Skin for dressing backlit vehicle interior parts, method and installation for manufacturing thereof

Abstract

Skin for dressing backlit vehicle interior parts comprising a perforated opaque decorative layer and a light transmitting material filling the holes wherein the light transmitting material is a reactive hotmelt adhesive which forms a base layer extended over the back side of the opaque decorative layer and comprising a central portion and a transition portion surrounding the central portion and several projections protruding from the central portion of the base layer and completely filling the through holes. Method and an installation for manufacturing said skin for dressing backlit vehicle interior parts.

Claims

1. A skin (1) for covering backlit vehicle interior parts (10) comprising: an opaque decorative layer (2) having: a front side (2.1) and a back side (2.2) several through holes (2.3), each one having a diameter less than 2.5 mm, a light transmitting filler (3) comprising a reactive hotmelt adhesive, the light transmitting filler having: a base layer (3.1) extended over the back side (2.2) of the opaque decorative layer (2) and comprising a central portion (3.1.3) and a transition portion (3.1.4) surrounding the central portion (3.1.3), several projections (3.2) protruding from the central portion of the base layer (3.1) and completely filling the through holes (2.3), each projection comprising: a bottom end (3.2.1) connecting the projection (3.2) to the base layer (3.1) and a light exit part (3.2.2) being flush with the front side (2.1) of the opaque decorative layer (2), wherein the reactive hotmelt adhesive has a dynamic viscosity between 10,000 and 30,000 cPs at a temperature between 110 and 170 C., wherein the central portion (3.1.3) has a constant thickness of less than 0.25 mm, and the transition portion (3.1.4) has a thickness that progressively decreases from the thickness of the central portion (3.1.3) to a thickness of 0 mm at a periphery of the base layer (3.1) and a width measured between the central portion (3.1.3) and the periphery of the base layer (3.1) of at least 5 mm.

2. The skin (1) according to claim 1, wherein the light exit part (3.2.2) has a predefined textured surface.

3. The skin of claim 2, wherein the predefined textured surface of the light exit part (3.2.2) is configured to diffuse light passing through the light exit part (3.2.2).

4. The skin (1) according to claim 1, wherein the light transmitting filler (3) is colored or transparent.

5. The skin of claim 4, wherein the light transmitting filler (3) is colored, wherein a color of the light transmitting filler (3) is chosen according to a color of the decorative opaque layer (2) such that the through holes (2.3) are not visually perceptible when not being backlit or is chosen in order to provide an intentional color contrast with the decorative opaque layer (2), and/or in order to provide a diffusing lighting effect.

6. The skin of claim 1, wherein the continuous thickness of the central portion (3.1.3) is less than 0.2 mm and the width of the transition portion (3.1.4) is about 10 mm.

7. The skin of claim 1, wherein the opaque decorative layer (2) is a flexible layer comprising leather or synthetic leather.

8. The skin of claim 1, wherein the reactive hotmelt adhesive is a reactive polyurethane-based hotmelt adhesive or a reactive polyolefin-based hotmelt adhesive.

9. A backlit vehicle interior part (10) comprising: the skin (1) according to claim 1, and a light transmitting carrier (4), wherein the skin (1) is connected to the light transmitting carrier (4) with an adhesive (5).

10. A method for manufacturing the skin (1) for covering backlit vehicle interior parts (10) according to claim 1, wherein the method comprises the following steps: a) providing the opaque decorative layer, b) laying the opaque decorative layer (2) on a bearing means (7) comprising: a flat bearing surface (7.1) being in contact with the front side (2.1) of the opaque decorative layer (2), and a cooling means (7.2) for keeping the flat bearing surface (7.1) at a temperature less than 40 C., c) applying the light transmitting filler (3) comprising the reactive hotmelt adhesive having-a the dynamic viscosity between 10,000 and 30,000 cPs during its application at the temperature between 100 and 170 C. on the back side (2.2) of the opaque decorative layer (2) and completely filling the through holes (2.3) by means of a dosing head (8) comprising a pressure part (8.1) and a dosing nozzle (8.2) and being slidably movable in a direction S, wherein the pressure part (8.1) comprises a pressure surface (8.1.1) positioned in contact with the back side (2.2) of the opaque decorative layer (2) and exerts a first pressure P1 on the opaque decorative layer (2), higher than 0.3 kg/cm.sup.2, and an open internal cavityto provide a shape for the base layer of the light transmitting filler (3), and the dosing nozzle (8.2) applies the light transmitting filler (3) at the application temperature and at a second pressure P.sub.2, the second pressure P.sub.2 being less than the first pressure P.sub.1, d) cooling the light transmitting filler (3) upon contacting the flat bearing surface (7.1) being at a temperature less than 40 C. and creating a solid surface barrier of the light exit part being flush with the front side (2.1) of the opaque decorative layer (2), e) cooling the remaining part of the light transmitting filler (3) and curing the whole light transmitting filler (3).

11. The method of claim 10, wherein the second pressure P.sub.2 is 0 kg/cm.sup.2 at the periphery of the base layer (3.1) and is within a range of 0.25 to 1 kg/cm.sup.2 through a length of the base layer (3.1).

12. The method according to claim 10, wherein P.sub.1 is less than 4 kg/cm.sup.2.

13. The method according to claim 10, wherein the method further comprises a step of embossing the light exit part (3.2.2) of the light transmitting filler (3) being flush with the front side (2.1) of the opaque decorative layer (2) by being in contact with a predefined textured surface of the flat bearing surface (7.1).

14. The method of claim 10, wherein the open internal cavity (8.1.2) comprises a first portion having a constant depth and being defined by a main top wall (8.1.2.1) and two lateral portions having a progressively decreasing depth and being defined by two beveled walls (8.1.2.2, 8. 1.2.3), which connect the main wall (8.1.2.1) to the pressure surface (8.1.1).

15. The method of claim 10, wherein the light transmitting filler (3) is colored or transparent.

16. An apparatus for manufacturing the skin (1) for covering backlit vehicle interior parts (10) according to claim 1, wherein the apparatus comprises: i) a bearing means (7) for supporting the opaque decorative layer (2), the bearing means comprising: a flat bearing surface (7.1) configured to be in contact with the front side (2.1) of the opaque decorative layer (2), and a cooling means (7.2) for keeping the flat bearing surface (7.1) at a temperature less than 40 C., ii) a movable dosing head (8), configured to slidably move over the back side (2.2) of the opaque decorative layer (2) in a direction S, and for applying the light transmitting filler (3) to the back side (2.2) of the opaque decorative layer (2) in order to form the base layer and completely filling the through holes (2.3) in order to form the several projections with the light exit part (3.2.2) of each projection being in contact with the flat bearing surface (7.1), wherein the movable dosing head comprises: a pressure part (8.1) comprising a pressure surface (8.1.1) positioned in contact with the back side (2.2) of the opaque decorative layer (2) and for exerting a first pressure P1 on the opaque decorative layer (2) higher than 0.3 kg/cm.sup.2, and an open internal cavity configured to provide a shape for the base layer of the light transmitting filler (3), and a dosing nozzle (8.2) for applying the light transmitting filler (3) at an application temperature between 110 and 170 C. and at a second pressure P.sub.2, the second pressure P.sub.2 being less than the first pressure P.sub.1T.

17. The apparatus of claim 16, wherein the second pressure P.sub.2 is 0 kg/cm.sup.2 at the periphery of the base layer (3.1) and is within a range of 0.25 to 1 kg/cm.sup.2 through a length of the base layer (3.1).

18. The apparatus according to claim 16, wherein the first pressure P1 is less than 4 kg/cm.sup.2.

19. The apparatus according to claim 16, wherein the bearing surface (7.1) has a predefined textured surface configured to form a predefined textured surface of the light exit part (3.2.2).

20. The apparatus according to claim 16, wherein the open internal cavity (8.1.2) comprises a first portion having a constant depth and being defined by a main top wall (8.1.2.1) and two lateral portions having a progressively decreasing depth and being defined by two beveled walls (8.1.2.2, 8.1.2.3), which connect the main wall (8.1.2.1) to the pressure surface (8.1.1).

Description

DESCRIPTION OF THE FIGURES

(1) The present descriptive memory is completed by a set of figures illustrating the preferred embodiment and in no way limiting the invention.

(2) FIG. 1 shows a top view of the skin for dressing backlit vehicle interior parts from its front side.

(3) FIG. 2 shows a top view of the skin for dressing backlit vehicle interior parts from its back side.

(4) FIG. 3 shows an enlarged cross-sectional view of the skin for dressing backlit vehicle interior parts according to the plane AA represented in the FIG. 1.

(5) FIG. 4 shows a cross-sectional view of the backlit vehicle interior part comprising a skin according to the invention.

(6) FIG. 5 shows a detail view of the skin for dressing backlit vehicle interior parts according to the detail D represented in the FIG. 4.

(7) FIGS. 6, 7, 8 and 9 show a schematic representation of the installation for manufacturing the skin for dressing backlit vehicle interior parts.

(8) Particularly FIG. 6 shows a schematic representation of the bearing means and the dosing head, FIG. 7 shows a detail E of the dosing head represented in FIG. 6, FIG. 8 shows a cross-sectional view of the dosing head according to the plane BB represented in the FIG. 6 and FIG. 9 shows a detail F of the pressure part of dosing head represented in FIG. 8.

DETAILED DESCRIPTION

(9) FIG. 1 shows the front side (1.1) of a skin (1) for dressing backlit vehicle interior parts (10) and FIG. 2 shows the back side (1.2) thereof. Particularly, the skin (1) comprises and an opaque decorative layer (2) and a light transmitting filler (3).

(10) As shows FIG. 3, the opaque decorative layer (2) has a front side (2.1), a back side (2.2) and several through holes (2.3) extended from the back side (2.2) to the front side (2.1) and having a diameter less than 2.5 mm. More preferably the diameter is between 0.6 and 2 mm.

(11) Preferably, the opaque decorative layer (2) is a flexible layer such as leather or synthetic leather and its thickness is between 0.6 and 1.5 mm. More preferably the thickness is between 0.75 and 1.25 mm.

(12) The through holes (2.3) are configured to the light can pass through them. They can form a decorative or signaling design, for example it can be configured for indicating the position of a capacitive switch or for indicating a particular state of the vehicle.

(13) The light transmitting filler (3) completely fills the through holes (2.3) of the opaque decorative layer (2) and allows the light provided by a lighting device (20), schematically represented in FIG. 4, pass through it in order to illuminate the vehicle cabin (VC). The light transmitting filler (3) can be transparent or translucent.

(14) In the case of being translucent, the light transmitting filler (3) can be colored. The color can be chosen according to the color of the decorative opaque layer (2) in order to improve the visual continuity between the perforated areas and the non-perforated areas thereof in such a way that the through holes (2.3) are not visually perceptible when the lighting device (20) is switched off, or in order to create an intentional color contrast providing a decorative effect.

(15) In addition, the colored light transmitting filler (3) can provide a diffusing lighting effect in order to improve the light homogeneity.

(16) The light transmitting filler (3) comprises a reactive hotmelt adhesive having a dynamic viscosity between 10.000 cPs and 30.000 cPs at a temperature between 110 and 170 C. Particularly, it can be a reactive polyurethane-based hotmelt adhesive (PUR) or a reactive polyolefin-based hotmelt adhesive (POR).

(17) The light transmitting filler (3) comprises a base layer (3.1) and several projections (3.2) protruding from the base layer (3.1) and completely filling the through holes (2.3).

(18) The base layer (3.1) extends over the back side (2.2) of the opaque decorative layer (2) and it has a front side (3.1.1) being in contact with the decorative opaque layer (2) and a back side (3.1.2) opposite to the front side (3.1.1), and it comprises a central portion (3.1.3) where the projections (3.2) protrude and a transition portion (3.1.4) surrounding the central portion (3.1.3) having a width w.

(19) Particularly, as FIGS. 1 and 2 show, the transition portion (3.1.4) comprises in turn, a first part formed by two portions, a front portion (3.1.4.1) and a back portion (3.1.4.2), each of them continuously extended in a direction essentially perpendicular to the direction S of motion of the dosing head (8) described below, and a second part formed by two lateral portions (3.1.4.3, 3.1.4.4), each of them continuously extended in said direction S.

(20) The central portion (3.1.3) has a continuous thickness e of less than 0.25 mm, and more preferably less than 0.2 mm. The transition portion (3.1.4) has a width w of at least 5 mm wherein its thickness progressively decreases from a thickness less than 0.25 mm, the thickness of the central portion (3.1.3), to a thickness of 0 mm at the periphery of the base layer (3.1). According to a more preferably embodiment the width w is around 10 mm.

(21) The projections (3.2) comprise a bottom end (3.2.1) connecting the projection (3.2) to the base layer (3.1) and a light exit part (3.2.2), opposite to the bottom end (3.2.1), being flush with the front side (2.1) of the opaque decorative layer (2), where the light exits from the backlit vehicle interior part (10) to the vehicle cabin (VC).

(22) According to an embodiment represented in the FIG. 5, the light exit part (3.2.2) has a predefined textured surface configured intentionally in order to diffuse the light passing through said light exit part (3.2.2) and consequently improving the homogeneity of the light obtained at the vehicle cabin (VC).

(23) FIG. 4 shows a backlit vehicle interior part (10) comprising the skin above described. Particularly, it comprises a light transmitting carrier (4) connected by an adhesive (5) to a skin (1) according to the invention.

(24) Preferably, the light transmitting carrier (4) and the skin (1) are connected by laminating.

(25) As FIG. 4 shows the soft transition provided by the transition portion (3.1.4) minimizes the risk of visible perceptible marks on the front side of the backlit vehicle interior part (10).

(26) FIGS. 6, 7, 8 and 9 show a schematic representation of an installation for manufacturing a skin (1) for dressing backlit vehicle interior parts (10) comprising the technical features described above, as well as the method for manufacturing said skin (1).

(27) Particularly the method comprises the steps a) to e) described below.

(28) a) Providing an opaque decorative layer (2) having a front side (2.1) and a back side (2.2), and having several through holes (2.3) extended from the back side (2.2) to the front side (2.1) wherein the through holes (2.3) have a diameter less than 2.5 mm. More preferably the diameter is between 0.6 and 2 mm.

(29) The opaque decorative layer (2) is previously perforated for example by perforating means such as die punching not represented since this aspect is not relevant to the invention.

(30) b) Laying the opaque decorative layer (2) on a bearing means (7) comprising:

(31) a flat bearing surface (7.1) being in contact with the front side (2.1) of the opaque decorative layer (2), and a cooling means (7.2) for keeping the flat bearing surface (7.1) at a temperature less than 40 C., and more preferably less than 30 C.

(32) c) Applying a light transmitting filler (3) being a reactive hotmelt adhesive having a dynamic viscosity between 10.000 cPs and 30.000 cPs during its application at a temperature between 110 and 170 C. on the back side (2.2) of the opaque decorative layer (2) by means of a dosing head (8) comprising a pressure part (8.1) and a dosing nozzle (8.2) and being slidably movable in a direction S corresponding to the direction of motion of the dosing nozzle (8.2), wherein in order to configure a base layer (3.1) having a central portion (3.1.3) and a transition portion (3.1.4) surrounding the central portion (3.1.3) and several projections (3.2) protruding from the central portion (3.1.3) and completely filling the through holes (2.3):

(33) the pressure part (8.1) exerts a first pressure P.sub.1 on the opaque decorative layer (2), being higher than 0.3 kg/cm.sup.2. Preferably said first pressure P.sub.1 being less than 4 kg/cm.sup.2.

(34) the pressure part (8.1) comprises a pressure surface (8.1.1) configured to be in contact with the back side (2.2) of the opaque decorative layer (2) and to exert the first pressure P.sub.1, and an open internal cavity (8.1.2) configured to provide the shape of the light transmitting filler (3), particularly the shape of the second part of the transition portion (3.1.4) and the central portion (3.1.3) as FIG. 8 shows,

(35) the dossing nozzle (8.2) applies the light transmitting filler (3) at a temperature between 110 and 170 C. and at a second pressure P.sub.2, being 0 at a periphery of the transition portion (3.1.4) and being between the range of 0.25 and 1 kg/cm.sup.2 through the length of the base layer (3.1), the second pressure P.sub.2 being less than the first pressure P.sub.1.

(36) d) cooling a part of the light transmitting filler (3) upon contacting the flat bearing surface (7.1) being at a temperature less than 40 C. and creating a solid surface barrier being flush with the front side (2.1) of the opaque decorative layer (2),

(37) e) cooling the remaining part of the light transmitting filler (3) and curing the whole light transmitting filler (3).

(38) According to an embodiment the light transmitting filler (3) can be cured under the environmental moisture present during the method of manufacturing or under moisture added during the method to accelerate said curing.

(39) According to an embodiment, the method further comprises a step of embossing a part of the light transmitting filler (3) being flush with the front side (2.1) of the opaque decorative layer (2) and being in contact with a predefined textured surface of the flat bearing surface (7.1), namely the light exit part (3.2.2) above defined.

(40) According to the invention, the installation for manufacturing a skin (1) for dressing backlit vehicle interior parts (10) comprising the technical features described above comprises:

(41) i) Bearing means (7) for supporting an opaque decorative layer (2) having a front side (2.1) and a back side (2.2) and having several through holes (2.3) extended from the back side (2.2) to the front side (2.1), wherein the through holes (2.3) have a diameter less than 2.5 mm, the bearing means (7) represented in the FIG. 6 comprising:

(42) a flat bearing surface (7.1) configured to be in contact with the front side (2.1) of the opaque decorative layer (2), and cooling means (7.2) for keeping the flat bearing surface (7.1) at a temperature less than 40 C., and more preferably less than 30 C.

(43) According to an embodiment the flat bearing surface (7.1) comprises a predefined textured surface configured to emboss a part of the light transmitting filler (3) being in contact with it, namely the light exit part (3.2.2) above defined.

(44) This configuration is particularly advantageous due to the fact that the light exit part (3.2.2) gets the predefined textured surface directly during the application of the light transmitting filler (3) without any special additional step being required for configuring said predefined textured surface.

(45) ii) a movable dosing head (8), configured to slidably move over the back side (2.2) of the opaque decorative layer (2) in a direction S, for applying a light transmitting filler (3) to the back side (2.2) of the opaque decorative layer (2) in order to configure a base layer (3.1) having a central portion (3.1.3) and a transition portion (3.1.4) surrounding the central portion (3.1.3) and several projections (3.2) protruding from the central portion (3.1.3) and completely filling the through holes (2.3).

(46) Particularly, as it has been mentioned above, the transition portion (3.1.4) comprises in turn, a first part and a second part according to the particular features described above.

(47) As FIGS. 6 and 7 show, the movable dosing head (8) comprises a pressure part (8.1) and a dossing nozzle (8.2).

(48) The pressure part (8.1) is configured to exert a first pressure P.sub.1 on the opaque decorative layer (2), being higher than 0.3 kg/cm.sup.2, more preferably being less than 4 kg/cm.sup.2.

(49) In addition, as FIGS. 8 and 9 show, and as it has been described above, the pressure part (8.1) comprises a pressure surface (8.1.1) configured to be in contact with the back side (2.2) of the opaque decorative layer (2) and to exert the first pressure P.sub.1, and an open internal cavity (8.1.2) configured to provide the shape of the light transmitting filler (3), particularly the shape of the second part of the transition portion (3.1.4) and the central portion (3.1.3).

(50) Particularly, the open internal cavity (8.1.2) comprises a first portion having a constant thickness and being defined by a main top wall (8.1.2.1) and two lateral portions having a progressively decreasing thickness and being defined by two beveled walls (8.1.2.2, 8.1.2.3) which connect the main wall (8.1.2.1) to the pressure surface (8.1.1).

(51) The dossing nozzle (8.2) is configured to apply the light transmitting filler (3) at a temperature between 110 and 170 C. and at a second pressure P.sub.2, being 0 at a periphery of the transition portion (3.1.4) and being between the range of 0.25 and 1 kg/cm.sup.2 through the length of the base layer (3.1), the second pressure P.sub.2 being less than the first pressure P.sub.1.

(52) As mentioned above, the light transmitting filler (3) is a reactive hotmelt adhesive having a dynamic viscosity between 10.000 cPs and 30.000 cPs at a temperature between 110 and 170 C., that is, at the application temperature of the light transmitting filler (3).