Panel suitable for assembling a waterproof floor or wall covering, method of producing a panel

1. A panel suitable for assembling a waterproof floor or wall covering by interconnecting a plurality of said panels with each other,

wherein the panel has a substantially planar top surface, and a substantially planar bottom surface, at least four substantially linear side edges comprising at least one pair of opposite side edges which are provided with interconnecting coupling means for interconnecting one panel within another, comprising two pairs of opposite side edges which are provided with interconnecting coupling means

the panel having a sandwich structure which comprises a flexible central layer basically composed of a thermoplastic material, a rigid top layer and a rigid bottom layer,

wherein the panel is rigid and has a thickness of 8 mm or smaller, and

wherein the rigid top layer comprises two plies of cellulose-based layer and a cured resin, wherein the cellulose-based layer of both plies each contain fibers oriented in a main direction, wherein the main direction of the cellulose-based layer of one ply differs from the main direction of the cellulose-based layer of the other ply.

2. The panel according to claim 1 , wherein the overall rigidity of the panel is above 35-N/mm2 according to the test method described in the European norm EN-310.

3. The panel according to claim 1 , wherein the thermoplastic material has a foam structure obtained by an extrusion process.

4. The panel according to claim 1 , wherein the cellulose-based layer is paper.

5. The panel according to claim 4 , wherein the cellulose-based layer is kraft paper.

6. The panel according to claim 1 , wherein the cured resin comprises at least one of a melamine resin and a phenolic resin.

7. The panel according to claim 1 , wherein the rigid top layer contains abrasion resistant particles, and/or its top surface is provided with a relief pattern.

8. The panel according to claim 1 , wherein the rigid top layer is provided on its bottom side with a buffer layer of one or more materials chosen from the group comprising cork, rubber, a solid foam material, vinyl, polyethylene and ethylene vinyl acetate.

9. The panel according to claim 1 , wherein the rigid bottom layer comprises a ply basically composed of a polyvinyl chloride or of a non-woven fabric.

10. A waterproof floor or wall covering composed of a plurality of panels according to claim 1 , which panels are interconnected.

11. A method of producing an interconnectable panel, for a waterproof floor or wall covering, comprising the steps of:

a) providing a central layer basically composed of a thermoplastic material,

b) curing a top layer comprising two plies of a cellulose-based layer impregnated with a cured resin under a pressure of 10 to 18 MPa,

c) curing a bottom layer comprising at least one ply of cellulose-based layer impregnated with resin, and

d) adhering the cured bottom layer on the bottom side of the central layer, and adhering the cured top layer on the top side of the central layer to create a rigid interconnectable panel,

wherein the cellulose-based layer of both plies each contain fibers oriented in a main direction, wherein the main direction of the cellulose-based layer of one ply differs from the main direction of the cellulose-based layer of the other ply.

12. The method according to 11 , wherein at least two plies of the top layer contain a cellulose-based layer which is impregnated with at least 70 to 130 wt. % resin.

13. The panel according to claim 1 , wherein the main direction of the cellulose-based layer of the one ply differs from the main direction of the cellulose-based layer of the other ply by an angle in the range of 45 to 135 degrees.

14. The panel according to claim 13 , wherein the main direction of the cellulose-based layer of the one ply differs from the main direction of the cellulose-based layer of the other ply by an angle in the range of 80 to 100 degrees.