FR3121859A1 - Method and device for manufacturing a decorative object from at least one layer of extruded cord. - Google Patents

Abstract

The invention relates to a method for manufacturing a decorative object from at least one layer of an extruded cord comprising a step of passing a polymer-based composition through an extrusion die (50), the temperature of the extruded cord being between 180°C and 260°C, the extruded cord being deposited on a support (21, 22, 23) for receiving the layer of extruded cord by the effect of gravitation and in that the support reception is heated to a heating temperature of between 85°C and 140°C. Figure to be published with abstract: Fig. 6

Description

Method and device for manufacturing a decorative object from at least one layer of extruded cord.

Technical area.

The subject of the invention is a process for manufacturing a decorative object from at least one layer of extruded cord and the device for implementing said process. The term decorative object refers to an object whose sole function is ornamental, both indoors and outdoors.

The invention relates in particular, but not exclusively, to the technical field of temporary or permanent light decorations, and more specifically to light decorations located outdoors, such as those traditionally installed for parties or other events. The invention can also find many other applications, for example in the field of advertising decorations or for the animation of commercial windows.

State of the art.

Decorative objects, such as light decorations in particular, are usually made from an aluminum frame on which are attached one or more light garlands, generally formed by a succession of LEDs.

In the patent documents FR 2796446 and FR 3069800, in the name of the applicant, this support frame for the garlands is partly produced by injection-extrusion of plastic material.

Thus, such decorative objects, due to the fact that they must fix or maintain lighting in the form of garlands or other decorative elements, require a partial or total frame made of a mechanically resistant material. In general, this frame material for the support of lights or the like consists of aluminum, since this material is light while being mechanically strong.

Nevertheless, such decorative objects are complex to produce, because they require two distinct steps, a first step of making the metal frame and a second step of molding a plastic over all or part of the metal frame, to house the lights and/or or to form an original shape.

Decorative objects made entirely of plastic are currently known, but then these objects are made of extruded cords having a very high thickness or diameter, of the order of at least three centimeters in thickness or in diameter. .

Until now, attempts to produce decorative objects with less thick extruded cords have led to reserving the use of a very small number of polymers, which do not necessarily have interesting properties for the present use, at the risk of problems. processability in the extrusion die and/or degraded mechanical properties.

An objective of the present invention aims to remedy the drawbacks of existing methods by defining a method capable of producing a decorative object from extruded cords - from a wide range of polymers, including those with the best properties / qualities - d a small thickness or a reduced diameter, much less than the thickness or the diameter of the current extruded cords, while having a stable structure and sufficiently mechanically resistant taking into account the uses of the decorative object.

Indeed, this decorative object is intended to be preferably installed outside, whatever the environmental conditions.

Another objective of the invention consists in proposing an economical and reliable manufacturing method, that is to say allowing perfect reproducibility of the decorative object as many times as desired.

Presentation of the invention.

After multiple trials and attempts, the applicant has developed a process allowing it to produce a decorative object, manufactured economically, comprising at least one layer of extruded cord having:
- A thickness or a diameter of between five and nine millimeters, advantageously between six and eight millimeters, and very advantageously a layer of extruded cord with a thickness or diameter of seven millimeters;
- A height of between two and six millimeters, advantageously between three and five millimeters, and very advantageously a layer of extruded bead with a height of four millimeters.

Thus, when the bead comes out of the extrusion head, it has a circular section, but following its placement on the receiving support, the extruded bead flattens to ultimately have a thickness (or diameter) greater than its height, according to the data presented above.

The solution proposed by the invention is a process for manufacturing a decorative object from at least one layer of an extruded bead of a polymer-based composition, comprising a step of passing a polymer-based composition in an extrusion die from a supply inlet of said composition to an extrusion head, from which emerges an extruded bead of said composition, the temperature of the extruded bead, at the exit of the extrusion head, being between 180°C and 260°C.

The method according to the invention is characterized in that the extruded bead is deposited on a support for receiving the layer of extruded bead by the effect of gravitation and in that the receiving support is heated to a heating temperature comprised between 85°C and 170°C.

The expression "decorative object" means an object whose purpose is the aesthetic decoration of a place, interior or exterior. Of course, this decorative object can be associated with one or more other visual elements such as for example garlands or lights and in this case the decorative object serves, or has the function, of support for these elements associated with the object. decorative.

Thanks to this precise setting of the temperature of the receiving support, whatever the chemical nature of the polymer composition, or almost whatever this chemical nature of said composition, the extruded bead does not drop too quickly in temperature so that the final polymerization and/or crosslinking reactions occur outside the extrusion die. Thus, we obtain extruded cords, and finally a decorative object, presenting mechanical qualities and optimum physico-chemical properties for the various uses, in an often very rigorous environment, envisaged for the decorative object.

Also thanks to the method according to the invention, the process of manufacturing a decorative object is automated in such a way as to eliminate, or at least limit, labor.

The term “heating temperature” is understood to mean in relation to the receiving support the fact that the latter has this temperature range at its upper surface, i.e. the surface in contact (or likely to be in contact) with the extruded bead.

It should be noted here that the expression "effect of gravitation" concerning the extruded bead refers to the fact that the movement of the extruded bead, from its exit from the extrusion head to the receiving support, is constrained or directed solely by the weight of said cord. This effect is made possible in particular by the fact that the extrusion die is arranged or oriented vertically, in other words in the direction of application of the gravitational force. Of course, it is necessary to consider the thrust exerted by the extrusion die on the extruded bead, in other words the kinetic energy of the latter leaving the extrusion head, but this force or this kinetic energy is also oriented in the direction, and sense, of the gravitational force.

Other advantageous features of the invention are listed below. Each of these characteristics can be considered alone or in combination with the remarkable characteristics defined above. Each of these characteristics contributes, where appropriate, to the resolution of specific technical problems defined further on in the description and to which the remarkable characteristics defined above do not necessarily participate. The latter may be the subject, where appropriate, of one or more divisional patent applications:

Very advantageously, the reception support is made of aluminum or an aluminum-based alloy, preferably aluminum. In the following, the applicant presents some test results and comparative tests which have made it possible to highlight the very particular interest of aluminium. The receiving support then has an appropriate mechanical adhesion function for the extruded cord.

Advantageously, the receiving support also has a coating intended to allow chemical adhesion of the extruded cord. This coating consists of a polymer coating, from a few microns (µm) up to one or more millimeters (at most two millimeters). Preferably, this coating consists of a polyetherimide (PEI).

Preferably, the heating temperature is between 95°C and 125°C. Such a temperature excludes at least one polymer included in the scope of the present invention - namely in this case the Polycarbonate presented below as an example of a possible polymer - but most of the polymers that can be used in the context of the process and the device according to the invention are used with such a heating temperature range of 95°C to 125°C.

According to an advantageous feature of the invention, the extrusion head is located at a distance H of between two and eight millimeters from the aforementioned receiving support.

Advantageously, the extruded cord has, at the outlet of the extrusion head, a viscosity of between four hundred (400) and four hundred and fifty (450) Pascal per second (Pa.s ^-1 ) defined according to the ISO 11443 standard.

According to a feature of the invention, advantageously, the temperature of the extruded bead is between 200°C and 240°C.

Advantageously, the decorative object comprises a plurality of layers of extruded cords, each successive layer, after the first layer of extruded cord, then forming the support for receiving the next layer of extruded cord.

Preferably, the polymer-based composition consists of a polymer matrix comprising at least 70% by weight, advantageously at least 95% by weight, of acrylonitrile butadiene styrene (ABS), of polylactic acid (polyester PLA) or of polycarbonate ( pc).
According to one aspect of the invention, the invention can be implemented with a method for manufacturing a decorative object from at least one layer of an extruded bead of a polymer-based composition, comprising a step of passing of a polymer-based composition in an extrusion die from a feed inlet of said composition to an extrusion head, having an opening diameter D, from which an extruded bead of said composition emerges, the temperature of the extruded bead, at the outlet of the extrusion head, being between 180° C. and 260° C., the method according to the invention being characterized in that the extrusion head is located at a distance H between two and eight millimeters of a support for receiving the layer of the extruded cord, the extruded cord being deposited on the receiving support by the effect of gravity, and in that the opening diameter D of the head of extrusion is equal to H +/- 1 millimeter.

The sign "+/-" means "more or less". Thus, by way of example, if we consider a distance H equal to five millimeters, the diameter D of the extrusion head is between four and six millimeters, upper and lower limits included.

Thanks to this precise setting of the distance, or height, from the extrusion head to the receiving support, as a function of the opening diameter D of this same extrusion head, an extruded bead is obtained having a thickness or a uniform diameter over its entire length, said thickness or said diameter or thickness D being substantially equal to seven millimeters, plus or minus two millimeters, and a height of four millimeters, plus or minus two millimeters. Here and in the following, the expression "the distance from the extrusion head to the receiving support" means that this distance is considered from the lower end of the extrusion head to the surface upper, or the surface facing the extrusion head, of the receiving support.

Preferably, the distance H is between four and six millimeters, advantageously the distance H is equal to four millimeters.

Advantageously, the extrusion head moves at a speed of between forty and one hundred and fifty millimeters per second, advantageously between sixty and one hundred millimeters per second.

Preferably, the extruded bead comes out of the extrusion head at a rate of between five and fifteen kilos per hour, advantageously between six and ten kilos per hour.

• passage d’une composition à base polymère dans une filière d’extrusion depuis une entrée d’alimentation en ladite composition jusqu’à une tête d’extrusion déplaçable de laquelle sort le cordon extrudé, une première couche de cordon extrudé étant déposée sur un support de réception,
• déplacement de la tête d’extrusion selon une trajectoire d’extrusion prédéfinie, de sorte que l’objet décoratif présente des couches d’au moins un cordon extrudé empilées les unes au-dessus des autres, lesdites couches étant parallèles au support de réception et définissant des niveaux d’extrusion,

caractérisé en ce que l’extrusion est réalisée de sorte que l’objet décoratif comprend au moins une première zone présentant un premier nombre de couches et une deuxième zone présentant un deuxième nombre de couches différent dudit premier nombre.According to one aspect relating to the decorative object, the latter can be obtained by a process for manufacturing a decorative object formed by the hot extrusion of at least one bead of a polymer-based composition, comprising the steps following:

• passage of a polymer-based composition through an extrusion die from an inlet for supplying said composition to a movable extrusion head from which the extruded bead emerges, a first layer of extruded bead being deposited on a support reception,
• movement of the extrusion head along a predefined extrusion path, so that the decorative object has layers of at least one extruded bead stacked one above the other, said layers being parallel to the receiving support and defining extrusion levels,

characterized in that the extrusion is carried out so that the decorative object comprises at least a first zone having a first number of layers and a second zone having a second number of layers different from said first number.

• le premier nombre de couches dans la première zone est supérieur ou égal à 1, et
• le deuxième nombre de couches dans la deuxième zone est supérieur ou égal à 3,

Advantageously:

• the first number of layers in the first zone is greater than or equal to 1, and
• the second number of layers in the second zone is greater than or equal to 3,

Preferably, the manufacturing method comprises a step consisting in equipping the extrusion head with a movable shutter between an open position allowing the exit of the cord from said head and a closed position preventing the exit of the cord from said head.

• placer l’obturateur en position fermée après la fin de l’extrusion de la couche de niveau M dans la deuxième zone,
• déplacer la tête d’extrusion depuis la deuxième zone vers une position d’extrusion située en vis-à-vis d’une couche de niveau N-1 de la première zone, l’obturateur étant maintenu dans la position fermée,
• lorsque la tête d’extrusion est positionnée dans la position d’extrusion de la première zone, placer l’obturateur en position ouverte et extruder la couche de niveau N en la déposant sur la couche de niveau N-1 de ladite première zone.

Preferably, to extrude a layer of level N in the first zone from a layer of level M in the second zone, such that M greater than or equal to N+1, the following steps are carried out:

• place the shutter in the closed position after the end of the extrusion of the layer of level M in the second zone,
• moving the extrusion head from the second zone to an extrusion position located opposite a layer at level N-1 of the first zone, the shutter being held in the closed position,
• when the extrusion head is positioned in the extrusion position of the first zone, placing the shutter in the open position and extruding the level N layer by depositing it on the level N-1 layer of said first zone.

• placer l’obturateur en position fermée après la fin de l’extrusion de la couche de niveau M,
• déplacer la tête d’extrusion vers une position d’extrusion située en vis-à-vis d’une couche de niveau N-1 de ladite deuxième zone, l’obturateur étant maintenu dans la position fermée,
• lorsque la tête d’extrusion est positionnée dans la position d’extrusion de la deuxième zone, placer l’obturateur en position ouverte et extruder la couche de niveau N en la déposant sur la couche de niveau N-1 de ladite deuxième zone.

According to an advantageous embodiment, to extrude a layer of level N in the second zone from a layer of level M in said second zone, such that M greater than or equal to N+2, the following steps are carried out:

• place the shutter in the closed position after the end of the extrusion of the layer of level M,
• moving the extrusion head to an extrusion position located opposite a layer at level N-1 of said second zone, the shutter being held in the closed position,
• when the extrusion head is positioned in the extrusion position of the second zone, placing the shutter in the open position and extruding the level N layer by depositing it on the level N-1 layer of said second zone.

• placer l’obturateur en position fermée après la fin de l’extrusion de la couche de niveau N,
• déplacer la tête d’extrusion vers une position d’extrusion située en vis-à-vis d’une couche de niveau M-1 de la deuxième zone, l’obturateur étant maintenu dans la position fermée,
• lorsque la tête d’extrusion est positionnée dans la position d’extrusion de la deuxième zone, placer l’obturateur en position ouverte et extruder la couche de niveau M en la déposant sur la couche de niveau M-1 de ladite deuxième zone.

Advantageously, to extrude a layer of level M in the second zone from a layer of level N in said second zone, such that M greater than or equal to N+2, the following steps are carried out:

• place the shutter in the closed position after the end of the extrusion of the level N layer,
• moving the extrusion head to an extrusion position located opposite a level M-1 layer of the second zone, the shutter being held in the closed position,
• when the extrusion head is positioned in the extrusion position of the second zone, placing the shutter in the open position and extruding the level layer M by depositing it on the level layer M-1 of said second zone.

Preferably, the manufacturing method comprises a step consisting in securing the extrusion head to a robotic manipulation arm so that said head can be inclined at an angle α of between 0° and 90° with respect to a normal of the receiving medium.

• après la fin de l’extrusion de la couche de niveau M, orienter la tête d’extrusion perpendiculairement aux bordures,
• déplacer la tête d’extrusion de manière à extruder un cordon le long des bordures, depuis la couche de niveau M, jusqu’à atteindre une position d’extrusion de la couche de niveau N, laquelle position est située en vis-à-vis d’une couche de niveau N-1 de la deuxième zone,
• orienter la tête d’extrusion perpendiculairement à la couche de niveau N-1 et extruder la couche de niveau N en la déposant sur ladite couche de niveau N-1.

In this context, advantageously, at least in the second zone, the layers are extruded so as to present adjacent borders and in which to extrude a layer of level N in the second zone from a layer of level M in said second zone, such that M is greater than or equal to N+2, the following steps are carried out:

• after the end of the extrusion of the level layer M, orient the extrusion head perpendicular to the borders,
• move the extrusion head so as to extrude a bead along the borders, from the layer at level M, until reaching a position for extruding the layer at level N, which position is located opposite a level N-1 layer of the second zone,
• orienting the extrusion head perpendicular to the layer of level N-1 and extruding the layer of level N by depositing it on said layer of level N-1.

• une filière d’extrusion disposant à une extrémité d’une entrée d’alimentation et à l’autre extrémité d’une tête d’extrusion, ladite filière étant alimentée avec au moins une composition à base de polymère sortant sous la forme d’un cordon extrudé par la tête d’extrusion,
• un support de réception du cordon extrudé,
• des moyens de commande et de déplacement de la filière d’extrusion.

Another aspect of the invention relates to a manufacturing device for manufacturing a decorative object from at least one extruded bead of a polymer-based composition, for implementing the method according to any one of claims previous ones, including:

• an extrusion die having at one end a feed inlet and at the other end an extrusion head, said die being fed with at least one polymer-based composition exiting in the form of a bead extruded by the extrusion head,
• a support for receiving the extruded cord,
• means for controlling and moving the extrusion die.

The device according to the invention is characterized in that the extrusion die is arranged vertically with respect to the receiving support and the device comprises a receiving support on which the bead layer is deposited by the effect of gravity and in that the receiving medium is heated to a heating temperature of between 85°C and 170°C.

Advantageously, according to a preferred embodiment of the invention, the extrusion die is also – like the extrusion head – mounted on an arm, controlled by said control and displacement means; this arm forming a section of the robotic arm presented above. In the following, the present invention is illustrated with this embodiment, but it can be provided that the extrusion die is not mounted on the robotic arm and remote from the latter, the extrusion head remaining for its part present on the extremity – distal portion – of the robotic arm, oriented vertically.

Advantageously, the control and displacement means comprise a robotic arm, the control and displacement means comprise a robotic arm and an electronic management unit allowing the automatic or manual management of the robotic arm and of the extrusion die, in particular its supply of polymer-based composition, its extrusion rate, the direction and the speed of movement of the robotic arm.

Advantageously, the aforesaid arm forms the distal portion of the robotic arm.

Brief description of figures.

Other advantages and characteristics of the invention will appear better on reading the description of a preferred embodiment which will follow, with reference to the appended drawings, produced by way of indicative and non-limiting examples and in which:
is a schematic view of a decorative object capable of being manufactured with the method and the device according to the invention.
is a side view of the device for manufacturing a decorative object from at least one extruded bead of a polymer-based composition according to the present invention.
is an enlargement of part A present on the , showing in particular the end of the extrusion head and the receiving support.
is a top view of the device visible on the .
is another side view of the device visible on the .
is a perspective view of the device visible on the .
is an alternative embodiment of a manufacturing system or device according to the present invention.

Description of embodiments.

The method and the device that is the subject of the invention make it possible to produce decorative objects. These decorative objects have a rigid structure most often used as a support frame for a light installation, such as one or more garlands.

On the , the decorative object 1 consists of a stylized snowflake 2 installed on a volute 3. By way of example, its length is between 50 centimeters (cm) and two meters while its width is between twenty centimeters and one metre. Regarding its thickness, a particularity of the present invention lies in the fact that such a decorative object 1 or 2, 3 is formed of at least one layer of extruded cord, possibly a plurality of layers of extruded cords and these extruded cords have all have a substantially identical thickness, between three and ten millimeters, preferably of the order – i.e. plus or minus one – of seven millimeters, and a height of four millimeters, preferably plus or minus one millimeter.

Depending on its monolayer or multilayer nature, it is referred to as a two-dimensional (2D) or three-dimensional (3D) decorative object respectively. This decorative object 1 can be attached to a cable or fixed to a pole or a wall for outdoor installation, for example in a street or on the facade of a monument, or even inside a dwelling.

The decorative object 1 can incorporate one or more light garlands, not visible in this attached figure.

Figures 2 to 6 attempt to show the elements of the device for manufacturing a decorative object from at least one extruded bead of a polymer-based composition. These elements allow the implementation of the method according to the invention so that a characteristic linked to the device finds application to the method, and vice versa.

This device 10 comprises a support 20 for receiving the extruded cord. As can be seen in particular on the , in the example chosen to illustrate the invention, this receiving support 20 is in the form of an L, with two rectangular portions 21, 22 of substantially identical shape and dimensions extending perpendicular to one to the other. These two rectangular portions 21, 22 each form the end portions of the receiving support 20 while a square portion is arranged at the junction angle formed between these two end portions 21, 22. By way of example , the end portions 21, 22, rectangular, have a length of between fifty centimeters and two meters and a width of between fifty centimeters and one hundred and fifty centimeters. The junction portion 23 is a square with a length of between fifty centimeters and one hundred and fifty centimeters, it being considered that the width of the end portions 21, 22 is advantageously equal to the length of the side of the junction portion 23 in such a way that the end edges of the receiving support 20 are indeed continuous and essentially linear or rectilinear.

The choice of the heating temperature of the support for receiving the extruded cord as well as its nature or its material have been determined after multiple trials and comparative tests. Some of the results of these trials and tests are shown in the table below.

The first criterion sought in the context of the present invention is the shrinkage criterion which must be at most equal to 2% to satisfy the invention. Consequently, the specimens tested not satisfying this criterion of 2% shrinkage were not subjected to the mechanical tests. Test results are shown in Table 1 below. Table 1 receiving support (plate) Cord Heating temperature Withdrawal (%) Young's modulus
(MPa) Elongation at break (%) Copper ABS 70°C
100°C
200°C > 2
2 <
> 2 -
1400
- -
15
- computer 70°C
100°C
200°C > 2
2 <
> 2 -
2100
- -
100
- PLA 70°C
100°C
200°C > 2
2 <
> 2 -
2850
- -
12
- Stainless steel ABS 70°C
100°C
200°C > 2
2 <
> 2 -
1420
- -
16
- computer 70°C
100°C
200°C > 2
2 <
> 2 -
2150
- -
105
- PLA 70°C
100°C
200°C > 2
2 <
> 2 -
2900
- -
12.1
- Brass ABS 70°C
100°C
200°C > 2
2 <
> 2 -
1490
- -
16
- computer 70°C
100°C
200°C > 2
2 <
> 2 -
2180
- -
111
- PLA 70°C
100°C
200°C > 2
2 <
> 2 -
2980
- -
12.1
- Cupronickel ABS 70°C
100°C
200°C > 2
2 <
> 2 -
1490
- -
16
- computer 70°C
100°C
200°C > 2
2 <
> 2 -
2200
- -
111
- PLA 70°C
100°C
200°C > 2
2 <
> 2 -
2950
- -
12.2
- Copper-Aluminum Alloy ABS 70°C
100°C
200°C > 2
2 <
> 2 -
1550
- -
18
- computer 70°C
80°C
200°C > 2
2 <
> 2 -
2250
- -
110
- PLA 70°C
80°C
200°C > 2
2 <
> 2 -
2960
- -
12.3
- Aluminum ABS 70°C
80°C
200°C > 2
2 <
> 2 -
1600
- -
20
- computer 70°C
80°C
200°C > 2
2 <
> 2 -
2300
- -
120
- PLA 70°C
100°C
200°C > 2
2 <
> 2 -
3020
- -
12.6
-

The shrinkage criterion is considered, possibly with a slight structural adjustment, according to the ISO 294 standard. The ISO 527-1 standard is considered for the determination of the Young's Modulus and the elongation at break. ABS: Acrylonitrile butadiene styrene; PC: Polycarbonate and PLA: polylactic acid polymer.

Firstly, thanks to the application of a heating temperature in the range of 85° C. to 140° C., preferably from 95° C. to 125° C., extruded beads are obtained having low shrinkage and mechanical properties satisfactory, even very satisfactory. If we add to this first essential characteristic the fact that the receiving support 20 is made of aluminum, or an aluminum alloy, then we further improve the shrinkage/mechanical results and we obtain an easily detachable decorative object, without degradation, of the reception medium 20.

This receiving support 20 has a thickness of between five millimeters and thirty millimeters. Secondary functions of this receiving support 20 consist in receiving the extruded cord without the latter adhering to the receiving support 20, nor of course being deformed or degraded by the latter.

Considering this reception support 20, an important aspect lies in its location around the robotic arm 30, or at least partly around this robotic arm 30. Thus, here the reception support 20 has a general L shape, the robotic arm 30 being located near the junction portion 23 substantially equidistant from the end portions 21, 22. It is also possible that the receiving support 20 is in the general form of a square or circular frame surrounding the arm robotic arm 30, the latter 30 being completely surrounded or surrounded by the receiving support 20. Finally, the receiving support 20 may have a general I-shape or even a general U-shape with three sides surrounding the robotic arm 30.

The reception support 20 is mounted on an elevation base 40, for example made of metal such as steel or wood, which makes it possible to place the reception support 20 at a height from the ground of between twenty centimeters and one meter, from so as to adapt to the dimensions of the robotic arm 30 and to facilitate the gripping and handling of the decorative object 1 made on the receiving support 20.

The means for controlling and moving the extrusion die consist partly of the robotic arm 30. This robotic arm 30 comprises two sections, a first section 31 extending from the base 32 of the robotic arm 30 and a second section 33 extending in the continuity of the first section 31, this second section 33 carrying or fixing at its free end the distal portion 34, forming an arm, on which the extrusion die 50 is mounted and fixed. The first section 31 of the robotic arm 30 is mounted free in rotation on the part forming a base 32 of the robotic arm 30 and can also be oriented transversely to be placed facing a portion 21, 22 or 23 of the receiving support 20. Thus, this first section 31 of the robotic arm 30 is capable, in the example chosen to illustrate the invention, of being oriented transversely at an angle of at least 180°, given that the receiving support 20 forms an L.

The robotic arm 30 is fixed to a base structure 35 intended to hold and stabilize it.

The second section 33 of the robotic arm 30 is also mounted free in rotation, at its end close to the first section 31, while it 33 carries at its other end the distal portion 34 on which the extrusion die is mounted and fixed. 50. Unlike the first section 31, this second section 33 has no possibility of transverse orientation and of course follows a possible transverse displacement of the first section 31.

The connections between the first section 31 and the base 32, between the first section 31 and the second section 33, between the second section 33 and the distal portion (or arm) of the robotic arm 30 form the joints of the latter.

Actuating means, of the jack and/or rotary motor type, arranged at the level of these joints ultimately make it possible to produce translational and possibly rotational movements of the extrusion die 50.

The dimensions of the first and second sections 31, 33 are adapted to the use of the robotic arm 30, that is to say to the manufacture of the decorative object 1 on the receiving support 20.

The extrusion die 50 is a conventional extrusion die which is not modified in any way in the context of the present invention, except at the level of the opening diameter D of its extrusion head 51 which is in connection with the distance or the height H at which this extrusion head 51 is or is located from the surface of the receiving support 20. It should be noted here that the does not present any limiting or restrictive character at the level of the dimensioning of the values D and H so that no dimensional value, or ratio of values, can be deduced from this figure. Of course, when the manufacturing method according to the invention is envisaged to produce a multilayer decorative object 1, that is to say by superimposing a plurality of extruded cords placed on top of each other, it is the surface of the last layer of extruded cords which forms the receiving support 20. Consequently, in the latter case, the distance H is no longer that between the receiving support 20 and the extrusion head 51, but the distance or the height, always designated H, between the upper surface of the extruded bead and the extrusion head 51.

Considering the extrusion die 50, the opening diameter D of the extrusion head can be fixed or variable, according to possibilities well known in the technical field, but of course, this opening diameter D being generally constant during the cord extrusion time to form the decorative object 1. In the event that this opening diameter D is variable or different during the manufacture of the decorative object 1, the ratio defined within the framework of the present invention between the lengths H and D still remains valid. Thus, if D were modified during the manufacture of a decorative object 1 according to the invention, then H is modified accordingly.

The means for controlling and moving the extrusion die further comprise an electronic management unit, not shown in the appended figures. The movements of the robotic arm 30 are controlled by this electronic management unit. The electronic management unit is in particular in the form of a portable or fixed computer, provided in particular with a processor, microprocessor or CPU (for "Central Processing Unit") and a memory, in which software is stored. the instructions of which, when executed by the processor, microprocessor or CPU, make it possible to control the movement of the extrusion die in space. This electronic management unit also manages the extrusion die, that is to say in particular the supply of polymer-based composition and the extrusion rate.

The term “software” can be understood as: computer application, computer programs or “software”. For the sake of clarity, it should be understood within the meaning of the invention that “the robotic arm does something” means “the software executed by the processor, microprocessor or CPU of the electronic management unit does something”.

Moving the extrusion die 50 along a predefined trajectory makes it possible to manufacture a decorative object 1 by depositing material, for a single-layer decorative object, or by adding material (additive manufacturing) by stacking extruded cords in layers. These layers of extruded cords can be stacked one above the other and/or optionally one beside the other. The stacking of the layers of extruded cords creates the volume of the decorative object 1 even if such an object 1 having monolayer cord already has a thickness of at least several millimeters. The trajectory of the extrusion die 50 along the longitudinal, axial and possibly vertical axes, i.e. along three mutually perpendicular directions, makes it possible to produce all types of contours and curves of the desired decorative object 1.

In practice, a designer draws the desired decorative object 1 using a computer-aided design (CAD) tool. The file obtained is processed by the software stored in the memory of the electronic management unit which organizes the cutting into slices of the different layers necessary for the production of the decorative object 1. The robotic arm 30 is controlled according to this cutting into slices , so that the extrusion die 50 deposits the bead layer by layer, if necessary, until the final decorative object 1 is obtained. The decorative object 1 is thus obtained quickly, precisely and with optimum repeatability.

The illustrates a variant embodiment where the extrusion head 51 is secured to a carriage 8 which is movable along the axes X, Y and Z of a Cartesian coordinate system. The carriage 8 is for example movably mounted on a first slider - or rail - 80 of axis X. This first slider is itself movably mounted on a second slider 81 of axis Y. A drive mechanism, for example rack or jack type, controlled by the aforementioned management unit, makes it possible to translate the carriage 8 on the first slide 80, and to translate said first slide on the second slide 81. It is thus possible to move longitudinally and transversely the head of extrusion 51 relative to the surface of the support 20. The vertical displacement of the extrusion head 51 (along the Z axis) is made possible by mounting the second slide 81 movable in translation on vertical guides 83. A mechanism of drive, for example of the rack or jack type, controlled by the aforementioned management unit, makes it possible to translate the second slide 81 along the vertical guides 83. A similar result is obtained by securing the extrusion head 51 to a overhead crane.

According to another variant embodiment, the extrusion head 51 is fixed and it is the support 20 which is moved. It is in this case the support 20 which is secured to a means of movement of the robotic arm 30 or carriage 8 type mentioned above, the movement of said plate being controlled by the management unit.

Although the invention has been described in connection with several particular embodiments, it is obvious that it is in no way limited thereto and that it includes all the technical equivalents of the means described as well as their combinations if these fall within the scope of the invention.

• la forme et les dimensions du support de réception 20 du cordon extrudé sont variables, en fonction de l’objet décoratif 1 à réaliser, mais surtout en fonction de la disposition et des dimensions du bras robotisé 30, plus ces dernières sont grandes plus les dimensions du support de réception 20 peuvent être variées et grandes,
• le bras robotisé 30 peut présenter autant de sections 21, 22, 23 que nécessaires ou utiles pour la fabrication de l’objet décoratif 1. De la même manière, la forme et le degré de liberté du bras robotisé 30 sont variables pour autant qu’ils offrent la possibilité d’amener la tête d’extrusion 51 à la hauteur souhaitée du support de réception 20, compte tenu du diamètre d’ouverture D de la tête d’extrusion 51. On peut également prévoir qu’il y ait une pluralité de bras robotisé 30, par exemple au moins deux bras robotisé 30 travaillant de concert pour fabriquer un objet décoratif 1 selon l’invention.

The arrangement of the various elements and/or means and/or steps of the invention, in the embodiments described above, should not be understood as requiring such an arrangement in all implementations. Various variants can be provided, and in particular:

• the shape and dimensions of the support 20 for receiving the extruded cord are variable, depending on the decorative object 1 to be produced, but above all depending on the layout and dimensions of the robotic arm 30, the larger the latter, the greater the dimensions of the reception support 20 can be varied and large,
• the robotic arm 30 can have as many sections 21, 22, 23 as necessary or useful for the manufacture of the decorative object 1. Similarly, the shape and the degree of freedom of the robotic arm 30 are variable provided that they offer the possibility of bringing the extrusion head 51 to the desired height of the receiving support 20, taking into account the opening diameter D of the extrusion head 51. It is also possible to provide for there to be a plurality robotic arm 30, for example at least two robotic arms 30 working together to manufacture a decorative object 1 according to the invention.

The use of the verb "to comprise", "to understand" or "to include" and of its conjugated forms does not exclude the presence of other elements or other steps than those set out in a claim.

In the claims, any reference sign in parentheses cannot be interpreted as a limitation of the claim.

Claims (10)

Method for manufacturing a decorative object (1) from at least one layer of an extruded bead of a polymer-based composition, comprising a step of passing a polymer-based composition through an extrusion die (50) from a supply inlet of said composition to an extrusion head (51) from which emerges an extruded bead of said composition, the temperature of the extruded bead, at the outlet of the extrusion head (51 ), being between 180°C and 260°C,
characterized in that the extruded cord is deposited on a support (20) for receiving the layer of extruded cord by the effect of gravitation and in that the receiving support (20) is heated to a heating temperature of between 85°C and 170°C. Method according to claim 1, wherein the receiving support (20) is made of aluminum or an aluminum-based alloy, preferably aluminum. Process according to Claim 1 or 2, in which the heating temperature is between 95°C and 125°C. Method according to one of the preceding claims, in which the extrusion head (51) is located at a distance H of between two and eight millimeters from the aforesaid receiving support (20). Method according to one of the preceding claims, in which the extruded cord has, at the outlet of the extrusion head (51), a viscosity of between four hundred and four hundred and fifty Pascals per second defined according to the ISO 11443 standard. Process according to one of the preceding claims, in which the temperature of the extruded bead is between 200°C and 240°C. Method according to one of the preceding claims, in which the decorative object (1) comprises a plurality of layers of extruded cords, each successive layer, after the first layer of extruded cord, then forming the support for receiving the layer of cord next extrude. Process according to one of the preceding claims, in which the polymer-based composition consists of a polymer matrix comprising at least 70% by weight, advantageously at least 95% by weight, of acrylonitrile butadiene styrene (ABS), polylactic acid (polyester PLA) or polycarbonate (PC). Device (10) for manufacturing a decorative object (1) from at least one extruded bead of a polymer-based composition, for implementing the method according to any one of the preceding claims, comprising:

• an extrusion die (50) having at one end a feed inlet and at the other end an extrusion head (51), said die (50) being fed with at least one composition based of polymer exiting in the form of a bead extruded by the extrusion head (51),
• a receiving support (20) for the extruded cord,
• means for controlling and moving the extrusion die (50),

characterized in that the extrusion die (50) is arranged vertically with respect to the receiving support (20) and the device (10) comprises a receiving support (20) on which the bead layer is deposited by the effect gravitation and in that the receiving support (20) is heated to a heating temperature of between 85°C and 140°C. Device (10) according to claim 9, in which the control and movement means comprise a robotic arm (30) and an electronic management unit allowing automatic or manual management of the robotic arm (30) and of the die. extrusion (50), in particular its supply of polymer-based composition, its extrusion rate, the direction and the speed of movement of the robotic arm.