FR3133558A1 - Process for manufacturing a decorative object from at least one layer of extruded cord. - Google Patents

Abstract

The invention relates to a method of manufacturing a decorative object from at least one layer of an extruded cord of a polymer-based composition, comprising a step of producing the decorative pattern by extrusion of the polymer cord according to the aforementioned path consisting of tracing a first line representing the decorative object, then tracing a second line parallel to the above-mentioned first line, offset from 2 millimeters to 10 millimeters from this first line, to form a two-layer drawing of the decorative object, then closing all the free ends of the two-layer design by connecting the first and second lines to said ends, and finally positioning cuts and connections between the first and second lines so as to have a continuous path from any point in the two-layer drawing. Figure to be published with the abstract: Fig. 9

Description

Process for manufacturing a decorative object from at least one layer of extruded cord. Technical area.

The subject of the invention is a method of manufacturing a decorative object from at least one layer of extruded cord. 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 precisely to light decorations located outdoors, such as those traditionally installed for festivals or other events. The invention can also find numerous 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 one or more light garlands are attached, generally formed by a succession of LEDs.

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

Thus, such decorative objects, because 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 material forming a frame for supporting lighting or the like consists of aluminum because this material is light while being mechanically resistant.

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

We currently know a process for manufacturing decorative patterns by extruding a polymer cord onto a conventionally horizontal support.

This current production process has operating inertia, making stopping/restarting the extrusion of the polymer cord difficult to control. Therefore, it is necessary to produce the desired parts with an uninterrupted line, and without overlap, that is to say that each segment must only be covered once during production.

To resolve this problem, “rural postman problem ” type algorithms can partly respond to this problem but make the process implemented less flexible and generate numerous constraints and limitations to the achievable forms.

Thus, at present, there is no solution for manufacturing all types of decorative patterns, whatever their complexity, by extruding a polymer cord onto a support by creating a unique path, or path, of the extrusion head.

An objective of the present invention aims to remedy the disadvantages of existing processes by defining a process capable of producing any decorative object from extruded cords - from a wide range of polymers including those having the best properties/quality – without complicating the manufacturing process, or even significantly reducing manufacturing time compared to much more complex techniques.

This decorative object is intended to be preferably installed outdoors, whatever the environmental conditions.

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

Presentation of the invention.

After multiple tests and attempts, the applicant has developed a manufacturing process allowing it to produce, in a single outline of the extrusion head, any shape of a decorative object.

The solution proposed by the invention is a method of manufacturing a decorative object from at least one layer of an extruded cord of a polymer-based composition, comprising:
- a step of passing a polymer-based composition through an extrusion die from an inlet for supplying said composition to an extrusion head, having an axis z'z, from which an extruded bead of said composition, the extruded cord being deposited on a receiving support by the effect of gravitation, and
- a step of defining by digitizing the path of the extrusion head in means for controlling said die and said head so as to produce the decorative object; And
- a step of producing the decorative pattern by extrusion of the polymer cord following the above path.

The method according to the invention is characterized in that the above-mentioned step of defining the path of the extrusion head comprises the successive steps of:
- tracing a first line representing the decorative object;
- tracing a second line parallel to the above-mentioned first line, offset from 2 millimeters to 10 millimeters from this first line, to form a two-layer design of the decorative object;
- closure of all the free ends of the two-layer design by connecting the first and the second line to said ends;
- positioning of cuts and connections between the first and second lines so as to have a continuous path from any point of the two-layer drawing.

Thanks to the manufacturing process according to the invention, all types of decorative patterns can be produced, whatever the geometric complexity of the decorative pattern.

Furthermore, the manufacturing of the decorative pattern is thus rapid and automated from the production of an initial drawing of the decorative pattern, it being understood that this initial drawing can be produced in any way. Indeed, if this initial drawing has superfluous lines, a step prior to tracing the second drawing consists of cleaning the first path line representing the decorative object. The expression “superfluous line” refers to a portion of line not necessary to globally represent the decorative motif. Of course, this notion of "superfluous feature" is subjective and refers to a compromise between the aesthetic representation of the decorative pattern and its ease of production in production (manufacturing time and final aesthetic rendering of the decorative pattern taking into account the production of a bilayer of extruded cords).

By the expression “decorative object” we mean 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 supporting these elements associated with the object. decorative.

By the expression z'z axis relating to the extrusion head is meant the fact that the extrusion head comprises a nozzle for ejecting the polymer-based composition, this nozzle having a linear axis, here defined by this axis z'z.

It should be noted here that the expression "effect of gravitation" regarding 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 head is arranged or oriented vertically, in other words in the direction of application of the gravitational force. Of course, it is also necessary to consider the thrust exerted by the extrusion die on the extruded bead, in other words the kinetic energy of the latter at the outlet of the extrusion head, and this force or this kinetic energy can possibly also be oriented in the direction, and sense, of the gravitational force. In fact, this force resulting from the thrust exerted by the die is oriented at an angle different from the gravitational force when the receiving support is in relief.

The term “relief” in connection with the receiving support is understood to mean any portion of said support which projects from a flat surface in which the receiving support extends generally or generally. Thus, this relief can consist of a negative relief in relation to this flat surface, i.e. a hollow, a recess, a cavity or, on the contrary, a positive relief, i.e. a bump, a protuberance, a crest.

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

Advantageously, the second line is offset from the first line by a distance of between 6 and 8 millimeters, preferably 7 millimeters.

According to an advantageous mode of execution, once the first line has been traced, the following steps are automatic.

According to an advantageous aspect of the invention, the step of positioning the cuts comprises a step of digital incrementation of all the closed curves of the decorative pattern, the numbers of each of the closed curves being located substantially at the geometric center of each closed curve.

Preferably, a cutoff line is created connecting the numbers of the closed curves following the shortest path, possibly including a crossroads point.

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), of polycarbonate ( PC) or Polyethylene terephthalate (PET).

According to an advantageous embodiment, the thickness or diameter of the extruded cord is between 3 mm and 10 mm, preferably between 4 mm and 8 mm.

Preferably, the extruded bead exits the extrusion head with a flow rate of between five and fifteen kilos per hour, advantageously between eight and twelve kilos per hour.

Advantageously, the extruded bead has, at the outlet of the extrusion head, a viscosity of between four hundred and four hundred and fifty Pascals per second defined according to the ISO 11443 standard.

Preferably, the temperature of the extruded bead, at the outlet of the extrusion head, being between 160°C and 260°C, preferably between 200°C and 240°C.

The present invention also relates to a method of manufacturing a decorative object from at least one layer of an extruded cord of a polymer-based composition, comprising a step of passing a polymer-based composition into an extrusion die from a supply inlet of said composition to an extrusion head, having an axis z'z, from which an extruded bead of said composition emerges, the extruded bead being deposited on a receiving support by the effect of gravitation, characterized in that the receiving support is in the form of a plate comprising at least one raised portion, the extrusion head being controlled by control means and being orientable according to the three axes and in that the extrusion head is continuously oriented by the control means so that the axis z'z is perpendicular to the receiving support, including at the level of the raised portion.

Preferably, it should be noted here that, when the receiving support is fixed, resting horizontally (or at least one side of the relief extending horizontally), the extrusion head follows the contour of the relief perpendicularly – the relief portion of the support - up to a slope of the latter of at most 50°, this limit of 50° being included (the reliefs visible in Figures 5 to 8 have slopes less than 50°). Thus, so that the extrusion head always follows the relief support perpendicularly at the level of this/its relief, the receiving support is advantageously mounted movable so as to tilt it preferably by an angle of at most 40° . In this way, the extrusion head is able to follow the receiving support perpendicularly whatever the slope of its relief or its portion of relief.

However, if a means of cooling the extruded bead is used, such as in particular inert gas blowing of the latter and/or the choice of a specific viscosity of the polymer-based composition, the slope can be increased. maximum relief up to nearly 90°, while allowing perpendicular tracking of the extrusion head. Indeed, if the polymer bead freezes quickly upon exiting the extrusion head, then the extrusion head can be used whatever the slope of the relief or of the relief portion, without requiring that the receiving support is angularly mobile.

The extrusion head can be oriented along the three axes – longitudinally, transversely and in height – to follow exactly and precisely the surface of the support, including and especially at the level of its raised portion.

According to one possibility offered by the invention, it can be noted here that the receiving support can be mobile independently of the extrusion head, the latter being able to remain immobile as long as the objective of presenting the extrusion head perpendicular to the surface of the receiving medium is reached.

According to a particularly advantageous aspect, the receiving support is mounted movable and controlled by the control means so that the axis z'z of the extrusion head is perpendicular to the receiving support.

It should be noted here that this characteristic relating to the mobility of the receiving support, controlled by the control means, may consist of an alternative to the aforementioned characteristics relating to the extrusion head, in other words the fact that the latter is orientable according to the three axes.

Advantageously, a robotic arm, controlled by the control means, comprises means for storing a volume of the polymer-based composition as well as means for transporting said polymer to the extrusion head.

According to a first embodiment, the extrusion die is mounted at one end of the robotic arm.

According to a second embodiment, the extrusion die is mounted at a distance from the robotic arm so that only said extrusion head is moved to follow the continuous path (cf. ).

According to one embodiment, when the receiving support extends along a plane or horizontally, the invention also relates to a method of manufacturing a decorative object from at least one layer of an extruded cord of 'a polymer-based composition, comprising a step of passing a polymer-based composition through an extrusion die from an inlet for supplying said composition to an extrusion head, from which an extruded bead of said composition, the temperature of the extruded bead, at the outlet of the extrusion head, being between 180°C and 260°C, 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 of between 85°C and 170°C and in that the receiving support is made of aluminum or an alloy based on aluminum, preferably aluminum.

The applicant has test results and comparative trials which have made it possible to highlight the very particular interest of aluminum or an aluminum alloy. The receiving support then presents in particular a mechanical adhesion function suitable for the extruded cord.

By the expression “heating temperature” we mean in relation to the receiving support the fact that the latter presents this temperature range at its upper surface, i.e. the surface in contact (or likely to be in contact) with the extruded bead.

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.

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 above receiving support.

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.

According to another aspect, the invention relates to a method of manufacturing a decorative object from at least one layer of an extruded cord of a polymer-based composition, comprising a step of passing a composition based on polymer in an extrusion die from a supply 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 process according to the invention being characterized in that the extrusion head is located at a distance H of between two and eight millimeters from a support for receiving the layer of the extruded bead, the extruded bead being deposited on the receiving support by the effect of gravitation, and in that the opening diameter D of the extrusion head is equal to H + /- 1 millimeter.

The “+/-” sign means “more or less”. Thus, for 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.

The applicant has carried out comparative tests showing that when D = +/- 1 mm (millimeter), and only within the framework of this equation, optimum mechanical properties are obtained for the extruded cord of a layer of the decorative object. These tests include Young's Modulus and elongation at break (ISO 527-1) as well as the Charpy notched impact test (ISO 179-1).

Thanks to this precise setting of the distance, or the height, of the extrusion head to the receiving support, as a function of the opening diameter D of this same extrusion head, we obtain an extruded bead having a thickness or a uniform diameter over its entire length, said thickness or said diameter D being substantially equal to seven millimeters, plus or minus two millimeters, and a height of four millimeters, plus or minus two millimeters. We understand, here and in the following, with the expression "the distance from the extrusion head to the receiving support" the fact 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 manufacturing process comprises a step consisting of equipping the extrusion head with a movable shutter between an open position allowing the bead to exit from said head and a closed position preventing the bead from exiting said head. In the same way, the device according to the invention comprises a movable shutter between an open position allowing the cord to exit from said head and a closed position preventing the cord from exiting 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 level M layer in the second zone,
• move the extrusion head from the second zone to an extrusion position located opposite a layer of level N-1 of the first zone, the shutter being maintained in the closed position,
• when the extrusion head is positioned in the extrusion position of the first zone, place the shutter in the open position and extrude the layer of level N by depositing it on the layer of level N-1 of said first zone.

Brief description of the figures.

Other advantages and characteristics of the invention will appear better on reading the description of a preferred embodiment which follows, with reference to the appended drawings, produced as 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 cord 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 a side view of another embodiment of the device for manufacturing a decorative object from at least one extruded cord of a polymer-based composition according to the present invention in which the receiving support, or at least a portion of said support has a pyramid relief.
is another view of the device visible on the in which the extrusion head is located on one side of the raised receiving support.
is a view of a device substantially identical to that visible on the in which the receiving support has a half-spherical relief.
is a side view of another embodiment of the device for manufacturing a decorative object from at least one extruded cord of a polymer-based composition according to the present invention in which the extrusion die is distant from the motorized arm, only a conduit bringing the polymer-based composition.
is a diagram illustrating the steps of the manufacturing process according to the present invention for producing a so-called simple decorative pattern.
is a diagram illustrating the steps of the manufacturing process according to the present invention for producing a decorative pattern integrating an ornamental figure.
is a diagram illustrating more precisely the step of positioning cuts, the two lines being subsequently connected.

Description of the embodiments.

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

The control means comprise memory means making it possible to store or memorize on the one hand the decorative object to be produced, layer by layer, and on the other hand the surface of the receiving support 20. These two pieces of information make it possible to define the path precision of the extrusion head 51 to produce the decorative object.

The present invention is more particularly described here with the attached Figures 9 to 11.

Thus, the manufacture of a decorative pattern in accordance with the , in terms of defining the path of the extrusion head, follows the following successive steps:
1. realization of the design: this involves defining the visual aspect of the part to be produced, without taking into account the specific technical constraints inherent to its manufacture. This step corresponds to the creation of the first line of the path of the extrusion head.
2. cleaning: a possible pre-processing step (carry out only if step 1 above requires such cleaning) aimed at making the path of the first line functional for subsequent operations, either by connecting the “open” curves », by removing the ends of curves that are too long, by eliminating isolated pieces of curves, etc.
3. offset: in order to be able to produce a part following this layout, each line must be divided in two, spaced by a predefined value. This value depends on the type of printed polymer bead and the desired line thickness. This offset value is conventionally set at 7 mm, and can vary from 2 to 10 mm.
4. closure: once these new curves have been produced, they must be made coherent by cutting them so as to obtain a bundle of non-coincident curves, and spaced by the value adapted to the polymer bead and the desired line thickness.
5. positioning of the cuts: here it is necessary to position the cutting lines, positioning the different connection points.
6. final union: here it involves connecting the two route lines following the cuts. Thus, all the curves are connected in such a way that the entire path of the extrusion head can be carried out in an uninterrupted manner.
7. duplication for multilayers: the layout of the extrusion head thus obtained must be duplicated at a different height, so as to be able to produce thicker parts or even referred to as three-dimensional decorative parts or patterns.

It should be noted here that only steps 1 and 5 above require an operator, the other steps being carried out automatically by a computer program product stored or implemented in the control means.

It should also be noted that step 1 consists of the artistic creation of the decorative motif and requires a creative operator but of course, once this aesthetic creation is ready or recorded in a database, the action of an operator does not is no longer mandatory for the manufacture/production of the decorative pattern considered.

The manufacture of a decorative pattern in accordance with the , in terms of defining the path of the extrusion head, follows the following successive steps:
1. realization of the design: identical to what is noted above in connection with the .
2. cleaning: identical to what is noted above in connection with the .
3. shift: identical to what is noted above in connection with the .
4. rough cutting of the ornamental figure: the ornamental figure is positioned over the base path and cut to be inscribed in the line (first and second path lines of the extrusion head) offset inwards.
5. finishing cutting: cutting is continued so as to eliminate all parts of the ornamental figure not inscribed inside the basic line.
6. cutting the interior contour: in order to make the decorative pattern uninterrupted, one line out of two of the interior contour must be eliminated.
7. positioning of the cuts: identical to what is noted above in connection with the .
8. final union: identical to what is noted above in connection with the .
9. duplication for multilayers: identical to what is noted above in connection with the .

On the we can see in more detail the implementation of the step of positioning the cuts, then connecting the two path lines of the extrusion head.

Thus, in order to position the cuts in a relevant manner, it is appropriate to produce the graph of the adjacencies of the different closed curves, after offset. Such an adjacency graph is visible in the right column of the . The numerical increment of each closed curve is represented here in the graph by a circle at the center of which is inscribed a reference number of the closed curve, this number being advantageously located or positioned at the geometric center of each closed curve. Of course, this positioning of the number in each closed curve does not need to be precise and can be offset from the true center of geometry of each closed curve.

Once this graph of adjacencies has been established, we establish a path connecting all of these closed curves in the most direct way possible, without stopping, but with the possibility of creating crossroads. As an example, we can note that the closed curve numbered “9” corresponds to a crossroads.

Again here, only steps 1 and 5 above require an operator, the other steps being carried out automatically by a computer program product stored and/or implemented in the control means.

Overall, the process of manufacturing a decorative pattern is divided into two technical aspects.

When the receiving support 20 is planar or horizontal, a receiving support 20 consisting of aluminum or an aluminum alloy is advantageously used and the receiving support 20 is heated to a specific heating temperature, as mentioned previously.

When the receiving support 20 is in relief – hollow and/or bump/protrusion – or has at least one raised portion, the receiving support 20 is advantageously made of wood of a specific nature and the receiving support 20 is not not necessarily heated above room temperature.

As seen previously, the term "relief" in connection with the receiving support 20 is understood to mean any portion of said support which projects from a flat surface in which the receiving support 20 extends generally or generally. Thus , this relief can consist of a negative relief in relation to this flat surface, i.e. a hollow, a recess, a cavity or, on the contrary, a positive relief, i.e. a bump, a protuberance, a crest.

Of course, we can provide a receiving support 20 which is partly made of aluminum or aluminum alloy, heated to a certain heating temperature, and partly in relief, this time made of wood of a specific nature.

• une filière d’extrusion 50 disposant à une extrémité d’une entrée d’alimentation et à l’autre extrémité d’une tête d’extrusion 51, comportant une buse d’axe z’z, ladite filière 50 étant alimenté avec au moins une composition à base de polymère sortant sous la forme d’un cordon extrudé par la tête d’extrusion 51, le cordon extrudé présente, en sortie de la tête d’extrusion 51, une viscosité comprise entre quatre cents et quatre cent cinquante Pascal par seconde définie selon la norme ISO 1144,
• un support de réception 20 du cordon extrudé se présentant sous la forme d’un plateau,
• des moyens de commande et de déplacement de la filière d’extrusion 50 et de la tête d’extrusion 51,
• un bras robotisé 30, commandé par les moyens de commande, comporte un moyen de stockage d’un volume de la composition à base polymère ainsi que des moyens de transport dudit polymère jusqu’à la tête d’extrusion 51,

caractérisé en ce que le support de réception 20 présente au moins une portion en relief et consiste en du bois présentant une dureté Brinell comprise entre 20 N.mm^-2(Newton par millimètre carré) et 30 N.mm^-2.When the receiving support 20 is in relief or has at least one raised portion, we will advantageously consider a device 10 for manufacturing a decorative object 1 from at least one extruded cord of a polymer-based composition, comprising :

• an extrusion die 50 having at one end a feed inlet and at the other end an extrusion head 51, comprising a z'z axis nozzle, said die 50 being fed with at least a composition based on polymer leaving in the form of a bead extruded by the extrusion head 51, the extruded bead 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 1144 standard,
• a support 20 for receiving the extruded cord in the form of a plate,
• means for controlling and moving the extrusion die 50 and the extrusion head 51,
• a robotic arm 30, controlled by the control means, comprises means for storing a volume of the polymer-based composition as well as means for transporting said polymer to the extrusion head 51,

characterized in that the receiving support 20 has at least one raised portion and consists of wood having a Brinell hardness of between 20 N.mm ^-2 (Newton per square millimeter) and 30 N.mm ^-2 .

Advantageously, the receiving support 20 is made of laminated wood, assembled with a polymer resin. Very advantageously, the receiving support 20 consists of birch.

The applicant has carried out comparative trials and tests showing that these characteristics (wood having a Brinell hardness of between 20 N.mm ^-2 and 30 N.mm ^-2 , advantageously in laminated wood, very advantageously in birch) are particularly advantageous with regard to in particular the criterion of thermal conductivity and that of thermal expansion.

On the , the decorative object 1 consists of a stylized snowflake 2 installed on a volute 3. For example, its length is between 50 centimeters (cm) and two meters while its width is between twenty centimeters and one metre. Concerning 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 – or more or less one – of seven millimeters, and a height of four millimeters, preferably more or less one millimeter.

Depending on its single-layer or multi-layer nature, we respectively speak of a two-dimensional (2D) or three-dimensional (3D) decorative object. However, the term “relief” is used to mean that a layer – or at least layer – does not extend along a plane since it includes at least one relief. Thus, a two-dimensional layer can present one or more reliefs while a multilayer can only assemble layers without relief so that this multilayer does not present any relief.

This decorative object 1 can be attached to a cable or fixed to a post or a wall for an exterior installation, for example in a street or on the facade of a monument, or even inside a home.

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

Figures 2 to 8 attempt to show the elements of the device for manufacturing a decorative object from at least one extruded cord of a polymer-based composition. These elements allow the implementation of the method according to the invention so that, in the context of the present invention, a characteristic linked to the device 10 is applied to the method, and vice versa.

This device 10 includes a support 20 for receiving the extruded cord. As can be seen in particular in Figures 2 to 4, in the example chosen here to illustrate the invention, this receiving support 20 is in the shape of an L, with two rectangular portions 21, 22 of shape and of substantially identical dimensions extending perpendicular to each 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 rectangular end portions 21, 22 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 so as to so that the end edges of the receiving support 20 are very continuous and essentially linear or rectilinear.

When the receiving support 20 is planar or horizontal, then, as seen below, the receiving support 20 is advantageously heated, in a specific temperature range, and consists of aluminum or an aluminum alloy .

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, we obtain extruded beads 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 recessed/mechanical results and we obtain a decorative object that is easily detachable, without degradation of the receiving support 20.

When the receiving support is in relief or has at least one relief, protuberance or hollow, then the applicant is advantageously made of class B wood according to Brinell hardness, as can be seen in table 2 below.

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

Considering this receiving 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 receiving 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 can also be provided that the receiving support 20 is in the general form of a square or circular frame surrounding the arm robot 30, the latter 30 being completely surrounded or surrounded by the receiving support 20. Finally, the receiving support 20 can have a general I shape or even a general U shape with three sides surrounding the robotic arm 30.

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

The means for controlling and moving the extrusion die 50 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 continuity with 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. 31 of the robotic arm 30 is mounted freely in rotation on the part forming the 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 orienting transversely at an angle of at least 180°, taking into account that the receiving support 20 forms an L.

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

The second section 33 of the robotic arm 30 is also mounted to rotate freely, 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 does not present any possibility of transverse orientation and of course follows a possible transverse movement 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.

Actuation means, such as cylinders and/or rotary motors, arranged at 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 height H at which this extrusion head 51 is located 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 in terms of the dimensions of the D and H values so that no dimensional value, or ratio of values, can be deduced from this figure. Of course, when the manufacturing process according to the invention is envisaged to produce a multi-layer decorative object 1, that is to say by superposition of 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 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 51 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 duration of extrusion of the cord 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 in the context of the present invention between the lengths H and D still remains valid. Thus, if D was 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 50 also comprise an electronic management unit, not shown in the attached 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 recorded. whose instructions, when executed by the processor, microprocessor or CPU, make it possible to control the movement of the extrusion die 50 in space. This electronic management unit also manages the extrusion die 50, that is to say in particular the supply of polymer-based composition and the extrusion flow rate.

The term “software” can be understood as: computer application, computer programs or “software”. For the sake of clarity, it should be understood in the sense 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 possibly next to each other. The stacking of layers of extruded cords creates the volume of the decorative object 1 even if such an object 1 having a single-layer 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. in 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 recorded in the memory of the electronic management unit according to equation The robotic arm 30 is controlled according to this equation decorative 1 is thus obtained quickly, precisely and with optimal repeatability.

Figures 5 to 8 illustrate the invention more specifically when one seeks to produce a decorative object in relief or having at least one portion in relief. To do this, at least one corresponding portion of the receiving support 20 has a relief which forms, by application of the extruded cord, said decorative object.

As we can see in these figures, this relief can consist for example of a pyramid (see figures 5 and 6) or a half-sphere (see. ) but can of course be presented in all forms. It can be noted here that these reliefs advantageously have a flat face so as to be easily positioned on a support, preferably on the flat or horizontal part of the receiving support 20. Thus, it can also be envisaged that the receiving support 20 in relief does not have any flat surface but of course, in this case, this receiving support 20 in relief is held by an arm or the like. In this hypothesis, this arm or the like holding the receiving support 20 in relief is advantageously movable so that the extrusion head 51 follows the surface more easily in a perpendicular manner.

There illustrates an embodiment in which the extrusion die 50 is arranged at a distance from the robotic arm 30, which makes it possible to lighten the latter 30 and thus facilitate the movements of the extrusion head 51. Ideally, as illustrated in this Figure, the extrusion die 50 is arranged near the control means or part of said control means of the device 10 according to the invention.

According to another alternative 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 aforementioned trolley 8 type, 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 quite obvious that it is in no way limited 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 également 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.

The arrangement of the different 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 planned, and in particular:

• the shape and dimensions of the receiving support 20 of the extruded cord are variable, depending on the decorative object 1 to be produced but also depending on the arrangement and dimensions of the robotic arm 30, the larger the latter, the greater the dimensions of the receiving support 20 can be varied and large.

The use of the verb “include”, “understand” or “include” and 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 parenthetical reference sign shall not be construed as a limitation of the claim.

Claims (10)

Method for manufacturing a decorative object (1) from at least one layer of an extruded cord of a polymer-based composition, comprising:
- a step of passing a polymer-based composition into an extrusion die (50) from an inlet for supplying said composition to an extrusion head (51), having an axis z'z, of which produces an extruded bead from said composition, the extruded bead being deposited on a receiving support (20) by the effect of gravitation, and
- a step of defining by digitizing the path of the extrusion head in means for controlling said die and said head so as to produce the decorative object; And
- a step of producing the decorative pattern by extrusion of the polymer cord following the above path;
characterized in that the above-mentioned step of defining the path of the extrusion head comprises the successive steps of:
- tracing a first line representing the decorative object;
- tracing a second line parallel to the above-mentioned first line, offset from 2 millimeters to 10 millimeters from this first line, to form a two-layer design of the decorative object;
- closure of all the free ends of the two-layer design by connecting the first and the second line to said ends;
- positioning of cuts and connections between the first and second lines so as to have a continuous path from any point of the two-layer drawing. Method according to claim 1, in which the second line is offset from the first line by a distance of between 6 and 8 millimeters, preferably 7 millimeters. Method according to claim 1 or 2, in which, once the first line has been traced, the said following steps are automatic. Method according to one of the preceding claims, in which the step of positioning the cuts comprises a step of digital incrementation of all the closed curves of the decorative pattern, the numbers of each of the closed curves being located substantially at the geometric center of each curve closed. Method according to claim 4, in which a cutoff line is produced connecting the numbers of the closed curves along a shortest path, possibly including a crossroads point. Method 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), of polylactic acid (PLA polyester), polycarbonate (PC) or Polyethylene terephthalate (PET). Method according to one of the preceding claims, in which the thickness or diameter of the extruded cord is between 3 mm and 10 mm, preferably between 4 mm and 8 mm. Method according to one of the preceding claims, in which the extruded cord leaves the extrusion head (51) with a flow rate of between five and fifteen kilos per hour, advantageously between eight and twelve kilos per hour. Method according to one of the preceding claims, in which the extruded bead 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. Method according to one of the preceding claims, in which the temperature of the extruded bead, at the outlet of the extrusion head (51), being between 160°C and 260°C, preferably between 200°C and 240°C. °C.