Self-locking slab for floor covering

Abstract

The present invention relates to a self-locking slab (1) for floor covering, remarkable in that it has a multi-layer structure comprising: - a back layer (2) having, in its thickness, a first reinforcing reinforcement (4a), and comprising on its four sides male assembly means (5a) in projections in complementarity of assembly with female assembly means (5b) defined between two male assembly means (5a), for assembly with an adjacent slab (1); - a decorative layer (3) linked to the back layer (2), totally covering the assembly means (5a, 5b) on two adjacent sides (1a) of the back layer (2), and totally uncovering the assembly means (5a, 5b) on two opposite adjacent sides (1b).

Description

TECHNICAL FIELD

[0001] The present invention relates to the technical field of floor coverings, and more particularly concerns a self-locking slab for floor covering, that is to say of the type comprising, on its four sides, male assembly means projecting in complementary assembly with female assembly means defined between two male assembly means, allowing the slabs to be laid by vertical assembly. PREVIOUS ART

[0002] In the field of floor coverings, square or rectangular tiles are well known, having a multi-layer structure comprising at least one backing layer and a decorative layer bonded to the backing layer. To ensure the vertical assembly of two adjacent tiles, this type of tile comprises male / female assembly means on its four sides, for example dovetails.

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

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

[0005] Another disadvantage 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 is also the current configuration of the multi-layer structure of the slabs, so that the dovetail joining means have a relatively low resistance to the traction of two adjacent slabs in order to separate them from each other. STATEMENT OF THE INVENTION

[0007] One of the aims of the invention is therefore to overcome these drawbacks by proposing a self-locking slab for floor covering, particularly for premises used collectively where there is heavy traffic, of simple and inexpensive design, allowing quick and easy installation, while presenting an improved aesthetic appearance.

[0008] An objective of the invention is that the slab is classified U4P4S according to the classification of the French UPEC standard. In other words, the U4 classification means that the slab is intended for premises for collective use and that it must therefore be able to withstand, when subjected to heavy traffic, dirt, scratches, abrasion, not settle, nor change its appearance. The P4S classification means that the slab must be able to be intended for premises where heavy load handling equipment or heavy maintenance equipment normally circulate or which are subject to severe impacts.

[0009] Another objective is to propose a slab presenting slip values ​​conforming to the level r1 or even r2 defined according to the method of "Determination of slip resistance - Mr.bis test" described in the e-Cahier n°3562 of the Scientific and Technical Center for Construction of March 2007. This test consists of finding the stress to be applied to a truncated steel nail of 3mm diameter, from which there is irreversible penetration (critical stress), and the stress from which there is perforation of the coating (maximum stress). The level r1 is obtained if the maximum stress is greater than or equal to 7N / mm 2< . The level r2 is obtained if the critical stress is greater than or equal to 30N / mm 2< 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 45N / mm 2< .

[0010] Another objective of the invention is to provide such a slab making it possible to reduce the accumulation of dirt in the gap between two adjacent slabs, and to facilitate its cleaning.

[0011] Finally, another objective of the invention is to provide such a slab whose tensile strength of the assembly means, when assembled, is increased.

[0012] For this purpose, and in accordance with the invention, a self-locking slab for floor covering is proposed, remarkable in that it has a multi-layer structure comprising at least: a backing layer having, in its thickness, a first reinforcement frame making it possible to improve resistance to industrial traffic, and comprising on its four sides male assembly means projecting in complementarity of assembly with female assembly means defined between two male assembly means, for assembly with an adjacent slab; a decorative layer linked to the backing layer, completely covering the assembly means on two adjacent sides of the backing layer, and completely uncovering the assembly means on two opposite adjacent sides.

[0013] The male and female assembly means have, for example, a general trapezoidal shape and more particularly a dovetail shape with rounded edges.

[0014] It goes without saying that the male assembly means, and consequently the female assembly means, may have a different shape without departing from the scope of the invention.

[0015] Thus, according to the invention, given that the decorative layer of general square or rectangular shape covers the assembly means on two adjacent sides and uncovers them on two opposite adjacent sides, this makes it possible to have a rectilinear border between two adjacent slabs, thus contributing to improving the aesthetic appearance of the slab.

[0016] Furthermore, since the visible gap between two adjacent slabs no longer follows a sinusoidal configuration, but rather a rectilinear one, this limits the accumulation of dirt between two adjacent slabs. In particular, the gap between two adjacent slabs located at the right of a male assembly element is less deep and therefore accumulates less dirt, thus facilitating cleaning.

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

[0018] Thus, the visible gap between two adjacent tiles has a reduced depth, in particular equal to the thickness of the decorative layer. This reduces the accumulation of dirt and also makes it easier to clean, for example by vacuuming.

[0019] A reinforcing frame may be obtained from a woven or non-woven textile, or from a grid and / or a veil of glass fibers, a grid and a glass veil being able to be complexed. According to a particular embodiment, the reinforcing frame is a glass fiber grid which preferably comprises at least two parallel strands extending in the axis of each male coupling means.

[0020] From the above, this allows to improve the tensile strength of the joining means, when assembled.

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

[0022] According to another embodiment, the decorative layer comprises a transparent wear layer bonded to a decorative film. In this configuration, the decorative layer preferably comprises a compact layer bonded to the wear layer, the decorative film being positioned between the wear layer and the compact layer. Still in this configuration, and in order to improve the resistance to slipping, the backing layer comprises a second reinforcing reinforcement bonded to the surface of the backing layer.

[0023] Preferably, the first reinforcing reinforcement 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 reinforcement.

[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 backing layer has, for example, a linear stiffness greater than 2 N / mm 2< , or greater than 4 N / mm 2< , or greater than 6 N / mm 2< . A linear stiffness greater than 2N / mm 2< makes it possible to improve the tensile strength of the joining means of two adjacent slabs in order to separate them from each other. A linear stiffness greater than 4N / mm 2< makes it possible to improve the tensile strength of the joining means of two adjacent slabs, in particular when the slab is subjected to medium traffic. A linear stiffness greater than 6N / mm 2< makes it possible to improve the tensile strength of the joining means of two adjacent slabs, in particular when the slab is subjected to heavy traffic. For the same force applied to the covering, a linear stiffness greater than 6N / mm 2< makes it possible to limit the appearance of a boundary between two adjacent slabs, thus improving the aesthetics and reducing the soiling of the floor covering.

[0026] Typically, the backing layer is composed of 30-45% polyvinyl chloride, 10-20% plasticizer, 10-60% filler and 1-5% 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 method of manufacturing a slab of the aforementioned type.

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

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

[0031] Other advantages and characteristics will emerge more clearly from the following description of a single variant embodiment, given as a non-limiting example, of the self-locking slab in accordance with the invention, with reference to the appended drawings in which: there figure 1 is a top view of a floor covering slab according to the invention, the figure 2 is a bottom view of a floor covering slab according to the invention, the figure 3is a side view of the slab at the level of the decorative layer covering, the figure 4 is a side view of the slab at the level of the removal of the decorative layer, the Figure 5 is a bottom view of the slab at one corner of the slab. DETAILED DESCRIPTION OF THE INVENTION

[0032] In reference to the figures 1 to 5 , the invention relates to a self-locking slab (1) intended to constitute a floor covering, and has, for example, a square shape and is produced according to a multi-layer structure. The slab (1), and a set of slabs (1) can be laid floating on any supports, new or during renovation.

[0033] In reference to the 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, bonded 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 connected to each other by any suitable connecting means, such as by gluing for example. The decorative layer (3) comprises for example at least one layer of pressed granules, or a transparent wear layer (3a) connected to a decorative film (3b) for example obtained from PVC. Alternatively, the decorative film (3b) can be replaced by a printing layer printed directly on the back of the transparent wear layer (3a), by any known means.

[0035] In order not to degrade the visual appearance and to prevent 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), in particular without swelling agent, obtained by pressing, calendering or extrusion and preferably made from plasticized PVC. The compact layer (3c) is bonded to the wear layer (3a), the decorative film (3b) being 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, 1% additives. The mechanical properties of this decorative layer (3) are as follows: Young's modulus: 31 MPa Poisson's ratio: 0.46 Bulk 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 / mm 2< , or greater than 4 N / mm 2< , or greater than 6 N / mm 2< .

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

[0039] A reinforcing frame (4a, 4b) is for example in the form of a grid or a grid of textile threads of negligible thickness. The textile threads of said reinforcing frame are for example obtained from glass fibers, and are preferably spaced from each other by 3 mm, according to 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 frame (4a) are as follows: Young's modulus: 142 MPa Poisson's ratio: 0.47 Bulk modulus: 789 MPa Shear modulus: 48 MPa

[0041] The backing layer (2) generally has a Shore D hardness according to ISO 527 standard 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 floor covering.

[0043] These tensile mechanical properties are determined according to ISO 527 standard on a Shimadzu Autograph AGS-X type 5 tensile bench, on dumbbell-shaped samples of 58 mm (length between the jaws) x 5 mm (straight width excluding the gripping zone) x 2 mm thickness, at a speed of 10 mm / min.

[0044] The backing (2) and decorative (3) layers are assembled by heat-sealing and then machined using the method of the invention. The floor covering thus formed has slip values ​​in accordance with level r1 or even r2 defined according to the method of “Determination of slip resistance - Mr.bis test” described in e-Cahier No. 3562 of the Scientific and Technical Center for Construction of March 2007.

[0045] In a particular embodiment, the backing 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] For 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) comprises a compact layer (3c) and in order to improve the resistance to slipping, the backing layer (2) comprises 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] In reference to the figures 1, 2 And 5 , and to ensure the assembly of two adjacent slabs (1), the slab (1) comprises on its four sides male assembly means (5a) projecting in assembly complementarity 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 backing layer (2) of the multilayer structure.

[0050] It is obvious that the assembly means (5a, 5b) can have different shapes without departing from the scope of the invention. Preferably, the assembly means (5a, 5b) have a general trapezoidal shape, and more particularly dovetails with rounded edges.

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

[0052] To do this, it is appropriate, starting from the slab (1) having a multi-layer structure comprising a backing layer (2) having a first reinforcement frame (4a) in its thickness, and a decorative layer (3) bonded to the backing layer (2) by heat-sealing: to machine on two adjacent sides (1a) and from the backing layer (2), the assembly means (5a, 5b) only in the thickness of the backing 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) of the two opposite adjacent sides (1b).

[0053] Thus, it results from the present invention that the visible border between two adjacent assembled slabs (1) is rectilinear instead of having a so-called sinusoidal shape initially linked to the succession of male (5a) / female (5b) assembly means. This makes it possible to improve the general aesthetics of the floor covering after laying and assembly of the slabs (1).

[0054] Furthermore, since the assembly means (5a, 5b) are machined in a multi-layer structure whose layers are already bonded together by heat-sealing, the stability and strength of the slab are increased. The slab (1) can thus claim U4P4S classification.

[0055] According to a particular embodiment, and in order to avoid the accumulation of dirt in the visible gap between two adjacent slabs (1), the decorative layer (3) projects by a distance (d) beyond the backing layer (2) on two adjacent sides (1a), and uncovers the assembly means (5a, 5b) on the two opposite adjacent sides (1b) while being set back from the assembly means (5a, 5b) by a distance corresponding to the overflow distance (d) of the decorative layer (3). Thus, the rectilinear gap visible between two adjacent slabs (1) has a depth equivalent to the thickness of the wear layer (3a), and is not in direct communication with the ground on which the slab (1) is laid. In this way, the dirt accumulated in the gap is in smaller quantity, and can be easily removed by suction for example.

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

Claims

1. Self-locking slab (1) for floor covering, characterized in that it has a multi-layer structure comprising: - a backing layer (2) having, in its thickness, a first reinforcement frame (4a), and comprising on its four sides male assembly means (5a) projecting in assembly complementarity with female assembly means (5b) defined between two male assembly means (5a), for assembly with an adjacent slab (1); - a decorative layer (3) linked 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).

2. Slab (1) according to claim 1, characterized in thatthe 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 extension of the decorative layer (3).

3. Slab (1) according to claim 1, characterized in that the first reinforcing frame (4a) is a glass fiber grid comprising at least two parallel strands (6) extending in the axis of each of the male assembly means (5a).

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

5. Slab (1) according to claim 4, 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).

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

7. Slab (1) according to claim 1, characterized in that the first reinforcement frame (4a) is positioned in the middle of the thickness of the backing layer (2).

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

9. Slab (1) according to claim 1, characterized in that the backing layer (2) has an elastic modulus of between 100 Mpa and 500 Mpa.

10. Method of manufacturing a slab (1) according to claim 1 , characterized in that, from a slab (1) having a multi-layer structure comprising at least one backing layer (2) having a reinforcement in its thickness, and a decorative layer bonded to the backing layer (2) by heat-sealing, the method consists of: - machining on two adjacent sides (1a) and from the backing layer (2), complementary male (5a) and female (5b) assembly means only in the thickness of the backing layer (2); - machining on two opposite adjacent sides (1b) complementary male (5a) and female (5b) assembly means throughout the thickness of the multi-layer structure; - removing by machining the decorative layer (3) present on the male assembly means (5a) of the two opposite adjacent sides (1b).

11. Method of manufacturing a slab (1) according to claim 1 , characterized in that, from a backing layer (2) having a reinforcement in its thickness, and a decorative layer (3), the method consists of: - machining on four sides (1a) of the backing layer (2), complementary male (5a) and female (5b) assembly means throughout the thickness of said backing layer (2); - gluing or heat-bonding the decorative layer (3) onto the male assembly means (5a) on 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.

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