RU2618247C2 - Core, panel workpiece, floor panel and methods of their manufacturing - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: floor panel includes the core consisting of two substantially parallel main surfaces and comprises a plurality of bars from the first material extending between said main surfaces and arranged so that their respective main directions are substantially parallel to said main surfaces and extend under the angle of 90°±45° to the main direction of the core, and a plurality of bars of the second material extending between said main surfaces arranged alternately with said bars of the first material along the main direction of the core. The bars of the first material and said bars of the second material differ, substantially, in at least one property of the material.

EFFECT: increasing the strength of the panels.

15 cl, 10 dwg

Description

Technical field

The present disclosure relates to building panels and, in particular, to floor panels.

More specifically, the present disclosure relates to a core included in a building panel, such as a floor panel, to a blank for creating building panels, and to methods for creating such a core, blank and a building panel.

State of the art

It is known to provide parquet floor panels containing a core formed from a plurality of low-grade wood bars (also called “slats” or “lamellas” that are arranged with a fiber direction extending perpendicular to the longitudinal direction of the floor panel. The core is sandwiched between a decorative layer, typically a wood surface layer about 3 mm thick, and a leveling layer, usually wood veneer, about 2 mm thick.The decorative layer and the leveling layer adhere to the core.

The floor panels described above have been produced since the 1940s, and in addition to improvements in surface treatment, gluing technology and the introduction of mechanical locks have undergone relatively few changes.

Examples of such parquet floor panels are disclosed, for example, in patents W096 / 30177 A1 and US2005 / 0208255A1.

It is desirable to further reduce the cost of floor panels of the type mentioned above.

Definitions

The expression "panel blank" is understood as a part of a material that has essentially the same format as the finished product, but which is not yet completed with respect to creating, for example, a locking system at the edges.

The expression "blank" is understood as part of a material intended to be divided into multiple blanks of the panel.

A “main surface” is usually the up or down surface of a core, a workpiece, a panel blank, or a building panel or floor panel. These surfaces are usually parallel to each other.

The "main direction" of the core, preform, prefabricated panel or building panel or floor panel may be a longitudinal direction in the case where the part is elongated (i.e., substantially rectangular and not square). As an alternative or addition, the main direction may be a direction that is substantially parallel to the direction along which another layer besides the intermediate layer, for example, a decorative layer and / or a leveling layer forming part of a preform, a preform of a panel or a floor panel, exhibits the greatest bending strength and / or greatest tensile strength, for example, the main direction of the fibers of the decorative layer and / or leveling layer.

The “main fiber direction” is defined as the direction along which the largest portion of the fiber of a bar of wood or veneer passes. Typically, the main direction of the fibers substantially coincides with the longitudinal direction of the wooden bar, since lumber is usually cut so that its fibers extend substantially in the longitudinal direction.

By "foamed polymeric material" is meant a polymeric material containing a resin and a significant amount of gas-filled inclusions.

SUMMARY OF THE INVENTION

The objective of the present invention is to eliminate or mitigate in general some of the disadvantages of the floor panels of the prior art, with particular emphasis on cost reduction.

The invention is defined in the independent claims, with the embodiments set forth in the dependent claims in the following description and drawings.

In accordance with a first aspect, a core is provided for incorporation into a building panel. The core is two essentially parallel main surfaces and comprises a plurality of bars of the first material extending between said main surfaces and arranged so that their respective main directions are substantially parallel to said main surfaces and extend at an angle of 90 ° ± 45 ° to the main direction of the core; and a plurality of bars of the second material extending between said main surfaces, arranged alternately with said bars of the first material along the main direction of the core. The bars of the first material and said bars of the second material differ in essentially at least one property of the material.

Such a core allows better control of properties related to the core, for example, strength and weight, as well as the cost of the core.

The “core core direction” can be understood as the longitudinal direction of the core, which is especially applicable when the core is manufactured as an elongated or substantially continuous sheet product.

The bars of the first material preferably extend at an angle of 90 ° ± 30 °, 90 ° ± 15 °, 90 ° ± 5 °, or substantially perpendicular to the main direction of the core. The bars of the second material can usually extend substantially parallel to the bars of the first material.

The expression "significantly differ" means that the difference is greater than that which could arise due to a simple random deviation that is observed between bars of the same type of material and orientation, for example, between two pieces of the same type of wood, or appearing in the case of production tolerances, etc.

The core between its main surfaces may have a thickness of from about 5 mm to about 50 mm, preferably from about 7 mm to about 15 mm.

In the cross section of the core, taken along the main direction of the core, which is perpendicular to the main surfaces and contains the same number of whole bars of the first material and whole bars of the second material, the area of said bars of the second material can be less than 50%.

Consequently, the bars of the first material can form more than 50% of the core volume without taking into account any inserts reinforcing the edges.

The core may contain at least one sheet, which can be attached to one of the main surfaces of the core and, essentially, at least cover it.

The sheet may comprise at least one of a non-woven material, a woven material, cellulose-based material and a polymer film.

The sheet may contain a material having adhesive properties with respect to said first bars and / or said bars from a second material.

The sheet can be flexible enough so that the core can bend at an angle of more than 5 °, preferably more than 10 °, more than 15 °, more than 20 ° or more than 25 °, formed between the normals to the main surfaces of two adjacent bars of the first material.

The bars of the first material and the bars of the second material can be created from materials that differ in at least one of: the type of material, the composition of the material, the density of the material, the hardness of the material, the tensile strength of the material and the modulus of elasticity of the material.

As for the “type of material”, the bars can be made from different materials, for example wood and foamed polymeric material, or different types of polymeric materials or different types of wood.

Regarding the "composition of the material", the bars can be created from polymeric materials having a different composition of materials and / or polymeric materials containing various types of fillers or additives.

As for the "density of the material", the bars of the first material may have a higher density than the bars of the second material.

Regarding the “hardness of the material”, bars of the first material may be harder than bars of the second material.

Regarding the "orientation of the material", the bars of the first material and the bars of the second material can have anisotropic properties and can be oriented in different directions. For example, bars of the first material may have fibers extending substantially perpendicular to the main direction of the core, while bars of the second material may extend substantially parallel to the main direction of the core or parallel to the direction of core thickness.

Regarding the “tensile strength of the material”, the bars of the first material may have higher tensile strength than the bars of the second material.

As for the "modulus of elasticity of the material", the first and second materials may exhibit different bending stiffness. Such varying bending stiffness can usually be manifested, at least in relation to the longitudinal direction of the material of the bars.

The main direction of the bars of the first material may be substantially parallel to the direction of the main bending stiffness and / or the main tensile strength of the bars of the first material.

In one set of embodiments, bars of the first material may be made of wood material. The main direction of the bars of the first material can thus be substantially parallel to the main direction of the fibers of the wood material.

Wood bars may contain bars with wood quality lower than or equal to V in accordance with the Swedish Grona boken (Green Book) standard of 1960, preferably lower than or equal to VI or lower than or equal to VII. Alternatively, the wooden bars may be made of wood with a quality lower than or equal to B according to the Swedish Blaa boken (Blue Book) standard of 1994, preferably lower than either equal to C or lower than or equal to D. As yet another alternative, wood bars may comprise wood bars having a quality lower than or equal to G4-2 / G2-2 according to European Standard EN 1611-1 of 2000, preferably lower than or equal to G4-3 / G2-3 or lower than or equal to G4-4 / G2-4.

Preferably, the quality of the wood is V or VI in accordance with the Grona boken standard or a similar quality in accordance with any other standard.

Wood bars can also alternatively have a strength class lower than or equal to C18 according to EN 338, preferably lower than or equal to C16 or lower than or equal to C14.

In another set of embodiments, bars of the first material may be made of composite material.

The composite material may comprise a polymer matrix material and a filler and / or reinforcing material.

The filler may comprise wood dust, wood fibers, sawdust, wood shavings, mineral filler, or polymeric material.

To ensure the anisotropic strength properties of the composite material, a reinforcing material may be placed.

For example, the reinforcing material may comprise elongated fibers extending substantially parallel to the main direction of the bars of the first material. Therefore, the bars of the first material can be created from a composite material based on wood.

Non-limiting examples of wood-based composite materials include fiberboards, chipboards, and remodeled veneers. You can create bars from the first and second material by using different types of wood-based composite materials.

The bars of the second material can be created from a foamed polymeric material, a composite material based on wood or non-foamed polymeric material.

Foamed polymer bars may contain at least one of: polyethylene foam, polypropylene foam, expanded polystyrene or extruded expanded polystyrene.

The foamed polymeric material may or may not contain, for example, fillers in the form of wood dust, wood fibers, sawdust, wood shavings, mineral fillers and / or polymeric materials.

Typically, the bars of the second material are made of a composite material based on wood having a lower price, strength and / or density than the bars of the first material.

Typically, the non-foamed polymeric material may contain one or more polymeric matrix materials and fillers in the form of wood dust, wood fibers, sawdust, wood shavings, mineral fillers and / or polymeric materials having a lower price, strength and / or density than for bars of the first material. Density may be lower or higher. A low density provides weight advantages, while a higher density can provide the desired sound absorption or attenuation properties. According to a second aspect, a blank is provided for creating a building panel comprising a core described above and at least one structural layer essentially covering at least one of the main surfaces of the core.

A construction panel, by way of non-limiting examples, may be a floor panel, a wall panel, a ceiling panel, or a roof panel.

The structural layer may comprise a decorative layer and / or a top layer.

The structural layer may further comprise a reinforcing layer located between the core and the decorative layer.

In one set of embodiments, the decorative layer may comprise a laminate.

In another set of embodiments, the decorative layer may comprise wood.

In another set of embodiments, the decorative layer may comprise (or mainly consist of), for example, a plastic material including polyvinyl chloride, acrylic, epoxy, polyurethane, rubber or rubber-like material or linoleum.

In some embodiments, the implementation of the decorative layer can be created essentially from solid wood material.

The preform may further comprise a leveling layer comprising wood veneer, a polymer film, a woven sheet, a nonwoven sheet and / or cellulose-based material.

The main direction of the core can be essentially parallel to the direction of the main bending stiffness of at least one of the structural layers.

The main direction of the core may be substantially parallel to the longitudinal direction of the workpiece.

In accordance with a third aspect, a building panel is provided created from the blank described above. Such a floor panel may be provided with a locking system along at least two of its opposite edge sections.

In accordance with a fourth aspect, there is provided a method of manufacturing a core for a building panel, the core being two substantially parallel main surfaces. The method comprises providing a plurality of bars of the first material, arranging a plurality of bars of the first material located with their main directions of fibers, essentially parallel to the main surfaces and essentially perpendicular to the main direction of the core, and providing bars of the second material, located alternately with the said bars from the first material in said main direction of the core.

The step of providing said bars of the second material may comprise arranging the prepared bars of the second material in turn with said bars of the first material.

The step of providing said bars of second material may comprise providing a resin of polymeric material in a space allowing separation of two of said bars of first material in a longitudinal direction and a subsequent increase in the volume of resin of polymer material.

The step of providing a bar of second material may comprise providing a bar of second material with a thickness that is at least initially larger than said bars of first material.

The method may further comprise pressing said bars of second material in combination with the application of a sheet or structural layer to the core.

The method may further comprise using said bar of second material to provide adhesion between the core and the layer.

In accordance with a fifth aspect, a method for manufacturing a building panel is provided, the method comprising providing a workpiece as described above, cutting the workpiece of the building panel from the workpiece along the main core direction in a size suitable for providing the building panel, and providing means for mechanically joining along at least at least one edge of the blank of the floor panel.

The method may further comprise providing surface treatment to at least a portion of the mechanical bonding means. Alternatively or additionally, the surface treatment may comprise coating the exposed portion of said bar of second material. Alternatively or additionally, the surface treatment may comprise hot forming an open portion of said bar from a second material.

According to a sixth aspect, a floor panel is provided comprising a decorative layer and an intermediate layer. The core is located below the decorative layer when the floor panel is essentially oriented horizontally. The intermediate layer contains a plurality of wood bars arranged so that their respective main directions of the fibers are substantially parallel to the plane defined by the main surface of the floor panel and are substantially perpendicular to the main direction of the floor panel. The intermediate layer contains a plurality of bars of the second material made of a different material than the said wood bars, and along the main direction of the floor panel, the intermediate layer is intermittent sections formed of the said wood bars and the said bars of the second material.

By “bar from a second material” is meant a bar from a material that is different from bars from a wood material. The bars of the second material may, for example, have a generally lower quality (strength and / or stiffness) and / or cost than the bars of wood. Therefore, the bars of the second material mainly serve to fill the space between the bars of wood and can provide sound insulation.

A floor panel containing a plurality of bars of a second material can be manufactured at a lower cost than a floor panel containing only bars of wood, since such a second material can even be cheaper than low-grade wood.

In addition, the second material can reduce the weight of the floor panel compared to a floor panel containing only wood, thereby reducing transportation costs and facilitating installation.

Along the main direction of the floor panel, the total length of the bars of the second material may be less than the total length of the bars of wood.

Along the main direction of the floor panel, the total length of the bars of the second material may be more than 5%, preferably more than 10%, 20%, 30% or 40% of the total length of the floor panel. Typically, the total length of the bars of the second material is less than 50% of the total length of the floor panel.

The bars of the second material may have a lower density than said wood bars and / or lower tensile strength in a direction parallel to the main fiber direction than said wood bars.

The bars of the second material may comprise bars of a foamed polymer of at least, for example, one of: polyethylene foam, polypropylene, expanded polystyrene or extruded expanded polystyrene.

Alternatively or in addition, bars of the second material may comprise a composite wood material.

As yet another alternative or addition, bars of the second material may contain non-foamed polymeric material containing a filler.

Wood bars may contain bars with wood quality lower than or equal to V in accordance with the Swedish Grona boken (Green Book) standard of 1960, preferably lower than or equal to VI or lower than or equal to VII. Alternatively, the wooden bars can be made of wood with a quality lower than or equal to B in accordance with the Swedish Blaa boken (Blue Book) standard of 1994, preferably lower than or equal to C or lower than or equal to D. B as yet another alternative, wood bars may comprise wood bars having a quality lower than or equal to G4-2 / G2-2 according to European Standard EN 1611-1 of 2000, preferably lower than or equal to G4-3 / G2-3 or lower than or equal to G4-4 / G2-4.

Wood bars may alternatively also comprise or consist essentially of wood bars with a strength class lower than or equal to C18 of EN 338, preferably lower than or equal to C16 or lower than or equal to C14.

Consequently, bars of wood of low or very low quality and therefore cost can be used to a large extent.

The intermediate layer may further comprise a section with a reinforcing insert, which may be provided at the short edge of the floor panel portion.

Typically, the intermediate layer of the floor panel may consist of approximately 80-99% of the volume, possibly 90-95% of the volume, of alternating wood bars and bars of the second material. The rest may, inter alia, consist of parts of inserts configured to provide specific parts of the locking system.

The bars of the second material may be provided with a surface coating at an edge portion where said bars of the second material are exposed.

Alternatively or as an addition, the bars of the second material may be areas of increased density at the edge portion where said bars of the second material are exposed.

The decorative layer may contain or consist mainly of natural wood.

The floor panel may comprise a leveling layer, and an intermediate layer may be sandwiched between the leveling layer and the decorative layer.

In accordance with a seventh aspect, there is provided a method of manufacturing a floor panel comprising coplanarly positioning side by side a plurality of elongated wood blocks, with their respective longitudinal directions, substantially parallel to each other, to create an intermediate layer. The method further comprises providing an intermediate layer with at least a decorative layer to create a panel blank, and cutting the panel blank to create an elongated floor panel blank so that the longitudinal directions of the wood bars are substantially perpendicular to the main direction of the floor panel blank. The method further comprises providing a plurality of bars of the second material arranged alternately with the bars of wood along the main direction of the blank of the floor panel. The bars of the second material have a lower density than said wood bars and / or lower tensile strength in a direction parallel to the main fiber direction than said wood bars.

The method may further comprise providing fixation means along said main direction of the floor panel blank.

Brief Description of the Drawings

FIG. 1 is a schematic exploded view of a panel blank.

FIG. 2 is a schematic perspective view of a panel blank.

FIG. 3 is a schematic perspective view of a part of a floor panel.

FIG. 4 is a schematic plan view of a floor panel.

FIG. 5 is a schematic cross-sectional view of a floor panel.

In FIG. 6a-6c schematically show a method for manufacturing a preform or a preform of a panel.

In FIG. 7a-7d schematically show a first alternative method for manufacturing a blank or panel blank.

In FIG. 8a-8b schematically show a second alternative method of manufacturing a preform or panel preform.

In FIG. 9a-9c schematically show a core.

In FIG. 10 schematically shows a third alternative method of manufacturing a preform or panel preform.

Description of Embodiments

FIG. 1 is a schematic exploded view of a blank 1 of a floor panel comprising a decorative layer 13, an intermediate layer 10, 11 and a leveling layer 12. FIG. 2 shows the blank l ’of the floor panel in the assembled state. The intermediate layer 10, 11 is made of bars 10 of wood and bars 11 of foamed polymer, located alternately along the longitudinal direction L of the blank of the floor panel. For example, this longitudinal direction of the floorboard preform may be substantially parallel to the main direction of the wood veneer fibers, forming a visually open upper surface of the decorative layer 13.

The wood bars 10 can be substantially elongated, with the corresponding main direction of their fibers substantially coinciding with the corresponding longitudinal direction I of the corresponding bar 10. The cross section of the wood bars 10 can have a thickness Tw and a width Ww. The width Ww may be greater than the thickness Tw.

The longitudinal direction I of the wood bars 10 can extend at an angle of 90 ° ± 45 ° to the longitudinal direction L of the floorboard blank. Preferably, the wood bars extend at an angle of 90 ° ± 30 °, 90 ° ± 15 °, 90 ° ± 5 ° or 90 ° ± 1 ° to the longitudinal direction of the panel blank.

Wood bars may contain any kind of bars, but for economic reasons, it is preferable that the wood bars possibly contain, or consist essentially of (for example, consisted of at least 50%, at least 70%, at least at least 90% or at least 95%) of wood, with a quality lower than or equal to VI or lower than or equal to VII. Alternatively, the wooden bars may be made of wood with a quality lower than or equal to B according to the Swedish Blaa boken (Blue Book) standard of 1994, preferably lower than either equal to C or lower than or equal to D. As yet another alternative, wood bars may comprise wood bars having a quality lower than or equal to G4-2 / G2-2 according to European Standard EN 1611-1 of 2000, preferably lower than or equal to G4-3 / G2-3 or lower than or equal to G4-4 / G2-4.

In addition, wood blocks may have a strength class lower than or equal to C18 according to EN 338, preferably lower than or equal to C16 or lower than or equal to C14.

Wood blocks can be created from elongated wooden beams, and / or shorter wooden segments joined together (for example, using spike joints, dovetail joints and / or glued joints).

The foamed polymer bars 11 may be so-called “rigid polymer foams”, which can be defined as foams having an elastic modulus (E) of about 0.02-0.4 GPa, preferably about 0.1-0.4 GPa. The density may be in the region of 20-400 kg / m ³ , preferably from about 10-100 kg / m ³ , most preferably from about 20-50 kg / m ³ .

Alternatively, the foamed polymer bars 11 may be so-called “flexible polymer foams”, which can be defined as foams having an elastic modulus (E) of about 0.0003-0.0015 GPa. The density may be in the region of 5-200 kg / m ³ .

The foamed polymer bars 11 may be a so-called closed-cell foamed polymer or an open-cell foamed polymer.

Examples of materials include polystyrene, polyurethane, polyolefin (e.g., polyethylene, polypropylene), thermosets (phenoplast, melamine, urea, or combinations thereof) and polyvinyl chloride (PVC).

Foamed polymer bars may contain additives, for example, wood shavings, sawdust, wood dust (sawdust, wood flour) or wood fibers; mineral fillers (calcium, dolomite, etc.); polymer fillers (e.g. recycled polymers, rubber or rubber-like materials). The foamed polymer bars 11 are shown to be substantially elongated, while the corresponding longitudinal direction is parallel to the longitudinal directions I of the wood bars 10. The cross section of the foamed polymer bars 11 may be a thickness Tp and a width Wp. The width Wp may be larger than the thickness Tp.

The thickness Tw of the wood bars can typically be on the order of about 5-50 mm, more often about 5-25 mm, or about 7-15 mm and most often about 10 mm.

Typically, the thickness Tw of the wood bars 10 can be substantially the same or exactly the same as the thickness Tp of the foamed polymer bars 11.

The width Ww of the wood bars 10 may be larger than the width Wp of the foam bars 11 of the polymer. By way of non-limiting examples, the width Wp of the foamed polymer bars 11 may be less than about 90%, less than about 80%, less than about 70%, or less than about 60% of the width Ww of the wood bars 10.

The 1 "floor panel may thus have a core formed of alternating wood and foam blocks along substantially its entire length except possibly one or two short side edges, which may be provided with a reinforcing insert that may be made of wood having a higher quality than the bars 10 of wood, of a different type of wood and / or of wood having a different fiber direction, for example, perpendicular to the direction of the fibers of the bars 10 of wood. wafers can be made from another material, for example, MDF, HDF, a polymer or a polymer composite (for example, reinforced polymer). Each insert can pass through less than 15% of the length of a 1 "floor panel, preferably less than 10%, less than 5% or less than 3% of the length of a 1 "floor panel.

Such inserts may be further provided on one or both long side edges, in which case the inserts extend along all or part of the long side edge (s) and perpendicular to the main direction of the floor panel.

Turning to FIG. 3 and 4, the 1 "floor panel may be provided with a locking system 30, 31, 32, 33 adapted to connect the 1" floor panel to similar or identical floor panels. Such a locking system can be positioned to provide mechanical or latched horizontal and / or vertical joints, i.e. floor panels can be joined together fully or partially without the use of glue.

In one embodiment, the long side of the castle system 30, 31 may be identical to the short side of the castle system 32, 33. In another embodiment, the long side of the castle system 30, 31 may differ from the short side of the castle system in terms of, for example, geometry and / or mechanical properties of the castle system.

Many different systems are known for mechanically joining floor panels and methods for their manufacture. Non-limiting examples of such systems are shown in US Pat. the present description by reference.

Therefore, an additional description of the castle system seems inappropriate.

With reference to FIG. 6a-6c, a method for manufacturing a floor panel 1 "is disclosed.

Pre-cut bars 10 of wood, as well as prepared (for example, cut or molded) bars 11 of foamed polymer can be placed on the first sheet, which can be a leveling layer 12 or a decorative layer 13. The first sheet 12, 13 and / or the side of the bars 10 11 facing the first sheet may be provided with adhesive for attaching the bars 10, 11 to the first sheet 12. In addition, a second sheet 13 is provided and its side facing the bars 10, 11 and / or the side of the bars 10, 11 facing to the second sheet, provided with glue, after bringing the second sheet 13 connected to the bars.

The bars 10, 11 may be positioned so as to abut each other along their longitudinal direction I. Alternatively, a small space in the longitudinal direction L of the floor panel may be provided between the elements of each pair of adjacent bars. The space may have a size of the order of 0.1-5 mm, preferably 1-3 mm. After the sheets 12, 13 and the bars 10, 11 are connected, they can be subjected to compression, batch or continuous, for example, using rollers or a belt press. Compression can be supplemented by heating or other means to activate the adhesive, for example, ultrasound, microwaves, etc.

Typically, these steps are performed to provide a preform that can have a size of the order of about, for example, 1.2 m × 2.4 m. This preform can be cut into preforms 1 'of the floor panel, that is, into preforms having a generally finished floor shape 1 ”panels, but without any locking systems 30, 31, 32, 33 formed along its edges. The blanks L 'of the floor panel can then be milled and in some cases added to individual elements (locking languages, locking elements, locking strips and etc.) to provide the required Lock systems 30, 31, 32, 33.

The decorative layer 13 may be in the form of a solid wood sheet, which usually has a thickness of about 2-5 mm, most often about 3 mm. A wood sheet may consist of one or more bars of wood or a plurality of lamellas for forming bars on a surface of a pattern.

Typically, most or at least some of these slats are elongated and extend substantially parallel to the longitudinal direction L of the floor panel. Alternatively, some of the lamellas extend perpendicular to the longitudinal direction L of the floor panel, as is the case with floor panels, to provide a so-called Dutch floor pattern.

Alternatively, a decorative layer can be created from multiple layers, for example, a reinforcing layer, in combination with a thin surface layer that is laminated or glued to the reinforcing layer. The surface layer can be created from, for example, thin (0.5-2 mm) wood veneer or laminate, that is, a layer with an artificial pattern (for example, printed), which can be laminated or integrated with the top layer and which can contain a polymer material with fillers and additives to provide a solid surface. The reinforcing layer may be made of plywood, MDF, HDF or other sheet materials.

The decorative layer 13 of wood or wood veneer can be natural, that is, uncoated, or coated / treated, for example, with varnish, wax, oil or any other type of surface finish, for example, acrylic or urethane-based floor coverings.

The leveling layer 12 can be created from a thin (0.5-2 mm) sheet of wood or plywood. Alternatively, the alignment layer may be made of a polymer film, woven or non-woven sheets, cellulose-based materials (eg, paper), or other wood-polymer composite materials.

The floor panel usually forms part of a set of substantially identical floor panels that must be joined together to provide flooring.

With reference to FIG. 7a-7d, a first alternative preform creation method will be described. A first structural layer is provided, for example, a leveling layer 12 (or decorative layer 13) (Fig. 7a). A certain number of bars 10 of wood is provided and is located on the first structural layer. Additionally, the wood bars 10 can be attached (temporarily or permanently) to the structural layer. The wood bars 10 are spaced apart along the main direction L on the workpiece.

The polymer resin 9, adapted for foaming, is located in the spaces between the bars of wood (Fig. 7b). The polymer resin may, for example, contain one or more expandable substances.

A second structural layer, for example, a decorative layer 13 (or a leveling layer 12), is arranged to grip the bars 10 of wood between the first and second structural layers (Fig. 7c). The second structural layer can be attached to the bars of wood (temporarily or permanently).

The expandable material (a) present in the polymer resin 9 is then activated to expand in order to substantially fill the space between the wood blocks 10. As the polymer resin sets, hardens or cools, bars 11 of foamed polymer are provided.

The activation of the expandable substance (c) can be achieved by providing heat in a microwave oven, ultrasound, vacuum, UV radiation, etc.

The activation of the expandable material may also cause the activation of glue or other fixing means for attaching the structural layers to the wooden blocks.

In an embodiment of this method, the wood bars 10 can be clamped between the structural layers 12, 13 prior to the introduction of the resin 9. In this case, the resin can subsequently be introduced into the spaces formed between the wooden bars and the structural layers. In this case, the resin may, but not necessarily, be activated directly upon administration, for example, upon contact with the surrounding atmosphere.

It is also possible to introduce a non-foaming and possibly polymeric resin with a filler into the spaces formed between the bars of wood (or bars of another material).

Resin 9, in addition to providing the foamed polymer bars 11, may also allow the joining of the bars to the structural layers of both the foamed polymer bars and the wood bars. For example, wood bars can be constructed or arranged to provide a sufficient amount of resin to be inserted between the wood bars and structural layers, thereby providing adhesion.

With reference to FIG. 8a-8b, another alternative method for manufacturing a preform will be described.

The foamed polymer bars 11 are provided with a thickness Tp exceeding the thickness Tw of the wood bars 10 (Fig. 8a). The bars may be provided in the form of preformed bars or by activating a blowing agent prior to application of the second structural layer.

Then, a second structural layer 13 can be applied, after which the foamed polymer bars 11 are pressed (FIG. 8b). Pressing may be provided in the pressing step described with reference to FIG. 6a-6c.

With reference to FIG. 9a-9c, a method for manufacturing a core (without structural layers) will be described.

In the first embodiment (Fig. 9a), the core can be made by joining interleaved bars 10 of wood and bars 11 of foamed polymer by, for example, adhesion (surface to surface) to form a continuous core without any structural layers.

If the foamed polymer bars 11 are relatively flexible, the core may be bent and possibly even be rolled up.

In the second embodiment (Fig. 9b), the core can be provided with a sheet 20 to which the bars 10, 11 are attached as to the main surface of the core, in the same way as was disclosed for the first structural layer 12.

The sheet 20 may be a polymer film, a non-woven sheet, a woven sheet, a cellulose-based sheet (paper or an analogue of paper), a rubber film, etc. Therefore, the sheet can be flexible enough to be bent and rolled up. The sheet may have a thickness in the region of about 0.1-3 mm, and preferably about 0.1-1 mm.

In the third embodiment (Fig. 9b), a second sheet 21 may be provided on the second front side Sc1 of the core. The second sheet may be identical to the first sheet, or it may be a different type of material.

You can create a sheet of material, which, for example, when activated, will act as a binder, adhesive or adhesive with respect to the core and / or to the structural layers. It is also possible to coat or impregnate the sheet with a material that, for example, upon activation will act as a binder, adhesive or adhesive with respect to the core and / or to the structural layers. If such material is sticky or is activated by pressure, it is also possible to provide a protective film on one or both open surfaces of the sheets 20, 21. Such a protective film can thus be removed when the core provided with the sheet is to be attached to, for example, a structural layer.

It should be noted that the panel creation methods described with reference to FIG. 6a-6d, 7a-7d, and 8a-8b may be applied to the core creation described with reference to FIGS. 9A-9C, provided that the possibility of external adhesion or gluing is controlled by, for example, a protective film, and provided that the pressure is applied correctly.

Therefore, it is possible to provide a core that can be rolled up, as schematically shown in FIG. 10. The core can then be deployed from a roll and, under pressure Fp, any type of structural layer can be laminated on it to produce a substantially continuous blank, for example, a wood decorative layer or a laminate or protective layers.

It should be noted that the above descriptions of the manufacture of the workpiece can be applied to the panel blank, as well as if it is desirable to produce the panel blank directly, and not create it by dividing the blank into several smaller parts.

The combination of wood bars and foam bars is to be understood as an example of an embodiment of the present disclosure. In general, wood bars can be considered as bars of the first material, and foam polymer bars can be considered as bars of the second material.

Bars of the first material can thus be provided not from wood, but from another material, for example, from polymer / plastic. The bars can be created from a composite material containing a binder, for example, a polymer matrix, one or more fillers and / or one or more reinforcing fibers.

Examples of fillers include one or more: wood shavings, sawdust, wood dust (sawdust, wood flour) or wood fibers, mineral fillers (calcium, dolomite, etc.), polymer fillers (e.g., pieces or particles of recycled polymers rubber or rubber-like materials).

Examples of reinforcing fibers include one or more: glass fibers, carbon fibers, plant fibers (eg, hemp, grass, bamboo or wood fibers or wood shavings) or polymer fibers.

Therefore, the bars of the first material can be created from the so-called "composite wood" or "reconstructed veneer", which as such are known, for example, from the patents WO 2009 / 140136A2 and W02010 / 082137A1, the full contents of which are incorporated into this description by reference.

Examples of polymer matrices include one or more materials, thermoplastic (polyethylene, polypropylene, etc.), epoxy, polyurethane, thermosetting (phenol, melamine, urea, or combinations thereof), acrylic and polyester.

The bars of the second material may differ from the bars of the first material in respect of at least one of: the type of material (that is, they can be created from a completely different material), the composition of the material (that is, they can be created from the same materials as bars from the first material, but with different proportions), the density of the material (that is, they can be created (for example, foaming) with a different density than the bars from the first material), the hardness of the material (that is, they can be processed to acquire pain s or lower hardness), and material modulus of elasticity. Typically, bars of the first material can have a higher modulus of elasticity along direction I, which is perpendicular or runs at a different angle to the main direction L of the core, than bars of the second material, such bars are more rigid. This can be achieved by, for example, arranging the elongated fibers so that they extend substantially perpendicular to the main direction L of the core.

The bars of the second material can have a substantially lower density than the bars of the first material due, for example, to foam.

Alternatively, the bars of the second material may have a substantially higher density than the bars of the second material, due to, for example, that they contain a relatively heavy filler. This may be desirable to reduce noise.

While the bars of the first material can be selected to provide the necessary bending strength and bond strength, the bars of the second material can be selected to provide another property, for example, less weight, low cost and / or noise reduction.

The bars of the second material, with reference to the foregoing, can be created from any material that may have a lower cost, lower density and / or lower tensile strength in a direction parallel to the main direction of the wood fibers of the wood bars.

Therefore, the bars of the second material may contain structural wood products. A first example of such a material is the so-called LDF (low density fiber board) or VLDF (very low density fiber board), which can be a board created by molding or compressing wood chips, sawdust and / or dust. Such a material can be molded during a wet or wet environment in which there is no or very little need to add an additional binder.

For example, an LDF plate having a density of 160-500 kg / m ³ can be used.

Alternatively, a VLDF board having a density of 200-300 kg / m ³ may be used. LDF and VLDF boards are known from Rowell, R. et al.: "Dimensionally Stabilized Very Low Density Fiberboard", Wood and Fiber Science, 27 (4), pp. 428-436 (1995), the entire contents of which are incorporated herein link.

In yet another alternative, a ULDF board (ultra low density fiber board) having a density of 50-200 kg / m ³ may be used. Such fiber boards are known from the work of Xie, Y. et al: "Manufacture and Properties of Ultra-Low Density foamed Fiberboard from Wood Fibr", BioResources 6 (4), 4055-4066 (2011), the entire contents of which are incorporated herein by links.

Therefore, fiber boards having a low, very low, or ultra-low density can be provided essentially without a binder (wet / wet pressing), with a binder and / or with an additional additive.

It is also possible to replace or supplement the foamed polymer bars or the second material bars with bars of non-foamed composite polymer material containing a polymer matrix and fillers, for example, wood shavings, sawdust, wood dust (sawdust, wood flour) or wood fibers, mineral fillers ( calcium, dolomite, etc.), polymer fillers (for example, recycled polymers, rubber or rubber-like materials).

Exposed areas of bars of a second wood fiber material (e.g., LDF, VLDF, ULDF) or a polymer material with a filler may also be provided with a surface treatment to increase, for example, strength, friction (reduction) or wear resistance properties. Such processing may include the application of an impregnating substance or a coating agent, for example, varnish and / or thermosetting polymers.

At least one type of material bar may be flexible enough so that the core can be bent to provide an angle of more than 5 °, preferably more than 10 °, more than 15 °, more than 20 ° or more than 25 ° between the normals to the main surface of two adjacent (but at least one other bar of material between them) bars of material of the same type.

Bending can also be made possible or facilitated by using the space in the longitudinal direction between the adjacent bar of the first and second material. Such a space may have a size of the order of 0.1-5 mm, preferably 0.5-3 mm, more preferably 1-3 mm.

Also, as appropriate, the sheet 20, 21 may be flexible enough to allow such folding as described above.

It should be understood that the core may contain two or more types of bars of material, which can be arranged alternately in the main direction L of the core, while their main directions I are essentially perpendicular to the main direction L of the core.

It should also be understood that while the aforementioned blanks, panel blanks and floor panels were disclosed as a three-layer structure (decorative layer, an intermediate layer and a leveling layer), the core according to the present disclosure can also be used for two-layer panels, i.e. panels, containing a decorative layer and an intermediate layer. Such panels can be installed and glued to the base of the floor. They can be flexible enough to compensate for or correspond to the deviations of the floor base in height.

In specific embodiments, the following core types may be mentioned:

- a combination of bars of wood (first material) and bars with or without filler made of foamed polymer (second material);

- a combination of wood bars (first material) and low density fiberboard (ULDF, VLDF, LDF) bars (second material); and

- a combination of wood bars (first material) and foamed polymer bars without filler (second material). Such cores can be used for floor panels having any type of decorative layer and leveling layer disclosed herein.

Claims (40)

1. The floor panel, containing: decorative layer (13), and an intermediate layer (10, 11) located below the decorative layer (13) when the floor panel is essentially oriented horizontally, a leveling layer, the intermediate layer being sandwiched between the leveling layer and the decorative layer, the intermediate layer contains many bars (10) of wood, located with their main directions of the fibers, essentially parallel to the plane (So) defined by the main surface of the floor panel and essentially perpendicular to the main direction (L) of the floor panel, moreover, the intermediate layer (10, 11) contains many bars (11) of the second material made of a different material than the said bars (10) of wood, and while along the main direction (L) of the floor panel, the intermediate layer is intermittent sections formed of said bars (10) of wood and said bars (11) of a second material, moreover, the bars of the second material have a lower density than the said bars of wood and / or lower tensile strength in a direction parallel to the main direction of the fibers than the said bars of wood, moreover, the bars (10) of wood contain bars with the quality of a tree, which: lower than or equal to V according to the Swedish Standard, Green Book (Grona boken), from 1960, preferably lower than or equal to VI or lower than or equal to VII; lower than or equal to B according to the Swedish Standard, the “Blue Book” (“Blaa boken”) of 1994, preferably lower than or equal to C or lower than or equal to D; and / or lower than or equal to G4-2 / G2-2 according to the European standard EN 1611-1 of 2000, preferably lower than or equal to G4-3 / G2-3 or lower than or equal to G4-4 / G2-4, while the thickness (Tw) of said wood bars (10) is substantially the same or exactly the same as the thickness (Tp) of said bars (11) of second material, and wherein the leveling layer comprises wood veneer, a polymer film, a woven sheet or a non-woven sheet. 2. The floor panel according to claim 1, wherein along the main direction (L) of the floor panel, the total length of the bars (11) of the second material is less than the total length of the bars (10) of wood. 3. The floor panel according to claim 1, in which along the main direction (L) of the floor panel, the total length of the foamed bars (11) of the second material is more than 5%, preferably more than 10%, 20%, 30% or 40% of the total floor panel lengths. 4. The floor panel of claim 1, wherein the bars of the second material comprise bars of a foamed polymer, for example at least one of: polyethylene foam, polypropylene foam, polystyrene foam or extruded polystyrene foam. 5. The floor panel of claim 1, wherein the bars of the second material comprise wood-based composite materials. 6. The floor panel of claim 1, wherein the bars of the second material comprise non-foamed polymeric material containing a filler. 7. The floor panel of claim 1, wherein the intermediate layer further comprises a portion of a reinforcing insert. 8. The floor panel according to claim 1, wherein the bars (11) of the second material are provided with a surface coating on the edge portion where said bars of the second material are exposed. 9. The floor panel according to claim 1, in which the bars (11) of the second material are a plot of increased density at the edge section, where said bars of the second material are exposed. 10. The floor panel according to claim 1, in which the decorative layer (13) contains wood. 11. A method of manufacturing a floor panel, in which: place a lot of elongated bars (10) of wood side by side in the same plane, with their respective longitudinal directions (I), essentially parallel to each other, to create an intermediate layer, provide an intermediate layer with at least a decorative layer (13) to create a panel blank, providing an intermediate layer with a leveling layer so that the intermediate layer is clamped between the leveling layer and the decorative layer, cutting the panel blank to create an elongated blank of the floor panel so that the longitudinal directions (I) of the wood bars are substantially perpendicular to the main direction (L) of the floor panel blank, provide a plurality of bars (11) of the second material, located alternately with the bars (10) of the tree along the main direction (L) of the blank of the floor panel, wherein said bars of the second material have a lower density than said bars of wood and / or lower tensile strength in a direction parallel to the main direction of the fibers than said bars (10) of wood, whetstones (10) made of wood contain whetstones of wood with wood quality, which: lower than or equal to V according to the Swedish Standard, Green Book (Grona boken), from 1960, preferably lower than or equal to VI or lower than or equal to VII; lower than or equal to B according to the Swedish Standard, the “Blue Book” (“Blaa boken”) of 1994, preferably lower than or equal to C or lower than or equal to D; and / or lower than or equal to G4-2 / G2-2 according to the European standard EN 1611-1 of 2000, preferably lower than or equal to G4-3 / G2-3 or lower than or equal to G4-4 / G2-4, while the thickness (Tw) of said wood bars (10) is substantially the same or exactly the same as the thickness (Tp) of said bars (11) of second material, and wherein the leveling layer comprises wood veneer, a polymer film, a woven sheet or a non-woven sheet. 12. The method according to p. 11, in which additionally create means of fixation (30, 31) along the main direction (L) of the workpiece floor panel. 13. The method according to p. 12, in which additionally provide surface treatment, at least in part of the means for mechanical connection. 14. The method of claim 13, wherein the surface treatment comprises coating an exposed portion of said bar of second material. 15. The method according to p. 13 or 14, in which the surface treatment includes hot forming the open part of the said bar from the second material.

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