REINFORCED FILAMENT EXTRUSION TOOLING FOR ADDITIVE MANUFACTURING
The extrusion tooling system addresses the limitations of conventional 3D printing by coating reinforcing fibers with multiple thermoplastics, facilitating multi-material deposition and structural reinforcement, enhancing speed and aesthetics in 3D printed objects.
Patent Information
- Application Number
- FR2022011927
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2022-11-16
- Publication Date
- 2025-10-17
- Estimated Expiration
- 2042-11-16
AI Technical Summary
Conventional fused filament deposition modeling techniques in 3D printing are slow, limited to single-material deposition, and unable to effectively incorporate continuous reinforcements like glass or carbon fibers due to thermoformability issues, resulting in weak and aesthetically unappealing objects.
An extrusion tooling system that coats a continuous reinforcing fiber with multiple immiscible thermoplastic materials, allowing for the production of reinforced filaments that can be deposited using standard 3D printing heads, enabling multi-material deposition and maintaining structural integrity during printing.
Enables faster production of structurally reinforced and aesthetically superior 3D printed objects by allowing simultaneous deposition of multiple thermoplastic materials, eliminating the need for separate cutting tools, and integrating continuous fiber reinforcements.
Smart Images
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Abstract
Description
Title of the invention: REINFORCED FILAMENT EXTRUSION TOOLING FOR ADDITIVE MANUFACTURING Technical field
[0001] The present invention relates to the general technical field of fused filament fabrication (FFF) and additive manufacturing by filament deposition (FDM). The invention therefore relates to devices and systems for depositing molten polymers and shaping them on a support by an automated system.
[0002] The invention relates more particularly to the field of additive manufacturing devices, 3D printing, 3D overprinting or any other similar device using a reinforced filament.
[0003] By reinforced filament is meant a filament comprising a core, generally flexible but not thermoformable, having increased mechanical performance. This core is made up of a long and continuous reinforcing fiber, mineral, organic or metallic. By way of example, mention may be made of fiberglass, carbon fiber, flax fiber, hemp fiber, copper fiber or basalt fiber. Such a reinforcing fiber is then coated with at least one thermoplastic material to constitute the reinforced filament. State of the art
[0004] Additive manufacturing based on polymer materials, known as 3D printing by the general public, consists of depositing and superimposing layers of materials on a support with a suitable device according to the coordinates transmitted by a 3D file, this device generally comprising an automated system of the multi-axis robot type or gantry or tripod or motorized cross table.
[0005] The most well-known part manufacturing technique is based on a modeling technique by depositing molten polymer filaments of circular section from a coil of thermoplastic material wire. This technique consists of depositing layer by layer a filament or rod of molten thermoplastic material often above 200°C which, by superimposing, gives shape to the object. The print head moves according to X, Y and Z coordinates (length, width and height) or R, 0, Z (radius, height angle) transmitted by a 3D file corresponding to the 3D model of the object to be manufactured. According to this prior technique, the rod is single-material, of constant diameter and is deposited along an extrusion axis which is usually vertical, or at least perpendicular to the deposition plane.
[0006] While it allows you to make all kinds of objects or repair broken objects, this manufacturing technique also has many limitations.
[0007] First of all, the conventional technique of modeling by molten filament deposition is very slow, because the diameter of the thermoplastic material wire deposited is very small and the material is consequently deposited in very small quantities. An increase in the diameter of the wire makes it possible to address this problem of slowness, but then poses problems of aesthetics and solidity of the manufactured object which are due to the superposition of rods of cylindrical material which adhere poorly to each other due to their circular section. Despite constant improvements, this technique is also known for the lack of solidity of the manufactured objects and for the unattractive appearance of the latter, which have a lumpy appearance instead of being smooth.
[0008] Another limitation of the conventional fused filament deposition modeling technique is that it only allows one material to be deposited at a time, and does not allow several distinct materials to be deposited simultaneously. For obvious reasons of solidity of the manufactured object, the deposited material must also weld to that deposited in the other layers, which limits the number of materials that can be used by this technique.
[0009] The conventional fused filament deposition modeling technique is also not designed to allow the manufactured object to be reinforced by adding a continuous reinforcement, for example a glass or carbon fiber, during the fused filament deposition. Indeed, when one wishes to deposit reinforced filaments via 3D printing, one encounters additional difficulties, because the core of the reinforced filament is not thermoformable. Standard 3D printing heads are designed to be fed by a filament whose inlet section, given by its diameter, is 1.75 mm or 2.85 mm. The outlet section of 3D printing heads is given by the diameter of the orifice of a printing nozzle, which is generally between 0.4 mm and 1.00 mm. A reinforcing filament therefore has a coating whose material can be softened or melted and therefore formable, unlike the reinforcing fiber.It is therefore impossible to use reinforced filaments with a standard diameter in standard print heads.
[0010] Document US 10,562,226 B1 discloses an extrusion tool for delivering a reinforced filament comprising a reinforcing fiber coated with a thermoplastic material, characterized in that it comprises a feed block associated with a system for feeding and heating the thermoplastic material, a covering nozzle, an engagement and guide nozzle partially passing through the covering nozzle to engage and guide the reinforcing fiber through the extrusion tool, the engagement and guide nozzle opening into the covering nozzle, at least one channel arranged in the feed block and at least one distribution space arranged at the periphery of a portion of the engagement and guide nozzle, so as to convey the molten thermoplastic material under pressure. in an annular space extending around said engaging and guiding nozzle and thereby coating with said molten thermoplastic material the reinforcing fiber in the covering nozzle. The described tooling further comprises a cutting tool for severing the reinforced filament. This document does not describe a covering block on which the covering nozzle is mounted.
[0011] Also known from document EP 2 444 227 A1 is a method for manufacturing an LED strip coated with a thermoplastic material. The extrusion tooling described in this document does not include a covering nozzle mounted on a covering block. Description of the invention
[0012] The object of the present invention therefore aims to overcome the drawbacks of the prior art by proposing a new extrusion tool for the manufacture of a reinforced filament intended to be used in a standard 3D printing head.
[0013] Another object of the present invention is to propose a new extrusion tool making it possible to manufacture a reinforced filament using one or more different and immiscible thermoplastic materials.
[0014] Another object of the present invention is to propose a new additive manufacturing system making it possible to do away with the use of a standard print head.
[0015] Another object of the present invention is to propose a breakability of the reinforced filament by using a dimensioning, respectively of the reinforcing fiber and of the thermoplastic material.
[0016] The extrusion tooling according to the invention has the remarkable advantage that it can, for certain additive manufacturing operations, replace the 3D printing head of the additive manufacturing system.
[0017] Another advantage of the extrusion tooling according to the invention lies in its ability to manufacture a reinforced filament capable of being deposited on a support by direct printing of said reinforced filament.
[0018] Another advantage of the extrusion tooling according to the invention lies in its ability to manufacture a reinforced filament capable of being deposited on a support by means of a standard print head (also called a depositing head), which was previously impossible.
[0019] Another advantage of the extrusion tool according to the invention lies in the possibility of obtaining by coextrusion a reinforced filament having a sheathing of the reinforcing fiber with one or more different and immiscible thermoplastic materials. The sheathing may advantageously consist of a core and an outer skin, having different respective mechanical or physicochemical properties. The core of the sheathing, for example a compact or expanded thermoplastic material, for recycled example is advantageously made of a material promoting adhesion with the reinforcing fiber. The outer skin is advantageously made of a thermoplastic material improving the adhesion of the different layers to each other, of a material having shock absorption properties, porosity and / or electrical or thermal conductivity properties different from those of the core.
[0020] Another advantage of the extrusion tooling according to the invention lies in the possibility of manufacturing a reinforced filament having a sheathing comprising one, two or more layers of thermoplastic materials.
[0021] The configuration of the extrusion tooling according to the invention also has the advantage that the structure of the reinforced filament (core(s) and skin(s)) is preserved during its printing.
[0022] Furthermore, the additive manufacturing system by wire deposition according to the invention is remarkable in that it makes it possible to dispense with a cutting tool for cutting the reinforced filament at the end of the laying operation.
[0023] The objects assigned to the invention are achieved using an extrusion tool for delivering a reinforced filament intended for additive manufacturing by wire deposition, said reinforced filament comprising a long and continuous reinforcing fiber, coated with at least one thermoplastic material M1, characterized in that it comprises a feed block associated with a system for feeding and heating the thermoplastic material M1, a covering block fixed under the feed block, a covering nozzle mounted on the covering block, an engagement and guide nozzle passing through the feed block, the covering block and partly the covering nozzle to engage and guide the reinforcing fiber through the extrusion tool, the engagement and guide nozzle opening into the covering nozzle,at least one channel arranged in the feed block and at least one distribution space arranged at the interface of the feed block and the covering block and on the periphery of a part of the engagement and guide nozzle, so as to convey under pressure the molten thermoplastic material Ml into an annular space extending around said engagement and guide nozzle and thus coat with said molten thermoplastic material Ml the reinforcing fiber in the covering nozzle, as soon as it leaves the engagement and guide nozzle.
[0024] According to an exemplary embodiment, the extrusion tool comprises at least one complementary channel and at least one complementary distribution space arranged in the covering block, said complementary distribution space extending at the periphery of a part of the engagement and guide nozzle, to bring under pressure at least one other molten thermoplastic material M2, delivered by another supply and melting system, into the annular space surrounding the engagement and guide nozzle and containing the molten thermoplastic material M1, to that said other thermoplastic material extends around the thermoplastic material Ml.
[0025] According to an exemplary embodiment, the thermoplastic material M1 and the other thermoplastic material M2 are different and immiscible materials, so that the other thermoplastic material M2 forms a skin enveloping a core formed by the thermoplastic material M1 coating the reinforcing fiber 6.
[0026] According to an exemplary embodiment, the covering nozzle has a flared, trumpet-shaped, revolution-shaped extrusion orifice, making it possible to improve the quality of deposition of the reinforced filament comprising the reinforcing fiber.
[0027] According to an exemplary embodiment, the covering nozzle has an extrusion orifice whose geometric shape, of the grooved or honeycomb type, fits into a circle of given diameter d and whose area is less than the area of a circle of the same diameter d.
[0028] The objects assigned to the invention are also achieved using an additive manufacturing system by wire deposition comprising a deposition head, an extrusion tool described above and actuating members for moving the deposition head in translation along three orthogonal axes or following a vectorial displacement or following a polar or tripodal displacement, in a plane parallel to a deposition plane of the reinforced filament, characterized in that the extrusion tool constitutes the deposition head.
[0029] According to an exemplary embodiment, the additive manufacturing system by wire deposition comprises control means for controlling, at the end of the deposition operation, a sudden acceleration of the displacement movement or a rapid retraction of the extrusion tool, generating an elongation then a cutting of the reinforced filament in the vicinity of the covering nozzle.
[0030] The objects assigned to the invention are also achieved using a wire deposition additive manufacturing system comprising a deposition head, actuating members for moving the deposition head in translation along three orthogonal axes or following a vectorial displacement or following a polar or tripodal displacement, in a plane parallel to a deposition plane, characterized in that it comprises an extrusion tool according to claim 5, delivering the reinforced filament to feed the deposition head, which comprises complementary heating members for softening the thermoplastic material M1 or for softening the thermoplastic material M1 enveloped by the other thermoplastic material M2 and thus allowing 3D printing of the reinforced filament.
[0031] According to an exemplary embodiment of the additive manufacturing system, the extrusion tooling is mounted so as to move with the deposition head. Brief description of the drawings
[0032] Other characteristics and advantages of the present invention will appear more clearly on reading the description which follows, given with reference to the appended drawings, given as non-limiting examples, in which:
[0033] [Fig-1] [Fig.l] is a side view of an example of the production of a tool extrusion according to the invention, allowing for example the manufacture of a reinforced filament
[0034] [Fig.2] [Fig.2] is a sectional view of the extrusion tooling of [Fig.l],
[0035] [Fig.3] [Fig.3] is a partial enlargement of [Fig.2],
[0036] [Fig.4] a [Fig.4] is a front view of an example of reinforced filament obtained from using the extrusion tooling according to the invention,
[0037] [Fig.5] [Fig.5] is a longitudinal sectional view of the reinforced filament of the [Fig.4],
[0038] [Fig.6] [Fig.6] is a sectional view of another exemplary embodiment of the extrusion tooling according to the invention, allowing for example direct additive manufacturing of a printed object without going through a step of heating the reinforced filament,
[0039] [Fig.7] [Fig.7] is an enlarged detail of [Fig.6],
[0040] [Fig.8] [Fig.8] is a sectional view of the extrusion tooling of [Fig.2] in the framework of another use,
[0041] [Fig.9] [Fig.9] is an enlarged detail of [Fig.8],
[0042] [Fig. 10] [Fig. 10] is a sectional view of another example of embodiment of the extrusion tooling according to the invention, allowing for example the manufacture of a reinforced filament comprising for example two layers of thermoplastic materials around a continuous reinforcing fiber,
[0043] [Fig. 11] [Fig. 11] is an enlarged detail of [Fig. 10],
[0044] [Fig. 12] [Fig. 12] is a front view of another example of reinforced filament obtained with the extrusion tooling according to the invention and illustrated in [Fig. 10],
[0045] [Fig. 13] [Fig. 13] is a longitudinal sectional view of the reinforced filament of [Fig. 12], comprising in this example two layers of thermoplastic materials around a continuous reinforcing fiber,
[0046] [Fig. 14] [Fig. 14] is a front view of an exemplary embodiment of a covering nozzle of the extrusion tooling according to the invention,
[0047] [Fig. 15] [Fig. 15] is a side view of the cover nozzle of [Fig. 14],
[0048] [Fig. 16] [Fig. 16] a front view of another example of embodiment of a nozzle of covering the extrusion tooling according to the invention, and
[0049] [Fig. 17] [Fig. 17] is a side view of the cover nozzle of [Fig. 16]. Method(s) of carrying out the invention
[0050] Structurally and functionally identical elements present in several distinct figures are assigned the same numerical or alphanumeric reference.
[0051] [Fig. 1] is a side view of an exemplary embodiment of an extrusion tool 1 comprising a power supply unit 2 and a covering unit 3 fixed under said power supply unit 2 by any means, in particular screws.
[0052] The extrusion tool 1 also comprises a feed and heating system 4 for injecting a molten thermoplastic material into said feed block 2. The feed and heating system 4 is for example screwed onto the feed block 2. A locking nut 5, mounted on the feed and heating system 4, advantageously makes it possible to lock the extrusion tool 1 on a support.
[0053] The feed block 2 has an upper opening 2a for inserting a reinforcing filament 6. The latter is provided with a thermoplastic sheathing when it is expelled from the covering block 3 via a covering nozzle 7 screwed into said covering block 3. The extrusion tool 1 therefore makes it possible to deliver a reinforced filament 8.
[0054] [Fig.2] is a sectional view of the extrusion tool 1 and [Fig.3] is an enlargement partial dissection A of [Fig.2].
[0055] The extrusion tool 1 comprises an engagement and guide nozzle 9 passing through the feed block 2, the covering block 3 and partly the covering nozzle 7, to engage and guide the reinforcing fiber 6 through the extrusion tool 1. The upper opening 2a is therefore located above and opposite the inlet orifice of the engagement and guide nozzle 9. The latter is held and fixed in the feed block 2 using a clamping washer 9a and screws 9b.
[0056] The extrusion tool 1 also comprises a channel (10) and a distribution space 11 arranged respectively in the feed block 2 and at the interface of the feed block 2 and the covering block 3, said distribution space 11 extending at the periphery of the engagement and guide nozzle 9. The channel 10, the distribution space 11 and an annular space 12 surrounding a part of the engagement and guide nozzle 9, are in fluid communication to convey the molten thermoplastic material M1, under pressure, into the annular space 12 located around said engagement and guide nozzle 9 over part of its length. The thermoplastic material M1 therefore passes through this annular space 12 arranged in the covering block 3.
[0057] The outlet orifice of the engagement and guide nozzle 9 opens into a space of the covering nozzle 7, said space extending in the extension of the annular space 12. Thus, when the reinforcing fiber 6 emerges from the outlet orifice of the engagement and guide nozzle 9, it is coated by the molten thermoplastic material M1 and this in the covering nozzle 7. The latter then delivers the reinforced filament 8.
[0058] [Fig.4] is a front view of the reinforced filament 8 obtained using the tooling extrusion 1 and [Fig.5] is a view along a longitudinal AA section of said reinforced filament 8 of [Fig.4]. The reinforced filament 8 therefore comprises a core constituted by the reinforcing fiber 6 and a sheath constituted by the thermoplastic material ML
[0059] [Fig.6] is a sectional view of another exemplary embodiment and use of the extrusion tool 1 directly as a head for depositing the reinforced filament 8. [Fig. 7] is an enlarged detail B of [Fig. 6]. In this embodiment, the covering nozzle 7 has a flared, trumpet-shaped extrusion orifice 7a of revolution. Such a shape greatly facilitates the change in direction of movement of the extrusion tool 1 when depositing the reinforced filament 8 on a support. The quality of the deposits is therefore improved.
[0060] The direction of movement of the extrusion tool 1 is for example indicated by the arrow V.
[0061] [Fig.8] is a sectional view of the extrusion tooling of [Fig.2] in the frame of another use and [Fig.9] is an enlarged detail C of [Fig.8].
[0062] In fact, [Fig.8] or 9 is an illustration of a use of the extrusion tool 1 directly as a head for depositing the reinforced filament 8. [Fig.2], on the other hand, illustrates a use of the extrusion tool 1, aimed only at manufacturing the reinforced filament 8 for a subsequent depositing operation by means of a depositing or 3D printing head. The direction of movement of the extrusion tool 1 is for example indicated by the arrow V.
[0063] [Fig. 10] is a sectional view of another example of the tooling embodiment. extrusion 1 and [Fig.11] is an enlarged detail D of [Fig.10].
[0064] The extrusion tool 1 comprises a complementary channel 13 and a complementary distribution space 14 arranged in the covering block 3 to bring, under pressure, another molten thermoplastic material M2, delivered by another supply and melting system (not shown), into the annular space 12. The complementary distribution space 14 extends at the periphery of the annular space 12 and opens onto said annular space 12. The complementary distribution space 14 is located downstream of the distribution space 11 in the direction of flow of the thermoplastic material M1 towards the extrusion orifice 7a of the covering nozzle 7.
[0065] The extrusion tool 1 illustrated in [Fig. 10] can also constitute a deposition head for carrying out direct deposition of the reinforced filament 8 on a support.
[0066] The thermoplastic material M1 therefore passes through the annular space 12 and the other thermoplastic material M2 extends around the thermoplastic material M1 to form an outer skin.
[0067] [Fig. 12] is a front view of another example of reinforced filament 8 obtained with the extrusion tool 1 illustrated in [Fig. 10] and [Fig. 13] is a longitudinal sectional view of the reinforced filament 8 of [Fig. 12]. The reinforced filament 8 therefore comprises a core made of the reinforcing fiber 6 and a coextruded sheath comprising a core formed by the thermoplastic material M1 and an outer skin formed by the other thermoplastic material M2.
[0068] Advantageously, the thermoplastic material M1 and the other thermoplastic material M2 are different and immiscible materials, so that the other thermoplastic material M2 forms a skin enveloping a core formed by the thermoplastic material M1 coating the reinforcing fiber 6.
[0069] [Fig. 14] is a front view of an exemplary embodiment of a covering nozzle 7 of the extrusion tool 1 and [Fig. 15] is a profile view of the covering nozzle 7 of [Fig. 14]. The covering nozzle 7 has an extrusion orifice 7b, 7c whose grooved or honeycombed geometric shape fits into a circle of given diameter d and whose area is less than the area of a circle of the same diameter d. Thus the extrusion orifice 7b illustrated in [Fig. 14] has a star-shaped grooved shape, which determines the shape of the reinforced filament 8 extruded and illustrated in [Fig. 15].
[0070] [Fig. 16] is a front view of another embodiment of a covering nozzle 7 of the extrusion tool 1 and [Fig. 17] is a side view of the covering nozzle 7 of [Fig.16]. The extrusion orifice 7c illustrated in [Fig.16] has a three-lobed T-shape, which determines the shape of the reinforced filament 8 extruded and illustrated in [Fig. 17].
[0071] The different configurations of the covering nozzles 7, more precisely the different shapes of the extrusion orifices 7b and 7c of said covering nozzles 7 are compatible with the coextrusion of several superimposed layers of thermoplastic materials M1, M2. A cladding with alternating cores and skins is conceivable.
[0072] The invention also relates to a wire deposition additive manufacturing system. Such a wire deposition additive manufacturing system is already generally known and will therefore not be described below in full detail.
[0073] The additive manufacturing system by wire deposition, in accordance with the invention, comprises a deposition head, the extrusion tool 1 as described above and members actuating means for moving said deposition head in translation along three orthogonal axes or following a vectorial displacement, in a plane parallel to a deposition plane of the reinforced filament 8.
[0074] According to one embodiment and use, the extrusion tool 1 advantageously constitutes the deposition head.
[0075] According to another embodiment and use, the additive manufacturing system by wire deposition comprises a deposition head, actuating members for moving said deposition head in translation along three orthogonal axes or following a vectorial displacement, in a plane parallel to a deposition plane. In this other embodiment and use, the additive manufacturing system comprises the extrusion tooling 1 described above, for example with a covering nozzle 7 having a flared revolution extrusion orifice 7a of the trumpet horn type, delivering the reinforced filament 8 to feed the deposition head. The latter then comprises complementary heating members for softening or melting the thermoplastic material M1 or for softening the assembly constituted by the thermoplastic material M1 enveloped by the other thermoplastic material M2 and thus allowing 3D printing of the reinforced filament 8.
[0076] According to an exemplary embodiment of the system, the extrusion tool 1 is mounted so as to move with the dispensing head. The extrusion tool 1 can advantageously be mounted on the displacement member on which the dispensing head is mounted.
[0077] The additive manufacturing system according to the invention further comprises control means for controlling, at the end of the deposition operation, a sudden acceleration of the displacement movement or a rapid retraction of the extrusion tool 1, generating an elongation then a cutting of the reinforced filament 8. This cutting occurs in the vicinity of the covering nozzle 7 without it being necessary to resort to a specific cutting means.
[0078] According to an exemplary embodiment, the thermoplastic materials M1, M2 mentioned may also comprise a thermosetting material or any other material which can be softened and then shaped under pressure by an extrusion principle. The molten material can advantageously expand at the outlet of the extrusion tool 1 or remain compact.
[0079] It is obvious that the present description is not limited to the examples explicitly described, but also includes other embodiments and / or implementations. Thus, a described technical characteristic is likely to be replaced by an equivalent technical characteristic without departing from the scope of the present invention as defined by the claims.
Claims
Claims
1. Extrusion tooling (1) for delivering a reinforced filament (8) intended for additive manufacturing by wire deposition, said reinforced filament (8) comprising a long and continuous reinforcing fiber (6), coated with at least one thermoplastic material (Ml) comprising: - a feed block (2) associated with a system for feeding and heating (4) the thermoplastic material (Ml), - a covering nozzle (7), - an engagement and guide nozzle (9) passing through the feed block (2) and partly the covering nozzle (7) to engage and guide the reinforcing fiber (6) through the extrusion tooling (1), - the engagement and guide nozzle (9) opening into the covering nozzle (7), - at least one channel (10) arranged in the feed block (2) and at least one distribution space (11) arranged at the periphery of a part of the engagement and guide nozzle guidance (9),so as to convey under pressure the molten thermoplastic material (Ml) into an annular space (12) extending around said engagement and guide nozzle (9) and thus coat with said molten thermoplastic material (Ml) the reinforcing fiber (6) in the covering nozzle (7), as soon as it leaves the engagement and guide nozzle (9), characterized in that the covering nozzle (7) is mounted on a covering block (3), said covering block (3) being fixed under the supply block (2), the engagement and guide nozzle (9) passing through the covering block (3) and the distribution space (11) being provided at the interface of the supply block (2) and the covering block (3).,
2. Extrusion tool (1) according to claim 1, characterized in that it comprises at least one complementary channel (13) and at least one complementary distribution space (14) arranged in the covering block (3), said complementary distribution space (14) extending at the periphery of a part of the engagement and guide nozzle (9), to bring under pressure at least one other molten thermoplastic material (M2), delivered by another supply and melting system, into the annular space (12) surrounding the engagement and guide nozzle (9) and containing the molten thermoplastic material (M1), so that said other thermoplastic material (M2) extends around the thermoplastic material (M1).
3. Extrusion tool (1) according to claim 2, characterized in that it makes it possible to coextrude a reinforced filament (8) and to sheath the reinforcing fiber (6) with the thermoplastic material (Ml) and the other thermoplastic material (M2), which are different and immiscible materials, so that the other thermoplastic material (M2) forms a skin enveloping a core formed by the thermoplastic material (Ml) coating the reinforcing fiber (6).
4. Extrusion tool (1) according to any one of claims 1 to 3, characterized in that the covering nozzle (7) has a flared, trumpet-shaped extrusion orifice (7a) of revolution, making it possible to improve the quality of deposition of the reinforced filament (8) comprising the reinforcing fiber (6).
5. Extrusion tool (1) according to any one of claims 1 to 3, characterized in that the covering nozzle (7) has an extrusion orifice (7b, 7c) whose geometric shape, of the grooved or honeycomb type, fits into a circle of given diameter (d) and whose Do is less than the area of a circle of the same diameter (d).
6. Additive manufacturing system by wire deposition comprising a deposition head, an extrusion tool (1) according to any one of claims 1 to 4 and actuating members for moving the deposition head in translation along three orthogonal axes or following a vectorial displacement or following a polar or tripodal displacement, in a plane parallel to a deposition plane of the reinforced filament (8), the extrusion tool (1) constituting the deposition head.
7. Additive manufacturing system according to claim 6, characterized in that it comprises control means for controlling, at the end of the deposition operation, a sudden acceleration of the displacement movement or a rapid retraction of the extrusion tool (1), generating an elongation then a cutting of the reinforced filament (8) in the vicinity of the covering nozzle (7).
8. Additive manufacturing system by wire deposition comprising a deposition head, actuating members for moving the deposition head in translation along three orthogonal axes or following a vectorial displacement or following a polar or tripodal displacement, in a plane parallel to a deposition plane, said system comprising an extrusion tool (1) according to claim 5, delivering the reinforced filament (8) to feed the deposition head, which comprises complementary heating members for softening the thermo- plastic (Ml) or to soften the thermoplastic material (Ml) wrapped by the other thermoplastic material (M2) and thus allow 3D printing of the reinforced filament (8).
9. Additive manufacturing system according to claim 8, characterized in that the extrusion tool (1) is mounted so as to move with the deposition head.