Panel forming
Building panels, especially laminated floor panels are shown, which are provided with a locking system and several core grooves at the rear side in order to save material and decrease weight. Building panels, each having a surface layer on a front side, a backing layer on a rear side and an intermediate core, wherein the intermediate core and the surface and the backing layer all comprise wood fibres and thermosetting resins, the building panels are provided with a locking system for vertical and horizontal locking of a first edge of a first building panel to an adjacent second edge of a second building panel.
1. A wood based floor panel comprising:
an upper layer of high-density fibreboard; and
a lower layer of high-density fibreboard,
wherein the lower layer comprises cavities,
wherein the upper layer forms an upper part of the cavities, and
wherein a pair of opposite panel edges comprises a mechanical locking system for locking the floor panel to an adjacent essentially identical floor panel.
2. The wood based floor panel according to claim 1 , wherein a thickness of the upper layer is about the same as a thickness of the lower layer.
3. The wood based floor panel according to claim 1 , wherein a thickness of the upper layer is smaller than a thickness of the lower layer.
4. The wood based floor panel according to claim 1 , wherein the mechanical locking system comprises a tongue and a tongue groove for horizontal locking.
5. The wood based floor panel according to claim 1 , wherein the mechanical locking system comprises a locking element and a downwardly open locking groove for vertical locking.
6. The wood based floor panel according to claim 1 , wherein the mechanical locking system is formed partly in the lower layer.
7. The wood based floor panel according to claim 1 , wherein the mechanical locking system is formed completely in the lower layer.
8. The wood based floor panel according to claim 1 , wherein the wood based floor panel is a core in a laminated panel.
9. The wood based floor panel according to claim 8 , wherein said laminated panel further comprises one or more upper layers of decorative material.
10. The wood based floor panel according to claim 8 , wherein said laminated panel further comprises a balancing layer on a rear side of the core.
11. The wood based floor panel according to claim 8 , wherein a thickness of the laminated panel is about 8-12 mm.
12. The wood based floor panel according to claim 1 , wherein the cavities each comprise an opening and an inner part, the opening having a groove width that is larger than the inner part.
13. The wood based floor panel according to claim 1 , wherein the lower layer further comprises core grooves, each core groove having an opening pointing downwards.
14. The wood based floor panel according to claim 1 , wherein the lower layer and the upper layer are glued to each other.
15. The wood based floor panel according to claim 1 , wherein floor panel is rectangular and configured to be mechanically joined on both long sides and short sides of the floor panel.
16. The wood based floor panel according to claim 1 , wherein a horizontal extension of the upper layer is smaller than a horizontal extension of the lower layer.
17. A wood based floor panel comprising:
an upper layer of high-density fibreboard; and
a lower layer of high-density fibreboard,
wherein the lower layer comprises cavities,
wherein the upper layer forms an upper part of the cavities, and
wherein a horizontal extension of the upper layer is smaller than a horizontal extension of the lower layer.
18. The wood based floor panel according to claim 17 , wherein a thickness of the upper layer is about the same as a thickness of the lower layer.
19. The wood based floor panel according to claim 17 , wherein a thickness of the upper layer is smaller than a thickness of the lower layer.
20. The wood based floor panel according to claim 17 , wherein the wood based floor panel is a core in a laminated panel.