FR3079448A1 - METHOD FOR MANUFACTURING A TRIM AND CORRESPONDING CLAD - Google Patents

Abstract

The manufacturing method makes it possible to manufacture a covering comprising an aspect coating (6) at least partially covering a substrate (4). The manufacturing method comprises: - the manufacture of the multilayer coating (6) comprising a decorative layer (8), a barrier layer (10) comprising a sealed barrier film (16) and a reinforcing layer (12), the barrier layer (10) being interposed between the decorative layer (8) and the reinforcing layer (12); then - assembling the appearance coating (6) and the substrate (4), the reinforcing layer (12) being located on the side of the substrate (4) and the decorative layer (8) being located on the opposite side.

Description

METHOD FOR MANUFACTURING A COVERING AND CORRESPONDING COVERING

The present invention relates to the field of skins, in particular vehicle skins, in particular motor vehicle skins.

It is possible to manufacture a covering comprising a substrate and a decorative layer covering the substrate and intended to impart a particular appearance to the covering. It is in particular possible to provide a decorative layer in the form of a sheet woven of carbon threads, to give the covering the appearance of a part made of plastic material reinforced with carbon threads.

However, the carbon threads of the decorative layer can move relative to one another during the shaping of the decorative layer carried out during the manufacture of the covering. Furthermore, molten material from another layer of the covering, molten material from the substrate or glue used during the manufacture of the covering can pass between the carbon wires and be visible on the visible side of the decorative layer of the covering. This produces defects in the appearance of the clothing which affect the perceived quality.

One of the aims of the invention is to propose a method of manufacturing a covering making it possible to limit the risks of appearance defect.

To this end, the invention provides a method of manufacturing a covering, in particular for a vehicle, comprising an appearance coating at least partially covering a substrate, the manufacturing method comprising:

- the manufacture of the multilayer appearance coating comprising a decorative layer, a barrier layer comprising a waterproof barrier film, and a reinforcing layer, the barrier layer being interposed between the decorative layer and the reinforcing layer; then

- the assembly of the appearance coating and the substrate, the reinforcing layer being located on the side of the substrate and the decorative layer being located on the opposite side.

In particular modes of implementation, the method may include one or more of the following optional characteristics, taken in isolation or in any technically possible combination:

- the manufacture of the appearance coating includes the pressing of the decorative layer, the barrier layer and the reinforcing layer on top of each other for their assembly;

the barrier layer comprises at least one adhesive layer covering one face of the barrier film, one or each face of the barrier film being covered with an adhesive layer;

the barrier film is produced in a thermoplastic elastomer, for example in thermoplastic polyurethane;

- The method comprises the shaping of the appearance coating before the assembly of the appearance coating and the substrate and / or during the assembly of the appearance coating and the substrate;

- The assembly of the appearance coating and the substrate is carried out by overmolding of the substrate on the appearance coating or by bonding of the appearance coating on the substrate supplied beforehand;

- It includes the application of a protective layer on the decorative layer of the appearance coating, on the side of a visible front face of the appearance coating, before the assembly of the appearance coating and the substrate;

- the protective layer is made of a material chosen from polyurethane, epoxy and unsaturated polyester.

- the protective layer is molded on the decorative layer;

the protective layer is molded on the decorative layer with a molding pressure equal to or less than 20 bars, in particular equal to or less than 5 bars;

the protective layer has a glass transition temperature equal to or greater than 70 ° C, in particular equal to or greater than 80 ° C, a Young's modulus equal to or greater than 2,500 N / mm ² in the temperature range between 50 ° C and 100 ° C, a shore D hardness equal to or greater than 70 shore D in the temperature range between 50 ° C and 100 ° C, and / or a thickness equal to or greater than 0.5 mm; and

the decorative layer is a sheet of wood, a sheet of metal, a sheet of mineral or a fabric, in particular a fabric of carbon threads or a fabric of Kevlar threads.

The invention also relates to a covering, in particular for a vehicle, comprising a substrate and an appearance coating covering the substrate, the appearance coating being multilayer and comprising a decorative layer, a barrier layer comprising a waterproof barrier film, and a layer reinforcing, the barrier layer being interposed between the decorative layer and the reinforcing layer, the reinforcing layer being located on the side of the substrate and the decorative layer being located on the side opposite to the substrate.

In particular embodiments, the covering may include one or more of the following optional characteristics, taken in isolation or in any technically possible combination:

the barrier film is produced in a thermoplastic elastomer, for example in thermoplastic polyurethane;

- the substrate is overmolded on the appearance coating or bonded to the appearance coating;

- The appearance coating includes a protective layer covering the decorative layer on the side opposite the substrate;

- the protective layer is made of a material chosen from polyurethane, epoxy and unsaturated polyester;

- the protective layer (14) has a glass transition temperature equal to or greater than 70 ° C, in particular equal to or greater than 80 ° C, a Young's modulus equal to or greater than 2,500 N / m ² in the range temperature between 50 ° C and 100 ° C, a shore D hardness equal to or greater than 70 shore D in the temperature range between 50 ° C and 100 ° C, and / or a thickness equal to or greater than 0.5 mm .

The invention and its advantages will be better understood on reading the description which follows, given solely by way of example, and made with reference to the appended drawings, in which:

- Figure 1 is a sectional view of a covering;

- Figure 2 is a sectional view of a barrier layer of the covering of Figure 1;

- Figure 3 is a schematic view illustrating a step of manufacturing a coating of appearance of the covering of Figure 1, in which the barrier layer is integrated;

- Figure 4 is a schematic view illustrating a step of applying a protective layer of the appearance coating;

- Figure 5 is a schematic view illustrating the overmolding of a substrate on the coating to obtain the covering;

- Figure 6 is a schematic view illustrating a step of shaping an appearance coating;

- Figure 7 is a schematic view illustrating the bonding of an appearance coating on a substrate to obtain a covering; and

- Figure 8 is a schematic view illustrating a step of manufacturing a coating appearance of a covering.

The covering 2 illustrated in FIG. 1 comprises a substrate 4 and an appearance coating 6 assembled to the substrate 4.

The covering 2 is for example a vehicle covering, in particular a motor vehicle covering.

The substrate 4 gives the covering 2 its general shape. In an exemplary embodiment, the substrate 4 is made of plastic, in particular of molded thermoplastic.

The appearance coating 6 at least partially covers the substrate 4. The appearance coating 6 completely covers the substrate 4 here.

The aspect coating 6 is intended to be visible and to give a particular appearance to the covering 2.

The appearance coating 6 includes a visible front face 6A facing away from the substrate 4 and an opposite rear face 6B, hidden and facing the substrate 4.

In the following description, the terms "front", "rear", "front", "behind" refer to the visible front face 6A and the hidden rear face 6B of the aspect coating 6 located respectively in front and behind.

In a particular embodiment, the substrate 4 is overmolded on the aspect coating 6, more precisely on the reverse side of the appearance coating 6, Le. on the rear face 6B of the aspect coating 6. This reverse molding is for example carried out by compression molding or by injection molding (or BIM for "back injection molding" in English).

The aspect 6 coating is laminated. It is multilayer and formed by superposition and assembly of layers between them. Such a laminated aspect 6 coating is generally called a "laminate complex".

The appearance coating 6 comprises a decorative layer 8, a barrier layer 10 and a reinforcing layer 12. The barrier layer 10 is sandwiched between the decorative layer 8 and the reinforcing layer 12.

The decorative layer 8 is located on the side of a visible front face 6A facing away from the substrate 4 and the reinforcing layer 12 is located on the side of a hidden rear face 6B facing towards the substrate 4.

The decorative layer 8 located on the visible side gives its appearance to the appearance coating 6, and therefore to the covering provided with this appearance coating 6.

The decorative layer 8 is for example a sheet, preferably chosen from a textile sheet, a sheet of wood, a mineral sheet, a sheet of metal, a sheet of glass and a sheet of plastic material reinforced with fibers or threads.

A textile sheet is woven, non-woven or knitted and made of natural or synthetic threads, for example made of carbon threads, aramid threads (or Kevlar®), cotton threads, wool threads, threads hemp and / or plastic yarn. A metallic decorative sheet is for example an aluminum sheet. A fiber-reinforced plastic decorative sheet includes a matrix of plastic reinforced with carbon fibers or aramid fibers embedded in the matrix. A mineral decorative sheet is for example a layer of quartz or shale stone such as slate or mica.

In a preferred embodiment, the decorative layer 8 is a textile sheet woven from carbon threads or a textile sheet woven from aramid threads, a sheet of wood or a mineral sheet.

In a particular embodiment, the decorative layer 8 is a textile sheet woven from carbon threads with inclusions of metallic threads, for example aluminum threads. The inclusion of metallic threads, and in particular aluminum threads, in a textile made of carbon threads, gives an attractive aspect.

The reinforcing layer 12 is provided to reinforce the decorative layer 8, in order to obtain a coating of appearance 6 which is easy to handle and which can be easily used to manufacture the covering 2. The reinforcing layer 12 also promotes the assembly of the appearance coating 6 with the substrate 4.

In one embodiment, the reinforcing layer 12 is a sheet, for example a woven, nonwoven or knitted textile sheet made of natural or synthetic threads, a sheet of cardboard, a sheet of paper, a sheet of plastic material or a metallic foil ...

A laminated aspect coating 6 comprising a decorative layer 8 of wood is generally called "laminated wood complex" (or WSC for "wood sheet complex").

A coating with a laminated appearance comprising a decorative layer 8 of carbon threads is generally called "laminated carbon complex" (or CSC for "carbon sheet complex").

The barrier layer 10 is tight so as to prevent the passage of fluids in the viscous or liquid state during the manufacture of the appearance coating 6 and the covering 2.

Thus, the barrier layer 10 prevents a fluid in the viscous state or a fluid in the liquid state, coming from the side of the reinforcing layer 12, from impregnating the decorative layer 8.

The barrier layer 10 also prevents the suction of fluid in the viscous state or of fluid in the liquid state by the reinforcing layer 12, by capillary action and through the decorative sheet 8, which would increase the impregnation of the layer. decorative 8.

Optionally, and as illustrated in FIG. 1, the appearance coating 6 comprises a protective layer 14 covering the decorative layer 8 on the side of the visible face 6A of the appearance coating 6. The decorative layer 8 is sandwiched between the protective layer 14 and the barrier layer 10.

The protective layer 14 has the function of protecting the decorative layer 8 during the manufacture of the covering 2, in particular during the assembly of the appearance coating 6 and the substrate 4.

In particular, in the event of overmolding of the substrate 4 on the appearance coating 6 by injection or compression molding, the material of the substrate 4 under pressure can crush the decorative layer 8, in particular by crushing the wires of the decorative layer 8, which can alter the visual aspect. The protective layer 14 covering the decorative layer 8 prevents such crushing.

In an exemplary embodiment, the protective layer 14 is a resin layer, preferably thermosetting. The protective layer 14 is for example a layer of polyurethane, epoxy, polyester.

Preferably, the protective layer 14 is produced in a two-component resin which is obtained by mixing two components, the mixing of these two components causing the resin to harden. Such resins harden quickly, generally faster than one-component resins, which facilitates the manufacture of the coating of appearance 6.

The protective layer 14 preferably has one or more of the following characteristics:

a glass transition temperature of 70 ° C or more, especially 80 ° C or more;

a Young's modulus equal to or greater than 2,500 N / mm ² in the temperature range between 50 ° C and 100 ° C;

a shore D hardness equal to or greater than 70 shore D in the temperature range between 50 ° C and 100 ° C; and / or a thickness of 0.5 mm or more.

These characteristics of the protective layer 14 make it possible to effectively protect the decorative layer 8 during manufacture.

The glass transition temperature above a determined threshold makes it possible to ensure that the protective layer 14 retains sufficient mechanical characteristics (Young's modulus and / or shore hardness D) during the assembly of the appearance coating 6 and the substrate 4, in particular when the assembly is carried out hot, as is the case during an overmolding by injection or by compression.

The Young's modulus greater than a determined threshold in a determined temperature range and / or the shore hardness D greater than a determined threshold in a determined temperature range make it possible to ensure that the protective layer 14 will withstand the mechanical stresses exerted during of the assembly of the appearance coating 6 and the substrate 4, and in particular the pressure exerted during an overmolding by injection or compression, without the appearance coating 6 being negatively affected.

The thickness greater than a determined threshold makes it possible to ensure that the protective layer 14 is sufficiently thick to ensure a distribution of the stresses such that the appearance coating 6 is not negatively affected during the application of pressure, especially during injection or compression molding.

As illustrated in FIG. 1, the covering 2 optionally includes a surface layer 15. The surface layer 15 protects the appearance coating 6 from blows, scratches and / or ultraviolet radiation. The surface layer 15 is for example a layer of synthetic resin, for example a varnish. The surface layer 15 is transparent or translucent, and optionally colored. The surface layer 15 here covers the protective layer 14

As illustrated in FIG. 2, the barrier layer 10 comprises a tight barrier film intended to prevent the passage of fluids in the viscous or liquid state during the manufacture of the appearance coating 6 and of the covering 2.

The barrier layer 10 can comprise at least one adhesive layer making it possible to assemble the barrier layer 10 to another layer of the appearance coating 6.

In the example illustrated, the barrier layer 10 is formed of a barrier film 16 sandwiched between two adhesive layers 18. The barrier layer 10 is produced for example by co-extrusion-blowing of the barrier film 16 between two adhesive layers 16 ,

18.

The barrier film 16 has a thickness between 20 μm and 200 μπι, in particular a thickness between 20 μπι and 60 μπι, in particular a thickness of approximately 40 μπι.

The barrier film 16 is for example made of elastomeric material, in particular of thermoplastic polyurethane (or TPU for "thermoplastic polyurethan" in English).

In a particular example, the barrier film 16 is made of TPU with a thickness of around 40 μm.

The two adhesive layers 18 have the same thickness or different thicknesses. The two adhesive layers 18 each have a thickness of between 10 μm and 200 μm, in particular a thickness of between 20 μm and 60 μm, in particular a thickness of approximately 40 μm.

The two adhesive layers 18 are for example made of the same material. Alternatively, they are made of different materials. Each of the two adhesive layers 18 is produced for example from copolyamide.

The barrier layer 10 comprising adhesive layers 18 facilitates the manufacture of the appearance coating 6, in particular facilitating the assembly of the decorative layer 8, the barrier layer 10 and the reinforcement layer 12.

A method of manufacturing the covering of FIG. 1 and variants will now be described with reference to FIGS. 3 to 8.

The manufacturing process includes assembling the decorative layer 8, the barrier layer 10 and the reinforcement layer 12 (Figure 3), then, optionally, applying a protective layer 14 on the coating. aspect (Figure 4), then the assembly of the aspect coating 6 and the substrate 4 (Figure 5).

In the example illustrated in FIG. 3, the decorative layer 8, the barrier layer 10 and the reinforcement layer 12 are produced separately, then assembled to produce the coating of appearance 6 in the form of a laminated complex.

In one embodiment, the appearance coating 6 is formed by superimposing the decorative layer 8, the barrier layer 10 and the reinforcing layer 12, and pressing them one on the other to assemble them. The adhesive layer 8, the barrier layer 10 and the reinforcement layer 12 are assembled by the adhesive layers 18.

The decorative layer 8, the barrier layer 10 and the reinforcing layer 12 are here superimposed and pressed against each other by passage between two parallel and counter-rotating rollers 20 of a pressing station 22. This type of pressing is also called rolling .

A single pressing station 22 is shown in Figure 3, but it is of course possible to provide several successive pressing stations.

The decorative layer 8, the barrier layer 10 and the reinforcement layer 12 are here pressed simultaneously. As a variant, it is also possible to proceed successively, by pressing the barrier layer 10 with one of the decorative layer 8 and the reinforcing layer 12 to assemble them, then by pressing the subassembly thus formed with the other. among the decorative layer 8 and the reinforcing layer 12.

Optionally, the decorative layer 8, the barrier layer 10 and the reinforcement layer 12 are hot pressed, and in particular hot rolled.

To do this, at least one of these layers of the appearance coating 6 is heated before and / or during pressing. For heating before pressing, it is possible to provide heating devices arranged upstream of pressing to heat at least one of the sheets of the appearance coating 6. For heating during pressing, it is possible to provide heated pressing (here 20 heating rollers).

In the example illustrated, the heating is carried out upstream of the pressing by means of heating devices 23 arranged to heat the barrier layer 10.

Preferably, and as illustrated in FIG. 3, the decorative layer 8, the barrier layer 10 and the reinforcement layer 12 are packaged in the form of continuous strips 24, 26, 28 which are superimposed and pressed by passing through at least a pressing station 22 to form a complex continuous strip 30 which is then cut in a cutting station 32 to form coatings of discrete appearance 6.

The protective layer 14 is applied to the decorative layer 8 after the step of assembling the decorative layer 8, the barrier layer 10 and the reinforcing layer 12.

In an exemplary embodiment, the protective layer 14 is produced by inserting the appearance coating 6 in a molding cavity 34 of a mold 36 and then molding the protective layer 14 in the molding cavity 34.

In the example illustrated in Figure 4, the protective layer 14 is formed from a two-component resin. The mold 36 comprises two reservoirs 38 each containing a respective component of the two-component resin, a mixer 40 for mixing the two components, and a filling device 41 for injecting the mixture into the molding cavity 34.

The mixer 40 is for example configured to carry out the spray mixing of the two components at high pressure, for example at a pressure of the order of 120 bars. This allows rapid and efficient mixing of the two components for rapid polymerization. The mixing is carried out in a separate mixing chamber separate from the molding cavity 34.

The filling of the mold cavity 34 is carried out at a filling pressure equal to or less than 20 bars, preferably equal to or less than 5 bars, in particular equal to or less than 4 bars.

Optionally, a filling overpressure can be observed punctually at the very end of filling due to the reaction time between the detection of the complete filling of the molding cavity 34 and the stopping of the filling device 41.

The molding of the protective layer 14 at low pressure avoids damaging the decorative layer 8 during molding, and thus preserving its appearance, for a better final result.

In any event, the filling pressure is strictly lower than the molding pressure of the substrate 4 when the substrate 4 is produced by compression or injection molding.

In the example illustrated in FIG. 5, the appearance coating 6 and the substrate 4 are assembled by overmolding of the substrate 4 on the appearance coating 6, more precisely here on the appearance coating 6 covered with the protective layer 14.

To do this, the appearance coating 6 is placed in an overmolding mold 42 in the presence of molten plastic 44 intended to form the substrate 4 after molding.

The overmolding mold 42 here comprises two mold parts 46, 48 movable with respect to one another to selectively open and close the overmolding mold 42.

In one embodiment, the molding of the substrate 4 is carried out by injection molding. In this case, the previously manufactured appearance coating 6 is placed in the overmolding mold 42, then molten plastic material 44 is injected into the mold by at least one supply channel 50 formed in a mold part 48 , to mold the substrate 4.

In another embodiment, the molding of the substrate 4 is carried out by compression molding. Molten plastic and the coating of appearance 6 are arranged in the overmolding mold 42 open, then the overmolding mold 42 is closed so that the molten plastic material previously introduced into the overmolding mold 42 is molded inside the overmolding mold 42 against the appearance coating 6, and forms the substrate 4.

In an exemplary implementation, the appearance coating 6 is shaped into the desired three-dimensional shape together with overmolding of the substrate 4 on the appearance coating 6. The appearance coating 6 is inserted substantially flat in the mold overmolding 42, and the shaping of the coating of appearance 6 in its final three-dimensional form results from the closing of the mold for overmolding 42 and / or from the overmolding of the substrate 4 on the coating of appearance 6.

After the overmolding of the substrate 4, an assembly is obtained comprising the substrate 4 covered with the appearance coating 6.

Optionally, the manufacturing method comprises at least one step of cutting and / or machining the appearance coating 6, implemented between the assembly of the appearance coating 6 and the step of assembling the substrate 4 and aspect coating 6.

Cutting includes, for example, cutting openings in the appearance coating and / or cutting the outer edges of the appearance coating. The machining includes for example the machining of internal edges of openings of the aspect coating 6 and / or of an external edge of the appearance coating 6.

When the appearance coating 6 comprises a protective layer 14, it is possible to provide a step of cutting and / or machining the appearance coating 6 before the application of the protective layer 14, and / or a cutting and / or machining step between applying a protective layer 14 and assembling the substrate 4 and the appearance coating 6.

Optionally, when the appearance coating 6 comprises a protective layer 14, the manufacturing process comprises a step of surfacing the protective layer 14. The surfacing step comprises for example sanding and / or polishing.

Optionally, the manufacturing process includes the application of the surface layer 15 (Figure 1). The surface layer 15 is applied after the appearance coating 6 and the substrate 4 have been assembled. The surface layer 15 is applied for example by spraying.

When the appearance coating 6 comprises a protective layer 14 and the manufacturing process comprises a surfacing step, the application of a surface layer is for example carried out after the surfacing step.

As an option, and as illustrated in FIG. 6, the manufacturing process comprises shaping the appearance coating 6 to give it a permanent three-dimensional shape, before the substrate 4 and the appearance coating 6 are assembled.

The shaping is advantageously carried out by thermoforming. Thermoforming includes heating and deformation of the heated aspect coating 6 to give it the desired three-dimensional shape.

As illustrated in FIG. 6, the shaping is here carried out in a shaping mold 50 comprising two mold parts 52, 54 configured to be brought together to shape the coating d 'aspect 6 inserted between the two mold parts 52, 54.

In an embodiment particularly suitable for shaping the appearance coating 6 before it is assembled with the substrate 4, the reinforcing layer 12 is a textile sheet made of thermoplastic threads.

When the appearance coating 6 has a protective layer 14, the shaping is for example carried out before the application of the protective layer 14, as illustrated in FIG. 6.

Thus, the protective layer 14 is applied to the appearance coating 6 already shaped. The appearance coating 6 can be shaped by applying a low pressure so as not to adversely affect the decorative layer 8. As a variant, the protective layer 14 is applied before the shaping step. The protective layer 14 then protects the decorative layer 8 during the shaping of the appearance coating 6 provided with the protective layer 14.

When a step of cutting and / or machining the coating 6 is provided before assembling the coating of appearance 6 and the substrate 4, this step of cutting and / or machining is preferably carried out before the shaping.

Instead of overmolding the substrate 4 on the aspect coating 6, the manufacturing process may include supplying the substrate 4 and then assembling the substrate 4 and the appearance coating 6, as illustrated in Figure 7.

The appearance coating 6 is for example glued to the substrate 4 using a layer of glue applied between the two as shown diagrammatically by a glue tank 56 in FIG. 7, and / or hot pressed against the substrate 4 , so that the appearance coating 6 and the substrate 4 are joined together.

When the appearance coating 6 comprises a protective layer 14, this is applied before or after the assembly of the substrate 4 and the appearance coating 6. As illustrated in FIG. 7, the protection layer 14 is of preference applied before assembling the substrate 4 and the appearance coating 6.

In the example illustrated in Figures 1 to 3, the barrier layer 10 comprises a barrier film 16 sandwiched between two adhesive layers 18.

In a variant illustrated in FIG. 8, the barrier layer 10 is formed only from a thermoplastic barrier film 16 (being devoid of adhesive layers).

In this case, for the assembly of the decorative layer 8, the barrier layer 10 and the reinforcement layer 12, at least the thermoplastic barrier film 16 is heated to be brought to a temperature higher than its glass transition temperature, and the decorative layer 8, the barrier layer 10 and the overlapping reinforcement layer 12 are pressed when the barrier layer 10 is above its glass transition temperature.

This allows the decorative layer 8, the barrier layer 10 and the reinforcement layer 12 to be assembled by softening the barrier film 10 due to heating, then hardening of the barrier layer 10 during cooling. The barrier layer 10 adheres to each of the decorative layer 8 and the reinforcing layer 12.

In one embodiment, the decorative layer 8, the barrier layer 10 and the reinforcing layer 12 are heated so that the temperature of the barrier layer 10 rises above its glass transition temperature and pressed. As a variant, only the barrier layer 10 is heated so that the temperature of the barrier film 10 passes above its glass transition temperature, the decorative layer 8 and the reinforcing layer 12 not being specifically heated.

As a variant or as an alternative, as illustrated diagrammatically in FIG. 8 by the glue tanks 56, the manufacture of the coating of appearance 6 comprises the supply of glue between the decorative layer 8 and the barrier layer 10 and / or glue between the barrier layer 10 and the reinforcement layer 12.

It is possible to provide an adhesive supply between the decorative layer 8 and the barrier layer 10 and an adhesive supply between the barrier layer 10 and the reinforcing layer 12, to provide an adhesive supply between the decorative layer 8 and the layer barrier 10 without providing an adhesive supply between the barrier layer 10 and the reinforcing layer 12, or providing an adhesive supply between the barrier layer 10 and the reinforcing layer 12, without providing an adhesive supply between the decorative layer 8 and barrier layer 10.

It is possible to bond the assembly formed by the superposition of the decorative layer 8, the barrier layer 10 and the reinforcing layer 12 in a single pressing operation.

As a variant, it is also possible to proceed successively, by bonding the barrier layer 10 with one of the decorative layer 8 and the reinforcing layer 12, then by bonding the sub-assembly with the other from among the decorative layer 8 and the reinforcing layer 12.

It is possible to provide a barrier layer 10 having a barrier film 16 and a single adhesive layer 18 serving to bond the barrier layer 10 with one of the decorative layer 8 and the reinforcing layer 12, the other being bonded to the barrier layer 10 with a supply of glue before pressing.

Thus, in general, the barrier layer 10 consists of a barrier film or comprises an adhesive layer 18 on only one of the two faces of the barrier film 16 or an adhesive layer 18 on each face of the barrier film 16.

The covering 2 and the associated manufacturing process make it possible to limit the risks of appearance defect of the covering 2, which preserves the quality perceived by the user.

The barrier layer 10 interposed between the decorative layer 8 and the reinforcing layer 12 has the function of stabilizing the decorative layer 8. In particular, when the decorative layer 8 is a woven or meshed textile sheet, the barrier layer 10 applied and glued against the decorative layer 8 prevents the wires from moving relative to each other, and also makes it possible to stabilize its overall geometry.

The waterproof barrier layer 10 interposed between the decorative layer 8 and the reinforcing layer 12 also has the function of preventing the impregnation of the decorative layer 8 by a fluid during the manufacture of the coating itself and of the covering. in general.

If the substrate 4 is overmolded onto the appearance coating 6, the impermeable barrier layer 10 prevents the plastic overmolding material from impregnating the decorative layer 8.

If glue is used to assemble the appearance coating 6 and the substrate 4, the barrier layer 10 prevents the glue from impregnating the decorative layer 8.

Furthermore, when the appearance coating 6 is provided with a protective layer 14 or a surface layer 15 in contact with the appearance layer 8, the barrier layer 10 prevents the suction of the protective layer 14 or of the surface layer 15 by the reinforcing layer 12, by capillarity phenomenon, through the decorative layer 8, which would cause excessive impregnation of the decorative layer 8 by the protective layer.

Thus, the barrier layer 10 makes it possible to preserve the appearance of the decorative layer 8 by stabilizing the decorative layer during a possible shaping and by avoiding or limiting the impregnation of the decorative layer 8 by a fluid used during the manufacture of the coating itself and of its assembly with the substrate 4.

Furthermore, the protective layer 14 protects the decorative layer 8 during the manufacturing process, so as to preserve the visual appearance of the decorative layer 8, in particular despite the pressure and the crushing stresses suffered by the decorative layer 8 at during the manufacturing process, in particular during the assembly 5 of the substrate 4 and the appearance coating 6.

The protective layer 14 is advantageous independently of the waterproof barrier layer 10 in order to preserve the decorative layer 8 during the manufacture of the covering.

Thus, in general, the invention also relates to a method for manufacturing a covering, in particular for a vehicle, the manufacturing method comprising the provision of a coating of multilayer appearance having a decorative layer, a reinforcing layer situated behind the decorative layer and a protective layer located in front of the decorative layer, then assembling the appearance coating on a substrate, the reinforcing layer being located on the side of the substrate and the decorative layer being located on the opposite side. The assembly is carried out for example by overmolding the substrate on the appearance coating, in particular by compression overmolding or by injection.

Claims (17)

1. - Method for manufacturing a covering, in particular for a vehicle, comprising an appearance coating (6) at least partially covering a substrate (4), the manufacturing method comprising: - the manufacture of the multilayered appearance coating (6) comprising a decorative layer (8), a barrier layer (10) comprising a waterproof barrier film (16), and a reinforcing layer (12), the barrier layer (10) being interposed between the decorative layer (8) and the reinforcing layer (12); then - The assembly of the appearance coating (6) and the substrate (4), the reinforcing layer (12) being located on the side of the substrate (4) and the decorative layer (8) being located on the opposite side, in which the decorative layer (8) is a sheet of wood, a sheet of metal, a sheet of mineral, a fabric of carbon threads or a fabric of Kevlar threads. 2. - The manufacturing method according to claim 1, wherein the manufacture of the appearance coating (6) comprises pressing the decorative layer (8), the barrier layer (10) and the reinforcement layer (12) on top of each other for assembly. 3. - The manufacturing method according to claim 1 or claim 2, wherein the barrier layer (10) comprises at least one adhesive layer (18) covering one side of the barrier film (16), one or each side of the barrier film. (16) being covered with an adhesive layer (18). 4. - Manufacturing process according to any one of the preceding claims, in which the barrier film (16) is produced in a thermoplastic elastomer (TPE), for example in thermoplastic polyurethane (TPU). 5. - Manufacturing method according to any one of the preceding claims, comprising the shaping of the appearance coating (6) before assembly of the appearance coating (6) and the substrate (4) and / or during assembling the appearance coating (6) and the substrate (4). 6. - Manufacturing process according to any one of the preceding claims, in which the assembly of the appearance coating (6) and the substrate (4) is carried out by overmolding of the substrate (4) on the appearance coating ( 6) or by bonding the appearance coating (6) to the substrate (4) previously supplied. 7. - Manufacturing method according to any one of the preceding claims, comprising the application of a protective layer (14) on the decorative layer (8) of the appearance coating (6), on the side of a face before (6A) visible from the appearance coating (6), before the assembly of the appearance coating (6) and the substrate (4). 8. - The manufacturing method according to claim 7, wherein the protective layer (14) is made of a material chosen from polyurethane (PUR), epoxy and unsaturated polyester. 9. - The manufacturing method according to claim 7 or claim 8, wherein the protective layer (14) is molded on the decorative layer (8). 10. - Manufacturing method according to any one of claims 7 to 9, wherein the protective layer (14) is molded on the decorative layer (8) with a molding pressure equal to or less than 20 bar, in particular equal or less than 5 bars. 11. - Manufacturing process according to any one of claims 7 to 10, in which the protective layer (14) has: a glass transition temperature of 70 ° C or more, especially 80 ° C or more; a Young's modulus equal to or greater than 2500 N / mm ² in the temperature range between 50 ° C and 100 ° C; a shore D hardness equal to or greater than 70 shore D in the temperature range between 50 ° C and 100 ° C; and / or a thickness of 0.5 mm or more. 12. - Cover, in particular for a vehicle, comprising a substrate (4) and an appearance coating (6) covering the substrate (4), the appearance coating (6) being multilayer and comprising a decorative layer (8), a barrier layer (10) comprising a waterproof barrier film (16), and a reinforcing layer (12), the barrier layer (10) being interposed between the decorative layer (8) and the reinforcing layer (12), the layer reinforcement (12) being located on the side of the substrate (4) and the decorative layer (8) being located on the side opposite the substrate (4), in which the decorative layer (8) is a sheet of wood, a sheet of metal , a mineral sheet, a fabric of carbon threads or a fabric of Kevlar threads. 13. - covering according to claim 12, wherein the barrier film (16) is made of a thermoplastic elastomer (TPE), for example thermoplastic polyurethane (TPU). 14. - Dressing according to claim 12 or claim 13, wherein the substrate (4) is overmolded on the appearance coating (6) or bonded to the appearance coating (6). 15. - Dressing according to any one of claims 12 to 14, wherein the appearance coating (6) comprises a protective layer (14) covering the decorative layer (8) on the side opposite the substrate (4). 16. - covering according to claim 15, wherein the protective layer (14) 5 is made of a material chosen from polyurethane, epoxy and unsaturated polyester. 17. - Dressing according to claim 15 or claim 16, wherein the protective layer (14) has: a glass transition temperature of 70 ° C or more, especially 80 ° C or more; 10 - a Young's modulus equal to or greater than 2,500 N / m ² in the temperature range between 50 ° C and 100 ° C; a shore D hardness equal to or greater than 70 shore D in the temperature range between 50 ° C and 100 ° C; and / or a thickness of 0.5 mm or more.