FR3107285A1 - A method of manufacturing a coating with an improved appearance, in particular a motor vehicle floor covering - Google Patents

Abstract

A method of manufacturing a coating with an improved appearance, in particular a motor vehicle floor covering The method comprises: a step of supplying a sheet (20) of first fibers (15), - a step of looping the first fibers (15), a step of accumulating the loops formed by the looping, a step of depositing of a reinforcing ply (38), formed of reinforcing fibers (17), on the accumulated loops, a step of needling the reinforcing ply (38) and the loops, in order to secure them, and a step of mowing curls. It comprises, together with the step of providing the web (20), providing at least one layer (21) of second fibers (17) different from the first fibers (15), and the superposition of the web (20). ) and the layer (21) on top of each other, the web (20) and the layer (21) passing together in the looping device (28). Figure for abstract: Figure 1

Description

Process for manufacturing a coating with improved appearance, in particular a motor vehicle floor covering

The present invention relates to a process for manufacturing an interior lining, in particular a floor covering for a motor vehicle.

Devices for manufacturing interior linings for motor vehicles are already known in the state of the art, comprising in particular a needling machine of the DILOUR® type.

For example, the document FR3041001 describes a coating manufacturing device capable of producing a homogeneous, high-density pile.

Such a device has the particularity of comprising conveyors covered with brushes which are used to form a homogeneous pile.

More particularly, the velvet is manufactured by implementing a preliminary step of producing a sheet of fibers elongated in a longitudinal direction, in particular by lapping with interlacing of the fibers, then a step of passing the sheet of fibers along the longitudinal direction, through a looping device comprising a set of rotating discs and fixed looping elements. The curling device curls the fibers by verticalizing them, thus forming undulations, then the sheet of fibers is brought on a conveyor equipped with brushes, so that the undulations accumulate in the brushes so as to reach a predetermined density.

In accordance with this known device, the structure constituted by the undulations of densified fibers is thus temporarily blocked inside the brushes of the conveyor of a Dilour machine, that is to say by a purely mechanical trapping and therefore without it is necessary to use a glue. This document then provides for the waves to penetrate deeper inside the brushes up to the depth corresponding to the height of the pile desired for the finished product.

It should be noted that this known device mainly makes it possible to manufacture a monochromatic and homogeneous coating. It could be possible to manufacture a two-tone covering by using fibers of two different colors in the initial layer of fibers, but the result would lead to a "quilting", which would not be aesthetically satisfactory.

The purpose of the present invention is in particular to allow the production of a two-tone and/or heterogeneous aesthetic coating, in a simple, economical and effective manner.

To this end, the subject of the invention is in particular a process for manufacturing a coating, in particular an interior coating of a motor vehicle, comprising the following steps:

- a step of supplying a sheet of first fibers,

- a step of looping the first fibers by means of a looping device comprising a set of rotating discs and fixed looping elements,

- a step of accumulation of the loops formed by the looping, in a conveyor equipped with brushes, arranged at the exit of the looping device,

- a step of depositing a reinforcing ply, formed of reinforcing fibers, on the loops accumulated in the brushes,

- a step of needling the reinforcement ply and the loops, in order to secure them, and

- a loop mowing step,

characterized in that it comprises, together with the step of supplying the web of first fibers, the supply of at least one layer of second fibers different from the first fibers, and the superposition of the web and of the layer one on top of the other, the sheet and the layer passing together through the looping device.

It is possible, thanks to the invention, to achieve various aesthetic effects by varying the fibers of the sheet and the fibers of the layer superimposed on this sheet.

For example, the first and second fibers can have different colors, which makes it possible to produce a two-tone coating.

As a variant, the first and second fibers can be of different natures, or arranged with different densities, which makes it possible to obtain various aesthetic effects.

Indeed, the loops made with the fibers of the web are superimposed with the loops made with the fibers of the diaper, so that all these fibers become visible after the loops have been sheared.

A manufacturing method according to the invention may also comprise one or more of the following characteristics, taken alone or in any technically conceivable combination.

- The first fibers have a first color, and the second fibers have a second color different from the first color.

- The layer of second fibers forms a sheet.

- The web of first fibers has a surface mass greater than that of the layer of second fibers.

- The layer of second fibers comprises fusible fibers, the method comprising a preliminary step of heating the layer of second fibers before it is packaged, before the step of supplying this layer.

- The method comprises a prior step of orienting the first fibers with respect to a longitudinal direction of advance, such that, the looping step being configured to generate undulations formed by loops each having a predefined width G in a direction perpendicular to the longitudinal direction, and a predefined height H in an elevation direction perpendicular to the transverse direction and to the longitudinal direction, the orientation step is configured to orient the fibers parallel to a general direction forming an angle α with the longitudinal direction (X), given by the relation sinα=G/2H to within +/- 5°.

- The first fibers are of a different nature from the second fibers, and have for example a different titer, a different shine, and/or are made of different materials.

The invention also relates to a device for manufacturing a coating, in particular a motor vehicle interior coating, comprising:

- a device for manufacturing a sheet of first fibers,

- a looping device for the first fibers comprising a set of rotating discs and fixed looping elements,

- a device for accumulating the loops formed by the looping, comprising a conveyor equipped with brushes, arranged at the exit of the looping device,

- a device for depositing a reinforcing ply, made up of reinforcing fibers, on the loops accumulated in the brushes,

- a needling device for the reinforcement ply and the loops, in order to join them together, and

- a loop mowing device,

characterized in that it comprises means for supplying at least one layer of second fibres, arranged upstream of the looping device, configured to superimpose the sheet and the layer on one another, upstream of the closure.

The invention finally relates to a covering, in particular the interior covering of a motor vehicle, having a face layer of fibers which are unbonded and parallel to one another, and a back layer forming a sole formed of fibers bonded together, characterized in that the face layer is formed of a succession of first fibers and second fibers, all connected to the back layer, the first and second fibers being different.

The invention will be better understood on reading the following description, given solely by way of example and made with reference to the appended figures, among which:

- FIG. 1 schematically represents a device for manufacturing a coating making it possible to carry out the manufacturing method according to an exemplary embodiment of the invention;

- Figure 2 is a partial sectional view of a coating produced by the manufacturing device of Figure 1, prior to the mowing of this coating;

- Figure 3 is a top view of a fiber web as it is inserted into the manufacturing device of Figure 1.

There is shown in Figure 1, a device 10 for manufacturing a needled covering 12.

The covering 12 forms for example an interior covering, and more particularly an interior covering of a motor vehicle, intended to be placed on the ground or on a wall of the vehicle. Alternatively, liner 12 may form any conceivable interior liner.

The coating 12 has a face layer 14 of unbonded fibers parallel to each other, and a back layer 16 forming a sole formed essentially of fibers bonded together.

Face layer 14 has a velvety outer appearance. This pile consists of fibers in the form of sheared loops, as will be described later in more detail.

The thickness of the face layer 14 is generally greater than that of the sole 16. The face layer 14 has for example a thickness of between 2 and 8 mm.

The pile density in the face layer 14 is preferably between 0.05 and 0.12 g/cm3, for example between 0.07 and 0.08 g/cm3. Such a density ensures a good appearance, good resistance to abrasion and ease of cleaning.

This density is measured for example by determining the ratio between the mass of the material obtained by shaving the entire face layer 14 up to the sole 16, relative to the initial volume of the shaved layer.

The yield of the pile, consisting of the ratio of the weight of pile after total shaving up to the sole relative to the total weight of the part 12, is for example between 50 and 80%.

The manufacturing device 10 comprises a carding device followed by a lapping device 18 (known as a crosslapper) with interlacing fibers, capable of producing a lap 20 of first fibers 15.

The length of the first fibers 15 used is generally between 40 and 150 mm.

The title of the first fibers 15 is preferably between 4 and 17 dtex.

The crimp of the first fibers 15 is preferably between 2.5 and 4 undulations per cm.

The carding operation is carried out in a conventional manner and makes it possible to obtain a veil with a surface weight of between 40 and 160 g/m², for example 50 g/m². Such a web is formed by first individualized fibers 15 mostly oriented in a longitudinal direction, corresponding to a production direction (machine direction). Nevertheless, these first fibers 15 overlapping slightly due to their crimp, it is accepted that the average angle with respect to the longitudinal direction of this type of veil is between 5 and 10° (We resonate here by positioning ourselves in a half plane with respect to the axis of the longitudinal direction, because the first fibers 15 are positioned symmetrically with respect to this axis). In the following and to facilitate the description, we will assume that this value, unless otherwise specified, is close to 0°.

The first fibers 15 are for example made from a thermoplastic polymer, such as polypropylene, polyethylene terephthalate (PET), polyamide, polylactic acid, their mixtures or their copolymers. As a variant, the first fibers can be fibers of natural origin such as flax or hemp fibers used alone or in mixtures.

It should be noted that, in the embodiment described, the first fibers have a first color. More particularly, all the first fibers forming the web 20 have the same first color, possibly with slight nuances.

The topping device 18 is of the conventional type, and will therefore not be described in more detail. The particularity of the use of this device in the context of the invention is that only one ply is made, so that the first fibers 15 intersected by the crosslapper extend parallel to a direction forming an average angle β of about 60° with the longitudinal direction X, obviously in the case where the layup width corresponds to the carding width.

The sheet 20 at this stage of the process therefore consists of two superposed webs having their first fibers 15 mainly oriented with an average angle β of 60° symmetrically with respect to the longitudinal axis X materializing the machine direction.

The manufacturing device 10 preferably comprises, following the laying device 18, a device 22 for orienting the first fibers 15 of the layer of fibers 20. This orientation device 22 can be placed at the outlet of the laying device 18, or alternatively be disposed at a distance, in which case the sheet of fibers 20 is moved from the lapping device 18 towards the orientation device 22.

The orientation device 22 is capable of modifying the orientation of the first fibers 15, initially oriented with the mean entry angle β, to parallelize them to a general direction A, B forming a predetermined mean angle α with the longitudinal direction X, as shown in Figure 3. The first fibers 15 being intersected, some are aligned parallel to a first general direction A forming an angle α with the longitudinal direction X in a clockwise direction, and others are aligned parallel to a second general direction B forming an angle α with the longitudinal direction X in a counterclockwise direction.

The orientation device 22 is, for example, a device for drawing the layer of fibers 20, the first fibers 15 of which are criss-crossed. This stretching device 22 comprising a first set 24 of upstream drive rolls, and a second set 26 of downstream drive rolls. Each set 24, 26 comprises two complementary cylinders between which the sheet 20 passes, in contact with these two cylinders. The rotational drive of the cylinders of each assembly 24, 26 therefore allows the sheet 20 to be driven along the longitudinal direction X.

This device 22 is strictly speaking an orientation device and not a stretching device, although the web 20 sees its surface mass reduced between the two sets of cylinders, because its role is to rotate the first fibers 15 relative to each other (their point of intersection serving as a pivot point) and not to stretch the web by causing the fibers to slide parallel to each other as in a conventional textile stretching device. As a result, the aim is to position the two sets of cylinders as close as possible. Thus if L is the length of the first fiber 15, the distance between the pinch lines of the two sets of cylinders will be slightly greater than L.cosβ.

However, later on, we can speak of stretching and stretched web in reference to this variation in surface mass of the web.

The downstream drive cylinders of the second set 26 are rotatable with a rotational speed greater than that of the upstream drive cylinders of the first set 24, so that the sheet of fibers 20 is not driven with the same speed. over its entire length. This web of fibers 20, passing between the cylinders of each assembly 24, 26, is then stretched due to this difference in speed.

This stretching makes it possible to align the first fibers 15 of the web 20 parallel to the desired general directions A and B.

We will note Ve the peripheral speed of the inlet cylinders and Pe the surface mass of the sheet engaging between the inlet cylinders, Vs the peripheral speed of the outlet cylinders and Ps the surface mass of the sheet engaging between the input cylinders. We will note α the average angle of the fibers with respect to the longitudinal direction X of the outlet sheet.

We have the following relation: E (stretching)=Ve/Vs=Pe/Ps=cosα/cosβ.

Thus, the value of E can be determined as a function of the desired angle α and the angle β which depends on the width of the web at the card outlet and the width of the topping.

We have tan β = 2 Ln/Lv,

with Ln topping width and Lv veil width.

So if Lv = Ln (for example in the case of a 2.5m wide card for a 2.5m topping corresponding to the width of the finished product) which will generally be the case, β≈60°.

If, for example, the desired value of α is 20°, we will therefore have E=cos 20°/cos 60°= 1.8

We have described a stretching device consisting of two sets of cylinders but this stretching could be carried out by different means. For example, it could take place between the end of the tablecloth supply belt and the discs of the device 30.

The manufacturing device 10 according to the invention also comprises at least one device 31 for supplying a layer 21 of second fibers 17.

The supply device 31 is arranged so as to superimpose the layer 21 with the web 20. In the example described, the layer 21 is superimposed on the web 20, but it could alternatively be superimposed under the web 20.

In the example described, the supply device 31 is an unwinder, carrying the rolled up layer 21 and unrolling it on the sheet 20 as the sheet 20 advances in the direction X. For example, the layer 21 is deposited on the web 20 just upstream of the drive rolls 26, so that it is also driven by these drive rolls 26, together with the web 20.

Layer 21 could alternatively be deposited on web 20 further upstream or further downstream.

It will be noted that the layer 21 can also have the form of a sheet, made in the same way as the sheet 20, but prior to the present manufacturing process. This sheet is then rolled up beforehand for its packaging, with a view to its unrolling as described above.

Optionally, the layer 21 can be obtained from a mixture of fibers comprising fusible fibers, in which case this layer 21 can be heated before conditioning, so as to present a certain cohesion and thus be more easily rolled up and unrolled.

As a variant, the layer 21 can be made parallel to the web 20, by means of a carding and alignment device similar to that described above, before being conveyed to be deposited on the web 20.

As a variant, the layer 21 can also come from a nonwoven such as a nonwoven of the weakly bonded “spunbonded” type.

In other variants, the layer 21 can be formed by any conceivable addition of textile material, in particular doupions, fragments of rovings, continuous filaments, etc.

In the example described, the second fibers 17 have a second color different from the first color. For example, the first color is black, and the second color is red or gray.

The second fibers 17 are for example made from a thermoplastic polymer, such as polypropylene, polyethylene terephthalate (PET), polyamide, polylactic acid, their mixtures or their copolymers. As a variant, the second fibers 17 can be fibers of natural origin such as flax or hemp fibers used alone or in mixtures.

The second fibers 17 are for example of the same nature as the first fibers 15.

However, in a variant, the second fibers 17 are of a different nature from that of the first fibers 15. The first 15 and second 17 fibers have for example a different fineness, a different shine, and/or are made of different materials. For example, the first fibers 15 can be based on polyamide while the second fibers 17 will be based on PET.

Alternatively or additionally, the layer 21 has a different density from that of the sheet 20.

Preferably, web 20 has a surface weight greater than that of layer 21. For example, web 20 may have a surface weight of about 50 g/m², and layer 21 a surface weight of about 20 g/m². m².

According to a variant, the device 10 could include at least one other device for supplying at least one other layer, in addition to the layer 21. All the layers are then superimposed on each other, and on the sheet 20. The layers can be formed from fibers of different types and/or colors.

The layer 20 and the superposed layer 21 then pass through a looping device 28, arranged at the outlet of the orientation device 22.

It will be noted that the sheet 20 and the layer 21 are not linked together, so that they react independently of each other to this looping device 28.

The looping device 28 is intended to loop the first fibers 15 of the sheet 20 and the second fibers 17 of the layer 21 by verticalizing them, thus forming superimposed undulations.

The looping device 28 comprises a set of rotating discs 30 carried on a common transverse axis, driven in continuous rotation at a peripheral speed preferably equal to the entry speed of the assembly of the veil 20 and the layer 21 in this looping device 28.

The rotating discs 30 are each preferably provided on its periphery with a set of teeth allowing the web 20 and the layer 21 to be driven.

The looping device 28 also comprises looping elements, in particular looping fingers 32, each being arranged between two adjacent discs 30 . The looper fingers 32 extend to one end which is substantially tangentially relative to the discs 30. Thus, each fiber 15, 17 is pre-looped by being driven at each end by a respective disc 30, overcoming the finger corresponding looper 32 disposed between these two discs 30.

The routing of a fiber 15, 17 between two adjacent discs 30 will now be described.

The fiber 15, 17 presents itself with an angle α with the longitudinal direction X, which is also the direction of advance of the web 20 in the looping device 28.

A front part of the fiber is driven by one of the discs 30, and a rear part of this fiber is driven by the other disc 30. These two discs being integral with the same axis, their speeds of rotation are identical.

The front part of the fiber arrives first at the end of its travel, against an abutment which will be described later. While the front part is in abutment, the rear part continues to advance until it also comes into abutment, thus bending the fiber which then forms a loop.

The fibers passing through the looping device 28 all have the same behavior as described above, so that all of the looped fibers form undulations over the width of the sheet 20 and of the layer 21, taken in one direction. transverse perpendicular to the longitudinal direction X.

Each loop of the web 20 has a height H, taken in an elevation direction perpendicular to the longitudinal direction and to the transverse direction, and a width G taken in the transverse direction. It should be noted that the width G corresponds substantially to the interval between two adjacent discs 30.

The loops of the layer 21 are superimposed on the loops of the web 20, as shown in Figure 2. Indeed, the fibers of the layer 21 are looped with the fibers of the web 20. Each loop of the layer 21 has a height H2.

The discs 30 are positioned in such a way that they penetrate to a depth P≤H2 inside the brushes of a belt 33 of the same type as the brushes equipping the conveyor of a Dilour® machine. At the location of the discs, the bristles making up the brushes are flexible enough to move apart and gather in the free space between the discs.

This type of band serves as a stopper as mentioned above. Indeed, when they are no longer in the presence of the discs, the brush bristles, by returning to their initial position, exert pressure on the fibers which makes it possible to block and then maintain the structure of the undulations.

The abutment mentioned above is therefore formed by a belt 33 of a conveyor 34. The belt 33 is an endless belt, extending between two drive cylinders. Strip 33 is provided with brushes.

The strip 33 is moved, in the longitudinal direction X, with a speed lower than the tangential speed of the rotating discs 30, so that they have the effect of a stop for the fibers coming out of these rotating discs 30.

The undulations then accumulate on the brushes of the strip 33, with a density depending on the difference in speed between the rotating discs 30 and the strip 33. Those skilled in the art will be able to determine this difference in speed as a function of the density desired.

It will be noted that the undulations of the web 20 come to accumulate independently of the accumulation of the undulations of the layer 21.

After accumulation, it will thus be possible to obtain, for example, a product of 700g/m² having two rows of superimposed loops of 500g/m² and 200g/m². After shearing this will result in rows of thicker first fibers alternating with rows of more discreet second fibers.

This device makes it possible to obtain a high density of velvet, which is generally not achievable by conventional methods.

The brushes also prevent the fibers from being drawn upwards by the discs 30, which would harm the formation of the waves.

The manufacturing device 10 then comprises a device 36 for depositing a reinforcing ply 38 on the corrugations accumulated on the brushes. The reinforcing ply 38 is formed by reinforcing fibers.

The reinforcing fibers are for example made from a thermoplastic polymer, such as polypropylene, polyethylene terephthalate (PET), polyamide, polylactic acid, their mixtures or their copolymers. As a variant, the reinforcing fibers can be fibers of natural origin such as flax or hemp fibers used alone or in mixtures.

The reinforcing fibers are for example of the same nature as the first fibers 15 and/or of the same nature as the second fibers 17.

However, in one variant, the reinforcing fibers are of a different nature from that of the first fibers 15 and/or from that of the second fibers 17. different.

The reinforcing ply 38 can also be formed from a mixture comprising a percentage of binder fibers, that is to say, for example, bi-component fibers, one of the components of which has a lower melting point than the other.

It should be noted that the reinforcing ply 38 is preferably pre-needled. Thus, the reinforcing fibers are bonded together by this pre-needling operation.

The structure formed by stacking the corrugated fibers 15, 17 and this reinforcing ply 38 is then intended to pass under a needling device 40 or needling head, comprising at least one needle board 41.

The assembly formed by the brush conveyor 34 and the needle boards is known per se, and for example formed by a machine of the Dilour® type.

The needle board 41 is arranged opposite the strip 33 of the conveyor 34, and it can be deployed vertically towards this strip 33 to pierce said structure.

The needle plate 41 carries a plurality of needles, the implantation of the needles of which complies with the Dilour® process and leads to homogeneous needling. Thus, this implantation can be arbitrary (known as “random” type) without in any way favoring a particular lineage.

This board of needles 41 makes it possible to secure the reinforcing ply 38 to the structure made up of superimposed undulations, by extracting reinforcing fibers from the ply 38 and causing them to penetrate into the ply 20 and the layer 21.

The needling device is configured so that the depth of penetration of the reinforcing fibers of the reinforcing ply 38 into the ply 20 and the layer 21 is sufficiently small so that the reinforcing fibers are not visible on the pile side after shearing. . This height depends on the type of needles fitted to the needling head of the Dilour® machine, and the nature of the reinforcement ply 38.

During this needling, the face layer 14 is formed, as well as the sole 16.

The device 10 then comprises a device for bonding the fibers of the face layer 14 in the sole 16. This bonding device 42 is for example a heat-setting device, in particular a through-air oven or an infrared oven.

The bonding can be carried out in any conceivable way, for example by incorporating a latex into the reinforcing ply 38, or between the reinforcing ply 38 and the superposition of the ply 20 and the layer 21, or by incorporating thermofusible binder fibers among the fibers of the web of fibers 20 and/or among the fibers of the layer 21 and/or in the reinforcing web 38. Binder fibers are generally preferred to latex, for reasons of recyclability.

This binding, necessary for all constructions of the needle-punched type to ensure sufficient cohesion of the fibers of the pile with the sole and to avoid problems of tearing or abrasion, is carried out in a conventional manner and will therefore not be described in more detail.

The device 10 then comprises a device 44 for shearing the top of the accumulated undulations of the structure, thus forming a pile of vertical fibers. Due to the verticalization of the corrugations in the looping device 28 and the perfect parallelism of the fibers resulting therefrom, the sheared fibers all have the same height, so that the appearance of the pile is optimized. It should be noted that the scraps of shorn fibers can be subsequently recycled. The mowing is carried out in such a way as to mow the loops of the web 20 that are under the loops of the layer 21, according to the mowing line T shown in Figure 2.

After mowing the loops, the first fibers 15 which were under the second fibers 17 are visible. Thus, by providing second fibers 17 of a color other than that of the first fibers 15, a two-tone effect of stripes is obtained. Other effects are possible by choosing first 15 and second 17 fibers of different natures.

Finally, the device 10 comprises a device 46 for rolling up the coating 12 formed, with a view to handling it.

It should be noted that, so that the pile has an optimal appearance, in particular an optimal density, and that it does not have prematurely broken fibers in the looping discs, which would harm its general appearance, the angle α of orientation of the fibers must respect the relation sinα=G/2H to within +/- 5°. The orientation of the fibers according to this angle α is implemented by the parameter setting of the orientation device 22.

The device according to the invention makes it possible to carry out a method for manufacturing a two-tone needled coating, which will now be described.

The manufacturing process comprises a step of producing a web and then the web of first fibers 20 having only one ply, by lapping with interlacing of the fibers. It will be recalled here that the first fibers 15 are for example chosen with a first color.

The manufacturing method then includes a step of orienting the first fibers 15 parallel to the first A or the second B general direction, each forming an angle α (clockwise or counterclockwise respectively) with the longitudinal direction X. This orientation step is carried out by means of the orientation device 22, configured so that the angle α responds to the relation sinα=G/2H, to within +/- 5°, G and H being predetermined, as indicated previously.

Prior to the production of the sheet 20, or in parallel, the manufacturing method comprises a step of producing a layer 21 of second fibers 17. It will be recalled here that the second fibers 17 are for example chosen in a second color different from the first one.

The method then includes the stacking of the web 20 and the layer 21, one on the other.

The method then comprises a step of passing the sheet of fibers 20 and the stacked layer 21, along the longitudinal direction X, through the looping device 28, so as to generate undulations.

The manufacturing process then includes a step of bringing the sheet of fibers 20 and the layer 21 onto the conveyor 34 equipped with brushes, and of accumulating the undulations in the brushes so as to reach a predetermined density. The conveyor 34 is arranged at the output of the discs 30, so that this feed step is carried out by the discs 30.

As mentioned earlier, the ripple density depends on the difference in speeds between the discs 30 and the belt 33.

It should be noted that the corrugated fibers thus accumulated are perfectly parallelized between them, so that the appearance of the coating 12 produced is optimal.

The method then includes a step of depositing the reinforcing ply 38, preferably pre-needled, on the accumulated corrugations. This reinforcement ply 38 is intended to form at least in part the sole 16.

The method then includes a step of needling the sheet of fibers 20 through the brushes of the strip 33, to form the structure comprising the face layer 14 and the sole 16, in accordance with a conventional needling process. Thanks to the needling step, the coating produced by the process according to the invention is thermoformable, therefore entirely suitable for the production of motor vehicle floor coverings.

The method then includes a step of removing the structure thus formed from the conveyor 34.

The method then includes a step of blocking or bonding the fibers of the face layer 14 in the sole 16. This blocking step is carried out in the blocking device 42, by any conceivable means.

The method then includes a step of mowing the top of the accumulated undulations of the structure. During this step, the first fibers 15 which were under the loops of second fibers 17 become visible, as shown in Figure 2.

The method finally comprises a step of rolling up the coating 12 thus formed, with a view to handling it.

It will be noted that the invention is not limited to the embodiments described above, and could present various variants.

In particular, the applications of this type of coating can extend to sectors other than the automotive industry, such as housing or rail transport, even in cases where formability is not required.

Claims (9)

Process for manufacturing a coating (12), in particular a motor vehicle interior coating, comprising the following steps:
- a step of supplying a layer (20) of first fibers (15),
- a step of looping the first fibers (15) by means of a looping device (28) comprising a set of rotating discs (30) and fixed looping elements (32),
- a step of accumulating the loops formed by the looping, in a conveyor (34) equipped with brushes, arranged at the output of the looping device (28),
- a step of depositing a reinforcing ply (38), formed of reinforcing fibers (17), on the loops accumulated in the brushes,
- a step of needling the reinforcing ply (38) and the loops, in order to secure them, and
- a loop mowing step,
characterized in that it comprises, together with the step of supplying the sheet (20) of first fibers (15), the supply of at least one layer (21) of second fibers (17) different from the first fibers ( 15), and the superposition of the web (20) and the layer (21) one on the other, the web (20) and the layer (21) passing together through the looping device (28). A manufacturing method according to claim 1, wherein the first fibers (15) have a first color, and the second fibers (17) have a second color different from the first color. Manufacturing process according to claim 1 or 2, in which the layer (21) of second fibers (17) forms a web. Manufacturing method according to any one of the preceding claims, in which the layer (20) of first fibers has a basis weight greater than that of the layer (21) of second fibers. Manufacturing method according to any one of the preceding claims, in which the layer (21) of second fibers comprises fusible fibers, the method comprising a preliminary step of heating the layer of second fibers before its conditioning, before the step of provision of this layer (21). Manufacturing process according to any one of the preceding claims, comprising a prior step of orienting the first fibers (15) with respect to a longitudinal direction (X) of advance, such that, the looping step being configured to generate undulations formed by loops each having a predefined width G in a transverse direction perpendicular to the longitudinal direction, and a predefined height H in an elevation direction perpendicular to the transverse direction and to the longitudinal direction, the orientation step is configured to orient the fibers parallel to a general direction forming an angle α with the longitudinal direction (X), given by the relation sinα=G/2H to within +/- 5°. Manufacturing process according to any one of the preceding claims, in which the first fibers (15) are of a different nature from the second fibers (17), and have for example a different fineness, a different shine, and/or are produced in different materials. Device for manufacturing a coating, in particular a motor vehicle interior coating, for implementing the method of claim 1, the device comprising:
- a device (18, 22) for manufacturing a sheet (20) of first fibers (15),
- a device (28) for looping the first fibers (15) comprising a set of rotating discs (30) and fixed looping elements (32),
- a device for accumulating the loops formed by the looping, comprising a conveyor (34) equipped with brushes, arranged at the output of the looping device (28),
- a device (36) for depositing a reinforcing ply (38), formed of reinforcing fibers, on the loops accumulated in the brushes,
- a device (40) for needling the reinforcing ply (38) and the loops, in order to secure them, and
- a loop mowing device (44),
characterized in that it comprises means (31) for supplying at least one layer (31) of second fibers (17), arranged upstream of the looping device (28), configured to superimpose the sheet (20) and the layer (21) one on top of the other, upstream of the looping device (28). Lining (12), in particular the interior lining of a motor vehicle, having a face layer (14) of fibers which are unbonded and parallel to one another, and a back layer (16) forming a sole formed of fibers bonded to one another, characterized in that the face layer (14) is formed of a succession of first fibers (15) and second fibers (17), all connected to the back layer (16), the first and second fibers being different .