METHOD FOR MANUFACTURING AN UPHOLSTERY ELEMENT FOR A VEHICLE SEAT

Description

[0001] The present invention relates to a method for manufacturing a padding element for a vehicle seat, comprising a foam block, including a first and a second substantially opposite face; and a reinforcing layer, attached to the first face of the foam block.

[0002] A similar padding element is notably known from document FR3092044 in the name of the Applicant. Document US 2018 / 297490 A1 discloses a manufacturing process for a vehicle seat padding element and a vehicle seat padding element.

[0003] The reinforcing layer of a padding element, as described above, is specifically designed to minimize abrasion on the non-visible side of the padding element. However, the presence of such a layer complicates the recycling of the padding element when the foam block and the reinforcing layer are of different chemical compositions.

[0004] The aim of the invention is to provide a padding element that combines good strength with a configuration that facilitates recycling.

[0005] To this end, the invention relates to a method for manufacturing a padding element of the aforementioned type, comprising the following steps: supply of a mold comprising a mold base and a lid, capable of being removably assembled to form an enclosure; the mold base and the lid being separated, a first fluid composition, precursor of the foam block, being deposited in the mold base, said first fluid composition comprising an expanding agent; and a layer of a second fluid composition, precursor of the reinforcement layer, being deposited in the lid; expansion of the first fluid composition; and assembly of the mold base and the lid during said expansion, so as to bond the foam block and the reinforcement layer.

[0006] According to other advantageous aspects of the invention, the method comprises one or more of the following features, taken individually or in all technically possible combinations: Each of the first and second compositions comprises polyurethane; the first fluid composition is deposited by pouring into the bottom of the mold; the second fluid composition is deposited by spraying onto the lid of said second fluid composition; the lid comprises: a molding surface, configured to form the enclosure; and a continuous or discontinuous rib, forming a periphery of said molding surface; the spraying onto the lid of the second fluid composition is carried out on the molding surface and on the rib; the process includes the application of a release agent to the lid and / or the bottom of the mold, before the deposition of the first and second fluid compositions.

[0007] The invention further relates to a padding element produced by a process as described above.

[0008] According to other advantageous aspects of the invention, the padding element comprises one or more of the following characteristics, taken individually or in all technically possible combinations: The foam block comprises at least 50% by mass of polyurethane relative to the total mass of said block; and the reinforcement layer comprises at least 50% by mass of polyurethane relative to the total mass of said layer; the foam block comprises 100% by mass of polyurethane relative to the total mass of said block; and the reinforcement layer comprises 100% by mass of polyurethane relative to the total mass of said layer; the foam block has a first thickness of between 5 mm and 200 mm between the first and second faces; and the reinforcement layer has a second thickness of between 30 µm and 5 mm.

[0009] The invention further relates to a vehicle seat, comprising a padding element as described above.

[0010] The invention will become clearer upon reading the following description, given solely by way of non-limiting example, and made with reference to the drawings in which: there figure 1 is a detailed, cross-sectional view of a vehicle seat according to an embodiment of the invention, comprising a padding element according to an embodiment of the invention; and the figure 2 is a schematic representation of a step in a manufacturing process for the padding element of the figure 1 , according to one embodiment of the invention.

[0011] There figure 1 This schematically represents a detailed cross-sectional view of a vehicle seat 10 according to an embodiment of the invention. The seat 10 is intended to be mounted in a land, air, or sea vehicle, for example, in a car, bus, truck, train, airplane, motorcycle, boat, agricultural vehicle, etc. The seat 10 includes, in particular, a padding element 12 and a cover 14.

[0012] More specifically, the padding element 12 and the covering 14 of the figure 1 are part of a seat base 10, or of a backrest of said seat 10.

[0013] The padding element 12 includes a block 16 and a layer 18 of reinforcement.

[0014] Block 16 is formed from an elastically deformable foam, said foam being composed of a first plastic material. By "foam," it is understood that block 16 has a flexible alveolar structure with open cells (not shown).

[0015] Preferably, the foam forming block 16 has a density between 30 kg / m³ and 100 kg / m³. Preferably, the foam forming block 16 has a pressure-strain characteristic between 3 kPa and 30 kPa according to DIN EN ISO 3386.

[0016] Preferably, the first plastic material comprises polyurethane. More preferably, the first plastic material comprises at least 50% by mass of polyurethane relative to the total mass of said first plastic material, and even more preferably 100% by mass of polyurethane. For example, when the first plastic material comprises less than 100% by mass of polyurethane, the first plastic material comprises polyurethane as well as a bio-based or recycled material and / or a material derived from tires and / or polyethylene terephthalate and / or an inorganic filler.

[0017] The foam block 16 comprises a first 20 and a second 22 faces, substantially opposite. The block 16 has a first thickness 24 between the first 20 and second 22 faces. Preferably, the first thickness 24 is between 5 mm and 200 mm.

[0018] The reinforcement layer 18 is integral with the first face 20 of the foam block 16.

[0019] The reinforcing layer 18 is formed of a second plastic material. More preferably, the second plastic material is non-expanded, that is to say, said second material does not contain closed cells.

[0020] Preferably, the second plastic material comprises polyurethane. More preferably, the second plastic material comprises at least 50% by mass of polyurethane relative to the total mass of said second plastic material, preferably 100% by mass of polyurethane. In a specific example, the second plastic material comprises polyurethane as well as a bio-based or recycled material and / or a material derived from tires and / or polyethylene terephthalate and / or an inorganic filler.

[0021] Preferably, the second plastic material has a density between 200 Kg / m 3< and 1 200 Kg / m 3< .

[0022] The reinforcement layer 18 has a second thickness 26, preferably between 30 µm and 5 mm, even more preferably between 250 µm and 2 mm.

[0023] The seat cover 14 of the seat 10 is assembled to the second face 22 of the foam block 16. More specifically, the reinforcement layer 18 is intended to form the non-visible face of the padding element 12 in the seat 10.

[0024] Preferably, the coating 14 forms a flexible layer. The coating 14 is, for example, made of a textile material, natural or synthetic, or of natural or synthetic leather.

[0025] There figure 2 shows a 30-unit installation for manufacturing the 12-unit padding described above.

[0026] The installation 30 includes in particular a mold 32 and at least one application device 34, 36.

[0027] The mold 32 comprises: a mold base 40, having a first surface 42; and a lid 44, having a second surface 46. The first surface 42 has in particular a shape complementary to the second face 22 of the foam block 16.

[0028] The base 40 of the mold and the lid 44 are able to be assembled in a removable manner, to form an enclosure 48 defined by the first 42 and second 46 surfaces.

[0029] Preferably, the lid 44 has a rib (not shown), continuous or not, forming a periphery of the second surface 46. Said rib is able to fit into an edge of the first surface 42 of the bottom 40 of the mold, when assembling said bottom 40 and the lid 44.

[0030] Preferably, the mold 32 also includes vents (not shown) allowing degassing of the enclosure 48.

[0031] In the embodiment shown, the installation 30 comprises a first 34 and a second 36 application devices.

[0032] The first application device 34 is suitable for depositing a first fluid composition 50 in the bottom 40 of the mold, in contact with the first surface 42. The first fluid composition 50 is a precursor of the foam block 16 and includes an expanding agent.

[0033] Preferably, the first application device 34 is adapted for a pouring deposition of the first fluid composition 50 into the bottom 40 of the mold.

[0034] The second application device 36 is capable of depositing a second fluid composition 52 in the lid 44, in contact with the second surface 46.

[0035] The second fluid composition 52 is a precursor to the reinforcing layer 18. Preferably, the second fluid composition 52 comprises a blowing agent, for example, water. Advantageously, the second fluid composition 52 comprises a chain extender, for example, butanediol, and / or a crosslinking agent, for example, glycerol, and / or a reinforcing fiber, for example, glass fiber, natural fiber, and / or synthetic fiber, and / or graphene, and / or graphite, and / or carbon nanotube. The use of a chain extender, a crosslinking agent, a reinforcing fiber, graphene, graphite, and / or carbon nanotube improves the mechanical strength of the reinforcing layer 18.

[0036] Preferably, the second application device 36 is adapted for spraying the second fluid composition 52 into the lid 44.

[0037] A method for manufacturing the above padding element 12, using the installation 30 described above, will now be described.

[0038] Optionally, a release agent is first applied to the first 42 and second 46 surfaces of the mold 32. Such a release agent is, for example, in the form of a liquid solution, sprayed onto the relevant surfaces. For example, the release agent may contain an incorporated noise-reducing compound. Alternatively, a noise-reducing compound may be sprayed over the release agent after the release agent has been applied.

[0039] Next, the second fluid composition 52 is sprayed onto the second surface 46 of the cover 44, using the second application device 36. Preferably, said second fluid composition is also sprayed onto the rib forming the periphery of the second surface 46, and optionally around said rib.

[0040] Next, using the first application device 34, the first fluid composition 50 is poured into the bottom 40 of the mold, in contact with the first surface 42.

[0041] Next, once the second fluid composition 52 has at least partially hardened, the mold 32 is closed by assembling the mold base 40 and the lid 44. The enclosure 48 is thus formed. The first fluid composition 50 expands, filling said enclosure 48 to form the foam block 16.

[0042] During the expansion of the first fluid composition 50, the foam thus formed adheres to the hardening reinforcement layer 18, ensuring the bonding of said layer 18 with the foam block 16.

[0043] Preferably, the mold 32 is closed while the first fluid composition 50 is already partially expanded. This facilitates the degassing of the mold 32.

[0044] After hardening of the first fluid composition 50, leading to the formation of the foam block 16, the resulting padding element 12 is demolded.

[0045] During demolding, the presence of the rib on the lid 44 facilitates the separation of the reinforcement layer 18 from excess material resulting from the spraying of the second fluid composition 52 around the second surface 46 of the lid.

[0046] The seat 10 is then obtained by assembling the covering 14 with said padding element 12, in particular with the second face 22 of the block 16.

[0047] In cases where both the foam block 16 and the reinforcement layer 18 have a high polyurethane content, recycling the padding element 12 is easier compared to a block 16 and layer 18 made of separate materials. Furthermore, such a padding element 12 exhibits good abrasion resistance at the reinforcement layer 18.

Claims

1. A method for manufacturing a cushioning element (12) for a vehicle seat (10), said cushioning element comprising: a foam block (16) comprising a first (20) and a second (22) face that are substantially opposite; and a reinforcing layer (18) secured to the first face (20) of the foam block; the method comprising the following steps: - providing a mold (32) comprising a mold bottom (40) and a cover (44), capable of being removably assembled to form an enclosure (48); - with the mold bottom and cover separated, depositing into the mold bottom (40) a first fluid composition (50), which is a precursor to the foam block (16), said first fluid composition comprising a blowing agent; and depositing into the cover a layer of a second fluid composition (52), which is a precursor to the reinforcing layer (18); - expansion of the first fluid composition; and joining the mold bottom and the cover during said expansion, so as to secure the foam block and the reinforcing layer together.

2. The manufacturing method according to claim 1, wherein each of the first (50) and second (52) compositions comprises polyurethane.

3. The manufacturing method according to claim 1 or 2, wherein the first fluid composition (50) is deposited by pouring it into the mold bottom (40).

4. The manufacturing method according to any of the preceding claims, wherein the layer of the second fluid composition (52) is deposited by spraying said second fluid composition onto the cover (44).

5. The manufacturing method according to any of the preceding claims, wherein the cover (44) comprises: a molding surface (46), configured to form the enclosure (48); and a rib, which may or may not be continuous, forming a periphery of said molding surface (46).

6. The manufacturing method according to claim 5 in combination with claim 4, wherein the spraying of the second fluid composition (52) onto the cover (44) is carried out on the molding surface (46) and on the rib.

7. The manufacturing method according to any of the preceding claims, comprising applying a release agent to the cover (44) and / or the mold bottom (40) prior to depositing the first and second fluid compositions.

8. A cushioning element (12) for a vehicle seat (10), produced by a method according to any of the preceding claims.

9. The cushioning element according to claim 8 in combination with claim 2, wherein the foam block (16) comprises at least 50% by weight of polyurethane with respect to the total weight of said block; and the reinforcing layer (18) comprises at least 50% by weight of polyurethane with respect to the total weight of said layer.

10. The cushioning element according to claim 9, wherein the foam block (16) comprises 100% by weight of polyurethane with respect to the total weight of said block; and the reinforcing layer (18) comprises 100% by weight of polyurethane with respect to the total weight of said layer.

11. The cushioning element according to any of claims 8 to 10, wherein the foam block (16) has a first thickness (24) of between 5 mm and 200 mm between the first (20) and second (22) faces; and the reinforcing layer (18) has a second thickness (26) of between 30 µm and 5 mm.

12. A vehicle seat (10) comprising a cushioning element (12) according to any of claims 8 to 11.