BR102017022948A2 - DUAL EXTRUSOR DEVICE CORRUGATIVE, VERTICAL AND MODULAR THREAD AND EXTRUSION PROCESS OF THE SAME - Google Patents

Abstract

The present invention is in the technical field of additive manufacturing and material processing, and describes a modular corrugating double screw extruder designed to process small amounts of material and to be used in 3D printing equipment such as a deposition head. interchangeable and can also be used in other types of equipment. The proposed invention aims to solve the technical problem of the absence of a modular and corrugating double screw extruder device that allows processing quantities between 0.1 kg / h and 0.2 kg / h, in order to generate multifunctional components with higher mechanical strength and more uniform property. regardless of the direction of request. Additionally, the present invention solves the problem of mixing and / or additive of different materials either in liquid, granular or powder form, for the formulation of composites and polymeric blends, according to the type and state of the material to be processed.

Description

CORROTACTIVE, VERTICAL AND MODULAR DOUBLE THREAD EXTRUDER AND EXTRUSION PROCESS OF THE SAME

FIELD OF THE INVENTION:

[001] The present invention falls within the technical field of Additive Manufacturing and materials processing, and describes a corroborative and modular double screw extruder device, designed to process small amounts of material, and to be used in 3D printing equipment, as a interchangeable deposition head, and can also be used in other types of equipment.

[002] The proposed invention aims to solve the technical problem of the lack of a corrective and modular double screw extruder that allows processing quantities between 0.1 kg / h to 0.2 kg / h, in order to generate multifunctional components with greater mechanical resistance and more uniform properties, regardless of the direction of request.

[003] Additionally, the present invention solves the problem of mixing and / or adding different materials

be in the form liquid, in granules or powder, for formulation of composites and blends polymeric, more specifically under state in powder, according with the type and

state of the material to be processed.

TECHNICAL STATUS:

[004] Additive Manufacturing (MA), known as the popularized 3D printing term, is a design and manufacturing technology formed by a set of additive manufacturing techniques, which can be applied both in the generation of visual prototypes and in final products,

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2/29 depending on the structuring method used, state of the raw material and the project requirements.

[005] His interest can be attributed to the ability of Additive Manufacturing processes to produce physical objects part by part, line by line, surface by surface or layer by layer, directly from digital information, without the need for intermediate tools.

[006] More specifically, the MA processes deposit, unite and / or transform basic volumetric elements of raw material, called voxels, to generate a final object, thus defining the object's geometry and material properties.

[007] It should be noted that the shape and size of each voxel, as well as the final adhesion between them, are determined by the raw material (s), the manufacturing equipment and the process parameters. In turn, the object's geometry is determined by the tool's path, projection patterns or a combination of these factors.

[008] In relation to additive processes, these are characterized by increasing the mass of the workpiece, and together with the subtractive and transformative processes, in which the mass of the workpieces is respectively reduced and conserved, make up the three main current manufacturing technology classes.

[009] It is important to note that currently, there are about seven MA techniques based on the type of raw material structuring, namely: binder blasting, deposition with directed energy, material extrusion, material blasting, powder bed melting , lamination of

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3/29 leaves and light curing in vat.

[010] Regarding MA technologies based on deposition of extruded material (ME3DP, Material Extrusion 3D Printing), it is worth mentioning that the raw material used is generally supplied in solid state, and may also be in the form of filament or powder. Still regarding the deposition of extruded material, we can highlight the commercial process FDM (Fused Deposition Modeling ”), which uses materials in the form of filaments, which are fed with the aid of a pair of tractor rollers in a heated chamber and the chamber being responsible for softening the material. Furthermore, it is important to note that, at the entrance of the chamber, the solid portion of the filament acts as a piston, in order to force the melt through a nozzle, which is responsible for depositing the material on a substrate.

[011] Still on the FDM process, it should be noted that the so-called FDM extrusion head assembly basically comprises a pair of tractor rollers, a heating chamber and a printing nozzle, and the whole assembly generally moves in the horizontal plane ( xy) for printing a layer with geometry equivalent to the cross section of the object under construction, while the substrate is moved in the z direction, thereby allowing the formation of more complex three-dimensional geometries, layer by layer.

[012] Specifically in relation to the head, it allows the use of different filaments, which can be one for the construction of the piece and the other for the construction of supports for cantilever structures, structures that

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4/29 can later be removed, either manually or with the aid of a solvent.

[013] Furthermore, the printing filaments used in FDM technology are generally thermoplastic and preferably amorphous polymers, such as ABS (acrylonitrile butadiene styrene copolymer) and PC (polycarbonate), since they must be heated in order to achieve a softened state, allowing the extrusion of lines that maintain the shape and height, thereby determining the precision of the process.

[014] Although widely used, FDM technology has certain limitations, mainly related to restrictions on the variety of raw materials available for printing and on the functionality of the objects obtained with these filaments, as well as high anisotropy of the mechanical properties associated with the printing direction. .

[015] In this sense, efforts have been made aiming at the development of new materials, either through the combination of thermoplastic polymers with different additives, in order to obtain composites or even the combination of different polymers, to obtain blends that allow generating multifunctional components, with greater mechanical resistance and more uniform properties regardless of the direction of application.

[016] Additionally and with regard to the equipment used in the 3D printing process by extrusion, several constructive solutions have been developed in order to allow extrusion systems with soft, granular or filamentary materials, however, the

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5/29 most of them focused only on the transport phenomenon.

[017] As an example of one of the solutions mentioned above, document US 6,030,199 describes an apparatus for structuring three-dimensional objects from the deposition of materials in planes by means of a nozzle with an adjustable orifice in the form of a gap. Said apparatus uses two extruder threads, whose function is only to transport the material, either construction or support, to the deposition nozzle. The North American document also mentions the possibility of using metallic or ceramic construction materials, as well as low-temperature softening support materials, waxes or polymers, which, however, must be previously heated and homogenized in a high-shear mixer. forming a paste for later deposition. Although the use of two threads is mentioned in the North American document, the apparatus is actually provided with two separate screw extruders, separate and non-modular, so that they do not allow mixing, melting or softening and homogenizing different raw materials.

[018] US 5,121,329 presents a basic constructive solution of the FDM process, one of the most used for small and low-cost three-dimensional printers, consisting of a movable head formed by a heated chamber that precedes a deposition nozzle. In the proposed solution, the material reaches the chamber in a solid state, in the form of a filament, being heated until it reaches a softened state when it is then pushed through a hole of predetermined diameter in the nozzle and

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6/29 deposited on a substrate. The solution proposed in the North American document described above does not, however, allow feeding with different powder or liquid materials, in addition to not allowing the combination of raw materials to obtain a material with different physical-chemical properties and that can be extruded or deposited layer-by-layer for the generation of three-dimensional objects.

[019] US 6.866.807 B2 details the process for obtaining a filament used in FDM technology, which includes the use of single screw extruder. The extrudate is pulled along a refrigeration system, which in addition to solidifying the material, is responsible for helping to control the final dimensions of the filament. Despite using the extrusion process itself, the conceptual solution has only one thread, which implies limited mixing capacity and restricts the application of the apparatus only to generate filaments for 3D printing from thermoplastic polymers and additives without reinforcing action, such as dyes, stabilizers and antioxidants. In addition, only after the filament manufacturing step, the filament should be fed into the usual 3D printing heads of the FDM type, in contrast to the equipment of this invention, which can be used directly for material processing and deposition on substrate.

020] In the aforementioned documents, the material is forced through the hole by applying pressure, which is analogous to what occurs in the

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7/29 piston extrusion, in which there is no homogenization / mixing of the material or generation of heat by friction. In contrast, WO 2011092269 presents a constructive solution that includes a vertical single screw extruder for the construction of three-dimensional objects, used only to transport the material that was previously softened in a side barrel, with the help of external resistors. Despite providing for the use of raw materials in the form of granules or powder, the conceptual solution is energy inefficient, since all the heat necessary to soften the polymers must be supplied by external heaters, since the material in the solid state is not subjected to shear in the single screw extruder.

[021] In addition, document BR 102014005143 describes a vertical extrusion head for 3D printers, with single thread (mono-thread), designed for processing powdered raw materials, being able to deposit filaments or points for the construction of three-dimensional objects layer a layer. In that document, the extruder thread has a constant pitch, simple thread and decreasing channel depth, which allows the transport and compression of the product (s) inside the barrel, favoring its homogenization and plasticization, for later extrusion through a nozzle with a circular hole. However, the proposed head does not describe modular components that facilitate the cleaning or variation of parts, promoting greater flexibility to the process. In addition, it does not contain elements that favor the mixing of materials for the proper production of composites or

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Polymeric 8/29.

[022] Additionally, it is important to emphasize that the screw extrusion process is one of the most used in the thermoplastic resin processing industry, and the rotation of one or more threads inside a barrel allows different materials in liquid form, from granules or powders are subjected to cyclic shear and elongation deformations, which generates part of the heat necessary for the plasticization of the product and effectively provides mixing and homogenization of the materials.

[023] In this regard, single-screw or mono-screw extruders are commonly used for homogenization and plasticization, while double-screw extruders, due to their excellent mixing capacity, were developed and are predominantly used in the polymeric composting that involves additives and mixing for formulating polymeric composites and blends.

[024] Thus, it can be understood that the main functional difference between twin screw extruders, also called composters, and single screw extruders is related to the internal transport mechanisms and types of flow present in the machines.

[025] While in the single screw extruder the material transport occurs basically due to the drag - by friction - in the solids transport zone and due to the viscous drag in the molten transport zone, its production capacity is strongly dependent on the properties of the solid and cast material, in contrast, the twin screw extruders, in addition to the drag flow,

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9/29 function as positive displacement pumps because, as the threads rotate, the volumes between the fillets advance axially towards the matrix, since the material within each of these volumes is confined due to the sealing action provided by the interpenetration. Thus, in twin screw extruders the outlet flow is less dependent on the material properties and proportional to the rotation speed of the threads.

[026] Regarding the types of flow that can be developed in each machine, the complex movement of the material inside the twin screw extruders and the presence of thread elements with specific geometry are key characteristics that allow the generation of flows not only shear , important for distributive mixing, as with single screw extruders, but also highly elongational flows, which is essential for good dispersive mixing action.

[027] In addition, while single screw extruders operate fully filled, the filling in double screw extruders is generally partial, which adds an important process control feature, as it allows the variation of the completely filled length of the extruder and therefore of the sections that will contribute the most to increasing temperature and pressure.

[028] Finally, it is worth emphasizing that the processing capacity in extruders is generally measured in kg / h and depends on the speed of rotation and the diameter of the threads, whereas in double-screw table extruders with a diameter of 25 mm, the product flow varies between 0.5 kg / h to 15 kg / h.

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10/29 [029] As can be seen, in the state of the art documents and in the information about the aforementioned single and double screw extruders, there is a tendency for the development of small sized equipment that allows the processing of small materials quantity, either due to the high associated cost of raw materials or the applications of the process. It should also be noted that the search for differentiated applications involving 3D printing by extrusion of material (ME3DP) has driven the development of new systems that allow the combination of different materials, most of which are based on the single screw extrusion process .

[030] Thus, we can notice the absence of solutions as efficient as the double screw extrusion head of the present invention, with regard to the distributive and dispersive mixing capacity and, therefore, the suitability of the process for the development of composites and / or polymeric blends, which allow the processing of small amounts of material as well as the direct manufacture of three-dimensional objects layer by layer.

OBJECTIVES AND ADVANTAGES OF THE INVENTION:

[031] In view of the above, the present invention basically aims to solve the technical problem of the lack of a corrodible and modular double screw extruder device, which allows processing small amounts of material, and to be used in 3D printing equipment, such as an interchangeable depositing head, which can also be used in other types of equipment.

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11/29 [032] Therefore, it is one of the objectives of the present invention to reveal a corroding and modular double screw extruder that allows processing quantities between 0.1 kg / h to 0.2 kg / h, in order to generate multifunctional components with greater mechanical strength and more uniform properties regardless of the direction of application.

[033] It is yet another objective of the present invention to enable mixing and / or additives of different materials, whether in liquid, granule or powder form, for the formulation of polymeric composites and blends, according to the type and state of the material to be processed.

[034] It is also another objective of the present invention, an interchangeable and reduced size equipment, suitable not only for the processing of polymers combined with additives, other polymers, ceramics or metals, but also for the deposition of the processed product according to a layer-by-layer 3D printing strategy, with modular components for easy maintenance, cleaning and geometric variation, based on a corrective corrective double head, whose vertical positioning of the threads contributes to the reduction of the overall volume occupied by the set, favoring its interchangeability.

BRIEF DESCRIPTION OF THE INVENTION:

[035] The aforementioned objectives are achieved by means of a vertical, modular and corrective double screw extruder device comprising an electric drive motor, a speed reducing assembly, a torque transmission mechanism, an extruder head and

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12/29 a support plate with at least one clamp. The extruder head comprising: (i) two couplings, (ii) a modular feed hopper, (iii) a twin screw extruder set with a pair of spindles, a pair of first conveying elements, a pair of second elements of transport, a pair of first suitcases, a pair of second suitcases, a pair of third transport elements and a pair of fasteners, (iv) a modular container or barrel, (v) at least one heater external and a modular matrix set.

[036] In addition, the objectives of the present invention are achieved through the double-screw extrusion process using the corrective corrective, double-screw extruder device, which comprises the steps of feeding the silo with raw material and determining the path information and parameters of operation, activate the twin screw extruder assembly, transport the raw material by the first transport elements, compress and start the melting of the raw material by the second transport elements, mix dispersively and completely melt / soften the raw material through the first blocks bagging, mix distributively and pressurize the raw material through the second bagging blocks with reverse transport action, transport and compress the homogenized and mixed material by the third transport elements, direct the material flow through the fitting and threaded sleeve to the nozzle extrusion, extrude the material and / or deposit the filament on the deposition platform.

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13/29

BRIEF DESCRIPTION OF THE FIGURES:

[037] To obtain total and complete visualization of the object of this invention, figures are presented which are referred to, as follows.

[038] Figure 1 is a front view representation of a preferred embodiment of the extruder device, object of the present invention;

[039] Figure 2 is a sectional representation of the frontal view of the preferred mode of the extruder device, object of the present invention, showing its components;

[040] Figure 3 is an exploded view detailing the preferred mode of the extruder head of the extruder device, object of the present invention, showing the main components;

[041] Figure 4 is an exploded view detailing the assembly of the double thread, component of the preferred mode of the extruder head of the extruder device, object of the present invention, showing its components;

[042] Figure 5 is a flow chart illustrating the stages of the 3D printing process, using the extruder device, object of the present invention; and [043] Figure 6 is a schematic representation showing the operational concept, of the extruder device, object of the present invention.

DETAILED DESCRIPTION OF THE INVENTION:

[044] The object of the present invention will be described in more detail and explained based on the attached drawings, which are merely exemplary and non-limiting, since adaptations and modifications may

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14/29 without making it outside the scope of the protection claimed.

[045] In addition to the advantages previously described in relation to twin screw extruders, and mainly due to the fact that the twin screw extruder head 200, object of the present order, is corrective, allowing rotation in the same direction, it also offers other advantages such as, the ability to self-clean and the possibility to change the configuration of the threads due to the modular design principle of the thread elements. Such elements were designed according to the processing functions

that should be performed by extruder and are Classified basically in elements in transport it's from mixture. [046] Furthermore, it complies notice that The capacity in self-cleaning of the head double extruder thread 200 it is

closely related to the geometry of the thread elements 6B, 6D, 6F, 6H, 6J, which is characterized by the perfect fit between the thread threads, except for the necessary clearance between the threads that must be kept constant during their movement to avoid contact wear.

[047] For this purpose, several calculations were made until the basic thread profiles (called self-cleaning profile) were reached, whose parameters include: distance between centers of the thread axes, number of fillets, diameter of the modular container or barrel 7, step thread and clearance between the pair of threads and between the threads and the barrel 7. The self-cleaning profile is generally the same for

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15/29 the transport or mixing elements, constituting its cross section.

[048] Furthermore, it should be noted that the transport elements 6B, 6D, 6J are responsible for loading the material along the barrel 7 of the extruder towards the matrix set 9, also providing a distributive mixture when the fluid is forced between the end of the fillet and the wall of the barrel 7, besides helping to raise the temperature of the material with the heat generated due to its movement. Mixing elements 6F, 6H, in turn, have the appropriate geometry to intensively work the material, not only separating flows for distributive mixing but also generating areas of intense shear and elongational deformation that provide the breakdown of agglomerates and, thus, effective dispersive mixture.

[049] In this way and as can be seen from Figure 1, the extruder device 100 comprising, basically, at least one electric drive motor 1, a speed reduction system 2, a torque transmission mechanism 3 inside the which have at least two pairs of gears, a pair of couplings 4, an extruder head 200 provided with a feeding silo 5, a twin screw extruder assembly 6 arranged in the barrel 7, at least one heater 8, a modular matrix assembly 9 and at least one support plate 10 with at least one clamp 11. It is important to note that the heater (s) 8 is (are) external (s) and its position around the barrel 7 can be varied and in several areas around over the

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16/29 barrel length 7, allowing temperature control between 50 ° and 250 ° C, since the heater (s) 8 is (are) responsible only for supplying 30% to 50% of energy necessary for the fusion of the materials and the remainder being provided by the double thread set 6, still the heater (s) 8 being properly connected (s) to a temperature control device.

[050] It should be noted that the functional components of the extruder device 100 object of the present invention, such as electric motor 3 and heater (s) 8, are of conventional and commercially available models, and are not limited to a specific pattern. The pair of couplings 4, can be of conventional and commercially available models or specially designed for the desired application.

[051] Regarding the disposition and operation of the components of the extruder device 100, and as can be seen from Figure 2, the electric drive motor 1 is mechanically associated with the speed reducing system 2, which in turn is mechanically associated with the torque transmission system 3, which because it is mechanically associated with the extruder head 200, and this when activated, allows the movement of the twin screw extruder set 6 with the same torque, from 8 to 16 Nm, the same speed, from 10 to 20 rpm and counterclockwise.

[052] In an alternative embodiment, the transmission system 3 can present a more compact solution, e.g., that already comprises the speed reducing system 2

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17/29 required for drive motor 1 and a system for transmitting the desired speed to two corrective axes. Alternative solutions may also include worm and crown, toothed belt and internal gears.

[053] The modular assembly principle of the extruder device 100, allows its components, such as, for example, the feed silo 5, the barrel 7, the twin screw extruder set 6 and the extrusion die set 9, to be easily varied, assembled and disassembled for cleaning and / or geometry variation according to different process requirements. The twin screw extruder set 6, in particular, and as can be seen in Figure 4, is composed of a pair of spindles 6A and several screw elements 6B, 6D, 6F, 6H and 6J, for transport and mixing, which they can be arranged in different sequences or varied in their geometry in order to contribute to the flexibility of the extruder head 200.

[054] Due to the need for reduced dimensions and weight for application on experimental platforms for investigation of several research fronts in Additive Manufacturing, and as can be seen from Figures 1 and 2, the extruder head 200 presents the twin screw extruder set 6 with vertical arrangement, which allows the use of 6A spindles with reduced section, since the deflection caused in the cross section of the extruder axis by gravity is less pronounced in relation to the horizontal arrangements.

[055] In addition, the positioning of the

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18/29 feed 5 directly on the barrel 7, combined with the initial zone of the twin screw extruder set 6, constitutes a more compact single prismatic volume compared to the horizontal extruder arrangements, also allowing the use of the gravity force in favor of the feed and material transportation.

[056] Furthermore, device 100 allows the control of process parameters, such as the temperature in different sections of the barrel and the rotation speed of the threads, these parameters being associated with the quality of the extrusion product that constitutes the obtained prototype.

[057] In a preferred embodiment, and as shown in Figure 3, the extruder head 200 comprises a pair of couplings 4, a modular feed silo 5, a twin screw extruder set 6, a modular barrel 7 and a modular die set 9. The modular silo 5 having a conical side wall 5A and a flange 5B provided with fixing means 5C, the fixing means 5C which can be threaded holes or another type, which performs the same function, that is, to fix the silo 5 in barrel 7. In relation to barrel 7, it has a prismatic shape with two circular openings 7A spaced diametrically from each other at a distance between 10.1 mm and 10.5 mm, barrel 7 also comprising a pair of barrel flanges 7B arranged at the ends thereof, flanges 7B being provided with a flange recess 7C for positioning a sealing means, eg a gasket, in order to prevent possible leaks due to the developed pressure in the matrix between 2 and 5 MPa, and also comprising means of

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19/29 fixation of barrel 7D, which can be threaded holes or another type, since perform the same function, that is, to assemble barrel 7 in the matrix set 9. In turn, the matrix set 9 has a modular characteristic and is composed of an adapter 9A, a matrix flange 9B, a threaded sleeve 9E and an extrusion nozzle 9F. The adapter 9A having conical internal geometry, therefore being able to direct the flow of material from the twin screw extruder set 6 to the threaded sleeve 9E, and further comprising a flange 9B at its upper end, the flange 9B being provided with a recess 9C for positioning a sealing means, eg sealing gasket, and fixing means of the 9D die, which can be threaded holes or another type, provided that it performs the same function, that is, to assemble the die set 9 on the barrel 7. Finally, it should be noted that the threaded sleeve 9E allows compatibility between the adapter 9A and the extrusion nozzle 9F, whose hole can vary between 0.4 mm and 0.8 mm.

[058] As shown in Figure 4, the twin screw extruder set 6 is provided with a pair of spindles 6A, comprising a circular section 6A ', followed by a hexagonal section 6A ”and, by a threaded circular section 6A ”', It also has transport elements 6B, 6D, 6J, 6F, 6H mixing or mixing elements and 6L fastening elements.

[059] Figure 4 further illustrates a first double-threaded transport element 6B, type 18/18, which has a thread pitch of 18 mm, a total length of 18 mm and a central hexagonal hole 6C, a second transport element of

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20/29 6D double fillet of type 12/24, which has a thread pitch of 12 mm, total length of 24 mm and with a central hexagonal hole 6C, a first 6F trunk block with double fillet discs of type 45/8 / 28, which features 8 prismatic discs with a thickness of 3.5 mm, stacked with an angular offset of 45 ° in the direction favorable to flow 6E, forming an element with a total length of 28 mm and with a central hexagonal hole 6C, a second suitcase block with double filament discs 6H of the type 45/12/24 LH, which has 12 prismatic discs with a thickness of 2 mm, stacked with an angular offset of 45 ° in the opposite direction to the 6G flow, forming an element with a total length of 24 mm and with central hexagonal hole 6C, a third 6J double fillet transport element of the type 18/18, which has a thread pitch of 18 mm, total length of 18 mm and with a central hexagonal hole 6C.

[060] Regarding the arrangement of the preferred embodiment of the twin screw extruder assembly on the extruder head 200, it should be noted that the twin screw extruder assembly 6 is arranged inside the barrel centrally in the two openings 7A, in order to allow its rotation inside the barrel 7. Regarding the specific assembly of the twin screw extruder assembly 6, it is worth noting that the first transport element 6B, followed by the second transport element 6D, followed by the first suitcase block 6F, by the second suitcase block 6H and the third transport element 6J slide along the spindles 6A from the threaded section 6A ', and through the hexagonal section 6A, until the first

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21/29 transport element 6B is limited by the circular section 6A ', when then the fixing element 6L is positioned in the threaded section 6A ”'. Since in the present preferred embodiment the fastening elements 6L are nuts, they are threaded in the threaded section 6A ”'.

[061] It is worth mentioning that the thread elements 6B, 6D, 6F, 6H, 6J, present a cross section that provides self-cleaning action, with dimensions mathematically determined in a computational routine, with an external diameter between 11.5 and 12 mm, internal diameter between 8 and 8.5 mm and diameter inscribed in the hexagonal hole comprised between 5.5 to 6 mm.

[062] Due to the reduced dimensions of the thread elements 6B, 6D, 6F, 6H, 6J, common solutions of non-permanent union between shaft and hub, eg, keys, grooves or taper, are not viable - therefore it is necessary to use spindle 6A with hexagonal section 6A ”and thread elements 6B, 6D, 6F, 6H, 6J with central holes 6C equally hexagonal, as detailed in Figure 4. In addition, the geometric characteristics of the spindle 6A can be manufactured using of turning and / or milling processes and 6C hexagonal holes using “near net shape” additive processes such as, Direct Laser Metal Sintering or Selective Laser Sintering, combined with finishing processes, eg, grinding or blasting.

[063] As shown in Figure 5 and evidenced in Figure 6, the twin screw extrusion process using the extruder device 100, object of the present invention,

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22/29 comprises the following steps:

I. Manual feeding of the raw material in silo 5, and determination of the trajectory information of the head and the operational parameters;

II. Activation of the twin screw extruder set 6;

III. Transport of the raw material by the first transport element 6B;

IV. Compression, in the ratio of 1.5: 1, and start of melting of the raw material by the second transport element 6D, with the aid of external heating 8;

V. Dispersive mixing and complete melting of the raw material by the first 6F suitcase block, with the aid of external heating 8;

SAW. Distributive mixing and pressurization of the raw material by the second 6H packing element with reverse transport action, with the aid of external heating 8;

VII. Transport and compression, in the ratio 1.2: 1, of the material homogenized and mixed by the third transport element 6J, with the aid of external heating 8;

VIII. Direction of the material flow through the adapter 9A, with the aid of external heating 8, passing through the threaded sleeve 9E until the extrusion nozzle 9F;

IX. Extrusion of the material and / or deposition of the filament formed on a deposition platform 12.

[064] Still in relation to the process, it should be noted that in step I, the powdered raw material with a maximum granule size of up to 1.5 mm, liquid or viscous paste, formed

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23/29 by pure or mixed polymers, with or without added additives and / or reinforcement materials, is introduced manually into hopper 5 at room temperature, between 20 ° and 23 ° C or heated according to the softening temperature, eg from 80 ° to 120 ° C of materials introduced in liquid or paste form, with the aid of a spoon or spatula for materials in powder form, as well as a syringe or beaker for paste or liquid materials. The extruder device 100 is suitable for processing preferentially, but not only pure powder polymers, such as PLA, PCL, ABS, PDLA, PA 6 (or Nylon® 6) obtained in powder form as synthesized ”or by cryogenic grinding. In the case of mixing polymers with metals or ceramics (eg tungsten, alumina, titanium oxide, hydroxyapatite, tricalcium phosphate, graphene.) For the creation of composite systems, the proportion indicated is 2% to 5% of metallic or ceramic powder for 95% to 98% of thermoplastic material, which must be fed at the same time in silo 5. For cases of mixing polymers with one or more polymers to create blends (eg ABS / SEBS, ABS / SEBS / PEUAPM, PLA / PDLA, ABC / PC), it is recommended to add from 2% to 25% of the polymer in a smaller proportion, eg 20% of the polymer in a smaller proportion (SEBS), for the blend between ABS and SEBS (ABS / SEBS), which must be fed into the silo at the same time. For cases of mixing polymers with metals or ceramics for the creation of pre-metallic pastes (e.g. organic / polymeric binders + bronze or copper) or pre-ceramics (e.g. organic / polymeric binders + titanate

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24/29 lead zirconate), the proportion indicated is 50% to 97% of non-polymeric component. Materials must also be added to the silo at the same time.

[065] In addition, still in relation to step I, “head trajectory information” means the set of G codes (CNC language) that determine its movement speed and positioning coordinates, generally obtained in 3D printing machines through slicing and printing planning software (eg Slic3r), in which it is possible to choose the thickness of the layers in which the three-dimensional model will be sliced (usually between 0.1 mm to 0.25 mm, preferably 0.20 mm determining the accuracy of the printing), choose the percentage of filling the models (from 5% to 100%) depending on the trajectory of the interface program, preferably 90% for the mentioned ABS / SEBS blend, authorize the construction of support structures, etc. Regarding the operational parameters ”, these refer specifically to the extruder device object of this patent, including the rotation speed of the threads (10 to 20 rpm), 10 rpm for the aforementioned blend and the temperature of the external heaters (50 ° C at 250 ° C), around 105 ° C for the aforementioned blend.

[066] Furthermore, in step II, the activation of the torque transmission mechanism 3 and the reducer assembly 2 by the electric motor 1 according to parameters pre-established by the operator, promotes the rotation movement of the tree axes 6A, which, in turn, promote the rotation of the thread elements 6B, 6D, 6F, 6H, 6J formed

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25/29 preferably, but not necessarily, by the elements described;

[067] Already in the stage

III, the first transport element 6B, with a larger pitch, initiates the rapid transport of the raw material, towards the extrusion nozzle 9F.

[068] In step IV, reducing the step of the second 6D transport element causes an initial compression of

1.5: 1 and the heat generated by friction, together with the heat from external heaters 8, heated to a range of 50 °

250 ° C, starts melting / softening the material.

heater temperature will depend on the system of materials being processed, for example, PCL based systems have melting temperatures around 60 ° C, ABS based systems, softening temperature around 105 ° C, PLA based systems have temperature melting temperature around 150 ° C PA-based systems

6, melting temperature around 220 ° C. It should also be noted that the melting / softening temperatures vary according to the chemical composition and structural peculiarities of the aforementioned polymers and that, generally, the processing carried out at a temperature above the melting temperatures to ensure greater fluidity. In addition, mixing with additives, fillers or other polymers alters the processing temperatures, according to the nature of the components added.

[069] In step V, flows of intense shear and elongation are developed in the first block of malaxagem

6F, effect created by the forced passage of material between the end of wide fillets and the wall of the barrel 7, which

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26/29 favors the dispersive mixture. At the end of this stage the material must be completely melted.

[070] In step VI, the material is forced to remain for a longer time between narrow disks of malaxagem, which favors the multiple division of flows and, therefore, the distributive mixture. There is an increase in pressure and temperature due to the opposite direction of transport of the block. The continuous arrival of more material from the previous elements generates enough pressure, from 2 to 5 MPa, to push the accumulated material between the tapping discs in this stage.

[071] In step VII, the material is compressed one last time, 1.2: 1 ratio by the third transport element 6J with reduced pitch, to ensure uniformity of the material.

[072] In step VIII, the flow is directed through the 9A adapter to the 9F extrusion nozzle.

[073] Finally, in step IX, the material starts to be extruded and / or deposited in successive layers from the movement of the extruder device 100 in the XY direction on the deposition base 12, which moves in Z. The deposited filaments acquire , by cooling to the environment, the consistency of solid material, generating a prototype previously defined by the equipment operator.

[074]

It should be noted that, in relation to the material used to achieve the object of the present invention, the copolymer was used

ABS, which is one of the most used in 3D printers of the FDM type, and also for presenting relatively high viscosity, around 1340

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27/29

Pa.s (considering 10 rpm rotation, with the whole system, polymer + extruder at 240 ° C). Comparatively, for a polyamide 66 under the same temperature and thread rotation conditions, the viscosity would be 35.06 Pa.s. Thus, the ranges of values reported were obtained from experiments and calculations of resistant torque developed, viscous heating and pressure increase for ABS (pure or mixed with AI2O3 powder and SEBS powder).

[075] ABS, being a copolymer obtained from the mixture of SAN (styrene-acrylonitrile) with rubber (butadiene), is therefore considered an amorphous polymer, which has a softening around 105 ° C, since the term fusion is not commonly used for amorphous materials.

[076] In addition, as the polymer processing temperatures are around 250 ° C and since ABS has an average processability for extrusion (there are polymers with very low extrusion processability, such as PEUAPM), it is considered that equipment designed to be suitable for pure polymers, such as ABS, PLA, PCL, or mixed with ceramic or metallic powder additives, such as AI2O3, T1O2, W, hydroxyapatite, tricalcium phosphate, these in small quantities, less than 5%.

[077] Regarding the liquids that can be used, previously melted or softened polymers, such as PLA, PCL, PC, can be included to obtain blends, or even polymers in solution, such as PVA.

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28/29 [078] As can be seen in Figure 6, the extruder device 100 deposits the material on the deposition base 12, which consists of a table that can move in the Z direction, controlled by a microprocessor to control the equipment. The displacement of the table and the head follows the positioning and displacement speed information generated by the slicing software of three-dimensional models (e.g. Slic3r). The information is transmitted from the central processing unit (computer CPU) to a microcontroller (eg Arduino), which in turn controls the movement of the stepper motors coupled to the movement axes of the printing platform (structure) and the reduction / extruder device transmission.

[079] Those skilled in the art will value the knowledge presented here and will be able to reproduce the invention in the modality presented and in other variants, covered by the scope of the attached claims.

LEGEND OF THE DESCRIPTIVE REPORT AND LIST OF FIGURE ELEMENTS

- Electric drive motor

- Speed reduction system

- Torque transmission mechanism

- Pair of couplings

- Modular feeding silo

- Twin screw extruder set

6A - Spindles

6A '- Circular section

6A ”- Hexagonal section

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6A ”'- Threaded circular section

6B - First transport element

6C - Hexagonal hole

6D - Second transport element

6E - Direction favorable to flow

6F - First mixing or mixing block

6G - Direction contrary to flow

6H - Second mixing or mixing block

6J - Third transport element

6K - Hexagonal hole

6L - Pair of fasteners

- Modular container or barrel

7A - Circular openings

7B - Pair of barrel flanges

7C - Flange recess

7D - Barrel fixing means

- External heater (s)

- Modular matrix set

9A - Adapter

9B - Die flange

9C - Die recess

9D - Matrix fixation means

9E - Threaded sleeve

9F - Extrusion nozzle

- Support plate

- Clamp

- Deposition base

100 - Extruder device

200 - Extruder head

Claims (20)

1. Double-screw, vertical and modular screw extruder, the device (100) comprising an electric drive motor (1), a speed reduction assembly (2), a torque transmission mechanism (3), an extruder head ( 200) and a support plate (10) provided with at least one clamp (11); the extruder head (200) characterized by the fact that it comprises: two couplings (4); a modular feeding funnel (5); a twin screw extruder assembly (6), comprising: one pair in spindles (6A); one pair in first elements carriage (6B); one pair in second elements carriage ( 6D); one pair in first blocks of suitcase (6F) ^; one pair in second blocks of malaxing (6H); one pair in third elements carriage (6J); one pair in fastening elements (6L); a container modular or barrel (7 ); at least one external heater ( 8); and a modular matrix set (9). 2. Extruder device according to claim 1, characterized by the fact that each spindle (6A) of the twin screw extruder assembly (6) comprises a circular section (6A '), a hexagonal section (6A) and a threaded circular section (6A'). 3. Extruder device according to claim 1, characterized by the fact that the first transport element (6B) has a double thread, presenting a thread pitch of 18 mm, a total length of 18 mm and a hexagonal hole Petition 870170081405, of 10/24/2017, p. 37/51 2/6 central (6C); the second transport element (6D) has a double thread, presenting a thread pitch of 12 mm, a total length of 24 mm and a central hexagonal hole (6C); of the first suitcase block (6F) be equipped with double fillet discs, comprising eight 3.5 mm thick prismatic discs, stacked with 45 ° angular offset in the direction favorable to the flow (6E), total length of 28 mm and with central hexagonal hole (6C); the second mala block (6H) is equipped with double fillet discs, comprising 12 prismatic discs with a thickness of 2 mm, stacked with an angular offset of 45 ° in the opposite direction to the flow (6G), total length of 24 mm and a central hexagonal hole (6C); and the third transport element (6J) has a double thread, presenting a thread pitch of 18 mm, a total length of 18 mm and a central hexagonal hole (6C). 4. Extruder device according to claim 2 or 3, characterized in that each thread of the twin screw extruder assembly (6) is provided with a spindle (6A), a first transport element (6B), a second transport element (6D), a first suitcase block (6F), a second suitcase block (6H), a third transport element (6J) and a fastener (6L); wherein the arrangement of each spindle (6A) being, the first transport element (6B) positioned and limited by the circular section (6A '), the second transport element (6D) being limited in the direction of the circular section (6A ') by the first transport element (6B), the first suitcase block (6F) being limited in the direction of the circular section (6A') by the second transport element (6D), the Petition 870170081405, of 10/24/2017, p. 38/51 3/6 second trunk block (6H) being limited in the direction of the circular section (6A ') by the first trunk block 6F), the third transport element (6J) being in the direction of the circular section (6A ') by the second limited trunk block (6H) and limited in the direction of the threaded section (6A') by the fixing element (6L). 5. Extruder device according to claim 1, characterized by the fact that the modular container or barrel (7) has a prismatic shape with two circular openings (7A) and diametrically spaced from each other at a distance between 10.1 mm and 10.5 mm. 6. Extruder device according to claims 4 and 5, characterized in that the twin screw extruder assembly (6) is centrally arranged in the two openings (7A) of the modular container 7). 7. Extruder device according to claim 1, characterized by the fact that the modular matrix set 9), understand an adapter 9A), a threaded sleeve (9E) and an extrusion nozzle (9E). 8. Extruder device according to claim 1, characterized by the fact that the electric drive motor (1) is mechanically associated with the reduction mechanism (2) and this, with the torque transmission mechanism (3). 9. Extruder device according to claim 1, characterized by the fact that the torque transmission mechanism (3) drives the pair of spindles 6A) with the same speed and direction of rotation. 10. Extruder device, according to the Petition 870170081405, of 10/24/2017, p. 39/51 4/6 claims 1 or 7, characterized by the fact that the modular matrix set (9) is associated with the lower end of the barrel (7) and that a pair of external heaters are associated with the barrel (7) and connected to a temperature control. 11. Double-screw extrusion process using the corroborative, vertical, double-screw extruder device (100) defined in claims 1 to 10, characterized by the fact that it comprises the steps of: I. Feed the silo (5) with raw material and to determine the trajectory information and parameters of operation; II. Activate the twin screw extruder assembly (6); III. Transport the raw material for the first few transport elements (6B); IV. Compress and start melting the raw material for the second transport elements (6D); V. Mix dispersively and melt / soften completely the raw material for the first blocks of malaxing ( 6F); SAW. Mix distributively and pressurize the raw material for the second mala blocks (6H) with reverse transport action; VII. Transport and compress the material homogenized and mixed by the third transport elements (6J); VIII. Direct material flow through adaptation (9A), glove threaded (9E) to the extrusion nozzle (9F); and IX. Extrude the product and / or deposit the filament on the deposition platform (12). Petition 870170081405, of 10/24/2017, p. 40/51 5/6 12. Process, according to claim 11, characterized by the fact that, in step I, the raw material in powder, liquid or viscous paste is formed by pure or mixed polymers, solutions, suspensions, with or without additives or reinforcements of a metallic or ceramic nature and manually inserted into the silo (5) in the form of a funnel. 13. Process according to claim 12, characterized by the fact that in step I, information about the head trajectory, generated by software, must be provided, as well as information about the rotation speed of each screw in the twin screw extruder set (6) and the temperature of the external heaters (8). 14. Process, according to claim 12, characterized by the fact that, in step II, the activation of the torque transmission mechanism (3) and the speed reduction system (2) by the electric motor (1) promotes movement of rotation of the spindles (6A), which, in turn, promotes the rotation of the twin screw extruder assembly 6). 15. Process, according to claim 12, characterized by the fact that, in step III, the first conveying elements (6B), with a higher pitch, start the rapid transport of the raw material, towards the extrusion nozzle (9F ). 16. Process, according to claim 12, characterized in that, in step IV, the reduction of the step of the second transport elements (6D) compresses the material at a 1.5: 1 ratio, so that the heat generated by friction and by external heaters (8) start to Petition 870170081405, of 10/24/2017, p. 41/51 6/6 melting of the material. 17. Process, according to claim 12, characterized by the fact that, in step V, the material is subjected to shear and elongation that allows the breaking of agglomerates in the first suitcase blocks (6F) due to the passage between the end of wide fillets and the barrel wall (7), mixing dispersively. 18. Process, according to claim 12, characterized by the fact that, in step VI, the material must remain between the second mala blocks (6H) of narrow disks, partitioning the flows and mixing distributively, increasing the pressure and temperature as a function of the opposite direction of transport of the block and as a function of the amount of material coming from the first (6B) and second (6D) transport elements, which generates pressure between 2 and 5 MPa responsible for pushing the accumulated material between the packing discs . 19. Process, according to claim 12, characterized by the fact that, in step VII, the material is compressed at a ratio of 1.2: 1 by the third transport elements (6J), ensuring the uniformity of the material. 20. Process according to claim 12, featured by the fact in, in step VIII, the flow in material be directed for the mouthpiece extrusion (9F), and in step IX, the product to be extruded and / or deposited in successive layers on the deposition base (12).