Self-locking tile for floor covering and the method for manufacturing such tile

Description

TECHNICAL FIELD

[0001] The present invention relates to the technical field of floor coverings, and more particularly concerns a self-locking tile for floor covering, that is to say of the type comprising, on its four sides, protruding male assembly means in complementarity of assembly with female assembly means defined between two male assembly means, allowing the installation of the tiles by vertical assembly. EARLIER ART

[0002] In the field of floor coverings, square or rectangular tiles with a multi-layered structure are well known. These tiles include at least one backing layer and a decorative layer bonded to the backing layer. To ensure the vertical joining of two adjacent tiles, this type of tile incorporates tongue-and-groove joints on all four sides, for example, dovetail joints.

[0003] The four sides of the slab are generally strictly identical so that, during assembly, any side of a slab can be joined to any of the sides of an adjacent slab.

[0004] The disadvantage that emerges from this type of slab is the unsightly appearance of the border between two adjacent slabs, linked to the dovetail shape of the assembly means.

[0005] Another drawback is that the said border forms a gap, in communication with the ground on which the slabs are laid, and in which dirt can accumulate and be difficult to remove.

[0006] Another disadvantage of this type of slab also lies in the current configuration of the multilayer structure of the slabs, so that the dovetail assembly means present a relatively low tensile strength of two adjacent slabs in order to move them apart.

[0007] Document DE 202 15 223 U1 discloses a self-locking tile for floor covering according to the preamble of claim 1. DESCRIPTION OF THE INVENTION

[0008] One of the aims of the invention is therefore to remedy these disadvantages by proposing a self-locking slab for flooring, in particular for premises for collective use where traffic is high, of simple and inexpensive design, allowing quick and easy installation, while presenting an improved aesthetic appearance.

[0009] One objective of the invention is for the tile to be classified U4P4S according to the classification of the French UPEC standard. In other words, the U4 classification means that the tile is intended for use in communal areas and must therefore be able to withstand heavy traffic, resist soiling, scratches, and abrasion, without settling or changing appearance. The P4S classification means that the tile must be suitable for areas where heavy load handling equipment or heavy maintenance equipment regularly circulate, or which are subject to severe impacts.

[0010] Another objective is to provide a slab with scuffing values ​​conforming to level r1 or even r2, as defined by the "Determination of scuffing resistance - Mr.bis Test" method described in e-Notebook No. 3562 of the Scientific and Technical Center for Building (CSTB) from March 2007. This test consists of determining the stress that must be applied to a truncated steel nail with a 3 mm diameter, at which irreversible penetration occurs (critical stress), and the stress at which perforation of the coating occurs (maximum stress). Level r1 is achieved if the maximum stress is greater than or equal to 7 N / mm². Level r2 is achieved if the critical stress is greater than or equal to 30 N / mm² and if the maximum stress is greater than or equal to 1.5 times the critical stress, which corresponds to a maximum stress greater than or equal to 45 N / mm².

[0011] Another objective of the invention is to provide such a slab to reduce the accumulation of dirt in the gap between two adjacent slabs, and to facilitate its cleaning.

[0012] Finally, another objective of the invention is to provide such a slab in which the tensile strength of the assembly means, when assembled, is increased.

[0013] For this purpose, and in accordance with the invention, a self-locking slab for floor covering is proposed according to claim 1.

[0014] The male and female assembly means have a general trapezoidal shape and more specifically a dovetail shape with rounded edges.

[0015] Thus, according to the invention, since the decorative layer, generally square or rectangular in shape, covers the assembly means on two adjacent sides and exposes them on two opposite adjacent sides, this allows for a straight boundary between two adjacent slabs, thus contributing to the improvement of the aesthetic appearance of the slab.

[0016] Furthermore, since the visible gap between two adjacent slabs no longer follows a sinusoidal pattern, but rather a straight one, this limits the accumulation of dirt between them. In particular, the gap between two adjacent slabs located at a male connector is shallower and therefore accumulates less dirt, thus facilitating cleaning.

[0017] To further reduce the accumulation of dirt between two adjacent slabs, the decorative layer covers the joining means by extending beyond the back layer, and uncovers the joining means by being set back from the joining means by a distance corresponding to the overhang distance of the decorative layer.

[0018] Thus, the visible gap between two adjacent tiles has a reduced depth, specifically equal to the thickness of the decorative layer. This reduces the accumulation of dirt and also facilitates cleaning, for example by vacuuming.

[0019] The reinforcing armature is a fiberglass grid that includes at least two parallel strands extending along the axis of each male coupling means.

[0020] From the above, this makes it possible to improve the tensile strength of the assembly means when they are assembled.

[0021] According to a particular embodiment, the decorative layer comprises at least one layer of pressed granules.

[0022] In another embodiment, the decorative layer comprises a transparent wear layer bonded to a decorative film. In this configuration, the decorative layer preferably includes a compact layer bonded to the wear layer, with the decorative film positioned between the wear layer and the compact layer. Also in this configuration, and to improve scuff resistance, the backing layer includes a second reinforcing layer bonded to the surface of the backing layer.

[0023] The first reinforcing mesh is positioned in the middle of the thickness of the backing layer. In this configuration, the backing layer comprises, for example, two layers bonded together and positioned on either side of the reinforcing mesh.

[0024] The slab according to the invention has a thickness of between 4 and 8 mm. For example, the decorative layer has a thickness of between 0.3 and 2 mm, while the backing layer has a thickness of between 2 and 6 mm, and preferably between 2.5 and 5 mm.

[0025] The underside layer, for example, has a linear stiffness greater than 2 N / mm², or greater than 4 N / mm², or greater than 6 N / mm². A linear stiffness greater than 2 N / mm² improves the tensile strength of the joining elements between two adjacent slabs when separating them. A linear stiffness greater than 4 N / mm² improves the tensile strength of the joining elements between two adjacent slabs, particularly when the slab is subjected to medium traffic. A linear stiffness greater than 6 N / mm² improves the tensile strength of the joining elements between two adjacent slabs, particularly when the slab is subjected to heavy traffic. For the same stress on the coating, a linear stiffness greater than 6N / mm² helps to limit the appearance of a boundary between two adjacent slabs, thus improving the aesthetics and reducing soiling of the floor covering.

[0026] In general, the backing layer is composed of 30 to 45% polyvinyl chloride, 10 to 20% plasticizer, 10 to 60% filler and 1 to 5% additives.

[0027] According to a particular embodiment, the backing layer is composed of 41% polyvinyl chloride, 17% plasticizer, 41% filler and 1% additives.

[0028] The invention also relates to an advantageous manufacturing method for a slab of the aforementioned type according to claims 8 and 9.

[0029] According to the invention, and starting from a slab having a multilayer structure comprising at least one backing layer having a reinforcing mesh throughout its thickness, and a decorative layer bonded to the backing layer, for example by heat bonding, the process consists of: to machine on two adjacent sides and from the reverse layer, complementary male and female joining means only in the thickness of the reverse layer; to machine on two opposite adjacent sides, complementary male and female joining means in the entire thickness of the multilayer structure; to remove by machining the decorative layer present on the male joining means on the two opposite adjacent sides.

[0030] According to the invention, and starting from a backing layer having a reinforcing structure throughout its thickness, and a decorative layer, the process consists of: to machine on four sides of the reverse layer, complementary male and female assembly means throughout the thickness of said reverse layer; to glue, or even to heat-bond, the decorative layer onto the male assembly means on two adjacent sides so as to totally cover the assembly means on two adjacent sides of the reverse layer and to leave totally uncovered the assembly means on two opposite adjacent sides. SUMMARY DESCRIPTION OF THE FIGURES

[0031] Other advantages and characteristics will become clearer from the following description of a single embodiment, given by way of non-limiting example, of the self-locking slab according to the invention, with reference to the attached drawings in which: there figure 1 is a top view of a flooring slab according to the invention, the figure 2 is a view from below of a flooring tile according to the invention, the figure 3is a side view of the slab at the level of the decorative layer overlap, the figure 4 is a side view of the slab at the point where the decorative layer is removed, the figure 5 is a view from below the slab at the level of a corner of the slab. DETAILED DESCRIPTION OF THE INVENTION

[0032] With reference to figures 1 to 5 The invention relates to a self-locking slab (1) intended to form a floor covering, and which has, for example, a square shape and is made according to a multi-layer structure. The slab (1), and a set of slabs (1), can be laid floating on any substrate, new or renovated.

[0033] With reference to figures 3 and 4, the slab (1) thus comprises a backing layer (2) having a thickness of between 2 and 6 mm, and preferably between 2.5 and 5 mm, and intended to be laid on a floor, and a decorative layer (3) having a thickness of between 0.3 and 2 mm, linked to the backing layer (2) and intended to form the surface of the slab (1).

[0034] The decorative layer (3) and the backing layer (2) are superimposed and bonded together by any suitable means, such as gluing. The decorative layer (3) comprises, for example, at least one layer of pressed granules, or a transparent wear layer (3a) bonded to a decorative film (3b), for example, made from PVC. Alternatively, the decorative film (3b) may be replaced by a printed layer printed directly onto the back of the transparent wear layer (3a) by any known means.

[0035] To avoid degrading the visual appearance and preventing any deformation of the decorative layer (3) by the roughness of the surface of the backing layer (2), the latter advantageously comprises a compact layer (3c), notably without a blowing agent, obtained by pressing, calendering, or extrusion, and preferably made from plasticized PVC. The compact layer (3c) is bonded to the wear layer (3a), with the decorative film (3b) positioned between the wear layer (3a) and the compact layer (3c).

[0036] In a first embodiment, the decorative layer (3) is a pressed granular layer comprising 49% polyvinyl chloride, 20% plasticizer, 30% mineral filler, and 1% additives. The mechanical properties of this decorative layer (3) are as follows: Young's modulus: 31 MPa; Poisson's ratio: 0.46; Compressibility modulus: 129 MPa; Shear modulus: 10.5 MPa

[0037] The backing layer (2) is composed of 41% polyvinyl chloride, 17% plasticizer, 41% filler, and 1% additives. Preferably, the backing layer (2) has a linear stiffness greater than 2 N / mm², or greater than 4 N / mm², or greater than 6 N / mm².

[0038] In order to improve resistance to heavy industrial traffic, the back layer (2) includes a first reinforcing reinforcement (4a), in the form of a fiberglass grid, and is positioned in the middle of the thickness of the back layer (2).

[0039] A reinforcing mesh (4a, 4b) is, for example, in the form of a grid or grid of textile yarns of negligible thickness. The textile yarns of said reinforcing mesh are, for example, obtained from glass fibers, and are preferably spaced 3 mm apart along the longitudinal and transverse dimensions, and have a linear mass of between 20 g / m and 70 g / m, advantageously between 35 g / m and 50 g / m.

[0040] The mechanical properties of this backing layer (2) comprising a first reinforcing reinforcement (4a) are as follows: Young's modulus: 142 MPa; Poisson's ratio: 0.47; Compressibility modulus: 789 MPa; Shear modulus: 48 MPa

[0041] The back layer (2) generally has a Shore D hardness according to ISO 527 between 50 and 70.

[0042] The backing layer (2) generally has an elastic modulus (MPa) between 100 MPa and 500 MPa in order to improve the slip resistance properties of the flooring.

[0043] These tensile mechanical properties were determined according to ISO 527 on a Shimadzu Autograph AGS-X type 5 tensile testing machine, using dumbbell-shaped samples measuring 58 mm (length between jaws) x 5 mm (straight width excluding the gripping area) x 2 mm thick, at a speed of 10 mm / min

[0044] The backing (2) and decorative (3) layers are bonded together by heat-bonding and then machined according to the process of the invention. The floor covering thus formed exhibits slip resistance values ​​conforming to level r1 or even r2 defined according to the "Determination of Slip Resistance - Mr.bis Test" method described in e-Notebook No. 3562 of the Scientific and Technical Center for Building of March 2007.

[0045] In a particular embodiment, the back layer (2) comprises two extruded, calendered or pressed layers (2a, 2b) bonded together and positioned on either side of the first reinforcing frame (4a).

[0046] As an example, a first layer (2a) comprises approximately 33% PVC, 10% plasticizers (DINP), 4% additives (process aids, stabilizers, pigments), 3% PVC particles mixed with glass fibers and 50% fillers; the second layer (2b) comprises approximately 33% PVC, 10% plasticizers (DINP), 4% additives (process aids, stabilizers, pigments) and 53% fillers.

[0047] When the decorative layer (3) includes a compact layer (3c) and in order to improve resistance to ripping, the backing layer (2) includes a second reinforcing reinforcement (4b), for example also in the form of a fiberglass grid, bonded to the surface of the backing layer (2).

[0048] With reference to figures 1, 2 And 5 , and to ensure the assembly of two adjacent slabs (1), the slab (1) includes on its four sides protruding male assembly means (5a) in complementarity of assembly with female assembly means (5b) defined between two male assembly means (5a).

[0049] In particular, and according to the invention, the male (5a) and female (5b) assembly means are provided only on the reverse layer (2) of the multilayer structure.

[0050] The assembly means (5a, 5b) have a general trapezoidal shape, and more particularly dovetail joints with rounded edges.

[0051] According to another feature of the invention, the decorative layer (3) is positioned on the reverse layer (2) so as to totally cover, on two adjacent sides (1a), the assembly means (5a, 5b), and so as to totally uncover them, that is to say to let them appear, on two opposite adjacent sides (1b).

[0052] To do this, it is necessary, starting from the slab (1) having a multi-layer structure comprising a backing layer (2) having a first reinforcing reinforcement (4a) in its thickness, and a decorative layer (3) bonded to the backing layer (2) by heat bonding: to machine on two adjacent sides (1a) and from the reverse layer (2), the assembly means (5a, 5b) only in the thickness of the reverse layer (2); to machine on two opposite adjacent sides (1b) the assembly means (5a, 5b) in the entire thickness of the multilayer structure; to remove by machining the decorative layer (3) present on the male assembly means (5a) on the two opposite adjacent sides (1b).

[0053] Thus, it follows from the present invention that the visible boundary between two adjacent assembled slabs (1) is straight instead of having a sinusoidal shape initially linked to the succession of male (5a) / female (5b) joining means. This improves the overall aesthetics of the floor covering after installation and assembly of the slabs (1).

[0054] Furthermore, since the assembly means (5a, 5b) are machined into a multilayer structure whose layers are already bonded together by heat sealing, the stability and strength of the slab are increased. The slab (1) can therefore be classified as U4P4S.

[0055] In one particular embodiment, and to prevent the accumulation of dirt in the visible gap between two adjacent slabs (1), the decorative layer (3) extends a distance (d) beyond the backing layer (2) on two adjacent sides (1a), exposing the fastening means (5a, 5b) on the two opposite adjacent sides (1b) by being set back from the fastening means (5a, 5b) by a distance corresponding to the distance (d) of the decorative layer's overhang. Thus, the straight visible gap between two adjacent slabs (1) has a depth equivalent to the thickness of the wear layer (3a) and is not in direct contact with the ground on which the slab (1) is laid. In this way, the amount of dirt accumulated in the gap is reduced, and it can be easily removed, for example, by vacuuming.

[0056] In order to improve the strength of the joining means (5a, 5b) of two adjacent assembled slabs (1), and with reference to the figure 5 The reinforcing armature(s) (4a, 4b) in the form of fiberglass grids are positioned such that at least two parallel strands (6) of the grid(s) extend along the axis of each male coupling means (5a). figure 5 The diagram illustrates, in dotted lines, two strands of the fiberglass grid extending along the axis of a male assembly means. To improve the readability of the figure 5 The other strands are not shown.

Claims

1. A self-locking tile (1) for floor covering, the tile having a multilayer structure comprising: - a backing layer (2) comprising on its four sides male assembly means (5a) in protrusions complementary for assembly with female assembly means (5b) defined between two male assembly means (5a), for assembly with an adjacent tile (1), the assembly means (5a, 5b) having a general trapezoidal shape, and more particularly dovetails with rounded edges; - a decorative layer (3) bonded to the backing layer (2), completely covering the assembly means (5a, 5b) on two adjacent sides (1a) of the backing layer (2), and completely uncovering the assembly means (5a, 5b) on two opposite adjacent sides (1b), characterized in that the backing layer (2) has a first reinforcement frame (4a) positioned in the middle of the thickness of the backing layer (2) and obtained from a fiberglass grid comprising at least two parallel strands (6) extending in the axis of each of the male assembly means (5a).

2. The tile (1) according to claim 1, characterized in that the decorative layer (3) covers the assembly means (5a, 5b) by extending a distance (d) beyond the backing layer (2), and uncovers the assembly means (5a, 5b) by being set back from the assembly means (5a, 5b) by a distance corresponding to the distance (d) of the extension of the decorative layer (3).

3. The tile (1) according to claim 1, characterized in that the decorative layer (3) comprises a transparent wear layer (3a) bonded to a decorative film (3b).

4. The tile (1) according to claim 3, characterized in that the decorative layer (3) comprises a compact layer (3c) bonded to the wear layer (3a), the decorative film (3b) being positioned between the wear layer (3a) and the compact layer (3c).

5. The tile (1) according to claim 4, characterized in that the backing layer (2) comprises a second reinforcement frame (4b) bonded to the surface of the backing layer (2).

6. The tile (1) according to claim 1, characterized in that the backing layer (2) has a linear stiffness greater than 2 N / mm2, or greater than 4 N / mm2, or greater than 6 N / mm2.

7. The tile (1) according to claim 1, characterized in that the backing layer (2) has an elastic modulus between 100 MPa and 500 MPa.

8. A method of manufacturing a tile (1) according to claim 1, characterized in that, starting from a tile (1) having a multilayer structure comprising at least a backing layer (2) having, in the middle of its thickness, a reinforcement frame obtained from a fiberglass grid, and a decorative layer bonded to the backing layer (2) by heat-sealing, the method consists of: - to machine on two adjacent sides (1a) and from the backing layer (2), complementary male assembly means (5a) and female assembly means (5b) having a general trapezoidal shape, and more particularly dovetails with rounded edges, and only in the thickness of the backing layer (2), with at least two parallel strands (6) of the fiberglass grid extending in the axis of each of the male assembly means (5a); - to machine on two opposite adjacent sides (1b) complementary male assembly means (5a) and female assembly means (5b) in the entire thickness of the multilayer structure, with at least two parallel strands (6) of the fiberglass grid extending in the axis of each of the male assembly means (5a); - to remove by machining the decorative layer (3) present on the male assembly means (5a) of the two opposite adjacent sides (1b).

9. A method of manufacturing a tile (1) according to claim 1, characterized in that, starting from a backing layer (2) having, in the middle of its thickness, a reinforcement frame obtained from a fiberglass grid, and a decorative layer (3), the method consists of: - machining on four sides (1a) of the backing layer (2), complementary male assembly means (5a) and female assembly means (5b) having a general trapezoidal shape, and more particularly dovetails with rounded edges, and in the entire thickness of said backing layer (2), with at least two parallel strands (6) of the fiberglass grid extending in the axis of each of the male assembly means (5a); - gluing or heat-sealing the decorative layer (3) on the male assembly means (5a) of the two adjacent sides so as to completely cover the assembly means on two adjacent sides of the backing layer (2) and to leave completely uncovered the assembly means on two opposite adjacent sides.