Extruder Device, Extruder System, and Use of an Extruder Device and/or of an Extruder System

Abstract

An extruder apparatus for the extrusion of a strand of building material for 3D printing of a structural part includes an extruder nozzle and at least one inner element. The extruder nozzle has a discharge opening for the discharge of the strand of building material out of the extruder apparatus. The at least one inner element is designed for arrangement within the extruder nozzle for purposes of defining an inner edge of a flow cross section of building material within the extruder nozzle in order to specify an inner edge of a strand cross section of the discharged strand of building material.

Claims

1. to 15. (canceled)

16. An extruder apparatus for extrusion of a strand of building material for 3D printing of a structural part, comprising: an extruder nozzle, wherein the extruder nozzle has a discharge opening for discharge of the strand of building material out of the extruder apparatus; and at least one inner element, wherein the at least one inner element is designed for arrangement within the extruder nozzle for purposes of defining an inner edge of a flow cross section of building material within the extruder nozzle for purposes of specifying an inner edge of a strand cross section of the discharged strand of building material.

17. The extruder apparatus as claimed in claim 16, wherein the at least one inner element is designed to be variably settable for purposes of variable setting within the extruder nozzle for purposes of variably setting the inner edge of the flow cross section for purposes of variably setting the inner edge of the strand cross section during the discharge of the strand of building material.

18. The extruder apparatus as claimed in claim 17, wherein the at least one inner element, in a first setting, does not specify an inner edge of the strand cross section, and/or wherein the at least one inner element, in a second setting, specifies a division into two by way of an interruption in a horizontal direction of the strand cross section.

19. The extruder apparatus as claimed in claim 17, wherein the extruder apparatus has at least two inner elements, wherein the two inner elements are designed to be variably adjustable for purposes of variable arrangement with respect to one another for purposes of variably setting the inner edge of the flow cross section.

20. The extruder apparatus as claimed in claim 16, wherein the extruder nozzle specifies a discharge direction of the strand of building material out of the extruder apparatus, and wherein the at least one inner element has a flow-directing surface directing the flow of building material within the extruder nozzle for purposes of defining the inner edge of the flow cross section, wherein the flow-directing surface is designed for non-orthogonal orientation with respect to the discharge direction.

21. The extruder apparatus as claimed in claim 16, wherein the at least one inner element is an inner wall.

22. The extruder apparatus as claimed in claim 16, wherein the extruder nozzle has multiple peripheral walls, wherein the multiple peripheral walls define an outer edge of the flow cross section of building material for purposes of specifying an outer edge of the strand cross section of the discharged strand of building material.

23. The extruder apparatus as claimed in claim 22, wherein at least two of the peripheral walls are designed to be variably settable for purposes of variable arrangement with respect to one another for purposes of variably setting the outer edge of the flow cross section for purposes of variably setting the outer edge of the strand cross section during the discharge of the strand of building material.

24. The extruder apparatus as claimed in claim 16, wherein the extruder nozzle has at least one peripheral wall, wherein an extent of the extruder apparatus in a vertical direction is defined by the peripheral wall and wherein the discharge opening is peripherally partially defined by the peripheral wall, and/or wherein the extruder apparatus has a deflecting device, wherein the deflecting device is arranged upstream of the discharge opening and is designed to deflect a flow of building material in the direction of the discharge opening.

25. An extruder system for extrusion of a strand of building material for 3D printing of a structural part, comprising: an extruder apparatus as claimed in claim 16, and at least one controllable setting apparatus, wherein the at least one controllable setting apparatus is designed for variably setting the at least one inner element and/or at least one peripheral wall of the extruder nozzle.

26. The extruder system as claimed in claim 25, further comprising: a controllable movement apparatus, wherein the movement apparatus is designed to at least translationally move the extruder apparatus during the discharge of the strand of building material.

27. The extruder system as claimed in claim 26, wherein the movement apparatus is designed to move the extruder apparatus in a horizontal movement direction, and wherein the extruder apparatus is designed to discharge the strand of building material out of the extruder apparatus in a discharge direction, which is non-orthogonal with respect to the movement direction during the movement, and/or wherein the extruder system is designed for the discharge of the strand of building material out of the extruder apparatus with a variably settable discharge speed, and wherein the movement apparatus is designed to move the extruder apparatus with a movement speed which is approximately equal to the discharge speed during the discharge.

28. The extruder system as claimed in claim 26, further comprising: a controllable building material pump, wherein the building material pump is designed to convey building material out of the extruder apparatus.

29. The extruder system as claimed in claim 28, further comprising: a control device, wherein the control device is designed to automatically control the at least one setting apparatus, the movement apparatus, and/or the building material pump in a manner dependent on data of the structural part that is to be printed.

30. The use of an extruder apparatus as claimed in claim 16 for extrusion of a strand of building material for 3D printing of a structural part.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Further advantages and aspects of the invention arise from the claims and from the following description of preferred exemplary embodiments of the invention, which are explained below on the basis of the figures.

[0041] FIG. 1 shows a perspective view of an extruder system according to the invention with an extruder apparatus according to the invention.

[0042] FIG. 2 shows a further perspective view of the extruder system with the extruder apparatus of FIG. 1.

[0043] FIG. 3 shows a front view of the extruder system with the extruder apparatus of FIG. 1 with at least one inner element in a first setting, at least one peripheral wall in a first setting and at least one cover element in a second setting.

[0044] FIG. 4 shows a side view of the extruder system with the extruder apparatus of FIG. 3.

[0045] FIG. 5 shows a front view of the extruder system with the extruder apparatus of FIG. 1 with the at least one inner element in a second setting, the at least one peripheral wall in the first setting and the at least one cover element in a first setting, without an upper peripheral wall and without a hose.

[0046] FIG. 6 shows a perspective view of the extruder system with the extruder apparatus of FIG. 5.

[0047] FIG. 7 shows a front view of the extruder system with the extruder apparatus of FIG. 1 with the at least one inner element in the first setting and the at least one peripheral wall in a second setting, without an upper peripheral wall, without a hose and without a cover element.

[0048] FIG. 8 shows a perspective view of the extruder system with the extruder apparatus of FIG. 7.

[0049] FIG. 9 shows a perspective view of the extruder system with the extruder apparatus of FIG. 1 with the at least one cover element in a third setting.

[0050] FIG. 10 shows a perspective view of the extruder system with the extruder apparatus of FIG. 1 with a pivoted-open upper peripheral wall and a pivoted-open lower peripheral wall and with a hose without a cover element.

[0051] FIG. 11 shows a perspective view of the extruder system with the extruder apparatus of FIG. 1 and a movement apparatus.

[0052] FIG. 12 shows a perspective view of the extruder system with the extruder apparatus of FIG. 1 and a building material pump, in particular during use according to the invention.

[0053] FIG. 13 shows structural parts 3D-printed using an extruder apparatus according to the invention and/or an extruder system according to the invention and composed of extruded strands of building material.

[0054] FIG. 14 shows a perspective view of a further extruder system according to the invention with a further extruder apparatus according to the invention.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

[0055] FIGS. 1 to 12 and 14 in particular each show an extruder system 20 having an extruder apparatus 1 for extrusion of a strand ST of building material BS for 3D printing of a structural part BWT. The extruder apparatus 1 has an extruder nozzle 5 and at least one inner element 30a, 30b. The extruder nozzle 5 has an in particular rectangular discharge opening 2 for the discharge of the strand ST of building material BS out of the extruder apparatus 1. The at least one inner element 30a, 30b is designed for arrangement within the extruder nozzle 5 for the purposes of defining in particular at least one inner edge 351 of an in particular rectangular flow cross section 35 of building material BS within the extruder nozzle 5 for the purposes of specifying in particular at least one inner edge 41 of an in particular rectangular strand cross section 4 of the discharged strand ST of building material BS.

[0056] In the exemplary embodiments shown, the extruder apparatus 1 has in particular exactly two inner elements 30a, 30b. In alternative exemplary embodiments, the extruder apparatus may have in particular only one or at least three inner elements.

[0057] Furthermore, the at least one inner element 30a, 30b is designed to be variably settable, in particular movable relative to the extruder nozzle 5, in particular in/counter to a first peripheral direction y, for the purposes of variable setting within the extruder nozzle 5 for the purposes of variably setting the inner edge 351 of the flow cross section 35 for the purposes of variably setting the inner edge 41 of the strand cross section 4, in particular during the discharge of the strand ST of building material BS. In alternative exemplary embodiments, the at least one inner element may additionally or alternatively be movable in/counter to a second peripheral direction.

[0058] In detail, the at least one inner element 30a, 30b, in a first, in particular inner, setting, does not specify an inner edge of the strand cross section 4, as shown in FIGS. 7 and 8 and FIG. 13 a), b) at the bottom and top, c) at the bottom and top, d) at the bottom and e) at the bottom and in the middle.

[0059] Additionally or alternatively, in a second, in particular outer setting, the at least one inner element 30a, 30b specifies a division into two parts by means of an in particular rectangular interruption 4U, in particular in an particular horizontal direction, in particular in the first peripheral direction y, of the strand cross section 4, as shown in FIGS. 5 and 6 and FIG. 13 b) in the middle, c) in the middle, d) in the middle and at the top and e) at the top.

[0060] In the exemplary embodiments shown, the interruption 4U is entirely over an in particular maximum opening height HO of the discharge opening 2. In alternative exemplary embodiments, the interruption may be in particular only partially over the in particular maximum opening height of the discharge opening.

[0061] In addition, the two inner elements 30a, 30b are designed to be settable, in particular into the first setting and the second setting, for the purposes of variable arrangement with respect to one another for the purposes of variably setting the inner edge 351 of the flow cross section 35.

[0062] In the exemplary embodiments shown, in the first setting, the two inner elements 30a, 30b, by way of ends at the side of the discharge opening, are arranged close together or lie against one another. Thus, in the first setting, the two inner elements 30a, 30b do not specify an inner edge of the flow cross section 35, in particular close to or in the region of the discharge opening 2, and thus do not specify an inner edge of the strand cross section 4. In particular, the flow cross section 35 without an inner edge, in particular close to or in the region of the discharge opening 2, specifies the strand cross section 4 without an inner edge.

[0063] Additionally or alternatively, in the second setting, the two inner elements 30a, 30b, by way of the ends at the side of the discharge opening, are arranged remote from one another, in particular in/counter to the first peripheral direction y. Thus, in the second setting, the two inner elements 30a, 30b specify a division into two with an in particular rectangular interruption 35U, in particular in an in particular horizontal direction, in particular in the first peripheral direction y, of the flow cross section 35, in particular close to or in the region of the discharge opening 2, and thus the division into two, with the interruption 4U, of the strand cross section 4. In particular, the two-part flow cross section 35 with the interruption 35U, in particular close to or in the region of the discharge opening 2, specifies the two-part strand cross section 4 with the interruption 4U.

[0064] The extruder nozzle 5 furthermore specifies an in particular horizontal discharge direction x of the strand ST of building material BS out of the extruder apparatus 1. The at least one inner element 30a, 30b has in particular in each case one flow-directing surface 31a, 31b for directing the flow of building material BS within the extruder nozzle 5 for the purposes of defining the inner edge 351 of the flow cross section 35. The in particular at least one flow-directing surface 31a, 31b is designed, in particular oriented in the exemplary embodiments shown, for non-orthogonal, in particular parallel, orientation with respect to the discharge direction x.

[0065] Furthermore, the at least one inner element 30a, 30b is an inner wall 32a, 32b.

[0066] Furthermore, the extruder nozzle 5 has multiple peripheral walls 7a, 7b, 7c, 7d, four in the exemplary embodiments shown. The peripheral walls 7a, 7b, 7c, 7d define an outer edge 35A of the flow cross section 35 of building material BS for the purposes of specifying an outer edge 4A of the strand cross section 4 of the discharged strand ST of building material BS.

[0067] In detail, at least two, in the exemplary embodiments shown exactly two, of the peripheral walls 7a, 7b are designed to be variably settable for the purposes of variable arrangement with respect to one another for the purposes of variably setting the outer edge 35A of the flow cross section 35 for the purposes of variably setting the outer edge 4A of the strand cross section 4, in particular during the discharge of the strand ST of building material BS.

[0068] In the exemplary embodiments shown, a left-hand peripheral wall 7a and a right-hand peripheral wall 7b are in particular each designed to be variably settable, in particular movable in/counter to the first peripheral direction y, for the purposes of variably setting a width of the flow cross section 35 for the purposes of variably setting a width of the strand cross section 4 or an opening width BO of the discharge opening 2. Additionally or alternatively, in alternative exemplary embodiments, a lower peripheral wall and/or an upper peripheral wall may in particular each be designed to be variably settable, in particular movable in/counter to the second peripheral direction, for the purposes of variably setting a height of the flow cross section for the purposes of variably setting a height of the strand cross section or the opening height of the discharge opening.

[0069] In a first setting shown in FIGS. 1 to 6, the two peripheral walls 7a, 7b are in particular each arranged as far to the outside as possible, or with a maximum spacing to one another, such that the width of the flow cross section 35 and thus the width of the strand cross section 4 or the opening width BO of the discharge opening 2 is set to a maximum or to be wide, in the exemplary embodiments shown 400 mm.

[0070] In a second setting shown in FIGS. 7 and 8, which in particular differs from the first setting, the two peripheral walls 7a, 7b are in particular each arranged as far to the inside as possible, or with a minimum spacing to one another, or so as to be as close together as possible, such that the width of the flow cross section 35 and thus the width of the strand cross section 4 or the opening width BO of the discharge opening 2 is set to a minimum or to be narrow, in the exemplary embodiments shown 200 mm.

[0071] In the embodiments shown, an opening height HO of the discharge opening 2 is 50 mm, in particular in the second peripheral direction z.

[0072] In detail, the extruder apparatus 1 has a hose 40 that is expandable, in particular by approximately a factor of 2, wherein the expandable hose 40 is arranged and designed to seal off the peripheral walls 7a, 7b, 7c, 7d against a peripheral discharge of building material BS, as shown in FIG. 10. In particular, the at least one inner element 30a, 30b is designed, in particular arranged, for arrangement within the hose 40.

[0073] Additionally or alternatively, at least one of the peripheral walls 7c, 7d is designed for being peripherally pivoted open, in particular in/counter to the second peripheral direction z, as shown in FIG. 10. This, in particular the pivoting open, allows easy installation of the expandable hose 40 and easy cleaning of the extruder system 20, in particular of the extruder apparatus 1, after the extrusion process, in particular after the concreting process.

[0074] In addition, an extent of the extruder apparatus 1 in an in particular vertical direction, in particular counter to the second peripheral direction −, is defined by the in particular lower peripheral wall 7c. The discharge opening 2 is peripherally defined partially, in particular in the direction −z, by the in particular lower peripheral wall 7c.

[0075] Additionally or alternatively, the extruder apparatus 1 has a deflecting device 9. The deflecting device 9 is arranged upstream of the discharge opening 2 and is designed to deflect a flow of building material BS, in particular from a pipe flange, in the direction, in particular in the discharge direction x, of the discharge opening 2.

[0076] The extruder apparatus 1 also has at least one cover element 8a, 8b. The at least one cover element 8a, 8b has a variably settable design, in particular is movable, in particular in/counter to a first peripheral direction y and/or second peripheral direction z, in particular relative to the discharge opening 2 or the extruder nozzle 5, in particular into at least two, in particular at least three, different settings, for the variably settable covering of at least one part of the discharge opening 2.

[0077] In the exemplary embodiments shown, the extruder apparatus 1 has in particular exactly two cover elements 8a, 8b. In alternative exemplary embodiments, the extruder apparatus may have in particular only one or at least three cover elements.

[0078] In detail, the at least one cover element 8, 8a, 8b is designed to be variably settable for the purposes of separating off, in particular cutting off, the discharged strand ST of building material BS from the extruder apparatus 1, in particular at the discharge opening 2. This can allow an in particular clean or smooth end of the in particular discharged and/or deposited strand 4, in particular at a time after the extrusion, in particular during the transposition of the extruder apparatus 1, in particular between different wall elements.

[0079] In the exemplary embodiments shown, the at least one cover element 8a, 8b has a cutting plate or a blade 8aK, 8bK.

[0080] In a first setting shown in FIGS. 5 and 6, the at least one cover element 8a, 8b does not cover any part of the discharge opening 2. In particular, the at least one cover element 8a, 8b is lifted off in the second peripheral direction z.

[0081] In a second setting which is shown in FIGS. 1 and 4 and which in particular differs from the first, the at least one cover element 8a, 8b covers an in particular inner part of the discharge opening 2.

[0082] In a third setting which is shown in FIG. 9 and which in particular differs from the first and second, the at least one cover element 8a, 8b covers two in particular outer parts of the discharge opening 2.

[0083] By movement from/to the setting shown in FIGS. 1 to 4 to/from the setting shown in FIG. 9 of the at least one cover element 8a, 8b, in particular in/counter to the first peripheral direction y, the discharged strand ST of building material BS is separated off from the extruder apparatus 1.

[0084] Additionally or alternatively, an extent of the extruder apparatus 1 in an in particular horizontal direction, in particular in the discharge direction x, in particular toward the front, is defined by the at least one cover element 8a, 8b. This allows an in particular clean or smooth separating-off action and/or an in particular clean depositing of the discharged strand and/or an particular clean or smooth connection of the strand to an already extruded strand, in particular without damaging the latter.

[0085] Moreover, the extruder system 20 has an in particular controllable movement apparatus 22, as shown in FIG. 11. The movement apparatus 22 is designed to at least translationally move the extruder apparatus 1, in particular during the discharge of the strand ST of building material BS.

[0086] In the exemplary embodiment shown, the movement apparatus 22 has a movement arm. Additionally or alternatively, the movement apparatus 22 and/or the extruder apparatus 1 are/is designed to move the extruder apparatus 1 in rotation, in particular during the discharge of the strand ST of building material BS. In detail, the extruder apparatus 1 is rotatable about a longitudinal axis of the pipe flange by means of an in particular electric motor and in particular a screw drive.

[0087] In detail, the movement device 22 is designed to move the extruder apparatus 1 in an particular horizontal movement direction −x. The extruder apparatus 1 is designed for the discharge of the strand ST of building material BS out of the extruder apparatus 1 in the discharge direction x which is non-orthogonal, in particular opposite, to the movement direction −x, in particular during the movement.

[0088] Additionally or alternatively, the extruder system 20, in particular the extruder apparatus 1, is designed for the discharge of the strand ST of building material BS out of the extruder apparatus 1 with an in particular variably settable discharge speed vx. The movement apparatus 22 is designed to move the extruder apparatus 1 at a movement speed v-x approximately equal to the discharge speed vx, in particular during the discharge.

[0089] Furthermore, the extruder system 20 has an in particular controllable building material pump 23, as shown in FIG. 12. The building-material pump 23 is designed to convey building material BS out of the extruder apparatus 1.

[0090] In the exemplary embodiment shown, the building material pump is discontinuous, in particular a piston pump. Additionally or alternatively, the extruder system 20 has a building material conveying line, wherein the building material conveying line connects the building material pump 23 to the extruder apparatus 1 for a stream of building material BS from the building material pump 23 through the building material conveying line to the extruder apparatus 1.

[0091] Furthermore, the extruder system 20 has at least one in particular controllable setting apparatus 213, 217a, 217b, 218a, 218b. The at least one setting device 213, 217a, 217b, 218a, 218b is designed for the variable setting of the at least one in particular variably settable inner element 30a, 30b and/or of the at least one in particular variably settable peripheral wall 7a, 7b and in particular of the at least one in particular variably settable cover element 8a, 8b.

[0092] In the exemplary embodiments shown, the extruder apparatus 1 has the at least one setting apparatus 213, 217a, 217b, 218a, 218b.

[0093] In detail, the setting apparatus 213 for moving the at least one inner element 30a, 30b in/counter to the first peripheral direction y has an in particular electrical setting motor 213E and/or at least one movement deflecting mechanism 213U, in particular at least one lever mechanism, and/or an in particular mechanical linear drive 213L, in particular a threaded spindle drive. The setting motor 213E is arranged, counter to the discharge direction −x, behind the extruder nozzle 5 and in particular the deflecting device 9 and/or is connected in terms of movement to the at least one inner element 30a, 30b by means of the at least one movement deflecting mechanism 213U and/or the linear drive 213L.

[0094] In particular, the spindle, in particular in the deflecting device 9, is protected from the surrounding building material flow by means of a pipe.

[0095] In the exemplary embodiments shown, the two inner elements 30a, 30b are not designed to be mutually distinctly or individually or separately variably settable. In alternative exemplary embodiments, the two inner elements may in particular in each case be designed to be individually variably settable.

[0096] Furthermore, in FIGS. 1 to 9, the at least one setting apparatus 217a, 217b for moving the at least one peripheral wall 7a, 7b in/counter to the first peripheral direction y has an in particular electrical setting motor 217aE, 217bE and/or at least one movement deflecting mechanism 217aU, 217bU, in particular a lever mechanism, and/or at least one in particular mechanical linear drive 217aL, 217bL, in particular at least one threaded spindle drive. The at least one setting motor 217aE, 217bE is arranged, in particular transversely, in the second peripheral direction z above the extruder nozzle 5 or the peripheral wall 7d and/or is connected in terms of movement to the at least one peripheral wall 7a, 7b by means of the at least one movement deflecting mechanism 217aU, 217bU and/or the at least one linear drive 217aL, 217bL.

[0097] In addition, in FIG. 14, the at least one setting apparatus 217a, 217b for moving the at least one peripheral wall 7a, 7b in/counter to the first peripheral direction y has an in particular electrical setting motor 217aE, 217bE and/or at least one movement deflecting mechanism 217aU, 217bU, in particular a lever mechanism, and/or at least one in particular mechanical linear drive 217aL, 217bL, in particular at least one threaded spindle drive. The at least one setting motor 217aE, 217bE is arranged, in particular longitudinally, in/counter to the first peripheral direction y to the side of the extruder nozzle 5 or the at least one peripheral wall 7a, 7b and/or is connected in terms of movement to the at least one peripheral wall 7a, 7b by means of the at least one movement deflecting mechanism 217aU, 217bU and/or the at least one linear drive 217aL, 217bL. In particular, the extruder nozzle 5 has, proceeding from the discharge opening 2, in particular in the case of maximum opening height HO, counter to the discharge direction -x, a taper 5V in/counter to the first peripheral direction y, wherein the at least one setting motor 217aE, 217bE is arranged to the side of the extruder nozzle 5 at the taper 5V.

[0098] In the exemplary embodiment shown in particular in each case in FIGS. 1 to 9 and 14, the two peripheral walls 7a, 7b are in particular in each case designed to be mutually distinctly or individually or separately variably settable. In alternative exemplary embodiments, the two peripheral walls may be designed not to be mutually distinctly variably settable.

[0099] Furthermore, the setting apparatus 218a for moving the at least one cover element 8a, 8b in/counter to the second peripheral direction z has an in particular electrical setting motor 218aE and/or an in particular mechanical rotary drive 218aD. The setting motor 218aE is arranged in the second peripheral direction z above the extruder nozzle 5 or the peripheral wall 7d and/or is connected in terms of movement to the at least one cover element 8a, 8b by means of the rotary drive 218aD.

[0100] In addition, the setting apparatus 218b for moving the at least one cover element 8a, 8b in/counter to the first peripheral direction y has an in particular electrical setting motor 218bE and/or a movement deflecting mechanism 218bU, in particular a belt mechanism, and/or an in particular mechanical linear drive 218bL, in particular a threaded spindle drive. The setting motor 218bE is arranged in the second peripheral direction z above the extruder nozzle 5 or the peripheral wall 7d and/or is connected in terms of movement to the at least one cover element 8a, 8b by means of the movement deflecting mechanism 218bU and/or the linear drive 218bL.

[0101] Furthermore, the extruder system 20, in particular the extruder apparatus 1, has a number of in particular controllable injection nozzles, in particular cyclically operated high-pressure nozzles with a pressure greater than 10 bar, in particular greater than 100 bar. The injection nozzles are designed for injecting, in particular for admixing or introducing, an additive, in particular concrete accelerator, in particular directly into the building material BS before it is discharged. This, in particular the high pressure, allows the additive to be widely distributed such that no further mixing element is required. In detail, the number of injection nozzles is arranged above the extruder nozzle 5 or the peripheral wall 7d in the second peripheral direction z and/or behind the extruder nozzle 5, and in particular the deflecting device 9, counter to the discharge direction -x. This, in particular the arrangement, makes it possible that, in pumping intervals or interruptions in the printing process, the smallest possible amount of activated building material, in particular concrete, is present in the extruder system 20, in particular the extruder apparatus 1, and/or has to be disposed of.

[0102] The extruder system 20 furthermore has a control device 24. The control device 24 is designed to in particular automatically control the at least one in particular controllable setting apparatus 213, 217a, 217b, 218a, 218b and/or the in particular controllable movement apparatus 22 and/or the in particular controllable building material pump 23, and in particular the number of in particular controllable injection nozzles, in a manner dependent on data DBWT of the structural part BWT to be printed.

[0103] Furthermore, the extruder system 20, in particular the extruder apparatus 1, is designed to deposit the discharged strand ST such that the in particular deposited strand ST maintains its strand cross section 4, in particular of the discharged strand ST.

[0104] Furthermore, the strand ST may be deposited, in particular in layers, on an already extruded strand ST and/or a further strand ST may be deposited, in particular in layers, on the strand ST, as shown in FIG. 13.

[0105] In particular, FIGS. 12 and 13 show the use according to the invention of the extruder apparatus 1 and/or of the extruder system 20 for the extrusion of the strand ST of building material BS for 3D printing of the structural part BWT, and structural parts BWT 3D-printed by means of the extruder apparatus 1 and/or the extruder system 20 and composed of extruded strands ST of building material BS.

[0106] In detail, the rectangular strand cross section 4 shown in particular in each case in FIG. 13 a), b) at the bottom and top, c) at the bottom and top, d) at the bottom and e) at the bottom may be specified or is specified by the at least one inner element 30a, 30b in the first setting and by the peripheral walls 7a, 7b, in particular in each case in the first setting or situated as far to the outside as possible, in particular without a cover element.

[0107] The rectangular strand cross section 4 shown in particular in each case in FIG. 13 c) in the middle, d) in the middle and at the top and e) at the top may be specified or is specified by the at least one inner element 30a, 30b in the second setting and by the peripheral walls 7a, 7b, in particular in each case in the first setting or situated as far to the outside as possible, in particular without a cover element.

[0108] The rectangular strand cross in the middle section 4 shown in FIG. 13 b) may be specified or is specified by the at least one inner element 30a, 30b in the second setting, by the peripheral wall 7a in the first setting or situated as far to the outside as possible and by the peripheral wall 7b in the second setting or situated as far to the inside as possible, in particular without a cover element. In particular, the inner element 30b, in particular by way of the end at the side of the discharge opening, and the peripheral wall 7b may lie against one another, or said element and peripheral wall lie against one another.

[0109] It is thus possible for slots be produced vertically in a strand or a layer or a ply ST and horizontally on an outer side of the strand ST, as shown in FIG. 13, in particular b) to e). In particular, it is thus possible to generate two narrow or thin structural parts or walls BWT which are connected by means of webs and which have a passage, in order for the intermediate space to later be filled with insulation material or to accommodate installation lines. In particular, the strand cross sections 4 of FIGS. 13 c), d) and e) may be arranged in particular in this sequence in and/or counter to the discharge direction x. In addition or alternatively, it is thus possible to produce open strand cross sections 4 in order to generate a media channel. In particular, the strand cross sections 4 of FIGS. 13 a), b), c) and d) may be arranged in particular in this sequence in and/or counter to the discharge direction x. Further additionally or alternatively, a support structure such as a lattice may be arranged and/or is arranged on those strands ST which do not extend over the entire maximum opening width BO, in order to allow at least one further strand ST to be deposited. This can make it possible to prevent soft building material from sagging downward into the space, in particular hollow space.

[0110] As the exemplary embodiments shown and discussed above make clear, the invention provides an advantageous extruder apparatus for the extrusion of a strand of building material for 3D printing of a structural part, which extruder apparatus has improved characteristics, in particular allows more degrees of freedom. The invention furthermore provides an extruder system having such an extruder apparatus, and the use of such an extruder apparatus and/or of such an extruder system.