Core, panel blank, floor panel and methods of their production

Abstract

A core for inclusion in a building panel. The core presents a pair of substantially parallel major surfaces, and comprises a plurality of first material blocks, extending between said major surfaces and arranged with their respective principal directions substantially parallel with said major surfaces and extend 90°±45° to a principal direction of the core; and a plurality of second material blocks, extending between said major surfaces and being arranged alternatingly with said first material blocks along the principal direction of the core. The first material blocks and said second material blocks differ substantially with respect to at least one material property.

1 . A floor panel, comprising:
 a decorative layer, and   a core layer arranged below the decorative layer when the floor panel is substantially horizontally oriented,   a balancing layer, wherein the core layer is sandwiched between the balancing layer and the decorative layer,   wherein the core layer comprises a plurality of wood blocks arranged with their respective principal fiber directions substantially parallel with a plane defined by a major surface of the floor panel and substantially perpendicular to a principal direction of the floor panel,   wherein the core layer comprises a plurality of second material blocks, made from a different material than said wood blocks, and   wherein along the principal direction of the floor panel, the core layer presents alternating portions formed of said wood blocks and of said second material blocks,   wherein the second material blocks have lower density than said wood blocks and/or lower tensile strength in a direction parallel to said principal fiber directions than said wood blocks,   wherein the wood blocks comprise wood blocks of a wood quality, which is lower than or equal to at least one of the standards identified as V according to the Swedish “Gröna boken” (“The Green book”) standard of 1960, B according to the Swedish “Bl{dot over (a)}a boken” (“The Blue book”) standard of 1994, or G4-2/G2-2 of the European EN 1611-1 standard of 2000.   
     
     
         2 . The floor panel as claimed in  claim 1 , wherein along the principal direction of the floor panel, a total length of the second material blocks is less than a total length of the wood blocks. 
     
     
         3 . The floor panel as claimed in  claim 1 , wherein along the principal direction of the floor panel, a total length of the expanded second material blocks is more than 5%, preferably more than 10%, 20%, 30% or 40% of a total length of the floor panel. 
     
     
         4 . The floor panel as claimed in  claim 1 , wherein the second material blocks comprises expanded polymer material blocks, such as at least one of expanded polyethylene, expanded polypropylene and expanded polystyrene extruded polystyrene foam. 
     
     
         5 . The floor panel as claimed in  claim 1 , wherein the second material blocks comprise an engineered wood product. 
     
     
         6 . The floor panel as claimed in  claim 1 , wherein the second material blocks comprise a non-expanded polymer material comprising filler material. 
     
     
         7 . The floor panel as claimed in  claim 1 , wherein the core layer further comprises a reinforcing inset portion. 
     
     
         8 . The floor panel as claimed in  claim 1 , wherein the second material blocks are provided with surface coating at an edge portion where said second material blocks are exposed. 
     
     
         9 . The floor panel as claimed in  claim 1 , wherein the second material blocks present a portion of increased density at an edge portion where said second material blocks are exposed. 
     
     
         10 . The floor panel as claimed in  claim 1 , wherein the decorative layer comprises wood. 
     
     
         11 . The floor panel as claimed in  claim 1  wherein the wood blocks comprise wood blocks of a wood quality, which is lower than or equal to at least one of the standards identified as VI according to the Swedish “Gröna boken” (“The Green book”) standard of 1960, C according to the Swedish “Bl{dot over (a)}a boken” (“The Blue book”) standard of 1994, or G4-3/G2-3 of the European EN 1611-1 standard of 2000. 
     
     
         12 . The floor panel as claimed in  claim 1  wherein the wood blocks comprise wood blocks of a wood quality, which is lower than or equal to at least one of the standards identified as VII according to the Swedish “Gröna boken” (“The Green book”) standard of 1960, D according to the Swedish “Bl{dot over (a)}a boken” (“The Blue book”) standard of 1994, or G4-4/G2-4 of the European EN 1611-1 standard of 2000. 
     
     
         13 . A method of making a floor panel, comprising:
 arranging a plurality of elongate wood blocks side by side in a co-planar manner, with their respective longitudinal directions substantially parallel with each other to form a core layer,
 providing the core layer with at least a decorative layer to form a panel blank, 
   providing the core layer with a balancing layer, such that the core layer is sandwiched between the balancing layer and the decorative layer,
 cutting the panel blank to form an elongate floor panel blank, such that the longitudinal directions of the wood blocks are substantially perpendicular to a principal direction of the floor panel blank, 
 providing a plurality of second material blocks arranged alternatingly with the wood blocks along the principal direction of the floor panel blank, 
   said second material blocks having lower density than said wood blocks and/or lower tensile strength in a direction parallel to said principal fiber directions than said wood blocks,   the wood blocks comprising wood blocks of a wood quality, which is lower than or equal to at least one of the standards identified as V according to the Swedish “Gröna boken” (“The Green book”) standard of 1960, B according to the Swedish “Bl{dot over (a)}a boken” (“The Blue book”) standard of 1994, or G4-2/G2-2 of the European EN 1611-1 standard of 2000.   
     
     
         14 . The method as claimed in  claim 13 , further comprising forming locking means along said principal direction of the floor panel blank. 
     
     
         15 . The method as claimed in  claim 14 , further comprising providing a surface treatment on at least part of the mechanical connecting means. 
     
     
         16 . The method as claimed in  claim 15 , wherein the surface treatment comprises applying a coating to an exposed part of said second material block. 
     
     
         17 . The method as claimed in  claim 15 , wherein the surface treatment comprises thermoforming an exposed part of said second material block. 
     
     
         18 . The method as claimed in  claim 16 , wherein the surface treatment comprises thermoforming an exposed part of said second material block. 
     
     
         19 . The method as claimed in  claim 13  wherein the wood blocks comprise wood blocks of a wood quality, which is lower than or equal to at least one of the standards identified as VI according to the Swedish “Gröna boken” (“The Green book”) standard of 1960, C according to the Swedish “Bl{dot over (a)}a boken” (“The Blue book”) standard of 1994, or G4-3/G2-3 of the European EN 1611-1 standard of 2000. 
     
     
         20 . The method as claimed in  claim 13  wherein the wood blocks comprise wood blocks of a wood quality, which is lower than or equal to at least one of the standards identified as VII according to the Swedish “Gröna boken” (“The Green book”) standard of 1960, D according to the Swedish “Bl{dot over (a)}a boken” (“The Blue book”) standard of 1994, or G4-4/G2-4 of the European EN 1611-1 standard of 2000.