AU2022357420A1

AU2022357420A1 - Panel interconnectable with similar panels for forming a covering

Info

Publication number: AU2022357420A1
Application number: AU2022357420A
Authority: AU
Inventors: Eddy Alberic BOUCKÉ; Pieter Renaat Karel DEVOS
Original assignee: I4F Licensing NV
Current assignee: I4F Licensing NV
Priority date: 2021-09-30
Filing date: 2022-09-30
Publication date: 2024-05-02
Also published as: CA3231875A1; KR20240088931A; CN118043527A; WO2023052595A1

Abstract

The last ten years has seen enormous advance in the market for laminate for hard floor covering. It is known to install floor panels on a underlying floor in various ways. It is, for example, known that the floor panels are attached at the underlying floor, either by gluing or by nailing them on. The invention relates to a panel, in particular a floor panel, interconnectable with similar panels for forming a covering. The invention further relates to a covering consisting of mutually interconnected panels.

Description

Panel interconnectable with similar panels for forming a covering

The invention relates to a panel, in particular a floor panel, wall panel, or ceiling panel, interconnectable with similar panels for forming a covering. The invention further relates to a covering consisting of mutually interconnected panels.

The last ten years has seen enormous advance in the market for laminate for hard floor covering. It is known to install floor panels on a underlying floor in various ways. It is, for example, known that the floor panels are attached at the underlying floor, either by gluing or by nailing them on. This technique has a disadvantage that is rather complicated and that subsequent changes can only be made by breaking out the floor panels. According to an alternative installation method, the floor panels are installed loosely onto the subflooring, whereby the floor panels mutually match into each other by means of a tongue and groove coupling, whereby mostly they are glued together in the tongue and groove, too. The floor obtained in this manner, also called a floating parquet flooring, has as an advantage that it is easy to install and that the complete floor surface can move which often is convenient in order to receive possible expansion and shrinkage phenomena. A disadvantage with a floor covering of the above-mentioned type, above all, if the floor panels are installed loosely onto the subflooring, consists in that during the expansion of the floor and its subsequent shrinkage, the floor panels themselves can drift apart, as a result of which undesired gaps can be formed, for example, if the glue connection breaks. In order to remedy this disadvantage, techniques have already been through of whereby connection elements made of metal are provided between the single floor panels in order to keep them together. Such connection elements, however, are rather expensive to make and, furthermore, their provision or the installation thereof is a time-consuming occupation. There is a need to improve the coupling profiles of panels, in particular floor panels, which lead to a relatively reliable and durable connection at all edges, and which can be installed relatively easily, preferably without needing additional connection means, such as glue or metal connection elements.

One way of coupling panels, and floor panels in particular, that took flight over the last years is a coupling technique known as fold-down coupling, wherein all sides of a panel are coupled in the same motion. This motion typically comprises a rotational movement or angling movement along the long sides, or one pair of sides, of the panel. During this rotational movement the other pair of sides, or the short sides, naturally make a lowering or vertical movement, and the coupling parts of this pair of sides are made such that they allow coupling during this motion. When panels are coupled in this way, the angling or rotational movement it started first, and at some point in time the coupling parts on the other pair of sides are coupled. The first time the coupling parts on that pair of sides come into contact is typically the moment where the panel damages or breaks

It is an object of the invention to provide an improved floor panel, which can be coupled in an improved manner to other panels, and whereby preferably one or more of the aforementioned disadvantages are excluded.

The invention provides thereto a panel according to the preamble, comprising:

- a core provided with an upper side and a lower side, said core being provided with: o a first pair of opposite edges, comprising:

■ a first edge, preferably comprising a sideward protrusion, in particular a sideward tongue, extending in a direction substantially parallel to the upper side of the panel,

■ an opposite, second edge comprising a recess for accommodating at least a part of the first edge, preferably the sideward protrusion, in particular the sideward tongue, of a further panel, said recess being defined by an upper lip and a lower lip, said lower lip being provided with a upwardly protruding shoulder,

■ the first edge and the second edge being designed such that these edges allow to realize a locking between adjacent panels by insertion of the first edge, preferably the sideward protrusion, in particular the sideward tongue, of said panel into the recess of a further panel by means of an angling down movement and/or lowering movement and/or substantially vertical movement, typically about an axis parallel to the first edge; and o a second pair of opposite edges, comprising: ■ a third edge comprising a single upward tongue, at least one upward flank lying at a distance from the upward tongue and a single upward groove formed between the upward tongue and the upward flank, wherein at least a part of a side of the upward tongue facing toward the upward flank is preferably upwardly inclined towards the upward flank, and

■ a fourth edge comprising a single downward tongue, at least one downward flank lying at a distance from the downward tongue, and a single downward groove formed between the downward tongue and the downward flank, wherein at least a part of a side of the downward tongue facing toward the downward flank is preferably downwardly inclined towards the downward flank, and

(i) wherein at least a first distal end of the third edge, adjacent to the first edge, comprises at least one modified portion, for facilitating coupling and/or uncoupling of the panel with respect to another panel, wherein the modified portion preferably makes part of the upward tongue, and is more preferably located at least on or at the upper side of the upward tongue; and/or

(ii) wherein at least a first distal end of the fourth edge, adjacent to the first edge, comprises at least one modified portion, for facilitating coupling and/or uncoupling of the panel with respect to another panel, wherein the modified portion preferably makes part of the downward tongue, and is more preferably located at least on or at the bottom side of the downward tongue.

The panel according to the invention comprises at a first pair of opposing edges a first set of complementary coupling profiles and at a second pair of opposing edges a distinctive second set of complementary coupling profiles. The first and second edges facilitate an easy installation of a panel by inserting the sideward protrusion, in particular the sideward tongue, of the first edge of the panel to be coupled in an inclined position into the recess of the second edge of an already installed panel, after which that panel will be angled (pivoted) or otherwise moved downwardly until both panels are situated in the same plane. Although this angling down or alternative lowering process leads to locking of both panels at the first and second edges both in horizontal direction and in vertical direction, an improved locking will be realized due to the presence of the third and fourth edges, and more in particular by forcing the fourth edge of the panel to be coupled to snap or click or position into the third edge of another panel during the angling down movement of the panel to be coupled. Since the third and fourth edges are commonly perpendicular to the first and second edge, a scissoring movement may occur, leading to snapping or zipping of the fourth edge of a panel to be coupled and the third edge of an already installed panel into each other. Preferably, the third profile is provided with a closed upward groove, whereas at least a part of a side of the upward tongue facing toward the upward flank preferably extends in the direction of the normal of the upper side of the core (and hence is preferably upwardly inclined towards the upward flank), and since the fourth profile is preferably provided with a closed downward groove, whereas at least a part of a side of the downward tongue facing toward the downward flank preferably extends in the direction of the normal of the lower side of the core (and hence is preferably downwardly inclined towards the downward flank), an interconnection of the third and fourth edges of adjacent panels can only be established after a preferably temporary and/or preferably resilient deformation of the third edge and/or the fourth edge leading to a relatively firm, reliable, and durable connection at the third and fourth edges.

At least a first distal end of the third edge, adjacent to the first edge, preferably comprises at least one modified portion, for facilitating coupling and/or uncoupling of the panel with/from another panel and to prevent damage to the third or fourth edge during coupling, wherein the modified portion is preferably arranged on the upward tongue, more preferably at least on the upper side of the upward tongue and/or at least a first distal end of the fourth edge, adjacent to the first edge, preferably comprises at least one modified portion, for facilitating coupling and/or uncoupling of the panel with/from another panel, wherein the modified portion is preferably arranged on the downward tongue, more preferably at least on the bottom side of the downward tongue.

The modified portion may for instance locally weaken the coupling part, which facilitates deformation of the coupling part at least temporarily or permanently. In particular with closed groove coupling systems, wherein the side of the upward tongue facing the upward flank is inclined towards the upward flank, widening of the upward groove for instance needs to occur for coupling parts to be able to fit into each other. By locally weakening the coupling part, for instance the upper side of the upward tongue, deformation is facilitated at the edge of the upward tongue. It is this edge of the upward tongue that is typically the first portion of the third coupling part that encounters a further panel that is coupled to an existing panel. The weakening of this edge portion thus allows for an easier initial coupling or widening of the upward groove, which facilitates coupling and prevents breaking or damage in the initial stages of coupling. Hence, the panel according to invention can be assembled in a relatively easy manner, without the need of additional connection elements, while leading to a firm and durable connection. It is conceivable that the features as described for the upward tongue are present in the downward tongue, either in addition or instead of a weakening in the upward tongue, wherein the same advantages and optional features apply mutatis mutandis to the downward tongue features.

Each modified portion may be a recessed portion, a weakened portion, a thinnened portion, a milled portion, a cut-away portion, a relatively resilient portion, a processed portion and/or machined portion. In all cases the modified portion is a portion which allows easier coupling of panels at the first and second panel edges of adjacent panels. In terms of the invention, the relative term vertical relates to the direction from a rear side of the panel towards an front side of the panel. For floor panels lying horizontally on a floor this would be the vertical as we typically use the term. For wall panels this would be flipped 90 degrees, and for ceiling panels it would still be vertical but flipped 180 degrees.

As said, the third and fourth edges are commonly but not necessarily perpendicular to the first and second edge. During coupling of the third and fourth edges of adjacent panels a scissoring movement will occur, leading to snapping or zipping of the fourth edge of a panel to be coupled and the third edge of an already installed panel into each other. During this scissoring movement and before the snapping or zipping occurs, the downward tongue of the fourth edge is pressed against the upward tongue of the third edge, in this stage of the coupling process there is a relatively small contact area between the two panels to be coupled resulting in relatively high forces (and a high momentum). To lower these forces and to smoothen the coupling process, preventing damages to the panels during the scissoring movement, a panel according to the present invention one or more modified portions are located at the third edge and/or fourth edge, which are preferably located in the critical region(s) where the aforementioned high forces are created during coupling, being typically at the first distal end of the third edge and/or the first distal end of the fourth edge. Preferably, at least one modified portion comprises and/or is formed by a weakening and/or a cut-out portion at a first distal end of the third edge, in particular of the upward tongue of the third edge. This weakening and/or cut-out portion located near the first distal end of the third edge is advantageous because the forces in at least the third edge of a panel during the scissoring movement of a panel toward the third edge of yet another panel are more levelled. The weakening is preferably positioned such that during coupling the peak of the forces within the material of the upward tongue by the downward tongue is (significantly) decreased. The application of a cut-out portion creates space which may prevent the creation of critical peak stress and which may therefore facilitate smooth coupling and/or uncoupling of coupling profiles of adjacent panels, wherein the risk of damaging and/or breaking is strongly reduced and can even be eliminated. The weakening in the upward tongue may for example comprise at least one recess, at least one slot, and/or at least one slit in the upward tongue. A recess may result in a locally wider upward groove which eases the insertion of the downward tongue into the upward groove. A slit may result in a more flexible, less rigid, upward tongue and thus reducing the resistance to temporary deformation during the scissoring movement during coupling.

A panel according to the present invention facilitates that forces are distributed more evenly over the upward tongue and second locking element during scissoring movement of a panel during interconnection of panels. Due to the weakening, the internal tension within the material of the upward tongue of the panel is reduced during coupling. This prevents damaged panels, in particular a broken upward tongue, during coupling. It is advantageous to prevent this damage, since this will decrease waste of broken and/or damaged panels. It is also beneficial to prevent a damaged but still connectable panel to prevent an uncontrolled weak connection.

A panel according to the present invention may comprise a recess in the upward tongue, locally weakening the upward tongue while maintaining enough body in the upward tongue to provide for a good coupling. At least one, and preferably each modified portion may be arranged to deform at least temporarily or permanently during coupling of two panels, for facilitating the coupling and/or uncoupling. For example, when the modified portion comprises a recess or a slit, the material around the recess or slit may deform by being pressed toward the recess or slit, which locally decreases the thickness of the upward tongue, allowing it to fit into a downward groove of a further panel in an easier fashion.

It is imaginable and may even be preferably that both the third edge and the fourth edge comprise a modified portion at their first distal ends. Preferably, in coupled condition of two panels, at least one modified portion of one edge of the third edge and fourth edge of a first panel will face a portion of the complementary edge of the second panel. This latter mentioned portion may or may not be a modified portion. In case a modified portion is applied both at the first distal end of the third edge and at the first distal end of the fourth edge, the modified portions will face each other in coupled condition. The facing modified portions may have an identical design and/or identical dimensions, but may also have mutually different designs and/or mutually different dimensions. The facing modified portions may, in coupled condition of adjacent panels, be at least partially positioned at a distance from each other and/or may at least partially abut each other. In case of a mutual abutment, preferably the forces exerted by the modified portions onto each other are limited and preferably (practically) absent.

The third edge and/or fourth edge, and preferably the first distal end thereof, may have a varying cross section along the length of the third edge, and preferably as seen in a direction parallel to the first edge and second edge. Preferably this varying cross section increases (in surface area) and/or widens towards the first distal end of the respective edge. This varying cross section is typically the result of the modified portion, and can for instance be achieved by removing an oblique or chamfered portion from the upward tongue, in particular with closed groove coupling systems. In a closed groove system, the inside of the upward tongue is inclined towards the upward flank, such that the upper side of this inside lies further towards the upward flank compared to the lower side. By removing more of the upper side at the edge, and less away from the edge, an oblique or chamfered modified portion is provided, which in a coupled position thus results in a coupling system wherein at the edges the system is not as closed compared to the coupling system away from the edges.

The modified portion may comprise a section where panel material is removed, at least compared to a middle portion of the third or fourth edge or a portion of the third or fourth edge not adjacent the first edge, or compared to a portion of the third or fourth edge adjacent the second edge. The material removal for instance occurs by milling a recess or slit in the upward tongue. The material may be removed in an inline step during manufacturing of the panel. This is advantageous since an inline step is a cost-effective and fast way of producing.

At least a part of a side of the upward tongue facing away from the upward flank may comprise a first locking element; and the downward flank may comprises a second locking element adapted for co-action with the first locking element of a third edge of a further panel. The locking elements may be used to further lock at least two coupled panels in place, and for instance prevent and/or inhibit (undesired) uncoupling in vertical direction. The upward tongue and the downward tongue may prevent uncoupling of panels in a horizontal direction, and the closed groove or the inclined sides of the tongues facing the flanks may also aid in preventing uncoupling in vertical direction. Preferably, at least a part of the modified portion of the third edge, in particular of the upward tongue, is substantially free of said first locking element or comprises a modified first locking element.

The part of the side of the upward tongue facing toward the upward flank is preferably inclined towards the core, preferably such that the part of the side of the upward tongue and a plane of the core of the panel enclose an angle less than 90 degrees. An angle of 90 degrees would be a straight angle and the side of the upward tongue facing the upward flank would not be inclined towards the core. Preferably the angle lies between 45 and 89.9 degrees (not including 90 degrees), more in particular between 75 and 89.9 degrees (not including 90 degrees).

Alternatively the angle lies between 45 and 89.5 degrees, more in particular between 75 and 89.5 degrees. In a practical embodiment the angle is about 87.5 degrees. Compared to a vertical plane (wherein the inside would not be inclined) this results in an inward angle of about 2.5 degrees. This angle is a compromise between ease of coupling and sufficient vertical locking. Preferably, the same preferences apply to the preferred inclination of the (inner) side of the downward tongue facing the downward flank. Alternatively, it is imaginable that at least a part of a side of the upward tongue facing toward the upward flank is upwardly inclined away from the upward flank and/or that at least a part of a side of the downward tongue facing toward the downward flank is downwardly inclined away from the downward flank. This alternative embodiment would lead to an open groove configuration rather than a closed groove configuration.

The modified portion may extend along a part of the third or fourth edge, preferably at most along a third of the length of the third or fourth edge, more preferably at most a quarter of the length of the third or fourth edge. Preferably, the length of at least one, and preferably each, modified portion (as seen in the edge direction) is less than 10 mm, preferably less than 5 mm. Although the modified portion facilitates deformation and thus coupling of panels, it also provides for a weakening and thus a reduced locking effect locally. To maintain a desired state of locking and prevent uncoupling of panels the modified portion preferably extends along only a portion of the third or fourth edge, although it is also envisionable that the modified portion comprises a recess or slit extending along the full length, or almost the full length (more than half, for instance more than two thirds or more than three quarter) of the third or fourth edge.

At least one modified portion located at the first distal end of the third edge and/or fourth edge may be decreasing in height and/or width over at least part of its length, starting from the upper side of the (upward) tongue decreasing in height and/or width in a direction towards the first edge and may be positioned in a region near the first edge, preferably up to the first edge, of the panel. Preferably the decrease in height ends at the height substantially equal to the height of the upward groove. The decrease in height may be profiled or gradual. This decrease in height may be a portion of the modified portion. The decreasing height and/or width results in a more gradual forces within the material during coupling of two adjacent panels, reducing the height of the internal peak force during coupling.

The first distal end may comprise an oblique surface, wherein the oblique surface encloses an angle with the rear side of the panel and wherein the oblique surface preferably extends along the entire length of the modified portion. The oblique surface may for instance extend further compared to the modified portion. Alternatively, the upper side of the upward tongue may be inclined, for instance inclined downwards towards the side of the upward tongue facing away from the upward flank. The width of the oblique surface may for instance widen towards the first edge (as seen from a top view). At the first edge contact is most likely to occur first between panels during coupling. It is at that first edge where coupling may be facilitated most, whereas further along the coupling process less help is needed. The first distal end of the third edge may comprise at least one surface, which surface is a planar surface facing substantially upwards, extending over the entire length of the modified portion.

Preferably, the modified portion(s) of the first distal end of the third edge and/or of the fourth edge comprise(s) at least one slit or slot. This slit or slot may extend in a direction parallel to the third edge or fourth edge. This slit or slot may define a plane which coincides and/or runs parallel to a plane defined by the panel. Alternatively or additionally, this This slit or slot may define a plane perpendicular to a plane defined by the panel.

The modified portion located at the first distal end of the third edge and/or fourth edge may comprise at least two adjacent surfaces, preferably together extending over the entire length of the modified portion. Preferably a first surface of said adjacent surfaces is an oblique surface, wherein the height of the first surface may decrease towards The first edge. A second surface of said adjacent surfaces is preferably oriented substantially horizontal and located closer to the first edge of the panel compared to the first surface. In this embodiment, the first surface connects to the second surface, wherein both surfaces are oriented side-by-side as seen from the side view of the third edge and/or fourth edge. The adjacent surfaces may define the entire modified portion.

The modified portion located at the first distal end of the third edge and/or of the fourth edge may comprise a curved recess. The curvature of the curved recess may for instance be such that on the distal end the recess is deepest, or most material is removed, whereas increasingly more material is present towards the remainder of the panel. In this embodiment the panel the curvature smoothens the coupling of adjacent panels while maintaining enough body in the upward tongue for a good coupling.

The first distal end of the third edge and/or fourth edge may comprise at least one wedge-shaped recess, wherein the V of the wedge-shape runs substantially parallel to the first edge of the panel. Preferably, the wedge-shaped recess intersects the entire width of the upward tongue and/or of the downward tongue. The wedge-shaped recess in this embodiment creates a local weakness in the upward tongue, creating space for the material to, preferably temporarily, deform with less internal forces or tension in the material. The wedge-shape may be applied by a milling operation for example or by a press. Advantage of this embodiment is that relatively small amount of material may have to be removed to create the modified portion, wherein the remaining relatively more material still allows to realized a strong coupling.

In further embodiments, at least one modified portion may comprise a slit. Panels according to the present invention may be manufactured in an automated processing line lay-out. For manufacturing purposes it is advantageous when a slit runs substantially parallel to the third edge. For such a positioned slit, the slit may be manufactured in an in-line process step which makes the manufacturing step easy, fast and cheap, because it is possible to incorporate the manufacturing of the modified portion in an already existing automated processing line. Various embodiments are conceivable. They have in common that a balance is made between ease of coupling and strength of coupling once coupled. The slit may run from distal end to an opposing distal end of the third edge and/or fourth edge. The first distal end of the third edge may comprise a slit, which slit comprises at least one V-shaped slit, wherein the V-shaped slit runs substantially perpendicular to the first edge of the panel, preferably extending over the entire length of the upward tongue. The slit may be a continuous slit or a discontinuous (interrupted) slit. It may be preferred that at least one slit is merely present at the first distal end (section) of the third edge and/or fourth edge.

In another embodiment, the modified portion located at the first distal end of the third edge and/or fourth edge may comprise at least one substantially linear slit, preferably extending over at least part of the length of the respective edge, in particular over at least part of the length of the respective tongue of at least one of said edges. The slit may, for example, extend over the entire length of the third edge, wherein the slit may have an opening towards the upward flank, wherein the slit is oriented either as a horizontal slit, wherein the opening of the slit is oriented towards the upward flank or the slit may be angled or the opening of the slit may be oriented upwards when the slit is a vertical slit. A vertical slit is easier to manufacture than a horizontal slit.

In yet another embodiment, the first distal end of the third edge may comprise at least one slit, wherein the at least one slit is a substantially vertical slit which extends over the width of the upwardly protruded shoulder parallel to the first edge and is positioned near the first edge of the panel. The vertical position is advantageous because it is easily accessible and thus easy to manufacture. In this embodiment the effect of the slit in the modified portion is less than a slit over the entire length of the upward tongue, yet resulting in a stronger coupling once coupled.

The modified portion may comprise at least one slit, wherein the at least one slit is a substantially vertical slit which extends parallel to the third edge of the panel, preferably over the entire length of the upward tongue or downward tongue. It is also envisionable that the at least one slit is a substantially horizontal slit which extends over the length of the upward tongue or downward tongue, preferably wherein the slit starts at the side facing the single upward groove.

The modified portion may comprise at least one slit, wherein the at least one slit encloses an angle between substantially 20 to 40 degrees with the lower side of the panel, and preferably extends over the length of the upward tongue, preferably wherein the slit starts at the side facing the single upward groove.

In an embodiment of the present invention, the slit may extend in the width direction of the upward tongue and/or downward tongue along at least one third of the width of the upward tongue and/or downward tongue, preferably at least half of the width of the upward tongue and/or downward tongue. The extent to which the slit extends, in other words the depth of the slit, is a trade-off between a smooth coupling and a strong coupling once coupled. Depending on the material chosen this may be up to two third of the width of the upward tongue and/or downward tongue, or even three quarters of the width of the upward tongue and/or downward tongue. The larger the extent to which the slit extends, the easier the coupling will be, but sufficient strength and stiffness must remain when two panels are in coupled condition. The choice in this trade-off depends on the desired characteristics of the panel.

Any vertical or horizontal slit creates a hinging effect within the upward tongue (or downward tongue), which eases temporary deformation of the upward or downward groove during coupling. The small hinging facilitates the respective groove to temporarily widen the respective groove when the downward tongue and upward tongue are pressed against one another during a coupling movement. When the respective grooves, preferably temporarily, widens, the coupling is smoothened because less friction occurs between the upward and downward groove. Once coupled the upward and/or downward groove will expand back to its original shape, yet in a coupled position providing a coupling in horizontal and vertical direction.

In a preferred embodiment the panel comprises a closed groove system, wherein at least a part of a side of the downward tongue facing toward the downward flank may be inclined toward the downward flank and/or wherein at least a part of a side of the upward tongue facing toward the upward flank is inclined toward the upward flank.

The panel according to the invention is preferably a decorative panel. The panel may be used indoor and/or outdoor. In an embodiment variant the panel is manufactured at least partially from wood. The floor panel can herein form a wooden plank and/or a parquet floor panel. The panel according to the invention is however also exceptionally suitable for application as laminated panel, wherein the panel comprises a laminate of an optional balancing layer (backing layer), a core layer comprising a wood and/or plastic product and at least one top structure arranged on an upper side of the carrier layer. The top structure commonly comprises a decorative layer on top of which a transparent protective layer is applied. A wood or tile structure can further be pressed into the protective layer, whereby the top layer in fact also forms an embossed layer. The decorative layer is generally formed by a photo of wood or of tiles printed on paper usually saturated in melamine resin. It is also possible these days to print a decorative pattern directly onto the core layer by using dedicated printing devices. The core layer generally comprises a wood fibreboard, in particular an MDF board (Medium Density Fibreboard) or HDF board (High Density Fibreboard). It is also possible to envisage the floor panel being manufactured wholly from metal and/or textile instead of being manufactured from wood and/or plastic.

It is conceivable that each first edge (profile) and each third edge (profile) are compatible - hence may co-act and interlock - with each second edge (profile) and each fourth edge (profile) of another panel. This may also apply in case interlocking coupling profiles do not have a completely complementary shape. Preferably, each edge is at least partially formed by the core.

As indicated above, the core is preferably at least partially made of at least one polymer, in particular a thermoplastic material and/or a thermoset material, wherein, preferably, the core comprises a composite comprising at least one polymer, in particular a thermoplastic material and/or a thermoset material, and at least one non-polymeric material. Said non-polymeric material preferably at least one material selected from the group consisting of: steel, glass, polypropylene, wood, acrylic, alumina, curaua, carbon, cellulose, coconut, kevlar, nylon, perlon, rock wool, sisal, fique, a mineral filler, in particular chalk. This may further increase the strength of the panel and/or the water resistivity and/or the fireproof properties of the panel as such, and/or may lower the cost price of the panel as such.

Preferably, the base material of the core, or at least one core layer, comprises a (main) polymer, preferably a thermoplastic material, which is more preferably chosen from the group consisting of: PVC, PET, PP, PS, thermoplastic polyurethane (TPU), PE, in particular MDPE and/or HDPE; and combinations thereof. PS may be in the form of expanded PS (EPS) in order to further reduce the density of the floor covering element, which leads to a saving of costs and facilitates handling of the panels. Also in case another thermoplastic material is used, this material may be applied in foamed state in the core to reduce the density and costs. Nevertheless, it is also imaginable that the thermoplastic material used as main polymer is a solid polymer (i.e. an unfoamed polymer). Preferably, at least a fraction of the polymer used may be formed by recycled thermoplastic, such a recycled PVC or recycled PU. It is conceivable that a mix of virgin and recycled thermoplastic material is used to compose at least a part of the core. Instead of the thermoplastic material, also a thermoset polymer may be used, such as thermoset polyurethane.

At least a part of the core may be made of a composite of at least one polymer and at least one non-polymeric material. The composite of the core layer preferably comprises one or more fillers, wherein at least one filler is preferably selected from the group consisting of: talc, chalk, wood, calcium carbonate, titanium dioxide, calcined clay, porcelain, glass, carbon particles, silicon particular, a(nother) mineral filler, rice, a(nother) natural filler, a(nother) (auxiliary) polymer, such as an elastomer and/or latex. It is also imaginable that rubber and/or elastomeric parts (particles) are dispersed within the composite to improve the flexibility and/or impact resistance at least to some extent. The core may (thus) be rigid, semiflexible, or flexible, and so can be the floor covering element as such. The filler may be formed by fibres, such as glass fibers or synthetic or genuine leather fibers, and/or may be formed by dust-like particles. Here, the expression “dust” is understood as small dust-like particles (powder), like bamboo dust, wood dust, cork dust, or non-wood dust, like mineral dust, stone powder, in particular cement, and combinations thereof. The average particle size of the dust is preferably between 14 and 20 micron, more preferably between 16 and 18 micron. The primary role of this kind of filler is to provide the core, and the panel as such, sufficient hardness and/or to decrease the cost price of the core, and hence of the panel. Moreover, this kind of filler will typically also improve the impact strength of the core and of the panel as such. Preferably, the filler content in the composite material of the core is between 30 and 75% by weight of the composite material of the core, more preferably between 50 and 60% by weight of the composite material of the core. Preferably, the polymer content in the composite material of the core is between 25 and 70% by weight of the composite material of the core, more preferably between 40 and 50% by weight of the composite material of the core. The polymer can either be foamed or unfoamed. Preferably, the composite of the core comprises at least one filler selected from the group consisting of: a salt, a stearate salt, calcium stearate, and zinc stearate. Stearates have the function of a stabilizer, and lead to a more beneficial processing temperature, and counteract decomposition of components of the composite during processing and after processing, which therefore provide long-term stability. Instead of or in addition to a stearate, for example calcium zinc may also be used as stabilizer. The weight content of the stabilizer(s) in the composite will preferably be between 1 and 5%, and more preferably between 1 .5 and 4%. The composite of the core preferably comprises at least one impact modifier comprising at least one alkyl methacrylate, wherein said alkyl methacrylate is preferably chosen from the group consisting of: methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, t- butyl methacrylate and isobutyl methacrylate. The impact modifier typically improves the product performance, in particular the impact resistance. Moreover, the impact modifier typically toughens the core layer and can therefore also be seen as toughening agent, which further reduces the risk of breakage. Often, the modifier also facilitates the production process, for example, as already addressed above, in order to control the formation of the foam with a relatively consistent (constant) foam structure. The weight content of the impact modifier in the composite will preferably be between 1 and 9%, and more preferably between 3 and 6%. At least one plastic material used in the core layer is preferably free of any (toxic) plasticizer in order to increase the desired rigidity of the core layer, which is, moreover, also favourable from an environmental point of view. The core and/or another layer of the panel may comprise wood-based material, for example, MDF, HDF, wood dust, bamboo, prefabricated wood, more particularly so-called engineered wood. This wood-based material may be part of a composite material of the core.

It is imaginable that the core, and/or at least one core layer (and/or another layer), comprises a composite of at least one polymer and rice. Preferably, the rice is formed by rice hulls, more preferably a mixture of separated rice hulls and/or ground rice hulls and/or rice hull powder. Preferably, the different rice hull types have different average particle sizes. The polymer(s) act(s) as polymeric binder, wherein preferably an at least partially recycled plastic polymer, such as TPU, PP, PE, PET, and/or PVC, is used. The unground rice hull can for example be present in an amount of 1-98% by weight relative to the weight rice hull mixture. Likewise, the ground rice hull and powdered rice hull can also be present in an amount of 1 - 98% by weight relative to the weight of the rice hull mixture. Preferably, in one embodiment the rice hull mixture comprises 20-50% by weight of each of the unground rice hull, the ground rice hull and the rice hull powder. In a particularly preferred embodiment, the rice hull mixture comprises about 33% by weight of each of the unground rice hull, the ground rice hull and the rice hull powder. The amount of the polymeric binder present in the rice hull mixture can vary and may e.g. be 1 -30%, preferably 10-25%, more preferably 12-20% by weight of the rice hull mixture. The rice hull powder preferably has an average particle size of 0.175- 1.20 millimetre.

It is imaginable that at least one core layer (and/or at least one other layer) comprises rice hulls, rice straw, and vegetable adhesive. Preferably, the vegetable adhesive comprises natural grass and/or wood dust. Preferably the natural grass comprises any one or more selected from the group consisting of rice grass, glutinous rice grass, and starch grass. Preferably, rice straw and/or rice hulls is/are used in an amount of 20-50%, preferably 40-50%, more preferably 35-45%, by weight based upon the weight of the (core) layer in which the rice straw and/or rice hulls is/are incorporated, in particular embedded. When more than 50% by weight of rice straw is included, there may be a problem that the moisture resistance drops significantly, while applying less than 20% by weight of rice straw the binding force may drop. Preferably, the vegetable adhesive is used in an amount of 1 -20% by weight of the (core) layer.

The rice hull may be added as a main component of a thermal insulation material to provide porosity, thereby providing thermal and acoustic insulation effects. The rice straw may be added to provide binding to the insulation, with stem and leaf portions that leave the rice threshed. Preferably, the straw is cut to an appropriate length and preferably 3 centimetre or less.

The vegetable adhesive (vegetable binder), which may be used at least one core layer (and/or at least one other layer), preferably uses trees such as natural grass, pine bark, rubber trees, and the like prepared by mixing rice flour such as rice grass, glutinous rice grass, starch grass, and gluten with water. Preferably, the use of a mixture of natural grass and trees is preferred in terms of improving moisture resistance. When natural grass and tree-like liquid are mixed and used, the mixture is preferably used at a ratio of 2.5:7.5 to 6.5:3.5. In a preferred embodiment of the invention, at least one core layer and/or at least one other layer comprises a mixture of clay, in particular kaolin clay, and rice, in particular rice hull. The clay serves to increase the flash point of rice, in particular the rice hulls, which is advantageous from a fire safety point of view, and moreover serves to further increase the strength of the core layer (and/or other layer) in which the clay and rice are incorporated, in particular embedded.

Alternatively, the core is at least partially composed of another base material, such as a mineral material, like magnesium oxide, magnesium hydroxide, gypsum, (lightweight) concrete, and/or clay; and/or a wood or a wood-based material, such as HDF or MDF, or any other thermoplastic-free material, may be used as base material.

The density of the core typically varies from about 0.1 to 1 .5 grams/cm3, preferably from about 0.2 to 1 .4 grams/cm3, more preferably from about 0.3 to 1 .3 grams/cm3, even more preferably from about 0.4 to 1 .2 grams/cm3, even more preferably from about 0.5 to 1 .2 grams/cm3, and most preferably from about 0.6 to 1 .2 grams/cm3. It is imaginable that each panel comprises a plurality of core (sub)layers. Different core (sub)layers may have either identical compositions or different compositions, and/or different densities.

The decorative top structure preferably comprises at least one decorative layer and at least one transparent wear layer covering said decorative layer. The decorative top structure may additionally comprise at least one back layer situated in between said decorative layer and the core, wherein said back layer is preferably at least partially made of a vinyl compound, wood, paper, textile, such as, and/or combinations thereof. The one or more materials used in said at least one back layer may virgin materials, recycled materials, and combinations thereof. Here, it is for example imaginable and even preferred that the back layer comprises a mixture of wood, cotton; and at least one binding agent. Preferably, the back layer comprises wood in an amount of 20-60% by weight of the back layer, and a cotton based material, such as recycled jeans and/or raw cotton (virgin cotton), in an amount of 30-70% by weight of the back layer, and at least one binding agent, preferably in an amount of 1-7% by weight of the back layer. The back layer may be free of PVC and/or any other synthetic polymer. Optionally, the back layer may act as decorative layer (which does not require a separate decorative layer on top).

A lacquer layer or other protective layer may be applied on top of said wear layer. The protective layer and/or wear layer preferably comprises silicon oxide (SiO2). A finishing layer may be applied in between the decorative layer and the wear layer. The decorative layer will be visible and will be used to provide the panel an attractive appearance. To this end, the decorative layer may have a design pattern, which can, for example be a wood grain design, a mineral grain design that resembles marble, granite or any other natural stone grain, or a colour pattern, colour blend or single colour to name just a few design possibilities. It is imaginable and may even be preferred that the decorative layer comprises at least one recycled material and/or at least one natural material, such as e.g. wood, textile, and/or mixtures. The decorative layer may be free of PVC and/or any other synthetic polymer. Customized appearances, often realized by digital printing during the panel production process, are also imaginable. The decorative top structure may also be formed by a single layer. In an alternative embodiment, the decorative top structure is omitted, thus not applied, in the panel according to the invention. In this latter embodiment, the upper side of the core constitutes the upper side of the panel.

The decorative layer may be formed at least partially by a (digitally) printed plastic layer, in particular a thermoplastic layer, or a (digitally) printed film, in particular paper film or thermoplastic film. The plastic material, in particular the thermoplastic material, is used can be of various nature, but commonly PVC or PU, in particular TPU, is preferred as material. Preferably this (thermo)plastic layer or paper film is preferably a white plastic layer or white film, preferably an opaque white layer or opaque white film. White, and in particular opaque white, will provide a bright background which will reflect back to the viewer the light that travels through transparent ink colours.

The decorative layer may also be formed by an ink layer printed, preferably digitally printed, either directly or indirectly onto the core. The decorative layer may at least partially made of at least one biobased material, such as a polymer, in particular TPU, based upon plant-based oils such as canola oil or castor oil. The decorative may additionally comprise mineral components such as chalk. This combines sustainability with extremely high levels of resilience for an improved panel performance in terms of acoustic properties, indentation resistance, etcetera.

The decorative top structure may also comprise and/or constitute a carpet base having pile yarns projecting upwardly therefrom. The pile yarns can be made from a number of natural or synthetic fibres. Many types of yarn are made differently though, wherein there are typically two main types of yarn: spun and filament. The yarns may be made of nylon but other suitable synthetic yarns such as polyester, polypropylene, acrylic or blends thereof can be employed. The carpet tile may be either rigid or flexible. It is also conceivable that the base is free of any yarn or fibres. The pile yarns may consist of loop piles. It is however also possible that the pile yarns consist of cut piles, twisted piles or any other suitable pile yarns in for example a level- or multilevel configuration. The loop piles are possibly synthetic yarns, such as nylon, polyester, polypropylene, acrylic or blends thereof. In the shown embodiment, the loop piles are tufted in the carpet base. The carpet base preferably also comprises a backing sheet, which can for example be a non-woven sheet, a woven sheet, a non-woven polyester sheet, a polypropylene sheet, a glass fibre scrim or tissue sheet or combinations thereof. The backing sheet typically acts as support structure (holding structure) for holding the yarns. To more efficiently bond the tufts in position on the carpet base, and in particular on the backing sheet, preferably a pre-coat layer is applied. This pre-coat layer can for example be a latex layer.

Hence, it may be preferred that the panel or at least one panel layer, such as the core, is manufactured at least partially from plastic, in particular thermoplastic, preferably polyvinylchloride (PVC), polyurethane and/or polyolefin. It is possible here to envisage the floor panel according to the invention being manufactured substantially wholly from plastic. Preferably, the core is made of a laminate of material layers, wherein a central layer is made of at least one thermoplastic material, wherein the core has a top surface and a bottom surface. Affixed to the top surface of the core is print layer, wherein the print has a top surface and a bottom surface. Also, an overlay layer can be affixed directly to the top surface of the core, or affixed to the top surface of the print layer. The panel can optionally contain an underlay layer located and affixed between the bottom surface of the print layer and the top surface of the core. In more detail, the core in the thermoplastic laminate panel preferably comprises at least one thermoplastic material, the at least one thermoplastic material being polyvinyl chloride. Generally, any combinations thereof, alloys thereof, or mixtures of two or more thermoplastics wherein at least one thermoplastic material is polyvinyl chloride can be used to form the core, or at least a central layer thereof. Generally, such thermoplastic materials include, but are not limited to, vinyl containing thermoplastics such as polyvinyl acetate, polyvinyl alcohol, and other vinyl and vinylidene resins and copolymers thereof; polyethylenes such as low density polyethylenes and high density polyethylenes and copolymers thereof; styrenes such as ABS, SAN, and polystyrenes and copolymers thereof; polypropylene and copolymers thereof; saturated and unsaturated polyesters; acrylics; polyamides such as nylon containing types; engineering plastics such as acetyl, polycarbonate, polyimide, polysulfone, and polyphenylene oxide and sulphide resins and the like. One or more conductive polymers can be used to form the plank, which has applications in conductive flooring and the like. More preferably, the thermoplastic material is a rigid polyvinyl chloride but semi-rigid or flexible polyvinyl chloride may also be used. The flexibility of the thermoplastic material can be imparted by using at least one liquid or solid plasticizer which is preferably present in an amount of less than about 20 phr (parts per hundred parts of resin), and more preferably, less than 1 phr. A typical rigid PVC compound used in the present invention to form the core can also include, but is not limited to, pigments, impact modifiers, stabilizers, processing aids, lubricants, fillers, wood flours, other conventional additives, and the like.

The panel thickness is typically situated in between 3 and 12 mm, preferably between 4 and 8 mm.

The invention further relates to a covering consisting of mutually interconnected panels according to the invention.

The invention will be further elucidated according to the following non-limitative figures wherein:

Fig. 1 shows a perspective view on an embodiment of a rectangular panel according to the present invention before a weakening is applied wherein an example of a modified portion is schematically shown; Fig. 2 is a detailed perspective view on a first distal end of the third edge of a panel according to the present invention;

Fig. 3 shows a cross-sectional view indicated by section C-C in figure 1 ;

Fig. 3 a-f show a detailed view of section W from figure 3 showing different embodiments of a weakening in the first distal end of the third edge;

Figure 4 shows a covering of multiple panels according to the invention; and Figures 5A-5C show cross-sectional views of a third edge along different portions of a modified portion according to the invention.

In the figures the same reference numbers are used where applicable.

Figure 1 shows a rectangular floor panel 1 according to the present invention. The panel 1 is interconnectable with similar panels for forming a covering, as will be shown in figure 4. The floor panel 1 can be made of any material, though typical materials are wood, in particular HDF, MDF, and LDF, and plastic, in particular thermoplastic, more in particular PVC. Commonly, the floor panel 1 is made of a laminate comprising a central layer (core layer) enclosed by a backing structure and a top structure (not shown). The top structure commonly comprises a decorative layer, which may be printed onto the central layer, on top of which a protective layer is applied. The panel 1 comprises a centrally located core 2 provided with an upper side 3 and a lower side 4. The core 2 is integrally connected with a first pair of opposite edges, in particular a first edge 5 and a complementary second edge 6, located at the long lateral sides of the panel 1 . The core is also integrally connected with a second pair of opposite edges, in particular a third edge 7 and a complementary fourth edge 8, located at the short sides of the panel 1 in this exemplary embodiment. The panel 1 further comprises a modified portion 10 at a first distal end 11 of the third edge 7, adjacent to the first edge 5 for facilitating coupling of the panel with another panel. In this embodiment, an area for a modified portion 10 (for example a recess) is shown schematically by a dashed area. In figure 2 a more detailed view on the first distal end 11 is shown.

Figure 2 shows a detailed perspective view on a first distal end 11 of the third edge 7 of a panel according to the present invention. The panel comprises a modified portion 10 in the upward tongue 9 of the third edge 7, which weakening 10 is positioned at the distal end near the first edge 5. The modified portion 10 comprises two adjacent surfaces 12, 13, wherein a first oblique surface 12 is adjacent to a second horizontal surface 13. Both surfaces are facing towards the upper side 3 of the panel 1. In the shown embodiment the surfaces 12 and 13 are angled, but it is also possible that these surfaces form one curved surface. The surface(s) of the modified portion 10 may also be at least partly angled towards the upward flank 14. The height of the upward tongue 9 decreases towards the first edge 5.

Fig. 3 shows a cross-sectional view indicated by section C-C in figure 1 ;

Fig. 3a-3f show a detailed schematic view of section W from figure 3 showing different embodiments of a modified portion 10 in the first distal end of the third edge. The weakening 10, either a recess or a slit, is shown schematically by a line or a full area. Figure 3a shows an embodiment comprising an oblique recess 10a facing at least partly the upward flank. Figure 3b shows an embodiment which corresponds to an embodiment as shown in figure 2, where the weakening 10b comprises at least one oblique surface sloping downward towards the edge of the distal end. Figure 3c and 3d show a weakening 10c and 10d comprising a slit which runs over at least the area near the distal end of the third edge. Figure 3e shows an embodiment comprising a wedge shaped recess 10e. Figure 3f shows an embodiment where the wedge-shaped recess or slit 10f runs sideways, similar to the recess 10a.

Figure 4 shows a covering 31 of multiple panels 1 according to the invention. The sideward tongue 9 of the panel 1 is inserted partially into the corresponding recess 15 of a second edge of at least one (floor) panel already installed. The fourth edge 8 of the panel 1 to be installed is positioned substantially above the third edge 7 of the panel 1 already installed in the second row, wherein the fourth edge 8 and the third edge 7 of the panel 1 already installed in the second row, wherein the fourth edge 8 and the third edge 7 mutually enclose an angle (being the inclination angle of the panel to be coupled). During angling down of the panel 1 to be coupled both the first edge 5 and the fourth edge 8 of the panel 1 will be connected to adjacent panels 1 . The fourth edge 8 of the panel 1 to be coupled will make a downward scissoring movement with respect to the underlying third edge 7 and will zip (snap) into the third edge 7 and vice versa, leading to a firm and durable connection between the panels 1. The third edge 7 comprises a modified portion 10 at least near the first edge 5 reducing the internal tension within the material of the upward tongue 9 and/or the downward tongue 19 during the snap or zip connection in said downward scissoring movement.

Figure 5a-5c show various cross sectional views, similar to the C-C section in figure 1 , of a third edge of a panel, wherein the upper side of the upward tongue 9 is provided with a chamfered or angled modified portion 10. The first cross sectional view of figure 5A is at a section without, or outside the, modified portion 10, the second cross sectional view of figure 5B along a first part of the modified portion 10 and the third cross sectional view of figure 5C is at the distal edge, adjacent the angling side.

Figure 5a shows a closed groove system, wherein the coupling part of the third edge 7 comprises an upward flank 14, an upward groove 42 and an upward tongue 9. The inside 43 of the upward tongue 9 is at least partially inclined towards the upward flank 14, such that the inside 43 is at least partially titled towards the upward flank 14. This inclination or tilt results in the closed groove, which results in a vertical and horizontal locking of panels in coupled condition. The angle enclosed by the inclined inside and a plane defined by the upward flank or the normal of the upper side 3 for instance encloses an angle between 1 and 5 degrees.

The upper side 44 of the upward tongue 9 is inclined and runs downward towards the outside 45 of the upward tongue 9. The outside 45 of the upward tongue 9 is provided with a locking element 46 in the form of a bulge, with a curved upper side 47 and a flat and inclined lower side 48. The inclined lower side 48 encloses an angle with the outer vertical OV. The top portion of the upward flank 14 comprises a contact surface 50, which is typically vertical and arranged at an inner vertical IV, and is arranged to be in contact with a contact surface 50 of a further panel.

The width of the upward groove 42 can be measured from the inner vertical IV to the point of the inside 43 of the upward tongue 9 closest to the upward flank 14, and is indicated as distance D measured in the plane of the panel 1 .

Due to that a closed groove system is used, the point of the inside 43 of the upward tongue 9 closest to the upward flank 14 changes (and thus the distance D changes) when material is removed from the upper side 44 of the upward tongue 9. In transitioning from figure 5a to 5a to 5c an increasing amount of material is removed, which increases the distance D. An increased distance D makes it easier to couple two panel, as there is more space for, in this case, a downward tongue to it into the upward groove 42, as the groove is made slightly wider.

The features of the figures can be applied, either in combination or separate from each other, to other aspects and embodiments of the invention as well.

Hence, the above-described inventive concepts are illustrated by several illustrative embodiments. It is conceivable that individual inventive concepts may be applied without, in so doing, also applying other details of the described example. It is not necessary to elaborate on examples of all conceivable combinations of the abovedescribed inventive concepts, as a person skilled in the art will understand numerous inventive concepts can be (re)combined in order to arrive at a specific application.

By "horizontal" is meant a direction which extends parallel to a plane defined by the floor panel, and which may intersect the core. By “vertical” is meant a direction which is perpendicular to said plane defined by the floor panel. The ordinal numbers used in this document, like “first”, “second”, and “third” are used only for identification purposes. Hence, the use of the expressions “third locking element” and “second locking element” does therefore not necessarily require the copresence of a “first locking element”. By "complementary" coupling profiles is meant that these coupling profiles can cooperate with each other. However, to this end, the complementary coupling profiles do not necessarily have to have complementary forms. The expression “distal end” may also be considered as “distal end zone”, “distal end portion”, or “distal end region”. A “modified portion” is an edge portion which is purposively modified in order to facilitate coupling and/or uncoupling of adjacent panels.

It will be apparent that the invention is not limited to the working examples shown and described herein, but that numerous variants are possible within the scope of the attached claims that will be obvious to a person skilled in the art. The verb “comprise” and conjugations thereof used in this patent publication are understood to mean not only “comprise”, but are also understood to mean the phrases “contain”, “substantially consist of”, “formed by” and conjugations thereof.

Claims

1 . Panel, in particular a floor panel, wall panel or ceiling panel, interconnectable with similar panels for forming a covering, comprising:

■ a first edge comprising a sideward protrusion, in particular a sideward tongue, extending in a direction substantially parallel to the upper side of the panel,

■ an opposite, second edge comprising a recess for accommodating at least a part of the sideward protrusion, in particular the sideward tongue, of a further panel, said recess being defined by an upper lip and a lower lip, said lower lip being provided with a upwardly protruding shoulder,

■ the first edge and the second edge being designed such that these edges allow to realize a locking between adjacent panels by insertion of the sideward protrusion, in particular the sideward tongue, of said panel into the recess of a further panel by means of an angling down movement about an axis parallel to the first edge; and o a second pair of opposite edges, comprising:

■ a third edge comprising a single upward tongue, at least one upward flank (20) lying at a distance from the upward tongue and a single upward groove formed between the upward tongue and the upward flank (20), wherein at least a part of a side of the upward tongue facing toward the upward flank (20) is upwardly inclined towards the upward flank, and

■ a fourth edge comprising a single downward tongue, at least one downward flank (26) lying at a distance from the downward tongue, and a single downward groove formed between the downward tongue and the downward flank (26), wherein at least a part of a side of the downward tongue facing toward the downward flank (26) is downwardly inclined towards the downward flank, and wherein at least a first distal end of the third edge, adjacent to the first edge, comprises a modified portion, for facilitating coupling of the panel with another panel, wherein the modified portion preferably makes part of the upward tongue, and is more preferably located at least on the upper side of the upward tongue, and/or wherein at least a first distal end of the fourth edge, adjacent to the first edge, comprises a modified portion, for facilitating coupling of the panel with another panel, wherein the modified portion preferably makes part of the downward tongue, and is more preferably located at least on the bottom side of the downward tongue.

2. Panel according to claim 1 , wherein at least one modified portion is configured to deform at least temporarily during coupling of two panels.

3. Panel according to claim 1 or 2, wherein the modified portion of the upward tongue has a varying cross section along the length of the third edge, wherein, preferably, said cross section decreases towards the first distal end of the third edge.

4. Panel according to any of the previous claims, wherein at least one modified portion comprises a section where panel material is removed, at least compared to a middle portion of the third edge or a portion of the third edge not adjacent the first edge, or compared to a portion of the third edge adjacent the second edge.

5. Panel according to any of the previous claims, wherein at least a part of a side of the upward tongue facing away from the upward flank (20) comprises a first locking element; and wherein the downward flank (26) comprises a second locking element adapted for co-action with the first locking element of a third edge of yet a further panel.

6. Panel according to claim 5, wherein the modified portion of the upward tongue is free of said first locking element or comprises a modified first locking element.

7. Panel according to any of the previous claims, wherein at least one modified portion extends along a part of the third edge, preferably at most along a third of the length of the third edge, more preferably at most a quarter of the length of the third edge.

8. Panel according to any of the previous claims, wherein the modified portion of the upward tongue and/or downward tongue is decreasing in height and/or width over at least part of its length towards the first edge and is positioned in a region near the first edge, preferably up to the first edge.

9. Panel according to any of the previous claims, wherein the modified portion of the first distal end of the third edge, and preferably the modified portion of the upward tongue, and/or of the fourth edge comprises at least one slit or slot extending parallel to the third edge.

10. Panel according to claim 9, wherein a plane defined by at least one slit or slot is parallel to a plane defined by the panel.

11 . Panel according to claim 10, wherein a plane defined by at least one slit or slot is perpendicular to a plane defined by the panel.

12. Panel according to any of the previous claims, wherein the modified portion of the first distal end of the third edge comprises an oblique upper surface, enclosing an angle with the lower side of the panel, wherein said oblique upper surface preferably extends over the entire length of the modified portion.

13. Panel according to claim 12, wherein the width of the oblique surface widens towards the first edge.

14. Panel according to claim 12 or 13, wherein the oblique surface is at least partially curved.

15. Panel according to any of claims 12-14, wherein the modified portion of the first distal end of the third edge comprises an oblique upper surface portion, enclosing an angle with the lower side of the panel, and a horizontal upper surface portion connecting to said oblique upper surface portion, wherein the horizontal upper surface portion is located closer to the first distal end than the oblique upper surface portion.

16. Panel according to any of the previous claims, wherein at least one modified portion allows the first edge of the panel to be coupled to the second edge of an adjacent panel, by means of an angling down movement about an axis parallel to the first edge, such that the panel can be angled unobstructedly into each until the panels mutually enclose an angle of less than 45 degrees, preferably less than 30 degrees, more preferably less than 25 degrees.

17. Panel according to any of the previous claims, wherein the panel is substantially rigid.

18. Panel according to any of the previous claims, wherein the first distal end of the third edge comprises at least one wedge-shaped recess, wherein the V of the wedge-shape runs substantially parallel to the first edge of the panel, preferably extending over the entire width of the upward tongue.

19. Panel according to any of the previous claims, wherein the first distal end of the third edge comprises a slit, which slit comprises at least one V-shaped slit, wherein the V-shaped slit runs substantially perpendicular to the first edge of the panel, preferably extending over the entire length of the upward tongue.

20. Panel according to any of the previous claims, wherein the first distal end of the third edge comprises at least one substantially linear slit, preferably extending over at least part of the length of the respective tongue.

21 . Panel according to any of the previous claims, wherein at least a first distal end of the fourth edge adjacent to the first edge comprises a modified portion for facilitating coupling of the panel with another panel.

22. Panel according to any of the previous claims, wherein the first edge and the second edge being designed such that these edges allow to realize a locking between adjacent panels by insertion of the sideward protrusion, in particular the sideward tongue, of said panel into the recess of a further panel by means of an vertical movement.

23. Panel according to any of the previous claims, wherein the third edge and the fourth edge being designed such that these edges are configured to be coupled by means of a fold-down movement.

24. Panel according to any of the previous claims, wherein the panel is a decorative panel, and wherein the panel comprises a decorative top structure affixed, either directly or indirectly, to the upper side of the core.

25. Covering consisting of mutually interconnected panels according to any of the previous claims.