EP2274176A1

EP2274176A1 - Derived timber plate provided with a high-gloss laminate coating, and method for producing such a derived timber plate

Info

Publication number: EP2274176A1
Application number: EP09742101A
Authority: EP
Inventors: Andreas Arthold
Original assignee: Fritz Egger GmbH and Co OG
Current assignee: Fritz Egger GmbH and Co OG
Priority date: 2008-05-06
Filing date: 2009-05-06
Publication date: 2011-01-19
Anticipated expiration: 2029-05-06
Also published as: EP2274176B1; DE102008022403B3; PL2274176T3; WO2009135883A1; RU2444443C1

Abstract

The invention relates to a method for producing a derived timber plate, especially a chipboard, comprising a high-gloss laminate coating. According to said method, at least one plane wide surface of a derived timber plate is ground before the laminate coating is applied. The invention also relates to a derived timber plate, preferably chipboard, provided with a high-gloss laminate coating. The method is characterised by the following working steps: non-cutting smoothing of the ground, plane wide surface by compressing same by means of a roll-type or plate-type smoothing body, the smoothing surface of said smoothing body being tempered to at least 100°C or being at a temperature of at least 100°C, and the smoothed wide surface is coated by pressing a high-gloss laminate coating thereonto in the form of a direct coating. The invention further applies to a derived timber plate, preferably chipboard, provided with a gloss laminate coating, said laminate coating being applied as a direct coating to a wide surface of the derived timber plate, which is smoothed in a non-cutting manner, and the laminate coating has a gloss degree of at least 105, especially at least 110, and preferably at least 115 gloss units measured according to ISO 2813, with a 60° measuring geometry.

Description

Wood-based panel with a high-gloss laminate coating and method for producing such a wood-based panel

The invention relates to a method for producing a Hoizwerkstoffplatte having a high-gloss laminate coating, wherein at least one flat broad surface of a wood-based panel is ground before applying the laminate coating, and a wood-based panel, preferably chipboard, which is provided with a high-gloss laminate coating.

Various processes are available for the coating of wood-based materials. In the field of furniture and interior finishing, in addition to the liquid coating with paints and varnishes, the film lamination and the powder coating, the coating with laminates is out of the ordinary.

With regard to the laminate coating, in turn, different methods are known. These processes typically use multiple layers of paper impregnated with synthetic resin, usually melamine resin, melamine-urea resin or phenolic resin. The paper layers can be freely designed in their color and printed with any desired decors such as wood decors or fantasy decors. At elevated pressure and temperature, these paper layers are then pressed either directly (Direct Pressure Laminate (DPL)) or only after their processing into a so-called laminate with the wood-based panel (High Pressure Laminate (HPL) or Continuous Pressure Laminate (CPL)).

To improve the resistance to wear of the Lamänatbeschtchtung may optionally be an overlay paper, which may be additionally equipped with hard particles, such as corundum particles, provided. Through the use of laminates, wood-based panels with very resistant surfaces can be achieved. However, this type of laminate coating is more expensive than the direct coating (DPL technology) due to the two pressing steps required and thus causes higher costs. For most applications of wood-based materials used in furniture and interior design, panels are manufactured using the direct coating are finished, sufficiently wear-resistant. It usually used for this with melamine resin impregnated papers,

Laminates and coatings according to the DPL-Technoiogie are usually produced intermittently with single and multi-day presses or continuously with double belt presses.

High-gloss surfaces have recently become increasingly popular in the field of furniture and interior design.

In order to achieve particularly high-gloss laminate coatings, it has hitherto been necessary to recool after pressing. This means that after the actual pressing step at high pressure and high temperature a rapid lowering of the temperature - while maintaining the pressing pressure - is required. Furthermore, high-gloss press plates or appropriate allowances are required. This understandably requires specially designed pressing devices and is also possible only with high energy consumption. In order not to pollute the particularly high-quality surfaces of the press plates or supplements, clean room conditions must be fulfilled. Accordingly, the handling of the various pressing tools with the greatest cleanliness must meet. Fingerprints or dust grains on the surfaces of the press plates or additives can lead in the shortest possible time to laminate coatings that do not meet the requirements of a first choice or are even unsaleable as a committee.

Gloss is an optical property of light-reflecting surfaces. Physically, gloss is defined as the quotient of the directed and the diffusely reflected portion of the amount of light falling on a surface. It can be quantitatively determined with gloss meters; Details are given in the standards DIN 67530 and ISO 2813 respectively. For directly coated panels, the determination of the degree of gloss is specified in EN 14323 (current edition 2004-06-01). Then the degree of gloss is to be determined with a so-called reflectometer according to ISO 2813. The principle of the reflectometer is based on the measurement of the directed reflection. For this purpose, the intensity of the reflected light is measured in a narrow band of the reflection angle. The measurement results are not related to the amount of light emitted, but instead on a black, polished Gias standard with defined refractive index (1, 567), For this standard, the measurement value = 100 gloss units (GE or Gianzgradpunkte) is set. There are material surfaces that have a higher refractive index than the black glass standard used for calibration. Therefore gloss values result in certain material surfaces thoroughly from over 100 GE ₁ for example polished metals. For a better differentiation of the measured values one measures depending on the gloss with different measuring angles. According to the ISO 2813 standard, for high-gloss surfaces (≥ 70 GE), in addition to the conventional measurements with a 60 ° measurement geometry, measurements with a 20 ° measurement geometry must also be performed. However, the values given below refer exclusively to measurement results obtained with a 60 ° measuring geometry.

The present invention has for its object to provide a method for the coating of wood-based panels, in particular chipboard, can be provided with the high-gloss Laminatoberfiächen having wood-based panels cost. In particular, the invention has for its object to provide a provided with a high-gloss laminate coating wood material panel that can be produced inexpensively.

This object is achieved by a method having the features of claim 1 or by a wood-based panel having the features of claim 17. Preferred and advantageous embodiments of the invention are specified in the subclaims.

The inventive method in which a wood-based panel having at least one flat broad surface is ground on this broad surface is characterized by the work seh rites: non-cutting smoothing the ground, flat broad surface by compacting the same by means of a cylindrical or plate-shaped smoothing, the smoothing surface is at least 100X tempered or has a temperature of at least 100 ⁰ C, and coating the smoothed Breitoberfiäche by pressing a high-gloss laminate coating in the form of a direct coating.

The Holzwerkst off plate according to the invention, which is preferably formed from a chipboard, is accordingly provided with a glossy laminate coating, the is applied as a direct coating on a non-cutting smoothed Breitoberfiäche the wood-based panel and a gloss level of at least 105, in particular of at least 1 10 and preferably of at least 115 gloss units measured according to ISO 2813 with a 60 ° -Meßgeometrie has.

By a high-gloss laminate coating in the sense of the present invention is meant a laminate coating applied as a direct coating, based on at least one flat broad surface of the wood-based panel over its entire area or in a minimum area of at least 80%, preferably at least 90%, particularly preferably at least 95% of 1 m ² large flat broad surface of the Hoizwerkstoffplatte has a gloss level of at least 105 gloss units measured according to ISO 2813 with a 60 ° measuring geometry.

On the part of the Anmeideriπ it was recognized that wood-based panels with high-gloss laminate coatings can be produced inexpensively if the relevant broad surface of the wood-based panel is smoothed after sanding and before coating (pressing melaminharzimprägnierter paper layers). Unlike conventional grinding, smoothing takes place without chip removal. It is thereby effected by contact with a smooth, tempered surface, that after grinding nor from the surface protruding wood fibers or chips plasticized and flattened. This is achieved on the one hand, that small elevations, which have previously formed the wood fibers or wood chips on the plate surface, are largely eliminated, so that no more such elevations are embedded in the applied resin layer, on the other hand results from the smoothing a regular compression of the surface , which causes the coating resin over the

Surface forms a uniform film across. Both circumstances cause a significant improvement in the gloss level of the finished coated plate.

The chipless smoothing of the ground, flat broad surface of the wood-based panel by means of a tempered smoothing body can be carried out both cyclically and continuously in the method according to the invention. However, for smoothing wood boards of different lengths and to minimize the energy required for smoothing the smoothing of the ground wide surface of the wood-based panel is preferably continuous, for example, with a smooth, tempered roller. A roller used as a smoothing body should be pressed onto the wide surface to be smoothed when carrying out the method according to the invention with a force in the range from 200 to 1000 N / cm plate width, preferably in the range from 450 to 750 N / cm plate width. The non-cutting smoothing is carried out with one or more rollers arranged one behind the other.

It is also proposed that the smoothing surface of the smoothing body is heated to a temperature in the range of 15O ⁰ C to 240 ⁰ C, preferably in the range of 180 ⁰ C to 23O ⁰ C.

Experiments with rolls tempered at 200 ^° C., which were pressed onto the board from above and below with a force of approximately 350 N / cm board width, produced significantly smoother and more closed surfaces than the merely ground boards. For comparison, 88 gloss points were achieved in tests on non-smoothed plates, while in the case of such smoothed and similarly coated plates, in particular 106 gloss grades were achieved.

The peripheral speed of the tempered roller can correspond to the feed speed of the wood-based panel to be smoothed. The tempered roller can be used in particular at the same time as a transport roller for advancing the wood-based panel. In an advantageous embodiment of the method according to the invention can be carried out for smoothing the ground wood-based panel also a relative movement between the plate or roller-shaped smoothing tool and the smoothing broad surface of the wood material plate. As a result, the effect of the smoothing tool can be increased. When using a tempered smoothing roll this is rotated in this process variant with a peripheral speed which is greater or smaller than the feed rate of the wood-based panel to be smoothed, so to be smoothed between the smooth tempered contact surface (peripheral surface) of the roller and the thus in contact Surface of the wood material plate gives a slip.

The temperature of the Giättkörper or the smoothing roll does not have to be done by supplying heat energy or the like. Rather, it is also within the scope of the invention, to cause the tempering of the smoothing surface of the smoothing body or the smooth roller by friction between the smoothing body and the broad surface to be smoothed. Caused by a corresponding temperature of the friction Giättfläche is at least 100 ⁰ C, preferably at least 150 ⁰ C.

A further advantageous embodiment of the method according to the invention is characterized in that the temperature of the smooth surface of the body or the temperature of the smoothed broad surface of the Hoizwerkstoffplatte is measured, that the measured temperature is compared with a predetermined target temperature, and that the Reiativgeschwindigkeit between the to be smoothed Breitoberfiäche and the

Smoothing surface of the smoothing body and / or the force with which smoothing body is pressed against the flat surface to be smoothed, is controlled as a function of the measured temperature. In this way, the desired smoothing of Holzwerkstoffpiatte can be achieved particularly reliable and automated.

The use according to the invention of the DPL technology (direct coating) for applying a high-gloss laminate coating to a chiplessly smoothed wide surface of the hollow material plate offers the above-mentioned procedural and economic advantages in comparison with an application of HPL technology.

The rapid recooling while retaining the pressing pressure required in conventional methods for the production of high-gloss laminate coatings wood panels is not required in the inventive method. The method according to the invention therefore also offers cost advantages. Because the

Construction and control of a coating press required for carrying out the method according to the invention is simpler and its throughput higher than the throughput of a coating press whose pressing tools are provided with a cooling device. According to a preferred embodiment of the method according to the invention, the high-pressure laminate coating pressed onto the wood-based panel is therefore not subjected to forced cooling in the press.

The method according to the invention is equally suitable for medium density fibreboard (MDF boards) and chipboard. However, the method is particularly advantageous the use of chipboard, as they are much cheaper to manufacture than MDF-PSatten, on the other hand, are generally better suited for direct coating with a high-gloss laminate material than particle board. Strictly speaking, the method according to the invention only creates the prerequisite for being able to produce cost-effective chipboard with a high-gloss laminate coating pressed in by the direct coating method.

Another advantage of using chipboard compared to the use of MDF boards is that grinding of the chipboard is possible immediately after pressing and a brief cooling (about 10 to 20 minutes). On the other hand, after hot pressing, MDF boards are stored for 2 to 5 days in a maturing warehouse before they can be sanded and then further processed. This circumstance has a negative effect on the production logistics as well as on the production costs due to the need for corresponding storage capacities and the longer capital tie-up in the maturing warehouse.

With regard to the coating of chipboard for the production of high-gloss laminate-coated wood material plates provides a further preferred embodiment of the method according to the invention that a multi-layer chipboard is used or produced, which is composed of a middle layer of coarse chips and of cover layers with relatively fine chips.

In tests, multilayer particle boards were produced with an increased proportion of relatively fine cover shavings. By adding, for example, 5 to 7% more top layer chips compared to chipboard, which in cross-section about 60% coarser middle-layer chips and about 2 x 20% finer cover shavings have, otherwise the same binder dosage and the same plate thickness, was achieved that less large chips came to lie on the surface. The surfaces of this chipboard having an increased proportion of cover shavings were particularly smooth and closed after smoothing. In the finished coated panels, a further increase in the gloss level of at least 3 gloss grades was achieved.

When carrying out the method according to the invention, it is preferred that a chipboard is produced or used as the wood-based panel, the layers having different chip length distribution, with a middle layer, in which the maximum Span Span distribution is between 8 mm and 15 mm, and cover layers, in which the maximum of span length distribution at a span length between 3 mm and 8 mm, wherein the proportion of chips with a length of less than 6 mm in the chip material of the outer layers is at least 75 wt .-%, in particular at least 80 wt .-% and preferably at least 90 wt .-%.

When carrying out the process according to the invention, it is preferred to use a chipboard having a layer of different chip thickness distribution as the wood material, with a middle layer in which the maximum of

Spandickenverteilung is in the range of 1, 0 mm to 4.0 mm, and cover layers, in which the maximum of the chip thickness distribution at a chip thickness in the range of 0.1 mm to 0.8 mm, wherein the proportion of chips with a thickness of less than 0.6 mm in the chip material of the outer layers at least 75 wt .-%, in particular at least 80 wt .-% and preferably at least 90 wt .-% is

The inventive method is also advantageous when using single-layer chipboard. Experiments have shown that it is favorable for achieving the smoothest possible surface and a high degree of gloss Lamsnatbeschichtung both when using single-layer chipboard ais also when using multi-layer, especially three-layer chipboard, if according to a preferred embodiment of the method according to the invention a chipboard is used in the chip material, the proportion of chips having a thickness of less than 0.6 mm at least 50 wt .-%, in particular at least 65 wt .-% and preferably at least 80 wt .-% is. In particular, it is also advantageous if a chipboard is produced or used for carrying out the method according to the invention, in the chip material of the proportion of chips having a length of less than 8 mm at least 50 wt .-%, in particular at least 65 wt .-% and preferably at least 85 wt .-% is.

Particularly good results were also achieved in experiments in which only sawdust was used as cover shavings, which provided as compared with conventionally prepared wood chips, which may sometimes have minor pollution and bark components, largely free of foreign substances can be. The surfaces of these exclusively sawdust contained cover layers were particularly smooth and uniform. In the finished coated chipboard thus produced, a further increase in the gloss level was found.

The Bindemitteianteil was not varied in the experiments, but this is inevitably higher with increasing proportion of relatively fine cover shavings, since the cover shavings a higher binder content! have as the coarser middle-layer chips. Nevertheless, it can be expected that an increase in the binder content in the cover layer by, for example, 3% based on the absolutely dry mass of chips (ie, span span) causes an increase in the gloss level by at least 3 points (gloss units).

It is preferred in carrying out the process according to the invention that the binder content in the outer layers of Holzwerkst off plate based on the absolutely dry mass of the cover shavings at least 10 wt .-%, in particular at least 12 wt .-% is and preferably in the range of 15 to 25 % By weight.

The grinding of the wood-based panels, preferably chipboard is carried out in the inventive method usually in at least three stages. The grains in the different stages are coordinated. It has been recognized that a very fine final finish, for example, with a grain size of 180, brings no additional improvement. Smoothing therefore offers the advantage that it is possible to dispense with the use of particularly high-quality ground plates. According to a preferred embodiment, it is therefore provided that the broad surface of the wood-based panel to be smoothed is ground in a number of stages before the chipless smoothing, wherein the final cut is carried out with a maximum grain size of 180 _T, preferably a maximum of 120.

Another preferred Ausgestattung of the method according to the invention is that the Holzwerkstoffpiatte is moved along a grinding tool, wherein the smoothing broad surface before the chipless smoothing zusich by at least one transverse section with respect to the direction of movement of the wood material plate along the Grinding tool is ground. This makes it possible to achieve a further improvement in the gloss level of the finished Jaminatbeschichteten wood-based panel.

According to a further advantageous embodiment of the method according to the invention, it is provided that the broad surface of the Hoizwerkstoffplatte to be smoothed and / or the smoothing surface of the smoothing body are wetted before smoothing. In this way, the desired smoothness of the wood-based panel can be further improved, with the result that the gloss level of the high-gloss laminate coating of the wood-based panel, preferably chipboard, increases on average by a further three gloss units. The reason for this gloss increase can be seen in the fact that the moisture applied by the wetting is evaporated during the smoothing, this steam then causes an improved heat transfer and / or that the wetted surface of the wood-based panel is better pSastifiziert or formable in the short term, so that projecting fibers and / or chips can be embedded even better in the structure of the Hoizwerkstoffplatte.

The invention will be explained in more detail by means of examples with reference to the accompanying drawings. Show it:

1 shows an embodiment of the method according to the invention in the form of a schematic flow chart; and

2 shows a section of a Hoizwerkstoffplatte invention

Cross-sectional view.

By shredding solid wood in the form of Hofzstämmen and branches first chopped wood are produced. From the so produced chips and / or other shredded wood residues Hotzspäne be prepared. The cutting takes place in the state of the respective moisture of the wood, which depending on the origin of the wood and the season between 60 and 150% based on the

Wood dry mass may amount. Subsequently, the hoarfish chips are dried to a humidity in the range of about 1.5 to 3% and fractionated by screening or other suitable classification method, for example by air classification, according to cover layer and middle layer material. For the middle-layer chips used, the maximum thickness of the chip thickness distribution is in the range of 1.0 mm to 4.0 mm. In the case of the cover shavings used, on the other hand, the maximum of the chip thickness distribution is in the range of 0.1 mm to 0.8 mm for a chip thickness. Furthermore, the proportion of chips having a thickness of less than 0.6 mm in Spanmateriai the outer layers is at least 75 wt .-%, preferably at least 80 wt .-%.

Before or after screening (classification), the wood chips are cleaned of foreign matter such as metal particles and / or stone particles. Stone particles are separated by means of a density sorter, for example by means of an air sifter or in a downpipe in which the falling hoarfrost chips are laterally deflected by a blower while the relatively heavy rock particles are not or less strongly distracted and thus separated from the wood chips.

The wood shavings are subsequently glued separately after covering shavings and middle layer shavings with binder. The binders used are preferably urea resin and / or phenolic resin. Hardeners, water repellents (paraffin) and optionally additives (for example fungicides and anti-fouling agents) are added to the binder. The wood chips are glued by means of a mixer or a spraying device. The wood chips receive a very fine binder coating.

The glued topcoat chips have a binder content in the range of 15 to 25 wt .-%, based on the absolutely dry Spanmasse.

After gluing, the wood chips are scattered by means of a spreader into a multi-layer chip cake substantially mirror-symmetrical about the middle of the board. Preferably, a three-layered chip cake is produced consisting of a lower covering layer of fine chips, a middle layer of coarser chips and an upper covering layer of fine chips (compare FIG. 2). But a multi-layered structure can also be missing completely, then one speaks with regard to the finished pressed chipboard of single-layer chipboard. By hot pressing the chip cake, under the action of pressure and temperature, by hardening the binder, a stable chipboard is pressed, which can meet the requirements of the European standard 312-3

The hot pressing of the chip cake can be done in a one-storey or multi-daylight press (cycle press). The continuously spread chip cake is cut into suitable length sections by means of cutting tools. Preferably, however, the hot pressing of the chip cake takes place in a continuous double-belt press (so-called "conti-roll press"). ) The long division of the chip cake takes place in this case only after the pressing process

Preferably, the initially still relatively loose chip cake before the actual pressing process in a press with low pressure pre-compacted (pre-pressed) An advantage of pre-compression is that the heat in the main press or the end portion of the press reaches more quickly to the middle-lying chip, so that a more uniform heating of all chips and thus an optimal setting of the binder is achieved The precompression takes place optionally under the action of heat, wherein the contact surfaces of the press, for example, heated to etne temperature of about 50 ⁰ C.

In the main press or in the end section of the double belt press is of Spanekuchen at a temperature of about 200 ⁰ C and a pressure of for example about 25 kg / cm ² pressurized by the high heat in the press, the binder! activates and binds

Behind the double belt press, the endless chipboard produced in individual plates of predetermined length is cut in combination with the Ablangen is preferably trimming the particle board, so that this straight perpendicular to each other edges obtained The trimming is done for example by means of mutually parallel circular surfaces Then there is a cooling of the individual chipboard The cooling of the chipboard is preferably carried out in a so-called star turners, in which the particle boards are moved apart from each other about a rotation axis of the star turner, the particle boards being carried or supported by radially projecting from a rotating body of the star turning support rods Die for the cooling of the chipboard provided time period is in the range of about 10 to 30 minutes, preferably in the range of about 10 to 20 minutes.

Subsequently, the chipboard are ground, wherein at least one broad side of the respective chipboard is ground. Preferably, however, both broad sides of the respective chipboard are ground. The grinding of the chipboard is carried out by means of at least one Zyunderschleifmaschine and / or by means of at least one wide-belt sander. The cylindrical grinding machine has a cylinder rotating about its longitudinal central axis, on the lateral surface of which sandpaper is attached. In contrast, the broadband grinding machine has an endless sanding belt which runs over a plurality of rollers, wherein between at least two of the rollers a pressure plate is arranged which presses the endless sanding belt against the broad surface of the chipboard to be ground.

For carrying out the method according to the invention, it is preferred that the grinding of the wood-based panel or chipboard takes place by means of at least one wide-belt sanding machine.

The grinding of the respective broad side of the Hoizwerkstoffplatte or chipboard takes place in several stages, starting with a relatively coarse grain, such as a 40 grain size. For the subsequent grinding operations, abrasive papers or abrasive belts with a finer grain size are used. The final touch is made with a grain size of a maximum of 180, preferably a maximum of 120.

In addition to the grinding process, which takes place in the direction of movement (transport direction) of the wood-based material board along the wide-belt sanding machine or cylindrical grinding machine, preferably at least one transverse to the direction of the endless abrasive belt or transversely to the direction of movement of the wood-based panel Schieifvorgang (transverse grinding) is provided. By Querschlsff the sanding result can be significantly improved. In particular, can be reduced by the Querschüff the resulting Schieifstaubmenge for a given number of grinding operations.

Following the sanding of the wood-based panel, it is temporarily stored as a tire. During this intermediate storage, the wood-base panel adapts itself to the tire Humidity of the environment. The intermediate storage, which serves as a tire for the wood-based panel, takes 2 to 4 days.

The ground, flat broad sides of the chipboard or wood-based panels are then smoothed by compacting by means of at least one smoothing device without cutting. The smoothing device comprises at least one roller-shaped or plate-shaped body, the smoothing surface of which is tempered. For this purpose, the smoothing element is pressed against the broad side of the chipboard or wood-based panel to be smoothed.

Preferably, rolls of metal whose polished are used for smoothing

Lateral surfaces to at least 15O ⁰ C, for example! tempered to about 200 ⁰ C and are pressed with a force in the range of 450 to 750 N / cm plate width from above and below against the Holzwerkst off plate. In corresponding experiments, significantly smoother and more closed plate surfaces were obtained than those of only ground plates. Preferably, the non-cutting smoothing with several in the feed direction of the wood material plate successively arranged rollers.

The thus smoothed broad surfaces of the wooden worktop panels are then provided with a high-gloss laminate coating, which is pressed onto the respective smoothed broad surface as a direct coating. The direct coating of

Wood-based panels are made intermittently. The high-gloss laminate coating may have a court decor, floral decor, fantasy decor or a patterned, plain decor (Unidekor).

The wood-based panels produced by the process according to the invention and provided with a high-gloss laminate coating by the DPL technology, in particular chipboard, had a gloss level of at least 105 gloss units (gloss grades), measured in each case as SO 2813 with a 60 ° measuring geometry. In particular, high-gloss laminate-coated chipboards were obtained which had a gloss level of more than 110, in particular more than 15, gloss units.

In Fig. 2 is a section of a wood-based panel according to the invention is sketched, in which it is a chipboard with the properties described above Spanlängen- and / or Spaπdickenverteiiung acts. The transition from the middle layer 1 to the cover layers 2, 3 of the chipboard is marked by dashed lines. The ground and then Spanish smoothed broad surfaces of chipboard are provided with high-gloss laminate coatings 4, 5.

In Fig. 1, the essential steps and some preferred optional steps of the method according to the invention in the form of a flow chart are shown schematically. Accordingly, first a wood-based panel, preferably chipboard with the above-mentioned properties with respect to Spanlängen- and / or Spandicken- distribution selected or produced. At least one or both flat broad surfaces of Holzwerkst off plate are then ground one or more stages. The ground Breitoberfiäche is freed from grinding dust and wetted before the subsequent non-cutting smoothing. For wetting, for example, water can be used. However, it can also be advantageous to use a solution or emulsion as the wetting center! to use. For this purpose, the wide surface to be smoothed and / or the smoothing surface of the smoothing body can be wetted accordingly. Furthermore, the invention provides, if appropriate, to add to the wetting agent one or more additives which can further improve the smoothness effect, or also to achieve an improved bonding of the subsequently applied laminate coating to the surface of the wood-based panel. In this way, also a saving of impregnating resin can be achieved.

The wetting can be carried out very simply by spraying, preferably by producing a fine spray before the smoothing device, in particular smoothing roll. Even very small amounts of moisture or wetting agents are sufficient to a

Improvement of the smoothness effect to achieve. Preferably, the amount of wetting agent applied is in the range of 2 to 20 g / m ² , preferably in the range of 2 to 10 g / m *.

After wetting, the ground wide surface of the Hoizwerkstoffplatte is smoothed by compacting them without cutting. For this purpose, preferably a smoothing roll

Use whose smoothing surface has a temperature of at least 100 ⁰ C. The tempering of the smoothing roll or of the smoothing element takes place, for example, by activation of heating elements integrated in the smoothing element or results from the friction between the smoothing surface of the smoothing element and the broad surface to be smoothed. Optionally, the temperature of the smoothing surface of the flattening body and / or the temperature of the smoothed broad surface of the wood-based panel are measured and compared with a predeterminable soil temperature value in order to control the flattening process. For example, if the temperature at the flattening body or at the smoothing roll is too low, the relative speed between the wood-based panel and the smoothing surface of the co-planar body (preferably smoothing roll) and / or the contact force of the flattening member are increased to the surface to be flattened. The measurement of the temperature of the smoothing surface of the smoothing body or the smoothed broad surface of the Hoizwerkstoffplatte preferably takes place by means of non-contact temperature sensors.

Following the chipless smoothing, the smoothed wide surface of the Hoizwerkstoffplatte is coated with a high-gloss laminate coating. The thus coated Hoizwerkstoffplatte is finally further treated without forced cooling, for example, divided into smaller plate formats and stored in a warehouse (see Fig. 2).

The embodiment of the invention is not limited to the Ausführungs¬ shown in the drawing Beispiei. Rather, numerous variants are possible, which make use even in deviating embodiment of the reproduced in the appended claims inventive concept.

Claims

Patent claims

1. A process for producing a Hotzwerkstoffpiatte having a high-gloss laminate coating, in which a Hoizwerkstoffplatte having at least one flat broad surface is ground at this broad surface, characterized by the following steps: non-cutting smoothing the ground, flat broad surface by compacting the same by means of a rolling or plate-shaped smoothing body whose smoothing surface is tempered to at least 100 ° C or has a temperature of at least 100 ⁰ C, and coating the smoothed broad surface by pressing a hochgiänzenden laminate coating in the form of a direct coating.

2. The method according to claim 1, characterized in that the pressed onto the wood-based panel high-gloss laminate coating is not subjected to forced cooling.

3. The method according to claim 1 or 2, characterized in that ais to be coated Hoizwerkstoffplatte a chipboard is used.

4. The method according to any one of claims 1 to 3, characterized in that is used as Hoizwerkstoffplatte a chipboard having layers of different Spaniängenverteälung, with a middle layer in which the maximum of Spanlängenverteilung between 8 mm and 15 mm, and outer layers, in where the maximum of the Spanlängenverteilung is at a chip length between 3 mm and 8 mm, wherein the proportion of chips having a length of less than 6 mm in the chip material of the outer layers at least 75 wt .-%, in particular at least 80 wt .-%, and preferably at least 90 wt .-% is.

5. The method according to any one of claims 1 to 4, characterized in that as Hoizwerkstoffplatte a particle board is used which has layers of different chip thickness distribution, with a middle layer in which the maximum of the Spandickenverteitung in the range of 1, 0 mm to 4.0 mm lies, and Cover layers in which the maximum thickness of the chip thickness distribution lies in the range of 0.1 mm to 0.8 mm, the proportion of chips having a thickness of less than 0.6 mm in the chip material of the cover layers being at least 75% by weight. , in particular at least 80 wt .-% and preferably at least 90 wt .-% is.

6. The method according to claim 4 or 5, characterized in that the binder content in the outer layers of the Hoizwerkstoffplatte based on the absolutely dry mass of the cover shavings at least 10 wt .-%, in particular at least 12 wt .-%, and preferably in the range of 15 to 25 wt .-% is.

7. The method according to any one of claims 1 to 6, characterized in that a chipboard is used as the wood-based panel, in the chip material of the Antei! of chips having a thickness of less than 0.6 mm at least 50 wt .-%, in particular at least 65 wt .-% and preferably at least 80 wt .-% is.

8. The method according to any one of claims 1 to 7, characterized in that a chipboard is used as Holzwerkstoffpiatte, in the chip material, the proportion of chips with a length of less than 8 mm at least 50 wt .-%, in particular at least 65 wt. % and preferably at least 85 wt .-% is.

9. The method according to any one of claims 1 to 8, characterized in that as Giättkörper a roller with a force in the range of 200 to 1000 N / cm plates width, preferably in the range of 450 to 750 N / cm plate width on the flat surface to be smoothed is pressed.

10. The method according to any one of claims 1 to 9, characterized in that the smoothing Breitoberf surface of the wood-based material is sanded plate before cutting smoothing in several stages, the final touch is performed with a grain size of 180 maximum, preferably of 120 maximum ,

11. The method according to any one of claims 1 to 10, characterized in that the wood material board is moved along a grinding tool, wherein the smoothing broad surface before the chipless smoothing additionally by at least one Querschüff based on the movement movement of the wood material board along the grinding tool is ground.

12. The method according to any one of claims 1 to 11, characterized in that the smoothing surface of the smoothing body is heated to a temperature in the range of 150 ° C to 24O ⁰ C, preferably in the range of 18O ⁰ C to 230 ⁰ C.

13. The method according to any one of claims 1 to 12, characterized in that the non-cutting smoothing of the ground, flat Breitoberfiäche by compacting the same by means of at least 150 ⁰ C, preferably at least 18O ⁰ C tempered rolls is performed, the rolls from above and pressed down against the wood-based panel.

14. The method according to any one of claims 1 to 1 1, characterized in that the smoothing surface of the smoothing body by friction between the smoothing body and the flat surface to be smoothed has a temperature of at least 100 ⁰ C, preferably at least 150 ⁰ C.

15. The method according to any one of claims 1 to 14, characterized in that the temperature of the smoothing surface of the Giättkörpers or the temperature of the smoothed broad surface of Hofzwerkstoffplatte is measured, that the measured temperature is compared with a predetermined target temperature, and that the Reiativgeschwindigkeit between the large surface to be smoothed and the smoothing surface of the smoothing body and / or the force with which smoothing body is pressed against the broad surface to be smoothed, is controlled as a function of the measured temperature.

16. The method according to any one of claims 1 to 15, characterized in that the smoothing Breitoberfiäche the wood material plate and / or the smoothing surface of the GSättkörpers are wetted before smoothing with water, a solution and / or an emulsion.

17. Hoizwerkstoffplatte, preferably chipboard, which is provided with a giänzenden laminate coating (4, 5), characterized in that the laminate coating (4, 5) is applied as a direct coating on a chipless smoothed broad surface of the Hoizwerkstoffplatte, wherein the laminate coating (4, 5 ) has a gloss level of at least 105, in particular of at least 110 and preferably of at least 115 gloss units measured according to ISO 2813 with a 60 ° measuring geometry.

18. Hoizwerkstoffplatte according to claim 17, characterized in that it is formed of a chipboard.

19. Hoizwerkstoffplatte according to claim 17, characterized in that it is formed of a chipboard having layers of different Spanlängenverteilung, with a middle layer (1), in which the maximum of Spanlängenverteilung between 8 mm and 15 mm, and outer layers (2, 3), in which the maximum of the Spanlängenverteilung with a chip length between 3 mm and 8 mm, wherein the proportion of chips having a length of less than 6 mm in the chip material of the outer layers (2, 3) at least 75 wt .-%, in particular at least 80 wt .-% and preferably at least 90 wt .-% is.

20. H oizwerkstoff plate according to claim 17 or 19, characterized in that it is formed of a chipboard having layers of different Spandickenverteiiung, with a middle layer (1), in which the maximum of the Spandickenverteilung in the range of 1, 0 mm to 4 , 0 mm, and cover layers (2, 3), in which the maximum of the chip thickness distribution at a chip thickness in the range of 0, 1 mm to 0.8 mm, wherein the proportion of chips having a thickness of less than 0.6 mm in the chip material of the cover layers (2, 3) at least 75 wt .-%, in particular at least 80 wt .-% and preferably at least 90 wt .-% is.

21. Hoizwerkstoffplatte according to claim 19 or 20, characterized in that the binder content in the outer layers (2, 3) of the Hoizwerkstoffplatte based on the absolutely dry mass of the cover shavings at least 10 wt .-%, in particular at least 12 wt .-% is and preferably is in the range of 15 to 25% by weight,

22. Wood material board according to one of claims 17 or 19 to 21, characterized in that it is formed from a chipboard, in the Spanmateriai the proportion of chips having a thickness of less than 0.6 mm at least 50 wt .-%, in particular at least 65 wt .-% and preferably at least 80 wt .-% is.

23. Holzwerkstoffpiatte according to any one of claims 17 or 19 to 22, characterized in that it is formed of a chipboard, in the Spanmateriai the proportion of chips with a length of less than 8 mm at least 50 wt .-%, in particular at least 65 wt .-% and preferably at least 85 wt .-% is.