DE102021127824A1 - Device and method for surface treatment - Google Patents

Abstract

The invention relates to a device and a method for processing a surface of at least one extrusion strand extruded by a 3D printer. Surfaces of objects formed by a 3D printer usually suffer from poor quality. The invention has therefore set itself the task of ensuring improved dimensional accuracy with regard to the tolerances to be maintained and improved surface quality of a printed object formed by a 3D printer , comprising at least one molding tool, solved in that the molding tool has at least one molding, wherein the molding can be brought into contact with the at least one extrusion strand and the surface of the at least one extrusion strand can be processed by means of the molding.

Description

The invention relates to a device for processing a surface of at least one extrusion strand extruded by a 3D printer, comprising at least one mold. Furthermore, the invention relates to a method for processing a surface of at least one extrusion strand extruded by a 3D printer using a device according to the invention.

Various 3D printing processes are now known from the prior art, including fused filament fabrication, FFF printing process for short, also known as material extrusion processes, selective laser sintering, SLS printing process for short, and stereolithography -Printing process, SLA printing process for short.

In the material extrusion process, a thermoplastic material is applied layer by layer using a print head that can be moved relative to the printing platform, ultimately creating a component. The wire-like starting material is melted in the print head, pressed through a nozzle and placed on the print body. The liquid material cools down and solidifies, and the resulting extrusion has a pill-shaped cross-section. The width of this extrusion strand - which is influenced by how much material is extruded per time - is largely responsible for compliance with any component tolerances. Fluctuations in the material extrusion lead to fluctuations in the width of the extrusion strand and ultimately to a deterioration in the component tolerances. The fluctuations can have different causes. For example, fluctuating filament diameters, fluctuating temperatures in the print head or contamination/wear in the nozzle have an impact on component quality. Furthermore, the material properties of the building material used can vary from batch to batch.

For these reasons, the tolerances in 3D printing are still significantly worse in direct comparison to ablative processes such as milling or turning. In addition, due to the pill-shaped extrusion strands, the roughness of the surface is unsatisfactory. In order to improve this, it is known from the prior art to select a finer layer height when extruding the extruded strands, although this significantly increases the printing time and thus also the production time of the respective component. There is therefore an optimization conflict between print time and surface quality.

Additive manufacturing - i.e. applying layer by layer - using the material extrusion process also has the following relevant disadvantages compared to other conventional removal processes, namely that the geometric tolerances that can be achieved in each case and the achievable surface quality of the printed object are worse than with removal processes. There is also the problem of the so-called staircase effect in connection with the production of bevels in the respective component, whereby this is due to the layered production of the printed object in 3D printing. In addition, the production costs of the respective printed object are significantly influenced by the printing time, the printing time in turn being naturally increased if a rough surface is avoided and the layer height to be extruded is thus reduced.

• https://blog.prusaprinters.org/de/buegeln-mit-dem-prusaslicer-2-3-rcoberflaechen-superglatt-machen_41506/) beschrieben.

The solution to this problem is, among other things, already known from the prior art, with the help of a so-called “ironing” function, i.e. “ironing” function of any printing programs, also called “slicer” programs, the uppermost extrusion strand extruded by the 3D printer "iron flat" through the underside of a print nozzle on a 3D printer. Although the processing of the upper surface of an extruded strand by the printing nozzle of the 3D printer works very well, the application is limited to the horizontal layer, i.e. the XY plane. This procedure is for example in the article "Ironing - Make surfaces super smooth with PrusaSlicer 2.3 (RC)" (URL:

• https://blog.prusaprinters.org/en/ironing-with-the-prusaslicer-2-3-rcoberflaechen-superglatt-machen_41506/).

Subsequent processing of a printed object produced by a 3D printer is also known from the prior art. For example, the CN 105773970A a hybrid machine that combines 3D printing with a machining manufacturing device, here milling. Here, the outer contour of a printed extrusion strand is milled to size by a milling cutter, with this process being repeated for each newly extruded extrusion strand. However, this method only works for materials that cool down quickly. The process described here is therefore not suitable for high-performance plastics, which usually do not cool down quickly and would therefore still be tough and soft during milling. In addition, the extrusion strand is already extruded with excess to compensate for the loss of material due to subsequent milling. Ultimately, more material is required here than with conventional 3D printing and a lot of material is lost in the form of chips.

Furthermore, from the German patent DE 10 2016 111 047 B3 a method and a system for the combined additive and forming production of a metallic shaped body are already known. It is more or less a 3D printing process for metallic materials, in which both the production of the metallic printed object and the forming to improve the surface roughness are carried out in one manufacturing process. This is achieved in that, after a deposited and solidified layer has melted, it is shaped using a shaping tool that includes at least two rollers in accordance with geometry description data by guiding the at least two rollers laterally along the deposited layer.

Proceeding from this prior art and the problems arising from 3D printing described above, the object on which the invention is based is to ensure improved dimensional accuracy with regard to the tolerances to be maintained and improved surface quality of a printed object formed by a 3D printer.

This object is achieved with the aid of a device according to claim 1 in force. Furthermore, the object is achieved by the independent method claim 22. Advantageous configurations of the invention can be found in the dependent claims.

In a first aspect, the invention relates to a device for processing a surface of at least one extrusion strand extruded by a 3D printer, comprising at least one mold. The device according to the invention is characterized in that the molding tool has at least one molding. This shaped body can be brought into contact with the at least one extrusion strand, so that the surface of the at least one extrusion strand can be machined by means of the shaped body of the mold. A shaped body can assume any spatial configuration that is suitable for processing a surface. By processing the extruded strand by means of the shaped body, for example, the grooves otherwise present as a result of the extrusion of individual strands between the respective extruded strands can be greatly reduced or almost completely removed. As a result, a significantly smoother surface of the component can be achieved in this case.

In an advantageous embodiment, the molding tool has a connecting element to the molding. This makes it possible, among other things, to set the spatial alignment of the shaped body in relation to the mold, but also to enable the changing of shaped bodies on the at least one mold.

Furthermore, in an advantageous embodiment, the device provides that the shaped body has at least one shaped geometry. The shape geometry is preferably spherical, conical, cylindrical, square, rectangular, triangular, brush-shaped or a combination thereof. The mold geometry can also be connected to the mold body via a connecting element. The spatial orientation of the mold geometry relative to the mold body can thus be adjusted, but it is also possible to change mold geometries on the at least one mold body. The connecting element that connects the molded body to the mold geometry is preferably a ball and socket joint.

In order to be able to ensure gentle processing of the surface of at least one extrusion strand, the device provides in a further advantageous embodiment that the mold geometry is made of a soft material that clings to the surface of the extruded extrusion strand. A material that could come into question for this purpose would be silicone, for example.

Since three-dimensional components can ultimately be produced with 3D printing and the current shape or contour of the component to be produced can change with each extruded extrusion strand, the invention proposes for the device that the mold, the mold and/or the mold geometry be free is rotatable. As a result, it can be adapted to almost any contour or surface of the component to be formed. Particularly preferably, the molding tool, the molding and/or the molding geometry can be controlled individually. In this way, the free rotatability that is present in each case can ultimately be controlled individually.

Depending on the material used in 3D printing, the extruded strands cool or harden faster or slower or harden. This makes it difficult or impossible to process the surface of the extruded extrusion strand after the extrusion of an extrusion strand. In order to solve this problem, the invention proposes for the device in an advantageous embodiment that the shaped body and/or the mold geometry can be heated and/or cooled by means of a temperature control device. The shaped body that can be brought into contact with the extruded strand or the mold geometry that may be present can thus be removed by the heated or cooled shaped body or--if present--the heated or cooled mold geometry heats or cools the at least one extrusion strand, with the result that subsequent processing is made possible. Thus, on the one hand, an extrusion material that has already solidified can be reheated to such an extent that it can be deformed or reworked again. On the other hand, an extrusion material that is still too liquid can be cooled in such a way that it solidifies after forming or processing.

It is conceivable that the temperature control device is, for example, a heating beam source, in particular an infrared laser, with which the shaped body or the shaped geometry can be heated. This would have the significant advantage that, in the case of rotating or freely movable components of the shaped body or the shaped geometry, a complex construction, in particular to avoid twisting of any existing heating cables, can be avoided.

In another advantageous embodiment, the temperature control device is arranged inside the mold and/or the mold geometry. In this way, a targeted and possibly punctiform heating or cooling of the molded body and/or the mold geometry and thus ultimately the extrusion strand to be processed can be implemented.

In order to save material and thus ultimately weight in the molded body and/or the mold geometry, the invention provides for the device in an advantageous embodiment that the device contains recesses. In particular, recesses on the shaped body that have a temperature control device arranged within the shaped body and/or the mold geometry have proven to be advantageous, since this also allows heat flow into the mold to be minimized or prevented.

Furthermore, the invention provides for the device that the shaped body and/or the shaped geometry consists of a thermally conductive material. In this way, for example, short heating and cooling times can be achieved, which in turn can have a positive effect on the printing time. The thermally conductive material is preferably a metal or a coated metal. Depending on the material used, both high thermal conductivity and high surface quality of the molded body or mold geometry can be achieved.

So that the shape and contour that changes during the formation of a three-dimensional object can be dynamically adapted, the device provides that it has a plurality of molds and/or mold bodies and/or mold geometries and these are particularly preferably kept in a drum or magazine design . It is also conceivable that the device has a storage container for storing different shaped bodies and/or mold geometries and that the mold can change them automatically.

Furthermore, in another advantageous embodiment, the device provides that it is arranged on a print head of a 3D printer. It is conceivable that first an extrusion strand is extruded through the print head of a 3D printer and then the mold of the device is extended at the print head and the extrusion strand previously extruded by the print head is processed with the shaped body of the mold.

Alternatively, in a likewise advantageous embodiment, the device could also be integrated into a nozzle of a print head of a 3D printer. Thus, after an extrusion strand has been extruded through the print head, the previously extruded strand could be processed directly with the device according to the invention integrated into the nozzle without any further steps.

Furthermore, in another advantageous embodiment, the device provides that it has a movement device for moving the molding tool in at least one spatial direction. If the movement device can be moved in all three spatial directions, i.e. in the XYZ plane, the extrusion strand previously extruded by a print head of a 3D printer can be processed with the device according to the invention independently of a movable printing base plate that is usually present in the 3D printer.

In a second aspect, the invention relates to a method for processing a surface of at least one extrusion strand extruded by a 3D printer using a device according to the invention. The method is characterized in that the shaped body of the shaping tool is guided along the surface of the at least one extrusion strand extruded by a 3D printer, as a result of which the surface of the extrusion strand is smoothed.

In order to improve the result, ie the smoothing of the surface of the extruded strand, the method provides in an advantageous embodiment that the shaped body is guided along the extruded strand several times. Any unevenness caused by the smoothing process can thus be compensated for.

Furthermore, in a further advantageous embodiment, the method provides that after each extrusion strand extruded through the 3D printer, the shaped body of the molding tool is guided along the surface of the extrusion strand, with the shaping preferably being carried out after each printed layer, i.e. only when the respective layer is fully printed. Although it is reasonable to assume that by adding the process step, after each extruded extrusion line or each printed layer, the surface of the extruded extrusion line is first processed by means of the device according to the invention, this would lead to an increase in the printing time and thus to a slowdown in the printing speed.

This is also true if nothing is changed in the basic parameters, such as the layer thickness to be extruded. However, the layer thickness is usually selected as small as possible in order to improve the surface quality. However, since the surface quality can be significantly improved with the aid of the device according to the invention, a higher layer thickness can ultimately be selected. As a result, this leads to a significantly faster printing time, even if an additional process step is added.

Finally, in a further advantageous embodiment of the method, the shaped body of the shaping tool is guided along the extrusion strands extruded by the 3D printing only after the object to be formed by the 3D printer has been produced.

In the case of high-performance plastics, the extrusion strands of the printed object formed usually remain deformable even after the printing process, so that the surface treatment can also be carried out after the printing process has been completed. If, however, the extruded printing material has already solidified, the extrusion strands can be heated by means of a temperature control device, which is preferably arranged inside the shaped body and/or the mold geometry of the mold, whereby the extrusion strands can in turn be deformed and ultimately the surfaces by the shaped body or the mold geometry are editable.

The invention is explained in more detail below on the basis of several application examples.

• 1: eine Düse eines 3D-Druckkopfes und einen durch die Düse extrudierten Extrusionsstrang,
• 2: einen 3D-Drucker mit Druckkopf und einem Ausführungsbeispiel der erfindungsgemäßen Vorrichtung,
• 3: die exemplarische Auftragung eines Extrusionsstranges durch einen Druckkopf auf bereits extrudierte Extrusionsstränge,
• 4: die exemplarische Bearbeitung einer extrudierten Druckschicht
• 5: einen Querschnitt eines bearbeiteten Extrusionsstranges,
• 6: den Aufbau eines Ausführungsbeispiels eines Formwerkzeuges,
• 7: unterschiedliche Formgeometrien,
• 8: exemplarisch drei Fälle von unterschiedlichen zu bearbeitenden Oberflächen,
• 9: ein nicht bearbeitetes und ein bearbeitetes Druckobjekt jeweils im Querschnitt,
• 10: die Bearbeitung eines durch einen 3D-Drucker gebildeten Gewindes, sowie
• 11: die Bearbeitung eines durch einen 3D-Drucker gebildeten Zahnrads.

It shows:

• 1 : a nozzle of a 3D print head and an extrusion strand extruded through the nozzle,
• 2 : a 3D printer with a print head and an exemplary embodiment of the device according to the invention,
• 3 : the exemplary application of an extrusion strand by a print head to already extruded extrusion strands,
• 4 : the exemplary processing of an extruded print layer
• 5 : a cross-section of a machined extrusion strand,
• 6 : the structure of an exemplary embodiment of a mold,
• 7 : different shape geometries,
• 8th : exemplary three cases of different surfaces to be processed,
• 9 : an unprocessed and a processed print object in cross-section,
• 10 : the machining of a thread formed by a 3D printer, as well as
• 11 : the machining of a gear formed by a 3D printer.

1 shows a nozzle 2 of a print head of a 3D printer and an extrusion strand 1 extruded through this nozzle 2.

The wire-like starting material is melted in the print head, pressed through a nozzle 2 and the extrusion strand 1 formed in this way can be placed on a printed object 8 . The liquid material cools down, solidifies and the resulting extrusion strand 1 has a pill-shaped cross section 4. The width 5 of this pill-shaped extrusion strand 1, which is determined by how much material is extruded per time, is largely responsible for compliance with any component tolerances. Fluctuations in the material extrusion lead to fluctuations in the width 3 of the extrusion strand 1 and thus to a deterioration in the component tolerances. This problem is to be solved with the aid of the device according to the invention and the method according to the invention.

An exemplary embodiment of the device according to the invention is shown in 2 shown. This shows an exemplary and simplified representation of a 3D printer that has a device according to the invention.

In this exemplary embodiment, the 3D printer has, in addition to the conventional print head 6, a mold 7 with which the surface of at least one extrusion strand 1 can be reworked. The printed object 8 is seated here on a printing plate 9 which is driven in the Z-direction 10 can be. The carrier 11 can be driven in the Y direction 12 . The print head 6 and the forming tool 7 can be controlled independently of one another in the X direction. The print head thus has its own X1 axis 13 and the forming tool has its own X2 axis 14.

The printing process used in 2 3D printer shown, can be as follows. First, as in 3 shown, an extrusion line 1 is extruded with the print head 6 of the 3D printer onto existing extrusion lines of a printed object 8 . The molding tool 7 is in a parking position and is not necessarily involved in this phase.

The freshly applied extrusion strand 1 or the freshly applied print layer has the in 1 shown, classic pill shape and protrudes slightly over the already processed extrusion strands 15 out. Once the top extrusion line 16 or the print layer has been completely extruded, the print head 6 moves to its parking position and the second phase follows, which 4 is shown.

4 shows how the mold 7 travels the outer contour of the top extrusion strand 16. The exterior of the uppermost extrusion strand 16 is shaped by the mold 7 to a desired nominal size 18, as shown in FIG 5 shown, formed, whereby a smooth surface 17 is formed.

Here, the pill-shaped cross section 4 of the extrusion strand 1.16, as in 5 shown, deformed. The rounding of the pill-shaped cross section 4 is formed into a straight line. The protruding material 19 is pressed into the grooves 20 formed between the extrusion strands. Furthermore, it is possible to process the cover surfaces 26 of a printed object or of an uppermost extrusion strand 16, ie in the XY plane, with the underside of the mold 7.

A possible design of a mold 7 is shown in 6 shown. The mold 7 consists here essentially of three components, a receptacle 21, a temperature control device 22 and a shaped body 23. The receptacle 21 serves as a connecting element between the shaped body 23 and the mold 7. The shaped body 23 can have the temperature control device 22 located inside the shaped body 23 is located can be set to a desired temperature. The shape geometry 25 of the shaped body 23 is responsible for shaping the surface of the printed object 8 and therefore has a high surface quality with tight manufacturing tolerances. In the simplest case, however, the shape geometry 25 can be designed as a simple cylinder, see cylindrical shape geometry 33 in 7 .

The material of the molded body 23 and the mold geometry 25 can consist of a material with a high thermal conductivity coefficient in order to be able to quickly transport the heat through the molded body or the mold geometry into the plastic during heating or to be able to quickly dissipate the heat from the plastic during cooling. It is also conceivable here to implement a combination of several materials, for example by means of a coating.

A few recesses 24 are present in the shaped body 23 in order to reduce the cross section above the temperature control device 22 . This has the advantage that the flow of heat into the receptacle 21 can be minimized.

The shape geometry of a shaped body 23 can be designed in many different variants. Some examples of different mold geometries of a mold 23 are shown in 7 shown. These are a cylindrical shape geometry 33, a cylindrical shape geometry with a chamfer 34, a cylindrical shape geometry with a curve 35, a spherical shape geometry 36, a cylindrical shape geometry with two curves 37, a shape geometry for threads 38, a shape geometry for sharp undercuts 39 and a cylindrical form geometry with two chamfers 40.

Different shape geometries, as in 7 shown can be selected depending on the application. In order to be able to better demonstrate the need for different mold geometries for a mold body 23, this is illustrated using three examples that are shown in 8th are shown, explained in more detail.

The first example shows the shaping of vertical surfaces 27. In this case, the shaped surface is perpendicular to the printing plane, ie vertical. For this case, a likewise vertical surface 28 on a mold geometry is optimal.

In the second example, it concerns the forming of oblique surfaces without overhang 29. Here the formed surface is at an angle to the printing plane, but without overhang.

An example would be a tapered cone with the apex pointing upwards. In this case, the shape geometry has a sloping chamfer 30 on the lower edge. Without this chamfer 30, sloping surfaces of a printed object could only be approximated by “stairs”.

In the third and final example, the molding of sloping surfaces with an overhang 31 is shown. The situation here is similar to the second example, but in a mirrored version.

An example of a corresponding print object would be a printed cone with the tip pointing down. For this purpose, the mold geometry has an inclined chamfer 32 on the upper edge.

To create a sloping surface, as in the second and third example in 8th shown, to be able to reproduce perfectly, theoretically a suitable form geometry would be required for each angle. However, in order to avoid a large number of tools, the bevels can also be easily replaced by round shape geometries 35, 36, 37, as in 7 shown, approximate. Depending on the angle of the bevel to be processed, other areas of the rounding of the mold geometry 35, 36, 37 are used for the molding. The cylindrical form geometry 33 would be well suited, for example, for a printed object that only has vertical and horizontal surfaces. The thread geometry 38, on the other hand, is primarily suitable for reshaping threads formed by means of 3D printing, as shown in 10 shown.

In 9 shows the difference between a printed object with and without post-processing by a shaped body 23 . The upper figure shows a cross section 41 of a printed object with several extrusion strands without the corresponding post-processing. The strongly developed grooves 42 between the extrusion strands can be seen, which lead to poor surface quality. The figure arranged below shows a cross section 43 of a printed object with post-processing according to the invention. From this, a strong reduction of the grooves 42 can be seen without further ado, as a result of which a smooth surface 44 can ultimately be achieved.

10 shows a thread geometry 38 of a molded body 23 for machining a thread 45 formed by a 3D printer. The thread geometry 38 is ultimately a negative form of a thread flank. The thread 45 formed by 3D printing can thus be reshaped by means of the thread geometry 38 of the forming tool 7 by means of a helical travel path of the forming tool 7 .

This process can take place layer by layer or over several layers. It is also conceivable to reshape a complete thread 45 produced by a 3D printer in a downstream process. The machining can be done for both external and internal threads.

ultimately shows 11 the processing of a gear 47 formed by a 3D printer with a special gear geometry 46.

Here, the gear wheel geometry 46 has a special counter-shape of a gear wheel. For the machining of the gear formed by a 3D printer, each tooth of the gear with the gear geometry 46 is gradually removed. Since the gear wheel geometry 46 must always be correctly aligned with the printed gear wheel 47 here, the gear wheel geometry 46 can be controlled to rotate about the Z axis. The processing can also be carried out layer by layer or over several layers. The gear wheel geometry 46 can include several gear wheel geometries. Depending on what kind of gear is to be produced using 3D printing, the appropriate gear shape in the gear geometry 46 can always be selected by rotating the shaped body 23 or the gear geometry 46 .

Thus, a device and a method for processing a surface of at least one extrusion strand extruded by a 3D printer is disclosed above, whereby improved dimensional accuracy with regard to the tolerances to be maintained and improved surface quality of a printed object formed by a 3D printer can be ensured.

Reference List

1

extrusion strand

2

jet

3

Fluctuations in the width of the extrusion strand

4

Pill-shaped cross-section

5

Width of the extrusion line

6

printhead

7

molding tool

8th

component

9

printing plate

10

Z direction (Z axis)

11

carrier

12

Y direction (Y axis)

13

X1 direction (X1 axis)

14

X2 direction (X2 axis)

15

Machined extrusion strands

16

Top extrusion line

17

Smooth surface

18

nominal size

19

excess material

20

grooves

21

Recording

22

temperature control device

23

molding

24

recess

25

shape geometry

26

top surface

27

Vertical Faces

28

Vertical face on the shape geometry

29

Inclined surface without overhang

30

Inclined surface on the mold geometry on the bottom

31

Inclined surface with overhang

32

Inclined surface on the mold geometry on the top

33

Cylindrical shape geometry

34

Cylindrical shape geometry with chamfer

35

Cylindrical shape geometry with rounding

36

Spherical shape geometry

37

Cylindrical shape geometry with two curves

38

thread geometry

39

Shape geometry for sharp undercuts

40

Cylindrical shape geometry with two chamfers

41

cross-section

42

grooves

43

cross-section

44

Smooth surface

45

thread

46

gear geometry

47

gear

QUOTES INCLUDED IN DESCRIPTION

This list of 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

• CN 105773970A [0007]
• DE 102016111047 B3 [0008]

Claims (26)

Device for processing a surface of at least one extrusion strand extruded by a 3D printer, comprising at least one molding tool, characterized in that the molding tool has at least one molding, wherein the molding can be brought into contact with the at least one extrusion strand and by means of the molding the surface of the at least an extrusion strand is editable. device after claim 1 , characterized in that the mold has a connecting element for connecting the molded body to the mold. device after claim 1 or 2 , characterized in that the shaped body has at least one shape geometry. device after claim 3 , characterized in that the shape geometry is spherical, conical, cylindrical, square, rectangular, triangular, brush-shaped or a combination thereof. device after claim 3 or 4 , characterized in that the shaped body is connected to the mold geometry via a connecting element. device after claim 5 , characterized in that the connecting element is a ball joint. Device according to at least one of claims 3 until 6 , characterized in that the mold geometry consists of a soft material which clings to a surface of an extruded extrusion strand. Device according to at least one of the preceding claims, characterized in that the mold, the mold and/or the mold geometry is freely rotatable. device after claim 8 , characterized in that the free rotation is controllable. Device according to at least one of the preceding claims, characterized in that the shaped body and/or the mold geometry can be heated and/or cooled by means of a temperature control device. device after claim 10 , characterized in that the temperature control device is arranged within the shaped body and/or the mold geometry. Device according to one of the preceding claims, characterized in that the shaped body and/or the shaped geometry has recesses. Device according to at least one of the preceding claims, characterized in that the shaped body and/or the shaped geometry consists of a heat-conducting material. Device according to at least one of the preceding Claims 1 - 12 , characterized in that the surface of the mold geometry is structured in such a way that, in addition to smooth component surfaces, alternatively, depending on customer requirements, structured surfaces, such as roughened surfaces, can be produced. Device according to at least one of the preceding Claims 1 - 12 , characterized in that the molding tool can be used to produce engravings, such as engraving serial numbers or other identifiers into the surface of the component, by using a fine-tipped mold geometry. device after Claim 13 , 14 or 15 characterized in that the thermally conductive material is a metal and/or a coated metal. Device according to at least one of the preceding claims, characterized in that it has several molding tools and/or moldings and/or molding geometries. device after Claim 17 , characterized in that the plurality of molding tools and/or moldings and/or molding geometries are kept in a drum or magazine design. Device according to at least one of the preceding claims, characterized in that the forming tool is arranged on a print head of a 3D printer. Device according to at least one of the preceding claims, characterized in that the molding tool is integrated into a nozzle of a print head of a 3D printer. Device according to at least one of the preceding claims, characterized in that it has a movement device for moving the molding tool in at least one spatial direction. Method for processing a surface of at least one extruded strand extruded by a 3D printer with a device according to claims 1 until 21 , characterized in that the shaped body of the mold is guided along the surface of the at least one extruded strand extruded by a 3D printer, whereby a smoothing of the surface of the extruded strand is achieved. procedure after Claim 22 , characterized in that the shaped body is guided along the extruded strand several times. procedure after Claim 22 or 23 , characterized in that the at least one extruded strand is heated or cooled by means of the shaped body and/or the mold geometry. Method according to at least one of the preceding claims, characterized in that after each extrusion strand extruded through the 3D printer or after each extrusion strand or after each pressure layer, the shaped body of the molding tool is guided along the surface of the at least one extrusion strand extruded by the 3D printer. Method according to at least one of the preceding claims, characterized in that the shaped body of the shaping tool is guided along the extrusion strands extruded by the 3D printer only after the object to be formed by the 3D printer has been produced.

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