EP4442074A1

EP4442074A1 - Panel with electrical functionality

Info

Publication number: EP4442074A1
Application number: EP22823152.8A
Authority: EP
Inventors: Sam LEDEGEN
Original assignee: Unilin BV
Current assignee: Unilin BV
Priority date: 2021-12-02
Filing date: 2022-11-24
Publication date: 2024-10-09
Also published as: WO2023100042A1

Abstract

A sheet (30) comprises a carrier (31) and an induction coil (32) on a first side of the carrier and an electrical component (33) on the other side of the carrier. The sheet comprises, through the carrier, an electrically conductive connection (34) of the induction coil to the electrical component. This sheet may be incorporated in panels (1). In these panels the electrical component (33) can be supplied with current via the induction coil (32).

Description

Panel with electrical functionality

This invention relates to panels with electrical functionality. An example of said electrical functionality is electric heating, for example if said panels are used as floor panels or wall panels.

US2010/0089899A1 and US2011/0272392A1 describe panels for floor, wall or ceiling coverings. The panels comprise inbuilt electric heating elements. The panels comprise mechanical coupling parts that allow the panels to be coupled together to form a covering. The electric heating elements receive electric current via electrical conductors. For this purpose, the coupling parts of the panels comprise electrical conductors, which in the coupled state of the panels make electrically conductive contact with each other, so that electric current is led from the coupling parts of the panels to the various panels, and thus to the electric heating elements in the panels.

A drawback of such panels is that an electrically conductive coupling must be made to the mechanical couplings between the various panels that form the floor covering. Moreover, the heating element is located at the bottom of the panel; this means slow warming up, since the heat generated must first heat the whole panel before the room is warmed up effectively.

CN1046056551 describes panels that comprise electric heating elements that are supplied with current inductively. The inductively supplying coils and the inductively supplied coils are located in the panel. The structure of these panels is such that electrical conduction is required to the mechanical coupling parts that couple panels to each other.

WO2012/092561 Al describes a floor structure that is applied on a subfloor. The subfloor comprises coils that are supplied with electric current via electrical conductors. The floor structure comprises coils that are coupled inductively to the coils in the subfloor. The coils in the floor structure supply electric current to electronic components built into the floor structure. One aim of the invention is to make suitable elements available for the construction of panels with electrical functionality that can be built into the panels in a simple manner. One aim of the invention is to offer panels with electrical functionality - for example with heating elements - wherein no electrical connections have to be made at the coupling between the panels; and wherein the panels can be produced in a simple manner.

A specific aim of the invention is to make panels available that comprise electric heating elements that ensure quick warming up of the room in which these panels are installed, and wherein the panels can be produced in a simple manner.

The first aspect of the invention is a sheet, wherein the sheet comprises a carrier, and an induction coil on a first side of the carrier and an electrical component on the other side of the carrier. The sheet comprises, through the carrier, an electrically conductive connection of the induction coil to the electrical component.

This sheet can be integrated in a panel in a simple way, for example by laminating. By means of inductive coupling, electric current can be fed to the induction coil, which can be led via the electrically conductive connection to the electrical component on the other side of the carrier.

Preferably the electrically conductive connection is formed by an electrical conductor through an opening - preferably a perforation - in the carrier; for example by an electrically conductive polymer, or by a polymer that contains electrically conductive particles, or by an electrically conductive component through this opening. In this way, current can be led efficiently from the induction coil to the electrical component on the other side of the carrier.

In a preferred embodiment of the first aspect of the invention the induction coil is constructed from a metal film, for example a thin metal film.

This metal film may for example consist of copper, aluminium or an alloy of copper or aluminium. These metal films may be applied by printing, sputtering or vapour deposition. It is also possible to apply these metal films by means of a thin metal foil, parts of which have been etched away.

In a preferred embodiment of the first aspect of the invention, the induction coil is formed from a conductive polymer. Preferably this conductive polymer is selected from polypyrrole (PPy), polyaniline (PANI), polythiophene (PT), or poly(3,4- ethylenedi oxy thiophene) (PEDOT). These polymers can be applied on the carrier by known polymer techniques to form the induction coil.

In a preferred embodiment of the first aspect of the invention, the induction coil is formed from a polymer that contains conductive particles. Preferably this polymer is selected from an aminoplast, melamine resin, polyurethane, acrylate, polyvinyl alcohol or polyvinyl acetate. The use of said polymers has the advantage that they can provide adhesion between layers when laminating the sheet into for example a sheet material, for example by a polycondensation reaction of the polymer with layers adjacent to the sheet in the sheet material.

In a preferred embodiment of the first aspect of the invention the induction coil may be formed by means of a conductive ink. It is an advantage that by printing the sheet with the conductive ink, the pattern of the induction coil can be formed easily and correctly. Furthermore, these embodiments have the advantage that the induction coil is thin.

In a preferred embodiment of the first aspect of the invention, in the plane of the windings of the induction coil, between the windings of the induction coil there is electrically insulating material, preferably polymer for example such as melamine resin, polyurethane or a hotmelt. These embodiments are interesting for avoiding having the design of the induction coil showing through on the surface of the object - for example a panel - that comprises this sheet. This is especially important because it is desirable to place the sheet as close as possible to the surface of the object - for example panel - for efficiency of current consumption. The second aspect of the invention relates to a sheet, wherein the sheet comprises a carrier and a first side of the carrier, and on the other side of the carrier an electrical component, wherein the sheet comprises electrical conductors for supplying the electrical component conductively with electric current from outside the sheet. This sheet can be integrated in a panel in a simple way, for example by laminating. Because the electrical conductors are provided, the electrical component can easily be supplied with electric current.

In a preferred embodiment of the second aspect of the invention the sheet is rectangular and the electrical conductors are placed so that the electrical conductors on one of the short sides of the sheet can be supplied with current. This sheet can be incorporated in a panel in a simple way, for example by laminating. The sheet can be incorporated in such a way that the sheet is supplied with current via the short edges of a rectangular panel.

In an embodiment of the first aspect or of the second aspect of the invention, the electrical component is or comprises an electric heating element, preferably an electric heating element that generates heat by the Joule effect. In this way, it is possible to produce panels in a simple way wherein the heating element is located very close to the surface of the panel. As a result, it is warmed up faster and less heat is lost.

In an embodiment of the first aspect or of the second aspect of the invention, the electrical component is or comprises a second induction coil. This second induction coil may then be used for charging batteries of appliances that operate on batteries that can be charged inductively, by putting this equipment on the surface that comprises the second induction coil. Another application is for example the use of the sheet in a floor panel, wherein a lamp is supplied with current inductively via the second induction coil.

In an embodiment of the first aspect or of the second aspect of the invention, the electrical component may be a sensor or may comprise a sensor.

In a preferred embodiment of the first aspect or of the second aspect of the invention, the carrier is or comprises a sheet of paper impregnated or coated with polymer. It is an advantage that known technology can be used herein, for example such as using laminated panels that have an MDF or HDF substrate. This embodiment allows the sheet to be integrated easily in a panel by known laminating techniques.

Preferably the sheet of paper is impregnated with an aminoplast resin - for example melamine resin, urea formaldehyde resin or phenol-formaldehyde resin or a combination of said resins -, or with polyurethane or with acrylate. This allows the sheet to be integrated easily in a panel by known laminating techniques.

In a preferred embodiment of the first aspect or of the second aspect of the invention, the carrier is or comprises a plastic film, for example a polyester film. This allows flexible sheets to be made, which can be integrated in a board by laminating techniques, for example by means of adhesives.

In a preferred embodiment of the first aspect or of the second aspect of the invention, the electrical component comprises or consists of: metal, electrically conductive polymer or a polymer that contains electrically conductive particles. The use of electrically conductive polymer has the particular advantage that the quantity of conductive particles in the polymer allows the conductivity to be adjusted. This may for example be advantageous if the electrical component is a heating element that works by the Joule effect.

In a preferred embodiment of the first aspect or of the second aspect of the invention, the electrical component comprises an electrically conductive polymer, preferably selected from polypyrrole (PPy), polyaniline (PANI), polythiophene (PT), or poly(3,4- ethylenedi oxy thiophene) (PEDOT). These polymers can be applied on the carrier by known polymer techniques to form the electrical component.

In a preferred embodiment of the first aspect or of the second aspect of the invention the sheet has a constant thickness. These embodiments have the advantage that there is better avoidance of the design of the induction coil or electrical component showing through on the surface of the object - for example a panel - that comprises this sheet. Such embodiments may for example be carried out by embedding the induction coil and/or the electrical component in a polymer layer. This polymer layer may additionally be useful for providing adhesion when integrating - for example by laminating - the sheet in for example a panel. It is also possible to produce a constant thickness of the sheet by filling between and next to windings of the induction coil and/or of the electrical component with a polymer layer. This polymer layer may additionally be useful for providing adhesion when integrating - for example by laminating - the sheet in for example a panel.

The third aspect of the invention is a panel, wherein the panel at least comprises a substrate, a decorative layer, and a sheet such as in any embodiment of the first aspect or of the second aspect of the invention. The sheet is located between the substrate and the decorative layer. The first side of the carrier is preferably directed towards the substrate. Said panels are easy to produce, for example by laminating of the sheet.

When using a sheet according to the first aspect of the invention, said panels can easily be inductively coupled by placing these panels against or on a substrate that comprises induction coils for inductive supply of the induction coil(s) of the sheet.

Since the electrical component is located in the panel above the substrate, the energy consumption will be very efficient. If the electrical component is a heating element, this means that the heat developed is employed usefully very quickly, because the panel does not have to be warmed up through its thickness first. This is indeed the case if the heating element is not located close to the surface of the panel.

Preferably the panel is a wall panel, a ceiling panel or a floor panel.

In preferred embodiments of the third aspect of the invention, the substrate is a woodbased substrate, for example an MDF (Medium Density Fibreboard) panel, an HDF (High Density Fibreboard) panel, a chipboard, an OSB (Oriented Strand Board) board, or an assembled parquet (also known as "engineered wood"). Since such materials are likely to be thermal insulators, panels according to these embodiments have specific advantages if the electrical component is a heating element. Because the sheet - and thus the heating element - is positioned close to the surface of the panel, the heat generated is employed usefully immediately, without the substrate having to be warmed up first. The heat loss is also limited owing to this favourable positioning of the sheet in the panel. In preferred embodiments of the third aspect of the invention, the substrate comprises an inorganic binder; and preferably fillers. The inorganic binder may for example be one or more of magnesium oxide, Sorel cement, gypsum or Portland cement.

In preferred embodiments of the third aspect of the invention the substrate comprises a thermoplastic polymer as matrix, wherein this thermoplastic polymer matrix comprises fillers. Preferably this substrate contains more than 50 wt% of fillers relative to the total weight of the substrate. This thermoplastic polymer may for example be polyvinyl chloride or polyester.

In examples of the third aspect of the invention, the substrate comprises fillers selected from one or more of cellulose or wood-based fillers, for example such as wood fibres, wood particles or wood dust, and/or mineral fillers such as lime, limestone or stone particles.

The use of mineral fillers in a polymer matrix, especially if more than 50 wt% of mineral fillers is used relative to the total weight of the substrate, is that there is better avoidance of temperature effects in the substrate.

In preferred embodiments of the third aspect of the invention, the decorative layer of the panel is or comprises veneer. This veneer may be glued or pressed onto the sheet.

In preferred embodiments of the third aspect of the invention, the decorative layer of the panel is or comprises a printed paper sheet, impregnated or coated with a polymer or with a resin, more preferably impregnated with an aminoplast resin - for example melamine resin, urea formaldehyde resin or phenol-formaldehyde resin or a combination of said resins - or with a polyurethane or with an acrylate. Decorative layers of this kind can easily be integrated in panels according to the third aspect of the invention by known laminating processes.

In preferred embodiments of the third aspect of the invention, the decorative layer of the panel is or comprises a printed polymer film, preferably a printed polyvinyl chloride film. Decorative layers of this kind can be integrated well when the carrier of the sheet is compatible with the film of the decorative layer or can be glued thereon by means of a suitable glue.

Preferably the surface of the panel comprises a wear layer above the decorative layer, more preferably the wear layer is translucent or transparent.

In preferred embodiments of the third aspect of the invention, the wear layer comprises a layer of paper impregnated with polymer or resin, more preferably wherein the resin is or comprises a melamine resin, an acrylate, a polyurethane acrylate or a polyurethane. Said wear layers can be applied efficiently by known techniques. With a suitable composition of the sheet, decorative layer and substrate, it is even possible to laminate the substrate, sheet, decorative layer and the wear layer to each other in a single laminating step.

In preferred embodiments of the third aspect of the invention, the wear layer comprises a polymer film, preferably a polyvinyl chloride film. Said wear layers can be applied efficiently by known techniques. With a suitable composition of the sheet, decorative layer and substrate, it is even possible to laminate the substrate, sheet, decorative layer and the wear layer to each other in a single laminating step.

In preferred embodiments of the third aspect of the invention, the wear layer comprises or the wear layer consists of a polymer coating, more preferably an acrylate or a polyurethane polymer coating. It is possible for said coating to be applied on a wear layer as described in the two previous paragraphs.

Preferably the wear layer comprises wear-resistant particles, for example such as corundum, in order to increase the wear resistance of the surface of the panel.

In preferred embodiments of the third aspect of the invention, the substrate, the sheet and the decorative layer - and optionally the optional wear layer - are laminated on one another. Depending on the compositions, this laminating may take place by means of a condensation reaction and/or by means of thermal welding of layers of the panel together and/or by gluing with addition of a glue.

In preferred embodiments of the third aspect of the invention, adhesion between decorative layer and sheet on the one hand, and between the sheet and the substrate on the other hand, is obtained by means of melamine resin or by means of polyurethane.

In preferred embodiments of the third aspect of the invention the panel is rectangular, either square or oblong.

In preferred embodiments of the third aspect of the invention the panel comprises a first pair of opposite edges. The first pair of opposite edges is provided with coupling parts for coupling together two such panels on the first pair of opposite edges. Preferably the coupling parts are provided with locking elements, so that in the coupled state on the first pair of opposite edges locking is obtained in the direction perpendicular to the surface of the panels; and/or in the direction parallel to the surface of the panels and perpendicular to the first pair of opposite edges. Said panels can be placed easily, for example in a floating floor covering. Connection is simple, also because it is not necessary to make an electrically conductive connection between the panels.

Preferably, in the coupled state of two such panels, on their first pair of opposite edges there is no electrically conductive connection via these coupled edges.

In preferred embodiments of the third aspect of the invention, the panel comprises a second pair of opposite edges. The second pair of opposite edges is provided with coupling parts for coupling together two such panels on the second pair of opposite edges. More preferably, the coupling parts are provided with locking elements, so that in the coupled state on the second pair of opposite edges locking is obtained in the direction perpendicular to the surface of the panels; and/or in the direction parallel to the surface of the panels and perpendicular to the second pair of opposite edges. Said panels can be placed easily, for example in a floating floor covering. Connection is simple, also because it is not necessary to make an electrically conductive connection between the coupled panels.

Preferably, in the coupled state of two such panels on their second pair of opposite edges there is no electrically conductive connection via these coupled edges.

More preferably, the first and the second pair of opposite edges are provided with coupling parts so that these panels can be installed floating by means of the fold down technique.

In a preferred embodiment of the third aspect of the invention the panel comprises a second pair of opposite edges, wherein the second pair of opposite edges is not provided with mechanical coupling parts for coupling together two such panels on the second pair of opposite edges. More preferably said panel comprises a sheet such as in any embodiment of the second aspect of the invention, wherein the electrical conductors are placed so that the electrical conductors can be supplied with electric current on one of the edges of the panel that are not provided with mechanical coupling parts. This makes it possible for example to develop rectangular and elongated wall panels with for example mechanical coupling parts on their long edges. The other pair of edges, the short edges, are not provided with coupling parts and the electrical connection can be made on one of the short edges. With wall panels of this kind the electrical connection can then be made to the bottom of the room or when using floor-to-ceiling panels, to the ceiling. A skirting board may be placed to conceal this electrical connection. If the electrical component is or comprises an electric heating element, in this way heating can be provided via these wall panels.

The fourth aspect of the invention relates to a covering, for example a floor covering, a wall covering or a ceiling covering, wherein the covering comprises a plurality of panels, of which at least one and preferably a plurality of panels such as in any embodiment of the third aspect of the invention. A preferred embodiment of the fourth aspect of the invention relates to a covering, wherein the covering except one or more panels such as in any embodiment of the third aspect of the invention; comprises one or more panels with the same decorative layer as the one or more panels such as in any embodiment of the third aspect of the invention, but that do not comprise said sheet. This makes it possible to form a covering - for example a floor covering -, wherein only certain panels comprise said sheet. It is thus possible to heat certain zones of the floor covering by means of the panels, while others - otherwise identical panels, certainly identical in appearance and in manner of installation - do not comprise heating elements. It is also possible in this way to provide panels only at certain places, which comprise a sheet with a second induction coil, with which for example a lamp placed on the panel, a lamp that itself comprises an induction coil for inductive generation of current therein, can be supplied with current.

A preferred embodiment of the fourth aspect of the invention relates to a covering, wherein at least one and preferably a plurality of panels such as in any embodiment of the third aspect of the invention comprise a sheet such as in the first aspect of the invention, wherein the plurality of panels is placed on a sublayer, wherein the sublayer comprises one or more induction coils, wherein the sublayer comprises electrical conductors for supplying the one or more induction coils of the sublayer with electric current, wherein the one or more induction coils of the sublayer are provided for generating electric current by induction in the induction coil of the sheet of the panel as in any embodiment of the third aspect of the invention, or in one or more of the induction coils of the sheets of the panels such as in any embodiment of the first aspect of the invention.

A preferred embodiment of the fourth aspect of the invention relates to a covering, wherein at least one and preferably a plurality of panels such as in any embodiment of the third aspect of the invention comprise a sheet such as in the second aspect of the invention. Preferably this covering comprises a current supply, wherein the current supply is connected conductively to the electrical conductors of the sheet.

This covering may for example be a wall covering, wherein the panels are rectangular and are positioned with their long edge vertical, wherein the sheet in the panel is positioned so that the electrical conductors on one of the short sides of the panel can be supplied with electric current. These embodiments allow the covering to be installed in an elegant manner. The current supply may be provided at the bottom or at the top of the room, and for example may be concealed with a skirting board.

The fifth aspect of the invention relates to a method for making a panel as in any embodiment of the third aspect of the invention, wherein the sheet is integrated in the panel by means of a laminating step.

In preferred embodiments of the fifth aspect of the invention, the decorative layer is integrated in the panel by a laminating process. More preferably this takes place in the same laminating step in which the sheet is integrated in the panel. Such processes allow the panel to be manufactured efficiently by and with known and available laminating technology, especially when the sheet can also be integrated in the panel in this laminating step.

More preferably, the decorative layer is supplied as a high pressure laminate (HPL), as a continuous pressure laminate (CPL) or as a direct pressure laminate (DPL).

In preferred embodiments of the fifth aspect of the invention, the decorative layer - and optionally the optional wear layer - is integrated in the substrate in a continuous process, by means of a press of the continuous type or by means of a heated press band or a heated press roll. Such processes allow the panel to be manufactured efficiently by and with known and available laminating technology, especially when the sheet can also be integrated in the panel in this laminating step.

In preferred embodiments of the fifth aspect of the invention, the decorative layer - and optionally the optional wear layer - are integrated in the substrate in a discontinuous process, preferably by means of a pressing operation carried out with a short-cycle press. Such processes allow the panel to be manufactured efficiently by and with known and available laminating technology, especially when the sheet can also be integrated in the panel in this laminating step. In preferred embodiments of the fifth aspect of the invention the press element is a structured press element so that the surface of the panel is provided with a relief.

For the purpose of better illustration of the features of the invention, some preferred embodiments are described hereunder, as examples without any limiting character, referring to the appended drawings, in which:

Fig. 1 illustrates a floor covering according to one aspect of the invention;

Fig. 2 shows a panel such as may be used in the invention;

Fig. 3 shows the cross-section according to III-III of the panel in Fig. 2;

Figs. 4a, b and c illustrate schematically an example of a sheet according to the first aspect of the invention;

Fig. 5 illustrates an example of a covering according to the invention;

Figs. 6a, b and c illustrate schematically an example of a sheet according to the second aspect of the invention; and

Fig. 7 shows a panel that comprises a sheet according to the second aspect of the invention.

Fig. 1 illustrates a floor covering according to one aspect of the invention. This covering comprises panels 1. Said panel 1 is illustrated in Fig. 2. These example panels are rectangular and elongated and comprise a first pair of opposite edges 2, 3 and a second pair of opposite edges 4, 5. These panels 1 can be coupled together mechanically to form a floating floor covering. For this purpose the first pair of opposite edges 2, 3 and also the second pair of opposite edges 4, 5 are provided with coupling parts for the mechanical coupling together of the panels on their edges, wherein locking is also obtained in the direction perpendicular to the surface of the panels; as well as in the direction perpendicular to the coupled edges and parallel to the plane of the surface of the panel.

The coupling parts on the first pair of opposite edges are configured so that panels on the first pair of opposite edges 2, 3 can be coupled together by means of a rolling motion W. The coupling parts of the second pair of opposite edges 4, 5 are configured so that by means of a vertical motion of the edge of a first panel in the edge of the second panel, they can be coupled on their second pair of opposite edges 4, 5. Combined, this means that - as shown in Fig. 1 - the panels can be installed by the fold down technique, wherein the vertical motion on a second pair of opposite edges takes place simultaneously with the rolling motion on a first pair of opposite edges.

Fig. 3 shows the cross-section according to III-III of the panel in Fig. 2. The panel 1 comprises a substrate 19, a sheet 30 such as in the first aspect of the invention, a decorative layer 20 and a wear layer. The details of the sheet 30 are not visible in Fig. 3, but are explained in the other figures. The panel 1 comprises, on its first pair of opposite edges 2, 3, coupling parts, essentially in the form of a tongue 7 and a groove 8. These coupling parts 7, 8 comprise locking elements 10, 11 for locking the coupled panels in the direction perpendicular to the coupled edges and parallel to the plane of the surface of the panel 1.

Fig. 3 also shows the rolling motion W for the mechanical coupling together of panels on their first pair of opposite edges 2, 3.

Figs. 4a, b and c illustrate schematically an example of a sheet 30 according to the first aspect of the invention. The sheet 30 comprises a carrier 31. On the first side of the carrier 31 there is an induction coil 32; and on the other side of the carrier 31, an electrical component 33 is provided. Through the carrier 31, the sheet 30 has an electrically conductive connection 34 between the induction coil 32 and the electrical component 33. This electrical connection 34 is formed by an electrical conductor through an opening in the carrier 31.

Fig. 4a shows the cross-section of the sheet. Fig. 4b shows the side of the sheet 30 where the carrier comprises the induction coil 32. Fig. 4c shows the side of the sheet 30 where the carrier comprises the electrical component 33 (in this case a heating element 35).

Fig. 4c shows the heating element 35 as a linear conductor that has a particular design. It is, however, also possible that this heating element is or comprises a two-dimensional surface.

In the example shown in Fig. 4a, the sheet 30 has a constant thickness. This constant thickness may for example be achieved by embedding the sheet in polymer; or - as shown in Fig. 4a - by filling between and next to windings of the induction coil and/or electrical component with a polymer layer 37. Fig. 5 illustrates an example of a covering according to the invention. The reference numbers indicate the same elements as in the other drawings. The covering is in this case a floor covering. The covering comprises a plurality of floor panels 1, 51, shown in crosssection perpendicular to their first pair of opposite edges 2, 3. These edges have coupling parts, essentially in the form of a tongue 7 and a groove 8, with locking elements 10, 11, which prevent the panels sliding out of one another on their first pair of opposite edges in the direction perpendicular to these edges and parallel to the plane of the surface of the panel.

The panels 1, 51 comprise a substrate 19, a decorative layer 20 and a wear layer 21. The figure shows two panels 1 that also comprise a sheet 30 such as in the first aspect of the invention, and a panel 51 that does not comprise a sheet of this kind, but is otherwise identical to the panels 1. The panels 1 (with sheet 30) and panels 51 (without sheet) thus form a homogeneous covering.

The panels 1, 51 are placed on a sublayer 40. This sublayer comprises a number of induction coils 41. The sublayer further comprises electrical conductors 42 for supplying these induction coils 41 of the sublayer 40 with electric current. These induction coils 41 of the sublayer 40 are provided for generating electric current by induction in the induction coils 32 of the sheets 30 of the panels 1.

Figs. 6a, b and c illustrate schematically an example of a sheet 60 according to the second aspect of the invention. The sheet 60 comprises a carrier 31. On the first side of the carrier 31 there is no electrical component; and on the other side of the carrier 31 an electrical component 33 is provided. The sheet 60 comprises electrical conductors 61 for supplying the electrical component 33 with electric current conductively from outside the sheet.

Fig. 6a shows the cross-section of the sheet 60. Fig. 6b shows the first side of the sheet 60. Fig. 6c shows the other side of the sheet 60 where the carrier comprises the electrical component 33 (in this case a heating element 35).

Fig. 6c shows the heating element 35 as a one-dimensional conductor that is given a particular design. It is, however, also possible that this heating element is or comprises a two-dimensional surface. In the example shown in Fig. 6a, the sheet 30 has a constant thickness. This constant thickness may for example be achieved by embedding the sheet in polymer; or - as shown in Fig. 6a - by filling between and next to windings of the electrical component 33 with a polymer layer 37.

Fig. 7 shows a panel 1 that comprises a sheet according to the second aspect of the invention. The panel 1 is rectangular and elongated. The long edges 2, 3 are provided with mechanical coupling parts for coupling panels together on their long edges. The short edges 63, 64 do not comprise any mechanical coupling parts. A sheet according to the second aspect of the invention - in this case wherein the electrical component is an electric heating element 35 (drawn with a dotted line, because this electrical component is underneath the decorative layer 20 and so is not visible) - is according to the third aspect of the invention incorporated in the panel, so that the electrical conductors 61 that can provide power supply are located on one of the short edges. These panels may be used as wall covering, with their long edges vertically against a wall. It is possible to configure these panels as floor-to-ceiling. The current supply may be provided at the bottom or at the top, wherein a skirting board is placed.

Claims

1.- Sheet, wherein the sheet (30) comprises a carrier (31) and an induction coil (32) on a first side of the carrier and an electrical component (33) on the other side of the carrier, wherein the sheet comprises an electrically conductive connection (34) through the carrier from the induction coil to the electrical component.

2.- Sheet as in claim 1, wherein the electrically conductive connection is formed by an electrical conductor (34) through an opening - preferably a perforation - in the carrier; for example by an electrically conductive polymer, or a polymer that contains electrically conductive particles, or an electrically conductive component through this opening.

3.- Sheet as in any of the preceding claims, wherein the induction coil (32) is constructed from a metal film, for example from a thin metal film.

4.- Sheet as in claim 3, wherein the metal film consists of copper, aluminium or an alloy of copper or aluminium.

5.- Sheet as in any of the preceding claims 3-4, wherein the metal film is applied by sputtering, vapour deposition or printing, or by means of a thin metal foil from which parts have been etched away.

6.- Sheet as in any of the preceding claims 1-5, wherein the induction coil (32) is formed from a conductive polymer, preferably selected from polypyrrole (PPy), polyaniline (PANI), polythiophene (PT), or poly(3,4-ethylenedioxythiophene) (PEDOT).

7.- Sheet as in any of the preceding claims 1-5, wherein the induction coil (32) is formed from a polymer that contains conductive particles, preferably wherein the polymer comprises or consists of an aminoplast, melamine resin, polyurethane, acrylate, polyvinyl alcohol or polyvinyl acetate. Sheet as in any of the preceding claims 1-5, wherein the induction coil (32) is formed by means of a conductive ink. Sheet as in any of the preceding claims, wherein, in the plane of the windings of the induction coil (32) between the windings of the induction coil, there is electrically insulating material (37), preferably polymer for example such as melamine resin, polyurethane or a hotmelt. Sheet, wherein the sheet (60) comprises a carrier (31) and a first side of the carrier

(31), and an electrical component (33) on the other side of the carrier, wherein the sheet comprises electrical conductors (61) in order to supply the electrical component conductively with electric current from outside the sheet. Sheet as in claim 10, wherein the sheet (60) is rectangular, wherein the electrical conductors (61) are placed so that the electrical conductors can be supplied with electric current on one of the short sides of the sheet. Sheet as in any of the preceding claims 1-11, wherein the electrical component is or comprises an electric heating element (35), preferably an electric heating element that generates heat by the Joule effect. Sheet as in any of the preceding claims 1-11, wherein the electrical component is or comprises a second induction coil. Sheet as in any of the preceding claims 1-11, wherein the electrical component is or comprises a sensor. Sheet as in any of the preceding claims, wherein the carrier (31) is or comprises a sheet of paper impregnated and/or coated with polymer. 19 Sheet as in claim 15, wherein the sheet of paper has been impregnated with aminoplast resin - for example melamine resin, urea formaldehyde resin or phenolformaldehyde resin or a combination of said resins -, or with polyurethane or with acrylate. Sheet as in any of the preceding claims 1-14, wherein the carrier (31) is or comprises a plastic film, for example a polyester film. Sheet as in any of the preceding claims, wherein the electrical component (33) consists of or comprises: metal, electrically conductive polymer or a polymer that contains electrically conductive particles. Sheet as in any of the preceding claims 1-18, wherein the electrical component (33) comprises an electrically conductive polymer, preferably selected from polypyrrole (PPy), polyaniline (PANI), polythiophene (PT), or poly(3,4- ethylenedi oxy thiophene) (PEDOT). Sheet as in any of the preceding claims, wherein the sheet has a constant thickness. Panel, wherein the panel (1) at least comprises:

- a substrate (19),

- a decorative layer (20), and

- a sheet (30) as in any of the preceding claims 1-20, wherein the sheet is located between the substrate and the decorative layer; preferably wherein the first side of the carrier (31) is directed towards the substrate. Panel as in claim 21, wherein the panel is a wall panel, a ceiling panel or a floor panel. Panel, as in any of the preceding claims 21-22, wherein the substrate is a woodbased substrate, for example an MDF panel, an HDF panel, a chipboard, an OSB board, or an assembled parquet. 20 Panel as in any of the preceding claims 21-22, wherein the substrate comprises an inorganic binder; and preferably fillers. Panel as in claim 24, wherein the inorganic binder comprises or is one or more of magnesium oxide, Sorel cement, gypsum or Portland cement. Panel as in any of the preceding claims 21-22, wherein the substrate comprises a thermoplastic polymer as matrix, wherein this thermoplastic polymer matrix comprises fillers - preferably more than 50 wt% of fillers relative to the total weight of the substrate -; for example wherein this thermoplastic polymer is polyvinyl chloride or polyester. Panel as in any of claims 24-26, wherein the fillers comprise one or more of cellulose or wood-based fillers for example such as wood fibres, wood particles or wood dust, and/or mineral fillers such as lime, limestone or stone particles. Panel as in any of the preceding claims 21-27, wherein the decorative layer is or comprises veneer, preferably wherein this veneer is glued or pressed onto the sheet. Panel as in any of the preceding claims 21-27, wherein the decorative layer comprises a printed paper sheet, impregnated or coated with a polymer or with a resin, preferably impregnated with an aminoplast resin - for example melamine resin, urea formaldehyde resin or phenol-formaldehyde resin or a combination of said resins -, or with a polyurethane or with an acrylate. Panel as in any of the preceding claims 21-27, wherein the decorative layer comprises a printed polymer film, preferably a printed polyvinyl chloride film. Panel as in any of the preceding claims 21-30, wherein the surface of the panel comprises a wear layer above the decorative layer, preferably wherein the wear layer is translucent or transparent. 21 Panel as in claim 31, wherein the wear layer comprises a layer of paper impregnated with polymer or resin, preferably wherein the resin is or comprises a melamine resin, an acrylate, a polyurethane acrylate or a polyurethane. Panel as in claim 31, wherein the wear layer comprises a polymer film, preferably a polyvinyl chloride film. Panel as in any of the preceding claims 31-33, wherein the wear layer comprises or consists of a polymer coating, preferably an acrylate, or a polyurethane polymer coating. Panel as in any of the preceding claims 31-34, wherein the wear layer contains wearresistant particles, for example such as corundum. Panel as in any of the preceding claims 21-35, wherein the substrate, the sheet and the decorative layer - and optionally the optional wear layer -, are laminated on one another. Panel as in claim 36, wherein the adhesion between decorative layer and sheet on the one hand, and between the sheet and the substrate on the other hand, is obtained by means of melamine resin or by means of polyurethane. Panel as in any of the preceding claims 21-37, wherein the panel is rectangular, either square or oblong. Panel as in any of the preceding claims 21-38, wherein the panel (1) comprises a first pair of opposite edges (2, 3), wherein the first pair of opposite edges is provided with coupling parts (7, 8) for coupling together two such panels on the first pair of opposite edges, preferably wherein the coupling parts are provided with locking elements (10, 11), so that in the coupled state on the first pair of opposite edges locking is obtained in the direction perpendicular to the surface of the panels; and/or 22 in the direction parallel to the surface of the panels and perpendicular to the first pair of opposite edges. Panel as in claim 39, wherein in the coupled state of two such panels on their first pair of opposite edges, there is no electrically conductive connection via these coupled edges. Panel as in any of the preceding claims 39-40, wherein the panel comprises a second pair of opposite edges (4, 5), wherein the second pair of opposite edges is provided with coupling parts for coupling together two such panels on the second pair of opposite edges, preferably wherein the coupling parts are provided with locking elements, so that in the coupled state on the second pair of opposite edges locking is obtained in the direction perpendicular to the surface of the panels; and/or in the direction parallel to the surface of the panels and perpendicular to the second pair of opposite edges; preferably wherein panels can be installed floating, by the fold down technique. Panel as in claim 41, wherein in the coupled state of two such panels on their second pair of opposite edges there is no electrically conductive connection via these coupled edges. Panel as in any of the preceding claims 39-40, wherein the panel comprises a second pair of opposite edges, wherein the second pair of opposite edges is not provided with mechanical coupling parts for coupling together two such panels on the second pair of opposite edges. Panel as in claim 43, wherein the panel comprises a sheet as in claim 10 and optionally as in any of the preceding claims 11-20, wherein the electrical conductors are placed so that the electrical conductors can be supplied with electric current on one of the edges of the panel that are not provided with mechanical coupling parts. 23 Covering, for example a floor covering, a wall covering or a ceiling covering, wherein the covering comprises a plurality of panels (1), at least one of which and preferably a plurality of panels as in any of the preceding claims 21-44. Covering as in claim 45, wherein the covering except one or more panels (1) as in any of the preceding claims 21-44; comprises one or more panels (51) with the same decorative layer (20) as the one or more panels (1) as in any of claims 21-44, but that do not comprise said sheet. Covering as in any of the preceding claims 45-46, wherein the one or more panels as in any of the preceding claims 21-43, comprise a sheet as in any of the preceding claims 1-9 and optionally as in any of the preceding claims 12 -20, wherein the plurality of panels is placed on a sublayer (40), wherein the sublayer comprises one or more induction coils (41), wherein the sublayer comprises electrical conductors (42) for supplying the one or more induction coils (41) of the sublayer with electric current, wherein the one or more induction coils (41) of the sublayer are provided for generating electric current by induction in the induction coil (32) of the sheet (30) of the panel (1) as in any of the preceding claims 19-40, or in one or more of the induction coils (32) of the sheets (30) of the panels (1) as in any of the preceding claims 21-43. Covering as in any of the preceding claims 45-46, wherein the one or more panels as in any of the preceding claims 20-41 comprise a sheet as in claim 10 and optionally as in any of the preceding claims 11-19. Covering as in claim 48, wherein the covering comprises a current supply, wherein the current supply is connected conductively to the electrical conductors of the sheet. Covering as in any of the preceding claims 48-49, wherein the covering is a wall covering, wherein the panels are rectangular and are positioned with their long edge vertical, wherein the sheet in the panel is positioned so that the electrical conductors on one of the short sides of the panel can be supplied with electric current. 24

51. - Method for making a panel as in any of the preceding claims 21-44, wherein the sheet is integrated in the panel by means of a laminating step.

52.- Method as in claim 51, wherein the decorative layer is integrated in the panel by a laminating process, preferably in the same laminating step in which the sheet is integrated in the panel.

53.- Method as in claim 52, wherein the decorative layer is supplied as a high-pressure laminate (HPL), a continuous pressure laminate (CPL) or as a direct pressure laminate (DPL).

54.- Method as in any of the preceding claims 51-53, wherein the decorative layer - and optionally the optional wear layer - are integrated in the substrate in a continuous process, by means of a press of the continuous type or by means of a heated press band or heated press roll.

55.- Method as in any of the preceding claims 51-53, wherein the decorative layer - and optionally the optional wear layer - are integrated in the substrate in a discontinuous process, preferably by means of a pressing operation carried out with a short-cycle press.

56.- Method as in any of the preceding claims 54-55, wherein the press element is a structured press element so that the surface of the panel is provided with a relief.