FR3062595A1 - METHOD FOR PRINTING A TRANSPARENT OR TRANSLUCENT PIECE AND PIECE OBTAINED - Google Patents

Abstract

The present invention relates to a method for printing a transparent part (1) comprising first and second faces (2, 3). It comprises: - a first printing step, in which: a substance is deposited by a printing head (5 ', 5' ') directly on the first face (2) of the workpiece (1) and the workpiece (1) is moved by the support device (4) relative to the deposition means (6, 6 ', 6' ') to form a first printed pattern, - a second printing step, in which: a substance is deposited by a printing head (5 ', 5' ') directly on the second face (3) of the workpiece (1) and the workpiece (1) is moved by the support device (4) relative to the means deposition (6, 6 ', 6' ') to form a second printed pattern.

Description

DESCRIPTION

The present invention relates to the field of printing a transparent or translucent part and relates to a method of printing such a part, as well as a part obtained from this process.

Many methods of decorating plastic parts are known, such as screen printing, pad printing, laser treatment or inkjet printing. Such methods are generally used to decorate the visible surface of an opaque plastic part. These traditional techniques, however, have several limitations. Not all types of part shapes can be decorated, and the pattern can be limited in color, size, finesse, line. Finally, it is most often impossible to achieve games and effects of depths, when the material is transparent.

We already know from the publication FR 2 974 767 of the applicant, a method of manufacturing a surface element with a light pattern. This element comprises a partially transparent visible layer comprising a rear face on which an opaque coating layer is deposited and in which a pattern is etched by laser ablation, and a visible face on which a first pattern is foamed by foaming the material. This manufacturing process has the drawback of being complex to implement, since removal of material is required to produce the various decoration patterns, and of depending on the material of the transparent layer.

Publication EP 2 239 238 A1 describes a glass article decorated with a printed pattern. However, an acrylic resin adhesion layer, interposed between the glass substrate and the printed pattern, is necessary to guarantee an acceptable rendering.

The purpose of the present invention is to propose a solution suitable for the production of decorations on transparent or translucent parts making it possible to overcome the major limitations of the state of the art indicated above.

The invention relates to a method of printing at least part of a wall of a transparent or translucent part and comprising at

-2 minus a first face and a second face opposite to each other, process characterized in that it comprises at least:

- A first printing step, during which: the part is placed on a support device so that at least one printhead forming part of deposition means is placed facing the first face, then at least one substance is deposited by said at least one print head directly on the first face of the part and the part is moved simultaneously and in a controlled manner by the support device relative to the deposition means to form at least a first printed pattern,

- A second printing step, during which: the part is placed on a support device so that at least one printhead forming part of the deposition means is placed facing the second face, then at least one substance is deposited by said at least one print head directly on the second face of the part and the part is moved simultaneously and in a controlled manner by the support device with respect to the deposition means to form at least a second printed pattern, said support device and the depositing means being relatively movable relative to each other in a controlled manner by a management and control unit, the first printing step and the second printing step being spatially coordinated with each other so that the first printed pattern and the second printed pattern are present on the first side and the second respectively me face mutually spatially adjusted to provide in a direction of incident observation with respect to the first and second faces of a resulting composite pattern by superposing the first and the second printed pattern printed pattern.

The invention also relates to a translucent or transparent part comprising at least one wall comprising at least a first face and a second face opposite to each other, characterized in that the part is obtained in accordance with the printing process as described above, and in that at least one first printed pattern is located directly on the first side, at least one second printed pattern is located directly on the second side and the first side and / or the second side includes at least one unprinted area, to provide

-3 in a direction of incident observation with respect to one of the first and second faces, a resultant pattern composite by superposition of the first printed pattern and the second printed pattern.

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

FIG. IA is a schematic view of a part, a support device, deposition means and drying means for implementing the first printing step of the method according to the invention in the first variant FIG. 1B is a schematic view of a storage area, during the implementation of the first storage step of the method according to the invention in the first variant embodiment, FIG. 1C is a view of the piece, of the support device, of the deposition means and of the drying means shown in FIG. 1A, during the implementation of the second printing step of the method according to the invention in the first variant embodiment, FIG. 1D is a schematic view of a storage area, during the implementation of the second storage step of the method according to the invention in the first variant embodiment, FIG. 2A is a schematic view of a part, of the first support device, of depositing means and of drying means, during the implementation of the first printing step of the method according to the invention in the second variant embodiment, FIG. 2B is a schematic view of the part, the first support device and the second support device, during the implementation of the transfer step of the method according to the invention in the second variant embodiment, FIG. 2C is a schematic view of the part, of the second support device, of depositing means and of drying means, during the implementation of the second printing step of the method according to the invention in the second variant embodiment, FIG. 2D is schematic view of a storage area during the implementation of the storage step of the method according to the invention in the second variant embodiment,

FIG. 3 is a view of a support device, a first printing head and a second printing head and drying means, during the implementation of the first printing step and of the second printing step of the method according to the invention in the third variant embodiment, FIG. 4 is a sectional view of a part according to the invention in a first variant embodiment, FIG. 5 is a view in section of a part according to the invention in a second alternative embodiment, Figure 6 is a sectional view of a part according to the invention in a third alternative embodiment, and Figure 7 is a sectional view of 'a part according to the invention in a fourth embodiment.

According to the invention, the method of printing at least part of a wall of a transparent or translucent part 1 and comprising at least a first face 2 and a second face 3 opposite to each other, is characterized in what he understands at least:

- a first printing step, during which: the part 1 is arranged on a support device 4, 4 ′, 4 ”so that at least one printhead 5, 5 ′, 5” making part of deposition means 6, 6 ′, 6 ”is placed facing the first face 2, then at least one substance (not shown) is deposited by said at least one printing head 5, 5 ′, 5” directly on the first face 2 of the part 1 and the part 1 is moved simultaneously and in a controlled manner by the support device

4, 4 ’, 4” relative to the depositing means 6, 6 ’, 6” to form at least a first printed pattern 7 (FIGS. 1A, 2A, 3),

- a second printing step, during which: the part 1 is placed on a support device 4, 4 ′, 4 ”so that at least one printhead 5, 5 ′, 5” making part of deposition means 6, 6 ′, 6 ”is placed facing the second face 3, then at least one substance is deposited by said at least one printing head 5, 5 ′, 5” directly on the second face 3 of the part 1 and the part 1 is moved simultaneously and in a controlled manner by the support device 4, 4 ', 4 ”relative to the depositing means 6, 6', 6” to form at least one second printed pattern 8 (Figures IC, 2C, 3),

-5said support device 4, 4 ', 4 ”and the depositing means 6, 6', 6” being movable relative to each other in a controlled manner by a management and control unit (not shown ), the first printing step and the second printing step being spatially coordinated with one another so that the first printed pattern 7 and the second printed pattern 8 present respectively on the first face 2 and the second face 3 are mutually spatially adjusted to provide, in a direction of incident observation with respect to one of the first and second faces 2, 3, a composite resulting pattern by superposition of the first printed pattern 7 and the second printed pattern 8 (FIGS. 4 to 7).

Advantageously, such a method makes it possible to decorate a transparent or translucent part 1 at its first face 2 and its second face 3 by means of at least a first printed pattern 7 and at least a second printed pattern 8. The choice to decorate room 1 with 5, 5 ', 5 ”printheads provides first and second printed patterns 7, 8 which are free in shape and color. Furthermore, this method allows great flexibility and precision in the placement of the first and second printed patterns 7, 8. The resulting composite pattern obtained can form three-dimensional effects or depth effects based on both the transparency of the material. and on the first and second printed patterns 7, 8. This method has the advantage of adapting to different types of workpiece materials 1, since the nature of the substance can be chosen so that the substance hooks correctly to the first and second sides 2, 3 of part 1.

The deposition means 6, 6 ’, 6” can allow the projection of droplets of said at least one substance and be of the ink jet printing type. Advantageously, this deposition technique has the advantage of being inexpensive, proven and well known to those skilled in the art.

The deposition means 6, 6 ′, 6 ”can comprise a single composite print head 5, 5 ′, 5” or an arrangement of several distinct print heads, of monochromatic, bi-chromatic or quadri-chromatic type, with integrated drying systems, UV pinning type.

The first and second printing steps can be carried out, by the coating process as described in the publication

Advantageously, first and second printed patterns 7, 8 are then obtained which are in relief and which are textured (FIGS. 8A and 8B). In addition, this way of operating has the advantage of being based on an inexpensive deposition technique, proven and well known to those skilled in the art and has many other advantages, among which: great flexibility in terms of shapes, profile , thickness, color of the decorative patterns and textures obtained, high resistance of the latter to scratches, abrasion and friction, as well as the possibility of offering different degrees of gloss / dullness.

This coating or covering process, possibly with specific coloring, of the first and / or the second face 2, 3 of the part 1 with simultaneous production of a structured surface comprising protruding formations or structures, in particular grainy or having texturing in relief or the like, by means of deposition means 6, 6 ”, 6” of liquid substance (s) in droplets 17, 17 ', 18 in particular by jet, consists, for each site concerned of the first and / or the second face 2, 3 to be printed, to deposit successively at least two, preferably at least three, layers 19, 19 ′ superimposed with a first chosen substance, possibly depending on the characteristics of the first and / or of the second side 2, 3 to be printed, in the group formed by a primer, a varnish, an adhesion or bonding agent and a coating agent, preferably white or transparent and, where appropriate LEMENT, of at least one second substance of the coloring substance or mixture of coloring substances type, each of the successive layers 19, 19 'being formed by depositing individual and distinct droplets 17, 17', 18, arranged in each layer according to a pattern predetermined and preferably with a determined offset of the pattern between successive layers 19, 19 ′, immediately consecutive and adjacent or not, in the superposition of layers 19, 19 ′.

After each deposition of layers 19, 19 ′, a (preferably active) phase of drying / crosslinking / more or less extensive polymerization is advantageously carried out, the degree of drying / crosslinking / polymerization depending for example on the nature of the substance deposited last. and / or of the rank of the layer 19, 19 ′ considered.

In accordance with a first variant of this coating process, it can be provided that all the layers 19, 19 ’

-7 superimposed are formed exclusively of a first transparent substance, with strong adhesive power and having a high resistance to abrasion and a high hardness after solidification. This variant is appropriate when the color, the decorative pattern and the surface condition of the first and / or the second visible face 2, 3 of the part 1 must be preserved and be visible. The droplets 18 deposited according to a pattern or a pattern of deposition determined at each layer 19 ’, can be the same size or at least two different sizes.

In accordance with a second alternative embodiment of this coating process, the various superposed layers 19, 19 ′ consist alternately of a first substance and of a second substance, in particular successively and alternately of a layer of varnish or resin transparent 19 ′ or the like and a layer of coloring substance (s) 19.

The combination, on the one hand, of the alternation of layers 19 of colored or coloring substance and of functional and structuring layers 19 '(bonding, adhesion, aggregation, hardening, consolidation) and, on the other hand, of a constitution in individual and distinct droplets of each layer 19, 19 ′ (improved bonding between successive layers, non-smooth interfaces), makes it possible to achieve, by synergistic effect, structures or formations colored in relief having a very high resistance to tearing, abrasion, scratching, shock and impact and friction.

In addition, an improvement in the visual rendering, in particular a notable increase in the intensity of the colors, has also been observed, due in particular to the multiple superposition of colored layers 19.

Matting has also been found to be substantially proportional to the number of colored layers of the texture, making it possible to obtain controlled mat / gloss resulting effects.

Depending on the nature and characteristics of the first face and / or the second face 2, 3, as well as the properties sought in priority, the first layer deposited on the latter may be a colored layer 19 or a functional layer 19 ' (transparent or not).

Preferably, the first layer deposited on the first face and / or the second face 2, 3 to be coated is a layer 19 ’formed of droplets 18 of the first substance, preferably a substance

-8providing reinforced adhesion or attachment with the material of the first face and / or of the second face 2, 3. Advantageously, to increase the visual rendering of the colors, this first layer 19 ′ may be white or at least clear, the other layers 19 ′ being transparent.

Advantageously, the last deposited layer, or finishing layer, is a layer 19 ′ formed of droplets 5 of the first or a third substance, advantageously varnish or transparent resin.

The substance forming this last layer is preferably of a type allowing the production of a transparent protective coating, this substance being deposited, in terms of covered area and quantity, so as to encapsulate, in cooperation with the intermediate layers 19, l 'set of layers 19, 19' previous (at their edges), and therefore the formation considered.

The intermediate functional layers 19 ′ can advantageously extend laterally with respect to the respectively underlying colored layers 19, so as to cover the lateral edges (edges) of the latter and thus form, together, a protective layer on the flanks of the protruding formations.

Of course, the same substance, for example of the transparent varnish type, can form the first layer 19 ’(bonding), the functional intermediate layers 19’ and the last layer 19 ’(protective).

Nevertheless, the first layer 19 ′ may also consist of a specific layer of bonding primer (for example white), different from the transparent intermediate layers 19 ′ (sandwiched between the colored layers 19), the final coating layer (or of encapsulation) being of the same nature as the intermediate layers 19 ′ or of a different nature.

In order to avoid, with the accumulation of layers 19, 19 ′, the emergence of hollows and peaks in the formations, and simultaneously favor the bonding between successive layers 19, 19 ′ by physical nesting, provision may be made for shift two successive layers of the same type between them by a fraction, for example of half or a third, of the pitch of the pattern, this in particular according to the total number of layers and the number of different substances deposited, the pattern preferably being the even for all layers 19, 19 '.

In order to promote adhesion between successive layers 19, 19 ′, this coating process can consist in depositing each new layer 19, 19 ′ before the preceding layer 19, 19 ′ is completely crosslinked or solidified, in particular when said layer previous layer still has a sticky effect on the surface, each layer advantageously being subjected immediately after deposition to an active and controlled phase of crosslinking or solidification before application of the next layer 19, 19 ′. This step is optional.

Depending on the nature of the substance forming a layer 19 and the rank of this layer 19, 19 'in the set of layers 19, 19' to be deposited, different modes of drying / crosslinking / polymerization of the droplets 17, 17 'deposited may be considered, if necessary before depositing the following layer 19, 19':

- crosslinking / surface polymerization (pinning: anchoring) for the bonding layer, first layer or primary covering layer (white), as well as for layers 19 of coloring substance deposited subsequently;

- cross-linking / polymerization at heart (curing) of the first substance layers or 19 ’intermediate and final functional layers (varnish);

- a crosslinking / final polymerization phase of all the layers 19, 19 ’deposited, after depositing the top cover / overlay layer (last layer), to ensure the consistency of all the superimposed layers.

According to one embodiment of this coating method providing optimized results, the method consists in depositing at least the first layer, preferably all the layers 19, of coloring substance (s) in the form of several populations of droplets 17, 17 ′ of different sizes or not, applied simultaneously or successively to the first face and / or to the second face 2, 3 of the part 1 to be printed and arranged according to at least two complementary screens, nested one inside the other and together forming the pattern of the layer 19 considered.

These different populations of droplets can of course be deposited, for each layer 19, at the same time.

- 10 However, in accordance with a preferred variant of this embodiment of this coating process, the two populations of droplets 17 and 17 ′ forming a layer 19 have different sizes and are deposited successively on the previous layer 19 ’.

According to an additional characteristic, the different droplets 17, 17 ′ of coloring substance (s) of the same layer 19 (possibly belonging to different populations) are substantially adjoining to each other, each population of droplets 17, 17 'being arranged according to a given frame, for example in mutually spaced lines or staggered, the frames of the two populations of the same layer 19 being complementary and the volume ratio between the droplets 17, 17' of the two populations being between 2 and 5, preferably around 3.

To achieve a deposit of high precision, with in particular a well-defined spatial configuration, this coating process can consist, for each layer 19 of coloring substance (s), first depositing the small droplets 17 (spaced apart), then cross-link or partially solidify the latter (their shape freezes) and then deposit the large droplets 17 '.

The small droplet frames 17 thus form a positioning mesh for holding the large droplets 17 ′ preventing their displacement and spreading, and retaining their shape until they crosslink. The addition of the frames makes it possible to cover the entire surface substantially continuously, with a redundant overlap from two colored layers 19.

When the coloring substances are UV inks (for example: white, black, cyan, yellow, magenta) the freezing of the droplets 17 can be carried out by UV drying (by LED) and their complete crosslinking as well as that of the droplets 17 ′ is obtained by UV curing.

In accordance with an optional characteristic, provision may be made to deposit at least the first layer 19 ′, preferably all the layers 19 ′, formed of droplets 18 of first substance of the type of adhesion, bonding or coating, preferably transparent, according to the same operating mode, in particular in terms of size and arrangement of the droplets 18, as the layers 19 of coloring substance (s).

- 11 The technical and characteristic provisions in terms of different populations of droplets, their arrangement in the pattern of deposition and their chronology of deposition, mentioned above in relation to the droplets 17, 17 ′ of second substance can therefore also be applied to and verified by the droplets 18 of first substance.

However, the layers 19 ′ of first substance of a structuring, adherent and protective nature (for example varnish or resin), may possibly be formed only by droplets 18 of the same size (with a detached arrangement between successive layers 19 ′) .

This coating process also makes it possible to create relief structures having profiles in variable section, compatible with the required structural cohesion requirements.

Nevertheless, taking into account the physical aggressions to which these relief structures can be exposed, forms without salient angles or with progressive profiles are to be preferred.

Thus, although the various formations reported on the first face and / or the second face 2, 3 may have sections with heights, lengths and lateral angles of attack (with the first face and / or the second face 2 , 3) variables, it is preferable that the angle is less than about 30 °, preferably at most 20 °.

The height of the formations can, in turn, in practice and depending on the number of layers 19, 19 ’deposited, generally vary between a few tens of pm and several hundred pm.

To this end, provision may be made for gradually reducing the surface size of the successive superimposed layers 19, 19 ′, so as to obtain structures or formations in relief, colored or transparent, which have lateral faces inclined at an acute angle relative to at their base resting on the face, so as to present in section along a transverse vertical plane a substantially triangular or arcuate shape; the material (s) of the layers 19 ′ formed by the first or a third substance covering the edge or the laterally visible edge of the layers 19 formed of the first substance immediately underlying respectively.

Depending on the circumstances under which this coating process is carried out and the purpose to be achieved, various parameters must be taken into account and calibrated beforehand.

- 12Thus this coating process can consist in adjusting beforehand the contact angle of the droplets 17, 17 ', 18, the total number of layers 19, 19' superimposed and / or the number of droplets 17, 17 ', 18 by surface unit to achieve a desired height of structure or formation in textured relief, the first face and / or the second face 2, 3 of the part 1 to be printed is advantageously subjected to a treatment in order to adjust its tension surface before the deposition of the first layer 19, 19 ′ of coloring substance (s) or first substance.

The droplets 18 of second or third substance typically have a single size, for example a size identical to that of large droplets 17 ’of colored substance.

For example, the large droplets 17 ′ may for example have a volume of approximately 42 picoliters and the small droplets 17 a volume of approximately 14 picoliters.

The distance between the rows of droplets 17, 17 ’of the same type can be of the order of approximately 140 μm, for a print density of 360 dpi.

With these values, the formations, comprising nine superimposed layers, have a height of approximately 120 μm and a contact angle with the first face and / or the second face 2, 3 of approximately 20 °.

The information necessary for the realization of the structured surface can be provided in different ways and is presented in different forms.

Preferably, provision may be made to use pre-established digital printing files, and depending on the desired structured surface, to produce the droplet patterns 17, 17 ', 18 of each layer 19, 19' of substance (s) ) colored (s) and / or of first substance, preferably all the layers 19, 19 ′, or the complementary screens forming these patterns, and to possibly adjust other printing parameters specific to each or to some of the layers ( s) 19, 19 '.

Advantageously, it is possible to provide for providing a three-dimensional representation of the first face and / or of the second face 2, 3 (to be printed) of at least part 1, preferably by acquiring its shape while said part 1 is installed. on a 4, 4 ', 4 ”support device used during printing, for example by scanning

- 13 3D laser, before establishing digital print files, in particular for processing a series of identical parts 1.

Regarding the practical implementation of this coating process, the latter may consist in depositing all of the droplets 17, 17 ', 18 of the different layers 19, 19' with a single composite print head 5, 5 ', 5 ”Or an arrangement of several distinct printheads, comprising a plurality of ejection orifices calibrated and controlled according to the nature and the quantity of substance to be sprayed, said printhead 5, 5 ', 5” or said arrangement, on the one hand, and said first and / or second side 2, 3 to be printed, on the other hand, being able to be displaced relatively relative to one another in at least two directions perpendicular to each other, where appropriate three mutually perpendicular directions when said first and / or second face 2, 3 to be printed is non-planar, the ejection of droplets 17, 17 ', 18 and the relative displacements being for example commanded and controlled on the basis of i information from digital print files.

The first and second printing steps of the method according to the present invention can be followed respectively by a first drying step and a second drying step. During the first drying step, said at least one substance of said at least one first printed pattern 7 is dried or crosslinked or polymerized by drying means 16, 16 ’, 16”. During the second drying step, said at least one substance of said at least one second printed pattern 8 is dried or crosslinked or polymerized by drying means 16, 16 ’, 16”. Such drying means 16, 16 ’, 16” can be provided for drying or crosslinking or polymerizing the substance deposited by the deposition means 6, 6 ’, 6”. By way of nonlimiting example, the drying means 16, 16 ’, 16” can consist of an ultraviolet lamp and can be mounted on a base 10, 10 ’, 10” as described below.

According to a first alternative embodiment of the method according to the invention, during the first printing step, the part 1 can be supported by a single support device 4 (FIG. IA). And during the second printing step, the part 1 can be supported by the single support device 4 (FIG. IC). And during the first printing step, the substance can be deposited on the first face 2 by a single printing head 5 mounted on a base 10 (FIG. IA). Then successively during a first storage step, the part 1 can be

- 14detached from the single support device 4 and can be stored at a storage area 9 (Figure IB). Then successively in the storage step and prior to the second printing step, the part 1 can be secured to the single support device 4. Then during the second printing step, the substance can be deposited on the second face 3 by the same single print head 5 (Figure IC).

Alternatively, the single print head 5 can be replaced by a single arrangement of several separate print heads.

Preferably, during the first printing step, the part 1 is supported by its second face 3 by the single support device 4.

Preferably, during the second printing step, the part 1 is supported on the side of its first face 2 by the single support device 4.

After the second printing step, or if necessary the second drying step, the part 1 can be stored in the storage area 9 (FIG. 1D).

According to a second alternative embodiment of the method according to the invention, during the first printing step, the part 1 can be supported by a first support device 4 ’(FIG. 2A). And during the second printing step, the part 1 can be supported by a second 4 ”support device (Figure 2C). And during the first printing step, the substance can be deposited on the first face 2 by a first printing head 5 ’mounted on a first base 10’ (FIG. 2A). Then successively, during a transfer step, the part 1 can be secured to the second support device 4 ", then separated from the first support device 4" (FIG. 2B). Then during the second printing step, the substance can be deposited on the second face 3 by a second 5 ”printing head mounted on a second 10” base (FIG. 2C).

Advantageously, this second alternative embodiment makes it possible to reduce the cycle time of the process compared to the first alternative variant.

The first and second variant embodiments of the invention are particularly suitable for decorating parts 1 having three-dimensional shapes.

- 15 Preferably, during the first printing step, the part 1 is supported by its second face 3 by the first support device 4 ’.

Preferably, during the second printing step, the part 1 is supported by its first face 2 by the second support device 4 ’’.

After the second printing step, or if necessary the second drying step, the part 1 can be stored in the storage area 9 (Figure 2D).

According to a third alternative embodiment of the method according to the invention illustrated in FIG. 3, during the first printing step and the second printing step, the part 1 can be supported by a single support device 4, and the part 1 can be arranged between a first print head 5 'mounted on a first base 10' and a second print head 5 ”mounted on a second base 10”, the second print head 5 'being distinct from the first 5 ”print head and arranged substantially opposite it. And during the first printing step, the substance can be deposited on the first face 2 of the part 1 by the first printing head 5 ’. And during the second printing step, the substance can be deposited on the second face 3 by the second 5 "printing head.

In this third alternative embodiment, the first base 10 'and the second base 10 ”can be mounted facing each other and spaced apart by a distance greater than the thickness of the part 1 between the first face 2 and the second side 3.

Preferably, the part 1 is supported by the support device 4 by a third lateral face 11 different from the first face 2 and from the second face 3. Preferably, the part 1 is supported by the support device 4 by a face of room 1 which is not intended to be decorated.

According to the third variant embodiment, the first printing step and the second printing step can be simultaneous.

Advantageously, this third alternative embodiment is faster than the first and second alternative embodiments, since the first printing step and the second printing step can be simultaneous. In addition, the placement of the printed patterns 7, 8 is very precise.

- 16 and easier to develop. This third embodiment is particularly suitable for decorating rooms with flat shapes.

According to the first and third alternative embodiments, Tunic support device 4 comprises a single robotic arm 12 and a gripping member 20. The gripping member 20 is mounted at the end of the robotic arm 12, the latter being further controlled by T management and control unit (Figures IA, IC, 3). Or according to the second alternative embodiment, the first support device 4 'comprises a first robotic arm 12' and a gripping member 20 'and the second support device 4 ”comprises a second robotic arm 12” and a gripping member 20 ”. Each gripping member 20 ’, 20” is mounted at the end of the corresponding 12 ’, 12” robotic arm, each 12 ’, 12” robotic arm being further controlled by the management and control unit (FIGS. 2A and 2C).

The robotic arm 12, 12 ’, 12” advantageously allows the relative movement of the part 1 relative to the deposition means 6, 6 ’, 6”.

The gripping member 20, 20 ’, 20” advantageously allows the gripping of the part 1 or supporting it.

These single, first and second robotic arms 12, 12 ', 12 ”are movable and carry, by means of the gripping member 20, 20', 20”, the part 1 which is moved in front of the head (s) 5, 5 ', 5 ”which are fixed.

These single, first and second robotic arms 12, 12 ’, 12” can have six axes.

The gripping member 20 can be a gripping hand.

Figures IA to 3 illustrate first, second and third alternative embodiments of an installation according to the invention for implementing the printing method according to the invention as described above.

In all these variants the installation includes:

- deposition means 6, 6 ’, 6” comprising at least one print head 5, 5 ’, 5”,

- a support device 4, 4 ’, 4” to support part 1,

- a management and control unit to control the relative movement between the support device 4, 4 ’, 4” and the deposit means 6, 6 ’, 6”.

The deposition means 6, 6 ’, 6” are preferably of the inkjet type as described above. For example, the deposition means 6, 6 ’, 6” may consist of effectors of ink jet printing means.

The support device 4, 4 ’, 4” can include a robotic arm 12, 12 ’, 12” and a gripping member 20, 20 ’, 20” as described above.

The installation according to the first variant embodiment, illustrated in FIGS. 1A to 1D, comprises a single support device 4 and a single arrangement of deposition means 6 comprising at least one print head 5. The support device 4 is mobile relative to the deposit means 6 which remain fixed.

The installation according to the second variant embodiment, illustrated in FIGS. 2A to 2D, comprises a first support device 4 and a second support device. It further comprises first deposition means 6 ’comprising at least one 5’ print head and second deposition means 6 ”comprising at least one 5’ print head. The support devices 4 ’, 4” are movable relatively and respectively with respect to the first and second deposition means 6 ’, 6” which remain fixed.

The installation according to the third variant embodiment, illustrated in FIG. 3, comprises a single support device 4. It also comprises first deposition means 6 ′ comprising at least one print head 5 ′ and second means for 6 ”6 'deposit including at least one 5” print head. These depositing means 6 ’, 6” being arranged opposite one another so that the printheads 5 ’, 5” are substantially opposite one another.

In all cases, the installation may also include drying means 16, 16 ’, 16” as described above.

The translucent or transparent part 1 comprises at least one wall comprising at least a first face 2 and a second face 3 opposite to each other.

The term “translucent or transparent part 1” means a part 1 transmitting light at least in part.

According to the invention, the part 1 is characterized in that the part 1 is obtained in accordance with the printing process as described above, and in that at least one first printed pattern 7

- 18 comprising at least one substance is located directly on the first side 2, at least one second printed pattern 8 comprising at least one substance is located directly on the second side 3 and the first side 2 and / or the second side 3 comprises at least an unprinted area 14, 14 ′, for providing, in a direction of observation incident with respect to one of the first and second faces 2, 3, a resultant pattern composite by superposition of the first printed pattern 7 and the second printed pattern 8 .

Advantageously, the unprinted zone 14, 14 ’plays the role of a window. Thus, an observer located in a direction of incident observation with respect to the second face 3 can directly see at least one second printed pattern 8 and can see through the wall of the part 1, at least in part at least a first printed pattern 7 which is located below an unprinted area 14 'of the second face 3, since the part 1 is transparent or translucent (Figures 4, 5, 6 and 7). If necessary, an observer located in a direction of incident observation with respect to the first face 2 can see directly at least one first printed pattern 7 and can see through the wall of the part 1, at least one second printed pattern 8 which is located below the unprinted zone 14 of the first face 2, since the part 1 is transparent or translucent (FIGS. 4, 5 and 6).

Preferably, the first face 2 and the second face 3 can be arranged in two distinct planes and substantially parallel to each other (Figures 4 to 7).

According to a first alternative embodiment of the part 1 according to the invention, the first printed pattern 7 and the second printed pattern 8 can be superimposed and offset one with respect to the other. And the first printed pattern 7 can coincide with a second unprinted area 14 'and the second printed pattern 8 can coincide with a first unprinted area 14' in a direction of incident observation substantially orthogonal to one of the first and second faces 2, 3 (Figure 4).

Advantageously, an observer located substantially opposite the second face 3 can directly see the second printed pattern 8 and can see through the wall of the part 1, the first printed pattern 7 in its entirety which is located below a unprinted area 14 'of the second face 3, since the part 1 is transparent or translucent

- 19 (Figure 4). In addition, an observer located substantially opposite the first face 2 can directly see the first printed pattern 7 and can see through the wall of the part 1, the second printed pattern 8 in its entirety which is located below the unprinted zone 14 of the first face 2, since the part 1 is transparent or translucent (FIG. 4).

According to a second alternative embodiment of the part 1 according to the invention illustrated in FIG. 5, the first face 2 can comprise a plurality of first printed patterns 7 spaced from each other by a predetermined pitch forming a plurality of first non- printed 14. The second face 3 may comprise a plurality of second printed patterns 8 spaced from each other by a predetermined pitch forming a plurality of second unprinted areas 14 '. And the first printed patterns 7 and the second unprinted areas 14 'can coincide and the second printed patterns 8 and the first unprinted areas 14 can coincide in a direction of incident observation substantially orthogonal to one of the first and second sides 2, 3.

Advantageously, an observer located substantially opposite the second face 3 can directly see a plurality of second printed patterns 8 and can see through the wall of the part 1, a plurality of first printed patterns 7 in their entirety and which are each located below an unprinted area 14 'of the second face 3, since the part 1 is transparent or translucent (FIG. 5). In addition, an observer located substantially opposite the first face 2 can directly see a plurality of first printed patterns 7 and can see through the wall of the room 1, a plurality of second printed patterns 8 in their entirety and which are each located below an unprinted area 14 of the second face 3, since the part 1 is transparent or translucent (FIG. 5).

Preferably, the predetermined pitch which spaces the first printed patterns 7 can be substantially equal to the predetermined pitch which spaces the second printed patterns 8 (FIG. 5).

Preferably, the plurality of first printed patterns 7 can be identical. Preferably, the plurality of second printed patterns 8 can be identical (FIG. 5).

According to the first and second alternative embodiments of the part 1 according to the invention, the first printed pattern 7 and the second printed pattern 8 may have identical geometric shapes. These

-20first and second printed pattern 7, 8 may also have identical dimensions.

According to a third alternative embodiment of the part 1 according to the invention illustrated in FIG. 6, the first face 2 can comprise a plurality of first printed patterns 7 spaced from each other by a predetermined pitch forming a plurality of first non- printed 14. The second face 3 may comprise a plurality of second printed patterns 8 spaced from each other by a predetermined pitch forming a plurality of second unprinted areas 14 '. And the first printed pattern 7 and the second printed pattern 8 can have different geometric shapes.

Advantageously, an observer located substantially opposite the second face 3 can directly see a plurality of second printed patterns 8 and can see through the wall of the part 1, a plurality of first printed patterns 7 in their entirety, since the part 1 is transparent or translucent (FIG. 6) and that a pair of adjacent first printed patterns 7 are located below an unprinted area 14 ′ of the second face 3. In addition, an observer located substantially opposite the first side 2 can directly see a plurality of first printed patterns 7 and can see through the wall of the room 1, a plurality of second printed patterns 8 in their entirety and which are each located below an unprinted area 14 of the second face 3, since the part 1 is transparent or translucent (Figure 6).

Preferably, the first printed patterns 7 can all be identical. Likewise, the second printed patterns 8 can all be identical. In this case, the dimension of the first printed patterns 7 may be less than the dimension of the second printed patterns 8.

Preferably, the predetermined pitch which spaces the first printed patterns 7 can be less than the predetermined pitch which spaces the second printed patterns 8 (FIG. 6).

According to a fourth alternative embodiment of the part 1 according to the invention illustrated in FIG. 7, the first face can comprise a plurality of third printed patterns 7 ′ arranged between two adjacent first printed patterns 7 or between a first printed pattern 7 and a edge 15 of the part 1. And at least part of the third printed patterns 7 ′ and of the second printed patterns 8 can be superimposed and

-21 may overlap at least partially at the level of at least one overlapping zone 13.

A first face 2 is completely covered with the first and third printed patterns 7, 7 ', since the third printed pattern 7' fills the unprinted space between two adjacent first printed patterns 7 or between a first printed pattern 7 and an edge 15 Advantageously, an observer located substantially opposite the second face 3 can directly see a plurality of second printed patterns 8 and can see through the wall of the piece 1, a plurality of first printed patterns 7 in their all and a plurality of third patterns 7 'excluding those of the overlap zone, since the part 1 is transparent or translucent (FIG. 7) and that a pair of adjacent first printed patterns 7 and a third printed pattern 7 'are located below an unprinted area 14' of the second face 3. In addition, an observer located substantially opposite the first face 2 can see directly a plurality of first printed patterns 7 and a plurality of third printed patterns 7 ’, but cannot see through the wall of the part 1 because the first face 2 is made opaque (FIG. 7).

The substance can be chosen alone or in combination from an ink, a colored ink, an ultraviolet crosslinking ink, a varnish, a primer, a bonding agent, a bonding agent, a coating agent.

Advantageously, the use of different colored inks makes it possible to print the first, second and if appropriate third printed patterns 7, 7 ’, 8 in four colors. The use of an ultraviolet crosslinking ink makes it possible to obtain first, second, and if necessary third printed patterns 7, 7 ’, 8 which can be directly exposed to the open air. The use of a varnish makes it possible to provide a protective layer covering the first printed pattern 7 and / or the second printed pattern 8 and if necessary the third printed pattern 7 ’.

The first printed pattern 7 and the second printed pattern 8 may respectively comprise a single layer of at least one substance. The printed patterns 7, 8 can respectively comprise one or more single layers of at least one surface and / or make it possible to generate a texture and / or a relief.

The part 1 can be made of a material chosen from glass, a polymer, preferably polymethyl methacrylate or polystyrene or polycarbonate.

The first face 2 and the second face 3 can be 5 substantially flat and the thickness between the first face 2 and the second face 3 can be between 0.2 millimeters and 5 millimeters, preferably between 2.5 millimeters and 3 millimeters.

The part 1 according to the invention is particularly suitable for the automotive field and may consist of automotive glazing.

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 (5)

1. Method for printing at least part of a wall of a transparent or translucent part (1) and comprising at least one first face ( 2) and a second face (3) opposite to each other, process 5 characterized in that it comprises at least: - a first printing step, during which: the part (1) is arranged on a support device (4, 4 ′, 4 ”) so that at least one printhead (5, 5 ', 5 ”) forming part of the depositing means (6, 6', 6”) is arranged opposite the first face (2), then at least 10 a substance is deposited by said at least one printing head (5, 5 ′, 5 ”) directly on the first face (2) of the part (1) and the part (1) is moved simultaneously and in a controlled manner by the support device (4, 4 ', 4 ”) relative to the depositing means (6, 6', 6”) to form at least a first printed pattern (7), 15 - a second printing step, during which: the part (1) is arranged on a support device (4, 4 ′, 4 ”) so that at least one printhead (5, 5 ', 5 ”) forming part of deposition means (6, 6', 6”) is arranged opposite the second face (3), then at least one substance is deposited by said at least one printing head 20 (5, 5 ', 5 ”) directly on the second face (3) of the workpiece (1) and the workpiece (1) is moved simultaneously and in a controlled manner by the support device (4, 4', 4” ) relative to the depositing means (6, 6 ', 6 ”) to form at least one second printed pattern (8), said support device (4, 4', 4”) and the depositing means (6, 25 6 ', 6 ”) being relatively movable relative to each other in a controlled manner by a management and control unit, the first printing step and the second printing step being spatially coordinated from one another such that the first printed pattern (7) and the second printed pattern (8) 30 respectively present on the first face (2) and the second face (3) are mutually spatially adjusted to provide in a direction of observation incident with respect to one of the first and second faces (2, 3), a resulting pattern composite by superimposing the first printed pattern (7) and the second printed pattern (8). -242. Method according to claim 1, characterized in that during the first printing step, the part (1) is supported by a single support device (4), and during the second printing step, the part (1 ) is supported by a support device (4), and in that during the first printing step, the substance is deposited on the first face (2) by a single printing head (5) mounted on a base (10), then successively during a first storage step, the part (1) is detached from the support device (4) and is stored at a storage area (9), then successively at the storage step and prior to the second printing step, the part (1) is secured to a support device (4), then during the second printing step, the substance is deposited on the second face (3) by the same single print head (5). 3. Method according to claim 1, characterized in that during the first printing step, the part (1) is supported by a first support device (4 '), and during the second printing step, the workpiece (1) is supported by a second support device (4 ”), and in that during the first printing step, the substance is deposited on the first face (2) by a first printing head (5 ') mounted on a first base (10'), then successively during a transfer step, the part (1) is secured to the second support device (4 ”), then separated from the first support device (4 '), then during the second printing step, the substance is deposited on the second face (3) by a second printing head (5 ”) mounted on a second base (10”). 4. Method according to claim 1, characterized in that during the first printing step and the second printing step, the part (1) is supported by a single support device (4), and the part (1 ) is arranged between a first print head (5 ') mounted on a first base (10') and a second print head (5 ”) mounted on a second base (10”), the second print head (5 ') being distinct from the first printing head (5 ”) and arranged substantially opposite the latter, and in that during the first printing step, the substance is deposited on the first face (2 ) of the part (1) by the first printing head (5 ') and in that during the second printing step, the substance is deposited on the second face (3) by the second printing head ( 5 ”). -255. Method according to claim 4, characterized in that the first printing step and the second printing step are simultaneous. 6. Method according to any one of claims 1 to 5, characterized in that the single support device (4) is mounted on a single robotic arm (12) controlled by the management and control unit or in that that the first support device (4 ') is mounted on a first robotic arm (12') controlled by the control unit and the second support device (4 ') is mounted on a second robotic arm (12') controlled by the management and control unit. 7. translucent or transparent part (1) comprising at least one wall comprising at least a first face (2) and a second face (3) opposite to each other, characterized in that the part (1) is obtained in accordance with the method of printing according to any one of claims 1 to 6, and in that at least one first printed pattern (7) comprising at least one substance is located directly on the first face (2), at least one second printed pattern (8 ) comprising at least one substance is located directly on the second face (3) and the first face (2) and / or the second face (3) comprises at least one unprinted zone (14, 14 '), to provide according to a direction of incident observation with respect to one of the first and second faces (2, 3), a composite resulting pattern by superposition of the first printed pattern (7) and the second printed pattern (8). 8. Part according to claim 7, characterized in that the first face (2) and the second face (3) are arranged in two distinct planes and substantially parallel to each other. 9. Part according to any one of claims 7 to 8, characterized in that the first printed pattern (7) and the second printed pattern (8) are superimposed and offset relative to each other and in that the first printed pattern (7) coincides with a second unprinted area (14 ') and the second printed pattern (8) coincides with a first unprinted area (14') in an incident viewing direction substantially orthogonal to the 'one of the first and second faces (2, 3). 10. Part according to any one of claims 7 to 8, characterized in that the first face (2) comprises a plurality of first printed patterns (7) spaced from each other by a pitch -26 predetermined forming a plurality of first unprinted areas (14), the second face (3) comprises a plurality of second printed patterns (8) spaced from each other by a predetermined pitch forming a plurality of second unprinted areas (14 ') and in that the first printed patterns (7) and the second unprinted areas (14') coincide and the second printed patterns (8) and the first unprinted areas (14) coincide in a direction of incident observation substantially orthogonal to one of the first and second faces (2, 3). 11. Part according to any one of claims 7 to 10, characterized in that the first printed pattern (7) and the second printed pattern (8) have identical geometric shapes. 12. Part according to any one of claims 7 to 8, characterized in that the first face (2) comprises a plurality of first printed patterns (7) spaced from each other by a predetermined pitch forming a plurality of first zones unprinted (14), the second face (3) comprises a plurality of second printed patterns (8) spaced from each other by a predetermined pitch forming a plurality of second unprinted areas (14 ') and in that the first printed pattern (7) and the second printed pattern (8) have different geometric shapes. 13. Part according to claim 12, characterized in that the first face comprises a plurality of third printed patterns (7 ') arranged between two adjacent first printed patterns (7) or between a first printed pattern (7) and an edge (15 ) of the part (1) and in that at least a part of the third printed patterns (7 ') and of the second printed patterns (8) are superimposed and overlap at least partially at the level of at least one zone of cover (13). 14. Part according to any one of claims 7 to 13, characterized in that the substance is chosen alone or in combination from an ink, a colored ink, an ultraviolet crosslinking ink, a varnish, a primer, an agent for adhesion, a bonding agent, a coating agent. 15. Part according to any one of claims 7 to 14, characterized in that the first printed pattern (7), the second printed pattern (8) and if necessary the third printed pattern (7 ') respectively comprise a single layer at least one substance. -2716. Piece according to any one of claims 7 to 15, characterized in that the piece (1) is made of a material chosen from glass, a polymer, preferably, polymethyl methacrylate or polystyrene or polycarbonate. 5 17. Part according to any one of claims 7 to 16, characterized in that the first face (2) and the second face (3) are substantially plane and in that the thickness between the first face (2) and the second face (3) is between 0.2 millimeters and 5 millimeters, preferably between 2.5 millimeters and 3 millimeters. 1/7