FR3067636A1 - 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 for vehicles, in particular for motor vehicles.

It is possible to manufacture a vehicle interior covering comprising a structure having a support surface and a sheet applied and glued 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 a defect in appearance detrimental to the perceived quality.

To remedy this, it is possible to form the hot sheet in order to impart to it, irreversibly, the three-dimensional shape of the support surface of the structure, before gluing it onto the support surface. Thus, the sheet intrinsically has the shape of the support surface and the risk of delamination is reduced.

However, hot forming can increase the cycle time (i.e. the manufacturing time of an interior covering) and / or can cause surface defects on a visible face of the sheet, which may affect the perceived quality.

One of the aims of the invention is to provide a method of manufacturing a vehicle interior covering making it possible to obtain a satisfactory perceived quality.

To this end, the invention provides a method of manufacturing a vehicle interior covering, the covering comprising a sheet having a first face and a second opposite face, the manufacturing method comprising a step of cold forming the sheet. to give it a three-dimensional shape, 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 limit the risk of generation of surface defects on the sheet. The crosslinking of a first varnish covering the first face of the sheet and / or of a second varnish covering the second face of the sheet after the cold forming of the sheet makes it possible to stiffen the first varnish and / or the second varnish a once the sheet is in the desired three-dimensional shape, and to freeze the sheet in this three-dimensional shape. The sheet can then be glued to a support surface of corresponding three-dimensional shape by limiting the risk of delamination.

In particular embodiments, the manufacturing method includes one or more of the following optional characteristics, taken individually or in any technically possible combination:

- the sheet is provided with the first varnish and / or the second varnish before the cold forming step of the sheet, in a non-polymerized 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 (s) 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 the heating of 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 cold forming;

- the sheet is fixed to 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 covering, the covering comprising a three-dimensional sheet 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 covering comprises one or more of the following optional characteristics, taken individually or in any technically possible combination:

- The structure has an opening to the right of the sheet;

- The first varnish is transparent or translucent, and / or the second varnish is transparent or translucent.

The invention also 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 follows, given solely by way of nonlimiting example, and made with reference to the appended drawings, in which:

- Figures 1 to 4 illustrate steps of 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 an interior trim 2 of a vehicle, the interior trim 2 comprising a sheet 4 comprising a first face 4A and a second opposite face 4B. The sheet 4 is here fixed, for example glued, on 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 can be plastically deformed without adding heat so as to give it a final shape different from the initial shape, the sheet 4 retaining the final shape at after 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 with 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 of the second varnish 12 is suitable for being polymerized, for example by adding heat 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 non-crosslinked state. The term “crosslinked” here designates the complete or almost complete polymerization of the varnish so that the varnish is hardened and rigid. Each varnish 10, 12 is not polymerized, i.e. that the polymerization has not started, or partially polymerized or "prepolymerized", i.e. that the polymerization has started but is incomplete.

The first varnish 10 and the second varnish can be of identical or different compositions from each other. 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 hidden side of the sheet 4 can 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 already being 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 carried out beforehand, for example by a manufacturer of the sheet 4.

In a variant, as shown in Figure 1 in dotted lines, the manufacturing method 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 among 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 of the second face 4B, the manufacturing method 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 cold formed, for example using a press 16. The press 16 comprises for example two press parts 18, 20.

During the cold forming step, the press 16 is opened by spreading the press parts 18, 20 from one another, the sheet 4 in its initial form is introduced between the press parts 18, 20 , then the press 16 is closed by bringing the press parts 18, 20 closer to one another 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 carried out cold. This means that no heat is supplied in order 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 cold forming in the unpolymerized or partially polymerized state are capable of accompanying the deformations of the sheet 4 during cold forming without generating significant stress. Thus, the cold forming of the sheet 4 is not hampered.

Preferably, the first varnish 10 and the second varnish 12 applied to the sheet 4 before cold forming are partially polymerized. This prevents the first varnish 10 and the second varnish 12 from being sticky and adhering 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 of the second varnish 12 contributes to stabilizing the sheet 4 in the desired final shape. In fact, the cold-formed sheet 4 can tend to deform from its final shape in the direction of a return to its initial shape due to the gradual relaxation 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 shape, oppose the relaxation of the residual stresses present in the sheet 4 and maintain sheet 4 in the desired final shape.

The crosslinking of the first varnish 10 and / or of 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 to 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 facing the support surface 6 and the first face 4A of the sheet turned on the side opposite 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 illustrated, the structure 8 has an opening 26 in line with the sheet 4. The interior covering 2 formed by the assembly of the structure 8 and the sheet 4 is for example intended to be integrated into a set of interior covering comprising the interior covering 2 and a light device (not shown) covered by the interior covering 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 a liquid crystal screen of LCD type backlit by light-emitting diodes (or LED), or a composite screen diodes, for example organic light-emitting diodes (or OLEDs).

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

During a step of supplying the sheet 4 illustrated in FIG. 5, the sheet 4 is initially devoid of non-polymerized or partially polymerized varnish before cold forming.

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

During an application step illustrated in FIG. 7, a varnish is applied to at least one of the two faces 4A, 4B of the sheet, for example by spraying. In the example illustrated, 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 non-polymerized or partially polymerized varnish.

During 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 cold forming, the varnish being crosslinked after cold forming when the sheet 4 is in the desired final shape, for example by exposure to UV radiation and / or by heating, before fixing the sheet 4 to 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 exemplary embodiment, the sheet 4 is provided only with a first varnish 10 on the first side 4A or, alternatively, only with a second varnish 12 on the second side 4B.

The developments relating to the first varnish 10 and to the second varnish 12 for the exemplary embodiments of FIGS. 1 to 4 and of FIGS. 5 to 9 in which the sheet 4 is provided with a first varnish 10 and with a second varnish 12, s also apply to the first varnish 10 and to 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 1 4 and Figures 5 to 9, only one of the first varnish 10 and the second varnish 12 is present before cold forming, and the other is applied after cold forming.

More precisely, only one of the first varnish 10 and the second varnish 12 is present on the corresponding face among the first face 4A and the second face 4B, said varnish being unpolymerized or partially polymerized, then the sheet 4 is cold formed, then the other from 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 unpolymerized or partially polymerized varnish 10 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 crosslinking.

According to the other alternative, the second face 4B is covered with the second unpolymerized or partially polymerized varnish 12 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 cold formed, 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 crosslinking.

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

The provision of the first varnish 10 and / or the second varnish 12, applied to the sheet 4 before cold forming in the non-polymerized or partially polymerized state or after cold forming, and crosslinked (s) after cold forming makes it possible to stabilize the sheet 4 in the three-dimensional shape which has been given to it during cold forming.

This avoids deformation of the sheet 4 in its final form which would be due to a relaxation 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 crosslinking step is necessary compared to a simple cold forming. The crosslinking step can be carried out quickly, in particular in the case of thin varnish, 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 detachment of the sheet 4 fixed on a support surface 6, which can make it possible to limit the rate of rejects from the interior linings for defect in appearance or manufacturing.

Claims (14)

1Method of manufacturing an interior covering (2) of a vehicle, the covering comprising a sheet (4) having a first face (4A) and a second face (4B) opposite, the manufacturing method comprising a cold forming step 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. - Manufacturing method 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, in a state non-polymerized or partially polymerized. 3. - Manufacturing method 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 a non-polymerized or partially polymerized state. 4. - Manufacturing method 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. - Manufacturing method 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. - Manufacturing method according to any one of the preceding claims, in which the first varnish (10) and / or the second varnish (12) is (are) polymerizable (s) by exposure to ultraviolet (UV) radiation, the crosslinking step comprising exposing the sheet (4) to ultraviolet (UV) radiation. 7. Manufacturing method according to any one of the preceding claims, in which the first varnish (10) and / or the second varnish (12) is (are) polymerizable (s) hot, the crosslinking step comprising heating of the sheet. 8. - Manufacturing method 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) at the end of the cold forming. 9. - Manufacturing method according to claim 8, wherein the sheet (4) is fixed to the support surface (6) by gluing. 10.- Manufacturing method 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. 5 11.- Interior trim (2) of a 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 10 - a structure (8) having a support surface (8) of shape complementary to the sheet (4), the sheet (4) being fixed on the support surface (8) of the structure (8). 12, - Interior covering (2) according to claim 11, wherein the structure has an opening (26) in line with the sheet (4). 15 13.- interior covering (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) .