Cladding panels

Abstract

A cladding panel having a substrate (6) and a decorative top layer (7), wherein the substrate (6) comprises a plastic composite material, optionally filled with a plastic composite material, wherein the cladding panel (1) is provided with mechanical coupling means (15) on at least a first pair of two opposite edges (2-3), which allow two such panels (1) to be coupled to each other on the first pair of edges in question (2-3), wherein locking is obtained in a vertical direction (V1) perpendicular to the plane of the coupled panels (1) and in a horizontal direction (H1) perpendicular to the respective edges (2-3) and in the plane of the coupled panels (1), the cladding panel being characterized in that the above-mentioned mechanical coupling means (15) or coupling portion allows displacement in the direction of the coupled edges, and wherein horizontally acting locking and / or contact surfaces (23) are formed on the second pair of opposite edges, preferably just below the position where the upper surfaces of the coupled panels (1) abut against each other, and wherein the contact surfaces (23) are mainly and preferably only formed on the compressible portion of the substrate and / or top layer.

Description

[0001] The present invention relates to a coated panel.

[0002] In particular, the invention relates to a cladding panel having a substrate and a decorative top layer, wherein the decorative top layer comprises a print and a transparent top layer applied thereon. Such panels are widely known, for example from WO 97 / 47834, WO 2006 / 066776, WO 2010 / 023042 and WO 2011 / 077311, and can, for example, imitate parquet panels or stone or ceramic tiles. From WO 97 / 47834 it is known to provide a coupling device for such a panel, so that a floating floor covering can be assembled on the basis of such a panel.

[0003] The cladding panels from WO 97 / 47834 and WO 2006 / 066776 comprise a wood-based core, such as HDF, coated with a top layer of a rigid decorative laminate. The floor panels of WO '834 are therefore sensitive to moisture penetration and they produce annoying walking noises in use. Furthermore, the panels of WO '834 are susceptible to dimensional changes when the air humidity in the environment changes.

[0004] Panels from WO 2010 / 023042 and WO 2011 / 077311 describe panels with a flexible core, for example of flexible PVC, and a thermoplastic layer, for example also made of PVC, as a wear layer. Such panels are made of waterproof material and provide a more acceptable walking sound. However, such panels are also prone to dimensional changes, but only when the ambient temperature changes. In contrast to the air humidity, the ambient temperature of the area covered with the panels may be significantly non-uniform. In the case of panels such as from WO'042 and WO'311, this can lead to local expansion effects, for example where sunlight shines directly on the covering. In the market, such local expansion effects are indicated by "hot spots". The inventors have determined that floor coverings assembled with panels of the prior art may therefore rise locally and certain bubbles may form and / or the seams between the individual panels may bulge upwards. This last-mentioned phenomenon is sometimes referred to in the market as "arching".

[0005] The present invention firstly relates to an alternative cladding panel in which, according to various preferred embodiments, solutions are provided to the problems of prior art cladding panels.

[0006] To this end, according to a first independent aspect, the present invention relates to a cladding panel having a substrate and a decorative top layer, wherein the substrate comprises a plastic layer, optionally filled with a plastic layer, which plastic layer is preferably a thermoplastic plastic layer, wherein the cladding panel is provided with mechanical coupling means on at least a first pair of two opposite edges, which allow two such panels to be coupled to each other on the first pair of edges in question, wherein locking is obtained in a vertical direction perpendicular to the plane of the coupled panels and in a horizontal direction perpendicular to the respective edges and in the plane of the coupled panels, the cladding panel being characterized in that the above-mentioned mechanical coupling means or coupling portions allow displacement in the direction of the coupled edges, and wherein horizontally acting locking and / or contact surfaces are formed on the second pair of opposite edges, preferably directly below the positions of the upper surfaces of the coupled panels that abut each other, and which contact surfaces are mainly and preferably only formed on the compressible parts of the substrate and / or the top layer.

[0007] Since displacement is possible on the first pair of edges, possible local expansions in the direction of the first pair of edges can always be compensated by displacement. The compressibility at the location of the horizontally acting locking or contact surfaces on the first and / or second pair of edges ensures that no troublesome deformations or upward squeezing of the seam can occur due to expansions perpendicular to the direction of these edges.

[0008] Preferably, in a floor covering assembled from the cladding panels of the invention, a plurality of rows of panels are formed, wherein in each case at least the first pair of edges extend in the direction of the respective row. In this way, the risk of the formation of air bubbles and "arching" can be minimized most effectively. For example, they can be rectangular and elongated panels, wherein they are mounted in a row extending in the longitudinal direction of the panel. A pair of long edges is thereby formed.

[0009] Preferably, both measures, ie the displaceable and compressible horizontally acting locking surfaces, are present at least on a first pair of edges, which preferably form a pair of long edges of the elongated panel.

[0010] According to a practical embodiment, the above-mentioned horizontally acting locking or contact surface is formed on a first layer of a substrate and optionally on an overlying decorative top layer, wherein the above-mentioned first layer of the substrate is more flexible than the second layer below. Preferably, both the first layer and the second layer are plastic layers, optionally filled with a plastic layer, preferably a thermoplastic layer. Preferably, both the first layer and the second layer comprise PVC, wherein the above-mentioned first layer of the substrate comprises a higher proportion of plasticizer than the second layer located below it. Preferably, the first layer comprises at least 5 phr more plasticizer than the above-mentioned second layer.

[0011] The above-mentioned mechanical coupling means or coupling part of the first pair of relative edges can produce clearance, fit or clamping.Certainly, any clamping may only produce a negligible influence on the possibility of required displacement.

[0012] Preferably, the energy per unit length required for the first pair of edges in the coupled state to be displaced a certain distance from each other is less than the energy per unit length required for the second pair of edges to be displaced over the same distance in the mounted state of two such panels. The energy can be obtained by recording the movement obtained over the corresponding displacement distance according to the applied force. The area under the curve obtained is the required energy. Preferably, the energy per unit length required for the coupling of these edges on the first pair of edges is less than 90%, or even less than 75%, of the energy per unit length required for the combination of these edges on the second pair of edges. In order to keep the installed, coupled or combined length unchanged during the determination of the corresponding energy, one edge can be made significantly longer than the other edge so that the relevant length during the complete recording of the displacement is equal to the length of the other edge mentioned above. Obviously, the smaller required energy makes the displaceability of the first pair of edges better compared to the displaceability of the second pair of edges.

[0013] Preferably, for a first pair of edges in the coupled state, the force per unit length required to overcome the static clamping force is less than for a second pair of edges in the mounted or assembled state of two such panels. The force required to overcome the static clamping force is the maximum force reached before the edges begin to move relative to each other. Obviously, a smaller static clamping force results in a better displaceability of the first pair of edges compared to the displaceability of the second pair of edges.

[0014] Preferably, the static clamping force on the first pair of edges is less than 25N per meter of connected edge, and preferably less than 10N per meter of connected edge. In combination with the above preferred embodiments, the static clamping force on the second pair of edges is preferably greater than 25N, or correspondingly greater than 10N per meter of connected edge.

[0015] Preferably, the above-mentioned mechanical coupling means of the first pair of edges is configured as a tongue and groove delimited by an upper lip and a lower lip, wherein the above-mentioned tongue and groove are provided with a locking portion which resists the above-mentioned tongue and groove from moving apart in the above-mentioned horizontal direction, wherein, in the coupled state, the above-mentioned lower lip is preferably unloaded or, preferably, exhibits a maximum deflection of 0.07 mm or less, or 0.04 mm or less. The unloaded state or the load-limited state of the lower lip avoids large clamping forces in the coupling of the first edges and prevents too limited displaceability.

[0016] Preferably, the coupling means of the first pair of edges in the coupled state always have one or more contact surfaces. As can be seen in a cross section through the coupled edges, the one or more contact surfaces preferably cover less than 25% of the contour of the respective edge, or even less than 15% or less than 10%. Due to the limited contact surface, a displacement with less resistance can be achieved.

[0017] Preferably, the second pair of edges is also provided with a male coupling part and a female coupling part with a protruding lip, wherein the male coupling part and the female coupling part are provided with a locking part, which resists the coupling part from moving apart in the horizontal direction, or in other words, is provided with a horizontally acting locking part. Then, in the coupled state, the protruding lip is preferably unloaded, or preferably, the protruding lip shows a maximum deflection greater than the lower lip on the first pair of edges. Thus, for example, for the protruding lip, it is possible to act with a deflection greater than 0.07 mm or greater than 0.04 mm, respectively. Obviously, the male coupling part and the female coupling part of the second pair of edges can be configured as a tongue and a groove defined by an upper lip and a lower lip, wherein the protruding lip is preferably formed by the lower lip. It is also clear that the compressible horizontally acting locking or contact surface then forms a stop surface for horizontally moving the coupled panels toward each other.

[0018] According to a different variant and / or another definition of the invention, the above-mentioned mechanical coupling means or coupling portions of the first pair of edges, instead of showing characteristics that they allow displacement in the direction of the coupling edges, can show characteristics related to the energy required for displacement, the clamping force, the unloaded state or limited load state of the lower lip and / or the percentage of contact surface in the coupled state, as described above based on the preferred embodiments. According to yet another possibility, the panel can be provided with a lubricant, such as graphite, oil or wax, at least on the first pair of edges.

[0019] Preferably, the panel is rectangular, wherein the panel is provided with connecting devices on a pair of long edges and a pair of short edges, wherein the connecting devices on the pair of long edges preferably allow two such panels to be connected to each other by a flipping movement, and the connecting devices on the pair of short edges preferably allow two such panels to be connected to each other by a downward movement, wherein the pair of long edges preferably forms the above-mentioned first pair of edges, and the pair of short edges preferably forms the above-mentioned second pair of edges.

[0020] Preferably, at least a portion of the coupling means on the first pair of edges is provided with a waterproof substance. Since the coupling portions on the first pair of edges are slidable or clamped only to a limited extent, water may penetrate into the joint formed between two such panels. The waterproof substance may prevent penetration.

[0021] Preferably, the decorative top layer comprises printing and a transparent wear layer applied thereon.

[0022] The panel may have a stepped-down edge region on at least one edge, wherein both the print and the wear layer may extend continuously from the central region of the panel to the stepped-down edge region.

[0023] The presence of a descending edge region on one or more edges, in particular on the aforementioned second pair of edges, can further limit the risk of arching.

[0024] Preferably, the descending edge region is chamfered. Preferably, the angle formed by the chamfer with the upper surface or the horizontal plane is less than 25°, or better still 15° or less. An ideal value is 11°. Preferably, the chamfer extends over a distance of less than 2.5 mm measured in the panel area. The actual relevant depth is therefore limited, particularly preferably less than 1.15 mm, more preferably less than 0.67 mm or less than 0.5 mm.

[0025] According to a most preferred embodiment, the chamfer extends to a depth that is less than the thickness of the wear layer at a central upper surface location of the cladding panel.

[0026] Preferably, the wear-resistant layer has a thickness of 0.3 mm or more at the center region, but preferably less than 0.75 mm.

[0027] Preferably, the wear layer consists essentially of a thermoplastic, such as polyvinyl chloride, PVC. Using a thermoplastic on the surface is desirable because it minimizes knocking sounds when the panel is used as a floor panel or scratching sounds when the panel is used as a furniture panel or wall panel. Producing a dropped edge region in the thermoplastic top layer, particularly in the case of PVC, in the prior art results in a glossy region along the edge to which the dropped edge region is applied.

[0028] Preferably, the above-mentioned print is located on a thermoplastic carrier film, and it is formed with the film, such as a printed PVC film, PU film, PP film or PET film. In the case of a PP film, it can be, for example, an oriented polypropylene film. In the case of a PVC film, it is preferably a rigid PVC film, i.e. a film based on PVC without a plasticizer or a plasticizer ratio less than 5phr (parts of additives per 100 parts of resin). The rigid PVC film can be printed with higher precision, certainly when printing with water-based ink. In this case, a drying operation based on heat supply during printing is ideal, but due to the selection of rigid PVC, the possible expansion of the film is limited. As mentioned above, the wear-resistant layer preferably also includes a thermoplastic material, such as flexible or rigid PVC, PU, ​​PP or PET. In the case of a PVC wear-resistant layer, it preferably includes a plasticizer greater than a ratio of 5phr, or even more than 10phr or 15phr.

[0029] According to one alternative, it is not excluded to apply the printing on the underside of the wear layer. According to another alternative, the printing is formed directly on the substrate by printing on the substrate, preferably providing one or more bottom coverings.

[0030] Preferably, the surface of said descending edge region is substantially formed by the material of said wear resistant layer. In this way, similar wear resistance can be achieved over the entire surface of the cladding panel.

[0031] Preferably, the plane in which the printed matter extends at the position of the descending edge region is the same plane as the plane in which the printed matter extends at the position of the central region. Therefore, the substrate is preferably not deformed at the position of the descending edge region.

[0032] Preferably, the substrate comprises a plastic layer with fillers, or it mainly consists of plastic and fillers. The plastic is preferably polyvinyl chloride (PVC), but on the other hand can also be selected from polypropylene (PP), polyurethane (PU), polyethylene (PE) and polyethylene terephthalate (PET).

[0033] According to a particular embodiment, the cladding panel of the invention has coupling means on the second pair of edges which can be assembled to each other by a downward movement.

[0034] According to a particular embodiment, as described above, the substrate comprises a plurality of layers. Preferably, a first layer having a first hardness is located between the print and a second layer having a second hardness greater than the first hardness. The first layer can bring specific features to the cladding panel and / or in the manufacture. Thus, for example, additional damping of knocking noise is obtained and deeper structural features can be provided in the surface of the panel. The hardness difference is preferably at least 10 Shore A hardness scale. The second layer then preferably has a hardness of 80 Shore A or higher. The different hardnesses in the layers can be achieved, for example, because both the first layer and the second layer comprise polyvinyl chloride, wherein the content of plasticizer in the first layer is higher than the content of plasticizer in the second layer. Preferably, there is a difference of at least 5 phr between the corresponding layers. Preferably, in the coupled state of two such panels, a locking and / or contact surface appears directly below the joint of the corresponding upper surface of the coupled panels, wherein the contact surface is mainly or even only formed on the material of the first layer of the two coupled panels and optionally on the upper cladding layer of the decorative top layer. The inventors have noticed that, by the described geometry of the joint of the upper surface, the tendency of the upper edge to bulge or bend due to dimensional changes after installation and / or due to the application of so-called preload can be reduced. The remaining tendency can be further masked by applying a descending edge. As described above, the preload is achieved by providing an overlap in the profile of the male coupling part and the female coupling part, thereby producing a slight drive assembly. Preferably, the overlap is at least located and preferably substantially located at the position of the above-mentioned horizontal acting locking surface. As a result, preferably, a bend occurs on the lower side of the panel, for example on the side with the groove. The bend then presses the male coupling part against the female coupling part in an attempt to return to its static state. Therefore, preferably, a tension is generated on the above-mentioned contact surface below the joint of the upper surface of the connected panel. Due to the formation of the contact surface on the above-mentioned first layer, this tension will cause a reduced degree of bulging. As described above, any load on the lower lip of the groove on the first pair of edges is preferably limited to a load that causes a maximum bend of 0.07 mm.

[0035] Obviously, the effects described above can also be achieved when there is a coating, for example with a water-repellent substance, on one or both contact surfaces. Preferably, in this case, it is a coating of limited thickness, preferably less than 0.1 mm thick, or even less than 0.01 mm thick. It can, for example, be a coating with a water-repellent substance as described in more detail below. In the context of the present invention, for this configuration, the contact surface will always be considered to be formed on the substrate and optionally on a covering layer at the level of the decorative top layer.

[0036] Preferably, the substrate comprises one or more glass fiber layers. In this way, dimensional changes of the panel can be limited overall. Any deformation that may occur due to dimensional changes can be further minimized or prevented by the measures of the invention, i.e. the displaceability or limited clamping on the first pair of edges and the compressible contact surface on the second pair of edges.

[0037] Preferably, at least a portion of the surface of the above-mentioned coupling means is provided with a waterproof substance. Due to the use of a waterproof substance, the applied preload may be limited while still achieving a sufficient waterproof effect for the joint between the coupled panels. This possibility reduces the tendency of the upper edge of the coupling to bend. Preferably, the above-mentioned waterproof substance is provided just below the junction of the upper surfaces of the coupled panels, or at least at a position above the actual coupling means, i.e. at a level above the above-mentioned horizontal locking surfaces, and preferably also above the level of any vertically acting locking surfaces.

[0038] A fluorine-containing copolymer is preferably used as the above-mentioned water-repellent substance.

[0039] The above-mentioned coupling device can have one or a combination of two or more of the following features:

[0040] - a mechanical coupling device or coupling part mainly configured as a tongue and groove feature delimited by an upper lip and a lower lip, wherein the tongue and groove are mainly responsible for locking in the above-mentioned vertical direction, wherein the tongue and groove are provided with a secondary locking part mainly responsible for locking in the above-mentioned horizontal direction. Preferably, the locking part comprises a protrusion on the underside of the tongue and a recess in the lower lip of the groove. Such a coupling device and locking part are known, for example, from WO97 / 47834;

[0041] - the feature that the mechanical coupling means or coupling parts press the coupled floor panels against each other, for example because these mechanical coupling means are provided with a so-called pre-tensioning, for example known per se from EP 1 026 341. The clamping force of the floor panels against or towards each other can be obtained, for example, in combination with the above-mentioned features by a lower lip that is bent outwards in the coupling position, or another part of the female coupling part, which, when trying to spring back, presses on the underside of the tongue or male coupling part;

[0042] - mechanical coupling means allowing the feature of a coupling based on a horizontal or almost horizontal sliding movement of the panels towards each other;

[0043] - The mechanical coupling means allow the feature of coupling based on a tilting movement along the respective edges;

[0044] - Mechanical coupling means allow the feature of coupling based on the downward movement of a male coupling part, such as a tongue, with a female coupling part, such as a groove. As mentioned before, this type of panel presents a risk of arching;

[0045] The mechanical coupling means, or at least the associated upper edge, is a feature produced based on a milling operation using a rotating milling cutter.

[0046] It is obvious that the cladding panels of the invention according to the most preferred embodiment are floor panels for forming floating floor coverings. However, it is not excluded that the invention can be applied to wall panels, ceiling panels or furniture panels.

[0047] The thickness of the cladding panel of the present invention is preferably between 3 mm and 8 mm, more preferably between 4 mm and 6 mm.

[0048] Preferably, the cladding panels of the invention have a useful area, ie the area that remains visible in a covering assembled from such panels, of a width between 12 and 25 cm, preferably between 15 and 22 cm, and a length between 110 and 210 cm, preferably between 115 and 150 cm.

[0049] In order to better illustrate the features of the present invention, some preferred embodiments will be described below with reference to the accompanying drawings, which are provided as examples and do not have any limiting features. In the accompanying drawings:

[0050] Figure 1 A cladding panel having features of the invention is shown;

[0051] Figure 2 and Figure 3 Shown on an enlarged scale along Figure 1 Cross-sectional views taken along lines II-II and III-III.

[0052] Figure 4 Shown on an enlarged scale Figure 3 Figure 3 shows the area marked with F4 in Figure 3.

[0053] Figure 5 The stereogram shows Figures 1 to 4 How the panels are assembled into floating floor coverings;

[0054] Figure 6 and Figure 7 Similar to Figure 2 and Figure 3 The view shows the connection status;

[0055] Figure 8 Shows Figure 7 A profile of a coupling device with a groove in it; and

[0056] Fig. 9 and 10 Possible advantages of the present invention are further described.

[0057] Figure 1There is shown a rectangular and elongated cladding panel 1, in this case a floor panel having a first pair of long opposing edges 2-3 and a second pair of short opposing edges 4-5.

[0058] Figure 2 and 3 The panel 1 shown comprises a substrate 6 and a decorative top layer 7, wherein the decorative top layer 7 comprises a print 8 and a transparent wear layer 9 applied thereon.

[0059] The panel 1 has a dropped edge region 10 on at least one edge, in this case on two pairs of edges, a pair of short opposing edges 4-5 and a pair of long opposing edges 2-3. In this case, the dropped edge region 10 is a chamfer, the angle A of which with the horizontal plane is less than 25°, in this case about 11°.

[0060] Figure 4 The thickness T of the wear layer 7 shown is at least 0.3 mm, in this case approximately 0.55 mm. The wear layer 7 consists essentially of a thermoplastic, in this case polyvinyl chloride, and has a surface layer 11 on the surface, for example based on radiation-cured polyurethane or acrylate compounds.

[0061] Both the print 8 and the wear layer 9 extend continuously from the central region 12 of the panel 1 to the descending edge region 10, the surface of the descending edge region being substantially formed by the wear layer 9 without including the surface layer 11. The plane in which the print 8 extends at the location of the descending edge region 10 is the same plane as the plane in which it extends at the location of the central region 12.

[0062] In the example, the print 8 is applied on a thermoplastic carrier film 13 and the substrate 6 consists mainly of plastic and / or fillers (e.g. PVC and calcium carbonate). On the underside of the substrate 6, a layer 14, preferably a foam layer, based on cross-linked polyethylene, is applied, for example, to reduce noise and / or adapt to irregularities of the substrate.

[0063] Figure 2 and Figure 3It is clearly shown that the floor panels 1 are provided on both pairs of opposite edges 2-3, 4-5 with coupling means 15, which allow two such panels 1 to be coupled to each other on the respective edges 2-3, 4-5. In the coupled state, locking occurs in a vertical direction V1 perpendicular to the plane of the coupled floor panels 1 and in a horizontal direction H1-H2 perpendicular to the respective edges 2-3, 4-5 and in the plane of the coupled panels 1. The coupling means 15 are configured in each case as a male coupling part 16 and a female coupling part 17, wherein in the coupled state a horizontally acting locking surface 18 is formed which resists the coupled floor panels 1 from moving apart in the horizontal direction. On a pair of long opposite edges 2-3, the male coupling part 16 is formed by a laterally protruding tongue 19, and the female coupling part is formed by a groove 20.

[0064] As shown, the substrate 6 comprises a plurality of layers 21-22, wherein the first layer 21 having a first hardness is located between the above-mentioned print 8 and the second layer 22 having a second hardness greater than the above-mentioned first hardness. Both the first layer 21 and the second layer 22 contain polyvinyl chloride. The content of plasticizer in the above-mentioned first layer 21 is higher than the content of plasticizer in the above-mentioned second layer 22. In the coupled state of two such panels 1, the horizontally acting contact surface 23 is directly below the joint of the corresponding upper surfaces, wherein the contact surface 23 is formed only on the above-mentioned first layer 21 and on the upper covering layers 8-9 of the decorative top layer 7, that is, in particular, at least on the first layer 21 and the wear-resistant layer 9 without including the surface layer 11. The above-mentioned horizontally acting locking surface 18 that resists the tongue 19 and the groove 20 from moving apart is formed only on the material of the above-mentioned second layer 22.

[0065] Figure 4 It is further shown that at least a portion of the surface of the coupling device 15 is provided with a waterproof substance 24. Preferably, the waterproof substance is provided at least directly below the junction of the upper surface of the coupled panels 1, i.e. at a position above the actual coupling device 15, i.e. above the junction of the tongue 19 in the groove 20 in the case of the long opposing edges 2-3, i.e. above the level of any vertically acting locking surface 25. In this case, the waterproof substance 24 is provided at least on the above-mentioned horizontally acting contact surface 23 located directly below the junction of the upper surface.

[0066] Figure 5 Shown Figures 1 to 4 The floor panel 1 is suitable for being assembled into a floating floor covering. In this case, the coupling devices 15 on a pair of long edges 2-3 can be coupled to each other by a flipping movement W, and the coupling devices 15 on a pair of short edges 4-5 can be coupled to each other by a downward movement N.

[0067] Figure 6 and Figure 7The coupling states of the coupling means 15 are shown on a pair of short opposing edges 4-5 and a pair of long opposing edges 2-3, respectively.The coupling means 15 and the associated upper edge 26 are produced based on a milling operation using a rotating milling cutter.

[0068] like Figure 6 As shown, the coupling means 15 on a pair of short opposite edges 4-5 are configured as a male coupling part 16 and a female coupling part 17, which can be assembled with each other. The male coupling part 16 includes a hook-shaped portion 27 protruding on the upper side of the panel 1, and the female coupling part 17 includes a hook-shaped portion 27 in the form of a lip protruding on the lower side of the panel 1. The hook-shaped portion 27 of the male coupling part 16 includes a locking portion 28 protruding downwards, which can interact with a recess 29 in the hook-shaped portion 27 of the female coupling part 17. The interaction of the locking portion 28 protruding downwards and the recess 29 is mainly responsible for the locking in the horizontal direction H1. The hook-shaped portion 27 is also provided with one or more snap portions 30 and an undercut portion 31 interacting therewith, which provide locking in the vertical direction V1.

[0069] like Figure 7 As shown, the coupling device 15 on a pair of long opposite edges 2-3 is as described above, and the coupling device is configured as a tongue 19 and a groove 20 defined by an upper lip 32 or uppermost lip and a lower lip 33 or lowermost lip. The tongue 19 and the groove 20 provide locking in the vertical direction V1 mentioned above, and are provided with locking portions 34-35 that are mainly responsible for locking in the horizontal direction H2 mentioned above. In the example, the locking portion includes a protrusion 34 on the lower side of the tongue 19 and a recess 35 in the lower lip 33 of the groove 20.

[0070] In this case, the mechanical coupling device 15 is provided with a preload obtained on the basis of the lower lip 33 which bends outwards in the coupling position and tries to spring back against the underside of the tongue 19 .

[0071] The coupling means 15 shown here also allow a coupling based on a horizontal sliding movement S of the panels 1 towards each other.

[0072] Also in Figure 6 In the example of FIG. 1 , the preload is applied by bending a portion 36 of the protruding lip of the female coupling part 17, in this case an upwardly extending element 36 on the hook 27 of the female coupling part 17. This element 36 tries to spring back and presses against the male part 16, more specifically against its downwardly protruding locking portion 28.

[0073] Figure 7 It is further shown that the lower lip 33 of the groove 20 exhibits a maximum deflection B in the coupled state. In this case, the maximum deflection B is less than 0.07 mm, ie approximately 0.04 mm.

[0074] Figure 7 and Figure 8 It is further shown that the coupling device 15 of the first pair of edges 2-3 in the coupled state always has one or more contact surfaces 37-38-39, in this case three contact surfaces 37-38-39, namely a contact portion 37 at the location of the above-mentioned locking or contact surface 23, a contact portion 37 at the location of the vertically acting locking surface 25 (i.e. between the upper side of the tongue 19 and the lower side of the upper lip 33), and a contact portion 38 at the location of the locking surface 18. As can be seen in a cross section taken through the coupling edge and in Figure 8 In the example shown, the contact surfaces 37-38-39 together cover only a limited portion of the profile 40 of the edge 3. In this case, the contact surfaces 37-38-39 cover less than 10% of the length of this profile, as seen in a cross section perpendicular to the joining edge, as shown in FIG. Figure 8 shown.

[0075] Fig. 9 and Fig.10 A floor covering 41 is shown assembled on the basis of a panel 1 having the features of the invention, more specifically, on Figures 1 to 8 On the basis of the panels 1 shown, the floor coverings 41 differ only in that they are placed in different directions, namely at right angles to each other.

[0076] The floor covering 41 is in each case arranged in a room with a window section 42, through which sunlight can directly shine into the floor covering. This causes hot spots to appear on the floor covering 41, as indicated by the dashed lines 43. Within the dashed lines 43, the panel will expand. In the floor coverings of the prior art, this would lead to the formation of air bubbles at this location and possibly to the appearance of bulging at the seams 44.

[0077] For the cladding panel 1 of the present invention, Fig. 9 In the case of , the expansion in the direction L will be able to push and displace the other panels in each row 45 showing a hot spot, so that no bubble will be formed. The expansion of the panels located in the hot spot in the direction W can be compensated by compression at the location of the contact surface 23, without bulging. The displacement in the direction W is limited because the panels not located in the hot spot prevent or counteract the displacement. Now, these panels will not expand to the same extent, so the width of the row 45 will change very little, if at all.

[0078] exist Fig.10 The same action occurs in the case of the floor covering 41 in FIG. The dimensional expansion in direction L is compensated by displacement, whereas the dimensional expansion in direction W causes a compression at the location of the locking or contact surface 23 .

[0079] The invention is by no means limited to the described embodiments, but rather such a cladding panel, a method for its production and a milling tool used therein can be realized within the scope of the invention.

Claims

1. A cladding panel having a substrate (6) and a decorative top layer (7), wherein: The substrate (6) comprises a plastic layer, optionally filled with a plastic layer, wherein the cladding panel (1) is provided with mechanical coupling means (15) on at least a first pair of opposite edges, the mechanical coupling means allowing two such panels (1) to be coupled to each other on the first pair of opposite edges, wherein locking is obtained in a vertical direction (V1) perpendicular to the plane of the coupled panels (1) and in a horizontal direction (H1) perpendicular to the first pair of opposite edges and in the plane of the coupled panels (1), wherein the mechanical coupling means (15) allow displacement in the direction of the coupled edges, and wherein horizontally acting locking and / or contact surfaces (23) are formed on the first pair of opposite edges and / or the second pair of opposite edges, the horizontally acting locking and / or contact surfaces being formed just below the position where the upper surfaces of the coupled panels abut against each other, and wherein the contact surfaces (23) are formed on a compressible portion of the substrate and / or the top layer, wherein the mechanical coupling means of the first pair of opposite edges are provided with a mechanical coupling means (15) which allows locking of two such panels (1) on the first pair of opposite edges, wherein the mechanical coupling means (15) allow displacement in the direction of the coupled edges, and wherein horizontally acting locking and / or contact surfaces (23) are formed on the first pair of opposite edges and / or the second pair of opposite edges, wherein the horizontally acting locking and / or contact surfaces are formed on the compressible portion of the substrate and / or the top layer, The coupling device (15) is configured as a tongue and groove defined by an upper lip and a lower lip, wherein the tongue and groove are provided with a locking portion that resists the tongue and groove from moving apart in the horizontal direction (H1), and wherein the second pair of opposing edges are provided with a male coupling portion and a female coupling portion, and the male coupling portion and the female coupling portion are provided with a locking portion that resists the male coupling portion and the female coupling portion from moving apart in the horizontal direction, wherein the lower lip in the coupled state is unloaded or exhibits a maximum deflection of less than 0.07 mm, wherein the energy per unit length required to displace the first pair of opposing edges in the coupled state by a certain distance is less than the energy per unit length required to displace the second pair of opposing edges by the same distance in the mounted state of two such panels, and wherein the panel (1) is rectangular, wherein a pair of long edges form the first pair of opposing edges and a pair of short edges form the second pair of opposing edges.

2. The cladding panel according to claim 1, wherein: The contact surface is formed only on a compressible portion of the substrate and / or the top layer.

3. The cladding panel according to claim 1, wherein: The horizontally acting locking and / or contact surface is formed on a first layer (21) of the substrate (6) and on the overlying decorative top layer (7), wherein the first layer (21) of the substrate (6) is more flexible than a second layer (22) below, wherein both the first layer (21) and the second layer (22) comprise PVC, and the first layer (21) of the substrate has a higher proportion of plasticizer than the second layer (22) located below the first layer.

4. The cladding panel according to any one of claims 1 to 3, wherein: The mechanical coupling means (15) of the first pair of opposing edges are configured to have a gap, configured to fit or configured to clamp.

5. The cladding panel according to any one of claims 1 to 3, wherein: For the first pair of opposing edges in the coupled state, the force per unit length required to overcome the static clamping force is less than the force on the second pair of opposing edges in the mounted state of two such panels.

6. A cladding panel according to any one of claims 1 to 3, wherein the panel (1) is provided with coupling means (15) on both the pair of long edges (2-3) and the pair of short edges (4-5), wherein the coupling means (15) on the pair of long edges (2-3) allow two such panels (1) to be coupled to each other by a turning movement (W), and the coupling means on the pair of short edges (4-5) allow two such panels to be coupled to each other by a downward movement (N).

7. The cladding panel according to any one of claims 1 to 3, wherein at least a portion of the coupling means (15) is provided with a waterproofing substance (24) on the first pair of opposite edges.

8. The cladding panel according to any one of claims 1 to 3, wherein: The decorative top layer (7) comprises a print (8) and a thermoplastic wear layer (9) applied to the print, wherein the panel (1) has a descending edge region (10) on at least one edge, wherein both the print (8) and the wear layer (9) extend continuously from a central region (12) of the panel (1) to the descending edge region (10).

9. The cladding panel according to claim 8, wherein: The lowered edge region (10) is a chamfer.

10. The cladding panel according to claim 8, wherein: The surface of the descending edge region (10) is substantially formed by the wear-resistant layer (9).

11. The cladding panel according to claim 8, wherein: The plane in which the printed matter (8) extends at the position of the descending edge region (10) and the plane in which the printed matter (8) extends at the position of the central region (12) are the same plane.

12. The cladding panel according to claim 8, wherein: The substrate (6) comprises a plurality of layers, wherein a first layer (21) having a first hardness is located between the printed matter (8) and a second layer (22) having a second hardness greater than the first hardness.

13. The cladding panel according to claim 12, wherein: Both the first layer (21) and the second layer (22) contain polyvinyl chloride, wherein the plasticizer content in the first layer (21) is higher than the plasticizer content in the second layer (22).

14. The cladding panel according to claim 12, wherein: In the coupled state of two such panels (1), the horizontally acting locking and / or contact surface (23) appears just below the junction of the respective upper surfaces of the coupled panels (1), wherein the contact surface (23) is formed on or even only on the material of the first layer (21) and of the layer of the overlying decorative top layer (7).

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