EP2050514A2 - Method and device for manufacturing a structured surface of a varnished material plate - Google Patents

Abstract

The arrangement has a painting device (5) for applying a smooth, non-structured covering coat of paint to the board (8), an application roller (1) for applying a paint structure (10) to the covering coat, a dosing device (4) for dosing paint onto the roller and a transport device (12) for transporting the board from the painting device to the application roller. The application roller has a rubberized surface (3) with recesses corresponding to the paint structure to be applied for transferring paint from the dosing device to the cover coat.

Description

The invention relates to a method for producing a structured surface of a lacquered material plate according to the preamble of claim 1 and to an apparatus for producing such a structured surface according to the preamble of claim 12.

In a method of the present type, a uniform, non-structured topcoat layer is first applied to a material plate. Even before the final curing of this topcoat layer, a paint structure is applied to the topcoat layer in a continuous process by means of an applicator roll.

The corresponding device comprises a painting device for applying a uniform, non-structured topcoat layer to the material plate, an applicator roll for applying a lacquer structure to the topcoat layer, a metering device for metering lacquer on the applicator roll, and a transport device for transporting the material plate from the lacquering device to the applicator roll.

Wherever natural materials with structured surfaces, such as in particular wood or stone, are replaced by material plates that can be processed more easily and with consistent production quality, such as in particular fiberboard or laminates, the aim is to improve the visible and tactile surfaces of these replacement products To structure that they get the look and, if possible, the feel of the replaced natural products.

For example, the visual appearance of wood-based panels to replace real wood panels, panels or planks, usually produced by means of a multi-color printing, which is printed either directly on the corresponding receptive material plate surface or on this aufzulaminierende paper or film web and a Wooden surface simulates. In order to make the print abrasion resistant, one or more transparent topcoat layers are then usually applied and cured.

The problem here is that the replica of the natural product surface, even if it looks optically deceptively true, immediately recognizable as a replica when the surface is viewed or touched in the back light. The difference between this and the natural product is evident because of the optical reflections that emerge in the backlight or because of the very smooth surface of the paint. An improvement of these optical and in particular haptic properties of material plates of the present type and a better approximation to the natural material surfaces to be simulated can therefore only be achieved if the topcoat layer is patterned, ideally congruent with the printed optical structure. If this works, for example, in the case of wood-based panels to which a printed film is laminated, still quite well by means of conventional embossing rollers, which impress a structure in the relatively thick and soft laminating foil, then such embossing is not possible in the case of material panels with a topcoat in a continuous process.

In the EP 1 645 339 A1 has been proposed to solve this problem, a material plate, which is printed with a decor and then provided with a transparent topcoat, thereby provided with a structured surface that applied before the curing of the topcoat layer, a paint structure of preferably the same paint on the topcoat becomes. Since the smooth topcoat layer has not yet cured, the coating structure applied in the second step combines with the topcoat layer to form a more or less uniform layer.

In this prior art document two fundamentally different ways of applying a lacquer structure are proposed. The first procedure uses an embossing roller, on the entire surface of which is applied paint and accordingly applies corresponding to the elevations and depressions of the roll surface over the material plate surface across varying amounts of paint, so that there is a surface structure. The alternative second approach exploits the inability of the human eye and the human sense of touch to distinguish pits from pits with small structures on the order of 100 microns, which are structurally visible and palpable. Accordingly, it is proposed, in particular wood surface structures in such a way that the existing in the natural wood surface pores, so wells are formed in the finished paint structure as elevations. The lacquer structure which is applied to the topcoat layer thus inversely reflects the natural wood surface structure.

However, such quite thin paint structures that inversely replicate the pores of a natural wood surface can not be applied with an embossing roll. For this purpose, it is rather proposed to apply the paint structure in the indirect gravure printing process, ie to transfer the desired printed image onto a blanket applicator roll with a correspondingly engraved steel cylinder, which then removes the lacquer structure onto the material plate surface. However, in this case only lacquer structures with elevations of around 5 μm can be produced, since the applicator roll flattens the lacquer structure when rolling on the material plate. Although such small elevations can be perceived by the eye, resulting in the optical surface impression of a structured surface, the human sense of touch can not feel such small elevations, leaving the impression of a smooth and thus not natural surface haptically.

The present invention is therefore based on the object to improve a method and an apparatus of the type mentioned in that in particular the feel of a correspondingly structured surface is improved, that is, the structure of the surface is clearly noticeable.

This object is achieved by a method having the features of claim 1 and by an apparatus having the features of claim 12. A corresponding material plate is defined in claim 23.

Advantageous developments of the method according to the invention will become apparent from the claims 2 to 11, preferred embodiments of the device according to the invention are set forth in claims 13 to 22.

The present invention improves a method for producing a structured surface of a lacquered material plate, in which a uniform, non-structured topcoat layer is applied to the material plate and a lacquer structure is applied to the topcoat layer by means of an applicator roll prior to curing of the topcoat lacquer layer a rubberized applicator roll is used for applying the lacquer structure, the rubber coating of which is provided with depressions corresponding to the structure to be applied for transferring lacquer from a metering device to the topcoat layer of the material plate.

The device according to the invention accordingly comprises a painting device for applying a uniform, non-structured topcoat layer to the material plate, an applicator roll for applying a lacquer structure to the topcoat layer, a metering device for metering lacquer onto the applicator roll, and a transport device for transporting the material plate from the coating device to the applicator roll wherein the applicator roll has a rubberized surface with, corresponding to the applied lacquer structure, wells for transferring paint from the metering device to the topcoat layer of the material plate.

Thus, the present invention employs a direct gravure printing process. This is not, as is common in direct gravure, a rigid, usually made of steel pressure cylinder used, but a rubberized applicator roll, in the gumming of the recesses for transferring the paint are placed on the surface of the material. In the prior art, it has hitherto been avoided as far as possible to carry out a direct gravure printing process, for example by means of a rubberized roller, since the soft rubber coating produces a sharp printed image impossible. Hard-to-print materials that can not adapt to a rotogravure steel cylinder, as has been the case in the past, have thus far always been printed by indirect gravure printing.

Accordingly, the present invention is based on the finding that a sharp printed image is not at all necessary in the production of structured lacquer surfaces of the present type. On the contrary: the certain blurring that inevitably results from the softness of the rubber coating of the applicator roll in print leads to a particularly natural, since irregular appearance of the surface of a natural product imitative surface of the painted material plate. For this blurred image contributes not only that the edges of the recesses in the rubber give off when rolling on the material plate surface and occupy a defined position, but also that the recesses in the rubber coating the paint is not completely on the uncured topcoat layer Release material plate surface. Thus, recesses in the rubberized applicator roll, which preferably have a depth of about 200 to about 250 microns, ultimately lead to coating structures of a haptic perceptible height of about 100 to 120 microns.

The rubberized applicator roll can be configured as a steel cylinder with a rubber coating, wherein the recesses in the rubber jacket can be introduced by means of a laser or by other known techniques.

The present invention is preferably used to simulate a structure of a natural or quasi-natural wood surface, whereby a quasi-natural wood surface is to be understood as meaning a surface which is modeled on a natural surface but does not have a natural model in the narrower sense - for example using numerical methods and algorithms. Of course, this does not exclude that imitations of other natural material surfaces, such as stone or leather, can be improved within the scope of the invention.

In this case, it is preferred that the structure of the natural or quasi-natural wood surface is inversely modeled such that the elevations on the topcoat layer formed by the paint structure correspond to the depressions of the natural or quasi-natural wood surface. However, it is of course also in the context of the present invention, if the structure of the natural or quasi-natural wood surface is not replicated inverse, so that the raised areas formed by the paint structure on the topcoat also correspond to the elevations of the natural or quasi-natural wood surface.

Depending on the wood surface structure that is to be simulated, in the context of a further preferred embodiment of the present invention, it may be advantageous to inversely model only a part of the structure, while another part of the structure is non-inversely modeled. For example, it may be useful to non-inversely model large-area structures such as Asteinschlies, while pores are imitated inversely in the wood surface.

It is expedient in this case if an optical image of the wood surface, which is modeled on the paint structure, is printed on the material plate before the application of the topcoat layer, either directly or on a paper web or film, which is applied to the material plate and insofar part of the material plate Surface becomes. Here it is expedient, however, because of the small, indistinguishable from the human hand structures by no means necessary when the paint structure is brought into line with the printed optical image of the wood surface.

If a blurred resist structure is applied in relation to the optical contrasts of the structure of the natural or quasi-natural wood surface, in particular by the fact that the recesses in the rubberized surface of the applicator roll are made wider than the depressions of the natural or quasi-natural wood surface an additional blur in the printed image, which is advantageously suitable to enhance the visual and haptic impression of a natural surface.

In order to apply the lacquer to the applicator roll, a doctor blade or a metering roll rolling on the applicator roll can be used as a metering device to coat the lacquer in the depressions of the applicator roll. Since the applicator roll according to the invention is provided with a rubberized surface, it is sometimes difficult to clean the paint into the recesses of the applicator roll. However, due to the above-described effects of an improved appearance of naturalness due to a certain blurring of the pressure, it is not detrimental if the application of the lacquer in the depressions can not be done with the greatest possible cleanliness. A particularly simple dosing of the paint for the paint structure so the present invention also allows.

According to a preferred method of the present invention, after the application of the topcoat layer, a curing device, for example, with UV lamps or the like, in which the topcoat layer is cured only so far that it receives a gel-like nature. The lacquer structure is then applied to the thus-lacquered topcoat. On the one hand, this ensures that the lacquer structure adheres to and bonds to the topcoat layer and, on the other hand, prevents the applied lacquer structure, especially if it is the same lacquer as used for the topcoat lacquer, from on the not yet cured topcoat layer dissolves and rises in this.

If a mechanically particularly abrasion-resistant surface of the material board painted according to the invention is required, for example in floorboards, it may be provided in the context of the invention to cure the topcoat layer and the paint structure applied thereto and then to coat it with an additional resistant protective layer.

In the apparatus according to the invention, as is known per se, a pressure gap for the material plates are formed on the applicator roll by assigning the applicator roll a counter-pressure device, for example a roller or a table.

Figur 1

eine schematische Schnittdarstellung einer erfindungsgemäßen Vorrichtung;

Figur 2

eine Draufsicht auf die Vorrichtung aus Figur 1;

Figur 3

ein Detail aus Figur 1;

Figur 4

ein Ausschnitt aus einer Oberfläche einer Auftragswalze einer erfindungsgemäßen Vorrichtung.

To illustrate the method according to the invention, an embodiment of a device according to the invention will be described and explained in more detail below with reference to the accompanying drawings. Show it:

FIG. 1

a schematic sectional view of a device according to the invention;

FIG. 2

a plan view of the device FIG. 1 ;

FIG. 3

a detail from FIG. 1 ;

FIG. 4

a section of a surface of an applicator roll of a device according to the invention.

In the FIG. 1 schematically illustrated apparatus comprises an applicator roll 1 with a steel core 2 and a rubber jacket 3, a rolling on the rubber jacket 3 of the applicator roll 1 metering roller 4, a painting device 5 shown here only schematically for applying a topcoat layer and a curing device 6, which consists essentially of a UV Lamp exists. The metering roller 4 forms with the applicator roll 1 together a metering gap 7, in which the paint is kept, and from which the applicator roll 1 insofar takes paint to a material plate 8, as in the rubber sheath 3 recesses 9 are introduced. Since the entirety of the depressions 9 form a structure, a paint structure 10 is transferred from the dosing gap 7 onto the surface of the material plate 8 in total by the depressions 9. This paint structure 10 is applied to a topcoat layer 11, which has been previously applied by the painting device 5 shown schematically as a blanket cylinder and gelated by means of the curing device 6. An impression cylinder 12, which is opposite to the applicator roll 1, ensures the continuous transport of the material plate 8 through the printing gap formed thereby.

In the FIGS. 2 to 4 are the same elements with identical reference numerals as in FIG. 1 provided, so that reference is made essentially to the description there.

In the illustration after FIG. 2 illustrates that in the rubber coating 3 of the applicator roll 1 irregular recesses 9 are introduced to apply the paint structure 10 on the material plate 8. Here, it is also clear that by the rotational movements of the applicator roller 1 and the metering roller 4 in the metering 7 in a coating of the paint from the metering 7 into the recesses 9 is achieved.

FIG. 3 shows a detail FIG. 1 namely, the applicator roll 1 with its steel core 2 and its rubber coating 3, as it rolls on the material plate 8. As in a detail magnification in FIG. 4 even more clearly shown, the recesses 9 in the surface of the rubber sheath 3 are not regularly formed, but designed varying both in their width and in their depth. This results in a particularly natural feel through the thus formed irregular paint structure 10. Since the rubber sheath 3 soft and elastic rolls on the surface of the material plate 8, the depressions 9 deform when dispensing the paint to form the resist structure 10, so that also thereby a additional blurring and irregularity of the paint structure 10 results, which further improves the natural feel.

Claims (23)

Method for producing a structured surface of a lacquered material plate, wherein a uniform, non-structured topcoat layer is applied to the material plate and a lacquer structure is applied to the topcoat lacquer before the final curing of the topcoat lacquer layer in a continuous process by means of an applicator roll,
characterized,
in that a rubberized application roller is used for applying the lacquer structure, the rubber coating of which is provided with depressions corresponding to the structure to be applied for transferring lacquer from a metering device to the topcoat layer of the material plate. Method according to claim 1,
characterized,
that a lacquer structure, which is modeled on the structure of a natural or quasi-natural wood surface, is applied to the topcoat layer. Method according to claim 2,
characterized,
in that the structure of the natural or quasi-natural wood surface is inversely modeled such that the elevations formed on the topcoat layer by the lacquer structure correspond to the depressions of the natural or quasi-natural wood surface. Method according to claim 2,
characterized,
that the structure of the natural or quasi-natural wood surface is only partially inversely replicated in such a way that the elevations on the topcoat layer formed by the lacquer structure correspond to the depressions of the natural or quasi-natural wood surface, and otherwise non-inversely reproduced. Method according to at least one of claims 2 to 4,
characterized,
that a blurred paint structure is applied in relation to the optical contrasts of the structure of the natural or quasi-natural wood surface. Method according to at least one of claims 2 to 5,
characterized,
that an optical image of the wood surface, which is modeled on the paint structure, is printed on the material plate before the application of the topcoat layer. Method according to claim 6,
characterized,
that the lacquer structure is brought into coincidence with the printed optical image of the wood surface. Method according to at least one of claims 1 to 7,
characterized,
in that a doctor blade or a metering roller rolling on the applicator roll is used as the metering device to coat the lacquer in the depressions of the applicator roll. Method according to at least one of claims 1 to 8,
characterized,
that the topcoat layer is gelled before application of the lacquer structure. Method according to at least one of claims 1 to 9,
characterized,
that lacquer structures with a height of about 100 to about 120 microns are applied to the topcoat layer. Method according to at least one of claims 1 to 10,
characterized,
that the topcoat layer and the paint structure applied thereto are cured and then coated with a protective layer. Device for producing a structured surface of a lacquered material plate, comprising a lacquering device (5) for applying a uniform, non-structured topcoat layer (11) to the material plate (8), an applicator roll (1) for applying a lacquer structure (10) to the topcoat layer (10) 11), a metering device (4) for metering paint onto the applicator roll (1), and a transport device (12) for transporting the material plate (8) from the lacquering device (5) to the applicator roll (1),
characterized,
that the applicator roll (1) has a rubberized surface (3), the applied resist pattern (10) has corresponding depressions (9) for transferring lacquer from the metering device (4, 7) onto the top coat layer (11) of the material plate (8) , Device according to claim 12,
characterized,
that the indentations in the rubber-coated surface (3) of the applicator roll (1) to simulate a natural or quasi-natural wood surface. Device according to claim 13,
characterized,
in that the depressions (9) in the rubberized surface (3) of the applicator roll (1) correspond to the recesses of the natural or quasi-natural wood surface in order to inversely reproduce the structure of the wood surface in the paint structure to be applied. Device according to claim 13,
characterized,
that only a part of the recesses (9) in the rubberized surface (3) of the applicator roll (1) corresponds to the recesses of the natural or quasi-natural wood surface, to replicate the structure of the wood surface in the paint structure to be applied partially inverse and partly non-inverse. Device according to at least one of claims 13 to 15,
characterized,
in that the depressions (9) in the rubberized surface (3) of the applicator roll (1) are wider than the depressions of the natural or quasi-natural wood surface. Device according to at least one of claims 13 to 16,
characterized,
in that the depressions (9) in the rubberized surface (3) of the application roller (1) reproduce a wood surface whose optical image is printed on the material plate (8). Device according to at least one of claims 12 to 17,
characterized,
in that at least some of the recesses (9) in the rubberized surface (3) of the applicator roll (1) have a depth of approximately 200 to approximately 250 μm. Device according to at least one of claims 12 to 18,
characterized,
that the metering device, a doctor blade or on the applicator roll (1) rolling metering roll (4) for swabbing the paint comprises in the recesses (9) of the application roller (1). Device according to at least one of claims 12 to 19,
characterized,
in that between the painting device (5) and the applicator roll (1) a curing device (6) for fixing the topcoat layer (11) is arranged. Device according to at least one of claims 12 to 20,
characterized,
in that the transport device (12) comprises a counter-pressure device (12) opposite the applicator roller (1) for forming a pressure gap for the material plate (8). Device according to at least one of claims 12 to 21,
characterized,
in that the applicator roll (1) has a device for curing the topcoat layer (11) and the resist structure (10) and a device for covering the material plate (8) with a protective layer. Material plate (8) with a topcoat layer (11) and a paint structure applied thereto (10),
characterized,
that it has been produced by a method according to at least one of claims 1 to 10 and has a lacquer structure (10) with elevations of at least about 100 μm.

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