Sublimation on leather or polycarbonate automotive parts

Abstract

The invention relates to a method for decorating a surface (12) of a body panel (10) of a motor vehicle, the decoration method comprising the following steps: a) supplying or manufacturing a body panel (10) comprising a surface; b) printing a decoration (16) by ink sublimation onto the surface. The body panel (10) comprises a porous material forming the surface; the porous material comprising pores with widths between 0.08 µm and 1.10 µm. In step b) printing, the ink penetrates said pores by sublimation. The outer part is a leather seat cover, or a polycarbonate part of a motor vehicle. Figure to be published with the abbreviation: Figure 2

Description

Title of the invention: Sublimation on leather or polycarbonate parts of motor vehicles

[0001] The invention relates to the personalized decoration of visible parts of a motor vehicle. More specifically, the invention relates to a method for decorating a part of a motor vehicle.

[0002] In order to personalize a motor vehicle in a specific and potentially unique way, it is advantageous to add local decoration. This enhances the perceived quality of the motor vehicle. However, decoration produced in small batches must be integrated into a large-scale production process to optimize costs.

[0003] There are various techniques for customizing the appearance of a motor vehicle. These include applying paint using a stencil and applying adhesives. However, these techniques require the application of protective coatings, which are then removed. Furthermore, they create localized areas of excess thickness, which detracts from the overall appearance. In addition, they require further heat treatment. Finally, certain geometries of the elements to be decorated are inherently incompatible. Resistance to ultraviolet radiation and abrasion reduces the lifespan of a decoration.

[0004] To meet certain constraints, the sublimation printing process is known. This method reduces labor time and is quickly implementable.

[0005] Document EP1439094B1 describes an exterior vehicle part comprising a decorative film. The external component consists of an injection-molded skin of a transparent or translucent thermoplastic material extending in two perpendicular directions, with a thinner layer of decorative film applied to its inner surface and attached by adhesive. The skin may be colored, contain opaque particles such as glitter, or have opaque areas created by painting, pad printing, or the application of opaque materials.

[0006] US patent 11453202B2 describes a thermoformable decorative material for automotive interiors comprising: a decorative layer including a textile substrate; a digitally printed design disposed on at least one side of the textile substrate and comprising a dispersion ink and / or a pigment ink; and a superimposed adhesive coating applied to the digitally printed design. The superimposed adhesive coating includes an adhesive that comprises polyurethane and / or polyacrylate.

[0007] The material has a decorative layer with a digitally printed pattern and a textile substrate. A sublimation-resistant ink is used.

[0008] Document EP1841542A1 describes a process for applying a decorative image to a surface in the vehicle. The image in question is applied by sublimation to the previously coated surface.

[0009] However, the proposed solutions create a localized excess thickness at the level of the applied decoration. This excess thickness detracts from the perceived quality and can generate a point of friction susceptible to abrasion.

[0010] The invention aims to address at least one of the problems or drawbacks encountered in the prior art. In particular, the invention aims to improve the durability of a printed decoration on a motor vehicle part. The invention also aims to optimize the resistance, cost, and gloss of a decoration for a motor vehicle part.

[0011] According to a first aspect, the invention proposes a method for decorating a surface of a part of a motor vehicle, the decoration method comprising the following steps: a) supplying or making a part comprising a material; b) printing a decoration by sublimation of ink on the part; remarkable in that the outer part comprises a porous material forming the surface; the porous material comprises pores of widths between 0.08 pm and 1.10 pm; in step b) printing, the ink penetrating said pores by sublimation.

[0012] The invention combines a decoration with a piece made of porous material that incorporates said decoration or information by sublimation thanks to the properties of its pores. This improves the adhesion of the decoration. The decoration becomes embedded in the material constituting the piece, which strengthens and protects it. Consequently, the decoration becomes more durable against abrasion and detachment. Furthermore, the arrangement of the decoration within the material maintains the smooth appearance of the surface without affecting the flexibility of the piece, thus contributing to the perceived quality.

[0013] Preferably, the porous material comprises pores with widths between 0.10 pm and 0.80 pm.

[0014] Preferably, the porous material comprises pores with widths between 0.10 pm and 0.40 pm.

[0015] Preferably, pores with widths between 0.10 pm and 0.40 pm represent at least 50% of the pores of the porous material.

[0016] Preferably, at least 90% of the pores of the porous material have widths between 0.10 pm and 0.60 pm.

[0017] Preferably, the pore widths exhibit a width distribution; said distribution having a center between 0.10 pm and 0.60 pm.

[0018] Preferably, the center is between 0.20 pm and 0.40 pm.

[0019] Preferably, during step b) printing, an inflated bag exerts pressure against the envelope piece; and / or step b) printing includes applying a pressure of 100 g / m2 to 200 g / m2 to the envelope piece.

[0020] Preferably, in step b) printing, the ink includes a sublimation temperature, step b) printing being carried out at a temperature between 100% and 130% of said sublimation temperature; preferably, step b) printing includes a temperature between 80°C and 120°.

[0021] Preferably, step b) printing the decoration includes a substep b1) supplying a transfer sheet; a substep b2) printing a pattern on the transfer sheet; a substep b4) applying the transfer sheet to the part; a substep b5) heating the transfer sheet against the part; a substep b6) removing the transfer sheet.

[0022] Preferably, in step b) printing the decoration by sublimation, said decoration comprises several colors; and / or step b) printing the decoration by sublimation is repeated in order to implement several decorations stacked one on top of the other.

[0023] Preferably, the porous material is transparent.

[0024] Preferably, the porous material comprises a porosity of between 55% and 65%.

[0025] Preferably, the porous material comprises polycarbonate, polyester, polystyrene, polyvinyl chloride, polypropylene, polymethyl methacrylate, acrylonitrile butadiene styrene methacrylate, or a mixture of several of these.

[0026] Preferably, the porous material is polycarbonate.

[0027] Preferably the part is a motor vehicle bumper skin.

[0028] Preferably, the porous material is natural leather or artificial leather.

[0029] Preferably, the part is a vehicle seat or headrest cover automotive, or dashboard trim.

[0030] Preferably, the pore widths are the pore diameters.

[0031] Preferably, the surface is an interior surface or an exterior surface.

[0032] Preferably, the part comprises a first layer, a second layer opposite the first layer and forming the surface; the decoration being in the thickness of the second layer; preferentially, the decoration is at a distance from the first layer.

[0033] Preferably, the porous material comprises a modulus of elasticity of at least 2 GPa.

[0034] Preferably, the porous material comprises a Poisson's ratio of at least 0.3.

[0035] Preferably, the envelope piece comprises a thickness between 0.50 mm and 4.00 mm.

[0036] Preferably, step c) printing of the decoration includes a substep c3) treatment of the transfer sheet in order to dry the ink.

[0037] Preferably, substep c3) treatment includes heating, exposure to ultraviolet radiation, or placement under vacuum.

[0038] Preferably, the pores of the porous material form a network of pores traversing said envelope piece.

[0039] Each feature introduced by the expression "preferably" given in relation to one of the aspects of the invention applies to all other aspects of the invention.

[0040] The invention will be well understood and other aspects and advantages will become clear upon reading the following description, given with reference to the attached figures listed below.

[0041] Fig. 1 illustrates a diagram of a method for decorating a part of the bodywork of a motor vehicle according to the invention.

[0042] Figure 2 is a cross-section of a piece during a printing step of a decorative element for a motor vehicle according to an embodiment of the invention.

[0043] In the following description, the term "include" is synonymous with "include" and is not limiting in that it permits the presence of other steps in the process to which it relates. It is understood that the term "include" includes the terms "consist of". The terms "external" and "internal" shall respectively designate what is oriented towards the outside of the vehicle and towards the inside of the vehicle.

[0044] In this description, the ranges of values ​​include the bounds that delimit them.

[0045] In the present description, the equality between the values ​​is not to be understood in the strict sense insofar as each equality allows a variation of at most 10%, preferably at most 5%, more preferably at most 2%, between these values.

[0046] In this description, the terms "vertical" and "horizontal" are not to be understood in their strict sense. Indeed, they allow an inclination of at most 20°, preferably at most 10°, more preferably at most 5°, and even more preferably at most 2°; with respect to the strict meaning of these terms.

[0047] Throughout the description, the different figures use the same reference signs to designate identical or similar entities.

[0048] Fig. 1 represents a diagram of a method for decorating a part of the body of a motor vehicle, according to an embodiment of the invention.

[0049] Such a motor vehicle generally includes energy storage means and at least one engine (not shown) adapted to drive said Motor vehicle. A motor vehicle comprises a structure forming an outer body, or the main frame of the motor vehicle. This structure locally forms the body of the motor vehicle. Its precision and homogeneity enhance the perceived quality.

[0050] The structure defines a passenger compartment. The passenger compartment includes seats and aesthetic elements that contribute to the perceived quality of the motor vehicle. The aesthetic elements are envelope parts such as trim pieces or body panels. The envelope parts cover raw surfaces or close openings in the structure.

[0051] The motor vehicle can, for example, be a private motor vehicle or a commercial motor vehicle.

[0052] The decoration process comprises the following steps, carried out in the following order:

[0053] a) supply or production 100 of an envelope part;

[0054] b) printing 102 of a decoration by ink sublimation on the surface.

[0055] Step a) supply or production 100 may include cutting, shaping assembly by molding or cutting, or by stitching. Other assembly methods, such as gluing, are also considered.

[0056] The enclosure comprises a surface. This surface is formed by a porous material. The porous material comprises pores with widths ranging from 0.08 µm to 1.10 µm; preferably, the pores of the porous material have widths ranging from 0.10 µm to 0.60 µm; more preferably, the pores have widths ranging from 0.10 µm to 0.40 µm. The pore widths correspond to the pore diameters. The pore widths, and the pore diameters respectively, are the values ​​measured at the surface. The pore widths and the distribution of said widths are determined by mercury intrusion porosimetry analysis, according to ISO 15901-1:2016.

[0057] Preferably, at least 90% of the pores in the porous material have widths between 0.10 pm and 0.60 pm; more preferably, pores with widths between 0.10 pm and 0.40 pm represent at least 50% of the pores in the porous material. The distribution of pore widths is centered on a value between 0.10 pm and 0.60 pm. In general, the pores exhibit a width distribution. The distribution has a center between 0.10 pm and 0.60 pm; preferably between 0.20 pm and 0.40 pm; more preferably between 0.30 pm and 0.40 pm.

[0058] According to one embodiment of the invention, the porous material is polycarbonate. According to another alternative of the invention, the porous material is polyester, polystyrene, polyvinyl chloride, polypropylene, polymethyl methacrylate, or Acrylonitrile butadiene styrene methacrylate, or a mixture of several of these, is used. For example, the outer casing is a bumper skin or a protective side strip. It may comprise a composite material with reinforcing fibers and a polymer resin.

[0059] According to one embodiment of the invention, the porous material is natural leather or artificial leather. Artificial leather comprises natural or synthetic fibers to which a layer of polyvinyl chloride, polyester, polypropylene, or cellulose is added. For example, the covering piece is a seat or headrest cover, or a dashboard cover for a motor vehicle.

[0060] Before step b) printing 102, the decoration process includes cleaning the envelope part. The cleaning includes a chemical treatment of the surface.

[0061] In step b) printing 102, the ink is embedded in the surface by sublimation. The ink blends with the material. The ink penetrates the material by entering the pores of the material. Step b) printing 102 includes holding at temperature for 15 to 20 minutes. The ink is of a sublimation-specific type. Sublimation ink formulations use dyes as opposed to pigments. These dyes are transformed by heating into gaseous elements necessary for sublimation transfer.

[0062] Following step b) printing 102, the decoration is embedded within the surface thickness. It is contained within the porous material. Following step b) printing 102, the coating is concentrated in a sub-layer, or an outer film of the surface. The surface thickness remains constant at the edges of the decoration. Thus, the surface maintains a smooth and continuous appearance. This contributes to the perceived quality of the motor vehicle.

[0063] According to one embodiment, the envelope piece comprises an edge with two opposing faces and a slice connecting the opposing faces. The edge forms a ridge. In step b) printing 102, the decoration covers the ridge and the opposing faces. This optimizes the perceived quality.

[0064] According to one option of the invention, the envelope piece further comprises a rib. The rib forms a raised line, set back from the edges of the envelope piece. It may correspond to a style line. In step b) printing 102, the decoration covers said rib. It extends on both sides of the rib. The decoration runs along the rib.

[0065] During step b) printing 102, an inflatable bag exerts pressure against the envelope piece. The use of an inflatable bag allows for the application of constant pressure, which facilitates control of the sublimation phenomenon. Furthermore, the inflatable bag can adapt to complex surface geometries, particularly those with ribs. It is quickly applied to the surface, or support surface. The same The inflatable bag model can be used on various surface geometries. Therefore, using inflatable bags optimizes printing quality and costs.

[0066] Step b) printing 102 includes applying a pressure of 100 g / m² to 200 g / m² to the envelope piece, directed from the decoration towards the envelope piece. This pressure range optimizes the rendering on a surface with pore widths between 0.08 pm and 1.10 pm; preferably between 0.10 pm and 0.60 pm; more preferably between 0.10 pm and 0.40 pm.

[0067] In step b) printing 102, the ink used has a sublimation temperature. Step b) printing 102 is carried out at a temperature between 100% and 150%, preferably between 100% and 130%, of said sublimation temperature. Step b) printing 102 involves a temperature between 80°C and 120°C. The temperature increase is ensured by an additional heat source. Step b) printing 102 is optionally carried out under vacuum.

[0068] Prior to step b) printing 102, the decoration process includes a drying and degassing step of the surface. Degassing aims to empty the pores, or at least to expel any gas that could disrupt the sublimation printing process by penetrating these pores. This step limits the occurrence of blistering of the coating and the risk of oxidation. It contributes to the perceived quality.

[0069] This step b) printing 102 can be iterated. It is then repeated to implement several decorative layers stacked one on top of the other. These stacked layers can be of equal thickness and / or of the same color(s). This improves the rendering, thanks to decorative layers of lesser thickness. In step b) printing 102, the decoration includes several colors. This makes it possible to create polychrome patterns.

[0070] Step b) printing 102 comprises substep b1) supplying 110 a transfer sheet; substep b2) printing 112 a decoration onto the transfer sheet; substep b3) processing 114 the transfer sheet to dry the ink; substep b4) applying 116 the transfer sheet to the envelope piece; substep c5) heating 118 the transfer sheet against the envelope piece; and substep c6) removing 120 the transfer sheet. The transfer sheet is also referred to as the medium or temporary support.

[0071] In substep b2) printing 112, the decoration is printed symmetrically with respect to the final version on the envelope piece. In other words, during step b) printing 102, a selected image is printed in mirror image onto heat-resistant sublimation paper. Once printed, the image is heat-transferred to the surface. Under the effect of high temperature and pressure, the boiling inks cool instantly upon contact with the material. surface. The inks transform into a gas and are then permanently imprinted onto the envelope piece. The surface texture is preserved.

[0072] Substep b3) treatment 114 of the transfer sheet remains optional. It includes heating, exposure to ultraviolet radiation, or vacuum treatment to degas it.

[0073] The body panel is an inner or outer body panel of the motor vehicle. It forms the outer skin of the motor vehicle, such as a bumper skin, or a surface delimiting the interior of the vehicle, such as the passenger compartment or a seat element. The body panel is generally a visible part; visible from inside or outside the motor vehicle.

[0074] Figure 2 shows a motor vehicle body part during a step sublimation printing, according to an embodiment of the invention. The motor vehicle may correspond to the one shown in relation to [Fig. 1]. The wrap part and the printing step correspond to those shown in relation to [Fig. 1].

[0075] The trim piece 10 is the general support for the decoration 16. The trim piece 10 can be an interior panel in the passenger compartment, or an exterior panel representing the bodywork. It can form the structure of the motor vehicle. The trim piece 10 is a finishing piece. The trim piece 10 can be an upholstery element of the motor vehicle. It is a visible part, from the inside and / or outside of the vehicle. The trim piece 10 comprises a plastic material, or leather.

[0076] The leather of the outer part 10 is natural leather or synthetic leather. Natural leather is leather of animal origin. It may be bovine leather or leather from another animal species. The leather may be recycled leather, which helps to limit the overall carbon footprint of the motor vehicle. The porous leather material has a porosity of at least 10%, preferably at least 30%. The porosity is between 50% and 70%; preferably between 55% and 65%.

[0077] The plastic part is preferably made of polycarbonate. It is, for example, transparent or translucent. The transparent material is used, for example, to form a quarter window, glazing, headlight, taillight, or grille. It can be a headlight or taillight lens; the printing is done on the inner surface. This configuration protects it while leaving it visible from the outside. This contributes to the perceived quality.

[0078] The envelope part 10 has a surface 12. The surface 12 is treated. The surface 12 is a support surface. The surface forms a target surface for printing by Sublimation. It is essentially smooth. Surface 12 covers the envelope part 10. Surface 12 is an interior surface within the passenger compartment or in a device such as a lighting device. Alternatively, surface 12 is an exterior surface forming the vehicle body, or the cover of a seat, for example.

[0079] The outer casing 10 is made of a porous material. This porous material forms the surface 12 and has pores with widths ranging from 0.08 pm to 1.10 pm; preferably, between 0.10 pm and 0.60 pm; more preferably, between 0.10 pm and 0.40 pm. These pores constitute the majority of the porous material. The porous material may include pores with other widths.

[0080] The decoration 16 is temporarily supported by a transfer sheet 18, or temporary backing sheet. The transfer sheet 18 is waterproof. The decoration 16 is printed onto the transfer sheet 18 before being applied to the envelope piece 10. The transfer sheet 18 conforms to the geometry of the surface 12. The transfer sheet 18 is waterproof in order to control the sublimation of the ink of the decoration 16, and in particular to prevent ink loss. The transfer sheet 18 is stacked vertically on the envelope piece 10.

[0081] During the sublimation printing step, an inflatable bag 20 exerts pressure against the envelope piece 10. The pressure is maintained for a predetermined time. The inflatable bag 20 is advantageously inflated with a gas. The inflatable bag 20 forms a template for applying the transfer sheet. Its geometry is complementary to that of the envelope piece 10. The inflatable bag 20 reproduces the ribs and slanted edges of the envelope piece 10. It conforms to the shape of the envelope piece 10.

[0082] The inflated bag 20 allows for the application of homogeneous pressure to the decoration 16. It exerts a pressure of 100 g / m2 to 200 g / m2 on the envelope piece 10, in particular on the surface 12 through the decoration 16 and the transfer sheet 18. For example, the pressure is 150 g / m2.

[0083] The invention comprises the combination of all the embodiments illustrated by all the figures.

Claims

Demands

1. A method for decorating a surface (12) of a motor vehicle body part (10), the decoration method comprising the following steps: • a) supplying or producing (100) a body part (10) comprising a surface; • b) printing (102) a decoration (16) by ink sublimation onto the surface; characterized in that the body part (10) comprises a porous material forming the surface; the porous material comprises pores of widths between 0.08 pm and 1.10 pm; in step b) printing (102), the ink penetrating said pores by sublimation.

2. A method according to claim 1, characterized in that the pores comprise widths between 0.10 pm and 0.40 pm; preferably the pores with widths between 0.10 pm and 0.40 pm represent at least 50% of the pores of the porous material.

3. A method according to any one of claims 1 to 2, characterized in that at least 90% of the pores of the porous material have widths between 0.10 pm and 0.60 pm; preferably, the pore widths exhibit a width distribution; said distribution having a center between 0.10 pm and 0.60 pm.

4. A method according to any one of claims 1 to 3, characterized in that during step b) printing (102), an inflated bag (20) exerts pressure against the envelope piece (10); and / or step b) printing (102) comprises applying a pressure of 100 g / m2 to 200 g / m2 on the envelope piece (10).

5. A method according to any one of claims 1 to 4, characterized in that in step b) printing (102), the ink comprises a sublimation temperature, step b) printing (102) being carried out at a temperature between 100% and 130% of said sublimation temperature; preferably, step b) printing (102) comprises a temperature between 80°C and 120°C.

6. A method according to any one of claims 1 to 5, characterized in that step b) printing (102) of the decoration (16) comprises a substep b1) supplying (110) of a transfer sheet (18); a substep b2) printing (112) of a pattern on the transfer sheet (18); a substep b4) application (116) of the transfer sheet (18) onto the part (10); a substep b5) heating (118) of the transfer sheet (18) against the envelope part (10); a substep b6) removal (120) of the transfer sheet (18).

7. A method according to any one of claims 1 to 6, characterized in that in step b) printing (102) of the decoration (16) by sublimation, said decoration (16) comprises several colors; and / or step b) printing (102) of decoration by sublimation is repeated in order to implement several decorations stacked one on top of the other.

8. A method according to any one of claims 1 to 7, characterized in that the porous material is transparent or the porous material comprises a porosity of between 55% and 65%.

9. A method according to any one of claims 1 to 8, characterized in that the porous material is polycarbonate; preferably the envelope piece (10) is a motor vehicle bumper skin.

10. A method according to any one of claims 1 to 8, characterized in that the porous material is natural leather or artificial leather; preferably, the cover piece (10) is a motor vehicle seat or headrest cover, or dashboard cover.

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