Panel suitable for assembling a floor covering

Abstract

Panel suitable for assembling a floor covering by interconnecting a plurality of said panels with each other, wherein the panel has a substantially planar top side, and a substantially planar bottom side, at least four substantially linear side edges comprising at least one pair of opposite side edges, the panel having a layered structure which comprises a decorative top layer and a core layer wherein the decorative top layer and the core layer have a different chemical composition, wherein a reinforcement layer is positioned between the top layer and the core layer, and having a modulus of elasticity of at least 2 Mpa.

Claims

1. A panel suitable for assembling a floor covering by interconnecting a plurality of said panel with each other, wherein the panel has a substantially planar top side, and a substantially planar bottom side, at least four substantially linear side edges comprising at least one pair of opposite side edges, the panel having a layered structure that comprises: a decorative top layer; a core layer; wherein the decorative top layer and the core layer have a different chemical composition; and a reinforcement layer, positioned between the top layer and the core layer, and having a modulus of elasticity of at least 2 Mpa.

2. The panel according to claim 1, wherein the core and the top layer have a different dimensional stability when exposed to temperature, humidity, or temperature and humidity fluctuations.

3. The panel according to claim 1, wherein the reinforcement layer is a chosen from a group of ductile materials with high modulus of elasticity and high yield strength, or brittle materials with high modulus of elasticity and high breaking strength, comprising but not limited to foamed olefin polymers, foamed PP, foamed PE, non-foamed PE, foamed polyurethane, carbon fiber, foamed PVC, polyurethane foam, expanded polystyrene.

4. The panel according to claim 1, wherein the reinforcement layer is a high-strength polymer foam.

5. The panel according to claim 1, wherein the reinforcement layer is 0.5-4 mm thick.

6. The panel according to claim 1, wherein the reinforcement layer has a density lower than 1000 kg/m3.

7. The panel according to claim 1, wherein the reinforcement layer is applied with either a glue; a hot melt material; cold pressing after applying the reinforcement layer between the top layer and the core layer.

8. The panel according to claim 1, wherein the reinforcement layer is a co-extruded reinforcement layer.

9. The panel according to claim 1, wherein the core layer comprises a material from a group of a mineral or ceramic compound including calcium oxide and/or silica, magnesium oxide and/or magnesium hydroxide and/or limestone or chalk with a suitable binder, such as a thermoplastic resin, a mixture comprising lignocellulose and a thermosetting resin.

10. The panel according to claim 1, wherein the decorative top layer comprises mineral or ceramic compound with a thermoplastic or thermosetting binder, or a hygroscopic, lignocellulosic veneer and/or paper layer, or a stone veneer, or a ceramic tile or a mosaic.

11. The panel according to claim 1, wherein the decorative top layer is 0.2-8 mm thick.

12. The panel according to claim 1, wherein the panel is provided with interconnecting coupling means for interconnecting one panel with another.

13. The panel according to claim 1, provided with interconnecting coupling means for interconnecting the panel with a similar one.

Description

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

(1) The decorative top layer can comprise as primary components for example a mineral or ceramic compound with a thermoplastic or thermosetting binder, or a hygroscopic, lignocellulosic veneer and/or paper layer, or a stone veneer, or a ceramic tile or a mosaic.

(2) Below a non-exhaustive exemplary overview is given of combinations materials suitable to create a core and/or a decorative top layer of, together with their approximate dimensional stability when exposed to temperature and/or humidity fluctuations. It is the goal of this overview to indicate that the addition of flexible acoustic layers common in the industry between this top decorative layer and the core carrier plate will lead to visual defects of the installed surface.

(3) TABLE-US-00001 Temperature Relative Humidity ISO 23999 ISO 23999 ISO 24339 ISO 24339 Type Material Contents (80 C.-23 C.) (23 C.-60 C.) (20%-80%) (80%-20%) Top layer Vinyl 50% PVC, −0.25% 0.30% — — 30% limestone, 10% DOTP Top layer Paper 45% lignocellulose, 0.05% −0.10% 0.20% −0.30% 55% Thermosetting resin Top layer Oak veneer 95% lignocellulose, 0.10% −0.15% 0.50% −0.40% (avg long./transv.)  5% Polyurethane Top layer Polypropylene 50% polypropylene, −0.30% 0.25% — —  5% polyethylene, 45% chalk Top layer Ceramic 80% SiO2, — — — — mineral composite Top layer Stone veneer Mineral composite — — — — Core layer SPC (high density 30% PVC, −0.20% 0.15% — — PVC, 2000 kg/m3) 60% limestone, 10% DOTP Core layer WPC (low density 50% PVC, −0.50% 0.40% — — PVC, 950 kg/m3) 30% limestone, 10% DOTP Core layer Polypropylene −0.20% 0.15% — — Core layer Ceramic 50% MgO, — — 0.10% −0.10% composite 10% hydroxides, 40% salt

(4) The effect of combining different layers can be used to further illustrate the defect inherent to the existing art. As a first example, a vinyl top layer will show shrinking of −0.25% when tested according to ISO 23999, on a panel of 1.2 m length this will result in a transverse shrinking of 3 mm. Combined to a core or carrier plate which shows no shrinking under temperature fluctuations, such as a ceramic material, and a flexible acoustic layer in between, an actual flooring installation will become defective and show gaps of 3 mm in between each planks after only 5 heat/cold cycles.

(5) As a second example, a decorative top paper layer will exhibit expansion when the relative humidity in the atmosphere increases. When combined to a WPC core or carrier plate that does not exhibit the same property, and a flexible acoustic layer in between these two layers, an actual flooring installation will become defective and show visible deformation of up to 0.4 mm when the relative humidity (RH) of the atmosphere increases from 20% to 80% and the top layers expands unchecked. This is directly visible as “cupping” or “buckling” as the ends of the boards are forced upward due to inherent stresses in the panel.

(6) It is the conclusion of the inventors that a panel produced according to the state of the art will cause visual defects in actual installation due to a difference in dimensional stability between top and bottom layer, where the flexible acoustic layer interposed between core or carrier and the top layer is not able to withstand the stresses created as a result.

(7) These disadvantages are taken away by ensuring the acoustic layer is a reinforcement layer having a high modulus of elasticity or MOE and/or a high yield strength. This means in effect that the reinforcement layer is either not a flexible layer, or a flexible layer with a high MOE. For a ductile material this means the material will resist deformation until it reaches a certain point, and recovers from deformation easily without being showing plastic (lasting) deformation. For a brittle material this means it exhibits a strong resistance to plastic (lasting) deformation and breaking. Through experimenting, the inventors have identified the following materials that exhibit the correct non-elastic properties. Some of these materials are low density materials that exhibit sound absorbing properties.

(8) TABLE-US-00002 Modulus of elasticity Material Composition ASTM D638 Conclusion 1 mm WPC  65% PVC, limestone, 4.05 Mpa Pass 800 kg/m3  2% plasticizer 2 mm WPC  65% PVC, limestone, 2.03 Mpa Pass 380 kg/m3  10% plasticizer 1 mm Foamed 100% Polypropylene 2.88 Mpa Pass PP 100 kg/m3 1 mm PET 100% Polyethylene 5.02 Mpa Pass 950 kg/m3

(9) An additional advantage is that this buffer/reinforcement layer has a lower density than the top layer, and serves as buffer for impacts for both acoustic reasons, as for improvement of the impact resistance of the board.

(10) The reinforcement layer can be applied with a glue, a hot melt material or by cold pressing after applying it between the top layer and the core. In some embodiments, it may also be an intermediate core layer produced in a co-extrusion process.