WO2020002787A1

WO2020002787A1 - Acoustic panel for producing a floor covering

Info

Publication number: WO2020002787A1
Application number: PCT/FR2019/051172
Authority: WO
Inventors: Nicolas DUMANT; Olivier Moulin; Olivier Ceysson
Original assignee: Gerflor
Priority date: 2018-06-26
Filing date: 2019-05-22
Publication date: 2020-01-02
Also published as: FR3082859B1; FR3082859A1; EP3827145A1; EP3827145B1; EP3827145C0

Abstract

The invention concerns a multilayer panel for producing a floor covering having acoustic insulation properties, comprising, successively, a top layer providing wear resistance and decorative functions, a non-woven textile layer comprising textile fibres and a backing layer comprising at least one non-flexible layer made from a thermoplastic material, said layers being linked together to form the multilayer panel, the non-woven textile layer comprising a so-called free thickness in which the textile fibres are free and not impregnated.

Description

ACOUSTIC PANEL FOR THE PRODUCTION OF A COATING

OF SOIL

Technical area

The present invention relates to the technical sector of floor coverings and more particularly a multilayer panel for the production of a floor covering or the like. The panel according to the invention has a slab or blade shape and has good mechanical and acoustic properties.

Prior art

It is well known to produce floor coverings from modular elements in the form of boards or slabs. These modular elements can be glued to the floor or laid loose, especially when they have male-female assembly means. Such male-female means of connecting or assembling panels are notably described in documents GB 2 256 023, EP 1 026 341, WO 2012/004701, EP 2 843 153 or also WO 2016/030627.

Floor coverings in the form of planks and tiles are known in particular made from one or more layers of non-flexible or rigid PVC, these being particularly advantageous since they are easier to transport than rolls of PVC floor coverings. Their installation is also simple and fast. They are therefore often used in renovations to cover existing floors. In order to improve the dimensional stability of this type of coating, it is sometimes used a reinforcement glass veil embedded in the thickness of a layer of PVC.

However, this type of coating generally has poor acoustic properties, in particular in terms of sound insulation, sound when walking, shock absorption and comfort when walking.

Statement of the invention One of the aims of the invention is therefore to propose a panel for producing a floor covering having good performance in terms of running sound and sound insulation while retaining good mechanical properties.

Another object of the invention is to propose a panel comprising male-female means of connection or assembly.

Another object of the invention is to provide a panel having improved shock absorption properties according to standard EN14808, in particular greater than 3%.

An objective of the invention is also to propose a panel classified A or even B according to standard NF S31 074 in terms of sound when walking, that is to say having a value Ln, e, w of less than 75db. This measurement is made according to standard NF S31 074, using a microphone measuring the level of standardized impact noise in the room where the floor covering is laid.

An objective of the invention is also to propose an acoustic panel having a reduction in weighted impact noise (AFw) according to standard ISO 10140-3 and the classification according to ISO 717-2: 20l3 greater than 12db.

To this end, a multilayer panel is proposed for producing a floor covering having acoustic insulation properties successively comprising an upper layer providing wear resistance and decor functions, a non-woven fabric layer. woven fabric comprising textile fibers and a backing layer comprising at least one non-flexible layer produced from a thermoplastic material, said layers being bonded together to form the multilayer panel, the non-woven fabric layer comprising at least one so-called free thickness in which the textile fibers are free and not impregnated.

It is therefore important that part of the thickness of the layer of nonwoven fabric remains free and not impregnated by the upper and reverse layers. By free thickness is meant that the fibers of the nonwoven textile layer are free to move in this thickness, in the same way that they can move in the textile layer before it is linked to the upper layers and backing. In the free thickness, the textile fibers are not impregnated by any means used to bond the layer of nonwoven fabric to the top and back layers.

Advantageously, the layer of nonwoven fabric consists of the so-called free thickness bordered by at least one thickness known as the bonding of the layer of nonwoven fabric with the upper layer or the backing layer, the thickness of connection being less than or equal to the free thickness.

Preferably, the layer of nonwoven fabric consists of the so-called free thickness bordered by two thicknesses known as of connection with the upper layer and the reverse layer, the sum of the connection thicknesses is less than or equal to the free thickness.

The so-called bonding thicknesses of the nonwoven fabric layer are a function of the means or means used to bond the nonwoven fabric layer to the upper layer and to the reverse layer. The layer of nonwoven fabric may in particular be bonded to the backing layer or to the upper layer by thermo lamination, cold bonding, hot bonding, extrusion of the backing layer onto the layer of nonwoven fabric, by powdering hot-melt glue or by using a double-sided adhesive. The bonding thickness will be for example a few microns if the layer of nonwoven fabric is bonded by thermo lamination. It is for example possible to thermally bond a backing layer made from PVC and a layer of nonwoven fabric made of polyester fibers.

It is also possible to bond by cold or hot gluing the nonwoven fabric layer to the upper layer and / or to the reverse layer, for example using a hotmelt glue. The impregnation of the adhesive is in this case limited to the fibers arranged on the surface of the layer of nonwoven fabric. It is also envisaged to bond the layer of nonwoven fabric using a hot-melt powder glue. This process is described in particular in patent application EP 1570 920 B1 of the applicant, in particular by dusting with polyester, co-polyester or EVA (ethylene vinyl acetate) glue. Conventional bond thicknesses will be between 25 qm and 300qm, preferably between 50 µm and 130 µm in the case of bonding. Alternatively, it is possible to bond the layer of nonwoven fabric to the upper layer or to the reverse layer using a layer of plastisol deposited in the liquid state on the layer of nonwoven fabric and then gelled. By gelling the plastisol layer will impregnate the fibers of the non-woven textile layer on the bonding thickness. A layer of gelled plastisol can in particular be a layer of PVC plastisol with a thickness of at least 50 mhi and generally less than 1 mm after gelling, preferably between 50 mhi and 0.5 mm.

Due to its position in the multilayer panel, the nonwoven fabric layer makes it possible to attenuate impact noise and limit their transmission from the upper layer to the backing layer while retaining a so-called free thickness. This free thickness makes it possible to conserve an amount of air inside the layer of nonwoven fabric. The invention thus makes it possible to obtain a multilayer panel for the production of a floor covering having sound insulation properties. Depending on the thickness of the nonwoven fabric and the composition of the panel, it may be classified A or even B according to standard NF S31 074 in terms of sound when walking, that is to say having a value Ln, e, w less than 75db. On the other hand, the invention makes it possible to obtain an acoustic panel having a reduction in weighted impact noise (ALw) according to standard ISO 10140-3 and the classification according to ISO 717-2: 2013 greater than 12db.

The layer of nonwoven fabric has a thickness generally of between 0.5 mm and 2 mm and a surface mass of between 80 g / m ² and 250 g / m ² . Preferably, the nonwoven fabric layer has a thickness of between 0.65 mm and 1.1 mm and a surface mass between 120 g / m ² and 200 g / m ^{2 in} order to present a good compromise between acoustic performance and the puncture resistance of the floor covering according to the invention.

Advantageously, the nonwoven textile layer comprises natural textile fibers such as cellulose fibers, cotton fibers, linen fibers, synthetic textile fibers, in particular polyester fibers, polyamide fibers, polyethylene terephthalate fibers, aramid fibers, Nomex, ethylene polynaphthalate, polypropylene or also synthetic mineral textile fibers such as glass fibers or basalt fibers. Preferably, the non-woven textile layer comprises only polyester fibers because these have good acoustic properties without generating too high a manufacturing cost.

Advantageously, the upper layer and the layer of nonwoven fabric of the multilayer panel according to the invention are linked together by a first bonding layer impregnating less than 50% of the thickness of the layer of nonwoven fabric. Impregnation of less than 50% of the thickness of the nonwoven fabric layer makes it possible to obtain good cohesion of the upper layer with the nonwoven fabric layer. Preferably, the upper layer and the layer of nonwoven fabric are bonded together by a first bonding layer permeating less than 30%, more preferably less than 15% of the thickness of the layer of nonwoven fabric. By decreasing the impregnation thickness, a greater thickness of nonwoven fabric layer can be left free. The greater the thickness of the free nonwoven fabric layer, the more the acoustic properties of the panel according to the invention will be improved. Advantageously, the first bonding layer is a layer of gelled plastisol or a hot-melt adhesive.

Advantageously, the backing layer and the nonwoven fabric layer are linked together by a second bonding layer impregnating less than 45% of the thickness of the nonwoven fabric layer. Preferably, the upper layer and the layer of nonwoven fabric are linked together by a second bonding layer impregnating less than 30%, more preferably less than 15% of the thickness of the layer of nonwoven fabric. By decreasing the impregnation thickness, a greater thickness of nonwoven fabric layer can be left free. In general, in an example of a method for manufacturing the multilayer panel according to the invention, the upper layer, the first bonding layer and the layer of nonwoven fabric are assembled together in a first manufacturing step. The by-product obtained is then bonded to the backing layer by the second bonding layer. Advantageously, the second bonding layer is an adhesive, for example a double-sided adhesive.

The upper layer providing wear resistance and decorative functions is for example made of polyvinyl chloride and generally has a thickness of between 0.10 and 1 mm, preferably between 0.20 and 0.70 mm. According to the invention, the upper layer may comprise a wear layer transparent to visible light so that a decoration printed on the reverse side of the wear layer or else on a printed film disposed between the wear layer and the nonwoven fabric can be seen through the wear layer. According to the invention, the upper layer can also be a decorative layer obtained by pressing or calendering of tinted polymer granules or by coating and gelling of a tinted plastisol. Advantageously, the upper layer comprises a reinforcing reinforcement embedded in the thickness of the upper layer. The presence of a reinforcement reinforcement improves the dimensional stability of the upper layer. On the other hand, the reinforcing reinforcement can be used as a coating support in order to obtain an upper layer from a plastisol. The plastisol is coated on one or two sides of the reinforcement and then gelled.

The backing layer of the panel according to the invention comprises at least one non-flexible layer made from a thermoplastic material, that is to say that it has a stiffness in bending greater than the stiffness in maximum bending to meet the International Standard ISO 24344: 2008. In this method, flexibility is defined by the ability of a panel or layer of flooring to be wrapped around a 20mm core, without cracks or cracks forming. Thus, the non-flexible layer of the backing layer subjected to this test would exhibit breaks, cracks, cracks and other permanent defects. The non-flexible layer can in particular be made from PVC.

The backing layer of the panels according to the invention generally has a thickness of between 0.5 mm and 6 mm. Thus, the panel according to the invention has stable dimensions, the backing layer having good dimensional and mechanical stability properties while having good acoustic properties. Advantageously, the back layer of the panel according to the invention back layer comprises at least one rigid layer. Preferably, the back layer of the panel according to the invention is sufficiently rigid so that male-female assembly means can be machined there, formed by injection molding or cut on the edges of said layer. The assembly of said male-female assembly means allows blocking of the panels together under normal conditions of use, this blocking preventing the panels from being disassembled in at least one direction. Those skilled in the art will be able to define the different compositions and thicknesses of the layer or layers forming the backing layer to achieve the expected rigidity.

Advantageously, the backing layer of the panel according to the invention comprises at least one rigid layer whose modulus value for 1% elongation is greater than 20 daN / cm and whose flexibility value is preferably greater than 25N for 20mm .

The use of a layer having these elongation characteristics makes it possible to obtain a panel according to the invention, the dimensions of which are stable as a function of temperature variations in the room where it is installed.

Advantageously, the backing layer of the panel according to the invention has a module for 1% elongation whose value is greater than 20 daN / cm and whose flexibility value is preferably greater than 25N for 20mm. The use of a layer having these elongation characteristics makes it possible to obtain a panel according to the invention whose dimensions are more stable as a function of temperature variations in the room where it is installed.

Advantageously, the backing layer of the panel according to the invention comprises at least one rigid layer whose modulus value for 1% elongation is greater than 45 daN / cm and whose flexibility value is preferably greater than 90N for 20mm of deflection. The use of a layer having these elongation characteristics makes it possible to further improve the dimensional stability of the panel according to the temperature variations of the room where it is installed, in particular when it is placed in a so-called free way, that is to say without adding glue.

Advantageously, the backing layer of the panel according to the invention has a module for 1% elongation whose value is greater than 45 daN / cm and whose flexibility value is greater than 90N for 20mm of deflection. The use of a layer having these elongation characteristics makes it possible to obtain a very rigid panel and thus to improve the dimensional stability of the panel as a function of temperature variations in the room where it is installed. In particular, a backing layer having such characteristics makes it possible to obtain a panel which can be installed in a so-called free manner in places particularly exposed to the rays of the sun.

All the module values for 1% elongation set out in this application are obtained according to the Ml-Ueatc method according to standard NF 189.

All the flexibility values for 20mm deflection set out in this application are obtained according to standard NF EN ISO 24344: April 2012.

The desired values of elongation and flexibility of each layer and in particular of the backing layer can easily be obtained by a person skilled in the art depending on the thermoplastic material used for its production. Thermoplastic materials such as PVC, thermoplastic polyurethane or thermoplastic polyolefins, such as polyethylene or polypropylene, may be used to obtain the backing layer, one of the layers of the backing layer or of all the layers of the backing layer. PVC is preferred for its ease of transformation and its mechanical properties. It is for example well known that in the case of PVC, the amount of filler and / or liquid plasticizer used in the composition of the layer makes it possible to vary its behavior in elongation and in bending. Alternatively, the thermoplastic material may be completely or partially replaced by rubber, natural or synthetic or even linoleum.

Advantageously, the backing layer or at least one rigid layer of the backing layer is obtained from a composition comprising at least PVC and at least one liquid plasticizer, the proportion of liquid plasticizer by mass of the layer obtained being less than 10%, preferably less than or equal to 5%. A proportion of liquid plasticizer less than 10% increases the rigidity of the panel while allowing this layer to be produced by conventional calendering or extrusion processes. A proportion of liquid plasticizer less than or equal to 5% further increases the rigidity of the multilayer panel as well as the dimensional stability of the panel.

The incorporation of a quantity of liquid plasticizer less than 10% by mass of the rigid layer allows it to be simpler to transform and to be less brittle while retaining good dimensional stability properties. The presence of a low level of liquid plasticizer, ie less than 10% by mass of the layer obtained, also facilitates the use of PVC at a temperature less than or equal to 180 ° C., thus limiting the risks of degradation of the material. This property is particularly advantageous in the processes for manufacturing a rigid layer by calendering. The incorporation of a quantity of liquid plasticizer of less than 5%, more preferably between 1 and 5% by mass of the layer makes it possible to obtain a better compromise between the properties of dimensional stability and ease of manufacture.

Advantageously, the backing layer or at least one rigid layer of the backing layer is obtained from a composition comprising at least PVC and shock absorbers. The incorporation of shock absorbers makes the layer obtained less brittle, especially at low temperature, depending on the applications considered for the panel according to the invention.

Advantageously, the shock absorbers that can be used are elastomeric polymer particles. These elastomeric polymer particles are called "core-shell particles" in English and are well known to those skilled in the art. These are formed from a “hard” thermoplastic shell, preferably based on an acrylate polymer, for example polymethyl methacrylate (PMMA), and an elastomeric core generally based on butadiene, often copolymerized with styrene. , or acrylic based. Mention may in particular be made, for obtaining an elastomeric core, of acrylonitrile-butadiene-styrene polymers (ABS), acrylonitrile-styrene acrylate polymers (ASA), methacrylate-butadiene-styrene polymers (MBS), methacrylate-acrylonitrile polymers. - butadiene-styrene (MABS), ethylene / vinyl acetate copolymers (EVA), ethylene / vinyl acrylate (E / VAC), grafted vinyl chloride / vinyl-acrylate / ethylene (E / VAC / VC) terpolymers, polyethylene chlorinated (CPE); polyurethane elastomers (PUR), butadiene / 2-vinylpyridine, butadiene / methyl isoproprenyl ketone, butadiene / fumaric ester copolymers and mixtures thereof.

These shock absorbers thus contain a crosslinked or weakly crosslinked elastomeric core, surrounded by a thermoplastic shell, often a polymer of methyl methacrylate (PMMA). The patents US 3,985,703, US 4,304,709, US 6,433,091, EP 1256615 or US 6,869,497 describe in particular such particles, which are thus well known to those skilled in the art. Core-shell polymers are available from many suppliers.

By way of examples, it is possible to use as shock absorbers the particles MBS Clearstrength C301, C303H, C223, C350, C351, E920 or C859 from the company Arkema, MBS C301 and C303H being preferred. Durastrength D300 or D340 particles from Arkema, which have an acrylic core surrounded by a PMMA envelope, can also be used. Similarly, it is also possible to use the MBSs developed by the company Rohm and Haas, in particular Paraloid ™ BTA 753, Advastab or Advalube, styrene / anhydride-maleic copolymers modified by a rubber such as polymers of Elix 300 series sold by Monsanto. Other shock absorbers such as the Hytrel 3495 polymers marketed by the company DuPont, or CPE marketed under the brand Tyrin by the company DuPont, as well as the range called Kane Ace MX marketed by the company Kaneka are also usable. Other shock absorbers with an acrylic core surrounded by a rubber cover can be used.

Advantageously, the shock absorbers are polymeric plasticizers. Polymeric plasticizers which can also be used according to the invention are the copolymers and terpolymers of the Elvaloy and Elvaloy HP series marketed by the company Dupont, thermoplastic polyurethane particles (TPU) especially marketed by the company BASF under the Elastollan range, or by the company Lanxess under the Baymod range. These TPUs can be aromatic, more preferably aliphatic, formed from polyether polyols, or more preferably formed from polyester polyols, formed from caprolactone derivatives or formed from thermoplastic copolyesters.

The various shock absorbers mentioned can be used alone or as a mixture.

Preferably, the proportion of mass shock absorbers of the backing layer or of the rigid layer of the backing layer is less than 25%, preferably between 1% and 15% by mass of the layer . The quantity of mass shock absorbers of the layer depends on the grade of shock absorbers used, and in particular on the chain length of the longest of the polymers forming the shock absorber. This quantity could easily be adapted by a person skilled in the art as a function of the glass transition temperature of the composition of the layer obtained.

Preferably and in order to improve the acoustic insulation of the panel according to the invention, the backing layer comprises a damping underlay intended to be in contact with the ground. A damping underlayer may in particular consist of a layer of polyurethane foam, a layer of polyolefin foam such as polyethylene, a layer of PVC foam, a layer of rubber foam or even a layer of nonwoven fabric. A damping underlay generally has a thickness of between 0.5 mm and 3 mm.

The fillers which can be used are in particular inorganic fillers, for example clays, silica, kaolin, talc, calcium carbonate.

Advantageously, the backing layer comprises between 0% and 90% by weight of the layer, advantageously between 10% and 60% by weight of the layer. The liquid plasticizers which can be used in each of the layers of the floor covering according to the invention are in particular the plasticizers such as Diisononyl Phthalate (DINP), Diisodecyl Phthalate (DIDP), 2-Ethylhexyl Diphenyl Phosphate (DPO), Dioctyl terephthalate (DOTP), 1,2-cyclohexane dicarboxylic acid diisononyl ester (DINCH), plasticizers of the benzoate family, plasticizers of the adipate family, plasticizers sold under the brand name PEVALEN ^® by the company Perstorp, l epoxidized soybean oil (HSE), octyl epoxy stearate (ESO), fully or partially biosourced plasticizers such as, for example, plasticizers from the polysorb® ID 37 range sold by Roquette Pharma, plasticizers from the range citrofol sold by the company Jungbunzlauer International AG, or the plasticizers from the soft-n-safe range sold by the company Danisco. Liquid plasticizers can be used alone or as a mixture.

The panels according to the invention are in the form of strips or slabs, each panel comprising an upper face intended to be in contact with the user, a lower face intended to be in contact with the ground and four edges. Preferably, the backing layer comprises male-female means for connecting or assembling several panels together.

The edges of the backing layer of the panels according to the invention can be machined to present male-female assembly means making it possible to connect several panels together. By male-female assembly means means in particular means comprising a groove machined on one of the edges of a panel and configured to be assembled with a tongue machined on the opposite edge of a neighboring panel. Male-female assembly means are assembled perpendicular to the ground and using machining profiles in the form of dovetails are also envisaged.

The panels according to the invention have a thickness generally between 2.5mm and 10mm, preferably between 3.5mm and 6mm. This thickness is measured between the upper face of the upper layer intended to be in contact with the user and the lower face of the backing layer intended to be in contact with the ground. The panels according to the invention have a width between 8 cm and 70 cm, preferably between 15 cm and 25 cm and a length between 50 cm and 240 cm, preferably between 100 and 150 cm.

Without limitation, the panels according to the invention may be grained and / or covered with a surface varnish, in particular in order to facilitate their maintenance and to protect them against wear.

Brief description of the figures

Other advantages and characteristics will emerge more clearly from the description which follows, given by way of nonlimiting example, with reference to the appended figures in which:

- Figure 1 schematically illustrates a cross-sectional view of a first embodiment of a multilayer panel for the production of a floor covering according to the invention;

- Figure 2 is a schematic representation similar to that of Figure 1, of a second embodiment of a multilayer panel for the production of a floor covering according to the invention;

- Figure 3 is a schematic representation similar to that of Figure 2, the backing layer comprising a rigid layer;

- Figure 4 is a schematic representation similar to that of Figure 2, the backing layer comprising a rigid layer complexed between two non-flexible layers;

Detailed Description of the Invention

With reference to FIGS. 1 to 4, the multilayer panel (1) for producing a floor covering according to the invention having sound insulation properties successively comprises:

- an upper layer (2) providing wear resistance and decor functions;

- a layer of nonwoven fabric (3); - a backing layer (4) comprising at least one non-flexible layer (4a) made from a thermoplastic material.

The layers (2, 3, 4) are linked together to form the multilayer panel

(1). The nonwoven fabric layer (3) comprises a so-called free thickness in which the textile fibers are free and not impregnated. In the free thickness, the textile fibers of the nonwoven fabric layer (3) are not impregnated by the upper layers

(2) and backwards (4).

Advantageously, the layer of nonwoven fabric (3) consists of the so-called free thickness bordered by at least one thickness called the bond with the upper layer (2) or the backing layer (4), the thickness of bond being less than or equal to the free thickness.

Preferably, the nonwoven fabric layer (3) consists of a so-called free thickness bordered by two thicknesses known as bonding with the upper layer (2) and the backing layer (4), the sum of the bonding thicknesses. is less than or equal to the free thickness.

Optionally, the backing layer (4) of the floor covering (1) according to the invention also comprises a damping underlay (7) intended to be in contact with the ground.

The nonwoven fabric layer (3) can in particular be bonded to the backing layer (4) and / or to the upper layer (2) without adding material, for example by thermo lamination. The bond thickness will then be a few tens of microns. It is for example possible to thermolier a backing layer (4) made from PVC and a non-woven fabric layer (3) made of polyester fibers. An example of a method of manufacturing the panel according to the invention (1) may include a step consisting of extruding the backing layer (4) and laminating the nonwoven fabric layer (3) directly at the exit of the extrading the backing layer (4) in order to bond them. The backing layer (4) is then hot enough to obtain a good bond between the two layers (3, 4 °). It is also possible to bond cold or hot the layer of nonwoven fabric (3) to the backing layer (4) and / or to the upper layer (2), for example using a hotmelt glue, the impregnation of the glue being limited to the fibers arranged on the surface of the layer of nonwoven fabric (3). It is also envisaged to bond the layer of nonwoven fabric (3) using a hot melt powder glue. This process is described in particular in patent application EP 1570 920 B1 of the applicant, in particular by dusting with polyester, co-polyester or EVA (ethylene vinyl acetate) glue. An alternative may be to bond the layer of nonwoven fabric (3) to the backing layer (4) and / or to the top layer (2) using an adhesive, for example a double-sided adhesive. or thanks to a hot-melt film.

Typical bond thicknesses will be between 25 pm and 300 pm, preferably between 50 pm and 130 pm in the case of bonding.

Alternatively, it is possible to bond the layer of nonwoven fabric (3) to the upper layer (2) or to the reverse layer (4) by using a layer of gelled plastisol which will impregnate the fibers of the layer of non-woven fabric (3) on the bonding thickness. A layer of gelled plastisol can in particular be a layer of PVC plastisol with a thickness of at least 50 μm and generally less than 1 mm, preferably between 50 μm and 0.5 mm.

Preferably and according to FIGS. 2 to 4, the upper layer and the reverse layer are thus bonded together by a first bonding layer (5a) impregnating less than 50% of the thickness of the non-textile layer. woven (3). The first bonding layer is for example a layer of gelled plastisol or else a hot-melt adhesive. Different types of plastisol can be used, in particular a PVC plastisol. A layer of gelled PVC plastisol with the advantage of being able to be deposited continuously on the upper layer (2) or on the nonwoven fabric layer (3) quickly, in particular on production lines having a running speed more than 10 meters per minute, this solution then being the most economical. After plastisol has been deposited on the upper layer (2) or on the nonwoven fabric layer, the layer to be bonded is deposited on the plastisol which is still liquid or pregelified, then the by-product formed by the upper (2), bonding and nonwoven fabric (3) layers pass through an oven or any other gelling means allowing the plastisol to be gelled completely.

The use of a hot-melt adhesive makes it possible to limit the thickness of impregnation of the nonwoven fabric by the bonding layer. Polyurethane hot melt glue, "hotmelt" in English, may in particular be used.

Still according to FIGS. 2 to 4, the backing layer (4) and the nonwoven fabric layer (3) can be bonded together by a second bonding layer (5b) impregnating less than 45% of the thickness. of the nonwoven fabric layer (3). The second bonding layer is for example an adhesive, for example a double-sided adhesive. A hot melt film, such as a copolyamide film may also be used. A hot-melt adhesive or film also limits the thickness of impregnation of the nonwoven fabric by the bonding layer (5a, 5b).

The layer of nonwoven fabric (3) has a thickness generally between 0.5 mm and 2 mm and a surface mass of between 80 g / m ² and 250 g / m ² , preferably between 120 g / m ² and 200 g / m ² . More preferably, the nonwoven fabric layer has a thickness of between 0.65 mm and 1.1 mm and a surface mass between 120 g / m ² and 200 g / m ² .

Advantageously, the nonwoven textile layer (3) comprises natural fibers such as cellulose fibers, cotton fibers, linen fibers, synthetic fibers, in particular polyester fibers, polyamide fibers, polyethylene terephthalate fibers, aramid fibers, Nomex, ethylene polynaphthalate, polypropylene or even synthetic mineral fibers such as glass fibers or basalt fibers.

The upper layer (2) is for example obtained from tinted granules, for example made from PVC and then pressed or else by coating and gelling of a tinted plastisol, by extrusion in a flat die or by calendering.

According to Figures 3 and 4, the upper layer (2) may also include a transparent wear layer (2a) and a decor layer (2b). According to the invention, the layer wear (2a) is sufficiently transparent to visible light so that a decoration printed on the back of the wear layer or on a printed film placed directly in contact with the back of the wear layer can be visible through the transparent wear layer (2a). The decorative layer (2b) can therefore consist of a layer printed on the reverse side of the wear layer (2a), a printed film or even a layer printed on the face of the layer directly facing the back of the layer d 'wear (2a). A decorative layer (2b) can be printed by any known technique, in particular by gravure printing or by inkjet printing.

The transparent wear layer (2a) can for example be made from unloaded plasticized PVC, in particular gelled PVC plastisol, polyurethane or even polyolefin. The thickness of the transparent wear layer is generally between 0.1 mm and 1 mm, preferably between 0.20 and 0.70 mm. This thickness is determined according to the resistance to traffic sought. The transparent wear layer (2a) is generally obtained by coating with plastisol, by extrusion in a flat die or by calendering.

The transparent wear layer (2a) can be varnished to improve resistance to staining and scratching.

According to FIGS. 3 and 4, the upper layer may also include a layer of gelled plastisol (2c) comprising a reinforcing reinforcement (2d) embedded in the thickness of the layer of gelled plastisol (2c). A reinforcing reinforcement (2d) can for example be a reinforcing grid or a layer of nonwoven fabric such as a glass or polyester veil. Materials in the form of fibers which can be used to obtain a reinforcing reinforcement (2d) are in particular Polyethylene, Polyethylene Terephtlate (PET), glass fibers, polyester fibers, aramid, carbon fibers, nitrile fibers, ethylene vinyl acetate (EVA), high density polyethylene (HDPE), low density polyethylene (LDPE), polyvinyl chloride (PVC).

Advantageously, the reinforcing reinforcement (2d) is a layer of nonwoven fabric of thickness less than 1 mm, preferably a veil of glass fibers or polyester. More preferably, the reinforcing reinforcement (2d) is a layer of nonwoven fabric with a thickness of less than 0.6 mm.

A gelled layer (2c) can be obtained by coating and then gelling a plastisol on one or each side of a reinforcing reinforcement (2d) so as to drown it in the gelled layer. In general and in a manner well known to those skilled in the art, a gelled layer (2c) comprising a reinforcing reinforcement (2d) can be obtained from a composition comprising a thermoplastic polymer, for example PVC, a plasticizer, fillers and possibly stabilizers, lubricants, additives and a reinforcing reinforcement whose thickness is completely impregnated in the thickness of the reinforced layer.

Alternatively, a decorative layer (2b) can be printed on the upper face of the gelled layer (2c). In order to obtain a good rendering of the decor layer, it may be envisaged to deposit a layer of smoothing plastisol on the gelled layer (2c) and to print the decor layer on the layer of gelled smoothing plastisol (not shown). . Advantageously, it is also possible to obtain a graining of the upper layer by printing a decorative layer on a smoothing layer comprising a blowing agent. Thus, by printing a decorative layer according to a first pattern with an ink without expansion inhibitor and by printing a second decorative layer on the reinforced layer with an ink containing an expansion inhibitor, the expansion of the smoothing layer will be partially inhibited.

A process for manufacturing the upper layer (2) can therefore comprise the following steps which consist in:

• coat and gel a first layer of plastisol (2c) on a reinforcing reinforcement (2d) so as to completely impregnate it;

• optionally, coat and gel a second layer of liquid smoothing plastisol on the face of the layer of plastisol (2c) intended to be printed;

• print a pattern on the plastisol layer (2c) or if necessary on the gelled smoothing layer so as to obtain a decorative layer (2b);

• coat and gel or complex a wear layer (2a) on the decor layer

(2b); Alternatively, a process for manufacturing the upper layer (2) can therefore comprise the following steps which consist in:

• coat and gel a first layer of plastisol on a first reinforcement frame so as to completely impregnate it;

• coat and pre-gel a second layer of liquid plastisol comprising a blowing agent on the face of the first layer of reinforced plastisol intended to be printed;

• print a pattern on the second layer of pre-gelled plastisol with an ink comprising expansion-inhibiting agents so as to obtain a decorative layer;

• coat a layer of wear on the decor layer;

• gel the second layer of plastisol and the wear layer so as to obtain a grained upper layer.

According to Figures 2 to 4, the backing layer (4) may comprise assembly or male-female connection means (6a, 6b). For this, the edges of the backing layer (4) of the panels according to the invention can be machined to present male-female assembly means (6a, 6b) making it possible to connect several panels together. Generally, the male-female assembly means comprise a first machining profile machined on one edge of a panel and configured to be assembled with a second machining profile machined on an opposite edge of a neighboring panel. . The panels thus obtained can thus have one or more generally two pairs of machining profile, each pair comprising a first and a second machining profile on two opposite edges of a panel. The first and second machining profiles of each pair are not necessarily similar, in particular depending on the length of the edge considered and the desired direction of assembly. The assembly of the panels can in particular be carried out in a direction perpendicular to the ground in the case of so-called “vertical” assembly means, in a direction parallel to the ground in the case of so-called “horizontal” assembly means, or else in more complex directions, for example by rotation and / or translation of a male assembly means in a female assembly means. Such assembly means are notably described in the documents GB 2 256 023, EP 1 026 341, WO 2012/004701 or also WO 2016/030627. Preferably, the assembly means once assembled block the movement of two panels both in a vertical direction, that is to say perpendicular to the ground, and in a direction which is perpendicular to the edge of the panel on which the assembly means considered is machined and parallel to the plane formed by the ground. The assembly means and their machining profiles can in particular be obtained by in-line machining, by injection molding of the panel or also by cutting, in particular with a cookie cutter.

According to Figures 1, 2 and 4, the backing layer (4) comprises at least one non-flexible layer (4a) made from a thermoplastic material, for example from plasticized PVC. A non-flexible layer (4a) has a bending stiffness greater than the maximum bending stiffness which makes it possible to satisfy the International Standard ISO 24344: 2008.

According to an alternative embodiment illustrated in Figures 3 and 4, the backing layer (4) may include a rigid layer (4b) in order to improve the dimensional stability of the panel.

According to an alternative embodiment illustrated in Figure 4, the backing layer (4) comprises a rigid layer (4b) complexed between two non-flexible layers (4a, 4c). This alternative embodiment makes it possible to obtain a backing layer (4) whose dimensions are stable, whose acoustic properties are improved and whose weight is limited. This embodiment of the backing layer (4) in combination with a layer of nonwoven fabric (3) according to the invention makes it possible to obtain a panel having acoustic properties and a reduced weight.

Optionally, the backing layer (4) of the floor covering (1) according to the invention also comprises a damping underlay (7) intended to be in contact with the floor. A damping underlayer (7) may in particular consist of a layer of polyurethane foam, a layer of rubber foam or even a layer of nonwoven fabric. A damping underlay (7) generally has a thickness of between 0.5 mm and 3 mm. The advantage of such a damping underlay is to provide the panel according to the invention with good acoustic insulation performance. A damping under layer (7) consisting of a layer of nonwoven fabric with a thickness of between 0.5 mm and 3 mm makes it possible to guarantee a good compromise between the performance of sound insulation, and the resistance of male means. assembly women (6a, 6b) for traffic and this for most of the machining profiles of these assembly means (6a, 6b). It may indeed be that male-female means assemblies (6a, 6b) used in combination with a damping underlay (7) of nonwoven fabric with a thickness greater than 3 mm may disassemble or break under the effect traffic, the thickness of the nonwoven fabric making the entire panel too flexible and increasing the stresses on the assembly means (6a, 6b). On the other hand, a thickness of damping underlay (7) in non-woven fabric of less than 0.5 mm can limit the acoustic insulation provided by the panel.

Advantageously, the damping sub-layer (7) has a thickness of between 1 mm and 2.5 mm. This thickness range makes it possible to achieve a better compromise between the performance of acoustic insulation and the resistance of the assembly means to traffic if the backing layer includes it, in particular an acoustic attenuation according to the higher ISO 10140-3 standard. at 15dB.

Preferably, the damping sub-layer in nonwoven fabric comprises a compressive strength greater than or equal to 20Kpa, more preferably greater than or equal to OKPa. Compressive strength is an important property of the damping underlayment, which is decisive for maintaining good sound insulation over time provided by the underlayment while contributing to the resistance of the assembly means to traffic. The resistance to compression is measured according to standard CEN / TS 16354: 20l2 which itself refers to standard NF EN 826 of May 2013. This method corresponds to a measurement of compression for a deformation of 0.5mm.

A shock-absorbing non-woven textile underlay comprising a compressive strength greater than or equal to 20Kpa makes it possible to provide good acoustic insulation while contributing to the resistance of the assembly means to traffic. However, when the coating is subject to heavy traffic, especially in reception halls or corridors, it is preferable that the damping underlay in non-woven fabric include a compressive strength greater than or equal to OKOKpa in order to maintain its acoustic properties over time.

More preferably, the non-woven textile damping underlay (7) comprises a compressive strength greater than or equal to 400KPa. This achieves a better result both for the preservation of the sound insulation performance over time and the resistance of the assembly means to traffic. It is in fact observed that a compressive strength greater than or equal to 400KPa allows the underlay to maintain its thickness despite repeated traffic of heavy loads and created less stress in terms of assembly means. It is for example observed that the assembly means having a so-called “vertical” assembly direction, namely perpendicular to the plane of the ground covered by the floor covering panel, present less risk of unclipping if they are used in combination with a non-woven fabric underlay comprising a compressive strength greater than or equal to 400KPa.

Advantageously, the damping underlayer (7) of nonwoven fabric comprises natural fibers such as cellulose fibers, cotton, linen, synthetic fibers, in particular polyester fibers, polyamide, polyethylene terephthalate, d aramid, Nomex, ethylene polynaphthalate, polypropylene or even synthetic mineral fibers such as glass fibers or basalt fibers.

Advantageously, the damping underlayer (7) of nonwoven fabric is produced from a mixture of natural fibers and synthetic fibers and / or synthetic mineral fibers. In a nonlimiting manner, the damping sub-layer of nonwoven fabric has a surface mass greater than 100 g / m ² and less than 600 g / m ² . In a nonlimiting manner, the shock-absorbing sub-layer (7) of nonwoven fabric has a ratio corresponding to its surface mass over its thickness greater than 200 g / m ² per millimeter of thickness.

The damping underlayer (7) can be bonded to the non-flexible layer (4a) or to the rigid layer (4b) by any known means, in particular by thermo lamination, cold bonding, hot bonding, extrusion of the layer (4a, 4b) on the damping underlay (7), by powdering hot-melt adhesive or by using a double-sided adhesive or a hot-melt film. Alternatively, it is possible to bond the damping underlayer (7) to the non-flexible (4a) or rigid (4b) layer, using a layer of gelled plastisol.

Example of realization:

In order to carry out acoustic and mechanical tests, nine examples of panels (1) according to FIG. 3 are prepared.

These panels (1) consist successively:

- A layer of polyurethane varnish (not shown) with a thickness of less than 20pm;

- A wear layer (2a) obtained from an unloaded gelled PVC plastisol;

- A decorative layer (2b) printed by gravure printing on the face of the layer of gelled plastisol (2c) with regard to the wear layer (2a) of approximately 0.15 mm;

- A veil of glass fibers (2d) with a surface mass of 55 g / m ² embedded in a layer of gelled plastisol (2c) with a thickness of 0.62 mm;

- A layer of polyester nonwoven fabric (3);

- A backing layer (4) consisting of a rigid layer (4b) 4.5 mm thick based on PVC and optionally a shock absorbing undercoat (7);

The layers being linked together to form the multilayer panel (1).

The composition of the rigid layer (4b) is detailed in Table 1 below (the designation "% (w / w)" corresponds to the percentage by mass of the constituent relative to the total mass of the composition).

Table 1

Process aids can in particular include optical brighteners, internal or external lubricants, pigments, titanium dioxide, ...

The rigid layer (4b) obtained has a modulus value for 1% elongation of 52.3 daN / cm and a flexibility of 105 N for 20mm of deflection.

Male-female means of connection or assembly (6a, 6b) for assembling several panels are machined on all four sides in the rigid layer (4b). These means make it possible to assemble the blades in a direction perpendicular to the ground and are described in patent application WO 2016/030627 of the applicant, the content of which is incorporated in the present application.

The non-woven textile layer (3) and the upper layer (2) are bonded together by impregnating the layer of gelled plastisol (2d). The thickness of the first tie layer (5a) measured is about 50 µm. In the bonding thickness, the fibers of the non-woven textile layer (3) are completely impregnated by the gel layer (2d). The rigid layer (4b) and the nonwoven fabric layer (3) are bonded by a polyurethane hotmelt adhesive. The thickness of the second bonding layer (5b) is about 50 µm.

The thicknesses and characteristics of each of the assembled panels are described in Tables 2 and 3 below.

Table 2

Table 3 Where appropriate, the shock absorbing sub-layer (7) is bonded to the rigid layer (4b) using a double-sided adhesive coated on both sides with acrylic adhesive.

The different examples of panel (1) according to the invention are compared with existing floor coverings. These reference panels are made up successively:

- A transparent wear layer

- A decorative layer, namely a printed PVC film

- A layer of back

- Optionally a cushioning underlay

The different layers being linked together to form the reference floor covering. The characteristics of the references are detailed in Table 4.

Table 4

The composition of the rigid back layers of references 1 and 2 is identical to the composition of the rigid layer (4b) detailed in Table 1.

The non-flexible backing layer of reference 3 comprises approximately 33% of PVC, 10% of plasticizers (DINP), 4% of additives (process aids, stabilizers, pigments), 3% of PVC particles mixed with glass fibers and 50% fillers. The non-flexible layer obtained has a modulus value for 1% elongation of 21.4 daN / cm and a flexibility of 27.3 N for 20mm of deflection. The acoustic properties of the references and examples measured in dB are presented in Table 5.

Table 5

The results obtained show that the panels (1) according to the invention all reach class B according to the NF S31 074 standard for classification of walking sound (table 6). The benchmarks compared are all less efficient in terms of sound insulation and / or sound when walking. The insulation results also show ALw values always greater than 12db and up to 2ldb for the panels according to the invention.

Table 6 In order to compare the shock absorption capacities of the panels according to the invention, references 1 and 3 are also compared to Example 1. The absorption test of shock (standard EN 14808) is representative of the absorption of energy during a race for an athlete of 1.80m / 80kg running one lOOm in lOs.

The results presented in Table 7 show a marked improvement in shock absorption thanks to the panel according to the invention, the values being greater than 3%. Thus the panel makes it possible to limit the transmission of noise in the room where it is placed and also to improve the walking comfort of the flooring obtained.

Claims

1. Multilayer panel (1) for producing a floor covering having sound insulation properties successively comprising an upper layer (2) providing wear resistance and decor functions, a non-textile layer woven fabric (3) comprising textile fibers and a backing layer (4) comprising at least one non-flexible layer (4a) produced from a thermoplastic material, said layers (2, 3, 4) being bonded together to forming the multilayer panel (1), characterized in that the nonwoven fabric layer (3) comprises at least one so-called free thickness in which the textile fibers are free and not impregnated.

2. Multilayer panel (1) according to claim 1, characterized in that the non-woven textile layer (3) consists of the so-called free thickness bordered by at least one so-called bonding thickness of the non-woven textile layer woven (3) with the upper layer (2) or the reverse layer (4), the bonding thickness being less than or equal to the free thickness.

3. Multilayer panel (1) according to claim 1, characterized in that the non-woven textile layer (3) consists of the so-called free thickness bordered by two thicknesses called connection with the upper layer (2) and the reverse layer (4), the sum of the bond thicknesses is less than or equal to the free thickness.

4. Multilayer panel (1) according to claim 1, characterized in that the backing layer (4) comprises at least one rigid layer (4b).

5. Multilayer panel (1) according to claim 1, characterized in that the upper layer (2) and the nonwoven fabric layer (3) are bonded together by a first bonding layer (5a) impregnating less than 50 % of the thickness of the nonwoven fabric layer (3).

6. Multilayer panel (1) according to claim 5, characterized in that the first bonding layer (5a) is a layer of gelled plastisol.

7. Multilayer panel (1) according to claim 5, characterized in that the first bonding layer (5a) is a hot-melt adhesive.

8. Multilayer panel (1) according to claim 1, characterized in that the backing layer (4) and the nonwoven fabric layer (3) are linked together by a second bonding layer (5b) impregnating less 45% of the thickness of the nonwoven fabric layer (3)

9. Multilayer panel (1) according to claim 8, characterized in that the second bonding layer (5b) is an adhesive.

10. Multilayer panel (1) according to claim 1, characterized in that the non-flexible layer (4a) is made from PVC.

11. Multilayer panel (1) according to claim 1, characterized in that the upper layer (2) comprises a reinforcing reinforcement (2d) embedded in the thickness of the upper layer (2).

12. Multilayer panel (1) according to claim 1, characterized in that the backing layer (4) comprises male-female means of connection or assembly (6a, 6b) of several panels together.

13. Multilayer panel (1) according to claim 1, characterized in that the backing layer (4) comprises a damping underlay (7) intended to be in contact with the ground.