WO2024069091A1

WO2024069091A1 - Method and apparatus for manufacturing seat padding, and associated padding

Info

Publication number: WO2024069091A1
Application number: PCT/FR2023/051474
Authority: WO
Inventors: Mathieu Cluet; Benoît GAZANIOL; David BOUDOT; Michael Neidhofer; Frank Laymann
Original assignee: Faurecia Sièges d'Automobile
Priority date: 2022-09-30
Filing date: 2023-09-25
Publication date: 2024-04-04
Also published as: FR3140296A1

Abstract

The present disclosure relates to a method for manufacturing a seat padding, wherein the padding (MAT) obtained comprises a 3D entanglement of irregularly arranged continuous thermoplastic fibres (1) forming loops that are welded together, said method comprising the steps of: - providing a 3D entanglement of irregularly arranged continuous thermoplastic fibres forming loops that are welded together, and - providing raised portions on at least one face of the entanglement, or even on two opposite faces of the entanglement, by passing the 3D entanglement between two counter-rotating calendering members (OC1, OC2).

Description

-ij _trG . METHOD AND APPARATUS FOR THE MANUFACTURE OF A

¹ ' SEAT PADDING AND PADDING AS SUCH

[0001] The present disclosure relates to a method of manufacturing a seat cushion comprising a 3D tangle of continuous thermoplastic fibers arranged randomly, which is highlighted on at least one of its faces, or even on two of its faces. its opposite sides.

[0002] The present disclosure also relates to a seat padding typically obtained by such a manufacturing process, as well as a seat comprising such padding.

Technical area

[0003] The present disclosure relates to the field of automobile vehicle seats which comprise a typically metallic structure, typically with a seat frame and a backrest frame. The structure is classically obtained by stamping techniques. The seats still have padding, including a layer of seat padding and a layer of back padding which provide softness to the seat and back, and contribute to comfort in the seat.

Prior art

[0004] The seat and back paddings are conventionally made of urethane polymer foam, and shaped in molds. Polyurethane foam padding is satisfactory, but can retain moisture in humid conditions.

[0005] Furthermore, a polyurethane foam is conventionally produced by mixing, among other things, polyols with isocyanates. The chemical reaction carried out emits CO2 to form a foam, the CO2 emitted contributing to global warming.

[0006] Furthermore, polyurethane foam is difficult to recycle. [0007] Also, it appears desirable to limit the use of polyurethane in the padding of vehicle seat elements.

Summary

[0008] This disclosure improves the situation, in whole or in part.

[0009] It is proposed, according to a first aspect, a method of manufacturing a seat cushion in which a cushion is obtained comprising a 3D tangle of continuous thermoplastic fibers arranged irregularly forming loops welded together, the 3D tangle of fibers having at least one raised, non-planar face, or said entanglement having two raised, non-planar, opposite faces, said method comprising:

- a supply of a 3D tangle of continuous thermoplastic fibers arranged irregularly forming loops welded together, and

- a highlighting of said at least one face of the entanglement, or of the two opposite faces of the entanglement, by passing the 3D entanglement between two counter-rotating calendering members, rotatably arranged along two parallel articulation axes , at least one of the two calendering members comprising a relief-shaped calendering wall configured to ensure the relief of said raised face, or the two calendering members respectively comprising relief-shaped calendering walls configured to respectively ensure the highlighting of the two opposite faces of the entanglement.

[0010] Generally speaking, and according to a first possibility, the shaping of the padding by the counter-rotating calendering members can be a final shaping. In such a case, the process does not provide for an additional shaping step, typically by thermoforming.

[0011] According to a second possibility, the shaping of the padding by the counter-rotating calendering members can only be an intermediate shaping, the 3D entanglement shaped by the contra-rotating calendering members being only a preform. [0012] The final shaping of the padding may then require, after cutting a length section of the preform, an additional shaping step, typically by thermoforming. Such shaping in two stages can be advantageous, to create high amplitude reliefs, such as for example side flanges of the padding, and in comparison to shaping in a single step (for example by thermoforming only ) which can cause excessive stress on the fibers, in areas of the padding requiring a high shaping amplitude, and thus lead to local tearing or at least areas of the padding where the fibers are weakened.

[0013] The characteristics set out in the following paragraphs can optionally be implemented. They can be implemented independently of each other or in combination with each other:

[0014] According to one embodiment, the relief-shaped calendering wall, or else the relief-shaped calendering walls are:

- of variable radius at least along a line of the calendering wall of the calendering member, at the intersection between a plane passing through the axis of rotation of the calendering member and the calendering wall so as to produce a 3D tangle forming the padding which is shaped in relief, following the direction of the counter-rotating members and/or,

-of radius variable angularly around the axis of rotation of the counter-rotating member, so as to produce a 3D entanglement forming the padding which is shaped in relief, of variable section following the direction of travel of the 3D entanglement during the rotations of the two counter-rotating organs.

[0015] According to a first embodiment, the process can be continuous, comprising:

- /A/ Extrusion of a thermoplastic polymer in an extrusion die comprising extrusion nozzles distributed in a lengthwise direction and in a widthwise direction of the extrusion die, generating a curtain of melted, falling continuous fibers by gravity,

- /B/ Receiving the curtain of molten continuous fibers falling by gravity between said two counter-rotating calendering members, rotatably arranged in two parallel articulation axes, with a generation of the 3D tangle of fibers according to an irregular distribution with fusion of loops between the continuous fibers and according to a section layer determined locally by a space between the calendering walls of the two counter-rotating members,

- /C/ Solidification of the 3D tangle of fibers by immersion in a cooling liquid. Said highlighting of the entanglement, by passing the 3D entanglement between the two contra-rotating calendering members, is then carried out in /B/, simultaneously with the generation of the 3D entanglement.

[0016] According to such an embodiment, the section of the 3D entanglement shaped by the two calendering members is determined locally by the sectional space between the two calendering walls, along a plane passing through the two axes rotation of the counter-rotating calendering members. When the calendering member(s) are of angularly variable radius around the axis of rotation of the counter-rotating member so that said space is of variable section following the rotations of the counter-rotating members, the nozzles can advantageously be controllable, configured so to be able to change the section of the fiber curtain. For this purpose, a logic processing unit is provided having a control module comprising a microprocessor and a memory comprising instructions for, in /A/, controlling the nozzles so as to generate a curtain of molten fibers, of variable section during the extrusion following the length direction the calendering walls, in real time, during the rotations of the counter-rotating members.

[0017] According to a second embodiment, the shaping of the entanglement, by passing the 3D entanglement between the two contra-rotating calendering members, is obtained successively to said provision of the 3D entanglement, subsequent to the generation of 3D entanglement.

[0018] In general, and in particular according to the first or second embodiment, a first of the two counter-rotating members can be a first counter-rotating member configured to conform a front face of the padding intended to receive the occupant, and in which the calendering wall of said first counter-rotating member has, at least along an angular section of the first counter-rotating member, a variable radius along a line L1 of the calendering wall of the first calendering member, at the intersection between a plane passing through the axis of rotation and the calendering wall, said first calendering member configured to form:

-a central portion, following a projecting relief from the calendering wall, configured to conform a central part of a front face of the padding facing the occupant of the seat intended to receive the user's buttocks for the padding of the seat or the back of the occupant for backrest padding, and

- lateral portions, on either side, of the central portion, following two recessed reliefs of the calendering wall, said recessed reliefs configured so as to form two lateral flanges of the padding, projecting from the central part , on the front face, the side flanges configured to ensure lateral support for the occupant.

[0019] According to one embodiment, the first rotary member being configured to conform the front face of the padding, the second rotating member being configured to conform the dorsal face of the padding, having, at least on one angular section around the second counter-rotating member, a variable radius along a line L2 of the calendering wall of the second calendering member, at the intersection between a plane passing through the axis of rotation and the calendering wall, said second calendering member configured to form:

- a central portion, following a second recessed relief configured to extend to the right of the projecting relief of the first rotating member,

- lateral portions, following second projecting reliefs, on either side of the central wall, configured to extend to the right of the two hollow reliefs so as to form on a dorsal face the 3D tangle of the padding, opposite the front face, a central portion of a padding, projecting relative to lateral portions of the dorsal face, located on the back of the two side flanges.

[0020] According to one embodiment, the padding shaped by the work of the first calendering member generating the central part and the side flanges on the front face, or even shaped by the work of the second calendering member generating the central portion projecting relative to the lateral portions on the dorsal face, is a preform of constant section, following the direction of travel of the entanglement between said contra-rotating members.

[0021]

Said method further comprises a step of cutting a length section of the preform, and a step of shaping the preform by thermoforming the length section of the preform. Such a shaping step by thermoforming can in particular allow shaping of the padding, following the direction of the preform oriented in the direction of travel.

[0022] According to one embodiment, the padding has all or part of the following characteristics:

- the fibers have a diameter of between 0.2 mm and 2 mm, preferably between 0.3 mm and 1.5 mm,

- the 3D tangle of the padding has an apparent density of between 20kg/m3 and 70 kg/m3, for example between 45 kg/m3 and 65 kg/m3,

- the composition of the fibers comprises at least 95% by weight of PET, and for example the fiber composition comprises by weight, 95% to 99% of PET, 1% to 5% of a second polymer distinct from PET such as PTT or PBT.

[0023] According to a second aspect, the present disclosure still relates to a seat or backrest padding of a seat, the padding suitable for being obtained according to the method of the present disclosure comprising a 3D tangle of continuous thermoplastic fibers arranged randomly, forming loops welded together between the fibers, and in which:

- the fibers are hollow fibers and/or solid fibers, with a diameter of between 0.2 mm and 2 mm, preferably between 0.3 mm and 1.5 mm,

- the composition of the fibers comprising at least 95% by weight of PET,

- the 3D tangle of the padding has an apparent density of between 20kg/m3 and 70 kg/m3, and for example between 45 kg/m3 and 65 kg/m3, and in which the 3D tangle of continuous fibers presents:

- a front face shaped in relief by the calendering wall of a first rotary calendering member and/or - a dorsal face shaped in relief by the calendering wall of a second rotary calendering member.

[0024] According to a third aspect, the present disclosure still relates to a vehicle seat comprising:

- a typically metallic structure comprising a seat structure and/or a back structure,

- a padding, according to this disclosure, such as a back padding or a seat padding, resting on the structure,

- possibly a cap covering the front face of the padding

[0025] According to one embodiment, the shaped front face comprises a central part, and two projecting side flanges intended to ensure lateral support of the occupant.

According to one embodiment, the opposite dorsal face comprises a central portion, projecting relative to two lateral portions of the padding, and in which:

-- for a seat cushion, the central portion of the dorsal face is inserted between two puddles of the seat structure while the two lateral portions come to rest respectively on the two flanges,

-- for a back padding, the central portion of the dorsal face is inserted between two uprights of the backrest structure while the two lateral portions rest respectively on the two uprights.

[0027] According to a fourth aspect, the present disclosure still relates to equipment suitable for implementing the method according to the present disclosure, said equipment comprising:

- an extrusion die comprising extrusion nozzles distributed in a lengthwise direction and in a widthwise direction of the extrusion die, generating a curtain of melted continuous fibers, falling by gravity,

- two counter-rotating calendering members, rotatably arranged along two parallel articulation axes ensuring the reception of the melted fibers falling by gravity with a generation of a 3D entanglement of fibers according to an irregular distribution with fusion of loops between the continuous fibers and according to a layer of section determined locally by a space between the calendering walls of the two counter-rotating members.

[0028] At least one of the two calendering members comprises a calendering wall of relief shape configured to ensure the relief of said raised face, or the two calendering members respectively comprising calendering walls of shape in relief configured to respectively ensure the relief of the two opposite faces of the entanglement.

[0029] Notably, the relief-shaped calendering wall, or else the relief-shaped calendering walls, have a variable radius at least along a line of the calendering wall of the calendering member, at l the intersection between a plane passing through the axis of rotation of the calendering member and the calendering wall so as to produce an entanglement forming the padding which is shaped in relief, following the direction of the counter-rotating members.

[0030] According to an advantageous embodiment, said calendering member comprises:

- a cylindrical core, extending along the length of said calendering member

- a set of rings, removably mounted on the core, distributed juxtaposed along the length of said calendering member, so as to form the calendering wall in relief shape, of variable radius along the length of said calendering member.

[0031] The removable rings, of modular design, can make it possible to quickly change the design of the relief to the shaping of the desired padding, and at lower cost compared to a one-piece design of the calendering member. The core of the calendering member is in fact preserved, only the rings being replaced.

The removable rings are typically integral in rotation with the core which is typically rotated by a motor.

[0033] According to one embodiment, the core may comprise an internal pipe for a cooling liquid, radial orifices, distributed along the length and periphery of the core, in communication with radial orifices of the rings, allowing a flow of the liquid cooling according to directions radials from the internal pipe of the core to the periphery of the calendering member, through the radial orifices of the core and the rings.

[0034] Such an internal cooling system makes it possible to obtain solidification of the 3D entanglement, even for large production capacities, and in comparison to solidification by cooling based only on partial immersion of the counter-rotating calendering members in a coolant.

Brief description of the drawings

[0035] Other characteristics, details and advantages will appear on reading the detailed description below, and on analyzing the appended drawings, in which:

Fig. 1

[0036] [Fig. 1] is a schematic view of a manufacturing process allowing the manufacture of the 3D entanglement comprising an extrusion of a thermoplastic polymer in an extrusion die generating a curtain of melted continuous fibers, falling by gravity, receiving the curtain of continuous fibers melted between two counter-rotating calendering members, with generation of a 3D tangle of fibers and solidification of the 3D tangle of fibers by immersion in a cooling liquid, then obtaining padding by transverse cuts to the direction of travel, the calendering members being rollers of constant diameter, guaranteeing the calendering of the 3D entanglement according to a constant thickness following the length direction of the calendering rollers, and following a constant section or course of the calendering following the direction of scrolling the 3D entanglement between the two counter-rotating rollers;

Fig. 2

[0037] [Fig. 2] is a schematic view of a continuous manufacturing process according to the present disclosure allowing the manufacture of the 3D entanglement comprising an extrusion of a thermoplastic polymer in an extrusion die generating a curtain of melted continuous fibers, falling through gravity, the reception of the curtain of continuous fibers melted between two calendering members counter-rotating, with a generation of a 3D tangle of fibers and the solidification of the 3D tangle of fibers by immersion in a cooling liquid, then obtaining padding by cuts transverse to the direction of travel, and in which so notable, the calendering members are configured to ensure the highlighting of the 3D tangle of the padding, the two counter-rotating members respectively presenting calendering walls of relief shape, in particular:

- of variable radius along a line of the calendering wall which is defined at the intersection between a plane passing through the axis of rotation of the calendering member, and said calendering wall, so as to produce a 3D entanglement forming the padding having two calendered faces in relief, following the direction of the counter-rotating members,

- of angularly variable radius around the axis of rotation of the contra-rotating member so as to produce an entanglement, of variable section, following the direction of travel of the 3D entanglement during the rotations of the two contra-rotating calendering members.

Fig. 3a

[0038] [Fig. 3a] is seen, on the left, of the section of the space between the calendering wall of the first calendering member intended for highlighting a front face of the padding and the calendering wall of the second calendering member intended to the highlighting of a dorsal face of the padding, the section seen along a plane passing through the axes of rotation of the calendering members, at a time t1, for which the section between the calendering members is configured to conform:

- a central part of the front face of the padding facing the occupant of the seat intended to receive the user's buttocks for the seat padding or the back of the occupant for a backrest padding, and

- two side flanges of the padding, projecting from the central part, on the front face, the side flanges configured to ensure lateral support of the occupant, and Figure 3a illustrating on the right, the control at this instant t1 of nozzles pilotable of the extrusion die for the generation of a curtain of fibers taking up in section at this instant t1, the section between the two calendering members.

Fig. 3b

[0039] [Fig. 3b] is a view, on the left, of the section of the space between the calendering wall of the first calendering member and the calendering wall of the second calendering member, the section seen along a plane passing through the axes of rotation of the calendering members, at a time t2, different from t1, for which the section between the calendering members is configured to conform on the dorsal face a transverse groove, in particular configured to ensure nesting on a spacer such as a tube, on the rear structure of the seat, Figure 3b illustrating on the right, the control at this instant t2 of the adjustable pi nozzles of the extrusion die for the generation of a curtain of fibers resuming in section at this instant t2, the section between the two calendering members.

Fig. 4

[0040] [Fig. 4] shows a seat structure, comprising:

- a seat structure comprising two flanges extending in parallel from a rear edge of the seat and to a front edge of the seat, as well as spacers between the flanges, and,

- a backrest structure comprising two uprights, extending in parallel, from a rear portion of the seat to an upper crosspiece of the backrest structure.

Fig. 5

[0041] [Fig. 5] is a view of the assembly of a seat padding on the seat structure, the padding having on its dorsal face calendered in relief by the second calendering member, on the one hand, a central portion interposed between two flanges of the seat structure and, on the other hand, the side portions respectively resting on the flanges, the padding fixed to the structure by a cap covering the front face calendered in relief by the first calendering member.

Fig. 6 [0042] [Fig. 6] is a top view of a seat structure comprising:

- a seat structure comprising two flanges extending in parallel from a rear edge of the seat and to a front edge of the seat, as well as spacers between the flanges, and notably a metal suspension 'extending in support between a front spacer and a rear spacer,

- a backrest structure comprising two uprights, extending in parallel, from a rear portion of the seat to an upper crosspiece of the backrest structure, and notably, a metal suspension extending between the two uprights of the backrest structure, Figure 6 showing at the bottom, a nesting of a rear tube bracing the flanges of the seat frame, in a transverse groove on the dorsal face of a seat padding.

Fig. 7

[Fig. 7] is a view of a manufacturing process according to a second embodiment, said entanglement, of constant section, following the direction of travel of the 3D entanglement during the rotations of the two contra-rotating calendering members, the first member of calendering and the second calendering member being of variable radius depending on the length of the calendering members, the calendering wall of the first calendering member being intended to highlight a front face of the padding and the calendering wall of the second calendering member intended to highlight a dorsal face of the padding, the section seen along a plane passing through the axes of rotation of the calendering members being configured to conform, at all times, the front face which comprises::

- two side flanges of the padding, projecting from the central part, on the front face, the side flanges configured to ensure lateral support for the occupant.

[0043] Fig. 8 [0044] [Fig. 8] is a consecutive view of Figure 7 for which a padding preform is shaped, on the one hand, on its front face by the work of the first calendering member, and on the other hand, on its dorsal face by the work of the second calendering member, said padding preform being of constant section following the direction of travel of the entanglement between the two calendering members, Figure 8 illustrating a step of cutting a length section of the preform thus formed and a step of shaping the preform by thermoforming the length section of the preform, in particular necessary for the final shaping of the padding.

Fig. 9

[0045] [Fig. 9] is a schematic view of modular design of a calendering member comprising a central core and a set of juxtaposed rings, crossed by the cylindrical core, the rings juxtaposed along the length of said calendering member defining the variable relief of said member calendering along its axis.

Fig. 10

[0046] [Fig. 10] is a schematic view of modular design of a calendering member comprising the central core and a set of rings intended to be juxtaposed, crossed by the cylindrical core, the rings illustrated removed from the core, the figure further illustrating in a manner notable:

- a motor configured to drive said rotating core in rotation, and the rings secured in rotation to the core,

- a tubular design of the core which includes an internal conduit for a coolant, and as illustrated by arrows and radial orifices, distributed along the length and periphery of the core, in communication with radial orifices of the rings, allowing a flow of the cooling liquid in directions radial to the axis of rotation of the calendering member, from the internal pipe to the periphery of the calendering member.

Fig. 11

[0047] [Fig. 11] is a view of the section of the padding, during shaping in two stages, the first shaping by the calendering members, at namely the preform illustrated in solid lines, the final shaping, by thermoforming, illustrated in dotted lines.

Description of embodiments

[0048] The drawings and the description below contain, for the most part, elements of a certain nature. They can therefore not only be used to better understand this disclosure, but also contribute to its definition, if necessary.

[0049] The present disclosure relates to a method of manufacturing a seat padding in which a MAT padding is obtained comprising a 3D tangle of continuous thermoplastic fibers 1 arranged irregularly forming loops welded together, the 3D tangle of fibers 1 having at least one raised, non-planar face, or else said entanglement presenting two raised, non-planar, opposite faces.

[0050] Said manufacturing process comprises:

- a provision of a 3D tangle of continuous thermoplastic fibers arranged irregularly, in particular randomly, forming loops welded together, and

- a highlighting of said at least one face of the entanglement, or even of the two opposite faces of the entanglement, by passing the 3D entanglement between two contra-rotating calendering members OC1, OC2, arranged rotatably according to two parallel articulation axes A1, A2.

[0051] At least one of the two calendering members comprises a calendering wall of relief shape configured to ensure the relief of said face of the 3D tangle of fiber. According to this possibility, the other calendering member can be cylindrical, and therefore configured to ensure calendering of the opposite face of the entanglement, then flat.

[0052] According to another possibility, in particular illustrated in the figures, the two calendering members OC1, 002 can advantageously respectively comprise calendering walls of relief shape configured to respectively ensure the relief of the two opposite faces of the entanglement 3D. [0053] In general, the relief-shaped calendering wall, or the two relief-shaped calendering walls, can be of variable radius, following the direction of the axis of rotation A1, A2, at least according to a line L1 (or respectively L2) of the calendering wall of the calendering member OC1 (or respectively OC2), at the intersection between a plane passing through the axis of rotation A1 (or respectively A2) and the wall of calendering of the calendering member 001 (or respectively A2).

[0054] Such an embodiment is illustrated for information purposes in Figure 3a. It makes it possible to produce a 3D tangle 1 forming the MAT padding (or at the very least a padding preform), which is shaped in relief, following the direction of the counter-rotating members 001, 002 and which can possibly have a constant section following the direction of scrolling of the entanglement between the two contra-rotating organs. Such an embodiment comprising a padding of constant section following the direction of travel is in particular illustrated in Figure 7 for which the first calendering member 001, and the second calendering member 002 are bodies of revolution, of variable radius, following the direction of the axis of rotation A1, A2, over the entire periphery of the organs around the axis of rotation A1, A2.

[0055] Alternatively or additionally (in particular according to the mode of Figure 2), the calendering wall of relief shape, or even the two calendering walls of relief shape can be of radius variable angularly around the axis of rotation A1 (respectively A2) of the counter-rotating member 0C1 (respectively 0C2), such an embodiment makes it possible to conform in relief the 3D entanglement (forming the padding (MAT) which is shaped in relief, following the direction of travel of the 3D entanglement of fibers between the contra-rotating organs 0C1, 002.

[0056] Such an embodiment makes it possible to ensure a change in the section of the calendering space between the two counter-rotating members, during the rotation of the counter-rotating calendering members. This makes it possible to conform in relief the 3D tangle of fibers which is then of variable section following the direction of travel of the 3D tangle during the rotations of the two counter-rotating members 001, 002. [0057] In general, and as illustrated in Figure 2 according to a non-limiting example, the 3D entanglement can be, according to an advantageous embodiment, not only shaped in relief, following the direction of the counter-rotating members OC1, OC2, following a first direction of the padding in particular transverse to the padding, but still of variable section following the direction of travel of the 3D entanglement during the rotations of the two counter-rotating members 001, 0C2, and therefore shaped in relief following a second direction of the padding, perpendicular to the first, and in particular following a longitudinal direction of the padding.

[0058] According to one embodiment, illustrated for information purposes in Figure 2, the highlighting of one or both opposite faces of the 3D entanglement can advantageously be obtained simultaneously with the generation of the 3D entanglement.

[0059] According to such an embodiment, the manufacturing process can be a continuous process, comprising:

- /A/ Extrusion of a thermoplastic polymer in an extrusion die 2 comprising extrusion nozzles 20 distributed in a length direction X and in a width direction Y of the extrusion die 2, generating a curtain R of melted continuous fibers, falling by gravity,

- /B/ Reception of the curtain of molten continuous fibers falling by gravity between said two counter-rotating calendering members 001, 002, rotatably arranged along two parallel articulation axes, with generation of the 3D entanglement of fibers 1 s according to a distribution irregular, typically random, with fusion of loops between the continuous fibers and according to a layer of section determined locally by a space between the calendering walls of the two counter-rotating members,

- /G/ Solidification of the 3D tangle of fibers by immersion in a cooling liquid.

[0060] The temperature of the extrusion carried out in /A/ in the extrusion die can be between 180°C and 240°C, or even more. The extrusion die is typically supplied with thermoplastic granules.

[0061] According to such an embodiment, said highlighting of the entanglement, obtained by the passage of the 3D entanglement between the two organs of contra-rotating calendaring OC1, OC2, is carried out in /B/, simultaneously with the generation of the 3D entanglement between the contra-rotating members OC1, OC2.

[0062] The 3D tangle of fibers, running downstream of the calendering members, forms a strip which can run continuously, comprising in particular in series a plurality of MAT seat pads, shaped in relief, in particular, adjoining each other, via PT 1 fiber bridges which each extend in a direction transverse to the strip. These PT1 fiber bridges are regularly spaced following the direction of the strip. The strip comprising a series of padding in the direction of travel can be dried, in particular by vibrating the strip. These PT1 fiber bridges are then sectioned along CT cutting lines, transverse to the strip to separate the different paddings of the series. Each padding can be shaped into a form of back padding or a form of seat padding.

[0063] According to one embodiment (example not illustrated), the calendering members OC1, OC2 can be configured to obtain a single series of paddings depending on the direction of travel.

[0064] According to another embodiment (example illustrated in Figure 2), the process, in particular the dimension of the extrusion die 2, and the calendering walls of the counter-rotating calendering members OC1, OC2, can ( wind) be configured to manufacture a strip comprising several series of padding, arranged in parallel, the different series of padding offset in a transverse direction. Figure 2 thus shows two series of parallel padding offset in the transverse direction. The padding of each series of padding extends, one after the other, following the direction of the strip. The different series of padding are adjoined via at least a second bridge of PT2 fibers, extending longitudinally to the strip. This second bridge of PT2 fibers is sectioned along a cutting line CL, longitudinal to the strip, to separate the series of padding.

[0065] In general, the section of the 3D entanglement shaped by the two calendering members OC1, OC2 is determined locally by the space in section between the two calendering walls, along a plane passing through the two axes of rotation A1, A2 of the counter-rotating calendering members OC1, OCE.

When the calendering member(s) have an angularly variable radius around the axis of rotation A1 (respectively A2) of the counter-rotating member OC1 (respectively OC2), said space in section between the two calendering members OC1, OC2 is variable over time, depending on the rotations of the counter-rotating members, typically synchronized for example at the same angular speed and according to opposite rotations.

[0067] Figures 3a and 3b illustrate, on the left, this section between the two calendering members OC1, OC2, at two times t1 and t2, when the section between calendering members is variable. At time t1, the section delimited between the two calendering members OC1, OC2 provides relief of a front face comprising a central portion PC, and two lateral flanges BL, on either side of the central portion .

[0068] At time t2, the section delimited between the two calendering members OC1, 002, is of constant dimension following the direction of the axes of the members, and the section is therefore distinct from that at time t1.

[0069] In such a case, the nozzles of the extrusion die can advantageously be controllable, namely that the controllable nozzles can be closed and opened in real time, independently, i.e. individually or at the very least in subsections. -groups. These controllable nozzles are configured so as to be able to change the section of the fiber curtain.

[0070] A logic processing unit U can have a control module comprising a microprocessor and a memory comprising instructions for, in /A/, controlling the nozzles so as to generate a curtain of molten fibers, of variable section during the the extrusion following the length direction X and/or the width direction Y of the extrusion die 2, in a manner synchronized with the rotations of the counter-rotating members.

[0071] Such a control module advantageously makes it possible to adapt the section of the curtain of molten fibers R, to the sectional space between the calendering walls, in real time, during the rotations of the counter-rotating members. [0072] When the calendering member(s) have a constant radius angularly around the axis of rotation A1 (respectively A2) of the counter-rotating member OC1 (respectively OC2), said space in section between the two calendering members OC1, OC2 has a constant section over time, during the rotations of the contra-rotating organs. Such an embodiment is illustrated in Figure 7.

[0073] According to another embodiment, distinct from that of Figure 2 (or Figure 7), the shaping of the entanglement obtained by passing the 3D entanglement between the two contra-rotating calendering members can be obtained successively to said provision of the 3D entanglement, subsequent to the generation of the 3D entanglement.

[0074] For example, the prior provision of the entanglement can be obtained according to the continuous process, in particular illustrated in Figure 1 and comprising:

- Extrusion of a thermoplastic polymer in an extrusion die 2 comprising extrusion nozzles 20 distributed in a length direction X and in a width direction Y of the extrusion die, generating a curtain R of melted continuous fibers , falling by gravity,

- Receiving the curtain of molten continuous fibers falling by gravity between said two counter-rotating calendering cylinders CC1, CC2, rotatably arranged along two parallel axes of articulation, with generation of the 3D tangle of fibers according to an irregular, typically random distribution, with fusion of loops between the continuous fibers and according to a section layer determined locally by a space between the calendering walls of the two counter-rotating calendering cylinders,

- Solidification of the 3D tangle of fibers by immersion in a cooling liquid.

[0075] The temperature of the extrusion A/ in the extrusion die can be between 180°C and 240°C or even more. The extrusion die is typically supplied with thermoplastic granules.

The padding strip thus obtained is of constant thickness, over the length of the strip, the front face and the back face of the 3D tangle of fibers being substantially flat. [0077] The highlighting of the 3D entanglement by the counter-rotating calendering members, namely the highlighting of one of the two opposite faces, or even of the two opposite faces, can thus be obtained, subsequent to the solidification of 3D entanglement, in particular on a calendering station, located downstream from the calendering cylinders, depending on the direction of travel of the strip.

[0078] In such a case, the calendering members are configured to print in relief one of the calendered faces, or even the two calendered faces of the tangle 3 of fibers. The calendering members are heated so as to obtain at least the softening of the plastic of the fibers with a view to obtaining the plastic deformation of the fibers.

[0079] According to one embodiment, a first of the two counter-rotating members can be a first counter-rotating member configured to conform a front face FF of the padding intended to receive the occupant.

[0080] The calendering wall of the first counter-rotating member OC1 can present, at least along an angular section of the first counter-rotating member, in particular according to the embodiment of Figure 2, a variable radius, along a line L1 of the calendering wall of the first calendering member, at the intersection between a plane passing through the axis of rotation and the calendering wall.

[0081] For example, such a variable radius along line L1 is configured to form:

- a central portion, following a projecting relief RS1 of the calendering wall, configured to conform a central part PC of a front face FF of the MAT padding facing the occupant of the seat intended to receive the user's buttocks for the seat cushion or the back of the occupant for a back cushion, and

- lateral portions, on either side, of the central portion, following two hollow reliefs RC1 of the calendering wall, configured to conform two lateral flanges BL of the padding, projecting from the central part PC, on the front face FF, the side flanges BL configured to ensure lateral support for the occupant. [0082] According to the embodiment, in particular illustrated in Figure 2, the first calendering member OC1 is also of variable radius, around the axis of rotation A1 of the first member; the section of the tangle shaped by the work of the calendering members OC1, OC2 is then variable over time.

[0083] According to another embodiment, in particular illustrated in Figure 7, the calendering wall of the first counter-rotating member OC1 can present, all around the axis 1 of the first counter-rotating member OC1, said variable radius, along a line L1 of the calendering wall of the first calendering member, at the intersection between a plane passing through the axis of rotation and the calendering wall. On the other hand, the first calendering member OC1 is a body of revolution and the second calendering member 002 is a body of revolution: the section of the shaped tangle is constant over time, as the members rotate of calendering 001, OC2.

[0084] According to this embodiment of Figure 7, and in the same manner as illustrated in Figure 3a, such a variable radius along the line L1 is configured to form:

- lateral portions, on either side, of the central portion, following two hollow reliefs RC1 of the calendering wall, configured to conform two lateral flanges BL of the padding, projecting from the central part PC, on the front face FF, the side flanges BL configured to ensure lateral support for the occupant.

[0085] The first contra-rotating calendering member OC1 being configured to conform the front face FF of the padding, the second contra-rotating calendering member 002 is then configured to conform the dorsal face FD of the padding.

[0086] For this purpose, the second calendering member 002 may have at least one angular section around the second counter-rotating calendering member, a variable radius along a line L2 of the calendering wall of the second calendering member OC2, at the intersection between a plane passing through the axis of rotation A2 and the calendering wall.

[0087] For example, such a variable radius along line L2 is configured to form:

- a central portion, following a second recessed relief RC2 configured to extend to the right of the projecting relief RS1 of the first rotating member,

- lateral portions, following second protruding reliefs RS2, on either side of the central wall, configured to extend to the right of the two recessed reliefs RC1 so as to form on a dorsal face FD of the tangle of the padding, opposite the front face FF, a central portion PCE, of a padding, projecting relative to the lateral portions PL of the dorsal face FD, located at the back of the two lateral flanges BL.

[0088] According to the embodiment of Figure 2, the second calendering member OC2 is also of variable radius, around the axis of rotation A2 of the second calendering member forming the padding MAT which is shaped in relief, of section variable following the direction of travel of the 3D entanglement during the rotations of the two contra-rotating members OC1, OC2.

[0089] According to another embodiment, the calendering wall of the second counter-rotating member 002 can present, around the axis 2 of the second counter-rotating member, in particular according to the embodiment of Figure 7, said variable radius, the along a line L2 of the calendering wall of the second calendering member, at the intersection between a plane passing through the axis of rotation and the calendering wall. On the other hand, the radius of the second calendering member 002 is constant around the axis of rotation A2.

[0090] According to one embodiment, in particular illustrated in Figure 7, the padding shaped by the work of the first calendering member 001 generating the central part PC and the lateral flanges BL on the front face FF, or even, shaped by the work of the second calendering member 002 generating the central portion PCE projecting relative to the lateral portions PL on the face dorsal, is a PF preform of constant section, following the direction of travel.

[0091] The method can then comprise a step of cutting a length section of the preform, and a step of shaping the preform by thermoforming the length section of the preform, and as illustrated in Figure 8.

[0092] Thermoforming equipment comprising a mold part M1 and a second mold part M2, then typically thermoforms the preform in order to obtain the complete shaping of the padding, and in particular to confer a relief in the direction of scrolling of the padding, or even accentuate the relief between the side flanges BL and the central part PC, following the direction perpendicular to the direction of scrolling.

[0093] Thus Figure 11 is a view of the section of the padding, during shaping in two stages, the first shaping by the calendering members, namely of the preform illustrated in solid lines, the shaping, by thermoforming, final illustrated in dotted lines. Such shaping in two stages is advantageous for creating high amplitude reliefs, such as for example the lateral flanges BL of the padding visible in Figure 1 1, and in comparison to shaping in a single step (for example by thermoforming only) which can cause excessive stress on the fibers, in the areas of the padding requiring a large shaping amplitude, and thus lead to local tearing or at the very least areas where the fibers are weakened.

[0094] According to one embodiment, the MAT padding may have all or part of the following characteristics:

- the 3D tangle of the padding has an apparent density of between 20kg/m3 and 70 kg/m3, for example between 45kg/m3 and 65 kg/m3,

- the composition of the fibers comprises at least 95% by weight of PET, and for example the fiber composition comprises by weight, 95% to 99% of PET, 1% to 5% of a second polymer distinct from PET such as PTT or PBT. [0095] Full fibers can preferably be used, superficially on the front face FF intended to be in contact with the occupant of the seat in order to form a first “soft” layer, and preferably hollow, “structural” fibers. on the remainder of the thickness of the padding below this first layer to form a structural underlayer.

[0096] The present disclosure also relates to a MAT seat, base or backrest padding suitable for being obtained according to the method according to the present disclosure.

[0097] The MAT padding comprises a 3D tangle of continuous thermoplastic fibers arranged irregularly, in particular randomly, forming loops welded together between the fibers, and in which:

- the fibers are hollow fibers and/or solid fibers, for example with a diameter of between 0.2 mm and 2 mm, preferably between 0.3 mm and 1.5 mm,

- the composition of the fibers comprising in particular at least 95% by weight of PET,

- the 3D tangle of the padding has an apparent density for example between 20kg/m ³ and 70 kg/m ³ , and for example between 45 kg/m ³ and 65 kg/m ³ .

[0098] By “continuous” in “continuous fibers” is meant the fact that the fibers are of length much greater than the diameter of the fibers, and due to the processes described above, typically at least by a ratio 100, even 500, even 1000.

Very often, and in particular as can be understood from the manufacturing process, the fibers typically extend from a first end on a first edge of the 3D entanglement and to a second end on a second edge of the 3D entanglement , opposite the first edge.

[0100] Notably, the 3D entanglement of the MAT padding presents:

- a front face FF shaped in relief by the calendering wall of a first rotary calendering member OC1 and/or

- a dorsal face FD shaped in relief by the calendering wall of a second rotary calendering member OC2.

[0101] The present disclosure also relates to a vehicle seat comprising: - a typically metallic structure 3 comprising a seat structure 3A and/or a backrest structure 3B,

- a MAT padding, according to this disclosure, such as a back padding or a seat padding, resting on the structure,

- possibly a CF cap, covering the front face of the padding.

[0102] The seat padding preferably extends:

- in length from a rear edge of the seat structure 3A and to a front edge of the seat structure 3A,

- in width from a (first) flange 31 of the seat structure and up to a (second) flange 31 of the seat structure.

[0103] The back padding preferably extends:

- in length from a lower edge of the 3D backrest structure and to an upper edge of the 3B backrest structure,

- in width from a (first) upright 32 of the backrest structure and up to a (second) upright 32 of the backrest structure 3B.

[0104] Generally speaking, advantageously, the shaped front face FF may comprise a central part PC, and two projecting lateral flanges BL intended to ensure lateral support of the occupant. The central part PC and the two side flanges are obtained by the relief calendering of the first calendering member OC1, and in particular by the work of printing the hollow reliefs RC1 and the projecting relief RS1, along the line L1.

[0105] Advantageously, the dorsal face FD, opposite the front face FF, can comprise a central portion PCE, projecting relative to two lateral portions PL of the padding. The central portion PCT and the two lateral portions PL are obtained by the relief calendering of the second calendering member OC2, and in particular the printing work of the second hollow relief RC2 and the second projecting reliefs RS2, along the line L2.

[0106] For a seat cushion, the central portion PCE of the dorsal face is inserted between the two puddles 31 of the seat structure A3 while the two lateral portions PL respectively bear on the two flanges 31. [0107] For back padding, the central portion PCE of the dorsal face is inserted between the two uprights 32 of the backrest structure 3B while the two lateral portions PL respectively come to rest on the two uprights 32.

[0108] Note that the lateral portions PL, on the dorsal face can respectively have grooves, on the back of the lateral flange BL, extending along the lengths of the flanges, inside which the flanges 31 of the padding can fit seat, or the amounts of the back padding. These grooves can be formed by the printing work of the second projecting reliefs RS2, and as can be understood from Figure 3a. Such grooves used for nesting the structure contribute to the good centering of the padding on the structure 3. In general, the cover can be fixed on the structure 3 and in particular so as to ensure that the padding MT is maintained on the structure 3.

[0109] The dorsal face FD of the seat cushioning may also include a transverse groove G configured to receive in interlocking a rear tube bracing between the two flanges 31 of the seat structure. In general, such a transverse groove G can be advantageously shaped by the work of the second calendering member OC2, and as can be understood by way of example from Figure 2.

[0110] According to a fourth aspect, the present disclosure still relates to equipment suitable for implementing the manufacturing process according to the present disclosure, said equipment comprising:

- an extrusion die 2 comprising extrusion nozzles 20 distributed along a length direction X and along a width direction Y of the extrusion die, generating a curtain R of melted continuous fibers, falling by gravity,

- two contra-rotating calendering members OC1, OC2, rotatably arranged along two parallel articulation axes ensuring the reception of the melted fibers falling by gravity with a generation of a 3D entanglement 1 of fibers according to an irregular distribution with fusion of loops between the fibers continuous and according to a section layer determined locally by a space between the calendering walls of the two counter-rotating members. [0111] The two calendering members OC1, OC2 can be partially immersed in a basin of said equipment, to obtain the solidification of the 3D tangle of fibers by immersion in a cooling liquid.

[0112] According to the present disclosure, at least one of the two calendering members comprises a calendering wall of relief shape configured to ensure the relief of said raised face, or the two calendering members respectively comprising relief-shaped calendering walls configured to respectively ensure the relief of the two opposite faces of the entanglement.

[0113] Also notably, the relief-shaped calendering wall, or else the relief-shaped calendering walls, are of variable radius at least along a line of the calendering wall of the calendering member, at l intersection between a plane passing through the axis of rotation of the calendering member and the calendering wall so as to produce a 3D entanglement 1 forming the padding MAT which is shaped in relief, following the direction of the counter-rotating members OC1, OC2 .

[0114] According to an advantageous embodiment, said calendering member 001; 002 (first and/or second organ) may include:

- a cylindrical NY core, extending along the length of said calendering member

- a set of rings B1, B2, B3, removably mounted on the core, distributed juxtaposed along the length of said calendering member, so as to form the calendering wall of relief shape, of variable radius along the length of said calendering member .

[0115] For the purpose of simplification, Figure 9 illustrates an embodiment comprising three juxtaposed rings, including a first ring B1, a second ring B2 and a third ring B3. Juxtaposed. It is quite understandable that the number of rings can be significantly greater than three in, and particular depending on the complexity of the desired design. [0116] According to an embodiment illustrated schematically in Figure 10, the core comprises an internal pipe for a cooling liquid. The core is typically rotated by an MOT motor.

[0117] ODR radial orifices are distributed along the length and periphery of the NY core, in communication with ODR radial orifices of the rings B1, B2, B3, authorizing a flow of the cooling liquid in radial directions from the internal pipe of the core to the periphery of the calendering member, through the radial orifices of the core and the rings.

List of reference signs

[0118] - 1: 3D entanglement of thermoplastic fibers,

- 2. Extrusion die,

- 20. Nozzles,

- R. Curtain of melted fibers,

- F.F. Front face (shaped by molding)

- BL. Side flanges (front face),

-PC. Central part (Front face),

- FD. Dorsal face (not shaped by molding),

- PCE. Central portion (dorsal side)

- PL. Lateral portions (dorsal side)

- 3. Structure,

- 3A. Seating structure,

- 3B. Folder structure,

- 31. Flanges (seat structure),

- 32. Amounts

- MAT. Padding,

- SUP. Suspension

- X, Y, Z. Longitudinal direction, transverse direction, and vertical direction,

- OC1. First calendering member,

- A1. Axis of rotation (first calendering member)

- RC1. Hollow reliefs (of the calendering wall of the first calendering member along line L1)

-RS1. Projecting relief (from the calendering wall of the first calendering member following line L1)

- 0C2. Second calendering member,

- RC2. Second hollow relief (of the calendering wall of the second calendering member along line L2) - RS2. Projecting relief (from the calendering wall of the second calendering member along line L2)

-PT1. Fiber bridges (following directions transverse to the strip),

- PT2. Second fiber bridge (following a longitudinal direction of the strip),

-PF. Preform (figures 7 and 8, even 11), - Fl. Final shape of the padding (dotted figure 1 1),

- ODR. Radial ports (core and rings)

- M1, M2. First mold part and second mold part (thermoforming equipment,

-NY. Core (calendering member), - B1, B2, B3 rings (first, second and third),

- WORD. Motorization for rotating the core and the rings secured in rotation to the core,

Claims

[Claim 1] Method for manufacturing a seat padding in which a padding (MAT) is obtained comprising a 3D tangle of continuous thermoplastic fibers (1) arranged irregularly forming loops welded together, the 3D tangle of fibers ( 1) presenting at least one raised, non-planar face, or said entanglement presenting two raised, non-planar, opposite faces, said method comprising:

- a highlighting of said at least one face of the entanglement, or of the two opposite faces of the entanglement, by passing the 3D entanglement between two counter-rotating calendering members (OC1, 002), rotatably arranged in two parallel articulation axes, at least one of the two calendering members comprising a calendering wall of relief shape configured to ensure the highlighting of said raised face, or the two calendering members respectively comprising walls of calendering of relief shape configured to respectively ensure the relief of the two opposite faces of the entanglement.

[Claim 2] Method according to claim 1 in which the relief-shaped calendering wall, or else the relief-shaped calendering walls, are:

- of variable radius at least along a line of the calendering wall of the calendering member, at the intersection between a plane passing through the axis of rotation of the calendering member and the calendering wall so as to produce a 3D entanglement (1) forming the padding (MAT) which is shaped in relief, following the direction of the counter-rotating members (0C1, 002) and/or,

-of angularly variable radius around the axis of rotation of the counter-rotating member, so as to produce a 3D entanglement (1) forming the padding (MAT) which is shaped in relief, of variable section following the direction of scrolling of the 3D entanglement during the rotations of the two contra-rotating organs (OC1, OC2).

[Claim 3] Manufacturing process according to claim 1 or 2, continuous, comprising:

- /A/ Extrusion of a thermoplastic polymer in an extrusion die (2) comprising extrusion nozzles (20) distributed in a length direction (X) and in a width direction (Y) of the die d extrusion, generating a curtain (R) of melted continuous fibers, falling by gravity,

- /B/ Receiving the curtain of molten continuous fibers falling by gravity between said two counter-rotating calendering members (OC1, OC2), rotatably arranged along two parallel articulation axes, with generation of the 3D entanglement (1) of fibers according to an irregular distribution with fusion of loops between the continuous fibers and according to a layer of section determined locally by a space between the calendering walls of the two counter-rotating members,

- /C/ Solidification of the 3D tangle of fibers by immersion in a cooling liquid and in which said highlighting of the tangle, by passing the 3D tangle between the two counter-rotating calendering members, is carried out in / B/, simultaneously with the generation of the 3D entanglement.

[Claim 4] Method according to claim 3, in which the section of the 3D entanglement shaped by the two calendering members (OC1, OC2) is determined locally by the sectional space between the two calendering walls, according to a plane passing through the two axes of rotation of the counter-rotating calendering members, and in which the calendering member(s) are of angularly variable radius around the axis of rotation of the counter-rotating member so that said space is of variable section following the rotations of the counter-rotating members and in which the nozzles are controllable, configured so as to be able to change the section of the curtain of fibers, and in which a logical processing unit (U) is provided having a control module comprising a microprocessor and a memory comprising instructions for, in /A/, controlling the nozzles so as to generate a curtain of molten fibers, of variable section during extrusion following the length direction adapt the section of the curtain of molten fibers, to the sectional space between the calendering walls, in real time, during the rotations of the counter-rotating members.

[Claim 5] Method according to one of claims 1 or 2 in which the shaping of the entanglement, by passing the 3D entanglement between the two counter-rotating calendering members, is obtained successively to said provision of the entanglement 3D, subsequent to the generation of the 3D entanglement.

[Claim 6] Method according to one of claims 1 to 5, in which a first of the two counter-rotating members is a first counter-rotating member (OC1) configured to shape a front face (FF) of the padding intended to receive the occupant, and in which the calendering wall of said first counter-rotating member (OC1) has, at least along an angular section of the first counter-rotating member, a variable radius along a line L1 of the calendering wall of the first calendering member (001) , at the intersection between a plane passing through the axis of rotation (A1) and the calendering wall, first calendering member (001) configured to form:

-a central portion, following a projecting relief (RS1) of the calendering wall, configured to conform a central part (PC) of a front face (FF) of the padding (MAT) facing the occupant of the seat intended to receive the user's buttocks for the seat padding or the occupant's back for backrest padding, and

- lateral portions, on either side, of the central portion, following two hollow reliefs (RC1) of the calendering wall, configured so as to form two lateral flanges (BL) of the padding, projecting from the central part (PC), on the front face (FF), the side flanges (BL) configured to ensure lateral support of the occupant.

[Claim 7] Method according to claim 6, in which the first rotating member (001) being configured to conform the front face (FF) of the padding, the second rotating member (002) being configured to conform the dorsal face (FD) of the padding, presenting, at least on an angular section around the second counter-rotating member, a variable radius along a line L2 of the calendering wall of the second calendering member (OC2), at the intersection between a plane passing through the axis of rotation (A2) and the calendering wall, said second calendering member (OC2) configured to form:

- a central portion, following a second recessed relief (RC2) configured to extend to the right of the projecting relief (RS1) of the first rotating member,

- lateral portions, following second projecting reliefs (RS2), on either side of the central wall, configured to extend to the right of the two recessed reliefs (RC1) so as to form on a dorsal face ( FD) of the 3D entanglement of the padding, opposite the front face (FF), a central portion (PCE), of a padding, projecting relative to the lateral portions (PL) of the dorsal face (FD), located on the back of the two side flanges (BL).

[Claim 8] Method according to claim 6 or 7, in which the padding shaped by the work of the first calendering member (OC1) generating the central part (PC) and the side flanges (BL) on the front face (FF), even when dependent on claim 7, shaped by the work of the second calendering member (OC2) generating the central portion (PCE) projecting relative to the lateral portions (PL) on the dorsal face, is a preform (PF) of constant section , following the direction of travel and in said method comprises a step of cutting a length section of the preform, and a step of shaping the preform by thermoforming the length section of the preform.

[Claim 9] Method according to one of claims 1 to 8, in which the padding (MAT) has all or part of the following characteristics:

- the 3D tangle of the padding has an apparent density of between 20kg/m ³ and 70 kg/m ³ , for example between 45 kg/m ³ and 65 kg/m ³ ,

- the composition of the fibers comprises at least 95% by weight of PET, and by example the fiber composition comprises by weight, 95% to 99% of PET, 1% to 5% of a second polymer distinct from PET such as PTT or PBT.

[Claim 10] Cushioning (MAT) of the seat or back of a seat suitable for being obtained according to the method according to one of claims 1 to 9 comprising a 3D entanglement of continuous thermoplastic fibers arranged randomly, forming loops welded between they between the fibers, and in which:

- the composition of the fibers comprising at least 95% by weight of PET,

- the 3D entanglement of the padding has an apparent density of between 20kg/m ³ and 70 kg/m ³ , and for example between 45 kg/m ³ and 65 kg/m ³ , and in which the 3D entanglement of continuous fibers present:

- a front face (FF) shaped in relief by the calendering wall of a first rotary calendering member (OC1) and/or

- a dorsal face (FD) shaped in relief by the calendering wall of a second rotary calendering member (OC2).

[Claim 11] Vehicle seat comprising:

- a typically metallic structure (3) comprising a seat structure (3A) and/or a backrest structure (3B),

- a padding (MAT), according to claim 10, such as a back padding or a seat padding, resting on the structure (3),

- possibly a cap (CF), covering the front face (FF) of the padding

[Claim 12] Vehicle seat according to claim 11, in which the shaped front face (FF) comprises a central part (PC), and two projecting side flanges (BL) intended to ensure lateral support of the occupant.

[Claim 13] Seat according to claim 11 or 12 in which the opposite dorsal face (FD) comprises a central portion (PCE), projecting relative to two lateral portions (PL) of the padding, and in which:

-- for a seat cushion, the central portion of the dorsal face is inserted between two puddles (31) of the seat structure (A3) while the two lateral portions (PL) come respectively to rest on the two flasks (31), -- for a back padding, the central portion (PCE) of the dorsal face is inserted between two uprights (32) of the back structure (3B) while the two lateral portions (PL) come respectively to rest on the two uprights (32).

[Claim 14] Equipment suitable for implementing the process according to one of claims 1 to 13, comprising:

- an extrusion die (2) comprising extrusion nozzles (20) distributed in a length direction (X) and in a width direction (Y) of the extrusion die, generating a curtain (R) of continuous melted fibers, falling by gravity,

- two counter-rotating calendering members (OC1, OC2), rotatably arranged along two parallel articulation axes ensuring the reception of the melted fibers falling by gravity with a generation of a 3D entanglement (1) of fibers according to an irregular distribution with fusion of loops between the continuous fibers and according to a layer of section determined locally by a space between the calendering walls of the two counter-rotating members, and in which at least one of the two calendering members comprises a calendering wall of relief shape configured to ensure the relief of said raised face, or the two calendering members respectively comprising calendering walls of relief shape configured to respectively ensure the relief of the two opposite faces of the entanglement characterized in that the wall relief-shaped calendering walls, or else the relief-shaped calendering walls, are of variable radius at least along a line of the calendering wall of the calendering member, at the intersection between a plane passing through the axis of rotation of the calendering member and the calendering wall so as to produce a 3D entanglement (1) forming the padding (MAT) which is shaped in relief, following the direction of the counter-rotating members (OC1, OC2).

[Claim 15] Equipment according to claim 14, in which said calendering member (OC1; OC2) comprises:

- a cylindrical core (NY), extending along the length of said calendering member

- a set of rings (B1, B2, B3), removably mounted on the core, crossed by the core, distributed juxtaposed along the length of said calendering member, so as to form the calendering wall with a relief shape, of variable radius depending on the length of said calendering member.

[Claim 16] Equipment according to claim 15, in which the core comprises an internal pipe for a cooling liquid, radial orifices, distributed along the length and periphery of the core, in communication with radial orifices of the rings, authorizing a flow of the coolant in radial directions from the internal pipe of the core to the periphery of the calendering member (OC1, OC2), through the radial orifices of the core (NY) and the rings (B1, B2, B3 ).