Seat padding

Abstract

Seat padding (12) comprising: - a 3D entanglement (10) of irregularly arranged fibers (5) forming loops welded together between the fibers (5), the fibers having a material comprising at least one thermoplastic polymer, - a flat area (14) formed on a predetermined area (18) of the 3D entanglement (10) by ultrasonic welding of said fibers (5) in said predetermined area (18), the flat area (14) comprising a continuous surface of said fiber material (5). Abstract figure: Figure 2

Description

Title of the invention: Seat padding technical field

[0001] This disclosure relates to seat padding, a vehicle seat component comprising such seat padding, a vehicle seat comprising such a vehicle seat component, and a method for manufacturing such seat padding. Previous technique

[0002] This disclosure relates to the field of automobile seats, which generally comprise a metallic structure with a lower seat frame and a seat back frame. The structure is conventionally produced using stamping techniques. The seats further comprise padding, including a lower seat padding layer and a seat back padding layer that provide softness to the lower seat and seat back, and contribute to seat comfort. This padding is generally covered by protective coverings.

[0003] The lower and backrest seat padding is conventionally made of urethane polymer foam and is molded. The polyurethane padding is conventionally covered with a protective layer. Polyurethane foam padding is satisfactory but can retain moisture in humid conditions. This can cause discomfort for a vehicle seat occupant if one of the seat components includes such padding.

[0004] Furthermore, polyurethane foam is conventionally produced by mixing, among other things, polyols with isocyanates. The chemical reaction used emits CO2 to form a foam, and the emitted CO2 contributes to global warming.

[0005] Furthermore, polyurethane foam is not recyclable. It therefore seems desirable to limit the use of polyurethane in the padding of vehicle seat components.

[0006] SUMMARY

[0007] This disclosure improves the situation.

[0008] According to one aspect, a seat padding is proposed comprising: a. a 3D entanglement of irregularly arranged fibers, forming loops welded together between the fibers, the fibers having a material comprising at least one thermoplastic polymer, b. a flat area formed on a predetermined area of ​​the 3D entanglement by ultrasonic welding of said fibers in said predetermined area, the flat area comprising a continuous surface of said fiber material.

[0009] The presence of a flat area on a specific area of ​​the seat padding made with the material forming the fibers provides a useful area for marking or for sticking a label.

[0010] By "plane area" is meant an area having a flat surface.

[0011] By "continuous surface", it is understood that the surface is made of a material continuous, unlike the rest of the seat padding, which consists of said 3D entanglement of fibers forming loops welded together between the fibers. Said material is the material comprising said at least one thermoplastic polymer of the fibers, since the flat area is obtained by ultrasonic welding of the fibers in the specific area. The flat area is therefore formed from the fiber material by ultrasonic welding of a portion thereof in the predetermined area.

[0012] The seat padding is made of a material other than polyurethane foam. This padding material is advantageously a recyclable polymer material, and its production generates fewer CO2 emissions than the production of polyurethane foam. Furthermore, padding made with this material can be significantly lighter than similar padding made of polyurethane foam. In addition, the padding material can be more breathable, allowing air and any moisture to pass more easily through the padding.

[0013] It should be noted that in padding made of polyurethane foam, a traceability reference is easily marked on the padding itself. The mold bears such a mark with the reference, so that when the padding is formed, the mark is also formed on the padding. It is also possible to print a reference on the surface of polyurethane foam with an inkjet printer, as the foam's density is sufficient to obtain a continuous, printable surface. This cannot be achieved for seat padding with a 3D entanglement of irregularly arranged fibers, forming loops welded together between the fibers, because the surface of such seat padding is neither continuous nor printable.

[0014] The present disclosure makes it possible to obtain a seat padding having a 3D entanglement of irregularly arranged fused fibers, forming welded loops between the fibers and a specific flat area that can be used for marking, for example.

[0015] The following features may optionally be implemented, separately or in combination with each other:

[0016] The flat area may include, for example, marked symbols. The marked symbols may be engraved on the flat area. Alternatively, or in addition, the marked symbols may be printed on the flat area. Alternatively, or in addition, the marked symbols may be produced on a label that is affixed to the flat area. Such a label may include a polymer, such as polypropylene, polyester, or polyamide, for example. The adhesive may include an adhesive material.

[0017] The presence of marked symbols can be useful to provide on the seat padding a specific reference linked to the specific seat padding for traceability purposes for example.

[0018] The flat area may have a rectangular shape, with a length between 1 cm and 10 cm, preferably between 4 cm and 5 cm, and a width between 0.2 mm and 1.2 mm, preferably between 0.3 mm and 0.8 mm. The flat area may have another shape, such as an oblong shape or a diamond shape.

[0019] The predetermined zone may have a higher density than the rest of the 3D entanglement obtained by thermoforming the fibers in this predetermined zone. Indeed, thermoforming can locally densify the 3D fiber entanglement. The seat padding in the predetermined zone may have a predetermined, controlled thickness obtained by thermoforming. Indeed, thermoforming allows control of the padding thickness and the fiber density in this predetermined zone. The thermoforming may have been carried out before or simultaneously with the ultrasonic welding.

[0020] The predetermined area may be located on a rear face of the seat padding. Alternatively, the predetermined area may be located on a side of the seat padding. Advantageously, the predetermined area is located on a surface of the seat padding, preferably in an area that will not be in direct or indirect contact with any part of a user who is seated on a seat comprising the seat padding.

[0021] The seat padding may include a groove formed in a front face of the seat padding. In such a case, the predetermined area may be located in the bottom of said groove. Such a groove may be used, for example, to attach a seat cover or trim.

[0022] At least one thermoplastic polymer may be chosen from the group consisting of a polyester, such as PET (polyethylene terephthalate), PTT (polytrimethylene terephthalate) or PBT (polybutylene terephthalate). The material constituting the The fibers can be recycled. Therefore, seat padding containing such fibers can be recycled.

[0023] The composition of the fiber material preferably comprises at least 95% by weight of PET (polyethylene terephthalate). For example, the composition of the fibers, or even the seat padding, comprises: - 95% to 99% by weight of a first polymer from the polyester family such as PET, - 1% to 5% by weight of a second polymer from the polyester family, such as PTT (polytrimethylene terephthalate) or PBT (polybutylene terephthalate). The sum of PET and PTT (or PBT) can be 100% by weight of the fibers, or even of the seat padding.

[0024] The fibers of the 3D entanglement of the seat padding can have a diameter between 0.2 mm and 2 mm, preferably between 0.3 mm and 1.5 mm.

[0025] The 3D entanglement of the seat padding has, for example, an apparent density of between 20 kg / m3 and 70 kg / m3, or even between 35 kg / m3 and 55 kg / m3.

[0026] In another aspect, in combination with any element or part of the above, a vehicle seat element is proposed comprising seat padding as shown above.

[0027] The vehicle seat element may consist of at least one of the following: - a file, - a base; - an armrest; - a headrest; - a device for adjusting the upper backrest; and - a device for adjusting the seat length.

[0028] The vehicle seat element may in particular be a seat consisting of a backrest and a seat, also called a cushion.

[0029] According to an example, the thickness of the seat padding, when the seat element is a backrest, can be between 30 mm and 60 mm and / or the thickness of the padding, when the seat element is a seat, can be between 40 mm and 120 mm.

[0030] In another aspect, in combination with any element or part of the above, a vehicle seat is proposed comprising a vehicle seat element as shown above.

[0031] In another aspect, in combination with any element or part of the foregoing, a method for manufacturing seat padding, such as the seat padding shown above, is proposed, the method comprising: a. the formation by extrusion of a 3D tangle with fibers being arranged irregularly, forming loops welded together in said 3D tangle, the fibers having a material comprising at least one thermoplastic material, b. the ultrasonic welding of a predetermined area of ​​the seat padding, preferably using a sonotrode and anvil, so as to form a flat area comprising a continuous surface of said fiber material.

[0032] Ultrasonic welding can be performed at a frequency between 20 kHz and 40 kHz, preferably 20 kHz, 30 kHz, or 40 kHz, and more preferably 20 kHz or 30 kHz. The ultrasonic welding time can exceed 3 seconds. The force between the sonotrode and the anvil can be adjusted to form the flat area, taking into account factors such as the thickness of the seat padding or the distance between the sonotrode and the anvil.

[0033] The seat upholstery may have a first face and a second face opposite the first face. During ultrasonic welding, using a sonotrode and an anvil, the sonotrode may be applied to or brought close to the first face, while the anvil may be applied to or brought close to the second face. In such a case, the first face may include the flat area after ultrasonic welding. The first face may be either a front face or a back face. When the first face is the front face of the seat upholstery, then the second face is the back face of the seat upholstery. When the first face is the back face of the seat upholstery, then the second face of the seat upholstery is the front face of the seat upholstery.

[0034] The process may include thermoforming the fibers in said predetermined area, simultaneously with or prior to ultrasonic welding. Such thermoforming may facilitate ultrasonic welding. Thermoforming may also allow for control of the thickness between the first and second sides of the seat padding.

[0035] Thermoforming may involve creating a groove in the seat padding. In such a case, ultrasonic welding may be performed on the bottom of the groove. A flat area is then created in the bottom of the groove. Such a groove may be used to store extra stitching length and / or for attaching trim or protective material. In the latter case, several types of trim attachment may be used; this disclosure does not limit the choice of attachment methods.

[0036] The method may include producing marked symbols by engraving the flat area, in particular using a sonotrode. The sonotrode may include a raised mark so that during ultrasonic welding, a marked symbol can be simultaneously engraved on the flat area. The marked symbols can be engraved by another tool, after ultrasonic welding has formed the flat area. The process may include the creation of symbols marked by printing, in particular by inkjet printing on the flat area.

[0037] The method may include sticking a label onto the flat area, the label preferably comprising symbols printed or engraved on it.

[0038] This method of marking a portion of the seat padding allows for strong traceability to be linked to the seat padding in the predetermined area across the flat surface. Furthermore, the process allows for the implementation of various marking solutions for traceability, such as inkjet printing, adhesive labels, and engraving.

[0039] The extrusion formation of a 3D tangle with fibers may include: a. the supply of said material comprising said at least one thermoplastic polymer, b. the extrusion of said material through an extrusion die comprising a plurality of extrusion nozzles to form a curtain of molten fibres, c. the formation of a 3D entanglement with said fused fibers, the fused fibers being arranged irregularly, forming loops welded together in said 3D entanglement, d. the solidification of said 3D entanglement by cooling.

[0040] The fused fiber curtain comprises continuous fiber filaments that preferably fall by gravity. “Continuous fibers” means that the fibers have a length much greater than their diameter, generally by at least a ratio of 100, or even 500, or even 1000.

[0041] The formation of the 3D entanglement may include receiving the curtain of fused fibers falling by gravity between two counter-rotating guide elements, so as to form said 3D entanglement of fused fibers forming loops welded together according to an irregular, generally random distribution.

[0042] Cooling for solidification of the 3D tangle can be achieved using a liquid or a gas. Cooling the 3D tangle can consist of immersing the 3D fiber tangle in a coolant bath, in particular a water bath, the initial temperature of the liquid preferably being between 8 °C and 10 °C.

[0043] The process may include cutting the seat padding, particularly when the quantity of fibers is sufficient to create the seat padding. Such cutting may be carried out by any known means, in particular by laser or waterjet cutting, using a cutting press, or other techniques and equipment. Cutting consists, for example, of forming a flat padding, with the main opposite faces extending in two parallel planes.

[0044] Preferably, the empty spaces between the fibers of the 3D fiber entanglement of the padding are left free. A highly air-permeable padding is obtained, thanks to the numerous interstices (empty spaces) between the fibers which promote air circulation.

[0045] Ultrasonic welding can be implemented after cutting the seat padding. Brief description of the drawings

[0046] Other features, details and advantages will be illustrated in the detailed description that follows and in the figures, in which:

[0047] [Fig. 1] schematically illustrates a side and partially exploded view of an example of a vehicle seat comprising an example of a vehicle seat element including an example of seat padding.

[0048] [Fig.2] is a partial and schematic front view of a front face of an example seat padding.

[0049] [Fig.3] is a partial and schematic front view of a front face of an example of seat padding.

[0050] [Fig.4] is a partial and schematic front view of a front face of an example seat padding.

[0051] [Fig.5] is a partial and schematic front view of a rear face of an example of seat padding.

[0052] [Fig.6] is a partial and schematic front view of a side part of an example of seat padding.

[0053] [Fig.7] schematically illustrates an example of implementation of the process before ultrasonic welding.

[0054] [Fig.8] schematically illustrates an example of the implementation of part of the process.

[0055] [Fig.9] schematically illustrates an example of the implementation of part of the process.

[0056] [Fig. 10] schematically illustrates an example of the implementation of part of the process. Description of the implementation methods

[0057] In the various figures, the same reference numerals designate identical or similar elements. For the sake of simplicity, only the elements that are useful for understanding the example described are illustrated in the figures and are described in detail below.

[0058] In the following description, when reference is made to terms qualifying an absolute position, such as the terms "front", "rear", "top", "bottom", "left", "right", etc., or to relative terms, such as the terms "above", "below", "superior", "lower", etc., or to orienting qualifiers, such as "horizontal", "vertical", etc., reference is made, unless otherwise indicated, to the orientation of the figures or of a vehicle seat in its normal position of use.

[0059] Reference is now made to [Fig. 1] illustrating a vehicle seat element 20 comprising seat padding 12, and a vehicle seat 100 comprising such a vehicle seat element 20. The vehicle seat element 20 comprises, in this example, a backrest 21 and a seat 22, which is also referred to as a cushion. [Fig. 1] schematically illustrates a portion of a vehicle seat 100 as it is being manufactured, mounted on a sliding mechanism 32. This seat (100) comprises a metal frame, so as to form a seat frame (33) and a backrest frame (36).

[0060] The thickness of the seat padding 12, when the seat element 20 is a backrest 21, can be between 30 mm and 60 mm. The thickness of the seat padding 12, when the seat element 20 is a seat 22, can be between 40 mm and 120 mm.

[0061] In other examples, the vehicle seat element 20 may consist of at least one of an armrest, a headrest, an upper backrest adjustment device and a seat length adjustment device.

[0062] The seat element (20) may include a protective element constituting the finishing element of the seat visible to the user. The protective element is, for example, made of woven material, non-woven material, leather, artificial leather, or leather.

[0063] As better illustrated in [Fig. 2], for example, the padding The seat cushion 12 comprises a 3D tangle 10 of irregularly arranged fibers 5, forming loops welded together between the fibers 5. The fibers 5 have a material comprising at least one thermoplastic polymer. The seat cushion 12 also includes a flat area 14 formed on a predetermined area 18 of the 3D tangle 10 by ultrasonic welding of the fibers 5 into the predetermined area 18, the flat area 14 comprising, as illustrated, a continuous surface of the material of the fibers 5. The flat area 14 has a rectangular shape in this example, having a length of between 1 cm and 10 cm, preferably between 4 cm and 5 cm, and a width of between 0.2 mm and 1.2 mm, preferably between 0.3 mm and 0.8 mm. The flat area may have another shape, such as another oblong shape, a diamond shape, or some other shape, in other examples.

[0064] In this example, the predetermined area 18 is also treated by thermoforming the fibers 5 before or simultaneously with ultrasonic welding. The predetermined area 18 has a higher density than the rest of the 3D entanglement 10 obtained by thermoforming the fibers 5 in said predetermined zone 18.

[0065] In the example of [Fig.3], the flat area 14 includes marked symbols 16. In this example, the marked symbols are printed on the flat area 14.

[0066] In the example of [Fig.4], the symbols marked 16 are made on a label 17 which is glued to the flat area 14.

[0067] In the examples in Figures 2 to 4, the seat padding 12 includes a groove 25 formed in a front face 26 of the seat padding 12. The predetermined area 18 is located in a bottom 19 of said groove 25. The thermoforming operation mentioned above may have produced such a groove 25.

[0068] In the example of [Fig.5], the predetermined area 18 is located on a rear face 27 of the seat padding 12.

[0069] In the example of [Fig.6], the predetermined area 18 is located on a lateral part 28 of the seat padding 12.

[0070] The predetermined area 18 is advantageously located on a surface of the seat padding, preferably in an area that will not be in direct or indirect contact with any part of a user who is sitting on a seat comprising the seat padding, i.e. on the bottom of the groove in the front face of the seat padding, on the side face or on the back face.

[0071] Fig. 7 illustrates an example of installation 1 for implementing part of a process for manufacturing seat padding 12.

[0072] The process includes the extrusion formation of the 3D entanglement 10 with fibers 5 being arranged irregularly, forming loops welded together in said 3D entanglement 10, the fibers 5 having a material comprising at least one thermoplastic material.

[0073] The process, which is continuous in this example, includes supplying a material P comprising at least one thermoplastic polymer. The material P may be polymer granules. The at least one thermoplastic polymer is, for example, a polyester, such as PET (polyethylene terephthalate), PTT (polytrimethylene terephthalate), or PBT (polybutylene terephthalate). The material preferably comprises at least 95% PET by weight.

[0074] The material P is introduced into a hopper 2. The material P is guided towards an extrusion die (3). The process comprises extruding the material P through the extrusion die (3). The extrusion temperature can be between 210 °C and 250 °C, being equal to 230 °C for example.

[0075] The extrusion die (3) comprises a plurality of extrusion nozzles (4). In this example, the extrusion nozzles (4) are regularly distributed in two perpendicular directions to form an extrusion nozzle matrix, i.e. in the lengthwise and widthwise directions of the extrusion die (3). The extrusion of material P forms, after passing through the extrusion nozzles 4, a curtain 9 of molten fibers 5, as illustrated in [Fig. 7]. The curtain (9) is formed with continuous fiber filaments falling by gravity out of the extrusion die (3). Here, the extrusion nozzles (4) are distributed in a horizontal plane. Also, in order to keep the density of the fibers 5 substantially constant in the cross-section of the curtain 9 of fibers 5, the fibers 5 are here dragged by gravity at the exit of the extrusion die 3, as illustrated by the arrow in [Fig. 7].

[0076] After passing through the extrusion nozzles 4, the process includes forming a 3D tangle 10 with the molten fibers 5. In the 3D tangle (10), the molten fibers (5) are arranged irregularly, forming loops welded together. The process further includes solidifying the 3D tangle 10 by cooling to obtain the seat padding 12.

[0077] As illustrated in [Fig. 7], the formation of the 3D tangle 10 comprises guiding the fused fiber curtain between two counter-rotating guide elements 11 by forming a mass of fibers upstream of the two guide elements 11, so as to form said 3D tangle of fused fibers forming loops welded together. The thickness of the 3D tangle layer is determined by the center distance between the two counter-rotating guide elements (11). The thickness of the padding layer formed by the 3D tangle can be adjusted by changing the center distance between the two guide elements (11).

[0078] The cooling of the 3D tangle can be done using a liquid or a gas. In this example, the cooling of the 3D tangle consists of immersing the 3D fiber tangle in a bath (15) of coolant, in particular in a water bath, the initial temperature of the liquid preferably being between 8 °C and 10 °C.

[0079] The two guiding elements (11) are rotated at a speed generally lower than the falling speed of the fibers (5), ensuring an accumulation of fibers that leads to the formation of loops which are welded together between the fibers, generating the irregular or random 3D entanglement (10). Solidification is achieved immediately after the formation of the 3D entanglement (10), the two guiding elements (11) being half-immersed in the bath (15) provided for this purpose, in this example.

[0080] In this example, the empty spaces between the fibers (5) of the 3D entanglement (10) of the padding are left free.

[0081] The fiber layer (5) of the 3D entanglement (10), continuously moving past, is then guided out of the bath (15) to be dried, generally by agitation / vibration. The moving layer is then cut by transverse cuts, allowing to obtain different seat paddings 12, and as can be seen in [Fig.7]. These paddings (12) extend lengthwise along a longitudinal direction.

[0082] Cutting the padding, see the scissors schematically illustrating the cutting in [Fig. 7], can be carried out when the quantity of fibers 5 in the 3D entanglement 10 is sufficient to create the padding 12. Such cutting can be performed by any known means, in particular by laser or waterjet cutting, using a cutting press, or other techniques and equipment. The cutting can be carried out, in this example, on a flat, flowing layer, with the opposite principal faces of the padding (12) extending in two parallel planes.

[0083] As a possible variant, the 3D entanglement can be solidified when profiled in a mold cavity by immersion in a coolant.

[0084] According to one example, the extrusion nozzles (4) are adjustable, configured so as to be able to modify the shape of the fiber curtain (9). A logic processing unit can be provided which includes a control module comprising a microprocessor and a memory comprising instructions to control the extrusion nozzles (4) so ​​as to generate a curtain (9) of molten fibers (5) of variable shape during extrusion in the length direction and / or in the width direction of the extrusion die (3).

[0085] According to one example, in particular according to the process of [Fig. 7], the apparent density can be homogeneous along the length and width of the layer. The density of the number of extrusion nozzles (4) is thus homogeneous along the length of the extrusion die (3). According to another example, it is possible to have different zones with different apparent densities.

[0086] Figures 8, 9, and 10 illustrate the subsequent steps of an example of the process.

[0087] Figure 8 illustrates the thermoforming of the fibers 5 in the predetermined area 18.

[0088] In this example, the thermoforming includes creating a groove 25 in the seat padding 12 with a tool T. Such thermoforming can facilitate simultaneous or subsequent ultrasonic welding.

[0089] After thermoforming the fibers 5 in this predetermined zone 18, the predetermined zone 18 has a higher density than the rest of the 3D entanglement. Indeed, thermoforming locally densifies the 3D entanglement 10 of the fibers 5.

[0090] Furthermore, after thermoforming, the seat padding 12 in the predetermined area 18 has a predetermined controlled thickness h. Thermoforming allows for thickness control between the first and second faces of the seat padding, the first face being, in this example, the front face 26 and the second face being, in this example, the rear face 27. The tool and the operation of Thermoforming allows the predetermined thickness h to be obtained between the front face 26 and the rear face 27 in the predetermined area 18.

[0091] The process, as illustrated in [Fig. 9], comprises ultrasonic welding of the predetermined area 18 of the seat padding 12. The ultrasonic welding uses in this example a sonotrode S applied along the downward arrow on the side of the first face formed in this example by the front face 26 and an anvil A applied along the upward arrow on the side of the second face formed in this example by the rear face 27 of the seat padding 12. The ultrasonic welding forms the flat area 14 comprising a continuous surface of said fiber material 5.

[0092] In this example, ultrasonic welding is carried out in the bottom 19 of the groove 25. Thus, the flat area 14 is formed in the bottom 19 of the groove 25. Such a groove can be used to store an additional length of stitching and / or for attaching trim or protection. In the latter case, several types of trim attachment can be used; this disclosure does not limit the choice of attachment methods.

[0093] Ultrasonic welding can be carried out at a frequency between 20 kHz and 40 kHz, preferably 20 kHz or 30 kHz. The ultrasonic welding time can be greater than 3 seconds. The force between the sonotrode S and the anvil A can be chosen to form the flat area depending on the thickness of the seat padding, for example, or the distance between the sonotrode and the anvil.

[0094] In this example, the thermoforming of the fibers 5 in said predetermined zone 18, as illustrated in [Fig.8], is carried out simultaneously or before ultrasonic welding.

[0095] The process also includes the production of marked symbols, as illustrated in [Fig. 10], in this example by printing, in particular by inkjet printing of marked symbols 16 with an inkjet printer I on the flat area 14.

[0096] The method may alternatively include producing marked symbols by engraving the flat area, in particular using a sonotrode. In such a case, the sonotrode may include a raised mark so that, during ultrasonic welding, a marked symbol can be simultaneously engraved on the flat area. The marked symbols may be engraved by another tool after the ultrasonic welding that forms the flat area.

[0097] In another example, the method includes sticking a label onto the flat area, the label preferably including symbols printed on it.

[0098] The marking of the seat padding allows traceability to be strongly attached to the seat padding 12 in the predetermined area 18 through the flat area 14.

Claims

Demands

1. Seat padding (12) comprising: - a 3D entanglement (10) of irregularly arranged fibers (5), forming loops welded together between the fibers (5), the fibers having a material comprising at least one thermoplastic polymer, - a flat area (14) formed on a predetermined area (18) of the 3D entanglement (10) by ultrasonic welding of said fibers (5) in said predetermined area (18), the flat area (14) comprising a continuous surface of said fiber material (5).

2. Seat padding (12) according to claim 1, wherein the flat area (14) comprises marked symbols (16), the marked symbols (16) being engraved or printed on the flat area (14) or being made on a label (17) which is glued to the flat area (14).

3. Seat padding (12) according to claim 1 or 2, wherein the predetermined area (18) has a density greater than the rest of the 3D entanglement (10) obtained by thermoforming the fibers (5) in said predetermined area (18).

4. Seat padding (12) according to any one of the preceding claims, wherein the predetermined area is located on a rear face (27) of the seat padding (12) or on a side part (28) of the seat padding (12).

5. Seat padding (12) according to any one of claims 1 to 3, wherein the seat padding (12) comprises a groove (25) formed in a front face (26) of the seat padding (12), wherein the predetermined area (18) is located in a bottom (19) of said groove (25).

6. Vehicle seat component (20) comprising seat padding (12) according to any one of the preceding claims.

7. Vehicle seat (100) comprising a vehicle seat element (20) according to the preceding claim.

8. A method for manufacturing seat padding (12), such as the seat padding (12) according to any one of claims 1 to 5, the method comprising: - the extrusion formation of a 3D tangle (10) with fibers (5) arranged irregularly, forming loops welded together in said 3D tangle (10), the fibres (5) having a material comprising at least one thermoplastic material, - ultrasonic welding of a predetermined area (18) of the seat padding (12) using a sonotrode and anvil, so as to form a flat area (14) comprising a continuous surface of said fibre material (5).

9. Method according to the preceding claim, comprising making marked symbols (16) by engraving the flat surface (14), in particular by the sonotrode, or by printing, in particular by inkjet printing, on the flat area (14).

10. A method according to claim 8, comprising gluing a label (17) onto the flat area (14), the label (17) preferably comprising symbols (16) printed thereon.

11. A method according to any one of claims 8 to 10, comprising thermoforming the fibers (5) in said predetermined zone (18), simultaneously or prior to ultrasonic welding.

12. Method according to the preceding claim, wherein the thermoforming comprises making a groove (25) in the seat padding (12) and ultrasonic welding is carried out in a bottom (19) of said groove (25).

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