METHOD AND DEVICE FOR PRODUCEING A DECORATED WALL OR FLOOR PANEL

Description

[0001] The present invention relates to a method for producing a decorated wall or floor panel, comprising the method steps: a) Providing a molten polymer mass; b) Extruding the molten polymer mass through a nozzle; c) Calibrating the molten polymer mass to form a plate-shaped carrier by means of an arrangement of several rotatable rollers, wherein the individual rollers are arranged one above the other or one behind the other and each individual roller forms at least one calibration gap with adjacent rollers through which the molten polymer mass is passed, wherein the calibration gap heights can be variably adjusted via a horizontal and / or vertical movement of individual rollers during the production process; d) Applying a decoration simulating a decoration template to at least a partial area of ​​the at least partially calibrated carrier, and e) Applying a protective layer to at least a partial area of ​​the decoration.

[0002] Also described is a device for producing a decorated wall or floor panel and a wall or floor panel produced according to the method described above.

[0003] Decorated panels are well known and are used, for example, in interior design as flooring or wall coverings. The term "wall panel" also includes panels suitable for ceiling cladding. The panels typically consist of a carrier or core made of a solid material, such as a wood-based material, which is covered on at least one side with a decorative layer and a cover layer, as well as optionally with additional layers, such as a wear layer arranged between the decorative and cover layers. The decorative layer is usually printed paper impregnated with a resin. The cover layer and the other layers are also usually made of resin.

[0004] Panel manufacturing processes typically involve several steps. For example, a "cake" of granulate pellets can be applied to the lower belt of a press via a spreading machine. During production, this cake is typically fed into a hot belt press with steel and / or Teflon belts, where the granulate pellets are heated and melted. Simultaneously with melting, the material can be pressed and formed into a substrate. Subsequently, controlled cooling causes the substrate material to solidify or crystallize. The waste heat remains largely unused, as the usable temperature difference due to the controlled cooling is too small for other uses. Heat transfer in this belt pressing process occurs from above and below through contact with the press.Another disadvantage for cooling is that the heat must pass through the glass-fiber-reinforced Teflon belt. Only then does the heat transfer occur through conduction into the pellet bed or the carrier material. These physical processes are very slow because the pellet cake initially still contains air from the pellet bed, which, due to the physical properties of the product, can only be slowly expelled from the carrier. To achieve acceptable belt speeds in production, a high temperature gradient must be created for cooling, which leads to considerable waste heat losses.

[0005] One possible method for producing a decorated wall or floor panel is described, for example, in EP3140129 B1. The method comprises the following steps: a) providing a pourable carrier material, in particular a granulate, b) arranging the carrier material between two belt-like conveying means, c) shaping the carrier material under the influence of temperature to form a web-shaped carrier, d) compressing the carrier, e) treating the carrier under the influence of pressure using a two-belt press, wherein the carrier is cooled in or before the two-belt press, f) optionally further cooling the carrier, g) optionally applying a decorative substrate to at least a partial area of ​​the carrier;h) applying a decoration simulating a decorative template to at least a partial area of ​​the carrier, i) applying a protective layer to at least a partial area of ​​the decoration, j) optionally structuring the protective layer to insert pores and / or the edge area of ​​the carrier to form connecting elements, and k) optionally treating the carrier for electrostatic discharge before one of the aforementioned process steps. ;

[0006] US 2019 / 016024 A1 discloses a calender comprising a base and a set of calender rolls arranged on the base, wherein the set of calender rolls comprises a set of primary calender rolls and a set of embossing rolls used for embossing a material to be processed; wherein the set of primary calender rolls and the set of embossing rolls are spaced apart from each other by a distance to allow the material to be cooled before passing from the set of primary calender rolls into the set of embossing rolls. The calender can achieve a better embossing effect, and integrated production can be realized by using the calender in the manufacture of a foamed floor.

[0007] CN 107 738 394 A discloses a calender comprising a machine base and calender roll groups arranged on the machine base. The calender is characterized in that each calender roll group comprises a main calender roll group and an embossing roll group for embossing materials to be processed. Each main calender roll group and the corresponding embossing roll group are arranged at a certain distance so that the materials can be cooled before entering another roll group from one roll group. The calender can achieve a better embossing effect. The calender is used for the production of a foam flooring, so that integrated production of the foam flooring can be realized.

[0008] CN 106 985 408 A discloses a production line for a six-layer co-extruded wood-plastic composite floor (WPC) in a one-step process.The production line includes extrusion machines, a mold, a five-roll forming machine, a cooling carrier, a two-roll embossing forming machine, a carrier, a drawing machine, a plate shearing machine, a conveying carrier, and an automatic plate lifting device. The mold is mounted on the extrusion machine and coordinated with the five-roll forming machine to directly send the extruded material into the five-roll forming machine. The cooling carrier is arranged at the outlet of the five-roll forming machine and coordinated with the five-roll forming machine to cool the base pressed and formed by the five-roll forming machine. The two-roll embossing forming machine is arranged at the rear of the cooling carrier and connected to the drawing machine through the carrier. The drawing machine is connected to the plate shearing machine and the conveying carrier; and the automatic plate lifting machine is arranged at the rear of the conveying carrier.

[0009] US 2019 / 292793 A1 discloses a floor panel comprising a substrate made of thermoplastic material, a decorative element applied thereto, and connecting parts made at least partially of the substrate on at least one pair of opposite edges. The connecting parts enable a mechanical interlock between two floor panels, wherein the substrate comprises a rigid substrate layer made of thermoplastic material and a fiberglass layer is present in the floor panel.

[0010] DE 10 2011 003604 A1 discloses a device for calibrating and cooling an extruded flat plastic product, comprising at least two main rollers and a polishing stack with several rollers arranged one behind the other, which is arranged downstream of the main rollers. An adjustable calibration gap is arranged between all adjacent rollers. The calibration gap is adjustable so that the flat product is squeezed to a greater or lesser extent during an extrusion process.

[0011] US 2017 / 182685 A1 discloses a method for smoothing and cooling plastic sheet material and a multi-nip take-off and cooling section with a first smoothing roll and a second smoothing roll. A positioning, calibration, and cooling roll is arranged near the second smoothing roll. The positioning, calibration, and cooling roll is movable relative to the second smoothing roll. A first stationary calibration and cooling roll is arranged near the positioning, calibration, and cooling roll. The first stationary calibration and cooling roll is in a fixed position relative to the second smoothing roll. A first movable calibration and cooling roll is arranged near the first fixed calibration and cooling roll. The first movable calibration and cooling roll is movable relative to the first fixed calibration and cooling roll.Actuators work together with the positioning, calibration and chill roll and the first movable chill roll to control both the nip pressure and the gap.

[0012] DE 20 2016 101306 U1 discloses a carrier material for producing a carrier for a decorated wall or floor panel, wherein the carrier material comprises a matrix material comprising a plastic and a solid material, wherein the solid material is formed by talc to an extent of at least 50 wt.%, in particular at least 80 wt.%, in particular at least 95 wt.%, based on the solid material, wherein the matrix material is present in an amount, based on the carrier material, of ≥ 30 wt.% to ≤ 70 wt.%, in particular of ≥ 40 wt.% to ≤ 60 wt.%, and wherein the solid material is present in an amount, based on the carrier material, of ≥ 30 wt.% to ≤ 70 wt.%, in particular of ≥ 40 wt.% to ≤ 60 wt.%, and wherein the carrier material and the solid material together, based on the Carrier material (20), in an amount of ≥ 95 wt.%, in particular ≥ 99 wt.%.

[0013] Panel manufacturing may offer further potential for improvement.

[0014] It is therefore the object of the present invention to provide an improved method for producing decorated wall or floor panels.

[0015] This object is achieved by a method according to claim 1 and by a device according to claim 6.

[0016] The invention thus proposes a method for producing a decorated wall or floor panel, comprising the following process steps: a) Providing a molten polymer mass; b) Extruding the molten polymer mass through a nozzle; c) Calibrating the molten polymer mass to form a plate-shaped carrier by means of an arrangement of several rotatable rollers, wherein the individual rollers are arranged one above the other or one behind the other and each individual roller forms, with adjacent rollers, at least one calibration gap through which the molten polymer mass is passed, wherein the calibration gap heights are variably adjustable via a horizontal and / or vertical movement of individual rollers during the production process;d) applying a decoration simulating a decoration template to at least a partial area of ​​the at least partially calibrated carrier, and e) applying a protective layer to at least a partial area of ​​the decoration, wherein the calibration in method step c) is carried out using at least one main roller pair (3) consisting of two rollers with a larger diameter and at least three calibrating rollers (7) arranged one behind the other with a smaller diameter than the main roller pair (6), and wherein the height of the calibrating gap of the main roller pair (6) HH differs by greater than or equal to 10% and less than or equal to 50% from the heights of the calibrating gaps of the calibrating rollers (7) HK, and wherein the height of the last and / or the penultimate calibrating gap (7) is selected such that the carrier is compressed in height by a factor of less than or equal to 10% and greater than or equal to 3%.

[0017] Surprisingly, it was found that the process described above enables improved production of a wall or floor panel. By aggregating the process steps, high-quality panels with improved decorative properties can be obtained within very short process times. Due in particular to the calibration step according to the invention, the panels have particularly even support surfaces, to which high-quality decorations can be applied particularly efficiently. Without being bound by theory, decorations applied according to the invention exhibit particularly high-quality optical properties due to the particularly smooth and defect-free surface of the support material. The process described above also enables high throughput at high line speeds and reduces the proportion of non-conforming panels.In particular, the inventive integration of the roller calibration step into the production process allows the proportion of air inclusions on the panel surface to be reduced, which can probably be attributed to improved removal of air present in the substrate and improved exclusion of air in the roller gaps. In addition to the direct process advantages, the flexible process using individually controllable rollers also allows the setup and run-in times of the system to be shortened, resulting in greater process efficiency. Furthermore, a larger proportion of the process energy can be recovered precisely through the inventive calibration step, which overall contributes to a smaller CO2 footprint of the process used and thus also of the manufactured panel.

[0018] The method according to the invention is a method for producing a decorated wall or floor panel. The term "decorated wall or floor panel" or "decorative panel" refers, in particular, to wall, ceiling, or floor panels that have a decoration applied to a carrier plate that replicates a decorative template. Decorative panels are used in a variety of ways, both in the interior design of rooms and for the decorative cladding of buildings, for example, in trade fair construction. One of the most common applications for decorative panels is their use as floor coverings. The decorative panels often have a decoration that is intended to replicate a natural material.

[0019] Examples of such replicated natural materials or decorative patterns include wood species such as maple, oak, birch, cherry, ash, walnut, chestnut, wenge, and even exotic woods such as panga-panga, mahogany, bamboo, and bubinga. Natural materials such as stone or ceramics can also be replicated.

[0020] Accordingly, a "decorative template" in the sense of the present invention can be understood in particular to mean that such a natural material or at least its surface is to be imitated or recreated by the decoration.

[0021] Process step a) comprises providing a molten polymer mass. The molten polymer mass exhibits, at least partially, the properties of a flowable, viscous liquid and can be obtained, for example, by a thermal treatment step of polymers typically present as granules. The molten polymer mass can consist of only one homogeneous polymer mass or of several polymer masses that are mixed with one another or layered one on top of the other in a defined form (feedblock). A "granule" or "granular material" can be understood as a solid or a heap of a solid that comprises or consists of a large number of solid particles, such as grains or spheres. Examples, but not limited to, granular or powdery materials or suitable recycling materials present as milled materials are mentioned here.

[0022] The polymer mass or the granulate can have a carrier material based on a plastic, a compound based on inorganic fillers, or a wood-plastic composite material (WPC). For example, the molten polymer mass and thus also the carrier plate can be made essentially of a thermoplastic, elastomeric, or thermosetting plastic. Furthermore, recycled materials made from the materials mentioned can be used in the process according to the invention. Preferably, thermoplastics such as polyvinyl chloride, polyolefins (e.g., polyethylene (PE), polypropylene (PP), polyamides (PA), polyurethanes (PU), polystyrene (PS), acrylonitrile butadiene styrene (ABS), polymethyl methacrylate (PMMA), polycarbonate (PC), polyethylene terephthalate (PET), polyetheretherketone (PEEK) or mixtures or copolymers thereof can be used as the molten polymer mass.Regardless of the base material of the carrier, plasticizers can be provided, for example, which can be present in a range from ≥ 0 wt.% to ≤ 20 wt.%, in particular ≤ 10 wt.%, preferably ≤ 7 wt.%, for example in a range from ≥ 5 wt.% to ≤ 10 wt.%. Suitable plasticizers include, for example, the plasticizer sold under the trade name "Dinsch" by BASF. Furthermore, copolymers such as acrylates or methacrylates or blends with thermoplastic elastomers (TPEs) can be provided as replacements for conventional plasticizers.

[0023] To produce a molten polymer mass, one or more so-called dry blends, i.e., dry plastic powders with additives, can be melted. Other possible additives include "fiber materials" such as paper and nonwovens based on plant, animal, mineral, or even artificial fibers or cardboard. Examples include fiber materials made from plant fibers and, in addition to paper and nonwovens made from cellulose fibers, boards made from biomass such as straw, corn stalks, bamboo, leaves, algae extracts, hemp, cotton, or oil palm fibers. Examples of animal fiber materials include keratin-based materials such as wool or horsehair. Examples of mineral fiber materials include mineral wool or glass wool.

[0024] These materials can be provided in process step a), for example, by a screw extruder, in which the polymeric material or the dry blends are melted, optionally homogenized and passed on to process step b) by means of pressure, temperature and shear forces.

[0025] In process step b), the molten polymer mass is extruded through a nozzle. The molten and plasticized polymer mass is forced through a nozzle using pressure, with the choice of nozzle geometry advantageously already predetermining part of the final product geometry. For panels, the choice of a slot or wide-slot die has proven particularly suitable, with a slot width to height ratio of more than approximately 4:1 (width:height), preferably more than 10:1, and furthermore preferably more than 20:1. Particularly for the panels according to the invention, this rather wide and narrow nozzle geometry allows a large portion of the support structure to be preformed, which can minimize the subsequent effort required to calibrate the extruded polymer mass. In particular, it can be advantageous for the wide-slot die to have means for adjusting the nozzle gap.These means can, for example, be used to extremely flatten the edge areas of the extruded flat strand, so that in these edge areas, flatter joints between different panels can be formed in a further process step without great calibration effort compared to medium panel thicknesses.

[0026] In process step c), the molten polymer mass is calibrated to form a plate-shaped carrier using an arrangement of several rotatable rollers, wherein the individual rollers are arranged one above the other or one behind the other and each individual roller forms at least one calibration gap with neighboring rollers through which the molten polymer mass is passed. The calibration gap heights can be variably adjusted via a horizontal or vertical movement of individual rollers during the production process. In contrast to the prior art, the panels are not formed and calibrated using a flat press, but rather by using rollers. The molten polymer mass is passed through the gaps between the rollers formed by the roller arrangement, and due to the mechanical stress in the roller gaps, the mass is squeezed and brought to the desired thickness.In addition to the mechanical forces exerted by the rollers, the polymer mass can also be cooled simultaneously. This can be achieved via the rollers or by means of other coolants, e.g., by blowing air. It is surprising that efficient calibration can be achieved using the roller arrangement and the roller gaps, since the viscoelastic properties of the molten polymer mass suggest the use of presses with a large surface area. The relatively small active calibration surface in the roller gaps compared to the presses should, in fact, lead to insufficient calibration on small calibration surfaces due to the rheological properties of the polymer mass, such as its thixotropic properties.

[0027] Surprisingly, this is not the case, so that efficient and time-saving production can be ensured by arranging several rollers. In this context, several rollers means more than four, for example five rollers, with the multiple rollers forming at least three or four separate gaps. The gaps are preferably arranged one behind the other, separated by the rollers. In particular, the invention also provides for the calibration of the carrier to take place solely by guiding the molten carrier material through the roller gaps. In this respect, the invention can also provide for the method to completely dispense with the use of plate-shaped pressing devices, such as belt presses. It can also be provided for the calibration of the carriers to take place solely by the rollers arranged one behind the other, in direct succession at one location in the device.Dividing the roller arrangement, for example, first into two roller gaps, followed by, for example, a cooling section and then one or two more roller gaps, would not be in accordance with the invention in this case. According to the invention, it can further be provided that the calibration takes place directly after the extrusion of the carrier material, eliminating any further significant calibration or smoothing steps.

[0028] The calibration gap heights can be variably adjusted by horizontally or vertically moving individual rollers during the manufacturing process. This means that by changing the position of an individual roller, the gap dimensions of the gap(s) formed between adjacent rollers also change. In this way, the gap dimensions and thus the support height can be influenced by the distance between the rollers. The relative height of the individual rollers can also be used to change the angle at which the molten polymer material is drawn off or hit the roller. This results in different mechanical forces, possibly different cooling properties and surfaces, as well as possible air inclusions between the roller and the polymer. A roller is variably adjustable during the manufacturing process if the roller can change its X and / or Y position as the polymer material passes through.During production, the individual gaps can be controlled either isobarically or isochorically. The former applies a mechanical force to the polymeric carrier material in the nip, whereas the latter relies on a constant gap thickness between two rolls. In the former, the roll positions are dynamically adjusted, whereas in the latter, the roll positions are kept more constant relative to each other.

[0029] It is particularly advantageous if different calibration gaps can be set between several or all of the rollers. This can counteract fluctuations in the substrate thickness that occur during production and potentially inconsistent cooling performance of the individual rollers. Each of the rollers can simply "run along" or support the conveying of the film, which is why the rollers can be driven individually or together. Depending on the roller positioning, the substrate material can pass through the rollers in a wave-like pattern, thus coming into contact with one side and then the other of successive rollers.To ensure that the influence of the contact surfaces between the roller and the support surface is largely equal for both sides of the support, the diameter of the main rollers and the downstream rollers can be selected so that the contact surfaces between the support and the rollers are largely equal on both sides of the support. When wrapping around a particular roller, only one side of the extrudate can be cooled at a time, which may cause stresses in the sheet. To counteract this uneven cooling profile, a more uniform cooling effect on the support can be achieved, for example, by actively introducing cold air from the back (e.g., using an air knife).

[0030] Since the cooling behavior can vary across the width of the extrudate and to counteract a neck-in effect, it is also possible to apply heat to the edge area on the opposite side. IR radiators, for example, can be used for this purpose. Further measures for uniform cooling of the molded polymer mass can include vacuum boxes, which ensure air-free application of the polymer melt to the roller, or edge pinning, in which the edge area is electrostatically fixed to the roller.

[0031] In process step d), a decoration simulating a decorative template is applied to at least a portion of the at least partially calibrated carrier. The decorative template can therefore be applied after the fully calibrated carrier has passed through the roller arrangement or before it passes through the last roller calibration gap. Thanks to the process according to the invention, the carrier not only has a particularly smooth surface with low roughness, but also a surface with particularly few air inclusions. These two factors can contribute to a particularly reproducible and high-quality decorated end product. Without being bound by theory, the relatively small volume in the roller gap between the roller pairs allows the air in the carrier to escape significantly more easily than in a flat press. This can lead to carriers and carrier surfaces with particularly few air inclusions.By applying a second, white-colored polymer melt on top of the molten and extruded polymer, a smooth, void-free printing base can be applied. Unlike prior art solutions, this base does not require the addition of a layer of non-polymer thermosets. This has the advantage of being made from a nearly identical thermoplastic polymer matrix to the carrier plate. This can be very advantageous for efficient recycling.

[0032] Furthermore, a decoration replicating a decorative template is applied to at least a portion of the substrate. The decoration can be applied, for example, by so-called direct printing. The term "direct printing" in the context of the invention refers to the application of a decoration directly to the substrate of a panel or to a non-printed fiber material layer applied to the substrate, or to a decorative substrate. Various printing techniques can be used, such as flexographic printing, offset printing, or screen printing. In particular, inkjet or laser printing processes can be used as digital printing techniques.

[0033] For example, in order to imitate or recreate a decorative template in a particularly detailed and highly precise manner in three-dimensional form, the decoration can be applied identically to the template after passing through the roller arrangement. In particular, the three-dimensional decorative data can be provided by a three-dimensional scanning of the decorative template using electromagnetic radiation, for example, by a three-dimensional scanner (3D scanner). In this case, a plurality of decorative layers with at least partially different surface coverage can be successively applied based on the provided three-dimensional decorative data.

[0034] Furthermore, the decorative layers can be formed from a particularly radiation-curable paint and / or ink. For example, a UV-curable paint or ink can be used. In this embodiment, a particularly detailed and consistent reproduction of the decorative template can be achieved. Firstly, a synchronous pore can be achieved with high precision in this way without the provision of further measures. A synchronous pore can in particular be a pore or another type of structure which is spatially arranged exactly where it is optically represented by a haptic structuring that matches the optical decorative features. This is essentially the case automatically in this embodiment, since the structural design is created precisely by the paint or ink.Furthermore, decorative templates, such as wood-based materials, often exhibit a variation in color impression not only along their width or length, but also along their depth. This color impression or color gradient can also be recreated with particular accuracy in this design, which also makes the overall appearance of the panel appear even more uniform. Particularly if the paint or ink used is radiation-curable, particularly rapid solidification can be achieved, allowing the multiple layers to be applied quickly on top of one another. This also makes the overall process faster and thus particularly cost-effective.

[0035] For the purposes of the invention, the term radiation-curable paint is understood to mean a composition containing binders and / or fillers and color pigments, which can be at least partially polymerized by electromagnetic radiation of a suitable wavelength, such as UV radiation or electron beams.

[0036] In the context of the invention, the term radiation-curable ink is to be understood as meaning a composition which is essentially free of fillers and contains color pigments and which can be at least partially polymerized by electromagnetic radiation of a suitable wavelength, such as UV radiation or electron beams.

[0037] The decorative layers can be applied in thicknesses of ≥ 5µm to ≤ 10µm.

[0038] It can also be provided that, in addition to a positive image in terms of color and / or structure, a corresponding negative image of the decorative template is also applied. In detail, as is known, for example, from positive or negative staining for wood materials, the color impression of, for example, a grain can be reversed by using digital data, so that a negative is created with regard to the color, or in particular lighter and darker areas. The same is also possible for the applied structure in addition to the color impression, so that a negative can also be realized with regard to the structural design. Such effects can also be easily integrated into a manufacturing process on the basis of digital three-dimensional data and without lead time or modifications.

[0039] In process step e), a protective layer is applied to at least a partial area of ​​the decoration. Such a layer for protecting the applied decoration can be applied in particular as a wear or covering layer above the decorative layer in a subsequent process step, which in particular protects the decorative layer from wear or damage caused by dirt, moisture, or mechanical influences, such as abrasion. For example, it can be provided that the wear and / or covering layer is applied as a pre-produced overlay layer, for example based on melamine, onto the printed carrier and bonded to it by the application of pressure and / or heat. Furthermore, it can be preferred that a radiation-curable composition, such as a radiation-curable lacquer, such as an acrylic lacquer, is also applied to form the wear and / or covering layer.The wear layer may contain hard materials such as titanium nitride, titanium carbide, silicon nitride, silicon carbide, boron carbide, tungsten carbide, tantalum carbide, aluminum oxide (corundum), zirconium oxide, or mixtures thereof to increase the wear resistance of the layer. The coating can be applied, for example, using rollers such as rubber rollers or by means of casting devices.

[0040] Furthermore, the top coat can first be partially cured and then a final coat of paint with a urethane acrylate and a final curing, for example with a gallium lamp, can be carried out.

[0041] Furthermore, the cover and / or wear layer can comprise agents for reducing the static (electrostatic) charge of the final laminate. For example, the cover and / or wear layer can comprise compounds such as choline chloride. The antistatic agent can be contained, for example, in a concentration between ≥ 0.1 wt.% and ≤ 40.0 wt.%, preferably between ≥ 1.0 wt.% and ≤ 30.0 wt.% in the cover and / or composition for forming the wear layer.

[0042] A transparent wear layer made of thermoplastic polymers, laminated as a film onto the decorative layer, may also be suitable. Adequate adhesion may require the use of a primer, which crosslinks with the decorative layer through radiation curing from above ("adhesive varnish") or seals it thermally ("hot melt"). A thermoplastic wear layer offers further advantages for the recycling process of the entire structure. Surface structuring can be easily applied using heated structured sheets via a press or structured rollers via a calender (these can also be applied synchronously with the decor).

[0043] Furthermore, it can be provided that a structure, in particular a surface structure matching the decor, is introduced into the protective or wear-resistant or covering layer by introducing pores. It can be provided that the carrier plate already has a structure and an alignment of a printing tool for applying the decor and the carrier plate to one another takes place depending on the structuring of the carrier plate detected by means of an optical method. In order to align the printing tool and the carrier plate to one another, it can be provided that a relative movement between the printing tool and the carrier plate, which is necessary for alignment, takes place by moving the carrier plate or by moving the printing tool. Furthermore, it can be provided that a structuring of the decorative panels takes place after the application of the covering and / or wear layer.For this purpose, it can preferably be provided that a hardenable composition is applied as a covering and / or wear layer and a hardening process only takes place to the extent that only partial hardening of the covering and / or wear layer takes place. A desired surface structure is embossed into the partially hardened layer using suitable tools, such as a hard metal textured roller or a stamp, during or after the calibration step. The embossing takes place in accordance with the applied decoration. To ensure sufficient correspondence between the structure to be applied and the decoration, it can be provided that the carrier plate and the embossing tool are aligned to one another by appropriate relative movements. Following the introduction of the desired structure into the partially hardened covering and / or wear layer, the now structured covering and / or wear layer is further hardened.In a further step, the decorative carrier board can then be divided into individual panels using suitable mechanical processes. This can be achieved, for example, by cutting the extruded strand at regular intervals or at regular intervals. Preferably, this process step can produce cut panels of equal length.

[0044] According to the invention, calibration in process step c) is carried out using at least one main roller pair consisting of two rollers with a larger diameter and at least three calibrating rollers arranged one behind the other with a smaller diameter than the main roller pair. To achieve the most uniform surface structure possible for receiving the decoration, it has proven particularly advantageous to apply mechanical and, if necessary, thermal forces to the substrate unevenly using different roller sizes. This measure can lead to particularly smooth substrate surfaces, which can be decorated particularly easily and reproducibly.The majority of the desired and necessary deformation can be achieved via the larger pair of rollers, whereas the other, smaller calibration rollers exert only low forces to obtain a uniformly calibrated product and transport air out of the carrier in a controlled manner. This allows high line speeds to be achieved while maintaining only minimal thickness fluctuations in the produced carrier. The roller diameters differ in diameter if the corresponding diameters of the main and calibration rollers differ by at least 10%. The above-mentioned arrangement results in, for example, the following gap arrangements for the molten polymer material. The molten polymer material necessarily passes through the gap between the main rollers and at least the two gaps between the at least three calibration rollers. The arrangement can, for example, have a total of 8, preferably 6, furthermore preferably 4 calibration rollers.This number of individual columns has proven particularly suitable for obtaining decorated panels with improved surface and decorative properties.

[0045] The height of the calibration gap of the main roller pair HH differs by greater than or equal to 10% and less than or equal to 50% from the heights of the calibration gaps of the calibration rollers HK. The above-mentioned gap height ratio between the main and calibration rollers has proven particularly suitable for obtaining particularly smooth carrier surfaces and for obtaining carrier materials with particularly low mechanical stress. This specification allows the force acting on the carrier to be determined, so that a force distribution that is particularly suitable for the production of decorated panels is specified for the roller arrangement. This results in particularly favorable properties both with regard to the presence of air pockets and with regard to the occurrence of stress cracks in the carrier material. In addition, the distance between the mechanical force application and the shaping of the carrier, in relation to the location where the decoration is applied, also appears to play an important role.In a preferred embodiment, it has proven particularly suitable for the height of the calibration gap(s) to be greater than or equal to 10% and less than or equal to 50% smaller than the height of the main roll gap. This can contribute to high line speeds without loss of the surface quality of the decorated panel.

[0046] In a further aspect of the process, the height of the last and / or penultimate calibration gap can be selected such that the substrate is compressed in height by a factor of less than or equal to 10% and greater than or equal to 3%. The compression ratio specified above has proven particularly advantageous for obtaining substrate surfaces with particularly low air inclusions and particularly smooth surfaces. The ratio can be determined, for example, by measuring the thickness of the substrate before and after passing through the gap. The desired compression rate can be adjusted via the height profile ratio of the calibration roll gaps or via the force applied in the individual roll gaps.

[0047] In a further preferred characteristic of the process, process step d) can additionally comprise the application of a decorative substrate to at least a partial area of ​​the carrier prior to the application of the decoration. At the same time as or shortly before the application of the decorative layer, or even during the roller arrangement, further optional layers, such as a decorative substrate or a primer layer, can of course also be applied to the carrier. It can be advantageous, for example, to apply these further layers to the carrier before the last roller, since improved adhesion of these further layer(s) to the carrier can be achieved by the at least one mechanical treatment in the further calibration gap. Furthermore, the carrier can be pretreated by an electrostatic discharge between or after the roller arrangement.This can be used, in particular, to prevent blurring during the decorative application process. This is particularly suitable for printing processes for applying decorative layers, since the electrostatic charge that builds up in the substrates to be printed during the production process leads to a deflection of the ink droplets on their way from the print head to the surface to be printed. The resulting inaccuracy in the ink application leads to the noticeable blurring of the printed image.

[0048] A possible device for dissipating electrostatic charges can comprise at least one of the rollers or a separate roller, brush, or lip made of a conductive material with a conductivity ≥ 1*10 3 < Sm -1 <, which electrically contacts the carrier at least in the area of ​​the printing unit and is connected to an electrical ground potential. The electrical ground potential can be provided, for example, by grounding. Furthermore, a device for dissipating electrostatic charges can be, for example, a device for generating a corona discharge.

[0049] A decorative substrate can, for example, initially comprise a primer, particularly for printing processes, with a thickness of approximately ≥ 10 µm to ≤ 60 µm. The primer can be a liquid radiation-curing mixture based on a urethane or a urethane acrylate, optionally with one or more of a photoinitiator, a reactive diluent, a UV stabilizer, a rheological agent such as a thickener, a radical scavenger, a flow control agent, a defoamer or preservative, a pigment, and / or a dye. For example, the urethane acrylate can be contained in the primer composition in the form of reactive oligomers or prepolymers. The term "reactive oligomer" or "prepolymer" in the context of the invention refers to a compound containing urethane acrylate units which, when induced by radiation, optionallywith the addition of a reactive binder or a reactive diluent to form the urethane or urethane acrylate polymer. Urethane acrylates within the meaning of the invention are compounds which are essentially composed of one or more aliphatic structural elements and urethane groups. Aliphatic structural elements include both alkylene groups, preferably having 4 to 10 C atoms, and cycloalkylene groups, preferably having 6 to 20 C atoms. Both the alkylene and the cycloalkylene groups can be mono- or polysubstituted by C 1 -C 4 alkyl, in particular by methyl, and can contain one or more non-adjacent oxygen atoms. The aliphatic structural elements are optionally bonded to one another via quaternary or tertiary carbon atoms, via urea groups, biureth, urethdione, allophanate, cyanurate, urethane, ester or amide groups, or via ether oxygen or amine nitrogen.Furthermore, urethane acrylates within the meaning of the invention can also contain ethylenically unsaturated structural elements. These are preferably vinyl or allyl groups, which can also be substituted by C 1 -C 4 -alkyl, especially methyl, and which are derived in particular from α,β-ethylenically unsaturated carboxylic acids or their amides. Particularly preferred ethylenically unsaturated structural units are acryloyl and methacryloyl groups, such as acrylamido and methacrylamido, and especially acryloxy and methacryloxy. Radiation-curable within the meaning of the invention means that the primer composition can be at least partially polymerized by electromagnetic radiation of a suitable wavelength, such as UV or electron beams.

[0050] The use of radiation-curable primers based on urethane acrylates particularly advantageously enables the immediate application of a decorative finish following the application and radiation-induced curing of the primer layer, for example, using digital printing technology. The primer layer ensures good adhesion of the applied decorative finish to the primer-coated substrate surface. Urethane acrylates have the advantage of good adhesion to both the substrate material and the decorative layer, i.e., the decorative paint or ink. This is due, among other things, to the polymerization reactions that occur with this type of polymer, which involve, on the one hand, radiation-induced radical polymerization of the OH groups and, on the other hand, post-curing of the polymer via the NCO groups.This results in a tack-free and further processable surface being immediately obtained after radiation-induced curing, while the final properties of the primer layer are also influenced by the NCO group-based post-curing and ensure a secure bond to the substrate. Furthermore, the resulting post-curing ensures that sufficient layer stability is achieved even in less or unexposed areas of the substrate. As a result, the process according to the invention can be used to reliably apply a primer layer to pre-structured substrates, i.e., substrates whose surface already has a three-dimensional structure. This ensures that the subsequently applied decoration is firmly bonded to the substrate.

[0051] In the process according to the invention, the primer can preferably be applied by means of rubber rollers, a casting machine, or by spraying onto the carrier plate passing through the roller arrangement. It is also possible for the primer to be applied after the roller arrangement but before the application of the decoration. The primer is preferably applied in an amount between ≥1 g / m 2 and ≤100 g / m 2 , preferably between ≥10 g / m 2 and ≤50 g / m 2 , in particular between ≥20 g / m 2 and ≤40 g / m 2 . Following application of the primer to the carrier surface, irradiation with a radiation source of a suitable wavelength takes place.

[0052] In addition to the use of a primer, it is possible to apply the decoration to a decorative paper printable with a corresponding decoration, which can be provided, for example, by means of a resin layer previously applied to the carrier as a bonding agent. Such a printing substrate is suitable for flexographic printing, offset printing or screen printing processes, as well as in particular for digital printing techniques such as inkjet processes or laser printing processes. To apply the resin layer, it can preferably be provided that a resin composition is applied which has, as a resin component, at least one compound selected from the group consisting of melamine resin, formaldehyde resin, urea resin, phenolic resin, epoxy resin, unsaturated polyester resin, diallyl phthalate or mixtures thereof.The resin composition can be applied, for example, in a quantity between ≥ 5 g / m 2 and ≤ 40 g / m 2 , preferably ≥ 10 g / m 2 and ≤ 30 g / m 2 . Furthermore, a paper or nonwoven with a grammage between ≥ 30 g / m 2 and ≤ 80 g / m 2 , preferably between ≥ 40 g / m 2 and ≤ 70 g / m 2 , can be applied to the plate-shaped carrier.

[0053] Within the scope of a preferred embodiment of the method, at least the application of the decorative substrate to a partial area of ​​the carrier in method step d) can take place before the last roller in the roller arrangement of method step c). To create a particularly close bond between the decorative substrate and the carrier, it has proven particularly suitable for the calibration rollers to be used not only for adjusting the carrier height, but also for applying and mechanically fixing the decorative substrate. This measure enables a particularly efficient process to be implemented, whereby in particular the drying of the decorative substrate can be accelerated since the carrier has higher temperatures at this point in the process. This makes it possible to eliminate the need for further mechanical components and optimize the temperature control during cooling.The total amount of heat to be dissipated by the material can be reduced, for example, by the heat capacity of the decorative substrate.

[0054] In a further preferred embodiment of the method, the roller arrangement can have at least four additional calibration rollers in addition to the main roller pair, with one of the nips of the calibration rollers being operated isobarically. In contrast to operating with constant gap thicknesses between the calibration rollers, it has proven particularly advantageous for the surface properties of the carriers if at least one of the nips is operated isobarically, i.e. with a constant force acting on the carrier. This enables very fast process times while maintaining the smoothest possible carrier surface. Isobaric operation within the meaning of the invention means that by controlling the roller spacing, the force acting on the carrier in the nip fluctuates by less than 10%, preferably less than 5%, and furthermore preferably by less than 2.5% during carrier production.The forces required to produce a carrier can be measured, for example, using a force sensor on or in the roller or using one or more force sensors in the carrier material.

[0055] Within a preferred aspect of the process, the main and calibration rolls can be equipped with temperature control, and the temperature-controllable surface of the calibration rolls can be larger than that of the main rolls by a factor of greater than or equal to 1.1 to less than or equal to 2.5. In addition to the mechanical treatment of the molten polymer mass, the roll arrangement can also simultaneously thermally treat the carrier. The thermal treatment can in principle consist of partial heating or partial cooling of the carrier. Advantageously, the molten material is cooled by the rolls at the roll surface. This can be achieved, for example, by providing the individual rolls with a supply of heat transfer media, such as a cooling liquid, inside the rolls.Another advantage is that the surface temperatures of the individual rollers in the roller arrangement can be controlled separately. This can contribute to a particularly reproducible and gentle forming and cooling process. The above-specified ratio of cooling surfaces between the main and calibration rollers has proven particularly suitable for obtaining decorated panels with particularly low mechanical stress and very few air pockets. Without being bound by theory, the higher-quality decorations result from the controlled amount of heat dissipated in the individual steps, which is also proportional to the surface area of ​​the roller pairs. Within this range, very high web speeds and particularly efficient expulsion of air pockets from the substrates can be achieved.Furthermore, the individual roller temperatures, and consequently the cooling rates achievable at them, can be selected as a function of the mechanical force exerted on the support. Greater forces, for example, due to high compression of the support material, can be accompanied by a higher temperature gradient between the roller and the support material, resulting in a support with lower mechanical stresses.

[0056] Furthermore, the invention relates to a device for producing a decorated wall or floor panel, wherein the device has means for carrying out the method according to the invention. For the advantages of the device according to the invention, explicit reference is made to the advantages of the method according to the invention. A preferred embodiment of the device can comprise a temperature-controlled screw extruder and a slot die with a variable profile. Furthermore, the device can have temperature-controlled and, in particular, coolable rollers. The individual rollers can be moved relative to one another in their positions during the production process, and consequently the dimensions of the roller gaps forming between the rollers can also be changed.Preferably, at least one larger main roller pair and several, preferably at least 3, more preferably 4, and even more preferably 5 additional, smaller calibrating rollers can be used to form and calibrate the carrier. The rollers can each be equipped with separately adjustable temperatures. Downstream of the roller arrangement, the device according to the invention can further comprise means for applying additional layers, such as a decorative substrate, a decoration and / or a wear-resistant layer. The means for applying these layers can be arranged downstream of the calibrating rollers. The decoration is preferably applied downstream of the roller arrangement using a direct printing process. The application of a decorative protective layer can be carried out, for example, by lamination under pressure or by brushing or doctoring a liquid or pasty protective layer mass.The device can also have further means for the final cooling of the carrier. It is also possible for the device to have further means for returning the heat dissipated from the carrier back into the product cycle. This can be done, for example, via heat exchangers. The recovered waste heat can, for example, be used to temperature-control the extruder. In addition, the device can have further means for mechanically processing the carrier, for example for the special profiling of the carrier edges. Furthermore, the device can have further means for dividing the extruded sheet into smaller, essentially equal-length panels. This dividing or cutting can be done, for example, using a saw. Circular or band saws can be suitable for this purpose.However, it is also possible for the extruded and decorated sheet to be divided into smaller panels by other physical means, such as a laser.

[0057] Furthermore, a wall or floor panel is described which is produced according to the method according to the invention. For the advantages of the wall and

[0058] For floor panels, explicit reference is made to the advantages of the method according to the invention and to the advantages of the device according to the invention. In particular, it should be noted that, at very high line speeds, panels can be obtained using the method according to the invention. These panels are characterized by particularly smooth surfaces and a low air content in and in the form of pores on the surface of the panels. The number and size of surface defects caused by air can be significantly reduced. Furthermore, the temperature control and mechanical treatment result in very low-stress supports. The method and device are also suitable for processing a wide variety of materials.

[0059] Particularly advantageously, the carrier material can comprise or consist of wood-polymer materials (wood-plastic composite, WPC). For example, wood and a polymer can be suitable here, which can be present in a ratio of 40 / 60 to 70 / 30, for example 50 / 50. Polypropylene, polyethylene, or a copolymer of the two aforementioned materials can be used as polymer components. Such materials offer the advantage that they can be formed into a carrier even at low temperatures, such as in a range of ≥ 180°C to ≤ 200°C, using the method described above, thus enabling particularly effective process control, for example with line speeds in a range of 6 m / min.For example, a WPC product with a 50 / 50 distribution of wood and polymer components with an exemplary product thickness of 4.1 mm is possible, which can enable a particularly effective manufacturing process.

[0060] In a preferred embodiment of the wall or floor panel, the panel can comprise greater than or equal to 50 wt.% and less than or equal to 100 wt.% of a WPC material or a PVC material. Furthermore, it can be particularly advantageous for the carrier material to comprise or consist of a PVC-based material. Such materials can also be used particularly advantageously for high-quality panels, which can also be used without problems in damp rooms. Furthermore, PVC-based carrier materials also offer a particularly effective manufacturing process, as line speeds of 8 m / min are possible with an exemplary product thickness of 4.1 mm, which can enable a particularly effective manufacturing process. Furthermore, such carriers also have advantageous elasticity and water compatibility, which can lead to the aforementioned advantages.

[0061] Mineral fillers can be advantageous for plastic-based panels, as well as for WPC-based panels. Particularly suitable materials include talc or calcium carbonate (chalk), aluminum oxide, silica gel, quartz flour, wood flour, and gypsum. For example, chalk can be used in a range of ≥ 30 wt.% to ≤ 70 wt.%, whereby the fillers, especially chalk, can improve the slip of the substrate. They can also be colored in a known manner. In particular, the panel material can be provided with a flame retardant.

[0062] In a preferred embodiment of the wall or floor panel, the carrier material of the panel can comprise a matrix material and a solid material, wherein the matrix material is present in an amount, based on the carrier material, of ≥ 25 wt.% to ≤ 55 wt.%, in particular of ≥ 35 wt.% to ≤ 45 wt.%, and wherein the solid material is present in an amount, based on the carrier material, of ≥ 45 wt.% to ≤ 75 wt.%, in particular of ≥ 55 wt.% to ≤ 65 wt.%, and wherein the matrix material and the solid material together are present, based on the carrier material, in an amount of ≥ 95 wt.%, in particular ≥ 99 wt.%, wherein the solid material comprises at least 50 wt.%, in particular at least 80 wt.%, in particular at least 95 wt.-%, based on the solid material, is formed from a solid composition consisting of at least a first layered silicate powder and a second layered silicate powder, and the matrix material is formed to at least 50 wt.%, in particular to at least 80 wt.%, in particular to at least 95 wt.%, based on the matrix material, by a plastic composition consisting of a homopolymer and at least a first copolymer and a second copolymer. Surprisingly, it has been found that the process according to the invention can also be used to process compositions made up of several polymers that are difficult to process, in particular those whose surface is difficult to smooth, and that are filled with silicates. The surfaces can be processed at high line speeds using the process according to the invention, and the smoothing obtainable at high speeds is comparable to or better than that of the prior art processes.

[0063] In detail, the carrier material comprises a solid material and a matrix material. The matrix material is present in an amount, based on the carrier material, of ≥ 25 wt.% to ≤ 55 wt.%, in particular of ≥ 35 wt.% to ≤ 45 wt.%. Furthermore, the solid material is present in an amount, based on the carrier material, of ≥ 45 wt.% to ≤ 75 wt.%, in particular of ≥ 55 wt.% to ≤ 65 wt.%.

[0064] Depending on the desired application and the desired properties of the panel, the proportions of matrix material or solid material can be selected. This allows for good adaptability to the desired application. However, it may generally be preferable for the proportion of solid material to be greater than or equal to the proportion of matrix material.

[0065] It is further provided that the matrix material and the solid material together, based on the carrier material, are present in an amount of ≥ 95 wt.%, in particular ≥ 99 wt.%.

[0066] In other words, it can be provided that, in addition to the solid material and the matrix material, further substances are present in the carrier material only in a proportion of <5 wt.%, preferably <1 wt.%, based on the carrier material. Thus, it can be advantageous for the carrier material to consist largely of the solid material and the matrix material. Particularly preferably, it can be provided that the matrix material and the solid material together are present in an amount of 100 wt.%, based on the carrier material, so that the carrier material thus consists of the matrix material and the solid material.

[0067] By limiting the materials used for the substrate and thus reducing the number of materials required for manufacturing the substrate, the substrate can be produced particularly cost-effectively. Furthermore, the process for manufacturing a substrate or panel can be very simple, making production simple and cost-effective.

[0068] In detail, it is further provided that the solid material is formed to at least 50 wt.%, in particular to at least 80 wt.%, in particular to at least 95 wt.%, based on the solid material, from a solid composition consisting of at least one first layered silicate powder and one second layered silicate powder.

[0069] Phyllosilicate powder is understood, in the conventional sense, to be a powder made from a phyllosilicate. Phyllosilicates are minerals from the silicate group whose silicate anions are usually arranged in layers. For example, phyllosilicates include minerals from the mica group, the chlorite group, the kaolinite group, and the serpentine group.

[0070] Thus, the solid material is advantageously composed at least largely of the mineral substance phyllosilicate, which can be used in powder form or present in the carrier material in the form of particles. In principle, the solid material can consist of a powdered solid. Phyllosilicates offer the advantage of allowing the production of a carrier with good mechanical properties and, at the same time, their layered structure allows them to be easily processed into corresponding powders.

[0071] In one embodiment of the invention, the first layered silicate powder or the second layered silicate powder may comprise talc. Talc is understood, in a conventional manner, to mean a magnesium silicate hydrate, which may, for example, have the chemical formula Mg 3 [Si 4 O 10 (OH) 2 ]. In a further embodiment of the invention, the first layered silicate powder and the second layered silicate powder may comprise talc. In a further preferred embodiment, the first layered silicate powder and the second layered silicate powder may consist of at least 80 wt.%, particularly preferably at least 95 wt.%, talc.

[0072] Talc, in particular, offers the advantage of enabling particularly gentle production of the carrier, as it can be easily embedded in the matrix material and thus does not have an abrasive effect on the pressing units used.

[0073] In particular, a mixture of a homopolymer and a first copolymer and a second copolymer can enable particularly advantageous properties for the matrix material. Such materials also offer the advantage that they can be formed into a carrier even at low temperatures, such as in a range of ≥ 180°C to ≤ 200°C in the process described above, so that particularly effective process control can be enabled, for example with exemplary line speeds in a range of 6 m / min. Effective process control can be achieved in particular by the carrier material having an advantageous mass flow rate. By mixing a homopolymer and a first copolymer and a second copolymer, it can be achieved, for example, that the carrier material has a mass flow rate of ≥ 20 g / 10 min to ≤ 30 g / 10 min, preferably of ≥ 24 g / 10 min to ≤ 26 g / 10 min.The use of at least two copolymers can be particularly advantageous, as this makes it possible to achieve improved elastic properties of the carrier produced. In particular, it can be achieved that panels produced with the carrier material have an advantageous flexural modulus. Based on the carrier material, for example, a panel can be provided which has a flexural modulus of ≥ 3000 MPa to ≤ 4000 MPa, preferably of ≥ 3400 MPa to ≤ 3600 MPa. It can also be achieved that panels produced with the carrier material have an advantageous flexural strength. Based on the carrier material, for example, a panel can be provided which has a flexural strength of ≥ 30 MPa to ≤ 34 MPa, preferably of ≥ 31 MPa to ≤ 33 MPa. Furthermore, it can be achieved that panels produced with the carrier material have an advantageous flexural elongation.For example, a panel can be provided on the basis of the carrier material which has a bending strain of ≥ 2.0% to ≤ 2.8%, preferably of ≥ 2.3% to ≤ 2.5%.

[0074] It can preferably be provided that the homopolymer, the first copolymer, and the second copolymer comprise polypropylene. Polypropylene is particularly suitable as a matrix material because, on the one hand, it is inexpensive to obtain and, on the other hand, as a thermoplastic, it has good properties as a matrix material for embedding the solid material.

[0075] In a preferred embodiment of the wall or floor panel, the panel can have a multilaminar plastic carrier material with a plurality N of layer sequences ABA, wherein layer A comprises a first thermoplastic and layer B comprises a second thermoplastic, and wherein the first thermoplastic is a virgin plastic and the second plastic is a recycled plastic, and wherein 250 ≥ N ≥ 2, preferably 200 ≥ N ≥ 3, preferably 125 ≥ N ≥ 4, even more preferably 100 ≥ N ≥ 5. It has surprisingly been shown that such a plastic carrier material can be produced using the method according to the invention at high line speeds and with high dimensional accuracy. The different layers can be deposited as a coextrudate via several nozzles simultaneously or sequentially and processed using the method according to the invention.Such wall, ceiling, or floor panels exhibit improved moisture resistance, particularly with reduced moisture- or heat-induced swelling, as well as good mechanical properties and improved processability. Furthermore, the plastic carrier material according to the invention is ecologically advantageous because it can be manufactured to a significant extent from recycled plastic, thus conserving resources. ABCBA composites are also suitable, for example, as variants of paint, filler, foam, in-house recycling, or even polymer composites.

[0076] The recycled thermoplastic of layer B can, for example, comprise an amorphous polyethylene terephthalate (PET). Polyethylene terephthalate (PET) is produced in large quantities in the packaging industry, where it is used primarily for food packaging and beverage bottles. Since the highest standards must be met in the food packaging sector, recycling of PET is generally only possible to a limited extent. Even despite the recycling processes now available, such as the URRC (United Resource Recovery Corporation) process, large quantities of PET are not recycled locally but are exported for the production of synthetic fibers. The process according to the invention offers another possible use for recycled PET.

[0077] Preferably, the proportion of recycled polyethylene terephthalate in layer B can be in a range between ≥10 wt.% and ≤100 wt.% based on the polymer content of layer B. Particularly preferably, the proportion of recycled polyethylene terephthalate in layer B can be in a range between ≥15 wt.% and ≤90 wt.%, ≥20 wt.% and ≤80 wt.%, in particular based on the polymer content of layer B.

[0078] In addition to the recycled polyethylene terephthalate, a virgin polyethylene terephthalate can be provided in layer B. The proportion of virgin PET can be in a range between ≥0 wt.% and ≤90 wt.% based on the polymer content of layer B. Particularly preferably, the proportion of virgin polyethylene terephthalate in layer B can be in a range between ≥10 wt.% and ≤80 wt.%, ≥15 wt.% and ≤75 wt.%, in particular based on the polymer content of layer B. By providing virgin PET in layer B, an improved bond to layers A can be achieved.

[0079] In a preferred embodiment, PET-based polymer masses, in particular, can be subjected to a separate annealing / tempering process within the structure. The annealing / tempering process helps reduce the stresses present in the sheet through calibration, thus improving dimensional stability. The subsequent heat treatment can, for example, take the form of additional tempering rollers, which are wrapped around the web-like extrudate. Other annealing options include temperature-controlled circulating air lines or heated water baths, whereby the annealing temperature should be selected so that it does not lead to post-crystallization of the polymer mass.

[0080] According to a further embodiment of the invention, it can be provided that the layer B comprises a filler in addition to the thermoplastic material, wherein the filler is preferably selected from the group consisting of chalk, non-asbestos silicate, preferably magnesium silicate, wood flour, expanded clay, volcanic ash, pumice, aerated concrete, in particular inorganic foams, cellulose or a blowing agent.

[0081] Preferably, the proportion of filler can be in a range between ≥1 wt.% and ≤60 wt.%, in particular in a range between ≥5 wt.% and ≤50 wt.%, based on the total mass of the material forming layer B.

[0082] The addition of fillers advantageously makes it possible to adjust the material properties of the multilaminar plastic substrate, such as its specific gravity or its calorific value. The latter is particularly relevant to the question of the wall, ceiling, or floor covering formed on the basis of a corresponding multilaminar plastic substrate and the fire load introduced into a building by such a covering. In general, the proportions of thermoplastic material or filler material can be selected depending on the desired application and the desired properties of a panel formed on the basis of a multilaminar plastic substrate according to the invention. This can enable good adaptability to the desired application.

[0083] Particularly preferably, a layered silicate, such as talc, can be provided as the filler in layer B. In this case, talc is understood in a conventional manner to mean a magnesium silicate hydrate, which can, for example, have the chemical formula Mg 3 [Si 4 O 10 (OH) 2 ]. Thus, the solid portion is advantageously formed at least largely from the mineral substance talc, whereby this substance can be used, for example, in powder form or can be present in the carrier material in the form of particles. In principle, the solid material can consist of a powdered solid.

[0084] In a preferred embodiment of the wall or floor panel, the panel can comprise wood and / or chalk particles with a particle size between ≥ 0 µm and ≤ 600 µm and a particle size distribution D 50 of ≥ 400 µm. According to a particularly preferred embodiment of the invention, the carrier material consists of a mixture of a PE / PP block copolymer with wood. The proportion of the PE / PP block copolymer and the proportion of wood can be between ≥ 45 wt.% and ≤ 55 wt.% Furthermore, the carrier material can comprise between ≥ 0 wt.% and ≤ 10 wt.% of further additives, such as flow aids, heat stabilizers or UV stabilizers. The particle size of the wood is between > 0 µm and ≤ 600 µm with a preferred particle size distribution D 50 of ≥ 400 µm. In particular, the carrier material can comprise wood with a particle size distribution D 10 of ≥ 400 µm.The particle size distribution is based on the volumetric diameter and refers to the volume of the particles. Particularly preferably, the carrier material is provided as a granulated or pelletized pre-extruded mixture of a PE / PP block copolymer with wood particles of the specified particle size distribution. The granules and / or pellets can preferably have a grain size in a range of ≥ 400 µm to ≤ 10 mm, preferably ≥ 600 µm to ≤ 10 mm, in particular ≥ 800 µm to ≤ 10 mm.

[0085] To determine the particle size distribution, well-known methods such as laser diffraction can be used, which can determine particle sizes in the range from a few nanometers to several millimeters. This method can also be used to determine the size distributions of the feedstocks and thus the D 50 and D 10 values. The quantiles indicate the particle sizes at which 50% and 10% of the measured particles are smaller than the specified value.

[0086] With regard to further technical features and advantages of the wall or floor panel, explicit reference is hereby made to the description of the method, the device and the figures.

[0087] The invention is further explained below with reference to the figures and an embodiment. Fig. 1 shows a schematic cross-sectional view of an apparatus configuration for carrying out the method according to the invention; Fig. 2 shows a schematic top view of an apparatus configuration for carrying out the method according to the invention; Fig. 3 shows a schematic top view of an apparatus configuration for carrying out the method according to the invention; Fig. 4 shows a schematic view of the guidance of molten polymer material through a calibration roller arrangement; Fig. 5 shows a schematic view of the guidance of molten polymer material through a calibration roller arrangement; Fig. 6 shows a schematic view of the guidance of molten polymer material through a calibration roller arrangement with an enlarged detail; and Fig. 7 shows a schematic cross-sectional view of one possibility for carrying out the method according to the invention.

[0088] The device 1 according to Figure 1 is suitable for a process for producing a decorated wall or floor panel. The Figure 1shows a cross-sectional view of the possible design of the device for producing decorated panels 1, with this figure particularly showing the assemblies of the extrusion device 2 with nozzle 5, main roller pair 3 and calibration roller arrangement 4. In this embodiment, six calibration rollers 7 are shown, each of which can be controlled independently of one another in their X and Y positions. A possible rotational direction sequence for the individual calibration rollers 7 is indicated by the arrows. The device 1 schematically shows the extrusion device 2, which is divided into an extruder (not shown separately) for the thermal treatment of polymer granulate and the actual nozzle 5. The molten polymer strand emerging from the nozzle can be guided through the nip of the main roller arrangement 3 with the individual main rollers 6.The height of the roll gap between the two main rolls 6 can be variably adjusted by moving the main rolls 6 relative to each other. After the molten polymer mass has undergone initial shaping and, if necessary, cooling by the main roll gap, the strand is transferred to the calibration roll arrangement 4. In the calibration roll arrangement 4, the molten polymer strand is further reduced in height or calibrated. The strand is guided through the gaps between the individual calibration rolls 7 and its height changes as a function of the gap distance. The individual calibration rolls 7 do not always have to be the same distance from each other, so that different gap heights between the calibration rolls 7 can be set during the process. The calibration rolls 7 do not have to be the same height either, but can also be offset from one another.This can alter the mechanical stretching properties of the molten polymer strand. After calibration by the main roller assembly 3 and the individual calibration rollers 7, the calibrated and smoothed material can be decorated using a printing unit (not shown). Furthermore, the decorated surface of the panel can be coated with one or more additional layers, such as protective layers.

[0089] The Figure 2shows a plan view of a device 1 according to the invention. Shown is the extrusion device 2, with extruder and nozzle, which transfers a molten polymer strand to the main roller arrangement 3. The distance between the main roller arrangement 3 and the extrusion device 2 is variable and can be varied, for example, via controlled electric motors. After the molten polymer mass has passed through the gap of the main roller arrangement 3, the carrier, whose height has been adjusted and possibly already slightly cooled by the main roller arrangement 3, is guided into the calibration roller arrangement 4. The calibration roller arrangement 4 is composed of the individual calibration rollers 7, which each form gaps among themselves, through which the calibrated carrier is guided and further shaped. The individual calibration rollers 7 can be moved as a whole or each separately in their relative position to one another.Furthermore, it is possible for the individual calibration rollers 7 to be controlled as a whole or each separately in their roller surface temperature.

[0090] The Figure 3 essentially shows the design of the Figure 2 , whereby the decorative arrangement 8 is additionally shown here. The decorative arrangement 8 is arranged after the calibration rollers 7 and applies a decoration to the calibrated and optionally cooled carrier. The decorative arrangement 8 can, for example, consist of an inkjet printer and a further unit which applies a further protective layer at least partially to the printed decoration. Furthermore, it is possible to use no printer, but rather a decoration which has already been applied to a carrier and which is, for example, deposited onto the calibrated carrier via a roller. In addition, the carrier can be further cooled, profiled or, for example, mechanically processed on the long sides at this point.

[0091] The Figure 4 shows a possible routing of the molten polymer carrier 9 through the calibration roll gaps. By resting on the calibration rolls 7, the molten polymer carrier 9 can be cooled, for example. In this arrangement of the individual calibration rolls 7, the thickness of the molten polymer carrier 9 is changed more by the mechanical tension of the rolls. The individual calibration rolls 7 are too far apart for the molten polymer carrier 9 to experience direct squeezing or compression due to the gap between the calibration rolls 7.

[0092] The Figure 5 shows a similar calibration roller arrangement 4 with two calibration rollers 7 as in the Figure 4, wherein the calibration rollers 7 are closer together and form a gap which is smaller than the thickness of the molten polymeric carrier 9. Because the molten polymeric carrier 9 is at least partially thicker than the calibration gap, the height of the molten polymeric carrier 9 is evened out by the calibration gap between the calibration rollers 7.

[0093] The Figure 6 shows again the calibration roller section of the Figure 5together with an enlarged section. In the enlarged section, it can be seen that excess material of the molten polymer carrier 9 is pushed up at the beginning of the calibration gap. This adjusts the height of the molten polymer carrier 9 to the height of the calibration gap. The distance between the calibration rollers 7 allows the height of the calibration gap and thus the carrier height to be adjusted. According to the invention, it is advantageous that the calibration rollers 7 are positioned so close together that as little ambient air as possible can get between the calibration rollers 7 and the molten polymer carrier 9. The narrow gap passage ensures that as little additional air as possible is pressed into the carrier surface. This can contribute to an improved calibrated carrier surface.

[0094] The Figure 7shows a further embodiment of a device 1 for producing decorated panels according to the invention. The device 1 also has an extrusion device 2, for example, with a slot die and an extruder. The molten polymer mass is extruded through the die and passes via the gap of the main rollers 3 to the calibration roller arrangement 4 with the individual calibration rollers 7. This figure shows that the individual calibration rollers 7 do not necessarily have to be at the same height as one another. By deflecting the height of a calibration roller 7, for example, the mechanical forces and also the cooling properties can be changed across an air gap.Furthermore, the figure shows that an additional layer 10 can be applied within the calibration roller arrangement 4 with the different calibration rollers 7. This additional layer 10 is available, for example, as a rolled product and can be introduced at a wide variety of points on the calibration roller arrangement 4. The additional layer can be, for example, a primer or a decorative substrate. By applying the additional layer 10 within the calibration roller arrangement 4, the layer can be subjected to additional mechanical treatment by the calibration rollers 7, which can lead to better adhesion of the additional layer to the carrier. Furthermore, this ensures that the application of the additional layer 10 does not deviate from the desired height dimensions of the carrier, since both the carrier and the additional layer 10 run through the last calibration gap.After applying the additional layer 10, a decorative layer and a protective layer can be applied, at least partially, to the calibrated carrier by the decorative arrangement 8. Furthermore, it is possible for the carrier to be either further tempered / cooled in a defined manner or mechanically reworked using additional means 11. Suitable additional means 11 for this purpose can be cooling or tempering surfaces or mechanical milling machines for further profiling, for example, of the carrier edges. Reference symbol:

[0095] 1Device 2Extrusion device 3Main roller assembly 4Calibration roller assembly 5Die 6Main roller 7Calibration roller 8Printer assembly 9Molted polymeric carrier 10Additional layer 11Further post-processing

Claims

1. Method for producing a decorated wall or floor panel, comprising the method steps: a) providing a melted polymer mass; b) extruding the melted polymer mass through a die (5); c) finish-sizing the melted polymer mass to form a plate-like carrier (9) by means of an assembly of a plurality of rotatable rollers (6, 7), wherein the individual rollers (6, 7) are arranged one above or behind the other and each individual roller (6, 7) forms with adjacent rollers (6, 7) at least one finish-sizing nip through which the melted polymer mass (9) is passed, wherein the finish-sizing nip heights are variably adjustable by a horizontal and / or vertical movement of individual rollers (6, 7) during the production process; d) applying a decoration reproducing a decoration template onto at least one sub-region of the at least partially finish-sized carrier; and e) applying a protective coating to at least a sub-region of the decoration, characterized in that the finish-sizing in method step c) is carried out by use of at least one main roller pair (3) consisting of two rollers with a larger diameter and at least three finish-sizing rollers (7) arranged one behind the other with a smaller diameter compared to that of the main roller pair (6) and wherein the height of the finish-sizing nip of the main roller pair (6) HH differs from the heights of the finish-sizing nips of the finish-sizing rollers (7) HK by greater than or equal to 10% and less than or equal to 50%, wherein the height of the last and / or the penultimate finish-sizing nip (7) is selected such that the carrier is compressed in its height by a factor of less than or equal to 10 % and greater than or equal to 3%.

2. . Method according to claim 1, wherein method step d) prior to the application of the decoration additionally comprises the application of a decoration subsurface onto at least a sub-region of the carrier.

3. . Method according to claim 2, wherein at least the application of the decoration subsurface onto a sub-region of the carrier in method step d) takes place upstream of the last roller of the roller assembly (7) of method step c).

4. . Method according to any one of claims 1 to 3, wherein the roller assembly comprises, in addition to the main roller pair (6), at least four further finish-sizing rollers (7), wherein one of the roller nips of the finish-sizing rollers (7) is operated isobarically.

5. . Method according to any one of claims 1 to 4, wherein the main rollers (6) and the finish-sizing rollers (7) are equipped to be temperature-controlled and the temperature-controlled surface of the finish-sizing rollers (7) is greater by a factor of greater than or equal to 1.1 up to less than or equal to 2.5 compared to that of the main rollers (7).

6. . Device for producing a decorated wall or floor panel, characterized in that the device comprises means adapted for carrying out the method according to any one of claims 1 to 5.