FR3067636B1 - METHOD FOR MANUFACTURING A VEHICLE INTERIOR TRIM - Google Patents

Abstract

This method of manufacture comprises a step of cold forming a sheet (4) to give it a three-dimensional shape, the sheet having a first face (4A) and a second face (4B) opposite, then the sheet (4) being in the three-dimensional form, a step of crosslinking a first varnish (10) covering the first face (4A) and / or a second varnish (12) covering the second face (4B) of the sheet (4).

Description

Method of manufacturing a vehicle interior trim

The present invention relates to the field of interior trim of a vehicle, especially a motor vehicle. It is possible to manufacture a vehicle interior trim comprising a structure having a support surface and a sheet applied and adhered to the support surface.

When the support surface of the structure is non-planar, there is a risk that the sheet will peel off the support surface, leading to an appearance defect detrimental to the perceived quality.

To remedy this, it is possible to form the hot sheet to give it, irreversibly, the three-dimensional shape of the support surface of the structure, before gluing on the support surface. Thus, the sheet intrinsically has the shape of the support surface and the risk of separation is reduced.

However, hot forming can increase the cycle time (i.e. the manufacturing time of an inner liner) and / or can cause surface defects on a visible side of the sheet, which can adversely affect the perceived quality.

One of the aims of the invention is to provide a method of manufacturing a vehicle interior trim to obtain a satisfactory perceived quality. For this purpose, the invention proposes a method of manufacturing a vehicle interior trim, the trim comprising a sheet having a first face and a second opposite face, the manufacturing method comprising a step of cold forming of the sheet. to give it a three-dimensional shape, and then, the sheet being in the three-dimensional shape, a step of crosslinking a first varnish covering the first face and / or a second varnish covering the second face of the sheet.

Cold forming of the sheet can reduce the risk of generating surface defects on the sheet. Crosslinking a first varnish covering the first face of the sheet and / or a second varnish covering the second face of the sheet after the cold forming of the sheet stiffens the first varnish and / or the second varnish a once the sheet is in the desired three-dimensional shape, and freeze the sheet into this three-dimensional shape. The sheet can then be glued to a corresponding three-dimensional support surface by limiting the risk of delamination.

In particular embodiments, the method of manufacture comprises one or more of the following optional features, taken individually or in any technically possible combination: the sheet is provided with the first varnish and / or the second varnish before the step cold forming the sheet, in an unpolymerized or partially polymerized state; the method comprises a step of applying the first varnish and / or the second varnish to the sheet before the cold forming of the sheet, in an unpolymerized or partially polymerized state; the method comprises a step of applying the first varnish and / or the second varnish to the sheet after the cold forming step of the sheet and before the crosslinking step; the first face is intended to be visible and the second face is intended to be invisible; the first varnish and / or the second varnish is (are) polymerizable by exposure to ultraviolet (UV) radiation, the crosslinking step comprising exposing the sheet to ultraviolet (UV) radiation; - the first varnish and / or the second varnish is (are) polymerizable (s) hot, the crosslinking step comprising heating the sheet; - The method comprises a step of assembling the sheet against a support surface of a structure, the support surface having a three-dimensional shape corresponding to that of the sheet after the cold forming; the sheet is fixed on the support surface by gluing; the sheet is provided with the first varnish and the second varnish, the first varnish and the second varnish being of identical compositions or of different compositions. The invention also relates to a vehicle interior trim, the trim comprising a sheet of three-dimensional shape having a first face and a second opposite face, the first face being covered with a first varnish in the crosslinked state and / or the second face being covered with a second varnish in the crosslinked state, and a structure having a support surface of shape complementary to the sheet, the sheet being fixed on the support surface of the structure.

In particular embodiments, the interior cladding comprises one or more of the following optional features, taken individually or in any technically possible combination: the structure has an opening at the right of the sheet; the first varnish is transparent or translucent, and / or the second varnish is transparent or translucent. The invention further relates to an interior trim assembly comprising the interior trim as defined above and a light device visible through the opening of the structure and through the sheet. The invention and its advantages will be better understood on reading the description which will follow, given solely by way of nonlimiting example, and with reference to the appended drawings, in which: FIGS. 1 to 4 illustrate steps of FIG. 'a method of manufacturing a vehicle interior trim; and - Figures 5 to 9 illustrate steps of a method of manufacturing a vehicle interior trim according to a variant.

Figures 1 to 4 illustrate steps of a method of manufacturing a vehicle interior lining 2, the interior lining 2 comprising a sheet 4 comprising a first face 4A and a second face 4B opposite. The sheet 4 is here fixed, for example bonded, to a support surface 6 of a structure 8.

The sheet 4 is made of a cold formable material. By "cold formable" is meant that the sheet 4 having an initial shape may be plastically deformed without heat input so as to give it a final shape different from the initial shape, the sheet 4 retaining the final shape at the end cold forming.

The sheet 4 is for example made of glass or plastic for example polycarbonate (PC) or acrylic (PMMA).

The first visible face 4A is intended to be turned towards an occupant of the passenger compartment, opposite the support surface 6. The second face 4B is intended to be turned towards the support surface 6.

The sheet 4 is provided with a first varnish 10 covering the first face 4A of the sheet 4 and / or a second varnish 12 covering the second face 4B of the sheet 4. The sheet 4 is here provided with a first varnish 10 and a second varnish 12.

Each of the first varnish 10 and the second varnish 12 is capable of being polymerized, for example by heat input and / or by exposure to radiation, in particular ultraviolet (UV) radiation. The polymerization of each of the first varnish 10 and the second varnish 12 causes it to harden and stiffen.

The sheet 4 is provided with the first varnish 10 and the second varnish 12 in the uncrosslinked state. The term "crosslinked" here means the complete or almost complete polymerization of the varnish so that the varnish is hardened and rigid. Each varnish 10, 12 is unpolymerized, i.e. the polymerization has not started, or partially polymerized or "prepolymerized", i.e. the polymerization has started but is incomplete.

The first varnish 10 and the second varnish may be of identical or different compositions from one another. The first varnish 10 located on the visible side of the sheet 4 can be chosen for its visual rendering properties. The second varnish 12 located on the masked side of the sheet 4 may be chosen for its compatibility with an adhesive used for bonding the sheet 4 to the support surface 6.

The sheet 4 is obtained by being already coated with the first varnish 10 and the second varnish 12, the application of the first varnish 10 and the second varnish 12 having been made beforehand, for example by a manufacturer of the sheet 4.

Alternatively, as shown in Figure 1 in dashed lines, the method of manufacture comprises the application of the first varnish 10 and the second varnish 12, for example by spraying.

In an exemplary embodiment, the sheet 4 is obtained with one of the first varnish 10 and the second varnish 12 already applied to the sheet 4, the method comprising the application of the other of the first varnish 10 and the second varnish 12 .

In an exemplary embodiment, the sheet 4 is obtained without varnish on each of the first face 4A and the second face 4B, the method of manufacture comprising the application of the first varnish 10 and the second varnish 12.

The leaf has an initial shape. As illustrated in Figure 1, the sheet 4 is here initially planar.

In a forming step illustrated in FIG. 2, the sheet 4 is formed cold, for example by means of a press 16. The press 16 comprises, for example, two press parts 18, 20.

In the cold forming step, the press 16 is opened by moving apart the press parts 18, 20 from each other, the sheet 4 in its initial form is inserted between the press parts 18, 20 then the press 16 is closed by bringing the press parts 18, 20 closer to each other so as to deform the sheet 4 between the press parts 18, 20. When the press 16 is closed, each part press 18, 20 bears against a respective face 4A, 4B of the sheet 4.

The forming is done cold. This means that no heat input is made to heat the sheet 4 before or during cold forming. In particular, the sheet 4 is not heated before it is introduced into the press 16 or inside the press 16. In particular, the press parts 18, 20 are not heated so as to heat the sheet 4.

The first varnish 10 and the second varnish 12 present on the sheet 4 before the cold forming in the unpolymerized or partially polymerized state are adapted to accompany the deformations of the sheet 4 during cold forming without generating significant stress. Thus, the cold forming of the sheet 4 is not hindered.

Preferably, the first varnish 10 and the second varnish 12 applied to the sheet 4 before the cold forming are partially polymerized. This prevents the first varnish 10 and the second varnish 12 are sticky and adhere to the press parts 18, 20.

In a crosslinking step illustrated in Figure 3, the first varnish 10 and the second varnish 12 are crosslinked. Thus, the first varnish 10 and the second varnish 12 are completely polymerized and become rigid.

The stiffening of the first varnish 10 and the second varnish 12 contributes to stabilize the sheet 4 in the desired final shape. Indeed, the cold formed sheet 4 may have a tendency to deform from its final shape in the direction of a return to its initial shape due to the gradual release of residual stresses introduced into the material constituting the sheet 4 during cold forming. The first varnish 10 and the second varnish 12 crosslinked after the cold forming of the sheet 4, and therefore stiffened while the sheet 4 is in its desired final form, oppose the relaxation of the residual stresses present in the sheet 4 and maintain the sheet 4 in the desired final shape.

The crosslinking of the first varnish 10 and / or the second varnish 12 is carried out for example by exposure to ultraviolet (UV) radiation 22 and / or by heating 24.

In Figure 3, the first varnish 10 is polymerized by exposure to ultraviolet radiation and the second varnish 12 is polymerized by heating. Alternatively, the configuration is reversed. Alternatively, the first varnish 10 and the second varnish 12 are polymerized by exposure to ultraviolet radiation, or, alternatively, by heating.

In an assembly step illustrated in FIG. 4, the sheet 4 is applied and fixed on the support surface 6 of the structure 8. The sheet 4 is applied against the support surface 6 with the second face 4B of the sheet 4 turned towards the support surface 6 and the first face 4A of the sheet turned on the opposite side to the support surface 6. The support surface 6 has a three-dimensional shape corresponding to that of the sheet 4 in its final form.

In the example shown, the structure 8 has an opening 26 to the right of the sheet 4. The inner lining 2 formed by the assembly of the structure 8 and the sheet 4 is for example intended to be integrated in a set of interior cladding comprising the interior cladding 2 and a light device (not shown) covered by the interior cladding 2, the light device being visible through the opening 26 of the structure, through the sheet 4.

The light device is for example a light source or a screen comprising a pixel matrix configured to generate images, for example an LCD-type liquid crystal display backlit by light-emitting diodes (or LEDs), or a composite screen. diodes, for example organic light-emitting diodes (or OLED).

The sheet 4 is in this case made of a transparent or translucent material allowing the passage of light. The first varnish 10 and the second varnish 12 are each transparent or translucent, at least after crosslinking.

The method of manufacture of Figures 5 to 8 differs from that of Figures 1 to 4 in that the sheet 4 is formed cold before applying a varnish on at least one of the first face 4A and the second face 4B of the sheet 4, and crosslink the or each varnish.

In a step of supplying the sheet 4 illustrated in Figure 5, the sheet 4 is initially free of unpolymerized or partially polymerized varnish before cold forming.

In a cold forming step illustrated in Figure 6, the sheet 4 is formed cold, for example between two press parts 18, 20 of a cold forming press 16.

During an application step illustrated in Figure 7, a varnish is applied to at least one of the two faces 4A, 4B of the sheet, for example by spraying. In the illustrated example, a first varnish 10 is applied to the first face 4A and a second varnish 12 is applied to the second face 4B The application of the first varnish 10 and the second varnish 12 after the cold forming of the sheet 4 avoids polluting the cold forming press 16 with unpolymerized or partially polymerized varnish.

In a polymerization step illustrated in FIG. 8, the first varnish 10 and the second varnish 12 are crosslinked, for example by exposure to ultraviolet radiation and / or by heating.

During an assembly step, the sheet 4 is applied and fixed against the support surface 6 of the structure 8, for example by gluing. The invention is not limited to the exemplary embodiments illustrated and described above.

In an exemplary embodiment, only one of the first face 4A and the second face 4B is provided with a varnish applied to this face before or after the cold forming, the varnish being crosslinked after the cold forming when the sheet 4 is in the desired final form, for example by exposure to UV radiation and / or by heating, before fixing the sheet 4 on the support surface 6, for example by gluing. One of the first face 4A and the second face 4B remains devoid of varnish.

In such an embodiment, the sheet 4 is provided only with a first varnish 10 on the first face 4A or, alternatively, only with a second varnish 12 on the second face 4B.

The developments relating to the first varnish 10 and the second varnish 12 for the embodiments of Figures 1 to 4 and Figures 5 to 9 in which the sheet 4 is provided with a first varnish 10 and a second varnish 12, s also apply to the first varnish 10 and the second varnish 12 when the sheet 4 is provided with only one of the first varnish 10 and the second varnish 12.

Furthermore, it is possible to combine the embodiments of Figures 14 and 5 to 9, only one of the first varnish 10 and the second varnish 12 is present before the cold forming, and the other is applied after cold forming.

More specifically, only one of the first varnish 10 and the second varnish 12 is present on the corresponding face of the first face 4A and the second face 4B, said varnish being uncured or partially polymerized, then the sheet 4 is formed cold, then the other of the first varnish 10 and the second varnish 12 is applied to the corresponding face after the cold forming of the sheet 4, when the sheet 4 is already in its final form, then the first varnish 10 and the second varnish 12 are crosslinked to stabilize the three-dimensional shape imparted to the sheet during cold forming.

Thus, according to an alternative, the first face 4A is covered with the first varnish 10 unpolymerized or partially polymerized before the cold forming of the sheet 4, the second face 4B not being coated with the second varnish 12, then the sheet 4 is cold formed, then the second varnish 12 is applied to the second face 4B after the cold forming of the sheet 4, then the first varnish 10 and the second varnish 12 are crosslinked during the crosslinking.

According to the other alternative, the second face 4B is covered with the second varnish 12 unpolymerized or partially polymerized before the cold forming of the sheet 4, the first face 4A not being coated with the first varnish 10, then the sheet 4 is formed cold, then the first face 4A is covered with the first varnish 10 after the cold forming of the sheet 4, then the first varnish 10 and the second varnish 12 are crosslinked during the crosslinking.

Thanks to the invention, the inner lining obtained can limit the risk of separation of the sheet 4 and the structure 8.

The prediction of the first varnish 10 and / or the second varnish 12, applied on the sheet 4 before the cold forming in the unpolymerized or partially polymerized state or after the cold forming, and crosslinked after the Cold forming makes it possible to stabilize the sheet 4 in the three-dimensional shape conferred on it during cold forming.

This avoids a deformation of the sheet 4 in its final form which would be due to a release of residual stresses induced in the sheet 4 by cold forming.

The manufacturing method is simple and quick to implement. When the sheet 4 is originally provided with the first varnish 10 and / or the second varnish 12, only an additional step of crosslinking is necessary compared to a simple cold forming. The crosslinking step can be carried out rapidly, in particular in the case of low thickness varnishes, and when the crosslinking is carried out by UV radiation and / or by heating.

The stabilization of the sheet 4 in the desired final shape can avoid the separation of the sheet 4 fixed on a support surface 6, which can reduce the rejection rate of the interior trim for lack of appearance or manufacturing.

Claims (14)

1. -Method of manufacturing a vehicle interior trim (2), the trim comprising a sheet (4) having a first face (4A) and a second face (4B) opposite, the method of manufacture comprising a step of cold forming of the sheet (4) to give it a three-dimensional shape, then, the sheet (4) being in the three-dimensional shape, a step of crosslinking a first varnish (10) covering the first face (4A) and / or a second varnish (12) covering the second face (4B) of the sheet (4). 2. - Method of manufacture according to claim 1, wherein the sheet (4) is provided with the first varnish (10) and / or the second varnish (12) before the cold forming step of the sheet, to a state unpolymerized or partially polymerized. 3. - Method of manufacture according to claim 1 or 2, comprising a step of applying the first varnish (10) and / or the second varnish (12) on the sheet (4) before the cold forming of the sheet (4). ), in an unpolymerized or partially polymerized state. 4. - Method of manufacture according to any one of the preceding claims, comprising a step of applying the first varnish (10) and / or the second varnish (12) on the sheet (4) after the cold forming step of the sheet (4) and before the crosslinking step. 5. - Method of manufacture according to any one of the preceding claims, wherein the first face (4A) is intended to be visible and the second face (4B) is intended to be invisible. 6. - Method of manufacture according to any one of the preceding claims, wherein the first varnish (10) and / or the second varnish (12) is (are) polymerizable (s) by exposure to ultraviolet radiation (UV), the crosslinking step comprising exposing the sheet (4) to ultraviolet (UV) radiation. 7. Method of manufacture according to any one of the preceding claims, wherein the first varnish (10) and / or the second varnish (12) is (are) polymerizable (s) hot, the crosslinking step including heating of the leaf. 8. - Method of manufacture according to any one of the preceding claims, comprising a step of assembling the sheet (4) against a support surface (6) of a structure (8), the support surface (6) having a three-dimensional shape corresponding to that of the sheet (4) after the cold forming. 9. - Method of manufacture according to claim 8, wherein the sheet (4) is fixed on the support surface (6) by gluing. 10. - Method of manufacture according to any one of the preceding claims, wherein the sheet (4) is provided with the first varnish (10) and the second varnish (12), the first varnish (10) and the second varnish (12). ) being of identical compositions or of different compositions. 11. - Interior trim (2) vehicle, the trim comprising: - a sheet (4) of three-dimensional shape having a first face (4A) and a second face (4B) opposite, the first face (4A) being covered with a first varnish (10) in the crosslinked state and / or the second face (4B) being covered with a second varnish (12) in the crosslinked state; and - a structure (8) having a support surface (8) of complementary shape to the sheet (4), the sheet (4) being fixed on the support surface (8) of the structure (8). 12. - interior cladding (2) according to claim 11, wherein the structure has an opening (26) to the right of the sheet (4). 13. - interior cladding (2) according to claim 11 or claim 12, wherein the first varnish (10) is transparent or translucent, and / or the second varnish (12) is transparent or translucent. 14. - interior trim assembly comprising the interior trim (2) according to any one of claims 11 to 13 and a light device visible through the opening (26) of the structure and through the sheet (4) .