Magnetohydrodynamic printing head

Abstract

There is provided an arrangement and a method for extruding a conductive material through an orifice by the means of magnetohydrodynamic forces. The device and the method allow for increased temperature control of the extruded material compared to prior art solutions. The arrangement and method further allow the conductive material to be extruded at a controllable angle out of the orifice.

Description

[0001] MAGNETOHYDRODYNAMIC PRINTING HEAD

[0002] BACKGROUND

[0003] Electromagnetic pumps (EM pumps) rely on electromagnetic forces, called Lorentz forces, to bring a conductive liquid into fluid motion. For all EM pumps, the electromagnetic forces that allow fluid motion is achieved by the interaction between an electric current in the conductive liquid and an externally applied magnetic flux.

[0004] Generally, in the art, EM pumps are divided into conductive and inductive devices. Conductive EM pumps known in the art, see for example the published US patent US 6,202,734 Bl, expose a conductive liquid to a constant magnetic flux as well as to a controllable electric current, orthogonal to the magnetic flux, generated by an electrode pair. This way, a Lorentz force orthogonal to both the electric current and the magnetic flux is achieved. The flow rate and direction of the conductive liquid is controlled by the magnitude and direction of the applied electric field between the electrodes.

[0005] Inductive EM pumps know in the art, see for example the published US patent US 4,842,170 Bl, instead expose the conductive liquid to a rapidly alternating magnetic flux. This induces eddy currents within the conductive liquid having an associated magnetic flux which is perpendicular to said applied rapidly alternating magnetic flux. This results in magnetic repulsion and the generation of a force component in the direction of the applied magnetic field. Since the required electrical current in the conductive liquid is achieved via eddy currents, there is no need to generate any electric current in the conductive liquid using electrodes.

[0006] A problem for both conductive and inductive EM pumps is that of Joule heating of the conductive liquid. For conductive EM pumps any change of flow rate or flow direction is achieved by altering the magnitude and / or direction of the applied electric current. This has direct consequences for the temperature control as it affects the degree of resistive heating of the conductive liquid.

[0007] Similarly, for inductive EM pumps, changes to flow rate or flow direction are achieved by altering the frequency of the magnetic flux which affects the amount of inductive heating of the conductive liquid, this too impairs on temperature control.

[0008] Joule heating is a particularly inconvenient problem in applications where temperature control of the conductive liquid is of importance, for example during filament extrusion processes, injection moulding or metal 3D printing. Hence, there is a need for a solution which enables extrusion processes of liquid conductive materials with improved temperature control.

[0009] SUMMARY OF THE INVENTION

[0010] The invention is set out in the appended set of claims. This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description.

[0011] It is an object of the present invention to provide a solution wherein the control of the temperature of the material to be extruded is considerably improved compared to the prior art.

[0012] According to a first aspect there is provided an arrangement for extruding conductive materials. The arrangement has a chamber comprised of a non- conductive material for receiving a conductive material at a first end. The chamber is fluidly connected to an orifice at a second end through which a received conductive material can be extruded. The arrangement for extruding conductive materials further has an electrode pair for generating an electric current through conductive material received in the chamber, and one or more electromagnets for generating a magnetic flux. The magnetic flux through material received in the chamber is defined by an angular direction and a magnitude. The position and direction of the electrode pair and the one or more electromagnets define an intersection between the electric current and the magnetic flux in conductive material received in the chamber.

[0013] In a second aspect of the invention there is provided a method for extruding conductive materials. The method comprising: receiving a conductive material in a chamber being fluidly connected to an orifice through which the received conductive material can be extruded; generating a current through the conductive material received in the chamber via an electrode pair; exposing the conductive material received in the chamber to a magnetic flux defined by an angular direction and a magnitude, said magnetic flux intersecting said current, said magnetic flux being generated by one or more electromagnets; extruding the conductive material from said orifice by controlling the direction and magnitude of the magnetic flux to which the received conductive material is exposed.

[0014] Because the present invention circumvents using a varying electric current through the conductive material received in the chamber, the present invention results in that varying resistive heating and / or inductive heating is avoided, and the overall temperature control is improved.

[0015] A further scope of applicability will become apparent from the detailed description given below. However, it should be understood that the detailed description and specific examples are given by way of illustration only.

[0016] BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above and other aspects will now be described in more detail, with reference to appended figures. The figures should not be considered limiting; instead they are used for explaining and understanding.

[0018] As illustrated in the figures, the certain aspects of the depicted elements may be exaggerated for illustrative purposes and, thus, are provided to illustrate the general. Like reference numerals refer to like elements throughout. Fig. 1: Illustrates an embodiment of the arrangement having one electromagnet.

[0019] Fig. 2: Schematic illustration of the interaction between the electric current and the magnetic field, and the direction of the achieved extrusion force.

[0020] Fig. 3: Illustrates an embodiment of the arrangement having two electromagnets oriented along a common axis.

[0021] Fig. 4: Illustrates the principle of the interaction between two non-parallel electromagnets and how the resulting magnetic flux can be influenced by the currents suppled to the electromagnets.

[0022] Fig. 5A: Illustrates examples of embodiments of the arrangement having two electromagnets being non-parallel with one another.

[0023] Fig. 5B: Illustrates yet another example embodiment of an arrangement having three electromagnets being non-parallel with one another.

[0024] Fig. 6: Schematic illustration of the interaction between the electric current and the magnetic field, and the direction of the achieved extrusion force as well as the extrusion direction.

[0025] Fig. 7: Is a flow diagram of steps of an embodiment of a method for extruding for extruding conductive materials.

[0026] DETAILED DESCRIPTION

[0027] It is to be understood that the terminology used herein is for purpose of describing particular embodiments only, and is not intended to be limiting. It must be noted that, as used in the specification and the appended claim, the articles "a," "an," "the," and "said" are intended to mean that there are one or more of the elements unless the context clearly dictates otherwise. Thus, for example, reference to "a unit" or "the unit" may include several devices, and the like. Furthermore, the words "comprising", "including", "containing" and similar wordings does not exclude other elements or steps. The prior art is associated with a limited possibility of having control of the temperature as the manipulation of an extrusion force is achieved by varying the current through a conductive material received in the chamber in conductive EM pumps, or by varying the frequency of the rapidly switching magnetic flux in inductive EM pumps. This results in a varying Joule heating, due to a varying resistive heating and inductive heating for conductive EM pumps and inductive EM pumps, respectively. Both resistive heating and inductive heating heats the material from within, hence these types of heating are more rapid compared to the more sluggish heating and cooling provided by an external heater and by the conductive dissipation of heat from the material to its surroundings, respectively. This limits the possibilities to achieve well-defined temperatures in prior art solutions. Because the present invention neither uses a varying electric current nor a rapidly switching magnetic flux though the conductive material received in the chamber for manipulating the extrusion force, the varying resistive heating and / or inductive heating is avoided and thereby the overall knowledge of the temperature conditions is improved.

[0028] One of the implications of a limited control of the temperature conditions, as in prior art, is that of excessive heating of the extruded material, resulting in increased evaporation and instability of the material which is to be extruded. Furthermore, poor knowledge of the instantly prevailing temperature may also causes variation in the viscosity of the material which in turn causes undesirable variations in for example extrusion rates or in the quality of the extruded material.

[0029] Hence, to obtain a well-defined and preferably essentially stable temperature is a key factor in many applications where conductive materials, for example metals, are extruded.

[0030] Figure 1 illustrates an arrangement 1 for extruding a conductive material. The arrangement can be used to extrude any conductive material and the examples given herein should not be interpreted as limiting. Also, the arrangement 1 can be used for various applications wherein extrusion of a conductive material is required. Non-limiting examples of such applications include additive manufacturing, filament extrusion and injection molding applications.

[0031] The arrangement 1 comprises a chamber 10 for receiving a conductive material at a first end 11, the chamber 10 being fluidly connected to an orifice 20 through which a received conductive material can be extruded. The chamber 10 is illustrated in Fig. 1 as being a cylindrical tube, however this is a non-limiting example as alternative shapes and forms may be used for the chamber 10. The chamber 10 is at least partly comprised of a non-conductive material, i.e. a dielectric material. Non-limiting examples of such materials include alumina, volcanic rock, limestone, clay, graphite, or their composites. Many other materials exhibiting dielectric properties and thermal shock resistance are possible candidates.

[0032] The arrangement for extruding a conductive material 1 further comprises electrodes 30a, 30b of an electrode pair. The electrodes 30a, 30b are electrically insulated from one another by the dielectric material from which the chamber 10 is comprised. The electrode pair is arranged to generate an electric current through conductive material received in the chamber 10. Therefore the electrode pair is arranged such that the electrodes 30a, 30b are brought into an electrical connection with each other only via a conductive material received in the chamber 10. A nonlimiting example of such an arrangement includes the insertion of the respective electrode 30a, 30b into bores of the chamber 10. However, other arrangements, which ensure that the electrodes 30a, 30b are brought into electrical contact with one another only via a conductive material received in the chamber 10 are possible. Preferably, the electric current through material received in the chamber 10 may be considered as a non-varying electric current in the sense that its magnitude and direction is not changed for the controlling of the extrusion of conductive material received in the chamber 10, i.e. a more or less stable potential is kept between the electrodes 30a, 30b. The magnitude of the electric current is determined by the electrode potential and the resistivity of a conductive material received in the chamber 10. Hence different electric currents may be used for different conductive materials received in the chamber 10 to obtain suitable operation material conditions. Provided the non-varying electric current through conductive material received in the chamber 10, a constant Joule heating is attained as a result of a nonvarying resistive heating. This non-varying heating is particularly beneficial for the obtaining control of the temperature of the conductive material received in the chamber 10. Smaller variations in the electric current, giving rise to temperature variations that are neglectable for the overall temperature conditions may, however, be allowed.

[0033] The arrangement 1 for extruding a conductive material further comprises one or more electromagnets 40, in the present embodiment one electromagnet 40, for generating a magnetic flux defined by having a magnitude and an angular direction. One or more current controllers 50 are electrically connected to the one or more electromagnets 40 for controlling currents supplied to the one or more electromagnets 40. Hence the magnitude and direction of the magnetic flux generated by the one or more electromagnets 40 is controlled by the one or more current controllers 50.

[0034] With reference to Fig. 2, a position and direction of the electrode pair and the one or more electromagnets, defines and intersection 60 between the electric current 31 and the magnetic flux 41 in conductive material received in the chamber. Said intersection 60 being an intersection wherein the direction of the electric current 31 and the direction of the magnetic flux 41 are non-parallel to one another. Fig. 2 provides a simplified illustration of this intersection 60 formed by the electric current 31 and the magnetic flux 41. Although the illustration in Fig. 2 may be interpreted as if the intersection 60 is defined by a plane, the skilled person would understand that the interaction 60 is defined by a volume wherein the electric current 31 and the magnetic flux 41 intersect. At said intersection 60, an extrusion force 70 acting on conductive material received in the chamber is achieved by the interaction between the magnetic flux 41 and the electric current 31 through material received in the chamber. The achieved extrusion force 70 is orthogonal to both the direction of the magnetic flux 41 as well as to the direction of the electric current 31. The achieved extrusion force 70 is defined by Equation 1, and its direction is further defined by the well-known right-hand rule.

[0035] F = pzE + J X B Equation 1

[0036] With additional reference to Fig. 1, since the electric current preferably is a non-varying electric current as defined earlier, it is the currents supplied by said one or more current controllers 50 to the one or more electromagnets 40 which determines the magnitude and direction of the magnetic flux, and thereby an angular direction and a magnitude of the extrusion force achieved by said interaction between the magnetic flux and the non-varying electric current. In some embodiments, as e.g. shown in Fig 1, where the arrangement 1 for extruding a conductive material comprises one electromagnet 40, the current supplied to the one electromagnet will determine the magnitude of the magnetic flux, meanwhile the position and direction of the electromagnet 40 relative to the electrode pair will determine the angular direction and magnitude of the magnetic flux at said intersection 60. Switching the direction of the current supplied to the one electromagnet also switches the direction of the magnetic flux. In other words, the angular direction of the magnetic flux, and thereby also the direction of the extrusion force, is changed by 180° degrees. This may be useful when ensuring that no material accidentally exits the orifice 20.

[0037] In arrangements comprising one electromagnet, the electromagnet is preferably positioned and directed such that the magnetic flux and the non-varying current intersect one another at near right angels. This is, however, a non-limiting example as the one electromagnet may also be positioned and directed such that the intersection 60 of the magnetic flux and the non-varying electric current occurs at any angle where the two are non-parallel. In other words, in embodiments having only one electromagnet 40, the direction of the magnetic flux and hence the direction of the extrusion force is strongly dependent on the direction of the one electromagnet 40. In another embodiment, as shown in figure 3, the arrangement for extruding a conductive material 1 comprises two electromagnets 40 positioned and directed along a common axis 45. Each of the two electromagnets 40 along the common axis 45 may be supplied with currents from an independent current controller 50. The direction of the currents supplied to each of the two electromagnets 40 may be such that the poles of the two electromagnets 40 facing each other along axis 45 either repel or attract one another. In the case where the two facing poles attract, the resulting magnetic flux 41 is more uniform compared to embodiments comprising one magnet. Similarly to embodiments having one electromagnet 40, embodiments comprising two electromagnets 40 positioned and directed along a common axis 45, preferably has the common axis 45 positioned and directed such that the magnetic flux 41 and the electric current 31 intersect at right angles. Again, this is a nonlimiting example as the two electromagnets 40 positioned and directed along a common axis 45 may also be positioned and directed such that the intersection 60 of the magnetic flux 41 and the non-varying electric current 31 occurs at any angle where the two are non-parallel.

[0038] In other embodiments, the arrangement 1 for extruding a conductive material 1 may comprise two or more electromagnets 40 wherein at least two of the two or more electromagnets 40 are positioned and directed to be non-parallel with at least one or more of the two or more electromagnets 40. In such embodiments, the currents supplied by said one or more current controllers 50 to the two or more electromagnets 40 and their relative positions and directions, determines a relative contribution from each one of the two or more electromagnets 40, to the angular direction and magnitude of the magnetic flux 41 though conductive material received in the chamber 10. This is schematically explained in Fig. 4 wherein the direction of the magnetic flux 41 at the intersection 60 is changed when the polarity of electromagnet 40b is switched, i.e. the direction of the current supplied the electromagnet 40b by its current controller is reversed. Thereby, both the magnitude and direction of the magnetic flux 41 generated by the two or more non- parallel electromagnets 40 can be controlled in a step-less manner, by individually controlling the currents supplied to each of the at least two electromagnets 40.

[0039] Fig. 5 provides two non-limiting examples of such embodiments. Fig. 5a shows an embodiment comprising two electromagnets 40a, 40b being positioned and directed to be non-parallel with each other. One of the electromagnets 40a is further positioned and directed such that its contribution to the magnetic flux is at right angles relative to the electric current.

[0040] Another example of an embodiment comprising multiple non-parallel electromagnets 40a, 40b, 40c is shown in Fig. 5b wherein none of the three electromagnets 40a, 40b, 40c are positioned or arranged to be parallel with one another nor with the electric current.

[0041] In some embodiments, with at least two or more electromagnets 40, each electromagnet 40 has its own current supplying current controller 50, as exemplified in Fig 5a.

[0042] In other embodiments, some of the two or more electromagnets 40 may be grouped based on their relative positions and directions. Electromagnets 40 are preferably grouped with consideration for symmetrical aspects pertaining to the direction of the magnetic flux 41 collectively generated by the electromagnets 40 in a group. An example of such a group is two electromagnets positioned and directed along a common axis. A group of electromagnets 40 may be supplied with currents from one current controller 50 such that the same amount of current is supplied to each electromagnet 40 within the group. The direction of the supplied current within the coils of the electromagnets 40 in a group need not be the same for all electromagnets in the group. Grouping electromagnets 40 this way, allows said symmetrical aspects of the magnetic flux generated by the electromagnets in a group to be maintained while manipulating the magnitude of the same. Different groups of electromagnets 40 within the same embodiment may contribute to different directions of the magnetic flux 41 at the intersection 60 with the electric current 31. Hence, a plurality of currents supplied to a plurality of groups of electromagnets 40 may be independently controlled to control the direction of the magnetic flux at said intersection 60 and thereby controlling the direction of the extrusion force 70.

[0043] In order to fully utilize the directional control of the extrusion force, the orifice is preferably arranged to enable extrusion of conductive material therefrom in a plurality of angular directions. Preferably, as illustrated in Fig. 6, the orifice 20 is arranged to be proximate to the intersection 60. the direction of the extruded material out of the orifice is henceforth referred to as the extrusion direction 71 defined by an angular direction 72 relative to the orifice 20. The extrusion direction 71 is determined by the direction of the extrusion force 70. Equally, since the direction of the extrusion force 70 is determined by, i.e. orthogonal to, the direction of the magnetic flux 41, the orifice 20 can be said to be arranged to enable extrusion of conductive material therefrom in an extrusion direction 71 being determined by the angular direction of the magnetic flux 41, this is exemplified in Fig. 6. The extrusion direction 71 can also be said to be determined by the currents supplied to the one or more electromagnets since the direction of the magnetic flux 41 is determined by said supplied currents.

[0044] As the magnetic flux 41 generated by an electromagnet 40 is temperature dependent, and because the supplying of a current to and electromagnet 40 is associated with a heating of the same, the arrangement 1 for extruding a conductive material may preferably further comprise means for providing cooling 80 of the electromagnets 40 for increased control of the generated magnetic flux 41, as schematically indicated in Figs. 5a and 5b. Said means for providing cooling 80 may include any cooling solution known in the art, non-limiting examples being air- cooling, liquid cooling and solid-state cooling.

[0045] The arrangement 1 for extruding a conductive material may preferably also comprise a heater unit 90 as shown in Fig. 5a and 5b. The heater unit 90 being positioned and arranged to maintain conductive material received in the chamber 10 at a desired temperature. The desired temperature may be chosen based on the specific conductive material received in the chamber 10 or based on desired material properties associated with a specific temperature or temperature range for a given material. The heater 90 may be comprised of an induction coil, as shown in Fig. 5a and 5b, or of resistive heating elements. Such heating equipment is, as such, well known for a person skilled in the art.

[0046] In a second aspect of the invention, there is provided a method for extruding conductive materials. Preferably, the method is performed using the arrangement 1 according to the first aspect of the invention, embodiments of which are described above. An embodiment of the method comprising: receiving SI a conductive material in a chamber 10 being fluidly connected to an orifice 20 through which the received conductive material can be extruded; generating S2 a current 31 through the conductive material received in the chamber 10 via an electrode pair 30a, 30b; exposing S3 the conductive material received in the chamber 10 to a magnetic flux 41 having an angular direction and a magnitude, said magnetic flux 41 intersecting said current at an intersection 60, said magnetic flux 41 being generated by one or more electromagnets 40; and extruding conductive material from said orifice 20 by controlling S4 the direction and magnitude of the magnetic flux 41 to which the received conductive material is exposed.

[0047] In one embodiment of the method the generation S2 of a current 31 though the received conductive material is a generation of a non-varying current 31. The current 31 being a non-varying current in the sense that its magnitude and direction is not changed for the controlling S4 of the extrusion of conductive material received in the chamber 10. The non-varying current 31 is determined by the potential applied across the electrode pair 30a and 30b and the resistivity of the material received in the chamber 10. Hence different non-varying currents 31 can be applied depending on the material received in the chamber 10 and the applied potential.

[0048] In a further embodiment, the method is further characterized by that said controlling S4 of the direction and magnitude of the magnetic flux 41 to which the received conductive material is exposed S3 comprises supplying of controlled currents to the one or more electromagnets 40. The controlling of currents may in some embodiments mean controlling the supplying of controlled currents to at least two non-parallel electromagnets 40. The non-parallel electromagnets 40 each contributes to a direction of the magnetic flux 41 to which the material received in the chamber 10 is exposed. In other words, the direction of the magnetic flux 41 can be controlled S4 in a plurality of directions by controlling the currents supplied to each electromagnet 40.

[0049] In some embodiments, the controlling of the supplied current to the electromagnets is performed individually for each electromagnet 40 in the arrangement.

[0050] In other embodiments, one or more electromagnets 40 may be grouped into groups, said groups supplying said magnetic flux 41 in different angles, and said controlling the supplied currents to the electromagnets is performed equally for all magnets in the same group.

[0051] Yet another characterizing feature of the method is that an angular direction of the conductive material out of the orifice is controlled by controlling S4 the contributions to the direction of the magnetic flux, i.e. by the controlling of the supplied currents to the electromagnets or groups of electromagnets.

[0052] The embodiments described above are to be understood as a few illustrative examples of the present invention. It will be understood by those skilled in the art that various modifications, combinations and changes may be made to the embodiments without departing from the scope of the present invention. In particular, different part solutions in the different embodiments can be combined in other configurations, where technically possible. The scope of the present invention is, however, defined by the appended claims.

Claims

CLAIMS1. An arrangement (1) for extruding conductive materials comprising: a chamber (10) comprised of a non-conductive material configured to receive a conductive material at a first end (11), the chamber (10) being fluidly connected to an orifice (20) through which the received conductive material can be extruded; an electrode pair (30a, 30b) configured to generate a non-varying electric current (31) through the conductive material received in the chamber (10); one or more electromagnets (40) for generating a magnetic flux (41) defined by an angular direction and a magnitude; wherein a position and direction of the electrode pair (30a, 30b) and the one or more electromagnets (40) define an intersection (60) between the electric current (31) and the magnetic flux (41) in the conductive material received in the chamber, said intersection (60) being proximate to said orifice (20), and wherein an interaction between the electrical current (31) generated by the electrode pair (31a, 31b), and the magnetic flux (41) generated by the one or more electromagnets (40) gives rise to an extrusion force (70) acting on the conductive material received in the chamber (10), wherein the arrangement further comprises one or more current controllers (50) electrically connected to the one or more electromagnets (40), and configured to control currents supplied to the one or more electromagnets (40), wherein the controlled currents supplied to the electromagnet (41) controls an extrusion direction (71) of extruded material out of the orifice (20).2.The arrangement according to claim 1, further comprising one or more current controllers (50) electrically connected to the one or more electromagnets (40) for controlling currents supplied to the one or more electromagnets.

3. The arrangement according to any of the claims 1 or 2 comprising two or more electromagnets (40), wherein at least one of the two or more electromagnets(40) are positioned and arranged to be non-parallel with at least one or more of the two or more electromagnets (40).

4. The arrangement according to any to the claims 1 to 3 wherein the one or more electromagnets (40) are provided with means for cooling (80).

5. The arrangement according to any of the claim 1 to 4 further comprising a heater unit (90) for controlling the temperature of a conductive material received in the chamber (10).

6. The arrangement according to any of the claims 1 to 5 wherein said currents supplied by said one or more current controllers (50) to the one or more electromagnets (40) determines a relative contribution, from each one or more electromagnets (40), to the angular direction and magnitude of the magnetic flux (41) though conductive material received in the chamber (10).

7. The arrangement according to any of the claims 1 to 6 wherein said electric current (31) through material received in the chamber (10) is a non-varying electric current (31).

8. The arrangement according to any of the claims 1 to 7 wherein said currents supplied by said one or more current controllers (50) to the one or more electromagnets (40) determines both an angular direction and a magnitude of an extrusion force (70) achieved by the interaction between the magnetic flux (41) and the electric current (31) through conductive material received in the chamber (10).

9. The arrangement according to any of the claims 1 to 8 wherein said extrusion force (70) is orthogonal to both said magnetic flux (41) and said current (31) though conductive material received in the chamber (10).

10. The arrangement according to any of the claims 1 to 9 wherein said orifice (20) is arranged to enable extrusion of the conductive material therefrom in an angular direction (72) being controlled by the angular direction of the magnetic flux (41).

11. The arrangement according to any of the claims 1 to 10 wherein said orifice (20) is arranged to enable extrusion of the conductive material therefrom in an angular direction (72) being determined by the angular direction of the extrusion force (70).

12. A method for extruding conductive materials, the method comprising: receiving (SI) a conductive material in a chamber (10) being fluidly connected to an orifice (20) through which the received conductive material can be extruded; generating (S2) a current (31) through the conductive material received in the chamber (10) via an electrode pair (30a, 30b); exposing (S3) the conductive material received in the chamber (10) to a magnetic flux (41) having an angular direction and a magnitude, said magnetic flux (41) intersecting said current (31), said magnetic flux (41) being generated by one or more electromagnets (40); extruding the conductive material from said orifice (20) by controlling (S4) the direction and magnitude of the magnetic flux (41) to which the received conductive material is exposed (S3).

13. The method for extruding conductive materials according to claim 12, wherein said generating (S2) a current (31) though the received conductive material is a generation (S2) of a non-varying current (31).

14. The method for extruding conductive materials according to claims 12 or 13 wherein said controlling (S4) of the direction and magnitude of the magnetic flux (41) to which the received conductive material is exposed (S3) comprises supplying of controlled currents to said one or more electromagnets (40).

15. The method for extruding conductive materials according to any of the claims 12 to 14 wherein said controlling (S4) of the direction and magnitude of the magnetic flux (41) to which the received conductive material is exposed (S3) comprises supplying of controlled currents to at least two non-parallel electromagnets (40).

16. The method for extruding conductive materials according to claims 12 to 15 wherein said controlling the supplied current to the electromagnets (40) is performed individually for each electromagnet (40).

17. The method for extruding conductive materials according to claims 12 to 15 wherein the one or more electromagnets (40) are grouped into groups supplying said magnetic flux (41) in different angles, and said controlling the supplied currents to the electromagnets (40) is performed equally for all electromagnets (40) in the same group.

18. The method for extruding conductive materials according to claims 12 to 17 wherein an angular direction (72) of the conductive material out of the orifice (20) is controlled by controlling (S4) the relative contributions to the magnetic flux (41) from the one or more electromagnets (40).

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