren
C Chemie; Hüttenwesen
D Textilien; Papier
E Bauwesen; Erdbohren; Bergbau
F Maschinenbau; Beleuchtung; Heizung; Waffen; Sprengen
G Physik
H Elektrotechnik

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