DE102017003495A1 - Process for the production and modeling of shaped articles by layer melting of metal and ceramic powder filled filaments - Google Patents

Abstract

The core idea of the present invention is that metal or ceramic powder are mixed with an organic binder and then extruded into a solid filament. This filament is then modeled in a layer-melting process to form a freely determinable shaped body. Subsequently, the organic binder is chemically removed and the remaining metal or ceramic structure is densified in a thermal process.

Description

For the production of metal or ceramic components with complex geometries made of difficult-to-machine materials such as stainless steel, carbide or titanium, so far only machining methods and selected non-cutting manufacturing processes are available. In machining, a complex geometry leads to very long machining times and a high degree of machining. The materials required in each case can lead to excessive tool wear.

If such a component is manufactured using an alternative non-cutting shaping process, the investment casting and the metal injection molding method (MIM) are generally available. Precision casting is only suitable for a small part of the applications due to its high tolerances and low surface quality. MIM, on the other hand, is a modern manufacturing process that combines the outstanding properties of metallic materials with the complex design possibilities of plastics technology. The shaping by the injection molding of metal powders opens a maximum of freedom in terms of geometry and material, which is far beyond the possibilities of metal cutting and fusion metallurgical design. The use of expensive, high-strength alloys, corrosion-resistant or other high-grade stainless steels is possible because no costs are incurred by downstream machining. MIM components are characterized by high accuracies, material density and surface quality. A disadvantage is the resulting tooling costs and the long development time which is associated with the production of the molds. It is therefore not surprising that more and more companies are evaluating the industrial use of additive manufacturing technologies. These processes have long been introduced in prototype production, and their use in series production is still rare, as mass production places significantly higher demands on process reliability, process monitoring, traceability and data exchange than on prototype production.

Additive manufacturing processes or 3D printing have progressed far in recent years, so that today high-quality components and components made of different metals can be printed. Numerous applications, for example from the aerospace industry and medical technology, illustrate that additive manufacturing processes in the production of series parts offer completely new possibilities in terms of product design, efficiency, speed and flexibility. By methods such as "3D metal printing" offers the possibilities of the construction of metallic components with hollow and lattice structures as well as projections. 3D metal printing includes the well-known processes such as laser melting, laser sintering and electron beam melting. Based on successful applications, it is now possible to demonstrate that the design of metallic components is no longer guided by the restrictions of manufacturing technology, but component functionality - provided that developers are aware of the design freedom of the generative technologies and the resulting possibilities and apply them selectively.

The inventive ideas relate to a novel generative manufacturing technology that combines the benefits of additive manufacturing with a debinding and sintering process. The process consists of two phases - the additive construction of green parts from extrusion-based metal- or ceramic-filled filaments on the one hand and the subsequent debindering, sintering and reworking of these parts on the other hand. The method underlying the individual inventions is characterized by simple material handling and low costs compared to powder-based generative methods. The construction of a 3D printer for metal- or ceramic-filled filaments, however, is significantly more demanding than that of a printer for conventional plastic filaments and the corresponding process control is more complex.

The first step of the process according to the invention is the production of a so-called feedstock. To produce the feedstock, metal or ceramic powder is first mixed together according to the desired alloy. Subsequently, thermoplastic materials and additives are added and homogenized with the powder mix. In an extrusion process, this mass is processed into a flexible filament. In this case, the starting material is melted in an extruder, compressed in front of a screw conveyor, formed via a nozzle into a filament having a defined (for example round) cross section and then cooled. In an advantageous embodiment, this filament has a cross section of 1 to 3 mm.

In a second process step, this metal- or ceramic-filled filament is modeled in a process of melt stratification into a freely definable body. The resulting molding (green part) consists of metal or ceramic powder and organic binders. It shows the geometry of the later final component on a scaled scale, ie it has a volume increased by the binder content. It has in an advantageous embodiment, a share of about 2 to 30 percent binder and 70 to 98 percent metal or ceramic powder. It is more appropriate Production via a strength similar to thermoplastic plastic parts and a homogeneous powder distribution with or without orientation of the individual particles.

1. 1. Das auf einen Rolle aufgewickelte Filament kann aufgrund seines hohen Eigengewichts und seiner geringen Festigkeit nicht von einer konventionellen Spule heruntergezogen werden ohne seinen Querschnitt zu verändern oder zu zerreißen. Vielmehr muss die Abwickelspule aktiv angetrieben und je nach Abwickelgrad des Filaments mit der Förderbewegung des Druckers synchronisiert werden.
2. 2. Die Förderung des Filaments in Richtung des Druckkopfes erfordert eine sehr genau dosierte Zugkraft und einen gut verteilten Kraftschluss zwischen Antriebseinheit und Filament. Der erfindungsgegenständliche Vortrieb sieht für das Förderrad eine formschlüssige Formgebung abgestimmt auf den Durchmesser bzw. die Kontur des Filaments vor, so dass sich eine maximale Kontaktfläche zwischen Rad und Filament ergibt. Das Förderrad kann durch weitere Förderräder, die durch ein Getriebe angetrieben sind unterstützt werden. Dadurch sinkt der Anpressdruck des einzelnen Förderades und der Vorschub des Filamentes wird genauer.
3. 3. Das vergleichsweise schwere, gut wärmeleitende und leicht zu deformierende Filament wird im Druckkopf aufgeschmolzen und schichtweise als sogenannte „Raupe“ auf dem Formteil als Schmelzschicht abgelegt. Der Filamentvorschub ebenso wie der Filamentdurchmesser werden sensorisch erfasst und mit den Druckparametern koordiniert. Dadurch werden Druckfehler vermieden. Durch die hohe Wärmeleitfähigkeit des Filaments wird der Abschnitt des Filaments welcher sich unmittelbar vor dem Schmelzabschnitt befindet unzulässig warm und somit derart instabil, dass die Fördereinheit das Filament deformieren oder gar zerreißen könnte. Um dies zu verhindern sieht das erfindungsgegenständliche Verfahren eine Thermobarriere bzw. eine Kühlung zwischen der Schmelzzone und der Förderzone des Filaments vor.
4. 4. Bei Nutzung metallgefüllter Filamente leitet der schichtweise entstehende Formkörper aufgrund seines hohen Füllgrades die von dem Schmelzelement eingeleitete Wärme wirksam in die darunterliegenden Schichten des Formkörpers. Beim Drucken von Auskragungen oder feinen Geometrien kann diese Wärme aber nicht mehr hinreichend schnell abgeführt werden. Als Folge schmilzt das Bauteil in diesen Bauzonen lokal auf und verliert die gewünschte Form. Um dies zu verhindern sieht das erfindungsgegenständliche Verfahren eine Kühlung der Druckzone bzw. der unmittelbar abgelegten Druckraupe vor.
5. 5. Um einen thermisch bedingten Verzug des Bauteils zu vermeiden kann das Bauteil abhängig von seiner Geometrie durch in der Grundplatte bzw. der Umrandung eingebrachte Infrarot-Dioden gleichmäßig erwärmt werden. Hierzu wird eine Infrarot-Aufnahme des entstehenden Formkörper gemacht und entsprechend des thermischen Profils eine selektive Ansteuerung der IR-Dioden bewirkt bis das Bauteil gleichmäßige Temperaturen an allen geometrischen Konturen aufweist. Gleichzeitig dient die Infrarotaufnahme zur Baufortschrittskontrolle, da sie einen permanenten Abgleich zwischen Soll - und Ist-Daten des Bauteils durchführt. Bei Auftreten eines Druckfehlers wird der Maschinenbediener informiert und/oder der Prozess gestoppt.
6. 6. Die Genauigkeiten moderner 3D-Drucker bewegen sich im Bereich von ein bis zwei Hunderstel Millimeter. Die von der Schmelzdüse erzeugte „Raupe“ hat in einer vorteilhaften Ausführung eine Breite von 0,1 bis 1,0 mm. Für eine eng tolerierte Fertigung ist es notwendig die Steuerung des Druckers um die halbe Raupenbreite zu korrigieren. Die entstehende Schmelzschichtstufe an der Außenkontur wird durch eine anschließende erfindungsgemäße mechanische Glättung beseitigt. Diese Formkorrektur wird in den Algorithmus der Druckersteuerung mit aufgenommen.
7. 7. Eine optimale Oberflächengüte des späteren gesinterten Bauteils ergibt sich wenn besonders fein fraktionierte Metallpulver verwendet werden. Diese feinen Pulver sind aber aufgrund des höheren Bearbeitungsaufwandes spürbar teurer als gröber fraktionierte Pulver. Das erfindungsgegenständliche Druckverfahren sieht vor mit Hilfe mehrerer Druckköpfe die Randzonen eines Bauteils mit fein fraktionierten Filamenten und die Kernzone mit grob fraktionierten Filamenten zu drucken. Die gleiche Methode kann genutzt werden, um funktionale Schichten aus speziellen Werkstoffen an Stellen des Bauteils anzubringen, an denen sie benötigt werden, z.B. Lager oder Rasten. Darüber hinaus sieht das erfindungsgegenständliche Verfahren vor den Kernbereich zum Zweck der Materialersparnis mit einer Anordnung von kleineren und größeren Hohlkammern zu durchsetzen. Diese Hohlkammern können durch ein FEM-Programm hinsichtlich Größe und Anordnung optimiert werden.
8. 8. Bei Bauteilen mit unterschiedlichen lokalen Anforderungen können verschiedene Metalle mit ähnlichem Schmelzpunkt aber unterschiedlichen Eigenschaften über mehrere Druckköpfe in einem sogenannten Multimaterial-Bauteil kombiniert werden. Dies gilt auch für keramische Werkstoffe.
9. 9. Für den anschließenden Sinterprozess müssen die Formkörper mit einer mitsinternden Unterlage gedruckt werden um einen Verzug durch das Anhaften der Bauteile auf der Aufstandsfläche des Ofens zu vermeiden. Besitzt das zu sinternde Bauteil keine ebene Auflagefläche, müssen die Formkörper während des Sinterprozesses durch eine mitsinternde Unterlage gestützt werden, um einen Verzug infolge der Schwerkraft zu vermeiden. Diese Unterlage wird separat oder gemeinsam mit dem Bauteil gedruckt. Die Unterlage kann in der erfindungsgegenständlichen Ausführung als Vollkörper oder als eine Gitterstruktur gedruckt werden. Sie wird nach dem Sintervorgang verworfen. Zwischen Unterlage und Werkstück ist ein Trennmittel vorzusehen.
10. 10. Alternativ zu einer mitsinternden Unterlage kann eine Sinterauflage aus einem höherschmelzenden Werkstoff - in der Regel Keramik - gedruckt werden. Diese Auflagen dienen zur Abstützung überhängender Abschnitte des Bauteils und werden wiederverwendet. Sie sind in einer vorteilhaften Ausführung als Strebenstruktur und/oder als Rollen ausgeführt. Zwischen Stütze und Bauteil ist ein Trennmittel vorzusehen.
11. 11. Nach Entnahme aus dem Drucker weist das Formteil (Grünteil) eine verfahrenstypische Schmelzschichtstufung auf. Ist die Stufung technisch oder ästhetisch nicht erwünscht, so sieht das erfindungsgegenständliche Verfahren eine Strahlung mit einem weichen Strahlmittel wie beispielsweise PE-Granulat oder dem Bauteile-identischen Feedstock vor. Durch dieses Strahlverfahren werden die Stufen geglättet.
12. 12. Um die Festigkeits- und andere Eigenschaften eines Bauteils optimal zu definieren wird eine Slicer-Software genutzt die es ermöglicht eine gradierte Form des Infills zu erzeugen. Das bedeutet, dass der Übergang von der äußeren Hülle zu den Hohlkammerstrukturen nicht abbrupt sondern allmählich verläuft.
13. 13. Zur Verhinderung des Tropfens (Oozen) nach Aufheizen des Filaments auf Drucktemperatur wird eine verschließbare Druckerdüse verwendet. Der Verschluss wird in einer vorteilhaften Ausführung piezoelektrisch, elektromagnetisch, pneumatisch oder hydraulisch betätigt.

The ideas according to the invention relate to the handling and conveying of the metal-filled filament in and on the 3D printer, the thermal process control in the printer and the subsequent post-processing of the molded part (green part) modeled in the printer. The ideas are based on the peculiarities of the previously described novel generative method: Since the metal- or ceramic-filled filament, in contrast to today well-known plastic filaments, heavy, good heat conducting and mechanically unstable at the same time, the following special precautions have to be taken for its processing:

1. 1. The wound onto a roll filament can not be pulled down by a conventional coil without its cross section to change or tear due to its high weight and low strength. Rather, the supply reel must be actively driven and synchronized with the conveying movement of the printer, depending on the unwinding degree of the filament.
2. 2. The promotion of the filament in the direction of the print head requires a very precisely metered tensile force and a well-distributed adhesion between the drive unit and filament. The inventive propulsion provides for the feed wheel a form-fitting shape matched to the diameter or the contour of the filament, so that there is a maximum contact surface between the wheel and filament. The conveyor wheel can be supported by further conveyor wheels, which are driven by a gear. As a result, the contact pressure of the individual conveying wheel decreases and the advance of the filament becomes more accurate.
3. 3. The comparatively heavy, good heat-conducting and easily deformable filament is melted in the print head and layered as a so-called "bead" placed on the molding as a melt layer. The filament feed as well as the filament diameter are sensory detected and coordinated with the pressure parameters. This avoids misprints. Due to the high thermal conductivity of the filament, the portion of the filament which is located immediately before the melting section becomes unduly warm and thus unstable so that the conveyor unit could deform or even tear the filament. To prevent this, the process according to the invention provides for a thermal barrier or cooling between the melting zone and the conveying zone of the filament.
4. 4. When using metal-filled filaments, the layered body resulting due to its high degree of filling conducts the heat introduced from the melting element effectively in the underlying layers of the molding. When printing overhangs or fine geometries, however, this heat can no longer be dissipated sufficiently quickly. As a result, the component melts locally in these building zones and loses the desired shape. In order to prevent this, the method according to the invention provides for cooling the pressure zone or the directly deposited print bead.
5. 5. In order to avoid a thermally induced distortion of the component, the component can be uniformly heated depending on its geometry by introduced in the base plate or the border infrared diodes. For this purpose, an infrared image of the resulting molded body is made and, in accordance with the thermal profile, a selective control of the IR diodes is effected until the component has uniform temperatures at all geometrical contours. At the same time, the infrared image serves to monitor the progress of the construction site, as it performs a permanent comparison between the nominal and actual data of the component. If a printing error occurs, the machine operator is informed and / or the process is stopped.
6. 6. The accuracies of modern 3D printers are in the range of one to two hundredths of a millimeter. The "bead" produced by the melt nozzle has, in an advantageous embodiment, a width of 0.1 to 1.0 mm. For a tightly tolerated production, it is necessary to correct the control of the printer by half the bead width. The resulting melt layer step on the outer contour is eliminated by a subsequent mechanical smoothing according to the invention. This shape correction is included in the printer control algorithm.
7. 7. An optimal surface quality of the later sintered component results when very finely fractionated metal powders are used. However, these fine powders are noticeably more expensive than coarser fractionated powders because of the higher processing costs. The printing process according to the invention provides for printing the edge zones of a component with finely fractionated filaments and the core zone with coarsely fractionated filaments with the aid of a plurality of print heads. The same method can be used to attach functional layers of special materials to locations where they are needed, such as bearings or notches. In addition, the method according to the invention provides for Core area for the purpose of saving material with an arrangement of smaller and larger hollow chambers to enforce. These hollow chambers can be optimized by a FEM program in terms of size and arrangement.
8. 8. For components with different local requirements, different metals with similar melting point but different properties can be combined over multiple print heads in a so-called multi-material component. This also applies to ceramic materials.
9. 9. For the subsequent sintering process, the moldings must be printed with a mitsinternden pad to avoid a delay caused by the adhesion of the components on the footprint of the furnace. If the component to be sintered does not have a plane bearing surface, the shaped bodies must be supported by a mitsinternde pad during the sintering process in order to avoid a delay due to gravity. This document is printed separately or together with the component. The pad can be printed in the embodiment of the invention as a solid body or as a grid structure. It is discarded after the sintering process. Between pad and workpiece, a release agent is provided.
10. 10. As an alternative to a mitsinternden pad a sintering pad of a higher melting material - usually ceramic - are printed. These pads serve to support overhanging sections of the component and are reused. They are designed in an advantageous embodiment as a strut structure and / or as rollers. Between the support and component, a release agent is provided.
11. 11. After removal from the printer, the molded part (green part) has a process-typical melt layer gradation. If the grading is technically or aesthetically undesirable, the method according to the invention provides radiation with a soft blasting agent such as, for example, PE granules or the component-identical feedstock. By this blasting process, the steps are smoothed.
12. 12. In order to optimally define the strength and other properties of a component, a slicer software is used which makes it possible to generate a graded shape of the infill. This means that the transition from the outer shell to the hollow chamber structures does not break off but progresses gradually.
13. 13. To prevent dripping (Oozen) after heating the filament to the pressure temperature, a sealable pressure nozzle is used. The closure is actuated piezoelectrically, electromagnetically, pneumatically or hydraulically in an advantageous embodiment.

The subsequent process steps of debindering and sintering are state of the art. The structure of the sintered parts allows galvanic and electrolytic surface finishing (nickel plating, electropolishing, etc.) without pretreatment. For case hardening, case hardening characteristics are achieved whose values are comparable to those of case hardening steels. The inventive component is - as far as provided in its specifications - weldable. However, the refining process is optional. Immediately after the sintering process, a ready-to-install workpiece can also be present directly.

• 1 das erfindungsgemäße Verfahren zur Abwicklung eines metallgefüllten Filaments von einer kugel- bzw. rollengelagerten Rolle, deren Antriebsgeschwindigkeit fortlaufend auf die Fördergeschwindigkeit des nachgelagerten Verarbeitungsschritts sowie den sich verändernden Rollendurchmesser bzw. Abwicklungsgrad des Filaments abgestimmt werden
• 2 das erfindungsgemäße Verfahren zur Vorwärtsförderung der Filamente basierend auf einen oder mehreren kontaktschlüssigen Rädern mit einer auf den Filamentendurchmesser bzw. -querschnitt abgestimmten Formgebung
• 3 das erfindungsgemäße Verfahren zur Vorwärtsförderung der Filamente basierend auf einer oder mehreren kontaktschlüssigen Raupen bzw. Ketten mit einer auf den Filamentendurchmesser bzw. - querschnitt abgestimmten Formgebung
• 4 die erfindungsgemäße Thermalbarriere welche die Temperatur des Filaments in dem beheizten Druckkopf abschirmt von der Temperatur des Filaments im Bereich unmittelbar vor dem Einzug in den Druckkopf
• 5 das erfindungsgemäße System zum thermischen Ausgleich des die Druckraupe umgebenden Bauteils durch gasförmige und/oder flüssige Medien und/oder differenzielle elektromagnetische Strahlung
• 6 der erfindungsgemäße Algorithmus zur Korrektur der Raupenbreite sowie der anschließenden Stufenglättung bei der Steuerung des Druckkopfes
• 7 das erfindungsgemäße Verfahren zur Schmelzschichtung mit mehreren Druckköpfen welches fein fraktioniertes Filament in der Randzone und grob fraktioniertes Filament in der Kernzone eines Bauteils verarbeiten
• 8 das erfindungsgemäße Verfahren zur Schmelzschichtung welche eine Anordnung von Hohlkammern verschiedener Größe in ein generativ erzeugtes Bauteil einbringt
• 9 das erfindungsgemäße Verfahren zur Schmelzschichtung mit mehreren Druckköpfen, welches Filamente aus verschiedenen Materialien bzw. Füllstoffen in einer beanspruchungsgerechten Art und Weise im Formkörper anordnet
• 10 das erfindungsgemäße Verfahren zur Schmelzschichtung, welches zusätzlich zum Bauteil eine mitsintemde Unterlage bzw. Stützstruktur aus einem zum Bauteil-Filament identischen Filament druckt
• 11 das erfindungsgemäße Verfahren zur Schmelzschichtung, welches zusätzlich zum Bauteil eine Stützstruktur aus einem im Vergleich zum Bauteil höher schmelzenden Filament-Füllstoff druckt
• 12 das erfindungsgemäße Verfahren zur Glättung der Schmelzschichtstufen mittels Strahlen durch Bauteile-identischen Feedstock
• 13 das erfindungsgemäße Verfahren zur Schmelzschichtung, welches zusätzlich zum Bauteil eine Stützstruktur aus Kunststoff (Organik) druckt, welche später während der Lösemittelentbinderung wieder extrahiert wird

Illustrations: The invention will be described below with reference to FIGS 1 to 13 described in more detail. Show it:

• 1 the method according to the invention for unwinding a metal-filled filament from a ball-bearing roller whose driving speed is continuously adjusted to the conveying speed of the downstream processing step and the changing roll diameter or unwinding degree of the filament
• 2 the inventive method for forward feeding of the filaments based on one or more contact wheels with a matched to the filament diameter or cross section shaping
• 3 the method according to the invention for forward feeding of the filaments based on one or more contact-connected beads or chains with a shape adapted to the filament diameter or cross-section
• 4 the thermal barrier of the present invention which shields the temperature of the filament in the heated printhead from the temperature of the filament in the region immediately prior to entry into the printhead
• 5 the inventive system for thermal compensation of the component surrounding the print bead by gaseous and / or liquid media and / or differential electromagnetic radiation
• 6 the inventive algorithm for correcting the bead width and the subsequent step smoothing in the control of the print head
• 7 the inventive method for melt stratification with multiple printheads which process finely fractionated filament in the edge zone and coarsely fractionated filament in the core zone of a component
• 8th the inventive method for melt stratification which introduces an arrangement of hollow chambers of different sizes in a generatively generated component
• 9 the inventive method for melt stratification with multiple printheads, which arranges filaments of different materials or fillers in a claim-appropriate manner in the molding
• 10 the inventive method for melt stratification, which prints in addition to the component a mitsintemde pad or support structure of a filament identical to the component filament
• 11 the inventive method for melt stratification, which prints in addition to the component a support structure of a higher compared to the component filament filler
• 12 the inventive method for smoothing the melt layer stages by means of beams through component-identical feedstock
• 13 the inventive method for melt stratification, which prints in addition to the component a support structure made of plastic (organics), which is later extracted again during the Lösemittelentbinderung

In 1 there is an embodiment of the inventive filament storage system (A) with an actively driven roller (B) which is synchronized with respect to their unwinding speed with the respective bobbin diameter (C) and the conveying speed of the downstream processing unit (D).

In 2 There is an embodiment of the inventive system for transporting a filament in the direction of the processing unit by means of one or more actively driven conveyor wheels (A) or a combination of driven conveyor wheels and passive support wheels (B) which have a positive fit to the filament (C)

In 3 There is an embodiment of the filament conveying system according to the invention by means of one or more actively powered conveyor caterpillars or chains (A) or a combination of driven conveyor caterpillars or chains and passively running support caterpillars or chains (B) which a positive fit to the filament (C)

In 4 there is an embodiment of the thermal barrier (A) according to the invention of a thermally insulating material and / or the cooling of the filament immediately before moving into the print head by means of gaseous (B) and / or liquid (C) media and / or differential electromagnetic radiation (D) ,

In 5 An exemplary embodiment of the shaped body temperature control system (A) according to the invention is provided with an infrared measuring device (B) and cooling device for the component zone surrounding the leaving print bead by means of gaseous (c) and / or liquid (D) media and / or differential electromagnetic radiation

In 6 there is an embodiment of the control algorithm (A) according to the invention with a mathematical correction element for the bead width (B) and a mathematical correction element for the subsequent surface smoothing (C).

In 7 there is an embodiment of the inventive filament melt layer system with multiple printheads (A), which places each filament with finely fractionated metal powder (B) in the edge zones and filament with coarsely fractionated metal powder (C) in the core zone of a shaped body.

In 8th there is an embodiment of the filament-melt layer system (A) according to the invention which hollow chambers of different sizes placed in a molded body (B).

In 9 there is an embodiment of the filament-melt layer system according to the invention with a plurality of printheads (A), which arranges each different filaments with different metal or ceramic fillings (B) in a claim-appropriate manner in the molding.

In 10 An exemplary embodiment of the filament-enamel layer system (A) according to the invention, which places a co-sintered support structure (B) of a filament identical to the component filament, below or next to a shaped body (C).

In 11 there is an embodiment of the filament-melt layer system according to the invention with a plurality of printheads (A), which under or next to the component (D) a reusable support body (C) of a filament with a higher melting compared to the metal or ceramic powder (B) generated.

In 12 There is an exemplary embodiment of the method according to the invention for smoothing the melt layer stages (A) by radiation with a feedstock (B) identical to the component.

Claims (15)

A method for producing a shaped body from one or more metal- or ceramic-filled filaments, characterized in that the filament (s) are removed from a low-friction and / or actively driven unwinding unit whose drive speed is continuously adapted to the processing speed of the printing process as well as the reel-reducing reel diameter becomes Method according to Claim 1 characterized in that the one or more filaments are conveyed by the one or more wheels, the contours of which have a force-matched to the contour of the respective filament shape Method according to Claim 1 characterized in that the one or more filaments are conveyed by one or more beads and / or chains, the contours of which have a force-matched to the contour of the respective filament shape Method according to Claim 1 characterized in that a thermal barrier made of an insulating and / or poorly heat-conducting material is placed between the heating zone in the print head and the filament fed directly in front of the print head Method according to Claim 1 characterized in that the or directly before the printhead supplied filaments are held by a gaseous and / or liquid and / or electromagnetic cooling in a favorable for a mechanical promotion temperature range Method according to Claim 1 characterized in that the resulting shaped body is kept in the region of the exiting print bead by a gaseous and / or liquid and / or electromagnetic cooling in a favorable for the shaping and preservation of the molded body temperature range Method according to Claim 1 characterized in that the used to build the shaped body a plurality of printheads, of which at least one printhead places a filament with finely fractionated metal powder in the edge zone of the molding and at least one further printhead a filament with coarsely fractionated metal powder in the core zone of the molding Method according to Claim 1 characterized in that the used for the construction of the molded body a plurality of print heads, which arrange filaments with different fillers in a claim-appropriate manner in the molding Method according to Claim 1 characterized in that a mitsintemde support structure is produced together with the molded body or a support structure below or separately from the molded body is produced, which has a higher melting temperature than the molded body itself Method according to Claim 1 characterized in that the control algorithm for moving the xy axis is corrected by a correction term in the size of half the melt bead width and / or the subsequent surface smoothing and / or the melt layer stages of the shaped body by blasting with a component-identical feedstock and / or another be smoothed suitable abrasive Method according to Claim 1 characterized in that the pressure nozzles in the printheads have a piezoelectrically, electromagnetically, pneumatically or hydraulically operated shutter mechanism Method according to Claim 1 characterized in that is used to melt the filament to be processed induction heat Method according to Claim 1 characterized in that the support structures are generated inside and outside of the component of a chemically soluble plastic Method according to Claim 1 characterized in that the feed and diameter of the filament to be processed are detected by sensors and the sensor data with the intended pressure parameters are continuously adjusted, such that made pressure corrections and / or printing errors are displayed to the operator Method according to Claim 1 characterized in that the support structures in the hollow bodies have no linear but a need-based density or spatial distribution

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