IT202200002396U1 - MULTILAYER WOOD FLOORING PLANK - Google Patents

Description

MULTILAYER WOOD FLOORING PLANK

[0001] The present invention relates to a multilayer wood floor board.

Scope of application

[0002] The innovation finds its destination in the construction and furnishing sector, with particular reference to wooden floors and coverings.

[0003] Recently, there has been an increase in demand for natural wood floor coverings, such as strips or slats, which can solve the well-known problems of traditional solid wood or parquet coverings. Among the disadvantages, for example, are the high cost and difficult availability of the raw material, the significant thickness and weight, the long installation times and the poor stability.

[0004] There are well-known and widespread layered elements, otherwise known as multilayer parquet or coverings according to the UNI EN 13756:2018 standard, which allow some of these problems to be solved advantageously. They are essentially composed of a walkable and visible upper layer in solid wood of limited thickness, otherwise known as the noble layer being in a quality essence suitable for the purpose, which is joined to a lower layer of greater thickness and cheaper, acting as a support structure or base layer, which is generally in multilayer wood or plywood, or blockboard. To make this lower layer, the well-known compact medium density panels in fibres or wood dust with glues are sometimes used, otherwise known as Medium Density Fibreboard or MDF with the English acronym. It should be noted that the lower support layer, according to the aforementioned standard, is made of a wood-based and/or lignified material, with a mass equal to or greater than 75% compared to its overall mass.

State of the art

[0005] In order to determine the state of the art relating to the proposed solution, a conventional check was carried out by interrogating public archives, which led to the identification of some prior art, including: D1 US7597947

D2 US2005136234

D3 US10576715

[0006] D1 offers a low-cost multilayer panel for furniture and flooring elements, which comprises a first support layer joined to a thin layer of quality wood in the manner of a veneer, with a further coating comprising melamine resin, transparent cellulose pulp and an optional decoration.

[0007] D2 describes a multilayer board of the strip or plank type for fireproof flooring, which is composed of a base layer of composite wood with polymers and various additives, of the type MDF, HDF, OSB or plywood where the wood content is between 2% and 95%, and a top layer of solid wood which is glued on top of it and has a thickness of between 4.6 mm and 6 mm, with a fireproof glue between the base layer and the top layer.

[0008] D3 offers a multilayer floor panel with a high degree of resistance, which includes a central layer made of a medium density or high density wood fibre panel, of the MDF or HDF type respectively. This central layer is joined to a thin upper layer, in a natural soft wood from gymnosperm or hard wood from angiosperm, with an external protective treatment; underneath, there is a further base layer in a natural wood.

Inconveniences

[0009] Known solutions allow covering a floor using a smaller quantity of quality wood than conventional solid wood parquet elements; however, they present some disadvantages such as, for example, the overall thickness and weight, the cost and the availability of the raw material.

[0010] In particular, it has been noted that the wood species most commonly used to create a support layer are birch, poplar, fir and hevea, as they can be easily worked with industrialisable production equipment and processes; for example, on these species it is necessary to carry out a peeling operation to create the individual sheets, otherwise known as veneers, suitable for forming a multilayer wood panel or plywood. It has been seen, however, that nowadays these materials are not always available on the market; often, in fact, it is necessary to import them from distant countries with long transfers and significant environmental costs. Furthermore, it has been noted that the creation of conventional support layers involves complex processes and significant industrial costs, as happens for plywood and for MDF and HDF panels. Furthermore, it has been seen that the known solutions comprising an OSB panel as the main support include particular polymers and adhesives, completion layers and/or additional processes, also with high thicknesses and weights.

[0011] Consequently, a more economical and environmentally sustainable solution is required, compared to conventional solutions, as well as simplified in structure and high-quality in the walkable covering. In particular, an innovative stratified slat composed of an upper layer of solid wood, in the conventionally requested essences, coupled with a single lower support layer, is desirable, which is cheaper and thinner than known solutions, is resistant and ensures stability on the laying surface, is suitable for gluing and is always available, being made with various wood essences.

[0012] All things considered, it is reasonable for companies in the sector to need to identify innovative solutions capable of overcoming at least the problems identified above and achieving the objectives set.

Summary of the finding

[0013] These and other purposes are achieved with the present innovation according to the characteristics set out in the attached claims, solving the problems set out by means of an innovative floor plank (10) in multilayer wood, as a layered element having a rectangular shape (L1, L2) and constant thickness (SP3), comprising a lower layer in composite wood (101) and a walkable upper layer in solid wood (102), where the lower layer is a support and balancing layer (101) consisting of a panel with lamellae and/or flakes and/or wood chips and/or wood dust layered and joined together with resins, of the OSB or LSB type, with a thickness (S1) between 6 mm and 18 mm, while the said upper layer (102) has a thickness (S2) between 0.3 mm and 4.5 mm, which are joined together by means of an interposed adhesive (103) of the polyurethane type and/or polyvinyl acetate based.

Purposes

[0014] Through the significant creative contribution whose effect constitutes an immediate technical progress, several goals are achieved.

[0015] A first aim was to make available an advantageous wooden support layer for multilayer flooring elements or planks, in the various commonly requested dimensions, which is more readily available on the market than conventional solutions, with a lower environmental impact.

[0016] A second aim was to make available a wooden support layer for the said elements, which has a high structural stability on the laying surface, facilitating the balancing, alignment of adjacent slats and gluing to the noble layer.

[0017] A third aim was to reduce the thickness and the overall weight.

[0018] A fourth aim was to make available a significantly cheaper solution.

[0019] A fifth aim was also to promote the recovery and reuse of wooden material.

[0020] It is therefore clarified that a further aim was to make available an advantageous and versatile solution, suitable for multilayer parquet type floors where the noble layer has a thickness conventionally equal to or greater than 2.5 mm, and also suitable for multilayer coverings where this thickness is less than 2.5 mm, including the following categories referred to in the aforementioned UNI EN 13756 standard: covering for wooden floors or category 4.2.2, covering for floors with wood veneers or category 4.2.2.1, composite covering for floors with wood veneers or category 4.2.2.2, composite covering for wooden floors or category 4.2.2.3. Therefore, in the description of the present invention, the term stave conventionally identifies a multilayer strip element for both parquet and coverings. In essence, the proposed solution of stave intends to include the common strips, lists, planks or planks of parquet floors, and also the common coverings where the thickness of the noble layer is thinner like a veneer.

[0021] Another aim was to create an advantageous plank for multilayer wooden floors, in compliance with the UNI EN 13489:2018 standard which is related to wooden flooring, parquet and multilayer elements, and with the European regulation C.P.R. 305/2011 which is related to building materials, and with the UNI EN 14342:2013 standard which is related to wooden flooring and parquet, and also with the UNI EN 13756:2018 standard which is related to wooden flooring and terminology.

[0022] These and other advantages will appear from the following detailed description of some preferential solutions of realization with the aid of the attached schematic drawings whose execution details are not to be considered limiting but only exemplifying.

Content of the drawings

Figure 1 is an orthogonal plan view of a multilayer wood floor board, according to the present invention; it is schematic, being referred to the perimeter of the upper walkable layer.

Figure 2 is a cross-section of the plank shown in Figure 1, corresponding to the section plane X - X, where lateral coupling and alignment means of the male and female interlocking type are also included in the support layer.

Figure 3 - a longitudinal section of the said stave, corresponding to the section plane Y - Y, where the aforementioned interlocking coupling and alignment means are also included in the support layer, as well as notches arranged perpendicular to the grain of the noble upper layer.

Practical implementation of the invention

[0023] With reference also to the figures (Figs. 1 - 3), the object of the present invention concerns an advantageous element for multilayer wood flooring called a slat (10), of substantially rectangular shape, composed of a lower support layer (101) in composite wood, joined with an adhesive (103) to a walkable upper layer (102) made of a high-quality solid wood, or noble wood, of a thickness (S2) lower than the thickness (S1) of said support layer. A single slat (10) has a width (L1) between 70 mm and 300 mm, a width (L2) between 500 mm and 3000 mm, and a total thickness (S3) between 6.3 mm and 22.5 mm. In particular, said lower layer acts as a support and balance (101) with a thickness (S1) between 6 mm and 18 mm; it ? a preformed panel made of lamellae and/or flakes and/or chips and/or wood dust layered together, of the type called Oriented Strand Board or OSB with the English acronym, or Light Strand Board or LSB.

[0024] More in technical detail, OSB panels are made up of wooden strips or flakes, i.e. long and narrow shavings, which are arranged and oriented on overlapping layers and then glued and pressed, in such a way as to make the product compact and flat, resistant and very stable. The dimensions of the aforementioned flakes can vary from panel to panel, as can the types of wood used, depending on the use and/or specific application; for this reason, the said OSB panels are sometimes identified as a family of panels. In particular, an LSB panel is conventionally included in the said OSB family as it is a superficially optimised variant, with similar constitutive and typological characteristics in part of its thickness; in fact, an LSB panel is lighter and has at least one smoother or more refined face, being externally stratified with much smaller and finer flakes, sometimes almost powdery.

[0025] For this reason, for the purposes of this invention, an LSB panel is more suitable than a common OSB panel to support a noble upper layer (102) of very thin thickness. For example, where this thickness is equal to a few tenths of a millimetre, like a veneer, the use of a support and balancing layer (101) in LSB allows to obtain an external walkable surface that is perfectly flat and smooth to the eye, even using a minimum thickness of adhesive (103). However, using an OSB panel in this case, surface imperfections caused by the size of the external flakes could be perceived. In essence, in this description, an LSB panel corresponds to a superficially optimised OSB panel, where at least one face is made up of fine elements; this can be the mating surface to improve the union between the layers, or the lower surface of the plank to improve its appearance and installation, or both.

[0026] It should also be noted that in the production of the panels of the aforementioned OSB family, including LSB panels, both coniferous wood, such as fir and pine, and the wood of certain broadleaf trees, such as poplar, are advantageously used, depending on local or seasonal availability, while still guaranteeing high performance levels for the purposes of this invention. In production, the wood chips are cut tangentially from the debarked trunks, held in a longitudinal position with respect to the saws, optimising their grain or resistance. After drying, a glue based on synthetic resins is sprayed onto the chips, and they are then joined and/or pressed; among the resins generally used, we recall the phenolic resins otherwise known as PF with the acronym, the urea resins reinforced with melamine known as MUF and the polyurethane resins known as PMDI, these resins being resistant to humidity.

[0027] The upper layer (102) of the plank (10), i.e. the noble walkable layer, is made of solid natural wood in the various fine essences conventionally required for flooring, in a thickness (S2) between 0.3 mm and 4.5 mm, where these values refer to the thickness before laying. It is therefore noted that this thickness (102, S2), in the proposed solution of plank (10), allows for the advantageous creation of both multilayer parquet, where it is conventionally equal to or greater than 2.5 mm, and coverings where it is conventionally less than 2.5 mm.

[0028] Structurally (Figs. 1, 2), the slat (10) is composed of a walkable upper layer (102, S2) of solid wood which is joined to a lower support and balancing layer (101, S1) made of a composite wood panel of the OSB or LSB type, as described above; these layers (101, 102) are glued together by means of an interposed adhesive (103), which is of the polyurethane type and/or polyvinyl acetate based, being pressed and/or laminated in such a way as to distribute it uniformly, obtaining a negligible thickness in the slat. In the preferential but not exclusive constructive configuration of the invention, the slat (10) comprises coupling and alignment means (104, 105) integrated laterally in the support and balancing layer (101) in order to facilitate the continuous laying of a flooring; furthermore, the same layer (101) includes notches (106) designed to give greater flexibility to the product, as shown below (Figs.2, 3). When the stave (10) is laid, neither the aforementioned coupling means nor the aforementioned notches are visible (Fig. 1), being entirely included in the said support and balancing layer (101).

[0029] Each slat is then profiled and ground to the expected total thickness (S3), with a tolerance of /- 0.3 mm, using sanding machines and abrasive belts which partially remove the material of the support layer and the material of the noble layer, so as to guarantee a uniform thickness throughout the entire product (10, S3). Finally, the upper layer (102) of the slat (10) is then provided with a surface finish, as set out below.

[0030] More in technical detail of the said notches (106), once the main layers (101, 102, 103) have been assembled, notches (106) are made in the support and balancing layer (101) which are parallel to each other and perpendicular to the grain direction of the wood of the said upper layer (102), with a distance between the individual notches (I) which is less than or equal to 250 mm; they are made on the lower surface, from edge to edge or across the entire width, with a depth (P) which is greater than two thirds of the thickness (S1) and in any case less than the entire thickness of the layer (101), or a depth (P) is expected to be almost equal to the thickness of the said OSB or LSB panel used. It should be noted that the said notches (106) give the plank greater flexibility and significantly facilitate installation; however, the plank may be without them.

[0031] More in technical detail of the said coupling and alignment means, it is expected that they too are entirely included in the support and balancing layer (101), of the said OSB or LSB panel, in order to leave the thickness of the noble part unchanged which for value and durability must not be compromised. Preferably, coupling means with lateral joints are envisaged, of the protruding or male type (104) and corresponding groove or female (105), with a thickness (H) of at least 2.6 mm; they are made in the perimeter of each single element or slat (10, 101), such as for example in a parquet list according to the definition of the aforementioned UNI EN 13756:2018 standard. These joints can be produced industrially with specific profiling and squaring machines, which form the desired joint by means of shaped tools and removal of the material of said support and balancing layer (101).

[0032] The strip (10), therefore, can provide coupling and alignment means made with a female edge element, a male edge element, a female head element, a male head element; alternatively, it can provide a female element integrated on the four sides in combination with a reported element, like an interposed tongue for joining adjacent elements. Furthermore, said coupling and alignment means can be mechanical snap-on hooks, for example of the type called clip, click, snap or similar quick and removable hooking solutions; therefore, this also includes calibrated interference hooks, integrated or reported on the sides of the strip. Among these, by way of example, we recall the interference fit where the male lateral element is also equipped with protrusions or teeth that are not coplanar with respect to the laying surface, so that they rotate into a corresponding female milling of the adjacent slat, preventing its translation like a hook.

[0033] Alternatively, a strip with a straight edge is envisaged, without grooves of the female type (105) and/or without male elements (104). In this way it is possible to guarantee, from time to time, an optimal result depending on the specific installation arrangement; for example, a homogeneous interlocking is envisaged for a ship's deck or track installation, or a specific interlocking with right and/or left elements for a herringbone, Hungarian or French installation. It should be noted, for the purposes of this description, that the aforementioned general dimensions of the strip (10, L1, L2) (Fig. 1) do not take into account the protruding profile of any coupling and alignment means (101, 104, 105) described above but refer substantially to the visible external surface of the strip, of which the upper layer (102) can be walked on, said means being integrated and invisible in the laid flooring.

[0034] In more technical detail of the finishes of the stave (10), it is expected that the upper layer (102) has the visible perimeter edge (107) alternatively sharp, that is not rounded, or provided with a chamfer in the form of a bevel, depending on the type of wood used and/or the desired aesthetic effect in the flooring. In the same layer (102), furthermore, there is a mechanical surface finish, such as for example brushing, rustication, planing or sawing; finally, as an alternative or in combination with these mechanical treatments, a completion finish is expected, applying for example a varnish and/or an oil and/or a wax and/or a colour.

[0035] In the preferential manufacturing configuration, the strip (10) includes both the aforementioned mechanical and completion surface finishes, like a pre-finished element; alternatively, it is deprived of them like a raw element, to be treated together with the adjacent strips after installation.

Legend

(10) wooden floor board, of the multilayer type, according to the present invention;

(101) support and balancing layer;

(102) walkable upper layer;

(103) sticker;

(104) coupling and alignment means, of the male interlocking type; (105) coupling and alignment means, of the female interlocking type; (106) notch;

(107) exposed edge;

(H) thickness of a male and female joint

(I) distance between notches;

(L1) width of the slat;

(L2) length of the stave;

(P) depth of the carving;

(S1) thickness of the support layer;

(S2) thickness of the top layer;

(S3) total thickness of the slat.

Claims (10)

1. A floor board (10) made of multilayer wood, in the form of a single slatted element having a rectangular shape (L1, L2) and constant thickness (SP3), comprising a lower layer of composite wood (101) and a walkable upper layer of solid wood (102) with a thickness (102, S2) less than the thickness of the support layer (101, S1), joined together by means of an interposed adhesive (103); said floor board (10), characterised in that said lower layer is a support and balancing layer (101) consisting of a panel comprising lamellae and/or flakes and/or wood chips and/or wood dust layered and joined together with resins, of the OSB or Oriented Strand Board family, with a thickness (S1) of between 6 mm and 18 mm, while the said upper layer (102) has a thickness (S2) of between 0.3 mm and 4.5 mm; and where the said adhesive (103) is of the polyurethane type and/or based on polyvinyl acetate; and where the said slat (10) has a width (L1) of between 70 mm and 300 mm, a length (L2) of between 500 mm and 3000 mm, a thickness (S3) of between 6.3 mm and 22.5 mm. 2. A floor plank (10), as per claim 1, characterised in that said support and balancing layer (101) is of the LSB or Light Strand Board type, with at least one refined face where it is laminated with small and/or fine and/or powdery flakes. 3. A floor plank (10), as per claim 1 or 2, characterised in that said support and balancing layer (101) comprises multiple notches (106) made starting from the lower surface, which are parallel to each other and perpendicular to the grain direction of the wood of said upper layer (102); and where between the individual notches (106) there is a distance (I) less than or equal to 250 mm, 4. A floor plank (10), as per claim 3, characterised in that said notches (106) have a depth (P) greater than two thirds of the thickness of the support layer (101, S1). 5. A floor plank (10), as per claim 1 or 2 or 3 or 4, characterised in that it comprises coupling and alignment means, integrated into the sides of said support layer (101). 6. A floor plank (10), as per claim 5, characterised in that said coupling and alignment means are lateral joints of the male (104) and female (105) type, with a thickness (H) of at least 2.6 mm. 7. A floor plank (10), as per claim 5, characterised in that said coupling and alignment means are mechanical hooks of the snap or interference type. 8. A floor plank (10), as per at least one of the previous claims, characterised in that said upper layer (102) has a surface finish obtained by mechanical processing, being alternatively: brushing, rustication, planing or sawing. 9. A floor plank (10), as per at least one of the preceding claims, characterised in that said upper layer (102) has a finishing surface finish obtained by applying a varnish and/or an oil and/or a wax and/or a colour. 10. A floor plank (10), as per at least one of the previous claims, characterised in that said upper layer (102) has a visible perimeter edge (107) which is alternatively: sharp or chamfered.