FR3058916A1 - METHOD FOR PROCESSING THE SURFACE OF A WORKPIECE, INSTALLATION FOR IMPLEMENTING SAID METHOD AND PIECE OBTAINED BY SAID PROCESSING METHOD - Google Patents

Abstract

The present invention relates to a method for treating a surface (2) of a workpiece (1) comprising a rough zone (3) having reliefs (3 ') and recesses (3 "), which method comprises: a step of taking data into account, in which a set of spatial data representative of the surface configuration of said rough zone (3), are taken into account and processed, in a management and control unit; a deposition step, during which a substance (4) is deposited on said rough zone (3) by deposition means (5) to form a layer of substance so as to cover the reliefs (3 ') and / or fill the depressions (3 "), a support device, on which the workpiece (1) is mounted, and the deposition means (5) being relatively moved by the management and control unit according to the spatial data.

Description

DESCRIPTION

The present invention relates to the field of surface treatment of a part made of plastic material, in particular an interior trim part for the automobile.

In the automotive field, plastic parts, for example trim parts or interior trim of a motor vehicle, often have a surface of structured or textured appearance, in particular grained, on the one hand, for aesthetic reasons, and d on the other hand, for reasons of resistance. By grainy-looking surface is meant a rough area with hollows and reliefs. Indeed, the grained surfaces appear matt and guarantee protection against scratches due to friction or against aging. In known manner, this grainy appearance is obtained by a mechanical action on the surface of the mold of the part which is prior to the manufacture of the part. This mechanical action may consist, for example, of etching, chemical attack, electroplating, sandblasting or the like of the mold surface. One of the drawbacks of these methods is that after the part has been manufactured, this grainy appearance is definitive and irreversible. A possible change in the appearance of the grained surface is made complex and costly.

To modify the surface appearance of such parts, it is for example known to use pad printing, or screen printing or laser scraping methods. The decorations obtained by the use of these methods do not make it possible to obtain a completely smooth or flat surface. Indeed, the grainy aspect of the surface is always perceptible under the decoration or the aspect coating. In addition, the grainy appearance interferes with the outline of the decor and disturbs the perception and readability. This results in poor quality and imprecise decoration, as well as poor aesthetics.

Another known way of proceeding consists in removing material locally or not, partially or totally, directly at the level of the grained appearance surface of the part, by means of either a milling process or a process of laser scraping. According to another possibility, the surface of the mold of the part can also be modified so as to produce a smooth imprint. Then, the part obtained with a treated area

-2plane can then be decorated. However, these methods have the drawback of lacking flexibility, of being costly and complex to implement.

The present invention aims to provide a flexible and easy to implement solution, allowing to overcome at least the main limitations of the prior art indicated above.

To this end, the present invention relates to a method of treating at least one surface of a part, said at least one surface comprising at least one rough area having a plurality of reliefs and hollows, treatment method characterized in that '' it successively includes at least:

a step of taking data into account, during which a set of spatial data representative of the surface configuration or the topography of said at least one rough area, are taken into account, and possibly processed, in a management unit and order,

a deposition step, during which at least one substance, preferably ink, is deposited on all or part of said at least one rough area by deposition means to form at least one layer of substance so as to at least partially, preferably completely, cover the reliefs and / or fill the hollows with at least a fraction of said at least one rough area, said at least one layer of substance having at least one apparent surface, preferably flat or smooth, a support device, on which the part is mounted, and the deposition means being, during the deposition step, moved relatively and in a controlled manner with respect to each other by the management and control unit in function of the spatial data relating to said at least one rough area or of information resulting from their processing.

The present invention also relates to an installation for the treatment of at least one surface of a part, said at least one surface comprising at least one rough area having a plurality of reliefs and hollows,

-3 installation characterized in that it allows the implementation of the treatment method described above, and in that it comprises at least:

- a management and control unit,

- means for depositing a substance, preferably ink,

- a support device, said support device and the depositing means being movable relative to one another in a controlled manner by the management and control unit.

The invention finally relates to a part, preferably made of plastic material, for example a trim or interior trim part of a motor vehicle, comprising at least one surface comprising at least one rough area having a plurality of reliefs and depressions, characterized in that that the part is obtained by treatment in accordance with the treatment method described above and, preferably, by means of the installation described above, and in that it comprises at least one layer of substance consisting of at least one substance covering the reliefs and / or filling the hollows with at least a fraction of said at least one rough area, said at least one layer of substance having at least one apparent surface, preferably flat and of smooth appearance.

The invention will be better understood from the following description, which relates to several preferred embodiments, given by way of non-limiting examples, and explained with reference to the appended schematic drawings, in which:

FIG. 1A is a sectional view of a part according to the invention in a first alternative embodiment before the treatment method according to the invention in a first alternative embodiment, FIG. 1B is a sectional view of the part shown in FIG. IA during the measurement step of the treatment method according to the invention in a first embodiment, FIG. IC is a sectional view of the part shown in FIG. IA during the deposition step of the method of treatment according to the invention in the first variant embodiment,

FIG. 4D is a sectional view of the part shown in FIG. 1A after the step of depositing the treatment method according to the invention in the first variant embodiment, FIG. 1E is a sectional view of the part shown in Figure ID during the printing step of the treatment method according to the invention in the first variant, Figure 1F is a sectional view of the part shown in Figure ID after the printing step of the treatment method according to the invention in the first variant embodiment, FIG. 2A is a section view of a part according to the invention in a second variant before the treatment method according to the invention in a second variant embodiment, FIG. 2B is a sectional view of the part shown in FIG. 2A during the measurement step of the treatment method according to the invention in the second variant embodiment, FIG. 2C is a sectional view of the part shown in FIG. 2A during the step of delimiting the treatment method according to the invention in the second variant embodiment, FIG. 2D is a sectional view of the part shown in the FIG. 2A after the step for delimiting the treatment method according to the invention in the second variant embodiment, FIG. 2E is a sectional view of the part shown in FIG. 2D during the step of depositing the treatment method according to the invention in the second alternative embodiment, FIG. 2F is a sectional view of the part shown in FIG. 2D after the step of depositing the treatment method according to the invention in the second alternative embodiment, FIG. 2G is a sectional view of the part shown in FIG. 2F during the printing step of the treatment method according to the invention in the second variant embodiment, FIG. ure 2H is a sectional view of the part shown in FIG. 2F after the printing step of the treatment method according to the invention in the second variant embodiment, FIG. 3 is a schematic view of the support device, deposition means and the installation management unit according to the invention,

FIG. 4 is a schematic view of the print head of the installation deposition means according to the invention, FIG. 5 is a schematic view of the instrument for measuring the installation according to the invention, FIG. 6A is a sectional view of a part according to the invention in a third variant during the step of depositing the treatment method according to the invention in the third variant embodiment, and FIG. 6B is a view in section of the part shown in FIG. 6A after the step of depositing the treatment method according to the invention in the third variant embodiment.

According to the invention, the method for treating at least one surface 2 of a part 1, said at least one surface 2 comprising at least one rough area 3 having a plurality of reliefs 3 'and of recesses 3 ”is characterized in that it successively comprises at least:

a step of taking into account data, during which a set of spatial data representative of the surface configuration or of the topography of said at least one rough area 3, are taken into account, and possibly processed, in a unit of management and control 13,

a deposition step, during which at least one substance 4, preferably ink, is deposited on all or part of said at least one rough zone 3 by deposition means 5 to form at least one layer of substance 6 so as to at least partially, preferably completely, cover the reliefs 3 ′ and / or fill the hollows 3 ”with at least a fraction of said at least one rough area 3, said at least one layer of substance 6 having at least an apparent surface 7, preferably flat or smooth, a support device 14, on which the part 1 is mounted, and the deposition means 5 being, during the deposition step, moved relatively and in a controlled manner relative to one another to the other by the management and control unit 13 as a function of the spatial data relating to said at least one rough area 3 or of information resulting from their processing.

Advantageously, this method makes it possible, by deposition means 5, to provide over all or a fraction of the rough area 3, a

-6 layer of substance 6 whose apparent surface 7 is preferably flat and smooth compared to that of the rough area, if necessary surrounding and untreated. It is thus possible to obtain a part 1 with a rough zone 3 and a smooth zone 6, 7 which may or may not be decorated (FIGS. 2F, 2G, 2H). For example, the spatial data set representative of the surface configuration or the topography of the rough area 3 may consist of two-dimensional or three-dimensional print files.

This method may include a measurement step, prior to the data taking step, during which a measuring instrument 8 explores the surface of said at least one rough area 3 concerned and provides the spatial data representative of its configuration. surface, which are transmitted to the management and control unit 13 (Figures IB and 2B).

Advantageously, this measurement step makes it possible to determine from the spatial data representative of the rough area surface configuration 3, for example three-dimensional files, the total volume to be filled with substance 4 at the time of the deposition step. This total volume can be broken down into several sub-volumes which can take the form of layers or strata. Two-dimensional print files can then be created in negative for the deposit step. Two-dimensional files can have different drop size values.

During the deposition step, the drops of substance 4 can have different volumes and can be controlled by the gray levels of the two-dimensional print file. For example, it is possible to have eight gray levels and therefore eight different drop sizes of substance 4 which can, for example, be between 8 and 48 picoliters.

Alternatively, during the data taking step, the spatial data can be transmitted to the management and control unit 13 in the form of at least one pre-established digital print file.

For example, the print file can be a two-dimensional file.

In this case, the preset print file can correspond to at least part of a print file used in a step of

-7 prior surface treatment having resulted in the creation of said at least one rough zone 3 considered.

Preferably, this print file used in a prior surface treatment step which has resulted in the creation of the rough area 3 considered is a graining or texturing file when the rough area 3 is of grained or textured appearance.

The step of taking into account spatial data may include or be followed by an inversion step leading to a set of data corresponding to a negative representation of the surface configuration of said at least one rough area 3.

As illustrated in FIGS. 1E, 1F, 2G, 2H, the method may include a printing step, subsequent to said deposition step, during which at least one ink 9 is deposited by deposition means 5, identical or not to the means 5 for depositing the substance 4, on at least part of the apparent surface 7 of the layer of substance 6 to form at least one ink pattern 10 and during which the support device 14 and the means for depositing 5 are moved relatively relative to each other and in a controlled manner by the management and control unit 13.

Advantageously, this printing step makes it possible to create an ink pattern 10 on the apparent surface 7 of the layer of substance 6. It follows that the part 1 comprises a rough area 3 and a layer of substance 6 decorated.

According to one possibility, the depositing and printing steps are carried out simultaneously. In this case, the means 5 for depositing the substance 4 and the ink 9 are identical.

This method can also include an adjustment step, prior to the deposition step, during which a lower reference altitude forming a zero level, preferably corresponding to the deepest hollow 3 ″ of the rough area 3, can be determined and at least a higher reference altitude can be determined arbitrarily or not.

During the deposition step, the substance 4 can be deposited by the deposition means up to said at least one higher reference altitude preferably between 5 micrometers and 0.5 millimeters relative to the zero level.

In this case, the minimum thickness of the layer of substance 6 that can be deposited can be equal to 5 micrometers.

According to a first variant embodiment of the method when the rough area 3 is delimited by at least one adjacent flat area 11 or a ledge, the upper reference altitude may correspond to the altitude of said adjacent flat area 11 or of said edge (FIGS. 1A to 1F).

Advantageously, in this case the layer of substance 6 which will be deposited will be flush with the flat area 11, as can be seen in FIGS. 1D to 1F.

According to a second alternative embodiment of the method, the higher reference altitude may correspond at least to the altitude of the highest relief 3 ’in the rough area 3 (FIGS. 2A to 2H).

In accordance with the second variant embodiment of the method, the method may further comprise a delimitation step, as illustrated in FIGS. 2E to 2F, prior to the deposition step, during which a substance 4 is deposited in the rough area 3 by the deposition means 5 in the form of at least one closed or open delimiting strip 12.

Advantageously, this way of proceeding makes it possible to create a delimitation, which may be peripheral, of the rough zone 3 which must be covered with the substance 4 at the time of the deposition step. It is thus possible to prevent the substance 4 from flowing over a fraction of the rough area 3 which should not be covered.

In the second alternative embodiment of the method, during the deposition step, the substance 4 can be deposited by the deposition means inside the closed delimitation strip 12.

Advantageously, thanks to the invention, a layer of substance 6 is obtained which is well delimited with respect to the rough area 3 which has not been covered, over a localized fraction of the rough area 3.

Preferably, the method according to the invention may consist, during the measurement step, of implementing a contactless measuring instrument 8, preferably a digital microscope or a three-dimensional scanner.

Advantageously, such a measuring instrument 8 makes it possible to determine the topography of the rough area 3 and to deduce therefrom the volume to be filled.

This measuring instrument 8 can be chosen from: a digital microscope, or an atomic force microscope (AFM) or a contact profilometer, preferably with a diamond tip 17, or an optical, scanning or matrix profilometer, or a roughness.

Preferably, during the measurement step, the support device 14 and the measurement instrument 8 can be moved relatively relative to one another and in a controlled manner by the management and control unit 13 .

Preferably, the deposition means 5 can comprise at least one print head 5 ’, preferably of the inkjet type.

Advantageously, the steps of depositing and printing the method according to the invention can thus be carried out by the same tool.

The deposition step of the process according to the invention can also be carried out in several passes. The number of passes is then for example defined as a function of the volume of drop of substance 4 used and the volume to be filled. For example, for a reference altitude greater than 0.5 millimeters, the number of passes and on average 25, with drops having a volume of 24 picoliters.

According to a third alternative embodiment of the method according to the invention, the deposition step may consist in depositing a layer of substance 6 which has higher reference altitude variations. Preferably, the substance 4 can be deposited over a distance d of between 5 and 50 millimeters. As a result, the apparent surface 7 is non-planar, as illustrated in FIG. 6B.

According to the invention, the installation for the treatment of at least one surface 2 of a part 1, said at least one surface 2 comprising at least one rough area 3 having a plurality of reliefs 3 ′ and of hollows 3 ” is characterized in that it allows the implementation of the treatment method as described above and in that it comprises at least:

a management and control unit 13 (FIG. 3),

- 10- means 5 for depositing a substance 4, preferably ink (FIGS. 3 and 4),

- a support device 14 (FIG. 3), said support device 14 and the depositing means 5 being movable relative to one another in a controlled manner by the management and control unit 13.

This installation can include a measuring instrument 8 and said support device 14 and the measuring instrument 8 can be movable relatively to each other in a controlled manner by the management and control unit 13.

This measuring instrument 8 can be a contact measuring instrument (FIG. 5) or contactless, preferably a digital microscope or a three-dimensional scanner.

Such a measuring instrument 8 can be as indicated above. In addition, the support device 14 can be mounted on a robotic arm 15 controlled by a control unit 16 connected to the management and control unit 13.

As illustrated in FIG. 5, the measuring instrument 8 can be a profilometer comprising a tip 17 preferably made of diamond mounted on an arm 18 connected to a motion sensor 19 by a pivot link 20. The tip 17 can be in contact with the rough area 3 and its topography can be determined by scanning the tip 17 on the surface of the rough area 3.

Preferably, the depositing means 5 comprise at least one print head 5 ’, preferably of the inkjet type, as illustrated in FIG. 4.

For example, as illustrated in FIG. 4, the print head 5 ’may include a piezoelectric element 21 connected to an electrical supply 22, a reservoir 23 and a nozzle 24 mounted on a plate 25.

The part 1, preferably made of plastic material, for example a trim or interior trim part of a motor vehicle, comprises at least one surface 2 comprising at least one rough area 3 having a plurality of reliefs 3 ′ and hollows 3 ”.

According to the invention, the part 1 is characterized in that it is obtained by treatment in accordance with the treatment process

- 11 previously described and, preferably, by means of the installation described above, and comprises at least one layer of substance 6 consisting of at least one substance 4 covering the reliefs 3 ′ and / or filling the hollows 3 ″ at least a fraction of said at least one rough area 3, said at least one layer of substance 6 having at least one apparent surface 7, preferably flat and of smooth appearance (FIGS. 1D and 2F).

Advantageously, the part 1 obtained can have a layer of substance 6, if necessary with a smooth appearance relative to the rough area 3 and the topography of which can be constant (FIGS. 1D, 1E, 1F, 2F, 2G, 2H) or of variable topography (Figure 6B).

Preferably, according to a first variant embodiment and a second variant embodiment, the apparent surface 7 of the layer of substance 6 can comprise at least one ink pattern 10 (FIGS. 1F and 2H).

Preferably, the rough zone 3 may have a grainy or grainy or textured appearance. Alternatively, the rough area 3 can consist of a relief decoration, such as one or more decorative or informative graphics, stylized or not, one or more writings , such as one or more number (s), letter (s), number (s) or word (s) or combinations thereof, but also in one or more groove (s), or groove (s), or edge (s) in relief.

The rough area 3 can extend over part of the surface 2 (FIGS. 1A to 1F) according to the first alternative embodiment or over the entire surface 2 (FIGS. 2A to 2H and 6B) according to the second and third variant embodiments.

The substance 4 may consist of ink, for example ink for an inkjet printer, or a colored or non-colored substance, possibly transparent, which can be applied by such a printer.

In addition, the layer of substance 6 can extend over the whole of the rough area 3 (FIGS. 1D to 1F) according to the first alternative embodiment or over a fraction of the rough area (FIGS. 2F to 2H) according to the second variant. of achievement.

- 12II is thus possible thanks to the invention to cover the reliefs 3 ′ and the hollows 3 ″ of the rough area 3 with precision to form a layer of substance 6 having an apparent surface 7 smooth and flat capable of serving as a support on which a decoration can preferably be applied, ink 9 forming an ink pattern 10. The present invention can be used on all types of rough areas 3 and in the case where the rough area 3 is grained on all types of grains. As a result, this ink pattern 10 has an improved visual appearance and the quality of the decoration is also improved.

Alternatively and according to a third alternative embodiment, the part 1 may comprise a layer of substance 6, the topography of which may be variable, leading to an apparent surface 7 which is not planar.

Preferably, the apparent surface 7 has gradual variations in altitude.

Advantageously, visual and tactile relief effects are obtained which may be in color or in monochrome, transparent or opaque, of the same color as the material of the part 1 or not.

In this case, the part 1 does not necessarily include an ink pattern 10 on the visible surface 7.

Alternatively and according to a variant embodiment not shown, it is also possible thanks to the invention to form another visual effect by only filling in the rough area 3, for example with one or more substances 4 having one or more colors of the color of the rough area 3. The upper reference altitude of the layer of substance 6 is then lower than the altitude of at least one of the reliefs 3 ′ or of the relief 3 ′ the highest.

Of course, the invention is not limited to the embodiments described and shown in the accompanying drawings. Modifications remain possible, in particular from the point of view of the constitution of the various elements or by substitution of technical equivalents, without thereby departing from the scope of protection of the invention.

Claims (20)

1. Method for treating at least one surface (2) of a part (1), said at least one surface (2) comprising at least one rough area (3) having a plurality of reliefs (3 ') and hollow (3 ”), treatment process characterized in that it successively comprises at least: - a step of taking data into account, during which a set of spatial data representative of the surface configuration or the topography of said at least one rough area (3), are taken into account, and possibly processed, in a management and control unit (13), - A deposition step, during which at least one substance (4), preferably ink, is deposited on all or part of said at least one rough area (3) by deposition means (5) to form at at least one layer of substance (6) so as to at least partially, preferably completely, cover the reliefs (3 ′) and / or fill the hollows (3 ″) with at least a fraction of said at least one rough area ( 3), said at least one layer of substance (6) having at least one apparent surface (7), preferably flat or smooth, a support device (14), on which the part (1) is mounted, and the means for depot (5) being, during the deposition step, moved relatively and in a controlled manner with respect to each other by the management and control unit (13) as a function of the spatial data relating to said at least a rough area (3) or information resulting from their processing. 2. Method according to claim 1, characterized in that it comprises a measuring step, prior to the step of taking data into account, during which a measuring instrument (8) explores the surface of said at least one rough area (3) concerned and provides the spatial data representative of its surface configuration, which are transmitted to the management and control unit (13). 3. Method according to claim 1, characterized in that during the step of taking into account data, the spatial data are - 14 transmitted to the management and control unit (13) in the form of at least one pre-established digital print file. 4. Method according to claim 3, characterized in that the pre-established print file corresponds to at least part of a print file used in a prior printing step having resulted in the creation of said at least one area rough (3) considered. 5. Method according to any one of claims 1 to 4, characterized in that the step of taking into account spatial data includes or is followed by a step of inversion leading to a set of data corresponding to a representation in negative of the surface configuration of said at least one rough area (3). 6. Method according to any one of claims 1 to 5, characterized in that it comprises a printing step, subsequent to said deposition step, during which at least one ink (9) is deposited by means of deposition (5) identical or not to the deposition means (5) of the substance (4), on at least part of the apparent surface (7) of the layer of substance (6) to form at least one ink pattern (10) and during which the support device (14) and the depositing means (5) are moved relatively relative to each other and in a controlled manner by the management and control unit (13) . 7. Method according to claim 6, characterized in that the deposition and printing steps are carried out simultaneously. 8. Method according to any one of claims 1 to 7, characterized in that during a setting step, prior to the deposition step, a lower reference altitude forming a zero level, preferably corresponding to the trough (3 ”) The deepest of the rough zone (3) is determined and in that at least one higher reference altitude is determined arbitrarily or not. 9. Method according to claim 8, characterized in that during the deposition step, the substance (4) is deposited by the deposition means (5) up to said at least one higher reference altitude preferably between 5 micrometers and 0.5 millimeters from the zero level. 10. Method according to claim 8, characterized in that the higher reference altitude corresponds to the altitude of the highest relief (3 ’) of the rough area (3) or, when the rough area (3) is - 15 delimited by at least one adjacent flat area (11) or a flange, the higher reference altitude corresponds to the altitude of said adjacent flat area (11) or said edge. 11. Method according to any one of claims 1 to 10, characterized in that during a delimitation step, prior to the deposition step, a substance (4) is deposited in the rough area (3) by the depositing means (5) in the form of at least one closed or open delimiting strip (12). 12. Method according to claim 11, characterized in that during the deposition step, the substance (4) is deposited by the deposition means inside the closed delimitation strip (12). 13. Method according to any one of claims 2 to 12, characterized in that it consists, during the measurement step, in implementing a measurement instrument (8) without contact, preferably a digital microscope or a scanner. three-dimensional. 14. Method according to any one of claims 13, characterized in that during the measuring step, the support device (14) and the measuring instrument (8) are moved relatively one relative to the 'other and in a controlled manner by the management and control unit (13). 15. Method according to any one of claims 1 to 14, characterized in that the deposition means (5) comprise at least one print head (5 ’), preferably of the inkjet type. 16. Installation for the treatment of at least one surface (2) of a part (1), said at least one surface (2) comprising at least one rough area (3) having a plurality of reliefs (3 ') and hollow (3 ”), installation characterized in that it allows the implementation of the treatment method according to any one of claims 1 to 15, and in that it comprises at least: - a management and control unit (13), - means for depositing (5) a substance (4), preferably ink, - a support device (14), said support device (14) and the depositing means (5) being relatively movable relative to one another in a controlled manner by the management and control unit (13 ). - 1617. Installation according to claim 16, characterized in that it comprises a measuring instrument (8) and in that said support device (14) and the measuring instrument (8) are relatively movable one by relationship to each other in a manner controlled by the management unit and 5 control (13). 18. Installation according to claim 17, characterized in that the measuring instrument (8) is a contact or contactless measuring instrument, preferably a digital microscope or a three-dimensional scanner. 10 19. Installation according to any one of claims 16 to 18, characterized in that the deposition means (5) comprise at least one print head (5 ’), preferably of the inkjet type. 20. Part (1), preferably made of plastic material, for example a trim or interior trim part of a vehicle 15 automobile, comprising at least one surface (2) comprising at least one rough area (3) having a plurality of reliefs (3 ') and recesses (3 ”), characterized in that the part (1) is obtained by treatment according to the treatment method according to any one of claims 1 to 15 and, preferably, by means of the installation 20 according to claims 16 to 19, and in that it comprises at least one layer of substance (6) consisting of at least one substance (4) covering the reliefs (3 ') and / or filling the hollows (3 ” ) at least a fraction of said at least one rough area (3), said at least one layer of substance (6) having at least one visible surface (7), 25 preferably flat and smooth in appearance. 21. Part according to claim 20, characterized in that the apparent surface (7) of the layer of substance (6) comprises at least one ink pattern (10). 1/4 U