DE102020214890A1 - Additive manufacturing process - Google Patents

Abstract

The invention relates to an additive manufacturing method, in which an object (20) is manufactured in that a thermoplastic structural material (22) is at least plasticized by heating and is applied in horizontal layers (21) to a base body (15) and solidifies. In order to enable the production of a mechanically resilient workpiece by melt coating, the invention provides that an electrically conductive conductor material (23) is applied in certain areas in order to produce conductor structures (24) within the object (20), and an electric current (1) within the Conductor structures (24) is produced, whereby layers (21) of the construction material (22) are heated at least in regions and at least plasticized, whereby their connection is strengthened.

Description

The invention relates to an additive manufacturing method.

There are currently various methods that can be used to produce three-dimensional models based on design data from amorphous or form-neutral materials such as powders (possibly with the addition of a binder) or liquids (including solids that are sometimes melted or plasticized). These methods are also known under collective terms such as "rapid prototyping", "rapid manufacturing" or "rapid tooling". A primary shaping step often takes place here, in which the starting material is either liquid from the outset or is liquefied or plasticized in the meantime and hardens at the intended location. A known method here is so-called melt coating (fused deposition modeling, FDM, also referred to as fused filament fabrication, FFF), in which a workpiece is built up in layers from thermoplastic material. For example, the plastic is fed in strand form, melted and applied in molten form by a print head, which successively applies individual, usually horizontal layers of the object to be produced. In this case, the individual layer is normally made up of strands or threads, but possibly also of individual drops.

Fusion coating is the most commonly used additive manufacturing process because it is comparatively inexpensive and easy to implement and delivers good quality. It can be realized with simple desktop printers, but is also used in various branches of industry using high-quality 3D printers. A major weak point of the process is the often insufficient cohesion of the individual layers with each other, i.e. the vertical cohesion. This is mainly due to the fact that when a layer is applied, the layer underneath is completely solidified and contact with the hot, liquid material of the new layer cannot normally cause it to melt or plasticize again. Under certain circumstances, a locally limited, minor melting can occur, which means that macromolecules can bond in the border area of the layers. Overall, however, the macromolecules of the thermoplastics used cannot become entangled with one another, or only to a small extent, since the plastic material from the previous layer has already cooled and the mobility of the macromolecules is therefore severely restricted. In addition, the macromolecules are aligned in the direction of movement of the print head, which also has a negative effect on the mechanical properties across the individual layers. This means that the connection has a relatively low resilience, which is why in many cases the manufactured component can only be used as a prototype for illustrative purposes. It is generally not possible to use mechanically resilient components for series production.

One way to improve vertical cohesion is to reheat the already applied top layers with a laser so that fusion occurs. However, this option is difficult to implement because the movement of the laser must be coordinated in space and time with the printing process. In addition, some materials are difficult to heat with a laser because they absorb the laser radiation - depending on the wavelength - only insufficiently.

the US 2015/0352785 A1 discloses a method for creating a three-dimensional object from digital data representing the object. In a first step, a first layer of particulate material is provided and at least a first portion of the first layer of particulate material is consolidated to form a consolidated first cross-section of the object. A first part of a conductive material is then applied to the solidified first cross section. This is followed by applying a second layer of particulate material to the consolidated first cross-section of the first layer and consolidating at least a second portion of the second layer of particulate material to form a consolidated second cross-section of the object.

In view of the state of the art shown, the manufacture of a mechanically resilient workpiece by melt coating still offers room for improvement. This applies in particular to the option of using simple means to improve the cohesion of the individual layers of the workpiece.

The invention is based on the object of making it possible to manufacture a workpiece that can be subjected to mechanical loads by melt coating.

According to the invention, the object is achieved by an additive manufacturing method with the features of claim 1, with the dependent claims relating to advantageous configurations of the invention.

It should be pointed out that the features and measures listed individually in the following description can be combined with one another in any technically sensible way and further developments of the invention show The description additionally characterizes and specifies the invention, in particular in connection with the figures.

An additive manufacturing method is made available by the invention. The process can be assigned to the field of rapid prototyping or rapid manufacturing. However, it is not only suitable for the production of prototypes or individual models, but also for series production.

In the manufacturing method according to the invention, an object is manufactured in that a thermoplastic construction material is at least plasticized by heating and is applied in horizontal layers to a base body and solidifies. The thermoplastic construction material is usually the material from which the finished object mainly consists after completion of production. The construction material is thermoplastic, i.e. it is a plastic that can be brought into a plastic or liquid state by heating and solidified again by cooling, which can in principle be repeated several times, although there are practical limits to the repeatability, since each When heated, the macromolecules within the plastic break off and shorten. This leads to a deterioration in the mechanical properties, in particular the plastic becomes increasingly brittle. The thermoplastic materials that can be used include, for example, polyethylene (PE), polypropylene (PP), polycarbonate (PC), polyetheretherketone (PEEK), polylactide (PLA), acrylonitrile butadiene styrene (ABS), acrylonitrile styrene Acrylate (ASA), polyethylene terephthalate (PET), glycol modified polyethylene terephthalate (PETG) and thermoplastic elastomers. In this context, the thermoplastic structural material can have different additives in addition to the actual thermoplastic. For example, fibers (to improve mechanical properties) or solid particles (to increase density, improve conductivity, color, etc.) can be embedded in the plastic. It goes without saying that these additives are generally not thermoplastic themselves, but the construction material can nevertheless be processed like a (pure) thermoplastic. The construction material is heated in such a way that it is at least plasticized or reaches the thermoplastic state in which it is no longer dimensionally stable but can be plastically deformed. This state can also be characterized as semi-liquid. Under certain circumstances, the liquid or free-flowing state can also be achieved. Although the invention is not limited thereto, the build material is usually fed in filamentary or strand-like form in solid form to a heating device, which is followed by a dispensing device (e.g. a nozzle), which can be associated, for example, with the print head of a 3D printer. The building material can be released in a controlled manner via the release device, for example by extrusion. After dispensing, the build material cools and solidifies. This process can be classified as fused deposition modeling (FDM) or fused filament fabrication (FFF).

The object is built up in layers or layer by layer on a base body, which means that the bottom layer is applied directly to the base body, while the subsequent layers are successively applied on top of each other on the bottom layer. In this context, the direction or level of progression of the layers is referred to as “horizontal”. Usually, but not necessarily, this also corresponds to the horizontal direction with respect to gravity, i.e. the planes are perpendicular to the direction of gravity. The application of the building material is, of course, machine-controlled based on specified data (e.g. CAM data) that correspond to the three-dimensional shape of the object to be finished. To a certain extent, each layer corresponds to a cross-section through the finished object. Normally, one layer at a time is completed before the next layer is applied. However, if the object is composed of several non-contiguous areas in some layers, for example, it would also be conceivable to first apply the layers of one area on top of one another and then the layers of another area. To produce a layer, the above-mentioned dispensing device or the print head can be moved horizontally in two dimensions according to a predetermined pattern, e.g. line by line or spirally, and in the process dispense building material. After the layer is completed, either the dispenser can be raised according to a layer thickness or the base body could be lowered according to a layer thickness.

The base body to which the bottom layer is applied preferably has a flat surface that runs horizontally, that is to say parallel to the intended direction of the layers. However, deviations from this are also possible, in which case the surface is not flat but, for example, curved. The base body can in particular also be designed as a base plate or base plate. Under certain circumstances it can be heated during the application of the layers in order to improve the adhesion of the bottom layer.

According to the invention, an electrically conductive conductor material is applied in regions to produce conductor structures within the object, and an electric current is generated within the conductor structures, whereby layers of the construction material are at least locally heated and at least plasticized, thereby strengthening their connection. This means that while the object consists partially, normally predominantly, of the construction material, which can generally be regarded as an electrical insulator, an electrically conductive conductor material is applied in certain areas. The application of the conductor material is part of additive manufacturing, ie it can be applied in an amorphous state, for example as a strand or drops. During the application, the conductor material can also be in a plastic or liquid state, with it preferably changing to the solid state after application. In contrast to the construction material, however, the conductor material does not have to be plasticizable or liquefiable again. The conductor material could be, for example, a conductive plastic, ie a material in which conductive particles are incorporated in a plastic matrix that is not conductive per se. The conductive additive is usually metal particles, but may also be a non-metallic conductive material such as graphite. The conductor structures, like the rest of the object, can be created by melt-coating.

By applying the conductive material, conductive structures are produced within the object, which in the finished object are normally completely or predominantly surrounded by the construction material. At least in sections, the individual conductor structure can be designed in a simple line-like manner (that is to say one-dimensionally), branched or unbranched, or else areally (that is to say two-dimensionally). If multiple conductor structures are discussed here, this does not rule out the possibility of multiple conductor structures being conductively connected to one another within the object. At least one conductor structure should preferably be produced in each layer or at least adjacent to each layer of the object. The distance between two adjacent conductor structures can be selected differently, but normally corresponds to at most a few layer thicknesses, for example at most 5 or at most 3 layer thicknesses. A maximum value for the distance between two conductor structures can be defined and the conductor structures can be planned and manufactured in such a way that the maximum value is not exceeded.

According to the invention, an electric current is generated within the conductor structures, as a result of which layers of the construction material are heated at least in regions and at least plasticized, whereby their connection is strengthened. The electrical current can be direct current or alternating current. In the method according to the invention, it is fundamentally not essential that a specific strength of the current is set exactly, i. H. For example, a voltage can also be set, so that the current intensity is set depending on the physical configuration of the respective conductor structure. When the electrical current flows through the conductor structures, part of the electrical energy is converted into heat, which is based in particular on the electrical resistance of the conductor material. As a result, the conductor structures are primarily heated and, secondarily (by thermal conduction), the structural material adjacent to the conductor structures is heated. In the case of alternating current, direct heating of the construction material is also conceivable, e.g. due to dielectric losses. The conductor structures can thus act to a certain extent as electrical heating elements or heating wires within the object. The temperature of adjacent layers of the construction material increases at least in certain areas in such a way that the construction material is at least plasticized or even becomes liquid and fuses. Depending on the material of the conductor structures, it is conceivable that these too partially plasticize or liquefy and fuse in themselves or with the construction material. For example, this can happen if the conductor structures are formed from a conductive plastic that is based on a thermoplastic that has a similar or even lower melting point than the construction material. By plasticizing or fusing the layers at least in some areas, the connection between the layers is strengthened and, after the building material has solidified again, a solid body with improved cohesion and higher mechanical strength is formed. In order to initiate the solidification of the building material, the electrical current can be reduced or switched off.

With the method according to the invention, an object can be produced by melt coating that has good cohesion not only in one layer plane (i.e. horizontal), but also between the layers (i.e. vertical) and thus a mechanical stability that is sufficient for many applications where an object manufactured by conventional melt coating cannot be used. The process does not require the use of lasers. The conductor structures, like the rest of the object, can be 3D-printed, e.g. by melt-coating using a conductive plastic that serves as the conductor material. Such a print with two different materials can be carried out without any problems. The difficulties that arise with regard to the coordina tion of the laser beam with the printing process in the prior art are omitted here. The generation of electricity, on which the heating and joining of the layers is based, can also be easily carried out using different methods, which will be discussed below. The temperature required for plasticizing or fusing, as well as the heating time, can be controlled with great accuracy via the characteristics of the current. Finally, the process can be used with all construction materials, since the heating is not based on the very different absorption of laser light depending on the material, but on heat conduction between the conductor structures and the adjacent construction material, which is usually always sufficient.

If the object has overhanging or projecting areas that would not have a vertical connection to the base body, support structures can be created on the object that are connected to the base body and are removed after the object is finished. The supporting structures, which like the rest of the object can be created by applying the building material in layers, are purely auxiliary structures that are not part of the desired final shape of the object. They are used to stabilize the object during production and possibly immediately afterwards, for example to prevent the object from tipping over. Such support structures may take the form of brackets, hangers, pillars, stilts or the like. Since these support structures are removed anyway after the object has been completed, they usually do not have to contain conductor structures, since the cohesion between the individual layers within the support structures does not have to be particularly strong and plasticizing or fusing these layers is therefore not necessary. Nevertheless, in some cases it can be useful to provide conductor structures in the support structures, e.g. to create connections to conductor structures within the actual object for optimal conduction of the current.

Process configurations are conceivable in which heating and plasticizing or fusing by means of electricity takes place during the construction of the object, e.g. in such a way that several layers including conductor structures are built up and connected by heating before further layers are built up. In general, however, it is more efficient if the electricity is generated after all layers of build material have been applied. One could also say that here the three-dimensional form of the object is completed and then the current is generated in the conductor structures in order to carry out the connection or fusion of the layers with one another. This is advantageous, among other things, because it avoids parts of the object being melted multiple times, which could entail the risk of deformation or deterioration of the construction material, for example. Additionally, such multiple reflow is typically unnecessary and thus inefficient. In addition, when the conductor structures and the surrounding material are heated, the three-dimensional shape of the conductor structures can change or locally completely dissolve. For this reason, too, (single) heating after the application of all layers of the building material is advantageous.

The construction material and the conductor material are preferably applied by two dispensing devices mounted in a stationary manner in relation to one another. The dispenser may be two nozzles on a common printhead. The print head is guided horizontally so that the respective dispensing device (e.g. nozzle) is arranged in the intended position for material dispensing. Due to the constant distance between the two dispensing devices, both the adjustment and the control of the print head are particularly simple. In addition, only the two- or three-dimensional movement of a single print head needs to be controlled.

Under certain circumstances it would be conceivable for the conductor material to be applied at least in regions between two layers of the construction material. However, this would generally entail problems with regard to the dimensionally accurate creation of the object, since the additional volume of the conductor material between the layers would have to be taken into account. It is therefore preferred that building material and conductor material are applied spatially alternately within a layer. Thus, within a layer there are areas that are made of structural material and other areas that are made of conducting material. The two materials are thus arranged next to one another in the horizontal direction. Structural material and conductor material are applied alternately in space within a layer, which does not necessarily mean that they are applied alternately in time. For example, it would be possible for all of the construction material of a layer to be applied first, leaving gaps into which the conductor material is then applied.

At least one continuous conductor structure is preferably produced, which extends vertically over a plurality of layers. The corresponding conductor structure thus forms a conductive connection via the plurality of layers mentioned. It extends vertically over a plurality of layers, and in particular it can run at least partially vertically. In this case will Conductor material is applied in a plurality of layers at the same position within the horizontal plane, resulting in a column-like structure of the conductor material overall. If current flows through such a conductor structure, it can lead to local plasticization or melting of all layers over which it extends. In particular, the conductor structure can extend in the vertical direction over all layers that are present in this area of the object.

It can further be preferred that a plurality of horizontally spaced conductor structures are produced. In particular, these conductor structures can extend or run vertically as described above. You can form a kind of grid or grid within the object that extends over all areas of the object. The horizontal distance between respectively adjacent conductor structures could be chosen to be constant, so that each conductor structure can be assigned a certain area of the object in the horizontal direction, which is heated by it. A possible advantage of horizontally spaced conductor structures, for example in contrast to horizontally connected conductor structures, can be that when a voltage is applied in the vertical direction, the individual conductor structures at issue have a greater resistance, which can lead to faster and more effective heating.

Under certain circumstances, however, it can also be advantageous if at least one conductor structure is produced which at least partially extends horizontally within a layer. This can be advantageous in particular when the object has a more complicated shape in which purely vertical conductor structures are difficult to arrange. Such a horizontally running conductor structure can be used, for example, to create a branch in an otherwise vertical conductor structure or to create a cross-connection between vertically running conductor structures.

There are different options for generating electricity. If an alternating current is generated, it can be generated contact-free, so to speak, by an alternating electric and/or magnetic field. In particular, a time-varying polarization of the conductor structures can be achieved by an alternating electrical field. A voltage can be induced in the conductor structure by an alternating magnetic field, which in turn generates a current. The frequency and strength of the alternating field can be adjusted in such a way that optimal heat conversion is achieved within the conductor structures. In this case, the conductor structures could, for example, be completely surrounded by the construction material. In general terms, one can say that the current is generated in at least one conductor structure without contact by the action of an electromagnetic alternating field. The current is thus generated by (electromagnetic) induction and/or induction (electrostatic induction). The term "contactless" refers to the fact that the conductor structure itself is not brought into electrical contact with an electrode or other external conductor. Under certain circumstances, an electrode can contact the object, although electrical contact with the conductor structure is prevented by the construction material lying in between. In particular, the at least one conductor structure can be insulated from all surfaces of the object by building material. It may be advantageous in this embodiment that the conductor structures cannot be seen on the surface of the object.

According to another embodiment, at least one conductor structure is produced, which has at least one externally accessible contact point on a surface of the object, with the current being generated by an electrical potential being applied to the at least one contact point. One could say that the point of contact is brought into contact with an electrode, the electrode carrying a potential that is thus applied to the point of contact. The contact point is of course a part of the conductor structure that is accessible from the outside of the surface of the object or that forms part of the surface of the object. The corresponding contact point can, for example, be arranged on the side of the object in the horizontal direction or on an upper side or underside of the object in the vertical direction. In the latter case, the contact point might be in direct contact with the base body during manufacture of the object.

In the above embodiment, it would be conceivable that the conductor structure has only one contact point and is excited with a potential that changes over time, as a result of which an alternating current flows through the conductor structure. However, it is often advantageous to generate a direct current as the heating current. In this case, at least one conductor structure is produced, which has two contact points, with the current being generated by applying an electrical voltage to the contact points. For example, the contact points could be located on opposite sides of the object. There could be a first point of contact at the bottom of the object while a second point of contact is at the top. The two contact point can touch two electrodes are brought, which have different potentials or between which an electrical voltage is applied. Due to the electrical voltage between the contact points, a current flows between them through the conductor structure.

Since the object normally has a certain stability before the layers have been connected to one another in the manner according to the invention, it can in principle be removed from the additive manufacturing device, e.g. the 3D printer, and the layers can be connected elsewhere. However, it would also be conceivable for the current to be generated while the object is arranged on the base body. This means that the layers can be connected immediately after the actual additive manufacturing by melt coating, i.e. within the same device as the application of construction material and conductor material. In this case, the conductor structures could have contact points on the underside, for example, which are in direct contact with the base body, and an electrical potential could be applied to the base body. If the conductor structures each have two contact points, a counter-electrode can be brought up to the respective other contact point, so that the current is generated via a voltage between the two electrodes. The base body could also form an electrode in the manner of a capacitor plate, by means of which an alternating electric field is generated, by means of which a current is generated within the conductor structures without contact.

• 1 - 5 verschiedene Phasen der Fertigung eines Objekts gemäß einer ersten Ausführungsform des erfindungsgemäßen Verfahrens; sowie
• 6 eine Phase der Fertigung eines Objekts gemäß einer zweiten Ausführungsform des erfindungsgemäßen Verfahrens.

Further advantageous details and effects of the invention are explained in more detail below with reference to exemplary embodiments illustrated in the figures. Show it

• 1 - 5 different phases of the production of an object according to a first embodiment of the method according to the invention; such as
• 6 a phase of manufacturing an object according to a second embodiment of the method according to the invention.

In the different figures, the same parts are always provided with the same reference numbers, which is why they are usually only described once.

1 and 2 12 schematically show the layered structure of an object 20 during a first phase of a first embodiment of the method according to the invention. A 3D printer 10 with a print head 12 having a first nozzle 13 and a second nozzle 14 can be seen. The print head 12 is arranged on a suspension 11, which is shown here in a greatly simplified manner. As indicated by the double arrows, the print head can be moved both in the horizontal direction along an X-axis and a Y-axis and in the vertical direction along a Z-axis. The 3D printer 10 also has a stationary base plate 15 . A construction material 22 consisting of a thermoplastic material can be extruded via the first nozzle 13 of the print head 12 . The building material 22 can be fed to the print head 12 as a strand-like filament by means of a feed device (not shown here) and is at least plasticized or possibly also liquefied within the print head 12 before it is discharged through the first nozzle 13 .

The build-up material 22 is applied according to CAM data, which represent the intended three-dimensional shape of the object 20 . However, the application does not take place without gaps, but a conductor material 23 is applied spatially alternating with the construction material 22 and is extruded via the second nozzle 14 . Conductor material 23 can be a conductive plastic that has, for example, a thermoplastic matrix in which conductive particles are embedded. The conductor material 23 can also be fed to the print head 12 as a strand-shaped filament and can be heated and plasticized in a similar manner to the construction material 22 .

As in 1 - 4 is clearly recognizable, the structure of the object 20 takes place in horizontal layers 21. By applying the conductor material 23, a plurality of horizontally spaced conductor structures 24 within the object 20 is produced. Each of the conductive patterns 24 extends vertically through all of the layers 21. Most of the conductive patterns 24 are straight and unbranched parallel to the Z-axis. However, two of the conductor structures 24 shown have a branch and each have a horizontal section 24.1. Despite the irregular shape of the object 20, this shape of the conductor structures 24 ensures that no area of the object 20 is further away from a conductor structure 24 than a certain predetermined maximum distance.

After all layers 21 have been applied as in 3 is shown, the conductor structures 24 each extend from at least one lower contact point 25 on the base plate 15 to an upper contact point 26. The contact points 25, 26 are each arranged on the surface of the object 20 and are therefore accessible from the outside. Each of the layers 21 of the object 20 has good mechanical cohesion in itself, ie in the horizontal direction. In contrast, the cohesion of the layers 21 in vertical direction, i.e. comparatively weak along the Z-axis.

In order to eliminate this problem, after the object 20 has actually been manufactured layer by layer, the layers 21 are connected by generating a current I within the conductor structures 24 . For this purpose, a voltage U is applied between the lower contact points 25 and the upper contact points 26 . The base plate 15 forms a first electrode 17 which is connected via a voltage source 16 to a second electrode 18 which is brought up to the upper contact points 26 and brought into contact with you. After the electrical contacts have been made, the voltage source 16 is switched on and the current I flows, which can be embodied in particular as a direct current, but possibly also as an alternating current. It goes without saying that the entire current 1 does not flow through the individual conductor structure 24 since the conductor structures 24 are connected in parallel with respect to the voltage source 16 . Due to the electrical resistance within the conductor structures 24, electrical energy is converted into heat, which leads to heating of the conductor material 23 of the conductor structures 24 and also to heating of the surrounding structural material 22. Finally, at least local or area-wise plasticization or even liquefaction of the building material 22 occurs, with material from different layers 21 connecting to one another and possibly fusing. After this has happened, the voltage source 16 is switched off and the building material 22 solidifies again. However, the layers 21 are no longer or hardly recognizable and an overall coherent body has emerged, as in 5 is shown. As also in 5 As can be seen, the layers within the conductor material 23 are also connected or fused to one another as a result of the heating.

In 5 the conductor structures 24 are still shown as separate from the surrounding construction material 22 . However, depending on the temperature curve and the composition of the structural material 22 and the conductor material 23 , the conductor structures 24 can also fuse with the surrounding structural material 22 . This is particularly the case when the thermoplastic matrix of the conductor material 23 is identical to the construction material 22 . In this case, the fusing can go so far that the conductor structures 24 only differ from the surrounding structural material 22 by the accumulation of conductive particles present there.

6 shows schematically a phase of a second embodiment of the method according to the invention. This corresponds in this respect 4 , when the object 20 including the conductor structures 24 has already been manufactured and now the individual layers 21 are to be connected to one another. In contrast to the first embodiment, the conductor structures 24 have no contact points 25, 26 and are therefore insulated from the surfaces of the object 20. The second electrode 18 does not even touch the object 20. In this case, an alternating voltage U is applied between the electrodes 17, 18 via the voltage source 16, which leads to an alternating electromagnetic field EM. At lower frequencies of the alternating field EM, this can be dominated by the electrical components; magnetic components are also present, at least qualitatively.

A contactless current is generated within the conductor structures 24 by the alternating field EM. The strength of this current is of course generally different from that of the current I flowing between the electrodes 17,18. The generation of electricity can be based on induction (or electrostatic induction) and partly on (electromagnetic) induction. At the in 6 shown structure, the alternating field EM is normally dominated by the electrical components. Alternatively, a predominantly alternating magnetic field EM could also be generated, for example by arranging one or more coils in the base plate 15 . Likewise, one or more coils could be arranged above the object 20 instead of the second electrode 18 . In this case the shape and arrangement of the conductor structures 24 could be adjusted in order to optimize the electromagnetic induction. In any case, the contactless generation of the current also leads to an at least local or regional plasticization or even liquefaction of the construction material 22, with material from different layers 21 connecting to one another and possibly fusing. It may be advantageous in this embodiment that the conductor structures 24 cannot be seen on the surface of the object 20 .

Reference List

10

3D printer

11

suspension

12

printhead

13:14

jet

15

base plate

16

voltage source

17, 18

electrode

20

object

21

layer

22

construction material

23

conductor material

24

ladder structure

24.1

horizontal section

25, 26

contact point

EM

alternating electromagnetic field

1

electricity

u

tension

X

X axis

Y

Y axis

Z

Z axis

QUOTES INCLUDED IN DESCRIPTION

This list of the documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• US 2015/0352785 A1 [0005]

Claims (10)

Additive manufacturing method, in which an object (20) is manufactured in that a thermoplastic construction material (22) is at least plasticized by heating and is applied in horizontal layers (21) to a base body (15) and solidifies, in which case an electrically conductive conductor material (23) is applied in order to produce conductor structures (24) within the object (20), and an electric current (1) is generated within the conductor structures (24), as a result of which layers (21) of the construction material (22) are heated at least in regions and at least plasticized, thereby strengthening their connection. manufacturing process claim 1 , characterized in that the current (1) is generated after all layers (21) of the construction material (22) have been applied. Manufacturing method according to one of the preceding claims, characterized in that the construction material (22) and the conductor material (23) are applied by two dispensing devices (13, 14) mounted stationary with respect to one another. Manufacturing method according to one of the preceding claims, characterized in that structural material (22) and conductor material (23) are applied alternately spatially within a layer (21). Manufacturing method according to one of the preceding claims, characterized in that at least one coherent conductor structure (24) is produced, which extends vertically over a plurality of layers (21). Manufacturing method according to one of the preceding claims, characterized in that a plurality of horizontally spaced conductor structures (24) are produced. Manufacturing method according to one of the preceding claims, characterized in that at least one conductor structure (24) is produced, which at least partially extends horizontally within a layer (21). Manufacturing method according to one of the preceding claims, characterized in that the current (1) in at least one conductor structure (24) is generated contactlessly by the action of an electromagnetic alternating field (EM). Manufacturing method according to one of the preceding claims, characterized in that at least one conductor structure (24) is produced which has at least one externally accessible contact point (25, 26) on a surface of the object (20), the current (1) being generated by an electrical potential being applied to the at least one contact point (25, 26). Manufacturing method according to one of the preceding claims, characterized in that the current (1) is generated while the object (20) is arranged (15) on the base body.

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